(arm_is_longcall_p): Update comment describing this funciton's behaviour.
[official-gcc.git] / libcpp / init.c
blobaaf1d6b353cc9f6578abd514ccfae03d55fa16c2
1 /* CPP Library.
2 Copyright (C) 1986, 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
22 #include "config.h"
23 #include "system.h"
24 #include "cpplib.h"
25 #include "internal.h"
26 #include "mkdeps.h"
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 *);
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
39 #define init_trigraph_map() /* Nothing. */
40 #define TRIGRAPH_MAP \
41 __extension__ const uchar _cpp_trigraph_map[UCHAR_MAX + 1] = {
43 #define END };
44 #define s(p, v) [p] = v,
46 #else
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;
52 #define END }
53 #define s(p, v) x[p] = v;
55 #endif
57 TRIGRAPH_MAP
58 s('=', '#') s(')', ']') s('!', '|')
59 s('(', '[') s('\'', '^') s('>', '}')
60 s('/', '\\') s('<', '{') s('-', '~')
61 END
63 #undef s
64 #undef END
65 #undef TRIGRAPH_MAP
67 /* A set of booleans indicating what CPP features each source language
68 requires. */
69 struct lang_flags
71 char c99;
72 char cplusplus;
73 char extended_numbers;
74 char std;
75 char cplusplus_comments;
76 char digraphs;
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 }
91 /* Sets internal flags correctly for a given language. */
92 void
93 cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
95 const struct lang_flags *l = &lang_defaults[(int) lang];
97 CPP_OPTION (pfile, lang) = lang;
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;
108 /* Initialize library global state. */
109 static void
110 init_library (void)
112 static int initialized = 0;
114 if (! initialized)
116 initialized = 1;
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 ();
123 #ifdef ENABLE_NLS
124 (void) bindtextdomain (PACKAGE, LOCALEDIR);
125 #endif
129 /* Initialize a cpp_reader structure. */
130 cpp_reader *
131 cpp_create_reader (enum c_lang lang, hash_table *table,
132 struct line_maps *line_table)
134 cpp_reader *pfile;
136 /* Initialize this instance of the library if it hasn't been already. */
137 init_library ();
139 pfile = xcalloc (1, sizeof (cpp_reader));
141 cpp_set_lang (pfile, lang);
142 CPP_OPTION (pfile, warn_multichar) = 1;
143 CPP_OPTION (pfile, discard_comments) = 1;
144 CPP_OPTION (pfile, discard_comments_in_macro_exp) = 1;
145 CPP_OPTION (pfile, show_column) = 1;
146 CPP_OPTION (pfile, tabstop) = 8;
147 CPP_OPTION (pfile, operator_names) = 1;
148 CPP_OPTION (pfile, warn_trigraphs) = 2;
149 CPP_OPTION (pfile, warn_endif_labels) = 1;
150 CPP_OPTION (pfile, warn_deprecated) = 1;
151 CPP_OPTION (pfile, warn_long_long) = !CPP_OPTION (pfile, c99);
152 CPP_OPTION (pfile, dollars_in_ident) = 1;
153 CPP_OPTION (pfile, warn_dollars) = 1;
154 CPP_OPTION (pfile, warn_variadic_macros) = 1;
156 /* Default CPP arithmetic to something sensible for the host for the
157 benefit of dumb users like fix-header. */
158 CPP_OPTION (pfile, precision) = CHAR_BIT * sizeof (long);
159 CPP_OPTION (pfile, char_precision) = CHAR_BIT;
160 CPP_OPTION (pfile, wchar_precision) = CHAR_BIT * sizeof (int);
161 CPP_OPTION (pfile, int_precision) = CHAR_BIT * sizeof (int);
162 CPP_OPTION (pfile, unsigned_char) = 0;
163 CPP_OPTION (pfile, unsigned_wchar) = 1;
164 CPP_OPTION (pfile, bytes_big_endian) = 1; /* does not matter */
166 /* Default to no charset conversion. */
167 CPP_OPTION (pfile, narrow_charset) = _cpp_default_encoding ();
168 CPP_OPTION (pfile, wide_charset) = 0;
170 /* Default the input character set to UTF-8. */
171 CPP_OPTION (pfile, input_charset) = _cpp_default_encoding ();
173 /* A fake empty "directory" used as the starting point for files
174 looked up without a search path. Name cannot be '/' because we
175 don't want to prepend anything at all to filenames using it. All
176 other entries are correct zero-initialized. */
177 pfile->no_search_path.name = (char *) "";
179 /* Initialize the line map. */
180 pfile->line_table = line_table;
182 /* Initialize lexer state. */
183 pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
185 /* Set up static tokens. */
186 pfile->avoid_paste.type = CPP_PADDING;
187 pfile->avoid_paste.val.source = NULL;
188 pfile->eof.type = CPP_EOF;
189 pfile->eof.flags = 0;
191 /* Create a token buffer for the lexer. */
192 _cpp_init_tokenrun (&pfile->base_run, 250);
193 pfile->cur_run = &pfile->base_run;
194 pfile->cur_token = pfile->base_run.base;
196 /* Initialize the base context. */
197 pfile->context = &pfile->base_context;
198 pfile->base_context.macro = 0;
199 pfile->base_context.prev = pfile->base_context.next = 0;
201 /* Aligned and unaligned storage. */
202 pfile->a_buff = _cpp_get_buff (pfile, 0);
203 pfile->u_buff = _cpp_get_buff (pfile, 0);
205 /* The expression parser stack. */
206 _cpp_expand_op_stack (pfile);
208 /* Initialize the buffer obstack. */
209 _obstack_begin (&pfile->buffer_ob, 0, 0,
210 (void *(*) (long)) xmalloc,
211 (void (*) (void *)) free);
213 _cpp_init_files (pfile);
215 _cpp_init_hashtable (pfile, table);
217 return pfile;
220 /* Free resources used by PFILE. Accessing PFILE after this function
221 returns leads to undefined behavior. Returns the error count. */
222 void
223 cpp_destroy (cpp_reader *pfile)
225 cpp_context *context, *contextn;
226 tokenrun *run, *runn;
228 free (pfile->op_stack);
230 while (CPP_BUFFER (pfile) != NULL)
231 _cpp_pop_buffer (pfile);
233 if (pfile->out.base)
234 free (pfile->out.base);
236 if (pfile->macro_buffer)
238 free (pfile->macro_buffer);
239 pfile->macro_buffer = NULL;
240 pfile->macro_buffer_len = 0;
243 if (pfile->deps)
244 deps_free (pfile->deps);
245 obstack_free (&pfile->buffer_ob, 0);
247 _cpp_destroy_hashtable (pfile);
248 _cpp_cleanup_files (pfile);
249 _cpp_destroy_iconv (pfile);
251 _cpp_free_buff (pfile->a_buff);
252 _cpp_free_buff (pfile->u_buff);
253 _cpp_free_buff (pfile->free_buffs);
255 for (run = &pfile->base_run; run; run = runn)
257 runn = run->next;
258 free (run->base);
259 if (run != &pfile->base_run)
260 free (run);
263 for (context = pfile->base_context.next; context; context = contextn)
265 contextn = context->next;
266 free (context);
269 free (pfile);
272 /* This structure defines one built-in identifier. A node will be
273 entered in the hash table under the name NAME, with value VALUE.
275 There are two tables of these. builtin_array holds all the
276 "builtin" macros: these are handled by builtin_macro() in
277 cppmacro.c. Builtin is somewhat of a misnomer -- the property of
278 interest is that these macros require special code to compute their
279 expansions. The value is a "builtin_type" enumerator.
281 operator_array holds the C++ named operators. These are keywords
282 which act as aliases for punctuators. In C++, they cannot be
283 altered through #define, and #if recognizes them as operators. In
284 C, these are not entered into the hash table at all (but see
285 <iso646.h>). The value is a token-type enumerator. */
286 struct builtin
288 const uchar *name;
289 unsigned short len;
290 unsigned short value;
293 #define B(n, t) { DSC(n), t }
294 static const struct builtin builtin_array[] =
296 B("__TIME__", BT_TIME),
297 B("__DATE__", BT_DATE),
298 B("__FILE__", BT_FILE),
299 B("__BASE_FILE__", BT_BASE_FILE),
300 B("__LINE__", BT_SPECLINE),
301 B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL),
302 /* Keep builtins not used for -traditional-cpp at the end, and
303 update init_builtins() if any more are added. */
304 B("_Pragma", BT_PRAGMA),
305 B("__STDC__", BT_STDC),
308 static const struct builtin operator_array[] =
310 B("and", CPP_AND_AND),
311 B("and_eq", CPP_AND_EQ),
312 B("bitand", CPP_AND),
313 B("bitor", CPP_OR),
314 B("compl", CPP_COMPL),
315 B("not", CPP_NOT),
316 B("not_eq", CPP_NOT_EQ),
317 B("or", CPP_OR_OR),
318 B("or_eq", CPP_OR_EQ),
319 B("xor", CPP_XOR),
320 B("xor_eq", CPP_XOR_EQ)
322 #undef B
324 /* Mark the C++ named operators in the hash table. */
325 static void
326 mark_named_operators (cpp_reader *pfile)
328 const struct builtin *b;
330 for (b = operator_array;
331 b < (operator_array + ARRAY_SIZE (operator_array));
332 b++)
334 cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
335 hp->flags |= NODE_OPERATOR;
336 hp->is_directive = 0;
337 hp->directive_index = b->value;
341 /* Read the builtins table above and enter them, and language-specific
342 macros, into the hash table. HOSTED is true if this is a hosted
343 environment. */
344 void
345 cpp_init_builtins (cpp_reader *pfile, int hosted)
347 const struct builtin *b;
348 size_t n = ARRAY_SIZE (builtin_array);
350 if (CPP_OPTION (pfile, traditional))
351 n -= 2;
353 for(b = builtin_array; b < builtin_array + n; b++)
355 cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
356 hp->type = NT_MACRO;
357 hp->flags |= NODE_BUILTIN | NODE_WARN;
358 hp->value.builtin = b->value;
361 if (CPP_OPTION (pfile, cplusplus))
362 _cpp_define_builtin (pfile, "__cplusplus 1");
363 else if (CPP_OPTION (pfile, lang) == CLK_ASM)
364 _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
365 else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
366 _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
367 else if (CPP_OPTION (pfile, c99))
368 _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
370 if (hosted)
371 _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
372 else
373 _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
375 if (CPP_OPTION (pfile, objc))
376 _cpp_define_builtin (pfile, "__OBJC__ 1");
379 /* Sanity-checks are dependent on command-line options, so it is
380 called as a subroutine of cpp_read_main_file (). */
381 #if ENABLE_CHECKING
382 static void sanity_checks (cpp_reader *);
383 static void sanity_checks (cpp_reader *pfile)
385 cppchar_t test = 0;
386 size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
388 /* Sanity checks for assumptions about CPP arithmetic and target
389 type precisions made by cpplib. */
390 test--;
391 if (test < 1)
392 cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
394 if (CPP_OPTION (pfile, precision) > max_precision)
395 cpp_error (pfile, CPP_DL_ICE,
396 "preprocessor arithmetic has maximum precision of %lu bits;"
397 " target requires %lu bits",
398 (unsigned long) max_precision,
399 (unsigned long) CPP_OPTION (pfile, precision));
401 if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
402 cpp_error (pfile, CPP_DL_ICE,
403 "CPP arithmetic must be at least as precise as a target int");
405 if (CPP_OPTION (pfile, char_precision) < 8)
406 cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
408 if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
409 cpp_error (pfile, CPP_DL_ICE,
410 "target wchar_t is narrower than target char");
412 if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
413 cpp_error (pfile, CPP_DL_ICE,
414 "target int is narrower than target char");
416 /* This is assumed in eval_token() and could be fixed if necessary. */
417 if (sizeof (cppchar_t) > sizeof (cpp_num_part))
418 cpp_error (pfile, CPP_DL_ICE,
419 "CPP half-integer narrower than CPP character");
421 if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
422 cpp_error (pfile, CPP_DL_ICE,
423 "CPP on this host cannot handle wide character constants over"
424 " %lu bits, but the target requires %lu bits",
425 (unsigned long) BITS_PER_CPPCHAR_T,
426 (unsigned long) CPP_OPTION (pfile, wchar_precision));
428 #else
429 # define sanity_checks(PFILE)
430 #endif
432 /* This is called after options have been parsed, and partially
433 processed. */
434 void
435 cpp_post_options (cpp_reader *pfile)
437 sanity_checks (pfile);
439 post_options (pfile);
441 /* Mark named operators before handling command line macros. */
442 if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
443 mark_named_operators (pfile);
446 /* Setup for processing input from the file named FNAME, or stdin if
447 it is the empty string. Return the original filename
448 on success (e.g. foo.i->foo.c), or NULL on failure. */
449 const char *
450 cpp_read_main_file (cpp_reader *pfile, const char *fname)
452 if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
454 if (!pfile->deps)
455 pfile->deps = deps_init ();
457 /* Set the default target (if there is none already). */
458 deps_add_default_target (pfile->deps, fname);
461 pfile->main_file
462 = _cpp_find_file (pfile, fname, &pfile->no_search_path, false);
463 if (_cpp_find_failed (pfile->main_file))
464 return NULL;
466 _cpp_stack_file (pfile, pfile->main_file, false);
468 /* For foo.i, read the original filename foo.c now, for the benefit
469 of the front ends. */
470 if (CPP_OPTION (pfile, preprocessed))
472 read_original_filename (pfile);
473 fname = pfile->line_table->maps[pfile->line_table->used-1].to_file;
475 return fname;
478 /* For preprocessed files, if the first tokens are of the form # NUM.
479 handle the directive so we know the original file name. This will
480 generate file_change callbacks, which the front ends must handle
481 appropriately given their state of initialization. */
482 static void
483 read_original_filename (cpp_reader *pfile)
485 const cpp_token *token, *token1;
487 /* Lex ahead; if the first tokens are of the form # NUM, then
488 process the directive, otherwise back up. */
489 token = _cpp_lex_direct (pfile);
490 if (token->type == CPP_HASH)
492 token1 = _cpp_lex_direct (pfile);
493 _cpp_backup_tokens (pfile, 1);
495 /* If it's a #line directive, handle it. */
496 if (token1->type == CPP_NUMBER)
498 _cpp_handle_directive (pfile, token->flags & PREV_WHITE);
499 read_original_directory (pfile);
500 return;
504 /* Backup as if nothing happened. */
505 _cpp_backup_tokens (pfile, 1);
508 /* For preprocessed files, if the tokens following the first filename
509 line is of the form # <line> "/path/name//", handle the
510 directive so we know the original current directory. */
511 static void
512 read_original_directory (cpp_reader *pfile)
514 const cpp_token *hash, *token;
516 /* Lex ahead; if the first tokens are of the form # NUM, then
517 process the directive, otherwise back up. */
518 hash = _cpp_lex_direct (pfile);
519 if (hash->type != CPP_HASH)
521 _cpp_backup_tokens (pfile, 1);
522 return;
525 token = _cpp_lex_direct (pfile);
527 if (token->type != CPP_NUMBER)
529 _cpp_backup_tokens (pfile, 2);
530 return;
533 token = _cpp_lex_direct (pfile);
535 if (token->type != CPP_STRING
536 || ! (token->val.str.len >= 5
537 && token->val.str.text[token->val.str.len-2] == '/'
538 && token->val.str.text[token->val.str.len-3] == '/'))
540 _cpp_backup_tokens (pfile, 3);
541 return;
544 if (pfile->cb.dir_change)
546 char *debugdir = alloca (token->val.str.len - 3);
548 memcpy (debugdir, (const char *) token->val.str.text + 1,
549 token->val.str.len - 4);
550 debugdir[token->val.str.len - 4] = '\0';
552 pfile->cb.dir_change (pfile, debugdir);
556 /* This is called at the end of preprocessing. It pops the last
557 buffer and writes dependency output, and returns the number of
558 errors.
560 Maybe it should also reset state, such that you could call
561 cpp_start_read with a new filename to restart processing. */
563 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
565 /* Warn about unused macros before popping the final buffer. */
566 if (CPP_OPTION (pfile, warn_unused_macros))
567 cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
569 /* cpplex.c leaves the final buffer on the stack. This it so that
570 it returns an unending stream of CPP_EOFs to the client. If we
571 popped the buffer, we'd dereference a NULL buffer pointer and
572 segfault. It's nice to allow the client to do worry-free excess
573 cpp_get_token calls. */
574 while (pfile->buffer)
575 _cpp_pop_buffer (pfile);
577 /* Don't write the deps file if there are errors. */
578 if (CPP_OPTION (pfile, deps.style) != DEPS_NONE
579 && deps_stream && pfile->errors == 0)
581 deps_write (pfile->deps, deps_stream, 72);
583 if (CPP_OPTION (pfile, deps.phony_targets))
584 deps_phony_targets (pfile->deps, deps_stream);
587 /* Report on headers that could use multiple include guards. */
588 if (CPP_OPTION (pfile, print_include_names))
589 _cpp_report_missing_guards (pfile);
591 return pfile->errors;
594 static void
595 post_options (cpp_reader *pfile)
597 /* -Wtraditional is not useful in C++ mode. */
598 if (CPP_OPTION (pfile, cplusplus))
599 CPP_OPTION (pfile, warn_traditional) = 0;
601 /* Permanently disable macro expansion if we are rescanning
602 preprocessed text. Read preprocesed source in ISO mode. */
603 if (CPP_OPTION (pfile, preprocessed))
605 pfile->state.prevent_expansion = 1;
606 CPP_OPTION (pfile, traditional) = 0;
609 if (CPP_OPTION (pfile, warn_trigraphs) == 2)
610 CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
612 if (CPP_OPTION (pfile, traditional))
614 CPP_OPTION (pfile, cplusplus_comments) = 0;
616 /* Traditional CPP does not accurately track column information. */
617 CPP_OPTION (pfile, show_column) = 0;
618 CPP_OPTION (pfile, trigraphs) = 0;
619 CPP_OPTION (pfile, warn_trigraphs) = 0;