2006-08-06 Paolo Carlini <pcarlini@suse.de>
[official-gcc.git] / libcpp / init.c
blob4330f884be72eceb17b908eaee0f46a516067c51
1 /* CPP Library.
2 Copyright (C) 1986, 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005 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
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.
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.
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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
22 #include "config.h"
23 #include "system.h"
24 #include "cpplib.h"
25 #include "internal.h"
26 #include "mkdeps.h"
27 #include "localedir.h"
29 static void init_library (void);
30 static void mark_named_operators (cpp_reader *);
31 static void read_original_filename (cpp_reader *);
32 static void read_original_directory (cpp_reader *);
33 static void post_options (cpp_reader *);
35 /* If we have designated initializers (GCC >2.7) these tables can be
36 initialized, constant data. Otherwise, they have to be filled in at
37 runtime. */
38 #if HAVE_DESIGNATED_INITIALIZERS
40 #define init_trigraph_map() /* Nothing. */
41 #define TRIGRAPH_MAP \
42 __extension__ const uchar _cpp_trigraph_map[UCHAR_MAX + 1] = {
44 #define END };
45 #define s(p, v) [p] = v,
47 #else
49 #define TRIGRAPH_MAP uchar _cpp_trigraph_map[UCHAR_MAX + 1] = { 0 }; \
50 static void init_trigraph_map (void) { \
51 unsigned char *x = _cpp_trigraph_map;
53 #define END }
54 #define s(p, v) x[p] = v;
56 #endif
58 TRIGRAPH_MAP
59 s('=', '#') s(')', ']') s('!', '|')
60 s('(', '[') s('\'', '^') s('>', '}')
61 s('/', '\\') s('<', '{') s('-', '~')
62 END
64 #undef s
65 #undef END
66 #undef TRIGRAPH_MAP
68 /* A set of booleans indicating what CPP features each source language
69 requires. */
70 struct lang_flags
72 char c99;
73 char cplusplus;
74 char extended_numbers;
75 char extended_identifiers;
76 char std;
77 char cplusplus_comments;
78 char digraphs;
81 static const struct lang_flags lang_defaults[] =
82 { /* c99 c++ xnum xid std // digr */
83 /* GNUC89 */ { 0, 0, 1, 0, 0, 1, 1 },
84 /* GNUC99 */ { 1, 0, 1, 0, 0, 1, 1 },
85 /* STDC89 */ { 0, 0, 0, 0, 1, 0, 0 },
86 /* STDC94 */ { 0, 0, 0, 0, 1, 0, 1 },
87 /* STDC99 */ { 1, 0, 1, 0, 1, 1, 1 },
88 /* GNUCXX */ { 0, 1, 1, 0, 0, 1, 1 },
89 /* CXX98 */ { 0, 1, 1, 0, 1, 1, 1 },
90 /* ASM */ { 0, 0, 1, 0, 0, 1, 0 }
91 /* xid should be 1 for GNUC99, STDC99, GNUCXX and CXX98 when no
92 longer experimental (when all uses of identifiers in the compiler
93 have been audited for correct handling of extended
94 identifiers). */
97 /* Sets internal flags correctly for a given language. */
98 void
99 cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
101 const struct lang_flags *l = &lang_defaults[(int) lang];
103 CPP_OPTION (pfile, lang) = lang;
105 CPP_OPTION (pfile, c99) = l->c99;
106 CPP_OPTION (pfile, cplusplus) = l->cplusplus;
107 CPP_OPTION (pfile, extended_numbers) = l->extended_numbers;
108 CPP_OPTION (pfile, extended_identifiers) = l->extended_identifiers;
109 CPP_OPTION (pfile, std) = l->std;
110 CPP_OPTION (pfile, trigraphs) = l->std;
111 CPP_OPTION (pfile, cplusplus_comments) = l->cplusplus_comments;
112 CPP_OPTION (pfile, digraphs) = l->digraphs;
115 /* Initialize library global state. */
116 static void
117 init_library (void)
119 static int initialized = 0;
121 if (! initialized)
123 initialized = 1;
125 /* Set up the trigraph map. This doesn't need to do anything if
126 we were compiled with a compiler that supports C99 designated
127 initializers. */
128 init_trigraph_map ();
130 #ifdef ENABLE_NLS
131 (void) bindtextdomain (PACKAGE, LOCALEDIR);
132 #endif
136 /* Initialize a cpp_reader structure. */
137 cpp_reader *
138 cpp_create_reader (enum c_lang lang, hash_table *table,
139 struct line_maps *line_table)
141 cpp_reader *pfile;
143 /* Initialize this instance of the library if it hasn't been already. */
144 init_library ();
146 pfile = XCNEW (cpp_reader);
148 cpp_set_lang (pfile, lang);
149 CPP_OPTION (pfile, warn_multichar) = 1;
150 CPP_OPTION (pfile, discard_comments) = 1;
151 CPP_OPTION (pfile, discard_comments_in_macro_exp) = 1;
152 CPP_OPTION (pfile, show_column) = 1;
153 CPP_OPTION (pfile, tabstop) = 8;
154 CPP_OPTION (pfile, operator_names) = 1;
155 CPP_OPTION (pfile, warn_trigraphs) = 2;
156 CPP_OPTION (pfile, warn_endif_labels) = 1;
157 CPP_OPTION (pfile, warn_deprecated) = 1;
158 CPP_OPTION (pfile, warn_long_long) = !CPP_OPTION (pfile, c99);
159 CPP_OPTION (pfile, dollars_in_ident) = 1;
160 CPP_OPTION (pfile, warn_dollars) = 1;
161 CPP_OPTION (pfile, warn_variadic_macros) = 1;
162 CPP_OPTION (pfile, warn_normalize) = normalized_C;
164 /* Default CPP arithmetic to something sensible for the host for the
165 benefit of dumb users like fix-header. */
166 CPP_OPTION (pfile, precision) = CHAR_BIT * sizeof (long);
167 CPP_OPTION (pfile, char_precision) = CHAR_BIT;
168 CPP_OPTION (pfile, wchar_precision) = CHAR_BIT * sizeof (int);
169 CPP_OPTION (pfile, int_precision) = CHAR_BIT * sizeof (int);
170 CPP_OPTION (pfile, unsigned_char) = 0;
171 CPP_OPTION (pfile, unsigned_wchar) = 1;
172 CPP_OPTION (pfile, bytes_big_endian) = 1; /* does not matter */
174 /* Default to no charset conversion. */
175 CPP_OPTION (pfile, narrow_charset) = _cpp_default_encoding ();
176 CPP_OPTION (pfile, wide_charset) = 0;
178 /* Default the input character set to UTF-8. */
179 CPP_OPTION (pfile, input_charset) = _cpp_default_encoding ();
181 /* A fake empty "directory" used as the starting point for files
182 looked up without a search path. Name cannot be '/' because we
183 don't want to prepend anything at all to filenames using it. All
184 other entries are correct zero-initialized. */
185 pfile->no_search_path.name = (char *) "";
187 /* Initialize the line map. */
188 pfile->line_table = line_table;
190 /* Initialize lexer state. */
191 pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
193 /* Set up static tokens. */
194 pfile->avoid_paste.type = CPP_PADDING;
195 pfile->avoid_paste.val.source = NULL;
196 pfile->eof.type = CPP_EOF;
197 pfile->eof.flags = 0;
199 /* Create a token buffer for the lexer. */
200 _cpp_init_tokenrun (&pfile->base_run, 250);
201 pfile->cur_run = &pfile->base_run;
202 pfile->cur_token = pfile->base_run.base;
204 /* Initialize the base context. */
205 pfile->context = &pfile->base_context;
206 pfile->base_context.macro = 0;
207 pfile->base_context.prev = pfile->base_context.next = 0;
209 /* Aligned and unaligned storage. */
210 pfile->a_buff = _cpp_get_buff (pfile, 0);
211 pfile->u_buff = _cpp_get_buff (pfile, 0);
213 /* The expression parser stack. */
214 _cpp_expand_op_stack (pfile);
216 /* Initialize the buffer obstack. */
217 _obstack_begin (&pfile->buffer_ob, 0, 0,
218 (void *(*) (long)) xmalloc,
219 (void (*) (void *)) free);
221 _cpp_init_files (pfile);
223 _cpp_init_hashtable (pfile, table);
225 return pfile;
228 /* Free resources used by PFILE. Accessing PFILE after this function
229 returns leads to undefined behavior. Returns the error count. */
230 void
231 cpp_destroy (cpp_reader *pfile)
233 cpp_context *context, *contextn;
234 tokenrun *run, *runn;
236 free (pfile->op_stack);
238 while (CPP_BUFFER (pfile) != NULL)
239 _cpp_pop_buffer (pfile);
241 if (pfile->out.base)
242 free (pfile->out.base);
244 if (pfile->macro_buffer)
246 free (pfile->macro_buffer);
247 pfile->macro_buffer = NULL;
248 pfile->macro_buffer_len = 0;
251 if (pfile->deps)
252 deps_free (pfile->deps);
253 obstack_free (&pfile->buffer_ob, 0);
255 _cpp_destroy_hashtable (pfile);
256 _cpp_cleanup_files (pfile);
257 _cpp_destroy_iconv (pfile);
259 _cpp_free_buff (pfile->a_buff);
260 _cpp_free_buff (pfile->u_buff);
261 _cpp_free_buff (pfile->free_buffs);
263 for (run = &pfile->base_run; run; run = runn)
265 runn = run->next;
266 free (run->base);
267 if (run != &pfile->base_run)
268 free (run);
271 for (context = pfile->base_context.next; context; context = contextn)
273 contextn = context->next;
274 free (context);
277 free (pfile);
280 /* This structure defines one built-in identifier. A node will be
281 entered in the hash table under the name NAME, with value VALUE.
283 There are two tables of these. builtin_array holds all the
284 "builtin" macros: these are handled by builtin_macro() in
285 macro.c. Builtin is somewhat of a misnomer -- the property of
286 interest is that these macros require special code to compute their
287 expansions. The value is a "builtin_type" enumerator.
289 operator_array holds the C++ named operators. These are keywords
290 which act as aliases for punctuators. In C++, they cannot be
291 altered through #define, and #if recognizes them as operators. In
292 C, these are not entered into the hash table at all (but see
293 <iso646.h>). The value is a token-type enumerator. */
294 struct builtin
296 const uchar *name;
297 unsigned short len;
298 unsigned short value;
301 #define B(n, t) { DSC(n), t }
302 static const struct builtin builtin_array[] =
304 B("__TIMESTAMP__", BT_TIMESTAMP),
305 B("__TIME__", BT_TIME),
306 B("__DATE__", BT_DATE),
307 B("__FILE__", BT_FILE),
308 B("__BASE_FILE__", BT_BASE_FILE),
309 B("__LINE__", BT_SPECLINE),
310 B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL),
311 /* Keep builtins not used for -traditional-cpp at the end, and
312 update init_builtins() if any more are added. */
313 B("_Pragma", BT_PRAGMA),
314 B("__STDC__", BT_STDC),
317 static const struct builtin operator_array[] =
319 B("and", CPP_AND_AND),
320 B("and_eq", CPP_AND_EQ),
321 B("bitand", CPP_AND),
322 B("bitor", CPP_OR),
323 B("compl", CPP_COMPL),
324 B("not", CPP_NOT),
325 B("not_eq", CPP_NOT_EQ),
326 B("or", CPP_OR_OR),
327 B("or_eq", CPP_OR_EQ),
328 B("xor", CPP_XOR),
329 B("xor_eq", CPP_XOR_EQ)
331 #undef B
333 /* Mark the C++ named operators in the hash table. */
334 static void
335 mark_named_operators (cpp_reader *pfile)
337 const struct builtin *b;
339 for (b = operator_array;
340 b < (operator_array + ARRAY_SIZE (operator_array));
341 b++)
343 cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
344 hp->flags |= NODE_OPERATOR;
345 hp->is_directive = 0;
346 hp->directive_index = b->value;
350 /* Read the builtins table above and enter them, and language-specific
351 macros, into the hash table. HOSTED is true if this is a hosted
352 environment. */
353 void
354 cpp_init_builtins (cpp_reader *pfile, int hosted)
356 const struct builtin *b;
357 size_t n = ARRAY_SIZE (builtin_array);
359 if (CPP_OPTION (pfile, traditional))
360 n -= 2;
361 else if (! CPP_OPTION (pfile, stdc_0_in_system_headers)
362 || CPP_OPTION (pfile, std))
364 n--;
365 _cpp_define_builtin (pfile, "__STDC__ 1");
368 for (b = builtin_array; b < builtin_array + n; b++)
370 cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
371 hp->type = NT_MACRO;
372 hp->flags |= NODE_BUILTIN | NODE_WARN;
373 hp->value.builtin = (enum builtin_type) b->value;
376 if (CPP_OPTION (pfile, cplusplus))
377 _cpp_define_builtin (pfile, "__cplusplus 1");
378 else if (CPP_OPTION (pfile, lang) == CLK_ASM)
379 _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
380 else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
381 _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
382 else if (CPP_OPTION (pfile, c99))
383 _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
385 if (hosted)
386 _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
387 else
388 _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
390 if (CPP_OPTION (pfile, objc))
391 _cpp_define_builtin (pfile, "__OBJC__ 1");
394 /* Sanity-checks are dependent on command-line options, so it is
395 called as a subroutine of cpp_read_main_file (). */
396 #if ENABLE_CHECKING
397 static void sanity_checks (cpp_reader *);
398 static void sanity_checks (cpp_reader *pfile)
400 cppchar_t test = 0;
401 size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
403 /* Sanity checks for assumptions about CPP arithmetic and target
404 type precisions made by cpplib. */
405 test--;
406 if (test < 1)
407 cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
409 if (CPP_OPTION (pfile, precision) > max_precision)
410 cpp_error (pfile, CPP_DL_ICE,
411 "preprocessor arithmetic has maximum precision of %lu bits;"
412 " target requires %lu bits",
413 (unsigned long) max_precision,
414 (unsigned long) CPP_OPTION (pfile, precision));
416 if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
417 cpp_error (pfile, CPP_DL_ICE,
418 "CPP arithmetic must be at least as precise as a target int");
420 if (CPP_OPTION (pfile, char_precision) < 8)
421 cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
423 if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
424 cpp_error (pfile, CPP_DL_ICE,
425 "target wchar_t is narrower than target char");
427 if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
428 cpp_error (pfile, CPP_DL_ICE,
429 "target int is narrower than target char");
431 /* This is assumed in eval_token() and could be fixed if necessary. */
432 if (sizeof (cppchar_t) > sizeof (cpp_num_part))
433 cpp_error (pfile, CPP_DL_ICE,
434 "CPP half-integer narrower than CPP character");
436 if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
437 cpp_error (pfile, CPP_DL_ICE,
438 "CPP on this host cannot handle wide character constants over"
439 " %lu bits, but the target requires %lu bits",
440 (unsigned long) BITS_PER_CPPCHAR_T,
441 (unsigned long) CPP_OPTION (pfile, wchar_precision));
443 #else
444 # define sanity_checks(PFILE)
445 #endif
447 /* This is called after options have been parsed, and partially
448 processed. */
449 void
450 cpp_post_options (cpp_reader *pfile)
452 sanity_checks (pfile);
454 post_options (pfile);
456 /* Mark named operators before handling command line macros. */
457 if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
458 mark_named_operators (pfile);
461 /* Setup for processing input from the file named FNAME, or stdin if
462 it is the empty string. Return the original filename
463 on success (e.g. foo.i->foo.c), or NULL on failure. */
464 const char *
465 cpp_read_main_file (cpp_reader *pfile, const char *fname)
467 if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
469 if (!pfile->deps)
470 pfile->deps = deps_init ();
472 /* Set the default target (if there is none already). */
473 deps_add_default_target (pfile->deps, fname);
476 pfile->main_file
477 = _cpp_find_file (pfile, fname, &pfile->no_search_path, false, 0);
478 if (_cpp_find_failed (pfile->main_file))
479 return NULL;
481 _cpp_stack_file (pfile, pfile->main_file, false);
483 /* For foo.i, read the original filename foo.c now, for the benefit
484 of the front ends. */
485 if (CPP_OPTION (pfile, preprocessed))
487 read_original_filename (pfile);
488 fname = pfile->line_table->maps[pfile->line_table->used-1].to_file;
490 return fname;
493 /* For preprocessed files, if the first tokens are of the form # NUM.
494 handle the directive so we know the original file name. This will
495 generate file_change callbacks, which the front ends must handle
496 appropriately given their state of initialization. */
497 static void
498 read_original_filename (cpp_reader *pfile)
500 const cpp_token *token, *token1;
502 /* Lex ahead; if the first tokens are of the form # NUM, then
503 process the directive, otherwise back up. */
504 token = _cpp_lex_direct (pfile);
505 if (token->type == CPP_HASH)
507 pfile->state.in_directive = 1;
508 token1 = _cpp_lex_direct (pfile);
509 _cpp_backup_tokens (pfile, 1);
510 pfile->state.in_directive = 0;
512 /* If it's a #line directive, handle it. */
513 if (token1->type == CPP_NUMBER)
515 _cpp_handle_directive (pfile, token->flags & PREV_WHITE);
516 read_original_directory (pfile);
517 return;
521 /* Backup as if nothing happened. */
522 _cpp_backup_tokens (pfile, 1);
525 /* For preprocessed files, if the tokens following the first filename
526 line is of the form # <line> "/path/name//", handle the
527 directive so we know the original current directory. */
528 static void
529 read_original_directory (cpp_reader *pfile)
531 const cpp_token *hash, *token;
533 /* Lex ahead; if the first tokens are of the form # NUM, then
534 process the directive, otherwise back up. */
535 hash = _cpp_lex_direct (pfile);
536 if (hash->type != CPP_HASH)
538 _cpp_backup_tokens (pfile, 1);
539 return;
542 token = _cpp_lex_direct (pfile);
544 if (token->type != CPP_NUMBER)
546 _cpp_backup_tokens (pfile, 2);
547 return;
550 token = _cpp_lex_direct (pfile);
552 if (token->type != CPP_STRING
553 || ! (token->val.str.len >= 5
554 && token->val.str.text[token->val.str.len-2] == '/'
555 && token->val.str.text[token->val.str.len-3] == '/'))
557 _cpp_backup_tokens (pfile, 3);
558 return;
561 if (pfile->cb.dir_change)
563 char *debugdir = (char *) alloca (token->val.str.len - 3);
565 memcpy (debugdir, (const char *) token->val.str.text + 1,
566 token->val.str.len - 4);
567 debugdir[token->val.str.len - 4] = '\0';
569 pfile->cb.dir_change (pfile, debugdir);
573 /* This is called at the end of preprocessing. It pops the last
574 buffer and writes dependency output, and returns the number of
575 errors.
577 Maybe it should also reset state, such that you could call
578 cpp_start_read with a new filename to restart processing. */
580 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
582 /* Warn about unused macros before popping the final buffer. */
583 if (CPP_OPTION (pfile, warn_unused_macros))
584 cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
586 /* lex.c leaves the final buffer on the stack. This it so that
587 it returns an unending stream of CPP_EOFs to the client. If we
588 popped the buffer, we'd dereference a NULL buffer pointer and
589 segfault. It's nice to allow the client to do worry-free excess
590 cpp_get_token calls. */
591 while (pfile->buffer)
592 _cpp_pop_buffer (pfile);
594 /* Don't write the deps file if there are errors. */
595 if (CPP_OPTION (pfile, deps.style) != DEPS_NONE
596 && deps_stream && pfile->errors == 0)
598 deps_write (pfile->deps, deps_stream, 72);
600 if (CPP_OPTION (pfile, deps.phony_targets))
601 deps_phony_targets (pfile->deps, deps_stream);
604 /* Report on headers that could use multiple include guards. */
605 if (CPP_OPTION (pfile, print_include_names))
606 _cpp_report_missing_guards (pfile);
608 return pfile->errors;
611 static void
612 post_options (cpp_reader *pfile)
614 /* -Wtraditional is not useful in C++ mode. */
615 if (CPP_OPTION (pfile, cplusplus))
616 CPP_OPTION (pfile, warn_traditional) = 0;
618 /* Permanently disable macro expansion if we are rescanning
619 preprocessed text. Read preprocesed source in ISO mode. */
620 if (CPP_OPTION (pfile, preprocessed))
622 pfile->state.prevent_expansion = 1;
623 CPP_OPTION (pfile, traditional) = 0;
626 if (CPP_OPTION (pfile, warn_trigraphs) == 2)
627 CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
629 if (CPP_OPTION (pfile, traditional))
631 CPP_OPTION (pfile, cplusplus_comments) = 0;
633 /* Traditional CPP does not accurately track column information. */
634 CPP_OPTION (pfile, show_column) = 0;
635 CPP_OPTION (pfile, trigraphs) = 0;
636 CPP_OPTION (pfile, warn_trigraphs) = 0;