xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/c-family/c-format.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /* Check calls to formatted I/O functions (-Wformat).
2    Copyright (C) 1992-2015 Free Software Foundation, Inc.
3 
4 This file is part of GCC.
5 
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
10 
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3.  If not see
18 <http://www.gnu.org/licenses/>.  */
19 
20 #include "config.h"
21 #include "system.h"
22 #include "coretypes.h"
23 #include "tm.h"
24 #include "hash-set.h"
25 #include "machmode.h"
26 #include "vec.h"
27 #include "double-int.h"
28 #include "input.h"
29 #include "alias.h"
30 #include "symtab.h"
31 #include "wide-int.h"
32 #include "inchash.h"
33 #include "real.h"
34 #include "tree.h"
35 #include "stringpool.h"
36 #include "flags.h"
37 #include "c-common.h"
38 #include "c-objc.h"
39 #include "intl.h"
40 #include "diagnostic-core.h"
41 #include "langhooks.h"
42 #include "c-format.h"
43 #include "alloc-pool.h"
44 #include "c-target.h"
45 
46 /* Handle attributes associated with format checking.  */
47 
48 /* This must be in the same order as format_types, except for
49    format_type_error.  Target-specific format types do not have
50    matching enum values.  */
51 enum format_type { printf_format_type, asm_fprintf_format_type,
52 		   gcc_diag_format_type, gcc_tdiag_format_type,
53 		   gcc_cdiag_format_type,
54 		   gcc_cxxdiag_format_type, gcc_gfc_format_type,
55 		   gcc_objc_string_format_type,
56 		   format_type_error = -1};
57 
58 typedef struct function_format_info
59 {
60   int format_type;			/* type of format (printf, scanf, etc.) */
61   unsigned HOST_WIDE_INT format_num;	/* number of format argument */
62   unsigned HOST_WIDE_INT first_arg_num;	/* number of first arg (zero for varargs) */
63 } function_format_info;
64 
65 static bool decode_format_attr (tree, function_format_info *, int);
66 static int decode_format_type (const char *);
67 
68 static bool check_format_string (tree argument,
69 				 unsigned HOST_WIDE_INT format_num,
70 				 int flags, bool *no_add_attrs,
71 				 int expected_format_type);
72 static bool get_constant (tree expr, unsigned HOST_WIDE_INT *value,
73 			  int validated_p);
74 static const char *convert_format_name_to_system_name (const char *attr_name);
75 static bool cmp_attribs (const char *tattr_name, const char *attr_name);
76 
77 static int first_target_format_type;
78 static const char *format_name (int format_num);
79 static int format_flags (int format_num);
80 
81 /* Check that we have a pointer to a string suitable for use as a format.
82    The default is to check for a char type.
83    For objective-c dialects, this is extended to include references to string
84    objects validated by objc_string_ref_type_p ().
85    Targets may also provide a string object type that can be used within c and
86    c++ and shared with their respective objective-c dialects. In this case the
87    reference to a format string is checked for validity via a hook.
88 
89    The function returns true if strref points to any string type valid for the
90    language dialect and target.  */
91 
92 static bool
93 valid_stringptr_type_p (tree strref)
94 {
95   return (strref != NULL
96 	  && TREE_CODE (strref) == POINTER_TYPE
97 	  && (TYPE_MAIN_VARIANT (TREE_TYPE (strref)) == char_type_node
98 	      || objc_string_ref_type_p (strref)
99 	      || (*targetcm.string_object_ref_type_p) ((const_tree) strref)));
100 }
101 
102 /* Handle a "format_arg" attribute; arguments as in
103    struct attribute_spec.handler.  */
104 tree
105 handle_format_arg_attribute (tree *node, tree ARG_UNUSED (name),
106 			     tree args, int flags, bool *no_add_attrs)
107 {
108   tree type = *node;
109   tree format_num_expr = TREE_VALUE (args);
110   unsigned HOST_WIDE_INT format_num = 0;
111 
112   if (!get_constant (format_num_expr, &format_num, 0))
113     {
114       error ("format string has invalid operand number");
115       *no_add_attrs = true;
116       return NULL_TREE;
117     }
118 
119   if (prototype_p (type))
120     {
121       /* The format arg can be any string reference valid for the language and
122          target.  We cannot be more specific in this case.  */
123       if (!check_format_string (type, format_num, flags, no_add_attrs, -1))
124 	return NULL_TREE;
125     }
126 
127   if (!valid_stringptr_type_p (TREE_TYPE (type)))
128     {
129       if (!(flags & (int) ATTR_FLAG_BUILT_IN))
130 	error ("function does not return string type");
131       *no_add_attrs = true;
132       return NULL_TREE;
133     }
134 
135   return NULL_TREE;
136 }
137 
138 /* Verify that the format_num argument is actually a string reference suitable,
139    for the language dialect and target (in case the format attribute is in
140    error).  When we know the specific reference type expected, this is also
141    checked.  */
142 static bool
143 check_format_string (tree fntype, unsigned HOST_WIDE_INT format_num,
144 		     int flags, bool *no_add_attrs, int expected_format_type)
145 {
146   unsigned HOST_WIDE_INT i;
147   bool is_objc_sref, is_target_sref, is_char_ref;
148   tree ref;
149   int fmt_flags;
150   function_args_iterator iter;
151 
152   i = 1;
153   FOREACH_FUNCTION_ARGS (fntype, ref, iter)
154     {
155       if (i == format_num)
156 	break;
157       i++;
158     }
159 
160   if (!ref
161       || !valid_stringptr_type_p (ref))
162     {
163       if (!(flags & (int) ATTR_FLAG_BUILT_IN))
164 	error ("format string argument is not a string type");
165       *no_add_attrs = true;
166       return false;
167     }
168 
169   /* We only know that we want a suitable string reference.  */
170   if (expected_format_type < 0)
171     return true;
172 
173   /* Now check that the arg matches the expected type.  */
174   is_char_ref =
175     (TYPE_MAIN_VARIANT (TREE_TYPE (ref)) == char_type_node);
176 
177   fmt_flags = format_flags (expected_format_type);
178   is_objc_sref = is_target_sref = false;
179   if (!is_char_ref)
180     is_objc_sref = objc_string_ref_type_p (ref);
181 
182   if (!(fmt_flags & FMT_FLAG_PARSE_ARG_CONVERT_EXTERNAL))
183     {
184       if (is_char_ref)
185 	return true; /* OK, we expected a char and found one.  */
186       else
187 	{
188 	  /* We expected a char but found an extended string type.  */
189 	  if (is_objc_sref)
190 	    error ("found a %<%s%> reference but the format argument should"
191 		   " be a string", format_name (gcc_objc_string_format_type));
192 	  else
193 	    error ("found a %qT but the format argument should be a string",
194 		   ref);
195 	  *no_add_attrs = true;
196 	  return false;
197 	}
198     }
199 
200   /* We expect a string object type as the format arg.  */
201   if (is_char_ref)
202     {
203       error ("format argument should be a %<%s%> reference but"
204 	     " a string was found", format_name (expected_format_type));
205       *no_add_attrs = true;
206       return false;
207     }
208 
209   /* We will assert that objective-c will support either its own string type
210      or the target-supplied variant.  */
211   if (!is_objc_sref)
212     is_target_sref = (*targetcm.string_object_ref_type_p) ((const_tree) ref);
213 
214   if (expected_format_type == (int) gcc_objc_string_format_type
215       && (is_objc_sref || is_target_sref))
216     return true;
217 
218   /* We will allow a target string ref to match only itself.  */
219   if (first_target_format_type
220       && expected_format_type >= first_target_format_type
221       && is_target_sref)
222     return true;
223   else
224     {
225       error ("format argument should be a %<%s%> reference",
226 	      format_name (expected_format_type));
227       *no_add_attrs = true;
228       return false;
229     }
230 
231   gcc_unreachable ();
232 }
233 
234 /* Verify EXPR is a constant, and store its value.
235    If validated_p is true there should be no errors.
236    Returns true on success, false otherwise.  */
237 static bool
238 get_constant (tree expr, unsigned HOST_WIDE_INT *value, int validated_p)
239 {
240   if (!tree_fits_uhwi_p (expr))
241     {
242       gcc_assert (!validated_p);
243       return false;
244     }
245 
246   *value = TREE_INT_CST_LOW (expr);
247 
248   return true;
249 }
250 
251 /* Decode the arguments to a "format" attribute into a
252    function_format_info structure.  It is already known that the list
253    is of the right length.  If VALIDATED_P is true, then these
254    attributes have already been validated and must not be erroneous;
255    if false, it will give an error message.  Returns true if the
256    attributes are successfully decoded, false otherwise.  */
257 
258 static bool
259 decode_format_attr (tree args, function_format_info *info, int validated_p)
260 {
261   tree format_type_id = TREE_VALUE (args);
262   tree format_num_expr = TREE_VALUE (TREE_CHAIN (args));
263   tree first_arg_num_expr
264     = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args)));
265 
266   if (TREE_CODE (format_type_id) != IDENTIFIER_NODE)
267     {
268       gcc_assert (!validated_p);
269       error ("unrecognized format specifier");
270       return false;
271     }
272   else
273     {
274       const char *p = IDENTIFIER_POINTER (format_type_id);
275 
276       p = convert_format_name_to_system_name (p);
277 
278       info->format_type = decode_format_type (p);
279 
280       if (!c_dialect_objc ()
281 	   && info->format_type == gcc_objc_string_format_type)
282 	{
283 	  gcc_assert (!validated_p);
284 	  warning (OPT_Wformat_, "%qE is only allowed in Objective-C dialects",
285 		   format_type_id);
286 	  info->format_type = format_type_error;
287 	  return false;
288 	}
289 
290       if (info->format_type == format_type_error)
291 	{
292 	  gcc_assert (!validated_p);
293 	  warning (OPT_Wformat_, "%qE is an unrecognized format function type",
294 		   format_type_id);
295 	  return false;
296 	}
297     }
298 
299   if (!get_constant (format_num_expr, &info->format_num, validated_p))
300     {
301       error ("format string has invalid operand number");
302       return false;
303     }
304 
305   if (!get_constant (first_arg_num_expr, &info->first_arg_num, validated_p))
306     {
307       error ("%<...%> has invalid operand number");
308       return false;
309     }
310 
311   if (info->first_arg_num != 0 && info->first_arg_num <= info->format_num)
312     {
313       gcc_assert (!validated_p);
314       error ("format string argument follows the args to be formatted");
315       return false;
316     }
317 
318   return true;
319 }
320 
321 /* Check a call to a format function against a parameter list.  */
322 
323 /* The C standard version C++ is treated as equivalent to
324    or inheriting from, for the purpose of format features supported.  */
325 #define CPLUSPLUS_STD_VER	(cxx_dialect < cxx11 ? STD_C94 : STD_C99)
326 /* The C standard version we are checking formats against when pedantic.  */
327 #define C_STD_VER		((int) (c_dialect_cxx ()		   \
328 				 ? CPLUSPLUS_STD_VER			   \
329 				 : (flag_isoc99				   \
330 				    ? STD_C99				   \
331 				    : (flag_isoc94 ? STD_C94 : STD_C89))))
332 /* The name to give to the standard version we are warning about when
333    pedantic.  FEATURE_VER is the version in which the feature warned out
334    appeared, which is higher than C_STD_VER.  */
335 #define C_STD_NAME(FEATURE_VER) (c_dialect_cxx ()		\
336 				 ? (cxx_dialect < cxx11 ? "ISO C++98" \
337 				    : "ISO C++11")		\
338 				 : ((FEATURE_VER) == STD_EXT	\
339 				    ? "ISO C"			\
340 				    : "ISO C90"))
341 /* Adjust a C standard version, which may be STD_C9L, to account for
342    -Wno-long-long.  Returns other standard versions unchanged.  */
343 #define ADJ_STD(VER)		((int) ((VER) == STD_C9L		      \
344 				       ? (warn_long_long ? STD_C99 : STD_C89) \
345 				       : (VER)))
346 
347 /* Enum describing the kind of specifiers present in the format and
348    requiring an argument.  */
349 enum format_specifier_kind {
350   CF_KIND_FORMAT,
351   CF_KIND_FIELD_WIDTH,
352   CF_KIND_FIELD_PRECISION
353 };
354 
355 static const char *kind_descriptions[] = {
356   N_("format"),
357   N_("field width specifier"),
358   N_("field precision specifier")
359 };
360 
361 /* Structure describing details of a type expected in format checking,
362    and the type to check against it.  */
363 typedef struct format_wanted_type
364 {
365   /* The type wanted.  */
366   tree wanted_type;
367   /* The name of this type to use in diagnostics.  */
368   const char *wanted_type_name;
369   /* Should be type checked just for scalar width identity.  */
370   int scalar_identity_flag;
371   /* The level of indirection through pointers at which this type occurs.  */
372   int pointer_count;
373   /* Whether, when pointer_count is 1, to allow any character type when
374      pedantic, rather than just the character or void type specified.  */
375   int char_lenient_flag;
376   /* Whether the argument, dereferenced once, is written into and so the
377      argument must not be a pointer to a const-qualified type.  */
378   int writing_in_flag;
379   /* Whether the argument, dereferenced once, is read from and so
380      must not be a NULL pointer.  */
381   int reading_from_flag;
382   /* The kind of specifier that this type is used for.  */
383   enum format_specifier_kind kind;
384   /* The starting character of the specifier.  This never includes the
385      initial percent sign.  */
386   const char *format_start;
387   /* The length of the specifier.  */
388   int format_length;
389   /* The actual parameter to check against the wanted type.  */
390   tree param;
391   /* The argument number of that parameter.  */
392   int arg_num;
393   /* The next type to check for this format conversion, or NULL if none.  */
394   struct format_wanted_type *next;
395 } format_wanted_type;
396 
397 /* Convenience macro for format_length_info meaning unused.  */
398 #define NO_FMT NULL, FMT_LEN_none, STD_C89
399 
400 static const format_length_info printf_length_specs[] =
401 {
402   { "h", FMT_LEN_h, STD_C89, "hh", FMT_LEN_hh, STD_C99, 0 },
403   { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C9L, 0 },
404   { "q", FMT_LEN_ll, STD_EXT, NO_FMT, 0 },
405   { "L", FMT_LEN_L, STD_C89, NO_FMT, 0 },
406   { "z", FMT_LEN_z, STD_C99, NO_FMT, 0 },
407   { "Z", FMT_LEN_z, STD_EXT, NO_FMT, 0 },
408   { "t", FMT_LEN_t, STD_C99, NO_FMT, 0 },
409   { "j", FMT_LEN_j, STD_C99, NO_FMT, 0 },
410   { "H", FMT_LEN_H, STD_EXT, NO_FMT, 0 },
411   { "D", FMT_LEN_D, STD_EXT, "DD", FMT_LEN_DD, STD_EXT, 0 },
412   { NO_FMT, NO_FMT, 0 }
413 };
414 
415 /* Length specifiers valid for asm_fprintf.  */
416 static const format_length_info asm_fprintf_length_specs[] =
417 {
418   { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C89, 0 },
419   { "w", FMT_LEN_none, STD_C89, NO_FMT, 0 },
420   { NO_FMT, NO_FMT, 0 }
421 };
422 
423 /* Length specifiers valid for GCC diagnostics.  */
424 static const format_length_info gcc_diag_length_specs[] =
425 {
426   { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C89, 0 },
427   { "w", FMT_LEN_none, STD_C89, NO_FMT, 0 },
428   { NO_FMT, NO_FMT, 0 }
429 };
430 
431 /* The custom diagnostics all accept the same length specifiers.  */
432 #define gcc_tdiag_length_specs gcc_diag_length_specs
433 #define gcc_cdiag_length_specs gcc_diag_length_specs
434 #define gcc_cxxdiag_length_specs gcc_diag_length_specs
435 
436 /* This differs from printf_length_specs only in that "Z" is not accepted.  */
437 static const format_length_info scanf_length_specs[] =
438 {
439   { "h", FMT_LEN_h, STD_C89, "hh", FMT_LEN_hh, STD_C99, 0 },
440   { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C9L, 0 },
441   { "q", FMT_LEN_ll, STD_EXT, NO_FMT, 0 },
442   { "L", FMT_LEN_L, STD_C89, NO_FMT, 0 },
443   { "z", FMT_LEN_z, STD_C99, NO_FMT, 0 },
444   { "t", FMT_LEN_t, STD_C99, NO_FMT, 0 },
445   { "j", FMT_LEN_j, STD_C99, NO_FMT, 0 },
446   { "H", FMT_LEN_H, STD_EXT, NO_FMT, 0 },
447   { "D", FMT_LEN_D, STD_EXT, "DD", FMT_LEN_DD, STD_EXT, 0 },
448   { NO_FMT, NO_FMT, 0 }
449 };
450 
451 
452 /* All tables for strfmon use STD_C89 everywhere, since -pedantic warnings
453    make no sense for a format type not part of any C standard version.  */
454 static const format_length_info strfmon_length_specs[] =
455 {
456   /* A GNU extension.  */
457   { "L", FMT_LEN_L, STD_C89, NO_FMT, 0 },
458   { NO_FMT, NO_FMT, 0 }
459 };
460 
461 
462 /* For now, the Fortran front-end routines only use l as length modifier.  */
463 static const format_length_info gcc_gfc_length_specs[] =
464 {
465   { "l", FMT_LEN_l, STD_C89, NO_FMT, 0 },
466   { NO_FMT, NO_FMT, 0 }
467 };
468 
469 
470 static const format_flag_spec printf_flag_specs[] =
471 {
472   { ' ',  0, 0, N_("' ' flag"),        N_("the ' ' printf flag"),              STD_C89 },
473   { '+',  0, 0, N_("'+' flag"),        N_("the '+' printf flag"),              STD_C89 },
474   { '#',  0, 0, N_("'#' flag"),        N_("the '#' printf flag"),              STD_C89 },
475   { '0',  0, 0, N_("'0' flag"),        N_("the '0' printf flag"),              STD_C89 },
476   { '-',  0, 0, N_("'-' flag"),        N_("the '-' printf flag"),              STD_C89 },
477   { '\'', 0, 0, N_("''' flag"),        N_("the ''' printf flag"),              STD_EXT },
478   { 'I',  0, 0, N_("'I' flag"),        N_("the 'I' printf flag"),              STD_EXT },
479   { 'w',  0, 0, N_("field width"),     N_("field width in printf format"),     STD_C89 },
480   { 'p',  0, 0, N_("precision"),       N_("precision in printf format"),       STD_C89 },
481   { 'L',  0, 0, N_("length modifier"), N_("length modifier in printf format"), STD_C89 },
482   { 0, 0, 0, NULL, NULL, STD_C89 }
483 };
484 
485 
486 static const format_flag_pair printf_flag_pairs[] =
487 {
488   { ' ', '+', 1, 0   },
489   { '0', '-', 1, 0   },
490   { '0', 'p', 1, 'i' },
491   { 0, 0, 0, 0 }
492 };
493 
494 static const format_flag_spec asm_fprintf_flag_specs[] =
495 {
496   { ' ',  0, 0, N_("' ' flag"),        N_("the ' ' printf flag"),              STD_C89 },
497   { '+',  0, 0, N_("'+' flag"),        N_("the '+' printf flag"),              STD_C89 },
498   { '#',  0, 0, N_("'#' flag"),        N_("the '#' printf flag"),              STD_C89 },
499   { '0',  0, 0, N_("'0' flag"),        N_("the '0' printf flag"),              STD_C89 },
500   { '-',  0, 0, N_("'-' flag"),        N_("the '-' printf flag"),              STD_C89 },
501   { 'w',  0, 0, N_("field width"),     N_("field width in printf format"),     STD_C89 },
502   { 'p',  0, 0, N_("precision"),       N_("precision in printf format"),       STD_C89 },
503   { 'L',  0, 0, N_("length modifier"), N_("length modifier in printf format"), STD_C89 },
504   { 0, 0, 0, NULL, NULL, STD_C89 }
505 };
506 
507 static const format_flag_pair asm_fprintf_flag_pairs[] =
508 {
509   { ' ', '+', 1, 0   },
510   { '0', '-', 1, 0   },
511   { '0', 'p', 1, 'i' },
512   { 0, 0, 0, 0 }
513 };
514 
515 static const format_flag_pair gcc_diag_flag_pairs[] =
516 {
517   { 0, 0, 0, 0 }
518 };
519 
520 #define gcc_tdiag_flag_pairs gcc_diag_flag_pairs
521 #define gcc_cdiag_flag_pairs gcc_diag_flag_pairs
522 #define gcc_cxxdiag_flag_pairs gcc_diag_flag_pairs
523 #define gcc_gfc_flag_pairs gcc_diag_flag_pairs
524 
525 static const format_flag_spec gcc_diag_flag_specs[] =
526 {
527   { '+',  0, 0, N_("'+' flag"),        N_("the '+' printf flag"),              STD_C89 },
528   { '#',  0, 0, N_("'#' flag"),        N_("the '#' printf flag"),              STD_C89 },
529   { 'q',  0, 0, N_("'q' flag"),        N_("the 'q' diagnostic flag"),          STD_C89 },
530   { 'p',  0, 0, N_("precision"),       N_("precision in printf format"),       STD_C89 },
531   { 'L',  0, 0, N_("length modifier"), N_("length modifier in printf format"), STD_C89 },
532   { 0, 0, 0, NULL, NULL, STD_C89 }
533 };
534 
535 #define gcc_tdiag_flag_specs gcc_diag_flag_specs
536 #define gcc_cdiag_flag_specs gcc_diag_flag_specs
537 #define gcc_cxxdiag_flag_specs gcc_diag_flag_specs
538 #define gcc_gfc_flag_specs gcc_diag_flag_specs
539 
540 static const format_flag_spec scanf_flag_specs[] =
541 {
542   { '*',  0, 0, N_("assignment suppression"), N_("the assignment suppression scanf feature"), STD_C89 },
543   { 'a',  0, 0, N_("'a' flag"),               N_("the 'a' scanf flag"),                       STD_EXT },
544   { 'm',  0, 0, N_("'m' flag"),               N_("the 'm' scanf flag"),                       STD_EXT },
545   { 'w',  0, 0, N_("field width"),            N_("field width in scanf format"),              STD_C89 },
546   { 'L',  0, 0, N_("length modifier"),        N_("length modifier in scanf format"),          STD_C89 },
547   { '\'', 0, 0, N_("''' flag"),               N_("the ''' scanf flag"),                       STD_EXT },
548   { 'I',  0, 0, N_("'I' flag"),               N_("the 'I' scanf flag"),                       STD_EXT },
549   { 0, 0, 0, NULL, NULL, STD_C89 }
550 };
551 
552 
553 static const format_flag_pair scanf_flag_pairs[] =
554 {
555   { '*', 'L', 0, 0 },
556   { 'a', 'm', 0, 0 },
557   { 0, 0, 0, 0 }
558 };
559 
560 
561 static const format_flag_spec strftime_flag_specs[] =
562 {
563   { '_', 0,   0, N_("'_' flag"),     N_("the '_' strftime flag"),          STD_EXT },
564   { '-', 0,   0, N_("'-' flag"),     N_("the '-' strftime flag"),          STD_EXT },
565   { '0', 0,   0, N_("'0' flag"),     N_("the '0' strftime flag"),          STD_EXT },
566   { '^', 0,   0, N_("'^' flag"),     N_("the '^' strftime flag"),          STD_EXT },
567   { '#', 0,   0, N_("'#' flag"),     N_("the '#' strftime flag"),          STD_EXT },
568   { 'w', 0,   0, N_("field width"),  N_("field width in strftime format"), STD_EXT },
569   { 'E', 0,   0, N_("'E' modifier"), N_("the 'E' strftime modifier"),      STD_C99 },
570   { 'O', 0,   0, N_("'O' modifier"), N_("the 'O' strftime modifier"),      STD_C99 },
571   { 'O', 'o', 0, NULL,               N_("the 'O' modifier"),               STD_EXT },
572   { 0, 0, 0, NULL, NULL, STD_C89 }
573 };
574 
575 
576 static const format_flag_pair strftime_flag_pairs[] =
577 {
578   { 'E', 'O', 0, 0 },
579   { '_', '-', 0, 0 },
580   { '_', '0', 0, 0 },
581   { '-', '0', 0, 0 },
582   { '^', '#', 0, 0 },
583   { 0, 0, 0, 0 }
584 };
585 
586 
587 static const format_flag_spec strfmon_flag_specs[] =
588 {
589   { '=',  0, 1, N_("fill character"),  N_("fill character in strfmon format"),  STD_C89 },
590   { '^',  0, 0, N_("'^' flag"),        N_("the '^' strfmon flag"),              STD_C89 },
591   { '+',  0, 0, N_("'+' flag"),        N_("the '+' strfmon flag"),              STD_C89 },
592   { '(',  0, 0, N_("'(' flag"),        N_("the '(' strfmon flag"),              STD_C89 },
593   { '!',  0, 0, N_("'!' flag"),        N_("the '!' strfmon flag"),              STD_C89 },
594   { '-',  0, 0, N_("'-' flag"),        N_("the '-' strfmon flag"),              STD_C89 },
595   { 'w',  0, 0, N_("field width"),     N_("field width in strfmon format"),     STD_C89 },
596   { '#',  0, 0, N_("left precision"),  N_("left precision in strfmon format"),  STD_C89 },
597   { 'p',  0, 0, N_("right precision"), N_("right precision in strfmon format"), STD_C89 },
598   { 'L',  0, 0, N_("length modifier"), N_("length modifier in strfmon format"), STD_C89 },
599   { 0, 0, 0, NULL, NULL, STD_C89 }
600 };
601 
602 static const format_flag_pair strfmon_flag_pairs[] =
603 {
604   { '+', '(', 0, 0 },
605   { 0, 0, 0, 0 }
606 };
607 
608 
609 static const format_char_info print_char_table[] =
610 {
611   /* C89 conversion specifiers.  */
612   { "di",  0, STD_C89, { T89_I,   T99_SC,  T89_S,   T89_L,   T9L_LL,  TEX_LL,  T99_SST, T99_PD,  T99_IM,  BADLEN,  BADLEN,  BADLEN  }, "-wp0 +'I",  "i",  NULL },
613   { "oxX", 0, STD_C89, { T89_UI,  T99_UC,  T89_US,  T89_UL,  T9L_ULL, TEX_ULL, T99_ST,  T99_UPD, T99_UIM, BADLEN,  BADLEN,  BADLEN }, "-wp0#",     "i",  NULL },
614   { "u",   0, STD_C89, { T89_UI,  T99_UC,  T89_US,  T89_UL,  T9L_ULL, TEX_ULL, T99_ST,  T99_UPD, T99_UIM, BADLEN,  BADLEN,  BADLEN }, "-wp0'I",    "i",  NULL },
615   { "fgG", 0, STD_C89, { T89_D,   BADLEN,  BADLEN,  T99_D,   BADLEN,  T89_LD,  BADLEN,  BADLEN,  BADLEN,  TEX_D32, TEX_D64, TEX_D128 }, "-wp0 +#'I", "",   NULL },
616   { "eE",  0, STD_C89, { T89_D,   BADLEN,  BADLEN,  T99_D,   BADLEN,  T89_LD,  BADLEN,  BADLEN,  BADLEN,  TEX_D32, TEX_D64, TEX_D128 }, "-wp0 +#I",  "",   NULL },
617   { "c",   0, STD_C89, { T89_I,   BADLEN,  BADLEN,  T94_WI,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN }, "-w",        "",   NULL },
618   { "s",   1, STD_C89, { T89_C,   BADLEN,  BADLEN,  T94_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN }, "-wp",       "cR", NULL },
619   { "p",   1, STD_C89, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN }, "-w",        "c",  NULL },
620   { "n",   1, STD_C89, { T89_I,   T99_SC,  T89_S,   T89_L,   T9L_LL,  BADLEN,  T99_SST, T99_PD,  T99_IM,  BADLEN,  BADLEN,  BADLEN }, "",          "W",  NULL },
621   /* C99 conversion specifiers.  */
622   { "F",   0, STD_C99, { T99_D,   BADLEN,  BADLEN,  T99_D,   BADLEN,  T99_LD,  BADLEN,  BADLEN,  BADLEN,  TEX_D32, TEX_D64, TEX_D128 }, "-wp0 +#'I", "",   NULL },
623   { "aA",  0, STD_C99, { T99_D,   BADLEN,  BADLEN,  T99_D,   BADLEN,  T99_LD,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN }, "-wp0 +#",   "",   NULL },
624   /* X/Open conversion specifiers.  */
625   { "C",   0, STD_EXT, { TEX_WI,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN }, "-w",        "",   NULL },
626   { "S",   1, STD_EXT, { TEX_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN }, "-wp",       "R",  NULL },
627   /* GNU conversion specifiers.  */
628   { "m",   0, STD_EXT, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN }, "-wp",       "",   NULL },
629   { NULL,  0, STD_C89, NOLENGTHS, NULL, NULL, NULL }
630 };
631 
632 static const format_char_info asm_fprintf_char_table[] =
633 {
634   /* C89 conversion specifiers.  */
635   { "di",  0, STD_C89, { T89_I,   BADLEN,  BADLEN,  T89_L,   T9L_LL,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "-wp0 +",  "i", NULL },
636   { "oxX", 0, STD_C89, { T89_UI,  BADLEN,  BADLEN,  T89_UL,  T9L_ULL, BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "-wp0#",   "i", NULL },
637   { "u",   0, STD_C89, { T89_UI,  BADLEN,  BADLEN,  T89_UL,  T9L_ULL, BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "-wp0",    "i", NULL },
638   { "c",   0, STD_C89, { T89_I,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "-w",       "", NULL },
639   { "s",   1, STD_C89, { T89_C,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "-wp",    "cR", NULL },
640 
641   /* asm_fprintf conversion specifiers.  */
642   { "O",   0, STD_C89, NOARGUMENTS, "",      "",   NULL },
643   { "R",   0, STD_C89, NOARGUMENTS, "",      "",   NULL },
644   { "I",   0, STD_C89, NOARGUMENTS, "",      "",   NULL },
645   { "L",   0, STD_C89, NOARGUMENTS, "",      "",   NULL },
646   { "U",   0, STD_C89, NOARGUMENTS, "",      "",   NULL },
647   { "r",   0, STD_C89, { T89_I,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "",  "", NULL },
648   { "@",   0, STD_C89, NOARGUMENTS, "",      "",   NULL },
649   { NULL,  0, STD_C89, NOLENGTHS, NULL, NULL, NULL }
650 };
651 
652 static const format_char_info gcc_diag_char_table[] =
653 {
654   /* C89 conversion specifiers.  */
655   { "di",  0, STD_C89, { T89_I,   BADLEN,  BADLEN,  T89_L,   T9L_LL,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
656   { "ox",  0, STD_C89, { T89_UI,  BADLEN,  BADLEN,  T89_UL,  T9L_ULL, BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
657   { "u",   0, STD_C89, { T89_UI,  BADLEN,  BADLEN,  T89_UL,  T9L_ULL, BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
658   { "c",   0, STD_C89, { T89_I,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
659   { "s",   1, STD_C89, { T89_C,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "pq", "cR", NULL },
660   { "p",   1, STD_C89, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "c",  NULL },
661 
662   /* Custom conversion specifiers.  */
663 
664   /* These will require a "tree" at runtime.  */
665   { "K",   0, STD_C89, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",    "",   NULL },
666 
667   { "r",   1, STD_C89, { T89_C,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "",    "cR",   NULL },
668   { "<>'R",0, STD_C89, NOARGUMENTS, "",      "",   NULL },
669   { "m",   0, STD_C89, NOARGUMENTS, "q",     "",   NULL },
670   { NULL,  0, STD_C89, NOLENGTHS, NULL, NULL, NULL }
671 };
672 
673 static const format_char_info gcc_tdiag_char_table[] =
674 {
675   /* C89 conversion specifiers.  */
676   { "di",  0, STD_C89, { T89_I,   BADLEN,  BADLEN,  T89_L,   T9L_LL,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
677   { "ox",  0, STD_C89, { T89_UI,  BADLEN,  BADLEN,  T89_UL,  T9L_ULL, BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
678   { "u",   0, STD_C89, { T89_UI,  BADLEN,  BADLEN,  T89_UL,  T9L_ULL, BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
679   { "c",   0, STD_C89, { T89_I,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
680   { "s",   1, STD_C89, { T89_C,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "pq", "cR", NULL },
681   { "p",   1, STD_C89, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "c",  NULL },
682 
683   /* Custom conversion specifiers.  */
684 
685   /* These will require a "tree" at runtime.  */
686   { "DFKTEV", 0, STD_C89, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q+", "",   NULL },
687 
688   { "v",   0, STD_C89, { T89_I,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q#",  "",   NULL },
689 
690   { "r",   1, STD_C89, { T89_C,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "",    "cR",   NULL },
691   { "<>'R",0, STD_C89, NOARGUMENTS, "",      "",   NULL },
692   { "m",   0, STD_C89, NOARGUMENTS, "q",     "",   NULL },
693   { NULL,  0, STD_C89, NOLENGTHS, NULL, NULL, NULL }
694 };
695 
696 static const format_char_info gcc_cdiag_char_table[] =
697 {
698   /* C89 conversion specifiers.  */
699   { "di",  0, STD_C89, { T89_I,   BADLEN,  BADLEN,  T89_L,   T9L_LL,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
700   { "ox",  0, STD_C89, { T89_UI,  BADLEN,  BADLEN,  T89_UL,  T9L_ULL, BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
701   { "u",   0, STD_C89, { T89_UI,  BADLEN,  BADLEN,  T89_UL,  T9L_ULL, BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
702   { "c",   0, STD_C89, { T89_I,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
703   { "s",   1, STD_C89, { T89_C,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "pq", "cR", NULL },
704   { "p",   1, STD_C89, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "c",  NULL },
705 
706   /* Custom conversion specifiers.  */
707 
708   /* These will require a "tree" at runtime.  */
709   { "DEFKTV", 0, STD_C89, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q+", "",   NULL },
710 
711   { "v",   0, STD_C89, { T89_I,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q#",  "",   NULL },
712 
713   { "r",   1, STD_C89, { T89_C,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "",    "cR",   NULL },
714   { "<>'R",0, STD_C89, NOARGUMENTS, "",      "",   NULL },
715   { "m",   0, STD_C89, NOARGUMENTS, "q",     "",   NULL },
716   { NULL,  0, STD_C89, NOLENGTHS, NULL, NULL, NULL }
717 };
718 
719 static const format_char_info gcc_cxxdiag_char_table[] =
720 {
721   /* C89 conversion specifiers.  */
722   { "di",  0, STD_C89, { T89_I,   BADLEN,  BADLEN,  T89_L,   T9L_LL,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
723   { "ox",  0, STD_C89, { T89_UI,  BADLEN,  BADLEN,  T89_UL,  T9L_ULL, BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
724   { "u",   0, STD_C89, { T89_UI,  BADLEN,  BADLEN,  T89_UL,  T9L_ULL, BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
725   { "c",   0, STD_C89, { T89_I,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
726   { "s",   1, STD_C89, { T89_C,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "pq", "cR", NULL },
727   { "p",   1, STD_C89, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "c",  NULL },
728 
729   /* Custom conversion specifiers.  */
730 
731   /* These will require a "tree" at runtime.  */
732   { "ADEFKSTVX",0,STD_C89,{ T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q+#",   "",   NULL },
733 
734   { "v", 0,STD_C89, { T89_I,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q#",  "",   NULL },
735 
736   /* These accept either an 'int' or an 'enum tree_code' (which is handled as an 'int'.)  */
737   { "CLOPQ",0,STD_C89, { T89_I,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q",  "",   NULL },
738 
739   { "r",   1, STD_C89, { T89_C,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "",    "cR",   NULL },
740   { "<>'R",0, STD_C89, NOARGUMENTS, "",      "",   NULL },
741   { "m",   0, STD_C89, NOARGUMENTS, "q",     "",   NULL },
742   { NULL,  0, STD_C89, NOLENGTHS, NULL, NULL, NULL }
743 };
744 
745 static const format_char_info gcc_gfc_char_table[] =
746 {
747   /* C89 conversion specifiers.  */
748   { "di",  0, STD_C89, { T89_I,   BADLEN,  BADLEN,  T89_L,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "", "", NULL },
749   { "u",   0, STD_C89, { T89_UI,  BADLEN,  BADLEN,  T89_UL,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "", "", NULL },
750   { "c",   0, STD_C89, { T89_I,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "", "", NULL },
751   { "s",   1, STD_C89, { T89_C,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "q", "cR", NULL },
752 
753   /* gfc conversion specifiers.  */
754 
755   { "C",   0, STD_C89, NOARGUMENTS, "",      "",   NULL },
756 
757   /* This will require a "locus" at runtime.  */
758   { "L",   0, STD_C89, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "", "R", NULL },
759 
760   /* These will require nothing.  */
761   { "<>",0, STD_C89, NOARGUMENTS, "",      "",   NULL },
762   { NULL,  0, STD_C89, NOLENGTHS, NULL, NULL, NULL }
763 };
764 
765 static const format_char_info scan_char_table[] =
766 {
767   /* C89 conversion specifiers.  */
768   { "di",    1, STD_C89, { T89_I,   T99_SC,  T89_S,   T89_L,   T9L_LL,  TEX_LL,  T99_SST, T99_PD,  T99_IM,  BADLEN,  BADLEN,  BADLEN }, "*w'I", "W",   NULL },
769   { "u",     1, STD_C89, { T89_UI,  T99_UC,  T89_US,  T89_UL,  T9L_ULL, TEX_ULL, T99_ST,  T99_UPD, T99_UIM, BADLEN,  BADLEN,  BADLEN }, "*w'I", "W",   NULL },
770   { "oxX",   1, STD_C89, { T89_UI,  T99_UC,  T89_US,  T89_UL,  T9L_ULL, TEX_ULL, T99_ST,  T99_UPD, T99_UIM, BADLEN,  BADLEN,  BADLEN }, "*w",   "W",   NULL },
771   { "efgEG", 1, STD_C89, { T89_F,   BADLEN,  BADLEN,  T89_D,   BADLEN,  T89_LD,  BADLEN,  BADLEN,  BADLEN,  TEX_D32, TEX_D64, TEX_D128 }, "*w'",  "W",   NULL },
772   { "c",     1, STD_C89, { T89_C,   BADLEN,  BADLEN,  T94_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN }, "*mw",   "cW",  NULL },
773   { "s",     1, STD_C89, { T89_C,   BADLEN,  BADLEN,  T94_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN }, "*amw",  "cW",  NULL },
774   { "[",     1, STD_C89, { T89_C,   BADLEN,  BADLEN,  T94_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN }, "*amw",  "cW[", NULL },
775   { "p",     2, STD_C89, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN }, "*w",   "W",   NULL },
776   { "n",     1, STD_C89, { T89_I,   T99_SC,  T89_S,   T89_L,   T9L_LL,  BADLEN,  T99_SST, T99_PD,  T99_IM,  BADLEN,  BADLEN,  BADLEN }, "",     "W",   NULL },
777   /* C99 conversion specifiers.  */
778   { "F",   1, STD_C99, { T99_F,   BADLEN,  BADLEN,  T99_D,   BADLEN,  T99_LD,  BADLEN,  BADLEN,  BADLEN,  TEX_D32, TEX_D64, TEX_D128 }, "*w'",  "W",   NULL },
779   { "aA",   1, STD_C99, { T99_F,   BADLEN,  BADLEN,  T99_D,   BADLEN,  T99_LD,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN }, "*w'",  "W",   NULL },
780   /* X/Open conversion specifiers.  */
781   { "C",     1, STD_EXT, { TEX_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN }, "*mw",   "W",   NULL },
782   { "S",     1, STD_EXT, { TEX_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN }, "*amw",  "W",   NULL },
783   { NULL, 0, STD_C89, NOLENGTHS, NULL, NULL, NULL }
784 };
785 
786 static const format_char_info time_char_table[] =
787 {
788   /* C89 conversion specifiers.  */
789   { "ABZab",		0, STD_C89, NOLENGTHS, "^#",     "",   NULL },
790   { "cx",		0, STD_C89, NOLENGTHS, "E",      "3",  NULL },
791   { "HIMSUWdmw",	0, STD_C89, NOLENGTHS, "-_0Ow",  "",   NULL },
792   { "j",		0, STD_C89, NOLENGTHS, "-_0Ow",  "o",  NULL },
793   { "p",		0, STD_C89, NOLENGTHS, "#",      "",   NULL },
794   { "X",		0, STD_C89, NOLENGTHS, "E",      "",   NULL },
795   { "y",		0, STD_C89, NOLENGTHS, "EO-_0w", "4",  NULL },
796   { "Y",		0, STD_C89, NOLENGTHS, "-_0EOw", "o",  NULL },
797   { "%",		0, STD_C89, NOLENGTHS, "",       "",   NULL },
798   /* C99 conversion specifiers.  */
799   { "C",		0, STD_C99, NOLENGTHS, "-_0EOw", "o",  NULL },
800   { "D",		0, STD_C99, NOLENGTHS, "",       "2",  NULL },
801   { "eVu",		0, STD_C99, NOLENGTHS, "-_0Ow",  "",   NULL },
802   { "FRTnrt",		0, STD_C99, NOLENGTHS, "",       "",   NULL },
803   { "g",		0, STD_C99, NOLENGTHS, "O-_0w",  "2o", NULL },
804   { "G",		0, STD_C99, NOLENGTHS, "-_0Ow",  "o",  NULL },
805   { "h",		0, STD_C99, NOLENGTHS, "^#",     "",   NULL },
806   { "z",		0, STD_C99, NOLENGTHS, "O",      "o",  NULL },
807   /* GNU conversion specifiers.  */
808   { "kls",		0, STD_EXT, NOLENGTHS, "-_0Ow",  "",   NULL },
809   { "P",		0, STD_EXT, NOLENGTHS, "",       "",   NULL },
810   { NULL,		0, STD_C89, NOLENGTHS, NULL, NULL, NULL }
811 };
812 
813 static const format_char_info monetary_char_table[] =
814 {
815   { "in", 0, STD_C89, { T89_D, BADLEN, BADLEN, BADLEN, BADLEN, T89_LD, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "=^+(!-w#p", "", NULL },
816   { NULL, 0, STD_C89, NOLENGTHS, NULL, NULL, NULL }
817 };
818 
819 /* This must be in the same order as enum format_type.  */
820 static const format_kind_info format_types_orig[] =
821 {
822   { "gnu_printf",   printf_length_specs,  print_char_table, " +#0-'I", NULL,
823     printf_flag_specs, printf_flag_pairs,
824     FMT_FLAG_ARG_CONVERT|FMT_FLAG_DOLLAR_MULTIPLE|FMT_FLAG_USE_DOLLAR|FMT_FLAG_EMPTY_PREC_OK,
825     'w', 0, 'p', 0, 'L', 0,
826     &integer_type_node, &integer_type_node
827   },
828   { "asm_fprintf",   asm_fprintf_length_specs,  asm_fprintf_char_table, " +#0-", NULL,
829     asm_fprintf_flag_specs, asm_fprintf_flag_pairs,
830     FMT_FLAG_ARG_CONVERT|FMT_FLAG_EMPTY_PREC_OK,
831     'w', 0, 'p', 0, 'L', 0,
832     NULL, NULL
833   },
834   { "gcc_diag",   gcc_diag_length_specs,  gcc_diag_char_table, "q+#", NULL,
835     gcc_diag_flag_specs, gcc_diag_flag_pairs,
836     FMT_FLAG_ARG_CONVERT|FMT_FLAG_M_OK,
837     0, 0, 'p', 0, 'L', 0,
838     NULL, &integer_type_node
839   },
840   { "gcc_tdiag",   gcc_tdiag_length_specs,  gcc_tdiag_char_table, "q+#", NULL,
841     gcc_tdiag_flag_specs, gcc_tdiag_flag_pairs,
842     FMT_FLAG_ARG_CONVERT|FMT_FLAG_M_OK,
843     0, 0, 'p', 0, 'L', 0,
844     NULL, &integer_type_node
845   },
846   { "gcc_cdiag",   gcc_cdiag_length_specs,  gcc_cdiag_char_table, "q+#", NULL,
847     gcc_cdiag_flag_specs, gcc_cdiag_flag_pairs,
848     FMT_FLAG_ARG_CONVERT|FMT_FLAG_M_OK,
849     0, 0, 'p', 0, 'L', 0,
850     NULL, &integer_type_node
851   },
852   { "gcc_cxxdiag",   gcc_cxxdiag_length_specs,  gcc_cxxdiag_char_table, "q+#", NULL,
853     gcc_cxxdiag_flag_specs, gcc_cxxdiag_flag_pairs,
854     FMT_FLAG_ARG_CONVERT|FMT_FLAG_M_OK,
855     0, 0, 'p', 0, 'L', 0,
856     NULL, &integer_type_node
857   },
858   { "gcc_gfc", gcc_gfc_length_specs, gcc_gfc_char_table, "q+#", NULL,
859     gcc_gfc_flag_specs, gcc_gfc_flag_pairs,
860     FMT_FLAG_ARG_CONVERT|FMT_FLAG_M_OK,
861     0, 0, 0, 0, 0, 0,
862     NULL, NULL
863   },
864   { "NSString",   NULL,  NULL, NULL, NULL,
865     NULL, NULL,
866     FMT_FLAG_ARG_CONVERT|FMT_FLAG_PARSE_ARG_CONVERT_EXTERNAL, 0, 0, 0, 0, 0, 0,
867     NULL, NULL
868   },
869   { "gnu_scanf",    scanf_length_specs,   scan_char_table,  "*'I", NULL,
870     scanf_flag_specs, scanf_flag_pairs,
871     FMT_FLAG_ARG_CONVERT|FMT_FLAG_SCANF_A_KLUDGE|FMT_FLAG_USE_DOLLAR|FMT_FLAG_ZERO_WIDTH_BAD|FMT_FLAG_DOLLAR_GAP_POINTER_OK,
872     'w', 0, 0, '*', 'L', 'm',
873     NULL, NULL
874   },
875   { "gnu_strftime", NULL,                 time_char_table,  "_-0^#", "EO",
876     strftime_flag_specs, strftime_flag_pairs,
877     FMT_FLAG_FANCY_PERCENT_OK|FMT_FLAG_M_OK, 'w', 0, 0, 0, 0, 0,
878     NULL, NULL
879   },
880   { "gnu_strfmon",  strfmon_length_specs, monetary_char_table, "=^+(!-", NULL,
881     strfmon_flag_specs, strfmon_flag_pairs,
882     FMT_FLAG_ARG_CONVERT, 'w', '#', 'p', 0, 'L', 0,
883     NULL, NULL
884   },
885   { "gnu_syslog",   printf_length_specs,  print_char_table, " +#0-'I", NULL,
886     printf_flag_specs, printf_flag_pairs,
887     FMT_FLAG_ARG_CONVERT|FMT_FLAG_DOLLAR_MULTIPLE|FMT_FLAG_USE_DOLLAR|FMT_FLAG_EMPTY_PREC_OK|FMT_FLAG_M_OK,
888     'w', 0, 'p', 0, 'L', 0,
889     &integer_type_node, &integer_type_node
890   },
891 };
892 
893 /* This layer of indirection allows GCC to reassign format_types with
894    new data if necessary, while still allowing the original data to be
895    const.  */
896 static const format_kind_info *format_types = format_types_orig;
897 /* We can modify this one.  We also add target-specific format types
898    to the end of the array.  */
899 static format_kind_info *dynamic_format_types;
900 
901 static int n_format_types = ARRAY_SIZE (format_types_orig);
902 
903 /* Structure detailing the results of checking a format function call
904    where the format expression may be a conditional expression with
905    many leaves resulting from nested conditional expressions.  */
906 typedef struct
907 {
908   /* Number of leaves of the format argument that could not be checked
909      as they were not string literals.  */
910   int number_non_literal;
911   /* Number of leaves of the format argument that were null pointers or
912      string literals, but had extra format arguments.  */
913   int number_extra_args;
914   location_t extra_arg_loc;
915   /* Number of leaves of the format argument that were null pointers or
916      string literals, but had extra format arguments and used $ operand
917      numbers.  */
918   int number_dollar_extra_args;
919   /* Number of leaves of the format argument that were wide string
920      literals.  */
921   int number_wide;
922   /* Number of leaves of the format argument that were empty strings.  */
923   int number_empty;
924   /* Number of leaves of the format argument that were unterminated
925      strings.  */
926   int number_unterminated;
927   /* Number of leaves of the format argument that were not counted above.  */
928   int number_other;
929   /* Location of the format string.  */
930   location_t format_string_loc;
931 } format_check_results;
932 
933 typedef struct
934 {
935   format_check_results *res;
936   function_format_info *info;
937   tree params;
938 } format_check_context;
939 
940 /* Return the format name (as specified in the original table) for the format
941    type indicated by format_num.  */
942 static const char *
943 format_name (int format_num)
944 {
945   if (format_num >= 0 && format_num < n_format_types)
946     return format_types[format_num].name;
947   gcc_unreachable ();
948 }
949 
950 /* Return the format flags (as specified in the original table) for the format
951    type indicated by format_num.  */
952 static int
953 format_flags (int format_num)
954 {
955   if (format_num >= 0 && format_num < n_format_types)
956     return format_types[format_num].flags;
957   gcc_unreachable ();
958 }
959 
960 static void check_format_info (function_format_info *, tree);
961 static void check_format_arg (void *, tree, unsigned HOST_WIDE_INT);
962 static void check_format_info_main (format_check_results *,
963 				    function_format_info *,
964 				    const char *, int, tree,
965                                     unsigned HOST_WIDE_INT, alloc_pool);
966 
967 static void init_dollar_format_checking (int, tree);
968 static int maybe_read_dollar_number (const char **, int,
969 				     tree, tree *, const format_kind_info *);
970 static bool avoid_dollar_number (const char *);
971 static void finish_dollar_format_checking (format_check_results *, int);
972 
973 static const format_flag_spec *get_flag_spec (const format_flag_spec *,
974 					      int, const char *);
975 
976 static void check_format_types (location_t, format_wanted_type *);
977 static void format_type_warning (location_t, format_wanted_type *, tree, tree);
978 
979 /* Decode a format type from a string, returning the type, or
980    format_type_error if not valid, in which case the caller should print an
981    error message.  */
982 static int
983 decode_format_type (const char *s)
984 {
985   int i;
986   int slen;
987 
988   s = convert_format_name_to_system_name (s);
989   slen = strlen (s);
990   for (i = 0; i < n_format_types; i++)
991     {
992       int alen;
993       if (!strcmp (s, format_types[i].name))
994 	return i;
995       alen = strlen (format_types[i].name);
996       if (slen == alen + 4 && s[0] == '_' && s[1] == '_'
997 	  && s[slen - 1] == '_' && s[slen - 2] == '_'
998 	  && !strncmp (s + 2, format_types[i].name, alen))
999 	return i;
1000     }
1001   return format_type_error;
1002 }
1003 
1004 
1005 /* Check the argument list of a call to printf, scanf, etc.
1006    ATTRS are the attributes on the function type.  There are NARGS argument
1007    values in the array ARGARRAY.
1008    Also, if -Wsuggest-attribute=format,
1009    warn for calls to vprintf or vscanf in functions with no such format
1010    attribute themselves.  */
1011 
1012 void
1013 check_function_format (tree attrs, int nargs, tree *argarray)
1014 {
1015   tree a;
1016 
1017   /* See if this function has any format attributes.  */
1018   for (a = attrs; a; a = TREE_CHAIN (a))
1019     {
1020       if (is_attribute_p ("format", TREE_PURPOSE (a)))
1021 	{
1022 	  /* Yup; check it.  */
1023 	  function_format_info info;
1024 	  decode_format_attr (TREE_VALUE (a), &info, /*validated=*/true);
1025 	  if (warn_format)
1026 	    {
1027 	      /* FIXME: Rewrite all the internal functions in this file
1028 		 to use the ARGARRAY directly instead of constructing this
1029 		 temporary list.  */
1030 	      tree params = NULL_TREE;
1031 	      int i;
1032 	      for (i = nargs - 1; i >= 0; i--)
1033 		params = tree_cons (NULL_TREE, argarray[i], params);
1034 	      check_format_info (&info, params);
1035 	    }
1036 	  if (warn_suggest_attribute_format && info.first_arg_num == 0
1037 	      && (format_types[info.format_type].flags
1038 		  & (int) FMT_FLAG_ARG_CONVERT))
1039 	    {
1040 	      tree c;
1041 	      for (c = TYPE_ATTRIBUTES (TREE_TYPE (current_function_decl));
1042 		   c;
1043 		   c = TREE_CHAIN (c))
1044 		if (is_attribute_p ("format", TREE_PURPOSE (c))
1045 		    && (decode_format_type (IDENTIFIER_POINTER
1046 					    (TREE_VALUE (TREE_VALUE (c))))
1047 			== info.format_type))
1048 		  break;
1049 	      if (c == NULL_TREE)
1050 		{
1051 		  /* Check if the current function has a parameter to which
1052 		     the format attribute could be attached; if not, it
1053 		     can't be a candidate for a format attribute, despite
1054 		     the vprintf-like or vscanf-like call.  */
1055 		  tree args;
1056 		  for (args = DECL_ARGUMENTS (current_function_decl);
1057 		       args != 0;
1058 		       args = DECL_CHAIN (args))
1059 		    {
1060 		      if (TREE_CODE (TREE_TYPE (args)) == POINTER_TYPE
1061 			  && (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (args)))
1062 			      == char_type_node))
1063 			break;
1064 		    }
1065 		  if (args != 0)
1066 		    warning (OPT_Wsuggest_attribute_format, "function might "
1067 			     "be possible candidate for %qs format attribute",
1068 			     format_types[info.format_type].name);
1069 		}
1070 	    }
1071 	}
1072     }
1073 }
1074 
1075 
1076 /* Variables used by the checking of $ operand number formats.  */
1077 static char *dollar_arguments_used = NULL;
1078 static char *dollar_arguments_pointer_p = NULL;
1079 static int dollar_arguments_alloc = 0;
1080 static int dollar_arguments_count;
1081 static int dollar_first_arg_num;
1082 static int dollar_max_arg_used;
1083 static int dollar_format_warned;
1084 
1085 /* Initialize the checking for a format string that may contain $
1086    parameter number specifications; we will need to keep track of whether
1087    each parameter has been used.  FIRST_ARG_NUM is the number of the first
1088    argument that is a parameter to the format, or 0 for a vprintf-style
1089    function; PARAMS is the list of arguments starting at this argument.  */
1090 
1091 static void
1092 init_dollar_format_checking (int first_arg_num, tree params)
1093 {
1094   tree oparams = params;
1095 
1096   dollar_first_arg_num = first_arg_num;
1097   dollar_arguments_count = 0;
1098   dollar_max_arg_used = 0;
1099   dollar_format_warned = 0;
1100   if (first_arg_num > 0)
1101     {
1102       while (params)
1103 	{
1104 	  dollar_arguments_count++;
1105 	  params = TREE_CHAIN (params);
1106 	}
1107     }
1108   if (dollar_arguments_alloc < dollar_arguments_count)
1109     {
1110       free (dollar_arguments_used);
1111       free (dollar_arguments_pointer_p);
1112       dollar_arguments_alloc = dollar_arguments_count;
1113       dollar_arguments_used = XNEWVEC (char, dollar_arguments_alloc);
1114       dollar_arguments_pointer_p = XNEWVEC (char, dollar_arguments_alloc);
1115     }
1116   if (dollar_arguments_alloc)
1117     {
1118       memset (dollar_arguments_used, 0, dollar_arguments_alloc);
1119       if (first_arg_num > 0)
1120 	{
1121 	  int i = 0;
1122 	  params = oparams;
1123 	  while (params)
1124 	    {
1125 	      dollar_arguments_pointer_p[i] = (TREE_CODE (TREE_TYPE (TREE_VALUE (params)))
1126 					       == POINTER_TYPE);
1127 	      params = TREE_CHAIN (params);
1128 	      i++;
1129 	    }
1130 	}
1131     }
1132 }
1133 
1134 
1135 /* Look for a decimal number followed by a $ in *FORMAT.  If DOLLAR_NEEDED
1136    is set, it is an error if one is not found; otherwise, it is OK.  If
1137    such a number is found, check whether it is within range and mark that
1138    numbered operand as being used for later checking.  Returns the operand
1139    number if found and within range, zero if no such number was found and
1140    this is OK, or -1 on error.  PARAMS points to the first operand of the
1141    format; PARAM_PTR is made to point to the parameter referred to.  If
1142    a $ format is found, *FORMAT is updated to point just after it.  */
1143 
1144 static int
1145 maybe_read_dollar_number (const char **format,
1146 			  int dollar_needed, tree params, tree *param_ptr,
1147 			  const format_kind_info *fki)
1148 {
1149   int argnum;
1150   int overflow_flag;
1151   const char *fcp = *format;
1152   if (!ISDIGIT (*fcp))
1153     {
1154       if (dollar_needed)
1155 	{
1156 	  warning (OPT_Wformat_, "missing $ operand number in format");
1157 	  return -1;
1158 	}
1159       else
1160 	return 0;
1161     }
1162   argnum = 0;
1163   overflow_flag = 0;
1164   while (ISDIGIT (*fcp))
1165     {
1166       int nargnum;
1167       nargnum = 10 * argnum + (*fcp - '0');
1168       if (nargnum < 0 || nargnum / 10 != argnum)
1169 	overflow_flag = 1;
1170       argnum = nargnum;
1171       fcp++;
1172     }
1173   if (*fcp != '$')
1174     {
1175       if (dollar_needed)
1176 	{
1177 	  warning (OPT_Wformat_, "missing $ operand number in format");
1178 	  return -1;
1179 	}
1180       else
1181 	return 0;
1182     }
1183   *format = fcp + 1;
1184   if (pedantic && !dollar_format_warned)
1185     {
1186       warning (OPT_Wformat_, "%s does not support %%n$ operand number formats",
1187 	       C_STD_NAME (STD_EXT));
1188       dollar_format_warned = 1;
1189     }
1190   if (overflow_flag || argnum == 0
1191       || (dollar_first_arg_num && argnum > dollar_arguments_count))
1192     {
1193       warning (OPT_Wformat_, "operand number out of range in format");
1194       return -1;
1195     }
1196   if (argnum > dollar_max_arg_used)
1197     dollar_max_arg_used = argnum;
1198   /* For vprintf-style functions we may need to allocate more memory to
1199      track which arguments are used.  */
1200   while (dollar_arguments_alloc < dollar_max_arg_used)
1201     {
1202       int nalloc;
1203       nalloc = 2 * dollar_arguments_alloc + 16;
1204       dollar_arguments_used = XRESIZEVEC (char, dollar_arguments_used,
1205 					  nalloc);
1206       dollar_arguments_pointer_p = XRESIZEVEC (char, dollar_arguments_pointer_p,
1207 					       nalloc);
1208       memset (dollar_arguments_used + dollar_arguments_alloc, 0,
1209 	      nalloc - dollar_arguments_alloc);
1210       dollar_arguments_alloc = nalloc;
1211     }
1212   if (!(fki->flags & (int) FMT_FLAG_DOLLAR_MULTIPLE)
1213       && dollar_arguments_used[argnum - 1] == 1)
1214     {
1215       dollar_arguments_used[argnum - 1] = 2;
1216       warning (OPT_Wformat_, "format argument %d used more than once in %s format",
1217 	       argnum, fki->name);
1218     }
1219   else
1220     dollar_arguments_used[argnum - 1] = 1;
1221   if (dollar_first_arg_num)
1222     {
1223       int i;
1224       *param_ptr = params;
1225       for (i = 1; i < argnum && *param_ptr != 0; i++)
1226 	*param_ptr = TREE_CHAIN (*param_ptr);
1227 
1228       /* This case shouldn't be caught here.  */
1229       gcc_assert (*param_ptr);
1230     }
1231   else
1232     *param_ptr = 0;
1233   return argnum;
1234 }
1235 
1236 /* Ensure that FORMAT does not start with a decimal number followed by
1237    a $; give a diagnostic and return true if it does, false otherwise.  */
1238 
1239 static bool
1240 avoid_dollar_number (const char *format)
1241 {
1242   if (!ISDIGIT (*format))
1243     return false;
1244   while (ISDIGIT (*format))
1245     format++;
1246   if (*format == '$')
1247     {
1248       warning (OPT_Wformat_, "$ operand number used after format without operand number");
1249       return true;
1250     }
1251   return false;
1252 }
1253 
1254 
1255 /* Finish the checking for a format string that used $ operand number formats
1256    instead of non-$ formats.  We check for unused operands before used ones
1257    (a serious error, since the implementation of the format function
1258    can't know what types to pass to va_arg to find the later arguments).
1259    and for unused operands at the end of the format (if we know how many
1260    arguments the format had, so not for vprintf).  If there were operand
1261    numbers out of range on a non-vprintf-style format, we won't have reached
1262    here.  If POINTER_GAP_OK, unused arguments are OK if all arguments are
1263    pointers.  */
1264 
1265 static void
1266 finish_dollar_format_checking (format_check_results *res, int pointer_gap_ok)
1267 {
1268   int i;
1269   bool found_pointer_gap = false;
1270   for (i = 0; i < dollar_max_arg_used; i++)
1271     {
1272       if (!dollar_arguments_used[i])
1273 	{
1274 	  if (pointer_gap_ok && (dollar_first_arg_num == 0
1275 				 || dollar_arguments_pointer_p[i]))
1276 	    found_pointer_gap = true;
1277 	  else
1278 	    warning_at (res->format_string_loc, OPT_Wformat_,
1279 			"format argument %d unused before used argument %d in $-style format",
1280 			i + 1, dollar_max_arg_used);
1281 	}
1282     }
1283   if (found_pointer_gap
1284       || (dollar_first_arg_num
1285 	  && dollar_max_arg_used < dollar_arguments_count))
1286     {
1287       res->number_other--;
1288       res->number_dollar_extra_args++;
1289     }
1290 }
1291 
1292 
1293 /* Retrieve the specification for a format flag.  SPEC contains the
1294    specifications for format flags for the applicable kind of format.
1295    FLAG is the flag in question.  If PREDICATES is NULL, the basic
1296    spec for that flag must be retrieved and must exist.  If
1297    PREDICATES is not NULL, it is a string listing possible predicates
1298    for the spec entry; if an entry predicated on any of these is
1299    found, it is returned, otherwise NULL is returned.  */
1300 
1301 static const format_flag_spec *
1302 get_flag_spec (const format_flag_spec *spec, int flag, const char *predicates)
1303 {
1304   int i;
1305   for (i = 0; spec[i].flag_char != 0; i++)
1306     {
1307       if (spec[i].flag_char != flag)
1308 	continue;
1309       if (predicates != NULL)
1310 	{
1311 	  if (spec[i].predicate != 0
1312 	      && strchr (predicates, spec[i].predicate) != 0)
1313 	    return &spec[i];
1314 	}
1315       else if (spec[i].predicate == 0)
1316 	return &spec[i];
1317     }
1318   gcc_assert (predicates);
1319   return NULL;
1320 }
1321 
1322 
1323 /* Check the argument list of a call to printf, scanf, etc.
1324    INFO points to the function_format_info structure.
1325    PARAMS is the list of argument values.  */
1326 
1327 static void
1328 check_format_info (function_format_info *info, tree params)
1329 {
1330   format_check_context format_ctx;
1331   unsigned HOST_WIDE_INT arg_num;
1332   tree format_tree;
1333   format_check_results res;
1334   /* Skip to format argument.  If the argument isn't available, there's
1335      no work for us to do; prototype checking will catch the problem.  */
1336   for (arg_num = 1; ; ++arg_num)
1337     {
1338       if (params == 0)
1339 	return;
1340       if (arg_num == info->format_num)
1341 	break;
1342       params = TREE_CHAIN (params);
1343     }
1344   format_tree = TREE_VALUE (params);
1345   params = TREE_CHAIN (params);
1346   if (format_tree == 0)
1347     return;
1348 
1349   res.number_non_literal = 0;
1350   res.number_extra_args = 0;
1351   res.extra_arg_loc = UNKNOWN_LOCATION;
1352   res.number_dollar_extra_args = 0;
1353   res.number_wide = 0;
1354   res.number_empty = 0;
1355   res.number_unterminated = 0;
1356   res.number_other = 0;
1357   res.format_string_loc = input_location;
1358 
1359   format_ctx.res = &res;
1360   format_ctx.info = info;
1361   format_ctx.params = params;
1362 
1363   check_function_arguments_recurse (check_format_arg, &format_ctx,
1364 				    format_tree, arg_num);
1365 
1366   location_t loc = format_ctx.res->format_string_loc;
1367   if (res.extra_arg_loc == UNKNOWN_LOCATION)
1368     res.extra_arg_loc = loc;
1369 
1370   if (res.number_non_literal > 0)
1371     {
1372       /* Functions taking a va_list normally pass a non-literal format
1373 	 string.  These functions typically are declared with
1374 	 first_arg_num == 0, so avoid warning in those cases.  */
1375       if (!(format_types[info->format_type].flags & (int) FMT_FLAG_ARG_CONVERT))
1376 	{
1377 	  /* For strftime-like formats, warn for not checking the format
1378 	     string; but there are no arguments to check.  */
1379 	  warning_at (loc, OPT_Wformat_nonliteral,
1380 		      "format not a string literal, format string not checked");
1381 	}
1382       else if (info->first_arg_num != 0)
1383 	{
1384 	  /* If there are no arguments for the format at all, we may have
1385 	     printf (foo) which is likely to be a security hole.  */
1386 	  while (arg_num + 1 < info->first_arg_num)
1387 	    {
1388 	      if (params == 0)
1389 		break;
1390 	      params = TREE_CHAIN (params);
1391 	      ++arg_num;
1392 	    }
1393 	  if (params == 0 && warn_format_security)
1394 	    warning_at (loc, OPT_Wformat_security,
1395 			"format not a string literal and no format arguments");
1396 	  else if (params == 0 && warn_format_nonliteral)
1397 	    warning_at (loc, OPT_Wformat_nonliteral,
1398 			"format not a string literal and no format arguments");
1399 	  else
1400 	    warning_at (loc, OPT_Wformat_nonliteral,
1401 			"format not a string literal, argument types not checked");
1402 	}
1403     }
1404 
1405   /* If there were extra arguments to the format, normally warn.  However,
1406      the standard does say extra arguments are ignored, so in the specific
1407      case where we have multiple leaves (conditional expressions or
1408      ngettext) allow extra arguments if at least one leaf didn't have extra
1409      arguments, but was otherwise OK (either non-literal or checked OK).
1410      If the format is an empty string, this should be counted similarly to the
1411      case of extra format arguments.  */
1412   if (res.number_extra_args > 0 && res.number_non_literal == 0
1413       && res.number_other == 0)
1414     warning_at (res.extra_arg_loc, OPT_Wformat_extra_args,
1415 		"too many arguments for format");
1416   if (res.number_dollar_extra_args > 0 && res.number_non_literal == 0
1417       && res.number_other == 0)
1418     warning_at (loc, OPT_Wformat_extra_args, "unused arguments in $-style format");
1419   if (res.number_empty > 0 && res.number_non_literal == 0
1420       && res.number_other == 0)
1421     warning_at (loc, OPT_Wformat_zero_length, "zero-length %s format string",
1422 	     format_types[info->format_type].name);
1423 
1424   if (res.number_wide > 0)
1425     warning_at (loc, OPT_Wformat_, "format is a wide character string");
1426 
1427   if (res.number_unterminated > 0)
1428     warning_at (loc, OPT_Wformat_, "unterminated format string");
1429 }
1430 
1431 /* Callback from check_function_arguments_recurse to check a
1432    format string.  FORMAT_TREE is the format parameter.  ARG_NUM
1433    is the number of the format argument.  CTX points to a
1434    format_check_context.  */
1435 
1436 static void
1437 check_format_arg (void *ctx, tree format_tree,
1438 		  unsigned HOST_WIDE_INT arg_num)
1439 {
1440   format_check_context *format_ctx = (format_check_context *) ctx;
1441   format_check_results *res = format_ctx->res;
1442   function_format_info *info = format_ctx->info;
1443   tree params = format_ctx->params;
1444 
1445   int format_length;
1446   HOST_WIDE_INT offset;
1447   const char *format_chars;
1448   tree array_size = 0;
1449   tree array_init;
1450   alloc_pool fwt_pool;
1451 
1452   if (TREE_CODE (format_tree) == VAR_DECL)
1453     {
1454       /* Pull out a constant value if the front end didn't.  */
1455       format_tree = decl_constant_value (format_tree);
1456       STRIP_NOPS (format_tree);
1457     }
1458 
1459   if (integer_zerop (format_tree))
1460     {
1461       /* Skip to first argument to check, so we can see if this format
1462 	 has any arguments (it shouldn't).  */
1463       while (arg_num + 1 < info->first_arg_num)
1464 	{
1465 	  if (params == 0)
1466 	    return;
1467 	  params = TREE_CHAIN (params);
1468 	  ++arg_num;
1469 	}
1470 
1471       if (params == 0)
1472 	res->number_other++;
1473       else
1474 	{
1475 	  if (res->number_extra_args == 0)
1476 	    res->extra_arg_loc = EXPR_LOC_OR_LOC (TREE_VALUE (params),
1477 						  input_location);
1478 	  res->number_extra_args++;
1479 	}
1480       return;
1481     }
1482 
1483   offset = 0;
1484   if (TREE_CODE (format_tree) == POINTER_PLUS_EXPR)
1485     {
1486       tree arg0, arg1;
1487 
1488       arg0 = TREE_OPERAND (format_tree, 0);
1489       arg1 = TREE_OPERAND (format_tree, 1);
1490       STRIP_NOPS (arg0);
1491       STRIP_NOPS (arg1);
1492       if (TREE_CODE (arg1) == INTEGER_CST)
1493 	format_tree = arg0;
1494       else
1495 	{
1496 	  res->number_non_literal++;
1497 	  return;
1498 	}
1499       /* POINTER_PLUS_EXPR offsets are to be interpreted signed.  */
1500       if (!cst_and_fits_in_hwi (arg1))
1501 	{
1502 	  res->number_non_literal++;
1503 	  return;
1504 	}
1505       offset = int_cst_value (arg1);
1506     }
1507   if (TREE_CODE (format_tree) != ADDR_EXPR)
1508     {
1509       res->number_non_literal++;
1510       return;
1511     }
1512   res->format_string_loc = EXPR_LOC_OR_LOC (format_tree, input_location);
1513   format_tree = TREE_OPERAND (format_tree, 0);
1514   if (format_types[info->format_type].flags
1515       & (int) FMT_FLAG_PARSE_ARG_CONVERT_EXTERNAL)
1516     {
1517       bool objc_str = (info->format_type == gcc_objc_string_format_type);
1518       /* We cannot examine this string here - but we can check that it is
1519          a valid type.  */
1520       if (TREE_CODE (format_tree) != CONST_DECL
1521 	  || !((objc_str && objc_string_ref_type_p (TREE_TYPE (format_tree)))
1522 		|| (*targetcm.string_object_ref_type_p)
1523 				     ((const_tree) TREE_TYPE (format_tree))))
1524 	{
1525 	  res->number_non_literal++;
1526 	  return;
1527 	}
1528       /* Skip to first argument to check.  */
1529       while (arg_num + 1 < info->first_arg_num)
1530 	{
1531 	  if (params == 0)
1532 	    return;
1533 	  params = TREE_CHAIN (params);
1534 	  ++arg_num;
1535 	}
1536       /* So, we have a valid literal string object and one or more params.
1537          We need to use an external helper to parse the string into format
1538          info.  For Objective-C variants we provide the resource within the
1539          objc tree, for target variants, via a hook.  */
1540       if (objc_str)
1541 	objc_check_format_arg (format_tree, params);
1542       else if (targetcm.check_string_object_format_arg)
1543 	(*targetcm.check_string_object_format_arg) (format_tree, params);
1544       /* Else we can't handle it and retire quietly.  */
1545       return;
1546     }
1547   if (TREE_CODE (format_tree) == ARRAY_REF
1548       && tree_fits_shwi_p (TREE_OPERAND (format_tree, 1))
1549       && (offset += tree_to_shwi (TREE_OPERAND (format_tree, 1))) >= 0)
1550     format_tree = TREE_OPERAND (format_tree, 0);
1551   if (offset < 0)
1552     {
1553       res->number_non_literal++;
1554       return;
1555     }
1556   if (TREE_CODE (format_tree) == VAR_DECL
1557       && TREE_CODE (TREE_TYPE (format_tree)) == ARRAY_TYPE
1558       && (array_init = decl_constant_value (format_tree)) != format_tree
1559       && TREE_CODE (array_init) == STRING_CST)
1560     {
1561       /* Extract the string constant initializer.  Note that this may include
1562 	 a trailing NUL character that is not in the array (e.g.
1563 	 const char a[3] = "foo";).  */
1564       array_size = DECL_SIZE_UNIT (format_tree);
1565       format_tree = array_init;
1566     }
1567   if (TREE_CODE (format_tree) != STRING_CST)
1568     {
1569       res->number_non_literal++;
1570       return;
1571     }
1572   if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (format_tree))) != char_type_node)
1573     {
1574       res->number_wide++;
1575       return;
1576     }
1577   format_chars = TREE_STRING_POINTER (format_tree);
1578   format_length = TREE_STRING_LENGTH (format_tree);
1579   if (array_size != 0)
1580     {
1581       /* Variable length arrays can't be initialized.  */
1582       gcc_assert (TREE_CODE (array_size) == INTEGER_CST);
1583 
1584       if (tree_fits_shwi_p (array_size))
1585 	{
1586 	  HOST_WIDE_INT array_size_value = tree_to_shwi (array_size);
1587 	  if (array_size_value > 0
1588 	      && array_size_value == (int) array_size_value
1589 	      && format_length > array_size_value)
1590 	    format_length = array_size_value;
1591 	}
1592     }
1593   if (offset)
1594     {
1595       if (offset >= format_length)
1596 	{
1597 	  res->number_non_literal++;
1598 	  return;
1599 	}
1600       format_chars += offset;
1601       format_length -= offset;
1602     }
1603   if (format_length < 1 || format_chars[--format_length] != 0)
1604     {
1605       res->number_unterminated++;
1606       return;
1607     }
1608   if (format_length == 0)
1609     {
1610       res->number_empty++;
1611       return;
1612     }
1613 
1614   /* Skip to first argument to check.  */
1615   while (arg_num + 1 < info->first_arg_num)
1616     {
1617       if (params == 0)
1618 	return;
1619       params = TREE_CHAIN (params);
1620       ++arg_num;
1621     }
1622   /* Provisionally increment res->number_other; check_format_info_main
1623      will decrement it if it finds there are extra arguments, but this way
1624      need not adjust it for every return.  */
1625   res->number_other++;
1626   fwt_pool = create_alloc_pool ("format_wanted_type pool",
1627                                 sizeof (format_wanted_type), 10);
1628   check_format_info_main (res, info, format_chars, format_length,
1629                           params, arg_num, fwt_pool);
1630   free_alloc_pool (fwt_pool);
1631 }
1632 
1633 
1634 /* Do the main part of checking a call to a format function.  FORMAT_CHARS
1635    is the NUL-terminated format string (which at this point may contain
1636    internal NUL characters); FORMAT_LENGTH is its length (excluding the
1637    terminating NUL character).  ARG_NUM is one less than the number of
1638    the first format argument to check; PARAMS points to that format
1639    argument in the list of arguments.  */
1640 
1641 static void
1642 check_format_info_main (format_check_results *res,
1643 			function_format_info *info, const char *format_chars,
1644 			int format_length, tree params,
1645                         unsigned HOST_WIDE_INT arg_num, alloc_pool fwt_pool)
1646 {
1647   const char *orig_format_chars = format_chars;
1648   tree first_fillin_param = params;
1649 
1650   const format_kind_info *fki = &format_types[info->format_type];
1651   const format_flag_spec *flag_specs = fki->flag_specs;
1652   const format_flag_pair *bad_flag_pairs = fki->bad_flag_pairs;
1653   location_t format_string_loc = res->format_string_loc;
1654 
1655   /* -1 if no conversions taking an operand have been found; 0 if one has
1656      and it didn't use $; 1 if $ formats are in use.  */
1657   int has_operand_number = -1;
1658 
1659   init_dollar_format_checking (info->first_arg_num, first_fillin_param);
1660 
1661   while (*format_chars != 0)
1662     {
1663       int i;
1664       int suppressed = FALSE;
1665       const char *length_chars = NULL;
1666       enum format_lengths length_chars_val = FMT_LEN_none;
1667       enum format_std_version length_chars_std = STD_C89;
1668       int format_char;
1669       tree cur_param;
1670       tree wanted_type;
1671       int main_arg_num = 0;
1672       tree main_arg_params = 0;
1673       enum format_std_version wanted_type_std;
1674       const char *wanted_type_name;
1675       format_wanted_type width_wanted_type;
1676       format_wanted_type precision_wanted_type;
1677       format_wanted_type main_wanted_type;
1678       format_wanted_type *first_wanted_type = NULL;
1679       format_wanted_type *last_wanted_type = NULL;
1680       const format_length_info *fli = NULL;
1681       const format_char_info *fci = NULL;
1682       char flag_chars[256];
1683       int alloc_flag = 0;
1684       int scalar_identity_flag = 0;
1685       const char *format_start;
1686 
1687       if (*format_chars++ != '%')
1688 	continue;
1689       if (*format_chars == 0)
1690 	{
1691           warning_at (format_string_loc, OPT_Wformat_,
1692 		      "spurious trailing %<%%%> in format");
1693 	  continue;
1694 	}
1695       if (*format_chars == '%')
1696 	{
1697 	  ++format_chars;
1698 	  continue;
1699 	}
1700       flag_chars[0] = 0;
1701 
1702       if ((fki->flags & (int) FMT_FLAG_USE_DOLLAR) && has_operand_number != 0)
1703 	{
1704 	  /* Possibly read a $ operand number at the start of the format.
1705 	     If one was previously used, one is required here.  If one
1706 	     is not used here, we can't immediately conclude this is a
1707 	     format without them, since it could be printf %m or scanf %*.  */
1708 	  int opnum;
1709 	  opnum = maybe_read_dollar_number (&format_chars, 0,
1710 					    first_fillin_param,
1711 					    &main_arg_params, fki);
1712 	  if (opnum == -1)
1713 	    return;
1714 	  else if (opnum > 0)
1715 	    {
1716 	      has_operand_number = 1;
1717 	      main_arg_num = opnum + info->first_arg_num - 1;
1718 	    }
1719 	}
1720       else if (fki->flags & FMT_FLAG_USE_DOLLAR)
1721 	{
1722 	  if (avoid_dollar_number (format_chars))
1723 	    return;
1724 	}
1725 
1726       /* Read any format flags, but do not yet validate them beyond removing
1727 	 duplicates, since in general validation depends on the rest of
1728 	 the format.  */
1729       while (*format_chars != 0
1730 	     && strchr (fki->flag_chars, *format_chars) != 0)
1731 	{
1732 	  const format_flag_spec *s = get_flag_spec (flag_specs,
1733 						     *format_chars, NULL);
1734 	  if (strchr (flag_chars, *format_chars) != 0)
1735 	    {
1736 	      warning_at (format_string_loc, OPT_Wformat_,
1737 			  "repeated %s in format", _(s->name));
1738 	    }
1739 	  else
1740 	    {
1741 	      i = strlen (flag_chars);
1742 	      flag_chars[i++] = *format_chars;
1743 	      flag_chars[i] = 0;
1744 	    }
1745 	  if (s->skip_next_char)
1746 	    {
1747 	      ++format_chars;
1748 	      if (*format_chars == 0)
1749 		{
1750 		  warning_at (format_string_loc, OPT_Wformat_,
1751 			      "missing fill character at end of strfmon format");
1752 		  return;
1753 		}
1754 	    }
1755 	  ++format_chars;
1756 	}
1757 
1758       /* Read any format width, possibly * or *m$.  */
1759       if (fki->width_char != 0)
1760 	{
1761 	  if (fki->width_type != NULL && *format_chars == '*')
1762 	    {
1763 	      i = strlen (flag_chars);
1764 	      flag_chars[i++] = fki->width_char;
1765 	      flag_chars[i] = 0;
1766 	      /* "...a field width...may be indicated by an asterisk.
1767 		 In this case, an int argument supplies the field width..."  */
1768 	      ++format_chars;
1769 	      if (has_operand_number != 0)
1770 		{
1771 		  int opnum;
1772 		  opnum = maybe_read_dollar_number (&format_chars,
1773 						    has_operand_number == 1,
1774 						    first_fillin_param,
1775 						    &params, fki);
1776 		  if (opnum == -1)
1777 		    return;
1778 		  else if (opnum > 0)
1779 		    {
1780 		      has_operand_number = 1;
1781 		      arg_num = opnum + info->first_arg_num - 1;
1782 		    }
1783 		  else
1784 		    has_operand_number = 0;
1785 		}
1786 	      else
1787 		{
1788 		  if (avoid_dollar_number (format_chars))
1789 		    return;
1790 		}
1791 	      if (info->first_arg_num != 0)
1792 		{
1793 		  if (params == 0)
1794                     cur_param = NULL;
1795                   else
1796                     {
1797                       cur_param = TREE_VALUE (params);
1798                       if (has_operand_number <= 0)
1799                         {
1800                           params = TREE_CHAIN (params);
1801                           ++arg_num;
1802                         }
1803                     }
1804 		  width_wanted_type.wanted_type = *fki->width_type;
1805 		  width_wanted_type.wanted_type_name = NULL;
1806 		  width_wanted_type.pointer_count = 0;
1807 		  width_wanted_type.char_lenient_flag = 0;
1808 		  width_wanted_type.scalar_identity_flag = 0;
1809 		  width_wanted_type.writing_in_flag = 0;
1810 		  width_wanted_type.reading_from_flag = 0;
1811                   width_wanted_type.kind = CF_KIND_FIELD_WIDTH;
1812 		  width_wanted_type.format_start = format_chars - 1;
1813 		  width_wanted_type.format_length = 1;
1814 		  width_wanted_type.param = cur_param;
1815 		  width_wanted_type.arg_num = arg_num;
1816 		  width_wanted_type.next = NULL;
1817 		  if (last_wanted_type != 0)
1818 		    last_wanted_type->next = &width_wanted_type;
1819 		  if (first_wanted_type == 0)
1820 		    first_wanted_type = &width_wanted_type;
1821 		  last_wanted_type = &width_wanted_type;
1822 		}
1823 	    }
1824 	  else
1825 	    {
1826 	      /* Possibly read a numeric width.  If the width is zero,
1827 		 we complain if appropriate.  */
1828 	      int non_zero_width_char = FALSE;
1829 	      int found_width = FALSE;
1830 	      while (ISDIGIT (*format_chars))
1831 		{
1832 		  found_width = TRUE;
1833 		  if (*format_chars != '0')
1834 		    non_zero_width_char = TRUE;
1835 		  ++format_chars;
1836 		}
1837 	      if (found_width && !non_zero_width_char &&
1838 		  (fki->flags & (int) FMT_FLAG_ZERO_WIDTH_BAD))
1839 		warning_at (format_string_loc, OPT_Wformat_,
1840 			    "zero width in %s format", fki->name);
1841 	      if (found_width)
1842 		{
1843 		  i = strlen (flag_chars);
1844 		  flag_chars[i++] = fki->width_char;
1845 		  flag_chars[i] = 0;
1846 		}
1847 	    }
1848 	}
1849 
1850       /* Read any format left precision (must be a number, not *).  */
1851       if (fki->left_precision_char != 0 && *format_chars == '#')
1852 	{
1853 	  ++format_chars;
1854 	  i = strlen (flag_chars);
1855 	  flag_chars[i++] = fki->left_precision_char;
1856 	  flag_chars[i] = 0;
1857 	  if (!ISDIGIT (*format_chars))
1858 	    warning_at (format_string_loc, OPT_Wformat_,
1859 			"empty left precision in %s format", fki->name);
1860 	  while (ISDIGIT (*format_chars))
1861 	    ++format_chars;
1862 	}
1863 
1864       /* Read any format precision, possibly * or *m$.  */
1865       if (fki->precision_char != 0 && *format_chars == '.')
1866 	{
1867 	  ++format_chars;
1868 	  i = strlen (flag_chars);
1869 	  flag_chars[i++] = fki->precision_char;
1870 	  flag_chars[i] = 0;
1871 	  if (fki->precision_type != NULL && *format_chars == '*')
1872 	    {
1873 	      /* "...a...precision...may be indicated by an asterisk.
1874 		 In this case, an int argument supplies the...precision."  */
1875 	      ++format_chars;
1876 	      if (has_operand_number != 0)
1877 		{
1878 		  int opnum;
1879 		  opnum = maybe_read_dollar_number (&format_chars,
1880 						    has_operand_number == 1,
1881 						    first_fillin_param,
1882 						    &params, fki);
1883 		  if (opnum == -1)
1884 		    return;
1885 		  else if (opnum > 0)
1886 		    {
1887 		      has_operand_number = 1;
1888 		      arg_num = opnum + info->first_arg_num - 1;
1889 		    }
1890 		  else
1891 		    has_operand_number = 0;
1892 		}
1893 	      else
1894 		{
1895 		  if (avoid_dollar_number (format_chars))
1896 		    return;
1897 		}
1898 	      if (info->first_arg_num != 0)
1899 		{
1900 		  if (params == 0)
1901                     cur_param = NULL;
1902                   else
1903                     {
1904                       cur_param = TREE_VALUE (params);
1905                       if (has_operand_number <= 0)
1906                         {
1907                           params = TREE_CHAIN (params);
1908                           ++arg_num;
1909                         }
1910                     }
1911 		  precision_wanted_type.wanted_type = *fki->precision_type;
1912 		  precision_wanted_type.wanted_type_name = NULL;
1913 		  precision_wanted_type.pointer_count = 0;
1914 		  precision_wanted_type.char_lenient_flag = 0;
1915 		  precision_wanted_type.scalar_identity_flag = 0;
1916 		  precision_wanted_type.writing_in_flag = 0;
1917 		  precision_wanted_type.reading_from_flag = 0;
1918                   precision_wanted_type.kind = CF_KIND_FIELD_PRECISION;
1919 		  precision_wanted_type.param = cur_param;
1920 		  precision_wanted_type.format_start = format_chars - 2;
1921 		  precision_wanted_type.format_length = 2;
1922 		  precision_wanted_type.arg_num = arg_num;
1923 		  precision_wanted_type.next = NULL;
1924 		  if (last_wanted_type != 0)
1925 		    last_wanted_type->next = &precision_wanted_type;
1926 		  if (first_wanted_type == 0)
1927 		    first_wanted_type = &precision_wanted_type;
1928 		  last_wanted_type = &precision_wanted_type;
1929 		}
1930 	    }
1931 	  else
1932 	    {
1933 	      if (!(fki->flags & (int) FMT_FLAG_EMPTY_PREC_OK)
1934 		  && !ISDIGIT (*format_chars))
1935 		warning_at (format_string_loc, OPT_Wformat_,
1936 			    "empty precision in %s format", fki->name);
1937 	      while (ISDIGIT (*format_chars))
1938 		++format_chars;
1939 	    }
1940 	}
1941 
1942       format_start = format_chars;
1943       if (fki->alloc_char && fki->alloc_char == *format_chars)
1944 	{
1945 	  i = strlen (flag_chars);
1946 	  flag_chars[i++] = fki->alloc_char;
1947 	  flag_chars[i] = 0;
1948 	  format_chars++;
1949 	}
1950 
1951       /* Handle the scanf allocation kludge.  */
1952       if (fki->flags & (int) FMT_FLAG_SCANF_A_KLUDGE)
1953 	{
1954 	  if (*format_chars == 'a' && !flag_isoc99)
1955 	    {
1956 	      if (format_chars[1] == 's' || format_chars[1] == 'S'
1957 		  || format_chars[1] == '[')
1958 		{
1959 		  /* 'a' is used as a flag.  */
1960 		  i = strlen (flag_chars);
1961 		  flag_chars[i++] = 'a';
1962 		  flag_chars[i] = 0;
1963 		  format_chars++;
1964 		}
1965 	    }
1966 	}
1967 
1968       /* Read any length modifier, if this kind of format has them.  */
1969       fli = fki->length_char_specs;
1970       length_chars = NULL;
1971       length_chars_val = FMT_LEN_none;
1972       length_chars_std = STD_C89;
1973       scalar_identity_flag = 0;
1974       if (fli)
1975 	{
1976 	  while (fli->name != 0
1977  		 && strncmp (fli->name, format_chars, strlen (fli->name)))
1978 	      fli++;
1979 	  if (fli->name != 0)
1980 	    {
1981  	      format_chars += strlen (fli->name);
1982 	      if (fli->double_name != 0 && fli->name[0] == *format_chars)
1983 		{
1984 		  format_chars++;
1985 		  length_chars = fli->double_name;
1986 		  length_chars_val = fli->double_index;
1987 		  length_chars_std = fli->double_std;
1988 		}
1989 	      else
1990 		{
1991 		  length_chars = fli->name;
1992 		  length_chars_val = fli->index;
1993 		  length_chars_std = fli->std;
1994 		  scalar_identity_flag = fli->scalar_identity_flag;
1995 		}
1996 	      i = strlen (flag_chars);
1997 	      flag_chars[i++] = fki->length_code_char;
1998 	      flag_chars[i] = 0;
1999 	    }
2000 	  if (pedantic)
2001 	    {
2002 	      /* Warn if the length modifier is non-standard.  */
2003 	      if (ADJ_STD (length_chars_std) > C_STD_VER)
2004 		warning_at (format_string_loc, OPT_Wformat_,
2005 			    "%s does not support the %qs %s length modifier",
2006 			    C_STD_NAME (length_chars_std), length_chars,
2007 			    fki->name);
2008 	    }
2009 	}
2010 
2011       /* Read any modifier (strftime E/O).  */
2012       if (fki->modifier_chars != NULL)
2013 	{
2014 	  while (*format_chars != 0
2015 		 && strchr (fki->modifier_chars, *format_chars) != 0)
2016 	    {
2017 	      if (strchr (flag_chars, *format_chars) != 0)
2018 		{
2019 		  const format_flag_spec *s = get_flag_spec (flag_specs,
2020 							     *format_chars, NULL);
2021 		  warning_at (format_string_loc, OPT_Wformat_,
2022 			      "repeated %s in format", _(s->name));
2023 		}
2024 	      else
2025 		{
2026 		  i = strlen (flag_chars);
2027 		  flag_chars[i++] = *format_chars;
2028 		  flag_chars[i] = 0;
2029 		}
2030 	      ++format_chars;
2031 	    }
2032 	}
2033 
2034       format_char = *format_chars;
2035       if (format_char == 0
2036 	  || (!(fki->flags & (int) FMT_FLAG_FANCY_PERCENT_OK)
2037 	      && format_char == '%'))
2038 	{
2039 	  warning_at (format_string_loc, OPT_Wformat_,
2040 		      "conversion lacks type at end of format");
2041 	  continue;
2042 	}
2043 
2044       if (format_char == 'm' && !(fki->flags & FMT_FLAG_M_OK))
2045         {
2046 	  warning (OPT_Wformat_,
2047 	      "%%m is only allowed in syslog(3) like functions");
2048 	  continue;
2049 	}
2050 
2051       format_chars++;
2052       fci = fki->conversion_specs;
2053       while (fci->format_chars != 0
2054 	     && strchr (fci->format_chars, format_char) == 0)
2055 	  ++fci;
2056       if (fci->format_chars == 0)
2057 	{
2058 	  if (ISGRAPH (format_char))
2059 	    warning_at (format_string_loc, OPT_Wformat_,
2060 			"unknown conversion type character %qc in format",
2061 			format_char);
2062 	  else
2063 	    warning_at (format_string_loc, OPT_Wformat_,
2064 			"unknown conversion type character 0x%x in format",
2065 			format_char);
2066 	  continue;
2067 	}
2068       if (pedantic)
2069 	{
2070 	  if (ADJ_STD (fci->std) > C_STD_VER)
2071 	    warning_at (format_string_loc, OPT_Wformat_,
2072 			"%s does not support the %<%%%c%> %s format",
2073 			C_STD_NAME (fci->std), format_char, fki->name);
2074 	}
2075 
2076       /* Validate the individual flags used, removing any that are invalid.  */
2077       {
2078 	int d = 0;
2079 	for (i = 0; flag_chars[i] != 0; i++)
2080 	  {
2081 	    const format_flag_spec *s = get_flag_spec (flag_specs,
2082 						       flag_chars[i], NULL);
2083 	    flag_chars[i - d] = flag_chars[i];
2084 	    if (flag_chars[i] == fki->length_code_char)
2085 	      continue;
2086 	    if (strchr (fci->flag_chars, flag_chars[i]) == 0)
2087 	      {
2088 		warning_at (format_string_loc,
2089                             OPT_Wformat_, "%s used with %<%%%c%> %s format",
2090 			    _(s->name), format_char, fki->name);
2091 		d++;
2092 		continue;
2093 	      }
2094 	    if (pedantic)
2095 	      {
2096 		const format_flag_spec *t;
2097 		if (ADJ_STD (s->std) > C_STD_VER)
2098 		  warning_at (format_string_loc, OPT_Wformat_,
2099 			      "%s does not support %s",
2100                               C_STD_NAME (s->std), _(s->long_name));
2101 		t = get_flag_spec (flag_specs, flag_chars[i], fci->flags2);
2102 		if (t != NULL && ADJ_STD (t->std) > ADJ_STD (s->std))
2103 		  {
2104 		    const char *long_name = (t->long_name != NULL
2105 					     ? t->long_name
2106 					     : s->long_name);
2107 		    if (ADJ_STD (t->std) > C_STD_VER)
2108 		      warning_at (format_string_loc, OPT_Wformat_,
2109 				  "%s does not support %s with the %<%%%c%> %s format",
2110 				  C_STD_NAME (t->std), _(long_name),
2111 				  format_char, fki->name);
2112 		  }
2113 	      }
2114 	  }
2115 	flag_chars[i - d] = 0;
2116       }
2117 
2118       if ((fki->flags & (int) FMT_FLAG_SCANF_A_KLUDGE)
2119 	  && strchr (flag_chars, 'a') != 0)
2120 	alloc_flag = 1;
2121       if (fki->alloc_char && strchr (flag_chars, fki->alloc_char) != 0)
2122 	alloc_flag = 1;
2123 
2124       if (fki->suppression_char
2125 	  && strchr (flag_chars, fki->suppression_char) != 0)
2126 	suppressed = 1;
2127 
2128       /* Validate the pairs of flags used.  */
2129       for (i = 0; bad_flag_pairs[i].flag_char1 != 0; i++)
2130 	{
2131 	  const format_flag_spec *s, *t;
2132 	  if (strchr (flag_chars, bad_flag_pairs[i].flag_char1) == 0)
2133 	    continue;
2134 	  if (strchr (flag_chars, bad_flag_pairs[i].flag_char2) == 0)
2135 	    continue;
2136 	  if (bad_flag_pairs[i].predicate != 0
2137 	      && strchr (fci->flags2, bad_flag_pairs[i].predicate) == 0)
2138 	    continue;
2139 	  s = get_flag_spec (flag_specs, bad_flag_pairs[i].flag_char1, NULL);
2140 	  t = get_flag_spec (flag_specs, bad_flag_pairs[i].flag_char2, NULL);
2141 	  if (bad_flag_pairs[i].ignored)
2142 	    {
2143 	      if (bad_flag_pairs[i].predicate != 0)
2144 		warning_at (format_string_loc, OPT_Wformat_,
2145 			    "%s ignored with %s and %<%%%c%> %s format",
2146 			    _(s->name), _(t->name), format_char,
2147 			    fki->name);
2148 	      else
2149 		warning_at (format_string_loc, OPT_Wformat_,
2150 			    "%s ignored with %s in %s format",
2151 			    _(s->name), _(t->name), fki->name);
2152 	    }
2153 	  else
2154 	    {
2155 	      if (bad_flag_pairs[i].predicate != 0)
2156 		warning_at (format_string_loc, OPT_Wformat_,
2157 			    "use of %s and %s together with %<%%%c%> %s format",
2158 			    _(s->name), _(t->name), format_char,
2159 			    fki->name);
2160 	      else
2161 		warning_at (format_string_loc, OPT_Wformat_,
2162 			    "use of %s and %s together in %s format",
2163 			    _(s->name), _(t->name), fki->name);
2164 	    }
2165 	}
2166 
2167       /* Give Y2K warnings.  */
2168       if (warn_format_y2k)
2169 	{
2170 	  int y2k_level = 0;
2171 	  if (strchr (fci->flags2, '4') != 0)
2172 	    if (strchr (flag_chars, 'E') != 0)
2173 	      y2k_level = 3;
2174 	    else
2175 	      y2k_level = 2;
2176 	  else if (strchr (fci->flags2, '3') != 0)
2177 	    y2k_level = 3;
2178 	  else if (strchr (fci->flags2, '2') != 0)
2179 	    y2k_level = 2;
2180 	  if (y2k_level == 3)
2181 	    warning_at (format_string_loc, OPT_Wformat_y2k,
2182 			"%<%%%c%> yields only last 2 digits of "
2183 			"year in some locales", format_char);
2184 	  else if (y2k_level == 2)
2185 	    warning_at (format_string_loc, OPT_Wformat_y2k,
2186 			"%<%%%c%> yields only last 2 digits of year",
2187 			format_char);
2188 	}
2189 
2190       if (strchr (fci->flags2, '[') != 0)
2191 	{
2192 	  /* Skip over scan set, in case it happens to have '%' in it.  */
2193 	  if (*format_chars == '^')
2194 	    ++format_chars;
2195 	  /* Find closing bracket; if one is hit immediately, then
2196 	     it's part of the scan set rather than a terminator.  */
2197 	  if (*format_chars == ']')
2198 	    ++format_chars;
2199 	  while (*format_chars && *format_chars != ']')
2200 	    ++format_chars;
2201 	  if (*format_chars != ']')
2202 	    /* The end of the format string was reached.  */
2203 	    warning_at (format_string_loc, OPT_Wformat_,
2204 			"no closing %<]%> for %<%%[%> format");
2205 	}
2206 
2207       wanted_type = 0;
2208       wanted_type_name = 0;
2209       if (fki->flags & (int) FMT_FLAG_ARG_CONVERT)
2210 	{
2211 	  wanted_type = (fci->types[length_chars_val].type
2212 			 ? *fci->types[length_chars_val].type : 0);
2213 	  wanted_type_name = fci->types[length_chars_val].name;
2214 	  wanted_type_std = fci->types[length_chars_val].std;
2215 	  if (wanted_type == 0)
2216 	    {
2217 	      warning_at (format_string_loc, OPT_Wformat_,
2218 			  "use of %qs length modifier with %qc type character",
2219 			  length_chars, format_char);
2220 	      /* Heuristic: skip one argument when an invalid length/type
2221 		 combination is encountered.  */
2222 	      arg_num++;
2223 	      if (params != 0)
2224                 params = TREE_CHAIN (params);
2225 	      continue;
2226 	    }
2227 	  else if (pedantic
2228 		   /* Warn if non-standard, provided it is more non-standard
2229 		      than the length and type characters that may already
2230 		      have been warned for.  */
2231 		   && ADJ_STD (wanted_type_std) > ADJ_STD (length_chars_std)
2232 		   && ADJ_STD (wanted_type_std) > ADJ_STD (fci->std))
2233 	    {
2234 	      if (ADJ_STD (wanted_type_std) > C_STD_VER)
2235 		warning_at (format_string_loc, OPT_Wformat_,
2236 			    "%s does not support the %<%%%s%c%> %s format",
2237 			    C_STD_NAME (wanted_type_std), length_chars,
2238 			    format_char, fki->name);
2239 	    }
2240 	}
2241 
2242       main_wanted_type.next = NULL;
2243 
2244       /* Finally. . .check type of argument against desired type!  */
2245       if (info->first_arg_num == 0)
2246 	continue;
2247       if ((fci->pointer_count == 0 && wanted_type == void_type_node)
2248 	  || suppressed)
2249 	{
2250 	  if (main_arg_num != 0)
2251 	    {
2252 	      if (suppressed)
2253 		warning_at (format_string_loc, OPT_Wformat_,
2254 			    "operand number specified with "
2255 			    "suppressed assignment");
2256 	      else
2257 		warning_at (format_string_loc, OPT_Wformat_,
2258 			    "operand number specified for format "
2259 			    "taking no argument");
2260 	    }
2261 	}
2262       else
2263 	{
2264 	  format_wanted_type *wanted_type_ptr;
2265 
2266 	  if (main_arg_num != 0)
2267 	    {
2268 	      arg_num = main_arg_num;
2269 	      params = main_arg_params;
2270 	    }
2271 	  else
2272 	    {
2273 	      ++arg_num;
2274 	      if (has_operand_number > 0)
2275 		{
2276 		  warning_at (format_string_loc, OPT_Wformat_,
2277 			      "missing $ operand number in format");
2278 		  return;
2279 		}
2280 	      else
2281 		has_operand_number = 0;
2282 	    }
2283 
2284 	  wanted_type_ptr = &main_wanted_type;
2285 	  while (fci)
2286 	    {
2287 	      if (params == 0)
2288                 cur_param = NULL;
2289               else
2290                 {
2291                   cur_param = TREE_VALUE (params);
2292                   params = TREE_CHAIN (params);
2293                 }
2294 
2295 	      wanted_type_ptr->wanted_type = wanted_type;
2296 	      wanted_type_ptr->wanted_type_name = wanted_type_name;
2297 	      wanted_type_ptr->pointer_count = fci->pointer_count + alloc_flag;
2298 	      wanted_type_ptr->char_lenient_flag = 0;
2299 	      if (strchr (fci->flags2, 'c') != 0)
2300 		wanted_type_ptr->char_lenient_flag = 1;
2301 	      wanted_type_ptr->scalar_identity_flag = 0;
2302 	      if (scalar_identity_flag)
2303 		wanted_type_ptr->scalar_identity_flag = 1;
2304 	      wanted_type_ptr->writing_in_flag = 0;
2305 	      wanted_type_ptr->reading_from_flag = 0;
2306 	      if (alloc_flag)
2307 		wanted_type_ptr->writing_in_flag = 1;
2308 	      else
2309 		{
2310 		  if (strchr (fci->flags2, 'W') != 0)
2311 		    wanted_type_ptr->writing_in_flag = 1;
2312 		  if (strchr (fci->flags2, 'R') != 0)
2313 		    wanted_type_ptr->reading_from_flag = 1;
2314 		}
2315               wanted_type_ptr->kind = CF_KIND_FORMAT;
2316 	      wanted_type_ptr->param = cur_param;
2317 	      wanted_type_ptr->arg_num = arg_num;
2318 	      wanted_type_ptr->format_start = format_start;
2319 	      wanted_type_ptr->format_length = format_chars - format_start;
2320 	      wanted_type_ptr->next = NULL;
2321 	      if (last_wanted_type != 0)
2322 		last_wanted_type->next = wanted_type_ptr;
2323 	      if (first_wanted_type == 0)
2324 		first_wanted_type = wanted_type_ptr;
2325 	      last_wanted_type = wanted_type_ptr;
2326 
2327 	      fci = fci->chain;
2328 	      if (fci)
2329 		{
2330                   wanted_type_ptr = (format_wanted_type *)
2331                       pool_alloc (fwt_pool);
2332 		  arg_num++;
2333 		  wanted_type = *fci->types[length_chars_val].type;
2334 		  wanted_type_name = fci->types[length_chars_val].name;
2335 		}
2336 	    }
2337 	}
2338 
2339       if (first_wanted_type != 0)
2340         check_format_types (format_string_loc, first_wanted_type);
2341     }
2342 
2343   if (format_chars - orig_format_chars != format_length)
2344     warning_at (format_string_loc, OPT_Wformat_contains_nul,
2345 		"embedded %<\\0%> in format");
2346   if (info->first_arg_num != 0 && params != 0
2347       && has_operand_number <= 0)
2348     {
2349       res->number_other--;
2350       res->number_extra_args++;
2351     }
2352   if (has_operand_number > 0)
2353     finish_dollar_format_checking (res, fki->flags & (int) FMT_FLAG_DOLLAR_GAP_POINTER_OK);
2354 }
2355 
2356 
2357 /* Check the argument types from a single format conversion (possibly
2358    including width and precision arguments).  LOC is the location of
2359    the format string.  */
2360 static void
2361 check_format_types (location_t loc, format_wanted_type *types)
2362 {
2363   for (; types != 0; types = types->next)
2364     {
2365       tree cur_param;
2366       tree cur_type;
2367       tree orig_cur_type;
2368       tree wanted_type;
2369       int arg_num;
2370       int i;
2371       int char_type_flag;
2372 
2373       wanted_type = types->wanted_type;
2374       arg_num = types->arg_num;
2375 
2376       /* The following should not occur here.  */
2377       gcc_assert (wanted_type);
2378       gcc_assert (wanted_type != void_type_node || types->pointer_count);
2379 
2380       if (types->pointer_count == 0)
2381 	wanted_type = lang_hooks.types.type_promotes_to (wanted_type);
2382 
2383       wanted_type = TYPE_MAIN_VARIANT (wanted_type);
2384 
2385       cur_param = types->param;
2386       if (!cur_param)
2387         {
2388           format_type_warning (loc, types, wanted_type, NULL);
2389           continue;
2390         }
2391 
2392       cur_type = TREE_TYPE (cur_param);
2393       if (cur_type == error_mark_node)
2394 	continue;
2395       orig_cur_type = cur_type;
2396       char_type_flag = 0;
2397 
2398       STRIP_NOPS (cur_param);
2399 
2400       /* Check the types of any additional pointer arguments
2401 	 that precede the "real" argument.  */
2402       for (i = 0; i < types->pointer_count; ++i)
2403 	{
2404 	  if (TREE_CODE (cur_type) == POINTER_TYPE)
2405 	    {
2406 	      cur_type = TREE_TYPE (cur_type);
2407 	      if (cur_type == error_mark_node)
2408 		break;
2409 
2410 	      /* Check for writing through a NULL pointer.  */
2411 	      if (types->writing_in_flag
2412 		  && i == 0
2413 		  && cur_param != 0
2414 		  && integer_zerop (cur_param))
2415 		warning (OPT_Wformat_, "writing through null pointer "
2416 			 "(argument %d)", arg_num);
2417 
2418 	      /* Check for reading through a NULL pointer.  */
2419 	      if (types->reading_from_flag
2420 		  && i == 0
2421 		  && cur_param != 0
2422 		  && integer_zerop (cur_param))
2423 		warning (OPT_Wformat_, "reading through null pointer "
2424 			 "(argument %d)", arg_num);
2425 
2426 	      if (cur_param != 0 && TREE_CODE (cur_param) == ADDR_EXPR)
2427 		cur_param = TREE_OPERAND (cur_param, 0);
2428 	      else
2429 		cur_param = 0;
2430 
2431 	      /* See if this is an attempt to write into a const type with
2432 		 scanf or with printf "%n".  Note: the writing in happens
2433 		 at the first indirection only, if for example
2434 		 void * const * is passed to scanf %p; passing
2435 		 const void ** is simply passing an incompatible type.  */
2436 	      if (types->writing_in_flag
2437 		  && i == 0
2438 		  && (TYPE_READONLY (cur_type)
2439 		      || (cur_param != 0
2440 			  && (CONSTANT_CLASS_P (cur_param)
2441 			      || (DECL_P (cur_param)
2442 				  && TREE_READONLY (cur_param))))))
2443 		warning (OPT_Wformat_, "writing into constant object "
2444 			 "(argument %d)", arg_num);
2445 
2446 	      /* If there are extra type qualifiers beyond the first
2447 		 indirection, then this makes the types technically
2448 		 incompatible.  */
2449 	      if (i > 0
2450 		  && pedantic
2451 		  && (TYPE_READONLY (cur_type)
2452 		      || TYPE_VOLATILE (cur_type)
2453 		      || TYPE_ATOMIC (cur_type)
2454 		      || TYPE_RESTRICT (cur_type)))
2455 		warning (OPT_Wformat_, "extra type qualifiers in format "
2456 			 "argument (argument %d)",
2457 			 arg_num);
2458 
2459 	    }
2460 	  else
2461 	    {
2462               format_type_warning (loc, types, wanted_type, orig_cur_type);
2463 	      break;
2464 	    }
2465 	}
2466 
2467       if (i < types->pointer_count)
2468 	continue;
2469 
2470       cur_type = TYPE_MAIN_VARIANT (cur_type);
2471 
2472       /* Check whether the argument type is a character type.  This leniency
2473 	 only applies to certain formats, flagged with 'c'.  */
2474       if (types->char_lenient_flag)
2475 	char_type_flag = (cur_type == char_type_node
2476 			  || cur_type == signed_char_type_node
2477 			  || cur_type == unsigned_char_type_node);
2478 
2479       /* Check the type of the "real" argument, if there's a type we want.  */
2480       if (lang_hooks.types_compatible_p (wanted_type, cur_type))
2481 	continue;
2482       /* If we want 'void *', allow any pointer type.
2483 	 (Anything else would already have got a warning.)
2484 	 With -Wpedantic, only allow pointers to void and to character
2485 	 types.  */
2486       if (wanted_type == void_type_node
2487 	  && (!pedantic || (i == 1 && char_type_flag)))
2488 	continue;
2489       /* Don't warn about differences merely in signedness, unless
2490 	 -Wpedantic.  With -Wpedantic, warn if the type is a pointer
2491 	 target and not a character type, and for character types at
2492 	 a second level of indirection.  */
2493       if (TREE_CODE (wanted_type) == INTEGER_TYPE
2494 	  && TREE_CODE (cur_type) == INTEGER_TYPE
2495 	  && ((!pedantic && !warn_format_signedness)
2496 	      || (i == 0 && !warn_format_signedness)
2497 	      || (i == 1 && char_type_flag))
2498 	  && (TYPE_UNSIGNED (wanted_type)
2499 	      ? wanted_type == c_common_unsigned_type (cur_type)
2500 	      : wanted_type == c_common_signed_type (cur_type)))
2501 	continue;
2502       /* Don't warn about differences merely in signedness if we know
2503 	 that the current type is integer-promoted and its original type
2504 	 was unsigned such as that it is in the range of WANTED_TYPE.  */
2505       if (TREE_CODE (wanted_type) == INTEGER_TYPE
2506 	  && TREE_CODE (cur_type) == INTEGER_TYPE
2507 	  && warn_format_signedness
2508 	  && TYPE_UNSIGNED (wanted_type)
2509 	  && cur_param != NULL_TREE
2510 	  && TREE_CODE (cur_param) == NOP_EXPR)
2511 	{
2512 	  tree t = TREE_TYPE (TREE_OPERAND (cur_param, 0));
2513 	  if (TYPE_UNSIGNED (t)
2514 	      && cur_type == lang_hooks.types.type_promotes_to (t))
2515 	    continue;
2516 	}
2517       /* Likewise, "signed char", "unsigned char" and "char" are
2518 	 equivalent but the above test won't consider them equivalent.  */
2519       if (wanted_type == char_type_node
2520 	  && (!pedantic || i < 2)
2521 	  && char_type_flag)
2522 	continue;
2523       if (types->scalar_identity_flag
2524 	  && (TREE_CODE (cur_type) == TREE_CODE (wanted_type)
2525 	      || (INTEGRAL_TYPE_P (cur_type)
2526 		  && INTEGRAL_TYPE_P (wanted_type)))
2527 	  && TYPE_PRECISION (cur_type) == TYPE_PRECISION (wanted_type))
2528 	continue;
2529       /* Now we have a type mismatch.  */
2530       format_type_warning (loc, types, wanted_type, orig_cur_type);
2531     }
2532 }
2533 
2534 
2535 /* Give a warning at LOC about a format argument of different type from that
2536    expected.  WANTED_TYPE is the type the argument should have, possibly
2537    stripped of pointer dereferences.  The description (such as "field
2538    precision"), the placement in the format string, a possibly more
2539    friendly name of WANTED_TYPE, and the number of pointer dereferences
2540    are taken from TYPE.  ARG_TYPE is the type of the actual argument,
2541    or NULL if it is missing.  */
2542 static void
2543 format_type_warning (location_t loc, format_wanted_type *type,
2544 		     tree wanted_type, tree arg_type)
2545 {
2546   int kind = type->kind;
2547   const char *wanted_type_name = type->wanted_type_name;
2548   const char *format_start = type->format_start;
2549   int format_length = type->format_length;
2550   int pointer_count = type->pointer_count;
2551   int arg_num = type->arg_num;
2552 
2553   char *p;
2554   /* If ARG_TYPE is a typedef with a misleading name (for example,
2555      size_t but not the standard size_t expected by printf %zu), avoid
2556      printing the typedef name.  */
2557   if (wanted_type_name
2558       && arg_type
2559       && TYPE_NAME (arg_type)
2560       && TREE_CODE (TYPE_NAME (arg_type)) == TYPE_DECL
2561       && DECL_NAME (TYPE_NAME (arg_type))
2562       && !strcmp (wanted_type_name,
2563 		  lang_hooks.decl_printable_name (TYPE_NAME (arg_type), 2)))
2564     arg_type = TYPE_MAIN_VARIANT (arg_type);
2565   /* The format type and name exclude any '*' for pointers, so those
2566      must be formatted manually.  For all the types we currently have,
2567      this is adequate, but formats taking pointers to functions or
2568      arrays would require the full type to be built up in order to
2569      print it with %T.  */
2570   p = (char *) alloca (pointer_count + 2);
2571   if (pointer_count == 0)
2572     p[0] = 0;
2573   else if (c_dialect_cxx ())
2574     {
2575       memset (p, '*', pointer_count);
2576       p[pointer_count] = 0;
2577     }
2578   else
2579     {
2580       p[0] = ' ';
2581       memset (p + 1, '*', pointer_count);
2582       p[pointer_count + 1] = 0;
2583     }
2584 
2585   if (wanted_type_name)
2586     {
2587       if (arg_type)
2588         warning_at (loc, OPT_Wformat_,
2589 		    "%s %<%s%.*s%> expects argument of type %<%s%s%>, "
2590 		    "but argument %d has type %qT",
2591 		    gettext (kind_descriptions[kind]),
2592 		    (kind == CF_KIND_FORMAT ? "%" : ""),
2593 		    format_length, format_start,
2594 		    wanted_type_name, p, arg_num, arg_type);
2595       else
2596         warning_at (loc, OPT_Wformat_,
2597 		    "%s %<%s%.*s%> expects a matching %<%s%s%> argument",
2598 		    gettext (kind_descriptions[kind]),
2599 		    (kind == CF_KIND_FORMAT ? "%" : ""),
2600 		    format_length, format_start, wanted_type_name, p);
2601     }
2602   else
2603     {
2604       if (arg_type)
2605         warning_at (loc, OPT_Wformat_,
2606 		    "%s %<%s%.*s%> expects argument of type %<%T%s%>, "
2607 		    "but argument %d has type %qT",
2608 		    gettext (kind_descriptions[kind]),
2609 		    (kind == CF_KIND_FORMAT ? "%" : ""),
2610 		    format_length, format_start,
2611 		    wanted_type, p, arg_num, arg_type);
2612       else
2613         warning_at (loc, OPT_Wformat_,
2614 		    "%s %<%s%.*s%> expects a matching %<%T%s%> argument",
2615 		    gettext (kind_descriptions[kind]),
2616 		    (kind == CF_KIND_FORMAT ? "%" : ""),
2617 		    format_length, format_start, wanted_type, p);
2618     }
2619 }
2620 
2621 
2622 /* Given a format_char_info array FCI, and a character C, this function
2623    returns the index into the conversion_specs where that specifier's
2624    data is located.  The character must exist.  */
2625 static unsigned int
2626 find_char_info_specifier_index (const format_char_info *fci, int c)
2627 {
2628   unsigned i;
2629 
2630   for (i = 0; fci->format_chars; i++, fci++)
2631     if (strchr (fci->format_chars, c))
2632       return i;
2633 
2634   /* We shouldn't be looking for a non-existent specifier.  */
2635   gcc_unreachable ();
2636 }
2637 
2638 /* Given a format_length_info array FLI, and a character C, this
2639    function returns the index into the conversion_specs where that
2640    modifier's data is located.  The character must exist.  */
2641 static unsigned int
2642 find_length_info_modifier_index (const format_length_info *fli, int c)
2643 {
2644   unsigned i;
2645 
2646   for (i = 0; fli->name; i++, fli++)
2647     if (strchr (fli->name, c))
2648       return i;
2649 
2650   /* We shouldn't be looking for a non-existent modifier.  */
2651   gcc_unreachable ();
2652 }
2653 
2654 /* Determine the type of HOST_WIDE_INT in the code being compiled for
2655    use in GCC's __asm_fprintf__ custom format attribute.  You must
2656    have set dynamic_format_types before calling this function.  */
2657 static void
2658 init_dynamic_asm_fprintf_info (void)
2659 {
2660   static tree hwi;
2661 
2662   if (!hwi)
2663     {
2664       format_length_info *new_asm_fprintf_length_specs;
2665       unsigned int i;
2666 
2667       /* Find the underlying type for HOST_WIDE_INT.  For the %w
2668 	 length modifier to work, one must have issued: "typedef
2669 	 HOST_WIDE_INT __gcc_host_wide_int__;" in one's source code
2670 	 prior to using that modifier.  */
2671       hwi = maybe_get_identifier ("__gcc_host_wide_int__");
2672       if (!hwi)
2673 	{
2674 	  error ("%<__gcc_host_wide_int__%> is not defined as a type");
2675 	  return;
2676 	}
2677       hwi = identifier_global_value (hwi);
2678       if (!hwi || TREE_CODE (hwi) != TYPE_DECL)
2679 	{
2680 	  error ("%<__gcc_host_wide_int__%> is not defined as a type");
2681 	  return;
2682 	}
2683       hwi = DECL_ORIGINAL_TYPE (hwi);
2684       gcc_assert (hwi);
2685       if (hwi != long_integer_type_node && hwi != long_long_integer_type_node)
2686 	{
2687 	  error ("%<__gcc_host_wide_int__%> is not defined as %<long%>"
2688 		 " or %<long long%>");
2689 	  return;
2690 	}
2691 
2692       /* Create a new (writable) copy of asm_fprintf_length_specs.  */
2693       new_asm_fprintf_length_specs = (format_length_info *)
2694 				     xmemdup (asm_fprintf_length_specs,
2695 					      sizeof (asm_fprintf_length_specs),
2696 					      sizeof (asm_fprintf_length_specs));
2697 
2698       /* HOST_WIDE_INT must be one of 'long' or 'long long'.  */
2699       i = find_length_info_modifier_index (new_asm_fprintf_length_specs, 'w');
2700       if (hwi == long_integer_type_node)
2701 	new_asm_fprintf_length_specs[i].index = FMT_LEN_l;
2702       else if (hwi == long_long_integer_type_node)
2703 	new_asm_fprintf_length_specs[i].index = FMT_LEN_ll;
2704       else
2705 	gcc_unreachable ();
2706 
2707       /* Assign the new data for use.  */
2708       dynamic_format_types[asm_fprintf_format_type].length_char_specs =
2709 	new_asm_fprintf_length_specs;
2710     }
2711 }
2712 
2713 /* Determine the type of a "locus" in the code being compiled for use
2714    in GCC's __gcc_gfc__ custom format attribute.  You must have set
2715    dynamic_format_types before calling this function.  */
2716 static void
2717 init_dynamic_gfc_info (void)
2718 {
2719   static tree locus;
2720 
2721   if (!locus)
2722     {
2723       static format_char_info *gfc_fci;
2724 
2725       /* For the GCC __gcc_gfc__ custom format specifier to work, one
2726 	 must have declared 'locus' prior to using this attribute.  If
2727 	 we haven't seen this declarations then you shouldn't use the
2728 	 specifier requiring that type.  */
2729       if ((locus = maybe_get_identifier ("locus")))
2730 	{
2731 	  locus = identifier_global_value (locus);
2732 	  if (locus)
2733 	    {
2734 	      if (TREE_CODE (locus) != TYPE_DECL
2735 		  || TREE_TYPE (locus) == error_mark_node)
2736 		{
2737 		  error ("%<locus%> is not defined as a type");
2738 		  locus = 0;
2739 		}
2740 	      else
2741 		locus = TREE_TYPE (locus);
2742 	    }
2743 	}
2744 
2745       /* Assign the new data for use.  */
2746 
2747       /* Handle the __gcc_gfc__ format specifics.  */
2748       if (!gfc_fci)
2749 	dynamic_format_types[gcc_gfc_format_type].conversion_specs =
2750 	  gfc_fci = (format_char_info *)
2751 		     xmemdup (gcc_gfc_char_table,
2752 			      sizeof (gcc_gfc_char_table),
2753 			      sizeof (gcc_gfc_char_table));
2754       if (locus)
2755 	{
2756 	  const unsigned i = find_char_info_specifier_index (gfc_fci, 'L');
2757 	  gfc_fci[i].types[0].type = &locus;
2758 	  gfc_fci[i].pointer_count = 1;
2759 	}
2760     }
2761 }
2762 
2763 /* Determine the types of "tree" and "location_t" in the code being
2764    compiled for use in GCC's diagnostic custom format attributes.  You
2765    must have set dynamic_format_types before calling this function.  */
2766 static void
2767 init_dynamic_diag_info (void)
2768 {
2769   static tree t, loc, hwi;
2770 
2771   if (!loc || !t || !hwi)
2772     {
2773       static format_char_info *diag_fci, *tdiag_fci, *cdiag_fci, *cxxdiag_fci;
2774       static format_length_info *diag_ls;
2775       unsigned int i;
2776 
2777       /* For the GCC-diagnostics custom format specifiers to work, one
2778 	 must have declared 'tree' and/or 'location_t' prior to using
2779 	 those attributes.  If we haven't seen these declarations then
2780 	 you shouldn't use the specifiers requiring these types.
2781 	 However we don't force a hard ICE because we may see only one
2782 	 or the other type.  */
2783       if ((loc = maybe_get_identifier ("location_t")))
2784 	{
2785 	  loc = identifier_global_value (loc);
2786 	  if (loc)
2787 	    {
2788 	      if (TREE_CODE (loc) != TYPE_DECL)
2789 		{
2790 		  error ("%<location_t%> is not defined as a type");
2791 		  loc = 0;
2792 		}
2793 	      else
2794 		loc = TREE_TYPE (loc);
2795 	    }
2796 	}
2797 
2798       /* We need to grab the underlying 'union tree_node' so peek into
2799 	 an extra type level.  */
2800       if ((t = maybe_get_identifier ("tree")))
2801 	{
2802 	  t = identifier_global_value (t);
2803 	  if (t)
2804 	    {
2805 	      if (TREE_CODE (t) != TYPE_DECL)
2806 		{
2807 		  error ("%<tree%> is not defined as a type");
2808 		  t = 0;
2809 		}
2810 	      else if (TREE_CODE (TREE_TYPE (t)) != POINTER_TYPE)
2811 		{
2812 		  error ("%<tree%> is not defined as a pointer type");
2813 		  t = 0;
2814 		}
2815 	      else
2816 		t = TREE_TYPE (TREE_TYPE (t));
2817 	    }
2818 	}
2819 
2820       /* Find the underlying type for HOST_WIDE_INT.  For the %w
2821 	 length modifier to work, one must have issued: "typedef
2822 	 HOST_WIDE_INT __gcc_host_wide_int__;" in one's source code
2823 	 prior to using that modifier.  */
2824       if ((hwi = maybe_get_identifier ("__gcc_host_wide_int__")))
2825 	{
2826 	  hwi = identifier_global_value (hwi);
2827 	  if (hwi)
2828 	    {
2829 	      if (TREE_CODE (hwi) != TYPE_DECL)
2830 		{
2831 		  error ("%<__gcc_host_wide_int__%> is not defined as a type");
2832 		  hwi = 0;
2833 		}
2834 	      else
2835 		{
2836 		  hwi = DECL_ORIGINAL_TYPE (hwi);
2837 		  gcc_assert (hwi);
2838 		  if (hwi != long_integer_type_node
2839 		      && hwi != long_long_integer_type_node)
2840 		    {
2841 		      error ("%<__gcc_host_wide_int__%> is not defined"
2842 			     " as %<long%> or %<long long%>");
2843 		      hwi = 0;
2844 		    }
2845 		}
2846 	    }
2847 	}
2848 
2849       /* Assign the new data for use.  */
2850 
2851       /* All the GCC diag formats use the same length specs.  */
2852       if (!diag_ls)
2853 	dynamic_format_types[gcc_diag_format_type].length_char_specs =
2854 	  dynamic_format_types[gcc_tdiag_format_type].length_char_specs =
2855 	  dynamic_format_types[gcc_cdiag_format_type].length_char_specs =
2856 	  dynamic_format_types[gcc_cxxdiag_format_type].length_char_specs =
2857 	  diag_ls = (format_length_info *)
2858 		    xmemdup (gcc_diag_length_specs,
2859 			     sizeof (gcc_diag_length_specs),
2860 			     sizeof (gcc_diag_length_specs));
2861       if (hwi)
2862 	{
2863 	  /* HOST_WIDE_INT must be one of 'long' or 'long long'.  */
2864 	  i = find_length_info_modifier_index (diag_ls, 'w');
2865 	  if (hwi == long_integer_type_node)
2866 	    diag_ls[i].index = FMT_LEN_l;
2867 	  else if (hwi == long_long_integer_type_node)
2868 	    diag_ls[i].index = FMT_LEN_ll;
2869 	  else
2870 	    gcc_unreachable ();
2871 	}
2872 
2873       /* Handle the __gcc_diag__ format specifics.  */
2874       if (!diag_fci)
2875 	dynamic_format_types[gcc_diag_format_type].conversion_specs =
2876 	  diag_fci = (format_char_info *)
2877 		     xmemdup (gcc_diag_char_table,
2878 			      sizeof (gcc_diag_char_table),
2879 			      sizeof (gcc_diag_char_table));
2880       if (t)
2881 	{
2882 	  i = find_char_info_specifier_index (diag_fci, 'K');
2883 	  diag_fci[i].types[0].type = &t;
2884 	  diag_fci[i].pointer_count = 1;
2885 	}
2886 
2887       /* Handle the __gcc_tdiag__ format specifics.  */
2888       if (!tdiag_fci)
2889 	dynamic_format_types[gcc_tdiag_format_type].conversion_specs =
2890 	  tdiag_fci = (format_char_info *)
2891 		      xmemdup (gcc_tdiag_char_table,
2892 			       sizeof (gcc_tdiag_char_table),
2893 			       sizeof (gcc_tdiag_char_table));
2894       if (t)
2895 	{
2896 	  /* All specifiers taking a tree share the same struct.  */
2897 	  i = find_char_info_specifier_index (tdiag_fci, 'D');
2898 	  tdiag_fci[i].types[0].type = &t;
2899 	  tdiag_fci[i].pointer_count = 1;
2900 	  i = find_char_info_specifier_index (tdiag_fci, 'K');
2901 	  tdiag_fci[i].types[0].type = &t;
2902 	  tdiag_fci[i].pointer_count = 1;
2903 	}
2904 
2905       /* Handle the __gcc_cdiag__ format specifics.  */
2906       if (!cdiag_fci)
2907 	dynamic_format_types[gcc_cdiag_format_type].conversion_specs =
2908 	  cdiag_fci = (format_char_info *)
2909 		      xmemdup (gcc_cdiag_char_table,
2910 			       sizeof (gcc_cdiag_char_table),
2911 			       sizeof (gcc_cdiag_char_table));
2912       if (t)
2913 	{
2914 	  /* All specifiers taking a tree share the same struct.  */
2915 	  i = find_char_info_specifier_index (cdiag_fci, 'D');
2916 	  cdiag_fci[i].types[0].type = &t;
2917 	  cdiag_fci[i].pointer_count = 1;
2918 	  i = find_char_info_specifier_index (cdiag_fci, 'K');
2919 	  cdiag_fci[i].types[0].type = &t;
2920 	  cdiag_fci[i].pointer_count = 1;
2921 	}
2922 
2923       /* Handle the __gcc_cxxdiag__ format specifics.  */
2924       if (!cxxdiag_fci)
2925 	dynamic_format_types[gcc_cxxdiag_format_type].conversion_specs =
2926 	  cxxdiag_fci = (format_char_info *)
2927 			xmemdup (gcc_cxxdiag_char_table,
2928 				 sizeof (gcc_cxxdiag_char_table),
2929 				 sizeof (gcc_cxxdiag_char_table));
2930       if (t)
2931 	{
2932 	  /* All specifiers taking a tree share the same struct.  */
2933 	  i = find_char_info_specifier_index (cxxdiag_fci, 'D');
2934 	  cxxdiag_fci[i].types[0].type = &t;
2935 	  cxxdiag_fci[i].pointer_count = 1;
2936 	  i = find_char_info_specifier_index (cxxdiag_fci, 'K');
2937 	  cxxdiag_fci[i].types[0].type = &t;
2938 	  cxxdiag_fci[i].pointer_count = 1;
2939 	}
2940     }
2941 }
2942 
2943 #ifdef TARGET_FORMAT_TYPES
2944 extern const format_kind_info TARGET_FORMAT_TYPES[];
2945 #endif
2946 
2947 #ifdef TARGET_OVERRIDES_FORMAT_ATTRIBUTES
2948 extern const target_ovr_attr TARGET_OVERRIDES_FORMAT_ATTRIBUTES[];
2949 #endif
2950 #ifdef TARGET_OVERRIDES_FORMAT_INIT
2951   extern void TARGET_OVERRIDES_FORMAT_INIT (void);
2952 #endif
2953 
2954 /* Attributes such as "printf" are equivalent to those such as
2955    "gnu_printf" unless this is overridden by a target.  */
2956 static const target_ovr_attr gnu_target_overrides_format_attributes[] =
2957 {
2958   { "gnu_printf",   "printf" },
2959   { "gnu_syslog",   "syslog" },
2960   { "gnu_scanf",    "scanf" },
2961   { "gnu_strftime", "strftime" },
2962   { "gnu_strfmon",  "strfmon" },
2963   { NULL,           NULL }
2964 };
2965 
2966 /* Translate to unified attribute name. This is used in decode_format_type and
2967    decode_format_attr. In attr_name the user specified argument is passed. It
2968    returns the unified format name from TARGET_OVERRIDES_FORMAT_ATTRIBUTES
2969    or the attr_name passed to this function, if there is no matching entry.  */
2970 static const char *
2971 convert_format_name_to_system_name (const char *attr_name)
2972 {
2973   int i;
2974 
2975   if (attr_name == NULL || *attr_name == 0
2976       || strncmp (attr_name, "gcc_", 4) == 0)
2977     return attr_name;
2978 #ifdef TARGET_OVERRIDES_FORMAT_INIT
2979   TARGET_OVERRIDES_FORMAT_INIT ();
2980 #endif
2981 
2982 #ifdef TARGET_OVERRIDES_FORMAT_ATTRIBUTES
2983   /* Check if format attribute is overridden by target.  */
2984   if (TARGET_OVERRIDES_FORMAT_ATTRIBUTES != NULL
2985       && TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT > 0)
2986     {
2987       for (i = 0; i < TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT; ++i)
2988         {
2989           if (cmp_attribs (TARGET_OVERRIDES_FORMAT_ATTRIBUTES[i].named_attr_src,
2990 			   attr_name))
2991             return attr_name;
2992           if (cmp_attribs (TARGET_OVERRIDES_FORMAT_ATTRIBUTES[i].named_attr_dst,
2993 			   attr_name))
2994             return TARGET_OVERRIDES_FORMAT_ATTRIBUTES[i].named_attr_src;
2995         }
2996     }
2997 #endif
2998   /* Otherwise default to gnu format.  */
2999   for (i = 0;
3000        gnu_target_overrides_format_attributes[i].named_attr_src != NULL;
3001        ++i)
3002     {
3003       if (cmp_attribs (gnu_target_overrides_format_attributes[i].named_attr_src,
3004 		       attr_name))
3005         return attr_name;
3006       if (cmp_attribs (gnu_target_overrides_format_attributes[i].named_attr_dst,
3007 		       attr_name))
3008         return gnu_target_overrides_format_attributes[i].named_attr_src;
3009     }
3010 
3011   return attr_name;
3012 }
3013 
3014 /* Return true if TATTR_NAME and ATTR_NAME are the same format attribute,
3015    counting "name" and "__name__" as the same, false otherwise.  */
3016 static bool
3017 cmp_attribs (const char *tattr_name, const char *attr_name)
3018 {
3019   int alen = strlen (attr_name);
3020   int slen = (tattr_name ? strlen (tattr_name) : 0);
3021   if (alen > 4 && attr_name[0] == '_' && attr_name[1] == '_'
3022       && attr_name[alen - 1] == '_' && attr_name[alen - 2] == '_')
3023     {
3024       attr_name += 2;
3025       alen -= 4;
3026     }
3027   if (alen != slen || strncmp (tattr_name, attr_name, alen) != 0)
3028     return false;
3029   return true;
3030 }
3031 
3032 /* Handle a "format" attribute; arguments as in
3033    struct attribute_spec.handler.  */
3034 tree
3035 handle_format_attribute (tree *node, tree ARG_UNUSED (name), tree args,
3036 			 int flags, bool *no_add_attrs)
3037 {
3038   tree type = *node;
3039   function_format_info info;
3040 
3041 #ifdef TARGET_FORMAT_TYPES
3042   /* If the target provides additional format types, we need to
3043      add them to FORMAT_TYPES at first use.  */
3044   if (TARGET_FORMAT_TYPES != NULL && !dynamic_format_types)
3045     {
3046       dynamic_format_types = XNEWVEC (format_kind_info,
3047 				      n_format_types + TARGET_N_FORMAT_TYPES);
3048       memcpy (dynamic_format_types, format_types_orig,
3049 	      sizeof (format_types_orig));
3050       memcpy (&dynamic_format_types[n_format_types], TARGET_FORMAT_TYPES,
3051 	      TARGET_N_FORMAT_TYPES * sizeof (dynamic_format_types[0]));
3052 
3053       format_types = dynamic_format_types;
3054       /* Provide a reference for the first potential external type.  */
3055       first_target_format_type = n_format_types;
3056       n_format_types += TARGET_N_FORMAT_TYPES;
3057     }
3058 #endif
3059 
3060   if (!decode_format_attr (args, &info, 0))
3061     {
3062       *no_add_attrs = true;
3063       return NULL_TREE;
3064     }
3065 
3066   if (prototype_p (type))
3067     {
3068       if (!check_format_string (type, info.format_num, flags,
3069 				no_add_attrs, info.format_type))
3070 	return NULL_TREE;
3071 
3072       if (info.first_arg_num != 0)
3073 	{
3074 	  unsigned HOST_WIDE_INT arg_num = 1;
3075 	  function_args_iterator iter;
3076 	  tree arg_type;
3077 
3078 	  /* Verify that first_arg_num points to the last arg,
3079 	     the ...  */
3080 	  FOREACH_FUNCTION_ARGS (type, arg_type, iter)
3081 	    arg_num++;
3082 
3083 	  if (arg_num != info.first_arg_num)
3084 	    {
3085 	      if (!(flags & (int) ATTR_FLAG_BUILT_IN))
3086 		error ("args to be formatted is not %<...%>");
3087 	      *no_add_attrs = true;
3088 	      return NULL_TREE;
3089 	    }
3090 	}
3091     }
3092 
3093   /* Check if this is a strftime variant. Just for this variant
3094      FMT_FLAG_ARG_CONVERT is not set.  */
3095   if ((format_types[info.format_type].flags & (int) FMT_FLAG_ARG_CONVERT) == 0
3096       && info.first_arg_num != 0)
3097     {
3098       error ("strftime formats cannot format arguments");
3099       *no_add_attrs = true;
3100       return NULL_TREE;
3101     }
3102 
3103   /* If this is a custom GCC-internal format type, we have to
3104      initialize certain bits at runtime.  */
3105   if (info.format_type == asm_fprintf_format_type
3106       || info.format_type == gcc_gfc_format_type
3107       || info.format_type == gcc_diag_format_type
3108       || info.format_type == gcc_tdiag_format_type
3109       || info.format_type == gcc_cdiag_format_type
3110       || info.format_type == gcc_cxxdiag_format_type)
3111     {
3112       /* Our first time through, we have to make sure that our
3113 	 format_type data is allocated dynamically and is modifiable.  */
3114       if (!dynamic_format_types)
3115 	format_types = dynamic_format_types = (format_kind_info *)
3116 	  xmemdup (format_types_orig, sizeof (format_types_orig),
3117 		   sizeof (format_types_orig));
3118 
3119       /* If this is format __asm_fprintf__, we have to initialize
3120 	 GCC's notion of HOST_WIDE_INT for checking %wd.  */
3121       if (info.format_type == asm_fprintf_format_type)
3122 	init_dynamic_asm_fprintf_info ();
3123       /* If this is format __gcc_gfc__, we have to initialize GCC's
3124 	 notion of 'locus' at runtime for %L.  */
3125       else if (info.format_type == gcc_gfc_format_type)
3126 	init_dynamic_gfc_info ();
3127       /* If this is one of the diagnostic attributes, then we have to
3128 	 initialize 'location_t' and 'tree' at runtime.  */
3129       else if (info.format_type == gcc_diag_format_type
3130 	       || info.format_type == gcc_tdiag_format_type
3131 	       || info.format_type == gcc_cdiag_format_type
3132 	       || info.format_type == gcc_cxxdiag_format_type)
3133 	init_dynamic_diag_info ();
3134       else
3135 	gcc_unreachable ();
3136     }
3137 
3138   return NULL_TREE;
3139 }
3140