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c-format.c (gcc_gfc_format_type, [...]): New.
[gcc.git] / gcc / c-format.c
1 /* Check calls to formatted I/O functions (-Wformat).
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
10 version.
11
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
20 02110-1301, USA. */
21
22 #include "config.h"
23 #include "system.h"
24 #include "coretypes.h"
25 #include "tm.h"
26 #include "tree.h"
27 #include "flags.h"
28 #include "c-common.h"
29 #include "toplev.h"
30 #include "intl.h"
31 #include "diagnostic.h"
32 #include "langhooks.h"
33 #include "c-format.h"
34 \f
35 /* Set format warning options according to a -Wformat=n option. */
36
37 void
38 set_Wformat (int setting)
39 {
40 warn_format = setting;
41 warn_format_extra_args = setting;
42 warn_format_zero_length = setting;
43 if (setting != 1)
44 {
45 warn_format_nonliteral = setting;
46 warn_format_security = setting;
47 warn_format_y2k = setting;
48 }
49 /* Make sure not to disable -Wnonnull if -Wformat=0 is specified. */
50 if (setting)
51 warn_nonnull = setting;
52 }
53
54 \f
55 /* Handle attributes associated with format checking. */
56
57 /* This must be in the same order as format_types, except for
58 format_type_error. Target-specific format types do not have
59 matching enum values. */
60 enum format_type { printf_format_type, asm_fprintf_format_type,
61 gcc_diag_format_type, gcc_tdiag_format_type,
62 gcc_cdiag_format_type,
63 gcc_cxxdiag_format_type, gcc_gfc_format_type,
64 scanf_format_type, strftime_format_type,
65 strfmon_format_type, format_type_error = -1};
66
67 typedef struct function_format_info
68 {
69 int format_type; /* type of format (printf, scanf, etc.) */
70 unsigned HOST_WIDE_INT format_num; /* number of format argument */
71 unsigned HOST_WIDE_INT first_arg_num; /* number of first arg (zero for varargs) */
72 } function_format_info;
73
74 static bool decode_format_attr (tree, function_format_info *, int);
75 static int decode_format_type (const char *);
76
77 static bool check_format_string (tree argument,
78 unsigned HOST_WIDE_INT format_num,
79 int flags, bool *no_add_attrs);
80 static bool get_constant (tree expr, unsigned HOST_WIDE_INT *value,
81 int validated_p);
82
83
84 /* Handle a "format_arg" attribute; arguments as in
85 struct attribute_spec.handler. */
86 tree
87 handle_format_arg_attribute (tree *node, tree ARG_UNUSED (name),
88 tree args, int flags, bool *no_add_attrs)
89 {
90 tree type = *node;
91 tree format_num_expr = TREE_VALUE (args);
92 unsigned HOST_WIDE_INT format_num = 0;
93 tree argument;
94
95 if (!get_constant (format_num_expr, &format_num, 0))
96 {
97 error ("format string has invalid operand number");
98 *no_add_attrs = true;
99 return NULL_TREE;
100 }
101
102 argument = TYPE_ARG_TYPES (type);
103 if (argument)
104 {
105 if (!check_format_string (argument, format_num, flags, no_add_attrs))
106 return NULL_TREE;
107 }
108
109 if (TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
110 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
111 != char_type_node))
112 {
113 if (!(flags & (int) ATTR_FLAG_BUILT_IN))
114 error ("function does not return string type");
115 *no_add_attrs = true;
116 return NULL_TREE;
117 }
118
119 return NULL_TREE;
120 }
121
122 /* Verify that the format_num argument is actually a string, in case
123 the format attribute is in error. */
124 static bool
125 check_format_string (tree argument, unsigned HOST_WIDE_INT format_num,
126 int flags, bool *no_add_attrs)
127 {
128 unsigned HOST_WIDE_INT i;
129
130 for (i = 1; i != format_num; i++)
131 {
132 if (argument == 0)
133 break;
134 argument = TREE_CHAIN (argument);
135 }
136
137 if (!argument
138 || TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE
139 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (argument)))
140 != char_type_node))
141 {
142 if (!(flags & (int) ATTR_FLAG_BUILT_IN))
143 error ("format string argument not a string type");
144 *no_add_attrs = true;
145 return false;
146 }
147
148 return true;
149 }
150
151 /* Verify EXPR is a constant, and store its value.
152 If validated_p is true there should be no errors.
153 Returns true on success, false otherwise. */
154 static bool
155 get_constant (tree expr, unsigned HOST_WIDE_INT *value, int validated_p)
156 {
157 if (TREE_CODE (expr) != INTEGER_CST || TREE_INT_CST_HIGH (expr) != 0)
158 {
159 gcc_assert (!validated_p);
160 return false;
161 }
162
163 *value = TREE_INT_CST_LOW (expr);
164
165 return true;
166 }
167
168 /* Decode the arguments to a "format" attribute into a
169 function_format_info structure. It is already known that the list
170 is of the right length. If VALIDATED_P is true, then these
171 attributes have already been validated and must not be erroneous;
172 if false, it will give an error message. Returns true if the
173 attributes are successfully decoded, false otherwise. */
174
175 static bool
176 decode_format_attr (tree args, function_format_info *info, int validated_p)
177 {
178 tree format_type_id = TREE_VALUE (args);
179 tree format_num_expr = TREE_VALUE (TREE_CHAIN (args));
180 tree first_arg_num_expr
181 = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args)));
182
183 if (TREE_CODE (format_type_id) != IDENTIFIER_NODE)
184 {
185 gcc_assert (!validated_p);
186 error ("unrecognized format specifier");
187 return false;
188 }
189 else
190 {
191 const char *p = IDENTIFIER_POINTER (format_type_id);
192
193 info->format_type = decode_format_type (p);
194
195 if (info->format_type == format_type_error)
196 {
197 gcc_assert (!validated_p);
198 warning (OPT_Wformat, "%qE is an unrecognized format function type",
199 format_type_id);
200 return false;
201 }
202 }
203
204 if (!get_constant (format_num_expr, &info->format_num, validated_p))
205 {
206 error ("format string has invalid operand number");
207 return false;
208 }
209
210 if (!get_constant (first_arg_num_expr, &info->first_arg_num, validated_p))
211 {
212 error ("%<...%> has invalid operand number");
213 return false;
214 }
215
216 if (info->first_arg_num != 0 && info->first_arg_num <= info->format_num)
217 {
218 gcc_assert (!validated_p);
219 error ("format string argument follows the args to be formatted");
220 return false;
221 }
222
223 return true;
224 }
225 \f
226 /* Check a call to a format function against a parameter list. */
227
228 /* The C standard version C++ is treated as equivalent to
229 or inheriting from, for the purpose of format features supported. */
230 #define CPLUSPLUS_STD_VER STD_C94
231 /* The C standard version we are checking formats against when pedantic. */
232 #define C_STD_VER ((int) (c_dialect_cxx () \
233 ? CPLUSPLUS_STD_VER \
234 : (flag_isoc99 \
235 ? STD_C99 \
236 : (flag_isoc94 ? STD_C94 : STD_C89))))
237 /* The name to give to the standard version we are warning about when
238 pedantic. FEATURE_VER is the version in which the feature warned out
239 appeared, which is higher than C_STD_VER. */
240 #define C_STD_NAME(FEATURE_VER) (c_dialect_cxx () \
241 ? "ISO C++" \
242 : ((FEATURE_VER) == STD_EXT \
243 ? "ISO C" \
244 : "ISO C90"))
245 /* Adjust a C standard version, which may be STD_C9L, to account for
246 -Wno-long-long. Returns other standard versions unchanged. */
247 #define ADJ_STD(VER) ((int) ((VER) == STD_C9L \
248 ? (warn_long_long ? STD_C99 : STD_C89) \
249 : (VER)))
250
251 /* Structure describing details of a type expected in format checking,
252 and the type to check against it. */
253 typedef struct format_wanted_type
254 {
255 /* The type wanted. */
256 tree wanted_type;
257 /* The name of this type to use in diagnostics. */
258 const char *wanted_type_name;
259 /* The level of indirection through pointers at which this type occurs. */
260 int pointer_count;
261 /* Whether, when pointer_count is 1, to allow any character type when
262 pedantic, rather than just the character or void type specified. */
263 int char_lenient_flag;
264 /* Whether the argument, dereferenced once, is written into and so the
265 argument must not be a pointer to a const-qualified type. */
266 int writing_in_flag;
267 /* Whether the argument, dereferenced once, is read from and so
268 must not be a NULL pointer. */
269 int reading_from_flag;
270 /* If warnings should be of the form "field precision should have
271 type 'int'", the name to use (in this case "field precision"),
272 otherwise NULL, for "format expects type 'long'" type
273 messages. */
274 const char *name;
275 /* The actual parameter to check against the wanted type. */
276 tree param;
277 /* The argument number of that parameter. */
278 int arg_num;
279 /* The next type to check for this format conversion, or NULL if none. */
280 struct format_wanted_type *next;
281 } format_wanted_type;
282
283
284 static const format_length_info printf_length_specs[] =
285 {
286 { "h", FMT_LEN_h, STD_C89, "hh", FMT_LEN_hh, STD_C99 },
287 { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C9L },
288 { "q", FMT_LEN_ll, STD_EXT, NULL, 0, 0 },
289 { "L", FMT_LEN_L, STD_C89, NULL, 0, 0 },
290 { "z", FMT_LEN_z, STD_C99, NULL, 0, 0 },
291 { "Z", FMT_LEN_z, STD_EXT, NULL, 0, 0 },
292 { "t", FMT_LEN_t, STD_C99, NULL, 0, 0 },
293 { "j", FMT_LEN_j, STD_C99, NULL, 0, 0 },
294 { NULL, 0, 0, NULL, 0, 0 }
295 };
296
297 /* Length specifiers valid for asm_fprintf. */
298 static const format_length_info asm_fprintf_length_specs[] =
299 {
300 { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C89 },
301 { "w", FMT_LEN_none, STD_C89, NULL, 0, 0 },
302 { NULL, 0, 0, NULL, 0, 0 }
303 };
304
305 /* Length specifiers valid for GCC diagnostics. */
306 static const format_length_info gcc_diag_length_specs[] =
307 {
308 { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C89 },
309 { "w", FMT_LEN_none, STD_C89, NULL, 0, 0 },
310 { NULL, 0, 0, NULL, 0, 0 }
311 };
312
313 /* The custom diagnostics all accept the same length specifiers. */
314 #define gcc_tdiag_length_specs gcc_diag_length_specs
315 #define gcc_cdiag_length_specs gcc_diag_length_specs
316 #define gcc_cxxdiag_length_specs gcc_diag_length_specs
317
318 /* This differs from printf_length_specs only in that "Z" is not accepted. */
319 static const format_length_info scanf_length_specs[] =
320 {
321 { "h", FMT_LEN_h, STD_C89, "hh", FMT_LEN_hh, STD_C99 },
322 { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C9L },
323 { "q", FMT_LEN_ll, STD_EXT, NULL, 0, 0 },
324 { "L", FMT_LEN_L, STD_C89, NULL, 0, 0 },
325 { "z", FMT_LEN_z, STD_C99, NULL, 0, 0 },
326 { "t", FMT_LEN_t, STD_C99, NULL, 0, 0 },
327 { "j", FMT_LEN_j, STD_C99, NULL, 0, 0 },
328 { NULL, 0, 0, NULL, 0, 0 }
329 };
330
331
332 /* All tables for strfmon use STD_C89 everywhere, since -pedantic warnings
333 make no sense for a format type not part of any C standard version. */
334 static const format_length_info strfmon_length_specs[] =
335 {
336 /* A GNU extension. */
337 { "L", FMT_LEN_L, STD_C89, NULL, 0, 0 },
338 { NULL, 0, 0, NULL, 0, 0 }
339 };
340
341 static const format_flag_spec printf_flag_specs[] =
342 {
343 { ' ', 0, 0, N_("' ' flag"), N_("the ' ' printf flag"), STD_C89 },
344 { '+', 0, 0, N_("'+' flag"), N_("the '+' printf flag"), STD_C89 },
345 { '#', 0, 0, N_("'#' flag"), N_("the '#' printf flag"), STD_C89 },
346 { '0', 0, 0, N_("'0' flag"), N_("the '0' printf flag"), STD_C89 },
347 { '-', 0, 0, N_("'-' flag"), N_("the '-' printf flag"), STD_C89 },
348 { '\'', 0, 0, N_("''' flag"), N_("the ''' printf flag"), STD_EXT },
349 { 'I', 0, 0, N_("'I' flag"), N_("the 'I' printf flag"), STD_EXT },
350 { 'w', 0, 0, N_("field width"), N_("field width in printf format"), STD_C89 },
351 { 'p', 0, 0, N_("precision"), N_("precision in printf format"), STD_C89 },
352 { 'L', 0, 0, N_("length modifier"), N_("length modifier in printf format"), STD_C89 },
353 { 0, 0, 0, NULL, NULL, 0 }
354 };
355
356
357 static const format_flag_pair printf_flag_pairs[] =
358 {
359 { ' ', '+', 1, 0 },
360 { '0', '-', 1, 0 },
361 { '0', 'p', 1, 'i' },
362 { 0, 0, 0, 0 }
363 };
364
365 static const format_flag_spec asm_fprintf_flag_specs[] =
366 {
367 { ' ', 0, 0, N_("' ' flag"), N_("the ' ' printf flag"), STD_C89 },
368 { '+', 0, 0, N_("'+' flag"), N_("the '+' printf flag"), STD_C89 },
369 { '#', 0, 0, N_("'#' flag"), N_("the '#' printf flag"), STD_C89 },
370 { '0', 0, 0, N_("'0' flag"), N_("the '0' printf flag"), STD_C89 },
371 { '-', 0, 0, N_("'-' flag"), N_("the '-' printf flag"), STD_C89 },
372 { 'w', 0, 0, N_("field width"), N_("field width in printf format"), STD_C89 },
373 { 'p', 0, 0, N_("precision"), N_("precision in printf format"), STD_C89 },
374 { 'L', 0, 0, N_("length modifier"), N_("length modifier in printf format"), STD_C89 },
375 { 0, 0, 0, NULL, NULL, 0 }
376 };
377
378 static const format_flag_pair asm_fprintf_flag_pairs[] =
379 {
380 { ' ', '+', 1, 0 },
381 { '0', '-', 1, 0 },
382 { '0', 'p', 1, 'i' },
383 { 0, 0, 0, 0 }
384 };
385
386 static const format_flag_pair gcc_diag_flag_pairs[] =
387 {
388 { 0, 0, 0, 0 }
389 };
390
391 #define gcc_tdiag_flag_pairs gcc_diag_flag_pairs
392 #define gcc_cdiag_flag_pairs gcc_diag_flag_pairs
393 #define gcc_cxxdiag_flag_pairs gcc_diag_flag_pairs
394
395 static const format_flag_pair gcc_gfc_flag_pairs[] =
396 {
397 { 0, 0, 0, 0 }
398 };
399
400 static const format_flag_spec gcc_diag_flag_specs[] =
401 {
402 { '+', 0, 0, N_("'+' flag"), N_("the '+' printf flag"), STD_C89 },
403 { 'q', 0, 0, N_("'q' flag"), N_("the 'q' diagnostic flag"), STD_C89 },
404 { 'p', 0, 0, N_("precision"), N_("precision in printf format"), STD_C89 },
405 { 'L', 0, 0, N_("length modifier"), N_("length modifier in printf format"), STD_C89 },
406 { 0, 0, 0, NULL, NULL, 0 }
407 };
408
409 #define gcc_tdiag_flag_specs gcc_diag_flag_specs
410 #define gcc_cdiag_flag_specs gcc_diag_flag_specs
411
412 static const format_flag_spec gcc_cxxdiag_flag_specs[] =
413 {
414 { '+', 0, 0, N_("'+' flag"), N_("the '+' printf flag"), STD_C89 },
415 { '#', 0, 0, N_("'#' flag"), N_("the '#' printf flag"), STD_C89 },
416 { 'q', 0, 0, N_("'q' flag"), N_("the 'q' diagnostic flag"), STD_C89 },
417 { 'p', 0, 0, N_("precision"), N_("precision in printf format"), STD_C89 },
418 { 'L', 0, 0, N_("length modifier"), N_("length modifier in printf format"), STD_C89 },
419 { 0, 0, 0, NULL, NULL, 0 }
420 };
421
422 static const format_flag_spec scanf_flag_specs[] =
423 {
424 { '*', 0, 0, N_("assignment suppression"), N_("the assignment suppression scanf feature"), STD_C89 },
425 { 'a', 0, 0, N_("'a' flag"), N_("the 'a' scanf flag"), STD_EXT },
426 { 'w', 0, 0, N_("field width"), N_("field width in scanf format"), STD_C89 },
427 { 'L', 0, 0, N_("length modifier"), N_("length modifier in scanf format"), STD_C89 },
428 { '\'', 0, 0, N_("''' flag"), N_("the ''' scanf flag"), STD_EXT },
429 { 'I', 0, 0, N_("'I' flag"), N_("the 'I' scanf flag"), STD_EXT },
430 { 0, 0, 0, NULL, NULL, 0 }
431 };
432
433
434 static const format_flag_pair scanf_flag_pairs[] =
435 {
436 { '*', 'L', 0, 0 },
437 { 0, 0, 0, 0 }
438 };
439
440
441 static const format_flag_spec strftime_flag_specs[] =
442 {
443 { '_', 0, 0, N_("'_' flag"), N_("the '_' strftime flag"), STD_EXT },
444 { '-', 0, 0, N_("'-' flag"), N_("the '-' strftime flag"), STD_EXT },
445 { '0', 0, 0, N_("'0' flag"), N_("the '0' strftime flag"), STD_EXT },
446 { '^', 0, 0, N_("'^' flag"), N_("the '^' strftime flag"), STD_EXT },
447 { '#', 0, 0, N_("'#' flag"), N_("the '#' strftime flag"), STD_EXT },
448 { 'w', 0, 0, N_("field width"), N_("field width in strftime format"), STD_EXT },
449 { 'E', 0, 0, N_("'E' modifier"), N_("the 'E' strftime modifier"), STD_C99 },
450 { 'O', 0, 0, N_("'O' modifier"), N_("the 'O' strftime modifier"), STD_C99 },
451 { 'O', 'o', 0, NULL, N_("the 'O' modifier"), STD_EXT },
452 { 0, 0, 0, NULL, NULL, 0 }
453 };
454
455
456 static const format_flag_pair strftime_flag_pairs[] =
457 {
458 { 'E', 'O', 0, 0 },
459 { '_', '-', 0, 0 },
460 { '_', '0', 0, 0 },
461 { '-', '0', 0, 0 },
462 { '^', '#', 0, 0 },
463 { 0, 0, 0, 0 }
464 };
465
466
467 static const format_flag_spec strfmon_flag_specs[] =
468 {
469 { '=', 0, 1, N_("fill character"), N_("fill character in strfmon format"), STD_C89 },
470 { '^', 0, 0, N_("'^' flag"), N_("the '^' strfmon flag"), STD_C89 },
471 { '+', 0, 0, N_("'+' flag"), N_("the '+' strfmon flag"), STD_C89 },
472 { '(', 0, 0, N_("'(' flag"), N_("the '(' strfmon flag"), STD_C89 },
473 { '!', 0, 0, N_("'!' flag"), N_("the '!' strfmon flag"), STD_C89 },
474 { '-', 0, 0, N_("'-' flag"), N_("the '-' strfmon flag"), STD_C89 },
475 { 'w', 0, 0, N_("field width"), N_("field width in strfmon format"), STD_C89 },
476 { '#', 0, 0, N_("left precision"), N_("left precision in strfmon format"), STD_C89 },
477 { 'p', 0, 0, N_("right precision"), N_("right precision in strfmon format"), STD_C89 },
478 { 'L', 0, 0, N_("length modifier"), N_("length modifier in strfmon format"), STD_C89 },
479 { 0, 0, 0, NULL, NULL, 0 }
480 };
481
482 static const format_flag_pair strfmon_flag_pairs[] =
483 {
484 { '+', '(', 0, 0 },
485 { 0, 0, 0, 0 }
486 };
487
488
489 static const format_char_info print_char_table[] =
490 {
491 /* C89 conversion specifiers. */
492 { "di", 0, STD_C89, { T89_I, T99_SC, T89_S, T89_L, T9L_LL, TEX_LL, T99_SST, T99_PD, T99_IM }, "-wp0 +'I", "i", NULL },
493 { "oxX", 0, STD_C89, { T89_UI, T99_UC, T89_US, T89_UL, T9L_ULL, TEX_ULL, T99_ST, T99_UPD, T99_UIM }, "-wp0#", "i", NULL },
494 { "u", 0, STD_C89, { T89_UI, T99_UC, T89_US, T89_UL, T9L_ULL, TEX_ULL, T99_ST, T99_UPD, T99_UIM }, "-wp0'I", "i", NULL },
495 { "fgG", 0, STD_C89, { T89_D, BADLEN, BADLEN, T99_D, BADLEN, T89_LD, BADLEN, BADLEN, BADLEN }, "-wp0 +#'I", "", NULL },
496 { "eE", 0, STD_C89, { T89_D, BADLEN, BADLEN, T99_D, BADLEN, T89_LD, BADLEN, BADLEN, BADLEN }, "-wp0 +#I", "", NULL },
497 { "c", 0, STD_C89, { T89_I, BADLEN, BADLEN, T94_WI, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-w", "", NULL },
498 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, T94_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp", "cR", NULL },
499 { "p", 1, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-w", "c", NULL },
500 { "n", 1, STD_C89, { T89_I, T99_SC, T89_S, T89_L, T9L_LL, BADLEN, T99_SST, T99_PD, T99_IM }, "", "W", NULL },
501 /* C99 conversion specifiers. */
502 { "F", 0, STD_C99, { T99_D, BADLEN, BADLEN, T99_D, BADLEN, T99_LD, BADLEN, BADLEN, BADLEN }, "-wp0 +#'I", "", NULL },
503 { "aA", 0, STD_C99, { T99_D, BADLEN, BADLEN, T99_D, BADLEN, T99_LD, BADLEN, BADLEN, BADLEN }, "-wp0 +#", "", NULL },
504 /* X/Open conversion specifiers. */
505 { "C", 0, STD_EXT, { TEX_WI, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-w", "", NULL },
506 { "S", 1, STD_EXT, { TEX_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp", "R", NULL },
507 /* GNU conversion specifiers. */
508 { "m", 0, STD_EXT, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp", "", NULL },
509 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
510 };
511
512 static const format_char_info asm_fprintf_char_table[] =
513 {
514 /* C89 conversion specifiers. */
515 { "di", 0, STD_C89, { T89_I, BADLEN, BADLEN, T89_L, T9L_LL, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp0 +", "i", NULL },
516 { "oxX", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp0#", "i", NULL },
517 { "u", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp0", "i", NULL },
518 { "c", 0, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-w", "", NULL },
519 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp", "cR", NULL },
520
521 /* asm_fprintf conversion specifiers. */
522 { "O", 0, STD_C89, NOARGUMENTS, "", "", NULL },
523 { "R", 0, STD_C89, NOARGUMENTS, "", "", NULL },
524 { "I", 0, STD_C89, NOARGUMENTS, "", "", NULL },
525 { "L", 0, STD_C89, NOARGUMENTS, "", "", NULL },
526 { "U", 0, STD_C89, NOARGUMENTS, "", "", NULL },
527 { "r", 0, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "", "", NULL },
528 { "@", 0, STD_C89, NOARGUMENTS, "", "", NULL },
529 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
530 };
531
532 static const format_char_info gcc_diag_char_table[] =
533 {
534 /* C89 conversion specifiers. */
535 { "di", 0, STD_C89, { T89_I, BADLEN, BADLEN, T89_L, T9L_LL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
536 { "ox", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
537 { "u", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
538 { "c", 0, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
539 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "pq", "cR", NULL },
540 { "p", 1, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "c", NULL },
541
542 /* Custom conversion specifiers. */
543
544 /* %H will require "location_t" at runtime. */
545 { "H", 0, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
546
547 /* These will require a "tree" at runtime. */
548 { "J", 0, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
549
550 { "<>'", 0, STD_C89, NOARGUMENTS, "", "", NULL },
551 { "m", 0, STD_C89, NOARGUMENTS, "q", "", NULL },
552 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
553 };
554
555 static const format_char_info gcc_tdiag_char_table[] =
556 {
557 /* C89 conversion specifiers. */
558 { "di", 0, STD_C89, { T89_I, BADLEN, BADLEN, T89_L, T9L_LL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
559 { "ox", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
560 { "u", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
561 { "c", 0, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
562 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "pq", "cR", NULL },
563 { "p", 1, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "c", NULL },
564
565 /* Custom conversion specifiers. */
566
567 /* %H will require "location_t" at runtime. */
568 { "H", 0, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
569
570 /* These will require a "tree" at runtime. */
571 { "DFJT", 0, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q+", "", NULL },
572
573 { "<>'", 0, STD_C89, NOARGUMENTS, "", "", NULL },
574 { "m", 0, STD_C89, NOARGUMENTS, "q", "", NULL },
575 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
576 };
577
578 static const format_char_info gcc_cdiag_char_table[] =
579 {
580 /* C89 conversion specifiers. */
581 { "di", 0, STD_C89, { T89_I, BADLEN, BADLEN, T89_L, T9L_LL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
582 { "ox", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
583 { "u", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
584 { "c", 0, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
585 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "pq", "cR", NULL },
586 { "p", 1, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "c", NULL },
587
588 /* Custom conversion specifiers. */
589
590 /* %H will require "location_t" at runtime. */
591 { "H", 0, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
592
593 /* These will require a "tree" at runtime. */
594 { "DEFJT", 0, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q+", "", NULL },
595
596 { "<>'", 0, STD_C89, NOARGUMENTS, "", "", NULL },
597 { "m", 0, STD_C89, NOARGUMENTS, "q", "", NULL },
598 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
599 };
600
601 static const format_char_info gcc_cxxdiag_char_table[] =
602 {
603 /* C89 conversion specifiers. */
604 { "di", 0, STD_C89, { T89_I, BADLEN, BADLEN, T89_L, T9L_LL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
605 { "ox", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
606 { "u", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
607 { "c", 0, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
608 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "pq", "cR", NULL },
609 { "p", 1, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "c", NULL },
610
611 /* Custom conversion specifiers. */
612
613 /* %H will require "location_t" at runtime. */
614 { "H", 0, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
615
616 /* These will require a "tree" at runtime. */
617 { "ADEFJTV",0,STD_C89,{ T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q+#", "", NULL },
618
619 /* These accept either an 'int' or an 'enum tree_code' (which is handled as an 'int'.) */
620 { "CLOPQ",0,STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
621
622 { "<>'", 0, STD_C89, NOARGUMENTS, "", "", NULL },
623 { "m", 0, STD_C89, NOARGUMENTS, "q", "", NULL },
624 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
625 };
626
627 static const format_char_info gcc_gfc_char_table[] =
628 {
629 /* C89 conversion specifiers. */
630 { "di", 0, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "", "", NULL },
631 { "c", 0, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "", "", NULL },
632 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "", "cR", NULL },
633
634 /* gfc conversion specifiers. */
635
636 { "C", 0, STD_C89, NOARGUMENTS, "", "", NULL },
637
638 /* This will require a "locus" at runtime. */
639 { "L", 0, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "", "R", NULL },
640
641 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
642 };
643
644 static const format_char_info scan_char_table[] =
645 {
646 /* C89 conversion specifiers. */
647 { "di", 1, STD_C89, { T89_I, T99_SC, T89_S, T89_L, T9L_LL, TEX_LL, T99_SST, T99_PD, T99_IM }, "*w'I", "W", NULL },
648 { "u", 1, STD_C89, { T89_UI, T99_UC, T89_US, T89_UL, T9L_ULL, TEX_ULL, T99_ST, T99_UPD, T99_UIM }, "*w'I", "W", NULL },
649 { "oxX", 1, STD_C89, { T89_UI, T99_UC, T89_US, T89_UL, T9L_ULL, TEX_ULL, T99_ST, T99_UPD, T99_UIM }, "*w", "W", NULL },
650 { "efgEG", 1, STD_C89, { T89_F, BADLEN, BADLEN, T89_D, BADLEN, T89_LD, BADLEN, BADLEN, BADLEN }, "*w'", "W", NULL },
651 { "c", 1, STD_C89, { T89_C, BADLEN, BADLEN, T94_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*w", "cW", NULL },
652 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, T94_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*aw", "cW", NULL },
653 { "[", 1, STD_C89, { T89_C, BADLEN, BADLEN, T94_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*aw", "cW[", NULL },
654 { "p", 2, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*w", "W", NULL },
655 { "n", 1, STD_C89, { T89_I, T99_SC, T89_S, T89_L, T9L_LL, BADLEN, T99_SST, T99_PD, T99_IM }, "", "W", NULL },
656 /* C99 conversion specifiers. */
657 { "FaA", 1, STD_C99, { T99_F, BADLEN, BADLEN, T99_D, BADLEN, T99_LD, BADLEN, BADLEN, BADLEN }, "*w'", "W", NULL },
658 /* X/Open conversion specifiers. */
659 { "C", 1, STD_EXT, { TEX_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*w", "W", NULL },
660 { "S", 1, STD_EXT, { TEX_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*aw", "W", NULL },
661 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
662 };
663
664 static const format_char_info time_char_table[] =
665 {
666 /* C89 conversion specifiers. */
667 { "ABZab", 0, STD_C89, NOLENGTHS, "^#", "", NULL },
668 { "cx", 0, STD_C89, NOLENGTHS, "E", "3", NULL },
669 { "HIMSUWdmw", 0, STD_C89, NOLENGTHS, "-_0Ow", "", NULL },
670 { "j", 0, STD_C89, NOLENGTHS, "-_0Ow", "o", NULL },
671 { "p", 0, STD_C89, NOLENGTHS, "#", "", NULL },
672 { "X", 0, STD_C89, NOLENGTHS, "E", "", NULL },
673 { "y", 0, STD_C89, NOLENGTHS, "EO-_0w", "4", NULL },
674 { "Y", 0, STD_C89, NOLENGTHS, "-_0EOw", "o", NULL },
675 { "%", 0, STD_C89, NOLENGTHS, "", "", NULL },
676 /* C99 conversion specifiers. */
677 { "C", 0, STD_C99, NOLENGTHS, "-_0EOw", "o", NULL },
678 { "D", 0, STD_C99, NOLENGTHS, "", "2", NULL },
679 { "eVu", 0, STD_C99, NOLENGTHS, "-_0Ow", "", NULL },
680 { "FRTnrt", 0, STD_C99, NOLENGTHS, "", "", NULL },
681 { "g", 0, STD_C99, NOLENGTHS, "O-_0w", "2o", NULL },
682 { "G", 0, STD_C99, NOLENGTHS, "-_0Ow", "o", NULL },
683 { "h", 0, STD_C99, NOLENGTHS, "^#", "", NULL },
684 { "z", 0, STD_C99, NOLENGTHS, "O", "o", NULL },
685 /* GNU conversion specifiers. */
686 { "kls", 0, STD_EXT, NOLENGTHS, "-_0Ow", "", NULL },
687 { "P", 0, STD_EXT, NOLENGTHS, "", "", NULL },
688 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
689 };
690
691 static const format_char_info monetary_char_table[] =
692 {
693 { "in", 0, STD_C89, { T89_D, BADLEN, BADLEN, BADLEN, BADLEN, T89_LD, BADLEN, BADLEN, BADLEN }, "=^+(!-w#p", "", NULL },
694 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
695 };
696
697 /* This must be in the same order as enum format_type. */
698 static const format_kind_info format_types_orig[] =
699 {
700 { "printf", printf_length_specs, print_char_table, " +#0-'I", NULL,
701 printf_flag_specs, printf_flag_pairs,
702 FMT_FLAG_ARG_CONVERT|FMT_FLAG_DOLLAR_MULTIPLE|FMT_FLAG_USE_DOLLAR|FMT_FLAG_EMPTY_PREC_OK,
703 'w', 0, 'p', 0, 'L',
704 &integer_type_node, &integer_type_node
705 },
706 { "asm_fprintf", asm_fprintf_length_specs, asm_fprintf_char_table, " +#0-", NULL,
707 asm_fprintf_flag_specs, asm_fprintf_flag_pairs,
708 FMT_FLAG_ARG_CONVERT|FMT_FLAG_EMPTY_PREC_OK,
709 'w', 0, 'p', 0, 'L',
710 NULL, NULL
711 },
712 { "gcc_diag", gcc_diag_length_specs, gcc_diag_char_table, "q+", NULL,
713 gcc_diag_flag_specs, gcc_diag_flag_pairs,
714 FMT_FLAG_ARG_CONVERT,
715 0, 0, 'p', 0, 'L',
716 NULL, &integer_type_node
717 },
718 { "gcc_tdiag", gcc_tdiag_length_specs, gcc_tdiag_char_table, "q+", NULL,
719 gcc_tdiag_flag_specs, gcc_tdiag_flag_pairs,
720 FMT_FLAG_ARG_CONVERT,
721 0, 0, 'p', 0, 'L',
722 NULL, &integer_type_node
723 },
724 { "gcc_cdiag", gcc_cdiag_length_specs, gcc_cdiag_char_table, "q+", NULL,
725 gcc_cdiag_flag_specs, gcc_cdiag_flag_pairs,
726 FMT_FLAG_ARG_CONVERT,
727 0, 0, 'p', 0, 'L',
728 NULL, &integer_type_node
729 },
730 { "gcc_cxxdiag", gcc_cxxdiag_length_specs, gcc_cxxdiag_char_table, "q+#", NULL,
731 gcc_cxxdiag_flag_specs, gcc_cxxdiag_flag_pairs,
732 FMT_FLAG_ARG_CONVERT,
733 0, 0, 'p', 0, 'L',
734 NULL, &integer_type_node
735 },
736 { "gcc_gfc", NULL, gcc_gfc_char_table, "", NULL,
737 NULL, gcc_gfc_flag_pairs,
738 FMT_FLAG_ARG_CONVERT,
739 0, 0, 0, 0, 0,
740 NULL, NULL
741 },
742 { "scanf", scanf_length_specs, scan_char_table, "*'I", NULL,
743 scanf_flag_specs, scanf_flag_pairs,
744 FMT_FLAG_ARG_CONVERT|FMT_FLAG_SCANF_A_KLUDGE|FMT_FLAG_USE_DOLLAR|FMT_FLAG_ZERO_WIDTH_BAD|FMT_FLAG_DOLLAR_GAP_POINTER_OK,
745 'w', 0, 0, '*', 'L',
746 NULL, NULL
747 },
748 { "strftime", NULL, time_char_table, "_-0^#", "EO",
749 strftime_flag_specs, strftime_flag_pairs,
750 FMT_FLAG_FANCY_PERCENT_OK, 'w', 0, 0, 0, 0,
751 NULL, NULL
752 },
753 { "strfmon", strfmon_length_specs, monetary_char_table, "=^+(!-", NULL,
754 strfmon_flag_specs, strfmon_flag_pairs,
755 FMT_FLAG_ARG_CONVERT, 'w', '#', 'p', 0, 'L',
756 NULL, NULL
757 }
758 };
759
760 /* This layer of indirection allows GCC to reassign format_types with
761 new data if necessary, while still allowing the original data to be
762 const. */
763 static const format_kind_info *format_types = format_types_orig;
764 /* We can modify this one. We also add target-specific format types
765 to the end of the array. */
766 static format_kind_info *dynamic_format_types;
767
768 static int n_format_types = ARRAY_SIZE (format_types_orig);
769
770 /* Structure detailing the results of checking a format function call
771 where the format expression may be a conditional expression with
772 many leaves resulting from nested conditional expressions. */
773 typedef struct
774 {
775 /* Number of leaves of the format argument that could not be checked
776 as they were not string literals. */
777 int number_non_literal;
778 /* Number of leaves of the format argument that were null pointers or
779 string literals, but had extra format arguments. */
780 int number_extra_args;
781 /* Number of leaves of the format argument that were null pointers or
782 string literals, but had extra format arguments and used $ operand
783 numbers. */
784 int number_dollar_extra_args;
785 /* Number of leaves of the format argument that were wide string
786 literals. */
787 int number_wide;
788 /* Number of leaves of the format argument that were empty strings. */
789 int number_empty;
790 /* Number of leaves of the format argument that were unterminated
791 strings. */
792 int number_unterminated;
793 /* Number of leaves of the format argument that were not counted above. */
794 int number_other;
795 } format_check_results;
796
797 typedef struct
798 {
799 format_check_results *res;
800 function_format_info *info;
801 tree params;
802 } format_check_context;
803
804 static void check_format_info (function_format_info *, tree);
805 static void check_format_arg (void *, tree, unsigned HOST_WIDE_INT);
806 static void check_format_info_main (format_check_results *,
807 function_format_info *,
808 const char *, int, tree,
809 unsigned HOST_WIDE_INT);
810
811 static void init_dollar_format_checking (int, tree);
812 static int maybe_read_dollar_number (const char **, int,
813 tree, tree *, const format_kind_info *);
814 static bool avoid_dollar_number (const char *);
815 static void finish_dollar_format_checking (format_check_results *, int);
816
817 static const format_flag_spec *get_flag_spec (const format_flag_spec *,
818 int, const char *);
819
820 static void check_format_types (format_wanted_type *, const char *, int);
821 static void format_type_warning (const char *, const char *, int, tree,
822 int, const char *, tree, int);
823
824 /* Decode a format type from a string, returning the type, or
825 format_type_error if not valid, in which case the caller should print an
826 error message. */
827 static int
828 decode_format_type (const char *s)
829 {
830 int i;
831 int slen;
832 slen = strlen (s);
833 for (i = 0; i < n_format_types; i++)
834 {
835 int alen;
836 if (!strcmp (s, format_types[i].name))
837 return i;
838 alen = strlen (format_types[i].name);
839 if (slen == alen + 4 && s[0] == '_' && s[1] == '_'
840 && s[slen - 1] == '_' && s[slen - 2] == '_'
841 && !strncmp (s + 2, format_types[i].name, alen))
842 return i;
843 }
844 return format_type_error;
845 }
846
847 \f
848 /* Check the argument list of a call to printf, scanf, etc.
849 ATTRS are the attributes on the function type.
850 PARAMS is the list of argument values. Also, if -Wmissing-format-attribute,
851 warn for calls to vprintf or vscanf in functions with no such format
852 attribute themselves. */
853
854 void
855 check_function_format (tree attrs, tree params)
856 {
857 tree a;
858
859 /* See if this function has any format attributes. */
860 for (a = attrs; a; a = TREE_CHAIN (a))
861 {
862 if (is_attribute_p ("format", TREE_PURPOSE (a)))
863 {
864 /* Yup; check it. */
865 function_format_info info;
866 decode_format_attr (TREE_VALUE (a), &info, 1);
867 check_format_info (&info, params);
868 if (warn_missing_format_attribute && info.first_arg_num == 0
869 && (format_types[info.format_type].flags
870 & (int) FMT_FLAG_ARG_CONVERT))
871 {
872 tree c;
873 for (c = TYPE_ATTRIBUTES (TREE_TYPE (current_function_decl));
874 c;
875 c = TREE_CHAIN (c))
876 if (is_attribute_p ("format", TREE_PURPOSE (c))
877 && (decode_format_type (IDENTIFIER_POINTER
878 (TREE_VALUE (TREE_VALUE (c))))
879 == info.format_type))
880 break;
881 if (c == NULL_TREE)
882 {
883 /* Check if the current function has a parameter to which
884 the format attribute could be attached; if not, it
885 can't be a candidate for a format attribute, despite
886 the vprintf-like or vscanf-like call. */
887 tree args;
888 for (args = DECL_ARGUMENTS (current_function_decl);
889 args != 0;
890 args = TREE_CHAIN (args))
891 {
892 if (TREE_CODE (TREE_TYPE (args)) == POINTER_TYPE
893 && (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (args)))
894 == char_type_node))
895 break;
896 }
897 if (args != 0)
898 warning (OPT_Wattributes, "function might be possible "
899 "candidate for %qs format attribute",
900 format_types[info.format_type].name);
901 }
902 }
903 }
904 }
905 }
906
907
908 /* Variables used by the checking of $ operand number formats. */
909 static char *dollar_arguments_used = NULL;
910 static char *dollar_arguments_pointer_p = NULL;
911 static int dollar_arguments_alloc = 0;
912 static int dollar_arguments_count;
913 static int dollar_first_arg_num;
914 static int dollar_max_arg_used;
915 static int dollar_format_warned;
916
917 /* Initialize the checking for a format string that may contain $
918 parameter number specifications; we will need to keep track of whether
919 each parameter has been used. FIRST_ARG_NUM is the number of the first
920 argument that is a parameter to the format, or 0 for a vprintf-style
921 function; PARAMS is the list of arguments starting at this argument. */
922
923 static void
924 init_dollar_format_checking (int first_arg_num, tree params)
925 {
926 tree oparams = params;
927
928 dollar_first_arg_num = first_arg_num;
929 dollar_arguments_count = 0;
930 dollar_max_arg_used = 0;
931 dollar_format_warned = 0;
932 if (first_arg_num > 0)
933 {
934 while (params)
935 {
936 dollar_arguments_count++;
937 params = TREE_CHAIN (params);
938 }
939 }
940 if (dollar_arguments_alloc < dollar_arguments_count)
941 {
942 if (dollar_arguments_used)
943 free (dollar_arguments_used);
944 if (dollar_arguments_pointer_p)
945 free (dollar_arguments_pointer_p);
946 dollar_arguments_alloc = dollar_arguments_count;
947 dollar_arguments_used = XNEWVEC (char, dollar_arguments_alloc);
948 dollar_arguments_pointer_p = XNEWVEC (char, dollar_arguments_alloc);
949 }
950 if (dollar_arguments_alloc)
951 {
952 memset (dollar_arguments_used, 0, dollar_arguments_alloc);
953 if (first_arg_num > 0)
954 {
955 int i = 0;
956 params = oparams;
957 while (params)
958 {
959 dollar_arguments_pointer_p[i] = (TREE_CODE (TREE_TYPE (TREE_VALUE (params)))
960 == POINTER_TYPE);
961 params = TREE_CHAIN (params);
962 i++;
963 }
964 }
965 }
966 }
967
968
969 /* Look for a decimal number followed by a $ in *FORMAT. If DOLLAR_NEEDED
970 is set, it is an error if one is not found; otherwise, it is OK. If
971 such a number is found, check whether it is within range and mark that
972 numbered operand as being used for later checking. Returns the operand
973 number if found and within range, zero if no such number was found and
974 this is OK, or -1 on error. PARAMS points to the first operand of the
975 format; PARAM_PTR is made to point to the parameter referred to. If
976 a $ format is found, *FORMAT is updated to point just after it. */
977
978 static int
979 maybe_read_dollar_number (const char **format,
980 int dollar_needed, tree params, tree *param_ptr,
981 const format_kind_info *fki)
982 {
983 int argnum;
984 int overflow_flag;
985 const char *fcp = *format;
986 if (!ISDIGIT (*fcp))
987 {
988 if (dollar_needed)
989 {
990 warning (OPT_Wformat, "missing $ operand number in format");
991 return -1;
992 }
993 else
994 return 0;
995 }
996 argnum = 0;
997 overflow_flag = 0;
998 while (ISDIGIT (*fcp))
999 {
1000 int nargnum;
1001 nargnum = 10 * argnum + (*fcp - '0');
1002 if (nargnum < 0 || nargnum / 10 != argnum)
1003 overflow_flag = 1;
1004 argnum = nargnum;
1005 fcp++;
1006 }
1007 if (*fcp != '$')
1008 {
1009 if (dollar_needed)
1010 {
1011 warning (OPT_Wformat, "missing $ operand number in format");
1012 return -1;
1013 }
1014 else
1015 return 0;
1016 }
1017 *format = fcp + 1;
1018 if (pedantic && !dollar_format_warned)
1019 {
1020 warning (OPT_Wformat, "%s does not support %%n$ operand number formats",
1021 C_STD_NAME (STD_EXT));
1022 dollar_format_warned = 1;
1023 }
1024 if (overflow_flag || argnum == 0
1025 || (dollar_first_arg_num && argnum > dollar_arguments_count))
1026 {
1027 warning (OPT_Wformat, "operand number out of range in format");
1028 return -1;
1029 }
1030 if (argnum > dollar_max_arg_used)
1031 dollar_max_arg_used = argnum;
1032 /* For vprintf-style functions we may need to allocate more memory to
1033 track which arguments are used. */
1034 while (dollar_arguments_alloc < dollar_max_arg_used)
1035 {
1036 int nalloc;
1037 nalloc = 2 * dollar_arguments_alloc + 16;
1038 dollar_arguments_used = XRESIZEVEC (char, dollar_arguments_used,
1039 nalloc);
1040 dollar_arguments_pointer_p = XRESIZEVEC (char, dollar_arguments_pointer_p,
1041 nalloc);
1042 memset (dollar_arguments_used + dollar_arguments_alloc, 0,
1043 nalloc - dollar_arguments_alloc);
1044 dollar_arguments_alloc = nalloc;
1045 }
1046 if (!(fki->flags & (int) FMT_FLAG_DOLLAR_MULTIPLE)
1047 && dollar_arguments_used[argnum - 1] == 1)
1048 {
1049 dollar_arguments_used[argnum - 1] = 2;
1050 warning (OPT_Wformat, "format argument %d used more than once in %s format",
1051 argnum, fki->name);
1052 }
1053 else
1054 dollar_arguments_used[argnum - 1] = 1;
1055 if (dollar_first_arg_num)
1056 {
1057 int i;
1058 *param_ptr = params;
1059 for (i = 1; i < argnum && *param_ptr != 0; i++)
1060 *param_ptr = TREE_CHAIN (*param_ptr);
1061
1062 /* This case shouldn't be caught here. */
1063 gcc_assert (*param_ptr);
1064 }
1065 else
1066 *param_ptr = 0;
1067 return argnum;
1068 }
1069
1070 /* Ensure that FORMAT does not start with a decimal number followed by
1071 a $; give a diagnostic and return true if it does, false otherwise. */
1072
1073 static bool
1074 avoid_dollar_number (const char *format)
1075 {
1076 if (!ISDIGIT (*format))
1077 return false;
1078 while (ISDIGIT (*format))
1079 format++;
1080 if (*format == '$')
1081 {
1082 warning (OPT_Wformat, "$ operand number used after format without operand number");
1083 return true;
1084 }
1085 return false;
1086 }
1087
1088
1089 /* Finish the checking for a format string that used $ operand number formats
1090 instead of non-$ formats. We check for unused operands before used ones
1091 (a serious error, since the implementation of the format function
1092 can't know what types to pass to va_arg to find the later arguments).
1093 and for unused operands at the end of the format (if we know how many
1094 arguments the format had, so not for vprintf). If there were operand
1095 numbers out of range on a non-vprintf-style format, we won't have reached
1096 here. If POINTER_GAP_OK, unused arguments are OK if all arguments are
1097 pointers. */
1098
1099 static void
1100 finish_dollar_format_checking (format_check_results *res, int pointer_gap_ok)
1101 {
1102 int i;
1103 bool found_pointer_gap = false;
1104 for (i = 0; i < dollar_max_arg_used; i++)
1105 {
1106 if (!dollar_arguments_used[i])
1107 {
1108 if (pointer_gap_ok && (dollar_first_arg_num == 0
1109 || dollar_arguments_pointer_p[i]))
1110 found_pointer_gap = true;
1111 else
1112 warning (OPT_Wformat,
1113 "format argument %d unused before used argument %d in $-style format",
1114 i + 1, dollar_max_arg_used);
1115 }
1116 }
1117 if (found_pointer_gap
1118 || (dollar_first_arg_num
1119 && dollar_max_arg_used < dollar_arguments_count))
1120 {
1121 res->number_other--;
1122 res->number_dollar_extra_args++;
1123 }
1124 }
1125
1126
1127 /* Retrieve the specification for a format flag. SPEC contains the
1128 specifications for format flags for the applicable kind of format.
1129 FLAG is the flag in question. If PREDICATES is NULL, the basic
1130 spec for that flag must be retrieved and must exist. If
1131 PREDICATES is not NULL, it is a string listing possible predicates
1132 for the spec entry; if an entry predicated on any of these is
1133 found, it is returned, otherwise NULL is returned. */
1134
1135 static const format_flag_spec *
1136 get_flag_spec (const format_flag_spec *spec, int flag, const char *predicates)
1137 {
1138 int i;
1139 for (i = 0; spec[i].flag_char != 0; i++)
1140 {
1141 if (spec[i].flag_char != flag)
1142 continue;
1143 if (predicates != NULL)
1144 {
1145 if (spec[i].predicate != 0
1146 && strchr (predicates, spec[i].predicate) != 0)
1147 return &spec[i];
1148 }
1149 else if (spec[i].predicate == 0)
1150 return &spec[i];
1151 }
1152 gcc_assert (predicates);
1153 return NULL;
1154 }
1155
1156
1157 /* Check the argument list of a call to printf, scanf, etc.
1158 INFO points to the function_format_info structure.
1159 PARAMS is the list of argument values. */
1160
1161 static void
1162 check_format_info (function_format_info *info, tree params)
1163 {
1164 format_check_context format_ctx;
1165 unsigned HOST_WIDE_INT arg_num;
1166 tree format_tree;
1167 format_check_results res;
1168 /* Skip to format argument. If the argument isn't available, there's
1169 no work for us to do; prototype checking will catch the problem. */
1170 for (arg_num = 1; ; ++arg_num)
1171 {
1172 if (params == 0)
1173 return;
1174 if (arg_num == info->format_num)
1175 break;
1176 params = TREE_CHAIN (params);
1177 }
1178 format_tree = TREE_VALUE (params);
1179 params = TREE_CHAIN (params);
1180 if (format_tree == 0)
1181 return;
1182
1183 res.number_non_literal = 0;
1184 res.number_extra_args = 0;
1185 res.number_dollar_extra_args = 0;
1186 res.number_wide = 0;
1187 res.number_empty = 0;
1188 res.number_unterminated = 0;
1189 res.number_other = 0;
1190
1191 format_ctx.res = &res;
1192 format_ctx.info = info;
1193 format_ctx.params = params;
1194
1195 check_function_arguments_recurse (check_format_arg, &format_ctx,
1196 format_tree, arg_num);
1197
1198 if (res.number_non_literal > 0)
1199 {
1200 /* Functions taking a va_list normally pass a non-literal format
1201 string. These functions typically are declared with
1202 first_arg_num == 0, so avoid warning in those cases. */
1203 if (!(format_types[info->format_type].flags & (int) FMT_FLAG_ARG_CONVERT))
1204 {
1205 /* For strftime-like formats, warn for not checking the format
1206 string; but there are no arguments to check. */
1207 warning (OPT_Wformat_nonliteral,
1208 "format not a string literal, format string not checked");
1209 }
1210 else if (info->first_arg_num != 0)
1211 {
1212 /* If there are no arguments for the format at all, we may have
1213 printf (foo) which is likely to be a security hole. */
1214 while (arg_num + 1 < info->first_arg_num)
1215 {
1216 if (params == 0)
1217 break;
1218 params = TREE_CHAIN (params);
1219 ++arg_num;
1220 }
1221 if (params == 0 && warn_format_security)
1222 warning (OPT_Wformat_security,
1223 "format not a string literal and no format arguments");
1224 else if (params == 0 && warn_format_nonliteral)
1225 warning (OPT_Wformat_nonliteral,
1226 "format not a string literal and no format arguments");
1227 else
1228 warning (OPT_Wformat_nonliteral,
1229 "format not a string literal, argument types not checked");
1230 }
1231 }
1232
1233 /* If there were extra arguments to the format, normally warn. However,
1234 the standard does say extra arguments are ignored, so in the specific
1235 case where we have multiple leaves (conditional expressions or
1236 ngettext) allow extra arguments if at least one leaf didn't have extra
1237 arguments, but was otherwise OK (either non-literal or checked OK).
1238 If the format is an empty string, this should be counted similarly to the
1239 case of extra format arguments. */
1240 if (res.number_extra_args > 0 && res.number_non_literal == 0
1241 && res.number_other == 0)
1242 warning (OPT_Wformat_extra_args, "too many arguments for format");
1243 if (res.number_dollar_extra_args > 0 && res.number_non_literal == 0
1244 && res.number_other == 0)
1245 warning (OPT_Wformat_extra_args, "unused arguments in $-style format");
1246 if (res.number_empty > 0 && res.number_non_literal == 0
1247 && res.number_other == 0)
1248 warning (OPT_Wformat_zero_length, "zero-length %s format string",
1249 format_types[info->format_type].name);
1250
1251 if (res.number_wide > 0)
1252 warning (OPT_Wformat, "format is a wide character string");
1253
1254 if (res.number_unterminated > 0)
1255 warning (OPT_Wformat, "unterminated format string");
1256 }
1257
1258 /* Callback from check_function_arguments_recurse to check a
1259 format string. FORMAT_TREE is the format parameter. ARG_NUM
1260 is the number of the format argument. CTX points to a
1261 format_check_context. */
1262
1263 static void
1264 check_format_arg (void *ctx, tree format_tree,
1265 unsigned HOST_WIDE_INT arg_num)
1266 {
1267 format_check_context *format_ctx = (format_check_context *) ctx;
1268 format_check_results *res = format_ctx->res;
1269 function_format_info *info = format_ctx->info;
1270 tree params = format_ctx->params;
1271
1272 int format_length;
1273 HOST_WIDE_INT offset;
1274 const char *format_chars;
1275 tree array_size = 0;
1276 tree array_init;
1277
1278 if (integer_zerop (format_tree))
1279 {
1280 /* Skip to first argument to check, so we can see if this format
1281 has any arguments (it shouldn't). */
1282 while (arg_num + 1 < info->first_arg_num)
1283 {
1284 if (params == 0)
1285 return;
1286 params = TREE_CHAIN (params);
1287 ++arg_num;
1288 }
1289
1290 if (params == 0)
1291 res->number_other++;
1292 else
1293 res->number_extra_args++;
1294
1295 return;
1296 }
1297
1298 offset = 0;
1299 if (TREE_CODE (format_tree) == PLUS_EXPR)
1300 {
1301 tree arg0, arg1;
1302
1303 arg0 = TREE_OPERAND (format_tree, 0);
1304 arg1 = TREE_OPERAND (format_tree, 1);
1305 STRIP_NOPS (arg0);
1306 STRIP_NOPS (arg1);
1307 if (TREE_CODE (arg1) == INTEGER_CST)
1308 format_tree = arg0;
1309 else if (TREE_CODE (arg0) == INTEGER_CST)
1310 {
1311 format_tree = arg1;
1312 arg1 = arg0;
1313 }
1314 else
1315 {
1316 res->number_non_literal++;
1317 return;
1318 }
1319 if (!host_integerp (arg1, 0)
1320 || (offset = tree_low_cst (arg1, 0)) < 0)
1321 {
1322 res->number_non_literal++;
1323 return;
1324 }
1325 }
1326 if (TREE_CODE (format_tree) != ADDR_EXPR)
1327 {
1328 res->number_non_literal++;
1329 return;
1330 }
1331 format_tree = TREE_OPERAND (format_tree, 0);
1332 if (TREE_CODE (format_tree) == ARRAY_REF
1333 && host_integerp (TREE_OPERAND (format_tree, 1), 0)
1334 && (offset += tree_low_cst (TREE_OPERAND (format_tree, 1), 0)) >= 0)
1335 format_tree = TREE_OPERAND (format_tree, 0);
1336 if (TREE_CODE (format_tree) == VAR_DECL
1337 && TREE_CODE (TREE_TYPE (format_tree)) == ARRAY_TYPE
1338 && (array_init = decl_constant_value (format_tree)) != format_tree
1339 && TREE_CODE (array_init) == STRING_CST)
1340 {
1341 /* Extract the string constant initializer. Note that this may include
1342 a trailing NUL character that is not in the array (e.g.
1343 const char a[3] = "foo";). */
1344 array_size = DECL_SIZE_UNIT (format_tree);
1345 format_tree = array_init;
1346 }
1347 if (TREE_CODE (format_tree) != STRING_CST)
1348 {
1349 res->number_non_literal++;
1350 return;
1351 }
1352 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (format_tree))) != char_type_node)
1353 {
1354 res->number_wide++;
1355 return;
1356 }
1357 format_chars = TREE_STRING_POINTER (format_tree);
1358 format_length = TREE_STRING_LENGTH (format_tree);
1359 if (array_size != 0)
1360 {
1361 /* Variable length arrays can't be initialized. */
1362 gcc_assert (TREE_CODE (array_size) == INTEGER_CST);
1363
1364 if (host_integerp (array_size, 0))
1365 {
1366 HOST_WIDE_INT array_size_value = TREE_INT_CST_LOW (array_size);
1367 if (array_size_value > 0
1368 && array_size_value == (int) array_size_value
1369 && format_length > array_size_value)
1370 format_length = array_size_value;
1371 }
1372 }
1373 if (offset)
1374 {
1375 if (offset >= format_length)
1376 {
1377 res->number_non_literal++;
1378 return;
1379 }
1380 format_chars += offset;
1381 format_length -= offset;
1382 }
1383 if (format_length < 1)
1384 {
1385 res->number_unterminated++;
1386 return;
1387 }
1388 if (format_length == 1)
1389 {
1390 res->number_empty++;
1391 return;
1392 }
1393 if (format_chars[--format_length] != 0)
1394 {
1395 res->number_unterminated++;
1396 return;
1397 }
1398
1399 /* Skip to first argument to check. */
1400 while (arg_num + 1 < info->first_arg_num)
1401 {
1402 if (params == 0)
1403 return;
1404 params = TREE_CHAIN (params);
1405 ++arg_num;
1406 }
1407 /* Provisionally increment res->number_other; check_format_info_main
1408 will decrement it if it finds there are extra arguments, but this way
1409 need not adjust it for every return. */
1410 res->number_other++;
1411 check_format_info_main (res, info, format_chars, format_length,
1412 params, arg_num);
1413 }
1414
1415
1416 /* Do the main part of checking a call to a format function. FORMAT_CHARS
1417 is the NUL-terminated format string (which at this point may contain
1418 internal NUL characters); FORMAT_LENGTH is its length (excluding the
1419 terminating NUL character). ARG_NUM is one less than the number of
1420 the first format argument to check; PARAMS points to that format
1421 argument in the list of arguments. */
1422
1423 static void
1424 check_format_info_main (format_check_results *res,
1425 function_format_info *info, const char *format_chars,
1426 int format_length, tree params,
1427 unsigned HOST_WIDE_INT arg_num)
1428 {
1429 const char *orig_format_chars = format_chars;
1430 tree first_fillin_param = params;
1431
1432 const format_kind_info *fki = &format_types[info->format_type];
1433 const format_flag_spec *flag_specs = fki->flag_specs;
1434 const format_flag_pair *bad_flag_pairs = fki->bad_flag_pairs;
1435
1436 /* -1 if no conversions taking an operand have been found; 0 if one has
1437 and it didn't use $; 1 if $ formats are in use. */
1438 int has_operand_number = -1;
1439
1440 init_dollar_format_checking (info->first_arg_num, first_fillin_param);
1441
1442 while (1)
1443 {
1444 int i;
1445 int suppressed = FALSE;
1446 const char *length_chars = NULL;
1447 enum format_lengths length_chars_val = FMT_LEN_none;
1448 enum format_std_version length_chars_std = STD_C89;
1449 int format_char;
1450 tree cur_param;
1451 tree wanted_type;
1452 int main_arg_num = 0;
1453 tree main_arg_params = 0;
1454 enum format_std_version wanted_type_std;
1455 const char *wanted_type_name;
1456 format_wanted_type width_wanted_type;
1457 format_wanted_type precision_wanted_type;
1458 format_wanted_type main_wanted_type;
1459 format_wanted_type *first_wanted_type = NULL;
1460 format_wanted_type *last_wanted_type = NULL;
1461 const format_length_info *fli = NULL;
1462 const format_char_info *fci = NULL;
1463 char flag_chars[256];
1464 int aflag = 0;
1465 const char *format_start = format_chars;
1466 if (*format_chars == 0)
1467 {
1468 if (format_chars - orig_format_chars != format_length)
1469 warning (OPT_Wformat, "embedded %<\\0%> in format");
1470 if (info->first_arg_num != 0 && params != 0
1471 && has_operand_number <= 0)
1472 {
1473 res->number_other--;
1474 res->number_extra_args++;
1475 }
1476 if (has_operand_number > 0)
1477 finish_dollar_format_checking (res, fki->flags & (int) FMT_FLAG_DOLLAR_GAP_POINTER_OK);
1478 return;
1479 }
1480 if (*format_chars++ != '%')
1481 continue;
1482 if (*format_chars == 0)
1483 {
1484 warning (OPT_Wformat, "spurious trailing %<%%%> in format");
1485 continue;
1486 }
1487 if (*format_chars == '%')
1488 {
1489 ++format_chars;
1490 continue;
1491 }
1492 flag_chars[0] = 0;
1493
1494 if ((fki->flags & (int) FMT_FLAG_USE_DOLLAR) && has_operand_number != 0)
1495 {
1496 /* Possibly read a $ operand number at the start of the format.
1497 If one was previously used, one is required here. If one
1498 is not used here, we can't immediately conclude this is a
1499 format without them, since it could be printf %m or scanf %*. */
1500 int opnum;
1501 opnum = maybe_read_dollar_number (&format_chars, 0,
1502 first_fillin_param,
1503 &main_arg_params, fki);
1504 if (opnum == -1)
1505 return;
1506 else if (opnum > 0)
1507 {
1508 has_operand_number = 1;
1509 main_arg_num = opnum + info->first_arg_num - 1;
1510 }
1511 }
1512 else if (fki->flags & FMT_FLAG_USE_DOLLAR)
1513 {
1514 if (avoid_dollar_number (format_chars))
1515 return;
1516 }
1517
1518 /* Read any format flags, but do not yet validate them beyond removing
1519 duplicates, since in general validation depends on the rest of
1520 the format. */
1521 while (*format_chars != 0
1522 && strchr (fki->flag_chars, *format_chars) != 0)
1523 {
1524 const format_flag_spec *s = get_flag_spec (flag_specs,
1525 *format_chars, NULL);
1526 if (strchr (flag_chars, *format_chars) != 0)
1527 {
1528 warning (OPT_Wformat, "repeated %s in format", _(s->name));
1529 }
1530 else
1531 {
1532 i = strlen (flag_chars);
1533 flag_chars[i++] = *format_chars;
1534 flag_chars[i] = 0;
1535 }
1536 if (s->skip_next_char)
1537 {
1538 ++format_chars;
1539 if (*format_chars == 0)
1540 {
1541 warning (OPT_Wformat, "missing fill character at end of strfmon format");
1542 return;
1543 }
1544 }
1545 ++format_chars;
1546 }
1547
1548 /* Read any format width, possibly * or *m$. */
1549 if (fki->width_char != 0)
1550 {
1551 if (fki->width_type != NULL && *format_chars == '*')
1552 {
1553 i = strlen (flag_chars);
1554 flag_chars[i++] = fki->width_char;
1555 flag_chars[i] = 0;
1556 /* "...a field width...may be indicated by an asterisk.
1557 In this case, an int argument supplies the field width..." */
1558 ++format_chars;
1559 if (has_operand_number != 0)
1560 {
1561 int opnum;
1562 opnum = maybe_read_dollar_number (&format_chars,
1563 has_operand_number == 1,
1564 first_fillin_param,
1565 &params, fki);
1566 if (opnum == -1)
1567 return;
1568 else if (opnum > 0)
1569 {
1570 has_operand_number = 1;
1571 arg_num = opnum + info->first_arg_num - 1;
1572 }
1573 else
1574 has_operand_number = 0;
1575 }
1576 else
1577 {
1578 if (avoid_dollar_number (format_chars))
1579 return;
1580 }
1581 if (info->first_arg_num != 0)
1582 {
1583 if (params == 0)
1584 {
1585 warning (OPT_Wformat, "too few arguments for format");
1586 return;
1587 }
1588 cur_param = TREE_VALUE (params);
1589 if (has_operand_number <= 0)
1590 {
1591 params = TREE_CHAIN (params);
1592 ++arg_num;
1593 }
1594 width_wanted_type.wanted_type = *fki->width_type;
1595 width_wanted_type.wanted_type_name = NULL;
1596 width_wanted_type.pointer_count = 0;
1597 width_wanted_type.char_lenient_flag = 0;
1598 width_wanted_type.writing_in_flag = 0;
1599 width_wanted_type.reading_from_flag = 0;
1600 width_wanted_type.name = _("field width");
1601 width_wanted_type.param = cur_param;
1602 width_wanted_type.arg_num = arg_num;
1603 width_wanted_type.next = NULL;
1604 if (last_wanted_type != 0)
1605 last_wanted_type->next = &width_wanted_type;
1606 if (first_wanted_type == 0)
1607 first_wanted_type = &width_wanted_type;
1608 last_wanted_type = &width_wanted_type;
1609 }
1610 }
1611 else
1612 {
1613 /* Possibly read a numeric width. If the width is zero,
1614 we complain if appropriate. */
1615 int non_zero_width_char = FALSE;
1616 int found_width = FALSE;
1617 while (ISDIGIT (*format_chars))
1618 {
1619 found_width = TRUE;
1620 if (*format_chars != '0')
1621 non_zero_width_char = TRUE;
1622 ++format_chars;
1623 }
1624 if (found_width && !non_zero_width_char &&
1625 (fki->flags & (int) FMT_FLAG_ZERO_WIDTH_BAD))
1626 warning (OPT_Wformat, "zero width in %s format", fki->name);
1627 if (found_width)
1628 {
1629 i = strlen (flag_chars);
1630 flag_chars[i++] = fki->width_char;
1631 flag_chars[i] = 0;
1632 }
1633 }
1634 }
1635
1636 /* Read any format left precision (must be a number, not *). */
1637 if (fki->left_precision_char != 0 && *format_chars == '#')
1638 {
1639 ++format_chars;
1640 i = strlen (flag_chars);
1641 flag_chars[i++] = fki->left_precision_char;
1642 flag_chars[i] = 0;
1643 if (!ISDIGIT (*format_chars))
1644 warning (OPT_Wformat, "empty left precision in %s format", fki->name);
1645 while (ISDIGIT (*format_chars))
1646 ++format_chars;
1647 }
1648
1649 /* Read any format precision, possibly * or *m$. */
1650 if (fki->precision_char != 0 && *format_chars == '.')
1651 {
1652 ++format_chars;
1653 i = strlen (flag_chars);
1654 flag_chars[i++] = fki->precision_char;
1655 flag_chars[i] = 0;
1656 if (fki->precision_type != NULL && *format_chars == '*')
1657 {
1658 /* "...a...precision...may be indicated by an asterisk.
1659 In this case, an int argument supplies the...precision." */
1660 ++format_chars;
1661 if (has_operand_number != 0)
1662 {
1663 int opnum;
1664 opnum = maybe_read_dollar_number (&format_chars,
1665 has_operand_number == 1,
1666 first_fillin_param,
1667 &params, fki);
1668 if (opnum == -1)
1669 return;
1670 else if (opnum > 0)
1671 {
1672 has_operand_number = 1;
1673 arg_num = opnum + info->first_arg_num - 1;
1674 }
1675 else
1676 has_operand_number = 0;
1677 }
1678 else
1679 {
1680 if (avoid_dollar_number (format_chars))
1681 return;
1682 }
1683 if (info->first_arg_num != 0)
1684 {
1685 if (params == 0)
1686 {
1687 warning (OPT_Wformat, "too few arguments for format");
1688 return;
1689 }
1690 cur_param = TREE_VALUE (params);
1691 if (has_operand_number <= 0)
1692 {
1693 params = TREE_CHAIN (params);
1694 ++arg_num;
1695 }
1696 precision_wanted_type.wanted_type = *fki->precision_type;
1697 precision_wanted_type.wanted_type_name = NULL;
1698 precision_wanted_type.pointer_count = 0;
1699 precision_wanted_type.char_lenient_flag = 0;
1700 precision_wanted_type.writing_in_flag = 0;
1701 precision_wanted_type.reading_from_flag = 0;
1702 precision_wanted_type.name = _("field precision");
1703 precision_wanted_type.param = cur_param;
1704 precision_wanted_type.arg_num = arg_num;
1705 precision_wanted_type.next = NULL;
1706 if (last_wanted_type != 0)
1707 last_wanted_type->next = &precision_wanted_type;
1708 if (first_wanted_type == 0)
1709 first_wanted_type = &precision_wanted_type;
1710 last_wanted_type = &precision_wanted_type;
1711 }
1712 }
1713 else
1714 {
1715 if (!(fki->flags & (int) FMT_FLAG_EMPTY_PREC_OK)
1716 && !ISDIGIT (*format_chars))
1717 warning (OPT_Wformat, "empty precision in %s format", fki->name);
1718 while (ISDIGIT (*format_chars))
1719 ++format_chars;
1720 }
1721 }
1722
1723 /* Read any length modifier, if this kind of format has them. */
1724 fli = fki->length_char_specs;
1725 length_chars = NULL;
1726 length_chars_val = FMT_LEN_none;
1727 length_chars_std = STD_C89;
1728 if (fli)
1729 {
1730 while (fli->name != 0 && fli->name[0] != *format_chars)
1731 fli++;
1732 if (fli->name != 0)
1733 {
1734 format_chars++;
1735 if (fli->double_name != 0 && fli->name[0] == *format_chars)
1736 {
1737 format_chars++;
1738 length_chars = fli->double_name;
1739 length_chars_val = fli->double_index;
1740 length_chars_std = fli->double_std;
1741 }
1742 else
1743 {
1744 length_chars = fli->name;
1745 length_chars_val = fli->index;
1746 length_chars_std = fli->std;
1747 }
1748 i = strlen (flag_chars);
1749 flag_chars[i++] = fki->length_code_char;
1750 flag_chars[i] = 0;
1751 }
1752 if (pedantic)
1753 {
1754 /* Warn if the length modifier is non-standard. */
1755 if (ADJ_STD (length_chars_std) > C_STD_VER)
1756 warning (OPT_Wformat,
1757 "%s does not support the %qs %s length modifier",
1758 C_STD_NAME (length_chars_std), length_chars,
1759 fki->name);
1760 }
1761 }
1762
1763 /* Read any modifier (strftime E/O). */
1764 if (fki->modifier_chars != NULL)
1765 {
1766 while (*format_chars != 0
1767 && strchr (fki->modifier_chars, *format_chars) != 0)
1768 {
1769 if (strchr (flag_chars, *format_chars) != 0)
1770 {
1771 const format_flag_spec *s = get_flag_spec (flag_specs,
1772 *format_chars, NULL);
1773 warning (OPT_Wformat, "repeated %s in format", _(s->name));
1774 }
1775 else
1776 {
1777 i = strlen (flag_chars);
1778 flag_chars[i++] = *format_chars;
1779 flag_chars[i] = 0;
1780 }
1781 ++format_chars;
1782 }
1783 }
1784
1785 /* Handle the scanf allocation kludge. */
1786 if (fki->flags & (int) FMT_FLAG_SCANF_A_KLUDGE)
1787 {
1788 if (*format_chars == 'a' && !flag_isoc99)
1789 {
1790 if (format_chars[1] == 's' || format_chars[1] == 'S'
1791 || format_chars[1] == '[')
1792 {
1793 /* 'a' is used as a flag. */
1794 i = strlen (flag_chars);
1795 flag_chars[i++] = 'a';
1796 flag_chars[i] = 0;
1797 format_chars++;
1798 }
1799 }
1800 }
1801
1802 format_char = *format_chars;
1803 if (format_char == 0
1804 || (!(fki->flags & (int) FMT_FLAG_FANCY_PERCENT_OK)
1805 && format_char == '%'))
1806 {
1807 warning (OPT_Wformat, "conversion lacks type at end of format");
1808 continue;
1809 }
1810 format_chars++;
1811 fci = fki->conversion_specs;
1812 while (fci->format_chars != 0
1813 && strchr (fci->format_chars, format_char) == 0)
1814 ++fci;
1815 if (fci->format_chars == 0)
1816 {
1817 if (ISGRAPH (format_char))
1818 warning (OPT_Wformat, "unknown conversion type character %qc in format",
1819 format_char);
1820 else
1821 warning (OPT_Wformat, "unknown conversion type character 0x%x in format",
1822 format_char);
1823 continue;
1824 }
1825 if (pedantic)
1826 {
1827 if (ADJ_STD (fci->std) > C_STD_VER)
1828 warning (OPT_Wformat, "%s does not support the %<%%%c%> %s format",
1829 C_STD_NAME (fci->std), format_char, fki->name);
1830 }
1831
1832 /* Validate the individual flags used, removing any that are invalid. */
1833 {
1834 int d = 0;
1835 for (i = 0; flag_chars[i] != 0; i++)
1836 {
1837 const format_flag_spec *s = get_flag_spec (flag_specs,
1838 flag_chars[i], NULL);
1839 flag_chars[i - d] = flag_chars[i];
1840 if (flag_chars[i] == fki->length_code_char)
1841 continue;
1842 if (strchr (fci->flag_chars, flag_chars[i]) == 0)
1843 {
1844 warning (OPT_Wformat, "%s used with %<%%%c%> %s format",
1845 _(s->name), format_char, fki->name);
1846 d++;
1847 continue;
1848 }
1849 if (pedantic)
1850 {
1851 const format_flag_spec *t;
1852 if (ADJ_STD (s->std) > C_STD_VER)
1853 warning (OPT_Wformat, "%s does not support %s",
1854 C_STD_NAME (s->std), _(s->long_name));
1855 t = get_flag_spec (flag_specs, flag_chars[i], fci->flags2);
1856 if (t != NULL && ADJ_STD (t->std) > ADJ_STD (s->std))
1857 {
1858 const char *long_name = (t->long_name != NULL
1859 ? t->long_name
1860 : s->long_name);
1861 if (ADJ_STD (t->std) > C_STD_VER)
1862 warning (OPT_Wformat,
1863 "%s does not support %s with the %<%%%c%> %s format",
1864 C_STD_NAME (t->std), _(long_name),
1865 format_char, fki->name);
1866 }
1867 }
1868 }
1869 flag_chars[i - d] = 0;
1870 }
1871
1872 if ((fki->flags & (int) FMT_FLAG_SCANF_A_KLUDGE)
1873 && strchr (flag_chars, 'a') != 0)
1874 aflag = 1;
1875
1876 if (fki->suppression_char
1877 && strchr (flag_chars, fki->suppression_char) != 0)
1878 suppressed = 1;
1879
1880 /* Validate the pairs of flags used. */
1881 for (i = 0; bad_flag_pairs[i].flag_char1 != 0; i++)
1882 {
1883 const format_flag_spec *s, *t;
1884 if (strchr (flag_chars, bad_flag_pairs[i].flag_char1) == 0)
1885 continue;
1886 if (strchr (flag_chars, bad_flag_pairs[i].flag_char2) == 0)
1887 continue;
1888 if (bad_flag_pairs[i].predicate != 0
1889 && strchr (fci->flags2, bad_flag_pairs[i].predicate) == 0)
1890 continue;
1891 s = get_flag_spec (flag_specs, bad_flag_pairs[i].flag_char1, NULL);
1892 t = get_flag_spec (flag_specs, bad_flag_pairs[i].flag_char2, NULL);
1893 if (bad_flag_pairs[i].ignored)
1894 {
1895 if (bad_flag_pairs[i].predicate != 0)
1896 warning (OPT_Wformat,
1897 "%s ignored with %s and %<%%%c%> %s format",
1898 _(s->name), _(t->name), format_char,
1899 fki->name);
1900 else
1901 warning (OPT_Wformat, "%s ignored with %s in %s format",
1902 _(s->name), _(t->name), fki->name);
1903 }
1904 else
1905 {
1906 if (bad_flag_pairs[i].predicate != 0)
1907 warning (OPT_Wformat,
1908 "use of %s and %s together with %<%%%c%> %s format",
1909 _(s->name), _(t->name), format_char,
1910 fki->name);
1911 else
1912 warning (OPT_Wformat, "use of %s and %s together in %s format",
1913 _(s->name), _(t->name), fki->name);
1914 }
1915 }
1916
1917 /* Give Y2K warnings. */
1918 if (warn_format_y2k)
1919 {
1920 int y2k_level = 0;
1921 if (strchr (fci->flags2, '4') != 0)
1922 if (strchr (flag_chars, 'E') != 0)
1923 y2k_level = 3;
1924 else
1925 y2k_level = 2;
1926 else if (strchr (fci->flags2, '3') != 0)
1927 y2k_level = 3;
1928 else if (strchr (fci->flags2, '2') != 0)
1929 y2k_level = 2;
1930 if (y2k_level == 3)
1931 warning (OPT_Wformat_y2k, "%<%%%c%> yields only last 2 digits of "
1932 "year in some locales", format_char);
1933 else if (y2k_level == 2)
1934 warning (OPT_Wformat_y2k, "%<%%%c%> yields only last 2 digits of "
1935 "year", format_char);
1936 }
1937
1938 if (strchr (fci->flags2, '[') != 0)
1939 {
1940 /* Skip over scan set, in case it happens to have '%' in it. */
1941 if (*format_chars == '^')
1942 ++format_chars;
1943 /* Find closing bracket; if one is hit immediately, then
1944 it's part of the scan set rather than a terminator. */
1945 if (*format_chars == ']')
1946 ++format_chars;
1947 while (*format_chars && *format_chars != ']')
1948 ++format_chars;
1949 if (*format_chars != ']')
1950 /* The end of the format string was reached. */
1951 warning (OPT_Wformat, "no closing %<]%> for %<%%[%> format");
1952 }
1953
1954 wanted_type = 0;
1955 wanted_type_name = 0;
1956 if (fki->flags & (int) FMT_FLAG_ARG_CONVERT)
1957 {
1958 wanted_type = (fci->types[length_chars_val].type
1959 ? *fci->types[length_chars_val].type : 0);
1960 wanted_type_name = fci->types[length_chars_val].name;
1961 wanted_type_std = fci->types[length_chars_val].std;
1962 if (wanted_type == 0)
1963 {
1964 warning (OPT_Wformat,
1965 "use of %qs length modifier with %qc type character",
1966 length_chars, format_char);
1967 /* Heuristic: skip one argument when an invalid length/type
1968 combination is encountered. */
1969 arg_num++;
1970 if (params == 0)
1971 {
1972 warning (OPT_Wformat, "too few arguments for format");
1973 return;
1974 }
1975 params = TREE_CHAIN (params);
1976 continue;
1977 }
1978 else if (pedantic
1979 /* Warn if non-standard, provided it is more non-standard
1980 than the length and type characters that may already
1981 have been warned for. */
1982 && ADJ_STD (wanted_type_std) > ADJ_STD (length_chars_std)
1983 && ADJ_STD (wanted_type_std) > ADJ_STD (fci->std))
1984 {
1985 if (ADJ_STD (wanted_type_std) > C_STD_VER)
1986 warning (OPT_Wformat,
1987 "%s does not support the %<%%%s%c%> %s format",
1988 C_STD_NAME (wanted_type_std), length_chars,
1989 format_char, fki->name);
1990 }
1991 }
1992
1993 main_wanted_type.next = NULL;
1994
1995 /* Finally. . .check type of argument against desired type! */
1996 if (info->first_arg_num == 0)
1997 continue;
1998 if ((fci->pointer_count == 0 && wanted_type == void_type_node)
1999 || suppressed)
2000 {
2001 if (main_arg_num != 0)
2002 {
2003 if (suppressed)
2004 warning (OPT_Wformat, "operand number specified with "
2005 "suppressed assignment");
2006 else
2007 warning (OPT_Wformat, "operand number specified for format "
2008 "taking no argument");
2009 }
2010 }
2011 else
2012 {
2013 format_wanted_type *wanted_type_ptr;
2014
2015 if (main_arg_num != 0)
2016 {
2017 arg_num = main_arg_num;
2018 params = main_arg_params;
2019 }
2020 else
2021 {
2022 ++arg_num;
2023 if (has_operand_number > 0)
2024 {
2025 warning (OPT_Wformat, "missing $ operand number in format");
2026 return;
2027 }
2028 else
2029 has_operand_number = 0;
2030 }
2031
2032 wanted_type_ptr = &main_wanted_type;
2033 while (fci)
2034 {
2035 if (params == 0)
2036 {
2037 warning (OPT_Wformat, "too few arguments for format");
2038 return;
2039 }
2040
2041 cur_param = TREE_VALUE (params);
2042 params = TREE_CHAIN (params);
2043
2044 wanted_type_ptr->wanted_type = wanted_type;
2045 wanted_type_ptr->wanted_type_name = wanted_type_name;
2046 wanted_type_ptr->pointer_count = fci->pointer_count + aflag;
2047 wanted_type_ptr->char_lenient_flag = 0;
2048 if (strchr (fci->flags2, 'c') != 0)
2049 wanted_type_ptr->char_lenient_flag = 1;
2050 wanted_type_ptr->writing_in_flag = 0;
2051 wanted_type_ptr->reading_from_flag = 0;
2052 if (aflag)
2053 wanted_type_ptr->writing_in_flag = 1;
2054 else
2055 {
2056 if (strchr (fci->flags2, 'W') != 0)
2057 wanted_type_ptr->writing_in_flag = 1;
2058 if (strchr (fci->flags2, 'R') != 0)
2059 wanted_type_ptr->reading_from_flag = 1;
2060 }
2061 wanted_type_ptr->name = NULL;
2062 wanted_type_ptr->param = cur_param;
2063 wanted_type_ptr->arg_num = arg_num;
2064 wanted_type_ptr->next = NULL;
2065 if (last_wanted_type != 0)
2066 last_wanted_type->next = wanted_type_ptr;
2067 if (first_wanted_type == 0)
2068 first_wanted_type = wanted_type_ptr;
2069 last_wanted_type = wanted_type_ptr;
2070
2071 fci = fci->chain;
2072 if (fci)
2073 {
2074 wanted_type_ptr = ggc_alloc (sizeof (main_wanted_type));
2075 arg_num++;
2076 wanted_type = *fci->types[length_chars_val].type;
2077 wanted_type_name = fci->types[length_chars_val].name;
2078 }
2079 }
2080 }
2081
2082 if (first_wanted_type != 0)
2083 check_format_types (first_wanted_type, format_start,
2084 format_chars - format_start);
2085
2086 if (main_wanted_type.next != NULL)
2087 {
2088 format_wanted_type *wanted_type_ptr = main_wanted_type.next;
2089 while (wanted_type_ptr)
2090 {
2091 format_wanted_type *next = wanted_type_ptr->next;
2092 ggc_free (wanted_type_ptr);
2093 wanted_type_ptr = next;
2094 }
2095 }
2096 }
2097 }
2098
2099
2100 /* Check the argument types from a single format conversion (possibly
2101 including width and precision arguments). */
2102 static void
2103 check_format_types (format_wanted_type *types, const char *format_start,
2104 int format_length)
2105 {
2106 for (; types != 0; types = types->next)
2107 {
2108 tree cur_param;
2109 tree cur_type;
2110 tree orig_cur_type;
2111 tree wanted_type;
2112 int arg_num;
2113 int i;
2114 int char_type_flag;
2115 cur_param = types->param;
2116 cur_type = TREE_TYPE (cur_param);
2117 if (cur_type == error_mark_node)
2118 continue;
2119 orig_cur_type = cur_type;
2120 char_type_flag = 0;
2121 wanted_type = types->wanted_type;
2122 arg_num = types->arg_num;
2123
2124 /* The following should not occur here. */
2125 gcc_assert (wanted_type);
2126 gcc_assert (wanted_type != void_type_node || types->pointer_count);
2127
2128 if (types->pointer_count == 0)
2129 wanted_type = lang_hooks.types.type_promotes_to (wanted_type);
2130
2131 wanted_type = TYPE_MAIN_VARIANT (wanted_type);
2132
2133 STRIP_NOPS (cur_param);
2134
2135 /* Check the types of any additional pointer arguments
2136 that precede the "real" argument. */
2137 for (i = 0; i < types->pointer_count; ++i)
2138 {
2139 if (TREE_CODE (cur_type) == POINTER_TYPE)
2140 {
2141 cur_type = TREE_TYPE (cur_type);
2142 if (cur_type == error_mark_node)
2143 break;
2144
2145 /* Check for writing through a NULL pointer. */
2146 if (types->writing_in_flag
2147 && i == 0
2148 && cur_param != 0
2149 && integer_zerop (cur_param))
2150 warning (OPT_Wformat, "writing through null pointer "
2151 "(argument %d)", arg_num);
2152
2153 /* Check for reading through a NULL pointer. */
2154 if (types->reading_from_flag
2155 && i == 0
2156 && cur_param != 0
2157 && integer_zerop (cur_param))
2158 warning (OPT_Wformat, "reading through null pointer "
2159 "(argument %d)", arg_num);
2160
2161 if (cur_param != 0 && TREE_CODE (cur_param) == ADDR_EXPR)
2162 cur_param = TREE_OPERAND (cur_param, 0);
2163 else
2164 cur_param = 0;
2165
2166 /* See if this is an attempt to write into a const type with
2167 scanf or with printf "%n". Note: the writing in happens
2168 at the first indirection only, if for example
2169 void * const * is passed to scanf %p; passing
2170 const void ** is simply passing an incompatible type. */
2171 if (types->writing_in_flag
2172 && i == 0
2173 && (TYPE_READONLY (cur_type)
2174 || (cur_param != 0
2175 && (CONSTANT_CLASS_P (cur_param)
2176 || (DECL_P (cur_param)
2177 && TREE_READONLY (cur_param))))))
2178 warning (OPT_Wformat, "writing into constant object "
2179 "(argument %d)", arg_num);
2180
2181 /* If there are extra type qualifiers beyond the first
2182 indirection, then this makes the types technically
2183 incompatible. */
2184 if (i > 0
2185 && pedantic
2186 && (TYPE_READONLY (cur_type)
2187 || TYPE_VOLATILE (cur_type)
2188 || TYPE_RESTRICT (cur_type)))
2189 warning (OPT_Wformat, "extra type qualifiers in format "
2190 "argument (argument %d)",
2191 arg_num);
2192
2193 }
2194 else
2195 {
2196 format_type_warning (types->name, format_start, format_length,
2197 wanted_type, types->pointer_count,
2198 types->wanted_type_name, orig_cur_type,
2199 arg_num);
2200 break;
2201 }
2202 }
2203
2204 if (i < types->pointer_count)
2205 continue;
2206
2207 cur_type = TYPE_MAIN_VARIANT (cur_type);
2208
2209 /* Check whether the argument type is a character type. This leniency
2210 only applies to certain formats, flagged with 'c'.
2211 */
2212 if (types->char_lenient_flag)
2213 char_type_flag = (cur_type == char_type_node
2214 || cur_type == signed_char_type_node
2215 || cur_type == unsigned_char_type_node);
2216
2217 /* Check the type of the "real" argument, if there's a type we want. */
2218 if (wanted_type == cur_type)
2219 continue;
2220 /* If we want 'void *', allow any pointer type.
2221 (Anything else would already have got a warning.)
2222 With -pedantic, only allow pointers to void and to character
2223 types. */
2224 if (wanted_type == void_type_node
2225 && (!pedantic || (i == 1 && char_type_flag)))
2226 continue;
2227 /* Don't warn about differences merely in signedness, unless
2228 -pedantic. With -pedantic, warn if the type is a pointer
2229 target and not a character type, and for character types at
2230 a second level of indirection. */
2231 if (TREE_CODE (wanted_type) == INTEGER_TYPE
2232 && TREE_CODE (cur_type) == INTEGER_TYPE
2233 && (!pedantic || i == 0 || (i == 1 && char_type_flag))
2234 && (TYPE_UNSIGNED (wanted_type)
2235 ? wanted_type == c_common_unsigned_type (cur_type)
2236 : wanted_type == c_common_signed_type (cur_type)))
2237 continue;
2238 /* Likewise, "signed char", "unsigned char" and "char" are
2239 equivalent but the above test won't consider them equivalent. */
2240 if (wanted_type == char_type_node
2241 && (!pedantic || i < 2)
2242 && char_type_flag)
2243 continue;
2244 /* Now we have a type mismatch. */
2245 format_type_warning (types->name, format_start, format_length,
2246 wanted_type, types->pointer_count,
2247 types->wanted_type_name, orig_cur_type, arg_num);
2248 }
2249 }
2250
2251
2252 /* Give a warning about a format argument of different type from that
2253 expected. DESCR is a description such as "field precision", or
2254 NULL for an ordinary format. For an ordinary format, FORMAT_START
2255 points to where the format starts in the format string and
2256 FORMAT_LENGTH is its length. WANTED_TYPE is the type the argument
2257 should have after POINTER_COUNT pointer dereferences.
2258 WANTED_NAME_NAME is a possibly more friendly name of WANTED_TYPE,
2259 or NULL if the ordinary name of the type should be used. ARG_TYPE
2260 is the type of the actual argument. ARG_NUM is the number of that
2261 argument. */
2262 static void
2263 format_type_warning (const char *descr, const char *format_start,
2264 int format_length, tree wanted_type, int pointer_count,
2265 const char *wanted_type_name, tree arg_type, int arg_num)
2266 {
2267 char *p;
2268 /* If ARG_TYPE is a typedef with a misleading name (for example,
2269 size_t but not the standard size_t expected by printf %zu), avoid
2270 printing the typedef name. */
2271 if (wanted_type_name
2272 && TYPE_NAME (arg_type)
2273 && TREE_CODE (TYPE_NAME (arg_type)) == TYPE_DECL
2274 && DECL_NAME (TYPE_NAME (arg_type))
2275 && !strcmp (wanted_type_name,
2276 lang_hooks.decl_printable_name (TYPE_NAME (arg_type), 2)))
2277 arg_type = TYPE_MAIN_VARIANT (arg_type);
2278 /* The format type and name exclude any '*' for pointers, so those
2279 must be formatted manually. For all the types we currently have,
2280 this is adequate, but formats taking pointers to functions or
2281 arrays would require the full type to be built up in order to
2282 print it with %T. */
2283 p = alloca (pointer_count + 2);
2284 if (pointer_count == 0)
2285 p[0] = 0;
2286 else if (c_dialect_cxx ())
2287 {
2288 memset (p, '*', pointer_count);
2289 p[pointer_count] = 0;
2290 }
2291 else
2292 {
2293 p[0] = ' ';
2294 memset (p + 1, '*', pointer_count);
2295 p[pointer_count + 1] = 0;
2296 }
2297 if (wanted_type_name)
2298 {
2299 if (descr)
2300 warning (OPT_Wformat, "%s should have type %<%s%s%>, "
2301 "but argument %d has type %qT",
2302 descr, wanted_type_name, p, arg_num, arg_type);
2303 else
2304 warning (OPT_Wformat, "format %q.*s expects type %<%s%s%>, "
2305 "but argument %d has type %qT",
2306 format_length, format_start, wanted_type_name, p,
2307 arg_num, arg_type);
2308 }
2309 else
2310 {
2311 if (descr)
2312 warning (OPT_Wformat, "%s should have type %<%T%s%>, "
2313 "but argument %d has type %qT",
2314 descr, wanted_type, p, arg_num, arg_type);
2315 else
2316 warning (OPT_Wformat, "format %q.*s expects type %<%T%s%>, "
2317 "but argument %d has type %qT",
2318 format_length, format_start, wanted_type, p, arg_num, arg_type);
2319 }
2320 }
2321
2322
2323 /* Given a format_char_info array FCI, and a character C, this function
2324 returns the index into the conversion_specs where that specifier's
2325 data is located. The character must exist. */
2326 static unsigned int
2327 find_char_info_specifier_index (const format_char_info *fci, int c)
2328 {
2329 unsigned i;
2330
2331 for (i = 0; fci->format_chars; i++, fci++)
2332 if (strchr (fci->format_chars, c))
2333 return i;
2334
2335 /* We shouldn't be looking for a non-existent specifier. */
2336 gcc_unreachable ();
2337 }
2338
2339 /* Given a format_length_info array FLI, and a character C, this
2340 function returns the index into the conversion_specs where that
2341 modifier's data is located. The character must exist. */
2342 static unsigned int
2343 find_length_info_modifier_index (const format_length_info *fli, int c)
2344 {
2345 unsigned i;
2346
2347 for (i = 0; fli->name; i++, fli++)
2348 if (strchr (fli->name, c))
2349 return i;
2350
2351 /* We shouldn't be looking for a non-existent modifier. */
2352 gcc_unreachable ();
2353 }
2354
2355 /* Determine the type of HOST_WIDE_INT in the code being compiled for
2356 use in GCC's __asm_fprintf__ custom format attribute. You must
2357 have set dynamic_format_types before calling this function. */
2358 static void
2359 init_dynamic_asm_fprintf_info (void)
2360 {
2361 static tree hwi;
2362
2363 if (!hwi)
2364 {
2365 format_length_info *new_asm_fprintf_length_specs;
2366 unsigned int i;
2367
2368 /* Find the underlying type for HOST_WIDE_INT. For the %w
2369 length modifier to work, one must have issued: "typedef
2370 HOST_WIDE_INT __gcc_host_wide_int__;" in one's source code
2371 prior to using that modifier. */
2372 hwi = maybe_get_identifier ("__gcc_host_wide_int__");
2373 if (!hwi)
2374 {
2375 error ("%<__gcc_host_wide_int__%> is not defined as a type");
2376 return;
2377 }
2378 hwi = identifier_global_value (hwi);
2379 if (!hwi || TREE_CODE (hwi) != TYPE_DECL)
2380 {
2381 error ("%<__gcc_host_wide_int__%> is not defined as a type");
2382 return;
2383 }
2384 hwi = DECL_ORIGINAL_TYPE (hwi);
2385 gcc_assert (hwi);
2386 if (hwi != long_integer_type_node && hwi != long_long_integer_type_node)
2387 {
2388 error ("%<__gcc_host_wide_int__%> is not defined as %<long%>"
2389 " or %<long long%>");
2390 return;
2391 }
2392
2393 /* Create a new (writable) copy of asm_fprintf_length_specs. */
2394 new_asm_fprintf_length_specs = (format_length_info *)
2395 xmemdup (asm_fprintf_length_specs,
2396 sizeof (asm_fprintf_length_specs),
2397 sizeof (asm_fprintf_length_specs));
2398
2399 /* HOST_WIDE_INT must be one of 'long' or 'long long'. */
2400 i = find_length_info_modifier_index (new_asm_fprintf_length_specs, 'w');
2401 if (hwi == long_integer_type_node)
2402 new_asm_fprintf_length_specs[i].index = FMT_LEN_l;
2403 else if (hwi == long_long_integer_type_node)
2404 new_asm_fprintf_length_specs[i].index = FMT_LEN_ll;
2405 else
2406 gcc_unreachable ();
2407
2408 /* Assign the new data for use. */
2409 dynamic_format_types[asm_fprintf_format_type].length_char_specs =
2410 new_asm_fprintf_length_specs;
2411 }
2412 }
2413
2414 /* Determine the type of a "locus" in the code being compiled for use
2415 in GCC's __gcc_gfc__ custom format attribute. You must have set
2416 dynamic_format_types before calling this function. */
2417 static void
2418 init_dynamic_gfc_info (void)
2419 {
2420 static tree locus;
2421
2422 if (!locus)
2423 {
2424 static format_char_info *gfc_fci;
2425
2426 /* For the GCC __gcc_gfc__ custom format specifier to work, one
2427 must have declared 'locus' prior to using this attribute. If
2428 we haven't seen this declarations then you shouldn't use the
2429 specifier requiring that type. */
2430 if ((locus = maybe_get_identifier ("locus")))
2431 {
2432 locus = identifier_global_value (locus);
2433 if (locus)
2434 {
2435 if (TREE_CODE (locus) != TYPE_DECL)
2436 {
2437 error ("%<locus%> is not defined as a type");
2438 locus = 0;
2439 }
2440 else
2441 locus = TREE_TYPE (locus);
2442 }
2443 }
2444
2445 /* Assign the new data for use. */
2446
2447 /* Handle the __gcc_gfc__ format specifics. */
2448 if (!gfc_fci)
2449 dynamic_format_types[gcc_gfc_format_type].conversion_specs =
2450 gfc_fci = (format_char_info *)
2451 xmemdup (gcc_gfc_char_table,
2452 sizeof (gcc_gfc_char_table),
2453 sizeof (gcc_gfc_char_table));
2454 if (locus)
2455 {
2456 const unsigned i = find_char_info_specifier_index (gfc_fci, 'L');
2457 gfc_fci[i].types[0].type = &locus;
2458 gfc_fci[i].pointer_count = 1;
2459 }
2460 }
2461 }
2462
2463 /* Determine the types of "tree" and "location_t" in the code being
2464 compiled for use in GCC's diagnostic custom format attributes. You
2465 must have set dynamic_format_types before calling this function. */
2466 static void
2467 init_dynamic_diag_info (void)
2468 {
2469 static tree t, loc, hwi;
2470
2471 if (!loc || !t || !hwi)
2472 {
2473 static format_char_info *diag_fci, *tdiag_fci, *cdiag_fci, *cxxdiag_fci;
2474 static format_length_info *diag_ls;
2475 unsigned int i;
2476
2477 /* For the GCC-diagnostics custom format specifiers to work, one
2478 must have declared 'tree' and/or 'location_t' prior to using
2479 those attributes. If we haven't seen these declarations then
2480 you shouldn't use the specifiers requiring these types.
2481 However we don't force a hard ICE because we may see only one
2482 or the other type. */
2483 if ((loc = maybe_get_identifier ("location_t")))
2484 {
2485 loc = identifier_global_value (loc);
2486 if (loc)
2487 {
2488 if (TREE_CODE (loc) != TYPE_DECL)
2489 {
2490 error ("%<location_t%> is not defined as a type");
2491 loc = 0;
2492 }
2493 else
2494 loc = TREE_TYPE (loc);
2495 }
2496 }
2497
2498 /* We need to grab the underlying 'union tree_node' so peek into
2499 an extra type level. */
2500 if ((t = maybe_get_identifier ("tree")))
2501 {
2502 t = identifier_global_value (t);
2503 if (t)
2504 {
2505 if (TREE_CODE (t) != TYPE_DECL)
2506 {
2507 error ("%<tree%> is not defined as a type");
2508 t = 0;
2509 }
2510 else if (TREE_CODE (TREE_TYPE (t)) != POINTER_TYPE)
2511 {
2512 error ("%<tree%> is not defined as a pointer type");
2513 t = 0;
2514 }
2515 else
2516 t = TREE_TYPE (TREE_TYPE (t));
2517 }
2518 }
2519
2520 /* Find the underlying type for HOST_WIDE_INT. For the %w
2521 length modifier to work, one must have issued: "typedef
2522 HOST_WIDE_INT __gcc_host_wide_int__;" in one's source code
2523 prior to using that modifier. */
2524 if ((hwi = maybe_get_identifier ("__gcc_host_wide_int__")))
2525 {
2526 hwi = identifier_global_value (hwi);
2527 if (hwi)
2528 {
2529 if (TREE_CODE (hwi) != TYPE_DECL)
2530 {
2531 error ("%<__gcc_host_wide_int__%> is not defined as a type");
2532 hwi = 0;
2533 }
2534 else
2535 {
2536 hwi = DECL_ORIGINAL_TYPE (hwi);
2537 gcc_assert (hwi);
2538 if (hwi != long_integer_type_node
2539 && hwi != long_long_integer_type_node)
2540 {
2541 error ("%<__gcc_host_wide_int__%> is not defined"
2542 " as %<long%> or %<long long%>");
2543 hwi = 0;
2544 }
2545 }
2546 }
2547 }
2548
2549 /* Assign the new data for use. */
2550
2551 /* All the GCC diag formats use the same length specs. */
2552 if (!diag_ls)
2553 dynamic_format_types[gcc_diag_format_type].length_char_specs =
2554 dynamic_format_types[gcc_tdiag_format_type].length_char_specs =
2555 dynamic_format_types[gcc_cdiag_format_type].length_char_specs =
2556 dynamic_format_types[gcc_cxxdiag_format_type].length_char_specs =
2557 diag_ls = (format_length_info *)
2558 xmemdup (gcc_diag_length_specs,
2559 sizeof (gcc_diag_length_specs),
2560 sizeof (gcc_diag_length_specs));
2561 if (hwi)
2562 {
2563 /* HOST_WIDE_INT must be one of 'long' or 'long long'. */
2564 i = find_length_info_modifier_index (diag_ls, 'w');
2565 if (hwi == long_integer_type_node)
2566 diag_ls[i].index = FMT_LEN_l;
2567 else if (hwi == long_long_integer_type_node)
2568 diag_ls[i].index = FMT_LEN_ll;
2569 else
2570 gcc_unreachable ();
2571 }
2572
2573 /* Handle the __gcc_diag__ format specifics. */
2574 if (!diag_fci)
2575 dynamic_format_types[gcc_diag_format_type].conversion_specs =
2576 diag_fci = (format_char_info *)
2577 xmemdup (gcc_diag_char_table,
2578 sizeof (gcc_diag_char_table),
2579 sizeof (gcc_diag_char_table));
2580 if (loc)
2581 {
2582 i = find_char_info_specifier_index (diag_fci, 'H');
2583 diag_fci[i].types[0].type = &loc;
2584 diag_fci[i].pointer_count = 1;
2585 }
2586 if (t)
2587 {
2588 i = find_char_info_specifier_index (diag_fci, 'J');
2589 diag_fci[i].types[0].type = &t;
2590 diag_fci[i].pointer_count = 1;
2591 }
2592
2593 /* Handle the __gcc_tdiag__ format specifics. */
2594 if (!tdiag_fci)
2595 dynamic_format_types[gcc_tdiag_format_type].conversion_specs =
2596 tdiag_fci = (format_char_info *)
2597 xmemdup (gcc_tdiag_char_table,
2598 sizeof (gcc_tdiag_char_table),
2599 sizeof (gcc_tdiag_char_table));
2600 if (loc)
2601 {
2602 i = find_char_info_specifier_index (tdiag_fci, 'H');
2603 tdiag_fci[i].types[0].type = &loc;
2604 tdiag_fci[i].pointer_count = 1;
2605 }
2606 if (t)
2607 {
2608 /* All specifiers taking a tree share the same struct. */
2609 i = find_char_info_specifier_index (tdiag_fci, 'D');
2610 tdiag_fci[i].types[0].type = &t;
2611 tdiag_fci[i].pointer_count = 1;
2612 i = find_char_info_specifier_index (tdiag_fci, 'J');
2613 tdiag_fci[i].types[0].type = &t;
2614 tdiag_fci[i].pointer_count = 1;
2615 }
2616
2617 /* Handle the __gcc_cdiag__ format specifics. */
2618 if (!cdiag_fci)
2619 dynamic_format_types[gcc_cdiag_format_type].conversion_specs =
2620 cdiag_fci = (format_char_info *)
2621 xmemdup (gcc_cdiag_char_table,
2622 sizeof (gcc_cdiag_char_table),
2623 sizeof (gcc_cdiag_char_table));
2624 if (loc)
2625 {
2626 i = find_char_info_specifier_index (cdiag_fci, 'H');
2627 cdiag_fci[i].types[0].type = &loc;
2628 cdiag_fci[i].pointer_count = 1;
2629 }
2630 if (t)
2631 {
2632 /* All specifiers taking a tree share the same struct. */
2633 i = find_char_info_specifier_index (cdiag_fci, 'D');
2634 cdiag_fci[i].types[0].type = &t;
2635 cdiag_fci[i].pointer_count = 1;
2636 i = find_char_info_specifier_index (cdiag_fci, 'J');
2637 cdiag_fci[i].types[0].type = &t;
2638 cdiag_fci[i].pointer_count = 1;
2639 }
2640
2641 /* Handle the __gcc_cxxdiag__ format specifics. */
2642 if (!cxxdiag_fci)
2643 dynamic_format_types[gcc_cxxdiag_format_type].conversion_specs =
2644 cxxdiag_fci = (format_char_info *)
2645 xmemdup (gcc_cxxdiag_char_table,
2646 sizeof (gcc_cxxdiag_char_table),
2647 sizeof (gcc_cxxdiag_char_table));
2648 if (loc)
2649 {
2650 i = find_char_info_specifier_index (cxxdiag_fci, 'H');
2651 cxxdiag_fci[i].types[0].type = &loc;
2652 cxxdiag_fci[i].pointer_count = 1;
2653 }
2654 if (t)
2655 {
2656 /* All specifiers taking a tree share the same struct. */
2657 i = find_char_info_specifier_index (cxxdiag_fci, 'D');
2658 cxxdiag_fci[i].types[0].type = &t;
2659 cxxdiag_fci[i].pointer_count = 1;
2660 i = find_char_info_specifier_index (cxxdiag_fci, 'J');
2661 cxxdiag_fci[i].types[0].type = &t;
2662 cxxdiag_fci[i].pointer_count = 1;
2663 }
2664 }
2665 }
2666
2667 #ifdef TARGET_FORMAT_TYPES
2668 extern const format_kind_info TARGET_FORMAT_TYPES[];
2669 #endif
2670
2671 /* Handle a "format" attribute; arguments as in
2672 struct attribute_spec.handler. */
2673 tree
2674 handle_format_attribute (tree *node, tree ARG_UNUSED (name), tree args,
2675 int flags, bool *no_add_attrs)
2676 {
2677 tree type = *node;
2678 function_format_info info;
2679 tree argument;
2680
2681 #ifdef TARGET_FORMAT_TYPES
2682 /* If the target provides additional format types, we need to
2683 add them to FORMAT_TYPES at first use. */
2684 if (TARGET_FORMAT_TYPES != NULL && !dynamic_format_types)
2685 {
2686 dynamic_format_types = xmalloc ((n_format_types + TARGET_N_FORMAT_TYPES)
2687 * sizeof (dynamic_format_types[0]));
2688 memcpy (dynamic_format_types, format_types_orig,
2689 sizeof (format_types_orig));
2690 memcpy (&dynamic_format_types[n_format_types], TARGET_FORMAT_TYPES,
2691 TARGET_N_FORMAT_TYPES * sizeof (dynamic_format_types[0]));
2692
2693 format_types = dynamic_format_types;
2694 n_format_types += TARGET_N_FORMAT_TYPES;
2695 }
2696 #endif
2697
2698 if (!decode_format_attr (args, &info, 0))
2699 {
2700 *no_add_attrs = true;
2701 return NULL_TREE;
2702 }
2703
2704 argument = TYPE_ARG_TYPES (type);
2705 if (argument)
2706 {
2707 if (!check_format_string (argument, info.format_num, flags,
2708 no_add_attrs))
2709 return NULL_TREE;
2710
2711 if (info.first_arg_num != 0)
2712 {
2713 unsigned HOST_WIDE_INT arg_num = 1;
2714
2715 /* Verify that first_arg_num points to the last arg,
2716 the ... */
2717 while (argument)
2718 arg_num++, argument = TREE_CHAIN (argument);
2719
2720 if (arg_num != info.first_arg_num)
2721 {
2722 if (!(flags & (int) ATTR_FLAG_BUILT_IN))
2723 error ("args to be formatted is not %<...%>");
2724 *no_add_attrs = true;
2725 return NULL_TREE;
2726 }
2727 }
2728 }
2729
2730 if (info.format_type == strftime_format_type && info.first_arg_num != 0)
2731 {
2732 error ("strftime formats cannot format arguments");
2733 *no_add_attrs = true;
2734 return NULL_TREE;
2735 }
2736
2737 /* If this is a custom GCC-internal format type, we have to
2738 initialize certain bits a runtime. */
2739 if (info.format_type == asm_fprintf_format_type
2740 || info.format_type == gcc_gfc_format_type
2741 || info.format_type == gcc_diag_format_type
2742 || info.format_type == gcc_tdiag_format_type
2743 || info.format_type == gcc_cdiag_format_type
2744 || info.format_type == gcc_cxxdiag_format_type)
2745 {
2746 /* Our first time through, we have to make sure that our
2747 format_type data is allocated dynamically and is modifiable. */
2748 if (!dynamic_format_types)
2749 format_types = dynamic_format_types = (format_kind_info *)
2750 xmemdup (format_types_orig, sizeof (format_types_orig),
2751 sizeof (format_types_orig));
2752
2753 /* If this is format __asm_fprintf__, we have to initialize
2754 GCC's notion of HOST_WIDE_INT for checking %wd. */
2755 if (info.format_type == asm_fprintf_format_type)
2756 init_dynamic_asm_fprintf_info ();
2757 /* If this is format __gcc_gfc__, we have to initialize GCC's
2758 notion of 'locus' at runtime for %L. */
2759 else if (info.format_type == gcc_gfc_format_type)
2760 init_dynamic_gfc_info ();
2761 /* If this is one of the diagnostic attributes, then we have to
2762 initialize 'location_t' and 'tree' at runtime. */
2763 else if (info.format_type == gcc_diag_format_type
2764 || info.format_type == gcc_tdiag_format_type
2765 || info.format_type == gcc_cdiag_format_type
2766 || info.format_type == gcc_cxxdiag_format_type)
2767 init_dynamic_diag_info ();
2768 else
2769 gcc_unreachable ();
2770 }
2771
2772 return NULL_TREE;
2773 }