1 /* Mainly the interface between cpplib and the C front ends.
2 Copyright (C) 1987, 1988, 1989, 1992, 1994, 1995, 1996, 1997
3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
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 #include "config.h"
24 #include "system.h"
25 #include "coretypes.h"
26 #include "tm.h"
27
28 #include "real.h"
29 #include "rtl.h"
30 #include "tree.h"
31 #include "input.h"
32 #include "output.h"
33 #include "c-tree.h"
34 #include "c-common.h"
35 #include "flags.h"
36 #include "timevar.h"
37 #include "cpplib.h"
38 #include "c-pragma.h"
39 #include "toplev.h"
40 #include "intl.h"
41 #include "tm_p.h"
42 #include "splay-tree.h"
43 #include "debug.h"
44
45 /* We may keep statistics about how long which files took to compile. */
46 static int header_time, body_time;
47 static splay_tree file_info_tree;
48
49 int pending_lang_change; /* If we need to switch languages - C++ only */
50 int c_header_level; /* depth in C headers - C++ only */
51
52 /* If we need to translate characters received. This is tri-state:
53 0 means use only the untranslated string; 1 means use only
54 the translated string; -1 means chain the translated string
55 to the untranslated one. */
56 int c_lex_string_translate = 1;
57
58 /* True if strings should be passed to the caller of c_lex completely
59 unmolested (no concatenation, no translation). */
60 bool c_lex_return_raw_strings = false;
61
62 static tree interpret_integer (const cpp_token *, unsigned int);
63 static tree interpret_float (const cpp_token *, unsigned int);
64 static enum integer_type_kind narrowest_unsigned_type
65 (unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT, unsigned int);
66 static enum integer_type_kind narrowest_signed_type
67 (unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT, unsigned int);
68 static enum cpp_ttype lex_string (const cpp_token *, tree *, bool);
69 static tree lex_charconst (const cpp_token *);
70 static void update_header_times (const char *);
71 static int dump_one_header (splay_tree_node, void *);
72 static void cb_line_change (cpp_reader *, const cpp_token *, int);
73 static void cb_ident (cpp_reader *, unsigned int, const cpp_string *);
74 static void cb_def_pragma (cpp_reader *, unsigned int);
75 static void cb_define (cpp_reader *, unsigned int, cpp_hashnode *);
76 static void cb_undef (cpp_reader *, unsigned int, cpp_hashnode *);
77
78 void
init_c_lex(void)79 init_c_lex (void)
80 {
81 struct cpp_callbacks *cb;
82 struct c_fileinfo *toplevel;
83
84 /* The get_fileinfo data structure must be initialized before
85 cpp_read_main_file is called. */
86 toplevel = get_fileinfo ("<top level>");
87 if (flag_detailed_statistics)
88 {
89 header_time = 0;
90 body_time = get_run_time ();
91 toplevel->time = body_time;
92 }
93
94 cb = cpp_get_callbacks (parse_in);
95
96 cb->line_change = cb_line_change;
97 cb->ident = cb_ident;
98 cb->def_pragma = cb_def_pragma;
99 cb->valid_pch = c_common_valid_pch;
100 cb->read_pch = c_common_read_pch;
101
102 /* Set the debug callbacks if we can use them. */
103 if (debug_info_level == DINFO_LEVEL_VERBOSE
104 && (write_symbols == DWARF2_DEBUG
105 || write_symbols == VMS_AND_DWARF2_DEBUG))
106 {
107 cb->define = cb_define;
108 cb->undef = cb_undef;
109 }
110 }
111
112 struct c_fileinfo *
get_fileinfo(const char * name)113 get_fileinfo (const char *name)
114 {
115 splay_tree_node n;
116 struct c_fileinfo *fi;
117
118 if (!file_info_tree)
119 file_info_tree = splay_tree_new ((splay_tree_compare_fn) strcmp,
120 0,
121 (splay_tree_delete_value_fn) free);
122
123 n = splay_tree_lookup (file_info_tree, (splay_tree_key) name);
124 if (n)
125 return (struct c_fileinfo *) n->value;
126
127 fi = XNEW (struct c_fileinfo);
128 fi->time = 0;
129 fi->interface_only = 0;
130 fi->interface_unknown = 1;
131 splay_tree_insert (file_info_tree, (splay_tree_key) name,
132 (splay_tree_value) fi);
133 return fi;
134 }
135
136 static void
update_header_times(const char * name)137 update_header_times (const char *name)
138 {
139 /* Changing files again. This means currently collected time
140 is charged against header time, and body time starts back at 0. */
141 if (flag_detailed_statistics)
142 {
143 int this_time = get_run_time ();
144 struct c_fileinfo *file = get_fileinfo (name);
145 header_time += this_time - body_time;
146 file->time += this_time - body_time;
147 body_time = this_time;
148 }
149 }
150
151 static int
dump_one_header(splay_tree_node n,void * ARG_UNUSED (dummy))152 dump_one_header (splay_tree_node n, void * ARG_UNUSED (dummy))
153 {
154 print_time ((const char *) n->key,
155 ((struct c_fileinfo *) n->value)->time);
156 return 0;
157 }
158
159 void
dump_time_statistics(void)160 dump_time_statistics (void)
161 {
162 struct c_fileinfo *file = get_fileinfo (input_filename);
163 int this_time = get_run_time ();
164 file->time += this_time - body_time;
165
166 fprintf (stderr, "\n******\n");
167 print_time ("header files (total)", header_time);
168 print_time ("main file (total)", this_time - body_time);
169 fprintf (stderr, "ratio = %g : 1\n",
170 (double) header_time / (double) (this_time - body_time));
171 fprintf (stderr, "\n******\n");
172
173 splay_tree_foreach (file_info_tree, dump_one_header, 0);
174 }
175
176 static void
cb_ident(cpp_reader * ARG_UNUSED (pfile),unsigned int ARG_UNUSED (line),const cpp_string * ARG_UNUSED (str))177 cb_ident (cpp_reader * ARG_UNUSED (pfile),
178 unsigned int ARG_UNUSED (line),
179 const cpp_string * ARG_UNUSED (str))
180 {
181 #ifdef ASM_OUTPUT_IDENT
182 if (!flag_no_ident)
183 {
184 /* Convert escapes in the string. */
185 cpp_string cstr = { 0, 0 };
186 if (cpp_interpret_string (pfile, str, 1, &cstr, false))
187 {
188 ASM_OUTPUT_IDENT (asm_out_file, (const char *) cstr.text);
189 free ((void *) cstr.text);
190 }
191 }
192 #endif
193 }
194
195 /* Called at the start of every non-empty line. TOKEN is the first
196 lexed token on the line. Used for diagnostic line numbers. */
197 static void
cb_line_change(cpp_reader * ARG_UNUSED (pfile),const cpp_token * token,int parsing_args)198 cb_line_change (cpp_reader * ARG_UNUSED (pfile), const cpp_token *token,
199 int parsing_args)
200 {
201 if (token->type != CPP_EOF && !parsing_args)
202 #ifdef USE_MAPPED_LOCATION
203 input_location = token->src_loc;
204 #else
205 {
206 source_location loc = token->src_loc;
207 const struct line_map *map = linemap_lookup (&line_table, loc);
208 input_line = SOURCE_LINE (map, loc);
209 }
210 #endif
211 }
212
213 void
fe_file_change(const struct line_map * new_map)214 fe_file_change (const struct line_map *new_map)
215 {
216 if (new_map == NULL)
217 return;
218
219 if (new_map->reason == LC_ENTER)
220 {
221 /* Don't stack the main buffer on the input stack;
222 we already did in compile_file. */
223 if (!MAIN_FILE_P (new_map))
224 {
225 #ifdef USE_MAPPED_LOCATION
226 int included_at = LAST_SOURCE_LINE_LOCATION (new_map - 1);
227
228 input_location = included_at;
229 push_srcloc (new_map->start_location);
230 #else
231 int included_at = LAST_SOURCE_LINE (new_map - 1);
232
233 input_line = included_at;
234 push_srcloc (new_map->to_file, 1);
235 #endif
236 (*debug_hooks->start_source_file) (included_at, new_map->to_file);
237 #ifndef NO_IMPLICIT_EXTERN_C
238 if (c_header_level)
239 ++c_header_level;
240 else if (new_map->sysp == 2)
241 {
242 c_header_level = 1;
243 ++pending_lang_change;
244 }
245 #endif
246 }
247 }
248 else if (new_map->reason == LC_LEAVE)
249 {
250 #ifndef NO_IMPLICIT_EXTERN_C
251 if (c_header_level && --c_header_level == 0)
252 {
253 if (new_map->sysp == 2)
254 warning (0, "badly nested C headers from preprocessor");
255 --pending_lang_change;
256 }
257 #endif
258 pop_srcloc ();
259
260 (*debug_hooks->end_source_file) (new_map->to_line);
261 }
262
263 update_header_times (new_map->to_file);
264 in_system_header = new_map->sysp != 0;
265 #ifdef USE_MAPPED_LOCATION
266 input_location = new_map->start_location;
267 #else
268 input_filename = new_map->to_file;
269 input_line = new_map->to_line;
270 #endif
271 }
272
273 static void
cb_def_pragma(cpp_reader * pfile,source_location loc)274 cb_def_pragma (cpp_reader *pfile, source_location loc)
275 {
276 /* Issue a warning message if we have been asked to do so. Ignore
277 unknown pragmas in system headers unless an explicit
278 -Wunknown-pragmas has been given. */
279 if (warn_unknown_pragmas > in_system_header)
280 {
281 const unsigned char *space, *name;
282 const cpp_token *s;
283 #ifndef USE_MAPPED_LOCATION
284 location_t fe_loc;
285 const struct line_map *map = linemap_lookup (&line_table, loc);
286 fe_loc.file = map->to_file;
287 fe_loc.line = SOURCE_LINE (map, loc);
288 #else
289 location_t fe_loc = loc;
290 #endif
291
292 space = name = (const unsigned char *) "";
293 s = cpp_get_token (pfile);
294 if (s->type != CPP_EOF)
295 {
296 space = cpp_token_as_text (pfile, s);
297 s = cpp_get_token (pfile);
298 if (s->type == CPP_NAME)
299 name = cpp_token_as_text (pfile, s);
300 }
301
302 warning (OPT_Wunknown_pragmas, "%Hignoring #pragma %s %s",
303 &fe_loc, space, name);
304 }
305 }
306
307 /* #define callback for DWARF and DWARF2 debug info. */
308 static void
cb_define(cpp_reader * pfile,source_location loc,cpp_hashnode * node)309 cb_define (cpp_reader *pfile, source_location loc, cpp_hashnode *node)
310 {
311 const struct line_map *map = linemap_lookup (&line_table, loc);
312 (*debug_hooks->define) (SOURCE_LINE (map, loc),
313 (const char *) cpp_macro_definition (pfile, node));
314 }
315
316 /* #undef callback for DWARF and DWARF2 debug info. */
317 static void
cb_undef(cpp_reader * ARG_UNUSED (pfile),source_location loc,cpp_hashnode * node)318 cb_undef (cpp_reader * ARG_UNUSED (pfile), source_location loc,
319 cpp_hashnode *node)
320 {
321 const struct line_map *map = linemap_lookup (&line_table, loc);
322 (*debug_hooks->undef) (SOURCE_LINE (map, loc),
323 (const char *) NODE_NAME (node));
324 }
325
326 /* Read a token and return its type. Fill *VALUE with its value, if
327 applicable. Fill *CPP_FLAGS with the token's flags, if it is
328 non-NULL. */
329
330 enum cpp_ttype
c_lex_with_flags(tree * value,location_t * loc,unsigned char * cpp_flags)331 c_lex_with_flags (tree *value, location_t *loc, unsigned char *cpp_flags)
332 {
333 static bool no_more_pch;
334 const cpp_token *tok;
335 enum cpp_ttype type;
336
337 timevar_push (TV_CPP);
338 retry:
339 tok = cpp_get_token (parse_in);
340 type = tok->type;
341
342 retry_after_at:
343 #ifdef USE_MAPPED_LOCATION
344 *loc = tok->src_loc;
345 #else
346 *loc = input_location;
347 #endif
348 switch (type)
349 {
350 case CPP_PADDING:
351 goto retry;
352
353 case CPP_NAME:
354 *value = HT_IDENT_TO_GCC_IDENT (HT_NODE (tok->val.node));
355 break;
356
357 case CPP_NUMBER:
358 {
359 unsigned int flags = cpp_classify_number (parse_in, tok);
360
361 switch (flags & CPP_N_CATEGORY)
362 {
363 case CPP_N_INVALID:
364 /* cpplib has issued an error. */
365 *value = error_mark_node;
366 errorcount++;
367 break;
368
369 case CPP_N_INTEGER:
370 *value = interpret_integer (tok, flags);
371 break;
372
373 case CPP_N_FLOATING:
374 *value = interpret_float (tok, flags);
375 break;
376
377 default:
378 gcc_unreachable ();
379 }
380 }
381 break;
382
383 case CPP_ATSIGN:
384 /* An @ may give the next token special significance in Objective-C. */
385 if (c_dialect_objc ())
386 {
387 location_t atloc = input_location;
388
389 retry_at:
390 tok = cpp_get_token (parse_in);
391 type = tok->type;
392 switch (type)
393 {
394 case CPP_PADDING:
395 goto retry_at;
396
397 case CPP_STRING:
398 case CPP_WSTRING:
399 type = lex_string (tok, value, true);
400 break;
401
402 case CPP_NAME:
403 *value = HT_IDENT_TO_GCC_IDENT (HT_NODE (tok->val.node));
404 if (objc_is_reserved_word (*value))
405 {
406 type = CPP_AT_NAME;
407 break;
408 }
409 /* FALLTHROUGH */
410
411 default:
412 /* ... or not. */
413 error ("%Hstray %<@%> in program", &atloc);
414 goto retry_after_at;
415 }
416 break;
417 }
418
419 /* FALLTHROUGH */
420 case CPP_HASH:
421 case CPP_PASTE:
422 {
423 unsigned char name[4];
424
425 *cpp_spell_token (parse_in, tok, name, true) = 0;
426
427 error ("stray %qs in program", name);
428 }
429
430 goto retry;
431
432 case CPP_OTHER:
433 {
434 cppchar_t c = tok->val.str.text[0];
435
436 if (c == '"' || c == '\'')
437 cpp_unterminated (parse_in, c);
438 else if (ISGRAPH (c))
439 error ("stray %qc in program", (int) c);
440 else
441 error ("stray %<\\%o%> in program", (int) c);
442 }
443 goto retry;
444
445 case CPP_CHAR:
446 case CPP_WCHAR:
447 *value = lex_charconst (tok);
448 break;
449
450 case CPP_STRING:
451 case CPP_WSTRING:
452 if (!c_lex_return_raw_strings)
453 {
454 type = lex_string (tok, value, false);
455 break;
456 }
457
458 /* FALLTHROUGH */
459
460 case CPP_PRAGMA:
461 *value = build_string (tok->val.str.len, (char *) tok->val.str.text);
462 break;
463
464 /* These tokens should not be visible outside cpplib. */
465 case CPP_HEADER_NAME:
466 case CPP_COMMENT:
467 case CPP_MACRO_ARG:
468 gcc_unreachable ();
469
470 default:
471 *value = NULL_TREE;
472 break;
473 }
474
475 if (cpp_flags)
476 *cpp_flags = tok->flags;
477
478 if (!no_more_pch)
479 {
480 no_more_pch = true;
481 c_common_no_more_pch ();
482 }
483
484 timevar_pop (TV_CPP);
485
486 return type;
487 }
488
489 enum cpp_ttype
c_lex(tree * value)490 c_lex (tree *value)
491 {
492 location_t loc;
493 return c_lex_with_flags (value, &loc, NULL);
494 }
495
496 /* Returns the narrowest C-visible unsigned type, starting with the
497 minimum specified by FLAGS, that can fit HIGH:LOW, or itk_none if
498 there isn't one. */
499
500 static enum integer_type_kind
narrowest_unsigned_type(unsigned HOST_WIDE_INT low,unsigned HOST_WIDE_INT high,unsigned int flags)501 narrowest_unsigned_type (unsigned HOST_WIDE_INT low,
502 unsigned HOST_WIDE_INT high,
503 unsigned int flags)
504 {
505 enum integer_type_kind itk;
506
507 if ((flags & CPP_N_WIDTH) == CPP_N_SMALL)
508 itk = itk_unsigned_int;
509 else if ((flags & CPP_N_WIDTH) == CPP_N_MEDIUM)
510 itk = itk_unsigned_long;
511 else
512 itk = itk_unsigned_long_long;
513
514 for (; itk < itk_none; itk += 2 /* skip unsigned types */)
515 {
516 tree upper = TYPE_MAX_VALUE (integer_types[itk]);
517
518 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (upper) > high
519 || ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (upper) == high
520 && TREE_INT_CST_LOW (upper) >= low))
521 return itk;
522 }
523
524 return itk_none;
525 }
526
527 /* Ditto, but narrowest signed type. */
528 static enum integer_type_kind
narrowest_signed_type(unsigned HOST_WIDE_INT low,unsigned HOST_WIDE_INT high,unsigned int flags)529 narrowest_signed_type (unsigned HOST_WIDE_INT low,
530 unsigned HOST_WIDE_INT high, unsigned int flags)
531 {
532 enum integer_type_kind itk;
533
534 if ((flags & CPP_N_WIDTH) == CPP_N_SMALL)
535 itk = itk_int;
536 else if ((flags & CPP_N_WIDTH) == CPP_N_MEDIUM)
537 itk = itk_long;
538 else
539 itk = itk_long_long;
540
541
542 for (; itk < itk_none; itk += 2 /* skip signed types */)
543 {
544 tree upper = TYPE_MAX_VALUE (integer_types[itk]);
545
546 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (upper) > high
547 || ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (upper) == high
548 && TREE_INT_CST_LOW (upper) >= low))
549 return itk;
550 }
551
552 return itk_none;
553 }
554
555 /* Interpret TOKEN, an integer with FLAGS as classified by cpplib. */
556 static tree
interpret_integer(const cpp_token * token,unsigned int flags)557 interpret_integer (const cpp_token *token, unsigned int flags)
558 {
559 tree value, type;
560 enum integer_type_kind itk;
561 cpp_num integer;
562 cpp_options *options = cpp_get_options (parse_in);
563
564 integer = cpp_interpret_integer (parse_in, token, flags);
565 integer = cpp_num_sign_extend (integer, options->precision);
566
567 /* The type of a constant with a U suffix is straightforward. */
568 if (flags & CPP_N_UNSIGNED)
569 itk = narrowest_unsigned_type (integer.low, integer.high, flags);
570 else
571 {
572 /* The type of a potentially-signed integer constant varies
573 depending on the base it's in, the standard in use, and the
574 length suffixes. */
575 enum integer_type_kind itk_u
576 = narrowest_unsigned_type (integer.low, integer.high, flags);
577 enum integer_type_kind itk_s
578 = narrowest_signed_type (integer.low, integer.high, flags);
579
580 /* In both C89 and C99, octal and hex constants may be signed or
581 unsigned, whichever fits tighter. We do not warn about this
582 choice differing from the traditional choice, as the constant
583 is probably a bit pattern and either way will work. */
584 if ((flags & CPP_N_RADIX) != CPP_N_DECIMAL)
585 itk = MIN (itk_u, itk_s);
586 else
587 {
588 /* In C99, decimal constants are always signed.
589 In C89, decimal constants that don't fit in long have
590 undefined behavior; we try to make them unsigned long.
591 In GCC's extended C89, that last is true of decimal
592 constants that don't fit in long long, too. */
593
594 itk = itk_s;
595 if (itk_s > itk_u && itk_s > itk_long)
596 {
597 if (!flag_isoc99)
598 {
599 if (itk_u < itk_unsigned_long)
600 itk_u = itk_unsigned_long;
601 itk = itk_u;
602 warning (0, "this decimal constant is unsigned only in ISO C90");
603 }
604 else
605 warning (OPT_Wtraditional,
606 "this decimal constant would be unsigned in ISO C90");
607 }
608 }
609 }
610
611 if (itk == itk_none)
612 /* cpplib has already issued a warning for overflow. */
613 type = ((flags & CPP_N_UNSIGNED)
614 ? widest_unsigned_literal_type_node
615 : widest_integer_literal_type_node);
616 else
617 type = integer_types[itk];
618
619 if (itk > itk_unsigned_long
620 && (flags & CPP_N_WIDTH) != CPP_N_LARGE
621 && !in_system_header && !flag_isoc99)
622 pedwarn ("integer constant is too large for %qs type",
623 (flags & CPP_N_UNSIGNED) ? "unsigned long" : "long");
624
625 value = build_int_cst_wide (type, integer.low, integer.high);
626
627 /* Convert imaginary to a complex type. */
628 if (flags & CPP_N_IMAGINARY)
629 value = build_complex (NULL_TREE, build_int_cst (type, 0), value);
630
631 return value;
632 }
633
634 /* Interpret TOKEN, a floating point number with FLAGS as classified
635 by cpplib. */
636 static tree
interpret_float(const cpp_token * token,unsigned int flags)637 interpret_float (const cpp_token *token, unsigned int flags)
638 {
639 tree type;
640 tree value;
641 REAL_VALUE_TYPE real;
642 char *copy;
643 size_t copylen;
644 const char *type_name;
645
646 /* FIXME: make %T work in error/warning, then we don't need type_name. */
647 if ((flags & CPP_N_WIDTH) == CPP_N_LARGE)
648 {
649 type = long_double_type_node;
650 type_name = "long double";
651 }
652 else if ((flags & CPP_N_WIDTH) == CPP_N_SMALL
653 || flag_single_precision_constant)
654 {
655 type = float_type_node;
656 type_name = "float";
657 }
658 else
659 {
660 type = double_type_node;
661 type_name = "double";
662 }
663
664 /* Copy the constant to a nul-terminated buffer. If the constant
665 has any suffixes, cut them off; REAL_VALUE_ATOF/ REAL_VALUE_HTOF
666 can't handle them. */
667 copylen = token->val.str.len;
668 if ((flags & CPP_N_WIDTH) != CPP_N_MEDIUM)
669 /* Must be an F or L suffix. */
670 copylen--;
671 if (flags & CPP_N_IMAGINARY)
672 /* I or J suffix. */
673 copylen--;
674
675 copy = (char *) alloca (copylen + 1);
676 memcpy (copy, token->val.str.text, copylen);
677 copy[copylen] = '\0';
678
679 real_from_string (&real, copy);
680 real_convert (&real, TYPE_MODE (type), &real);
681
682 /* Both C and C++ require a diagnostic for a floating constant
683 outside the range of representable values of its type. Since we
684 have __builtin_inf* to produce an infinity, it might now be
685 appropriate for this to be a mandatory pedwarn rather than
686 conditioned on -pedantic. */
687 if (REAL_VALUE_ISINF (real) && pedantic)
688 pedwarn ("floating constant exceeds range of %<%s%>", type_name);
689
690 /* Create a node with determined type and value. */
691 value = build_real (type, real);
692 if (flags & CPP_N_IMAGINARY)
693 value = build_complex (NULL_TREE, convert (type, integer_zero_node), value);
694
695 return value;
696 }
697
698 /* Convert a series of STRING and/or WSTRING tokens into a tree,
699 performing string constant concatenation. TOK is the first of
700 these. VALP is the location to write the string into. OBJC_STRING
701 indicates whether an '@' token preceded the incoming token.
702 Returns the CPP token type of the result (CPP_STRING, CPP_WSTRING,
703 or CPP_OBJC_STRING).
704
705 This is unfortunately more work than it should be. If any of the
706 strings in the series has an L prefix, the result is a wide string
707 (6.4.5p4). Whether or not the result is a wide string affects the
708 meaning of octal and hexadecimal escapes (6.4.4.4p6,9). But escape
709 sequences do not continue across the boundary between two strings in
710 a series (6.4.5p7), so we must not lose the boundaries. Therefore
711 cpp_interpret_string takes a vector of cpp_string structures, which
712 we must arrange to provide. */
713
714 static enum cpp_ttype
lex_string(const cpp_token * tok,tree * valp,bool objc_string)715 lex_string (const cpp_token *tok, tree *valp, bool objc_string)
716 {
717 tree value;
718 bool wide = false;
719 size_t concats = 0;
720 struct obstack str_ob;
721 cpp_string istr;
722
723 /* Try to avoid the overhead of creating and destroying an obstack
724 for the common case of just one string. */
725 cpp_string str = tok->val.str;
726 cpp_string *strs = &str;
727
728 if (tok->type == CPP_WSTRING)
729 wide = true;
730
731 retry:
732 tok = cpp_get_token (parse_in);
733 switch (tok->type)
734 {
735 case CPP_PADDING:
736 goto retry;
737 case CPP_ATSIGN:
738 if (c_dialect_objc ())
739 {
740 objc_string = true;
741 goto retry;
742 }
743 /* FALLTHROUGH */
744
745 default:
746 break;
747
748 case CPP_WSTRING:
749 wide = true;
750 /* FALLTHROUGH */
751
752 case CPP_STRING:
753 if (!concats)
754 {
755 gcc_obstack_init (&str_ob);
756 obstack_grow (&str_ob, &str, sizeof (cpp_string));
757 }
758
759 concats++;
760 obstack_grow (&str_ob, &tok->val.str, sizeof (cpp_string));
761 goto retry;
762 }
763
764 /* We have read one more token than we want. */
765 _cpp_backup_tokens (parse_in, 1);
766 if (concats)
767 strs = XOBFINISH (&str_ob, cpp_string *);
768
769 if (concats && !objc_string && !in_system_header)
770 warning (OPT_Wtraditional,
771 "traditional C rejects string constant concatenation");
772
773 if ((c_lex_string_translate
774 ? cpp_interpret_string : cpp_interpret_string_notranslate)
775 (parse_in, strs, concats + 1, &istr, wide))
776 {
777 value = build_string (istr.len, (char *) istr.text);
778 free ((void *) istr.text);
779
780 if (c_lex_string_translate == -1)
781 {
782 int xlated = cpp_interpret_string_notranslate (parse_in, strs,
783 concats + 1,
784 &istr, wide);
785 /* Assume that, if we managed to translate the string above,
786 then the untranslated parsing will always succeed. */
787 gcc_assert (xlated);
788
789 if (TREE_STRING_LENGTH (value) != (int) istr.len
790 || 0 != strncmp (TREE_STRING_POINTER (value), (char *) istr.text,
791 istr.len))
792 {
793 /* Arrange for us to return the untranslated string in
794 *valp, but to set up the C type of the translated
795 one. */
796 *valp = build_string (istr.len, (char *) istr.text);
797 valp = &TREE_CHAIN (*valp);
798 }
799 free ((void *) istr.text);
800 }
801 }
802 else
803 {
804 /* Callers cannot generally handle error_mark_node in this context,
805 so return the empty string instead. cpp_interpret_string has
806 issued an error. */
807 if (wide)
808 value = build_string (TYPE_PRECISION (wchar_type_node)
809 / TYPE_PRECISION (char_type_node),
810 "\0\0\0"); /* widest supported wchar_t
811 is 32 bits */
812 else
813 value = build_string (1, "");
814 }
815
816 TREE_TYPE (value) = wide ? wchar_array_type_node : char_array_type_node;
817 *valp = fix_string_type (value);
818
819 if (concats)
820 obstack_free (&str_ob, 0);
821
822 return objc_string ? CPP_OBJC_STRING : wide ? CPP_WSTRING : CPP_STRING;
823 }
824
825 /* Converts a (possibly wide) character constant token into a tree. */
826 static tree
lex_charconst(const cpp_token * token)827 lex_charconst (const cpp_token *token)
828 {
829 cppchar_t result;
830 tree type, value;
831 unsigned int chars_seen;
832 int unsignedp;
833
834 result = cpp_interpret_charconst (parse_in, token,
835 &chars_seen, &unsignedp);
836
837 if (token->type == CPP_WCHAR)
838 type = wchar_type_node;
839 /* In C, a character constant has type 'int'.
840 In C++ 'char', but multi-char charconsts have type 'int'. */
841 else if (!c_dialect_cxx () || chars_seen > 1)
842 type = integer_type_node;
843 else
844 type = char_type_node;
845
846 /* Cast to cppchar_signed_t to get correct sign-extension of RESULT
847 before possibly widening to HOST_WIDE_INT for build_int_cst. */
848 if (unsignedp || (cppchar_signed_t) result >= 0)
849 value = build_int_cst_wide (type, result, 0);
850 else
851 value = build_int_cst_wide (type, (cppchar_signed_t) result, -1);
852
853 return value;
854 }
855