varasm.c (assemble_variable): Remove call to lang_hooks.decls.prepare_assemble_variable.
[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
4 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 2, 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 COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
21 02110-1301, USA. */
22
23
24 /* This file handles generation of all the assembler code
25 *except* the instructions of a function.
26 This includes declarations of variables and their initial values.
27
28 We also output the assembler code for constants stored in memory
29 and are responsible for combining constants with the same value. */
30
31 #include "config.h"
32 #include "system.h"
33 #include "coretypes.h"
34 #include "tm.h"
35 #include "rtl.h"
36 #include "tree.h"
37 #include "flags.h"
38 #include "function.h"
39 #include "expr.h"
40 #include "hard-reg-set.h"
41 #include "regs.h"
42 #include "real.h"
43 #include "output.h"
44 #include "toplev.h"
45 #include "hashtab.h"
46 #include "c-pragma.h"
47 #include "ggc.h"
48 #include "langhooks.h"
49 #include "tm_p.h"
50 #include "debug.h"
51 #include "target.h"
52 #include "tree-mudflap.h"
53 #include "cgraph.h"
54 #include "cfglayout.h"
55 #include "basic-block.h"
56 #include "tree-iterator.h"
57
58 #ifdef XCOFF_DEBUGGING_INFO
59 #include "xcoffout.h" /* Needed for external data
60 declarations for e.g. AIX 4.x. */
61 #endif
62
63 /* The (assembler) name of the first globally-visible object output. */
64 extern GTY(()) const char *first_global_object_name;
65 extern GTY(()) const char *weak_global_object_name;
66
67 const char *first_global_object_name;
68 const char *weak_global_object_name;
69
70 struct addr_const;
71 struct constant_descriptor_rtx;
72 struct rtx_constant_pool;
73
74 struct varasm_status GTY(())
75 {
76 /* If we're using a per-function constant pool, this is it. */
77 struct rtx_constant_pool *pool;
78
79 /* Number of tree-constants deferred during the expansion of this
80 function. */
81 unsigned int deferred_constants;
82 };
83
84 #define n_deferred_constants (cfun->varasm->deferred_constants)
85
86 /* Number for making the label on the next
87 constant that is stored in memory. */
88
89 static GTY(()) int const_labelno;
90
91 /* Carry information from ASM_DECLARE_OBJECT_NAME
92 to ASM_FINISH_DECLARE_OBJECT. */
93
94 int size_directive_output;
95
96 /* The last decl for which assemble_variable was called,
97 if it did ASM_DECLARE_OBJECT_NAME.
98 If the last call to assemble_variable didn't do that,
99 this holds 0. */
100
101 tree last_assemble_variable_decl;
102
103 /* The following global variable indicates if the first basic block
104 in a function belongs to the cold partition or not. */
105
106 bool first_function_block_is_cold;
107
108 /* We give all constants their own alias set. Perhaps redundant with
109 MEM_READONLY_P, but pre-dates it. */
110
111 static HOST_WIDE_INT const_alias_set;
112
113 static const char *strip_reg_name (const char *);
114 static int contains_pointers_p (tree);
115 #ifdef ASM_OUTPUT_EXTERNAL
116 static bool incorporeal_function_p (tree);
117 #endif
118 static void decode_addr_const (tree, struct addr_const *);
119 static hashval_t const_desc_hash (const void *);
120 static int const_desc_eq (const void *, const void *);
121 static hashval_t const_hash_1 (const tree);
122 static int compare_constant (const tree, const tree);
123 static tree copy_constant (tree);
124 static void output_constant_def_contents (rtx);
125 static void output_addressed_constants (tree);
126 static unsigned HOST_WIDE_INT array_size_for_constructor (tree);
127 static unsigned min_align (unsigned, unsigned);
128 static void output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int);
129 static void globalize_decl (tree);
130 #ifdef BSS_SECTION_ASM_OP
131 #ifdef ASM_OUTPUT_BSS
132 static void asm_output_bss (FILE *, tree, const char *,
133 unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT);
134 #endif
135 #ifdef ASM_OUTPUT_ALIGNED_BSS
136 static void asm_output_aligned_bss (FILE *, tree, const char *,
137 unsigned HOST_WIDE_INT, int)
138 ATTRIBUTE_UNUSED;
139 #endif
140 #endif /* BSS_SECTION_ASM_OP */
141 static void mark_weak (tree);
142 static void output_constant_pool (const char *, tree);
143 \f
144 /* Well-known sections, each one associated with some sort of *_ASM_OP. */
145 section *text_section;
146 section *data_section;
147 section *readonly_data_section;
148 section *sdata_section;
149 section *ctors_section;
150 section *dtors_section;
151 section *bss_section;
152 section *sbss_section;
153
154 /* Various forms of common section. All are guaranteed to be nonnull. */
155 section *tls_comm_section;
156 section *comm_section;
157 section *lcomm_section;
158
159 /* A SECTION_NOSWITCH section used for declaring global BSS variables.
160 May be null. */
161 section *bss_noswitch_section;
162
163 /* The section that holds the main exception table, when known. The section
164 is set either by the target's init_sections hook or by the first call to
165 switch_to_exception_section. */
166 section *exception_section;
167
168 /* The section that holds the DWARF2 frame unwind information, when known.
169 The section is set either by the target's init_sections hook or by the
170 first call to switch_to_eh_frame_section. */
171 section *eh_frame_section;
172
173 /* asm_out_file's current section. This is NULL if no section has yet
174 been selected or if we lose track of what the current section is. */
175 section *in_section;
176
177 /* True if code for the current function is currently being directed
178 at the cold section. */
179 bool in_cold_section_p;
180
181 /* A linked list of all the unnamed sections. */
182 static GTY(()) section *unnamed_sections;
183
184 /* Return a nonzero value if DECL has a section attribute. */
185 #ifndef IN_NAMED_SECTION
186 #define IN_NAMED_SECTION(DECL) \
187 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
188 && DECL_SECTION_NAME (DECL) != NULL_TREE)
189 #endif
190
191 /* Hash table of named sections. */
192 static GTY((param_is (section))) htab_t section_htab;
193
194 /* A table of object_blocks, indexed by section. */
195 static GTY((param_is (struct object_block))) htab_t object_block_htab;
196
197 /* The next number to use for internal anchor labels. */
198 static GTY(()) int anchor_labelno;
199
200 /* A pool of constants that can be shared between functions. */
201 static GTY(()) struct rtx_constant_pool *shared_constant_pool;
202
203 /* TLS emulation. */
204
205 static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
206 htab_t emutls_htab;
207 static GTY (()) tree emutls_object_type;
208
209 #ifndef NO_DOT_IN_LABEL
210 # define EMUTLS_VAR_PREFIX "__emutls_v."
211 # define EMUTLS_TMPL_PREFIX "__emutls_t."
212 #elif !defined NO_DOLLAR_IN_LABEL
213 # define EMUTLS_VAR_PREFIX "__emutls_v$"
214 # define EMUTLS_TMPL_PREFIX "__emutls_t$"
215 #else
216 # define EMUTLS_VAR_PREFIX "__emutls_v_"
217 # define EMUTLS_TMPL_PREFIX "__emutls_t_"
218 #endif
219
220 /* Create an identifier for the struct __emutls_object, given an identifier
221 of the DECL_ASSEMBLY_NAME of the original object. */
222
223 static tree
224 get_emutls_object_name (tree name)
225 {
226 char *toname = alloca (strlen (IDENTIFIER_POINTER (name))
227 + sizeof (EMUTLS_VAR_PREFIX));
228 strcpy (toname, EMUTLS_VAR_PREFIX);
229 strcpy (toname + sizeof (EMUTLS_VAR_PREFIX) - 1, IDENTIFIER_POINTER (name));
230
231 return get_identifier (toname);
232 }
233
234 /* Create the structure for struct __emutls_object. This should match the
235 structure at the top of emutls.c, modulo the union there. */
236
237 static tree
238 get_emutls_object_type (void)
239 {
240 tree type, type_name, field, next_field, word_type_node;
241
242 type = emutls_object_type;
243 if (type)
244 return type;
245
246 emutls_object_type = type = lang_hooks.types.make_type (RECORD_TYPE);
247 type_name = get_identifier ("__emutls_object");
248 type_name = build_decl (TYPE_DECL, type_name, type);
249 TYPE_NAME (type) = type_name;
250
251 field = build_decl (FIELD_DECL, get_identifier ("__templ"), ptr_type_node);
252 DECL_CONTEXT (field) = type;
253 next_field = field;
254
255 field = build_decl (FIELD_DECL, get_identifier ("__offset"), ptr_type_node);
256 DECL_CONTEXT (field) = type;
257 TREE_CHAIN (field) = next_field;
258 next_field = field;
259
260 word_type_node = lang_hooks.types.type_for_mode (word_mode, 1);
261 field = build_decl (FIELD_DECL, get_identifier ("__align"), word_type_node);
262 DECL_CONTEXT (field) = type;
263 TREE_CHAIN (field) = next_field;
264 next_field = field;
265
266 field = build_decl (FIELD_DECL, get_identifier ("__size"), word_type_node);
267 DECL_CONTEXT (field) = type;
268 TREE_CHAIN (field) = next_field;
269
270 TYPE_FIELDS (type) = field;
271 layout_type (type);
272
273 return type;
274 }
275
276 /* Create a read-only variable like DECL, with the same DECL_INITIAL.
277 This will be used for initializing the emulated tls data area. */
278
279 static tree
280 get_emutls_init_templ_addr (tree decl)
281 {
282 tree name, to;
283 char *toname;
284
285 if (!DECL_INITIAL (decl))
286 return null_pointer_node;
287
288 name = DECL_ASSEMBLER_NAME (decl);
289 toname = alloca (strlen (IDENTIFIER_POINTER (name))
290 + sizeof (EMUTLS_TMPL_PREFIX));
291 strcpy (toname, EMUTLS_TMPL_PREFIX);
292 strcpy (toname + sizeof (EMUTLS_TMPL_PREFIX) - 1, IDENTIFIER_POINTER (name));
293 name = get_identifier (toname);
294
295 to = build_decl (VAR_DECL, name, TREE_TYPE (decl));
296 SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to));
297
298 DECL_ARTIFICIAL (to) = 1;
299 TREE_USED (to) = TREE_USED (decl);
300 TREE_READONLY (to) = 1;
301 DECL_IGNORED_P (to) = 1;
302 DECL_CONTEXT (to) = DECL_CONTEXT (decl);
303 DECL_WEAK (to) = DECL_WEAK (decl);
304 if (DECL_ONE_ONLY (decl))
305 {
306 make_decl_one_only (to);
307 TREE_STATIC (to) = TREE_STATIC (decl);
308 TREE_PUBLIC (to) = TREE_PUBLIC (decl);
309 DECL_VISIBILITY (to) = DECL_VISIBILITY (decl);
310 }
311 else
312 TREE_STATIC (to) = 1;
313
314 DECL_INITIAL (to) = DECL_INITIAL (decl);
315 DECL_INITIAL (decl) = NULL;
316
317 varpool_finalize_decl (to);
318 return build_fold_addr_expr (to);
319 }
320
321 /* When emulating tls, we use a control structure for use by the runtime.
322 Create and return this structure. */
323
324 tree
325 emutls_decl (tree decl)
326 {
327 tree name, to;
328 struct tree_map *h, in;
329 void **loc;
330
331 if (targetm.have_tls || decl == NULL || decl == error_mark_node
332 || TREE_CODE (decl) != VAR_DECL || ! DECL_THREAD_LOCAL_P (decl))
333 return decl;
334
335 /* Look up the object in the hash; return the control structure if
336 it has already been created. */
337 if (! emutls_htab)
338 emutls_htab = htab_create_ggc (512, tree_map_hash, tree_map_eq, 0);
339
340 name = DECL_ASSEMBLER_NAME (decl);
341
342 /* Note that we use the hash of the decl's name, rather than a hash
343 of the decl's pointer. In emutls_finish we iterate through the
344 hash table, and we want this traversal to be predictable. */
345 in.hash = htab_hash_string (IDENTIFIER_POINTER (name));
346 in.base.from = decl;
347 loc = htab_find_slot_with_hash (emutls_htab, &in, in.hash, INSERT);
348 h = *loc;
349 if (h != NULL)
350 to = h->to;
351 else
352 {
353 to = build_decl (VAR_DECL, get_emutls_object_name (name),
354 get_emutls_object_type ());
355
356 h = ggc_alloc (sizeof (struct tree_map));
357 h->hash = in.hash;
358 h->base.from = decl;
359 h->to = to;
360 *(struct tree_map **) loc = h;
361
362 DECL_ARTIFICIAL (to) = 1;
363 DECL_IGNORED_P (to) = 1;
364 TREE_READONLY (to) = 0;
365
366 SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to));
367 if (DECL_ONE_ONLY (decl))
368 make_decl_one_only (to);
369 DECL_CONTEXT (to) = DECL_CONTEXT (decl);
370 }
371
372 /* Note that these fields may need to be updated from time to time from
373 the original decl. Consider:
374 extern __thread int i;
375 int foo() { return i; }
376 __thread int i = 1;
377 in which I goes from external to locally defined and initialized. */
378
379 TREE_STATIC (to) = TREE_STATIC (decl);
380 TREE_USED (to) = TREE_USED (decl);
381 TREE_PUBLIC (to) = TREE_PUBLIC (decl);
382 DECL_EXTERNAL (to) = DECL_EXTERNAL (decl);
383 DECL_COMMON (to) = DECL_COMMON (decl);
384 DECL_WEAK (to) = DECL_WEAK (decl);
385 DECL_VISIBILITY (to) = DECL_VISIBILITY (decl);
386
387 return to;
388 }
389
390 static int
391 emutls_common_1 (void **loc, void *xstmts)
392 {
393 struct tree_map *h = *(struct tree_map **) loc;
394 tree args, x, *pstmts = (tree *) xstmts;
395 tree word_type_node;
396
397 if (! DECL_COMMON (h->base.from)
398 || (DECL_INITIAL (h->base.from)
399 && DECL_INITIAL (h->base.from) != error_mark_node))
400 return 1;
401
402 word_type_node = lang_hooks.types.type_for_mode (word_mode, 1);
403
404 /* The idea was to call get_emutls_init_templ_addr here, but if we
405 do this and there is an initializer, -fanchor_section loses,
406 because it would be too late to ensure the template is
407 output. */
408 x = null_pointer_node;
409 args = tree_cons (NULL, x, NULL);
410 x = build_int_cst (word_type_node, DECL_ALIGN_UNIT (h->base.from));
411 args = tree_cons (NULL, x, args);
412 x = fold_convert (word_type_node, DECL_SIZE_UNIT (h->base.from));
413 args = tree_cons (NULL, x, args);
414 x = build_fold_addr_expr (h->to);
415 args = tree_cons (NULL, x, args);
416
417 x = built_in_decls[BUILT_IN_EMUTLS_REGISTER_COMMON];
418 x = build_function_call_expr (x, args);
419
420 append_to_statement_list (x, pstmts);
421 return 1;
422 }
423
424 void
425 emutls_finish (void)
426 {
427 tree body = NULL_TREE;
428
429 if (emutls_htab == NULL)
430 return;
431
432 htab_traverse_noresize (emutls_htab, emutls_common_1, &body);
433 if (body == NULL_TREE)
434 return;
435
436 cgraph_build_static_cdtor ('I', body, DEFAULT_INIT_PRIORITY);
437 }
438
439 /* Helper routines for maintaining section_htab. */
440
441 static int
442 section_entry_eq (const void *p1, const void *p2)
443 {
444 const section *old = p1;
445 const char *new = p2;
446
447 return strcmp (old->named.name, new) == 0;
448 }
449
450 static hashval_t
451 section_entry_hash (const void *p)
452 {
453 const section *old = p;
454 return htab_hash_string (old->named.name);
455 }
456
457 /* Return a hash value for section SECT. */
458
459 static hashval_t
460 hash_section (section *sect)
461 {
462 if (sect->common.flags & SECTION_NAMED)
463 return htab_hash_string (sect->named.name);
464 return sect->common.flags;
465 }
466
467 /* Helper routines for maintaining object_block_htab. */
468
469 static int
470 object_block_entry_eq (const void *p1, const void *p2)
471 {
472 const struct object_block *old = p1;
473 const section *new = p2;
474
475 return old->sect == new;
476 }
477
478 static hashval_t
479 object_block_entry_hash (const void *p)
480 {
481 const struct object_block *old = p;
482 return hash_section (old->sect);
483 }
484
485 /* Return a new unnamed section with the given fields. */
486
487 section *
488 get_unnamed_section (unsigned int flags, void (*callback) (const void *),
489 const void *data)
490 {
491 section *sect;
492
493 sect = ggc_alloc (sizeof (struct unnamed_section));
494 sect->unnamed.common.flags = flags | SECTION_UNNAMED;
495 sect->unnamed.callback = callback;
496 sect->unnamed.data = data;
497 sect->unnamed.next = unnamed_sections;
498
499 unnamed_sections = sect;
500 return sect;
501 }
502
503 /* Return a SECTION_NOSWITCH section with the given fields. */
504
505 static section *
506 get_noswitch_section (unsigned int flags, noswitch_section_callback callback)
507 {
508 section *sect;
509
510 sect = ggc_alloc (sizeof (struct unnamed_section));
511 sect->noswitch.common.flags = flags | SECTION_NOSWITCH;
512 sect->noswitch.callback = callback;
513
514 return sect;
515 }
516
517 /* Return the named section structure associated with NAME. Create
518 a new section with the given fields if no such structure exists. */
519
520 section *
521 get_section (const char *name, unsigned int flags, tree decl)
522 {
523 section *sect, **slot;
524
525 slot = (section **)
526 htab_find_slot_with_hash (section_htab, name,
527 htab_hash_string (name), INSERT);
528 flags |= SECTION_NAMED;
529 if (*slot == NULL)
530 {
531 sect = ggc_alloc (sizeof (struct named_section));
532 sect->named.common.flags = flags;
533 sect->named.name = ggc_strdup (name);
534 sect->named.decl = decl;
535 *slot = sect;
536 }
537 else
538 {
539 sect = *slot;
540 if ((sect->common.flags & ~SECTION_DECLARED) != flags
541 && ((sect->common.flags | flags) & SECTION_OVERRIDE) == 0)
542 {
543 /* Sanity check user variables for flag changes. */
544 if (decl == 0)
545 decl = sect->named.decl;
546 gcc_assert (decl);
547 error ("%+D causes a section type conflict", decl);
548 }
549 }
550 return sect;
551 }
552
553 /* Return true if the current compilation mode benefits from having
554 objects grouped into blocks. */
555
556 static bool
557 use_object_blocks_p (void)
558 {
559 return flag_section_anchors;
560 }
561
562 /* Return the object_block structure for section SECT. Create a new
563 structure if we haven't created one already. Return null if SECT
564 itself is null. */
565
566 static struct object_block *
567 get_block_for_section (section *sect)
568 {
569 struct object_block *block;
570 void **slot;
571
572 if (sect == NULL)
573 return NULL;
574
575 slot = htab_find_slot_with_hash (object_block_htab, sect,
576 hash_section (sect), INSERT);
577 block = (struct object_block *) *slot;
578 if (block == NULL)
579 {
580 block = (struct object_block *)
581 ggc_alloc_cleared (sizeof (struct object_block));
582 block->sect = sect;
583 *slot = block;
584 }
585 return block;
586 }
587
588 /* Create a symbol with label LABEL and place it at byte offset
589 OFFSET in BLOCK. OFFSET can be negative if the symbol's offset
590 is not yet known. LABEL must be a garbage-collected string. */
591
592 static rtx
593 create_block_symbol (const char *label, struct object_block *block,
594 HOST_WIDE_INT offset)
595 {
596 rtx symbol;
597 unsigned int size;
598
599 /* Create the extended SYMBOL_REF. */
600 size = RTX_HDR_SIZE + sizeof (struct block_symbol);
601 symbol = ggc_alloc_zone (size, &rtl_zone);
602
603 /* Initialize the normal SYMBOL_REF fields. */
604 memset (symbol, 0, size);
605 PUT_CODE (symbol, SYMBOL_REF);
606 PUT_MODE (symbol, Pmode);
607 XSTR (symbol, 0) = label;
608 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_HAS_BLOCK_INFO;
609
610 /* Initialize the block_symbol stuff. */
611 SYMBOL_REF_BLOCK (symbol) = block;
612 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
613
614 return symbol;
615 }
616
617 static void
618 initialize_cold_section_name (void)
619 {
620 const char *stripped_name;
621 char *name, *buffer;
622 tree dsn;
623
624 gcc_assert (cfun && current_function_decl);
625 if (cfun->unlikely_text_section_name)
626 return;
627
628 dsn = DECL_SECTION_NAME (current_function_decl);
629 if (flag_function_sections && dsn)
630 {
631 name = alloca (TREE_STRING_LENGTH (dsn) + 1);
632 memcpy (name, TREE_STRING_POINTER (dsn), TREE_STRING_LENGTH (dsn) + 1);
633
634 stripped_name = targetm.strip_name_encoding (name);
635
636 buffer = ACONCAT ((stripped_name, "_unlikely", NULL));
637 cfun->unlikely_text_section_name = ggc_strdup (buffer);
638 }
639 else
640 cfun->unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
641 }
642
643 /* Tell assembler to switch to unlikely-to-be-executed text section. */
644
645 section *
646 unlikely_text_section (void)
647 {
648 if (cfun)
649 {
650 if (!cfun->unlikely_text_section_name)
651 initialize_cold_section_name ();
652
653 return get_named_section (NULL, cfun->unlikely_text_section_name, 0);
654 }
655 else
656 return get_named_section (NULL, UNLIKELY_EXECUTED_TEXT_SECTION_NAME, 0);
657 }
658
659 /* When called within a function context, return true if the function
660 has been assigned a cold text section and if SECT is that section.
661 When called outside a function context, return true if SECT is the
662 default cold section. */
663
664 bool
665 unlikely_text_section_p (section *sect)
666 {
667 const char *name;
668
669 if (cfun)
670 name = cfun->unlikely_text_section_name;
671 else
672 name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
673
674 return (name
675 && sect
676 && SECTION_STYLE (sect) == SECTION_NAMED
677 && strcmp (name, sect->named.name) == 0);
678 }
679
680 /* Return a section with a particular name and with whatever SECTION_*
681 flags section_type_flags deems appropriate. The name of the section
682 is taken from NAME if nonnull, otherwise it is taken from DECL's
683 DECL_SECTION_NAME. DECL is the decl associated with the section
684 (see the section comment for details) and RELOC is as for
685 section_type_flags. */
686
687 section *
688 get_named_section (tree decl, const char *name, int reloc)
689 {
690 unsigned int flags;
691
692 gcc_assert (!decl || DECL_P (decl));
693 if (name == NULL)
694 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
695
696 flags = targetm.section_type_flags (decl, name, reloc);
697
698 return get_section (name, flags, decl);
699 }
700
701 /* If required, set DECL_SECTION_NAME to a unique name. */
702
703 void
704 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
705 int flag_function_or_data_sections)
706 {
707 if (DECL_SECTION_NAME (decl) == NULL_TREE
708 && targetm.have_named_sections
709 && (flag_function_or_data_sections
710 || DECL_ONE_ONLY (decl)))
711 targetm.asm_out.unique_section (decl, reloc);
712 }
713
714 #ifdef BSS_SECTION_ASM_OP
715
716 #ifdef ASM_OUTPUT_BSS
717
718 /* Utility function for ASM_OUTPUT_BSS for targets to use if
719 they don't support alignments in .bss.
720 ??? It is believed that this function will work in most cases so such
721 support is localized here. */
722
723 static void
724 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
725 const char *name,
726 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
727 unsigned HOST_WIDE_INT rounded)
728 {
729 gcc_assert (strcmp (XSTR (XEXP (DECL_RTL (decl), 0), 0), name) == 0);
730 targetm.asm_out.globalize_decl_name (file, decl);
731 switch_to_section (bss_section);
732 #ifdef ASM_DECLARE_OBJECT_NAME
733 last_assemble_variable_decl = decl;
734 ASM_DECLARE_OBJECT_NAME (file, name, decl);
735 #else
736 /* Standard thing is just output label for the object. */
737 ASM_OUTPUT_LABEL (file, name);
738 #endif /* ASM_DECLARE_OBJECT_NAME */
739 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
740 }
741
742 #endif
743
744 #ifdef ASM_OUTPUT_ALIGNED_BSS
745
746 /* Utility function for targets to use in implementing
747 ASM_OUTPUT_ALIGNED_BSS.
748 ??? It is believed that this function will work in most cases so such
749 support is localized here. */
750
751 static void
752 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
753 const char *name, unsigned HOST_WIDE_INT size,
754 int align)
755 {
756 switch_to_section (bss_section);
757 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
758 #ifdef ASM_DECLARE_OBJECT_NAME
759 last_assemble_variable_decl = decl;
760 ASM_DECLARE_OBJECT_NAME (file, name, decl);
761 #else
762 /* Standard thing is just output label for the object. */
763 ASM_OUTPUT_LABEL (file, name);
764 #endif /* ASM_DECLARE_OBJECT_NAME */
765 ASM_OUTPUT_SKIP (file, size ? size : 1);
766 }
767
768 #endif
769
770 #endif /* BSS_SECTION_ASM_OP */
771
772 #ifndef USE_SELECT_SECTION_FOR_FUNCTIONS
773 /* Return the hot section for function DECL. Return text_section for
774 null DECLs. */
775
776 static section *
777 hot_function_section (tree decl)
778 {
779 if (decl != NULL_TREE
780 && DECL_SECTION_NAME (decl) != NULL_TREE
781 && targetm.have_named_sections)
782 return get_named_section (decl, NULL, 0);
783 else
784 return text_section;
785 }
786 #endif
787
788 /* Return the section for function DECL.
789
790 If DECL is NULL_TREE, return the text section. We can be passed
791 NULL_TREE under some circumstances by dbxout.c at least. */
792
793 section *
794 function_section (tree decl)
795 {
796 int reloc = 0;
797
798 if (first_function_block_is_cold)
799 reloc = 1;
800
801 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
802 if (decl != NULL_TREE
803 && DECL_SECTION_NAME (decl) != NULL_TREE)
804 return reloc ? unlikely_text_section ()
805 : get_named_section (decl, NULL, 0);
806 else
807 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
808 #else
809 return reloc ? unlikely_text_section () : hot_function_section (decl);
810 #endif
811 }
812
813 section *
814 current_function_section (void)
815 {
816 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
817 if (current_function_decl != NULL_TREE
818 && DECL_SECTION_NAME (current_function_decl) != NULL_TREE)
819 return in_cold_section_p ? unlikely_text_section ()
820 : get_named_section (current_function_decl,
821 NULL, 0);
822 else
823 return targetm.asm_out.select_section (current_function_decl,
824 in_cold_section_p,
825 DECL_ALIGN (current_function_decl));
826 #else
827 return (in_cold_section_p
828 ? unlikely_text_section ()
829 : hot_function_section (current_function_decl));
830 #endif
831 }
832
833 /* Return the read-only data section associated with function DECL. */
834
835 section *
836 default_function_rodata_section (tree decl)
837 {
838 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
839 {
840 const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
841
842 if (DECL_ONE_ONLY (decl) && HAVE_COMDAT_GROUP)
843 {
844 size_t len = strlen (name) + 3;
845 char* rname = alloca (len);
846
847 strcpy (rname, ".rodata");
848 strcat (rname, name + 5);
849 return get_section (rname, SECTION_LINKONCE, decl);
850 }
851 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
852 else if (DECL_ONE_ONLY (decl)
853 && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
854 {
855 size_t len = strlen (name) + 1;
856 char *rname = alloca (len);
857
858 memcpy (rname, name, len);
859 rname[14] = 'r';
860 return get_section (rname, SECTION_LINKONCE, decl);
861 }
862 /* For .text.foo we want to use .rodata.foo. */
863 else if (flag_function_sections && flag_data_sections
864 && strncmp (name, ".text.", 6) == 0)
865 {
866 size_t len = strlen (name) + 1;
867 char *rname = alloca (len + 2);
868
869 memcpy (rname, ".rodata", 7);
870 memcpy (rname + 7, name + 5, len - 5);
871 return get_section (rname, 0, decl);
872 }
873 }
874
875 return readonly_data_section;
876 }
877
878 /* Return the read-only data section associated with function DECL
879 for targets where that section should be always the single
880 readonly data section. */
881
882 section *
883 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
884 {
885 return readonly_data_section;
886 }
887
888 /* Return the section to use for string merging. */
889
890 static section *
891 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
892 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
893 unsigned int flags ATTRIBUTE_UNUSED)
894 {
895 HOST_WIDE_INT len;
896
897 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
898 && TREE_CODE (decl) == STRING_CST
899 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
900 && align <= 256
901 && (len = int_size_in_bytes (TREE_TYPE (decl))) > 0
902 && TREE_STRING_LENGTH (decl) >= len)
903 {
904 enum machine_mode mode;
905 unsigned int modesize;
906 const char *str;
907 HOST_WIDE_INT i;
908 int j, unit;
909 char name[30];
910
911 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
912 modesize = GET_MODE_BITSIZE (mode);
913 if (modesize >= 8 && modesize <= 256
914 && (modesize & (modesize - 1)) == 0)
915 {
916 if (align < modesize)
917 align = modesize;
918
919 str = TREE_STRING_POINTER (decl);
920 unit = GET_MODE_SIZE (mode);
921
922 /* Check for embedded NUL characters. */
923 for (i = 0; i < len; i += unit)
924 {
925 for (j = 0; j < unit; j++)
926 if (str[i + j] != '\0')
927 break;
928 if (j == unit)
929 break;
930 }
931 if (i == len - unit)
932 {
933 sprintf (name, ".rodata.str%d.%d", modesize / 8,
934 (int) (align / 8));
935 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
936 return get_section (name, flags, NULL);
937 }
938 }
939 }
940
941 return readonly_data_section;
942 }
943
944 /* Return the section to use for constant merging. */
945
946 section *
947 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
948 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
949 unsigned int flags ATTRIBUTE_UNUSED)
950 {
951 unsigned int modesize = GET_MODE_BITSIZE (mode);
952
953 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
954 && mode != VOIDmode
955 && mode != BLKmode
956 && modesize <= align
957 && align >= 8
958 && align <= 256
959 && (align & (align - 1)) == 0)
960 {
961 char name[24];
962
963 sprintf (name, ".rodata.cst%d", (int) (align / 8));
964 flags |= (align / 8) | SECTION_MERGE;
965 return get_section (name, flags, NULL);
966 }
967 return readonly_data_section;
968 }
969 \f
970 /* Given NAME, a putative register name, discard any customary prefixes. */
971
972 static const char *
973 strip_reg_name (const char *name)
974 {
975 #ifdef REGISTER_PREFIX
976 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
977 name += strlen (REGISTER_PREFIX);
978 #endif
979 if (name[0] == '%' || name[0] == '#')
980 name++;
981 return name;
982 }
983 \f
984 /* The user has asked for a DECL to have a particular name. Set (or
985 change) it in such a way that we don't prefix an underscore to
986 it. */
987 void
988 set_user_assembler_name (tree decl, const char *name)
989 {
990 char *starred = alloca (strlen (name) + 2);
991 starred[0] = '*';
992 strcpy (starred + 1, name);
993 change_decl_assembler_name (decl, get_identifier (starred));
994 SET_DECL_RTL (decl, NULL_RTX);
995 }
996 \f
997 /* Decode an `asm' spec for a declaration as a register name.
998 Return the register number, or -1 if nothing specified,
999 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
1000 or -3 if ASMSPEC is `cc' and is not recognized,
1001 or -4 if ASMSPEC is `memory' and is not recognized.
1002 Accept an exact spelling or a decimal number.
1003 Prefixes such as % are optional. */
1004
1005 int
1006 decode_reg_name (const char *asmspec)
1007 {
1008 if (asmspec != 0)
1009 {
1010 int i;
1011
1012 /* Get rid of confusing prefixes. */
1013 asmspec = strip_reg_name (asmspec);
1014
1015 /* Allow a decimal number as a "register name". */
1016 for (i = strlen (asmspec) - 1; i >= 0; i--)
1017 if (! ISDIGIT (asmspec[i]))
1018 break;
1019 if (asmspec[0] != 0 && i < 0)
1020 {
1021 i = atoi (asmspec);
1022 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
1023 return i;
1024 else
1025 return -2;
1026 }
1027
1028 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1029 if (reg_names[i][0]
1030 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
1031 return i;
1032
1033 #ifdef ADDITIONAL_REGISTER_NAMES
1034 {
1035 static const struct { const char *const name; const int number; } table[]
1036 = ADDITIONAL_REGISTER_NAMES;
1037
1038 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
1039 if (table[i].name[0]
1040 && ! strcmp (asmspec, table[i].name))
1041 return table[i].number;
1042 }
1043 #endif /* ADDITIONAL_REGISTER_NAMES */
1044
1045 if (!strcmp (asmspec, "memory"))
1046 return -4;
1047
1048 if (!strcmp (asmspec, "cc"))
1049 return -3;
1050
1051 return -2;
1052 }
1053
1054 return -1;
1055 }
1056 \f
1057 /* Return true if DECL's initializer is suitable for a BSS section. */
1058
1059 static bool
1060 bss_initializer_p (tree decl)
1061 {
1062 return (DECL_INITIAL (decl) == NULL
1063 || DECL_INITIAL (decl) == error_mark_node
1064 || (flag_zero_initialized_in_bss
1065 /* Leave constant zeroes in .rodata so they
1066 can be shared. */
1067 && !TREE_READONLY (decl)
1068 && initializer_zerop (DECL_INITIAL (decl))));
1069 }
1070
1071 /* Compute the alignment of variable specified by DECL.
1072 DONT_OUTPUT_DATA is from assemble_variable. */
1073
1074 void
1075 align_variable (tree decl, bool dont_output_data)
1076 {
1077 unsigned int align = DECL_ALIGN (decl);
1078
1079 /* In the case for initialing an array whose length isn't specified,
1080 where we have not yet been able to do the layout,
1081 figure out the proper alignment now. */
1082 if (dont_output_data && DECL_SIZE (decl) == 0
1083 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1084 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1085
1086 /* Some object file formats have a maximum alignment which they support.
1087 In particular, a.out format supports a maximum alignment of 4. */
1088 if (align > MAX_OFILE_ALIGNMENT)
1089 {
1090 warning (0, "alignment of %q+D is greater than maximum object "
1091 "file alignment. Using %d", decl,
1092 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
1093 align = MAX_OFILE_ALIGNMENT;
1094 }
1095
1096 /* On some machines, it is good to increase alignment sometimes. */
1097 if (! DECL_USER_ALIGN (decl))
1098 {
1099 #ifdef DATA_ALIGNMENT
1100 align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1101 #endif
1102 #ifdef CONSTANT_ALIGNMENT
1103 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
1104 align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl), align);
1105 #endif
1106 }
1107
1108 /* Reset the alignment in case we have made it tighter, so we can benefit
1109 from it in get_pointer_alignment. */
1110 DECL_ALIGN (decl) = align;
1111 }
1112
1113 /* Return the section into which the given VAR_DECL or CONST_DECL
1114 should be placed. PREFER_NOSWITCH_P is true if a noswitch
1115 section should be used wherever possible. */
1116
1117 static section *
1118 get_variable_section (tree decl, bool prefer_noswitch_p)
1119 {
1120 int reloc;
1121
1122 /* If the decl has been given an explicit section name, then it
1123 isn't common, and shouldn't be handled as such. */
1124 if (DECL_COMMON (decl) && DECL_SECTION_NAME (decl) == NULL)
1125 {
1126 if (DECL_THREAD_LOCAL_P (decl))
1127 return tls_comm_section;
1128 if (TREE_PUBLIC (decl) && bss_initializer_p (decl))
1129 return comm_section;
1130 }
1131
1132 if (DECL_INITIAL (decl) == error_mark_node)
1133 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
1134 else if (DECL_INITIAL (decl))
1135 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
1136 else
1137 reloc = 0;
1138
1139 resolve_unique_section (decl, reloc, flag_data_sections);
1140 if (IN_NAMED_SECTION (decl))
1141 return get_named_section (decl, NULL, reloc);
1142
1143 if (!DECL_THREAD_LOCAL_P (decl)
1144 && !(prefer_noswitch_p && targetm.have_switchable_bss_sections)
1145 && bss_initializer_p (decl))
1146 {
1147 if (!TREE_PUBLIC (decl))
1148 return lcomm_section;
1149 if (bss_noswitch_section)
1150 return bss_noswitch_section;
1151 }
1152
1153 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
1154 }
1155
1156 /* Return the block into which object_block DECL should be placed. */
1157
1158 static struct object_block *
1159 get_block_for_decl (tree decl)
1160 {
1161 section *sect;
1162
1163 if (TREE_CODE (decl) == VAR_DECL)
1164 {
1165 /* The object must be defined in this translation unit. */
1166 if (DECL_EXTERNAL (decl))
1167 return NULL;
1168
1169 /* There's no point using object blocks for something that is
1170 isolated by definition. */
1171 if (DECL_ONE_ONLY (decl))
1172 return NULL;
1173 }
1174
1175 /* We can only calculate block offsets if the decl has a known
1176 constant size. */
1177 if (DECL_SIZE_UNIT (decl) == NULL)
1178 return NULL;
1179 if (!host_integerp (DECL_SIZE_UNIT (decl), 1))
1180 return NULL;
1181
1182 /* Find out which section should contain DECL. We cannot put it into
1183 an object block if it requires a standalone definition. */
1184 if (TREE_CODE (decl) == VAR_DECL)
1185 align_variable (decl, 0);
1186 sect = get_variable_section (decl, true);
1187 if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
1188 return NULL;
1189
1190 return get_block_for_section (sect);
1191 }
1192
1193 /* Make sure block symbol SYMBOL is in block BLOCK. */
1194
1195 static void
1196 change_symbol_block (rtx symbol, struct object_block *block)
1197 {
1198 if (block != SYMBOL_REF_BLOCK (symbol))
1199 {
1200 gcc_assert (SYMBOL_REF_BLOCK_OFFSET (symbol) < 0);
1201 SYMBOL_REF_BLOCK (symbol) = block;
1202 }
1203 }
1204
1205 /* Return true if it is possible to put DECL in an object_block. */
1206
1207 static bool
1208 use_blocks_for_decl_p (tree decl)
1209 {
1210 /* Only data DECLs can be placed into object blocks. */
1211 if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != CONST_DECL)
1212 return false;
1213
1214 /* Detect decls created by dw2_force_const_mem. Such decls are
1215 special because DECL_INITIAL doesn't specify the decl's true value.
1216 dw2_output_indirect_constants will instead call assemble_variable
1217 with dont_output_data set to 1 and then print the contents itself. */
1218 if (DECL_INITIAL (decl) == decl)
1219 return false;
1220
1221 /* If this decl is an alias, then we don't want to emit a definition. */
1222 if (lookup_attribute ("alias", DECL_ATTRIBUTES (decl)))
1223 return false;
1224
1225 return true;
1226 }
1227
1228 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
1229 have static storage duration. In other words, it should not be an
1230 automatic variable, including PARM_DECLs.
1231
1232 There is, however, one exception: this function handles variables
1233 explicitly placed in a particular register by the user.
1234
1235 This is never called for PARM_DECL nodes. */
1236
1237 void
1238 make_decl_rtl (tree decl)
1239 {
1240 const char *name = 0;
1241 int reg_number;
1242 rtx x;
1243
1244 /* Check that we are not being given an automatic variable. */
1245 gcc_assert (TREE_CODE (decl) != PARM_DECL
1246 && TREE_CODE (decl) != RESULT_DECL);
1247
1248 /* A weak alias has TREE_PUBLIC set but not the other bits. */
1249 gcc_assert (TREE_CODE (decl) != VAR_DECL
1250 || TREE_STATIC (decl)
1251 || TREE_PUBLIC (decl)
1252 || DECL_EXTERNAL (decl)
1253 || DECL_REGISTER (decl));
1254
1255 /* And that we were not given a type or a label. */
1256 gcc_assert (TREE_CODE (decl) != TYPE_DECL
1257 && TREE_CODE (decl) != LABEL_DECL);
1258
1259 /* For a duplicate declaration, we can be called twice on the
1260 same DECL node. Don't discard the RTL already made. */
1261 if (DECL_RTL_SET_P (decl))
1262 {
1263 /* If the old RTL had the wrong mode, fix the mode. */
1264 x = DECL_RTL (decl);
1265 if (GET_MODE (x) != DECL_MODE (decl))
1266 SET_DECL_RTL (decl, adjust_address_nv (x, DECL_MODE (decl), 0));
1267
1268 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1269 return;
1270
1271 /* ??? Another way to do this would be to maintain a hashed
1272 table of such critters. Instead of adding stuff to a DECL
1273 to give certain attributes to it, we could use an external
1274 hash map from DECL to set of attributes. */
1275
1276 /* Let the target reassign the RTL if it wants.
1277 This is necessary, for example, when one machine specific
1278 decl attribute overrides another. */
1279 targetm.encode_section_info (decl, DECL_RTL (decl), false);
1280
1281 /* If the symbol has a SYMBOL_REF_BLOCK field, update it based
1282 on the new decl information. */
1283 if (MEM_P (x)
1284 && GET_CODE (XEXP (x, 0)) == SYMBOL_REF
1285 && SYMBOL_REF_HAS_BLOCK_INFO_P (XEXP (x, 0)))
1286 change_symbol_block (XEXP (x, 0), get_block_for_decl (decl));
1287
1288 /* Make this function static known to the mudflap runtime. */
1289 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1290 mudflap_enqueue_decl (decl);
1291
1292 return;
1293 }
1294
1295 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1296
1297 if (name[0] != '*' && TREE_CODE (decl) != FUNCTION_DECL
1298 && DECL_REGISTER (decl))
1299 {
1300 error ("register name not specified for %q+D", decl);
1301 }
1302 else if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1303 {
1304 const char *asmspec = name+1;
1305 reg_number = decode_reg_name (asmspec);
1306 /* First detect errors in declaring global registers. */
1307 if (reg_number == -1)
1308 error ("register name not specified for %q+D", decl);
1309 else if (reg_number < 0)
1310 error ("invalid register name for %q+D", decl);
1311 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
1312 error ("data type of %q+D isn%'t suitable for a register",
1313 decl);
1314 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
1315 error ("register specified for %q+D isn%'t suitable for data type",
1316 decl);
1317 /* Now handle properly declared static register variables. */
1318 else
1319 {
1320 int nregs;
1321
1322 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
1323 {
1324 DECL_INITIAL (decl) = 0;
1325 error ("global register variable has initial value");
1326 }
1327 if (TREE_THIS_VOLATILE (decl))
1328 warning (OPT_Wvolatile_register_var,
1329 "optimization may eliminate reads and/or "
1330 "writes to register variables");
1331
1332 /* If the user specified one of the eliminables registers here,
1333 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
1334 confused with that register and be eliminated. This usage is
1335 somewhat suspect... */
1336
1337 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
1338 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
1339 REG_USERVAR_P (DECL_RTL (decl)) = 1;
1340
1341 if (TREE_STATIC (decl))
1342 {
1343 /* Make this register global, so not usable for anything
1344 else. */
1345 #ifdef ASM_DECLARE_REGISTER_GLOBAL
1346 name = IDENTIFIER_POINTER (DECL_NAME (decl));
1347 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
1348 #endif
1349 nregs = hard_regno_nregs[reg_number][DECL_MODE (decl)];
1350 while (nregs > 0)
1351 globalize_reg (reg_number + --nregs);
1352 }
1353
1354 /* As a register variable, it has no section. */
1355 return;
1356 }
1357 }
1358 /* Now handle ordinary static variables and functions (in memory).
1359 Also handle vars declared register invalidly. */
1360 else if (name[0] == '*')
1361 {
1362 #ifdef REGISTER_PREFIX
1363 if (strlen (REGISTER_PREFIX) != 0)
1364 {
1365 reg_number = decode_reg_name (name);
1366 if (reg_number >= 0 || reg_number == -3)
1367 error ("register name given for non-register variable %q+D", decl);
1368 }
1369 #endif
1370 }
1371
1372 /* Specifying a section attribute on a variable forces it into a
1373 non-.bss section, and thus it cannot be common. */
1374 if (TREE_CODE (decl) == VAR_DECL
1375 && DECL_SECTION_NAME (decl) != NULL_TREE
1376 && DECL_INITIAL (decl) == NULL_TREE
1377 && DECL_COMMON (decl))
1378 DECL_COMMON (decl) = 0;
1379
1380 /* Variables can't be both common and weak. */
1381 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
1382 DECL_COMMON (decl) = 0;
1383
1384 if (use_object_blocks_p () && use_blocks_for_decl_p (decl))
1385 x = create_block_symbol (name, get_block_for_decl (decl), -1);
1386 else
1387 x = gen_rtx_SYMBOL_REF (Pmode, name);
1388 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
1389 SET_SYMBOL_REF_DECL (x, decl);
1390
1391 x = gen_rtx_MEM (DECL_MODE (decl), x);
1392 if (TREE_CODE (decl) != FUNCTION_DECL)
1393 set_mem_attributes (x, decl, 1);
1394 SET_DECL_RTL (decl, x);
1395
1396 /* Optionally set flags or add text to the name to record information
1397 such as that it is a function name.
1398 If the name is changed, the macro ASM_OUTPUT_LABELREF
1399 will have to know how to strip this information. */
1400 targetm.encode_section_info (decl, DECL_RTL (decl), true);
1401
1402 /* Make this function static known to the mudflap runtime. */
1403 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1404 mudflap_enqueue_decl (decl);
1405 }
1406 \f
1407 /* Output a string of literal assembler code
1408 for an `asm' keyword used between functions. */
1409
1410 void
1411 assemble_asm (tree string)
1412 {
1413 app_enable ();
1414
1415 if (TREE_CODE (string) == ADDR_EXPR)
1416 string = TREE_OPERAND (string, 0);
1417
1418 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
1419 }
1420
1421 /* Record an element in the table of global destructors. SYMBOL is
1422 a SYMBOL_REF of the function to be called; PRIORITY is a number
1423 between 0 and MAX_INIT_PRIORITY. */
1424
1425 void
1426 default_stabs_asm_out_destructor (rtx symbol ATTRIBUTE_UNUSED,
1427 int priority ATTRIBUTE_UNUSED)
1428 {
1429 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1430 /* Tell GNU LD that this is part of the static destructor set.
1431 This will work for any system that uses stabs, most usefully
1432 aout systems. */
1433 dbxout_begin_simple_stabs ("___DTOR_LIST__", 22 /* N_SETT */);
1434 dbxout_stab_value_label (XSTR (symbol, 0));
1435 #else
1436 sorry ("global destructors not supported on this target");
1437 #endif
1438 }
1439
1440 /* Write the address of the entity given by SYMBOL to SEC. */
1441 void
1442 assemble_addr_to_section (rtx symbol, section *sec)
1443 {
1444 switch_to_section (sec);
1445 assemble_align (POINTER_SIZE);
1446 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1447 }
1448
1449 /* Return the numbered .ctors.N (if CONSTRUCTOR_P) or .dtors.N (if
1450 not) section for PRIORITY. */
1451 section *
1452 get_cdtor_priority_section (int priority, bool constructor_p)
1453 {
1454 char buf[16];
1455
1456 /* ??? This only works reliably with the GNU linker. */
1457 sprintf (buf, "%s.%.5u",
1458 constructor_p ? ".ctors" : ".dtors",
1459 /* Invert the numbering so the linker puts us in the proper
1460 order; constructors are run from right to left, and the
1461 linker sorts in increasing order. */
1462 MAX_INIT_PRIORITY - priority);
1463 return get_section (buf, SECTION_WRITE, NULL);
1464 }
1465
1466 void
1467 default_named_section_asm_out_destructor (rtx symbol, int priority)
1468 {
1469 section *sec;
1470
1471 if (priority != DEFAULT_INIT_PRIORITY)
1472 sec = get_cdtor_priority_section (priority,
1473 /*constructor_p=*/false);
1474 else
1475 sec = get_section (".dtors", SECTION_WRITE, NULL);
1476
1477 assemble_addr_to_section (symbol, sec);
1478 }
1479
1480 #ifdef DTORS_SECTION_ASM_OP
1481 void
1482 default_dtor_section_asm_out_destructor (rtx symbol,
1483 int priority ATTRIBUTE_UNUSED)
1484 {
1485 assemble_addr_to_section (symbol, dtors_section);
1486 }
1487 #endif
1488
1489 /* Likewise for global constructors. */
1490
1491 void
1492 default_stabs_asm_out_constructor (rtx symbol ATTRIBUTE_UNUSED,
1493 int priority ATTRIBUTE_UNUSED)
1494 {
1495 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1496 /* Tell GNU LD that this is part of the static destructor set.
1497 This will work for any system that uses stabs, most usefully
1498 aout systems. */
1499 dbxout_begin_simple_stabs ("___CTOR_LIST__", 22 /* N_SETT */);
1500 dbxout_stab_value_label (XSTR (symbol, 0));
1501 #else
1502 sorry ("global constructors not supported on this target");
1503 #endif
1504 }
1505
1506 void
1507 default_named_section_asm_out_constructor (rtx symbol, int priority)
1508 {
1509 section *sec;
1510
1511 if (priority != DEFAULT_INIT_PRIORITY)
1512 sec = get_cdtor_priority_section (priority,
1513 /*constructor_p=*/true);
1514 else
1515 sec = get_section (".ctors", SECTION_WRITE, NULL);
1516
1517 assemble_addr_to_section (symbol, sec);
1518 }
1519
1520 #ifdef CTORS_SECTION_ASM_OP
1521 void
1522 default_ctor_section_asm_out_constructor (rtx symbol,
1523 int priority ATTRIBUTE_UNUSED)
1524 {
1525 assemble_addr_to_section (symbol, ctors_section);
1526 }
1527 #endif
1528 \f
1529 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1530 a nonzero value if the constant pool should be output before the
1531 start of the function, or a zero value if the pool should output
1532 after the end of the function. The default is to put it before the
1533 start. */
1534
1535 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1536 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1537 #endif
1538
1539 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1540 to be output to assembler.
1541 Set first_global_object_name and weak_global_object_name as appropriate. */
1542
1543 void
1544 notice_global_symbol (tree decl)
1545 {
1546 const char **type = &first_global_object_name;
1547
1548 if (first_global_object_name
1549 || !TREE_PUBLIC (decl)
1550 || DECL_EXTERNAL (decl)
1551 || !DECL_NAME (decl)
1552 || (TREE_CODE (decl) != FUNCTION_DECL
1553 && (TREE_CODE (decl) != VAR_DECL
1554 || (DECL_COMMON (decl)
1555 && (DECL_INITIAL (decl) == 0
1556 || DECL_INITIAL (decl) == error_mark_node))))
1557 || !MEM_P (DECL_RTL (decl)))
1558 return;
1559
1560 /* We win when global object is found, but it is useful to know about weak
1561 symbol as well so we can produce nicer unique names. */
1562 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl) || flag_shlib)
1563 type = &weak_global_object_name;
1564
1565 if (!*type)
1566 {
1567 const char *p;
1568 const char *name;
1569 rtx decl_rtl = DECL_RTL (decl);
1570
1571 p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0));
1572 name = ggc_strdup (p);
1573
1574 *type = name;
1575 }
1576 }
1577
1578 /* Output assembler code for the constant pool of a function and associated
1579 with defining the name of the function. DECL describes the function.
1580 NAME is the function's name. For the constant pool, we use the current
1581 constant pool data. */
1582
1583 void
1584 assemble_start_function (tree decl, const char *fnname)
1585 {
1586 int align;
1587 char tmp_label[100];
1588 bool hot_label_written = false;
1589
1590 cfun->unlikely_text_section_name = NULL;
1591
1592 first_function_block_is_cold = false;
1593 if (flag_reorder_blocks_and_partition)
1594 {
1595 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTB", const_labelno);
1596 cfun->hot_section_label = ggc_strdup (tmp_label);
1597 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDB", const_labelno);
1598 cfun->cold_section_label = ggc_strdup (tmp_label);
1599 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTE", const_labelno);
1600 cfun->hot_section_end_label = ggc_strdup (tmp_label);
1601 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDE", const_labelno);
1602 cfun->cold_section_end_label = ggc_strdup (tmp_label);
1603 const_labelno++;
1604 }
1605 else
1606 {
1607 cfun->hot_section_label = NULL;
1608 cfun->cold_section_label = NULL;
1609 cfun->hot_section_end_label = NULL;
1610 cfun->cold_section_end_label = NULL;
1611 }
1612
1613 /* The following code does not need preprocessing in the assembler. */
1614
1615 app_disable ();
1616
1617 if (CONSTANT_POOL_BEFORE_FUNCTION)
1618 output_constant_pool (fnname, decl);
1619
1620 resolve_unique_section (decl, 0, flag_function_sections);
1621
1622 /* Make sure the not and cold text (code) sections are properly
1623 aligned. This is necessary here in the case where the function
1624 has both hot and cold sections, because we don't want to re-set
1625 the alignment when the section switch happens mid-function. */
1626
1627 if (flag_reorder_blocks_and_partition)
1628 {
1629 switch_to_section (unlikely_text_section ());
1630 assemble_align (FUNCTION_BOUNDARY);
1631 ASM_OUTPUT_LABEL (asm_out_file, cfun->cold_section_label);
1632
1633 /* When the function starts with a cold section, we need to explicitly
1634 align the hot section and write out the hot section label.
1635 But if the current function is a thunk, we do not have a CFG. */
1636 if (!current_function_is_thunk
1637 && BB_PARTITION (ENTRY_BLOCK_PTR->next_bb) == BB_COLD_PARTITION)
1638 {
1639 switch_to_section (text_section);
1640 assemble_align (FUNCTION_BOUNDARY);
1641 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_label);
1642 hot_label_written = true;
1643 first_function_block_is_cold = true;
1644 }
1645 }
1646 else if (DECL_SECTION_NAME (decl))
1647 {
1648 /* Calls to function_section rely on first_function_block_is_cold
1649 being accurate. The first block may be cold even if we aren't
1650 doing partitioning, if the entire function was decided by
1651 choose_function_section (predict.c) to be cold. */
1652
1653 initialize_cold_section_name ();
1654
1655 if (cfun->unlikely_text_section_name
1656 && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
1657 cfun->unlikely_text_section_name) == 0)
1658 first_function_block_is_cold = true;
1659 }
1660
1661 in_cold_section_p = first_function_block_is_cold;
1662
1663 /* Switch to the correct text section for the start of the function. */
1664
1665 switch_to_section (function_section (decl));
1666 if (flag_reorder_blocks_and_partition
1667 && !hot_label_written)
1668 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_label);
1669
1670 /* Tell assembler to move to target machine's alignment for functions. */
1671 align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
1672 if (align < force_align_functions_log)
1673 align = force_align_functions_log;
1674 if (align > 0)
1675 {
1676 ASM_OUTPUT_ALIGN (asm_out_file, align);
1677 }
1678
1679 /* Handle a user-specified function alignment.
1680 Note that we still need to align to FUNCTION_BOUNDARY, as above,
1681 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1682 if (align_functions_log > align
1683 && cfun->function_frequency != FUNCTION_FREQUENCY_UNLIKELY_EXECUTED)
1684 {
1685 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1686 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1687 align_functions_log, align_functions - 1);
1688 #else
1689 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1690 #endif
1691 }
1692
1693 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1694 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1695 #endif
1696
1697 (*debug_hooks->begin_function) (decl);
1698
1699 /* Make function name accessible from other files, if appropriate. */
1700
1701 if (TREE_PUBLIC (decl))
1702 {
1703 notice_global_symbol (decl);
1704
1705 globalize_decl (decl);
1706
1707 maybe_assemble_visibility (decl);
1708 }
1709
1710 if (DECL_PRESERVE_P (decl))
1711 targetm.asm_out.mark_decl_preserved (fnname);
1712
1713 /* Do any machine/system dependent processing of the function name. */
1714 #ifdef ASM_DECLARE_FUNCTION_NAME
1715 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1716 #else
1717 /* Standard thing is just output label for the function. */
1718 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1719 #endif /* ASM_DECLARE_FUNCTION_NAME */
1720 }
1721
1722 /* Output assembler code associated with defining the size of the
1723 function. DECL describes the function. NAME is the function's name. */
1724
1725 void
1726 assemble_end_function (tree decl, const char *fnname ATTRIBUTE_UNUSED)
1727 {
1728 #ifdef ASM_DECLARE_FUNCTION_SIZE
1729 /* We could have switched section in the middle of the function. */
1730 if (flag_reorder_blocks_and_partition)
1731 switch_to_section (function_section (decl));
1732 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1733 #endif
1734 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1735 {
1736 output_constant_pool (fnname, decl);
1737 switch_to_section (function_section (decl)); /* need to switch back */
1738 }
1739 /* Output labels for end of hot/cold text sections (to be used by
1740 debug info.) */
1741 if (flag_reorder_blocks_and_partition)
1742 {
1743 section *save_text_section;
1744
1745 save_text_section = in_section;
1746 switch_to_section (unlikely_text_section ());
1747 ASM_OUTPUT_LABEL (asm_out_file, cfun->cold_section_end_label);
1748 if (first_function_block_is_cold)
1749 switch_to_section (text_section);
1750 else
1751 switch_to_section (function_section (decl));
1752 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_end_label);
1753 switch_to_section (save_text_section);
1754 }
1755 }
1756 \f
1757 /* Assemble code to leave SIZE bytes of zeros. */
1758
1759 void
1760 assemble_zeros (unsigned HOST_WIDE_INT size)
1761 {
1762 /* Do no output if -fsyntax-only. */
1763 if (flag_syntax_only)
1764 return;
1765
1766 #ifdef ASM_NO_SKIP_IN_TEXT
1767 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1768 so we must output 0s explicitly in the text section. */
1769 if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0)
1770 {
1771 unsigned HOST_WIDE_INT i;
1772 for (i = 0; i < size; i++)
1773 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1774 }
1775 else
1776 #endif
1777 if (size > 0)
1778 ASM_OUTPUT_SKIP (asm_out_file, size);
1779 }
1780
1781 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1782
1783 void
1784 assemble_align (int align)
1785 {
1786 if (align > BITS_PER_UNIT)
1787 {
1788 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1789 }
1790 }
1791
1792 /* Assemble a string constant with the specified C string as contents. */
1793
1794 void
1795 assemble_string (const char *p, int size)
1796 {
1797 int pos = 0;
1798 int maximum = 2000;
1799
1800 /* If the string is very long, split it up. */
1801
1802 while (pos < size)
1803 {
1804 int thissize = size - pos;
1805 if (thissize > maximum)
1806 thissize = maximum;
1807
1808 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1809
1810 pos += thissize;
1811 p += thissize;
1812 }
1813 }
1814
1815 \f
1816 /* A noswitch_section_callback for lcomm_section. */
1817
1818 static bool
1819 emit_local (tree decl ATTRIBUTE_UNUSED,
1820 const char *name ATTRIBUTE_UNUSED,
1821 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1822 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1823 {
1824 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1825 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name,
1826 size, DECL_ALIGN (decl));
1827 return true;
1828 #elif defined ASM_OUTPUT_ALIGNED_LOCAL
1829 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl));
1830 return true;
1831 #else
1832 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1833 return false;
1834 #endif
1835 }
1836
1837 /* A noswitch_section_callback for bss_noswitch_section. */
1838
1839 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
1840 static bool
1841 emit_bss (tree decl ATTRIBUTE_UNUSED,
1842 const char *name ATTRIBUTE_UNUSED,
1843 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1844 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1845 {
1846 #if defined ASM_OUTPUT_ALIGNED_BSS
1847 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl));
1848 return true;
1849 #else
1850 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded);
1851 return false;
1852 #endif
1853 }
1854 #endif
1855
1856 /* A noswitch_section_callback for comm_section. */
1857
1858 static bool
1859 emit_common (tree decl ATTRIBUTE_UNUSED,
1860 const char *name ATTRIBUTE_UNUSED,
1861 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1862 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1863 {
1864 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1865 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name,
1866 size, DECL_ALIGN (decl));
1867 return true;
1868 #elif defined ASM_OUTPUT_ALIGNED_COMMON
1869 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl));
1870 return true;
1871 #else
1872 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded);
1873 return false;
1874 #endif
1875 }
1876
1877 /* A noswitch_section_callback for tls_comm_section. */
1878
1879 static bool
1880 emit_tls_common (tree decl ATTRIBUTE_UNUSED,
1881 const char *name ATTRIBUTE_UNUSED,
1882 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1883 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1884 {
1885 #ifdef ASM_OUTPUT_TLS_COMMON
1886 ASM_OUTPUT_TLS_COMMON (asm_out_file, decl, name, size);
1887 return true;
1888 #else
1889 sorry ("thread-local COMMON data not implemented");
1890 return true;
1891 #endif
1892 }
1893
1894 /* Assemble DECL given that it belongs in SECTION_NOSWITCH section SECT.
1895 NAME is the name of DECL's SYMBOL_REF. */
1896
1897 static void
1898 assemble_noswitch_variable (tree decl, const char *name, section *sect)
1899 {
1900 unsigned HOST_WIDE_INT size, rounded;
1901
1902 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1903 rounded = size;
1904
1905 /* Don't allocate zero bytes of common,
1906 since that means "undefined external" in the linker. */
1907 if (size == 0)
1908 rounded = 1;
1909
1910 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1911 so that each uninitialized object starts on such a boundary. */
1912 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1913 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1914 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1915
1916 if (!sect->noswitch.callback (decl, name, size, rounded)
1917 && (unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded)
1918 warning (0, "requested alignment for %q+D is greater than "
1919 "implemented alignment of %wu", decl, rounded);
1920 }
1921
1922 /* A subroutine of assemble_variable. Output the label and contents of
1923 DECL, whose address is a SYMBOL_REF with name NAME. DONT_OUTPUT_DATA
1924 is as for assemble_variable. */
1925
1926 static void
1927 assemble_variable_contents (tree decl, const char *name,
1928 bool dont_output_data)
1929 {
1930 /* Do any machine/system dependent processing of the object. */
1931 #ifdef ASM_DECLARE_OBJECT_NAME
1932 last_assemble_variable_decl = decl;
1933 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1934 #else
1935 /* Standard thing is just output label for the object. */
1936 ASM_OUTPUT_LABEL (asm_out_file, name);
1937 #endif /* ASM_DECLARE_OBJECT_NAME */
1938
1939 if (!dont_output_data)
1940 {
1941 if (DECL_INITIAL (decl)
1942 && DECL_INITIAL (decl) != error_mark_node
1943 && !initializer_zerop (DECL_INITIAL (decl)))
1944 /* Output the actual data. */
1945 output_constant (DECL_INITIAL (decl),
1946 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
1947 DECL_ALIGN (decl));
1948 else
1949 /* Leave space for it. */
1950 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
1951 }
1952 }
1953
1954 /* Assemble everything that is needed for a variable or function declaration.
1955 Not used for automatic variables, and not used for function definitions.
1956 Should not be called for variables of incomplete structure type.
1957
1958 TOP_LEVEL is nonzero if this variable has file scope.
1959 AT_END is nonzero if this is the special handling, at end of compilation,
1960 to define things that have had only tentative definitions.
1961 DONT_OUTPUT_DATA if nonzero means don't actually output the
1962 initial value (that will be done by the caller). */
1963
1964 void
1965 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
1966 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
1967 {
1968 const char *name;
1969 rtx decl_rtl, symbol;
1970 section *sect;
1971
1972 if (! targetm.have_tls
1973 && TREE_CODE (decl) == VAR_DECL
1974 && DECL_THREAD_LOCAL_P (decl))
1975 {
1976 tree to = emutls_decl (decl);
1977
1978 /* If this variable is defined locally, then we need to initialize the
1979 control structure with size and alignment information. We do this
1980 at the last moment because tentative definitions can take a locally
1981 defined but uninitialized variable and initialize it later, which
1982 would result in incorrect contents. */
1983 if (! DECL_EXTERNAL (to)
1984 && (! DECL_COMMON (to)
1985 || (DECL_INITIAL (decl)
1986 && DECL_INITIAL (decl) != error_mark_node)))
1987 {
1988 VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, 4);
1989 constructor_elt *elt;
1990 tree type = TREE_TYPE (to);
1991 tree field = TYPE_FIELDS (type);
1992
1993 elt = VEC_quick_push (constructor_elt, v, NULL);
1994 elt->index = field;
1995 elt->value = fold_convert (TREE_TYPE (field), DECL_SIZE_UNIT (decl));
1996
1997 elt = VEC_quick_push (constructor_elt, v, NULL);
1998 field = TREE_CHAIN (field);
1999 elt->index = field;
2000 elt->value = build_int_cst (TREE_TYPE (field),
2001 DECL_ALIGN_UNIT (decl));
2002
2003 elt = VEC_quick_push (constructor_elt, v, NULL);
2004 field = TREE_CHAIN (field);
2005 elt->index = field;
2006 elt->value = null_pointer_node;
2007
2008 elt = VEC_quick_push (constructor_elt, v, NULL);
2009 field = TREE_CHAIN (field);
2010 elt->index = field;
2011 elt->value = get_emutls_init_templ_addr (decl);
2012
2013 DECL_INITIAL (to) = build_constructor (type, v);
2014
2015 /* Make sure the template is marked as needed early enough.
2016 Without this, if the variable is placed in a
2017 section-anchored block, the template will only be marked
2018 when it's too late. */
2019 record_references_in_initializer (to);
2020 }
2021
2022 decl = to;
2023 }
2024
2025 last_assemble_variable_decl = 0;
2026
2027 /* Normally no need to say anything here for external references,
2028 since assemble_external is called by the language-specific code
2029 when a declaration is first seen. */
2030
2031 if (DECL_EXTERNAL (decl))
2032 return;
2033
2034 /* Output no assembler code for a function declaration.
2035 Only definitions of functions output anything. */
2036
2037 if (TREE_CODE (decl) == FUNCTION_DECL)
2038 return;
2039
2040 /* Do nothing for global register variables. */
2041 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
2042 {
2043 TREE_ASM_WRITTEN (decl) = 1;
2044 return;
2045 }
2046
2047 /* If type was incomplete when the variable was declared,
2048 see if it is complete now. */
2049
2050 if (DECL_SIZE (decl) == 0)
2051 layout_decl (decl, 0);
2052
2053 /* Still incomplete => don't allocate it; treat the tentative defn
2054 (which is what it must have been) as an `extern' reference. */
2055
2056 if (!dont_output_data && DECL_SIZE (decl) == 0)
2057 {
2058 error ("storage size of %q+D isn%'t known", decl);
2059 TREE_ASM_WRITTEN (decl) = 1;
2060 return;
2061 }
2062
2063 /* The first declaration of a variable that comes through this function
2064 decides whether it is global (in C, has external linkage)
2065 or local (in C, has internal linkage). So do nothing more
2066 if this function has already run. */
2067
2068 if (TREE_ASM_WRITTEN (decl))
2069 return;
2070
2071 /* Make sure targetm.encode_section_info is invoked before we set
2072 ASM_WRITTEN. */
2073 decl_rtl = DECL_RTL (decl);
2074
2075 TREE_ASM_WRITTEN (decl) = 1;
2076
2077 /* Do no output if -fsyntax-only. */
2078 if (flag_syntax_only)
2079 return;
2080
2081 app_disable ();
2082
2083 if (! dont_output_data
2084 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
2085 {
2086 error ("size of variable %q+D is too large", decl);
2087 return;
2088 }
2089
2090 gcc_assert (MEM_P (decl_rtl));
2091 gcc_assert (GET_CODE (XEXP (decl_rtl, 0)) == SYMBOL_REF);
2092 symbol = XEXP (decl_rtl, 0);
2093 name = XSTR (symbol, 0);
2094 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
2095 notice_global_symbol (decl);
2096
2097 /* Compute the alignment of this data. */
2098
2099 align_variable (decl, dont_output_data);
2100 set_mem_align (decl_rtl, DECL_ALIGN (decl));
2101
2102 if (TREE_PUBLIC (decl))
2103 maybe_assemble_visibility (decl);
2104
2105 if (DECL_PRESERVE_P (decl))
2106 targetm.asm_out.mark_decl_preserved (name);
2107
2108 /* First make the assembler name(s) global if appropriate. */
2109 sect = get_variable_section (decl, false);
2110 if (TREE_PUBLIC (decl)
2111 && DECL_NAME (decl)
2112 && (sect->common.flags & SECTION_COMMON) == 0)
2113 globalize_decl (decl);
2114
2115 /* Output any data that we will need to use the address of. */
2116 if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node)
2117 output_addressed_constants (DECL_INITIAL (decl));
2118
2119 /* dbxout.c needs to know this. */
2120 if (sect && (sect->common.flags & SECTION_CODE) != 0)
2121 DECL_IN_TEXT_SECTION (decl) = 1;
2122
2123 /* If the decl is part of an object_block, make sure that the decl
2124 has been positioned within its block, but do not write out its
2125 definition yet. output_object_blocks will do that later. */
2126 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
2127 {
2128 gcc_assert (!dont_output_data);
2129 place_block_symbol (symbol);
2130 }
2131 else if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
2132 assemble_noswitch_variable (decl, name, sect);
2133 else
2134 {
2135 switch_to_section (sect);
2136 if (DECL_ALIGN (decl) > BITS_PER_UNIT)
2137 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl)));
2138 assemble_variable_contents (decl, name, dont_output_data);
2139 }
2140 }
2141
2142 /* Return 1 if type TYPE contains any pointers. */
2143
2144 static int
2145 contains_pointers_p (tree type)
2146 {
2147 switch (TREE_CODE (type))
2148 {
2149 case POINTER_TYPE:
2150 case REFERENCE_TYPE:
2151 /* I'm not sure whether OFFSET_TYPE needs this treatment,
2152 so I'll play safe and return 1. */
2153 case OFFSET_TYPE:
2154 return 1;
2155
2156 case RECORD_TYPE:
2157 case UNION_TYPE:
2158 case QUAL_UNION_TYPE:
2159 {
2160 tree fields;
2161 /* For a type that has fields, see if the fields have pointers. */
2162 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2163 if (TREE_CODE (fields) == FIELD_DECL
2164 && contains_pointers_p (TREE_TYPE (fields)))
2165 return 1;
2166 return 0;
2167 }
2168
2169 case ARRAY_TYPE:
2170 /* An array type contains pointers if its element type does. */
2171 return contains_pointers_p (TREE_TYPE (type));
2172
2173 default:
2174 return 0;
2175 }
2176 }
2177
2178 /* In unit-at-a-time mode, we delay assemble_external processing until
2179 the compilation unit is finalized. This is the best we can do for
2180 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay
2181 it all the way to final. See PR 17982 for further discussion. */
2182 static GTY(()) tree pending_assemble_externals;
2183
2184 #ifdef ASM_OUTPUT_EXTERNAL
2185 /* True if DECL is a function decl for which no out-of-line copy exists.
2186 It is assumed that DECL's assembler name has been set. */
2187
2188 static bool
2189 incorporeal_function_p (tree decl)
2190 {
2191 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
2192 {
2193 const char *name;
2194
2195 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
2196 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
2197 return true;
2198
2199 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
2200 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
2201 return true;
2202 }
2203 return false;
2204 }
2205
2206 /* Actually do the tests to determine if this is necessary, and invoke
2207 ASM_OUTPUT_EXTERNAL. */
2208 static void
2209 assemble_external_real (tree decl)
2210 {
2211 rtx rtl = DECL_RTL (decl);
2212
2213 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
2214 && !SYMBOL_REF_USED (XEXP (rtl, 0))
2215 && !incorporeal_function_p (decl))
2216 {
2217 /* Some systems do require some output. */
2218 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
2219 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
2220 }
2221 }
2222 #endif
2223
2224 void
2225 process_pending_assemble_externals (void)
2226 {
2227 #ifdef ASM_OUTPUT_EXTERNAL
2228 tree list;
2229 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list))
2230 assemble_external_real (TREE_VALUE (list));
2231
2232 pending_assemble_externals = 0;
2233 #endif
2234 }
2235
2236 /* Output something to declare an external symbol to the assembler.
2237 (Most assemblers don't need this, so we normally output nothing.)
2238 Do nothing if DECL is not external. */
2239
2240 void
2241 assemble_external (tree decl ATTRIBUTE_UNUSED)
2242 {
2243 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
2244 main body of this code is only rarely exercised. To provide some
2245 testing, on all platforms, we make sure that the ASM_OUT_FILE is
2246 open. If it's not, we should not be calling this function. */
2247 gcc_assert (asm_out_file);
2248
2249 #ifdef ASM_OUTPUT_EXTERNAL
2250 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
2251 return;
2252
2253 /* We want to output external symbols at very last to check if they
2254 are references or not. */
2255 pending_assemble_externals = tree_cons (0, decl,
2256 pending_assemble_externals);
2257 #endif
2258 }
2259
2260 /* Similar, for calling a library function FUN. */
2261
2262 void
2263 assemble_external_libcall (rtx fun)
2264 {
2265 /* Declare library function name external when first used, if nec. */
2266 if (! SYMBOL_REF_USED (fun))
2267 {
2268 SYMBOL_REF_USED (fun) = 1;
2269 targetm.asm_out.external_libcall (fun);
2270 }
2271 }
2272
2273 /* Assemble a label named NAME. */
2274
2275 void
2276 assemble_label (const char *name)
2277 {
2278 ASM_OUTPUT_LABEL (asm_out_file, name);
2279 }
2280
2281 /* Set the symbol_referenced flag for ID. */
2282 void
2283 mark_referenced (tree id)
2284 {
2285 TREE_SYMBOL_REFERENCED (id) = 1;
2286 }
2287
2288 /* Set the symbol_referenced flag for DECL and notify callgraph. */
2289 void
2290 mark_decl_referenced (tree decl)
2291 {
2292 if (TREE_CODE (decl) == FUNCTION_DECL)
2293 {
2294 /* Extern inline functions don't become needed when referenced.
2295 If we know a method will be emitted in other TU and no new
2296 functions can be marked reachable, just use the external
2297 definition. */
2298 struct cgraph_node *node = cgraph_node (decl);
2299 if (!DECL_EXTERNAL (decl)
2300 && (!node->local.vtable_method || !cgraph_global_info_ready
2301 || !node->local.finalized))
2302 cgraph_mark_needed_node (node);
2303 }
2304 else if (TREE_CODE (decl) == VAR_DECL)
2305 {
2306 struct varpool_node *node = varpool_node (decl);
2307 varpool_mark_needed_node (node);
2308 /* C++ frontend use mark_decl_references to force COMDAT variables
2309 to be output that might appear dead otherwise. */
2310 node->force_output = true;
2311 }
2312 /* else do nothing - we can get various sorts of CST nodes here,
2313 which do not need to be marked. */
2314 }
2315
2316
2317 /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS
2318 until we find an identifier that is not itself a transparent alias.
2319 Modify the alias passed to it by reference (and all aliases on the
2320 way to the ultimate target), such that they do not have to be
2321 followed again, and return the ultimate target of the alias
2322 chain. */
2323
2324 static inline tree
2325 ultimate_transparent_alias_target (tree *alias)
2326 {
2327 tree target = *alias;
2328
2329 if (IDENTIFIER_TRANSPARENT_ALIAS (target))
2330 {
2331 gcc_assert (TREE_CHAIN (target));
2332 target = ultimate_transparent_alias_target (&TREE_CHAIN (target));
2333 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
2334 && ! TREE_CHAIN (target));
2335 *alias = target;
2336 }
2337
2338 return target;
2339 }
2340
2341 /* Output to FILE (an assembly file) a reference to NAME. If NAME
2342 starts with a *, the rest of NAME is output verbatim. Otherwise
2343 NAME is transformed in a target-specific way (usually by the
2344 addition of an underscore). */
2345
2346 void
2347 assemble_name_raw (FILE *file, const char *name)
2348 {
2349 if (name[0] == '*')
2350 fputs (&name[1], file);
2351 else
2352 ASM_OUTPUT_LABELREF (file, name);
2353 }
2354
2355 /* Like assemble_name_raw, but should be used when NAME might refer to
2356 an entity that is also represented as a tree (like a function or
2357 variable). If NAME does refer to such an entity, that entity will
2358 be marked as referenced. */
2359
2360 void
2361 assemble_name (FILE *file, const char *name)
2362 {
2363 const char *real_name;
2364 tree id;
2365
2366 real_name = targetm.strip_name_encoding (name);
2367
2368 id = maybe_get_identifier (real_name);
2369 if (id)
2370 {
2371 tree id_orig = id;
2372
2373 mark_referenced (id);
2374 ultimate_transparent_alias_target (&id);
2375 if (id != id_orig)
2376 name = IDENTIFIER_POINTER (id);
2377 gcc_assert (! TREE_CHAIN (id));
2378 }
2379
2380 assemble_name_raw (file, name);
2381 }
2382
2383 /* Allocate SIZE bytes writable static space with a gensym name
2384 and return an RTX to refer to its address. */
2385
2386 rtx
2387 assemble_static_space (unsigned HOST_WIDE_INT size)
2388 {
2389 char name[12];
2390 const char *namestring;
2391 rtx x;
2392
2393 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
2394 ++const_labelno;
2395 namestring = ggc_strdup (name);
2396
2397 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
2398 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
2399
2400 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
2401 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
2402 BIGGEST_ALIGNMENT);
2403 #else
2404 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
2405 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
2406 #else
2407 {
2408 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
2409 so that each uninitialized object starts on such a boundary. */
2410 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
2411 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
2412 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
2413 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
2414 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
2415 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
2416 }
2417 #endif
2418 #endif
2419 return x;
2420 }
2421
2422 /* Assemble the static constant template for function entry trampolines.
2423 This is done at most once per compilation.
2424 Returns an RTX for the address of the template. */
2425
2426 static GTY(()) rtx initial_trampoline;
2427
2428 #ifdef TRAMPOLINE_TEMPLATE
2429 rtx
2430 assemble_trampoline_template (void)
2431 {
2432 char label[256];
2433 const char *name;
2434 int align;
2435 rtx symbol;
2436
2437 if (initial_trampoline)
2438 return initial_trampoline;
2439
2440 /* By default, put trampoline templates in read-only data section. */
2441
2442 #ifdef TRAMPOLINE_SECTION
2443 switch_to_section (TRAMPOLINE_SECTION);
2444 #else
2445 switch_to_section (readonly_data_section);
2446 #endif
2447
2448 /* Write the assembler code to define one. */
2449 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
2450 if (align > 0)
2451 {
2452 ASM_OUTPUT_ALIGN (asm_out_file, align);
2453 }
2454
2455 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
2456 TRAMPOLINE_TEMPLATE (asm_out_file);
2457
2458 /* Record the rtl to refer to it. */
2459 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
2460 name = ggc_strdup (label);
2461 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
2462 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2463
2464 initial_trampoline = gen_rtx_MEM (BLKmode, symbol);
2465 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
2466
2467 return initial_trampoline;
2468 }
2469 #endif
2470 \f
2471 /* A and B are either alignments or offsets. Return the minimum alignment
2472 that may be assumed after adding the two together. */
2473
2474 static inline unsigned
2475 min_align (unsigned int a, unsigned int b)
2476 {
2477 return (a | b) & -(a | b);
2478 }
2479
2480 /* Return the assembler directive for creating a given kind of integer
2481 object. SIZE is the number of bytes in the object and ALIGNED_P
2482 indicates whether it is known to be aligned. Return NULL if the
2483 assembly dialect has no such directive.
2484
2485 The returned string should be printed at the start of a new line and
2486 be followed immediately by the object's initial value. */
2487
2488 const char *
2489 integer_asm_op (int size, int aligned_p)
2490 {
2491 struct asm_int_op *ops;
2492
2493 if (aligned_p)
2494 ops = &targetm.asm_out.aligned_op;
2495 else
2496 ops = &targetm.asm_out.unaligned_op;
2497
2498 switch (size)
2499 {
2500 case 1:
2501 return targetm.asm_out.byte_op;
2502 case 2:
2503 return ops->hi;
2504 case 4:
2505 return ops->si;
2506 case 8:
2507 return ops->di;
2508 case 16:
2509 return ops->ti;
2510 default:
2511 return NULL;
2512 }
2513 }
2514
2515 /* Use directive OP to assemble an integer object X. Print OP at the
2516 start of the line, followed immediately by the value of X. */
2517
2518 void
2519 assemble_integer_with_op (const char *op, rtx x)
2520 {
2521 fputs (op, asm_out_file);
2522 output_addr_const (asm_out_file, x);
2523 fputc ('\n', asm_out_file);
2524 }
2525
2526 /* The default implementation of the asm_out.integer target hook. */
2527
2528 bool
2529 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2530 unsigned int size ATTRIBUTE_UNUSED,
2531 int aligned_p ATTRIBUTE_UNUSED)
2532 {
2533 const char *op = integer_asm_op (size, aligned_p);
2534 /* Avoid GAS bugs for large values. Specifically negative values whose
2535 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */
2536 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT)
2537 return false;
2538 return op && (assemble_integer_with_op (op, x), true);
2539 }
2540
2541 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2542 the alignment of the integer in bits. Return 1 if we were able to output
2543 the constant, otherwise 0. We must be able to output the constant,
2544 if FORCE is nonzero. */
2545
2546 bool
2547 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2548 {
2549 int aligned_p;
2550
2551 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2552
2553 /* See if the target hook can handle this kind of object. */
2554 if (targetm.asm_out.integer (x, size, aligned_p))
2555 return true;
2556
2557 /* If the object is a multi-byte one, try splitting it up. Split
2558 it into words it if is multi-word, otherwise split it into bytes. */
2559 if (size > 1)
2560 {
2561 enum machine_mode omode, imode;
2562 unsigned int subalign;
2563 unsigned int subsize, i;
2564
2565 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2566 subalign = MIN (align, subsize * BITS_PER_UNIT);
2567 omode = mode_for_size (subsize * BITS_PER_UNIT, MODE_INT, 0);
2568 imode = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2569
2570 for (i = 0; i < size; i += subsize)
2571 {
2572 rtx partial = simplify_subreg (omode, x, imode, i);
2573 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2574 break;
2575 }
2576 if (i == size)
2577 return true;
2578
2579 /* If we've printed some of it, but not all of it, there's no going
2580 back now. */
2581 gcc_assert (!i);
2582 }
2583
2584 gcc_assert (!force);
2585
2586 return false;
2587 }
2588 \f
2589 void
2590 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2591 {
2592 long data[4] = {0, 0, 0, 0};
2593 int i;
2594 int bitsize, nelts, nunits, units_per;
2595
2596 /* This is hairy. We have a quantity of known size. real_to_target
2597 will put it into an array of *host* longs, 32 bits per element
2598 (even if long is more than 32 bits). We need to determine the
2599 number of array elements that are occupied (nelts) and the number
2600 of *target* min-addressable units that will be occupied in the
2601 object file (nunits). We cannot assume that 32 divides the
2602 mode's bitsize (size * BITS_PER_UNIT) evenly.
2603
2604 size * BITS_PER_UNIT is used here to make sure that padding bits
2605 (which might appear at either end of the value; real_to_target
2606 will include the padding bits in its output array) are included. */
2607
2608 nunits = GET_MODE_SIZE (mode);
2609 bitsize = nunits * BITS_PER_UNIT;
2610 nelts = CEIL (bitsize, 32);
2611 units_per = 32 / BITS_PER_UNIT;
2612
2613 real_to_target (data, &d, mode);
2614
2615 /* Put out the first word with the specified alignment. */
2616 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2617 nunits -= units_per;
2618
2619 /* Subsequent words need only 32-bit alignment. */
2620 align = min_align (align, 32);
2621
2622 for (i = 1; i < nelts; i++)
2623 {
2624 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2625 nunits -= units_per;
2626 }
2627 }
2628 \f
2629 /* Given an expression EXP with a constant value,
2630 reduce it to the sum of an assembler symbol and an integer.
2631 Store them both in the structure *VALUE.
2632 EXP must be reducible. */
2633
2634 struct addr_const GTY(())
2635 {
2636 rtx base;
2637 HOST_WIDE_INT offset;
2638 };
2639
2640 static void
2641 decode_addr_const (tree exp, struct addr_const *value)
2642 {
2643 tree target = TREE_OPERAND (exp, 0);
2644 int offset = 0;
2645 rtx x;
2646
2647 while (1)
2648 {
2649 if (TREE_CODE (target) == COMPONENT_REF
2650 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2651
2652 {
2653 offset += int_byte_position (TREE_OPERAND (target, 1));
2654 target = TREE_OPERAND (target, 0);
2655 }
2656 else if (TREE_CODE (target) == ARRAY_REF
2657 || TREE_CODE (target) == ARRAY_RANGE_REF)
2658 {
2659 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2660 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2661 target = TREE_OPERAND (target, 0);
2662 }
2663 else
2664 break;
2665 }
2666
2667 switch (TREE_CODE (target))
2668 {
2669 case VAR_DECL:
2670 case FUNCTION_DECL:
2671 x = DECL_RTL (target);
2672 break;
2673
2674 case LABEL_DECL:
2675 x = gen_rtx_MEM (FUNCTION_MODE,
2676 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target)));
2677 break;
2678
2679 case REAL_CST:
2680 case STRING_CST:
2681 case COMPLEX_CST:
2682 case CONSTRUCTOR:
2683 case INTEGER_CST:
2684 x = output_constant_def (target, 1);
2685 break;
2686
2687 default:
2688 gcc_unreachable ();
2689 }
2690
2691 gcc_assert (MEM_P (x));
2692 x = XEXP (x, 0);
2693
2694 value->base = x;
2695 value->offset = offset;
2696 }
2697 \f
2698 /* Uniquize all constants that appear in memory.
2699 Each constant in memory thus far output is recorded
2700 in `const_desc_table'. */
2701
2702 struct constant_descriptor_tree GTY(())
2703 {
2704 /* A MEM for the constant. */
2705 rtx rtl;
2706
2707 /* The value of the constant. */
2708 tree value;
2709
2710 /* Hash of value. Computing the hash from value each time
2711 hashfn is called can't work properly, as that means recursive
2712 use of the hash table during hash table expansion. */
2713 hashval_t hash;
2714 };
2715
2716 static GTY((param_is (struct constant_descriptor_tree)))
2717 htab_t const_desc_htab;
2718
2719 static struct constant_descriptor_tree * build_constant_desc (tree);
2720 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2721
2722 /* Compute a hash code for a constant expression. */
2723
2724 static hashval_t
2725 const_desc_hash (const void *ptr)
2726 {
2727 return ((struct constant_descriptor_tree *)ptr)->hash;
2728 }
2729
2730 static hashval_t
2731 const_hash_1 (const tree exp)
2732 {
2733 const char *p;
2734 hashval_t hi;
2735 int len, i;
2736 enum tree_code code = TREE_CODE (exp);
2737
2738 /* Either set P and LEN to the address and len of something to hash and
2739 exit the switch or return a value. */
2740
2741 switch (code)
2742 {
2743 case INTEGER_CST:
2744 p = (char *) &TREE_INT_CST (exp);
2745 len = sizeof TREE_INT_CST (exp);
2746 break;
2747
2748 case REAL_CST:
2749 return real_hash (TREE_REAL_CST_PTR (exp));
2750
2751 case STRING_CST:
2752 p = TREE_STRING_POINTER (exp);
2753 len = TREE_STRING_LENGTH (exp);
2754 break;
2755
2756 case COMPLEX_CST:
2757 return (const_hash_1 (TREE_REALPART (exp)) * 5
2758 + const_hash_1 (TREE_IMAGPART (exp)));
2759
2760 case CONSTRUCTOR:
2761 {
2762 unsigned HOST_WIDE_INT idx;
2763 tree value;
2764
2765 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2766
2767 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
2768 if (value)
2769 hi = hi * 603 + const_hash_1 (value);
2770
2771 return hi;
2772 }
2773
2774 case ADDR_EXPR:
2775 case FDESC_EXPR:
2776 {
2777 struct addr_const value;
2778
2779 decode_addr_const (exp, &value);
2780 switch (GET_CODE (value.base))
2781 {
2782 case SYMBOL_REF:
2783 /* Don't hash the address of the SYMBOL_REF;
2784 only use the offset and the symbol name. */
2785 hi = value.offset;
2786 p = XSTR (value.base, 0);
2787 for (i = 0; p[i] != 0; i++)
2788 hi = ((hi * 613) + (unsigned) (p[i]));
2789 break;
2790
2791 case LABEL_REF:
2792 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2793 break;
2794
2795 default:
2796 gcc_unreachable ();
2797 }
2798 }
2799 return hi;
2800
2801 case PLUS_EXPR:
2802 case MINUS_EXPR:
2803 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2804 + const_hash_1 (TREE_OPERAND (exp, 1)));
2805
2806 case NOP_EXPR:
2807 case CONVERT_EXPR:
2808 case NON_LVALUE_EXPR:
2809 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2810
2811 default:
2812 /* A language specific constant. Just hash the code. */
2813 return code;
2814 }
2815
2816 /* Compute hashing function. */
2817 hi = len;
2818 for (i = 0; i < len; i++)
2819 hi = ((hi * 613) + (unsigned) (p[i]));
2820
2821 return hi;
2822 }
2823
2824 /* Wrapper of compare_constant, for the htab interface. */
2825 static int
2826 const_desc_eq (const void *p1, const void *p2)
2827 {
2828 const struct constant_descriptor_tree *c1 = p1;
2829 const struct constant_descriptor_tree *c2 = p2;
2830 if (c1->hash != c2->hash)
2831 return 0;
2832 return compare_constant (c1->value, c2->value);
2833 }
2834
2835 /* Compare t1 and t2, and return 1 only if they are known to result in
2836 the same bit pattern on output. */
2837
2838 static int
2839 compare_constant (const tree t1, const tree t2)
2840 {
2841 enum tree_code typecode;
2842
2843 if (t1 == NULL_TREE)
2844 return t2 == NULL_TREE;
2845 if (t2 == NULL_TREE)
2846 return 0;
2847
2848 if (TREE_CODE (t1) != TREE_CODE (t2))
2849 return 0;
2850
2851 switch (TREE_CODE (t1))
2852 {
2853 case INTEGER_CST:
2854 /* Integer constants are the same only if the same width of type. */
2855 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2856 return 0;
2857 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2858 return 0;
2859 return tree_int_cst_equal (t1, t2);
2860
2861 case REAL_CST:
2862 /* Real constants are the same only if the same width of type. */
2863 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2864 return 0;
2865
2866 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2867
2868 case STRING_CST:
2869 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2870 return 0;
2871
2872 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2873 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2874 TREE_STRING_LENGTH (t1)));
2875
2876 case COMPLEX_CST:
2877 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2878 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2879
2880 case CONSTRUCTOR:
2881 {
2882 VEC(constructor_elt, gc) *v1, *v2;
2883 unsigned HOST_WIDE_INT idx;
2884
2885 typecode = TREE_CODE (TREE_TYPE (t1));
2886 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2887 return 0;
2888
2889 if (typecode == ARRAY_TYPE)
2890 {
2891 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2892 /* For arrays, check that the sizes all match. */
2893 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2894 || size_1 == -1
2895 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2896 return 0;
2897 }
2898 else
2899 {
2900 /* For record and union constructors, require exact type
2901 equality. */
2902 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2903 return 0;
2904 }
2905
2906 v1 = CONSTRUCTOR_ELTS (t1);
2907 v2 = CONSTRUCTOR_ELTS (t2);
2908 if (VEC_length (constructor_elt, v1)
2909 != VEC_length (constructor_elt, v2))
2910 return 0;
2911
2912 for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
2913 {
2914 constructor_elt *c1 = VEC_index (constructor_elt, v1, idx);
2915 constructor_elt *c2 = VEC_index (constructor_elt, v2, idx);
2916
2917 /* Check that each value is the same... */
2918 if (!compare_constant (c1->value, c2->value))
2919 return 0;
2920 /* ... and that they apply to the same fields! */
2921 if (typecode == ARRAY_TYPE)
2922 {
2923 if (!compare_constant (c1->index, c2->index))
2924 return 0;
2925 }
2926 else
2927 {
2928 if (c1->index != c2->index)
2929 return 0;
2930 }
2931 }
2932
2933 return 1;
2934 }
2935
2936 case ADDR_EXPR:
2937 case FDESC_EXPR:
2938 {
2939 struct addr_const value1, value2;
2940
2941 decode_addr_const (t1, &value1);
2942 decode_addr_const (t2, &value2);
2943 return (value1.offset == value2.offset
2944 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
2945 }
2946
2947 case PLUS_EXPR:
2948 case MINUS_EXPR:
2949 case RANGE_EXPR:
2950 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
2951 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
2952
2953 case NOP_EXPR:
2954 case CONVERT_EXPR:
2955 case NON_LVALUE_EXPR:
2956 case VIEW_CONVERT_EXPR:
2957 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2958
2959 default:
2960 {
2961 tree nt1, nt2;
2962 nt1 = lang_hooks.expand_constant (t1);
2963 nt2 = lang_hooks.expand_constant (t2);
2964 if (nt1 != t1 || nt2 != t2)
2965 return compare_constant (nt1, nt2);
2966 else
2967 return 0;
2968 }
2969 }
2970
2971 gcc_unreachable ();
2972 }
2973 \f
2974 /* Make a copy of the whole tree structure for a constant. This
2975 handles the same types of nodes that compare_constant handles. */
2976
2977 static tree
2978 copy_constant (tree exp)
2979 {
2980 switch (TREE_CODE (exp))
2981 {
2982 case ADDR_EXPR:
2983 /* For ADDR_EXPR, we do not want to copy the decl whose address
2984 is requested. We do want to copy constants though. */
2985 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0)))
2986 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2987 copy_constant (TREE_OPERAND (exp, 0)));
2988 else
2989 return copy_node (exp);
2990
2991 case INTEGER_CST:
2992 case REAL_CST:
2993 case STRING_CST:
2994 return copy_node (exp);
2995
2996 case COMPLEX_CST:
2997 return build_complex (TREE_TYPE (exp),
2998 copy_constant (TREE_REALPART (exp)),
2999 copy_constant (TREE_IMAGPART (exp)));
3000
3001 case PLUS_EXPR:
3002 case MINUS_EXPR:
3003 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
3004 copy_constant (TREE_OPERAND (exp, 0)),
3005 copy_constant (TREE_OPERAND (exp, 1)));
3006
3007 case NOP_EXPR:
3008 case CONVERT_EXPR:
3009 case NON_LVALUE_EXPR:
3010 case VIEW_CONVERT_EXPR:
3011 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3012 copy_constant (TREE_OPERAND (exp, 0)));
3013
3014 case CONSTRUCTOR:
3015 {
3016 tree copy = copy_node (exp);
3017 VEC(constructor_elt, gc) *v;
3018 unsigned HOST_WIDE_INT idx;
3019 tree purpose, value;
3020
3021 v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt,
3022 CONSTRUCTOR_ELTS (exp)));
3023 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value)
3024 {
3025 constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL);
3026 ce->index = purpose;
3027 ce->value = copy_constant (value);
3028 }
3029 CONSTRUCTOR_ELTS (copy) = v;
3030 return copy;
3031 }
3032
3033 default:
3034 {
3035 tree t = lang_hooks.expand_constant (exp);
3036
3037 gcc_assert (t != exp);
3038 return copy_constant (t);
3039 }
3040 }
3041 }
3042 \f
3043 /* Return the alignment of constant EXP in bits. */
3044
3045 static unsigned int
3046 get_constant_alignment (tree exp)
3047 {
3048 unsigned int align;
3049
3050 align = TYPE_ALIGN (TREE_TYPE (exp));
3051 #ifdef CONSTANT_ALIGNMENT
3052 align = CONSTANT_ALIGNMENT (exp, align);
3053 #endif
3054 return align;
3055 }
3056
3057 /* Return the section into which constant EXP should be placed. */
3058
3059 static section *
3060 get_constant_section (tree exp)
3061 {
3062 if (IN_NAMED_SECTION (exp))
3063 return get_named_section (exp, NULL, compute_reloc_for_constant (exp));
3064 else
3065 return targetm.asm_out.select_section (exp,
3066 compute_reloc_for_constant (exp),
3067 get_constant_alignment (exp));
3068 }
3069
3070 /* Return the size of constant EXP in bytes. */
3071
3072 static HOST_WIDE_INT
3073 get_constant_size (tree exp)
3074 {
3075 HOST_WIDE_INT size;
3076
3077 size = int_size_in_bytes (TREE_TYPE (exp));
3078 if (TREE_CODE (exp) == STRING_CST)
3079 size = MAX (TREE_STRING_LENGTH (exp), size);
3080 return size;
3081 }
3082
3083 /* Subroutine of output_constant_def:
3084 No constant equal to EXP is known to have been output.
3085 Make a constant descriptor to enter EXP in the hash table.
3086 Assign the label number and construct RTL to refer to the
3087 constant's location in memory.
3088 Caller is responsible for updating the hash table. */
3089
3090 static struct constant_descriptor_tree *
3091 build_constant_desc (tree exp)
3092 {
3093 rtx symbol;
3094 rtx rtl;
3095 char label[256];
3096 int labelno;
3097 struct constant_descriptor_tree *desc;
3098
3099 desc = ggc_alloc (sizeof (*desc));
3100 desc->value = copy_constant (exp);
3101
3102 /* Propagate marked-ness to copied constant. */
3103 if (flag_mudflap && mf_marked_p (exp))
3104 mf_mark (desc->value);
3105
3106 /* Create a string containing the label name, in LABEL. */
3107 labelno = const_labelno++;
3108 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
3109
3110 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
3111 if (use_object_blocks_p ())
3112 {
3113 section *sect = get_constant_section (exp);
3114 symbol = create_block_symbol (ggc_strdup (label),
3115 get_block_for_section (sect), -1);
3116 }
3117 else
3118 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3119 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3120 SET_SYMBOL_REF_DECL (symbol, desc->value);
3121 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3122
3123 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
3124 set_mem_attributes (rtl, exp, 1);
3125 set_mem_alias_set (rtl, 0);
3126 set_mem_alias_set (rtl, const_alias_set);
3127
3128 /* Set flags or add text to the name to record information, such as
3129 that it is a local symbol. If the name is changed, the macro
3130 ASM_OUTPUT_LABELREF will have to know how to strip this
3131 information. This call might invalidate our local variable
3132 SYMBOL; we can't use it afterward. */
3133
3134 targetm.encode_section_info (exp, rtl, true);
3135
3136 desc->rtl = rtl;
3137
3138 return desc;
3139 }
3140
3141 /* Return an rtx representing a reference to constant data in memory
3142 for the constant expression EXP.
3143
3144 If assembler code for such a constant has already been output,
3145 return an rtx to refer to it.
3146 Otherwise, output such a constant in memory
3147 and generate an rtx for it.
3148
3149 If DEFER is nonzero, this constant can be deferred and output only
3150 if referenced in the function after all optimizations.
3151
3152 `const_desc_table' records which constants already have label strings. */
3153
3154 rtx
3155 output_constant_def (tree exp, int defer)
3156 {
3157 struct constant_descriptor_tree *desc;
3158 struct constant_descriptor_tree key;
3159 void **loc;
3160
3161 /* Look up EXP in the table of constant descriptors. If we didn't find
3162 it, create a new one. */
3163 key.value = exp;
3164 key.hash = const_hash_1 (exp);
3165 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
3166
3167 desc = *loc;
3168 if (desc == 0)
3169 {
3170 desc = build_constant_desc (exp);
3171 desc->hash = key.hash;
3172 *loc = desc;
3173 }
3174
3175 maybe_output_constant_def_contents (desc, defer);
3176 return desc->rtl;
3177 }
3178
3179 /* Subroutine of output_constant_def: Decide whether or not we need to
3180 output the constant DESC now, and if so, do it. */
3181 static void
3182 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
3183 int defer)
3184 {
3185 rtx symbol = XEXP (desc->rtl, 0);
3186 tree exp = desc->value;
3187
3188 if (flag_syntax_only)
3189 return;
3190
3191 if (TREE_ASM_WRITTEN (exp))
3192 /* Already output; don't do it again. */
3193 return;
3194
3195 /* We can always defer constants as long as the context allows
3196 doing so. */
3197 if (defer)
3198 {
3199 /* Increment n_deferred_constants if it exists. It needs to be at
3200 least as large as the number of constants actually referred to
3201 by the function. If it's too small we'll stop looking too early
3202 and fail to emit constants; if it's too large we'll only look
3203 through the entire function when we could have stopped earlier. */
3204 if (cfun)
3205 n_deferred_constants++;
3206 return;
3207 }
3208
3209 output_constant_def_contents (symbol);
3210 }
3211
3212 /* Subroutine of output_constant_def_contents. Output the definition
3213 of constant EXP, which is pointed to by label LABEL. ALIGN is the
3214 constant's alignment in bits. */
3215
3216 static void
3217 assemble_constant_contents (tree exp, const char *label, unsigned int align)
3218 {
3219 HOST_WIDE_INT size;
3220
3221 size = get_constant_size (exp);
3222
3223 /* Do any machine/system dependent processing of the constant. */
3224 #ifdef ASM_DECLARE_CONSTANT_NAME
3225 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
3226 #else
3227 /* Standard thing is just output label for the constant. */
3228 ASM_OUTPUT_LABEL (asm_out_file, label);
3229 #endif /* ASM_DECLARE_CONSTANT_NAME */
3230
3231 /* Output the value of EXP. */
3232 output_constant (exp, size, align);
3233 }
3234
3235 /* We must output the constant data referred to by SYMBOL; do so. */
3236
3237 static void
3238 output_constant_def_contents (rtx symbol)
3239 {
3240 tree exp = SYMBOL_REF_DECL (symbol);
3241 unsigned int align;
3242
3243 /* Make sure any other constants whose addresses appear in EXP
3244 are assigned label numbers. */
3245 output_addressed_constants (exp);
3246
3247 /* We are no longer deferring this constant. */
3248 TREE_ASM_WRITTEN (exp) = 1;
3249
3250 /* If the constant is part of an object block, make sure that the
3251 decl has been positioned within its block, but do not write out
3252 its definition yet. output_object_blocks will do that later. */
3253 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
3254 place_block_symbol (symbol);
3255 else
3256 {
3257 switch_to_section (get_constant_section (exp));
3258 align = get_constant_alignment (exp);
3259 if (align > BITS_PER_UNIT)
3260 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
3261 assemble_constant_contents (exp, XSTR (symbol, 0), align);
3262 }
3263 if (flag_mudflap)
3264 mudflap_enqueue_constant (exp);
3265 }
3266
3267 /* Look up EXP in the table of constant descriptors. Return the rtl
3268 if it has been emitted, else null. */
3269
3270 rtx
3271 lookup_constant_def (tree exp)
3272 {
3273 struct constant_descriptor_tree *desc;
3274 struct constant_descriptor_tree key;
3275
3276 key.value = exp;
3277 key.hash = const_hash_1 (exp);
3278 desc = htab_find_with_hash (const_desc_htab, &key, key.hash);
3279
3280 return (desc ? desc->rtl : NULL_RTX);
3281 }
3282 \f
3283 /* Used in the hash tables to avoid outputting the same constant
3284 twice. Unlike 'struct constant_descriptor_tree', RTX constants
3285 are output once per function, not once per file. */
3286 /* ??? Only a few targets need per-function constant pools. Most
3287 can use one per-file pool. Should add a targetm bit to tell the
3288 difference. */
3289
3290 struct rtx_constant_pool GTY(())
3291 {
3292 /* Pointers to first and last constant in pool, as ordered by offset. */
3293 struct constant_descriptor_rtx *first;
3294 struct constant_descriptor_rtx *last;
3295
3296 /* Hash facility for making memory-constants from constant rtl-expressions.
3297 It is used on RISC machines where immediate integer arguments and
3298 constant addresses are restricted so that such constants must be stored
3299 in memory. */
3300 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
3301
3302 /* Current offset in constant pool (does not include any
3303 machine-specific header). */
3304 HOST_WIDE_INT offset;
3305 };
3306
3307 struct constant_descriptor_rtx GTY((chain_next ("%h.next")))
3308 {
3309 struct constant_descriptor_rtx *next;
3310 rtx mem;
3311 rtx sym;
3312 rtx constant;
3313 HOST_WIDE_INT offset;
3314 hashval_t hash;
3315 enum machine_mode mode;
3316 unsigned int align;
3317 int labelno;
3318 int mark;
3319 };
3320
3321 /* Hash and compare functions for const_rtx_htab. */
3322
3323 static hashval_t
3324 const_desc_rtx_hash (const void *ptr)
3325 {
3326 const struct constant_descriptor_rtx *desc = ptr;
3327 return desc->hash;
3328 }
3329
3330 static int
3331 const_desc_rtx_eq (const void *a, const void *b)
3332 {
3333 const struct constant_descriptor_rtx *x = a;
3334 const struct constant_descriptor_rtx *y = b;
3335
3336 if (x->mode != y->mode)
3337 return 0;
3338 return rtx_equal_p (x->constant, y->constant);
3339 }
3340
3341 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
3342
3343 static int
3344 const_rtx_hash_1 (rtx *xp, void *data)
3345 {
3346 unsigned HOST_WIDE_INT hwi;
3347 enum machine_mode mode;
3348 enum rtx_code code;
3349 hashval_t h, *hp;
3350 rtx x;
3351
3352 x = *xp;
3353 code = GET_CODE (x);
3354 mode = GET_MODE (x);
3355 h = (hashval_t) code * 1048573 + mode;
3356
3357 switch (code)
3358 {
3359 case CONST_INT:
3360 hwi = INTVAL (x);
3361 fold_hwi:
3362 {
3363 const int shift = sizeof (hashval_t) * CHAR_BIT;
3364 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
3365 int i;
3366
3367 h ^= (hashval_t) hwi;
3368 for (i = 1; i < n; ++i)
3369 {
3370 hwi >>= shift;
3371 h ^= (hashval_t) hwi;
3372 }
3373 }
3374 break;
3375
3376 case CONST_DOUBLE:
3377 if (mode == VOIDmode)
3378 {
3379 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
3380 goto fold_hwi;
3381 }
3382 else
3383 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
3384 break;
3385
3386 case CONST_VECTOR:
3387 {
3388 int i;
3389 for (i = XVECLEN (x, 0); i-- > 0; )
3390 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data);
3391 }
3392 break;
3393
3394 case SYMBOL_REF:
3395 h ^= htab_hash_string (XSTR (x, 0));
3396 break;
3397
3398 case LABEL_REF:
3399 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
3400 break;
3401
3402 case UNSPEC:
3403 case UNSPEC_VOLATILE:
3404 h = h * 251 + XINT (x, 1);
3405 break;
3406
3407 default:
3408 break;
3409 }
3410
3411 hp = data;
3412 *hp = *hp * 509 + h;
3413 return 0;
3414 }
3415
3416 /* Compute a hash value for X, which should be a constant. */
3417
3418 static hashval_t
3419 const_rtx_hash (rtx x)
3420 {
3421 hashval_t h = 0;
3422 for_each_rtx (&x, const_rtx_hash_1, &h);
3423 return h;
3424 }
3425
3426 \f
3427 /* Create and return a new rtx constant pool. */
3428
3429 static struct rtx_constant_pool *
3430 create_constant_pool (void)
3431 {
3432 struct rtx_constant_pool *pool;
3433
3434 pool = ggc_alloc (sizeof (struct rtx_constant_pool));
3435 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
3436 const_desc_rtx_eq, NULL);
3437 pool->first = NULL;
3438 pool->last = NULL;
3439 pool->offset = 0;
3440 return pool;
3441 }
3442
3443 /* Initialize constant pool hashing for a new function. */
3444
3445 void
3446 init_varasm_status (struct function *f)
3447 {
3448 struct varasm_status *p;
3449
3450 p = ggc_alloc (sizeof (struct varasm_status));
3451 f->varasm = p;
3452
3453 p->pool = create_constant_pool ();
3454 p->deferred_constants = 0;
3455 }
3456 \f
3457 /* Given a MINUS expression, simplify it if both sides
3458 include the same symbol. */
3459
3460 rtx
3461 simplify_subtraction (rtx x)
3462 {
3463 rtx r = simplify_rtx (x);
3464 return r ? r : x;
3465 }
3466 \f
3467 /* Given a constant rtx X, make (or find) a memory constant for its value
3468 and return a MEM rtx to refer to it in memory. */
3469
3470 rtx
3471 force_const_mem (enum machine_mode mode, rtx x)
3472 {
3473 struct constant_descriptor_rtx *desc, tmp;
3474 struct rtx_constant_pool *pool;
3475 char label[256];
3476 rtx def, symbol;
3477 hashval_t hash;
3478 unsigned int align;
3479 void **slot;
3480
3481 /* If we're not allowed to drop X into the constant pool, don't. */
3482 if (targetm.cannot_force_const_mem (x))
3483 return NULL_RTX;
3484
3485 /* Record that this function has used a constant pool entry. */
3486 current_function_uses_const_pool = 1;
3487
3488 /* Decide which pool to use. */
3489 pool = (targetm.use_blocks_for_constant_p (mode, x)
3490 ? shared_constant_pool
3491 : cfun->varasm->pool);
3492
3493 /* Lookup the value in the hashtable. */
3494 tmp.constant = x;
3495 tmp.mode = mode;
3496 hash = const_rtx_hash (x);
3497 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
3498 desc = *slot;
3499
3500 /* If the constant was already present, return its memory. */
3501 if (desc)
3502 return copy_rtx (desc->mem);
3503
3504 /* Otherwise, create a new descriptor. */
3505 desc = ggc_alloc (sizeof (*desc));
3506 *slot = desc;
3507
3508 /* Align the location counter as required by EXP's data type. */
3509 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
3510 #ifdef CONSTANT_ALIGNMENT
3511 {
3512 tree type = lang_hooks.types.type_for_mode (mode, 0);
3513 if (type != NULL_TREE)
3514 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
3515 }
3516 #endif
3517
3518 pool->offset += (align / BITS_PER_UNIT) - 1;
3519 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
3520
3521 desc->next = NULL;
3522 desc->constant = tmp.constant;
3523 desc->offset = pool->offset;
3524 desc->hash = hash;
3525 desc->mode = mode;
3526 desc->align = align;
3527 desc->labelno = const_labelno;
3528 desc->mark = 0;
3529
3530 pool->offset += GET_MODE_SIZE (mode);
3531 if (pool->last)
3532 pool->last->next = desc;
3533 else
3534 pool->first = pool->last = desc;
3535 pool->last = desc;
3536
3537 /* Create a string containing the label name, in LABEL. */
3538 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
3539 ++const_labelno;
3540
3541 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
3542 the constants pool. */
3543 if (use_object_blocks_p () && targetm.use_blocks_for_constant_p (mode, x))
3544 {
3545 section *sect = targetm.asm_out.select_rtx_section (mode, x, align);
3546 symbol = create_block_symbol (ggc_strdup (label),
3547 get_block_for_section (sect), -1);
3548 }
3549 else
3550 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3551 desc->sym = symbol;
3552 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3553 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3554 SET_SYMBOL_REF_CONSTANT (symbol, desc);
3555
3556 /* Construct the MEM. */
3557 desc->mem = def = gen_const_mem (mode, symbol);
3558 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
3559 set_mem_align (def, align);
3560
3561 /* If we're dropping a label to the constant pool, make sure we
3562 don't delete it. */
3563 if (GET_CODE (x) == LABEL_REF)
3564 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3565
3566 return copy_rtx (def);
3567 }
3568 \f
3569 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3570
3571 rtx
3572 get_pool_constant (rtx addr)
3573 {
3574 return SYMBOL_REF_CONSTANT (addr)->constant;
3575 }
3576
3577 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3578 and whether it has been output or not. */
3579
3580 rtx
3581 get_pool_constant_mark (rtx addr, bool *pmarked)
3582 {
3583 struct constant_descriptor_rtx *desc;
3584
3585 desc = SYMBOL_REF_CONSTANT (addr);
3586 *pmarked = (desc->mark != 0);
3587 return desc->constant;
3588 }
3589
3590 /* Similar, return the mode. */
3591
3592 enum machine_mode
3593 get_pool_mode (rtx addr)
3594 {
3595 return SYMBOL_REF_CONSTANT (addr)->mode;
3596 }
3597
3598 /* Return the size of the constant pool. */
3599
3600 int
3601 get_pool_size (void)
3602 {
3603 return cfun->varasm->pool->offset;
3604 }
3605 \f
3606 /* Worker function for output_constant_pool_1. Emit assembly for X
3607 in MODE with known alignment ALIGN. */
3608
3609 static void
3610 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3611 {
3612 switch (GET_MODE_CLASS (mode))
3613 {
3614 case MODE_FLOAT:
3615 case MODE_DECIMAL_FLOAT:
3616 {
3617 REAL_VALUE_TYPE r;
3618
3619 gcc_assert (GET_CODE (x) == CONST_DOUBLE);
3620 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3621 assemble_real (r, mode, align);
3622 break;
3623 }
3624
3625 case MODE_INT:
3626 case MODE_PARTIAL_INT:
3627 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3628 break;
3629
3630 case MODE_VECTOR_FLOAT:
3631 case MODE_VECTOR_INT:
3632 {
3633 int i, units;
3634 enum machine_mode submode = GET_MODE_INNER (mode);
3635 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3636
3637 gcc_assert (GET_CODE (x) == CONST_VECTOR);
3638 units = CONST_VECTOR_NUNITS (x);
3639
3640 for (i = 0; i < units; i++)
3641 {
3642 rtx elt = CONST_VECTOR_ELT (x, i);
3643 output_constant_pool_2 (submode, elt, i ? subalign : align);
3644 }
3645 }
3646 break;
3647
3648 default:
3649 gcc_unreachable ();
3650 }
3651 }
3652
3653 /* Worker function for output_constant_pool. Emit constant DESC,
3654 giving it ALIGN bits of alignment. */
3655
3656 static void
3657 output_constant_pool_1 (struct constant_descriptor_rtx *desc,
3658 unsigned int align)
3659 {
3660 rtx x, tmp;
3661
3662 x = desc->constant;
3663
3664 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3665 whose CODE_LABEL has been deleted. This can occur if a jump table
3666 is eliminated by optimization. If so, write a constant of zero
3667 instead. Note that this can also happen by turning the
3668 CODE_LABEL into a NOTE. */
3669 /* ??? This seems completely and utterly wrong. Certainly it's
3670 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3671 functioning even with INSN_DELETED_P and friends. */
3672
3673 tmp = x;
3674 switch (GET_CODE (x))
3675 {
3676 case CONST:
3677 if (GET_CODE (XEXP (x, 0)) != PLUS
3678 || GET_CODE (XEXP (XEXP (x, 0), 0)) != LABEL_REF)
3679 break;
3680 tmp = XEXP (XEXP (x, 0), 0);
3681 /* FALLTHRU */
3682
3683 case LABEL_REF:
3684 tmp = XEXP (x, 0);
3685 gcc_assert (!INSN_DELETED_P (tmp));
3686 gcc_assert (!NOTE_P (tmp)
3687 || NOTE_LINE_NUMBER (tmp) != NOTE_INSN_DELETED);
3688 break;
3689
3690 default:
3691 break;
3692 }
3693
3694 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3695 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3696 align, desc->labelno, done);
3697 #endif
3698
3699 assemble_align (align);
3700
3701 /* Output the label. */
3702 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3703
3704 /* Output the data. */
3705 output_constant_pool_2 (desc->mode, x, align);
3706
3707 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3708 sections have proper size. */
3709 if (align > GET_MODE_BITSIZE (desc->mode)
3710 && in_section
3711 && (in_section->common.flags & SECTION_MERGE))
3712 assemble_align (align);
3713
3714 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3715 done:
3716 #endif
3717 return;
3718 }
3719
3720 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3721 to as used. Emit referenced deferred strings. This function can
3722 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3723
3724 static int
3725 mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED)
3726 {
3727 rtx x = *current_rtx;
3728
3729 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3730 return 0;
3731
3732 if (CONSTANT_POOL_ADDRESS_P (x))
3733 {
3734 struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x);
3735 if (desc->mark == 0)
3736 {
3737 desc->mark = 1;
3738 for_each_rtx (&desc->constant, mark_constant, NULL);
3739 }
3740 }
3741 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3742 {
3743 tree exp = SYMBOL_REF_DECL (x);
3744 if (!TREE_ASM_WRITTEN (exp))
3745 {
3746 n_deferred_constants--;
3747 output_constant_def_contents (x);
3748 }
3749 }
3750
3751 return -1;
3752 }
3753
3754 /* Look through appropriate parts of INSN, marking all entries in the
3755 constant pool which are actually being used. Entries that are only
3756 referenced by other constants are also marked as used. Emit
3757 deferred strings that are used. */
3758
3759 static void
3760 mark_constants (rtx insn)
3761 {
3762 if (!INSN_P (insn))
3763 return;
3764
3765 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3766 insns, not any notes that may be attached. We don't want to mark
3767 a constant just because it happens to appear in a REG_EQUIV note. */
3768 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3769 {
3770 rtx seq = PATTERN (insn);
3771 int i, n = XVECLEN (seq, 0);
3772 for (i = 0; i < n; ++i)
3773 {
3774 rtx subinsn = XVECEXP (seq, 0, i);
3775 if (INSN_P (subinsn))
3776 for_each_rtx (&PATTERN (subinsn), mark_constant, NULL);
3777 }
3778 }
3779 else
3780 for_each_rtx (&PATTERN (insn), mark_constant, NULL);
3781 }
3782
3783 /* Look through the instructions for this function, and mark all the
3784 entries in POOL which are actually being used. Emit deferred constants
3785 which have indeed been used. */
3786
3787 static void
3788 mark_constant_pool (void)
3789 {
3790 rtx insn, link;
3791
3792 if (!current_function_uses_const_pool && n_deferred_constants == 0)
3793 return;
3794
3795 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3796 mark_constants (insn);
3797
3798 for (link = current_function_epilogue_delay_list;
3799 link;
3800 link = XEXP (link, 1))
3801 mark_constants (XEXP (link, 0));
3802 }
3803
3804 /* Write all the constants in POOL. */
3805
3806 static void
3807 output_constant_pool_contents (struct rtx_constant_pool *pool)
3808 {
3809 struct constant_descriptor_rtx *desc;
3810
3811 for (desc = pool->first; desc ; desc = desc->next)
3812 if (desc->mark)
3813 {
3814 /* If the constant is part of an object_block, make sure that
3815 the constant has been positioned within its block, but do not
3816 write out its definition yet. output_object_blocks will do
3817 that later. */
3818 if (SYMBOL_REF_HAS_BLOCK_INFO_P (desc->sym)
3819 && SYMBOL_REF_BLOCK (desc->sym))
3820 place_block_symbol (desc->sym);
3821 else
3822 {
3823 switch_to_section (targetm.asm_out.select_rtx_section
3824 (desc->mode, desc->constant, desc->align));
3825 output_constant_pool_1 (desc, desc->align);
3826 }
3827 }
3828 }
3829
3830 /* Mark all constants that are used in the current function, then write
3831 out the function's private constant pool. */
3832
3833 static void
3834 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3835 tree fndecl ATTRIBUTE_UNUSED)
3836 {
3837 struct rtx_constant_pool *pool = cfun->varasm->pool;
3838
3839 /* It is possible for gcc to call force_const_mem and then to later
3840 discard the instructions which refer to the constant. In such a
3841 case we do not need to output the constant. */
3842 mark_constant_pool ();
3843
3844 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3845 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3846 #endif
3847
3848 output_constant_pool_contents (pool);
3849
3850 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3851 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3852 #endif
3853 }
3854 \f
3855 /* Write the contents of the shared constant pool. */
3856
3857 void
3858 output_shared_constant_pool (void)
3859 {
3860 output_constant_pool_contents (shared_constant_pool);
3861 }
3862 \f
3863 /* Determine what kind of relocations EXP may need. */
3864
3865 int
3866 compute_reloc_for_constant (tree exp)
3867 {
3868 int reloc = 0, reloc2;
3869 tree tem;
3870
3871 /* Give the front-end a chance to convert VALUE to something that
3872 looks more like a constant to the back-end. */
3873 exp = lang_hooks.expand_constant (exp);
3874
3875 switch (TREE_CODE (exp))
3876 {
3877 case ADDR_EXPR:
3878 case FDESC_EXPR:
3879 /* Go inside any operations that get_inner_reference can handle and see
3880 if what's inside is a constant: no need to do anything here for
3881 addresses of variables or functions. */
3882 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3883 tem = TREE_OPERAND (tem, 0))
3884 ;
3885
3886 if (TREE_PUBLIC (tem))
3887 reloc |= 2;
3888 else
3889 reloc |= 1;
3890 break;
3891
3892 case PLUS_EXPR:
3893 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3894 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3895 break;
3896
3897 case MINUS_EXPR:
3898 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3899 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3900 /* The difference of two local labels is computable at link time. */
3901 if (reloc == 1 && reloc2 == 1)
3902 reloc = 0;
3903 else
3904 reloc |= reloc2;
3905 break;
3906
3907 case NOP_EXPR:
3908 case CONVERT_EXPR:
3909 case NON_LVALUE_EXPR:
3910 case VIEW_CONVERT_EXPR:
3911 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3912 break;
3913
3914 case CONSTRUCTOR:
3915 {
3916 unsigned HOST_WIDE_INT idx;
3917 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
3918 if (tem != 0)
3919 reloc |= compute_reloc_for_constant (tem);
3920 }
3921 break;
3922
3923 default:
3924 break;
3925 }
3926 return reloc;
3927 }
3928
3929 /* Find all the constants whose addresses are referenced inside of EXP,
3930 and make sure assembler code with a label has been output for each one.
3931 Indicate whether an ADDR_EXPR has been encountered. */
3932
3933 static void
3934 output_addressed_constants (tree exp)
3935 {
3936 tree tem;
3937
3938 /* Give the front-end a chance to convert VALUE to something that
3939 looks more like a constant to the back-end. */
3940 exp = lang_hooks.expand_constant (exp);
3941
3942 switch (TREE_CODE (exp))
3943 {
3944 case ADDR_EXPR:
3945 case FDESC_EXPR:
3946 /* Go inside any operations that get_inner_reference can handle and see
3947 if what's inside is a constant: no need to do anything here for
3948 addresses of variables or functions. */
3949 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3950 tem = TREE_OPERAND (tem, 0))
3951 ;
3952
3953 /* If we have an initialized CONST_DECL, retrieve the initializer. */
3954 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem))
3955 tem = DECL_INITIAL (tem);
3956
3957 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR)
3958 output_constant_def (tem, 0);
3959 break;
3960
3961 case PLUS_EXPR:
3962 case MINUS_EXPR:
3963 output_addressed_constants (TREE_OPERAND (exp, 1));
3964 /* Fall through. */
3965
3966 case NOP_EXPR:
3967 case CONVERT_EXPR:
3968 case NON_LVALUE_EXPR:
3969 case VIEW_CONVERT_EXPR:
3970 output_addressed_constants (TREE_OPERAND (exp, 0));
3971 break;
3972
3973 case CONSTRUCTOR:
3974 {
3975 unsigned HOST_WIDE_INT idx;
3976 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
3977 if (tem != 0)
3978 output_addressed_constants (tem);
3979 }
3980 break;
3981
3982 default:
3983 break;
3984 }
3985 }
3986 \f
3987 /* Whether a constructor CTOR is a valid static constant initializer if all
3988 its elements are. This used to be internal to initializer_constant_valid_p
3989 and has been exposed to let other functions like categorize_ctor_elements
3990 evaluate the property while walking a constructor for other purposes. */
3991
3992 bool
3993 constructor_static_from_elts_p (tree ctor)
3994 {
3995 return (TREE_CONSTANT (ctor)
3996 && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE
3997 || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE)
3998 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (ctor)));
3999 }
4000
4001 /* Return nonzero if VALUE is a valid constant-valued expression
4002 for use in initializing a static variable; one that can be an
4003 element of a "constant" initializer.
4004
4005 Return null_pointer_node if the value is absolute;
4006 if it is relocatable, return the variable that determines the relocation.
4007 We assume that VALUE has been folded as much as possible;
4008 therefore, we do not need to check for such things as
4009 arithmetic-combinations of integers. */
4010
4011 tree
4012 initializer_constant_valid_p (tree value, tree endtype)
4013 {
4014 /* Give the front-end a chance to convert VALUE to something that
4015 looks more like a constant to the back-end. */
4016 value = lang_hooks.expand_constant (value);
4017
4018 switch (TREE_CODE (value))
4019 {
4020 case CONSTRUCTOR:
4021 if (constructor_static_from_elts_p (value))
4022 {
4023 unsigned HOST_WIDE_INT idx;
4024 tree elt;
4025 bool absolute = true;
4026
4027 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4028 {
4029 tree reloc;
4030 reloc = initializer_constant_valid_p (elt, TREE_TYPE (elt));
4031 if (!reloc)
4032 return NULL_TREE;
4033 if (reloc != null_pointer_node)
4034 absolute = false;
4035 }
4036 /* For a non-absolute relocation, there is no single
4037 variable that can be "the variable that determines the
4038 relocation." */
4039 return absolute ? null_pointer_node : error_mark_node;
4040 }
4041
4042 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
4043
4044 case INTEGER_CST:
4045 case VECTOR_CST:
4046 case REAL_CST:
4047 case STRING_CST:
4048 case COMPLEX_CST:
4049 return null_pointer_node;
4050
4051 case ADDR_EXPR:
4052 case FDESC_EXPR:
4053 value = staticp (TREE_OPERAND (value, 0));
4054 if (value)
4055 {
4056 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out to
4057 be a constant, this is old-skool offsetof-like nonsense. */
4058 if (TREE_CODE (value) == INDIRECT_REF
4059 && TREE_CONSTANT (TREE_OPERAND (value, 0)))
4060 return null_pointer_node;
4061 /* Taking the address of a nested function involves a trampoline. */
4062 if (TREE_CODE (value) == FUNCTION_DECL
4063 && decl_function_context (value)
4064 && !DECL_NO_STATIC_CHAIN (value))
4065 return NULL_TREE;
4066 /* "&{...}" requires a temporary to hold the constructed
4067 object. */
4068 if (TREE_CODE (value) == CONSTRUCTOR)
4069 return NULL_TREE;
4070 }
4071 return value;
4072
4073 case VIEW_CONVERT_EXPR:
4074 case NON_LVALUE_EXPR:
4075 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
4076
4077 case CONVERT_EXPR:
4078 case NOP_EXPR:
4079 {
4080 tree src;
4081 tree src_type;
4082 tree dest_type;
4083
4084 src = TREE_OPERAND (value, 0);
4085 src_type = TREE_TYPE (src);
4086 dest_type = TREE_TYPE (value);
4087
4088 /* Allow conversions between pointer types, floating-point
4089 types, and offset types. */
4090 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
4091 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
4092 || (TREE_CODE (dest_type) == OFFSET_TYPE
4093 && TREE_CODE (src_type) == OFFSET_TYPE))
4094 return initializer_constant_valid_p (src, endtype);
4095
4096 /* Allow length-preserving conversions between integer types. */
4097 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
4098 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
4099 return initializer_constant_valid_p (src, endtype);
4100
4101 /* Allow conversions between other integer types only if
4102 explicit value. */
4103 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
4104 {
4105 tree inner = initializer_constant_valid_p (src, endtype);
4106 if (inner == null_pointer_node)
4107 return null_pointer_node;
4108 break;
4109 }
4110
4111 /* Allow (int) &foo provided int is as wide as a pointer. */
4112 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
4113 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
4114 return initializer_constant_valid_p (src, endtype);
4115
4116 /* Likewise conversions from int to pointers, but also allow
4117 conversions from 0. */
4118 if ((POINTER_TYPE_P (dest_type)
4119 || TREE_CODE (dest_type) == OFFSET_TYPE)
4120 && INTEGRAL_TYPE_P (src_type))
4121 {
4122 if (TREE_CODE (src) == INTEGER_CST
4123 && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))
4124 return null_pointer_node;
4125 if (integer_zerop (src))
4126 return null_pointer_node;
4127 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
4128 return initializer_constant_valid_p (src, endtype);
4129 }
4130
4131 /* Allow conversions to struct or union types if the value
4132 inside is okay. */
4133 if (TREE_CODE (dest_type) == RECORD_TYPE
4134 || TREE_CODE (dest_type) == UNION_TYPE)
4135 return initializer_constant_valid_p (src, endtype);
4136 }
4137 break;
4138
4139 case PLUS_EXPR:
4140 if (! INTEGRAL_TYPE_P (endtype)
4141 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4142 {
4143 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4144 endtype);
4145 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4146 endtype);
4147 /* If either term is absolute, use the other terms relocation. */
4148 if (valid0 == null_pointer_node)
4149 return valid1;
4150 if (valid1 == null_pointer_node)
4151 return valid0;
4152 }
4153 break;
4154
4155 case MINUS_EXPR:
4156 if (! INTEGRAL_TYPE_P (endtype)
4157 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4158 {
4159 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4160 endtype);
4161 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4162 endtype);
4163 /* Win if second argument is absolute. */
4164 if (valid1 == null_pointer_node)
4165 return valid0;
4166 /* Win if both arguments have the same relocation.
4167 Then the value is absolute. */
4168 if (valid0 == valid1 && valid0 != 0)
4169 return null_pointer_node;
4170
4171 /* Since GCC guarantees that string constants are unique in the
4172 generated code, a subtraction between two copies of the same
4173 constant string is absolute. */
4174 if (valid0 && TREE_CODE (valid0) == STRING_CST
4175 && valid1 && TREE_CODE (valid1) == STRING_CST
4176 && operand_equal_p (valid0, valid1, 1))
4177 return null_pointer_node;
4178 }
4179
4180 /* Support narrowing differences. */
4181 if (INTEGRAL_TYPE_P (endtype))
4182 {
4183 tree op0, op1;
4184
4185 op0 = TREE_OPERAND (value, 0);
4186 op1 = TREE_OPERAND (value, 1);
4187
4188 /* Like STRIP_NOPS except allow the operand mode to widen.
4189 This works around a feature of fold that simplifies
4190 (int)(p1 - p2) to ((int)p1 - (int)p2) under the theory
4191 that the narrower operation is cheaper. */
4192
4193 while (TREE_CODE (op0) == NOP_EXPR
4194 || TREE_CODE (op0) == CONVERT_EXPR
4195 || TREE_CODE (op0) == NON_LVALUE_EXPR)
4196 {
4197 tree inner = TREE_OPERAND (op0, 0);
4198 if (inner == error_mark_node
4199 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4200 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
4201 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4202 break;
4203 op0 = inner;
4204 }
4205
4206 while (TREE_CODE (op1) == NOP_EXPR
4207 || TREE_CODE (op1) == CONVERT_EXPR
4208 || TREE_CODE (op1) == NON_LVALUE_EXPR)
4209 {
4210 tree inner = TREE_OPERAND (op1, 0);
4211 if (inner == error_mark_node
4212 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4213 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
4214 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4215 break;
4216 op1 = inner;
4217 }
4218
4219 op0 = initializer_constant_valid_p (op0, endtype);
4220 op1 = initializer_constant_valid_p (op1, endtype);
4221
4222 /* Both initializers must be known. */
4223 if (op0 && op1)
4224 {
4225 if (op0 == op1)
4226 return null_pointer_node;
4227
4228 /* Support differences between labels. */
4229 if (TREE_CODE (op0) == LABEL_DECL
4230 && TREE_CODE (op1) == LABEL_DECL)
4231 return null_pointer_node;
4232
4233 if (TREE_CODE (op0) == STRING_CST
4234 && TREE_CODE (op1) == STRING_CST
4235 && operand_equal_p (op0, op1, 1))
4236 return null_pointer_node;
4237 }
4238 }
4239 break;
4240
4241 default:
4242 break;
4243 }
4244
4245 return 0;
4246 }
4247 \f
4248 /* Output assembler code for constant EXP to FILE, with no label.
4249 This includes the pseudo-op such as ".int" or ".byte", and a newline.
4250 Assumes output_addressed_constants has been done on EXP already.
4251
4252 Generate exactly SIZE bytes of assembler data, padding at the end
4253 with zeros if necessary. SIZE must always be specified.
4254
4255 SIZE is important for structure constructors,
4256 since trailing members may have been omitted from the constructor.
4257 It is also important for initialization of arrays from string constants
4258 since the full length of the string constant might not be wanted.
4259 It is also needed for initialization of unions, where the initializer's
4260 type is just one member, and that may not be as long as the union.
4261
4262 There a case in which we would fail to output exactly SIZE bytes:
4263 for a structure constructor that wants to produce more than SIZE bytes.
4264 But such constructors will never be generated for any possible input.
4265
4266 ALIGN is the alignment of the data in bits. */
4267
4268 void
4269 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
4270 {
4271 enum tree_code code;
4272 unsigned HOST_WIDE_INT thissize;
4273
4274 /* Some front-ends use constants other than the standard language-independent
4275 varieties, but which may still be output directly. Give the front-end a
4276 chance to convert EXP to a language-independent representation. */
4277 exp = lang_hooks.expand_constant (exp);
4278
4279 if (size == 0 || flag_syntax_only)
4280 return;
4281
4282 /* See if we're trying to initialize a pointer in a non-default mode
4283 to the address of some declaration somewhere. If the target says
4284 the mode is valid for pointers, assume the target has a way of
4285 resolving it. */
4286 if (TREE_CODE (exp) == NOP_EXPR
4287 && POINTER_TYPE_P (TREE_TYPE (exp))
4288 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4289 {
4290 tree saved_type = TREE_TYPE (exp);
4291
4292 /* Peel off any intermediate conversions-to-pointer for valid
4293 pointer modes. */
4294 while (TREE_CODE (exp) == NOP_EXPR
4295 && POINTER_TYPE_P (TREE_TYPE (exp))
4296 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4297 exp = TREE_OPERAND (exp, 0);
4298
4299 /* If what we're left with is the address of something, we can
4300 convert the address to the final type and output it that
4301 way. */
4302 if (TREE_CODE (exp) == ADDR_EXPR)
4303 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0));
4304 /* Likewise for constant ints. */
4305 else if (TREE_CODE (exp) == INTEGER_CST)
4306 exp = build_int_cst_wide (saved_type, TREE_INT_CST_LOW (exp),
4307 TREE_INT_CST_HIGH (exp));
4308
4309 }
4310
4311 /* Eliminate any conversions since we'll be outputting the underlying
4312 constant. */
4313 while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR
4314 || TREE_CODE (exp) == NON_LVALUE_EXPR
4315 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
4316 {
4317 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp));
4318 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0)));
4319
4320 /* Make sure eliminating the conversion is really a no-op, except with
4321 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and
4322 union types to allow for Ada unchecked unions. */
4323 if (type_size > op_size
4324 && TREE_CODE (exp) != VIEW_CONVERT_EXPR
4325 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE)
4326 /* Keep the conversion. */
4327 break;
4328 else
4329 exp = TREE_OPERAND (exp, 0);
4330 }
4331
4332 code = TREE_CODE (TREE_TYPE (exp));
4333 thissize = int_size_in_bytes (TREE_TYPE (exp));
4334
4335 /* Give the front end another chance to expand constants. */
4336 exp = lang_hooks.expand_constant (exp);
4337
4338 /* Allow a constructor with no elements for any data type.
4339 This means to fill the space with zeros. */
4340 if (TREE_CODE (exp) == CONSTRUCTOR
4341 && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp)))
4342 {
4343 assemble_zeros (size);
4344 return;
4345 }
4346
4347 if (TREE_CODE (exp) == FDESC_EXPR)
4348 {
4349 #ifdef ASM_OUTPUT_FDESC
4350 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
4351 tree decl = TREE_OPERAND (exp, 0);
4352 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
4353 #else
4354 gcc_unreachable ();
4355 #endif
4356 return;
4357 }
4358
4359 /* Now output the underlying data. If we've handling the padding, return.
4360 Otherwise, break and ensure SIZE is the size written. */
4361 switch (code)
4362 {
4363 case BOOLEAN_TYPE:
4364 case INTEGER_TYPE:
4365 case ENUMERAL_TYPE:
4366 case POINTER_TYPE:
4367 case REFERENCE_TYPE:
4368 case OFFSET_TYPE:
4369 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
4370 EXPAND_INITIALIZER),
4371 MIN (size, thissize), align, 0))
4372 error ("initializer for integer value is too complicated");
4373 break;
4374
4375 case REAL_TYPE:
4376 if (TREE_CODE (exp) != REAL_CST)
4377 error ("initializer for floating value is not a floating constant");
4378
4379 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
4380 break;
4381
4382 case COMPLEX_TYPE:
4383 output_constant (TREE_REALPART (exp), thissize / 2, align);
4384 output_constant (TREE_IMAGPART (exp), thissize / 2,
4385 min_align (align, BITS_PER_UNIT * (thissize / 2)));
4386 break;
4387
4388 case ARRAY_TYPE:
4389 case VECTOR_TYPE:
4390 switch (TREE_CODE (exp))
4391 {
4392 case CONSTRUCTOR:
4393 output_constructor (exp, size, align);
4394 return;
4395 case STRING_CST:
4396 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
4397 size);
4398 assemble_string (TREE_STRING_POINTER (exp), thissize);
4399 break;
4400
4401 case VECTOR_CST:
4402 {
4403 int elt_size;
4404 tree link;
4405 unsigned int nalign;
4406 enum machine_mode inner;
4407
4408 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
4409 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
4410
4411 elt_size = GET_MODE_SIZE (inner);
4412
4413 link = TREE_VECTOR_CST_ELTS (exp);
4414 output_constant (TREE_VALUE (link), elt_size, align);
4415 thissize = elt_size;
4416 while ((link = TREE_CHAIN (link)) != NULL)
4417 {
4418 output_constant (TREE_VALUE (link), elt_size, nalign);
4419 thissize += elt_size;
4420 }
4421 break;
4422 }
4423 default:
4424 gcc_unreachable ();
4425 }
4426 break;
4427
4428 case RECORD_TYPE:
4429 case UNION_TYPE:
4430 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);
4431 output_constructor (exp, size, align);
4432 return;
4433
4434 case ERROR_MARK:
4435 return;
4436
4437 default:
4438 gcc_unreachable ();
4439 }
4440
4441 if (size > thissize)
4442 assemble_zeros (size - thissize);
4443 }
4444
4445 \f
4446 /* Subroutine of output_constructor, used for computing the size of
4447 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
4448 type with an unspecified upper bound. */
4449
4450 static unsigned HOST_WIDE_INT
4451 array_size_for_constructor (tree val)
4452 {
4453 tree max_index, i;
4454 unsigned HOST_WIDE_INT cnt;
4455 tree index, value, tmp;
4456
4457 /* This code used to attempt to handle string constants that are not
4458 arrays of single-bytes, but nothing else does, so there's no point in
4459 doing it here. */
4460 if (TREE_CODE (val) == STRING_CST)
4461 return TREE_STRING_LENGTH (val);
4462
4463 max_index = NULL_TREE;
4464 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value)
4465 {
4466 if (TREE_CODE (index) == RANGE_EXPR)
4467 index = TREE_OPERAND (index, 1);
4468 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
4469 max_index = index;
4470 }
4471
4472 if (max_index == NULL_TREE)
4473 return 0;
4474
4475 /* Compute the total number of array elements. */
4476 tmp = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)));
4477 i = size_binop (MINUS_EXPR, fold_convert (sizetype, max_index),
4478 fold_convert (sizetype, tmp));
4479 i = size_binop (PLUS_EXPR, i, build_int_cst (sizetype, 1));
4480
4481 /* Multiply by the array element unit size to find number of bytes. */
4482 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
4483
4484 return tree_low_cst (i, 1);
4485 }
4486
4487 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
4488 Generate at least SIZE bytes, padding if necessary. */
4489
4490 static void
4491 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
4492 unsigned int align)
4493 {
4494 tree type = TREE_TYPE (exp);
4495 tree field = 0;
4496 tree min_index = 0;
4497 /* Number of bytes output or skipped so far.
4498 In other words, current position within the constructor. */
4499 HOST_WIDE_INT total_bytes = 0;
4500 /* Nonzero means BYTE contains part of a byte, to be output. */
4501 int byte_buffer_in_use = 0;
4502 int byte = 0;
4503 unsigned HOST_WIDE_INT cnt;
4504 constructor_elt *ce;
4505
4506 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT);
4507
4508 if (TREE_CODE (type) == RECORD_TYPE)
4509 field = TYPE_FIELDS (type);
4510
4511 if (TREE_CODE (type) == ARRAY_TYPE
4512 && TYPE_DOMAIN (type) != 0)
4513 min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
4514
4515 /* As LINK goes through the elements of the constant,
4516 FIELD goes through the structure fields, if the constant is a structure.
4517 if the constant is a union, then we override this,
4518 by getting the field from the TREE_LIST element.
4519 But the constant could also be an array. Then FIELD is zero.
4520
4521 There is always a maximum of one element in the chain LINK for unions
4522 (even if the initializer in a source program incorrectly contains
4523 more one). */
4524 for (cnt = 0;
4525 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce);
4526 cnt++, field = field ? TREE_CHAIN (field) : 0)
4527 {
4528 tree val = ce->value;
4529 tree index = 0;
4530
4531 /* The element in a union constructor specifies the proper field
4532 or index. */
4533 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
4534 || TREE_CODE (type) == QUAL_UNION_TYPE)
4535 && ce->index != 0)
4536 field = ce->index;
4537
4538 else if (TREE_CODE (type) == ARRAY_TYPE)
4539 index = ce->index;
4540
4541 #ifdef ASM_COMMENT_START
4542 if (field && flag_verbose_asm)
4543 fprintf (asm_out_file, "%s %s:\n",
4544 ASM_COMMENT_START,
4545 DECL_NAME (field)
4546 ? IDENTIFIER_POINTER (DECL_NAME (field))
4547 : "<anonymous>");
4548 #endif
4549
4550 /* Eliminate the marker that makes a cast not be an lvalue. */
4551 if (val != 0)
4552 STRIP_NOPS (val);
4553
4554 if (index && TREE_CODE (index) == RANGE_EXPR)
4555 {
4556 unsigned HOST_WIDE_INT fieldsize
4557 = int_size_in_bytes (TREE_TYPE (type));
4558 HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0);
4559 HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0);
4560 HOST_WIDE_INT index;
4561 unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT);
4562
4563 for (index = lo_index; index <= hi_index; index++)
4564 {
4565 /* Output the element's initial value. */
4566 if (val == 0)
4567 assemble_zeros (fieldsize);
4568 else
4569 output_constant (val, fieldsize, align2);
4570
4571 /* Count its size. */
4572 total_bytes += fieldsize;
4573 }
4574 }
4575 else if (field == 0 || !DECL_BIT_FIELD (field))
4576 {
4577 /* An element that is not a bit-field. */
4578
4579 unsigned HOST_WIDE_INT fieldsize;
4580 /* Since this structure is static,
4581 we know the positions are constant. */
4582 HOST_WIDE_INT pos = field ? int_byte_position (field) : 0;
4583 unsigned int align2;
4584
4585 if (index != 0)
4586 pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1)
4587 * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0)));
4588
4589 /* Output any buffered-up bit-fields preceding this element. */
4590 if (byte_buffer_in_use)
4591 {
4592 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4593 total_bytes++;
4594 byte_buffer_in_use = 0;
4595 }
4596
4597 /* Advance to offset of this element.
4598 Note no alignment needed in an array, since that is guaranteed
4599 if each element has the proper size. */
4600 if ((field != 0 || index != 0) && pos != total_bytes)
4601 {
4602 gcc_assert (pos >= total_bytes);
4603 assemble_zeros (pos - total_bytes);
4604 total_bytes = pos;
4605 }
4606
4607 /* Find the alignment of this element. */
4608 align2 = min_align (align, BITS_PER_UNIT * pos);
4609
4610 /* Determine size this element should occupy. */
4611 if (field)
4612 {
4613 fieldsize = 0;
4614
4615 /* If this is an array with an unspecified upper bound,
4616 the initializer determines the size. */
4617 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4618 but we cannot do this until the deprecated support for
4619 initializing zero-length array members is removed. */
4620 if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE
4621 && TYPE_DOMAIN (TREE_TYPE (field))
4622 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field))))
4623 {
4624 fieldsize = array_size_for_constructor (val);
4625 /* Given a non-empty initialization, this field had
4626 better be last. */
4627 gcc_assert (!fieldsize || !TREE_CHAIN (field));
4628 }
4629 else if (DECL_SIZE_UNIT (field))
4630 {
4631 /* ??? This can't be right. If the decl size overflows
4632 a host integer we will silently emit no data. */
4633 if (host_integerp (DECL_SIZE_UNIT (field), 1))
4634 fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1);
4635 }
4636 }
4637 else
4638 fieldsize = int_size_in_bytes (TREE_TYPE (type));
4639
4640 /* Output the element's initial value. */
4641 if (val == 0)
4642 assemble_zeros (fieldsize);
4643 else
4644 output_constant (val, fieldsize, align2);
4645
4646 /* Count its size. */
4647 total_bytes += fieldsize;
4648 }
4649 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
4650 error ("invalid initial value for member %qs",
4651 IDENTIFIER_POINTER (DECL_NAME (field)));
4652 else
4653 {
4654 /* Element that is a bit-field. */
4655
4656 HOST_WIDE_INT next_offset = int_bit_position (field);
4657 HOST_WIDE_INT end_offset
4658 = (next_offset + tree_low_cst (DECL_SIZE (field), 1));
4659
4660 if (val == 0)
4661 val = integer_zero_node;
4662
4663 /* If this field does not start in this (or, next) byte,
4664 skip some bytes. */
4665 if (next_offset / BITS_PER_UNIT != total_bytes)
4666 {
4667 /* Output remnant of any bit field in previous bytes. */
4668 if (byte_buffer_in_use)
4669 {
4670 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4671 total_bytes++;
4672 byte_buffer_in_use = 0;
4673 }
4674
4675 /* If still not at proper byte, advance to there. */
4676 if (next_offset / BITS_PER_UNIT != total_bytes)
4677 {
4678 gcc_assert (next_offset / BITS_PER_UNIT >= total_bytes);
4679 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
4680 total_bytes = next_offset / BITS_PER_UNIT;
4681 }
4682 }
4683
4684 if (! byte_buffer_in_use)
4685 byte = 0;
4686
4687 /* We must split the element into pieces that fall within
4688 separate bytes, and combine each byte with previous or
4689 following bit-fields. */
4690
4691 /* next_offset is the offset n fbits from the beginning of
4692 the structure to the next bit of this element to be processed.
4693 end_offset is the offset of the first bit past the end of
4694 this element. */
4695 while (next_offset < end_offset)
4696 {
4697 int this_time;
4698 int shift;
4699 HOST_WIDE_INT value;
4700 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4701 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4702
4703 /* Advance from byte to byte
4704 within this element when necessary. */
4705 while (next_byte != total_bytes)
4706 {
4707 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4708 total_bytes++;
4709 byte = 0;
4710 }
4711
4712 /* Number of bits we can process at once
4713 (all part of the same byte). */
4714 this_time = MIN (end_offset - next_offset,
4715 BITS_PER_UNIT - next_bit);
4716 if (BYTES_BIG_ENDIAN)
4717 {
4718 /* On big-endian machine, take the most significant bits
4719 first (of the bits that are significant)
4720 and put them into bytes from the most significant end. */
4721 shift = end_offset - next_offset - this_time;
4722
4723 /* Don't try to take a bunch of bits that cross
4724 the word boundary in the INTEGER_CST. We can
4725 only select bits from the LOW or HIGH part
4726 not from both. */
4727 if (shift < HOST_BITS_PER_WIDE_INT
4728 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4729 {
4730 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4731 shift = HOST_BITS_PER_WIDE_INT;
4732 }
4733
4734 /* Now get the bits from the appropriate constant word. */
4735 if (shift < HOST_BITS_PER_WIDE_INT)
4736 value = TREE_INT_CST_LOW (val);
4737 else
4738 {
4739 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4740 value = TREE_INT_CST_HIGH (val);
4741 shift -= HOST_BITS_PER_WIDE_INT;
4742 }
4743
4744 /* Get the result. This works only when:
4745 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4746 byte |= (((value >> shift)
4747 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4748 << (BITS_PER_UNIT - this_time - next_bit));
4749 }
4750 else
4751 {
4752 /* On little-endian machines,
4753 take first the least significant bits of the value
4754 and pack them starting at the least significant
4755 bits of the bytes. */
4756 shift = next_offset - int_bit_position (field);
4757
4758 /* Don't try to take a bunch of bits that cross
4759 the word boundary in the INTEGER_CST. We can
4760 only select bits from the LOW or HIGH part
4761 not from both. */
4762 if (shift < HOST_BITS_PER_WIDE_INT
4763 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4764 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4765
4766 /* Now get the bits from the appropriate constant word. */
4767 if (shift < HOST_BITS_PER_WIDE_INT)
4768 value = TREE_INT_CST_LOW (val);
4769 else
4770 {
4771 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4772 value = TREE_INT_CST_HIGH (val);
4773 shift -= HOST_BITS_PER_WIDE_INT;
4774 }
4775
4776 /* Get the result. This works only when:
4777 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4778 byte |= (((value >> shift)
4779 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4780 << next_bit);
4781 }
4782
4783 next_offset += this_time;
4784 byte_buffer_in_use = 1;
4785 }
4786 }
4787 }
4788
4789 if (byte_buffer_in_use)
4790 {
4791 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4792 total_bytes++;
4793 }
4794
4795 if ((unsigned HOST_WIDE_INT)total_bytes < size)
4796 assemble_zeros (size - total_bytes);
4797 }
4798
4799 /* This TREE_LIST contains any weak symbol declarations waiting
4800 to be emitted. */
4801 static GTY(()) tree weak_decls;
4802
4803 /* Mark DECL as weak. */
4804
4805 static void
4806 mark_weak (tree decl)
4807 {
4808 DECL_WEAK (decl) = 1;
4809
4810 if (DECL_RTL_SET_P (decl)
4811 && MEM_P (DECL_RTL (decl))
4812 && XEXP (DECL_RTL (decl), 0)
4813 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
4814 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
4815 }
4816
4817 /* Merge weak status between NEWDECL and OLDDECL. */
4818
4819 void
4820 merge_weak (tree newdecl, tree olddecl)
4821 {
4822 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
4823 {
4824 if (DECL_WEAK (newdecl) && SUPPORTS_WEAK)
4825 {
4826 tree *pwd;
4827 /* We put the NEWDECL on the weak_decls list at some point
4828 and OLDDECL as well. Keep just OLDDECL on the list. */
4829 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd))
4830 if (TREE_VALUE (*pwd) == newdecl)
4831 {
4832 *pwd = TREE_CHAIN (*pwd);
4833 break;
4834 }
4835 }
4836 return;
4837 }
4838
4839 if (DECL_WEAK (newdecl))
4840 {
4841 tree wd;
4842
4843 /* NEWDECL is weak, but OLDDECL is not. */
4844
4845 /* If we already output the OLDDECL, we're in trouble; we can't
4846 go back and make it weak. This error cannot caught in
4847 declare_weak because the NEWDECL and OLDDECL was not yet
4848 been merged; therefore, TREE_ASM_WRITTEN was not set. */
4849 if (TREE_ASM_WRITTEN (olddecl))
4850 error ("weak declaration of %q+D must precede definition",
4851 newdecl);
4852
4853 /* If we've already generated rtl referencing OLDDECL, we may
4854 have done so in a way that will not function properly with
4855 a weak symbol. */
4856 else if (TREE_USED (olddecl)
4857 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
4858 warning (0, "weak declaration of %q+D after first use results "
4859 "in unspecified behavior", newdecl);
4860
4861 if (SUPPORTS_WEAK)
4862 {
4863 /* We put the NEWDECL on the weak_decls list at some point.
4864 Replace it with the OLDDECL. */
4865 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
4866 if (TREE_VALUE (wd) == newdecl)
4867 {
4868 TREE_VALUE (wd) = olddecl;
4869 break;
4870 }
4871 /* We may not find the entry on the list. If NEWDECL is a
4872 weak alias, then we will have already called
4873 globalize_decl to remove the entry; in that case, we do
4874 not need to do anything. */
4875 }
4876
4877 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
4878 mark_weak (olddecl);
4879 }
4880 else
4881 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
4882 weak. Just update NEWDECL to indicate that it's weak too. */
4883 mark_weak (newdecl);
4884 }
4885
4886 /* Declare DECL to be a weak symbol. */
4887
4888 void
4889 declare_weak (tree decl)
4890 {
4891 if (! TREE_PUBLIC (decl))
4892 error ("weak declaration of %q+D must be public", decl);
4893 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
4894 error ("weak declaration of %q+D must precede definition", decl);
4895 else if (SUPPORTS_WEAK)
4896 {
4897 if (! DECL_WEAK (decl))
4898 weak_decls = tree_cons (NULL, decl, weak_decls);
4899 }
4900 else
4901 warning (0, "weak declaration of %q+D not supported", decl);
4902
4903 mark_weak (decl);
4904 }
4905
4906 static void
4907 weak_finish_1 (tree decl)
4908 {
4909 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
4910 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4911 #endif
4912
4913 if (! TREE_USED (decl))
4914 return;
4915
4916 #ifdef ASM_WEAKEN_DECL
4917 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
4918 #else
4919 #ifdef ASM_WEAKEN_LABEL
4920 ASM_WEAKEN_LABEL (asm_out_file, name);
4921 #else
4922 #ifdef ASM_OUTPUT_WEAK_ALIAS
4923 {
4924 static bool warn_once = 0;
4925 if (! warn_once)
4926 {
4927 warning (0, "only weak aliases are supported in this configuration");
4928 warn_once = 1;
4929 }
4930 return;
4931 }
4932 #endif
4933 #endif
4934 #endif
4935 }
4936
4937 /* This TREE_LIST contains weakref targets. */
4938
4939 static GTY(()) tree weakref_targets;
4940
4941 /* Forward declaration. */
4942 static tree find_decl_and_mark_needed (tree decl, tree target);
4943
4944 /* Emit any pending weak declarations. */
4945
4946 void
4947 weak_finish (void)
4948 {
4949 tree t;
4950
4951 for (t = weakref_targets; t; t = TREE_CHAIN (t))
4952 {
4953 tree alias_decl = TREE_PURPOSE (t);
4954 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t));
4955
4956 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl)))
4957 /* Remove alias_decl from the weak list, but leave entries for
4958 the target alone. */
4959 target = NULL_TREE;
4960 #ifndef ASM_OUTPUT_WEAKREF
4961 else if (! TREE_SYMBOL_REFERENCED (target))
4962 {
4963 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not
4964 defined, otherwise we and weak_finish_1 would use a
4965 different macros. */
4966 # if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL
4967 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target));
4968 # else
4969 tree decl = find_decl_and_mark_needed (alias_decl, target);
4970
4971 if (! decl)
4972 {
4973 decl = build_decl (TREE_CODE (alias_decl), target,
4974 TREE_TYPE (alias_decl));
4975
4976 DECL_EXTERNAL (decl) = 1;
4977 TREE_PUBLIC (decl) = 1;
4978 DECL_ARTIFICIAL (decl) = 1;
4979 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl);
4980 TREE_USED (decl) = 1;
4981 }
4982
4983 weak_finish_1 (decl);
4984 # endif
4985 }
4986 #endif
4987
4988 {
4989 tree *p;
4990 tree t2;
4991
4992 /* Remove the alias and the target from the pending weak list
4993 so that we do not emit any .weak directives for the former,
4994 nor multiple .weak directives for the latter. */
4995 for (p = &weak_decls; (t2 = *p) ; )
4996 {
4997 if (TREE_VALUE (t2) == alias_decl
4998 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2)))
4999 *p = TREE_CHAIN (t2);
5000 else
5001 p = &TREE_CHAIN (t2);
5002 }
5003
5004 /* Remove other weakrefs to the same target, to speed things up. */
5005 for (p = &TREE_CHAIN (t); (t2 = *p) ; )
5006 {
5007 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2)))
5008 *p = TREE_CHAIN (t2);
5009 else
5010 p = &TREE_CHAIN (t2);
5011 }
5012 }
5013 }
5014
5015 for (t = weak_decls; t; t = TREE_CHAIN (t))
5016 {
5017 tree decl = TREE_VALUE (t);
5018
5019 weak_finish_1 (decl);
5020 }
5021 }
5022
5023 /* Emit the assembly bits to indicate that DECL is globally visible. */
5024
5025 static void
5026 globalize_decl (tree decl)
5027 {
5028
5029 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
5030 if (DECL_WEAK (decl))
5031 {
5032 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
5033 tree *p, t;
5034
5035 #ifdef ASM_WEAKEN_DECL
5036 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
5037 #else
5038 ASM_WEAKEN_LABEL (asm_out_file, name);
5039 #endif
5040
5041 /* Remove this function from the pending weak list so that
5042 we do not emit multiple .weak directives for it. */
5043 for (p = &weak_decls; (t = *p) ; )
5044 {
5045 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5046 *p = TREE_CHAIN (t);
5047 else
5048 p = &TREE_CHAIN (t);
5049 }
5050
5051 /* Remove weakrefs to the same target from the pending weakref
5052 list, for the same reason. */
5053 for (p = &weakref_targets; (t = *p) ; )
5054 {
5055 if (DECL_ASSEMBLER_NAME (decl)
5056 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5057 *p = TREE_CHAIN (t);
5058 else
5059 p = &TREE_CHAIN (t);
5060 }
5061
5062 return;
5063 }
5064 #endif
5065
5066 targetm.asm_out.globalize_decl_name (asm_out_file, decl);
5067 }
5068
5069 /* We have to be able to tell cgraph about the needed-ness of the target
5070 of an alias. This requires that the decl have been defined. Aliases
5071 that precede their definition have to be queued for later processing. */
5072
5073 typedef struct alias_pair GTY(())
5074 {
5075 tree decl;
5076 tree target;
5077 } alias_pair;
5078
5079 /* Define gc'd vector type. */
5080 DEF_VEC_O(alias_pair);
5081 DEF_VEC_ALLOC_O(alias_pair,gc);
5082
5083 static GTY(()) VEC(alias_pair,gc) *alias_pairs;
5084
5085 /* Given an assembly name, find the decl it is associated with. At the
5086 same time, mark it needed for cgraph. */
5087
5088 static tree
5089 find_decl_and_mark_needed (tree decl, tree target)
5090 {
5091 struct cgraph_node *fnode = NULL;
5092 struct varpool_node *vnode = NULL;
5093
5094 if (TREE_CODE (decl) == FUNCTION_DECL)
5095 {
5096 fnode = cgraph_node_for_asm (target);
5097 if (fnode == NULL)
5098 vnode = varpool_node_for_asm (target);
5099 }
5100 else
5101 {
5102 vnode = varpool_node_for_asm (target);
5103 if (vnode == NULL)
5104 fnode = cgraph_node_for_asm (target);
5105 }
5106
5107 if (fnode)
5108 {
5109 /* We can't mark function nodes as used after cgraph global info
5110 is finished. This wouldn't generally be necessary, but C++
5111 virtual table thunks are introduced late in the game and
5112 might seem like they need marking, although in fact they
5113 don't. */
5114 if (! cgraph_global_info_ready)
5115 cgraph_mark_needed_node (fnode);
5116 return fnode->decl;
5117 }
5118 else if (vnode)
5119 {
5120 varpool_mark_needed_node (vnode);
5121 return vnode->decl;
5122 }
5123 else
5124 return NULL_TREE;
5125 }
5126
5127 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
5128 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
5129 tree node is DECL to have the value of the tree node TARGET. */
5130
5131 static void
5132 do_assemble_alias (tree decl, tree target)
5133 {
5134 if (TREE_ASM_WRITTEN (decl))
5135 return;
5136
5137 TREE_ASM_WRITTEN (decl) = 1;
5138 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
5139
5140 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5141 {
5142 ultimate_transparent_alias_target (&target);
5143
5144 if (!targetm.have_tls
5145 && TREE_CODE (decl) == VAR_DECL
5146 && DECL_THREAD_LOCAL_P (decl))
5147 {
5148 decl = emutls_decl (decl);
5149 target = get_emutls_object_name (target);
5150 }
5151
5152 if (!TREE_SYMBOL_REFERENCED (target))
5153 weakref_targets = tree_cons (decl, target, weakref_targets);
5154
5155 #ifdef ASM_OUTPUT_WEAKREF
5156 ASM_OUTPUT_WEAKREF (asm_out_file, decl,
5157 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5158 IDENTIFIER_POINTER (target));
5159 #else
5160 if (!SUPPORTS_WEAK)
5161 {
5162 error ("%Jweakref is not supported in this configuration", decl);
5163 return;
5164 }
5165 #endif
5166 return;
5167 }
5168
5169 if (!targetm.have_tls
5170 && TREE_CODE (decl) == VAR_DECL
5171 && DECL_THREAD_LOCAL_P (decl))
5172 {
5173 decl = emutls_decl (decl);
5174 target = get_emutls_object_name (target);
5175 }
5176
5177 #ifdef ASM_OUTPUT_DEF
5178 /* Make name accessible from other files, if appropriate. */
5179
5180 if (TREE_PUBLIC (decl))
5181 {
5182 globalize_decl (decl);
5183 maybe_assemble_visibility (decl);
5184 }
5185
5186 # ifdef ASM_OUTPUT_DEF_FROM_DECLS
5187 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
5188 # else
5189 ASM_OUTPUT_DEF (asm_out_file,
5190 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5191 IDENTIFIER_POINTER (target));
5192 # endif
5193 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
5194 {
5195 const char *name;
5196 tree *p, t;
5197
5198 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5199 # ifdef ASM_WEAKEN_DECL
5200 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
5201 # else
5202 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
5203 # endif
5204 /* Remove this function from the pending weak list so that
5205 we do not emit multiple .weak directives for it. */
5206 for (p = &weak_decls; (t = *p) ; )
5207 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5208 *p = TREE_CHAIN (t);
5209 else
5210 p = &TREE_CHAIN (t);
5211
5212 /* Remove weakrefs to the same target from the pending weakref
5213 list, for the same reason. */
5214 for (p = &weakref_targets; (t = *p) ; )
5215 {
5216 if (DECL_ASSEMBLER_NAME (decl)
5217 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5218 *p = TREE_CHAIN (t);
5219 else
5220 p = &TREE_CHAIN (t);
5221 }
5222 }
5223 #endif
5224 }
5225
5226 /* First pass of completing pending aliases. Make sure that cgraph knows
5227 which symbols will be required. */
5228
5229 void
5230 finish_aliases_1 (void)
5231 {
5232 unsigned i;
5233 alias_pair *p;
5234
5235 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5236 {
5237 tree target_decl;
5238
5239 target_decl = find_decl_and_mark_needed (p->decl, p->target);
5240 if (target_decl == NULL)
5241 {
5242 if (! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5243 error ("%q+D aliased to undefined symbol %qs",
5244 p->decl, IDENTIFIER_POINTER (p->target));
5245 }
5246 else if (DECL_EXTERNAL (target_decl)
5247 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5248 error ("%q+D aliased to external symbol %qs",
5249 p->decl, IDENTIFIER_POINTER (p->target));
5250 }
5251 }
5252
5253 /* Second pass of completing pending aliases. Emit the actual assembly.
5254 This happens at the end of compilation and thus it is assured that the
5255 target symbol has been emitted. */
5256
5257 void
5258 finish_aliases_2 (void)
5259 {
5260 unsigned i;
5261 alias_pair *p;
5262
5263 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5264 do_assemble_alias (p->decl, p->target);
5265
5266 VEC_truncate (alias_pair, alias_pairs, 0);
5267 }
5268
5269 /* Emit an assembler directive to make the symbol for DECL an alias to
5270 the symbol for TARGET. */
5271
5272 void
5273 assemble_alias (tree decl, tree target)
5274 {
5275 tree target_decl;
5276 bool is_weakref = false;
5277
5278 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5279 {
5280 tree alias = DECL_ASSEMBLER_NAME (decl);
5281
5282 is_weakref = true;
5283
5284 ultimate_transparent_alias_target (&target);
5285
5286 if (alias == target)
5287 error ("weakref %q+D ultimately targets itself", decl);
5288 else
5289 {
5290 #ifndef ASM_OUTPUT_WEAKREF
5291 IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1;
5292 TREE_CHAIN (alias) = target;
5293 #endif
5294 }
5295 if (TREE_PUBLIC (decl))
5296 error ("weakref %q+D must have static linkage", decl);
5297 }
5298 else
5299 {
5300 #if !defined (ASM_OUTPUT_DEF)
5301 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
5302 error ("%Jalias definitions not supported in this configuration", decl);
5303 return;
5304 # else
5305 if (!DECL_WEAK (decl))
5306 {
5307 error ("%Jonly weak aliases are supported in this configuration", decl);
5308 return;
5309 }
5310 # endif
5311 #endif
5312 }
5313
5314 /* We must force creation of DECL_RTL for debug info generation, even though
5315 we don't use it here. */
5316 make_decl_rtl (decl);
5317 TREE_USED (decl) = 1;
5318
5319 /* A quirk of the initial implementation of aliases required that the user
5320 add "extern" to all of them. Which is silly, but now historical. Do
5321 note that the symbol is in fact locally defined. */
5322 if (! is_weakref)
5323 DECL_EXTERNAL (decl) = 0;
5324
5325 /* Allow aliases to aliases. */
5326 if (TREE_CODE (decl) == FUNCTION_DECL)
5327 cgraph_node (decl)->alias = true;
5328 else
5329 varpool_node (decl)->alias = true;
5330
5331 /* If the target has already been emitted, we don't have to queue the
5332 alias. This saves a tad o memory. */
5333 target_decl = find_decl_and_mark_needed (decl, target);
5334 if (target_decl && TREE_ASM_WRITTEN (target_decl))
5335 do_assemble_alias (decl, target);
5336 else
5337 {
5338 alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL);
5339 p->decl = decl;
5340 p->target = target;
5341 }
5342 }
5343
5344 /* Emit an assembler directive to set symbol for DECL visibility to
5345 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
5346
5347 void
5348 default_assemble_visibility (tree decl, int vis)
5349 {
5350 static const char * const visibility_types[] = {
5351 NULL, "protected", "hidden", "internal"
5352 };
5353
5354 const char *name, *type;
5355
5356 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5357 type = visibility_types[vis];
5358
5359 #ifdef HAVE_GAS_HIDDEN
5360 fprintf (asm_out_file, "\t.%s\t", type);
5361 assemble_name (asm_out_file, name);
5362 fprintf (asm_out_file, "\n");
5363 #else
5364 warning (OPT_Wattributes, "visibility attribute not supported "
5365 "in this configuration; ignored");
5366 #endif
5367 }
5368
5369 /* A helper function to call assemble_visibility when needed for a decl. */
5370
5371 int
5372 maybe_assemble_visibility (tree decl)
5373 {
5374 enum symbol_visibility vis = DECL_VISIBILITY (decl);
5375
5376 if (vis != VISIBILITY_DEFAULT)
5377 {
5378 targetm.asm_out.visibility (decl, vis);
5379 return 1;
5380 }
5381 else
5382 return 0;
5383 }
5384
5385 /* Returns 1 if the target configuration supports defining public symbols
5386 so that one of them will be chosen at link time instead of generating a
5387 multiply-defined symbol error, whether through the use of weak symbols or
5388 a target-specific mechanism for having duplicates discarded. */
5389
5390 int
5391 supports_one_only (void)
5392 {
5393 if (SUPPORTS_ONE_ONLY)
5394 return 1;
5395 return SUPPORTS_WEAK;
5396 }
5397
5398 /* Set up DECL as a public symbol that can be defined in multiple
5399 translation units without generating a linker error. */
5400
5401 void
5402 make_decl_one_only (tree decl)
5403 {
5404 gcc_assert (TREE_CODE (decl) == VAR_DECL
5405 || TREE_CODE (decl) == FUNCTION_DECL);
5406
5407 TREE_PUBLIC (decl) = 1;
5408
5409 if (SUPPORTS_ONE_ONLY)
5410 {
5411 #ifdef MAKE_DECL_ONE_ONLY
5412 MAKE_DECL_ONE_ONLY (decl);
5413 #endif
5414 DECL_ONE_ONLY (decl) = 1;
5415 }
5416 else if (TREE_CODE (decl) == VAR_DECL
5417 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
5418 DECL_COMMON (decl) = 1;
5419 else
5420 {
5421 gcc_assert (SUPPORTS_WEAK);
5422 DECL_WEAK (decl) = 1;
5423 }
5424 }
5425
5426 void
5427 init_varasm_once (void)
5428 {
5429 section_htab = htab_create_ggc (31, section_entry_hash,
5430 section_entry_eq, NULL);
5431 object_block_htab = htab_create_ggc (31, object_block_entry_hash,
5432 object_block_entry_eq, NULL);
5433 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
5434 const_desc_eq, NULL);
5435
5436 const_alias_set = new_alias_set ();
5437 shared_constant_pool = create_constant_pool ();
5438
5439 #ifdef TEXT_SECTION_ASM_OP
5440 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op,
5441 TEXT_SECTION_ASM_OP);
5442 #endif
5443
5444 #ifdef DATA_SECTION_ASM_OP
5445 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5446 DATA_SECTION_ASM_OP);
5447 #endif
5448
5449 #ifdef SDATA_SECTION_ASM_OP
5450 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5451 SDATA_SECTION_ASM_OP);
5452 #endif
5453
5454 #ifdef READONLY_DATA_SECTION_ASM_OP
5455 readonly_data_section = get_unnamed_section (0, output_section_asm_op,
5456 READONLY_DATA_SECTION_ASM_OP);
5457 #endif
5458
5459 #ifdef CTORS_SECTION_ASM_OP
5460 ctors_section = get_unnamed_section (0, output_section_asm_op,
5461 CTORS_SECTION_ASM_OP);
5462 #endif
5463
5464 #ifdef DTORS_SECTION_ASM_OP
5465 dtors_section = get_unnamed_section (0, output_section_asm_op,
5466 DTORS_SECTION_ASM_OP);
5467 #endif
5468
5469 #ifdef BSS_SECTION_ASM_OP
5470 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5471 output_section_asm_op,
5472 BSS_SECTION_ASM_OP);
5473 #endif
5474
5475 #ifdef SBSS_SECTION_ASM_OP
5476 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5477 output_section_asm_op,
5478 SBSS_SECTION_ASM_OP);
5479 #endif
5480
5481 tls_comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5482 | SECTION_COMMON, emit_tls_common);
5483 lcomm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5484 | SECTION_COMMON, emit_local);
5485 comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5486 | SECTION_COMMON, emit_common);
5487
5488 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
5489 bss_noswitch_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS,
5490 emit_bss);
5491 #endif
5492
5493 targetm.asm_out.init_sections ();
5494
5495 if (readonly_data_section == NULL)
5496 readonly_data_section = text_section;
5497 }
5498
5499 enum tls_model
5500 decl_default_tls_model (tree decl)
5501 {
5502 enum tls_model kind;
5503 bool is_local;
5504
5505 is_local = targetm.binds_local_p (decl);
5506 if (!flag_shlib)
5507 {
5508 if (is_local)
5509 kind = TLS_MODEL_LOCAL_EXEC;
5510 else
5511 kind = TLS_MODEL_INITIAL_EXEC;
5512 }
5513
5514 /* Local dynamic is inefficient when we're not combining the
5515 parts of the address. */
5516 else if (optimize && is_local)
5517 kind = TLS_MODEL_LOCAL_DYNAMIC;
5518 else
5519 kind = TLS_MODEL_GLOBAL_DYNAMIC;
5520 if (kind < flag_tls_default)
5521 kind = flag_tls_default;
5522
5523 return kind;
5524 }
5525
5526 /* Select a set of attributes for section NAME based on the properties
5527 of DECL and whether or not RELOC indicates that DECL's initializer
5528 might contain runtime relocations.
5529
5530 We make the section read-only and executable for a function decl,
5531 read-only for a const data decl, and writable for a non-const data decl. */
5532
5533 unsigned int
5534 default_section_type_flags (tree decl, const char *name, int reloc)
5535 {
5536 unsigned int flags;
5537
5538 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
5539 flags = SECTION_CODE;
5540 else if (decl && decl_readonly_section (decl, reloc))
5541 flags = 0;
5542 else if (current_function_decl
5543 && cfun
5544 && cfun->unlikely_text_section_name
5545 && strcmp (name, cfun->unlikely_text_section_name) == 0)
5546 flags = SECTION_CODE;
5547 else if (!decl
5548 && (!current_function_decl || !cfun)
5549 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
5550 flags = SECTION_CODE;
5551 else
5552 flags = SECTION_WRITE;
5553
5554 if (decl && DECL_ONE_ONLY (decl))
5555 flags |= SECTION_LINKONCE;
5556
5557 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5558 flags |= SECTION_TLS | SECTION_WRITE;
5559
5560 if (strcmp (name, ".bss") == 0
5561 || strncmp (name, ".bss.", 5) == 0
5562 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
5563 || strcmp (name, ".sbss") == 0
5564 || strncmp (name, ".sbss.", 6) == 0
5565 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
5566 flags |= SECTION_BSS;
5567
5568 if (strcmp (name, ".tdata") == 0
5569 || strncmp (name, ".tdata.", 7) == 0
5570 || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
5571 flags |= SECTION_TLS;
5572
5573 if (strcmp (name, ".tbss") == 0
5574 || strncmp (name, ".tbss.", 6) == 0
5575 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
5576 flags |= SECTION_TLS | SECTION_BSS;
5577
5578 /* These three sections have special ELF types. They are neither
5579 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
5580 want to print a section type (@progbits or @nobits). If someone
5581 is silly enough to emit code or TLS variables to one of these
5582 sections, then don't handle them specially. */
5583 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
5584 && (strcmp (name, ".init_array") == 0
5585 || strcmp (name, ".fini_array") == 0
5586 || strcmp (name, ".preinit_array") == 0))
5587 flags |= SECTION_NOTYPE;
5588
5589 return flags;
5590 }
5591
5592 /* Return true if the target supports some form of global BSS,
5593 either through bss_noswitch_section, or by selecting a BSS
5594 section in TARGET_ASM_SELECT_SECTION. */
5595
5596 bool
5597 have_global_bss_p (void)
5598 {
5599 return bss_noswitch_section || targetm.have_switchable_bss_sections;
5600 }
5601
5602 /* Output assembly to switch to section NAME with attribute FLAGS.
5603 Four variants for common object file formats. */
5604
5605 void
5606 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
5607 unsigned int flags ATTRIBUTE_UNUSED,
5608 tree decl ATTRIBUTE_UNUSED)
5609 {
5610 /* Some object formats don't support named sections at all. The
5611 front-end should already have flagged this as an error. */
5612 gcc_unreachable ();
5613 }
5614
5615 void
5616 default_elf_asm_named_section (const char *name, unsigned int flags,
5617 tree decl ATTRIBUTE_UNUSED)
5618 {
5619 char flagchars[10], *f = flagchars;
5620
5621 /* If we have already declared this section, we can use an
5622 abbreviated form to switch back to it -- unless this section is
5623 part of a COMDAT groups, in which case GAS requires the full
5624 declaration every time. */
5625 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5626 && (flags & SECTION_DECLARED))
5627 {
5628 fprintf (asm_out_file, "\t.section\t%s\n", name);
5629 return;
5630 }
5631
5632 if (!(flags & SECTION_DEBUG))
5633 *f++ = 'a';
5634 if (flags & SECTION_WRITE)
5635 *f++ = 'w';
5636 if (flags & SECTION_CODE)
5637 *f++ = 'x';
5638 if (flags & SECTION_SMALL)
5639 *f++ = 's';
5640 if (flags & SECTION_MERGE)
5641 *f++ = 'M';
5642 if (flags & SECTION_STRINGS)
5643 *f++ = 'S';
5644 if (flags & SECTION_TLS)
5645 *f++ = 'T';
5646 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5647 *f++ = 'G';
5648 *f = '\0';
5649
5650 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
5651
5652 if (!(flags & SECTION_NOTYPE))
5653 {
5654 const char *type;
5655 const char *format;
5656
5657 if (flags & SECTION_BSS)
5658 type = "nobits";
5659 else
5660 type = "progbits";
5661
5662 format = ",@%s";
5663 #ifdef ASM_COMMENT_START
5664 /* On platforms that use "@" as the assembly comment character,
5665 use "%" instead. */
5666 if (strcmp (ASM_COMMENT_START, "@") == 0)
5667 format = ",%%%s";
5668 #endif
5669 fprintf (asm_out_file, format, type);
5670
5671 if (flags & SECTION_ENTSIZE)
5672 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
5673 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5674 fprintf (asm_out_file, ",%s,comdat",
5675 lang_hooks.decls.comdat_group (decl));
5676 }
5677
5678 putc ('\n', asm_out_file);
5679 }
5680
5681 void
5682 default_coff_asm_named_section (const char *name, unsigned int flags,
5683 tree decl ATTRIBUTE_UNUSED)
5684 {
5685 char flagchars[8], *f = flagchars;
5686
5687 if (flags & SECTION_WRITE)
5688 *f++ = 'w';
5689 if (flags & SECTION_CODE)
5690 *f++ = 'x';
5691 *f = '\0';
5692
5693 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
5694 }
5695
5696 void
5697 default_pe_asm_named_section (const char *name, unsigned int flags,
5698 tree decl)
5699 {
5700 default_coff_asm_named_section (name, flags, decl);
5701
5702 if (flags & SECTION_LINKONCE)
5703 {
5704 /* Functions may have been compiled at various levels of
5705 optimization so we can't use `same_size' here.
5706 Instead, have the linker pick one. */
5707 fprintf (asm_out_file, "\t.linkonce %s\n",
5708 (flags & SECTION_CODE ? "discard" : "same_size"));
5709 }
5710 }
5711 \f
5712 /* The lame default section selector. */
5713
5714 section *
5715 default_select_section (tree decl, int reloc,
5716 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
5717 {
5718 if (DECL_P (decl))
5719 {
5720 if (decl_readonly_section (decl, reloc))
5721 return readonly_data_section;
5722 }
5723 else if (TREE_CODE (decl) == CONSTRUCTOR)
5724 {
5725 if (! ((flag_pic && reloc)
5726 || !TREE_READONLY (decl)
5727 || TREE_SIDE_EFFECTS (decl)
5728 || !TREE_CONSTANT (decl)))
5729 return readonly_data_section;
5730 }
5731 else if (TREE_CODE (decl) == STRING_CST)
5732 return readonly_data_section;
5733 else if (! (flag_pic && reloc))
5734 return readonly_data_section;
5735
5736 return data_section;
5737 }
5738
5739 enum section_category
5740 categorize_decl_for_section (tree decl, int reloc)
5741 {
5742 enum section_category ret;
5743
5744 if (TREE_CODE (decl) == FUNCTION_DECL)
5745 return SECCAT_TEXT;
5746 else if (TREE_CODE (decl) == STRING_CST)
5747 {
5748 if (flag_mudflap) /* or !flag_merge_constants */
5749 return SECCAT_RODATA;
5750 else
5751 return SECCAT_RODATA_MERGE_STR;
5752 }
5753 else if (TREE_CODE (decl) == VAR_DECL)
5754 {
5755 if (bss_initializer_p (decl))
5756 ret = SECCAT_BSS;
5757 else if (! TREE_READONLY (decl)
5758 || TREE_SIDE_EFFECTS (decl)
5759 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
5760 {
5761 /* Here the reloc_rw_mask is not testing whether the section should
5762 be read-only or not, but whether the dynamic link will have to
5763 do something. If so, we wish to segregate the data in order to
5764 minimize cache misses inside the dynamic linker. */
5765 if (reloc & targetm.asm_out.reloc_rw_mask ())
5766 ret = reloc == 1 ? SECCAT_DATA_REL_LOCAL : SECCAT_DATA_REL;
5767 else
5768 ret = SECCAT_DATA;
5769 }
5770 else if (reloc & targetm.asm_out.reloc_rw_mask ())
5771 ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO;
5772 else if (reloc || flag_merge_constants < 2)
5773 /* C and C++ don't allow different variables to share the same
5774 location. -fmerge-all-constants allows even that (at the
5775 expense of not conforming). */
5776 ret = SECCAT_RODATA;
5777 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
5778 ret = SECCAT_RODATA_MERGE_STR_INIT;
5779 else
5780 ret = SECCAT_RODATA_MERGE_CONST;
5781 }
5782 else if (TREE_CODE (decl) == CONSTRUCTOR)
5783 {
5784 if ((reloc & targetm.asm_out.reloc_rw_mask ())
5785 || TREE_SIDE_EFFECTS (decl)
5786 || ! TREE_CONSTANT (decl))
5787 ret = SECCAT_DATA;
5788 else
5789 ret = SECCAT_RODATA;
5790 }
5791 else
5792 ret = SECCAT_RODATA;
5793
5794 /* There are no read-only thread-local sections. */
5795 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5796 {
5797 /* Note that this would be *just* SECCAT_BSS, except that there's
5798 no concept of a read-only thread-local-data section. */
5799 if (ret == SECCAT_BSS
5800 || (flag_zero_initialized_in_bss
5801 && initializer_zerop (DECL_INITIAL (decl))))
5802 ret = SECCAT_TBSS;
5803 else
5804 ret = SECCAT_TDATA;
5805 }
5806
5807 /* If the target uses small data sections, select it. */
5808 else if (targetm.in_small_data_p (decl))
5809 {
5810 if (ret == SECCAT_BSS)
5811 ret = SECCAT_SBSS;
5812 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
5813 ret = SECCAT_SRODATA;
5814 else
5815 ret = SECCAT_SDATA;
5816 }
5817
5818 return ret;
5819 }
5820
5821 bool
5822 decl_readonly_section (tree decl, int reloc)
5823 {
5824 switch (categorize_decl_for_section (decl, reloc))
5825 {
5826 case SECCAT_RODATA:
5827 case SECCAT_RODATA_MERGE_STR:
5828 case SECCAT_RODATA_MERGE_STR_INIT:
5829 case SECCAT_RODATA_MERGE_CONST:
5830 case SECCAT_SRODATA:
5831 return true;
5832 break;
5833 default:
5834 return false;
5835 break;
5836 }
5837 }
5838
5839 /* Select a section based on the above categorization. */
5840
5841 section *
5842 default_elf_select_section (tree decl, int reloc,
5843 unsigned HOST_WIDE_INT align)
5844 {
5845 const char *sname;
5846 switch (categorize_decl_for_section (decl, reloc))
5847 {
5848 case SECCAT_TEXT:
5849 /* We're not supposed to be called on FUNCTION_DECLs. */
5850 gcc_unreachable ();
5851 case SECCAT_RODATA:
5852 return readonly_data_section;
5853 case SECCAT_RODATA_MERGE_STR:
5854 return mergeable_string_section (decl, align, 0);
5855 case SECCAT_RODATA_MERGE_STR_INIT:
5856 return mergeable_string_section (DECL_INITIAL (decl), align, 0);
5857 case SECCAT_RODATA_MERGE_CONST:
5858 return mergeable_constant_section (DECL_MODE (decl), align, 0);
5859 case SECCAT_SRODATA:
5860 sname = ".sdata2";
5861 break;
5862 case SECCAT_DATA:
5863 return data_section;
5864 case SECCAT_DATA_REL:
5865 sname = ".data.rel";
5866 break;
5867 case SECCAT_DATA_REL_LOCAL:
5868 sname = ".data.rel.local";
5869 break;
5870 case SECCAT_DATA_REL_RO:
5871 sname = ".data.rel.ro";
5872 break;
5873 case SECCAT_DATA_REL_RO_LOCAL:
5874 sname = ".data.rel.ro.local";
5875 break;
5876 case SECCAT_SDATA:
5877 sname = ".sdata";
5878 break;
5879 case SECCAT_TDATA:
5880 sname = ".tdata";
5881 break;
5882 case SECCAT_BSS:
5883 if (bss_section)
5884 return bss_section;
5885 sname = ".bss";
5886 break;
5887 case SECCAT_SBSS:
5888 sname = ".sbss";
5889 break;
5890 case SECCAT_TBSS:
5891 sname = ".tbss";
5892 break;
5893 default:
5894 gcc_unreachable ();
5895 }
5896
5897 if (!DECL_P (decl))
5898 decl = NULL_TREE;
5899 return get_named_section (decl, sname, reloc);
5900 }
5901
5902 /* Construct a unique section name based on the decl name and the
5903 categorization performed above. */
5904
5905 void
5906 default_unique_section (tree decl, int reloc)
5907 {
5908 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
5909 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
5910 const char *prefix, *name;
5911 size_t nlen, plen;
5912 char *string;
5913
5914 switch (categorize_decl_for_section (decl, reloc))
5915 {
5916 case SECCAT_TEXT:
5917 prefix = one_only ? ".gnu.linkonce.t." : ".text.";
5918 break;
5919 case SECCAT_RODATA:
5920 case SECCAT_RODATA_MERGE_STR:
5921 case SECCAT_RODATA_MERGE_STR_INIT:
5922 case SECCAT_RODATA_MERGE_CONST:
5923 prefix = one_only ? ".gnu.linkonce.r." : ".rodata.";
5924 break;
5925 case SECCAT_SRODATA:
5926 prefix = one_only ? ".gnu.linkonce.s2." : ".sdata2.";
5927 break;
5928 case SECCAT_DATA:
5929 prefix = one_only ? ".gnu.linkonce.d." : ".data.";
5930 break;
5931 case SECCAT_DATA_REL:
5932 prefix = one_only ? ".gnu.linkonce.d.rel." : ".data.rel.";
5933 break;
5934 case SECCAT_DATA_REL_LOCAL:
5935 prefix = one_only ? ".gnu.linkonce.d.rel.local." : ".data.rel.local.";
5936 break;
5937 case SECCAT_DATA_REL_RO:
5938 prefix = one_only ? ".gnu.linkonce.d.rel.ro." : ".data.rel.ro.";
5939 break;
5940 case SECCAT_DATA_REL_RO_LOCAL:
5941 prefix = one_only ? ".gnu.linkonce.d.rel.ro.local."
5942 : ".data.rel.ro.local.";
5943 break;
5944 case SECCAT_SDATA:
5945 prefix = one_only ? ".gnu.linkonce.s." : ".sdata.";
5946 break;
5947 case SECCAT_BSS:
5948 prefix = one_only ? ".gnu.linkonce.b." : ".bss.";
5949 break;
5950 case SECCAT_SBSS:
5951 prefix = one_only ? ".gnu.linkonce.sb." : ".sbss.";
5952 break;
5953 case SECCAT_TDATA:
5954 prefix = one_only ? ".gnu.linkonce.td." : ".tdata.";
5955 break;
5956 case SECCAT_TBSS:
5957 prefix = one_only ? ".gnu.linkonce.tb." : ".tbss.";
5958 break;
5959 default:
5960 gcc_unreachable ();
5961 }
5962 plen = strlen (prefix);
5963
5964 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5965 name = targetm.strip_name_encoding (name);
5966 nlen = strlen (name);
5967
5968 string = alloca (nlen + plen + 1);
5969 memcpy (string, prefix, plen);
5970 memcpy (string + plen, name, nlen + 1);
5971
5972 DECL_SECTION_NAME (decl) = build_string (nlen + plen, string);
5973 }
5974
5975 /* Like compute_reloc_for_constant, except for an RTX. The return value
5976 is a mask for which bit 1 indicates a global relocation, and bit 0
5977 indicates a local relocation. */
5978
5979 static int
5980 compute_reloc_for_rtx_1 (rtx *xp, void *data)
5981 {
5982 int *preloc = data;
5983 rtx x = *xp;
5984
5985 switch (GET_CODE (x))
5986 {
5987 case SYMBOL_REF:
5988 *preloc |= SYMBOL_REF_LOCAL_P (x) ? 1 : 2;
5989 break;
5990 case LABEL_REF:
5991 *preloc |= 1;
5992 break;
5993 default:
5994 break;
5995 }
5996
5997 return 0;
5998 }
5999
6000 static int
6001 compute_reloc_for_rtx (rtx x)
6002 {
6003 int reloc;
6004
6005 switch (GET_CODE (x))
6006 {
6007 case CONST:
6008 case SYMBOL_REF:
6009 case LABEL_REF:
6010 reloc = 0;
6011 for_each_rtx (&x, compute_reloc_for_rtx_1, &reloc);
6012 return reloc;
6013
6014 default:
6015 return 0;
6016 }
6017 }
6018
6019 section *
6020 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
6021 rtx x,
6022 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6023 {
6024 if (compute_reloc_for_rtx (x) & targetm.asm_out.reloc_rw_mask ())
6025 return data_section;
6026 else
6027 return readonly_data_section;
6028 }
6029
6030 section *
6031 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
6032 unsigned HOST_WIDE_INT align)
6033 {
6034 int reloc = compute_reloc_for_rtx (x);
6035
6036 /* ??? Handle small data here somehow. */
6037
6038 if (reloc & targetm.asm_out.reloc_rw_mask ())
6039 {
6040 if (reloc == 1)
6041 return get_named_section (NULL, ".data.rel.ro.local", 1);
6042 else
6043 return get_named_section (NULL, ".data.rel.ro", 3);
6044 }
6045
6046 return mergeable_constant_section (mode, align, 0);
6047 }
6048
6049 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
6050
6051 void
6052 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
6053 {
6054 rtx symbol;
6055 int flags;
6056
6057 /* Careful not to prod global register variables. */
6058 if (!MEM_P (rtl))
6059 return;
6060 symbol = XEXP (rtl, 0);
6061 if (GET_CODE (symbol) != SYMBOL_REF)
6062 return;
6063
6064 flags = SYMBOL_REF_FLAGS (symbol) & SYMBOL_FLAG_HAS_BLOCK_INFO;
6065 if (TREE_CODE (decl) == FUNCTION_DECL)
6066 flags |= SYMBOL_FLAG_FUNCTION;
6067 if (targetm.binds_local_p (decl))
6068 flags |= SYMBOL_FLAG_LOCAL;
6069 if (targetm.have_tls && TREE_CODE (decl) == VAR_DECL
6070 && DECL_THREAD_LOCAL_P (decl))
6071 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT;
6072 else if (targetm.in_small_data_p (decl))
6073 flags |= SYMBOL_FLAG_SMALL;
6074 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
6075 being PUBLIC, the thing *must* be defined in this translation unit.
6076 Prevent this buglet from being propagated into rtl code as well. */
6077 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
6078 flags |= SYMBOL_FLAG_EXTERNAL;
6079
6080 SYMBOL_REF_FLAGS (symbol) = flags;
6081 }
6082
6083 /* By default, we do nothing for encode_section_info, so we need not
6084 do anything but discard the '*' marker. */
6085
6086 const char *
6087 default_strip_name_encoding (const char *str)
6088 {
6089 return str + (*str == '*');
6090 }
6091
6092 #ifdef ASM_OUTPUT_DEF
6093 /* The default implementation of TARGET_ASM_OUTPUT_ANCHOR. Define the
6094 anchor relative to ".", the current section position. */
6095
6096 void
6097 default_asm_output_anchor (rtx symbol)
6098 {
6099 char buffer[100];
6100
6101 sprintf (buffer, "*. + " HOST_WIDE_INT_PRINT_DEC,
6102 SYMBOL_REF_BLOCK_OFFSET (symbol));
6103 ASM_OUTPUT_DEF (asm_out_file, XSTR (symbol, 0), buffer);
6104 }
6105 #endif
6106
6107 /* The default implementation of TARGET_USE_ANCHORS_FOR_SYMBOL_P. */
6108
6109 bool
6110 default_use_anchors_for_symbol_p (rtx symbol)
6111 {
6112 section *sect;
6113 tree decl;
6114
6115 /* Don't use anchors for mergeable sections. The linker might move
6116 the objects around. */
6117 sect = SYMBOL_REF_BLOCK (symbol)->sect;
6118 if (sect->common.flags & SECTION_MERGE)
6119 return false;
6120
6121 /* Don't use anchors for small data sections. The small data register
6122 acts as an anchor for such sections. */
6123 if (sect->common.flags & SECTION_SMALL)
6124 return false;
6125
6126 decl = SYMBOL_REF_DECL (symbol);
6127 if (decl && DECL_P (decl))
6128 {
6129 /* Don't use section anchors for decls that might be defined by
6130 other modules. */
6131 if (!targetm.binds_local_p (decl))
6132 return false;
6133
6134 /* Don't use section anchors for decls that will be placed in a
6135 small data section. */
6136 /* ??? Ideally, this check would be redundant with the SECTION_SMALL
6137 one above. The problem is that we only use SECTION_SMALL for
6138 sections that should be marked as small in the section directive. */
6139 if (targetm.in_small_data_p (decl))
6140 return false;
6141 }
6142 return true;
6143 }
6144
6145 /* Assume ELF-ish defaults, since that's pretty much the most liberal
6146 wrt cross-module name binding. */
6147
6148 bool
6149 default_binds_local_p (tree exp)
6150 {
6151 return default_binds_local_p_1 (exp, flag_shlib);
6152 }
6153
6154 bool
6155 default_binds_local_p_1 (tree exp, int shlib)
6156 {
6157 bool local_p;
6158
6159 /* A non-decl is an entry in the constant pool. */
6160 if (!DECL_P (exp))
6161 local_p = true;
6162 /* Weakrefs may not bind locally, even though the weakref itself is
6163 always static and therefore local. */
6164 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp)))
6165 local_p = false;
6166 /* Static variables are always local. */
6167 else if (! TREE_PUBLIC (exp))
6168 local_p = true;
6169 /* A variable is local if the user has said explicitly that it will
6170 be. */
6171 else if (DECL_VISIBILITY_SPECIFIED (exp)
6172 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6173 local_p = true;
6174 /* Variables defined outside this object might not be local. */
6175 else if (DECL_EXTERNAL (exp))
6176 local_p = false;
6177 /* If defined in this object and visibility is not default, must be
6178 local. */
6179 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6180 local_p = true;
6181 /* Default visibility weak data can be overridden by a strong symbol
6182 in another module and so are not local. */
6183 else if (DECL_WEAK (exp))
6184 local_p = false;
6185 /* If PIC, then assume that any global name can be overridden by
6186 symbols resolved from other modules. */
6187 else if (shlib)
6188 local_p = false;
6189 /* Uninitialized COMMON variable may be unified with symbols
6190 resolved from other modules. */
6191 else if (DECL_COMMON (exp)
6192 && (DECL_INITIAL (exp) == NULL
6193 || DECL_INITIAL (exp) == error_mark_node))
6194 local_p = false;
6195 /* Otherwise we're left with initialized (or non-common) global data
6196 which is of necessity defined locally. */
6197 else
6198 local_p = true;
6199
6200 return local_p;
6201 }
6202
6203 /* Determine whether or not a pointer mode is valid. Assume defaults
6204 of ptr_mode or Pmode - can be overridden. */
6205 bool
6206 default_valid_pointer_mode (enum machine_mode mode)
6207 {
6208 return (mode == ptr_mode || mode == Pmode);
6209 }
6210
6211 /* Default function to output code that will globalize a label. A
6212 target must define GLOBAL_ASM_OP or provide its own function to
6213 globalize a label. */
6214 #ifdef GLOBAL_ASM_OP
6215 void
6216 default_globalize_label (FILE * stream, const char *name)
6217 {
6218 fputs (GLOBAL_ASM_OP, stream);
6219 assemble_name (stream, name);
6220 putc ('\n', stream);
6221 }
6222 #endif /* GLOBAL_ASM_OP */
6223
6224 /* Default function to output code that will globalize a declaration. */
6225 void
6226 default_globalize_decl_name (FILE * stream, tree decl)
6227 {
6228 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
6229 targetm.asm_out.globalize_label (stream, name);
6230 }
6231
6232 /* Default function to output a label for unwind information. The
6233 default is to do nothing. A target that needs nonlocal labels for
6234 unwind information must provide its own function to do this. */
6235 void
6236 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
6237 tree decl ATTRIBUTE_UNUSED,
6238 int for_eh ATTRIBUTE_UNUSED,
6239 int empty ATTRIBUTE_UNUSED)
6240 {
6241 }
6242
6243 /* Default function to output a label to divide up the exception table.
6244 The default is to do nothing. A target that needs/wants to divide
6245 up the table must provide it's own function to do this. */
6246 void
6247 default_emit_except_table_label (FILE * stream ATTRIBUTE_UNUSED)
6248 {
6249 }
6250
6251 /* This is how to output an internal numbered label where PREFIX is
6252 the class of label and LABELNO is the number within the class. */
6253
6254 void
6255 default_internal_label (FILE *stream, const char *prefix,
6256 unsigned long labelno)
6257 {
6258 char *const buf = alloca (40 + strlen (prefix));
6259 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
6260 ASM_OUTPUT_INTERNAL_LABEL (stream, buf);
6261 }
6262
6263 /* This is the default behavior at the beginning of a file. It's
6264 controlled by two other target-hook toggles. */
6265 void
6266 default_file_start (void)
6267 {
6268 if (targetm.file_start_app_off && !flag_verbose_asm)
6269 fputs (ASM_APP_OFF, asm_out_file);
6270
6271 if (targetm.file_start_file_directive)
6272 output_file_directive (asm_out_file, main_input_filename);
6273 }
6274
6275 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
6276 which emits a special section directive used to indicate whether or
6277 not this object file needs an executable stack. This is primarily
6278 a GNU extension to ELF but could be used on other targets. */
6279
6280 int trampolines_created;
6281
6282 void
6283 file_end_indicate_exec_stack (void)
6284 {
6285 unsigned int flags = SECTION_DEBUG;
6286 if (trampolines_created)
6287 flags |= SECTION_CODE;
6288
6289 switch_to_section (get_section (".note.GNU-stack", flags, NULL));
6290 }
6291
6292 /* Output DIRECTIVE (a C string) followed by a newline. This is used as
6293 a get_unnamed_section callback. */
6294
6295 void
6296 output_section_asm_op (const void *directive)
6297 {
6298 fprintf (asm_out_file, "%s\n", (const char *) directive);
6299 }
6300
6301 /* Emit assembly code to switch to section NEW_SECTION. Do nothing if
6302 the current section is NEW_SECTION. */
6303
6304 void
6305 switch_to_section (section *new_section)
6306 {
6307 if (in_section == new_section)
6308 return;
6309
6310 if (new_section->common.flags & SECTION_FORGET)
6311 in_section = NULL;
6312 else
6313 in_section = new_section;
6314
6315 switch (SECTION_STYLE (new_section))
6316 {
6317 case SECTION_NAMED:
6318 if (cfun
6319 && !cfun->unlikely_text_section_name
6320 && strcmp (new_section->named.name,
6321 UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
6322 cfun->unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
6323
6324 targetm.asm_out.named_section (new_section->named.name,
6325 new_section->named.common.flags,
6326 new_section->named.decl);
6327 break;
6328
6329 case SECTION_UNNAMED:
6330 new_section->unnamed.callback (new_section->unnamed.data);
6331 break;
6332
6333 case SECTION_NOSWITCH:
6334 gcc_unreachable ();
6335 break;
6336 }
6337
6338 new_section->common.flags |= SECTION_DECLARED;
6339 }
6340
6341 /* If block symbol SYMBOL has not yet been assigned an offset, place
6342 it at the end of its block. */
6343
6344 void
6345 place_block_symbol (rtx symbol)
6346 {
6347 unsigned HOST_WIDE_INT size, mask, offset;
6348 struct constant_descriptor_rtx *desc;
6349 unsigned int alignment;
6350 struct object_block *block;
6351 tree decl;
6352
6353 gcc_assert (SYMBOL_REF_BLOCK (symbol));
6354 if (SYMBOL_REF_BLOCK_OFFSET (symbol) >= 0)
6355 return;
6356
6357 /* Work out the symbol's size and alignment. */
6358 if (CONSTANT_POOL_ADDRESS_P (symbol))
6359 {
6360 desc = SYMBOL_REF_CONSTANT (symbol);
6361 alignment = desc->align;
6362 size = GET_MODE_SIZE (desc->mode);
6363 }
6364 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6365 {
6366 decl = SYMBOL_REF_DECL (symbol);
6367 alignment = get_constant_alignment (decl);
6368 size = get_constant_size (decl);
6369 }
6370 else
6371 {
6372 decl = SYMBOL_REF_DECL (symbol);
6373 alignment = DECL_ALIGN (decl);
6374 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6375 }
6376
6377 /* Calculate the object's offset from the start of the block. */
6378 block = SYMBOL_REF_BLOCK (symbol);
6379 mask = alignment / BITS_PER_UNIT - 1;
6380 offset = (block->size + mask) & ~mask;
6381 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
6382
6383 /* Record the block's new alignment and size. */
6384 block->alignment = MAX (block->alignment, alignment);
6385 block->size = offset + size;
6386
6387 VEC_safe_push (rtx, gc, block->objects, symbol);
6388 }
6389
6390 /* Return the anchor that should be used to address byte offset OFFSET
6391 from the first object in BLOCK. MODEL is the TLS model used
6392 to access it. */
6393
6394 rtx
6395 get_section_anchor (struct object_block *block, HOST_WIDE_INT offset,
6396 enum tls_model model)
6397 {
6398 char label[100];
6399 unsigned int begin, middle, end;
6400 unsigned HOST_WIDE_INT min_offset, max_offset, range, bias, delta;
6401 rtx anchor;
6402
6403 /* Work out the anchor's offset. Use an offset of 0 for the first
6404 anchor so that we don't pessimize the case where we take the address
6405 of a variable at the beginning of the block. This is particularly
6406 useful when a block has only one variable assigned to it.
6407
6408 We try to place anchors RANGE bytes apart, so there can then be
6409 anchors at +/-RANGE, +/-2 * RANGE, and so on, up to the limits of
6410 a ptr_mode offset. With some target settings, the lowest such
6411 anchor might be out of range for the lowest ptr_mode offset;
6412 likewise the highest anchor for the highest offset. Use anchors
6413 at the extreme ends of the ptr_mode range in such cases.
6414
6415 All arithmetic uses unsigned integers in order to avoid
6416 signed overflow. */
6417 max_offset = (unsigned HOST_WIDE_INT) targetm.max_anchor_offset;
6418 min_offset = (unsigned HOST_WIDE_INT) targetm.min_anchor_offset;
6419 range = max_offset - min_offset + 1;
6420 if (range == 0)
6421 offset = 0;
6422 else
6423 {
6424 bias = 1 << (GET_MODE_BITSIZE (ptr_mode) - 1);
6425 if (offset < 0)
6426 {
6427 delta = -(unsigned HOST_WIDE_INT) offset + max_offset;
6428 delta -= delta % range;
6429 if (delta > bias)
6430 delta = bias;
6431 offset = (HOST_WIDE_INT) (-delta);
6432 }
6433 else
6434 {
6435 delta = (unsigned HOST_WIDE_INT) offset - min_offset;
6436 delta -= delta % range;
6437 if (delta > bias - 1)
6438 delta = bias - 1;
6439 offset = (HOST_WIDE_INT) delta;
6440 }
6441 }
6442
6443 /* Do a binary search to see if there's already an anchor we can use.
6444 Set BEGIN to the new anchor's index if not. */
6445 begin = 0;
6446 end = VEC_length (rtx, block->anchors);
6447 while (begin != end)
6448 {
6449 middle = (end + begin) / 2;
6450 anchor = VEC_index (rtx, block->anchors, middle);
6451 if (SYMBOL_REF_BLOCK_OFFSET (anchor) > offset)
6452 end = middle;
6453 else if (SYMBOL_REF_BLOCK_OFFSET (anchor) < offset)
6454 begin = middle + 1;
6455 else if (SYMBOL_REF_TLS_MODEL (anchor) > model)
6456 end = middle;
6457 else if (SYMBOL_REF_TLS_MODEL (anchor) < model)
6458 begin = middle + 1;
6459 else
6460 return anchor;
6461 }
6462
6463 /* Create a new anchor with a unique label. */
6464 ASM_GENERATE_INTERNAL_LABEL (label, "LANCHOR", anchor_labelno++);
6465 anchor = create_block_symbol (ggc_strdup (label), block, offset);
6466 SYMBOL_REF_FLAGS (anchor) |= SYMBOL_FLAG_LOCAL | SYMBOL_FLAG_ANCHOR;
6467 SYMBOL_REF_FLAGS (anchor) |= model << SYMBOL_FLAG_TLS_SHIFT;
6468
6469 /* Insert it at index BEGIN. */
6470 VEC_safe_insert (rtx, gc, block->anchors, begin, anchor);
6471 return anchor;
6472 }
6473
6474 /* Output the objects in BLOCK. */
6475
6476 static void
6477 output_object_block (struct object_block *block)
6478 {
6479 struct constant_descriptor_rtx *desc;
6480 unsigned int i;
6481 HOST_WIDE_INT offset;
6482 tree decl;
6483 rtx symbol;
6484
6485 if (block->objects == NULL)
6486 return;
6487
6488 /* Switch to the section and make sure that the first byte is
6489 suitably aligned. */
6490 switch_to_section (block->sect);
6491 assemble_align (block->alignment);
6492
6493 /* Define the values of all anchors relative to the current section
6494 position. */
6495 for (i = 0; VEC_iterate (rtx, block->anchors, i, symbol); i++)
6496 targetm.asm_out.output_anchor (symbol);
6497
6498 /* Output the objects themselves. */
6499 offset = 0;
6500 for (i = 0; VEC_iterate (rtx, block->objects, i, symbol); i++)
6501 {
6502 /* Move to the object's offset, padding with zeros if necessary. */
6503 assemble_zeros (SYMBOL_REF_BLOCK_OFFSET (symbol) - offset);
6504 offset = SYMBOL_REF_BLOCK_OFFSET (symbol);
6505 if (CONSTANT_POOL_ADDRESS_P (symbol))
6506 {
6507 desc = SYMBOL_REF_CONSTANT (symbol);
6508 output_constant_pool_1 (desc, 1);
6509 offset += GET_MODE_SIZE (desc->mode);
6510 }
6511 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6512 {
6513 decl = SYMBOL_REF_DECL (symbol);
6514 assemble_constant_contents (decl, XSTR (symbol, 0),
6515 get_constant_alignment (decl));
6516 offset += get_constant_size (decl);
6517 }
6518 else
6519 {
6520 decl = SYMBOL_REF_DECL (symbol);
6521 assemble_variable_contents (decl, XSTR (symbol, 0), false);
6522 offset += tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6523 }
6524 }
6525 }
6526
6527 /* A htab_traverse callback used to call output_object_block for
6528 each member of object_block_htab. */
6529
6530 static int
6531 output_object_block_htab (void **slot, void *data ATTRIBUTE_UNUSED)
6532 {
6533 output_object_block ((struct object_block *) (*slot));
6534 return 1;
6535 }
6536
6537 /* Output the definitions of all object_blocks. */
6538
6539 void
6540 output_object_blocks (void)
6541 {
6542 htab_traverse (object_block_htab, output_object_block_htab, NULL);
6543 }
6544
6545 /* This function provides a possible implementation of the
6546 TARGET_ASM_RECORD_GCC_SWITCHES target hook for ELF targets. When triggered
6547 by -frecord-gcc-switches it creates a new mergeable, string section in the
6548 assembler output file called TARGET_ASM_RECORD_GCC_SWITCHES_SECTION which
6549 contains the switches in ASCII format.
6550
6551 FIXME: This code does not correctly handle double quote characters
6552 that appear inside strings, (it strips them rather than preserving them).
6553 FIXME: ASM_OUTPUT_ASCII, as defined in config/elfos.h will not emit NUL
6554 characters - instead it treats them as sub-string separators. Since
6555 we want to emit NUL strings terminators into the object file we have to use
6556 ASM_OUTPUT_SKIP. */
6557
6558 int
6559 elf_record_gcc_switches (print_switch_type type, const char * name)
6560 {
6561 static char buffer[1024];
6562
6563 /* This variable is used as part of a simplistic heuristic to detect
6564 command line switches which take an argument:
6565
6566 "If a command line option does not start with a dash then
6567 it is an argument for the previous command line option."
6568
6569 This fails in the case of the command line option which is the name
6570 of the file to compile, but otherwise it is pretty reasonable. */
6571 static bool previous_name_held_back = FALSE;
6572
6573 switch (type)
6574 {
6575 case SWITCH_TYPE_PASSED:
6576 if (* name != '-')
6577 {
6578 if (previous_name_held_back)
6579 {
6580 unsigned int len = strlen (buffer);
6581
6582 snprintf (buffer + len, sizeof buffer - len, " %s", name);
6583 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6584 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6585 previous_name_held_back = FALSE;
6586 }
6587 else
6588 {
6589 strncpy (buffer, name, sizeof buffer);
6590 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6591 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6592 }
6593 }
6594 else
6595 {
6596 if (previous_name_held_back)
6597 {
6598 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6599 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6600 }
6601
6602 strncpy (buffer, name, sizeof buffer);
6603 previous_name_held_back = TRUE;
6604 }
6605 break;
6606
6607 case SWITCH_TYPE_DESCRIPTIVE:
6608 if (name == NULL)
6609 {
6610 /* Distinguish between invocations where name is NULL. */
6611 static bool started = false;
6612
6613 if (started)
6614 {
6615 if (previous_name_held_back)
6616 {
6617 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6618 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6619 }
6620 }
6621 else
6622 {
6623 section * sec;
6624
6625 sec = get_section (targetm.asm_out.record_gcc_switches_section,
6626 SECTION_DEBUG
6627 | SECTION_MERGE
6628 | SECTION_STRINGS
6629 | (SECTION_ENTSIZE & 1),
6630 NULL);
6631 switch_to_section (sec);
6632 started = true;
6633 }
6634 }
6635
6636 default:
6637 break;
6638 }
6639
6640 /* The return value is currently ignored by the caller, but must be 0.
6641 For -fverbose-asm the return value would be the number of characters
6642 emitted into the assembler file. */
6643 return 0;
6644 }
6645
6646 /* Emit text to declare externally defined symbols. It is needed to
6647 properly support non-default visibility. */
6648 void
6649 default_elf_asm_output_external (FILE *file ATTRIBUTE_UNUSED,
6650 tree decl,
6651 const char *name ATTRIBUTE_UNUSED)
6652 {
6653 /* We output the name if and only if TREE_SYMBOL_REFERENCED is
6654 set in order to avoid putting out names that are never really
6655 used. */
6656 if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
6657 && targetm.binds_local_p (decl))
6658 maybe_assemble_visibility (decl);
6659 }
6660
6661 #include "gt-varasm.h"