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.
5 This file is part of GCC.
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
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
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
24 #include "coretypes.h"
31 #include "diagnostic.h"
32 #include "langhooks.h"
35 /* Set format warning options according to a -Wformat=n option. */
38 set_Wformat (int setting)
40 warn_format = setting;
41 warn_format_extra_args = setting;
42 warn_format_zero_length = setting;
45 warn_format_nonliteral = setting;
46 warn_format_security = setting;
47 warn_format_y2k = setting;
49 /* Make sure not to disable -Wnonnull if -Wformat=0 is specified. */
51 warn_nonnull = setting;
55 /* Handle attributes associated with format checking. */
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_cdiag_format_type,
62 gcc_cxxdiag_format_type,
63 scanf_format_type, strftime_format_type,
64 strfmon_format_type, format_type_error = -1};
66 typedef struct function_format_info
68 int format_type; /* type of format (printf, scanf, etc.) */
69 unsigned HOST_WIDE_INT format_num; /* number of format argument */
70 unsigned HOST_WIDE_INT first_arg_num; /* number of first arg (zero for varargs) */
71 } function_format_info;
73 static bool decode_format_attr (tree, function_format_info *, int);
74 static int decode_format_type (const char *);
76 static bool check_format_string (tree argument,
77 unsigned HOST_WIDE_INT format_num,
78 int flags, bool *no_add_attrs);
79 static bool get_constant (tree expr, unsigned HOST_WIDE_INT *value,
83 /* Handle a "format_arg" attribute; arguments as in
84 struct attribute_spec.handler. */
86 handle_format_arg_attribute (tree *node, tree ARG_UNUSED (name),
87 tree args, int flags, bool *no_add_attrs)
90 tree format_num_expr = TREE_VALUE (args);
91 unsigned HOST_WIDE_INT format_num = 0;
94 if (!get_constant (format_num_expr, &format_num, 0))
96 error ("format string has invalid operand number");
101 argument = TYPE_ARG_TYPES (type);
104 if (!check_format_string (argument, format_num, flags, no_add_attrs))
108 if (TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
109 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
112 if (!(flags & (int) ATTR_FLAG_BUILT_IN))
113 error ("function does not return string type");
114 *no_add_attrs = true;
121 /* Verify that the format_num argument is actually a string, in case
122 the format attribute is in error. */
124 check_format_string (tree argument, unsigned HOST_WIDE_INT format_num,
125 int flags, bool *no_add_attrs)
127 unsigned HOST_WIDE_INT i;
129 for (i = 1; i != format_num; i++)
133 argument = TREE_CHAIN (argument);
137 || TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE
138 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (argument)))
141 if (!(flags & (int) ATTR_FLAG_BUILT_IN))
142 error ("format string argument not a string type");
143 *no_add_attrs = true;
150 /* Verify EXPR is a constant, and store its value.
151 If validated_p is true there should be no errors.
152 Returns true on success, false otherwise. */
154 get_constant (tree expr, unsigned HOST_WIDE_INT *value, int validated_p)
156 if (TREE_CODE (expr) != INTEGER_CST || TREE_INT_CST_HIGH (expr) != 0)
158 gcc_assert (!validated_p);
162 *value = TREE_INT_CST_LOW (expr);
167 /* Decode the arguments to a "format" attribute into a
168 function_format_info structure. It is already known that the list
169 is of the right length. If VALIDATED_P is true, then these
170 attributes have already been validated and must not be erroneous;
171 if false, it will give an error message. Returns true if the
172 attributes are successfully decoded, false otherwise. */
175 decode_format_attr (tree args, function_format_info *info, int validated_p)
177 tree format_type_id = TREE_VALUE (args);
178 tree format_num_expr = TREE_VALUE (TREE_CHAIN (args));
179 tree first_arg_num_expr
180 = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args)));
182 if (TREE_CODE (format_type_id) != IDENTIFIER_NODE)
184 gcc_assert (!validated_p);
185 error ("unrecognized format specifier");
190 const char *p = IDENTIFIER_POINTER (format_type_id);
192 info->format_type = decode_format_type (p);
194 if (info->format_type == format_type_error)
196 gcc_assert (!validated_p);
197 warning (OPT_Wformat, "%qE is an unrecognized format function type",
203 if (!get_constant (format_num_expr, &info->format_num, validated_p))
205 error ("format string has invalid operand number");
209 if (!get_constant (first_arg_num_expr, &info->first_arg_num, validated_p))
211 error ("%<...%> has invalid operand number");
215 if (info->first_arg_num != 0 && info->first_arg_num <= info->format_num)
217 gcc_assert (!validated_p);
218 error ("format string argument follows the args to be formatted");
225 /* Check a call to a format function against a parameter list. */
227 /* The C standard version C++ is treated as equivalent to
228 or inheriting from, for the purpose of format features supported. */
229 #define CPLUSPLUS_STD_VER STD_C94
230 /* The C standard version we are checking formats against when pedantic. */
231 #define C_STD_VER ((int) (c_dialect_cxx () \
232 ? CPLUSPLUS_STD_VER \
235 : (flag_isoc94 ? STD_C94 : STD_C89))))
236 /* The name to give to the standard version we are warning about when
237 pedantic. FEATURE_VER is the version in which the feature warned out
238 appeared, which is higher than C_STD_VER. */
239 #define C_STD_NAME(FEATURE_VER) (c_dialect_cxx () \
241 : ((FEATURE_VER) == STD_EXT \
244 /* Adjust a C standard version, which may be STD_C9L, to account for
245 -Wno-long-long. Returns other standard versions unchanged. */
246 #define ADJ_STD(VER) ((int) ((VER) == STD_C9L \
247 ? (warn_long_long ? STD_C99 : STD_C89) \
250 /* Structure describing details of a type expected in format checking,
251 and the type to check against it. */
252 typedef struct format_wanted_type
254 /* The type wanted. */
256 /* The name of this type to use in diagnostics. */
257 const char *wanted_type_name;
258 /* The level of indirection through pointers at which this type occurs. */
260 /* Whether, when pointer_count is 1, to allow any character type when
261 pedantic, rather than just the character or void type specified. */
262 int char_lenient_flag;
263 /* Whether the argument, dereferenced once, is written into and so the
264 argument must not be a pointer to a const-qualified type. */
266 /* Whether the argument, dereferenced once, is read from and so
267 must not be a NULL pointer. */
268 int reading_from_flag;
269 /* If warnings should be of the form "field precision should have
270 type 'int'", the name to use (in this case "field precision"),
271 otherwise NULL, for "format expects type 'long'" type
274 /* The actual parameter to check against the wanted type. */
276 /* The argument number of that parameter. */
278 /* The next type to check for this format conversion, or NULL if none. */
279 struct format_wanted_type *next;
280 } format_wanted_type;
283 static const format_length_info printf_length_specs[] =
285 { "h", FMT_LEN_h, STD_C89, "hh", FMT_LEN_hh, STD_C99 },
286 { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C9L },
287 { "q", FMT_LEN_ll, STD_EXT, NULL, 0, 0 },
288 { "L", FMT_LEN_L, STD_C89, NULL, 0, 0 },
289 { "z", FMT_LEN_z, STD_C99, NULL, 0, 0 },
290 { "Z", FMT_LEN_z, STD_EXT, NULL, 0, 0 },
291 { "t", FMT_LEN_t, STD_C99, NULL, 0, 0 },
292 { "j", FMT_LEN_j, STD_C99, NULL, 0, 0 },
293 { NULL, 0, 0, NULL, 0, 0 }
296 /* Length specifiers valid for asm_fprintf. */
297 static const format_length_info asm_fprintf_length_specs[] =
299 { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C89 },
300 { "w", FMT_LEN_none, STD_C89, NULL, 0, 0 },
301 { NULL, 0, 0, NULL, 0, 0 }
304 /* Length specifiers valid for GCC diagnostics. */
305 static const format_length_info gcc_diag_length_specs[] =
307 { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C89 },
308 { "w", FMT_LEN_none, STD_C89, NULL, 0, 0 },
309 { NULL, 0, 0, NULL, 0, 0 }
312 /* The custom diagnostics all accept the same length specifiers. */
313 #define gcc_cdiag_length_specs gcc_diag_length_specs
314 #define gcc_cxxdiag_length_specs gcc_diag_length_specs
316 /* This differs from printf_length_specs only in that "Z" is not accepted. */
317 static const format_length_info scanf_length_specs[] =
319 { "h", FMT_LEN_h, STD_C89, "hh", FMT_LEN_hh, STD_C99 },
320 { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C9L },
321 { "q", FMT_LEN_ll, STD_EXT, NULL, 0, 0 },
322 { "L", FMT_LEN_L, STD_C89, NULL, 0, 0 },
323 { "z", FMT_LEN_z, STD_C99, NULL, 0, 0 },
324 { "t", FMT_LEN_t, STD_C99, NULL, 0, 0 },
325 { "j", FMT_LEN_j, STD_C99, NULL, 0, 0 },
326 { NULL, 0, 0, NULL, 0, 0 }
330 /* All tables for strfmon use STD_C89 everywhere, since -pedantic warnings
331 make no sense for a format type not part of any C standard version. */
332 static const format_length_info strfmon_length_specs[] =
334 /* A GNU extension. */
335 { "L", FMT_LEN_L, STD_C89, NULL, 0, 0 },
336 { NULL, 0, 0, NULL, 0, 0 }
339 static const format_flag_spec printf_flag_specs[] =
341 { ' ', 0, 0, N_("' ' flag"), N_("the ' ' printf flag"), STD_C89 },
342 { '+', 0, 0, N_("'+' flag"), N_("the '+' printf flag"), STD_C89 },
343 { '#', 0, 0, N_("'#' flag"), N_("the '#' printf flag"), STD_C89 },
344 { '0', 0, 0, N_("'0' flag"), N_("the '0' printf flag"), STD_C89 },
345 { '-', 0, 0, N_("'-' flag"), N_("the '-' printf flag"), STD_C89 },
346 { '\'', 0, 0, N_("''' flag"), N_("the ''' printf flag"), STD_EXT },
347 { 'I', 0, 0, N_("'I' flag"), N_("the 'I' printf flag"), STD_EXT },
348 { 'w', 0, 0, N_("field width"), N_("field width in printf format"), STD_C89 },
349 { 'p', 0, 0, N_("precision"), N_("precision in printf format"), STD_C89 },
350 { 'L', 0, 0, N_("length modifier"), N_("length modifier in printf format"), STD_C89 },
351 { 0, 0, 0, NULL, NULL, 0 }
355 static const format_flag_pair printf_flag_pairs[] =
359 { '0', 'p', 1, 'i' },
363 static const format_flag_spec asm_fprintf_flag_specs[] =
365 { ' ', 0, 0, N_("' ' flag"), N_("the ' ' printf flag"), STD_C89 },
366 { '+', 0, 0, N_("'+' flag"), N_("the '+' printf flag"), STD_C89 },
367 { '#', 0, 0, N_("'#' flag"), N_("the '#' printf flag"), STD_C89 },
368 { '0', 0, 0, N_("'0' flag"), N_("the '0' printf flag"), STD_C89 },
369 { '-', 0, 0, N_("'-' flag"), N_("the '-' printf flag"), STD_C89 },
370 { 'w', 0, 0, N_("field width"), N_("field width in printf format"), STD_C89 },
371 { 'p', 0, 0, N_("precision"), N_("precision in printf format"), STD_C89 },
372 { 'L', 0, 0, N_("length modifier"), N_("length modifier in printf format"), STD_C89 },
373 { 0, 0, 0, NULL, NULL, 0 }
376 static const format_flag_pair asm_fprintf_flag_pairs[] =
380 { '0', 'p', 1, 'i' },
384 static const format_flag_pair gcc_diag_flag_pairs[] =
389 #define gcc_cdiag_flag_pairs gcc_diag_flag_pairs
390 #define gcc_cxxdiag_flag_pairs gcc_diag_flag_pairs
392 static const format_flag_spec gcc_diag_flag_specs[] =
394 { 'q', 0, 0, N_("'q' flag"), N_("the 'q' diagnostic flag"), STD_C89 },
395 { 'p', 0, 0, N_("precision"), N_("precision in printf format"), STD_C89 },
396 { 'L', 0, 0, N_("length modifier"), N_("length modifier in printf format"), STD_C89 },
397 { 0, 0, 0, NULL, NULL, 0 }
400 #define gcc_cdiag_flag_specs gcc_diag_flag_specs
402 static const format_flag_spec gcc_cxxdiag_flag_specs[] =
404 { '+', 0, 0, N_("'+' flag"), N_("the '+' printf flag"), STD_C89 },
405 { '#', 0, 0, N_("'#' flag"), N_("the '#' printf flag"), STD_C89 },
406 { 'q', 0, 0, N_("'q' flag"), N_("the 'q' diagnostic flag"), STD_C89 },
407 { 'p', 0, 0, N_("precision"), N_("precision in printf format"), STD_C89 },
408 { 'L', 0, 0, N_("length modifier"), N_("length modifier in printf format"), STD_C89 },
409 { 0, 0, 0, NULL, NULL, 0 }
412 static const format_flag_spec scanf_flag_specs[] =
414 { '*', 0, 0, N_("assignment suppression"), N_("the assignment suppression scanf feature"), STD_C89 },
415 { 'a', 0, 0, N_("'a' flag"), N_("the 'a' scanf flag"), STD_EXT },
416 { 'w', 0, 0, N_("field width"), N_("field width in scanf format"), STD_C89 },
417 { 'L', 0, 0, N_("length modifier"), N_("length modifier in scanf format"), STD_C89 },
418 { '\'', 0, 0, N_("''' flag"), N_("the ''' scanf flag"), STD_EXT },
419 { 'I', 0, 0, N_("'I' flag"), N_("the 'I' scanf flag"), STD_EXT },
420 { 0, 0, 0, NULL, NULL, 0 }
424 static const format_flag_pair scanf_flag_pairs[] =
431 static const format_flag_spec strftime_flag_specs[] =
433 { '_', 0, 0, N_("'_' flag"), N_("the '_' strftime flag"), STD_EXT },
434 { '-', 0, 0, N_("'-' flag"), N_("the '-' strftime flag"), STD_EXT },
435 { '0', 0, 0, N_("'0' flag"), N_("the '0' strftime flag"), STD_EXT },
436 { '^', 0, 0, N_("'^' flag"), N_("the '^' strftime flag"), STD_EXT },
437 { '#', 0, 0, N_("'#' flag"), N_("the '#' strftime flag"), STD_EXT },
438 { 'w', 0, 0, N_("field width"), N_("field width in strftime format"), STD_EXT },
439 { 'E', 0, 0, N_("'E' modifier"), N_("the 'E' strftime modifier"), STD_C99 },
440 { 'O', 0, 0, N_("'O' modifier"), N_("the 'O' strftime modifier"), STD_C99 },
441 { 'O', 'o', 0, NULL, N_("the 'O' modifier"), STD_EXT },
442 { 0, 0, 0, NULL, NULL, 0 }
446 static const format_flag_pair strftime_flag_pairs[] =
457 static const format_flag_spec strfmon_flag_specs[] =
459 { '=', 0, 1, N_("fill character"), N_("fill character in strfmon format"), STD_C89 },
460 { '^', 0, 0, N_("'^' flag"), N_("the '^' strfmon flag"), STD_C89 },
461 { '+', 0, 0, N_("'+' flag"), N_("the '+' strfmon flag"), STD_C89 },
462 { '(', 0, 0, N_("'(' flag"), N_("the '(' strfmon flag"), STD_C89 },
463 { '!', 0, 0, N_("'!' flag"), N_("the '!' strfmon flag"), STD_C89 },
464 { '-', 0, 0, N_("'-' flag"), N_("the '-' strfmon flag"), STD_C89 },
465 { 'w', 0, 0, N_("field width"), N_("field width in strfmon format"), STD_C89 },
466 { '#', 0, 0, N_("left precision"), N_("left precision in strfmon format"), STD_C89 },
467 { 'p', 0, 0, N_("right precision"), N_("right precision in strfmon format"), STD_C89 },
468 { 'L', 0, 0, N_("length modifier"), N_("length modifier in strfmon format"), STD_C89 },
469 { 0, 0, 0, NULL, NULL, 0 }
472 static const format_flag_pair strfmon_flag_pairs[] =
479 static const format_char_info print_char_table[] =
481 /* C89 conversion specifiers. */
482 { "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 },
483 { "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 },
484 { "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 },
485 { "fgG", 0, STD_C89, { T89_D, BADLEN, BADLEN, T99_D, BADLEN, T89_LD, BADLEN, BADLEN, BADLEN }, "-wp0 +#'I", "", NULL },
486 { "eE", 0, STD_C89, { T89_D, BADLEN, BADLEN, T99_D, BADLEN, T89_LD, BADLEN, BADLEN, BADLEN }, "-wp0 +#I", "", NULL },
487 { "c", 0, STD_C89, { T89_I, BADLEN, BADLEN, T94_WI, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-w", "", NULL },
488 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, T94_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp", "cR", NULL },
489 { "p", 1, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-w", "c", NULL },
490 { "n", 1, STD_C89, { T89_I, T99_SC, T89_S, T89_L, T9L_LL, BADLEN, T99_SST, T99_PD, T99_IM }, "", "W", NULL },
491 /* C99 conversion specifiers. */
492 { "F", 0, STD_C99, { T99_D, BADLEN, BADLEN, T99_D, BADLEN, T99_LD, BADLEN, BADLEN, BADLEN }, "-wp0 +#'I", "", NULL },
493 { "aA", 0, STD_C99, { T99_D, BADLEN, BADLEN, T99_D, BADLEN, T99_LD, BADLEN, BADLEN, BADLEN }, "-wp0 +#", "", NULL },
494 /* X/Open conversion specifiers. */
495 { "C", 0, STD_EXT, { TEX_WI, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-w", "", NULL },
496 { "S", 1, STD_EXT, { TEX_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp", "R", NULL },
497 /* GNU conversion specifiers. */
498 { "m", 0, STD_EXT, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp", "", NULL },
499 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
502 static const format_char_info asm_fprintf_char_table[] =
504 /* C89 conversion specifiers. */
505 { "di", 0, STD_C89, { T89_I, BADLEN, BADLEN, T89_L, T9L_LL, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp0 +", "i", NULL },
506 { "oxX", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp0#", "i", NULL },
507 { "u", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp0", "i", NULL },
508 { "c", 0, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-w", "", NULL },
509 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp", "cR", NULL },
511 /* asm_fprintf conversion specifiers. */
512 { "O", 0, STD_C89, NOARGUMENTS, "", "", NULL },
513 { "R", 0, STD_C89, NOARGUMENTS, "", "", NULL },
514 { "I", 0, STD_C89, NOARGUMENTS, "", "", NULL },
515 { "L", 0, STD_C89, NOARGUMENTS, "", "", NULL },
516 { "U", 0, STD_C89, NOARGUMENTS, "", "", NULL },
517 { "r", 0, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "", "", NULL },
518 { "@", 0, STD_C89, NOARGUMENTS, "", "", NULL },
519 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
522 static const format_char_info gcc_diag_char_table[] =
524 /* C89 conversion specifiers. */
525 { "di", 0, STD_C89, { T89_I, BADLEN, BADLEN, T89_L, T9L_LL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
526 { "ox", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
527 { "u", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
528 { "c", 0, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
529 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "pq", "cR", NULL },
530 { "p", 1, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "c", NULL },
532 /* Custom conversion specifiers. */
534 /* %H will require "location_t" at runtime. */
535 { "H", 0, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
537 /* These will require a "tree" at runtime. */
538 { "J", 0, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
540 { "<>'", 0, STD_C89, NOARGUMENTS, "", "", NULL },
541 { "m", 0, STD_C89, NOARGUMENTS, "q", "", NULL },
542 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
545 static const format_char_info gcc_cdiag_char_table[] =
547 /* C89 conversion specifiers. */
548 { "di", 0, STD_C89, { T89_I, BADLEN, BADLEN, T89_L, T9L_LL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
549 { "ox", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
550 { "u", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
551 { "c", 0, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
552 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "pq", "cR", NULL },
553 { "p", 1, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "c", NULL },
555 /* Custom conversion specifiers. */
557 /* %H will require "location_t" at runtime. */
558 { "H", 0, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
560 /* These will require a "tree" at runtime. */
561 { "DEFJT", 0, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
563 { "<>'", 0, STD_C89, NOARGUMENTS, "", "", NULL },
564 { "m", 0, STD_C89, NOARGUMENTS, "q", "", NULL },
565 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
568 static const format_char_info gcc_cxxdiag_char_table[] =
570 /* C89 conversion specifiers. */
571 { "di", 0, STD_C89, { T89_I, BADLEN, BADLEN, T89_L, T9L_LL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
572 { "ox", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
573 { "u", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
574 { "c", 0, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
575 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "pq", "cR", NULL },
576 { "p", 1, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "c", NULL },
578 /* Custom conversion specifiers. */
580 /* %H will require "location_t" at runtime. */
581 { "H", 0, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
583 /* These will require a "tree" at runtime. */
584 { "ADEFJTV",0,STD_C89,{ T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q+#", "", NULL },
586 /* These accept either an 'int' or an 'enum tree_code' (which is handled as an 'int'.) */
587 { "CLOPQ",0,STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "q", "", NULL },
589 { "<>'", 0, STD_C89, NOARGUMENTS, "", "", NULL },
590 { "m", 0, STD_C89, NOARGUMENTS, "q", "", NULL },
591 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
594 static const format_char_info scan_char_table[] =
596 /* C89 conversion specifiers. */
597 { "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 },
598 { "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 },
599 { "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 },
600 { "efgEG", 1, STD_C89, { T89_F, BADLEN, BADLEN, T89_D, BADLEN, T89_LD, BADLEN, BADLEN, BADLEN }, "*w'", "W", NULL },
601 { "c", 1, STD_C89, { T89_C, BADLEN, BADLEN, T94_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*w", "cW", NULL },
602 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, T94_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*aw", "cW", NULL },
603 { "[", 1, STD_C89, { T89_C, BADLEN, BADLEN, T94_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*aw", "cW[", NULL },
604 { "p", 2, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*w", "W", NULL },
605 { "n", 1, STD_C89, { T89_I, T99_SC, T89_S, T89_L, T9L_LL, BADLEN, T99_SST, T99_PD, T99_IM }, "", "W", NULL },
606 /* C99 conversion specifiers. */
607 { "FaA", 1, STD_C99, { T99_F, BADLEN, BADLEN, T99_D, BADLEN, T99_LD, BADLEN, BADLEN, BADLEN }, "*w'", "W", NULL },
608 /* X/Open conversion specifiers. */
609 { "C", 1, STD_EXT, { TEX_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*w", "W", NULL },
610 { "S", 1, STD_EXT, { TEX_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*aw", "W", NULL },
611 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
614 static const format_char_info time_char_table[] =
616 /* C89 conversion specifiers. */
617 { "ABZab", 0, STD_C89, NOLENGTHS, "^#", "", NULL },
618 { "cx", 0, STD_C89, NOLENGTHS, "E", "3", NULL },
619 { "HIMSUWdmw", 0, STD_C89, NOLENGTHS, "-_0Ow", "", NULL },
620 { "j", 0, STD_C89, NOLENGTHS, "-_0Ow", "o", NULL },
621 { "p", 0, STD_C89, NOLENGTHS, "#", "", NULL },
622 { "X", 0, STD_C89, NOLENGTHS, "E", "", NULL },
623 { "y", 0, STD_C89, NOLENGTHS, "EO-_0w", "4", NULL },
624 { "Y", 0, STD_C89, NOLENGTHS, "-_0EOw", "o", NULL },
625 { "%", 0, STD_C89, NOLENGTHS, "", "", NULL },
626 /* C99 conversion specifiers. */
627 { "C", 0, STD_C99, NOLENGTHS, "-_0EOw", "o", NULL },
628 { "D", 0, STD_C99, NOLENGTHS, "", "2", NULL },
629 { "eVu", 0, STD_C99, NOLENGTHS, "-_0Ow", "", NULL },
630 { "FRTnrt", 0, STD_C99, NOLENGTHS, "", "", NULL },
631 { "g", 0, STD_C99, NOLENGTHS, "O-_0w", "2o", NULL },
632 { "G", 0, STD_C99, NOLENGTHS, "-_0Ow", "o", NULL },
633 { "h", 0, STD_C99, NOLENGTHS, "^#", "", NULL },
634 { "z", 0, STD_C99, NOLENGTHS, "O", "o", NULL },
635 /* GNU conversion specifiers. */
636 { "kls", 0, STD_EXT, NOLENGTHS, "-_0Ow", "", NULL },
637 { "P", 0, STD_EXT, NOLENGTHS, "", "", NULL },
638 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
641 static const format_char_info monetary_char_table[] =
643 { "in", 0, STD_C89, { T89_D, BADLEN, BADLEN, BADLEN, BADLEN, T89_LD, BADLEN, BADLEN, BADLEN }, "=^+(!-w#p", "", NULL },
644 { NULL, 0, 0, NOLENGTHS, NULL, NULL, NULL }
647 /* This must be in the same order as enum format_type. */
648 static const format_kind_info format_types_orig[] =
650 { "printf", printf_length_specs, print_char_table, " +#0-'I", NULL,
651 printf_flag_specs, printf_flag_pairs,
652 FMT_FLAG_ARG_CONVERT|FMT_FLAG_DOLLAR_MULTIPLE|FMT_FLAG_USE_DOLLAR|FMT_FLAG_EMPTY_PREC_OK,
654 &integer_type_node, &integer_type_node
656 { "asm_fprintf", asm_fprintf_length_specs, asm_fprintf_char_table, " +#0-", NULL,
657 asm_fprintf_flag_specs, asm_fprintf_flag_pairs,
658 FMT_FLAG_ARG_CONVERT|FMT_FLAG_EMPTY_PREC_OK,
662 { "gcc_diag", gcc_diag_length_specs, gcc_diag_char_table, "q", NULL,
663 gcc_diag_flag_specs, gcc_diag_flag_pairs,
664 FMT_FLAG_ARG_CONVERT,
666 NULL, &integer_type_node
668 { "gcc_cdiag", gcc_cdiag_length_specs, gcc_cdiag_char_table, "q", NULL,
669 gcc_cdiag_flag_specs, gcc_cdiag_flag_pairs,
670 FMT_FLAG_ARG_CONVERT,
672 NULL, &integer_type_node
674 { "gcc_cxxdiag", gcc_cxxdiag_length_specs, gcc_cxxdiag_char_table, "q+#", NULL,
675 gcc_cxxdiag_flag_specs, gcc_cxxdiag_flag_pairs,
676 FMT_FLAG_ARG_CONVERT,
678 NULL, &integer_type_node
680 { "scanf", scanf_length_specs, scan_char_table, "*'I", NULL,
681 scanf_flag_specs, scanf_flag_pairs,
682 FMT_FLAG_ARG_CONVERT|FMT_FLAG_SCANF_A_KLUDGE|FMT_FLAG_USE_DOLLAR|FMT_FLAG_ZERO_WIDTH_BAD|FMT_FLAG_DOLLAR_GAP_POINTER_OK,
686 { "strftime", NULL, time_char_table, "_-0^#", "EO",
687 strftime_flag_specs, strftime_flag_pairs,
688 FMT_FLAG_FANCY_PERCENT_OK, 'w', 0, 0, 0, 0,
691 { "strfmon", strfmon_length_specs, monetary_char_table, "=^+(!-", NULL,
692 strfmon_flag_specs, strfmon_flag_pairs,
693 FMT_FLAG_ARG_CONVERT, 'w', '#', 'p', 0, 'L',
698 /* This layer of indirection allows GCC to reassign format_types with
699 new data if necessary, while still allowing the original data to be
701 static const format_kind_info *format_types = format_types_orig;
702 /* We can modify this one. We also add target-specific format types
703 to the end of the array. */
704 static format_kind_info *dynamic_format_types;
706 static int n_format_types = ARRAY_SIZE (format_types_orig);
708 /* Structure detailing the results of checking a format function call
709 where the format expression may be a conditional expression with
710 many leaves resulting from nested conditional expressions. */
713 /* Number of leaves of the format argument that could not be checked
714 as they were not string literals. */
715 int number_non_literal;
716 /* Number of leaves of the format argument that were null pointers or
717 string literals, but had extra format arguments. */
718 int number_extra_args;
719 /* Number of leaves of the format argument that were null pointers or
720 string literals, but had extra format arguments and used $ operand
722 int number_dollar_extra_args;
723 /* Number of leaves of the format argument that were wide string
726 /* Number of leaves of the format argument that were empty strings. */
728 /* Number of leaves of the format argument that were unterminated
730 int number_unterminated;
731 /* Number of leaves of the format argument that were not counted above. */
733 } format_check_results;
737 format_check_results *res;
738 function_format_info *info;
740 } format_check_context;
742 static void check_format_info (function_format_info *, tree);
743 static void check_format_arg (void *, tree, unsigned HOST_WIDE_INT);
744 static void check_format_info_main (format_check_results *,
745 function_format_info *,
746 const char *, int, tree,
747 unsigned HOST_WIDE_INT);
749 static void init_dollar_format_checking (int, tree);
750 static int maybe_read_dollar_number (const char **, int,
751 tree, tree *, const format_kind_info *);
752 static bool avoid_dollar_number (const char *);
753 static void finish_dollar_format_checking (format_check_results *, int);
755 static const format_flag_spec *get_flag_spec (const format_flag_spec *,
758 static void check_format_types (format_wanted_type *, const char *, int);
759 static void format_type_warning (const char *, const char *, int, tree,
760 int, const char *, tree, int);
762 /* Decode a format type from a string, returning the type, or
763 format_type_error if not valid, in which case the caller should print an
766 decode_format_type (const char *s)
771 for (i = 0; i < n_format_types; i++)
774 if (!strcmp (s, format_types[i].name))
776 alen = strlen (format_types[i].name);
777 if (slen == alen + 4 && s[0] == '_' && s[1] == '_'
778 && s[slen - 1] == '_' && s[slen - 2] == '_'
779 && !strncmp (s + 2, format_types[i].name, alen))
782 return format_type_error;
786 /* Check the argument list of a call to printf, scanf, etc.
787 ATTRS are the attributes on the function type.
788 PARAMS is the list of argument values. Also, if -Wmissing-format-attribute,
789 warn for calls to vprintf or vscanf in functions with no such format
790 attribute themselves. */
793 check_function_format (tree attrs, tree params)
797 /* See if this function has any format attributes. */
798 for (a = attrs; a; a = TREE_CHAIN (a))
800 if (is_attribute_p ("format", TREE_PURPOSE (a)))
803 function_format_info info;
804 decode_format_attr (TREE_VALUE (a), &info, 1);
805 check_format_info (&info, params);
806 if (warn_missing_format_attribute && info.first_arg_num == 0
807 && (format_types[info.format_type].flags
808 & (int) FMT_FLAG_ARG_CONVERT))
811 for (c = TYPE_ATTRIBUTES (TREE_TYPE (current_function_decl));
814 if (is_attribute_p ("format", TREE_PURPOSE (c))
815 && (decode_format_type (IDENTIFIER_POINTER
816 (TREE_VALUE (TREE_VALUE (c))))
817 == info.format_type))
821 /* Check if the current function has a parameter to which
822 the format attribute could be attached; if not, it
823 can't be a candidate for a format attribute, despite
824 the vprintf-like or vscanf-like call. */
826 for (args = DECL_ARGUMENTS (current_function_decl);
828 args = TREE_CHAIN (args))
830 if (TREE_CODE (TREE_TYPE (args)) == POINTER_TYPE
831 && (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (args)))
836 warning (OPT_Wattributes, "function might be possible "
837 "candidate for %qs format attribute",
838 format_types[info.format_type].name);
846 /* Variables used by the checking of $ operand number formats. */
847 static char *dollar_arguments_used = NULL;
848 static char *dollar_arguments_pointer_p = NULL;
849 static int dollar_arguments_alloc = 0;
850 static int dollar_arguments_count;
851 static int dollar_first_arg_num;
852 static int dollar_max_arg_used;
853 static int dollar_format_warned;
855 /* Initialize the checking for a format string that may contain $
856 parameter number specifications; we will need to keep track of whether
857 each parameter has been used. FIRST_ARG_NUM is the number of the first
858 argument that is a parameter to the format, or 0 for a vprintf-style
859 function; PARAMS is the list of arguments starting at this argument. */
862 init_dollar_format_checking (int first_arg_num, tree params)
864 tree oparams = params;
866 dollar_first_arg_num = first_arg_num;
867 dollar_arguments_count = 0;
868 dollar_max_arg_used = 0;
869 dollar_format_warned = 0;
870 if (first_arg_num > 0)
874 dollar_arguments_count++;
875 params = TREE_CHAIN (params);
878 if (dollar_arguments_alloc < dollar_arguments_count)
880 if (dollar_arguments_used)
881 free (dollar_arguments_used);
882 if (dollar_arguments_pointer_p)
883 free (dollar_arguments_pointer_p);
884 dollar_arguments_alloc = dollar_arguments_count;
885 dollar_arguments_used = XNEWVEC (char, dollar_arguments_alloc);
886 dollar_arguments_pointer_p = XNEWVEC (char, dollar_arguments_alloc);
888 if (dollar_arguments_alloc)
890 memset (dollar_arguments_used, 0, dollar_arguments_alloc);
891 if (first_arg_num > 0)
897 dollar_arguments_pointer_p[i] = (TREE_CODE (TREE_TYPE (TREE_VALUE (params)))
899 params = TREE_CHAIN (params);
907 /* Look for a decimal number followed by a $ in *FORMAT. If DOLLAR_NEEDED
908 is set, it is an error if one is not found; otherwise, it is OK. If
909 such a number is found, check whether it is within range and mark that
910 numbered operand as being used for later checking. Returns the operand
911 number if found and within range, zero if no such number was found and
912 this is OK, or -1 on error. PARAMS points to the first operand of the
913 format; PARAM_PTR is made to point to the parameter referred to. If
914 a $ format is found, *FORMAT is updated to point just after it. */
917 maybe_read_dollar_number (const char **format,
918 int dollar_needed, tree params, tree *param_ptr,
919 const format_kind_info *fki)
923 const char *fcp = *format;
928 warning (OPT_Wformat, "missing $ operand number in format");
936 while (ISDIGIT (*fcp))
939 nargnum = 10 * argnum + (*fcp - '0');
940 if (nargnum < 0 || nargnum / 10 != argnum)
949 warning (OPT_Wformat, "missing $ operand number in format");
956 if (pedantic && !dollar_format_warned)
958 warning (OPT_Wformat, "%s does not support %%n$ operand number formats",
959 C_STD_NAME (STD_EXT));
960 dollar_format_warned = 1;
962 if (overflow_flag || argnum == 0
963 || (dollar_first_arg_num && argnum > dollar_arguments_count))
965 warning (OPT_Wformat, "operand number out of range in format");
968 if (argnum > dollar_max_arg_used)
969 dollar_max_arg_used = argnum;
970 /* For vprintf-style functions we may need to allocate more memory to
971 track which arguments are used. */
972 while (dollar_arguments_alloc < dollar_max_arg_used)
975 nalloc = 2 * dollar_arguments_alloc + 16;
976 dollar_arguments_used = XRESIZEVEC (char, dollar_arguments_used,
978 dollar_arguments_pointer_p = XRESIZEVEC (char, dollar_arguments_pointer_p,
980 memset (dollar_arguments_used + dollar_arguments_alloc, 0,
981 nalloc - dollar_arguments_alloc);
982 dollar_arguments_alloc = nalloc;
984 if (!(fki->flags & (int) FMT_FLAG_DOLLAR_MULTIPLE)
985 && dollar_arguments_used[argnum - 1] == 1)
987 dollar_arguments_used[argnum - 1] = 2;
988 warning (OPT_Wformat, "format argument %d used more than once in %s format",
992 dollar_arguments_used[argnum - 1] = 1;
993 if (dollar_first_arg_num)
997 for (i = 1; i < argnum && *param_ptr != 0; i++)
998 *param_ptr = TREE_CHAIN (*param_ptr);
1000 /* This case shouldn't be caught here. */
1001 gcc_assert (*param_ptr);
1008 /* Ensure that FORMAT does not start with a decimal number followed by
1009 a $; give a diagnostic and return true if it does, false otherwise. */
1012 avoid_dollar_number (const char *format)
1014 if (!ISDIGIT (*format))
1016 while (ISDIGIT (*format))
1020 warning (OPT_Wformat, "$ operand number used after format without operand number");
1027 /* Finish the checking for a format string that used $ operand number formats
1028 instead of non-$ formats. We check for unused operands before used ones
1029 (a serious error, since the implementation of the format function
1030 can't know what types to pass to va_arg to find the later arguments).
1031 and for unused operands at the end of the format (if we know how many
1032 arguments the format had, so not for vprintf). If there were operand
1033 numbers out of range on a non-vprintf-style format, we won't have reached
1034 here. If POINTER_GAP_OK, unused arguments are OK if all arguments are
1038 finish_dollar_format_checking (format_check_results *res, int pointer_gap_ok)
1041 bool found_pointer_gap = false;
1042 for (i = 0; i < dollar_max_arg_used; i++)
1044 if (!dollar_arguments_used[i])
1046 if (pointer_gap_ok && (dollar_first_arg_num == 0
1047 || dollar_arguments_pointer_p[i]))
1048 found_pointer_gap = true;
1050 warning (OPT_Wformat,
1051 "format argument %d unused before used argument %d in $-style format",
1052 i + 1, dollar_max_arg_used);
1055 if (found_pointer_gap
1056 || (dollar_first_arg_num
1057 && dollar_max_arg_used < dollar_arguments_count))
1059 res->number_other--;
1060 res->number_dollar_extra_args++;
1065 /* Retrieve the specification for a format flag. SPEC contains the
1066 specifications for format flags for the applicable kind of format.
1067 FLAG is the flag in question. If PREDICATES is NULL, the basic
1068 spec for that flag must be retrieved and must exist. If
1069 PREDICATES is not NULL, it is a string listing possible predicates
1070 for the spec entry; if an entry predicated on any of these is
1071 found, it is returned, otherwise NULL is returned. */
1073 static const format_flag_spec *
1074 get_flag_spec (const format_flag_spec *spec, int flag, const char *predicates)
1077 for (i = 0; spec[i].flag_char != 0; i++)
1079 if (spec[i].flag_char != flag)
1081 if (predicates != NULL)
1083 if (spec[i].predicate != 0
1084 && strchr (predicates, spec[i].predicate) != 0)
1087 else if (spec[i].predicate == 0)
1090 gcc_assert (predicates);
1095 /* Check the argument list of a call to printf, scanf, etc.
1096 INFO points to the function_format_info structure.
1097 PARAMS is the list of argument values. */
1100 check_format_info (function_format_info *info, tree params)
1102 format_check_context format_ctx;
1103 unsigned HOST_WIDE_INT arg_num;
1105 format_check_results res;
1106 /* Skip to format argument. If the argument isn't available, there's
1107 no work for us to do; prototype checking will catch the problem. */
1108 for (arg_num = 1; ; ++arg_num)
1112 if (arg_num == info->format_num)
1114 params = TREE_CHAIN (params);
1116 format_tree = TREE_VALUE (params);
1117 params = TREE_CHAIN (params);
1118 if (format_tree == 0)
1121 res.number_non_literal = 0;
1122 res.number_extra_args = 0;
1123 res.number_dollar_extra_args = 0;
1124 res.number_wide = 0;
1125 res.number_empty = 0;
1126 res.number_unterminated = 0;
1127 res.number_other = 0;
1129 format_ctx.res = &res;
1130 format_ctx.info = info;
1131 format_ctx.params = params;
1133 check_function_arguments_recurse (check_format_arg, &format_ctx,
1134 format_tree, arg_num);
1136 if (res.number_non_literal > 0)
1138 /* Functions taking a va_list normally pass a non-literal format
1139 string. These functions typically are declared with
1140 first_arg_num == 0, so avoid warning in those cases. */
1141 if (!(format_types[info->format_type].flags & (int) FMT_FLAG_ARG_CONVERT))
1143 /* For strftime-like formats, warn for not checking the format
1144 string; but there are no arguments to check. */
1145 warning (OPT_Wformat_nonliteral,
1146 "format not a string literal, format string not checked");
1148 else if (info->first_arg_num != 0)
1150 /* If there are no arguments for the format at all, we may have
1151 printf (foo) which is likely to be a security hole. */
1152 while (arg_num + 1 < info->first_arg_num)
1156 params = TREE_CHAIN (params);
1159 if (params == 0 && warn_format_security)
1160 warning (OPT_Wformat_security,
1161 "format not a string literal and no format arguments");
1162 else if (params == 0 && warn_format_nonliteral)
1163 warning (OPT_Wformat_nonliteral,
1164 "format not a string literal and no format arguments");
1166 warning (OPT_Wformat_nonliteral,
1167 "format not a string literal, argument types not checked");
1171 /* If there were extra arguments to the format, normally warn. However,
1172 the standard does say extra arguments are ignored, so in the specific
1173 case where we have multiple leaves (conditional expressions or
1174 ngettext) allow extra arguments if at least one leaf didn't have extra
1175 arguments, but was otherwise OK (either non-literal or checked OK).
1176 If the format is an empty string, this should be counted similarly to the
1177 case of extra format arguments. */
1178 if (res.number_extra_args > 0 && res.number_non_literal == 0
1179 && res.number_other == 0)
1180 warning (OPT_Wformat_extra_args, "too many arguments for format");
1181 if (res.number_dollar_extra_args > 0 && res.number_non_literal == 0
1182 && res.number_other == 0)
1183 warning (OPT_Wformat_extra_args, "unused arguments in $-style format");
1184 if (res.number_empty > 0 && res.number_non_literal == 0
1185 && res.number_other == 0)
1186 warning (OPT_Wformat_zero_length, "zero-length %s format string",
1187 format_types[info->format_type].name);
1189 if (res.number_wide > 0)
1190 warning (OPT_Wformat, "format is a wide character string");
1192 if (res.number_unterminated > 0)
1193 warning (OPT_Wformat, "unterminated format string");
1196 /* Callback from check_function_arguments_recurse to check a
1197 format string. FORMAT_TREE is the format parameter. ARG_NUM
1198 is the number of the format argument. CTX points to a
1199 format_check_context. */
1202 check_format_arg (void *ctx, tree format_tree,
1203 unsigned HOST_WIDE_INT arg_num)
1205 format_check_context *format_ctx = (format_check_context *) ctx;
1206 format_check_results *res = format_ctx->res;
1207 function_format_info *info = format_ctx->info;
1208 tree params = format_ctx->params;
1211 HOST_WIDE_INT offset;
1212 const char *format_chars;
1213 tree array_size = 0;
1216 if (integer_zerop (format_tree))
1218 /* Skip to first argument to check, so we can see if this format
1219 has any arguments (it shouldn't). */
1220 while (arg_num + 1 < info->first_arg_num)
1224 params = TREE_CHAIN (params);
1229 res->number_other++;
1231 res->number_extra_args++;
1237 if (TREE_CODE (format_tree) == PLUS_EXPR)
1241 arg0 = TREE_OPERAND (format_tree, 0);
1242 arg1 = TREE_OPERAND (format_tree, 1);
1245 if (TREE_CODE (arg1) == INTEGER_CST)
1247 else if (TREE_CODE (arg0) == INTEGER_CST)
1254 res->number_non_literal++;
1257 if (!host_integerp (arg1, 0)
1258 || (offset = tree_low_cst (arg1, 0)) < 0)
1260 res->number_non_literal++;
1264 if (TREE_CODE (format_tree) != ADDR_EXPR)
1266 res->number_non_literal++;
1269 format_tree = TREE_OPERAND (format_tree, 0);
1270 if (TREE_CODE (format_tree) == ARRAY_REF
1271 && host_integerp (TREE_OPERAND (format_tree, 1), 0)
1272 && (offset += tree_low_cst (TREE_OPERAND (format_tree, 1), 0)) >= 0)
1273 format_tree = TREE_OPERAND (format_tree, 0);
1274 if (TREE_CODE (format_tree) == VAR_DECL
1275 && TREE_CODE (TREE_TYPE (format_tree)) == ARRAY_TYPE
1276 && (array_init = decl_constant_value (format_tree)) != format_tree
1277 && TREE_CODE (array_init) == STRING_CST)
1279 /* Extract the string constant initializer. Note that this may include
1280 a trailing NUL character that is not in the array (e.g.
1281 const char a[3] = "foo";). */
1282 array_size = DECL_SIZE_UNIT (format_tree);
1283 format_tree = array_init;
1285 if (TREE_CODE (format_tree) != STRING_CST)
1287 res->number_non_literal++;
1290 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (format_tree))) != char_type_node)
1295 format_chars = TREE_STRING_POINTER (format_tree);
1296 format_length = TREE_STRING_LENGTH (format_tree);
1297 if (array_size != 0)
1299 /* Variable length arrays can't be initialized. */
1300 gcc_assert (TREE_CODE (array_size) == INTEGER_CST);
1302 if (host_integerp (array_size, 0))
1304 HOST_WIDE_INT array_size_value = TREE_INT_CST_LOW (array_size);
1305 if (array_size_value > 0
1306 && array_size_value == (int) array_size_value
1307 && format_length > array_size_value)
1308 format_length = array_size_value;
1313 if (offset >= format_length)
1315 res->number_non_literal++;
1318 format_chars += offset;
1319 format_length -= offset;
1321 if (format_length < 1)
1323 res->number_unterminated++;
1326 if (format_length == 1)
1328 res->number_empty++;
1331 if (format_chars[--format_length] != 0)
1333 res->number_unterminated++;
1337 /* Skip to first argument to check. */
1338 while (arg_num + 1 < info->first_arg_num)
1342 params = TREE_CHAIN (params);
1345 /* Provisionally increment res->number_other; check_format_info_main
1346 will decrement it if it finds there are extra arguments, but this way
1347 need not adjust it for every return. */
1348 res->number_other++;
1349 check_format_info_main (res, info, format_chars, format_length,
1354 /* Do the main part of checking a call to a format function. FORMAT_CHARS
1355 is the NUL-terminated format string (which at this point may contain
1356 internal NUL characters); FORMAT_LENGTH is its length (excluding the
1357 terminating NUL character). ARG_NUM is one less than the number of
1358 the first format argument to check; PARAMS points to that format
1359 argument in the list of arguments. */
1362 check_format_info_main (format_check_results *res,
1363 function_format_info *info, const char *format_chars,
1364 int format_length, tree params,
1365 unsigned HOST_WIDE_INT arg_num)
1367 const char *orig_format_chars = format_chars;
1368 tree first_fillin_param = params;
1370 const format_kind_info *fki = &format_types[info->format_type];
1371 const format_flag_spec *flag_specs = fki->flag_specs;
1372 const format_flag_pair *bad_flag_pairs = fki->bad_flag_pairs;
1374 /* -1 if no conversions taking an operand have been found; 0 if one has
1375 and it didn't use $; 1 if $ formats are in use. */
1376 int has_operand_number = -1;
1378 init_dollar_format_checking (info->first_arg_num, first_fillin_param);
1383 int suppressed = FALSE;
1384 const char *length_chars = NULL;
1385 enum format_lengths length_chars_val = FMT_LEN_none;
1386 enum format_std_version length_chars_std = STD_C89;
1390 int main_arg_num = 0;
1391 tree main_arg_params = 0;
1392 enum format_std_version wanted_type_std;
1393 const char *wanted_type_name;
1394 format_wanted_type width_wanted_type;
1395 format_wanted_type precision_wanted_type;
1396 format_wanted_type main_wanted_type;
1397 format_wanted_type *first_wanted_type = NULL;
1398 format_wanted_type *last_wanted_type = NULL;
1399 const format_length_info *fli = NULL;
1400 const format_char_info *fci = NULL;
1401 char flag_chars[256];
1403 const char *format_start = format_chars;
1404 if (*format_chars == 0)
1406 if (format_chars - orig_format_chars != format_length)
1407 warning (OPT_Wformat, "embedded %<\\0%> in format");
1408 if (info->first_arg_num != 0 && params != 0
1409 && has_operand_number <= 0)
1411 res->number_other--;
1412 res->number_extra_args++;
1414 if (has_operand_number > 0)
1415 finish_dollar_format_checking (res, fki->flags & (int) FMT_FLAG_DOLLAR_GAP_POINTER_OK);
1418 if (*format_chars++ != '%')
1420 if (*format_chars == 0)
1422 warning (OPT_Wformat, "spurious trailing %<%%%> in format");
1425 if (*format_chars == '%')
1432 if ((fki->flags & (int) FMT_FLAG_USE_DOLLAR) && has_operand_number != 0)
1434 /* Possibly read a $ operand number at the start of the format.
1435 If one was previously used, one is required here. If one
1436 is not used here, we can't immediately conclude this is a
1437 format without them, since it could be printf %m or scanf %*. */
1439 opnum = maybe_read_dollar_number (&format_chars, 0,
1441 &main_arg_params, fki);
1446 has_operand_number = 1;
1447 main_arg_num = opnum + info->first_arg_num - 1;
1450 else if (fki->flags & FMT_FLAG_USE_DOLLAR)
1452 if (avoid_dollar_number (format_chars))
1456 /* Read any format flags, but do not yet validate them beyond removing
1457 duplicates, since in general validation depends on the rest of
1459 while (*format_chars != 0
1460 && strchr (fki->flag_chars, *format_chars) != 0)
1462 const format_flag_spec *s = get_flag_spec (flag_specs,
1463 *format_chars, NULL);
1464 if (strchr (flag_chars, *format_chars) != 0)
1466 warning (OPT_Wformat, "repeated %s in format", _(s->name));
1470 i = strlen (flag_chars);
1471 flag_chars[i++] = *format_chars;
1474 if (s->skip_next_char)
1477 if (*format_chars == 0)
1479 warning (OPT_Wformat, "missing fill character at end of strfmon format");
1486 /* Read any format width, possibly * or *m$. */
1487 if (fki->width_char != 0)
1489 if (fki->width_type != NULL && *format_chars == '*')
1491 i = strlen (flag_chars);
1492 flag_chars[i++] = fki->width_char;
1494 /* "...a field width...may be indicated by an asterisk.
1495 In this case, an int argument supplies the field width..." */
1497 if (has_operand_number != 0)
1500 opnum = maybe_read_dollar_number (&format_chars,
1501 has_operand_number == 1,
1508 has_operand_number = 1;
1509 arg_num = opnum + info->first_arg_num - 1;
1512 has_operand_number = 0;
1516 if (avoid_dollar_number (format_chars))
1519 if (info->first_arg_num != 0)
1523 warning (OPT_Wformat, "too few arguments for format");
1526 cur_param = TREE_VALUE (params);
1527 if (has_operand_number <= 0)
1529 params = TREE_CHAIN (params);
1532 width_wanted_type.wanted_type = *fki->width_type;
1533 width_wanted_type.wanted_type_name = NULL;
1534 width_wanted_type.pointer_count = 0;
1535 width_wanted_type.char_lenient_flag = 0;
1536 width_wanted_type.writing_in_flag = 0;
1537 width_wanted_type.reading_from_flag = 0;
1538 width_wanted_type.name = _("field width");
1539 width_wanted_type.param = cur_param;
1540 width_wanted_type.arg_num = arg_num;
1541 width_wanted_type.next = NULL;
1542 if (last_wanted_type != 0)
1543 last_wanted_type->next = &width_wanted_type;
1544 if (first_wanted_type == 0)
1545 first_wanted_type = &width_wanted_type;
1546 last_wanted_type = &width_wanted_type;
1551 /* Possibly read a numeric width. If the width is zero,
1552 we complain if appropriate. */
1553 int non_zero_width_char = FALSE;
1554 int found_width = FALSE;
1555 while (ISDIGIT (*format_chars))
1558 if (*format_chars != '0')
1559 non_zero_width_char = TRUE;
1562 if (found_width && !non_zero_width_char &&
1563 (fki->flags & (int) FMT_FLAG_ZERO_WIDTH_BAD))
1564 warning (OPT_Wformat, "zero width in %s format", fki->name);
1567 i = strlen (flag_chars);
1568 flag_chars[i++] = fki->width_char;
1574 /* Read any format left precision (must be a number, not *). */
1575 if (fki->left_precision_char != 0 && *format_chars == '#')
1578 i = strlen (flag_chars);
1579 flag_chars[i++] = fki->left_precision_char;
1581 if (!ISDIGIT (*format_chars))
1582 warning (OPT_Wformat, "empty left precision in %s format", fki->name);
1583 while (ISDIGIT (*format_chars))
1587 /* Read any format precision, possibly * or *m$. */
1588 if (fki->precision_char != 0 && *format_chars == '.')
1591 i = strlen (flag_chars);
1592 flag_chars[i++] = fki->precision_char;
1594 if (fki->precision_type != NULL && *format_chars == '*')
1596 /* "...a...precision...may be indicated by an asterisk.
1597 In this case, an int argument supplies the...precision." */
1599 if (has_operand_number != 0)
1602 opnum = maybe_read_dollar_number (&format_chars,
1603 has_operand_number == 1,
1610 has_operand_number = 1;
1611 arg_num = opnum + info->first_arg_num - 1;
1614 has_operand_number = 0;
1618 if (avoid_dollar_number (format_chars))
1621 if (info->first_arg_num != 0)
1625 warning (OPT_Wformat, "too few arguments for format");
1628 cur_param = TREE_VALUE (params);
1629 if (has_operand_number <= 0)
1631 params = TREE_CHAIN (params);
1634 precision_wanted_type.wanted_type = *fki->precision_type;
1635 precision_wanted_type.wanted_type_name = NULL;
1636 precision_wanted_type.pointer_count = 0;
1637 precision_wanted_type.char_lenient_flag = 0;
1638 precision_wanted_type.writing_in_flag = 0;
1639 precision_wanted_type.reading_from_flag = 0;
1640 precision_wanted_type.name = _("field precision");
1641 precision_wanted_type.param = cur_param;
1642 precision_wanted_type.arg_num = arg_num;
1643 precision_wanted_type.next = NULL;
1644 if (last_wanted_type != 0)
1645 last_wanted_type->next = &precision_wanted_type;
1646 if (first_wanted_type == 0)
1647 first_wanted_type = &precision_wanted_type;
1648 last_wanted_type = &precision_wanted_type;
1653 if (!(fki->flags & (int) FMT_FLAG_EMPTY_PREC_OK)
1654 && !ISDIGIT (*format_chars))
1655 warning (OPT_Wformat, "empty precision in %s format", fki->name);
1656 while (ISDIGIT (*format_chars))
1661 /* Read any length modifier, if this kind of format has them. */
1662 fli = fki->length_char_specs;
1663 length_chars = NULL;
1664 length_chars_val = FMT_LEN_none;
1665 length_chars_std = STD_C89;
1668 while (fli->name != 0 && fli->name[0] != *format_chars)
1673 if (fli->double_name != 0 && fli->name[0] == *format_chars)
1676 length_chars = fli->double_name;
1677 length_chars_val = fli->double_index;
1678 length_chars_std = fli->double_std;
1682 length_chars = fli->name;
1683 length_chars_val = fli->index;
1684 length_chars_std = fli->std;
1686 i = strlen (flag_chars);
1687 flag_chars[i++] = fki->length_code_char;
1692 /* Warn if the length modifier is non-standard. */
1693 if (ADJ_STD (length_chars_std) > C_STD_VER)
1694 warning (OPT_Wformat,
1695 "%s does not support the %qs %s length modifier",
1696 C_STD_NAME (length_chars_std), length_chars,
1701 /* Read any modifier (strftime E/O). */
1702 if (fki->modifier_chars != NULL)
1704 while (*format_chars != 0
1705 && strchr (fki->modifier_chars, *format_chars) != 0)
1707 if (strchr (flag_chars, *format_chars) != 0)
1709 const format_flag_spec *s = get_flag_spec (flag_specs,
1710 *format_chars, NULL);
1711 warning (OPT_Wformat, "repeated %s in format", _(s->name));
1715 i = strlen (flag_chars);
1716 flag_chars[i++] = *format_chars;
1723 /* Handle the scanf allocation kludge. */
1724 if (fki->flags & (int) FMT_FLAG_SCANF_A_KLUDGE)
1726 if (*format_chars == 'a' && !flag_isoc99)
1728 if (format_chars[1] == 's' || format_chars[1] == 'S'
1729 || format_chars[1] == '[')
1731 /* 'a' is used as a flag. */
1732 i = strlen (flag_chars);
1733 flag_chars[i++] = 'a';
1740 format_char = *format_chars;
1741 if (format_char == 0
1742 || (!(fki->flags & (int) FMT_FLAG_FANCY_PERCENT_OK)
1743 && format_char == '%'))
1745 warning (OPT_Wformat, "conversion lacks type at end of format");
1749 fci = fki->conversion_specs;
1750 while (fci->format_chars != 0
1751 && strchr (fci->format_chars, format_char) == 0)
1753 if (fci->format_chars == 0)
1755 if (ISGRAPH (format_char))
1756 warning (OPT_Wformat, "unknown conversion type character %qc in format",
1759 warning (OPT_Wformat, "unknown conversion type character 0x%x in format",
1765 if (ADJ_STD (fci->std) > C_STD_VER)
1766 warning (OPT_Wformat, "%s does not support the %<%%%c%> %s format",
1767 C_STD_NAME (fci->std), format_char, fki->name);
1770 /* Validate the individual flags used, removing any that are invalid. */
1773 for (i = 0; flag_chars[i] != 0; i++)
1775 const format_flag_spec *s = get_flag_spec (flag_specs,
1776 flag_chars[i], NULL);
1777 flag_chars[i - d] = flag_chars[i];
1778 if (flag_chars[i] == fki->length_code_char)
1780 if (strchr (fci->flag_chars, flag_chars[i]) == 0)
1782 warning (OPT_Wformat, "%s used with %<%%%c%> %s format",
1783 _(s->name), format_char, fki->name);
1789 const format_flag_spec *t;
1790 if (ADJ_STD (s->std) > C_STD_VER)
1791 warning (OPT_Wformat, "%s does not support %s",
1792 C_STD_NAME (s->std), _(s->long_name));
1793 t = get_flag_spec (flag_specs, flag_chars[i], fci->flags2);
1794 if (t != NULL && ADJ_STD (t->std) > ADJ_STD (s->std))
1796 const char *long_name = (t->long_name != NULL
1799 if (ADJ_STD (t->std) > C_STD_VER)
1800 warning (OPT_Wformat,
1801 "%s does not support %s with the %<%%%c%> %s format",
1802 C_STD_NAME (t->std), _(long_name),
1803 format_char, fki->name);
1807 flag_chars[i - d] = 0;
1810 if ((fki->flags & (int) FMT_FLAG_SCANF_A_KLUDGE)
1811 && strchr (flag_chars, 'a') != 0)
1814 if (fki->suppression_char
1815 && strchr (flag_chars, fki->suppression_char) != 0)
1818 /* Validate the pairs of flags used. */
1819 for (i = 0; bad_flag_pairs[i].flag_char1 != 0; i++)
1821 const format_flag_spec *s, *t;
1822 if (strchr (flag_chars, bad_flag_pairs[i].flag_char1) == 0)
1824 if (strchr (flag_chars, bad_flag_pairs[i].flag_char2) == 0)
1826 if (bad_flag_pairs[i].predicate != 0
1827 && strchr (fci->flags2, bad_flag_pairs[i].predicate) == 0)
1829 s = get_flag_spec (flag_specs, bad_flag_pairs[i].flag_char1, NULL);
1830 t = get_flag_spec (flag_specs, bad_flag_pairs[i].flag_char2, NULL);
1831 if (bad_flag_pairs[i].ignored)
1833 if (bad_flag_pairs[i].predicate != 0)
1834 warning (OPT_Wformat,
1835 "%s ignored with %s and %<%%%c%> %s format",
1836 _(s->name), _(t->name), format_char,
1839 warning (OPT_Wformat, "%s ignored with %s in %s format",
1840 _(s->name), _(t->name), fki->name);
1844 if (bad_flag_pairs[i].predicate != 0)
1845 warning (OPT_Wformat,
1846 "use of %s and %s together with %<%%%c%> %s format",
1847 _(s->name), _(t->name), format_char,
1850 warning (OPT_Wformat, "use of %s and %s together in %s format",
1851 _(s->name), _(t->name), fki->name);
1855 /* Give Y2K warnings. */
1856 if (warn_format_y2k)
1859 if (strchr (fci->flags2, '4') != 0)
1860 if (strchr (flag_chars, 'E') != 0)
1864 else if (strchr (fci->flags2, '3') != 0)
1866 else if (strchr (fci->flags2, '2') != 0)
1869 warning (OPT_Wformat_y2k, "%<%%%c%> yields only last 2 digits of "
1870 "year in some locales", format_char);
1871 else if (y2k_level == 2)
1872 warning (OPT_Wformat_y2k, "%<%%%c%> yields only last 2 digits of "
1873 "year", format_char);
1876 if (strchr (fci->flags2, '[') != 0)
1878 /* Skip over scan set, in case it happens to have '%' in it. */
1879 if (*format_chars == '^')
1881 /* Find closing bracket; if one is hit immediately, then
1882 it's part of the scan set rather than a terminator. */
1883 if (*format_chars == ']')
1885 while (*format_chars && *format_chars != ']')
1887 if (*format_chars != ']')
1888 /* The end of the format string was reached. */
1889 warning (OPT_Wformat, "no closing %<]%> for %<%%[%> format");
1893 wanted_type_name = 0;
1894 if (fki->flags & (int) FMT_FLAG_ARG_CONVERT)
1896 wanted_type = (fci->types[length_chars_val].type
1897 ? *fci->types[length_chars_val].type : 0);
1898 wanted_type_name = fci->types[length_chars_val].name;
1899 wanted_type_std = fci->types[length_chars_val].std;
1900 if (wanted_type == 0)
1902 warning (OPT_Wformat,
1903 "use of %qs length modifier with %qc type character",
1904 length_chars, format_char);
1905 /* Heuristic: skip one argument when an invalid length/type
1906 combination is encountered. */
1910 warning (OPT_Wformat, "too few arguments for format");
1913 params = TREE_CHAIN (params);
1917 /* Warn if non-standard, provided it is more non-standard
1918 than the length and type characters that may already
1919 have been warned for. */
1920 && ADJ_STD (wanted_type_std) > ADJ_STD (length_chars_std)
1921 && ADJ_STD (wanted_type_std) > ADJ_STD (fci->std))
1923 if (ADJ_STD (wanted_type_std) > C_STD_VER)
1924 warning (OPT_Wformat,
1925 "%s does not support the %<%%%s%c%> %s format",
1926 C_STD_NAME (wanted_type_std), length_chars,
1927 format_char, fki->name);
1931 main_wanted_type.next = NULL;
1933 /* Finally. . .check type of argument against desired type! */
1934 if (info->first_arg_num == 0)
1936 if ((fci->pointer_count == 0 && wanted_type == void_type_node)
1939 if (main_arg_num != 0)
1942 warning (OPT_Wformat, "operand number specified with "
1943 "suppressed assignment");
1945 warning (OPT_Wformat, "operand number specified for format "
1946 "taking no argument");
1951 format_wanted_type *wanted_type_ptr;
1953 if (main_arg_num != 0)
1955 arg_num = main_arg_num;
1956 params = main_arg_params;
1961 if (has_operand_number > 0)
1963 warning (OPT_Wformat, "missing $ operand number in format");
1967 has_operand_number = 0;
1970 wanted_type_ptr = &main_wanted_type;
1975 warning (OPT_Wformat, "too few arguments for format");
1979 cur_param = TREE_VALUE (params);
1980 params = TREE_CHAIN (params);
1982 wanted_type_ptr->wanted_type = wanted_type;
1983 wanted_type_ptr->wanted_type_name = wanted_type_name;
1984 wanted_type_ptr->pointer_count = fci->pointer_count + aflag;
1985 wanted_type_ptr->char_lenient_flag = 0;
1986 if (strchr (fci->flags2, 'c') != 0)
1987 wanted_type_ptr->char_lenient_flag = 1;
1988 wanted_type_ptr->writing_in_flag = 0;
1989 wanted_type_ptr->reading_from_flag = 0;
1991 wanted_type_ptr->writing_in_flag = 1;
1994 if (strchr (fci->flags2, 'W') != 0)
1995 wanted_type_ptr->writing_in_flag = 1;
1996 if (strchr (fci->flags2, 'R') != 0)
1997 wanted_type_ptr->reading_from_flag = 1;
1999 wanted_type_ptr->name = NULL;
2000 wanted_type_ptr->param = cur_param;
2001 wanted_type_ptr->arg_num = arg_num;
2002 wanted_type_ptr->next = NULL;
2003 if (last_wanted_type != 0)
2004 last_wanted_type->next = wanted_type_ptr;
2005 if (first_wanted_type == 0)
2006 first_wanted_type = wanted_type_ptr;
2007 last_wanted_type = wanted_type_ptr;
2012 wanted_type_ptr = ggc_alloc (sizeof (main_wanted_type));
2014 wanted_type = *fci->types[length_chars_val].type;
2015 wanted_type_name = fci->types[length_chars_val].name;
2020 if (first_wanted_type != 0)
2021 check_format_types (first_wanted_type, format_start,
2022 format_chars - format_start);
2024 if (main_wanted_type.next != NULL)
2026 format_wanted_type *wanted_type_ptr = main_wanted_type.next;
2027 while (wanted_type_ptr)
2029 format_wanted_type *next = wanted_type_ptr->next;
2030 ggc_free (wanted_type_ptr);
2031 wanted_type_ptr = next;
2038 /* Check the argument types from a single format conversion (possibly
2039 including width and precision arguments). */
2041 check_format_types (format_wanted_type *types, const char *format_start,
2044 for (; types != 0; types = types->next)
2053 cur_param = types->param;
2054 cur_type = TREE_TYPE (cur_param);
2055 if (cur_type == error_mark_node)
2057 orig_cur_type = cur_type;
2059 wanted_type = types->wanted_type;
2060 arg_num = types->arg_num;
2062 /* The following should not occur here. */
2063 gcc_assert (wanted_type);
2064 gcc_assert (wanted_type != void_type_node || types->pointer_count);
2066 if (types->pointer_count == 0)
2067 wanted_type = lang_hooks.types.type_promotes_to (wanted_type);
2069 wanted_type = TYPE_MAIN_VARIANT (wanted_type);
2071 STRIP_NOPS (cur_param);
2073 /* Check the types of any additional pointer arguments
2074 that precede the "real" argument. */
2075 for (i = 0; i < types->pointer_count; ++i)
2077 if (TREE_CODE (cur_type) == POINTER_TYPE)
2079 cur_type = TREE_TYPE (cur_type);
2080 if (cur_type == error_mark_node)
2083 /* Check for writing through a NULL pointer. */
2084 if (types->writing_in_flag
2087 && integer_zerop (cur_param))
2088 warning (OPT_Wformat, "writing through null pointer "
2089 "(argument %d)", arg_num);
2091 /* Check for reading through a NULL pointer. */
2092 if (types->reading_from_flag
2095 && integer_zerop (cur_param))
2096 warning (OPT_Wformat, "reading through null pointer "
2097 "(argument %d)", arg_num);
2099 if (cur_param != 0 && TREE_CODE (cur_param) == ADDR_EXPR)
2100 cur_param = TREE_OPERAND (cur_param, 0);
2104 /* See if this is an attempt to write into a const type with
2105 scanf or with printf "%n". Note: the writing in happens
2106 at the first indirection only, if for example
2107 void * const * is passed to scanf %p; passing
2108 const void ** is simply passing an incompatible type. */
2109 if (types->writing_in_flag
2111 && (TYPE_READONLY (cur_type)
2113 && (CONSTANT_CLASS_P (cur_param)
2114 || (DECL_P (cur_param)
2115 && TREE_READONLY (cur_param))))))
2116 warning (OPT_Wformat, "writing into constant object "
2117 "(argument %d)", arg_num);
2119 /* If there are extra type qualifiers beyond the first
2120 indirection, then this makes the types technically
2124 && (TYPE_READONLY (cur_type)
2125 || TYPE_VOLATILE (cur_type)
2126 || TYPE_RESTRICT (cur_type)))
2127 warning (OPT_Wformat, "extra type qualifiers in format "
2128 "argument (argument %d)",
2134 format_type_warning (types->name, format_start, format_length,
2135 wanted_type, types->pointer_count,
2136 types->wanted_type_name, orig_cur_type,
2142 if (i < types->pointer_count)
2145 cur_type = TYPE_MAIN_VARIANT (cur_type);
2147 /* Check whether the argument type is a character type. This leniency
2148 only applies to certain formats, flagged with 'c'.
2150 if (types->char_lenient_flag)
2151 char_type_flag = (cur_type == char_type_node
2152 || cur_type == signed_char_type_node
2153 || cur_type == unsigned_char_type_node);
2155 /* Check the type of the "real" argument, if there's a type we want. */
2156 if (wanted_type == cur_type)
2158 /* If we want 'void *', allow any pointer type.
2159 (Anything else would already have got a warning.)
2160 With -pedantic, only allow pointers to void and to character
2162 if (wanted_type == void_type_node
2163 && (!pedantic || (i == 1 && char_type_flag)))
2165 /* Don't warn about differences merely in signedness, unless
2166 -pedantic. With -pedantic, warn if the type is a pointer
2167 target and not a character type, and for character types at
2168 a second level of indirection. */
2169 if (TREE_CODE (wanted_type) == INTEGER_TYPE
2170 && TREE_CODE (cur_type) == INTEGER_TYPE
2171 && (!pedantic || i == 0 || (i == 1 && char_type_flag))
2172 && (TYPE_UNSIGNED (wanted_type)
2173 ? wanted_type == c_common_unsigned_type (cur_type)
2174 : wanted_type == c_common_signed_type (cur_type)))
2176 /* Likewise, "signed char", "unsigned char" and "char" are
2177 equivalent but the above test won't consider them equivalent. */
2178 if (wanted_type == char_type_node
2179 && (!pedantic || i < 2)
2182 /* Now we have a type mismatch. */
2183 format_type_warning (types->name, format_start, format_length,
2184 wanted_type, types->pointer_count,
2185 types->wanted_type_name, orig_cur_type, arg_num);
2190 /* Give a warning about a format argument of different type from that
2191 expected. DESCR is a description such as "field precision", or
2192 NULL for an ordinary format. For an ordinary format, FORMAT_START
2193 points to where the format starts in the format string and
2194 FORMAT_LENGTH is its length. WANTED_TYPE is the type the argument
2195 should have after POINTER_COUNT pointer dereferences.
2196 WANTED_NAME_NAME is a possibly more friendly name of WANTED_TYPE,
2197 or NULL if the ordinary name of the type should be used. ARG_TYPE
2198 is the type of the actual argument. ARG_NUM is the number of that
2201 format_type_warning (const char *descr, const char *format_start,
2202 int format_length, tree wanted_type, int pointer_count,
2203 const char *wanted_type_name, tree arg_type, int arg_num)
2206 /* If ARG_TYPE is a typedef with a misleading name (for example,
2207 size_t but not the standard size_t expected by printf %zu), avoid
2208 printing the typedef name. */
2209 if (wanted_type_name
2210 && TYPE_NAME (arg_type)
2211 && TREE_CODE (TYPE_NAME (arg_type)) == TYPE_DECL
2212 && DECL_NAME (TYPE_NAME (arg_type))
2213 && !strcmp (wanted_type_name,
2214 lang_hooks.decl_printable_name (TYPE_NAME (arg_type), 2)))
2215 arg_type = TYPE_MAIN_VARIANT (arg_type);
2216 /* The format type and name exclude any '*' for pointers, so those
2217 must be formatted manually. For all the types we currently have,
2218 this is adequate, but formats taking pointers to functions or
2219 arrays would require the full type to be built up in order to
2220 print it with %T. */
2221 p = alloca (pointer_count + 2);
2222 if (pointer_count == 0)
2224 else if (c_dialect_cxx ())
2226 memset (p, '*', pointer_count);
2227 p[pointer_count] = 0;
2232 memset (p + 1, '*', pointer_count);
2233 p[pointer_count + 1] = 0;
2235 if (wanted_type_name)
2238 warning (OPT_Wformat, "%s should have type %<%s%s%>, "
2239 "but argument %d has type %qT",
2240 descr, wanted_type_name, p, arg_num, arg_type);
2242 warning (OPT_Wformat, "format %q.*s expects type %<%s%s%>, "
2243 "but argument %d has type %qT",
2244 format_length, format_start, wanted_type_name, p,
2250 warning (OPT_Wformat, "%s should have type %<%T%s%>, "
2251 "but argument %d has type %qT",
2252 descr, wanted_type, p, arg_num, arg_type);
2254 warning (OPT_Wformat, "format %q.*s expects type %<%T%s%>, "
2255 "but argument %d has type %qT",
2256 format_length, format_start, wanted_type, p, arg_num, arg_type);
2261 /* Given a format_char_info array FCI, and a character C, this function
2262 returns the index into the conversion_specs where that specifier's
2263 data is located. The character must exist. */
2265 find_char_info_specifier_index (const format_char_info *fci, int c)
2269 for (i = 0; fci->format_chars; i++, fci++)
2270 if (strchr (fci->format_chars, c))
2273 /* We shouldn't be looking for a non-existent specifier. */
2277 /* Given a format_length_info array FLI, and a character C, this
2278 function returns the index into the conversion_specs where that
2279 modifier's data is located. The character must exist. */
2281 find_length_info_modifier_index (const format_length_info *fli, int c)
2285 for (i = 0; fli->name; i++, fli++)
2286 if (strchr (fli->name, c))
2289 /* We shouldn't be looking for a non-existent modifier. */
2293 /* Determine the type of HOST_WIDE_INT in the code being compiled for
2294 use in GCC's __asm_fprintf__ custom format attribute. You must
2295 have set dynamic_format_types before calling this function. */
2297 init_dynamic_asm_fprintf_info (void)
2303 format_length_info *new_asm_fprintf_length_specs;
2306 /* Find the underlying type for HOST_WIDE_INT. For the %w
2307 length modifier to work, one must have issued: "typedef
2308 HOST_WIDE_INT __gcc_host_wide_int__;" in one's source code
2309 prior to using that modifier. */
2310 hwi = maybe_get_identifier ("__gcc_host_wide_int__");
2313 error ("%<__gcc_host_wide_int__%> is not defined as a type");
2316 hwi = identifier_global_value (hwi);
2317 if (!hwi || TREE_CODE (hwi) != TYPE_DECL)
2319 error ("%<__gcc_host_wide_int__%> is not defined as a type");
2322 hwi = DECL_ORIGINAL_TYPE (hwi);
2324 if (hwi != long_integer_type_node && hwi != long_long_integer_type_node)
2326 error ("%<__gcc_host_wide_int__%> is not defined as %<long%>"
2327 " or %<long long%>");
2331 /* Create a new (writable) copy of asm_fprintf_length_specs. */
2332 new_asm_fprintf_length_specs = (format_length_info *)
2333 xmemdup (asm_fprintf_length_specs,
2334 sizeof (asm_fprintf_length_specs),
2335 sizeof (asm_fprintf_length_specs));
2337 /* HOST_WIDE_INT must be one of 'long' or 'long long'. */
2338 i = find_length_info_modifier_index (new_asm_fprintf_length_specs, 'w');
2339 if (hwi == long_integer_type_node)
2340 new_asm_fprintf_length_specs[i].index = FMT_LEN_l;
2341 else if (hwi == long_long_integer_type_node)
2342 new_asm_fprintf_length_specs[i].index = FMT_LEN_ll;
2346 /* Assign the new data for use. */
2347 dynamic_format_types[asm_fprintf_format_type].length_char_specs =
2348 new_asm_fprintf_length_specs;
2352 /* Determine the types of "tree" and "location_t" in the code being
2353 compiled for use in GCC's diagnostic custom format attributes. You
2354 must have set dynamic_format_types before calling this function. */
2356 init_dynamic_diag_info (void)
2358 static tree t, loc, hwi;
2360 if (!loc || !t || !hwi)
2362 static format_char_info *diag_fci, *cdiag_fci, *cxxdiag_fci;
2363 static format_length_info *diag_ls;
2366 /* For the GCC-diagnostics custom format specifiers to work, one
2367 must have declared 'tree' and/or 'location_t' prior to using
2368 those attributes. If we haven't seen these declarations then
2369 you shouldn't use the specifiers requiring these types.
2370 However we don't force a hard ICE because we may see only one
2371 or the other type. */
2372 if ((loc = maybe_get_identifier ("location_t")))
2374 loc = identifier_global_value (loc);
2377 if (TREE_CODE (loc) != TYPE_DECL)
2379 error ("%<location_t%> is not defined as a type");
2383 loc = TREE_TYPE (loc);
2387 /* We need to grab the underlying 'union tree_node' so peek into
2388 an extra type level. */
2389 if ((t = maybe_get_identifier ("tree")))
2391 t = identifier_global_value (t);
2394 if (TREE_CODE (t) != TYPE_DECL)
2396 error ("%<tree%> is not defined as a type");
2399 else if (TREE_CODE (TREE_TYPE (t)) != POINTER_TYPE)
2401 error ("%<tree%> is not defined as a pointer type");
2405 t = TREE_TYPE (TREE_TYPE (t));
2409 /* Find the underlying type for HOST_WIDE_INT. For the %w
2410 length modifier to work, one must have issued: "typedef
2411 HOST_WIDE_INT __gcc_host_wide_int__;" in one's source code
2412 prior to using that modifier. */
2413 if ((hwi = maybe_get_identifier ("__gcc_host_wide_int__")))
2415 hwi = identifier_global_value (hwi);
2418 if (TREE_CODE (hwi) != TYPE_DECL)
2420 error ("%<__gcc_host_wide_int__%> is not defined as a type");
2425 hwi = DECL_ORIGINAL_TYPE (hwi);
2427 if (hwi != long_integer_type_node
2428 && hwi != long_long_integer_type_node)
2430 error ("%<__gcc_host_wide_int__%> is not defined"
2431 " as %<long%> or %<long long%>");
2438 /* Assign the new data for use. */
2440 /* All the GCC diag formats use the same length specs. */
2442 dynamic_format_types[gcc_diag_format_type].length_char_specs =
2443 dynamic_format_types[gcc_cdiag_format_type].length_char_specs =
2444 dynamic_format_types[gcc_cxxdiag_format_type].length_char_specs =
2445 diag_ls = (format_length_info *)
2446 xmemdup (gcc_diag_length_specs,
2447 sizeof (gcc_diag_length_specs),
2448 sizeof (gcc_diag_length_specs));
2451 /* HOST_WIDE_INT must be one of 'long' or 'long long'. */
2452 i = find_length_info_modifier_index (diag_ls, 'w');
2453 if (hwi == long_integer_type_node)
2454 diag_ls[i].index = FMT_LEN_l;
2455 else if (hwi == long_long_integer_type_node)
2456 diag_ls[i].index = FMT_LEN_ll;
2461 /* Handle the __gcc_diag__ format specifics. */
2463 dynamic_format_types[gcc_diag_format_type].conversion_specs =
2464 diag_fci = (format_char_info *)
2465 xmemdup (gcc_diag_char_table,
2466 sizeof (gcc_diag_char_table),
2467 sizeof (gcc_diag_char_table));
2470 i = find_char_info_specifier_index (diag_fci, 'H');
2471 diag_fci[i].types[0].type = &loc;
2472 diag_fci[i].pointer_count = 1;
2476 i = find_char_info_specifier_index (diag_fci, 'J');
2477 diag_fci[i].types[0].type = &t;
2478 diag_fci[i].pointer_count = 1;
2481 /* Handle the __gcc_cdiag__ format specifics. */
2483 dynamic_format_types[gcc_cdiag_format_type].conversion_specs =
2484 cdiag_fci = (format_char_info *)
2485 xmemdup (gcc_cdiag_char_table,
2486 sizeof (gcc_cdiag_char_table),
2487 sizeof (gcc_cdiag_char_table));
2490 i = find_char_info_specifier_index (cdiag_fci, 'H');
2491 cdiag_fci[i].types[0].type = &loc;
2492 cdiag_fci[i].pointer_count = 1;
2496 /* All specifiers taking a tree share the same struct. */
2497 i = find_char_info_specifier_index (cdiag_fci, 'D');
2498 cdiag_fci[i].types[0].type = &t;
2499 cdiag_fci[i].pointer_count = 1;
2500 i = find_char_info_specifier_index (cdiag_fci, 'J');
2501 cdiag_fci[i].types[0].type = &t;
2502 cdiag_fci[i].pointer_count = 1;
2505 /* Handle the __gcc_cxxdiag__ format specifics. */
2507 dynamic_format_types[gcc_cxxdiag_format_type].conversion_specs =
2508 cxxdiag_fci = (format_char_info *)
2509 xmemdup (gcc_cxxdiag_char_table,
2510 sizeof (gcc_cxxdiag_char_table),
2511 sizeof (gcc_cxxdiag_char_table));
2514 i = find_char_info_specifier_index (cxxdiag_fci, 'H');
2515 cxxdiag_fci[i].types[0].type = &loc;
2516 cxxdiag_fci[i].pointer_count = 1;
2520 /* All specifiers taking a tree share the same struct. */
2521 i = find_char_info_specifier_index (cxxdiag_fci, 'D');
2522 cxxdiag_fci[i].types[0].type = &t;
2523 cxxdiag_fci[i].pointer_count = 1;
2524 i = find_char_info_specifier_index (cxxdiag_fci, 'J');
2525 cxxdiag_fci[i].types[0].type = &t;
2526 cxxdiag_fci[i].pointer_count = 1;
2531 #ifdef TARGET_FORMAT_TYPES
2532 extern const format_kind_info TARGET_FORMAT_TYPES[];
2535 /* Handle a "format" attribute; arguments as in
2536 struct attribute_spec.handler. */
2538 handle_format_attribute (tree *node, tree ARG_UNUSED (name), tree args,
2539 int flags, bool *no_add_attrs)
2542 function_format_info info;
2545 #ifdef TARGET_FORMAT_TYPES
2546 /* If the target provides additional format types, we need to
2547 add them to FORMAT_TYPES at first use. */
2548 if (TARGET_FORMAT_TYPES != NULL && !dynamic_format_types)
2550 dynamic_format_types = xmalloc ((n_format_types + TARGET_N_FORMAT_TYPES)
2551 * sizeof (dynamic_format_types[0]));
2552 memcpy (dynamic_format_types, format_types_orig,
2553 sizeof (format_types_orig));
2554 memcpy (&dynamic_format_types[n_format_types], TARGET_FORMAT_TYPES,
2555 TARGET_N_FORMAT_TYPES * sizeof (dynamic_format_types[0]));
2557 format_types = dynamic_format_types;
2558 n_format_types += TARGET_N_FORMAT_TYPES;
2562 if (!decode_format_attr (args, &info, 0))
2564 *no_add_attrs = true;
2568 argument = TYPE_ARG_TYPES (type);
2571 if (!check_format_string (argument, info.format_num, flags,
2575 if (info.first_arg_num != 0)
2577 unsigned HOST_WIDE_INT arg_num = 1;
2579 /* Verify that first_arg_num points to the last arg,
2582 arg_num++, argument = TREE_CHAIN (argument);
2584 if (arg_num != info.first_arg_num)
2586 if (!(flags & (int) ATTR_FLAG_BUILT_IN))
2587 error ("args to be formatted is not %<...%>");
2588 *no_add_attrs = true;
2594 if (info.format_type == strftime_format_type && info.first_arg_num != 0)
2596 error ("strftime formats cannot format arguments");
2597 *no_add_attrs = true;
2601 /* If this is a custom GCC-internal format type, we have to
2602 initialize certain bits a runtime. */
2603 if (info.format_type == asm_fprintf_format_type
2604 || info.format_type == gcc_diag_format_type
2605 || info.format_type == gcc_cdiag_format_type
2606 || info.format_type == gcc_cxxdiag_format_type)
2608 /* Our first time through, we have to make sure that our
2609 format_type data is allocated dynamically and is modifiable. */
2610 if (!dynamic_format_types)
2611 format_types = dynamic_format_types = (format_kind_info *)
2612 xmemdup (format_types_orig, sizeof (format_types_orig),
2613 sizeof (format_types_orig));
2615 /* If this is format __asm_fprintf__, we have to initialize
2616 GCC's notion of HOST_WIDE_INT for checking %wd. */
2617 if (info.format_type == asm_fprintf_format_type)
2618 init_dynamic_asm_fprintf_info ();
2619 /* If this is one of the diagnostic attributes, then we have to
2620 initialize 'location_t' and 'tree' at runtime. */
2621 else if (info.format_type == gcc_diag_format_type
2622 || info.format_type == gcc_cdiag_format_type
2623 || info.format_type == gcc_cxxdiag_format_type)
2624 init_dynamic_diag_info ();