fe60bb2397d3657700f72db10889ad10888d40c4
[gcc.git] / gcc / varasm.c
1 /* Output variables, constants and external declarations, for GNU compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
4 2010 Free Software Foundation, Inc.
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
12
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
21
22
23 /* This file handles generation of all the assembler code
24 *except* the instructions of a function.
25 This includes declarations of variables and their initial values.
26
27 We also output the assembler code for constants stored in memory
28 and are responsible for combining constants with the same value. */
29
30 #include "config.h"
31 #include "system.h"
32 #include "coretypes.h"
33 #include "tm.h"
34 #include "rtl.h"
35 #include "tree.h"
36 #include "flags.h"
37 #include "function.h"
38 #include "expr.h"
39 #include "hard-reg-set.h"
40 #include "regs.h"
41 #include "output.h"
42 #include "diagnostic-core.h"
43 #include "toplev.h"
44 #include "hashtab.h"
45 #include "ggc.h"
46 #include "langhooks.h"
47 #include "tm_p.h"
48 #include "debug.h"
49 #include "target.h"
50 #include "targhooks.h"
51 #include "tree-mudflap.h"
52 #include "cgraph.h"
53 #include "cfglayout.h"
54 #include "basic-block.h"
55 #include "tree-iterator.h"
56
57 #ifdef XCOFF_DEBUGGING_INFO
58 #include "xcoffout.h" /* Needed for external data
59 declarations for e.g. AIX 4.x. */
60 #endif
61
62 /* The (assembler) name of the first globally-visible object output. */
63 extern GTY(()) const char *first_global_object_name;
64 extern GTY(()) const char *weak_global_object_name;
65
66 const char *first_global_object_name;
67 const char *weak_global_object_name;
68
69 struct addr_const;
70 struct constant_descriptor_rtx;
71 struct rtx_constant_pool;
72
73 #define n_deferred_constants (crtl->varasm.deferred_constants)
74
75 /* Number for making the label on the next
76 constant that is stored in memory. */
77
78 static GTY(()) int const_labelno;
79
80 /* Carry information from ASM_DECLARE_OBJECT_NAME
81 to ASM_FINISH_DECLARE_OBJECT. */
82
83 int size_directive_output;
84
85 /* The last decl for which assemble_variable was called,
86 if it did ASM_DECLARE_OBJECT_NAME.
87 If the last call to assemble_variable didn't do that,
88 this holds 0. */
89
90 tree last_assemble_variable_decl;
91
92 /* The following global variable indicates if the first basic block
93 in a function belongs to the cold partition or not. */
94
95 bool first_function_block_is_cold;
96
97 /* We give all constants their own alias set. Perhaps redundant with
98 MEM_READONLY_P, but pre-dates it. */
99
100 static alias_set_type const_alias_set;
101
102 /* Whether we saw any functions with no_split_stack. */
103
104 static bool saw_no_split_stack;
105
106 static const char *strip_reg_name (const char *);
107 static int contains_pointers_p (tree);
108 #ifdef ASM_OUTPUT_EXTERNAL
109 static bool incorporeal_function_p (tree);
110 #endif
111 static void decode_addr_const (tree, struct addr_const *);
112 static hashval_t const_desc_hash (const void *);
113 static int const_desc_eq (const void *, const void *);
114 static hashval_t const_hash_1 (const tree);
115 static int compare_constant (const tree, const tree);
116 static tree copy_constant (tree);
117 static void output_constant_def_contents (rtx);
118 static void output_addressed_constants (tree);
119 static unsigned HOST_WIDE_INT array_size_for_constructor (tree);
120 static unsigned min_align (unsigned, unsigned);
121 static void globalize_decl (tree);
122 #ifdef BSS_SECTION_ASM_OP
123 #ifdef ASM_OUTPUT_BSS
124 static void asm_output_bss (FILE *, tree, const char *,
125 unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT);
126 #endif
127 #ifdef ASM_OUTPUT_ALIGNED_BSS
128 static void asm_output_aligned_bss (FILE *, tree, const char *,
129 unsigned HOST_WIDE_INT, int)
130 ATTRIBUTE_UNUSED;
131 #endif
132 #endif /* BSS_SECTION_ASM_OP */
133 static void mark_weak (tree);
134 static void output_constant_pool (const char *, tree);
135 \f
136 /* Well-known sections, each one associated with some sort of *_ASM_OP. */
137 section *text_section;
138 section *data_section;
139 section *readonly_data_section;
140 section *sdata_section;
141 section *ctors_section;
142 section *dtors_section;
143 section *bss_section;
144 section *sbss_section;
145
146 /* Various forms of common section. All are guaranteed to be nonnull. */
147 section *tls_comm_section;
148 section *comm_section;
149 section *lcomm_section;
150
151 /* A SECTION_NOSWITCH section used for declaring global BSS variables.
152 May be null. */
153 section *bss_noswitch_section;
154
155 /* The section that holds the main exception table, when known. The section
156 is set either by the target's init_sections hook or by the first call to
157 switch_to_exception_section. */
158 section *exception_section;
159
160 /* The section that holds the DWARF2 frame unwind information, when known.
161 The section is set either by the target's init_sections hook or by the
162 first call to switch_to_eh_frame_section. */
163 section *eh_frame_section;
164
165 /* asm_out_file's current section. This is NULL if no section has yet
166 been selected or if we lose track of what the current section is. */
167 section *in_section;
168
169 /* True if code for the current function is currently being directed
170 at the cold section. */
171 bool in_cold_section_p;
172
173 /* A linked list of all the unnamed sections. */
174 static GTY(()) section *unnamed_sections;
175
176 /* Return a nonzero value if DECL has a section attribute. */
177 #define IN_NAMED_SECTION(DECL) \
178 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
179 && DECL_SECTION_NAME (DECL) != NULL_TREE)
180
181 /* Hash table of named sections. */
182 static GTY((param_is (section))) htab_t section_htab;
183
184 /* A table of object_blocks, indexed by section. */
185 static GTY((param_is (struct object_block))) htab_t object_block_htab;
186
187 /* The next number to use for internal anchor labels. */
188 static GTY(()) int anchor_labelno;
189
190 /* A pool of constants that can be shared between functions. */
191 static GTY(()) struct rtx_constant_pool *shared_constant_pool;
192
193 /* Helper routines for maintaining section_htab. */
194
195 static int
196 section_entry_eq (const void *p1, const void *p2)
197 {
198 const section *old = (const section *) p1;
199 const char *new_name = (const char *) p2;
200
201 return strcmp (old->named.name, new_name) == 0;
202 }
203
204 static hashval_t
205 section_entry_hash (const void *p)
206 {
207 const section *old = (const section *) p;
208 return htab_hash_string (old->named.name);
209 }
210
211 /* Return a hash value for section SECT. */
212
213 static hashval_t
214 hash_section (section *sect)
215 {
216 if (sect->common.flags & SECTION_NAMED)
217 return htab_hash_string (sect->named.name);
218 return sect->common.flags;
219 }
220
221 /* Helper routines for maintaining object_block_htab. */
222
223 static int
224 object_block_entry_eq (const void *p1, const void *p2)
225 {
226 const struct object_block *old = (const struct object_block *) p1;
227 const section *new_section = (const section *) p2;
228
229 return old->sect == new_section;
230 }
231
232 static hashval_t
233 object_block_entry_hash (const void *p)
234 {
235 const struct object_block *old = (const struct object_block *) p;
236 return hash_section (old->sect);
237 }
238
239 /* Return a new unnamed section with the given fields. */
240
241 section *
242 get_unnamed_section (unsigned int flags, void (*callback) (const void *),
243 const void *data)
244 {
245 section *sect;
246
247 sect = ggc_alloc_section ();
248 sect->unnamed.common.flags = flags | SECTION_UNNAMED;
249 sect->unnamed.callback = callback;
250 sect->unnamed.data = data;
251 sect->unnamed.next = unnamed_sections;
252
253 unnamed_sections = sect;
254 return sect;
255 }
256
257 /* Return a SECTION_NOSWITCH section with the given fields. */
258
259 static section *
260 get_noswitch_section (unsigned int flags, noswitch_section_callback callback)
261 {
262 section *sect;
263
264 sect = ggc_alloc_section ();
265 sect->noswitch.common.flags = flags | SECTION_NOSWITCH;
266 sect->noswitch.callback = callback;
267
268 return sect;
269 }
270
271 /* Return the named section structure associated with NAME. Create
272 a new section with the given fields if no such structure exists. */
273
274 section *
275 get_section (const char *name, unsigned int flags, tree decl)
276 {
277 section *sect, **slot;
278
279 slot = (section **)
280 htab_find_slot_with_hash (section_htab, name,
281 htab_hash_string (name), INSERT);
282 flags |= SECTION_NAMED;
283 if (*slot == NULL)
284 {
285 sect = ggc_alloc_section ();
286 sect->named.common.flags = flags;
287 sect->named.name = ggc_strdup (name);
288 sect->named.decl = decl;
289 *slot = sect;
290 }
291 else
292 {
293 sect = *slot;
294 if ((sect->common.flags & ~SECTION_DECLARED) != flags
295 && ((sect->common.flags | flags) & SECTION_OVERRIDE) == 0)
296 {
297 /* Sanity check user variables for flag changes. */
298 if (decl == 0)
299 decl = sect->named.decl;
300 gcc_assert (decl);
301 error ("%+D causes a section type conflict", decl);
302 }
303 }
304 return sect;
305 }
306
307 /* Return true if the current compilation mode benefits from having
308 objects grouped into blocks. */
309
310 static bool
311 use_object_blocks_p (void)
312 {
313 return flag_section_anchors;
314 }
315
316 /* Return the object_block structure for section SECT. Create a new
317 structure if we haven't created one already. Return null if SECT
318 itself is null. */
319
320 static struct object_block *
321 get_block_for_section (section *sect)
322 {
323 struct object_block *block;
324 void **slot;
325
326 if (sect == NULL)
327 return NULL;
328
329 slot = htab_find_slot_with_hash (object_block_htab, sect,
330 hash_section (sect), INSERT);
331 block = (struct object_block *) *slot;
332 if (block == NULL)
333 {
334 block = ggc_alloc_cleared_object_block ();
335 block->sect = sect;
336 *slot = block;
337 }
338 return block;
339 }
340
341 /* Create a symbol with label LABEL and place it at byte offset
342 OFFSET in BLOCK. OFFSET can be negative if the symbol's offset
343 is not yet known. LABEL must be a garbage-collected string. */
344
345 static rtx
346 create_block_symbol (const char *label, struct object_block *block,
347 HOST_WIDE_INT offset)
348 {
349 rtx symbol;
350 unsigned int size;
351
352 /* Create the extended SYMBOL_REF. */
353 size = RTX_HDR_SIZE + sizeof (struct block_symbol);
354 symbol = ggc_alloc_zone_rtx_def (size, &rtl_zone);
355
356 /* Initialize the normal SYMBOL_REF fields. */
357 memset (symbol, 0, size);
358 PUT_CODE (symbol, SYMBOL_REF);
359 PUT_MODE (symbol, Pmode);
360 XSTR (symbol, 0) = label;
361 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_HAS_BLOCK_INFO;
362
363 /* Initialize the block_symbol stuff. */
364 SYMBOL_REF_BLOCK (symbol) = block;
365 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
366
367 return symbol;
368 }
369
370 static void
371 initialize_cold_section_name (void)
372 {
373 const char *stripped_name;
374 char *name, *buffer;
375 tree dsn;
376
377 gcc_assert (cfun && current_function_decl);
378 if (crtl->subsections.unlikely_text_section_name)
379 return;
380
381 dsn = DECL_SECTION_NAME (current_function_decl);
382 if (flag_function_sections && dsn)
383 {
384 name = (char *) alloca (TREE_STRING_LENGTH (dsn) + 1);
385 memcpy (name, TREE_STRING_POINTER (dsn), TREE_STRING_LENGTH (dsn) + 1);
386
387 stripped_name = targetm.strip_name_encoding (name);
388
389 buffer = ACONCAT ((stripped_name, "_unlikely", NULL));
390 crtl->subsections.unlikely_text_section_name = ggc_strdup (buffer);
391 }
392 else
393 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
394 }
395
396 /* Tell assembler to switch to unlikely-to-be-executed text section. */
397
398 section *
399 unlikely_text_section (void)
400 {
401 if (cfun)
402 {
403 if (!crtl->subsections.unlikely_text_section_name)
404 initialize_cold_section_name ();
405
406 return get_named_section (NULL, crtl->subsections.unlikely_text_section_name, 0);
407 }
408 else
409 return get_named_section (NULL, UNLIKELY_EXECUTED_TEXT_SECTION_NAME, 0);
410 }
411
412 /* When called within a function context, return true if the function
413 has been assigned a cold text section and if SECT is that section.
414 When called outside a function context, return true if SECT is the
415 default cold section. */
416
417 bool
418 unlikely_text_section_p (section *sect)
419 {
420 const char *name;
421
422 if (cfun)
423 name = crtl->subsections.unlikely_text_section_name;
424 else
425 name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
426
427 return (name
428 && sect
429 && SECTION_STYLE (sect) == SECTION_NAMED
430 && strcmp (name, sect->named.name) == 0);
431 }
432
433 /* Return a section with a particular name and with whatever SECTION_*
434 flags section_type_flags deems appropriate. The name of the section
435 is taken from NAME if nonnull, otherwise it is taken from DECL's
436 DECL_SECTION_NAME. DECL is the decl associated with the section
437 (see the section comment for details) and RELOC is as for
438 section_type_flags. */
439
440 section *
441 get_named_section (tree decl, const char *name, int reloc)
442 {
443 unsigned int flags;
444
445 gcc_assert (!decl || DECL_P (decl));
446 if (name == NULL)
447 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
448
449 flags = targetm.section_type_flags (decl, name, reloc);
450
451 return get_section (name, flags, decl);
452 }
453
454 /* If required, set DECL_SECTION_NAME to a unique name. */
455
456 void
457 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
458 int flag_function_or_data_sections)
459 {
460 if (DECL_SECTION_NAME (decl) == NULL_TREE
461 && targetm.have_named_sections
462 && (flag_function_or_data_sections
463 || DECL_ONE_ONLY (decl)))
464 targetm.asm_out.unique_section (decl, reloc);
465 }
466
467 #ifdef BSS_SECTION_ASM_OP
468
469 #ifdef ASM_OUTPUT_BSS
470
471 /* Utility function for ASM_OUTPUT_BSS for targets to use if
472 they don't support alignments in .bss.
473 ??? It is believed that this function will work in most cases so such
474 support is localized here. */
475
476 static void ATTRIBUTE_UNUSED
477 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
478 const char *name,
479 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
480 unsigned HOST_WIDE_INT rounded)
481 {
482 gcc_assert (strcmp (XSTR (XEXP (DECL_RTL (decl), 0), 0), name) == 0);
483 targetm.asm_out.globalize_decl_name (file, decl);
484 switch_to_section (bss_section);
485 #ifdef ASM_DECLARE_OBJECT_NAME
486 last_assemble_variable_decl = decl;
487 ASM_DECLARE_OBJECT_NAME (file, name, decl);
488 #else
489 /* Standard thing is just output label for the object. */
490 ASM_OUTPUT_LABEL (file, name);
491 #endif /* ASM_DECLARE_OBJECT_NAME */
492 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
493 }
494
495 #endif
496
497 #ifdef ASM_OUTPUT_ALIGNED_BSS
498
499 /* Utility function for targets to use in implementing
500 ASM_OUTPUT_ALIGNED_BSS.
501 ??? It is believed that this function will work in most cases so such
502 support is localized here. */
503
504 static void
505 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
506 const char *name, unsigned HOST_WIDE_INT size,
507 int align)
508 {
509 switch_to_section (bss_section);
510 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
511 #ifdef ASM_DECLARE_OBJECT_NAME
512 last_assemble_variable_decl = decl;
513 ASM_DECLARE_OBJECT_NAME (file, name, decl);
514 #else
515 /* Standard thing is just output label for the object. */
516 ASM_OUTPUT_LABEL (file, name);
517 #endif /* ASM_DECLARE_OBJECT_NAME */
518 ASM_OUTPUT_SKIP (file, size ? size : 1);
519 }
520
521 #endif
522
523 #endif /* BSS_SECTION_ASM_OP */
524
525 #ifndef USE_SELECT_SECTION_FOR_FUNCTIONS
526 /* Return the hot section for function DECL. Return text_section for
527 null DECLs. */
528
529 static section *
530 hot_function_section (tree decl)
531 {
532 if (decl != NULL_TREE
533 && DECL_SECTION_NAME (decl) != NULL_TREE
534 && targetm.have_named_sections)
535 return get_named_section (decl, NULL, 0);
536 else
537 return text_section;
538 }
539 #endif
540
541 /* Return the section for function DECL.
542
543 If DECL is NULL_TREE, return the text section. We can be passed
544 NULL_TREE under some circumstances by dbxout.c at least. */
545
546 section *
547 function_section (tree decl)
548 {
549 int reloc = 0;
550
551 if (first_function_block_is_cold)
552 reloc = 1;
553
554 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
555 if (decl != NULL_TREE
556 && DECL_SECTION_NAME (decl) != NULL_TREE)
557 return reloc ? unlikely_text_section ()
558 : get_named_section (decl, NULL, 0);
559 else
560 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
561 #else
562 return reloc ? unlikely_text_section () : hot_function_section (decl);
563 #endif
564 }
565
566 section *
567 current_function_section (void)
568 {
569 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
570 if (current_function_decl != NULL_TREE
571 && DECL_SECTION_NAME (current_function_decl) != NULL_TREE)
572 return in_cold_section_p ? unlikely_text_section ()
573 : get_named_section (current_function_decl,
574 NULL, 0);
575 else
576 return targetm.asm_out.select_section (current_function_decl,
577 in_cold_section_p,
578 DECL_ALIGN (current_function_decl));
579 #else
580 return (in_cold_section_p
581 ? unlikely_text_section ()
582 : hot_function_section (current_function_decl));
583 #endif
584 }
585
586 /* Return the read-only data section associated with function DECL. */
587
588 section *
589 default_function_rodata_section (tree decl)
590 {
591 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
592 {
593 const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
594
595 if (DECL_ONE_ONLY (decl) && HAVE_COMDAT_GROUP)
596 {
597 const char *dot;
598 size_t len;
599 char* rname;
600
601 dot = strchr (name + 1, '.');
602 if (!dot)
603 dot = name;
604 len = strlen (dot) + 8;
605 rname = (char *) alloca (len);
606
607 strcpy (rname, ".rodata");
608 strcat (rname, dot);
609 return get_section (rname, SECTION_LINKONCE, decl);
610 }
611 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
612 else if (DECL_ONE_ONLY (decl)
613 && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
614 {
615 size_t len = strlen (name) + 1;
616 char *rname = (char *) alloca (len);
617
618 memcpy (rname, name, len);
619 rname[14] = 'r';
620 return get_section (rname, SECTION_LINKONCE, decl);
621 }
622 /* For .text.foo we want to use .rodata.foo. */
623 else if (flag_function_sections && flag_data_sections
624 && strncmp (name, ".text.", 6) == 0)
625 {
626 size_t len = strlen (name) + 1;
627 char *rname = (char *) alloca (len + 2);
628
629 memcpy (rname, ".rodata", 7);
630 memcpy (rname + 7, name + 5, len - 5);
631 return get_section (rname, 0, decl);
632 }
633 }
634
635 return readonly_data_section;
636 }
637
638 /* Return the read-only data section associated with function DECL
639 for targets where that section should be always the single
640 readonly data section. */
641
642 section *
643 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
644 {
645 return readonly_data_section;
646 }
647
648 /* Return the section to use for string merging. */
649
650 static section *
651 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
652 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
653 unsigned int flags ATTRIBUTE_UNUSED)
654 {
655 HOST_WIDE_INT len;
656
657 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
658 && TREE_CODE (decl) == STRING_CST
659 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
660 && align <= 256
661 && (len = int_size_in_bytes (TREE_TYPE (decl))) > 0
662 && TREE_STRING_LENGTH (decl) >= len)
663 {
664 enum machine_mode mode;
665 unsigned int modesize;
666 const char *str;
667 HOST_WIDE_INT i;
668 int j, unit;
669 char name[30];
670
671 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
672 modesize = GET_MODE_BITSIZE (mode);
673 if (modesize >= 8 && modesize <= 256
674 && (modesize & (modesize - 1)) == 0)
675 {
676 if (align < modesize)
677 align = modesize;
678
679 str = TREE_STRING_POINTER (decl);
680 unit = GET_MODE_SIZE (mode);
681
682 /* Check for embedded NUL characters. */
683 for (i = 0; i < len; i += unit)
684 {
685 for (j = 0; j < unit; j++)
686 if (str[i + j] != '\0')
687 break;
688 if (j == unit)
689 break;
690 }
691 if (i == len - unit)
692 {
693 sprintf (name, ".rodata.str%d.%d", modesize / 8,
694 (int) (align / 8));
695 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
696 return get_section (name, flags, NULL);
697 }
698 }
699 }
700
701 return readonly_data_section;
702 }
703
704 /* Return the section to use for constant merging. */
705
706 section *
707 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
708 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
709 unsigned int flags ATTRIBUTE_UNUSED)
710 {
711 unsigned int modesize = GET_MODE_BITSIZE (mode);
712
713 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
714 && mode != VOIDmode
715 && mode != BLKmode
716 && modesize <= align
717 && align >= 8
718 && align <= 256
719 && (align & (align - 1)) == 0)
720 {
721 char name[24];
722
723 sprintf (name, ".rodata.cst%d", (int) (align / 8));
724 flags |= (align / 8) | SECTION_MERGE;
725 return get_section (name, flags, NULL);
726 }
727 return readonly_data_section;
728 }
729 \f
730 /* Given NAME, a putative register name, discard any customary prefixes. */
731
732 static const char *
733 strip_reg_name (const char *name)
734 {
735 #ifdef REGISTER_PREFIX
736 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
737 name += strlen (REGISTER_PREFIX);
738 #endif
739 if (name[0] == '%' || name[0] == '#')
740 name++;
741 return name;
742 }
743 \f
744 /* The user has asked for a DECL to have a particular name. Set (or
745 change) it in such a way that we don't prefix an underscore to
746 it. */
747 void
748 set_user_assembler_name (tree decl, const char *name)
749 {
750 char *starred = (char *) alloca (strlen (name) + 2);
751 starred[0] = '*';
752 strcpy (starred + 1, name);
753 change_decl_assembler_name (decl, get_identifier (starred));
754 SET_DECL_RTL (decl, NULL_RTX);
755 }
756 \f
757 /* Decode an `asm' spec for a declaration as a register name.
758 Return the register number, or -1 if nothing specified,
759 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
760 or -3 if ASMSPEC is `cc' and is not recognized,
761 or -4 if ASMSPEC is `memory' and is not recognized.
762 Accept an exact spelling or a decimal number.
763 Prefixes such as % are optional. */
764
765 int
766 decode_reg_name (const char *asmspec)
767 {
768 if (asmspec != 0)
769 {
770 int i;
771
772 /* Get rid of confusing prefixes. */
773 asmspec = strip_reg_name (asmspec);
774
775 /* Allow a decimal number as a "register name". */
776 for (i = strlen (asmspec) - 1; i >= 0; i--)
777 if (! ISDIGIT (asmspec[i]))
778 break;
779 if (asmspec[0] != 0 && i < 0)
780 {
781 i = atoi (asmspec);
782 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
783 return i;
784 else
785 return -2;
786 }
787
788 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
789 if (reg_names[i][0]
790 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
791 return i;
792
793 #ifdef ADDITIONAL_REGISTER_NAMES
794 {
795 static const struct { const char *const name; const int number; } table[]
796 = ADDITIONAL_REGISTER_NAMES;
797
798 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
799 if (table[i].name[0]
800 && ! strcmp (asmspec, table[i].name))
801 return table[i].number;
802 }
803 #endif /* ADDITIONAL_REGISTER_NAMES */
804
805 if (!strcmp (asmspec, "memory"))
806 return -4;
807
808 if (!strcmp (asmspec, "cc"))
809 return -3;
810
811 return -2;
812 }
813
814 return -1;
815 }
816 \f
817 /* Return true if DECL's initializer is suitable for a BSS section. */
818
819 static bool
820 bss_initializer_p (const_tree decl)
821 {
822 return (DECL_INITIAL (decl) == NULL
823 || DECL_INITIAL (decl) == error_mark_node
824 || (flag_zero_initialized_in_bss
825 /* Leave constant zeroes in .rodata so they
826 can be shared. */
827 && !TREE_READONLY (decl)
828 && initializer_zerop (DECL_INITIAL (decl))));
829 }
830
831 /* Compute the alignment of variable specified by DECL.
832 DONT_OUTPUT_DATA is from assemble_variable. */
833
834 void
835 align_variable (tree decl, bool dont_output_data)
836 {
837 unsigned int align = DECL_ALIGN (decl);
838
839 /* In the case for initialing an array whose length isn't specified,
840 where we have not yet been able to do the layout,
841 figure out the proper alignment now. */
842 if (dont_output_data && DECL_SIZE (decl) == 0
843 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
844 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
845
846 /* Some object file formats have a maximum alignment which they support.
847 In particular, a.out format supports a maximum alignment of 4. */
848 if (align > MAX_OFILE_ALIGNMENT)
849 {
850 warning (0, "alignment of %q+D is greater than maximum object "
851 "file alignment. Using %d", decl,
852 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
853 align = MAX_OFILE_ALIGNMENT;
854 }
855
856 /* On some machines, it is good to increase alignment sometimes. */
857 if (! DECL_USER_ALIGN (decl))
858 {
859 #ifdef DATA_ALIGNMENT
860 unsigned int data_align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
861 /* Don't increase alignment too much for TLS variables - TLS space
862 is too precious. */
863 if (! DECL_THREAD_LOCAL_P (decl) || data_align <= BITS_PER_WORD)
864 align = data_align;
865 #endif
866 #ifdef CONSTANT_ALIGNMENT
867 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
868 {
869 unsigned int const_align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl),
870 align);
871 /* Don't increase alignment too much for TLS variables - TLS space
872 is too precious. */
873 if (! DECL_THREAD_LOCAL_P (decl) || const_align <= BITS_PER_WORD)
874 align = const_align;
875 }
876 #endif
877 }
878
879 /* Reset the alignment in case we have made it tighter, so we can benefit
880 from it in get_pointer_alignment. */
881 DECL_ALIGN (decl) = align;
882 }
883
884 /* Return the section into which the given VAR_DECL or CONST_DECL
885 should be placed. PREFER_NOSWITCH_P is true if a noswitch
886 section should be used wherever possible. */
887
888 static section *
889 get_variable_section (tree decl, bool prefer_noswitch_p)
890 {
891 addr_space_t as = ADDR_SPACE_GENERIC;
892 int reloc;
893
894 if (TREE_TYPE (decl) != error_mark_node)
895 as = TYPE_ADDR_SPACE (TREE_TYPE (decl));
896
897 if (DECL_COMMON (decl))
898 {
899 /* If the decl has been given an explicit section name, or it resides
900 in a non-generic address space, then it isn't common, and shouldn't
901 be handled as such. */
902 gcc_assert (DECL_SECTION_NAME (decl) == NULL
903 && ADDR_SPACE_GENERIC_P (as));
904 if (DECL_THREAD_LOCAL_P (decl))
905 return tls_comm_section;
906 else if (TREE_PUBLIC (decl) && bss_initializer_p (decl))
907 return comm_section;
908 }
909
910 if (DECL_INITIAL (decl) == error_mark_node)
911 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
912 else if (DECL_INITIAL (decl))
913 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
914 else
915 reloc = 0;
916
917 resolve_unique_section (decl, reloc, flag_data_sections);
918 if (IN_NAMED_SECTION (decl))
919 return get_named_section (decl, NULL, reloc);
920
921 if (ADDR_SPACE_GENERIC_P (as)
922 && !DECL_THREAD_LOCAL_P (decl)
923 && !(prefer_noswitch_p && targetm.have_switchable_bss_sections)
924 && bss_initializer_p (decl))
925 {
926 if (!TREE_PUBLIC (decl))
927 return lcomm_section;
928 if (bss_noswitch_section)
929 return bss_noswitch_section;
930 }
931
932 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
933 }
934
935 /* Return the block into which object_block DECL should be placed. */
936
937 static struct object_block *
938 get_block_for_decl (tree decl)
939 {
940 section *sect;
941
942 if (TREE_CODE (decl) == VAR_DECL)
943 {
944 /* The object must be defined in this translation unit. */
945 if (DECL_EXTERNAL (decl))
946 return NULL;
947
948 /* There's no point using object blocks for something that is
949 isolated by definition. */
950 if (DECL_ONE_ONLY (decl))
951 return NULL;
952 }
953
954 /* We can only calculate block offsets if the decl has a known
955 constant size. */
956 if (DECL_SIZE_UNIT (decl) == NULL)
957 return NULL;
958 if (!host_integerp (DECL_SIZE_UNIT (decl), 1))
959 return NULL;
960
961 /* Find out which section should contain DECL. We cannot put it into
962 an object block if it requires a standalone definition. */
963 if (TREE_CODE (decl) == VAR_DECL)
964 align_variable (decl, 0);
965 sect = get_variable_section (decl, true);
966 if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
967 return NULL;
968
969 return get_block_for_section (sect);
970 }
971
972 /* Make sure block symbol SYMBOL is in block BLOCK. */
973
974 static void
975 change_symbol_block (rtx symbol, struct object_block *block)
976 {
977 if (block != SYMBOL_REF_BLOCK (symbol))
978 {
979 gcc_assert (SYMBOL_REF_BLOCK_OFFSET (symbol) < 0);
980 SYMBOL_REF_BLOCK (symbol) = block;
981 }
982 }
983
984 /* Return true if it is possible to put DECL in an object_block. */
985
986 static bool
987 use_blocks_for_decl_p (tree decl)
988 {
989 /* Only data DECLs can be placed into object blocks. */
990 if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != CONST_DECL)
991 return false;
992
993 /* Detect decls created by dw2_force_const_mem. Such decls are
994 special because DECL_INITIAL doesn't specify the decl's true value.
995 dw2_output_indirect_constants will instead call assemble_variable
996 with dont_output_data set to 1 and then print the contents itself. */
997 if (DECL_INITIAL (decl) == decl)
998 return false;
999
1000 /* If this decl is an alias, then we don't want to emit a
1001 definition. */
1002 if (lookup_attribute ("alias", DECL_ATTRIBUTES (decl)))
1003 return false;
1004
1005 return true;
1006 }
1007
1008 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
1009 have static storage duration. In other words, it should not be an
1010 automatic variable, including PARM_DECLs.
1011
1012 There is, however, one exception: this function handles variables
1013 explicitly placed in a particular register by the user.
1014
1015 This is never called for PARM_DECL nodes. */
1016
1017 void
1018 make_decl_rtl (tree decl)
1019 {
1020 const char *name = 0;
1021 int reg_number;
1022 rtx x;
1023
1024 /* Check that we are not being given an automatic variable. */
1025 gcc_assert (TREE_CODE (decl) != PARM_DECL
1026 && TREE_CODE (decl) != RESULT_DECL);
1027
1028 /* A weak alias has TREE_PUBLIC set but not the other bits. */
1029 gcc_assert (TREE_CODE (decl) != VAR_DECL
1030 || TREE_STATIC (decl)
1031 || TREE_PUBLIC (decl)
1032 || DECL_EXTERNAL (decl)
1033 || DECL_REGISTER (decl));
1034
1035 /* And that we were not given a type or a label. */
1036 gcc_assert (TREE_CODE (decl) != TYPE_DECL
1037 && TREE_CODE (decl) != LABEL_DECL);
1038
1039 /* For a duplicate declaration, we can be called twice on the
1040 same DECL node. Don't discard the RTL already made. */
1041 if (DECL_RTL_SET_P (decl))
1042 {
1043 /* If the old RTL had the wrong mode, fix the mode. */
1044 x = DECL_RTL (decl);
1045 if (GET_MODE (x) != DECL_MODE (decl))
1046 SET_DECL_RTL (decl, adjust_address_nv (x, DECL_MODE (decl), 0));
1047
1048 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1049 return;
1050
1051 /* ??? Another way to do this would be to maintain a hashed
1052 table of such critters. Instead of adding stuff to a DECL
1053 to give certain attributes to it, we could use an external
1054 hash map from DECL to set of attributes. */
1055
1056 /* Let the target reassign the RTL if it wants.
1057 This is necessary, for example, when one machine specific
1058 decl attribute overrides another. */
1059 targetm.encode_section_info (decl, DECL_RTL (decl), false);
1060
1061 /* If the symbol has a SYMBOL_REF_BLOCK field, update it based
1062 on the new decl information. */
1063 if (MEM_P (x)
1064 && GET_CODE (XEXP (x, 0)) == SYMBOL_REF
1065 && SYMBOL_REF_HAS_BLOCK_INFO_P (XEXP (x, 0)))
1066 change_symbol_block (XEXP (x, 0), get_block_for_decl (decl));
1067
1068 /* Make this function static known to the mudflap runtime. */
1069 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1070 mudflap_enqueue_decl (decl);
1071
1072 return;
1073 }
1074
1075 /* If this variable belongs to the global constant pool, retrieve the
1076 pre-computed RTL or recompute it in LTO mode. */
1077 if (TREE_CODE (decl) == VAR_DECL && DECL_IN_CONSTANT_POOL (decl))
1078 {
1079 SET_DECL_RTL (decl, output_constant_def (DECL_INITIAL (decl), 1));
1080 return;
1081 }
1082
1083 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1084
1085 if (name[0] != '*' && TREE_CODE (decl) != FUNCTION_DECL
1086 && DECL_REGISTER (decl))
1087 {
1088 error ("register name not specified for %q+D", decl);
1089 }
1090 else if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1091 {
1092 const char *asmspec = name+1;
1093 reg_number = decode_reg_name (asmspec);
1094 /* First detect errors in declaring global registers. */
1095 if (reg_number == -1)
1096 error ("register name not specified for %q+D", decl);
1097 else if (reg_number < 0)
1098 error ("invalid register name for %q+D", decl);
1099 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
1100 error ("data type of %q+D isn%'t suitable for a register",
1101 decl);
1102 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
1103 error ("register specified for %q+D isn%'t suitable for data type",
1104 decl);
1105 /* Now handle properly declared static register variables. */
1106 else
1107 {
1108 int nregs;
1109
1110 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
1111 {
1112 DECL_INITIAL (decl) = 0;
1113 error ("global register variable has initial value");
1114 }
1115 if (TREE_THIS_VOLATILE (decl))
1116 warning (OPT_Wvolatile_register_var,
1117 "optimization may eliminate reads and/or "
1118 "writes to register variables");
1119
1120 /* If the user specified one of the eliminables registers here,
1121 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
1122 confused with that register and be eliminated. This usage is
1123 somewhat suspect... */
1124
1125 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
1126 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
1127 REG_USERVAR_P (DECL_RTL (decl)) = 1;
1128
1129 if (TREE_STATIC (decl))
1130 {
1131 /* Make this register global, so not usable for anything
1132 else. */
1133 #ifdef ASM_DECLARE_REGISTER_GLOBAL
1134 name = IDENTIFIER_POINTER (DECL_NAME (decl));
1135 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
1136 #endif
1137 nregs = hard_regno_nregs[reg_number][DECL_MODE (decl)];
1138 while (nregs > 0)
1139 globalize_reg (reg_number + --nregs);
1140 }
1141
1142 /* As a register variable, it has no section. */
1143 return;
1144 }
1145 }
1146 /* Now handle ordinary static variables and functions (in memory).
1147 Also handle vars declared register invalidly. */
1148 else if (name[0] == '*')
1149 {
1150 #ifdef REGISTER_PREFIX
1151 if (strlen (REGISTER_PREFIX) != 0)
1152 {
1153 reg_number = decode_reg_name (name);
1154 if (reg_number >= 0 || reg_number == -3)
1155 error ("register name given for non-register variable %q+D", decl);
1156 }
1157 #endif
1158 }
1159
1160 /* Specifying a section attribute on a variable forces it into a
1161 non-.bss section, and thus it cannot be common. */
1162 /* FIXME: In general this code should not be necessary because
1163 visibility pass is doing the same work. But notice_global_symbol
1164 is called early and it needs to make DECL_RTL to get the name.
1165 we take care of recomputing the DECL_RTL after visibility is changed. */
1166 if (TREE_CODE (decl) == VAR_DECL
1167 && DECL_SECTION_NAME (decl) != NULL_TREE
1168 && DECL_INITIAL (decl) == NULL_TREE
1169 && DECL_COMMON (decl))
1170 DECL_COMMON (decl) = 0;
1171
1172 /* Variables can't be both common and weak. */
1173 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
1174 DECL_COMMON (decl) = 0;
1175
1176 if (use_object_blocks_p () && use_blocks_for_decl_p (decl))
1177 x = create_block_symbol (name, get_block_for_decl (decl), -1);
1178 else
1179 {
1180 enum machine_mode address_mode = Pmode;
1181 if (TREE_TYPE (decl) != error_mark_node)
1182 {
1183 addr_space_t as = TYPE_ADDR_SPACE (TREE_TYPE (decl));
1184 address_mode = targetm.addr_space.address_mode (as);
1185 }
1186 x = gen_rtx_SYMBOL_REF (address_mode, name);
1187 }
1188 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
1189 SET_SYMBOL_REF_DECL (x, decl);
1190
1191 x = gen_rtx_MEM (DECL_MODE (decl), x);
1192 if (TREE_CODE (decl) != FUNCTION_DECL)
1193 set_mem_attributes (x, decl, 1);
1194 SET_DECL_RTL (decl, x);
1195
1196 /* Optionally set flags or add text to the name to record information
1197 such as that it is a function name.
1198 If the name is changed, the macro ASM_OUTPUT_LABELREF
1199 will have to know how to strip this information. */
1200 targetm.encode_section_info (decl, DECL_RTL (decl), true);
1201
1202 /* Make this function static known to the mudflap runtime. */
1203 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1204 mudflap_enqueue_decl (decl);
1205 }
1206
1207 /* Like make_decl_rtl, but inhibit creation of new alias sets when
1208 calling make_decl_rtl. Also, reset DECL_RTL before returning the
1209 rtl. */
1210
1211 rtx
1212 make_decl_rtl_for_debug (tree decl)
1213 {
1214 unsigned int save_aliasing_flag, save_mudflap_flag;
1215 rtx rtl;
1216
1217 if (DECL_RTL_SET_P (decl))
1218 return DECL_RTL (decl);
1219
1220 /* Kludge alert! Somewhere down the call chain, make_decl_rtl will
1221 call new_alias_set. If running with -fcompare-debug, sometimes
1222 we do not want to create alias sets that will throw the alias
1223 numbers off in the comparison dumps. So... clearing
1224 flag_strict_aliasing will keep new_alias_set() from creating a
1225 new set. It is undesirable to register decl with mudflap
1226 in this case as well. */
1227 save_aliasing_flag = flag_strict_aliasing;
1228 flag_strict_aliasing = 0;
1229 save_mudflap_flag = flag_mudflap;
1230 flag_mudflap = 0;
1231
1232 rtl = DECL_RTL (decl);
1233 /* Reset DECL_RTL back, as various parts of the compiler expects
1234 DECL_RTL set meaning it is actually going to be output. */
1235 SET_DECL_RTL (decl, NULL);
1236
1237 flag_strict_aliasing = save_aliasing_flag;
1238 flag_mudflap = save_mudflap_flag;
1239
1240 return rtl;
1241 }
1242 \f
1243 /* Output a string of literal assembler code
1244 for an `asm' keyword used between functions. */
1245
1246 void
1247 assemble_asm (tree string)
1248 {
1249 app_enable ();
1250
1251 if (TREE_CODE (string) == ADDR_EXPR)
1252 string = TREE_OPERAND (string, 0);
1253
1254 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
1255 }
1256
1257 /* Record an element in the table of global destructors. SYMBOL is
1258 a SYMBOL_REF of the function to be called; PRIORITY is a number
1259 between 0 and MAX_INIT_PRIORITY. */
1260
1261 void
1262 default_stabs_asm_out_destructor (rtx symbol ATTRIBUTE_UNUSED,
1263 int priority ATTRIBUTE_UNUSED)
1264 {
1265 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1266 /* Tell GNU LD that this is part of the static destructor set.
1267 This will work for any system that uses stabs, most usefully
1268 aout systems. */
1269 dbxout_begin_simple_stabs ("___DTOR_LIST__", 22 /* N_SETT */);
1270 dbxout_stab_value_label (XSTR (symbol, 0));
1271 #else
1272 sorry ("global destructors not supported on this target");
1273 #endif
1274 }
1275
1276 /* Write the address of the entity given by SYMBOL to SEC. */
1277 void
1278 assemble_addr_to_section (rtx symbol, section *sec)
1279 {
1280 switch_to_section (sec);
1281 assemble_align (POINTER_SIZE);
1282 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1283 }
1284
1285 /* Return the numbered .ctors.N (if CONSTRUCTOR_P) or .dtors.N (if
1286 not) section for PRIORITY. */
1287 section *
1288 get_cdtor_priority_section (int priority, bool constructor_p)
1289 {
1290 char buf[16];
1291
1292 /* ??? This only works reliably with the GNU linker. */
1293 sprintf (buf, "%s.%.5u",
1294 constructor_p ? ".ctors" : ".dtors",
1295 /* Invert the numbering so the linker puts us in the proper
1296 order; constructors are run from right to left, and the
1297 linker sorts in increasing order. */
1298 MAX_INIT_PRIORITY - priority);
1299 return get_section (buf, SECTION_WRITE, NULL);
1300 }
1301
1302 void
1303 default_named_section_asm_out_destructor (rtx symbol, int priority)
1304 {
1305 section *sec;
1306
1307 if (priority != DEFAULT_INIT_PRIORITY)
1308 sec = get_cdtor_priority_section (priority,
1309 /*constructor_p=*/false);
1310 else
1311 sec = get_section (".dtors", SECTION_WRITE, NULL);
1312
1313 assemble_addr_to_section (symbol, sec);
1314 }
1315
1316 #ifdef DTORS_SECTION_ASM_OP
1317 void
1318 default_dtor_section_asm_out_destructor (rtx symbol,
1319 int priority ATTRIBUTE_UNUSED)
1320 {
1321 assemble_addr_to_section (symbol, dtors_section);
1322 }
1323 #endif
1324
1325 /* Likewise for global constructors. */
1326
1327 void
1328 default_stabs_asm_out_constructor (rtx symbol ATTRIBUTE_UNUSED,
1329 int priority ATTRIBUTE_UNUSED)
1330 {
1331 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1332 /* Tell GNU LD that this is part of the static destructor set.
1333 This will work for any system that uses stabs, most usefully
1334 aout systems. */
1335 dbxout_begin_simple_stabs ("___CTOR_LIST__", 22 /* N_SETT */);
1336 dbxout_stab_value_label (XSTR (symbol, 0));
1337 #else
1338 sorry ("global constructors not supported on this target");
1339 #endif
1340 }
1341
1342 void
1343 default_named_section_asm_out_constructor (rtx symbol, int priority)
1344 {
1345 section *sec;
1346
1347 if (priority != DEFAULT_INIT_PRIORITY)
1348 sec = get_cdtor_priority_section (priority,
1349 /*constructor_p=*/true);
1350 else
1351 sec = get_section (".ctors", SECTION_WRITE, NULL);
1352
1353 assemble_addr_to_section (symbol, sec);
1354 }
1355
1356 #ifdef CTORS_SECTION_ASM_OP
1357 void
1358 default_ctor_section_asm_out_constructor (rtx symbol,
1359 int priority ATTRIBUTE_UNUSED)
1360 {
1361 assemble_addr_to_section (symbol, ctors_section);
1362 }
1363 #endif
1364 \f
1365 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1366 a nonzero value if the constant pool should be output before the
1367 start of the function, or a zero value if the pool should output
1368 after the end of the function. The default is to put it before the
1369 start. */
1370
1371 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1372 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1373 #endif
1374
1375 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1376 to be output to assembler.
1377 Set first_global_object_name and weak_global_object_name as appropriate. */
1378
1379 void
1380 notice_global_symbol (tree decl)
1381 {
1382 const char **type = &first_global_object_name;
1383
1384 if (first_global_object_name
1385 || !TREE_PUBLIC (decl)
1386 || DECL_EXTERNAL (decl)
1387 || !DECL_NAME (decl)
1388 || (TREE_CODE (decl) != FUNCTION_DECL
1389 && (TREE_CODE (decl) != VAR_DECL
1390 || (DECL_COMMON (decl)
1391 && (DECL_INITIAL (decl) == 0
1392 || DECL_INITIAL (decl) == error_mark_node))))
1393 || !MEM_P (DECL_RTL (decl)))
1394 return;
1395
1396 /* We win when global object is found, but it is useful to know about weak
1397 symbol as well so we can produce nicer unique names. */
1398 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl) || flag_shlib)
1399 type = &weak_global_object_name;
1400
1401 if (!*type)
1402 {
1403 const char *p;
1404 const char *name;
1405 rtx decl_rtl = DECL_RTL (decl);
1406
1407 p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0));
1408 name = ggc_strdup (p);
1409
1410 *type = name;
1411 }
1412 }
1413
1414 /* Output assembler code for the constant pool of a function and associated
1415 with defining the name of the function. DECL describes the function.
1416 NAME is the function's name. For the constant pool, we use the current
1417 constant pool data. */
1418
1419 void
1420 assemble_start_function (tree decl, const char *fnname)
1421 {
1422 int align;
1423 char tmp_label[100];
1424 bool hot_label_written = false;
1425
1426 crtl->subsections.unlikely_text_section_name = NULL;
1427
1428 first_function_block_is_cold = false;
1429 if (flag_reorder_blocks_and_partition)
1430 {
1431 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTB", const_labelno);
1432 crtl->subsections.hot_section_label = ggc_strdup (tmp_label);
1433 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDB", const_labelno);
1434 crtl->subsections.cold_section_label = ggc_strdup (tmp_label);
1435 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTE", const_labelno);
1436 crtl->subsections.hot_section_end_label = ggc_strdup (tmp_label);
1437 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDE", const_labelno);
1438 crtl->subsections.cold_section_end_label = ggc_strdup (tmp_label);
1439 const_labelno++;
1440 }
1441 else
1442 {
1443 crtl->subsections.hot_section_label = NULL;
1444 crtl->subsections.cold_section_label = NULL;
1445 crtl->subsections.hot_section_end_label = NULL;
1446 crtl->subsections.cold_section_end_label = NULL;
1447 }
1448
1449 /* The following code does not need preprocessing in the assembler. */
1450
1451 app_disable ();
1452
1453 if (CONSTANT_POOL_BEFORE_FUNCTION)
1454 output_constant_pool (fnname, decl);
1455
1456 resolve_unique_section (decl, 0, flag_function_sections);
1457
1458 /* Make sure the not and cold text (code) sections are properly
1459 aligned. This is necessary here in the case where the function
1460 has both hot and cold sections, because we don't want to re-set
1461 the alignment when the section switch happens mid-function. */
1462
1463 if (flag_reorder_blocks_and_partition)
1464 {
1465 switch_to_section (unlikely_text_section ());
1466 assemble_align (DECL_ALIGN (decl));
1467 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_label);
1468
1469 /* When the function starts with a cold section, we need to explicitly
1470 align the hot section and write out the hot section label.
1471 But if the current function is a thunk, we do not have a CFG. */
1472 if (!cfun->is_thunk
1473 && BB_PARTITION (ENTRY_BLOCK_PTR->next_bb) == BB_COLD_PARTITION)
1474 {
1475 switch_to_section (text_section);
1476 assemble_align (DECL_ALIGN (decl));
1477 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1478 hot_label_written = true;
1479 first_function_block_is_cold = true;
1480 }
1481 }
1482 else if (DECL_SECTION_NAME (decl))
1483 {
1484 /* Calls to function_section rely on first_function_block_is_cold
1485 being accurate. The first block may be cold even if we aren't
1486 doing partitioning, if the entire function was decided by
1487 choose_function_section (predict.c) to be cold. */
1488
1489 initialize_cold_section_name ();
1490
1491 if (crtl->subsections.unlikely_text_section_name
1492 && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
1493 crtl->subsections.unlikely_text_section_name) == 0)
1494 first_function_block_is_cold = true;
1495 }
1496
1497 in_cold_section_p = first_function_block_is_cold;
1498
1499 /* Switch to the correct text section for the start of the function. */
1500
1501 switch_to_section (function_section (decl));
1502 if (flag_reorder_blocks_and_partition
1503 && !hot_label_written)
1504 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1505
1506 /* Tell assembler to move to target machine's alignment for functions. */
1507 align = floor_log2 (DECL_ALIGN (decl) / BITS_PER_UNIT);
1508 if (align > 0)
1509 {
1510 ASM_OUTPUT_ALIGN (asm_out_file, align);
1511 }
1512
1513 /* Handle a user-specified function alignment.
1514 Note that we still need to align to DECL_ALIGN, as above,
1515 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1516 if (! DECL_USER_ALIGN (decl)
1517 && align_functions_log > align
1518 && optimize_function_for_speed_p (cfun))
1519 {
1520 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1521 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1522 align_functions_log, align_functions - 1);
1523 #else
1524 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1525 #endif
1526 }
1527
1528 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1529 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1530 #endif
1531
1532 if (!DECL_IGNORED_P (decl))
1533 (*debug_hooks->begin_function) (decl);
1534
1535 /* Make function name accessible from other files, if appropriate. */
1536
1537 if (TREE_PUBLIC (decl))
1538 {
1539 notice_global_symbol (decl);
1540
1541 globalize_decl (decl);
1542
1543 maybe_assemble_visibility (decl);
1544 }
1545
1546 if (DECL_PRESERVE_P (decl))
1547 targetm.asm_out.mark_decl_preserved (fnname);
1548
1549 /* Do any machine/system dependent processing of the function name. */
1550 #ifdef ASM_DECLARE_FUNCTION_NAME
1551 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1552 #else
1553 /* Standard thing is just output label for the function. */
1554 ASM_OUTPUT_FUNCTION_LABEL (asm_out_file, fnname, current_function_decl);
1555 #endif /* ASM_DECLARE_FUNCTION_NAME */
1556
1557 if (lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (decl)))
1558 saw_no_split_stack = true;
1559 }
1560
1561 /* Output assembler code associated with defining the size of the
1562 function. DECL describes the function. NAME is the function's name. */
1563
1564 void
1565 assemble_end_function (tree decl, const char *fnname ATTRIBUTE_UNUSED)
1566 {
1567 #ifdef ASM_DECLARE_FUNCTION_SIZE
1568 /* We could have switched section in the middle of the function. */
1569 if (flag_reorder_blocks_and_partition)
1570 switch_to_section (function_section (decl));
1571 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1572 #endif
1573 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1574 {
1575 output_constant_pool (fnname, decl);
1576 switch_to_section (function_section (decl)); /* need to switch back */
1577 }
1578 /* Output labels for end of hot/cold text sections (to be used by
1579 debug info.) */
1580 if (flag_reorder_blocks_and_partition)
1581 {
1582 section *save_text_section;
1583
1584 save_text_section = in_section;
1585 switch_to_section (unlikely_text_section ());
1586 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_end_label);
1587 if (first_function_block_is_cold)
1588 switch_to_section (text_section);
1589 else
1590 switch_to_section (function_section (decl));
1591 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_end_label);
1592 switch_to_section (save_text_section);
1593 }
1594 }
1595 \f
1596 /* Assemble code to leave SIZE bytes of zeros. */
1597
1598 void
1599 assemble_zeros (unsigned HOST_WIDE_INT size)
1600 {
1601 /* Do no output if -fsyntax-only. */
1602 if (flag_syntax_only)
1603 return;
1604
1605 #ifdef ASM_NO_SKIP_IN_TEXT
1606 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1607 so we must output 0s explicitly in the text section. */
1608 if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0)
1609 {
1610 unsigned HOST_WIDE_INT i;
1611 for (i = 0; i < size; i++)
1612 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1613 }
1614 else
1615 #endif
1616 if (size > 0)
1617 ASM_OUTPUT_SKIP (asm_out_file, size);
1618 }
1619
1620 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1621
1622 void
1623 assemble_align (int align)
1624 {
1625 if (align > BITS_PER_UNIT)
1626 {
1627 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1628 }
1629 }
1630
1631 /* Assemble a string constant with the specified C string as contents. */
1632
1633 void
1634 assemble_string (const char *p, int size)
1635 {
1636 int pos = 0;
1637 int maximum = 2000;
1638
1639 /* If the string is very long, split it up. */
1640
1641 while (pos < size)
1642 {
1643 int thissize = size - pos;
1644 if (thissize > maximum)
1645 thissize = maximum;
1646
1647 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1648
1649 pos += thissize;
1650 p += thissize;
1651 }
1652 }
1653
1654 \f
1655 /* A noswitch_section_callback for lcomm_section. */
1656
1657 static bool
1658 emit_local (tree decl ATTRIBUTE_UNUSED,
1659 const char *name ATTRIBUTE_UNUSED,
1660 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1661 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1662 {
1663 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1664 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name,
1665 size, DECL_ALIGN (decl));
1666 return true;
1667 #elif defined ASM_OUTPUT_ALIGNED_LOCAL
1668 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl));
1669 return true;
1670 #else
1671 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1672 return false;
1673 #endif
1674 }
1675
1676 /* A noswitch_section_callback for bss_noswitch_section. */
1677
1678 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
1679 static bool
1680 emit_bss (tree decl ATTRIBUTE_UNUSED,
1681 const char *name ATTRIBUTE_UNUSED,
1682 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1683 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1684 {
1685 #if defined ASM_OUTPUT_ALIGNED_BSS
1686 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl));
1687 return true;
1688 #else
1689 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded);
1690 return false;
1691 #endif
1692 }
1693 #endif
1694
1695 /* A noswitch_section_callback for comm_section. */
1696
1697 static bool
1698 emit_common (tree decl ATTRIBUTE_UNUSED,
1699 const char *name ATTRIBUTE_UNUSED,
1700 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1701 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1702 {
1703 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1704 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name,
1705 size, DECL_ALIGN (decl));
1706 return true;
1707 #elif defined ASM_OUTPUT_ALIGNED_COMMON
1708 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl));
1709 return true;
1710 #else
1711 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded);
1712 return false;
1713 #endif
1714 }
1715
1716 /* A noswitch_section_callback for tls_comm_section. */
1717
1718 static bool
1719 emit_tls_common (tree decl ATTRIBUTE_UNUSED,
1720 const char *name ATTRIBUTE_UNUSED,
1721 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1722 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1723 {
1724 #ifdef ASM_OUTPUT_TLS_COMMON
1725 ASM_OUTPUT_TLS_COMMON (asm_out_file, decl, name, size);
1726 return true;
1727 #else
1728 sorry ("thread-local COMMON data not implemented");
1729 return true;
1730 #endif
1731 }
1732
1733 /* Assemble DECL given that it belongs in SECTION_NOSWITCH section SECT.
1734 NAME is the name of DECL's SYMBOL_REF. */
1735
1736 static void
1737 assemble_noswitch_variable (tree decl, const char *name, section *sect)
1738 {
1739 unsigned HOST_WIDE_INT size, rounded;
1740
1741 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1742 rounded = size;
1743
1744 /* Don't allocate zero bytes of common,
1745 since that means "undefined external" in the linker. */
1746 if (size == 0)
1747 rounded = 1;
1748
1749 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1750 so that each uninitialized object starts on such a boundary. */
1751 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1752 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1753 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1754
1755 if (!sect->noswitch.callback (decl, name, size, rounded)
1756 && (unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded)
1757 warning (0, "requested alignment for %q+D is greater than "
1758 "implemented alignment of %wu", decl, rounded);
1759 }
1760
1761 /* A subroutine of assemble_variable. Output the label and contents of
1762 DECL, whose address is a SYMBOL_REF with name NAME. DONT_OUTPUT_DATA
1763 is as for assemble_variable. */
1764
1765 static void
1766 assemble_variable_contents (tree decl, const char *name,
1767 bool dont_output_data)
1768 {
1769 /* Do any machine/system dependent processing of the object. */
1770 #ifdef ASM_DECLARE_OBJECT_NAME
1771 last_assemble_variable_decl = decl;
1772 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1773 #else
1774 /* Standard thing is just output label for the object. */
1775 ASM_OUTPUT_LABEL (asm_out_file, name);
1776 #endif /* ASM_DECLARE_OBJECT_NAME */
1777
1778 if (!dont_output_data)
1779 {
1780 if (DECL_INITIAL (decl)
1781 && DECL_INITIAL (decl) != error_mark_node
1782 && !initializer_zerop (DECL_INITIAL (decl)))
1783 /* Output the actual data. */
1784 output_constant (DECL_INITIAL (decl),
1785 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
1786 DECL_ALIGN (decl));
1787 else
1788 /* Leave space for it. */
1789 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
1790 }
1791 }
1792
1793 /* Assemble everything that is needed for a variable or function declaration.
1794 Not used for automatic variables, and not used for function definitions.
1795 Should not be called for variables of incomplete structure type.
1796
1797 TOP_LEVEL is nonzero if this variable has file scope.
1798 AT_END is nonzero if this is the special handling, at end of compilation,
1799 to define things that have had only tentative definitions.
1800 DONT_OUTPUT_DATA if nonzero means don't actually output the
1801 initial value (that will be done by the caller). */
1802
1803 void
1804 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
1805 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
1806 {
1807 const char *name;
1808 rtx decl_rtl, symbol;
1809 section *sect;
1810
1811 /* This function is supposed to handle VARIABLES. Ensure we have one. */
1812 gcc_assert (TREE_CODE (decl) == VAR_DECL);
1813
1814 /* Emulated TLS had better not get this far. */
1815 gcc_checking_assert (targetm.have_tls || !DECL_THREAD_LOCAL_P (decl));
1816
1817 last_assemble_variable_decl = 0;
1818
1819 /* Normally no need to say anything here for external references,
1820 since assemble_external is called by the language-specific code
1821 when a declaration is first seen. */
1822
1823 if (DECL_EXTERNAL (decl))
1824 return;
1825
1826 /* Do nothing for global register variables. */
1827 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
1828 {
1829 TREE_ASM_WRITTEN (decl) = 1;
1830 return;
1831 }
1832
1833 /* If type was incomplete when the variable was declared,
1834 see if it is complete now. */
1835
1836 if (DECL_SIZE (decl) == 0)
1837 layout_decl (decl, 0);
1838
1839 /* Still incomplete => don't allocate it; treat the tentative defn
1840 (which is what it must have been) as an `extern' reference. */
1841
1842 if (!dont_output_data && DECL_SIZE (decl) == 0)
1843 {
1844 error ("storage size of %q+D isn%'t known", decl);
1845 TREE_ASM_WRITTEN (decl) = 1;
1846 return;
1847 }
1848
1849 /* The first declaration of a variable that comes through this function
1850 decides whether it is global (in C, has external linkage)
1851 or local (in C, has internal linkage). So do nothing more
1852 if this function has already run. */
1853
1854 if (TREE_ASM_WRITTEN (decl))
1855 return;
1856
1857 /* Make sure targetm.encode_section_info is invoked before we set
1858 ASM_WRITTEN. */
1859 decl_rtl = DECL_RTL (decl);
1860
1861 TREE_ASM_WRITTEN (decl) = 1;
1862
1863 /* Do no output if -fsyntax-only. */
1864 if (flag_syntax_only)
1865 return;
1866
1867 if (! dont_output_data
1868 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
1869 {
1870 error ("size of variable %q+D is too large", decl);
1871 return;
1872 }
1873
1874 gcc_assert (MEM_P (decl_rtl));
1875 gcc_assert (GET_CODE (XEXP (decl_rtl, 0)) == SYMBOL_REF);
1876 symbol = XEXP (decl_rtl, 0);
1877
1878 /* If this symbol belongs to the tree constant pool, output the constant
1879 if it hasn't already been written. */
1880 if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
1881 {
1882 tree decl = SYMBOL_REF_DECL (symbol);
1883 if (!TREE_ASM_WRITTEN (DECL_INITIAL (decl)))
1884 output_constant_def_contents (symbol);
1885 return;
1886 }
1887
1888 app_disable ();
1889
1890 name = XSTR (symbol, 0);
1891 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1892 notice_global_symbol (decl);
1893
1894 /* Compute the alignment of this data. */
1895
1896 align_variable (decl, dont_output_data);
1897 set_mem_align (decl_rtl, DECL_ALIGN (decl));
1898
1899 if (TREE_PUBLIC (decl))
1900 maybe_assemble_visibility (decl);
1901
1902 if (DECL_PRESERVE_P (decl))
1903 targetm.asm_out.mark_decl_preserved (name);
1904
1905 /* First make the assembler name(s) global if appropriate. */
1906 sect = get_variable_section (decl, false);
1907 if (TREE_PUBLIC (decl)
1908 && (sect->common.flags & SECTION_COMMON) == 0)
1909 globalize_decl (decl);
1910
1911 /* Output any data that we will need to use the address of. */
1912 if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node)
1913 output_addressed_constants (DECL_INITIAL (decl));
1914
1915 /* dbxout.c needs to know this. */
1916 if (sect && (sect->common.flags & SECTION_CODE) != 0)
1917 DECL_IN_TEXT_SECTION (decl) = 1;
1918
1919 /* If the decl is part of an object_block, make sure that the decl
1920 has been positioned within its block, but do not write out its
1921 definition yet. output_object_blocks will do that later. */
1922 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
1923 {
1924 gcc_assert (!dont_output_data);
1925 place_block_symbol (symbol);
1926 }
1927 else if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
1928 assemble_noswitch_variable (decl, name, sect);
1929 else
1930 {
1931 switch_to_section (sect);
1932 if (DECL_ALIGN (decl) > BITS_PER_UNIT)
1933 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl)));
1934 assemble_variable_contents (decl, name, dont_output_data);
1935 }
1936 }
1937
1938 /* Return 1 if type TYPE contains any pointers. */
1939
1940 static int
1941 contains_pointers_p (tree type)
1942 {
1943 switch (TREE_CODE (type))
1944 {
1945 case POINTER_TYPE:
1946 case REFERENCE_TYPE:
1947 /* I'm not sure whether OFFSET_TYPE needs this treatment,
1948 so I'll play safe and return 1. */
1949 case OFFSET_TYPE:
1950 return 1;
1951
1952 case RECORD_TYPE:
1953 case UNION_TYPE:
1954 case QUAL_UNION_TYPE:
1955 {
1956 tree fields;
1957 /* For a type that has fields, see if the fields have pointers. */
1958 for (fields = TYPE_FIELDS (type); fields; fields = DECL_CHAIN (fields))
1959 if (TREE_CODE (fields) == FIELD_DECL
1960 && contains_pointers_p (TREE_TYPE (fields)))
1961 return 1;
1962 return 0;
1963 }
1964
1965 case ARRAY_TYPE:
1966 /* An array type contains pointers if its element type does. */
1967 return contains_pointers_p (TREE_TYPE (type));
1968
1969 default:
1970 return 0;
1971 }
1972 }
1973
1974 /* We delay assemble_external processing until
1975 the compilation unit is finalized. This is the best we can do for
1976 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay
1977 it all the way to final. See PR 17982 for further discussion. */
1978 static GTY(()) tree pending_assemble_externals;
1979
1980 #ifdef ASM_OUTPUT_EXTERNAL
1981 /* True if DECL is a function decl for which no out-of-line copy exists.
1982 It is assumed that DECL's assembler name has been set. */
1983
1984 static bool
1985 incorporeal_function_p (tree decl)
1986 {
1987 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
1988 {
1989 const char *name;
1990
1991 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
1992 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
1993 return true;
1994
1995 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1996 if (is_builtin_name (name))
1997 return true;
1998 }
1999 return false;
2000 }
2001
2002 /* Actually do the tests to determine if this is necessary, and invoke
2003 ASM_OUTPUT_EXTERNAL. */
2004 static void
2005 assemble_external_real (tree decl)
2006 {
2007 rtx rtl = DECL_RTL (decl);
2008
2009 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
2010 && !SYMBOL_REF_USED (XEXP (rtl, 0))
2011 && !incorporeal_function_p (decl))
2012 {
2013 /* Some systems do require some output. */
2014 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
2015 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
2016 }
2017 }
2018 #endif
2019
2020 void
2021 process_pending_assemble_externals (void)
2022 {
2023 #ifdef ASM_OUTPUT_EXTERNAL
2024 tree list;
2025 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list))
2026 assemble_external_real (TREE_VALUE (list));
2027
2028 pending_assemble_externals = 0;
2029 #endif
2030 }
2031
2032 /* This TREE_LIST contains any weak symbol declarations waiting
2033 to be emitted. */
2034 static GTY(()) tree weak_decls;
2035
2036 /* Output something to declare an external symbol to the assembler,
2037 and qualifiers such as weakness. (Most assemblers don't need
2038 extern declaration, so we normally output nothing.) Do nothing if
2039 DECL is not external. */
2040
2041 void
2042 assemble_external (tree decl ATTRIBUTE_UNUSED)
2043 {
2044 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
2045 main body of this code is only rarely exercised. To provide some
2046 testing, on all platforms, we make sure that the ASM_OUT_FILE is
2047 open. If it's not, we should not be calling this function. */
2048 gcc_assert (asm_out_file);
2049
2050 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
2051 return;
2052
2053 /* We want to output annotation for weak and external symbols at
2054 very last to check if they are references or not. */
2055
2056 if (TARGET_SUPPORTS_WEAK
2057 && DECL_WEAK (decl)
2058 /* TREE_STATIC is a weird and abused creature which is not
2059 generally the right test for whether an entity has been
2060 locally emitted, inlined or otherwise not-really-extern, but
2061 for declarations that can be weak, it happens to be
2062 match. */
2063 && !TREE_STATIC (decl)
2064 && lookup_attribute ("weak", DECL_ATTRIBUTES (decl))
2065 && value_member (decl, weak_decls) == NULL_TREE)
2066 weak_decls = tree_cons (NULL, decl, weak_decls);
2067
2068 #ifdef ASM_OUTPUT_EXTERNAL
2069 if (value_member (decl, pending_assemble_externals) == NULL_TREE)
2070 pending_assemble_externals = tree_cons (NULL, decl,
2071 pending_assemble_externals);
2072 #endif
2073 }
2074
2075 /* Similar, for calling a library function FUN. */
2076
2077 void
2078 assemble_external_libcall (rtx fun)
2079 {
2080 /* Declare library function name external when first used, if nec. */
2081 if (! SYMBOL_REF_USED (fun))
2082 {
2083 SYMBOL_REF_USED (fun) = 1;
2084 targetm.asm_out.external_libcall (fun);
2085 }
2086 }
2087
2088 /* Assemble a label named NAME. */
2089
2090 void
2091 assemble_label (FILE *file, const char *name)
2092 {
2093 ASM_OUTPUT_LABEL (file, name);
2094 }
2095
2096 /* Set the symbol_referenced flag for ID. */
2097 void
2098 mark_referenced (tree id)
2099 {
2100 TREE_SYMBOL_REFERENCED (id) = 1;
2101 }
2102
2103 /* Set the symbol_referenced flag for DECL and notify callgraph. */
2104 void
2105 mark_decl_referenced (tree decl)
2106 {
2107 if (TREE_CODE (decl) == FUNCTION_DECL)
2108 {
2109 /* Extern inline functions don't become needed when referenced.
2110 If we know a method will be emitted in other TU and no new
2111 functions can be marked reachable, just use the external
2112 definition. */
2113 struct cgraph_node *node = cgraph_node (decl);
2114 if (!DECL_EXTERNAL (decl)
2115 && (!node->local.vtable_method || !cgraph_global_info_ready
2116 || !node->local.finalized))
2117 cgraph_mark_needed_node (node);
2118 }
2119 else if (TREE_CODE (decl) == VAR_DECL)
2120 {
2121 struct varpool_node *node = varpool_node (decl);
2122 varpool_mark_needed_node (node);
2123 /* C++ frontend use mark_decl_references to force COMDAT variables
2124 to be output that might appear dead otherwise. */
2125 node->force_output = true;
2126 }
2127 /* else do nothing - we can get various sorts of CST nodes here,
2128 which do not need to be marked. */
2129 }
2130
2131
2132 /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS
2133 until we find an identifier that is not itself a transparent alias.
2134 Modify the alias passed to it by reference (and all aliases on the
2135 way to the ultimate target), such that they do not have to be
2136 followed again, and return the ultimate target of the alias
2137 chain. */
2138
2139 static inline tree
2140 ultimate_transparent_alias_target (tree *alias)
2141 {
2142 tree target = *alias;
2143
2144 if (IDENTIFIER_TRANSPARENT_ALIAS (target))
2145 {
2146 gcc_assert (TREE_CHAIN (target));
2147 target = ultimate_transparent_alias_target (&TREE_CHAIN (target));
2148 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
2149 && ! TREE_CHAIN (target));
2150 *alias = target;
2151 }
2152
2153 return target;
2154 }
2155
2156 /* Output to FILE (an assembly file) a reference to NAME. If NAME
2157 starts with a *, the rest of NAME is output verbatim. Otherwise
2158 NAME is transformed in a target-specific way (usually by the
2159 addition of an underscore). */
2160
2161 void
2162 assemble_name_raw (FILE *file, const char *name)
2163 {
2164 if (name[0] == '*')
2165 fputs (&name[1], file);
2166 else
2167 ASM_OUTPUT_LABELREF (file, name);
2168 }
2169
2170 /* Like assemble_name_raw, but should be used when NAME might refer to
2171 an entity that is also represented as a tree (like a function or
2172 variable). If NAME does refer to such an entity, that entity will
2173 be marked as referenced. */
2174
2175 void
2176 assemble_name (FILE *file, const char *name)
2177 {
2178 const char *real_name;
2179 tree id;
2180
2181 real_name = targetm.strip_name_encoding (name);
2182
2183 id = maybe_get_identifier (real_name);
2184 if (id)
2185 {
2186 tree id_orig = id;
2187
2188 mark_referenced (id);
2189 ultimate_transparent_alias_target (&id);
2190 if (id != id_orig)
2191 name = IDENTIFIER_POINTER (id);
2192 gcc_assert (! TREE_CHAIN (id));
2193 }
2194
2195 assemble_name_raw (file, name);
2196 }
2197
2198 /* Allocate SIZE bytes writable static space with a gensym name
2199 and return an RTX to refer to its address. */
2200
2201 rtx
2202 assemble_static_space (unsigned HOST_WIDE_INT size)
2203 {
2204 char name[12];
2205 const char *namestring;
2206 rtx x;
2207
2208 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
2209 ++const_labelno;
2210 namestring = ggc_strdup (name);
2211
2212 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
2213 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
2214
2215 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
2216 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
2217 BIGGEST_ALIGNMENT);
2218 #else
2219 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
2220 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
2221 #else
2222 {
2223 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
2224 so that each uninitialized object starts on such a boundary. */
2225 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
2226 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
2227 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
2228 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
2229 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
2230 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
2231 }
2232 #endif
2233 #endif
2234 return x;
2235 }
2236
2237 /* Assemble the static constant template for function entry trampolines.
2238 This is done at most once per compilation.
2239 Returns an RTX for the address of the template. */
2240
2241 static GTY(()) rtx initial_trampoline;
2242
2243 rtx
2244 assemble_trampoline_template (void)
2245 {
2246 char label[256];
2247 const char *name;
2248 int align;
2249 rtx symbol;
2250
2251 gcc_assert (targetm.asm_out.trampoline_template != NULL);
2252
2253 if (initial_trampoline)
2254 return initial_trampoline;
2255
2256 /* By default, put trampoline templates in read-only data section. */
2257
2258 #ifdef TRAMPOLINE_SECTION
2259 switch_to_section (TRAMPOLINE_SECTION);
2260 #else
2261 switch_to_section (readonly_data_section);
2262 #endif
2263
2264 /* Write the assembler code to define one. */
2265 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
2266 if (align > 0)
2267 ASM_OUTPUT_ALIGN (asm_out_file, align);
2268
2269 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
2270 targetm.asm_out.trampoline_template (asm_out_file);
2271
2272 /* Record the rtl to refer to it. */
2273 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
2274 name = ggc_strdup (label);
2275 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
2276 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2277
2278 initial_trampoline = gen_const_mem (BLKmode, symbol);
2279 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
2280 set_mem_size (initial_trampoline, GEN_INT (TRAMPOLINE_SIZE));
2281
2282 return initial_trampoline;
2283 }
2284 \f
2285 /* A and B are either alignments or offsets. Return the minimum alignment
2286 that may be assumed after adding the two together. */
2287
2288 static inline unsigned
2289 min_align (unsigned int a, unsigned int b)
2290 {
2291 return (a | b) & -(a | b);
2292 }
2293
2294 /* Return the assembler directive for creating a given kind of integer
2295 object. SIZE is the number of bytes in the object and ALIGNED_P
2296 indicates whether it is known to be aligned. Return NULL if the
2297 assembly dialect has no such directive.
2298
2299 The returned string should be printed at the start of a new line and
2300 be followed immediately by the object's initial value. */
2301
2302 const char *
2303 integer_asm_op (int size, int aligned_p)
2304 {
2305 struct asm_int_op *ops;
2306
2307 if (aligned_p)
2308 ops = &targetm.asm_out.aligned_op;
2309 else
2310 ops = &targetm.asm_out.unaligned_op;
2311
2312 switch (size)
2313 {
2314 case 1:
2315 return targetm.asm_out.byte_op;
2316 case 2:
2317 return ops->hi;
2318 case 4:
2319 return ops->si;
2320 case 8:
2321 return ops->di;
2322 case 16:
2323 return ops->ti;
2324 default:
2325 return NULL;
2326 }
2327 }
2328
2329 /* Use directive OP to assemble an integer object X. Print OP at the
2330 start of the line, followed immediately by the value of X. */
2331
2332 void
2333 assemble_integer_with_op (const char *op, rtx x)
2334 {
2335 fputs (op, asm_out_file);
2336 output_addr_const (asm_out_file, x);
2337 fputc ('\n', asm_out_file);
2338 }
2339
2340 /* The default implementation of the asm_out.integer target hook. */
2341
2342 bool
2343 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2344 unsigned int size ATTRIBUTE_UNUSED,
2345 int aligned_p ATTRIBUTE_UNUSED)
2346 {
2347 const char *op = integer_asm_op (size, aligned_p);
2348 /* Avoid GAS bugs for large values. Specifically negative values whose
2349 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */
2350 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT)
2351 return false;
2352 return op && (assemble_integer_with_op (op, x), true);
2353 }
2354
2355 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2356 the alignment of the integer in bits. Return 1 if we were able to output
2357 the constant, otherwise 0. We must be able to output the constant,
2358 if FORCE is nonzero. */
2359
2360 bool
2361 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2362 {
2363 int aligned_p;
2364
2365 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2366
2367 /* See if the target hook can handle this kind of object. */
2368 if (targetm.asm_out.integer (x, size, aligned_p))
2369 return true;
2370
2371 /* If the object is a multi-byte one, try splitting it up. Split
2372 it into words it if is multi-word, otherwise split it into bytes. */
2373 if (size > 1)
2374 {
2375 enum machine_mode omode, imode;
2376 unsigned int subalign;
2377 unsigned int subsize, i;
2378 enum mode_class mclass;
2379
2380 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2381 subalign = MIN (align, subsize * BITS_PER_UNIT);
2382 if (GET_CODE (x) == CONST_FIXED)
2383 mclass = GET_MODE_CLASS (GET_MODE (x));
2384 else
2385 mclass = MODE_INT;
2386
2387 omode = mode_for_size (subsize * BITS_PER_UNIT, mclass, 0);
2388 imode = mode_for_size (size * BITS_PER_UNIT, mclass, 0);
2389
2390 for (i = 0; i < size; i += subsize)
2391 {
2392 rtx partial = simplify_subreg (omode, x, imode, i);
2393 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2394 break;
2395 }
2396 if (i == size)
2397 return true;
2398
2399 /* If we've printed some of it, but not all of it, there's no going
2400 back now. */
2401 gcc_assert (!i);
2402 }
2403
2404 gcc_assert (!force);
2405
2406 return false;
2407 }
2408 \f
2409 void
2410 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2411 {
2412 long data[4] = {0, 0, 0, 0};
2413 int i;
2414 int bitsize, nelts, nunits, units_per;
2415
2416 /* This is hairy. We have a quantity of known size. real_to_target
2417 will put it into an array of *host* longs, 32 bits per element
2418 (even if long is more than 32 bits). We need to determine the
2419 number of array elements that are occupied (nelts) and the number
2420 of *target* min-addressable units that will be occupied in the
2421 object file (nunits). We cannot assume that 32 divides the
2422 mode's bitsize (size * BITS_PER_UNIT) evenly.
2423
2424 size * BITS_PER_UNIT is used here to make sure that padding bits
2425 (which might appear at either end of the value; real_to_target
2426 will include the padding bits in its output array) are included. */
2427
2428 nunits = GET_MODE_SIZE (mode);
2429 bitsize = nunits * BITS_PER_UNIT;
2430 nelts = CEIL (bitsize, 32);
2431 units_per = 32 / BITS_PER_UNIT;
2432
2433 real_to_target (data, &d, mode);
2434
2435 /* Put out the first word with the specified alignment. */
2436 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2437 nunits -= units_per;
2438
2439 /* Subsequent words need only 32-bit alignment. */
2440 align = min_align (align, 32);
2441
2442 for (i = 1; i < nelts; i++)
2443 {
2444 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2445 nunits -= units_per;
2446 }
2447 }
2448 \f
2449 /* Given an expression EXP with a constant value,
2450 reduce it to the sum of an assembler symbol and an integer.
2451 Store them both in the structure *VALUE.
2452 EXP must be reducible. */
2453
2454 struct GTY(()) addr_const {
2455 rtx base;
2456 HOST_WIDE_INT offset;
2457 };
2458
2459 static void
2460 decode_addr_const (tree exp, struct addr_const *value)
2461 {
2462 tree target = TREE_OPERAND (exp, 0);
2463 int offset = 0;
2464 rtx x;
2465
2466 while (1)
2467 {
2468 if (TREE_CODE (target) == COMPONENT_REF
2469 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2470 {
2471 offset += int_byte_position (TREE_OPERAND (target, 1));
2472 target = TREE_OPERAND (target, 0);
2473 }
2474 else if (TREE_CODE (target) == ARRAY_REF
2475 || TREE_CODE (target) == ARRAY_RANGE_REF)
2476 {
2477 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2478 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2479 target = TREE_OPERAND (target, 0);
2480 }
2481 else if (TREE_CODE (target) == INDIRECT_REF
2482 && TREE_CODE (TREE_OPERAND (target, 0)) == NOP_EXPR
2483 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (target, 0), 0))
2484 == ADDR_EXPR)
2485 target = TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (target, 0), 0), 0);
2486 else
2487 break;
2488 }
2489
2490 switch (TREE_CODE (target))
2491 {
2492 case VAR_DECL:
2493 case FUNCTION_DECL:
2494 x = DECL_RTL (target);
2495 break;
2496
2497 case LABEL_DECL:
2498 x = gen_rtx_MEM (FUNCTION_MODE,
2499 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target)));
2500 break;
2501
2502 case REAL_CST:
2503 case FIXED_CST:
2504 case STRING_CST:
2505 case COMPLEX_CST:
2506 case CONSTRUCTOR:
2507 case INTEGER_CST:
2508 x = output_constant_def (target, 1);
2509 break;
2510
2511 default:
2512 gcc_unreachable ();
2513 }
2514
2515 gcc_assert (MEM_P (x));
2516 x = XEXP (x, 0);
2517
2518 value->base = x;
2519 value->offset = offset;
2520 }
2521 \f
2522
2523 static GTY((param_is (struct constant_descriptor_tree)))
2524 htab_t const_desc_htab;
2525
2526 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2527
2528 /* Constant pool accessor function. */
2529
2530 htab_t
2531 constant_pool_htab (void)
2532 {
2533 return const_desc_htab;
2534 }
2535
2536 /* Compute a hash code for a constant expression. */
2537
2538 static hashval_t
2539 const_desc_hash (const void *ptr)
2540 {
2541 return ((const struct constant_descriptor_tree *)ptr)->hash;
2542 }
2543
2544 static hashval_t
2545 const_hash_1 (const tree exp)
2546 {
2547 const char *p;
2548 hashval_t hi;
2549 int len, i;
2550 enum tree_code code = TREE_CODE (exp);
2551
2552 /* Either set P and LEN to the address and len of something to hash and
2553 exit the switch or return a value. */
2554
2555 switch (code)
2556 {
2557 case INTEGER_CST:
2558 p = (char *) &TREE_INT_CST (exp);
2559 len = sizeof TREE_INT_CST (exp);
2560 break;
2561
2562 case REAL_CST:
2563 return real_hash (TREE_REAL_CST_PTR (exp));
2564
2565 case FIXED_CST:
2566 return fixed_hash (TREE_FIXED_CST_PTR (exp));
2567
2568 case STRING_CST:
2569 p = TREE_STRING_POINTER (exp);
2570 len = TREE_STRING_LENGTH (exp);
2571 break;
2572
2573 case COMPLEX_CST:
2574 return (const_hash_1 (TREE_REALPART (exp)) * 5
2575 + const_hash_1 (TREE_IMAGPART (exp)));
2576
2577 case VECTOR_CST:
2578 {
2579 tree link;
2580
2581 hi = 7 + TYPE_VECTOR_SUBPARTS (TREE_TYPE (exp));
2582
2583 for (link = TREE_VECTOR_CST_ELTS (exp); link; link = TREE_CHAIN (link))
2584 hi = hi * 563 + const_hash_1 (TREE_VALUE (link));
2585
2586 return hi;
2587 }
2588
2589 case CONSTRUCTOR:
2590 {
2591 unsigned HOST_WIDE_INT idx;
2592 tree value;
2593
2594 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2595
2596 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
2597 if (value)
2598 hi = hi * 603 + const_hash_1 (value);
2599
2600 return hi;
2601 }
2602
2603 case ADDR_EXPR:
2604 case FDESC_EXPR:
2605 {
2606 struct addr_const value;
2607
2608 decode_addr_const (exp, &value);
2609 switch (GET_CODE (value.base))
2610 {
2611 case SYMBOL_REF:
2612 /* Don't hash the address of the SYMBOL_REF;
2613 only use the offset and the symbol name. */
2614 hi = value.offset;
2615 p = XSTR (value.base, 0);
2616 for (i = 0; p[i] != 0; i++)
2617 hi = ((hi * 613) + (unsigned) (p[i]));
2618 break;
2619
2620 case LABEL_REF:
2621 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2622 break;
2623
2624 default:
2625 gcc_unreachable ();
2626 }
2627 }
2628 return hi;
2629
2630 case PLUS_EXPR:
2631 case POINTER_PLUS_EXPR:
2632 case MINUS_EXPR:
2633 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2634 + const_hash_1 (TREE_OPERAND (exp, 1)));
2635
2636 CASE_CONVERT:
2637 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2638
2639 default:
2640 /* A language specific constant. Just hash the code. */
2641 return code;
2642 }
2643
2644 /* Compute hashing function. */
2645 hi = len;
2646 for (i = 0; i < len; i++)
2647 hi = ((hi * 613) + (unsigned) (p[i]));
2648
2649 return hi;
2650 }
2651
2652 /* Wrapper of compare_constant, for the htab interface. */
2653 static int
2654 const_desc_eq (const void *p1, const void *p2)
2655 {
2656 const struct constant_descriptor_tree *const c1
2657 = (const struct constant_descriptor_tree *) p1;
2658 const struct constant_descriptor_tree *const c2
2659 = (const struct constant_descriptor_tree *) p2;
2660 if (c1->hash != c2->hash)
2661 return 0;
2662 return compare_constant (c1->value, c2->value);
2663 }
2664
2665 /* Compare t1 and t2, and return 1 only if they are known to result in
2666 the same bit pattern on output. */
2667
2668 static int
2669 compare_constant (const tree t1, const tree t2)
2670 {
2671 enum tree_code typecode;
2672
2673 if (t1 == NULL_TREE)
2674 return t2 == NULL_TREE;
2675 if (t2 == NULL_TREE)
2676 return 0;
2677
2678 if (TREE_CODE (t1) != TREE_CODE (t2))
2679 return 0;
2680
2681 switch (TREE_CODE (t1))
2682 {
2683 case INTEGER_CST:
2684 /* Integer constants are the same only if the same width of type. */
2685 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2686 return 0;
2687 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2688 return 0;
2689 return tree_int_cst_equal (t1, t2);
2690
2691 case REAL_CST:
2692 /* Real constants are the same only if the same width of type. */
2693 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2694 return 0;
2695
2696 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2697
2698 case FIXED_CST:
2699 /* Fixed constants are the same only if the same width of type. */
2700 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2701 return 0;
2702
2703 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1), TREE_FIXED_CST (t2));
2704
2705 case STRING_CST:
2706 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2707 return 0;
2708
2709 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2710 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2711 TREE_STRING_LENGTH (t1)));
2712
2713 case COMPLEX_CST:
2714 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2715 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2716
2717 case VECTOR_CST:
2718 {
2719 tree link1, link2;
2720
2721 if (TYPE_VECTOR_SUBPARTS (TREE_TYPE (t1))
2722 != TYPE_VECTOR_SUBPARTS (TREE_TYPE (t2)))
2723 return 0;
2724
2725 link2 = TREE_VECTOR_CST_ELTS (t2);
2726 for (link1 = TREE_VECTOR_CST_ELTS (t1);
2727 link1;
2728 link1 = TREE_CHAIN (link1))
2729 {
2730 if (!compare_constant (TREE_VALUE (link1), TREE_VALUE (link2)))
2731 return 0;
2732 link2 = TREE_CHAIN (link2);
2733 }
2734
2735 return 1;
2736 }
2737
2738 case CONSTRUCTOR:
2739 {
2740 VEC(constructor_elt, gc) *v1, *v2;
2741 unsigned HOST_WIDE_INT idx;
2742
2743 typecode = TREE_CODE (TREE_TYPE (t1));
2744 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2745 return 0;
2746
2747 if (typecode == ARRAY_TYPE)
2748 {
2749 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2750 /* For arrays, check that the sizes all match. */
2751 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2752 || size_1 == -1
2753 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2754 return 0;
2755 }
2756 else
2757 {
2758 /* For record and union constructors, require exact type
2759 equality. */
2760 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2761 return 0;
2762 }
2763
2764 v1 = CONSTRUCTOR_ELTS (t1);
2765 v2 = CONSTRUCTOR_ELTS (t2);
2766 if (VEC_length (constructor_elt, v1)
2767 != VEC_length (constructor_elt, v2))
2768 return 0;
2769
2770 for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
2771 {
2772 constructor_elt *c1 = VEC_index (constructor_elt, v1, idx);
2773 constructor_elt *c2 = VEC_index (constructor_elt, v2, idx);
2774
2775 /* Check that each value is the same... */
2776 if (!compare_constant (c1->value, c2->value))
2777 return 0;
2778 /* ... and that they apply to the same fields! */
2779 if (typecode == ARRAY_TYPE)
2780 {
2781 if (!compare_constant (c1->index, c2->index))
2782 return 0;
2783 }
2784 else
2785 {
2786 if (c1->index != c2->index)
2787 return 0;
2788 }
2789 }
2790
2791 return 1;
2792 }
2793
2794 case ADDR_EXPR:
2795 case FDESC_EXPR:
2796 {
2797 struct addr_const value1, value2;
2798 enum rtx_code code;
2799 int ret;
2800
2801 decode_addr_const (t1, &value1);
2802 decode_addr_const (t2, &value2);
2803
2804 if (value1.offset != value2.offset)
2805 return 0;
2806
2807 code = GET_CODE (value1.base);
2808 if (code != GET_CODE (value2.base))
2809 return 0;
2810
2811 switch (code)
2812 {
2813 case SYMBOL_REF:
2814 ret = (strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
2815 break;
2816
2817 case LABEL_REF:
2818 ret = (CODE_LABEL_NUMBER (XEXP (value1.base, 0))
2819 == CODE_LABEL_NUMBER (XEXP (value2.base, 0)));
2820 break;
2821
2822 default:
2823 gcc_unreachable ();
2824 }
2825 return ret;
2826 }
2827
2828 case PLUS_EXPR:
2829 case POINTER_PLUS_EXPR:
2830 case MINUS_EXPR:
2831 case RANGE_EXPR:
2832 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
2833 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
2834
2835 CASE_CONVERT:
2836 case VIEW_CONVERT_EXPR:
2837 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2838
2839 default:
2840 return 0;
2841 }
2842
2843 gcc_unreachable ();
2844 }
2845 \f
2846 /* Make a copy of the whole tree structure for a constant. This
2847 handles the same types of nodes that compare_constant handles. */
2848
2849 static tree
2850 copy_constant (tree exp)
2851 {
2852 switch (TREE_CODE (exp))
2853 {
2854 case ADDR_EXPR:
2855 /* For ADDR_EXPR, we do not want to copy the decl whose address
2856 is requested. We do want to copy constants though. */
2857 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0)))
2858 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2859 copy_constant (TREE_OPERAND (exp, 0)));
2860 else
2861 return copy_node (exp);
2862
2863 case INTEGER_CST:
2864 case REAL_CST:
2865 case FIXED_CST:
2866 case STRING_CST:
2867 return copy_node (exp);
2868
2869 case COMPLEX_CST:
2870 return build_complex (TREE_TYPE (exp),
2871 copy_constant (TREE_REALPART (exp)),
2872 copy_constant (TREE_IMAGPART (exp)));
2873
2874 case PLUS_EXPR:
2875 case POINTER_PLUS_EXPR:
2876 case MINUS_EXPR:
2877 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
2878 copy_constant (TREE_OPERAND (exp, 0)),
2879 copy_constant (TREE_OPERAND (exp, 1)));
2880
2881 CASE_CONVERT:
2882 case VIEW_CONVERT_EXPR:
2883 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2884 copy_constant (TREE_OPERAND (exp, 0)));
2885
2886 case VECTOR_CST:
2887 return build_vector (TREE_TYPE (exp),
2888 copy_list (TREE_VECTOR_CST_ELTS (exp)));
2889
2890 case CONSTRUCTOR:
2891 {
2892 tree copy = copy_node (exp);
2893 VEC(constructor_elt, gc) *v;
2894 unsigned HOST_WIDE_INT idx;
2895 tree purpose, value;
2896
2897 v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt,
2898 CONSTRUCTOR_ELTS (exp)));
2899 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value)
2900 {
2901 constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL);
2902 ce->index = purpose;
2903 ce->value = copy_constant (value);
2904 }
2905 CONSTRUCTOR_ELTS (copy) = v;
2906 return copy;
2907 }
2908
2909 default:
2910 gcc_unreachable ();
2911 }
2912 }
2913 \f
2914 /* Return the section into which constant EXP should be placed. */
2915
2916 static section *
2917 get_constant_section (tree exp, unsigned int align)
2918 {
2919 return targetm.asm_out.select_section (exp,
2920 compute_reloc_for_constant (exp),
2921 align);
2922 }
2923
2924 /* Return the size of constant EXP in bytes. */
2925
2926 static HOST_WIDE_INT
2927 get_constant_size (tree exp)
2928 {
2929 HOST_WIDE_INT size;
2930
2931 size = int_size_in_bytes (TREE_TYPE (exp));
2932 if (TREE_CODE (exp) == STRING_CST)
2933 size = MAX (TREE_STRING_LENGTH (exp), size);
2934 return size;
2935 }
2936
2937 /* Subroutine of output_constant_def:
2938 No constant equal to EXP is known to have been output.
2939 Make a constant descriptor to enter EXP in the hash table.
2940 Assign the label number and construct RTL to refer to the
2941 constant's location in memory.
2942 Caller is responsible for updating the hash table. */
2943
2944 static struct constant_descriptor_tree *
2945 build_constant_desc (tree exp)
2946 {
2947 struct constant_descriptor_tree *desc;
2948 rtx symbol, rtl;
2949 char label[256];
2950 int labelno;
2951 tree decl;
2952
2953 desc = ggc_alloc_constant_descriptor_tree ();
2954 desc->value = copy_constant (exp);
2955
2956 /* Propagate marked-ness to copied constant. */
2957 if (flag_mudflap && mf_marked_p (exp))
2958 mf_mark (desc->value);
2959
2960 /* Create a string containing the label name, in LABEL. */
2961 labelno = const_labelno++;
2962 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
2963
2964 /* Construct the VAR_DECL associated with the constant. */
2965 decl = build_decl (UNKNOWN_LOCATION, VAR_DECL, get_identifier (label),
2966 TREE_TYPE (exp));
2967 DECL_ARTIFICIAL (decl) = 1;
2968 DECL_IGNORED_P (decl) = 1;
2969 TREE_READONLY (decl) = 1;
2970 TREE_STATIC (decl) = 1;
2971 TREE_ADDRESSABLE (decl) = 1;
2972 /* We don't set the RTL yet as this would cause varpool to assume that the
2973 variable is referenced. Moreover, it would just be dropped in LTO mode.
2974 Instead we set the flag that will be recognized in make_decl_rtl. */
2975 DECL_IN_CONSTANT_POOL (decl) = 1;
2976 DECL_INITIAL (decl) = desc->value;
2977 /* ??? CONSTANT_ALIGNMENT hasn't been updated for vector types on most
2978 architectures so use DATA_ALIGNMENT as well, except for strings. */
2979 if (TREE_CODE (exp) == STRING_CST)
2980 {
2981 #ifdef CONSTANT_ALIGNMENT
2982 DECL_ALIGN (decl) = CONSTANT_ALIGNMENT (exp, DECL_ALIGN (decl));
2983 #endif
2984 }
2985 else
2986 align_variable (decl, 0);
2987
2988 /* Now construct the SYMBOL_REF and the MEM. */
2989 if (use_object_blocks_p ())
2990 {
2991 section *sect = get_constant_section (exp, DECL_ALIGN (decl));
2992 symbol = create_block_symbol (ggc_strdup (label),
2993 get_block_for_section (sect), -1);
2994 }
2995 else
2996 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
2997 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
2998 SET_SYMBOL_REF_DECL (symbol, decl);
2999 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3000
3001 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
3002 set_mem_attributes (rtl, exp, 1);
3003 set_mem_alias_set (rtl, 0);
3004 set_mem_alias_set (rtl, const_alias_set);
3005
3006 /* We cannot share RTX'es in pool entries.
3007 Mark this piece of RTL as required for unsharing. */
3008 RTX_FLAG (rtl, used) = 1;
3009
3010 /* Set flags or add text to the name to record information, such as
3011 that it is a local symbol. If the name is changed, the macro
3012 ASM_OUTPUT_LABELREF will have to know how to strip this
3013 information. This call might invalidate our local variable
3014 SYMBOL; we can't use it afterward. */
3015 targetm.encode_section_info (exp, rtl, true);
3016
3017 desc->rtl = rtl;
3018
3019 return desc;
3020 }
3021
3022 /* Return an rtx representing a reference to constant data in memory
3023 for the constant expression EXP.
3024
3025 If assembler code for such a constant has already been output,
3026 return an rtx to refer to it.
3027 Otherwise, output such a constant in memory
3028 and generate an rtx for it.
3029
3030 If DEFER is nonzero, this constant can be deferred and output only
3031 if referenced in the function after all optimizations.
3032
3033 `const_desc_table' records which constants already have label strings. */
3034
3035 rtx
3036 output_constant_def (tree exp, int defer)
3037 {
3038 struct constant_descriptor_tree *desc;
3039 struct constant_descriptor_tree key;
3040 void **loc;
3041
3042 /* Look up EXP in the table of constant descriptors. If we didn't find
3043 it, create a new one. */
3044 key.value = exp;
3045 key.hash = const_hash_1 (exp);
3046 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
3047
3048 desc = (struct constant_descriptor_tree *) *loc;
3049 if (desc == 0)
3050 {
3051 desc = build_constant_desc (exp);
3052 desc->hash = key.hash;
3053 *loc = desc;
3054 }
3055
3056 maybe_output_constant_def_contents (desc, defer);
3057 return desc->rtl;
3058 }
3059
3060 /* Subroutine of output_constant_def: Decide whether or not we need to
3061 output the constant DESC now, and if so, do it. */
3062 static void
3063 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
3064 int defer)
3065 {
3066 rtx symbol = XEXP (desc->rtl, 0);
3067 tree exp = desc->value;
3068
3069 if (flag_syntax_only)
3070 return;
3071
3072 if (TREE_ASM_WRITTEN (exp))
3073 /* Already output; don't do it again. */
3074 return;
3075
3076 /* We can always defer constants as long as the context allows
3077 doing so. */
3078 if (defer)
3079 {
3080 /* Increment n_deferred_constants if it exists. It needs to be at
3081 least as large as the number of constants actually referred to
3082 by the function. If it's too small we'll stop looking too early
3083 and fail to emit constants; if it's too large we'll only look
3084 through the entire function when we could have stopped earlier. */
3085 if (cfun)
3086 n_deferred_constants++;
3087 return;
3088 }
3089
3090 output_constant_def_contents (symbol);
3091 }
3092
3093 /* Subroutine of output_constant_def_contents. Output the definition
3094 of constant EXP, which is pointed to by label LABEL. ALIGN is the
3095 constant's alignment in bits. */
3096
3097 static void
3098 assemble_constant_contents (tree exp, const char *label, unsigned int align)
3099 {
3100 HOST_WIDE_INT size;
3101
3102 size = get_constant_size (exp);
3103
3104 /* Do any machine/system dependent processing of the constant. */
3105 targetm.asm_out.declare_constant_name (asm_out_file, label, exp, size);
3106
3107 /* Output the value of EXP. */
3108 output_constant (exp, size, align);
3109 }
3110
3111 /* We must output the constant data referred to by SYMBOL; do so. */
3112
3113 static void
3114 output_constant_def_contents (rtx symbol)
3115 {
3116 tree decl = SYMBOL_REF_DECL (symbol);
3117 tree exp = DECL_INITIAL (decl);
3118 unsigned int align;
3119
3120 /* Make sure any other constants whose addresses appear in EXP
3121 are assigned label numbers. */
3122 output_addressed_constants (exp);
3123
3124 /* We are no longer deferring this constant. */
3125 TREE_ASM_WRITTEN (decl) = TREE_ASM_WRITTEN (exp) = 1;
3126
3127 /* If the constant is part of an object block, make sure that the
3128 decl has been positioned within its block, but do not write out
3129 its definition yet. output_object_blocks will do that later. */
3130 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
3131 place_block_symbol (symbol);
3132 else
3133 {
3134 align = DECL_ALIGN (decl);
3135 switch_to_section (get_constant_section (exp, align));
3136 if (align > BITS_PER_UNIT)
3137 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
3138 assemble_constant_contents (exp, XSTR (symbol, 0), align);
3139 }
3140 if (flag_mudflap)
3141 mudflap_enqueue_constant (exp);
3142 }
3143
3144 /* Look up EXP in the table of constant descriptors. Return the rtl
3145 if it has been emitted, else null. */
3146
3147 rtx
3148 lookup_constant_def (tree exp)
3149 {
3150 struct constant_descriptor_tree *desc;
3151 struct constant_descriptor_tree key;
3152
3153 key.value = exp;
3154 key.hash = const_hash_1 (exp);
3155 desc = (struct constant_descriptor_tree *)
3156 htab_find_with_hash (const_desc_htab, &key, key.hash);
3157
3158 return (desc ? desc->rtl : NULL_RTX);
3159 }
3160
3161 /* Return a tree representing a reference to constant data in memory
3162 for the constant expression EXP.
3163
3164 This is the counterpart of output_constant_def at the Tree level. */
3165
3166 tree
3167 tree_output_constant_def (tree exp)
3168 {
3169 struct constant_descriptor_tree *desc, key;
3170 void **loc;
3171 tree decl;
3172
3173 /* Look up EXP in the table of constant descriptors. If we didn't find
3174 it, create a new one. */
3175 key.value = exp;
3176 key.hash = const_hash_1 (exp);
3177 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
3178
3179 desc = (struct constant_descriptor_tree *) *loc;
3180 if (desc == 0)
3181 {
3182 desc = build_constant_desc (exp);
3183 desc->hash = key.hash;
3184 *loc = desc;
3185 }
3186
3187 decl = SYMBOL_REF_DECL (XEXP (desc->rtl, 0));
3188 varpool_finalize_decl (decl);
3189 return decl;
3190 }
3191 \f
3192 /* Used in the hash tables to avoid outputting the same constant
3193 twice. Unlike 'struct constant_descriptor_tree', RTX constants
3194 are output once per function, not once per file. */
3195 /* ??? Only a few targets need per-function constant pools. Most
3196 can use one per-file pool. Should add a targetm bit to tell the
3197 difference. */
3198
3199 struct GTY(()) rtx_constant_pool {
3200 /* Pointers to first and last constant in pool, as ordered by offset. */
3201 struct constant_descriptor_rtx *first;
3202 struct constant_descriptor_rtx *last;
3203
3204 /* Hash facility for making memory-constants from constant rtl-expressions.
3205 It is used on RISC machines where immediate integer arguments and
3206 constant addresses are restricted so that such constants must be stored
3207 in memory. */
3208 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
3209
3210 /* Current offset in constant pool (does not include any
3211 machine-specific header). */
3212 HOST_WIDE_INT offset;
3213 };
3214
3215 struct GTY((chain_next ("%h.next"))) constant_descriptor_rtx {
3216 struct constant_descriptor_rtx *next;
3217 rtx mem;
3218 rtx sym;
3219 rtx constant;
3220 HOST_WIDE_INT offset;
3221 hashval_t hash;
3222 enum machine_mode mode;
3223 unsigned int align;
3224 int labelno;
3225 int mark;
3226 };
3227
3228 /* Hash and compare functions for const_rtx_htab. */
3229
3230 static hashval_t
3231 const_desc_rtx_hash (const void *ptr)
3232 {
3233 const struct constant_descriptor_rtx *const desc
3234 = (const struct constant_descriptor_rtx *) ptr;
3235 return desc->hash;
3236 }
3237
3238 static int
3239 const_desc_rtx_eq (const void *a, const void *b)
3240 {
3241 const struct constant_descriptor_rtx *const x
3242 = (const struct constant_descriptor_rtx *) a;
3243 const struct constant_descriptor_rtx *const y
3244 = (const struct constant_descriptor_rtx *) b;
3245
3246 if (x->mode != y->mode)
3247 return 0;
3248 return rtx_equal_p (x->constant, y->constant);
3249 }
3250
3251 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
3252
3253 static int
3254 const_rtx_hash_1 (rtx *xp, void *data)
3255 {
3256 unsigned HOST_WIDE_INT hwi;
3257 enum machine_mode mode;
3258 enum rtx_code code;
3259 hashval_t h, *hp;
3260 rtx x;
3261
3262 x = *xp;
3263 code = GET_CODE (x);
3264 mode = GET_MODE (x);
3265 h = (hashval_t) code * 1048573 + mode;
3266
3267 switch (code)
3268 {
3269 case CONST_INT:
3270 hwi = INTVAL (x);
3271 fold_hwi:
3272 {
3273 int shift = sizeof (hashval_t) * CHAR_BIT;
3274 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
3275 int i;
3276
3277 h ^= (hashval_t) hwi;
3278 for (i = 1; i < n; ++i)
3279 {
3280 hwi >>= shift;
3281 h ^= (hashval_t) hwi;
3282 }
3283 }
3284 break;
3285
3286 case CONST_DOUBLE:
3287 if (mode == VOIDmode)
3288 {
3289 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
3290 goto fold_hwi;
3291 }
3292 else
3293 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
3294 break;
3295
3296 case CONST_FIXED:
3297 h ^= fixed_hash (CONST_FIXED_VALUE (x));
3298 break;
3299
3300 case CONST_VECTOR:
3301 {
3302 int i;
3303 for (i = XVECLEN (x, 0); i-- > 0; )
3304 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data);
3305 }
3306 break;
3307
3308 case SYMBOL_REF:
3309 h ^= htab_hash_string (XSTR (x, 0));
3310 break;
3311
3312 case LABEL_REF:
3313 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
3314 break;
3315
3316 case UNSPEC:
3317 case UNSPEC_VOLATILE:
3318 h = h * 251 + XINT (x, 1);
3319 break;
3320
3321 default:
3322 break;
3323 }
3324
3325 hp = (hashval_t *) data;
3326 *hp = *hp * 509 + h;
3327 return 0;
3328 }
3329
3330 /* Compute a hash value for X, which should be a constant. */
3331
3332 static hashval_t
3333 const_rtx_hash (rtx x)
3334 {
3335 hashval_t h = 0;
3336 for_each_rtx (&x, const_rtx_hash_1, &h);
3337 return h;
3338 }
3339
3340 \f
3341 /* Create and return a new rtx constant pool. */
3342
3343 static struct rtx_constant_pool *
3344 create_constant_pool (void)
3345 {
3346 struct rtx_constant_pool *pool;
3347
3348 pool = ggc_alloc_rtx_constant_pool ();
3349 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
3350 const_desc_rtx_eq, NULL);
3351 pool->first = NULL;
3352 pool->last = NULL;
3353 pool->offset = 0;
3354 return pool;
3355 }
3356
3357 /* Initialize constant pool hashing for a new function. */
3358
3359 void
3360 init_varasm_status (void)
3361 {
3362 crtl->varasm.pool = create_constant_pool ();
3363 crtl->varasm.deferred_constants = 0;
3364 }
3365 \f
3366 /* Given a MINUS expression, simplify it if both sides
3367 include the same symbol. */
3368
3369 rtx
3370 simplify_subtraction (rtx x)
3371 {
3372 rtx r = simplify_rtx (x);
3373 return r ? r : x;
3374 }
3375 \f
3376 /* Given a constant rtx X, make (or find) a memory constant for its value
3377 and return a MEM rtx to refer to it in memory. */
3378
3379 rtx
3380 force_const_mem (enum machine_mode mode, rtx x)
3381 {
3382 struct constant_descriptor_rtx *desc, tmp;
3383 struct rtx_constant_pool *pool;
3384 char label[256];
3385 rtx def, symbol;
3386 hashval_t hash;
3387 unsigned int align;
3388 void **slot;
3389
3390 /* If we're not allowed to drop X into the constant pool, don't. */
3391 if (targetm.cannot_force_const_mem (x))
3392 return NULL_RTX;
3393
3394 /* Record that this function has used a constant pool entry. */
3395 crtl->uses_const_pool = 1;
3396
3397 /* Decide which pool to use. */
3398 pool = (targetm.use_blocks_for_constant_p (mode, x)
3399 ? shared_constant_pool
3400 : crtl->varasm.pool);
3401
3402 /* Lookup the value in the hashtable. */
3403 tmp.constant = x;
3404 tmp.mode = mode;
3405 hash = const_rtx_hash (x);
3406 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
3407 desc = (struct constant_descriptor_rtx *) *slot;
3408
3409 /* If the constant was already present, return its memory. */
3410 if (desc)
3411 return copy_rtx (desc->mem);
3412
3413 /* Otherwise, create a new descriptor. */
3414 desc = ggc_alloc_constant_descriptor_rtx ();
3415 *slot = desc;
3416
3417 /* Align the location counter as required by EXP's data type. */
3418 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
3419 #ifdef CONSTANT_ALIGNMENT
3420 {
3421 tree type = lang_hooks.types.type_for_mode (mode, 0);
3422 if (type != NULL_TREE)
3423 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
3424 }
3425 #endif
3426
3427 pool->offset += (align / BITS_PER_UNIT) - 1;
3428 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
3429
3430 desc->next = NULL;
3431 desc->constant = tmp.constant;
3432 desc->offset = pool->offset;
3433 desc->hash = hash;
3434 desc->mode = mode;
3435 desc->align = align;
3436 desc->labelno = const_labelno;
3437 desc->mark = 0;
3438
3439 pool->offset += GET_MODE_SIZE (mode);
3440 if (pool->last)
3441 pool->last->next = desc;
3442 else
3443 pool->first = pool->last = desc;
3444 pool->last = desc;
3445
3446 /* Create a string containing the label name, in LABEL. */
3447 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
3448 ++const_labelno;
3449
3450 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
3451 the constants pool. */
3452 if (use_object_blocks_p () && targetm.use_blocks_for_constant_p (mode, x))
3453 {
3454 section *sect = targetm.asm_out.select_rtx_section (mode, x, align);
3455 symbol = create_block_symbol (ggc_strdup (label),
3456 get_block_for_section (sect), -1);
3457 }
3458 else
3459 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3460 desc->sym = symbol;
3461 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3462 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3463 SET_SYMBOL_REF_CONSTANT (symbol, desc);
3464
3465 /* Construct the MEM. */
3466 desc->mem = def = gen_const_mem (mode, symbol);
3467 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
3468 set_mem_align (def, align);
3469
3470 /* If we're dropping a label to the constant pool, make sure we
3471 don't delete it. */
3472 if (GET_CODE (x) == LABEL_REF)
3473 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3474
3475 return copy_rtx (def);
3476 }
3477 \f
3478 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3479
3480 rtx
3481 get_pool_constant (rtx addr)
3482 {
3483 return SYMBOL_REF_CONSTANT (addr)->constant;
3484 }
3485
3486 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3487 and whether it has been output or not. */
3488
3489 rtx
3490 get_pool_constant_mark (rtx addr, bool *pmarked)
3491 {
3492 struct constant_descriptor_rtx *desc;
3493
3494 desc = SYMBOL_REF_CONSTANT (addr);
3495 *pmarked = (desc->mark != 0);
3496 return desc->constant;
3497 }
3498
3499 /* Similar, return the mode. */
3500
3501 enum machine_mode
3502 get_pool_mode (const_rtx addr)
3503 {
3504 return SYMBOL_REF_CONSTANT (addr)->mode;
3505 }
3506
3507 /* Return the size of the constant pool. */
3508
3509 int
3510 get_pool_size (void)
3511 {
3512 return crtl->varasm.pool->offset;
3513 }
3514 \f
3515 /* Worker function for output_constant_pool_1. Emit assembly for X
3516 in MODE with known alignment ALIGN. */
3517
3518 static void
3519 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3520 {
3521 switch (GET_MODE_CLASS (mode))
3522 {
3523 case MODE_FLOAT:
3524 case MODE_DECIMAL_FLOAT:
3525 {
3526 REAL_VALUE_TYPE r;
3527
3528 gcc_assert (GET_CODE (x) == CONST_DOUBLE);
3529 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3530 assemble_real (r, mode, align);
3531 break;
3532 }
3533
3534 case MODE_INT:
3535 case MODE_PARTIAL_INT:
3536 case MODE_FRACT:
3537 case MODE_UFRACT:
3538 case MODE_ACCUM:
3539 case MODE_UACCUM:
3540 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3541 break;
3542
3543 case MODE_VECTOR_FLOAT:
3544 case MODE_VECTOR_INT:
3545 case MODE_VECTOR_FRACT:
3546 case MODE_VECTOR_UFRACT:
3547 case MODE_VECTOR_ACCUM:
3548 case MODE_VECTOR_UACCUM:
3549 {
3550 int i, units;
3551 enum machine_mode submode = GET_MODE_INNER (mode);
3552 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3553
3554 gcc_assert (GET_CODE (x) == CONST_VECTOR);
3555 units = CONST_VECTOR_NUNITS (x);
3556
3557 for (i = 0; i < units; i++)
3558 {
3559 rtx elt = CONST_VECTOR_ELT (x, i);
3560 output_constant_pool_2 (submode, elt, i ? subalign : align);
3561 }
3562 }
3563 break;
3564
3565 default:
3566 gcc_unreachable ();
3567 }
3568 }
3569
3570 /* Worker function for output_constant_pool. Emit constant DESC,
3571 giving it ALIGN bits of alignment. */
3572
3573 static void
3574 output_constant_pool_1 (struct constant_descriptor_rtx *desc,
3575 unsigned int align)
3576 {
3577 rtx x, tmp;
3578
3579 x = desc->constant;
3580
3581 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3582 whose CODE_LABEL has been deleted. This can occur if a jump table
3583 is eliminated by optimization. If so, write a constant of zero
3584 instead. Note that this can also happen by turning the
3585 CODE_LABEL into a NOTE. */
3586 /* ??? This seems completely and utterly wrong. Certainly it's
3587 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3588 functioning even with INSN_DELETED_P and friends. */
3589
3590 tmp = x;
3591 switch (GET_CODE (tmp))
3592 {
3593 case CONST:
3594 if (GET_CODE (XEXP (tmp, 0)) != PLUS
3595 || GET_CODE (XEXP (XEXP (tmp, 0), 0)) != LABEL_REF)
3596 break;
3597 tmp = XEXP (XEXP (tmp, 0), 0);
3598 /* FALLTHRU */
3599
3600 case LABEL_REF:
3601 tmp = XEXP (tmp, 0);
3602 gcc_assert (!INSN_DELETED_P (tmp));
3603 gcc_assert (!NOTE_P (tmp)
3604 || NOTE_KIND (tmp) != NOTE_INSN_DELETED);
3605 break;
3606
3607 default:
3608 break;
3609 }
3610
3611 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3612 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3613 align, desc->labelno, done);
3614 #endif
3615
3616 assemble_align (align);
3617
3618 /* Output the label. */
3619 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3620
3621 /* Output the data. */
3622 output_constant_pool_2 (desc->mode, x, align);
3623
3624 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3625 sections have proper size. */
3626 if (align > GET_MODE_BITSIZE (desc->mode)
3627 && in_section
3628 && (in_section->common.flags & SECTION_MERGE))
3629 assemble_align (align);
3630
3631 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3632 done:
3633 #endif
3634 return;
3635 }
3636
3637 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3638 to as used. Emit referenced deferred strings. This function can
3639 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3640
3641 static int
3642 mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED)
3643 {
3644 rtx x = *current_rtx;
3645
3646 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3647 return 0;
3648
3649 if (CONSTANT_POOL_ADDRESS_P (x))
3650 {
3651 struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x);
3652 if (desc->mark == 0)
3653 {
3654 desc->mark = 1;
3655 for_each_rtx (&desc->constant, mark_constant, NULL);
3656 }
3657 }
3658 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3659 {
3660 tree decl = SYMBOL_REF_DECL (x);
3661 if (!TREE_ASM_WRITTEN (DECL_INITIAL (decl)))
3662 {
3663 n_deferred_constants--;
3664 output_constant_def_contents (x);
3665 }
3666 }
3667
3668 return -1;
3669 }
3670
3671 /* Look through appropriate parts of INSN, marking all entries in the
3672 constant pool which are actually being used. Entries that are only
3673 referenced by other constants are also marked as used. Emit
3674 deferred strings that are used. */
3675
3676 static void
3677 mark_constants (rtx insn)
3678 {
3679 if (!INSN_P (insn))
3680 return;
3681
3682 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3683 insns, not any notes that may be attached. We don't want to mark
3684 a constant just because it happens to appear in a REG_EQUIV note. */
3685 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3686 {
3687 rtx seq = PATTERN (insn);
3688 int i, n = XVECLEN (seq, 0);
3689 for (i = 0; i < n; ++i)
3690 {
3691 rtx subinsn = XVECEXP (seq, 0, i);
3692 if (INSN_P (subinsn))
3693 for_each_rtx (&PATTERN (subinsn), mark_constant, NULL);
3694 }
3695 }
3696 else
3697 for_each_rtx (&PATTERN (insn), mark_constant, NULL);
3698 }
3699
3700 /* Look through the instructions for this function, and mark all the
3701 entries in POOL which are actually being used. Emit deferred constants
3702 which have indeed been used. */
3703
3704 static void
3705 mark_constant_pool (void)
3706 {
3707 rtx insn, link;
3708
3709 if (!crtl->uses_const_pool && n_deferred_constants == 0)
3710 return;
3711
3712 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3713 mark_constants (insn);
3714
3715 for (link = crtl->epilogue_delay_list;
3716 link;
3717 link = XEXP (link, 1))
3718 mark_constants (XEXP (link, 0));
3719 }
3720
3721 /* Write all the constants in POOL. */
3722
3723 static void
3724 output_constant_pool_contents (struct rtx_constant_pool *pool)
3725 {
3726 struct constant_descriptor_rtx *desc;
3727
3728 for (desc = pool->first; desc ; desc = desc->next)
3729 if (desc->mark)
3730 {
3731 /* If the constant is part of an object_block, make sure that
3732 the constant has been positioned within its block, but do not
3733 write out its definition yet. output_object_blocks will do
3734 that later. */
3735 if (SYMBOL_REF_HAS_BLOCK_INFO_P (desc->sym)
3736 && SYMBOL_REF_BLOCK (desc->sym))
3737 place_block_symbol (desc->sym);
3738 else
3739 {
3740 switch_to_section (targetm.asm_out.select_rtx_section
3741 (desc->mode, desc->constant, desc->align));
3742 output_constant_pool_1 (desc, desc->align);
3743 }
3744 }
3745 }
3746
3747 /* Mark all constants that are used in the current function, then write
3748 out the function's private constant pool. */
3749
3750 static void
3751 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3752 tree fndecl ATTRIBUTE_UNUSED)
3753 {
3754 struct rtx_constant_pool *pool = crtl->varasm.pool;
3755
3756 /* It is possible for gcc to call force_const_mem and then to later
3757 discard the instructions which refer to the constant. In such a
3758 case we do not need to output the constant. */
3759 mark_constant_pool ();
3760
3761 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3762 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3763 #endif
3764
3765 output_constant_pool_contents (pool);
3766
3767 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3768 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3769 #endif
3770 }
3771 \f
3772 /* Write the contents of the shared constant pool. */
3773
3774 void
3775 output_shared_constant_pool (void)
3776 {
3777 output_constant_pool_contents (shared_constant_pool);
3778 }
3779 \f
3780 /* Determine what kind of relocations EXP may need. */
3781
3782 int
3783 compute_reloc_for_constant (tree exp)
3784 {
3785 int reloc = 0, reloc2;
3786 tree tem;
3787
3788 switch (TREE_CODE (exp))
3789 {
3790 case ADDR_EXPR:
3791 case FDESC_EXPR:
3792 /* Go inside any operations that get_inner_reference can handle and see
3793 if what's inside is a constant: no need to do anything here for
3794 addresses of variables or functions. */
3795 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3796 tem = TREE_OPERAND (tem, 0))
3797 ;
3798
3799 if (TREE_PUBLIC (tem))
3800 reloc |= 2;
3801 else
3802 reloc |= 1;
3803 break;
3804
3805 case PLUS_EXPR:
3806 case POINTER_PLUS_EXPR:
3807 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3808 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3809 break;
3810
3811 case MINUS_EXPR:
3812 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3813 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3814 /* The difference of two local labels is computable at link time. */
3815 if (reloc == 1 && reloc2 == 1)
3816 reloc = 0;
3817 else
3818 reloc |= reloc2;
3819 break;
3820
3821 CASE_CONVERT:
3822 case VIEW_CONVERT_EXPR:
3823 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3824 break;
3825
3826 case CONSTRUCTOR:
3827 {
3828 unsigned HOST_WIDE_INT idx;
3829 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
3830 if (tem != 0)
3831 reloc |= compute_reloc_for_constant (tem);
3832 }
3833 break;
3834
3835 default:
3836 break;
3837 }
3838 return reloc;
3839 }
3840
3841 /* Find all the constants whose addresses are referenced inside of EXP,
3842 and make sure assembler code with a label has been output for each one.
3843 Indicate whether an ADDR_EXPR has been encountered. */
3844
3845 static void
3846 output_addressed_constants (tree exp)
3847 {
3848 tree tem;
3849
3850 switch (TREE_CODE (exp))
3851 {
3852 case ADDR_EXPR:
3853 case FDESC_EXPR:
3854 /* Go inside any operations that get_inner_reference can handle and see
3855 if what's inside is a constant: no need to do anything here for
3856 addresses of variables or functions. */
3857 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3858 tem = TREE_OPERAND (tem, 0))
3859 ;
3860
3861 /* If we have an initialized CONST_DECL, retrieve the initializer. */
3862 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem))
3863 tem = DECL_INITIAL (tem);
3864
3865 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR)
3866 output_constant_def (tem, 0);
3867 break;
3868
3869 case PLUS_EXPR:
3870 case POINTER_PLUS_EXPR:
3871 case MINUS_EXPR:
3872 output_addressed_constants (TREE_OPERAND (exp, 1));
3873 /* Fall through. */
3874
3875 CASE_CONVERT:
3876 case VIEW_CONVERT_EXPR:
3877 output_addressed_constants (TREE_OPERAND (exp, 0));
3878 break;
3879
3880 case CONSTRUCTOR:
3881 {
3882 unsigned HOST_WIDE_INT idx;
3883 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
3884 if (tem != 0)
3885 output_addressed_constants (tem);
3886 }
3887 break;
3888
3889 default:
3890 break;
3891 }
3892 }
3893 \f
3894 /* Whether a constructor CTOR is a valid static constant initializer if all
3895 its elements are. This used to be internal to initializer_constant_valid_p
3896 and has been exposed to let other functions like categorize_ctor_elements
3897 evaluate the property while walking a constructor for other purposes. */
3898
3899 bool
3900 constructor_static_from_elts_p (const_tree ctor)
3901 {
3902 return (TREE_CONSTANT (ctor)
3903 && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE
3904 || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE
3905 || TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE));
3906 }
3907
3908 static tree initializer_constant_valid_p_1 (tree value, tree endtype,
3909 tree *cache);
3910
3911 /* A subroutine of initializer_constant_valid_p. VALUE is a MINUS_EXPR,
3912 PLUS_EXPR or POINTER_PLUS_EXPR. This looks for cases of VALUE
3913 which are valid when ENDTYPE is an integer of any size; in
3914 particular, this does not accept a pointer minus a constant. This
3915 returns null_pointer_node if the VALUE is an absolute constant
3916 which can be used to initialize a static variable. Otherwise it
3917 returns NULL. */
3918
3919 static tree
3920 narrowing_initializer_constant_valid_p (tree value, tree endtype, tree *cache)
3921 {
3922 tree op0, op1;
3923
3924 if (!INTEGRAL_TYPE_P (endtype))
3925 return NULL_TREE;
3926
3927 op0 = TREE_OPERAND (value, 0);
3928 op1 = TREE_OPERAND (value, 1);
3929
3930 /* Like STRIP_NOPS except allow the operand mode to widen. This
3931 works around a feature of fold that simplifies (int)(p1 - p2) to
3932 ((int)p1 - (int)p2) under the theory that the narrower operation
3933 is cheaper. */
3934
3935 while (CONVERT_EXPR_P (op0)
3936 || TREE_CODE (op0) == NON_LVALUE_EXPR)
3937 {
3938 tree inner = TREE_OPERAND (op0, 0);
3939 if (inner == error_mark_node
3940 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3941 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
3942 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3943 break;
3944 op0 = inner;
3945 }
3946
3947 while (CONVERT_EXPR_P (op1)
3948 || TREE_CODE (op1) == NON_LVALUE_EXPR)
3949 {
3950 tree inner = TREE_OPERAND (op1, 0);
3951 if (inner == error_mark_node
3952 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3953 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
3954 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3955 break;
3956 op1 = inner;
3957 }
3958
3959 op0 = initializer_constant_valid_p_1 (op0, endtype, cache);
3960 if (!op0)
3961 return NULL_TREE;
3962
3963 op1 = initializer_constant_valid_p_1 (op1, endtype,
3964 cache ? cache + 2 : NULL);
3965 /* Both initializers must be known. */
3966 if (op1)
3967 {
3968 if (op0 == op1
3969 && (op0 == null_pointer_node
3970 || TREE_CODE (value) == MINUS_EXPR))
3971 return null_pointer_node;
3972
3973 /* Support differences between labels. */
3974 if (TREE_CODE (op0) == LABEL_DECL
3975 && TREE_CODE (op1) == LABEL_DECL)
3976 return null_pointer_node;
3977
3978 if (TREE_CODE (op0) == STRING_CST
3979 && TREE_CODE (op1) == STRING_CST
3980 && operand_equal_p (op0, op1, 1))
3981 return null_pointer_node;
3982 }
3983
3984 return NULL_TREE;
3985 }
3986
3987 /* Helper function of initializer_constant_valid_p.
3988 Return nonzero if VALUE is a valid constant-valued expression
3989 for use in initializing a static variable; one that can be an
3990 element of a "constant" initializer.
3991
3992 Return null_pointer_node if the value is absolute;
3993 if it is relocatable, return the variable that determines the relocation.
3994 We assume that VALUE has been folded as much as possible;
3995 therefore, we do not need to check for such things as
3996 arithmetic-combinations of integers.
3997
3998 Use CACHE (pointer to 2 tree values) for caching if non-NULL. */
3999
4000 static tree
4001 initializer_constant_valid_p_1 (tree value, tree endtype, tree *cache)
4002 {
4003 tree ret;
4004
4005 switch (TREE_CODE (value))
4006 {
4007 case CONSTRUCTOR:
4008 if (constructor_static_from_elts_p (value))
4009 {
4010 unsigned HOST_WIDE_INT idx;
4011 tree elt;
4012 bool absolute = true;
4013
4014 if (cache && cache[0] == value)
4015 return cache[1];
4016 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4017 {
4018 tree reloc;
4019 reloc = initializer_constant_valid_p_1 (elt, TREE_TYPE (elt),
4020 NULL);
4021 if (!reloc)
4022 {
4023 if (cache)
4024 {
4025 cache[0] = value;
4026 cache[1] = NULL_TREE;
4027 }
4028 return NULL_TREE;
4029 }
4030 if (reloc != null_pointer_node)
4031 absolute = false;
4032 }
4033 /* For a non-absolute relocation, there is no single
4034 variable that can be "the variable that determines the
4035 relocation." */
4036 if (cache)
4037 {
4038 cache[0] = value;
4039 cache[1] = absolute ? null_pointer_node : error_mark_node;
4040 }
4041 return absolute ? null_pointer_node : error_mark_node;
4042 }
4043
4044 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
4045
4046 case INTEGER_CST:
4047 case VECTOR_CST:
4048 case REAL_CST:
4049 case FIXED_CST:
4050 case STRING_CST:
4051 case COMPLEX_CST:
4052 return null_pointer_node;
4053
4054 case ADDR_EXPR:
4055 case FDESC_EXPR:
4056 {
4057 tree op0 = staticp (TREE_OPERAND (value, 0));
4058 if (op0)
4059 {
4060 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out
4061 to be a constant, this is old-skool offsetof-like nonsense. */
4062 if (TREE_CODE (op0) == INDIRECT_REF
4063 && TREE_CONSTANT (TREE_OPERAND (op0, 0)))
4064 return null_pointer_node;
4065 /* Taking the address of a nested function involves a trampoline,
4066 unless we don't need or want one. */
4067 if (TREE_CODE (op0) == FUNCTION_DECL
4068 && DECL_STATIC_CHAIN (op0)
4069 && !TREE_NO_TRAMPOLINE (value))
4070 return NULL_TREE;
4071 /* "&{...}" requires a temporary to hold the constructed
4072 object. */
4073 if (TREE_CODE (op0) == CONSTRUCTOR)
4074 return NULL_TREE;
4075 }
4076 return op0;
4077 }
4078
4079 case NON_LVALUE_EXPR:
4080 return initializer_constant_valid_p_1 (TREE_OPERAND (value, 0),
4081 endtype, cache);
4082
4083 case VIEW_CONVERT_EXPR:
4084 {
4085 tree src = TREE_OPERAND (value, 0);
4086 tree src_type = TREE_TYPE (src);
4087 tree dest_type = TREE_TYPE (value);
4088
4089 /* Allow view-conversions from aggregate to non-aggregate type only
4090 if the bit pattern is fully preserved afterwards; otherwise, the
4091 RTL expander won't be able to apply a subsequent transformation
4092 to the underlying constructor. */
4093 if (AGGREGATE_TYPE_P (src_type) && !AGGREGATE_TYPE_P (dest_type))
4094 {
4095 if (TYPE_MODE (endtype) == TYPE_MODE (dest_type))
4096 return initializer_constant_valid_p_1 (src, endtype, cache);
4097 else
4098 return NULL_TREE;
4099 }
4100
4101 /* Allow all other kinds of view-conversion. */
4102 return initializer_constant_valid_p_1 (src, endtype, cache);
4103 }
4104
4105 CASE_CONVERT:
4106 {
4107 tree src = TREE_OPERAND (value, 0);
4108 tree src_type = TREE_TYPE (src);
4109 tree dest_type = TREE_TYPE (value);
4110
4111 /* Allow conversions between pointer types, floating-point
4112 types, and offset types. */
4113 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
4114 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
4115 || (TREE_CODE (dest_type) == OFFSET_TYPE
4116 && TREE_CODE (src_type) == OFFSET_TYPE))
4117 return initializer_constant_valid_p_1 (src, endtype, cache);
4118
4119 /* Allow length-preserving conversions between integer types. */
4120 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
4121 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
4122 return initializer_constant_valid_p_1 (src, endtype, cache);
4123
4124 /* Allow conversions between other integer types only if
4125 explicit value. */
4126 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
4127 {
4128 tree inner = initializer_constant_valid_p_1 (src, endtype, cache);
4129 if (inner == null_pointer_node)
4130 return null_pointer_node;
4131 break;
4132 }
4133
4134 /* Allow (int) &foo provided int is as wide as a pointer. */
4135 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
4136 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
4137 return initializer_constant_valid_p_1 (src, endtype, cache);
4138
4139 /* Likewise conversions from int to pointers, but also allow
4140 conversions from 0. */
4141 if ((POINTER_TYPE_P (dest_type)
4142 || TREE_CODE (dest_type) == OFFSET_TYPE)
4143 && INTEGRAL_TYPE_P (src_type))
4144 {
4145 if (TREE_CODE (src) == INTEGER_CST
4146 && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))
4147 return null_pointer_node;
4148 if (integer_zerop (src))
4149 return null_pointer_node;
4150 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
4151 return initializer_constant_valid_p_1 (src, endtype, cache);
4152 }
4153
4154 /* Allow conversions to struct or union types if the value
4155 inside is okay. */
4156 if (TREE_CODE (dest_type) == RECORD_TYPE
4157 || TREE_CODE (dest_type) == UNION_TYPE)
4158 return initializer_constant_valid_p_1 (src, endtype, cache);
4159 }
4160 break;
4161
4162 case POINTER_PLUS_EXPR:
4163 case PLUS_EXPR:
4164 /* Any valid floating-point constants will have been folded by now;
4165 with -frounding-math we hit this with addition of two constants. */
4166 if (TREE_CODE (endtype) == REAL_TYPE)
4167 return NULL_TREE;
4168 if (cache && cache[0] == value)
4169 return cache[1];
4170 if (! INTEGRAL_TYPE_P (endtype)
4171 || TYPE_PRECISION (endtype) >= TYPE_PRECISION (TREE_TYPE (value)))
4172 {
4173 tree ncache[4] = { NULL_TREE, NULL_TREE, NULL_TREE, NULL_TREE };
4174 tree valid0
4175 = initializer_constant_valid_p_1 (TREE_OPERAND (value, 0),
4176 endtype, ncache);
4177 tree valid1
4178 = initializer_constant_valid_p_1 (TREE_OPERAND (value, 1),
4179 endtype, ncache + 2);
4180 /* If either term is absolute, use the other term's relocation. */
4181 if (valid0 == null_pointer_node)
4182 ret = valid1;
4183 else if (valid1 == null_pointer_node)
4184 ret = valid0;
4185 /* Support narrowing pointer differences. */
4186 else
4187 ret = narrowing_initializer_constant_valid_p (value, endtype,
4188 ncache);
4189 }
4190 else
4191 /* Support narrowing pointer differences. */
4192 ret = narrowing_initializer_constant_valid_p (value, endtype, NULL);
4193 if (cache)
4194 {
4195 cache[0] = value;
4196 cache[1] = ret;
4197 }
4198 return ret;
4199
4200 case MINUS_EXPR:
4201 if (TREE_CODE (endtype) == REAL_TYPE)
4202 return NULL_TREE;
4203 if (cache && cache[0] == value)
4204 return cache[1];
4205 if (! INTEGRAL_TYPE_P (endtype)
4206 || TYPE_PRECISION (endtype) >= TYPE_PRECISION (TREE_TYPE (value)))
4207 {
4208 tree ncache[4] = { NULL_TREE, NULL_TREE, NULL_TREE, NULL_TREE };
4209 tree valid0
4210 = initializer_constant_valid_p_1 (TREE_OPERAND (value, 0),
4211 endtype, ncache);
4212 tree valid1
4213 = initializer_constant_valid_p_1 (TREE_OPERAND (value, 1),
4214 endtype, ncache + 2);
4215 /* Win if second argument is absolute. */
4216 if (valid1 == null_pointer_node)
4217 ret = valid0;
4218 /* Win if both arguments have the same relocation.
4219 Then the value is absolute. */
4220 else if (valid0 == valid1 && valid0 != 0)
4221 ret = null_pointer_node;
4222 /* Since GCC guarantees that string constants are unique in the
4223 generated code, a subtraction between two copies of the same
4224 constant string is absolute. */
4225 else if (valid0 && TREE_CODE (valid0) == STRING_CST
4226 && valid1 && TREE_CODE (valid1) == STRING_CST
4227 && operand_equal_p (valid0, valid1, 1))
4228 ret = null_pointer_node;
4229 /* Support narrowing differences. */
4230 else
4231 ret = narrowing_initializer_constant_valid_p (value, endtype,
4232 ncache);
4233 }
4234 else
4235 /* Support narrowing differences. */
4236 ret = narrowing_initializer_constant_valid_p (value, endtype, NULL);
4237 if (cache)
4238 {
4239 cache[0] = value;
4240 cache[1] = ret;
4241 }
4242 return ret;
4243
4244 default:
4245 break;
4246 }
4247
4248 return NULL_TREE;
4249 }
4250
4251 /* Return nonzero if VALUE is a valid constant-valued expression
4252 for use in initializing a static variable; one that can be an
4253 element of a "constant" initializer.
4254
4255 Return null_pointer_node if the value is absolute;
4256 if it is relocatable, return the variable that determines the relocation.
4257 We assume that VALUE has been folded as much as possible;
4258 therefore, we do not need to check for such things as
4259 arithmetic-combinations of integers. */
4260 tree
4261 initializer_constant_valid_p (tree value, tree endtype)
4262 {
4263 return initializer_constant_valid_p_1 (value, endtype, NULL);
4264 }
4265 \f
4266 /* Return true if VALUE is a valid constant-valued expression
4267 for use in initializing a static bit-field; one that can be
4268 an element of a "constant" initializer. */
4269
4270 bool
4271 initializer_constant_valid_for_bitfield_p (tree value)
4272 {
4273 /* For bitfields we support integer constants or possibly nested aggregates
4274 of such. */
4275 switch (TREE_CODE (value))
4276 {
4277 case CONSTRUCTOR:
4278 {
4279 unsigned HOST_WIDE_INT idx;
4280 tree elt;
4281
4282 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4283 if (!initializer_constant_valid_for_bitfield_p (elt))
4284 return false;
4285 return true;
4286 }
4287
4288 case INTEGER_CST:
4289 return true;
4290
4291 case VIEW_CONVERT_EXPR:
4292 case NON_LVALUE_EXPR:
4293 return
4294 initializer_constant_valid_for_bitfield_p (TREE_OPERAND (value, 0));
4295
4296 default:
4297 break;
4298 }
4299
4300 return false;
4301 }
4302
4303 /* output_constructor outer state of relevance in recursive calls, typically
4304 for nested aggregate bitfields. */
4305
4306 typedef struct {
4307 unsigned int bit_offset; /* current position in ... */
4308 int byte; /* ... the outer byte buffer. */
4309 } oc_outer_state;
4310
4311 static unsigned HOST_WIDE_INT
4312 output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int,
4313 oc_outer_state *);
4314
4315 /* Output assembler code for constant EXP to FILE, with no label.
4316 This includes the pseudo-op such as ".int" or ".byte", and a newline.
4317 Assumes output_addressed_constants has been done on EXP already.
4318
4319 Generate exactly SIZE bytes of assembler data, padding at the end
4320 with zeros if necessary. SIZE must always be specified.
4321
4322 SIZE is important for structure constructors,
4323 since trailing members may have been omitted from the constructor.
4324 It is also important for initialization of arrays from string constants
4325 since the full length of the string constant might not be wanted.
4326 It is also needed for initialization of unions, where the initializer's
4327 type is just one member, and that may not be as long as the union.
4328
4329 There a case in which we would fail to output exactly SIZE bytes:
4330 for a structure constructor that wants to produce more than SIZE bytes.
4331 But such constructors will never be generated for any possible input.
4332
4333 ALIGN is the alignment of the data in bits. */
4334
4335 void
4336 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
4337 {
4338 enum tree_code code;
4339 unsigned HOST_WIDE_INT thissize;
4340
4341 if (size == 0 || flag_syntax_only)
4342 return;
4343
4344 /* See if we're trying to initialize a pointer in a non-default mode
4345 to the address of some declaration somewhere. If the target says
4346 the mode is valid for pointers, assume the target has a way of
4347 resolving it. */
4348 if (TREE_CODE (exp) == NOP_EXPR
4349 && POINTER_TYPE_P (TREE_TYPE (exp))
4350 && targetm.addr_space.valid_pointer_mode
4351 (TYPE_MODE (TREE_TYPE (exp)),
4352 TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (exp)))))
4353 {
4354 tree saved_type = TREE_TYPE (exp);
4355
4356 /* Peel off any intermediate conversions-to-pointer for valid
4357 pointer modes. */
4358 while (TREE_CODE (exp) == NOP_EXPR
4359 && POINTER_TYPE_P (TREE_TYPE (exp))
4360 && targetm.addr_space.valid_pointer_mode
4361 (TYPE_MODE (TREE_TYPE (exp)),
4362 TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (exp)))))
4363 exp = TREE_OPERAND (exp, 0);
4364
4365 /* If what we're left with is the address of something, we can
4366 convert the address to the final type and output it that
4367 way. */
4368 if (TREE_CODE (exp) == ADDR_EXPR)
4369 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0));
4370 /* Likewise for constant ints. */
4371 else if (TREE_CODE (exp) == INTEGER_CST)
4372 exp = build_int_cst_wide (saved_type, TREE_INT_CST_LOW (exp),
4373 TREE_INT_CST_HIGH (exp));
4374
4375 }
4376
4377 /* Eliminate any conversions since we'll be outputting the underlying
4378 constant. */
4379 while (CONVERT_EXPR_P (exp)
4380 || TREE_CODE (exp) == NON_LVALUE_EXPR
4381 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
4382 {
4383 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp));
4384 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0)));
4385
4386 /* Make sure eliminating the conversion is really a no-op, except with
4387 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and
4388 union types to allow for Ada unchecked unions. */
4389 if (type_size > op_size
4390 && TREE_CODE (exp) != VIEW_CONVERT_EXPR
4391 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE)
4392 /* Keep the conversion. */
4393 break;
4394 else
4395 exp = TREE_OPERAND (exp, 0);
4396 }
4397
4398 code = TREE_CODE (TREE_TYPE (exp));
4399 thissize = int_size_in_bytes (TREE_TYPE (exp));
4400
4401 /* Allow a constructor with no elements for any data type.
4402 This means to fill the space with zeros. */
4403 if (TREE_CODE (exp) == CONSTRUCTOR
4404 && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp)))
4405 {
4406 assemble_zeros (size);
4407 return;
4408 }
4409
4410 if (TREE_CODE (exp) == FDESC_EXPR)
4411 {
4412 #ifdef ASM_OUTPUT_FDESC
4413 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
4414 tree decl = TREE_OPERAND (exp, 0);
4415 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
4416 #else
4417 gcc_unreachable ();
4418 #endif
4419 return;
4420 }
4421
4422 /* Now output the underlying data. If we've handling the padding, return.
4423 Otherwise, break and ensure SIZE is the size written. */
4424 switch (code)
4425 {
4426 case BOOLEAN_TYPE:
4427 case INTEGER_TYPE:
4428 case ENUMERAL_TYPE:
4429 case POINTER_TYPE:
4430 case REFERENCE_TYPE:
4431 case OFFSET_TYPE:
4432 case FIXED_POINT_TYPE:
4433 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
4434 EXPAND_INITIALIZER),
4435 MIN (size, thissize), align, 0))
4436 error ("initializer for integer/fixed-point value is too complicated");
4437 break;
4438
4439 case REAL_TYPE:
4440 if (TREE_CODE (exp) != REAL_CST)
4441 error ("initializer for floating value is not a floating constant");
4442 else
4443 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
4444 break;
4445
4446 case COMPLEX_TYPE:
4447 output_constant (TREE_REALPART (exp), thissize / 2, align);
4448 output_constant (TREE_IMAGPART (exp), thissize / 2,
4449 min_align (align, BITS_PER_UNIT * (thissize / 2)));
4450 break;
4451
4452 case ARRAY_TYPE:
4453 case VECTOR_TYPE:
4454 switch (TREE_CODE (exp))
4455 {
4456 case CONSTRUCTOR:
4457 output_constructor (exp, size, align, NULL);
4458 return;
4459 case STRING_CST:
4460 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
4461 size);
4462 assemble_string (TREE_STRING_POINTER (exp), thissize);
4463 break;
4464
4465 case VECTOR_CST:
4466 {
4467 int elt_size;
4468 tree link;
4469 unsigned int nalign;
4470 enum machine_mode inner;
4471
4472 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
4473 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
4474
4475 elt_size = GET_MODE_SIZE (inner);
4476
4477 link = TREE_VECTOR_CST_ELTS (exp);
4478 output_constant (TREE_VALUE (link), elt_size, align);
4479 thissize = elt_size;
4480 while ((link = TREE_CHAIN (link)) != NULL)
4481 {
4482 output_constant (TREE_VALUE (link), elt_size, nalign);
4483 thissize += elt_size;
4484 }
4485 break;
4486 }
4487 default:
4488 gcc_unreachable ();
4489 }
4490 break;
4491
4492 case RECORD_TYPE:
4493 case UNION_TYPE:
4494 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);
4495 output_constructor (exp, size, align, NULL);
4496 return;
4497
4498 case ERROR_MARK:
4499 return;
4500
4501 default:
4502 gcc_unreachable ();
4503 }
4504
4505 if (size > thissize)
4506 assemble_zeros (size - thissize);
4507 }
4508
4509 \f
4510 /* Subroutine of output_constructor, used for computing the size of
4511 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
4512 type with an unspecified upper bound. */
4513
4514 static unsigned HOST_WIDE_INT
4515 array_size_for_constructor (tree val)
4516 {
4517 tree max_index, i;
4518 unsigned HOST_WIDE_INT cnt;
4519 tree index, value, tmp;
4520
4521 /* This code used to attempt to handle string constants that are not
4522 arrays of single-bytes, but nothing else does, so there's no point in
4523 doing it here. */
4524 if (TREE_CODE (val) == STRING_CST)
4525 return TREE_STRING_LENGTH (val);
4526
4527 max_index = NULL_TREE;
4528 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value)
4529 {
4530 if (TREE_CODE (index) == RANGE_EXPR)
4531 index = TREE_OPERAND (index, 1);
4532 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
4533 max_index = index;
4534 }
4535
4536 if (max_index == NULL_TREE)
4537 return 0;
4538
4539 /* Compute the total number of array elements. */
4540 tmp = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)));
4541 i = size_binop (MINUS_EXPR, fold_convert (sizetype, max_index),
4542 fold_convert (sizetype, tmp));
4543 i = size_binop (PLUS_EXPR, i, size_one_node);
4544
4545 /* Multiply by the array element unit size to find number of bytes. */
4546 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
4547
4548 return tree_low_cst (i, 1);
4549 }
4550
4551 /* Other datastructures + helpers for output_constructor. */
4552
4553 /* output_constructor local state to support interaction with helpers. */
4554
4555 typedef struct {
4556
4557 /* Received arguments. */
4558 tree exp; /* Constructor expression. */
4559 unsigned HOST_WIDE_INT size; /* # bytes to output - pad if necessary. */
4560 unsigned int align; /* Known initial alignment. */
4561
4562 /* Constructor expression data. */
4563 tree type; /* Expression type. */
4564 tree field; /* Current field decl in a record. */
4565 tree min_index; /* Lower bound if specified for an array. */
4566
4567 /* Output processing state. */
4568 HOST_WIDE_INT total_bytes; /* # bytes output so far / current position. */
4569 bool byte_buffer_in_use; /* Whether byte ... */
4570 int byte; /* ... contains part of a bitfield byte yet to
4571 be output. */
4572
4573 int last_relative_index; /* Implicit or explicit index of the last
4574 array element output within a bitfield. */
4575 /* Current element. */
4576 tree val; /* Current element value. */
4577 tree index; /* Current element index. */
4578
4579 } oc_local_state;
4580
4581 /* Helper for output_constructor. From the current LOCAL state, output a
4582 RANGE_EXPR element. */
4583
4584 static void
4585 output_constructor_array_range (oc_local_state *local)
4586 {
4587 unsigned HOST_WIDE_INT fieldsize
4588 = int_size_in_bytes (TREE_TYPE (local->type));
4589
4590 HOST_WIDE_INT lo_index
4591 = tree_low_cst (TREE_OPERAND (local->index, 0), 0);
4592 HOST_WIDE_INT hi_index
4593 = tree_low_cst (TREE_OPERAND (local->index, 1), 0);
4594 HOST_WIDE_INT index;
4595
4596 unsigned int align2
4597 = min_align (local->align, fieldsize * BITS_PER_UNIT);
4598
4599 for (index = lo_index; index <= hi_index; index++)
4600 {
4601 /* Output the element's initial value. */
4602 if (local->val == NULL_TREE)
4603 assemble_zeros (fieldsize);
4604 else
4605 output_constant (local->val, fieldsize, align2);
4606
4607 /* Count its size. */
4608 local->total_bytes += fieldsize;
4609 }
4610 }
4611
4612 /* Helper for output_constructor. From the current LOCAL state, output a
4613 field element that is not true bitfield or part of an outer one. */
4614
4615 static void
4616 output_constructor_regular_field (oc_local_state *local)
4617 {
4618 /* Field size and position. Since this structure is static, we know the
4619 positions are constant. */
4620 unsigned HOST_WIDE_INT fieldsize;
4621 HOST_WIDE_INT fieldpos;
4622
4623 unsigned int align2;
4624
4625 if (local->index != NULL_TREE)
4626 fieldpos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (local->val)), 1)
4627 * ((tree_low_cst (local->index, 0)
4628 - tree_low_cst (local->min_index, 0))));
4629 else if (local->field != NULL_TREE)
4630 fieldpos = int_byte_position (local->field);
4631 else
4632 fieldpos = 0;
4633
4634 /* Output any buffered-up bit-fields preceding this element. */
4635 if (local->byte_buffer_in_use)
4636 {
4637 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4638 local->total_bytes++;
4639 local->byte_buffer_in_use = false;
4640 }
4641
4642 /* Advance to offset of this element.
4643 Note no alignment needed in an array, since that is guaranteed
4644 if each element has the proper size. */
4645 if ((local->field != NULL_TREE || local->index != NULL_TREE)
4646 && fieldpos != local->total_bytes)
4647 {
4648 gcc_assert (fieldpos >= local->total_bytes);
4649 assemble_zeros (fieldpos - local->total_bytes);
4650 local->total_bytes = fieldpos;
4651 }
4652
4653 /* Find the alignment of this element. */
4654 align2 = min_align (local->align, BITS_PER_UNIT * fieldpos);
4655
4656 /* Determine size this element should occupy. */
4657 if (local->field)
4658 {
4659 fieldsize = 0;
4660
4661 /* If this is an array with an unspecified upper bound,
4662 the initializer determines the size. */
4663 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4664 but we cannot do this until the deprecated support for
4665 initializing zero-length array members is removed. */
4666 if (TREE_CODE (TREE_TYPE (local->field)) == ARRAY_TYPE
4667 && TYPE_DOMAIN (TREE_TYPE (local->field))
4668 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (local->field))))
4669 {
4670 fieldsize = array_size_for_constructor (local->val);
4671 /* Given a non-empty initialization, this field had
4672 better be last. */
4673 gcc_assert (!fieldsize || !DECL_CHAIN (local->field));
4674 }
4675 else if (DECL_SIZE_UNIT (local->field))
4676 {
4677 /* ??? This can't be right. If the decl size overflows
4678 a host integer we will silently emit no data. */
4679 if (host_integerp (DECL_SIZE_UNIT (local->field), 1))
4680 fieldsize = tree_low_cst (DECL_SIZE_UNIT (local->field), 1);
4681 }
4682 }
4683 else
4684 fieldsize = int_size_in_bytes (TREE_TYPE (local->type));
4685
4686 /* Output the element's initial value. */
4687 if (local->val == NULL_TREE)
4688 assemble_zeros (fieldsize);
4689 else
4690 output_constant (local->val, fieldsize, align2);
4691
4692 /* Count its size. */
4693 local->total_bytes += fieldsize;
4694 }
4695
4696 /* Helper for output_constructor. From the current LOCAL and OUTER states,
4697 output an element that is a true bitfield or part of an outer one. */
4698
4699 static void
4700 output_constructor_bitfield (oc_local_state *local, oc_outer_state *outer)
4701 {
4702 /* Bit size of this element. */
4703 HOST_WIDE_INT ebitsize
4704 = (local->field
4705 ? tree_low_cst (DECL_SIZE (local->field), 1)
4706 : tree_low_cst (TYPE_SIZE (TREE_TYPE (local->type)), 1));
4707
4708 /* Relative index of this element if this is an array component. */
4709 HOST_WIDE_INT relative_index
4710 = (!local->field
4711 ? (local->index
4712 ? (tree_low_cst (local->index, 0)
4713 - tree_low_cst (local->min_index, 0))
4714 : local->last_relative_index + 1)
4715 : 0);
4716
4717 /* Bit position of this element from the start of the containing
4718 constructor. */
4719 HOST_WIDE_INT constructor_relative_ebitpos
4720 = (local->field
4721 ? int_bit_position (local->field)
4722 : ebitsize * relative_index);
4723
4724 /* Bit position of this element from the start of a possibly ongoing
4725 outer byte buffer. */
4726 HOST_WIDE_INT byte_relative_ebitpos
4727 = ((outer ? outer->bit_offset : 0) + constructor_relative_ebitpos);
4728
4729 /* From the start of a possibly ongoing outer byte buffer, offsets to
4730 the first bit of this element and to the first bit past the end of
4731 this element. */
4732 HOST_WIDE_INT next_offset = byte_relative_ebitpos;
4733 HOST_WIDE_INT end_offset = byte_relative_ebitpos + ebitsize;
4734
4735 local->last_relative_index = relative_index;
4736
4737 if (local->val == NULL_TREE)
4738 local->val = integer_zero_node;
4739
4740 while (TREE_CODE (local->val) == VIEW_CONVERT_EXPR
4741 || TREE_CODE (local->val) == NON_LVALUE_EXPR)
4742 local->val = TREE_OPERAND (local->val, 0);
4743
4744 if (TREE_CODE (local->val) != INTEGER_CST
4745 && TREE_CODE (local->val) != CONSTRUCTOR)
4746 {
4747 error ("invalid initial value for member %qE", DECL_NAME (local->field));
4748 return;
4749 }
4750
4751 /* If this field does not start in this (or, next) byte,
4752 skip some bytes. */
4753 if (next_offset / BITS_PER_UNIT != local->total_bytes)
4754 {
4755 /* Output remnant of any bit field in previous bytes. */
4756 if (local->byte_buffer_in_use)
4757 {
4758 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4759 local->total_bytes++;
4760 local->byte_buffer_in_use = false;
4761 }
4762
4763 /* If still not at proper byte, advance to there. */
4764 if (next_offset / BITS_PER_UNIT != local->total_bytes)
4765 {
4766 gcc_assert (next_offset / BITS_PER_UNIT >= local->total_bytes);
4767 assemble_zeros (next_offset / BITS_PER_UNIT - local->total_bytes);
4768 local->total_bytes = next_offset / BITS_PER_UNIT;
4769 }
4770 }
4771
4772 /* Set up the buffer if necessary. */
4773 if (!local->byte_buffer_in_use)
4774 {
4775 local->byte = 0;
4776 if (ebitsize > 0)
4777 local->byte_buffer_in_use = true;
4778 }
4779
4780 /* If this is nested constructor, recurse passing the bit offset and the
4781 pending data, then retrieve the new pending data afterwards. */
4782 if (TREE_CODE (local->val) == CONSTRUCTOR)
4783 {
4784 oc_outer_state output_state;
4785
4786 output_state.bit_offset = next_offset % BITS_PER_UNIT;
4787 output_state.byte = local->byte;
4788 local->total_bytes
4789 += output_constructor (local->val, 0, 0, &output_state);
4790 local->byte = output_state.byte;
4791 return;
4792 }
4793
4794 /* Otherwise, we must split the element into pieces that fall within
4795 separate bytes, and combine each byte with previous or following
4796 bit-fields. */
4797 while (next_offset < end_offset)
4798 {
4799 int this_time;
4800 int shift;
4801 HOST_WIDE_INT value;
4802 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4803 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4804
4805 /* Advance from byte to byte
4806 within this element when necessary. */
4807 while (next_byte != local->total_bytes)
4808 {
4809 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4810 local->total_bytes++;
4811 local->byte = 0;
4812 }
4813
4814 /* Number of bits we can process at once
4815 (all part of the same byte). */
4816 this_time = MIN (end_offset - next_offset,
4817 BITS_PER_UNIT - next_bit);
4818 if (BYTES_BIG_ENDIAN)
4819 {
4820 /* On big-endian machine, take the most significant bits
4821 first (of the bits that are significant)
4822 and put them into bytes from the most significant end. */
4823 shift = end_offset - next_offset - this_time;
4824
4825 /* Don't try to take a bunch of bits that cross
4826 the word boundary in the INTEGER_CST. We can
4827 only select bits from the LOW or HIGH part
4828 not from both. */
4829 if (shift < HOST_BITS_PER_WIDE_INT
4830 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4831 {
4832 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4833 shift = HOST_BITS_PER_WIDE_INT;
4834 }
4835
4836 /* Now get the bits from the appropriate constant word. */
4837 if (shift < HOST_BITS_PER_WIDE_INT)
4838 value = TREE_INT_CST_LOW (local->val);
4839 else
4840 {
4841 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4842 value = TREE_INT_CST_HIGH (local->val);
4843 shift -= HOST_BITS_PER_WIDE_INT;
4844 }
4845
4846 /* Get the result. This works only when:
4847 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4848 local->byte |= (((value >> shift)
4849 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4850 << (BITS_PER_UNIT - this_time - next_bit));
4851 }
4852 else
4853 {
4854 /* On little-endian machines,
4855 take first the least significant bits of the value
4856 and pack them starting at the least significant
4857 bits of the bytes. */
4858 shift = next_offset - byte_relative_ebitpos;
4859
4860 /* Don't try to take a bunch of bits that cross
4861 the word boundary in the INTEGER_CST. We can
4862 only select bits from the LOW or HIGH part
4863 not from both. */
4864 if (shift < HOST_BITS_PER_WIDE_INT
4865 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4866 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4867
4868 /* Now get the bits from the appropriate constant word. */
4869 if (shift < HOST_BITS_PER_WIDE_INT)
4870 value = TREE_INT_CST_LOW (local->val);
4871 else
4872 {
4873 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4874 value = TREE_INT_CST_HIGH (local->val);
4875 shift -= HOST_BITS_PER_WIDE_INT;
4876 }
4877
4878 /* Get the result. This works only when:
4879 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4880 local->byte |= (((value >> shift)
4881 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4882 << next_bit);
4883 }
4884
4885 next_offset += this_time;
4886 local->byte_buffer_in_use = true;
4887 }
4888 }
4889
4890 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
4891 Generate at least SIZE bytes, padding if necessary. OUTER designates the
4892 caller output state of relevance in recursive invocations. */
4893
4894 static unsigned HOST_WIDE_INT
4895 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
4896 unsigned int align, oc_outer_state * outer)
4897 {
4898 unsigned HOST_WIDE_INT cnt;
4899 constructor_elt *ce;
4900
4901 oc_local_state local;
4902
4903 /* Setup our local state to communicate with helpers. */
4904 local.exp = exp;
4905 local.size = size;
4906 local.align = align;
4907
4908 local.total_bytes = 0;
4909 local.byte_buffer_in_use = outer != NULL;
4910 local.byte = outer ? outer->byte : 0;
4911
4912 local.type = TREE_TYPE (exp);
4913
4914 local.last_relative_index = -1;
4915
4916 local.min_index = NULL_TREE;
4917 if (TREE_CODE (local.type) == ARRAY_TYPE
4918 && TYPE_DOMAIN (local.type) != NULL_TREE)
4919 local.min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (local.type));
4920
4921 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT);
4922
4923 /* As CE goes through the elements of the constant, FIELD goes through the
4924 structure fields if the constant is a structure. If the constant is a
4925 union, we override this by getting the field from the TREE_LIST element.
4926 But the constant could also be an array. Then FIELD is zero.
4927
4928 There is always a maximum of one element in the chain LINK for unions
4929 (even if the initializer in a source program incorrectly contains
4930 more one). */
4931
4932 local.field = NULL_TREE;
4933 if (TREE_CODE (local.type) == RECORD_TYPE)
4934 local.field = TYPE_FIELDS (local.type);
4935
4936 for (cnt = 0;
4937 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce);
4938 cnt++, local.field = local.field ? DECL_CHAIN (local.field) : 0)
4939 {
4940 local.val = ce->value;
4941 local.index = NULL_TREE;
4942
4943 /* The element in a union constructor specifies the proper field
4944 or index. */
4945 if ((TREE_CODE (local.type) == RECORD_TYPE
4946 || TREE_CODE (local.type) == UNION_TYPE
4947 || TREE_CODE (local.type) == QUAL_UNION_TYPE)
4948 && ce->index != NULL_TREE)
4949 local.field = ce->index;
4950
4951 else if (TREE_CODE (local.type) == ARRAY_TYPE)
4952 local.index = ce->index;
4953
4954 #ifdef ASM_COMMENT_START
4955 if (local.field && flag_verbose_asm)
4956 fprintf (asm_out_file, "%s %s:\n",
4957 ASM_COMMENT_START,
4958 DECL_NAME (local.field)
4959 ? IDENTIFIER_POINTER (DECL_NAME (local.field))
4960 : "<anonymous>");
4961 #endif
4962
4963 /* Eliminate the marker that makes a cast not be an lvalue. */
4964 if (local.val != NULL_TREE)
4965 STRIP_NOPS (local.val);
4966
4967 /* Output the current element, using the appropriate helper ... */
4968
4969 /* For an array slice not part of an outer bitfield. */
4970 if (!outer
4971 && local.index != NULL_TREE
4972 && TREE_CODE (local.index) == RANGE_EXPR)
4973 output_constructor_array_range (&local);
4974
4975 /* For a field that is neither a true bitfield nor part of an outer one,
4976 known to be at least byte aligned and multiple-of-bytes long. */
4977 else if (!outer
4978 && (local.field == NULL_TREE
4979 || !CONSTRUCTOR_BITFIELD_P (local.field)))
4980 output_constructor_regular_field (&local);
4981
4982 /* For a true bitfield or part of an outer one. */
4983 else
4984 output_constructor_bitfield (&local, outer);
4985 }
4986
4987 /* If we are not at toplevel, save the pending data for our caller.
4988 Otherwise output the pending data and padding zeros as needed. */
4989 if (outer)
4990 outer->byte = local.byte;
4991 else
4992 {
4993 if (local.byte_buffer_in_use)
4994 {
4995 assemble_integer (GEN_INT (local.byte), 1, BITS_PER_UNIT, 1);
4996 local.total_bytes++;
4997 }
4998
4999 if ((unsigned HOST_WIDE_INT)local.total_bytes < local.size)
5000 {
5001 assemble_zeros (local.size - local.total_bytes);
5002 local.total_bytes = local.size;
5003 }
5004 }
5005
5006 return local.total_bytes;
5007 }
5008
5009 /* Mark DECL as weak. */
5010
5011 static void
5012 mark_weak (tree decl)
5013 {
5014 DECL_WEAK (decl) = 1;
5015
5016 if (DECL_RTL_SET_P (decl)
5017 && MEM_P (DECL_RTL (decl))
5018 && XEXP (DECL_RTL (decl), 0)
5019 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
5020 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
5021 }
5022
5023 /* Merge weak status between NEWDECL and OLDDECL. */
5024
5025 void
5026 merge_weak (tree newdecl, tree olddecl)
5027 {
5028 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
5029 {
5030 if (DECL_WEAK (newdecl) && TARGET_SUPPORTS_WEAK)
5031 {
5032 tree *pwd;
5033 /* We put the NEWDECL on the weak_decls list at some point
5034 and OLDDECL as well. Keep just OLDDECL on the list. */
5035 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd))
5036 if (TREE_VALUE (*pwd) == newdecl)
5037 {
5038 *pwd = TREE_CHAIN (*pwd);
5039 break;
5040 }
5041 }
5042 return;
5043 }
5044
5045 if (DECL_WEAK (newdecl))
5046 {
5047 tree wd;
5048
5049 /* NEWDECL is weak, but OLDDECL is not. */
5050
5051 /* If we already output the OLDDECL, we're in trouble; we can't
5052 go back and make it weak. This error cannot be caught in
5053 declare_weak because the NEWDECL and OLDDECL was not yet
5054 been merged; therefore, TREE_ASM_WRITTEN was not set. */
5055 if (TREE_ASM_WRITTEN (olddecl))
5056 error ("weak declaration of %q+D must precede definition",
5057 newdecl);
5058
5059 /* If we've already generated rtl referencing OLDDECL, we may
5060 have done so in a way that will not function properly with
5061 a weak symbol. */
5062 else if (TREE_USED (olddecl)
5063 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
5064 warning (0, "weak declaration of %q+D after first use results "
5065 "in unspecified behavior", newdecl);
5066
5067 if (TARGET_SUPPORTS_WEAK)
5068 {
5069 /* We put the NEWDECL on the weak_decls list at some point.
5070 Replace it with the OLDDECL. */
5071 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
5072 if (TREE_VALUE (wd) == newdecl)
5073 {
5074 TREE_VALUE (wd) = olddecl;
5075 break;
5076 }
5077 /* We may not find the entry on the list. If NEWDECL is a
5078 weak alias, then we will have already called
5079 globalize_decl to remove the entry; in that case, we do
5080 not need to do anything. */
5081 }
5082
5083 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
5084 mark_weak (olddecl);
5085 }
5086 else
5087 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
5088 weak. Just update NEWDECL to indicate that it's weak too. */
5089 mark_weak (newdecl);
5090 }
5091
5092 /* Declare DECL to be a weak symbol. */
5093
5094 void
5095 declare_weak (tree decl)
5096 {
5097 if (! TREE_PUBLIC (decl))
5098 error ("weak declaration of %q+D must be public", decl);
5099 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
5100 error ("weak declaration of %q+D must precede definition", decl);
5101 else if (!TARGET_SUPPORTS_WEAK)
5102 warning (0, "weak declaration of %q+D not supported", decl);
5103
5104 mark_weak (decl);
5105 if (!lookup_attribute ("weak", DECL_ATTRIBUTES (decl)))
5106 DECL_ATTRIBUTES (decl)
5107 = tree_cons (get_identifier ("weak"), NULL, DECL_ATTRIBUTES (decl));
5108 }
5109
5110 static void
5111 weak_finish_1 (tree decl)
5112 {
5113 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
5114 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5115 #endif
5116
5117 if (! TREE_USED (decl))
5118 return;
5119
5120 #ifdef ASM_WEAKEN_DECL
5121 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
5122 #else
5123 #ifdef ASM_WEAKEN_LABEL
5124 ASM_WEAKEN_LABEL (asm_out_file, name);
5125 #else
5126 #ifdef ASM_OUTPUT_WEAK_ALIAS
5127 {
5128 static bool warn_once = 0;
5129 if (! warn_once)
5130 {
5131 warning (0, "only weak aliases are supported in this configuration");
5132 warn_once = 1;
5133 }
5134 return;
5135 }
5136 #endif
5137 #endif
5138 #endif
5139 }
5140
5141 /* This TREE_LIST contains weakref targets. */
5142
5143 static GTY(()) tree weakref_targets;
5144
5145 /* Forward declaration. */
5146 static tree find_decl_and_mark_needed (tree decl, tree target);
5147
5148 /* Emit any pending weak declarations. */
5149
5150 void
5151 weak_finish (void)
5152 {
5153 tree t;
5154
5155 for (t = weakref_targets; t; t = TREE_CHAIN (t))
5156 {
5157 tree alias_decl = TREE_PURPOSE (t);
5158 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t));
5159
5160 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl)))
5161 /* Remove alias_decl from the weak list, but leave entries for
5162 the target alone. */
5163 target = NULL_TREE;
5164 #ifndef ASM_OUTPUT_WEAKREF
5165 else if (! TREE_SYMBOL_REFERENCED (target))
5166 {
5167 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not
5168 defined, otherwise we and weak_finish_1 would use
5169 different macros. */
5170 # if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL
5171 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target));
5172 # else
5173 tree decl = find_decl_and_mark_needed (alias_decl, target);
5174
5175 if (! decl)
5176 {
5177 decl = build_decl (DECL_SOURCE_LOCATION (alias_decl),
5178 TREE_CODE (alias_decl), target,
5179 TREE_TYPE (alias_decl));
5180
5181 DECL_EXTERNAL (decl) = 1;
5182 TREE_PUBLIC (decl) = 1;
5183 DECL_ARTIFICIAL (decl) = 1;
5184 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl);
5185 TREE_USED (decl) = 1;
5186 }
5187
5188 weak_finish_1 (decl);
5189 # endif
5190 }
5191 #endif
5192
5193 {
5194 tree *p;
5195 tree t2;
5196
5197 /* Remove the alias and the target from the pending weak list
5198 so that we do not emit any .weak directives for the former,
5199 nor multiple .weak directives for the latter. */
5200 for (p = &weak_decls; (t2 = *p) ; )
5201 {
5202 if (TREE_VALUE (t2) == alias_decl
5203 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2)))
5204 *p = TREE_CHAIN (t2);
5205 else
5206 p = &TREE_CHAIN (t2);
5207 }
5208
5209 /* Remove other weakrefs to the same target, to speed things up. */
5210 for (p = &TREE_CHAIN (t); (t2 = *p) ; )
5211 {
5212 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2)))
5213 *p = TREE_CHAIN (t2);
5214 else
5215 p = &TREE_CHAIN (t2);
5216 }
5217 }
5218 }
5219
5220 for (t = weak_decls; t; t = TREE_CHAIN (t))
5221 {
5222 tree decl = TREE_VALUE (t);
5223
5224 weak_finish_1 (decl);
5225 }
5226 }
5227
5228 /* Emit the assembly bits to indicate that DECL is globally visible. */
5229
5230 static void
5231 globalize_decl (tree decl)
5232 {
5233
5234 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
5235 if (DECL_WEAK (decl))
5236 {
5237 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
5238 tree *p, t;
5239
5240 #ifdef ASM_WEAKEN_DECL
5241 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
5242 #else
5243 ASM_WEAKEN_LABEL (asm_out_file, name);
5244 #endif
5245
5246 /* Remove this function from the pending weak list so that
5247 we do not emit multiple .weak directives for it. */
5248 for (p = &weak_decls; (t = *p) ; )
5249 {
5250 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5251 *p = TREE_CHAIN (t);
5252 else
5253 p = &TREE_CHAIN (t);
5254 }
5255
5256 /* Remove weakrefs to the same target from the pending weakref
5257 list, for the same reason. */
5258 for (p = &weakref_targets; (t = *p) ; )
5259 {
5260 if (DECL_ASSEMBLER_NAME (decl)
5261 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5262 *p = TREE_CHAIN (t);
5263 else
5264 p = &TREE_CHAIN (t);
5265 }
5266
5267 return;
5268 }
5269 #endif
5270
5271 targetm.asm_out.globalize_decl_name (asm_out_file, decl);
5272 }
5273
5274 VEC(alias_pair,gc) *alias_pairs;
5275
5276 /* Given an assembly name, find the decl it is associated with. At the
5277 same time, mark it needed for cgraph. */
5278
5279 static tree
5280 find_decl_and_mark_needed (tree decl, tree target)
5281 {
5282 struct cgraph_node *fnode = NULL;
5283 struct varpool_node *vnode = NULL;
5284
5285 if (TREE_CODE (decl) == FUNCTION_DECL)
5286 {
5287 fnode = cgraph_node_for_asm (target);
5288 if (fnode == NULL)
5289 vnode = varpool_node_for_asm (target);
5290 }
5291 else
5292 {
5293 vnode = varpool_node_for_asm (target);
5294 if (vnode == NULL)
5295 fnode = cgraph_node_for_asm (target);
5296 }
5297
5298 if (fnode)
5299 {
5300 cgraph_mark_needed_node (fnode);
5301 return fnode->decl;
5302 }
5303 else if (vnode)
5304 {
5305 varpool_mark_needed_node (vnode);
5306 vnode->force_output = 1;
5307 return vnode->decl;
5308 }
5309 else
5310 return NULL_TREE;
5311 }
5312
5313 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
5314 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
5315 tree node is DECL to have the value of the tree node TARGET. */
5316
5317 static void
5318 do_assemble_alias (tree decl, tree target)
5319 {
5320 /* Emulated TLS had better not get this var. */
5321 gcc_assert(!(!targetm.have_tls
5322 && TREE_CODE (decl) == VAR_DECL
5323 && DECL_THREAD_LOCAL_P (decl)));
5324
5325 if (TREE_ASM_WRITTEN (decl))
5326 return;
5327
5328 /* We must force creation of DECL_RTL for debug info generation, even though
5329 we don't use it here. */
5330 make_decl_rtl (decl);
5331
5332 TREE_ASM_WRITTEN (decl) = 1;
5333 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
5334
5335 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5336 {
5337 ultimate_transparent_alias_target (&target);
5338
5339 if (!TREE_SYMBOL_REFERENCED (target))
5340 weakref_targets = tree_cons (decl, target, weakref_targets);
5341
5342 #ifdef ASM_OUTPUT_WEAKREF
5343 ASM_OUTPUT_WEAKREF (asm_out_file, decl,
5344 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5345 IDENTIFIER_POINTER (target));
5346 #else
5347 if (!TARGET_SUPPORTS_WEAK)
5348 {
5349 error_at (DECL_SOURCE_LOCATION (decl),
5350 "weakref is not supported in this configuration");
5351 return;
5352 }
5353 #endif
5354 return;
5355 }
5356
5357 #ifdef ASM_OUTPUT_DEF
5358 /* Make name accessible from other files, if appropriate. */
5359
5360 if (TREE_PUBLIC (decl))
5361 {
5362 globalize_decl (decl);
5363 maybe_assemble_visibility (decl);
5364 }
5365 if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl)))
5366 {
5367 #if defined (ASM_OUTPUT_TYPE_DIRECTIVE) && HAVE_GNU_INDIRECT_FUNCTION
5368 ASM_OUTPUT_TYPE_DIRECTIVE
5369 (asm_out_file, IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5370 IFUNC_ASM_TYPE);
5371 #else
5372 error_at (DECL_SOURCE_LOCATION (decl),
5373 "ifunc is not supported in this configuration");
5374 #endif
5375 }
5376
5377 # ifdef ASM_OUTPUT_DEF_FROM_DECLS
5378 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
5379 # else
5380 ASM_OUTPUT_DEF (asm_out_file,
5381 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5382 IDENTIFIER_POINTER (target));
5383 # endif
5384 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
5385 {
5386 const char *name;
5387 tree *p, t;
5388
5389 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5390 # ifdef ASM_WEAKEN_DECL
5391 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
5392 # else
5393 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
5394 # endif
5395 /* Remove this function from the pending weak list so that
5396 we do not emit multiple .weak directives for it. */
5397 for (p = &weak_decls; (t = *p) ; )
5398 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5399 *p = TREE_CHAIN (t);
5400 else
5401 p = &TREE_CHAIN (t);
5402
5403 /* Remove weakrefs to the same target from the pending weakref
5404 list, for the same reason. */
5405 for (p = &weakref_targets; (t = *p) ; )
5406 {
5407 if (DECL_ASSEMBLER_NAME (decl)
5408 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5409 *p = TREE_CHAIN (t);
5410 else
5411 p = &TREE_CHAIN (t);
5412 }
5413 }
5414 #endif
5415 }
5416
5417
5418 /* Remove the alias pairing for functions that are no longer in the call
5419 graph. */
5420
5421 void
5422 remove_unreachable_alias_pairs (void)
5423 {
5424 unsigned i;
5425 alias_pair *p;
5426
5427 if (alias_pairs == NULL)
5428 return;
5429
5430 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); )
5431 {
5432 if (!DECL_EXTERNAL (p->decl))
5433 {
5434 struct cgraph_node *fnode = NULL;
5435 struct varpool_node *vnode = NULL;
5436 fnode = cgraph_node_for_asm (p->target);
5437 vnode = (fnode == NULL) ? varpool_node_for_asm (p->target) : NULL;
5438 if (fnode == NULL && vnode == NULL)
5439 {
5440 VEC_unordered_remove (alias_pair, alias_pairs, i);
5441 continue;
5442 }
5443 }
5444
5445 i++;
5446 }
5447 }
5448
5449
5450 /* First pass of completing pending aliases. Make sure that cgraph knows
5451 which symbols will be required. */
5452
5453 void
5454 finish_aliases_1 (void)
5455 {
5456 unsigned i;
5457 alias_pair *p;
5458
5459 FOR_EACH_VEC_ELT (alias_pair, alias_pairs, i, p)
5460 {
5461 tree target_decl;
5462
5463 target_decl = find_decl_and_mark_needed (p->decl, p->target);
5464 if (target_decl == NULL)
5465 {
5466 if (! (p->emitted_diags & ALIAS_DIAG_TO_UNDEF)
5467 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5468 {
5469 error ("%q+D aliased to undefined symbol %qE",
5470 p->decl, p->target);
5471 p->emitted_diags |= ALIAS_DIAG_TO_UNDEF;
5472 }
5473 }
5474 else if (! (p->emitted_diags & ALIAS_DIAG_TO_EXTERN)
5475 && DECL_EXTERNAL (target_decl)
5476 /* We use local aliases for C++ thunks to force the tailcall
5477 to bind locally. This is a hack - to keep it working do
5478 the following (which is not strictly correct). */
5479 && (! TREE_CODE (target_decl) == FUNCTION_DECL
5480 || ! DECL_VIRTUAL_P (target_decl))
5481 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5482 {
5483 error ("%q+D aliased to external symbol %qE",
5484 p->decl, p->target);
5485 p->emitted_diags |= ALIAS_DIAG_TO_EXTERN;
5486 }
5487 }
5488 }
5489
5490 /* Second pass of completing pending aliases. Emit the actual assembly.
5491 This happens at the end of compilation and thus it is assured that the
5492 target symbol has been emitted. */
5493
5494 void
5495 finish_aliases_2 (void)
5496 {
5497 unsigned i;
5498 alias_pair *p;
5499
5500 FOR_EACH_VEC_ELT (alias_pair, alias_pairs, i, p)
5501 do_assemble_alias (p->decl, p->target);
5502
5503 VEC_truncate (alias_pair, alias_pairs, 0);
5504 }
5505
5506 /* Emit an assembler directive to make the symbol for DECL an alias to
5507 the symbol for TARGET. */
5508
5509 void
5510 assemble_alias (tree decl, tree target)
5511 {
5512 tree target_decl;
5513 bool is_weakref = false;
5514
5515 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5516 {
5517 tree alias = DECL_ASSEMBLER_NAME (decl);
5518
5519 is_weakref = true;
5520
5521 ultimate_transparent_alias_target (&target);
5522
5523 if (alias == target)
5524 error ("weakref %q+D ultimately targets itself", decl);
5525 else
5526 {
5527 #ifndef ASM_OUTPUT_WEAKREF
5528 IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1;
5529 TREE_CHAIN (alias) = target;
5530 #endif
5531 }
5532 if (TREE_PUBLIC (decl))
5533 error ("weakref %q+D must have static linkage", decl);
5534 }
5535 else
5536 {
5537 #if !defined (ASM_OUTPUT_DEF)
5538 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
5539 error_at (DECL_SOURCE_LOCATION (decl),
5540 "alias definitions not supported in this configuration");
5541 return;
5542 # else
5543 if (!DECL_WEAK (decl))
5544 {
5545 if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl)))
5546 error_at (DECL_SOURCE_LOCATION (decl),
5547 "ifunc is not supported in this configuration");
5548 else
5549 error_at (DECL_SOURCE_LOCATION (decl),
5550 "only weak aliases are supported in this configuration");
5551 return;
5552 }
5553 # endif
5554 #endif
5555 }
5556 TREE_USED (decl) = 1;
5557
5558 /* A quirk of the initial implementation of aliases required that the user
5559 add "extern" to all of them. Which is silly, but now historical. Do
5560 note that the symbol is in fact locally defined. */
5561 if (! is_weakref)
5562 DECL_EXTERNAL (decl) = 0;
5563
5564 /* Allow aliases to aliases. */
5565 if (TREE_CODE (decl) == FUNCTION_DECL)
5566 cgraph_node (decl)->alias = true;
5567 else
5568 varpool_node (decl)->alias = true;
5569
5570 /* If the target has already been emitted, we don't have to queue the
5571 alias. This saves a tad of memory. */
5572 if (cgraph_global_info_ready)
5573 target_decl = find_decl_and_mark_needed (decl, target);
5574 else
5575 target_decl= NULL;
5576 if (target_decl && TREE_ASM_WRITTEN (target_decl))
5577 do_assemble_alias (decl, target);
5578 else
5579 {
5580 alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL);
5581 p->decl = decl;
5582 p->target = target;
5583 p->emitted_diags = ALIAS_DIAG_NONE;
5584 }
5585 }
5586
5587 /* Emit an assembler directive to set symbol for DECL visibility to
5588 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
5589
5590 void
5591 default_assemble_visibility (tree decl ATTRIBUTE_UNUSED,
5592 int vis ATTRIBUTE_UNUSED)
5593 {
5594 #ifdef HAVE_GAS_HIDDEN
5595 static const char * const visibility_types[] = {
5596 NULL, "protected", "hidden", "internal"
5597 };
5598
5599 const char *name, *type;
5600
5601 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5602 type = visibility_types[vis];
5603
5604 fprintf (asm_out_file, "\t.%s\t", type);
5605 assemble_name (asm_out_file, name);
5606 fprintf (asm_out_file, "\n");
5607 #else
5608 warning (OPT_Wattributes, "visibility attribute not supported "
5609 "in this configuration; ignored");
5610 #endif
5611 }
5612
5613 /* A helper function to call assemble_visibility when needed for a decl. */
5614
5615 int
5616 maybe_assemble_visibility (tree decl)
5617 {
5618 enum symbol_visibility vis = DECL_VISIBILITY (decl);
5619
5620 if (vis != VISIBILITY_DEFAULT)
5621 {
5622 targetm.asm_out.assemble_visibility (decl, vis);
5623 return 1;
5624 }
5625 else
5626 return 0;
5627 }
5628
5629 /* Returns 1 if the target configuration supports defining public symbols
5630 so that one of them will be chosen at link time instead of generating a
5631 multiply-defined symbol error, whether through the use of weak symbols or
5632 a target-specific mechanism for having duplicates discarded. */
5633
5634 int
5635 supports_one_only (void)
5636 {
5637 if (SUPPORTS_ONE_ONLY)
5638 return 1;
5639 return TARGET_SUPPORTS_WEAK;
5640 }
5641
5642 /* Set up DECL as a public symbol that can be defined in multiple
5643 translation units without generating a linker error. */
5644
5645 void
5646 make_decl_one_only (tree decl, tree comdat_group)
5647 {
5648 gcc_assert (TREE_CODE (decl) == VAR_DECL
5649 || TREE_CODE (decl) == FUNCTION_DECL);
5650
5651 TREE_PUBLIC (decl) = 1;
5652
5653 if (SUPPORTS_ONE_ONLY)
5654 {
5655 #ifdef MAKE_DECL_ONE_ONLY
5656 MAKE_DECL_ONE_ONLY (decl);
5657 #endif
5658 DECL_COMDAT_GROUP (decl) = comdat_group;
5659 }
5660 else if (TREE_CODE (decl) == VAR_DECL
5661 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
5662 DECL_COMMON (decl) = 1;
5663 else
5664 {
5665 gcc_assert (TARGET_SUPPORTS_WEAK);
5666 DECL_WEAK (decl) = 1;
5667 }
5668 }
5669
5670 void
5671 init_varasm_once (void)
5672 {
5673 section_htab = htab_create_ggc (31, section_entry_hash,
5674 section_entry_eq, NULL);
5675 object_block_htab = htab_create_ggc (31, object_block_entry_hash,
5676 object_block_entry_eq, NULL);
5677 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
5678 const_desc_eq, NULL);
5679
5680 const_alias_set = new_alias_set ();
5681 shared_constant_pool = create_constant_pool ();
5682
5683 #ifdef TEXT_SECTION_ASM_OP
5684 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op,
5685 TEXT_SECTION_ASM_OP);
5686 #endif
5687
5688 #ifdef DATA_SECTION_ASM_OP
5689 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5690 DATA_SECTION_ASM_OP);
5691 #endif
5692
5693 #ifdef SDATA_SECTION_ASM_OP
5694 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5695 SDATA_SECTION_ASM_OP);
5696 #endif
5697
5698 #ifdef READONLY_DATA_SECTION_ASM_OP
5699 readonly_data_section = get_unnamed_section (0, output_section_asm_op,
5700 READONLY_DATA_SECTION_ASM_OP);
5701 #endif
5702
5703 #ifdef CTORS_SECTION_ASM_OP
5704 ctors_section = get_unnamed_section (0, output_section_asm_op,
5705 CTORS_SECTION_ASM_OP);
5706 #endif
5707
5708 #ifdef DTORS_SECTION_ASM_OP
5709 dtors_section = get_unnamed_section (0, output_section_asm_op,
5710 DTORS_SECTION_ASM_OP);
5711 #endif
5712
5713 #ifdef BSS_SECTION_ASM_OP
5714 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5715 output_section_asm_op,
5716 BSS_SECTION_ASM_OP);
5717 #endif
5718
5719 #ifdef SBSS_SECTION_ASM_OP
5720 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5721 output_section_asm_op,
5722 SBSS_SECTION_ASM_OP);
5723 #endif
5724
5725 tls_comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5726 | SECTION_COMMON, emit_tls_common);
5727 lcomm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5728 | SECTION_COMMON, emit_local);
5729 comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5730 | SECTION_COMMON, emit_common);
5731
5732 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
5733 bss_noswitch_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS,
5734 emit_bss);
5735 #endif
5736
5737 targetm.asm_out.init_sections ();
5738
5739 if (readonly_data_section == NULL)
5740 readonly_data_section = text_section;
5741 }
5742
5743 enum tls_model
5744 decl_default_tls_model (const_tree decl)
5745 {
5746 enum tls_model kind;
5747 bool is_local;
5748
5749 is_local = targetm.binds_local_p (decl);
5750 if (!flag_shlib)
5751 {
5752 if (is_local)
5753 kind = TLS_MODEL_LOCAL_EXEC;
5754 else
5755 kind = TLS_MODEL_INITIAL_EXEC;
5756 }
5757
5758 /* Local dynamic is inefficient when we're not combining the
5759 parts of the address. */
5760 else if (optimize && is_local)
5761 kind = TLS_MODEL_LOCAL_DYNAMIC;
5762 else
5763 kind = TLS_MODEL_GLOBAL_DYNAMIC;
5764 if (kind < flag_tls_default)
5765 kind = flag_tls_default;
5766
5767 return kind;
5768 }
5769
5770 /* Select a set of attributes for section NAME based on the properties
5771 of DECL and whether or not RELOC indicates that DECL's initializer
5772 might contain runtime relocations.
5773
5774 We make the section read-only and executable for a function decl,
5775 read-only for a const data decl, and writable for a non-const data decl. */
5776
5777 unsigned int
5778 default_section_type_flags (tree decl, const char *name, int reloc)
5779 {
5780 unsigned int flags;
5781
5782 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
5783 flags = SECTION_CODE;
5784 else if (decl && decl_readonly_section (decl, reloc))
5785 flags = 0;
5786 else if (current_function_decl
5787 && cfun
5788 && crtl->subsections.unlikely_text_section_name
5789 && strcmp (name, crtl->subsections.unlikely_text_section_name) == 0)
5790 flags = SECTION_CODE;
5791 else if (!decl
5792 && (!current_function_decl || !cfun)
5793 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
5794 flags = SECTION_CODE;
5795 else
5796 flags = SECTION_WRITE;
5797
5798 if (decl && DECL_ONE_ONLY (decl))
5799 flags |= SECTION_LINKONCE;
5800
5801 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5802 flags |= SECTION_TLS | SECTION_WRITE;
5803
5804 if (strcmp (name, ".bss") == 0
5805 || strncmp (name, ".bss.", 5) == 0
5806 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
5807 || strcmp (name, ".sbss") == 0
5808 || strncmp (name, ".sbss.", 6) == 0
5809 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
5810 flags |= SECTION_BSS;
5811
5812 if (strcmp (name, ".tdata") == 0
5813 || strncmp (name, ".tdata.", 7) == 0
5814 || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
5815 flags |= SECTION_TLS;
5816
5817 if (strcmp (name, ".tbss") == 0
5818 || strncmp (name, ".tbss.", 6) == 0
5819 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
5820 flags |= SECTION_TLS | SECTION_BSS;
5821
5822 /* These three sections have special ELF types. They are neither
5823 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
5824 want to print a section type (@progbits or @nobits). If someone
5825 is silly enough to emit code or TLS variables to one of these
5826 sections, then don't handle them specially. */
5827 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
5828 && (strcmp (name, ".init_array") == 0
5829 || strcmp (name, ".fini_array") == 0
5830 || strcmp (name, ".preinit_array") == 0))
5831 flags |= SECTION_NOTYPE;
5832
5833 return flags;
5834 }
5835
5836 /* Return true if the target supports some form of global BSS,
5837 either through bss_noswitch_section, or by selecting a BSS
5838 section in TARGET_ASM_SELECT_SECTION. */
5839
5840 bool
5841 have_global_bss_p (void)
5842 {
5843 return bss_noswitch_section || targetm.have_switchable_bss_sections;
5844 }
5845
5846 /* Output assembly to switch to section NAME with attribute FLAGS.
5847 Four variants for common object file formats. */
5848
5849 void
5850 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
5851 unsigned int flags ATTRIBUTE_UNUSED,
5852 tree decl ATTRIBUTE_UNUSED)
5853 {
5854 /* Some object formats don't support named sections at all. The
5855 front-end should already have flagged this as an error. */
5856 gcc_unreachable ();
5857 }
5858
5859 #ifndef TLS_SECTION_ASM_FLAG
5860 #define TLS_SECTION_ASM_FLAG 'T'
5861 #endif
5862
5863 void
5864 default_elf_asm_named_section (const char *name, unsigned int flags,
5865 tree decl ATTRIBUTE_UNUSED)
5866 {
5867 char flagchars[10], *f = flagchars;
5868
5869 /* If we have already declared this section, we can use an
5870 abbreviated form to switch back to it -- unless this section is
5871 part of a COMDAT groups, in which case GAS requires the full
5872 declaration every time. */
5873 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5874 && (flags & SECTION_DECLARED))
5875 {
5876 fprintf (asm_out_file, "\t.section\t%s\n", name);
5877 return;
5878 }
5879
5880 if (!(flags & SECTION_DEBUG))
5881 *f++ = 'a';
5882 if (flags & SECTION_WRITE)
5883 *f++ = 'w';
5884 if (flags & SECTION_CODE)
5885 *f++ = 'x';
5886 if (flags & SECTION_SMALL)
5887 *f++ = 's';
5888 if (flags & SECTION_MERGE)
5889 *f++ = 'M';
5890 if (flags & SECTION_STRINGS)
5891 *f++ = 'S';
5892 if (flags & SECTION_TLS)
5893 *f++ = TLS_SECTION_ASM_FLAG;
5894 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5895 *f++ = 'G';
5896 *f = '\0';
5897
5898 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
5899
5900 if (!(flags & SECTION_NOTYPE))
5901 {
5902 const char *type;
5903 const char *format;
5904
5905 if (flags & SECTION_BSS)
5906 type = "nobits";
5907 else
5908 type = "progbits";
5909
5910 format = ",@%s";
5911 #ifdef ASM_COMMENT_START
5912 /* On platforms that use "@" as the assembly comment character,
5913 use "%" instead. */
5914 if (strcmp (ASM_COMMENT_START, "@") == 0)
5915 format = ",%%%s";
5916 #endif
5917 fprintf (asm_out_file, format, type);
5918
5919 if (flags & SECTION_ENTSIZE)
5920 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
5921 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5922 {
5923 if (TREE_CODE (decl) == IDENTIFIER_NODE)
5924 fprintf (asm_out_file, ",%s,comdat", IDENTIFIER_POINTER (decl));
5925 else
5926 fprintf (asm_out_file, ",%s,comdat",
5927 IDENTIFIER_POINTER (DECL_COMDAT_GROUP (decl)));
5928 }
5929 }
5930
5931 putc ('\n', asm_out_file);
5932 }
5933
5934 void
5935 default_coff_asm_named_section (const char *name, unsigned int flags,
5936 tree decl ATTRIBUTE_UNUSED)
5937 {
5938 char flagchars[8], *f = flagchars;
5939
5940 if (flags & SECTION_WRITE)
5941 *f++ = 'w';
5942 if (flags & SECTION_CODE)
5943 *f++ = 'x';
5944 *f = '\0';
5945
5946 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
5947 }
5948
5949 void
5950 default_pe_asm_named_section (const char *name, unsigned int flags,
5951 tree decl)
5952 {
5953 default_coff_asm_named_section (name, flags, decl);
5954
5955 if (flags & SECTION_LINKONCE)
5956 {
5957 /* Functions may have been compiled at various levels of
5958 optimization so we can't use `same_size' here.
5959 Instead, have the linker pick one. */
5960 fprintf (asm_out_file, "\t.linkonce %s\n",
5961 (flags & SECTION_CODE ? "discard" : "same_size"));
5962 }
5963 }
5964 \f
5965 /* The lame default section selector. */
5966
5967 section *
5968 default_select_section (tree decl, int reloc,
5969 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
5970 {
5971 if (DECL_P (decl))
5972 {
5973 if (decl_readonly_section (decl, reloc))
5974 return readonly_data_section;
5975 }
5976 else if (TREE_CODE (decl) == CONSTRUCTOR)
5977 {
5978 if (! ((flag_pic && reloc)
5979 || !TREE_READONLY (decl)
5980 || TREE_SIDE_EFFECTS (decl)
5981 || !TREE_CONSTANT (decl)))
5982 return readonly_data_section;
5983 }
5984 else if (TREE_CODE (decl) == STRING_CST)
5985 return readonly_data_section;
5986 else if (! (flag_pic && reloc))
5987 return readonly_data_section;
5988
5989 return data_section;
5990 }
5991
5992 enum section_category
5993 categorize_decl_for_section (const_tree decl, int reloc)
5994 {
5995 enum section_category ret;
5996
5997 if (TREE_CODE (decl) == FUNCTION_DECL)
5998 return SECCAT_TEXT;
5999 else if (TREE_CODE (decl) == STRING_CST)
6000 {
6001 if (flag_mudflap) /* or !flag_merge_constants */
6002 return SECCAT_RODATA;
6003 else
6004 return SECCAT_RODATA_MERGE_STR;
6005 }
6006 else if (TREE_CODE (decl) == VAR_DECL)
6007 {
6008 if (bss_initializer_p (decl))
6009 ret = SECCAT_BSS;
6010 else if (! TREE_READONLY (decl)
6011 || TREE_SIDE_EFFECTS (decl)
6012 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
6013 {
6014 /* Here the reloc_rw_mask is not testing whether the section should
6015 be read-only or not, but whether the dynamic link will have to
6016 do something. If so, we wish to segregate the data in order to
6017 minimize cache misses inside the dynamic linker. */
6018 if (reloc & targetm.asm_out.reloc_rw_mask ())
6019 ret = reloc == 1 ? SECCAT_DATA_REL_LOCAL : SECCAT_DATA_REL;
6020 else
6021 ret = SECCAT_DATA;
6022 }
6023 else if (reloc & targetm.asm_out.reloc_rw_mask ())
6024 ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO;
6025 else if (reloc || flag_merge_constants < 2)
6026 /* C and C++ don't allow different variables to share the same
6027 location. -fmerge-all-constants allows even that (at the
6028 expense of not conforming). */
6029 ret = SECCAT_RODATA;
6030 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
6031 ret = SECCAT_RODATA_MERGE_STR_INIT;
6032 else
6033 ret = SECCAT_RODATA_MERGE_CONST;
6034 }
6035 else if (TREE_CODE (decl) == CONSTRUCTOR)
6036 {
6037 if ((reloc & targetm.asm_out.reloc_rw_mask ())
6038 || TREE_SIDE_EFFECTS (decl)
6039 || ! TREE_CONSTANT (decl))
6040 ret = SECCAT_DATA;
6041 else
6042 ret = SECCAT_RODATA;
6043 }
6044 else
6045 ret = SECCAT_RODATA;
6046
6047 /* There are no read-only thread-local sections. */
6048 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
6049 {
6050 /* Note that this would be *just* SECCAT_BSS, except that there's
6051 no concept of a read-only thread-local-data section. */
6052 if (ret == SECCAT_BSS
6053 || (flag_zero_initialized_in_bss
6054 && initializer_zerop (DECL_INITIAL (decl))))
6055 ret = SECCAT_TBSS;
6056 else
6057 ret = SECCAT_TDATA;
6058 }
6059
6060 /* If the target uses small data sections, select it. */
6061 else if (targetm.in_small_data_p (decl))
6062 {
6063 if (ret == SECCAT_BSS)
6064 ret = SECCAT_SBSS;
6065 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
6066 ret = SECCAT_SRODATA;
6067 else
6068 ret = SECCAT_SDATA;
6069 }
6070
6071 return ret;
6072 }
6073
6074 bool
6075 decl_readonly_section (const_tree decl, int reloc)
6076 {
6077 switch (categorize_decl_for_section (decl, reloc))
6078 {
6079 case SECCAT_RODATA:
6080 case SECCAT_RODATA_MERGE_STR:
6081 case SECCAT_RODATA_MERGE_STR_INIT:
6082 case SECCAT_RODATA_MERGE_CONST:
6083 case SECCAT_SRODATA:
6084 return true;
6085 break;
6086 default:
6087 return false;
6088 break;
6089 }
6090 }
6091
6092 /* Select a section based on the above categorization. */
6093
6094 section *
6095 default_elf_select_section (tree decl, int reloc,
6096 unsigned HOST_WIDE_INT align)
6097 {
6098 const char *sname;
6099 switch (categorize_decl_for_section (decl, reloc))
6100 {
6101 case SECCAT_TEXT:
6102 /* We're not supposed to be called on FUNCTION_DECLs. */
6103 gcc_unreachable ();
6104 case SECCAT_RODATA:
6105 return readonly_data_section;
6106 case SECCAT_RODATA_MERGE_STR:
6107 return mergeable_string_section (decl, align, 0);
6108 case SECCAT_RODATA_MERGE_STR_INIT:
6109 return mergeable_string_section (DECL_INITIAL (decl), align, 0);
6110 case SECCAT_RODATA_MERGE_CONST:
6111 return mergeable_constant_section (DECL_MODE (decl), align, 0);
6112 case SECCAT_SRODATA:
6113 sname = ".sdata2";
6114 break;
6115 case SECCAT_DATA:
6116 return data_section;
6117 case SECCAT_DATA_REL:
6118 sname = ".data.rel";
6119 break;
6120 case SECCAT_DATA_REL_LOCAL:
6121 sname = ".data.rel.local";
6122 break;
6123 case SECCAT_DATA_REL_RO:
6124 sname = ".data.rel.ro";
6125 break;
6126 case SECCAT_DATA_REL_RO_LOCAL:
6127 sname = ".data.rel.ro.local";
6128 break;
6129 case SECCAT_SDATA:
6130 sname = ".sdata";
6131 break;
6132 case SECCAT_TDATA:
6133 sname = ".tdata";
6134 break;
6135 case SECCAT_BSS:
6136 if (bss_section)
6137 return bss_section;
6138 sname = ".bss";
6139 break;
6140 case SECCAT_SBSS:
6141 sname = ".sbss";
6142 break;
6143 case SECCAT_TBSS:
6144 sname = ".tbss";
6145 break;
6146 default:
6147 gcc_unreachable ();
6148 }
6149
6150 if (!DECL_P (decl))
6151 decl = NULL_TREE;
6152 return get_named_section (decl, sname, reloc);
6153 }
6154
6155 /* Construct a unique section name based on the decl name and the
6156 categorization performed above. */
6157
6158 void
6159 default_unique_section (tree decl, int reloc)
6160 {
6161 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
6162 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
6163 const char *prefix, *name, *linkonce;
6164 char *string;
6165
6166 switch (categorize_decl_for_section (decl, reloc))
6167 {
6168 case SECCAT_TEXT:
6169 prefix = one_only ? ".t" : ".text";
6170 break;
6171 case SECCAT_RODATA:
6172 case SECCAT_RODATA_MERGE_STR:
6173 case SECCAT_RODATA_MERGE_STR_INIT:
6174 case SECCAT_RODATA_MERGE_CONST:
6175 prefix = one_only ? ".r" : ".rodata";
6176 break;
6177 case SECCAT_SRODATA:
6178 prefix = one_only ? ".s2" : ".sdata2";
6179 break;
6180 case SECCAT_DATA:
6181 prefix = one_only ? ".d" : ".data";
6182 break;
6183 case SECCAT_DATA_REL:
6184 prefix = one_only ? ".d.rel" : ".data.rel";
6185 break;
6186 case SECCAT_DATA_REL_LOCAL:
6187 prefix = one_only ? ".d.rel.local" : ".data.rel.local";
6188 break;
6189 case SECCAT_DATA_REL_RO:
6190 prefix = one_only ? ".d.rel.ro" : ".data.rel.ro";
6191 break;
6192 case SECCAT_DATA_REL_RO_LOCAL:
6193 prefix = one_only ? ".d.rel.ro.local" : ".data.rel.ro.local";
6194 break;
6195 case SECCAT_SDATA:
6196 prefix = one_only ? ".s" : ".sdata";
6197 break;
6198 case SECCAT_BSS:
6199 prefix = one_only ? ".b" : ".bss";
6200 break;
6201 case SECCAT_SBSS:
6202 prefix = one_only ? ".sb" : ".sbss";
6203 break;
6204 case SECCAT_TDATA:
6205 prefix = one_only ? ".td" : ".tdata";
6206 break;
6207 case SECCAT_TBSS:
6208 prefix = one_only ? ".tb" : ".tbss";
6209 break;
6210 default:
6211 gcc_unreachable ();
6212 }
6213
6214 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
6215 name = targetm.strip_name_encoding (name);
6216
6217 /* If we're using one_only, then there needs to be a .gnu.linkonce
6218 prefix to the section name. */
6219 linkonce = one_only ? ".gnu.linkonce" : "";
6220
6221 string = ACONCAT ((linkonce, prefix, ".", name, NULL));
6222
6223 DECL_SECTION_NAME (decl) = build_string (strlen (string), string);
6224 }
6225
6226 /* Like compute_reloc_for_constant, except for an RTX. The return value
6227 is a mask for which bit 1 indicates a global relocation, and bit 0
6228 indicates a local relocation. */
6229
6230 static int
6231 compute_reloc_for_rtx_1 (rtx *xp, void *data)
6232 {
6233 int *preloc = (int *) data;
6234 rtx x = *xp;
6235
6236 switch (GET_CODE (x))
6237 {
6238 case SYMBOL_REF:
6239 *preloc |= SYMBOL_REF_LOCAL_P (x) ? 1 : 2;
6240 break;
6241 case LABEL_REF:
6242 *preloc |= 1;
6243 break;
6244 default:
6245 break;
6246 }
6247
6248 return 0;
6249 }
6250
6251 static int
6252 compute_reloc_for_rtx (rtx x)
6253 {
6254 int reloc;
6255
6256 switch (GET_CODE (x))
6257 {
6258 case CONST:
6259 case SYMBOL_REF:
6260 case LABEL_REF:
6261 reloc = 0;
6262 for_each_rtx (&x, compute_reloc_for_rtx_1, &reloc);
6263 return reloc;
6264
6265 default:
6266 return 0;
6267 }
6268 }
6269
6270 section *
6271 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
6272 rtx x,
6273 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6274 {
6275 if (compute_reloc_for_rtx (x) & targetm.asm_out.reloc_rw_mask ())
6276 return data_section;
6277 else
6278 return readonly_data_section;
6279 }
6280
6281 section *
6282 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
6283 unsigned HOST_WIDE_INT align)
6284 {
6285 int reloc = compute_reloc_for_rtx (x);
6286
6287 /* ??? Handle small data here somehow. */
6288
6289 if (reloc & targetm.asm_out.reloc_rw_mask ())
6290 {
6291 if (reloc == 1)
6292 return get_named_section (NULL, ".data.rel.ro.local", 1);
6293 else
6294 return get_named_section (NULL, ".data.rel.ro", 3);
6295 }
6296
6297 return mergeable_constant_section (mode, align, 0);
6298 }
6299
6300 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
6301
6302 void
6303 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
6304 {
6305 rtx symbol;
6306 int flags;
6307
6308 /* Careful not to prod global register variables. */
6309 if (!MEM_P (rtl))
6310 return;
6311 symbol = XEXP (rtl, 0);
6312 if (GET_CODE (symbol) != SYMBOL_REF)
6313 return;
6314
6315 flags = SYMBOL_REF_FLAGS (symbol) & SYMBOL_FLAG_HAS_BLOCK_INFO;
6316 if (TREE_CODE (decl) == FUNCTION_DECL)
6317 flags |= SYMBOL_FLAG_FUNCTION;
6318 if (targetm.binds_local_p (decl))
6319 flags |= SYMBOL_FLAG_LOCAL;
6320 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
6321 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT;
6322 else if (targetm.in_small_data_p (decl))
6323 flags |= SYMBOL_FLAG_SMALL;
6324 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
6325 being PUBLIC, the thing *must* be defined in this translation unit.
6326 Prevent this buglet from being propagated into rtl code as well. */
6327 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
6328 flags |= SYMBOL_FLAG_EXTERNAL;
6329
6330 SYMBOL_REF_FLAGS (symbol) = flags;
6331 }
6332
6333 /* By default, we do nothing for encode_section_info, so we need not
6334 do anything but discard the '*' marker. */
6335
6336 const char *
6337 default_strip_name_encoding (const char *str)
6338 {
6339 return str + (*str == '*');
6340 }
6341
6342 #ifdef ASM_OUTPUT_DEF
6343 /* The default implementation of TARGET_ASM_OUTPUT_ANCHOR. Define the
6344 anchor relative to ".", the current section position. */
6345
6346 void
6347 default_asm_output_anchor (rtx symbol)
6348 {
6349 char buffer[100];
6350
6351 sprintf (buffer, "*. + " HOST_WIDE_INT_PRINT_DEC,
6352 SYMBOL_REF_BLOCK_OFFSET (symbol));
6353 ASM_OUTPUT_DEF (asm_out_file, XSTR (symbol, 0), buffer);
6354 }
6355 #endif
6356
6357 /* The default implementation of TARGET_USE_ANCHORS_FOR_SYMBOL_P. */
6358
6359 bool
6360 default_use_anchors_for_symbol_p (const_rtx symbol)
6361 {
6362 section *sect;
6363 tree decl;
6364
6365 /* Don't use anchors for mergeable sections. The linker might move
6366 the objects around. */
6367 sect = SYMBOL_REF_BLOCK (symbol)->sect;
6368 if (sect->common.flags & SECTION_MERGE)
6369 return false;
6370
6371 /* Don't use anchors for small data sections. The small data register
6372 acts as an anchor for such sections. */
6373 if (sect->common.flags & SECTION_SMALL)
6374 return false;
6375
6376 decl = SYMBOL_REF_DECL (symbol);
6377 if (decl && DECL_P (decl))
6378 {
6379 /* Don't use section anchors for decls that might be defined by
6380 other modules. */
6381 if (!targetm.binds_local_p (decl))
6382 return false;
6383
6384 /* Don't use section anchors for decls that will be placed in a
6385 small data section. */
6386 /* ??? Ideally, this check would be redundant with the SECTION_SMALL
6387 one above. The problem is that we only use SECTION_SMALL for
6388 sections that should be marked as small in the section directive. */
6389 if (targetm.in_small_data_p (decl))
6390 return false;
6391 }
6392 return true;
6393 }
6394
6395 /* Return true when RESOLUTION indicate that symbol will be bound to the
6396 definition provided by current .o file. */
6397
6398 static bool
6399 resolution_to_local_definition_p (enum ld_plugin_symbol_resolution resolution)
6400 {
6401 return (resolution == LDPR_PREVAILING_DEF
6402 || resolution == LDPR_PREVAILING_DEF_IRONLY);
6403 }
6404
6405 /* Return true when RESOLUTION indicate that symbol will be bound locally
6406 within current executable or DSO. */
6407
6408 static bool
6409 resolution_local_p (enum ld_plugin_symbol_resolution resolution)
6410 {
6411 return (resolution == LDPR_PREVAILING_DEF
6412 || resolution == LDPR_PREVAILING_DEF_IRONLY
6413 || resolution == LDPR_PREEMPTED_REG
6414 || resolution == LDPR_PREEMPTED_IR
6415 || resolution == LDPR_RESOLVED_IR
6416 || resolution == LDPR_RESOLVED_EXEC);
6417 }
6418
6419 /* Assume ELF-ish defaults, since that's pretty much the most liberal
6420 wrt cross-module name binding. */
6421
6422 bool
6423 default_binds_local_p (const_tree exp)
6424 {
6425 return default_binds_local_p_1 (exp, flag_shlib);
6426 }
6427
6428 bool
6429 default_binds_local_p_1 (const_tree exp, int shlib)
6430 {
6431 bool local_p;
6432 bool resolved_locally = false;
6433 bool resolved_to_local_def = false;
6434
6435 /* With resolution file in hands, take look into resolutions.
6436 We can't just return true for resolved_localy symbols,
6437 because dynamic linking might overwrite symbols
6438 in shared libraries. */
6439 if (TREE_CODE (exp) == VAR_DECL && TREE_PUBLIC (exp)
6440 && (TREE_STATIC (exp) || DECL_EXTERNAL (exp)))
6441 {
6442 struct varpool_node *vnode = varpool_get_node (exp);
6443 if (vnode && resolution_local_p (vnode->resolution))
6444 resolved_locally = true;
6445 if (vnode
6446 && resolution_to_local_definition_p (vnode->resolution))
6447 resolved_to_local_def = true;
6448 }
6449 else if (TREE_CODE (exp) == FUNCTION_DECL && TREE_PUBLIC (exp))
6450 {
6451 struct cgraph_node *node = cgraph_get_node_or_alias (exp);
6452 if (node
6453 && resolution_local_p (node->resolution))
6454 resolved_locally = true;
6455 if (node
6456 && resolution_to_local_definition_p (node->resolution))
6457 resolved_to_local_def = true;
6458 }
6459
6460 /* A non-decl is an entry in the constant pool. */
6461 if (!DECL_P (exp))
6462 local_p = true;
6463 /* Weakrefs may not bind locally, even though the weakref itself is
6464 always static and therefore local.
6465 FIXME: We can resolve this more curefuly by looking at the weakref
6466 alias. */
6467 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp)))
6468 local_p = false;
6469 /* Static variables are always local. */
6470 else if (! TREE_PUBLIC (exp))
6471 local_p = true;
6472 /* A variable is local if the user has said explicitly that it will
6473 be. */
6474 else if ((DECL_VISIBILITY_SPECIFIED (exp)
6475 || resolved_to_local_def)
6476 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6477 local_p = true;
6478 /* Variables defined outside this object might not be local. */
6479 else if (DECL_EXTERNAL (exp) && !resolved_locally)
6480 local_p = false;
6481 /* If defined in this object and visibility is not default, must be
6482 local. */
6483 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6484 local_p = true;
6485 /* Default visibility weak data can be overridden by a strong symbol
6486 in another module and so are not local. */
6487 else if (DECL_WEAK (exp)
6488 && !resolved_locally)
6489 local_p = false;
6490 /* If PIC, then assume that any global name can be overridden by
6491 symbols resolved from other modules. */
6492 else if (shlib)
6493 local_p = false;
6494 /* Uninitialized COMMON variable may be unified with symbols
6495 resolved from other modules. */
6496 else if (DECL_COMMON (exp)
6497 && !resolved_locally
6498 && (DECL_INITIAL (exp) == NULL
6499 || DECL_INITIAL (exp) == error_mark_node))
6500 local_p = false;
6501 /* Otherwise we're left with initialized (or non-common) global data
6502 which is of necessity defined locally. */
6503 else
6504 local_p = true;
6505
6506 return local_p;
6507 }
6508
6509 /* Return true when references to DECL must bind to current definition in
6510 final executable.
6511
6512 The condition is usually equivalent to whether the function binds to the
6513 current module (shared library or executable), that is to binds_local_p.
6514 We use this fact to avoid need for another target hook and implement
6515 the logic using binds_local_p and just special cases where
6516 decl_binds_to_current_def_p is stronger than binds local_p. In particular
6517 the weak definitions (that can be overwritten at linktime by other
6518 definition from different object file) and when resolution info is available
6519 we simply use the knowledge passed to us by linker plugin. */
6520 bool
6521 decl_binds_to_current_def_p (tree decl)
6522 {
6523 gcc_assert (DECL_P (decl));
6524 if (!TREE_PUBLIC (decl))
6525 return true;
6526 if (!targetm.binds_local_p (decl))
6527 return false;
6528 /* When resolution is available, just use it. */
6529 if (TREE_CODE (decl) == VAR_DECL && TREE_PUBLIC (decl)
6530 && (TREE_STATIC (decl) || DECL_EXTERNAL (decl)))
6531 {
6532 struct varpool_node *vnode = varpool_get_node (decl);
6533 if (vnode
6534 && vnode->resolution != LDPR_UNKNOWN)
6535 return resolution_to_local_definition_p (vnode->resolution);
6536 }
6537 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_PUBLIC (decl))
6538 {
6539 struct cgraph_node *node = cgraph_get_node_or_alias (decl);
6540 if (node
6541 && node->resolution != LDPR_UNKNOWN)
6542 return resolution_to_local_definition_p (node->resolution);
6543 }
6544 /* Otherwise we have to assume the worst for DECL_WEAK (hidden weaks
6545 binds localy but still can be overwritten).
6546 This rely on fact that binds_local_p behave as decl_replaceable_p
6547 for all other declaration types. */
6548 return !DECL_WEAK (decl);
6549 }
6550
6551 /* A replaceable function or variable is one which may be replaced
6552 at link-time with an entirely different definition, provided that the
6553 replacement has the same type. For example, functions declared
6554 with __attribute__((weak)) on most systems are replaceable.
6555
6556 COMDAT functions are not replaceable, since all definitions of the
6557 function must be equivalent. It is important that COMDAT functions
6558 not be treated as replaceable so that use of C++ template
6559 instantiations is not penalized. */
6560
6561 bool
6562 decl_replaceable_p (tree decl)
6563 {
6564 gcc_assert (DECL_P (decl));
6565 if (!TREE_PUBLIC (decl) || DECL_COMDAT (decl))
6566 return false;
6567 return !decl_binds_to_current_def_p (decl);
6568 }
6569
6570 /* Default function to output code that will globalize a label. A
6571 target must define GLOBAL_ASM_OP or provide its own function to
6572 globalize a label. */
6573 #ifdef GLOBAL_ASM_OP
6574 void
6575 default_globalize_label (FILE * stream, const char *name)
6576 {
6577 fputs (GLOBAL_ASM_OP, stream);
6578 assemble_name (stream, name);
6579 putc ('\n', stream);
6580 }
6581 #endif /* GLOBAL_ASM_OP */
6582
6583 /* Default function to output code that will globalize a declaration. */
6584 void
6585 default_globalize_decl_name (FILE * stream, tree decl)
6586 {
6587 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
6588 targetm.asm_out.globalize_label (stream, name);
6589 }
6590
6591 /* Default function to output a label for unwind information. The
6592 default is to do nothing. A target that needs nonlocal labels for
6593 unwind information must provide its own function to do this. */
6594 void
6595 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
6596 tree decl ATTRIBUTE_UNUSED,
6597 int for_eh ATTRIBUTE_UNUSED,
6598 int empty ATTRIBUTE_UNUSED)
6599 {
6600 }
6601
6602 /* Default function to output a label to divide up the exception table.
6603 The default is to do nothing. A target that needs/wants to divide
6604 up the table must provide it's own function to do this. */
6605 void
6606 default_emit_except_table_label (FILE * stream ATTRIBUTE_UNUSED)
6607 {
6608 }
6609
6610 /* This is how to output an internal numbered label where PREFIX is
6611 the class of label and LABELNO is the number within the class. */
6612
6613 void
6614 default_generate_internal_label (char *buf, const char *prefix,
6615 unsigned long labelno)
6616 {
6617 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
6618 }
6619
6620 /* This is how to output an internal numbered label where PREFIX is
6621 the class of label and LABELNO is the number within the class. */
6622
6623 void
6624 default_internal_label (FILE *stream, const char *prefix,
6625 unsigned long labelno)
6626 {
6627 char *const buf = (char *) alloca (40 + strlen (prefix));
6628 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
6629 ASM_OUTPUT_INTERNAL_LABEL (stream, buf);
6630 }
6631
6632
6633 /* The default implementation of ASM_DECLARE_CONSTANT_NAME. */
6634
6635 void
6636 default_asm_declare_constant_name (FILE *file, const char *name,
6637 const_tree exp ATTRIBUTE_UNUSED,
6638 HOST_WIDE_INT size ATTRIBUTE_UNUSED)
6639 {
6640 assemble_label (file, name);
6641 }
6642
6643 /* This is the default behavior at the beginning of a file. It's
6644 controlled by two other target-hook toggles. */
6645 void
6646 default_file_start (void)
6647 {
6648 if (targetm.asm_file_start_app_off
6649 && !(flag_verbose_asm || flag_debug_asm || flag_dump_rtl_in_asm))
6650 fputs (ASM_APP_OFF, asm_out_file);
6651
6652 if (targetm.asm_file_start_file_directive)
6653 output_file_directive (asm_out_file, main_input_filename);
6654 }
6655
6656 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
6657 which emits a special section directive used to indicate whether or
6658 not this object file needs an executable stack. This is primarily
6659 a GNU extension to ELF but could be used on other targets. */
6660
6661 int trampolines_created;
6662
6663 void
6664 file_end_indicate_exec_stack (void)
6665 {
6666 unsigned int flags = SECTION_DEBUG;
6667 if (trampolines_created)
6668 flags |= SECTION_CODE;
6669
6670 switch_to_section (get_section (".note.GNU-stack", flags, NULL));
6671 }
6672
6673 /* Emit a special section directive to indicate that this object file
6674 was compiled with -fsplit-stack. This is used to let the linker
6675 detect calls between split-stack code and non-split-stack code, so
6676 that it can modify the split-stack code to allocate a sufficiently
6677 large stack. We emit another special section if there are any
6678 functions in this file which have the no_split_stack attribute, to
6679 prevent the linker from warning about being unable to convert the
6680 functions if they call non-split-stack code. */
6681
6682 void
6683 file_end_indicate_split_stack (void)
6684 {
6685 if (flag_split_stack)
6686 {
6687 switch_to_section (get_section (".note.GNU-split-stack", SECTION_DEBUG,
6688 NULL));
6689 if (saw_no_split_stack)
6690 switch_to_section (get_section (".note.GNU-no-split-stack",
6691 SECTION_DEBUG, NULL));
6692 }
6693 }
6694
6695 /* Output DIRECTIVE (a C string) followed by a newline. This is used as
6696 a get_unnamed_section callback. */
6697
6698 void
6699 output_section_asm_op (const void *directive)
6700 {
6701 fprintf (asm_out_file, "%s\n", (const char *) directive);
6702 }
6703
6704 /* Emit assembly code to switch to section NEW_SECTION. Do nothing if
6705 the current section is NEW_SECTION. */
6706
6707 void
6708 switch_to_section (section *new_section)
6709 {
6710 if (in_section == new_section)
6711 return;
6712
6713 if (new_section->common.flags & SECTION_FORGET)
6714 in_section = NULL;
6715 else
6716 in_section = new_section;
6717
6718 switch (SECTION_STYLE (new_section))
6719 {
6720 case SECTION_NAMED:
6721 if (cfun
6722 && !crtl->subsections.unlikely_text_section_name
6723 && strcmp (new_section->named.name,
6724 UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
6725 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
6726
6727 targetm.asm_out.named_section (new_section->named.name,
6728 new_section->named.common.flags,
6729 new_section->named.decl);
6730 break;
6731
6732 case SECTION_UNNAMED:
6733 new_section->unnamed.callback (new_section->unnamed.data);
6734 break;
6735
6736 case SECTION_NOSWITCH:
6737 gcc_unreachable ();
6738 break;
6739 }
6740
6741 new_section->common.flags |= SECTION_DECLARED;
6742 }
6743
6744 /* If block symbol SYMBOL has not yet been assigned an offset, place
6745 it at the end of its block. */
6746
6747 void
6748 place_block_symbol (rtx symbol)
6749 {
6750 unsigned HOST_WIDE_INT size, mask, offset;
6751 struct constant_descriptor_rtx *desc;
6752 unsigned int alignment;
6753 struct object_block *block;
6754 tree decl;
6755
6756 gcc_assert (SYMBOL_REF_BLOCK (symbol));
6757 if (SYMBOL_REF_BLOCK_OFFSET (symbol) >= 0)
6758 return;
6759
6760 /* Work out the symbol's size and alignment. */
6761 if (CONSTANT_POOL_ADDRESS_P (symbol))
6762 {
6763 desc = SYMBOL_REF_CONSTANT (symbol);
6764 alignment = desc->align;
6765 size = GET_MODE_SIZE (desc->mode);
6766 }
6767 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6768 {
6769 decl = SYMBOL_REF_DECL (symbol);
6770 alignment = DECL_ALIGN (decl);
6771 size = get_constant_size (DECL_INITIAL (decl));
6772 }
6773 else
6774 {
6775 decl = SYMBOL_REF_DECL (symbol);
6776 alignment = DECL_ALIGN (decl);
6777 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6778 }
6779
6780 /* Calculate the object's offset from the start of the block. */
6781 block = SYMBOL_REF_BLOCK (symbol);
6782 mask = alignment / BITS_PER_UNIT - 1;
6783 offset = (block->size + mask) & ~mask;
6784 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
6785
6786 /* Record the block's new alignment and size. */
6787 block->alignment = MAX (block->alignment, alignment);
6788 block->size = offset + size;
6789
6790 VEC_safe_push (rtx, gc, block->objects, symbol);
6791 }
6792
6793 /* Return the anchor that should be used to address byte offset OFFSET
6794 from the first object in BLOCK. MODEL is the TLS model used
6795 to access it. */
6796
6797 rtx
6798 get_section_anchor (struct object_block *block, HOST_WIDE_INT offset,
6799 enum tls_model model)
6800 {
6801 char label[100];
6802 unsigned int begin, middle, end;
6803 unsigned HOST_WIDE_INT min_offset, max_offset, range, bias, delta;
6804 rtx anchor;
6805
6806 /* Work out the anchor's offset. Use an offset of 0 for the first
6807 anchor so that we don't pessimize the case where we take the address
6808 of a variable at the beginning of the block. This is particularly
6809 useful when a block has only one variable assigned to it.
6810
6811 We try to place anchors RANGE bytes apart, so there can then be
6812 anchors at +/-RANGE, +/-2 * RANGE, and so on, up to the limits of
6813 a ptr_mode offset. With some target settings, the lowest such
6814 anchor might be out of range for the lowest ptr_mode offset;
6815 likewise the highest anchor for the highest offset. Use anchors
6816 at the extreme ends of the ptr_mode range in such cases.
6817
6818 All arithmetic uses unsigned integers in order to avoid
6819 signed overflow. */
6820 max_offset = (unsigned HOST_WIDE_INT) targetm.max_anchor_offset;
6821 min_offset = (unsigned HOST_WIDE_INT) targetm.min_anchor_offset;
6822 range = max_offset - min_offset + 1;
6823 if (range == 0)
6824 offset = 0;
6825 else
6826 {
6827 bias = 1 << (GET_MODE_BITSIZE (ptr_mode) - 1);
6828 if (offset < 0)
6829 {
6830 delta = -(unsigned HOST_WIDE_INT) offset + max_offset;
6831 delta -= delta % range;
6832 if (delta > bias)
6833 delta = bias;
6834 offset = (HOST_WIDE_INT) (-delta);
6835 }
6836 else
6837 {
6838 delta = (unsigned HOST_WIDE_INT) offset - min_offset;
6839 delta -= delta % range;
6840 if (delta > bias - 1)
6841 delta = bias - 1;
6842 offset = (HOST_WIDE_INT) delta;
6843 }
6844 }
6845
6846 /* Do a binary search to see if there's already an anchor we can use.
6847 Set BEGIN to the new anchor's index if not. */
6848 begin = 0;
6849 end = VEC_length (rtx, block->anchors);
6850 while (begin != end)
6851 {
6852 middle = (end + begin) / 2;
6853 anchor = VEC_index (rtx, block->anchors, middle);
6854 if (SYMBOL_REF_BLOCK_OFFSET (anchor) > offset)
6855 end = middle;
6856 else if (SYMBOL_REF_BLOCK_OFFSET (anchor) < offset)
6857 begin = middle + 1;
6858 else if (SYMBOL_REF_TLS_MODEL (anchor) > model)
6859 end = middle;
6860 else if (SYMBOL_REF_TLS_MODEL (anchor) < model)
6861 begin = middle + 1;
6862 else
6863 return anchor;
6864 }
6865
6866 /* Create a new anchor with a unique label. */
6867 ASM_GENERATE_INTERNAL_LABEL (label, "LANCHOR", anchor_labelno++);
6868 anchor = create_block_symbol (ggc_strdup (label), block, offset);
6869 SYMBOL_REF_FLAGS (anchor) |= SYMBOL_FLAG_LOCAL | SYMBOL_FLAG_ANCHOR;
6870 SYMBOL_REF_FLAGS (anchor) |= model << SYMBOL_FLAG_TLS_SHIFT;
6871
6872 /* Insert it at index BEGIN. */
6873 VEC_safe_insert (rtx, gc, block->anchors, begin, anchor);
6874 return anchor;
6875 }
6876
6877 /* Output the objects in BLOCK. */
6878
6879 static void
6880 output_object_block (struct object_block *block)
6881 {
6882 struct constant_descriptor_rtx *desc;
6883 unsigned int i;
6884 HOST_WIDE_INT offset;
6885 tree decl;
6886 rtx symbol;
6887
6888 if (block->objects == NULL)
6889 return;
6890
6891 /* Switch to the section and make sure that the first byte is
6892 suitably aligned. */
6893 switch_to_section (block->sect);
6894 assemble_align (block->alignment);
6895
6896 /* Define the values of all anchors relative to the current section
6897 position. */
6898 FOR_EACH_VEC_ELT (rtx, block->anchors, i, symbol)
6899 targetm.asm_out.output_anchor (symbol);
6900
6901 /* Output the objects themselves. */
6902 offset = 0;
6903 FOR_EACH_VEC_ELT (rtx, block->objects, i, symbol)
6904 {
6905 /* Move to the object's offset, padding with zeros if necessary. */
6906 assemble_zeros (SYMBOL_REF_BLOCK_OFFSET (symbol) - offset);
6907 offset = SYMBOL_REF_BLOCK_OFFSET (symbol);
6908 if (CONSTANT_POOL_ADDRESS_P (symbol))
6909 {
6910 desc = SYMBOL_REF_CONSTANT (symbol);
6911 output_constant_pool_1 (desc, 1);
6912 offset += GET_MODE_SIZE (desc->mode);
6913 }
6914 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6915 {
6916 decl = SYMBOL_REF_DECL (symbol);
6917 assemble_constant_contents (DECL_INITIAL (decl), XSTR (symbol, 0),
6918 DECL_ALIGN (decl));
6919 offset += get_constant_size (DECL_INITIAL (decl));
6920 }
6921 else
6922 {
6923 decl = SYMBOL_REF_DECL (symbol);
6924 assemble_variable_contents (decl, XSTR (symbol, 0), false);
6925 offset += tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6926 }
6927 }
6928 }
6929
6930 /* A htab_traverse callback used to call output_object_block for
6931 each member of object_block_htab. */
6932
6933 static int
6934 output_object_block_htab (void **slot, void *data ATTRIBUTE_UNUSED)
6935 {
6936 output_object_block ((struct object_block *) (*slot));
6937 return 1;
6938 }
6939
6940 /* Output the definitions of all object_blocks. */
6941
6942 void
6943 output_object_blocks (void)
6944 {
6945 htab_traverse (object_block_htab, output_object_block_htab, NULL);
6946 }
6947
6948 /* This function provides a possible implementation of the
6949 TARGET_ASM_RECORD_GCC_SWITCHES target hook for ELF targets. When triggered
6950 by -frecord-gcc-switches it creates a new mergeable, string section in the
6951 assembler output file called TARGET_ASM_RECORD_GCC_SWITCHES_SECTION which
6952 contains the switches in ASCII format.
6953
6954 FIXME: This code does not correctly handle double quote characters
6955 that appear inside strings, (it strips them rather than preserving them).
6956 FIXME: ASM_OUTPUT_ASCII, as defined in config/elfos.h will not emit NUL
6957 characters - instead it treats them as sub-string separators. Since
6958 we want to emit NUL strings terminators into the object file we have to use
6959 ASM_OUTPUT_SKIP. */
6960
6961 int
6962 elf_record_gcc_switches (print_switch_type type, const char * name)
6963 {
6964 switch (type)
6965 {
6966 case SWITCH_TYPE_PASSED:
6967 ASM_OUTPUT_ASCII (asm_out_file, name, strlen (name));
6968 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6969 break;
6970
6971 case SWITCH_TYPE_DESCRIPTIVE:
6972 if (name == NULL)
6973 {
6974 /* Distinguish between invocations where name is NULL. */
6975 static bool started = false;
6976
6977 if (!started)
6978 {
6979 section * sec;
6980
6981 sec = get_section (targetm.asm_out.record_gcc_switches_section,
6982 SECTION_DEBUG
6983 | SECTION_MERGE
6984 | SECTION_STRINGS
6985 | (SECTION_ENTSIZE & 1),
6986 NULL);
6987 switch_to_section (sec);
6988 started = true;
6989 }
6990 }
6991
6992 default:
6993 break;
6994 }
6995
6996 /* The return value is currently ignored by the caller, but must be 0.
6997 For -fverbose-asm the return value would be the number of characters
6998 emitted into the assembler file. */
6999 return 0;
7000 }
7001
7002 /* Emit text to declare externally defined symbols. It is needed to
7003 properly support non-default visibility. */
7004 void
7005 default_elf_asm_output_external (FILE *file ATTRIBUTE_UNUSED,
7006 tree decl,
7007 const char *name ATTRIBUTE_UNUSED)
7008 {
7009 /* We output the name if and only if TREE_SYMBOL_REFERENCED is
7010 set in order to avoid putting out names that are never really
7011 used. */
7012 if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
7013 && targetm.binds_local_p (decl))
7014 maybe_assemble_visibility (decl);
7015 }
7016
7017 /* The default hook for TARGET_ASM_OUTPUT_SOURCE_FILENAME. */
7018
7019 void
7020 default_asm_output_source_filename (FILE *file, const char *name)
7021 {
7022 #ifdef ASM_OUTPUT_SOURCE_FILENAME
7023 ASM_OUTPUT_SOURCE_FILENAME (file, name);
7024 #else
7025 fprintf (file, "\t.file\t");
7026 output_quoted_string (file, name);
7027 putc ('\n', file);
7028 #endif
7029 }
7030
7031 /* Output a file name in the form wanted by System V. */
7032
7033 void
7034 output_file_directive (FILE *asm_file, const char *input_name)
7035 {
7036 int len;
7037 const char *na;
7038
7039 if (input_name == NULL)
7040 input_name = "<stdin>";
7041 else
7042 input_name = remap_debug_filename (input_name);
7043
7044 len = strlen (input_name);
7045 na = input_name + len;
7046
7047 /* NA gets INPUT_NAME sans directory names. */
7048 while (na > input_name)
7049 {
7050 if (IS_DIR_SEPARATOR (na[-1]))
7051 break;
7052 na--;
7053 }
7054
7055 targetm.asm_out.output_source_filename (asm_file, na);
7056 }
7057
7058 /* Create a DEBUG_EXPR_DECL / DEBUG_EXPR pair from RTL expression
7059 EXP. */
7060 rtx
7061 make_debug_expr_from_rtl (const_rtx exp)
7062 {
7063 tree ddecl = make_node (DEBUG_EXPR_DECL), type;
7064 enum machine_mode mode = GET_MODE (exp);
7065 rtx dval;
7066
7067 DECL_ARTIFICIAL (ddecl) = 1;
7068 if (REG_P (exp) && REG_EXPR (exp))
7069 type = TREE_TYPE (REG_EXPR (exp));
7070 else if (MEM_P (exp) && MEM_EXPR (exp))
7071 type = TREE_TYPE (MEM_EXPR (exp));
7072 else
7073 type = NULL_TREE;
7074 if (type && TYPE_MODE (type) == mode)
7075 TREE_TYPE (ddecl) = type;
7076 else
7077 TREE_TYPE (ddecl) = lang_hooks.types.type_for_mode (mode, 1);
7078 DECL_MODE (ddecl) = mode;
7079 dval = gen_rtx_DEBUG_EXPR (mode);
7080 DEBUG_EXPR_TREE_DECL (dval) = ddecl;
7081 SET_DECL_RTL (ddecl, dval);
7082 return dval;
7083 }
7084
7085 #include "gt-varasm.h"