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