* tree-ssa-phiopt.c, config/arm/arm.c, config/fr30/fr30.md,
[official-gcc.git] / gcc / c-lex.c
blob5e695365f32087fb08394c3b63b686f8de651052
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.
6 This file is part of GCC.
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.
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.
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, 59 Temple Place - Suite 330, Boston, MA
21 02111-1307, USA. */
23 #include "config.h"
24 #include "system.h"
25 #include "coretypes.h"
26 #include "tm.h"
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"
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;
49 int pending_lang_change; /* If we need to switch languages - C++ only */
50 int c_header_level; /* depth in C headers - C++ only */
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;
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;
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 *);
78 void
79 init_c_lex (void)
81 struct cpp_callbacks *cb;
82 struct c_fileinfo *toplevel;
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)
89 header_time = 0;
90 body_time = get_run_time ();
91 toplevel->time = body_time;
94 cb = cpp_get_callbacks (parse_in);
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;
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))
107 cb->define = cb_define;
108 cb->undef = cb_undef;
112 struct c_fileinfo *
113 get_fileinfo (const char *name)
115 splay_tree_node n;
116 struct c_fileinfo *fi;
118 if (!file_info_tree)
119 file_info_tree = splay_tree_new ((splay_tree_compare_fn) strcmp,
121 (splay_tree_delete_value_fn) free);
123 n = splay_tree_lookup (file_info_tree, (splay_tree_key) name);
124 if (n)
125 return (struct c_fileinfo *) n->value;
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;
136 static void
137 update_header_times (const char *name)
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)
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;
151 static int
152 dump_one_header (splay_tree_node n, void * ARG_UNUSED (dummy))
154 print_time ((const char *) n->key,
155 ((struct c_fileinfo *) n->value)->time);
156 return 0;
159 void
160 dump_time_statistics (void)
162 struct c_fileinfo *file = get_fileinfo (input_filename);
163 int this_time = get_run_time ();
164 file->time += this_time - body_time;
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");
173 splay_tree_foreach (file_info_tree, dump_one_header, 0);
176 static void
177 cb_ident (cpp_reader * ARG_UNUSED (pfile),
178 unsigned int ARG_UNUSED (line),
179 const cpp_string * ARG_UNUSED (str))
181 #ifdef ASM_OUTPUT_IDENT
182 if (!flag_no_ident)
184 /* Convert escapes in the string. */
185 cpp_string cstr = { 0, 0 };
186 if (cpp_interpret_string (pfile, str, 1, &cstr, false))
188 ASM_OUTPUT_IDENT (asm_out_file, (const char *) cstr.text);
189 free ((void *) cstr.text);
192 #endif
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
198 cb_line_change (cpp_reader * ARG_UNUSED (pfile), const cpp_token *token,
199 int parsing_args)
201 if (token->type != CPP_EOF && !parsing_args)
202 #ifdef USE_MAPPED_LOCATION
203 input_location = token->src_loc;
204 #else
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);
210 #endif
213 void
214 fe_file_change (const struct line_map *new_map)
216 if (new_map == NULL)
217 return;
219 if (new_map->reason == LC_ENTER)
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))
225 #ifdef USE_MAPPED_LOCATION
226 int included_at = LAST_SOURCE_LINE_LOCATION (new_map - 1);
228 input_location = included_at;
229 push_srcloc (new_map->start_location);
230 #else
231 int included_at = LAST_SOURCE_LINE (new_map - 1);
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)
242 c_header_level = 1;
243 ++pending_lang_change;
245 #endif
248 else if (new_map->reason == LC_LEAVE)
250 #ifndef NO_IMPLICIT_EXTERN_C
251 if (c_header_level && --c_header_level == 0)
253 if (new_map->sysp == 2)
254 warning ("badly nested C headers from preprocessor");
255 --pending_lang_change;
257 #endif
258 pop_srcloc ();
260 (*debug_hooks->end_source_file) (new_map->to_line);
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
273 static void
274 cb_def_pragma (cpp_reader *pfile, source_location loc)
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)
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
292 space = name = (const unsigned char *) "";
293 s = cpp_get_token (pfile);
294 if (s->type != CPP_EOF)
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);
302 warning ("%Hignoring #pragma %s %s", &fe_loc, space, name);
306 /* #define callback for DWARF and DWARF2 debug info. */
307 static void
308 cb_define (cpp_reader *pfile, source_location loc, cpp_hashnode *node)
310 const struct line_map *map = linemap_lookup (&line_table, loc);
311 (*debug_hooks->define) (SOURCE_LINE (map, loc),
312 (const char *) cpp_macro_definition (pfile, node));
315 /* #undef callback for DWARF and DWARF2 debug info. */
316 static void
317 cb_undef (cpp_reader * ARG_UNUSED (pfile), source_location loc,
318 cpp_hashnode *node)
320 const struct line_map *map = linemap_lookup (&line_table, loc);
321 (*debug_hooks->undef) (SOURCE_LINE (map, loc),
322 (const char *) NODE_NAME (node));
325 /* Read a token and return its type. Fill *VALUE with its value, if
326 applicable. Fill *CPP_FLAGS with the token's flags, if it is
327 non-NULL. */
329 enum cpp_ttype
330 c_lex_with_flags (tree *value, location_t *loc, unsigned char *cpp_flags)
332 static bool no_more_pch;
333 const cpp_token *tok;
334 enum cpp_ttype type;
336 timevar_push (TV_CPP);
337 retry:
338 tok = cpp_get_token (parse_in);
339 type = tok->type;
341 retry_after_at:
342 #ifdef USE_MAPPED_LOCATION
343 *loc = tok->src_loc;
344 #else
345 *loc = input_location;
346 #endif
347 switch (type)
349 case CPP_PADDING:
350 goto retry;
352 case CPP_NAME:
353 *value = HT_IDENT_TO_GCC_IDENT (HT_NODE (tok->val.node));
354 break;
356 case CPP_NUMBER:
358 unsigned int flags = cpp_classify_number (parse_in, tok);
360 switch (flags & CPP_N_CATEGORY)
362 case CPP_N_INVALID:
363 /* cpplib has issued an error. */
364 *value = error_mark_node;
365 break;
367 case CPP_N_INTEGER:
368 *value = interpret_integer (tok, flags);
369 break;
371 case CPP_N_FLOATING:
372 *value = interpret_float (tok, flags);
373 break;
375 default:
376 gcc_unreachable ();
379 break;
381 case CPP_ATSIGN:
382 /* An @ may give the next token special significance in Objective-C. */
383 if (c_dialect_objc ())
385 location_t atloc = input_location;
387 retry_at:
388 tok = cpp_get_token (parse_in);
389 type = tok->type;
390 switch (type)
392 case CPP_PADDING:
393 goto retry_at;
395 case CPP_STRING:
396 case CPP_WSTRING:
397 type = lex_string (tok, value, true);
398 break;
400 case CPP_NAME:
401 *value = HT_IDENT_TO_GCC_IDENT (HT_NODE (tok->val.node));
402 if (objc_is_reserved_word (*value))
404 type = CPP_AT_NAME;
405 break;
407 /* FALLTHROUGH */
409 default:
410 /* ... or not. */
411 error ("%Hstray %<@%> in program", &atloc);
412 goto retry_after_at;
414 break;
417 /* FALLTHROUGH */
418 case CPP_HASH:
419 case CPP_PASTE:
421 unsigned char name[4];
423 *cpp_spell_token (parse_in, tok, name, true) = 0;
425 error ("stray %qs in program", name);
428 goto retry;
430 case CPP_OTHER:
432 cppchar_t c = tok->val.str.text[0];
434 if (c == '"' || c == '\'')
435 error ("missing terminating %c character", (int) c);
436 else if (ISGRAPH (c))
437 error ("stray %qc in program", (int) c);
438 else
439 error ("stray %<\\%o%> in program", (int) c);
441 goto retry;
443 case CPP_CHAR:
444 case CPP_WCHAR:
445 *value = lex_charconst (tok);
446 break;
448 case CPP_STRING:
449 case CPP_WSTRING:
450 if (!c_lex_return_raw_strings)
452 type = lex_string (tok, value, false);
453 break;
456 /* FALLTHROUGH */
458 case CPP_PRAGMA:
459 *value = build_string (tok->val.str.len, (char *) tok->val.str.text);
460 break;
462 /* These tokens should not be visible outside cpplib. */
463 case CPP_HEADER_NAME:
464 case CPP_COMMENT:
465 case CPP_MACRO_ARG:
466 gcc_unreachable ();
468 default:
469 *value = NULL_TREE;
470 break;
473 if (cpp_flags)
474 *cpp_flags = tok->flags;
476 if (!no_more_pch)
478 no_more_pch = true;
479 c_common_no_more_pch ();
482 timevar_pop (TV_CPP);
484 return type;
487 enum cpp_ttype
488 c_lex (tree *value)
490 location_t loc;
491 return c_lex_with_flags (value, &loc, NULL);
494 /* Returns the narrowest C-visible unsigned type, starting with the
495 minimum specified by FLAGS, that can fit HIGH:LOW, or itk_none if
496 there isn't one. */
498 static enum integer_type_kind
499 narrowest_unsigned_type (unsigned HOST_WIDE_INT low,
500 unsigned HOST_WIDE_INT high,
501 unsigned int flags)
503 enum integer_type_kind itk;
505 if ((flags & CPP_N_WIDTH) == CPP_N_SMALL)
506 itk = itk_unsigned_int;
507 else if ((flags & CPP_N_WIDTH) == CPP_N_MEDIUM)
508 itk = itk_unsigned_long;
509 else
510 itk = itk_unsigned_long_long;
512 for (; itk < itk_none; itk += 2 /* skip unsigned types */)
514 tree upper = TYPE_MAX_VALUE (integer_types[itk]);
516 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (upper) > high
517 || ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (upper) == high
518 && TREE_INT_CST_LOW (upper) >= low))
519 return itk;
522 return itk_none;
525 /* Ditto, but narrowest signed type. */
526 static enum integer_type_kind
527 narrowest_signed_type (unsigned HOST_WIDE_INT low,
528 unsigned HOST_WIDE_INT high, unsigned int flags)
530 enum integer_type_kind itk;
532 if ((flags & CPP_N_WIDTH) == CPP_N_SMALL)
533 itk = itk_int;
534 else if ((flags & CPP_N_WIDTH) == CPP_N_MEDIUM)
535 itk = itk_long;
536 else
537 itk = itk_long_long;
540 for (; itk < itk_none; itk += 2 /* skip signed types */)
542 tree upper = TYPE_MAX_VALUE (integer_types[itk]);
544 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (upper) > high
545 || ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (upper) == high
546 && TREE_INT_CST_LOW (upper) >= low))
547 return itk;
550 return itk_none;
553 /* Interpret TOKEN, an integer with FLAGS as classified by cpplib. */
554 static tree
555 interpret_integer (const cpp_token *token, unsigned int flags)
557 tree value, type;
558 enum integer_type_kind itk;
559 cpp_num integer;
560 cpp_options *options = cpp_get_options (parse_in);
562 integer = cpp_interpret_integer (parse_in, token, flags);
563 integer = cpp_num_sign_extend (integer, options->precision);
565 /* The type of a constant with a U suffix is straightforward. */
566 if (flags & CPP_N_UNSIGNED)
567 itk = narrowest_unsigned_type (integer.low, integer.high, flags);
568 else
570 /* The type of a potentially-signed integer constant varies
571 depending on the base it's in, the standard in use, and the
572 length suffixes. */
573 enum integer_type_kind itk_u
574 = narrowest_unsigned_type (integer.low, integer.high, flags);
575 enum integer_type_kind itk_s
576 = narrowest_signed_type (integer.low, integer.high, flags);
578 /* In both C89 and C99, octal and hex constants may be signed or
579 unsigned, whichever fits tighter. We do not warn about this
580 choice differing from the traditional choice, as the constant
581 is probably a bit pattern and either way will work. */
582 if ((flags & CPP_N_RADIX) != CPP_N_DECIMAL)
583 itk = MIN (itk_u, itk_s);
584 else
586 /* In C99, decimal constants are always signed.
587 In C89, decimal constants that don't fit in long have
588 undefined behavior; we try to make them unsigned long.
589 In GCC's extended C89, that last is true of decimal
590 constants that don't fit in long long, too. */
592 itk = itk_s;
593 if (itk_s > itk_u && itk_s > itk_long)
595 if (!flag_isoc99)
597 if (itk_u < itk_unsigned_long)
598 itk_u = itk_unsigned_long;
599 itk = itk_u;
600 warning ("this decimal constant is unsigned only in ISO C90");
602 else if (warn_traditional)
603 warning ("this decimal constant would be unsigned in ISO C90");
608 if (itk == itk_none)
609 /* cpplib has already issued a warning for overflow. */
610 type = ((flags & CPP_N_UNSIGNED)
611 ? widest_unsigned_literal_type_node
612 : widest_integer_literal_type_node);
613 else
614 type = integer_types[itk];
616 if (itk > itk_unsigned_long
617 && (flags & CPP_N_WIDTH) != CPP_N_LARGE
618 && !in_system_header && !flag_isoc99)
619 pedwarn ("integer constant is too large for %qs type",
620 (flags & CPP_N_UNSIGNED) ? "unsigned long" : "long");
622 value = build_int_cst_wide (type, integer.low, integer.high);
624 /* Convert imaginary to a complex type. */
625 if (flags & CPP_N_IMAGINARY)
626 value = build_complex (NULL_TREE, build_int_cst (type, 0), value);
628 return value;
631 /* Interpret TOKEN, a floating point number with FLAGS as classified
632 by cpplib. */
633 static tree
634 interpret_float (const cpp_token *token, unsigned int flags)
636 tree type;
637 tree value;
638 REAL_VALUE_TYPE real;
639 char *copy;
640 size_t copylen;
641 const char *type_name;
643 /* FIXME: make %T work in error/warning, then we don't need type_name. */
644 if ((flags & CPP_N_WIDTH) == CPP_N_LARGE)
646 type = long_double_type_node;
647 type_name = "long double";
649 else if ((flags & CPP_N_WIDTH) == CPP_N_SMALL
650 || flag_single_precision_constant)
652 type = float_type_node;
653 type_name = "float";
655 else
657 type = double_type_node;
658 type_name = "double";
661 /* Copy the constant to a nul-terminated buffer. If the constant
662 has any suffixes, cut them off; REAL_VALUE_ATOF/ REAL_VALUE_HTOF
663 can't handle them. */
664 copylen = token->val.str.len;
665 if ((flags & CPP_N_WIDTH) != CPP_N_MEDIUM)
666 /* Must be an F or L suffix. */
667 copylen--;
668 if (flags & CPP_N_IMAGINARY)
669 /* I or J suffix. */
670 copylen--;
672 copy = (char *) alloca (copylen + 1);
673 memcpy (copy, token->val.str.text, copylen);
674 copy[copylen] = '\0';
676 real_from_string (&real, copy);
677 real_convert (&real, TYPE_MODE (type), &real);
679 /* Both C and C++ require a diagnostic for a floating constant
680 outside the range of representable values of its type. Since we
681 have __builtin_inf* to produce an infinity, it might now be
682 appropriate for this to be a mandatory pedwarn rather than
683 conditioned on -pedantic. */
684 if (REAL_VALUE_ISINF (real) && pedantic)
685 pedwarn ("floating constant exceeds range of %<%s%>", type_name);
687 /* Create a node with determined type and value. */
688 value = build_real (type, real);
689 if (flags & CPP_N_IMAGINARY)
690 value = build_complex (NULL_TREE, convert (type, integer_zero_node), value);
692 return value;
695 /* Convert a series of STRING and/or WSTRING tokens into a tree,
696 performing string constant concatenation. TOK is the first of
697 these. VALP is the location to write the string into. OBJC_STRING
698 indicates whether an '@' token preceded the incoming token.
699 Returns the CPP token type of the result (CPP_STRING, CPP_WSTRING,
700 or CPP_OBJC_STRING).
702 This is unfortunately more work than it should be. If any of the
703 strings in the series has an L prefix, the result is a wide string
704 (6.4.5p4). Whether or not the result is a wide string affects the
705 meaning of octal and hexadecimal escapes (6.4.4.4p6,9). But escape
706 sequences do not continue across the boundary between two strings in
707 a series (6.4.5p7), so we must not lose the boundaries. Therefore
708 cpp_interpret_string takes a vector of cpp_string structures, which
709 we must arrange to provide. */
711 static enum cpp_ttype
712 lex_string (const cpp_token *tok, tree *valp, bool objc_string)
714 tree value;
715 bool wide = false;
716 size_t concats = 0;
717 struct obstack str_ob;
718 cpp_string istr;
720 /* Try to avoid the overhead of creating and destroying an obstack
721 for the common case of just one string. */
722 cpp_string str = tok->val.str;
723 cpp_string *strs = &str;
725 if (tok->type == CPP_WSTRING)
726 wide = true;
728 retry:
729 tok = cpp_get_token (parse_in);
730 switch (tok->type)
732 case CPP_PADDING:
733 goto retry;
734 case CPP_ATSIGN:
735 if (c_dialect_objc ())
737 objc_string = true;
738 goto retry;
740 /* FALLTHROUGH */
742 default:
743 break;
745 case CPP_WSTRING:
746 wide = true;
747 /* FALLTHROUGH */
749 case CPP_STRING:
750 if (!concats)
752 gcc_obstack_init (&str_ob);
753 obstack_grow (&str_ob, &str, sizeof (cpp_string));
756 concats++;
757 obstack_grow (&str_ob, &tok->val.str, sizeof (cpp_string));
758 goto retry;
761 /* We have read one more token than we want. */
762 _cpp_backup_tokens (parse_in, 1);
763 if (concats)
764 strs = (cpp_string *) obstack_finish (&str_ob);
766 if (concats && !objc_string && warn_traditional && !in_system_header)
767 warning ("traditional C rejects string constant concatenation");
769 if ((c_lex_string_translate
770 ? cpp_interpret_string : cpp_interpret_string_notranslate)
771 (parse_in, strs, concats + 1, &istr, wide))
773 value = build_string (istr.len, (char *) istr.text);
774 free ((void *) istr.text);
776 if (c_lex_string_translate == -1)
778 int xlated = cpp_interpret_string_notranslate (parse_in, strs,
779 concats + 1,
780 &istr, wide);
781 /* Assume that, if we managed to translate the string above,
782 then the untranslated parsing will always succeed. */
783 gcc_assert (xlated);
785 if (TREE_STRING_LENGTH (value) != (int) istr.len
786 || 0 != strncmp (TREE_STRING_POINTER (value), (char *) istr.text,
787 istr.len))
789 /* Arrange for us to return the untranslated string in
790 *valp, but to set up the C type of the translated
791 one. */
792 *valp = build_string (istr.len, (char *) istr.text);
793 valp = &TREE_CHAIN (*valp);
795 free ((void *) istr.text);
798 else
800 /* Callers cannot generally handle error_mark_node in this context,
801 so return the empty string instead. cpp_interpret_string has
802 issued an error. */
803 if (wide)
804 value = build_string (TYPE_PRECISION (wchar_type_node)
805 / TYPE_PRECISION (char_type_node),
806 "\0\0\0"); /* widest supported wchar_t
807 is 32 bits */
808 else
809 value = build_string (1, "");
812 TREE_TYPE (value) = wide ? wchar_array_type_node : char_array_type_node;
813 *valp = fix_string_type (value);
815 if (concats)
816 obstack_free (&str_ob, 0);
818 return objc_string ? CPP_OBJC_STRING : wide ? CPP_WSTRING : CPP_STRING;
821 /* Converts a (possibly wide) character constant token into a tree. */
822 static tree
823 lex_charconst (const cpp_token *token)
825 cppchar_t result;
826 tree type, value;
827 unsigned int chars_seen;
828 int unsignedp;
830 result = cpp_interpret_charconst (parse_in, token,
831 &chars_seen, &unsignedp);
833 if (token->type == CPP_WCHAR)
834 type = wchar_type_node;
835 /* In C, a character constant has type 'int'.
836 In C++ 'char', but multi-char charconsts have type 'int'. */
837 else if (!c_dialect_cxx () || chars_seen > 1)
838 type = integer_type_node;
839 else
840 type = char_type_node;
842 /* Cast to cppchar_signed_t to get correct sign-extension of RESULT
843 before possibly widening to HOST_WIDE_INT for build_int_cst. */
844 if (unsignedp || (cppchar_signed_t) result >= 0)
845 value = build_int_cst_wide (type, result, 0);
846 else
847 value = build_int_cst_wide (type, (cppchar_signed_t) result, -1);
849 return value;