re PR preprocessor/12847 (xxx.c:1:20: xxxx.h: No such file or directory)
[gcc.git] / gcc / cppinit.c
1 /* CPP Library.
2 Copyright (C) 1986, 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
4 Contributed by Per Bothner, 1994-95.
5 Based on CCCP program by Paul Rubin, June 1986
6 Adapted to ANSI C, Richard Stallman, Jan 1987
7
8 This program is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by the
10 Free Software Foundation; either version 2, or (at your option) any
11 later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
21
22 #include "config.h"
23 #include "system.h"
24 #include "cpplib.h"
25 #include "cpphash.h"
26 #include "mkdeps.h"
27
28 static void init_library (void);
29 static void mark_named_operators (cpp_reader *);
30 static void read_original_filename (cpp_reader *);
31 static void read_original_directory (cpp_reader *);
32 static void post_options (cpp_reader *);
33
34 /* If we have designated initializers (GCC >2.7) these tables can be
35 initialized, constant data. Otherwise, they have to be filled in at
36 runtime. */
37 #if HAVE_DESIGNATED_INITIALIZERS
38
39 #define init_trigraph_map() /* Nothing. */
40 #define TRIGRAPH_MAP \
41 __extension__ const uchar _cpp_trigraph_map[UCHAR_MAX + 1] = {
42
43 #define END };
44 #define s(p, v) [p] = v,
45
46 #else
47
48 #define TRIGRAPH_MAP uchar _cpp_trigraph_map[UCHAR_MAX + 1] = { 0 }; \
49 static void init_trigraph_map (void) { \
50 unsigned char *x = _cpp_trigraph_map;
51
52 #define END }
53 #define s(p, v) x[p] = v;
54
55 #endif
56
57 TRIGRAPH_MAP
58 s('=', '#') s(')', ']') s('!', '|')
59 s('(', '[') s('\'', '^') s('>', '}')
60 s('/', '\\') s('<', '{') s('-', '~')
61 END
62
63 #undef s
64 #undef END
65 #undef TRIGRAPH_MAP
66
67 /* A set of booleans indicating what CPP features each source language
68 requires. */
69 struct lang_flags
70 {
71 char c99;
72 char cplusplus;
73 char extended_numbers;
74 char std;
75 char cplusplus_comments;
76 char digraphs;
77 };
78
79 static const struct lang_flags lang_defaults[] =
80 { /* c99 c++ xnum std // digr */
81 /* GNUC89 */ { 0, 0, 1, 0, 1, 1 },
82 /* GNUC99 */ { 1, 0, 1, 0, 1, 1 },
83 /* STDC89 */ { 0, 0, 0, 1, 0, 0 },
84 /* STDC94 */ { 0, 0, 0, 1, 0, 1 },
85 /* STDC99 */ { 1, 0, 1, 1, 1, 1 },
86 /* GNUCXX */ { 0, 1, 1, 0, 1, 1 },
87 /* CXX98 */ { 0, 1, 1, 1, 1, 1 },
88 /* ASM */ { 0, 0, 1, 0, 1, 0 }
89 };
90
91 /* Sets internal flags correctly for a given language. */
92 void
93 cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
94 {
95 const struct lang_flags *l = &lang_defaults[(int) lang];
96
97 CPP_OPTION (pfile, lang) = lang;
98
99 CPP_OPTION (pfile, c99) = l->c99;
100 CPP_OPTION (pfile, cplusplus) = l->cplusplus;
101 CPP_OPTION (pfile, extended_numbers) = l->extended_numbers;
102 CPP_OPTION (pfile, std) = l->std;
103 CPP_OPTION (pfile, trigraphs) = l->std;
104 CPP_OPTION (pfile, cplusplus_comments) = l->cplusplus_comments;
105 CPP_OPTION (pfile, digraphs) = l->digraphs;
106 }
107
108 /* Initialize library global state. */
109 static void
110 init_library (void)
111 {
112 static int initialized = 0;
113
114 if (! initialized)
115 {
116 initialized = 1;
117
118 /* Set up the trigraph map. This doesn't need to do anything if
119 we were compiled with a compiler that supports C99 designated
120 initializers. */
121 init_trigraph_map ();
122 }
123 }
124
125 /* Initialize a cpp_reader structure. */
126 cpp_reader *
127 cpp_create_reader (enum c_lang lang, hash_table *table)
128 {
129 cpp_reader *pfile;
130
131 /* Initialize this instance of the library if it hasn't been already. */
132 init_library ();
133
134 pfile = xcalloc (1, sizeof (cpp_reader));
135
136 cpp_set_lang (pfile, lang);
137 CPP_OPTION (pfile, warn_multichar) = 1;
138 CPP_OPTION (pfile, discard_comments) = 1;
139 CPP_OPTION (pfile, discard_comments_in_macro_exp) = 1;
140 CPP_OPTION (pfile, show_column) = 1;
141 CPP_OPTION (pfile, tabstop) = 8;
142 CPP_OPTION (pfile, operator_names) = 1;
143 CPP_OPTION (pfile, warn_trigraphs) = 2;
144 CPP_OPTION (pfile, warn_endif_labels) = 1;
145 CPP_OPTION (pfile, warn_deprecated) = 1;
146 CPP_OPTION (pfile, warn_long_long) = !CPP_OPTION (pfile, c99);
147 CPP_OPTION (pfile, dollars_in_ident) = 1;
148 CPP_OPTION (pfile, warn_dollars) = 1;
149
150 /* Default CPP arithmetic to something sensible for the host for the
151 benefit of dumb users like fix-header. */
152 CPP_OPTION (pfile, precision) = CHAR_BIT * sizeof (long);
153 CPP_OPTION (pfile, char_precision) = CHAR_BIT;
154 CPP_OPTION (pfile, wchar_precision) = CHAR_BIT * sizeof (int);
155 CPP_OPTION (pfile, int_precision) = CHAR_BIT * sizeof (int);
156 CPP_OPTION (pfile, unsigned_char) = 0;
157 CPP_OPTION (pfile, unsigned_wchar) = 1;
158 CPP_OPTION (pfile, bytes_big_endian) = 1; /* does not matter */
159
160 /* Default to no charset conversion. */
161 CPP_OPTION (pfile, narrow_charset) = 0;
162 CPP_OPTION (pfile, wide_charset) = 0;
163
164 /* A fake empty "directory" used as the starting point for files
165 looked up without a search path. Name cannot be '/' because we
166 don't want to prepend anything at all to filenames using it. All
167 other entries are correct zero-initialized. */
168 pfile->no_search_path.name = (char *) "";
169
170 /* Initialize the line map. Start at logical line 1, so we can use
171 a line number of zero for special states. */
172 linemap_init (&pfile->line_maps);
173 pfile->line = 1;
174
175 /* Initialize lexer state. */
176 pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
177
178 /* Set up static tokens. */
179 pfile->avoid_paste.type = CPP_PADDING;
180 pfile->avoid_paste.val.source = NULL;
181 pfile->eof.type = CPP_EOF;
182 pfile->eof.flags = 0;
183
184 /* Create a token buffer for the lexer. */
185 _cpp_init_tokenrun (&pfile->base_run, 250);
186 pfile->cur_run = &pfile->base_run;
187 pfile->cur_token = pfile->base_run.base;
188
189 /* Initialize the base context. */
190 pfile->context = &pfile->base_context;
191 pfile->base_context.macro = 0;
192 pfile->base_context.prev = pfile->base_context.next = 0;
193
194 /* Aligned and unaligned storage. */
195 pfile->a_buff = _cpp_get_buff (pfile, 0);
196 pfile->u_buff = _cpp_get_buff (pfile, 0);
197
198 /* The expression parser stack. */
199 _cpp_expand_op_stack (pfile);
200
201 /* Initialize the buffer obstack. */
202 _obstack_begin (&pfile->buffer_ob, 0, 0,
203 (void *(*) (long)) xmalloc,
204 (void (*) (void *)) free);
205
206 _cpp_init_files (pfile);
207
208 _cpp_init_hashtable (pfile, table);
209
210 return pfile;
211 }
212
213 /* Free resources used by PFILE. Accessing PFILE after this function
214 returns leads to undefined behavior. Returns the error count. */
215 void
216 cpp_destroy (cpp_reader *pfile)
217 {
218 cpp_context *context, *contextn;
219 tokenrun *run, *runn;
220
221 free (pfile->op_stack);
222
223 while (CPP_BUFFER (pfile) != NULL)
224 _cpp_pop_buffer (pfile);
225
226 if (pfile->out.base)
227 free (pfile->out.base);
228
229 if (pfile->macro_buffer)
230 {
231 free (pfile->macro_buffer);
232 pfile->macro_buffer = NULL;
233 pfile->macro_buffer_len = 0;
234 }
235
236 if (pfile->deps)
237 deps_free (pfile->deps);
238 obstack_free (&pfile->buffer_ob, 0);
239
240 _cpp_destroy_hashtable (pfile);
241 _cpp_cleanup_files (pfile);
242 _cpp_destroy_iconv (pfile);
243
244 _cpp_free_buff (pfile->a_buff);
245 _cpp_free_buff (pfile->u_buff);
246 _cpp_free_buff (pfile->free_buffs);
247
248 for (run = &pfile->base_run; run; run = runn)
249 {
250 runn = run->next;
251 free (run->base);
252 if (run != &pfile->base_run)
253 free (run);
254 }
255
256 for (context = pfile->base_context.next; context; context = contextn)
257 {
258 contextn = context->next;
259 free (context);
260 }
261
262 linemap_free (&pfile->line_maps);
263 free (pfile);
264 }
265
266 /* This structure defines one built-in identifier. A node will be
267 entered in the hash table under the name NAME, with value VALUE.
268
269 There are two tables of these. builtin_array holds all the
270 "builtin" macros: these are handled by builtin_macro() in
271 cppmacro.c. Builtin is somewhat of a misnomer -- the property of
272 interest is that these macros require special code to compute their
273 expansions. The value is a "builtin_type" enumerator.
274
275 operator_array holds the C++ named operators. These are keywords
276 which act as aliases for punctuators. In C++, they cannot be
277 altered through #define, and #if recognizes them as operators. In
278 C, these are not entered into the hash table at all (but see
279 <iso646.h>). The value is a token-type enumerator. */
280 struct builtin
281 {
282 const uchar *name;
283 unsigned short len;
284 unsigned short value;
285 };
286
287 #define B(n, t) { DSC(n), t }
288 static const struct builtin builtin_array[] =
289 {
290 B("__TIME__", BT_TIME),
291 B("__DATE__", BT_DATE),
292 B("__FILE__", BT_FILE),
293 B("__BASE_FILE__", BT_BASE_FILE),
294 B("__LINE__", BT_SPECLINE),
295 B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL),
296 /* Keep builtins not used for -traditional-cpp at the end, and
297 update init_builtins() if any more are added. */
298 B("_Pragma", BT_PRAGMA),
299 B("__STDC__", BT_STDC),
300 };
301
302 static const struct builtin operator_array[] =
303 {
304 B("and", CPP_AND_AND),
305 B("and_eq", CPP_AND_EQ),
306 B("bitand", CPP_AND),
307 B("bitor", CPP_OR),
308 B("compl", CPP_COMPL),
309 B("not", CPP_NOT),
310 B("not_eq", CPP_NOT_EQ),
311 B("or", CPP_OR_OR),
312 B("or_eq", CPP_OR_EQ),
313 B("xor", CPP_XOR),
314 B("xor_eq", CPP_XOR_EQ)
315 };
316 #undef B
317
318 /* Mark the C++ named operators in the hash table. */
319 static void
320 mark_named_operators (cpp_reader *pfile)
321 {
322 const struct builtin *b;
323
324 for (b = operator_array;
325 b < (operator_array + ARRAY_SIZE (operator_array));
326 b++)
327 {
328 cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
329 hp->flags |= NODE_OPERATOR;
330 hp->is_directive = 0;
331 hp->directive_index = b->value;
332 }
333 }
334
335 /* Read the builtins table above and enter them, and language-specific
336 macros, into the hash table. HOSTED is true if this is a hosted
337 environment. */
338 void
339 cpp_init_builtins (cpp_reader *pfile, int hosted)
340 {
341 const struct builtin *b;
342 size_t n = ARRAY_SIZE (builtin_array);
343
344 if (CPP_OPTION (pfile, traditional))
345 n -= 2;
346
347 for(b = builtin_array; b < builtin_array + n; b++)
348 {
349 cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
350 hp->type = NT_MACRO;
351 hp->flags |= NODE_BUILTIN | NODE_WARN;
352 hp->value.builtin = b->value;
353 }
354
355 if (CPP_OPTION (pfile, cplusplus))
356 _cpp_define_builtin (pfile, "__cplusplus 1");
357 else if (CPP_OPTION (pfile, lang) == CLK_ASM)
358 _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
359 else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
360 _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
361 else if (CPP_OPTION (pfile, c99))
362 _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
363
364 if (hosted)
365 _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
366 else
367 _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
368
369 if (CPP_OPTION (pfile, objc))
370 _cpp_define_builtin (pfile, "__OBJC__ 1");
371 }
372
373 /* Sanity-checks are dependent on command-line options, so it is
374 called as a subroutine of cpp_read_main_file (). */
375 #if ENABLE_CHECKING
376 static void sanity_checks (cpp_reader *);
377 static void sanity_checks (cpp_reader *pfile)
378 {
379 cppchar_t test = 0;
380 size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
381
382 /* Sanity checks for assumptions about CPP arithmetic and target
383 type precisions made by cpplib. */
384 test--;
385 if (test < 1)
386 cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
387
388 if (CPP_OPTION (pfile, precision) > max_precision)
389 cpp_error (pfile, CPP_DL_ICE,
390 "preprocessor arithmetic has maximum precision of %lu bits;"
391 " target requires %lu bits",
392 (unsigned long) max_precision,
393 (unsigned long) CPP_OPTION (pfile, precision));
394
395 if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
396 cpp_error (pfile, CPP_DL_ICE,
397 "CPP arithmetic must be at least as precise as a target int");
398
399 if (CPP_OPTION (pfile, char_precision) < 8)
400 cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
401
402 if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
403 cpp_error (pfile, CPP_DL_ICE,
404 "target wchar_t is narrower than target char");
405
406 if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
407 cpp_error (pfile, CPP_DL_ICE,
408 "target int is narrower than target char");
409
410 /* This is assumed in eval_token() and could be fixed if necessary. */
411 if (sizeof (cppchar_t) > sizeof (cpp_num_part))
412 cpp_error (pfile, CPP_DL_ICE,
413 "CPP half-integer narrower than CPP character");
414
415 if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
416 cpp_error (pfile, CPP_DL_ICE,
417 "CPP on this host cannot handle wide character constants over"
418 " %lu bits, but the target requires %lu bits",
419 (unsigned long) BITS_PER_CPPCHAR_T,
420 (unsigned long) CPP_OPTION (pfile, wchar_precision));
421 }
422 #else
423 # define sanity_checks(PFILE)
424 #endif
425
426 /* Add a dependency target. Can be called any number of times before
427 cpp_read_main_file(). If no targets have been added before
428 cpp_read_main_file(), then the default target is used. */
429 void
430 cpp_add_dependency_target (cpp_reader *pfile, const char *target, int quote)
431 {
432 if (!pfile->deps)
433 pfile->deps = deps_init ();
434
435 deps_add_target (pfile->deps, target, quote);
436 }
437
438 /* This is called after options have been parsed, and partially
439 processed. */
440 void
441 cpp_post_options (cpp_reader *pfile)
442 {
443 sanity_checks (pfile);
444
445 post_options (pfile);
446
447 /* Mark named operators before handling command line macros. */
448 if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
449 mark_named_operators (pfile);
450 }
451
452 /* Setup for processing input from the file named FNAME, or stdin if
453 it is the empty string. Returns true if the file was found. */
454 bool
455 cpp_find_main_file (cpp_reader *pfile, const char *fname)
456 {
457 if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
458 {
459 if (!pfile->deps)
460 pfile->deps = deps_init ();
461
462 /* Set the default target (if there is none already). */
463 deps_add_default_target (pfile->deps, fname);
464 }
465
466 pfile->main_file
467 = _cpp_find_file (pfile, fname, &pfile->no_search_path, false);
468 if (_cpp_find_failed (pfile->main_file))
469 return false;
470
471 if (CPP_OPTION (pfile, working_directory))
472 {
473 const char *dir = getpwd ();
474 char *dir_with_slashes = alloca (strlen (dir) + 3);
475
476 memcpy (dir_with_slashes, dir, strlen (dir));
477 memcpy (dir_with_slashes + strlen (dir), "//", 3);
478
479 if (pfile->cb.dir_change)
480 pfile->cb.dir_change (pfile, dir);
481 }
482 return true;
483 }
484
485 /* This function reads the file, but does not start preprocessing.
486 This will generate at least one file change callback, and possibly
487 a line change callback. */
488 void
489 cpp_push_main_file (cpp_reader *pfile)
490 {
491 _cpp_stack_file (pfile, pfile->main_file, false);
492
493 /* For foo.i, read the original filename foo.c now, for the benefit
494 of the front ends. */
495 if (CPP_OPTION (pfile, preprocessed))
496 read_original_filename (pfile);
497
498 /* Set this here so the client can change the option if it wishes,
499 and after stacking the main file so we don't trace the main
500 file. */
501 pfile->line_maps.trace_includes = CPP_OPTION (pfile, print_include_names);
502 }
503
504 /* For preprocessed files, if the first tokens are of the form # NUM.
505 handle the directive so we know the original file name. This will
506 generate file_change callbacks, which the front ends must handle
507 appropriately given their state of initialization. */
508 static void
509 read_original_filename (cpp_reader *pfile)
510 {
511 const cpp_token *token, *token1;
512
513 /* Lex ahead; if the first tokens are of the form # NUM, then
514 process the directive, otherwise back up. */
515 token = _cpp_lex_direct (pfile);
516 if (token->type == CPP_HASH)
517 {
518 token1 = _cpp_lex_direct (pfile);
519 _cpp_backup_tokens (pfile, 1);
520
521 /* If it's a #line directive, handle it. */
522 if (token1->type == CPP_NUMBER)
523 {
524 _cpp_handle_directive (pfile, token->flags & PREV_WHITE);
525 read_original_directory (pfile);
526 return;
527 }
528 }
529
530 /* Backup as if nothing happened. */
531 _cpp_backup_tokens (pfile, 1);
532 }
533
534 /* For preprocessed files, if the tokens following the first filename
535 line is of the form # <line> "/path/name//", handle the
536 directive so we know the original current directory. */
537 static void
538 read_original_directory (cpp_reader *pfile)
539 {
540 const cpp_token *hash, *token;
541
542 /* Lex ahead; if the first tokens are of the form # NUM, then
543 process the directive, otherwise back up. */
544 hash = _cpp_lex_direct (pfile);
545 if (hash->type != CPP_HASH)
546 {
547 _cpp_backup_tokens (pfile, 1);
548 return;
549 }
550
551 token = _cpp_lex_direct (pfile);
552
553 if (token->type != CPP_NUMBER)
554 {
555 _cpp_backup_tokens (pfile, 2);
556 return;
557 }
558
559 token = _cpp_lex_direct (pfile);
560
561 if (token->type != CPP_STRING
562 || ! (token->val.str.len >= 5
563 && token->val.str.text[token->val.str.len-2] == '/'
564 && token->val.str.text[token->val.str.len-3] == '/'))
565 {
566 _cpp_backup_tokens (pfile, 3);
567 return;
568 }
569
570 if (pfile->cb.dir_change)
571 {
572 char *debugdir = alloca (token->val.str.len - 3);
573
574 memcpy (debugdir, (const char *) token->val.str.text + 1,
575 token->val.str.len - 4);
576 debugdir[token->val.str.len - 4] = '\0';
577
578 pfile->cb.dir_change (pfile, debugdir);
579 }
580
581 /* We want to process the fake line changes as regular changes, to
582 get them output. */
583 _cpp_backup_tokens (pfile, 3);
584
585 CPP_OPTION (pfile, working_directory) = false;
586 }
587
588 /* This is called at the end of preprocessing. It pops the last
589 buffer and writes dependency output, and returns the number of
590 errors.
591
592 Maybe it should also reset state, such that you could call
593 cpp_start_read with a new filename to restart processing. */
594 int
595 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
596 {
597 /* Warn about unused macros before popping the final buffer. */
598 if (CPP_OPTION (pfile, warn_unused_macros))
599 cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
600
601 /* cpplex.c leaves the final buffer on the stack. This it so that
602 it returns an unending stream of CPP_EOFs to the client. If we
603 popped the buffer, we'd dereference a NULL buffer pointer and
604 segfault. It's nice to allow the client to do worry-free excess
605 cpp_get_token calls. */
606 while (pfile->buffer)
607 _cpp_pop_buffer (pfile);
608
609 /* Don't write the deps file if there are errors. */
610 if (CPP_OPTION (pfile, deps.style) != DEPS_NONE
611 && deps_stream && pfile->errors == 0)
612 {
613 deps_write (pfile->deps, deps_stream, 72);
614
615 if (CPP_OPTION (pfile, deps.phony_targets))
616 deps_phony_targets (pfile->deps, deps_stream);
617 }
618
619 /* Report on headers that could use multiple include guards. */
620 if (CPP_OPTION (pfile, print_include_names))
621 _cpp_report_missing_guards (pfile);
622
623 return pfile->errors;
624 }
625
626 static void
627 post_options (cpp_reader *pfile)
628 {
629 /* -Wtraditional is not useful in C++ mode. */
630 if (CPP_OPTION (pfile, cplusplus))
631 CPP_OPTION (pfile, warn_traditional) = 0;
632
633 /* Permanently disable macro expansion if we are rescanning
634 preprocessed text. Read preprocesed source in ISO mode. */
635 if (CPP_OPTION (pfile, preprocessed))
636 {
637 pfile->state.prevent_expansion = 1;
638 CPP_OPTION (pfile, traditional) = 0;
639 }
640
641 if (CPP_OPTION (pfile, warn_trigraphs) == 2)
642 CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
643
644 if (CPP_OPTION (pfile, traditional))
645 {
646 /* Traditional CPP does not accurately track column information. */
647 CPP_OPTION (pfile, show_column) = 0;
648 CPP_OPTION (pfile, trigraphs) = 0;
649 CPP_OPTION (pfile, warn_trigraphs) = 0;
650 }
651 }