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 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, 59 Temple Place - Suite 330, Boston, MA
24 #include "coretypes.h"
31 #include "diagnostic.h"
32 #include "langhooks.h"
34 /* Set format warning options according to a -Wformat=n option. */
40 warn_format = setting;
41 warn_format_y2k = setting;
42 warn_format_extra_args = setting;
43 warn_format_zero_length = setting;
46 warn_format_nonliteral = setting;
47 warn_format_security = 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, with format_type_error
59 enum format_type { printf_format_type, asm_fprintf_format_type,
60 scanf_format_type, strftime_format_type,
61 strfmon_format_type, format_type_error };
63 typedef struct function_format_info
65 enum format_type format_type; /* type of format (printf, scanf, etc.) */
66 unsigned HOST_WIDE_INT format_num; /* number of format argument */
67 unsigned HOST_WIDE_INT first_arg_num; /* number of first arg (zero for varargs) */
68 } function_format_info;
70 static bool decode_format_attr PARAMS ((tree,
71 function_format_info *, int));
72 static enum format_type decode_format_type PARAMS ((const char *));
76 /* Handle a "format_arg" attribute; arguments as in
77 struct attribute_spec.handler. */
79 handle_format_arg_attribute (node, name, args, flags, no_add_attrs)
81 tree name ATTRIBUTE_UNUSED;
87 tree format_num_expr = TREE_VALUE (args);
88 unsigned HOST_WIDE_INT format_num;
89 unsigned HOST_WIDE_INT arg_num;
92 /* Strip any conversions from the first arg number and verify it
94 while (TREE_CODE (format_num_expr) == NOP_EXPR
95 || TREE_CODE (format_num_expr) == CONVERT_EXPR
96 || TREE_CODE (format_num_expr) == NON_LVALUE_EXPR)
97 format_num_expr = TREE_OPERAND (format_num_expr, 0);
99 if (TREE_CODE (format_num_expr) != INTEGER_CST
100 || TREE_INT_CST_HIGH (format_num_expr) != 0)
102 error ("format string has invalid operand number");
103 *no_add_attrs = true;
107 format_num = TREE_INT_CST_LOW (format_num_expr);
109 /* If a parameter list is specified, verify that the format_num
110 argument is actually a string, in case the format attribute
112 argument = TYPE_ARG_TYPES (type);
115 for (arg_num = 1; argument != 0 && arg_num != format_num;
116 ++arg_num, argument = TREE_CHAIN (argument))
120 || TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE
121 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (argument)))
124 if (!(flags & (int) ATTR_FLAG_BUILT_IN))
125 error ("format string arg not a string type");
126 *no_add_attrs = true;
131 if (TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
132 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
135 if (!(flags & (int) ATTR_FLAG_BUILT_IN))
136 error ("function does not return string type");
137 *no_add_attrs = true;
145 /* Decode the arguments to a "format" attribute into a function_format_info
146 structure. It is already known that the list is of the right length.
147 If VALIDATED_P is true, then these attributes have already been validated
148 and this function will abort if they are erroneous; if false, it
149 will give an error message. Returns true if the attributes are
150 successfully decoded, false otherwise. */
153 decode_format_attr (args, info, validated_p)
155 function_format_info *info;
158 tree format_type_id = TREE_VALUE (args);
159 tree format_num_expr = TREE_VALUE (TREE_CHAIN (args));
160 tree first_arg_num_expr
161 = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args)));
163 if (TREE_CODE (format_type_id) != IDENTIFIER_NODE)
167 error ("unrecognized format specifier");
172 const char *p = IDENTIFIER_POINTER (format_type_id);
174 info->format_type = decode_format_type (p);
176 if (info->format_type == format_type_error)
180 warning ("`%s' is an unrecognized format function type", p);
185 /* Strip any conversions from the string index and first arg number
186 and verify they are constants. */
187 while (TREE_CODE (format_num_expr) == NOP_EXPR
188 || TREE_CODE (format_num_expr) == CONVERT_EXPR
189 || TREE_CODE (format_num_expr) == NON_LVALUE_EXPR)
190 format_num_expr = TREE_OPERAND (format_num_expr, 0);
192 while (TREE_CODE (first_arg_num_expr) == NOP_EXPR
193 || TREE_CODE (first_arg_num_expr) == CONVERT_EXPR
194 || TREE_CODE (first_arg_num_expr) == NON_LVALUE_EXPR)
195 first_arg_num_expr = TREE_OPERAND (first_arg_num_expr, 0);
197 if (TREE_CODE (format_num_expr) != INTEGER_CST
198 || TREE_INT_CST_HIGH (format_num_expr) != 0
199 || TREE_CODE (first_arg_num_expr) != INTEGER_CST
200 || TREE_INT_CST_HIGH (first_arg_num_expr) != 0)
204 error ("format string has invalid operand number");
208 info->format_num = TREE_INT_CST_LOW (format_num_expr);
209 info->first_arg_num = TREE_INT_CST_LOW (first_arg_num_expr);
210 if (info->first_arg_num != 0 && info->first_arg_num <= info->format_num)
214 error ("format string arg follows the args to be formatted");
221 /* Check a call to a format function against a parameter list. */
223 /* The meaningfully distinct length modifiers for format checking recognized
240 /* The standard versions in which various format features appeared. */
241 enum format_std_version
245 STD_C9L, /* C99, but treat as C89 if -Wno-long-long. */
250 /* The C standard version C++ is treated as equivalent to
251 or inheriting from, for the purpose of format features supported. */
252 #define CPLUSPLUS_STD_VER STD_C94
253 /* The C standard version we are checking formats against when pedantic. */
254 #define C_STD_VER ((int)(c_language == clk_cplusplus \
255 ? CPLUSPLUS_STD_VER \
258 : (flag_isoc94 ? STD_C94 : STD_C89))))
259 /* The name to give to the standard version we are warning about when
260 pedantic. FEATURE_VER is the version in which the feature warned out
261 appeared, which is higher than C_STD_VER. */
262 #define C_STD_NAME(FEATURE_VER) (c_language == clk_cplusplus \
264 : ((FEATURE_VER) == STD_EXT \
267 /* Adjust a C standard version, which may be STD_C9L, to account for
268 -Wno-long-long. Returns other standard versions unchanged. */
269 #define ADJ_STD(VER) ((int)((VER) == STD_C9L \
270 ? (warn_long_long ? STD_C99 : STD_C89) \
273 /* Flags that may apply to a particular kind of format checked by GCC. */
276 /* This format converts arguments of types determined by the
278 FMT_FLAG_ARG_CONVERT = 1,
279 /* The scanf allocation 'a' kludge applies to this format kind. */
280 FMT_FLAG_SCANF_A_KLUDGE = 2,
281 /* A % during parsing a specifier is allowed to be a modified % rather
282 that indicating the format is broken and we are out-of-sync. */
283 FMT_FLAG_FANCY_PERCENT_OK = 4,
284 /* With $ operand numbers, it is OK to reference the same argument more
286 FMT_FLAG_DOLLAR_MULTIPLE = 8,
287 /* This format type uses $ operand numbers (strfmon doesn't). */
288 FMT_FLAG_USE_DOLLAR = 16,
289 /* Zero width is bad in this type of format (scanf). */
290 FMT_FLAG_ZERO_WIDTH_BAD = 32,
291 /* Empty precision specification is OK in this type of format (printf). */
292 FMT_FLAG_EMPTY_PREC_OK = 64,
293 /* Gaps are allowed in the arguments with $ operand numbers if all
294 arguments are pointers (scanf). */
295 FMT_FLAG_DOLLAR_GAP_POINTER_OK = 128
296 /* Not included here: details of whether width or precision may occur
297 (controlled by width_char and precision_char); details of whether
298 '*' can be used for these (width_type and precision_type); details
299 of whether length modifiers can occur (length_char_specs). */
303 /* Structure describing a length modifier supported in format checking, and
304 possibly a doubled version such as "hh". */
307 /* Name of the single-character length modifier. */
309 /* Index into a format_char_info.types array. */
310 enum format_lengths index;
311 /* Standard version this length appears in. */
312 enum format_std_version std;
313 /* Same, if the modifier can be repeated, or NULL if it can't. */
314 const char *double_name;
315 enum format_lengths double_index;
316 enum format_std_version double_std;
317 } format_length_info;
320 /* Structure describing the combination of a conversion specifier
321 (or a set of specifiers which act identically) and a length modifier. */
324 /* The standard version this combination of length and type appeared in.
325 This is only relevant if greater than those for length and type
326 individually; otherwise it is ignored. */
327 enum format_std_version std;
328 /* The name to use for the type, if different from that generated internally
329 (e.g., "signed size_t"). */
331 /* The type itself. */
333 } format_type_detail;
336 /* Macros to fill out tables of these. */
337 #define NOARGUMENTS { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }
338 #define BADLEN { 0, NULL, NULL }
339 #define NOLENGTHS { BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }
342 /* Structure describing a format conversion specifier (or a set of specifiers
343 which act identically), and the length modifiers used with it. */
346 const char *format_chars;
348 enum format_std_version std;
349 /* Types accepted for each length modifier. */
350 format_type_detail types[FMT_LEN_MAX];
351 /* List of other modifier characters allowed with these specifiers.
352 This lists flags, and additionally "w" for width, "p" for precision
353 (right precision, for strfmon), "#" for left precision (strfmon),
354 "a" for scanf "a" allocation extension (not applicable in C99 mode),
355 "*" for scanf suppression, and "E" and "O" for those strftime
357 const char *flag_chars;
358 /* List of additional flags describing these conversion specifiers.
359 "c" for generic character pointers being allowed, "2" for strftime
360 two digit year formats, "3" for strftime formats giving two digit
361 years in some locales, "4" for "2" which becomes "3" with an "E" modifier,
362 "o" if use of strftime "O" is a GNU extension beyond C99,
363 "W" if the argument is a pointer which is dereferenced and written into,
364 "R" if the argument is a pointer which is dereferenced and read from,
365 "i" for printf integer formats where the '0' flag is ignored with
366 precision, and "[" for the starting character of a scanf scanset. */
371 /* Structure describing a flag accepted by some kind of format. */
374 /* The flag character in question (0 for end of array). */
376 /* Zero if this entry describes the flag character in general, or a
377 nonzero character that may be found in flags2 if it describes the
378 flag when used with certain formats only. If the latter, only
379 the first such entry found that applies to the current conversion
380 specifier is used; the values of `name' and `long_name' it supplies
381 will be used, if non-NULL and the standard version is higher than
382 the unpredicated one, for any pedantic warning. For example, 'o'
383 for strftime formats (meaning 'O' is an extension over C99). */
385 /* Nonzero if the next character after this flag in the format should
386 be skipped ('=' in strfmon), zero otherwise. */
388 /* The name to use for this flag in diagnostic messages. For example,
389 N_("`0' flag"), N_("field width"). */
391 /* Long name for this flag in diagnostic messages; currently only used for
392 "ISO C does not support ...". For example, N_("the `I' printf flag"). */
393 const char *long_name;
394 /* The standard version in which it appeared. */
395 enum format_std_version std;
399 /* Structure describing a combination of flags that is bad for some kind
403 /* The first flag character in question (0 for end of array). */
405 /* The second flag character. */
407 /* Nonzero if the message should say that the first flag is ignored with
408 the second, zero if the combination should simply be objected to. */
410 /* Zero if this entry applies whenever this flag combination occurs,
411 a nonzero character from flags2 if it only applies in some
412 circumstances (e.g. 'i' for printf formats ignoring 0 with precision). */
417 /* Structure describing a particular kind of format processed by GCC. */
420 /* The name of this kind of format, for use in diagnostics. Also
421 the name of the attribute (without preceding and following __). */
423 /* Specifications of the length modifiers accepted; possibly NULL. */
424 const format_length_info *length_char_specs;
425 /* Details of the conversion specification characters accepted. */
426 const format_char_info *conversion_specs;
427 /* String listing the flag characters that are accepted. */
428 const char *flag_chars;
429 /* String listing modifier characters (strftime) accepted. May be NULL. */
430 const char *modifier_chars;
431 /* Details of the flag characters, including pseudo-flags. */
432 const format_flag_spec *flag_specs;
433 /* Details of bad combinations of flags. */
434 const format_flag_pair *bad_flag_pairs;
435 /* Flags applicable to this kind of format. */
437 /* Flag character to treat a width as, or 0 if width not used. */
439 /* Flag character to treat a left precision (strfmon) as,
440 or 0 if left precision not used. */
441 int left_precision_char;
442 /* Flag character to treat a precision (for strfmon, right precision) as,
443 or 0 if precision not used. */
445 /* If a flag character has the effect of suppressing the conversion of
446 an argument ('*' in scanf), that flag character, otherwise 0. */
447 int suppression_char;
448 /* Flag character to treat a length modifier as (ignored if length
449 modifiers not used). Need not be placed in flag_chars for conversion
450 specifiers, but is used to check for bad combinations such as length
451 modifier with assignment suppression in scanf. */
452 int length_code_char;
453 /* Pointer to type of argument expected if '*' is used for a width,
454 or NULL if '*' not used for widths. */
456 /* Pointer to type of argument expected if '*' is used for a precision,
457 or NULL if '*' not used for precisions. */
458 tree *precision_type;
462 /* Structure describing details of a type expected in format checking,
463 and the type to check against it. */
464 typedef struct format_wanted_type
466 /* The type wanted. */
468 /* The name of this type to use in diagnostics. */
469 const char *wanted_type_name;
470 /* The level of indirection through pointers at which this type occurs. */
472 /* Whether, when pointer_count is 1, to allow any character type when
473 pedantic, rather than just the character or void type specified. */
474 int char_lenient_flag;
475 /* Whether the argument, dereferenced once, is written into and so the
476 argument must not be a pointer to a const-qualified type. */
478 /* Whether the argument, dereferenced once, is read from and so
479 must not be a NULL pointer. */
480 int reading_from_flag;
481 /* If warnings should be of the form "field precision is not type int",
482 the name to use (in this case "field precision"), otherwise NULL,
483 for "%s format, %s arg" type messages. If (in an extension), this
484 is a pointer type, wanted_type_name should be set to include the
485 terminating '*' characters of the type name to give a correct
488 /* The actual parameter to check against the wanted type. */
490 /* The argument number of that parameter. */
492 /* The next type to check for this format conversion, or NULL if none. */
493 struct format_wanted_type *next;
494 } format_wanted_type;
497 static const format_length_info printf_length_specs[] =
499 { "h", FMT_LEN_h, STD_C89, "hh", FMT_LEN_hh, STD_C99 },
500 { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C9L },
501 { "q", FMT_LEN_ll, STD_EXT, NULL, 0, 0 },
502 { "L", FMT_LEN_L, STD_C89, NULL, 0, 0 },
503 { "z", FMT_LEN_z, STD_C99, NULL, 0, 0 },
504 { "Z", FMT_LEN_z, STD_EXT, NULL, 0, 0 },
505 { "t", FMT_LEN_t, STD_C99, NULL, 0, 0 },
506 { "j", FMT_LEN_j, STD_C99, NULL, 0, 0 },
507 { NULL, 0, 0, NULL, 0, 0 }
510 /* Length specifiers valid for asm_fprintf. */
511 static const format_length_info asm_fprintf_length_specs[] =
513 { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C89 },
514 { "w", FMT_LEN_none, STD_C89, NULL, 0, 0 },
515 { NULL, 0, 0, NULL, 0, 0 }
518 /* This differs from printf_length_specs only in that "Z" is not accepted. */
519 static const format_length_info scanf_length_specs[] =
521 { "h", FMT_LEN_h, STD_C89, "hh", FMT_LEN_hh, STD_C99 },
522 { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C9L },
523 { "q", FMT_LEN_ll, STD_EXT, NULL, 0, 0 },
524 { "L", FMT_LEN_L, STD_C89, NULL, 0, 0 },
525 { "z", FMT_LEN_z, STD_C99, NULL, 0, 0 },
526 { "t", FMT_LEN_t, STD_C99, NULL, 0, 0 },
527 { "j", FMT_LEN_j, STD_C99, NULL, 0, 0 },
528 { NULL, 0, 0, NULL, 0, 0 }
532 /* All tables for strfmon use STD_C89 everywhere, since -pedantic warnings
533 make no sense for a format type not part of any C standard version. */
534 static const format_length_info strfmon_length_specs[] =
536 /* A GNU extension. */
537 { "L", FMT_LEN_L, STD_C89, NULL, 0, 0 },
538 { NULL, 0, 0, NULL, 0, 0 }
541 static const format_flag_spec printf_flag_specs[] =
543 { ' ', 0, 0, N_("` ' flag"), N_("the ` ' printf flag"), STD_C89 },
544 { '+', 0, 0, N_("`+' flag"), N_("the `+' printf flag"), STD_C89 },
545 { '#', 0, 0, N_("`#' flag"), N_("the `#' printf flag"), STD_C89 },
546 { '0', 0, 0, N_("`0' flag"), N_("the `0' printf flag"), STD_C89 },
547 { '-', 0, 0, N_("`-' flag"), N_("the `-' printf flag"), STD_C89 },
548 { '\'', 0, 0, N_("`'' flag"), N_("the `'' printf flag"), STD_EXT },
549 { 'I', 0, 0, N_("`I' flag"), N_("the `I' printf flag"), STD_EXT },
550 { 'w', 0, 0, N_("field width"), N_("field width in printf format"), STD_C89 },
551 { 'p', 0, 0, N_("precision"), N_("precision in printf format"), STD_C89 },
552 { 'L', 0, 0, N_("length modifier"), N_("length modifier in printf format"), STD_C89 },
553 { 0, 0, 0, NULL, NULL, 0 }
557 static const format_flag_pair printf_flag_pairs[] =
561 { '0', 'p', 1, 'i' },
565 static const format_flag_spec asm_fprintf_flag_specs[] =
567 { ' ', 0, 0, N_("` ' flag"), N_("the ` ' printf flag"), STD_C89 },
568 { '+', 0, 0, N_("`+' flag"), N_("the `+' printf flag"), STD_C89 },
569 { '#', 0, 0, N_("`#' flag"), N_("the `#' printf flag"), STD_C89 },
570 { '0', 0, 0, N_("`0' flag"), N_("the `0' printf flag"), STD_C89 },
571 { '-', 0, 0, N_("`-' flag"), N_("the `-' printf flag"), STD_C89 },
572 { 'w', 0, 0, N_("field width"), N_("field width in printf format"), STD_C89 },
573 { 'p', 0, 0, N_("precision"), N_("precision in printf format"), STD_C89 },
574 { 'L', 0, 0, N_("length modifier"), N_("length modifier in printf format"), STD_C89 },
575 { 0, 0, 0, NULL, NULL, 0 }
578 static const format_flag_pair asm_fprintf_flag_pairs[] =
582 { '0', 'p', 1, 'i' },
586 static const format_flag_spec scanf_flag_specs[] =
588 { '*', 0, 0, N_("assignment suppression"), N_("the assignment suppression scanf feature"), STD_C89 },
589 { 'a', 0, 0, N_("`a' flag"), N_("the `a' scanf flag"), STD_EXT },
590 { 'w', 0, 0, N_("field width"), N_("field width in scanf format"), STD_C89 },
591 { 'L', 0, 0, N_("length modifier"), N_("length modifier in scanf format"), STD_C89 },
592 { '\'', 0, 0, N_("`'' flag"), N_("the `'' scanf flag"), STD_EXT },
593 { 'I', 0, 0, N_("`I' flag"), N_("the `I' scanf flag"), STD_EXT },
594 { 0, 0, 0, NULL, NULL, 0 }
598 static const format_flag_pair scanf_flag_pairs[] =
605 static const format_flag_spec strftime_flag_specs[] =
607 { '_', 0, 0, N_("`_' flag"), N_("the `_' strftime flag"), STD_EXT },
608 { '-', 0, 0, N_("`-' flag"), N_("the `-' strftime flag"), STD_EXT },
609 { '0', 0, 0, N_("`0' flag"), N_("the `0' strftime flag"), STD_EXT },
610 { '^', 0, 0, N_("`^' flag"), N_("the `^' strftime flag"), STD_EXT },
611 { '#', 0, 0, N_("`#' flag"), N_("the `#' strftime flag"), STD_EXT },
612 { 'w', 0, 0, N_("field width"), N_("field width in strftime format"), STD_EXT },
613 { 'E', 0, 0, N_("`E' modifier"), N_("the `E' strftime modifier"), STD_C99 },
614 { 'O', 0, 0, N_("`O' modifier"), N_("the `O' strftime modifier"), STD_C99 },
615 { 'O', 'o', 0, NULL, N_("the `O' modifier"), STD_EXT },
616 { 0, 0, 0, NULL, NULL, 0 }
620 static const format_flag_pair strftime_flag_pairs[] =
631 static const format_flag_spec strfmon_flag_specs[] =
633 { '=', 0, 1, N_("fill character"), N_("fill character in strfmon format"), STD_C89 },
634 { '^', 0, 0, N_("`^' flag"), N_("the `^' strfmon flag"), STD_C89 },
635 { '+', 0, 0, N_("`+' flag"), N_("the `+' strfmon flag"), STD_C89 },
636 { '(', 0, 0, N_("`(' flag"), N_("the `(' strfmon flag"), STD_C89 },
637 { '!', 0, 0, N_("`!' flag"), N_("the `!' strfmon flag"), STD_C89 },
638 { '-', 0, 0, N_("`-' flag"), N_("the `-' strfmon flag"), STD_C89 },
639 { 'w', 0, 0, N_("field width"), N_("field width in strfmon format"), STD_C89 },
640 { '#', 0, 0, N_("left precision"), N_("left precision in strfmon format"), STD_C89 },
641 { 'p', 0, 0, N_("right precision"), N_("right precision in strfmon format"), STD_C89 },
642 { 'L', 0, 0, N_("length modifier"), N_("length modifier in strfmon format"), STD_C89 },
643 { 0, 0, 0, NULL, NULL, 0 }
646 static const format_flag_pair strfmon_flag_pairs[] =
653 #define T_I &integer_type_node
654 #define T89_I { STD_C89, NULL, T_I }
655 #define T_L &long_integer_type_node
656 #define T89_L { STD_C89, NULL, T_L }
657 #define T_LL &long_long_integer_type_node
658 #define T9L_LL { STD_C9L, NULL, T_LL }
659 #define TEX_LL { STD_EXT, NULL, T_LL }
660 #define T_S &short_integer_type_node
661 #define T89_S { STD_C89, NULL, T_S }
662 #define T_UI &unsigned_type_node
663 #define T89_UI { STD_C89, NULL, T_UI }
664 #define T_UL &long_unsigned_type_node
665 #define T89_UL { STD_C89, NULL, T_UL }
666 #define T_ULL &long_long_unsigned_type_node
667 #define T9L_ULL { STD_C9L, NULL, T_ULL }
668 #define TEX_ULL { STD_EXT, NULL, T_ULL }
669 #define T_US &short_unsigned_type_node
670 #define T89_US { STD_C89, NULL, T_US }
671 #define T_F &float_type_node
672 #define T89_F { STD_C89, NULL, T_F }
673 #define T99_F { STD_C99, NULL, T_F }
674 #define T_D &double_type_node
675 #define T89_D { STD_C89, NULL, T_D }
676 #define T99_D { STD_C99, NULL, T_D }
677 #define T_LD &long_double_type_node
678 #define T89_LD { STD_C89, NULL, T_LD }
679 #define T99_LD { STD_C99, NULL, T_LD }
680 #define T_C &char_type_node
681 #define T89_C { STD_C89, NULL, T_C }
682 #define T_SC &signed_char_type_node
683 #define T99_SC { STD_C99, NULL, T_SC }
684 #define T_UC &unsigned_char_type_node
685 #define T99_UC { STD_C99, NULL, T_UC }
686 #define T_V &void_type_node
687 #define T89_V { STD_C89, NULL, T_V }
688 #define T_W &wchar_type_node
689 #define T94_W { STD_C94, "wchar_t", T_W }
690 #define TEX_W { STD_EXT, "wchar_t", T_W }
691 #define T_WI &wint_type_node
692 #define T94_WI { STD_C94, "wint_t", T_WI }
693 #define TEX_WI { STD_EXT, "wint_t", T_WI }
694 #define T_ST &size_type_node
695 #define T99_ST { STD_C99, "size_t", T_ST }
696 #define T_SST &signed_size_type_node
697 #define T99_SST { STD_C99, "signed size_t", T_SST }
698 #define T_PD &ptrdiff_type_node
699 #define T99_PD { STD_C99, "ptrdiff_t", T_PD }
700 #define T_UPD &unsigned_ptrdiff_type_node
701 #define T99_UPD { STD_C99, "unsigned ptrdiff_t", T_UPD }
702 #define T_IM &intmax_type_node
703 #define T99_IM { STD_C99, "intmax_t", T_IM }
704 #define T_UIM &uintmax_type_node
705 #define T99_UIM { STD_C99, "uintmax_t", T_UIM }
707 static const format_char_info print_char_table[] =
709 /* C89 conversion specifiers. */
710 { "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" },
711 { "oxX", 0, STD_C89, { T89_UI, T99_UC, T89_US, T89_UL, T9L_ULL, TEX_ULL, T99_ST, T99_UPD, T99_UIM }, "-wp0#", "i" },
712 { "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" },
713 { "fgG", 0, STD_C89, { T89_D, BADLEN, BADLEN, T99_D, BADLEN, T89_LD, BADLEN, BADLEN, BADLEN }, "-wp0 +#'", "" },
714 { "eE", 0, STD_C89, { T89_D, BADLEN, BADLEN, T99_D, BADLEN, T89_LD, BADLEN, BADLEN, BADLEN }, "-wp0 +#", "" },
715 { "c", 0, STD_C89, { T89_I, BADLEN, BADLEN, T94_WI, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-w", "" },
716 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, T94_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp", "cR" },
717 { "p", 1, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-w", "c" },
718 { "n", 1, STD_C89, { T89_I, T99_SC, T89_S, T89_L, T9L_LL, BADLEN, T99_SST, T99_PD, T99_IM }, "", "W" },
719 /* C99 conversion specifiers. */
720 { "F", 0, STD_C99, { T99_D, BADLEN, BADLEN, T99_D, BADLEN, T99_LD, BADLEN, BADLEN, BADLEN }, "-wp0 +#'", "" },
721 { "aA", 0, STD_C99, { T99_D, BADLEN, BADLEN, T99_D, BADLEN, T99_LD, BADLEN, BADLEN, BADLEN }, "-wp0 +#", "" },
722 /* X/Open conversion specifiers. */
723 { "C", 0, STD_EXT, { TEX_WI, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-w", "" },
724 { "S", 1, STD_EXT, { TEX_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp", "R" },
725 /* GNU conversion specifiers. */
726 { "m", 0, STD_EXT, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp", "" },
727 { NULL, 0, 0, NOLENGTHS, NULL, NULL }
730 static const format_char_info asm_fprintf_char_table[] =
732 /* C89 conversion specifiers. */
733 { "di", 0, STD_C89, { T89_I, BADLEN, BADLEN, T89_L, T9L_LL, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp0 +", "i" },
734 { "oxX", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp0#", "i" },
735 { "u", 0, STD_C89, { T89_UI, BADLEN, BADLEN, T89_UL, T9L_ULL, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp0", "i" },
736 { "c", 0, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-w", "" },
737 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "-wp", "cR" },
739 /* asm_fprintf conversion specifiers. */
740 { "O", 0, STD_C89, NOARGUMENTS, "", "" },
741 { "R", 0, STD_C89, NOARGUMENTS, "", "" },
742 { "I", 0, STD_C89, NOARGUMENTS, "", "" },
743 { "L", 0, STD_C89, NOARGUMENTS, "", "" },
744 { "U", 0, STD_C89, NOARGUMENTS, "", "" },
745 { "r", 0, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "", "" },
746 { "@", 0, STD_C89, NOARGUMENTS, "", "" },
747 { NULL, 0, 0, NOLENGTHS, NULL, NULL }
750 static const format_char_info scan_char_table[] =
752 /* C89 conversion specifiers. */
753 { "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" },
754 { "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" },
755 { "oxX", 1, STD_C89, { T89_UI, T99_UC, T89_US, T89_UL, T9L_ULL, TEX_ULL, T99_ST, T99_UPD, T99_UIM }, "*w", "W" },
756 { "efgEG", 1, STD_C89, { T89_F, BADLEN, BADLEN, T89_D, BADLEN, T89_LD, BADLEN, BADLEN, BADLEN }, "*w'", "W" },
757 { "c", 1, STD_C89, { T89_C, BADLEN, BADLEN, T94_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*w", "cW" },
758 { "s", 1, STD_C89, { T89_C, BADLEN, BADLEN, T94_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*aw", "cW" },
759 { "[", 1, STD_C89, { T89_C, BADLEN, BADLEN, T94_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*aw", "cW[" },
760 { "p", 2, STD_C89, { T89_V, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*w", "W" },
761 { "n", 1, STD_C89, { T89_I, T99_SC, T89_S, T89_L, T9L_LL, BADLEN, T99_SST, T99_PD, T99_IM }, "", "W" },
762 /* C99 conversion specifiers. */
763 { "FaA", 1, STD_C99, { T99_F, BADLEN, BADLEN, T99_D, BADLEN, T99_LD, BADLEN, BADLEN, BADLEN }, "*w'", "W" },
764 /* X/Open conversion specifiers. */
765 { "C", 1, STD_EXT, { TEX_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*w", "W" },
766 { "S", 1, STD_EXT, { TEX_W, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "*aw", "W" },
767 { NULL, 0, 0, NOLENGTHS, NULL, NULL }
770 static const format_char_info time_char_table[] =
772 /* C89 conversion specifiers. */
773 { "ABZab", 0, STD_C89, NOLENGTHS, "^#", "" },
774 { "cx", 0, STD_C89, NOLENGTHS, "E", "3" },
775 { "HIMSUWdmw", 0, STD_C89, NOLENGTHS, "-_0Ow", "" },
776 { "j", 0, STD_C89, NOLENGTHS, "-_0Ow", "o" },
777 { "p", 0, STD_C89, NOLENGTHS, "#", "" },
778 { "X", 0, STD_C89, NOLENGTHS, "E", "" },
779 { "y", 0, STD_C89, NOLENGTHS, "EO-_0w", "4" },
780 { "Y", 0, STD_C89, NOLENGTHS, "-_0EOw", "o" },
781 { "%", 0, STD_C89, NOLENGTHS, "", "" },
782 /* C99 conversion specifiers. */
783 { "C", 0, STD_C99, NOLENGTHS, "-_0EOw", "o" },
784 { "D", 0, STD_C99, NOLENGTHS, "", "2" },
785 { "eVu", 0, STD_C99, NOLENGTHS, "-_0Ow", "" },
786 { "FRTnrt", 0, STD_C99, NOLENGTHS, "", "" },
787 { "g", 0, STD_C99, NOLENGTHS, "O-_0w", "2o" },
788 { "G", 0, STD_C99, NOLENGTHS, "-_0Ow", "o" },
789 { "h", 0, STD_C99, NOLENGTHS, "^#", "" },
790 { "z", 0, STD_C99, NOLENGTHS, "O", "o" },
791 /* GNU conversion specifiers. */
792 { "kls", 0, STD_EXT, NOLENGTHS, "-_0Ow", "" },
793 { "P", 0, STD_EXT, NOLENGTHS, "", "" },
794 { NULL, 0, 0, NOLENGTHS, NULL, NULL }
797 static const format_char_info monetary_char_table[] =
799 { "in", 0, STD_C89, { T89_D, BADLEN, BADLEN, BADLEN, BADLEN, T89_LD, BADLEN, BADLEN, BADLEN }, "=^+(!-w#p", "" },
800 { NULL, 0, 0, NOLENGTHS, NULL, NULL }
804 /* This must be in the same order as enum format_type. */
805 static const format_kind_info format_types_orig[] =
807 { "printf", printf_length_specs, print_char_table, " +#0-'I", NULL,
808 printf_flag_specs, printf_flag_pairs,
809 FMT_FLAG_ARG_CONVERT|FMT_FLAG_DOLLAR_MULTIPLE|FMT_FLAG_USE_DOLLAR|FMT_FLAG_EMPTY_PREC_OK,
811 &integer_type_node, &integer_type_node
813 { "asm_fprintf", asm_fprintf_length_specs, asm_fprintf_char_table, " +#0-", NULL,
814 asm_fprintf_flag_specs, asm_fprintf_flag_pairs,
815 FMT_FLAG_ARG_CONVERT|FMT_FLAG_EMPTY_PREC_OK,
817 &integer_type_node, &integer_type_node
819 { "scanf", scanf_length_specs, scan_char_table, "*'I", NULL,
820 scanf_flag_specs, scanf_flag_pairs,
821 FMT_FLAG_ARG_CONVERT|FMT_FLAG_SCANF_A_KLUDGE|FMT_FLAG_USE_DOLLAR|FMT_FLAG_ZERO_WIDTH_BAD|FMT_FLAG_DOLLAR_GAP_POINTER_OK,
825 { "strftime", NULL, time_char_table, "_-0^#", "EO",
826 strftime_flag_specs, strftime_flag_pairs,
827 FMT_FLAG_FANCY_PERCENT_OK, 'w', 0, 0, 0, 0,
830 { "strfmon", strfmon_length_specs, monetary_char_table, "=^+(!-", NULL,
831 strfmon_flag_specs, strfmon_flag_pairs,
832 FMT_FLAG_ARG_CONVERT, 'w', '#', 'p', 0, 'L',
837 /* This layer of indirection allows GCC to reassign format_types with
838 new data if necessary, while still allowing the original data to be
840 static const format_kind_info *format_types = format_types_orig;
842 /* Structure detailing the results of checking a format function call
843 where the format expression may be a conditional expression with
844 many leaves resulting from nested conditional expressions. */
847 /* Number of leaves of the format argument that could not be checked
848 as they were not string literals. */
849 int number_non_literal;
850 /* Number of leaves of the format argument that were null pointers or
851 string literals, but had extra format arguments. */
852 int number_extra_args;
853 /* Number of leaves of the format argument that were null pointers or
854 string literals, but had extra format arguments and used $ operand
856 int number_dollar_extra_args;
857 /* Number of leaves of the format argument that were wide string
860 /* Number of leaves of the format argument that were empty strings. */
862 /* Number of leaves of the format argument that were unterminated
864 int number_unterminated;
865 /* Number of leaves of the format argument that were not counted above. */
867 } format_check_results;
871 format_check_results *res;
872 function_format_info *info;
875 } format_check_context;
877 static void check_format_info PARAMS ((int *, function_format_info *, tree));
878 static void check_format_arg PARAMS ((void *, tree, unsigned HOST_WIDE_INT));
879 static void check_format_info_main PARAMS ((int *, format_check_results *,
880 function_format_info *,
881 const char *, int, tree,
882 unsigned HOST_WIDE_INT));
883 static void status_warning PARAMS ((int *, const char *, ...))
886 static void init_dollar_format_checking PARAMS ((int, tree));
887 static int maybe_read_dollar_number PARAMS ((int *, const char **, int,
889 const format_kind_info *));
890 static void finish_dollar_format_checking PARAMS ((int *, format_check_results *, int));
892 static const format_flag_spec *get_flag_spec PARAMS ((const format_flag_spec *,
895 static void check_format_types PARAMS ((int *, format_wanted_type *));
897 /* Decode a format type from a string, returning the type, or
898 format_type_error if not valid, in which case the caller should print an
900 static enum format_type
901 decode_format_type (s)
907 for (i = 0; i < (int) format_type_error; i++)
910 if (!strcmp (s, format_types[i].name))
912 alen = strlen (format_types[i].name);
913 if (slen == alen + 4 && s[0] == '_' && s[1] == '_'
914 && s[slen - 1] == '_' && s[slen - 2] == '_'
915 && !strncmp (s + 2, format_types[i].name, alen))
918 return ((enum format_type) i);
922 /* Check the argument list of a call to printf, scanf, etc.
923 ATTRS are the attributes on the function type.
924 PARAMS is the list of argument values. Also, if -Wmissing-format-attribute,
925 warn for calls to vprintf or vscanf in functions with no such format
926 attribute themselves. */
929 check_function_format (status, attrs, params)
936 /* See if this function has any format attributes. */
937 for (a = attrs; a; a = TREE_CHAIN (a))
939 if (is_attribute_p ("format", TREE_PURPOSE (a)))
942 function_format_info info;
943 decode_format_attr (TREE_VALUE (a), &info, 1);
944 check_format_info (status, &info, params);
945 if (warn_missing_format_attribute && info.first_arg_num == 0
946 && (format_types[info.format_type].flags
947 & (int) FMT_FLAG_ARG_CONVERT))
950 for (c = TYPE_ATTRIBUTES (TREE_TYPE (current_function_decl));
953 if (is_attribute_p ("format", TREE_PURPOSE (c))
954 && (decode_format_type (IDENTIFIER_POINTER
955 (TREE_VALUE (TREE_VALUE (c))))
956 == info.format_type))
960 /* Check if the current function has a parameter to which
961 the format attribute could be attached; if not, it
962 can't be a candidate for a format attribute, despite
963 the vprintf-like or vscanf-like call. */
965 for (args = DECL_ARGUMENTS (current_function_decl);
967 args = TREE_CHAIN (args))
969 if (TREE_CODE (TREE_TYPE (args)) == POINTER_TYPE
970 && (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (args)))
975 warning ("function might be possible candidate for `%s' format attribute",
976 format_types[info.format_type].name);
983 /* This function replaces `warning' inside the printf format checking
984 functions. If the `status' parameter is non-NULL, then it is
985 dereferenced and set to 1 whenever a warning is caught. Otherwise
986 it warns as usual by replicating the innards of the warning
987 function from diagnostic.c. */
989 status_warning (int *status, const char *msgid, ...)
991 diagnostic_info diagnostic ;
994 va_start (ap, msgid);
1000 /* This duplicates the warning function behavior. */
1001 diagnostic_set_info (&diagnostic, _(msgid), &ap,
1002 input_filename, input_line, DK_WARNING);
1003 report_diagnostic (&diagnostic);
1009 /* Variables used by the checking of $ operand number formats. */
1010 static char *dollar_arguments_used = NULL;
1011 static char *dollar_arguments_pointer_p = NULL;
1012 static int dollar_arguments_alloc = 0;
1013 static int dollar_arguments_count;
1014 static int dollar_first_arg_num;
1015 static int dollar_max_arg_used;
1016 static int dollar_format_warned;
1018 /* Initialize the checking for a format string that may contain $
1019 parameter number specifications; we will need to keep track of whether
1020 each parameter has been used. FIRST_ARG_NUM is the number of the first
1021 argument that is a parameter to the format, or 0 for a vprintf-style
1022 function; PARAMS is the list of arguments starting at this argument. */
1025 init_dollar_format_checking (first_arg_num, params)
1029 tree oparams = params;
1031 dollar_first_arg_num = first_arg_num;
1032 dollar_arguments_count = 0;
1033 dollar_max_arg_used = 0;
1034 dollar_format_warned = 0;
1035 if (first_arg_num > 0)
1039 dollar_arguments_count++;
1040 params = TREE_CHAIN (params);
1043 if (dollar_arguments_alloc < dollar_arguments_count)
1045 if (dollar_arguments_used)
1046 free (dollar_arguments_used);
1047 if (dollar_arguments_pointer_p)
1048 free (dollar_arguments_pointer_p);
1049 dollar_arguments_alloc = dollar_arguments_count;
1050 dollar_arguments_used = xmalloc (dollar_arguments_alloc);
1051 dollar_arguments_pointer_p = xmalloc (dollar_arguments_alloc);
1053 if (dollar_arguments_alloc)
1055 memset (dollar_arguments_used, 0, dollar_arguments_alloc);
1056 if (first_arg_num > 0)
1062 dollar_arguments_pointer_p[i] = (TREE_CODE (TREE_TYPE (TREE_VALUE (params)))
1064 params = TREE_CHAIN (params);
1072 /* Look for a decimal number followed by a $ in *FORMAT. If DOLLAR_NEEDED
1073 is set, it is an error if one is not found; otherwise, it is OK. If
1074 such a number is found, check whether it is within range and mark that
1075 numbered operand as being used for later checking. Returns the operand
1076 number if found and within range, zero if no such number was found and
1077 this is OK, or -1 on error. PARAMS points to the first operand of the
1078 format; PARAM_PTR is made to point to the parameter referred to. If
1079 a $ format is found, *FORMAT is updated to point just after it. */
1082 maybe_read_dollar_number (status, format, dollar_needed, params, param_ptr,
1085 const char **format;
1089 const format_kind_info *fki;
1093 const char *fcp = *format;
1094 if (! ISDIGIT (*fcp))
1098 status_warning (status, "missing $ operand number in format");
1106 while (ISDIGIT (*fcp))
1109 nargnum = 10 * argnum + (*fcp - '0');
1110 if (nargnum < 0 || nargnum / 10 != argnum)
1119 status_warning (status, "missing $ operand number in format");
1126 if (pedantic && !dollar_format_warned)
1128 status_warning (status,
1129 "%s does not support %%n$ operand number formats",
1130 C_STD_NAME (STD_EXT));
1131 dollar_format_warned = 1;
1133 if (overflow_flag || argnum == 0
1134 || (dollar_first_arg_num && argnum > dollar_arguments_count))
1136 status_warning (status, "operand number out of range in format");
1139 if (argnum > dollar_max_arg_used)
1140 dollar_max_arg_used = argnum;
1141 /* For vprintf-style functions we may need to allocate more memory to
1142 track which arguments are used. */
1143 while (dollar_arguments_alloc < dollar_max_arg_used)
1146 nalloc = 2 * dollar_arguments_alloc + 16;
1147 dollar_arguments_used = xrealloc (dollar_arguments_used, nalloc);
1148 dollar_arguments_pointer_p = xrealloc (dollar_arguments_pointer_p,
1150 memset (dollar_arguments_used + dollar_arguments_alloc, 0,
1151 nalloc - dollar_arguments_alloc);
1152 dollar_arguments_alloc = nalloc;
1154 if (!(fki->flags & (int) FMT_FLAG_DOLLAR_MULTIPLE)
1155 && dollar_arguments_used[argnum - 1] == 1)
1157 dollar_arguments_used[argnum - 1] = 2;
1158 status_warning (status,
1159 "format argument %d used more than once in %s format",
1163 dollar_arguments_used[argnum - 1] = 1;
1164 if (dollar_first_arg_num)
1167 *param_ptr = params;
1168 for (i = 1; i < argnum && *param_ptr != 0; i++)
1169 *param_ptr = TREE_CHAIN (*param_ptr);
1171 if (*param_ptr == 0)
1173 /* This case shouldn't be caught here. */
1183 /* Finish the checking for a format string that used $ operand number formats
1184 instead of non-$ formats. We check for unused operands before used ones
1185 (a serious error, since the implementation of the format function
1186 can't know what types to pass to va_arg to find the later arguments).
1187 and for unused operands at the end of the format (if we know how many
1188 arguments the format had, so not for vprintf). If there were operand
1189 numbers out of range on a non-vprintf-style format, we won't have reached
1190 here. If POINTER_GAP_OK, unused arguments are OK if all arguments are
1194 finish_dollar_format_checking (status, res, pointer_gap_ok)
1196 format_check_results *res;
1200 bool found_pointer_gap = false;
1201 for (i = 0; i < dollar_max_arg_used; i++)
1203 if (!dollar_arguments_used[i])
1205 if (pointer_gap_ok && (dollar_first_arg_num == 0
1206 || dollar_arguments_pointer_p[i]))
1207 found_pointer_gap = true;
1209 status_warning (status, "format argument %d unused before used argument %d in $-style format",
1210 i + 1, dollar_max_arg_used);
1213 if (found_pointer_gap
1214 || (dollar_first_arg_num
1215 && dollar_max_arg_used < dollar_arguments_count))
1217 res->number_other--;
1218 res->number_dollar_extra_args++;
1223 /* Retrieve the specification for a format flag. SPEC contains the
1224 specifications for format flags for the applicable kind of format.
1225 FLAG is the flag in question. If PREDICATES is NULL, the basic
1226 spec for that flag must be retrieved and this function aborts if
1227 it cannot be found. If PREDICATES is not NULL, it is a string listing
1228 possible predicates for the spec entry; if an entry predicated on any
1229 of these is found, it is returned, otherwise NULL is returned. */
1231 static const format_flag_spec *
1232 get_flag_spec (spec, flag, predicates)
1233 const format_flag_spec *spec;
1235 const char *predicates;
1238 for (i = 0; spec[i].flag_char != 0; i++)
1240 if (spec[i].flag_char != flag)
1242 if (predicates != NULL)
1244 if (spec[i].predicate != 0
1245 && strchr (predicates, spec[i].predicate) != 0)
1248 else if (spec[i].predicate == 0)
1251 if (predicates == NULL)
1258 /* Check the argument list of a call to printf, scanf, etc.
1259 INFO points to the function_format_info structure.
1260 PARAMS is the list of argument values. */
1263 check_format_info (status, info, params)
1265 function_format_info *info;
1268 format_check_context format_ctx;
1269 unsigned HOST_WIDE_INT arg_num;
1271 format_check_results res;
1272 /* Skip to format argument. If the argument isn't available, there's
1273 no work for us to do; prototype checking will catch the problem. */
1274 for (arg_num = 1; ; ++arg_num)
1278 if (arg_num == info->format_num)
1280 params = TREE_CHAIN (params);
1282 format_tree = TREE_VALUE (params);
1283 params = TREE_CHAIN (params);
1284 if (format_tree == 0)
1287 res.number_non_literal = 0;
1288 res.number_extra_args = 0;
1289 res.number_dollar_extra_args = 0;
1290 res.number_wide = 0;
1291 res.number_empty = 0;
1292 res.number_unterminated = 0;
1293 res.number_other = 0;
1295 format_ctx.res = &res;
1296 format_ctx.info = info;
1297 format_ctx.params = params;
1298 format_ctx.status = status;
1300 check_function_arguments_recurse (check_format_arg, &format_ctx,
1301 format_tree, arg_num);
1303 if (res.number_non_literal > 0)
1305 /* Functions taking a va_list normally pass a non-literal format
1306 string. These functions typically are declared with
1307 first_arg_num == 0, so avoid warning in those cases. */
1308 if (!(format_types[info->format_type].flags & (int) FMT_FLAG_ARG_CONVERT))
1310 /* For strftime-like formats, warn for not checking the format
1311 string; but there are no arguments to check. */
1312 if (warn_format_nonliteral)
1313 status_warning (status, "format not a string literal, format string not checked");
1315 else if (info->first_arg_num != 0)
1317 /* If there are no arguments for the format at all, we may have
1318 printf (foo) which is likely to be a security hole. */
1319 while (arg_num + 1 < info->first_arg_num)
1323 params = TREE_CHAIN (params);
1326 if (params == 0 && (warn_format_nonliteral || warn_format_security))
1327 status_warning (status, "format not a string literal and no format arguments");
1328 else if (warn_format_nonliteral)
1329 status_warning (status, "format not a string literal, argument types not checked");
1333 /* If there were extra arguments to the format, normally warn. However,
1334 the standard does say extra arguments are ignored, so in the specific
1335 case where we have multiple leaves (conditional expressions or
1336 ngettext) allow extra arguments if at least one leaf didn't have extra
1337 arguments, but was otherwise OK (either non-literal or checked OK).
1338 If the format is an empty string, this should be counted similarly to the
1339 case of extra format arguments. */
1340 if (res.number_extra_args > 0 && res.number_non_literal == 0
1341 && res.number_other == 0 && warn_format_extra_args)
1342 status_warning (status, "too many arguments for format");
1343 if (res.number_dollar_extra_args > 0 && res.number_non_literal == 0
1344 && res.number_other == 0 && warn_format_extra_args)
1345 status_warning (status, "unused arguments in $-style format");
1346 if (res.number_empty > 0 && res.number_non_literal == 0
1347 && res.number_other == 0 && warn_format_zero_length)
1348 status_warning (status, "zero-length %s format string",
1349 format_types[info->format_type].name);
1351 if (res.number_wide > 0)
1352 status_warning (status, "format is a wide character string");
1354 if (res.number_unterminated > 0)
1355 status_warning (status, "unterminated format string");
1358 /* Callback from check_function_arguments_recurse to check a
1359 format string. FORMAT_TREE is the format parameter. ARG_NUM
1360 is the number of the format argument. CTX points to a
1361 format_check_context. */
1364 check_format_arg (ctx, format_tree, arg_num)
1367 unsigned HOST_WIDE_INT arg_num;
1369 format_check_context *format_ctx = ctx;
1370 format_check_results *res = format_ctx->res;
1371 function_format_info *info = format_ctx->info;
1372 tree params = format_ctx->params;
1373 int *status = format_ctx->status;
1376 HOST_WIDE_INT offset;
1377 const char *format_chars;
1378 tree array_size = 0;
1381 if (integer_zerop (format_tree))
1383 /* Skip to first argument to check, so we can see if this format
1384 has any arguments (it shouldn't). */
1385 while (arg_num + 1 < info->first_arg_num)
1389 params = TREE_CHAIN (params);
1394 res->number_other++;
1396 res->number_extra_args++;
1402 if (TREE_CODE (format_tree) == PLUS_EXPR)
1406 arg0 = TREE_OPERAND (format_tree, 0);
1407 arg1 = TREE_OPERAND (format_tree, 1);
1410 if (TREE_CODE (arg1) == INTEGER_CST)
1412 else if (TREE_CODE (arg0) == INTEGER_CST)
1419 res->number_non_literal++;
1422 if (!host_integerp (arg1, 0)
1423 || (offset = tree_low_cst (arg1, 0)) < 0)
1425 res->number_non_literal++;
1429 if (TREE_CODE (format_tree) != ADDR_EXPR)
1431 res->number_non_literal++;
1434 format_tree = TREE_OPERAND (format_tree, 0);
1435 if (TREE_CODE (format_tree) == VAR_DECL
1436 && TREE_CODE (TREE_TYPE (format_tree)) == ARRAY_TYPE
1437 && (array_init = decl_constant_value (format_tree)) != format_tree
1438 && TREE_CODE (array_init) == STRING_CST)
1440 /* Extract the string constant initializer. Note that this may include
1441 a trailing NUL character that is not in the array (e.g.
1442 const char a[3] = "foo";). */
1443 array_size = DECL_SIZE_UNIT (format_tree);
1444 format_tree = array_init;
1446 if (TREE_CODE (format_tree) != STRING_CST)
1448 res->number_non_literal++;
1451 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (format_tree))) != char_type_node)
1456 format_chars = TREE_STRING_POINTER (format_tree);
1457 format_length = TREE_STRING_LENGTH (format_tree);
1458 if (array_size != 0)
1460 /* Variable length arrays can't be initialized. */
1461 if (TREE_CODE (array_size) != INTEGER_CST)
1463 if (host_integerp (array_size, 0))
1465 HOST_WIDE_INT array_size_value = TREE_INT_CST_LOW (array_size);
1466 if (array_size_value > 0
1467 && array_size_value == (int) array_size_value
1468 && format_length > array_size_value)
1469 format_length = array_size_value;
1474 if (offset >= format_length)
1476 res->number_non_literal++;
1479 format_chars += offset;
1480 format_length -= offset;
1482 if (format_length < 1)
1484 res->number_unterminated++;
1487 if (format_length == 1)
1489 res->number_empty++;
1492 if (format_chars[--format_length] != 0)
1494 res->number_unterminated++;
1498 /* Skip to first argument to check. */
1499 while (arg_num + 1 < info->first_arg_num)
1503 params = TREE_CHAIN (params);
1506 /* Provisionally increment res->number_other; check_format_info_main
1507 will decrement it if it finds there are extra arguments, but this way
1508 need not adjust it for every return. */
1509 res->number_other++;
1510 check_format_info_main (status, res, info, format_chars, format_length,
1515 /* Do the main part of checking a call to a format function. FORMAT_CHARS
1516 is the NUL-terminated format string (which at this point may contain
1517 internal NUL characters); FORMAT_LENGTH is its length (excluding the
1518 terminating NUL character). ARG_NUM is one less than the number of
1519 the first format argument to check; PARAMS points to that format
1520 argument in the list of arguments. */
1523 check_format_info_main (status, res, info, format_chars, format_length,
1526 format_check_results *res;
1527 function_format_info *info;
1528 const char *format_chars;
1531 unsigned HOST_WIDE_INT arg_num;
1533 const char *orig_format_chars = format_chars;
1534 tree first_fillin_param = params;
1536 const format_kind_info *fki = &format_types[info->format_type];
1537 const format_flag_spec *flag_specs = fki->flag_specs;
1538 const format_flag_pair *bad_flag_pairs = fki->bad_flag_pairs;
1540 /* -1 if no conversions taking an operand have been found; 0 if one has
1541 and it didn't use $; 1 if $ formats are in use. */
1542 int has_operand_number = -1;
1544 init_dollar_format_checking (info->first_arg_num, first_fillin_param);
1549 int suppressed = FALSE;
1550 const char *length_chars = NULL;
1551 enum format_lengths length_chars_val = FMT_LEN_none;
1552 enum format_std_version length_chars_std = STD_C89;
1556 int main_arg_num = 0;
1557 tree main_arg_params = 0;
1558 enum format_std_version wanted_type_std;
1559 const char *wanted_type_name;
1560 format_wanted_type width_wanted_type;
1561 format_wanted_type precision_wanted_type;
1562 format_wanted_type main_wanted_type;
1563 format_wanted_type *first_wanted_type = NULL;
1564 format_wanted_type *last_wanted_type = NULL;
1565 const format_length_info *fli = NULL;
1566 const format_char_info *fci = NULL;
1567 char flag_chars[256];
1569 if (*format_chars == 0)
1571 if (format_chars - orig_format_chars != format_length)
1572 status_warning (status, "embedded `\\0' in format");
1573 if (info->first_arg_num != 0 && params != 0
1574 && has_operand_number <= 0)
1576 res->number_other--;
1577 res->number_extra_args++;
1579 if (has_operand_number > 0)
1580 finish_dollar_format_checking (status, res, fki->flags & (int) FMT_FLAG_DOLLAR_GAP_POINTER_OK);
1583 if (*format_chars++ != '%')
1585 if (*format_chars == 0)
1587 status_warning (status, "spurious trailing `%%' in format");
1590 if (*format_chars == '%')
1597 if ((fki->flags & (int) FMT_FLAG_USE_DOLLAR) && has_operand_number != 0)
1599 /* Possibly read a $ operand number at the start of the format.
1600 If one was previously used, one is required here. If one
1601 is not used here, we can't immediately conclude this is a
1602 format without them, since it could be printf %m or scanf %*. */
1604 opnum = maybe_read_dollar_number (status, &format_chars, 0,
1606 &main_arg_params, fki);
1611 has_operand_number = 1;
1612 main_arg_num = opnum + info->first_arg_num - 1;
1616 /* Read any format flags, but do not yet validate them beyond removing
1617 duplicates, since in general validation depends on the rest of
1619 while (*format_chars != 0
1620 && strchr (fki->flag_chars, *format_chars) != 0)
1622 const format_flag_spec *s = get_flag_spec (flag_specs,
1623 *format_chars, NULL);
1624 if (strchr (flag_chars, *format_chars) != 0)
1626 status_warning (status, "repeated %s in format", _(s->name));
1630 i = strlen (flag_chars);
1631 flag_chars[i++] = *format_chars;
1634 if (s->skip_next_char)
1637 if (*format_chars == 0)
1639 status_warning (status, "missing fill character at end of strfmon format");
1646 /* Read any format width, possibly * or *m$. */
1647 if (fki->width_char != 0)
1649 if (fki->width_type != NULL && *format_chars == '*')
1651 i = strlen (flag_chars);
1652 flag_chars[i++] = fki->width_char;
1654 /* "...a field width...may be indicated by an asterisk.
1655 In this case, an int argument supplies the field width..." */
1657 if (has_operand_number != 0)
1660 opnum = maybe_read_dollar_number (status, &format_chars,
1661 has_operand_number == 1,
1668 has_operand_number = 1;
1669 arg_num = opnum + info->first_arg_num - 1;
1672 has_operand_number = 0;
1674 if (info->first_arg_num != 0)
1678 status_warning (status, "too few arguments for format");
1681 cur_param = TREE_VALUE (params);
1682 if (has_operand_number <= 0)
1684 params = TREE_CHAIN (params);
1687 width_wanted_type.wanted_type = *fki->width_type;
1688 width_wanted_type.wanted_type_name = NULL;
1689 width_wanted_type.pointer_count = 0;
1690 width_wanted_type.char_lenient_flag = 0;
1691 width_wanted_type.writing_in_flag = 0;
1692 width_wanted_type.reading_from_flag = 0;
1693 width_wanted_type.name = _("field width");
1694 width_wanted_type.param = cur_param;
1695 width_wanted_type.arg_num = arg_num;
1696 width_wanted_type.next = NULL;
1697 if (last_wanted_type != 0)
1698 last_wanted_type->next = &width_wanted_type;
1699 if (first_wanted_type == 0)
1700 first_wanted_type = &width_wanted_type;
1701 last_wanted_type = &width_wanted_type;
1706 /* Possibly read a numeric width. If the width is zero,
1707 we complain if appropriate. */
1708 int non_zero_width_char = FALSE;
1709 int found_width = FALSE;
1710 while (ISDIGIT (*format_chars))
1713 if (*format_chars != '0')
1714 non_zero_width_char = TRUE;
1717 if (found_width && !non_zero_width_char &&
1718 (fki->flags & (int) FMT_FLAG_ZERO_WIDTH_BAD))
1719 status_warning (status, "zero width in %s format",
1723 i = strlen (flag_chars);
1724 flag_chars[i++] = fki->width_char;
1730 /* Read any format left precision (must be a number, not *). */
1731 if (fki->left_precision_char != 0 && *format_chars == '#')
1734 i = strlen (flag_chars);
1735 flag_chars[i++] = fki->left_precision_char;
1737 if (!ISDIGIT (*format_chars))
1738 status_warning (status, "empty left precision in %s format",
1740 while (ISDIGIT (*format_chars))
1744 /* Read any format precision, possibly * or *m$. */
1745 if (fki->precision_char != 0 && *format_chars == '.')
1748 i = strlen (flag_chars);
1749 flag_chars[i++] = fki->precision_char;
1751 if (fki->precision_type != NULL && *format_chars == '*')
1753 /* "...a...precision...may be indicated by an asterisk.
1754 In this case, an int argument supplies the...precision." */
1756 if (has_operand_number != 0)
1759 opnum = maybe_read_dollar_number (status, &format_chars,
1760 has_operand_number == 1,
1767 has_operand_number = 1;
1768 arg_num = opnum + info->first_arg_num - 1;
1771 has_operand_number = 0;
1773 if (info->first_arg_num != 0)
1777 status_warning (status, "too few arguments for format");
1780 cur_param = TREE_VALUE (params);
1781 if (has_operand_number <= 0)
1783 params = TREE_CHAIN (params);
1786 precision_wanted_type.wanted_type = *fki->precision_type;
1787 precision_wanted_type.wanted_type_name = NULL;
1788 precision_wanted_type.pointer_count = 0;
1789 precision_wanted_type.char_lenient_flag = 0;
1790 precision_wanted_type.writing_in_flag = 0;
1791 precision_wanted_type.reading_from_flag = 0;
1792 precision_wanted_type.name = _("field precision");
1793 precision_wanted_type.param = cur_param;
1794 precision_wanted_type.arg_num = arg_num;
1795 precision_wanted_type.next = NULL;
1796 if (last_wanted_type != 0)
1797 last_wanted_type->next = &precision_wanted_type;
1798 if (first_wanted_type == 0)
1799 first_wanted_type = &precision_wanted_type;
1800 last_wanted_type = &precision_wanted_type;
1805 if (!(fki->flags & (int) FMT_FLAG_EMPTY_PREC_OK)
1806 && !ISDIGIT (*format_chars))
1807 status_warning (status, "empty precision in %s format",
1809 while (ISDIGIT (*format_chars))
1814 /* Read any length modifier, if this kind of format has them. */
1815 fli = fki->length_char_specs;
1816 length_chars = NULL;
1817 length_chars_val = FMT_LEN_none;
1818 length_chars_std = STD_C89;
1821 while (fli->name != 0 && fli->name[0] != *format_chars)
1826 if (fli->double_name != 0 && fli->name[0] == *format_chars)
1829 length_chars = fli->double_name;
1830 length_chars_val = fli->double_index;
1831 length_chars_std = fli->double_std;
1835 length_chars = fli->name;
1836 length_chars_val = fli->index;
1837 length_chars_std = fli->std;
1839 i = strlen (flag_chars);
1840 flag_chars[i++] = fki->length_code_char;
1845 /* Warn if the length modifier is non-standard. */
1846 if (ADJ_STD (length_chars_std) > C_STD_VER)
1847 status_warning (status, "%s does not support the `%s' %s length modifier",
1848 C_STD_NAME (length_chars_std), length_chars,
1853 /* Read any modifier (strftime E/O). */
1854 if (fki->modifier_chars != NULL)
1856 while (*format_chars != 0
1857 && strchr (fki->modifier_chars, *format_chars) != 0)
1859 if (strchr (flag_chars, *format_chars) != 0)
1861 const format_flag_spec *s = get_flag_spec (flag_specs,
1862 *format_chars, NULL);
1863 status_warning (status, "repeated %s in format", _(s->name));
1867 i = strlen (flag_chars);
1868 flag_chars[i++] = *format_chars;
1875 /* Handle the scanf allocation kludge. */
1876 if (fki->flags & (int) FMT_FLAG_SCANF_A_KLUDGE)
1878 if (*format_chars == 'a' && !flag_isoc99)
1880 if (format_chars[1] == 's' || format_chars[1] == 'S'
1881 || format_chars[1] == '[')
1883 /* `a' is used as a flag. */
1884 i = strlen (flag_chars);
1885 flag_chars[i++] = 'a';
1892 format_char = *format_chars;
1893 if (format_char == 0
1894 || (!(fki->flags & (int) FMT_FLAG_FANCY_PERCENT_OK)
1895 && format_char == '%'))
1897 status_warning (status, "conversion lacks type at end of format");
1901 fci = fki->conversion_specs;
1902 while (fci->format_chars != 0
1903 && strchr (fci->format_chars, format_char) == 0)
1905 if (fci->format_chars == 0)
1907 if (ISGRAPH(format_char))
1908 status_warning (status, "unknown conversion type character `%c' in format",
1911 status_warning (status, "unknown conversion type character 0x%x in format",
1917 if (ADJ_STD (fci->std) > C_STD_VER)
1918 status_warning (status, "%s does not support the `%%%c' %s format",
1919 C_STD_NAME (fci->std), format_char, fki->name);
1922 /* Validate the individual flags used, removing any that are invalid. */
1925 for (i = 0; flag_chars[i] != 0; i++)
1927 const format_flag_spec *s = get_flag_spec (flag_specs,
1928 flag_chars[i], NULL);
1929 flag_chars[i - d] = flag_chars[i];
1930 if (flag_chars[i] == fki->length_code_char)
1932 if (strchr (fci->flag_chars, flag_chars[i]) == 0)
1934 status_warning (status, "%s used with `%%%c' %s format",
1935 _(s->name), format_char, fki->name);
1941 const format_flag_spec *t;
1942 if (ADJ_STD (s->std) > C_STD_VER)
1943 status_warning (status, "%s does not support %s",
1944 C_STD_NAME (s->std), _(s->long_name));
1945 t = get_flag_spec (flag_specs, flag_chars[i], fci->flags2);
1946 if (t != NULL && ADJ_STD (t->std) > ADJ_STD (s->std))
1948 const char *long_name = (t->long_name != NULL
1951 if (ADJ_STD (t->std) > C_STD_VER)
1952 status_warning (status, "%s does not support %s with the `%%%c' %s format",
1953 C_STD_NAME (t->std), _(long_name),
1954 format_char, fki->name);
1958 flag_chars[i - d] = 0;
1961 if ((fki->flags & (int) FMT_FLAG_SCANF_A_KLUDGE)
1962 && strchr (flag_chars, 'a') != 0)
1965 if (fki->suppression_char
1966 && strchr (flag_chars, fki->suppression_char) != 0)
1969 /* Validate the pairs of flags used. */
1970 for (i = 0; bad_flag_pairs[i].flag_char1 != 0; i++)
1972 const format_flag_spec *s, *t;
1973 if (strchr (flag_chars, bad_flag_pairs[i].flag_char1) == 0)
1975 if (strchr (flag_chars, bad_flag_pairs[i].flag_char2) == 0)
1977 if (bad_flag_pairs[i].predicate != 0
1978 && strchr (fci->flags2, bad_flag_pairs[i].predicate) == 0)
1980 s = get_flag_spec (flag_specs, bad_flag_pairs[i].flag_char1, NULL);
1981 t = get_flag_spec (flag_specs, bad_flag_pairs[i].flag_char2, NULL);
1982 if (bad_flag_pairs[i].ignored)
1984 if (bad_flag_pairs[i].predicate != 0)
1985 status_warning (status, "%s ignored with %s and `%%%c' %s format",
1986 _(s->name), _(t->name), format_char,
1989 status_warning (status, "%s ignored with %s in %s format",
1990 _(s->name), _(t->name), fki->name);
1994 if (bad_flag_pairs[i].predicate != 0)
1995 status_warning (status, "use of %s and %s together with `%%%c' %s format",
1996 _(s->name), _(t->name), format_char,
1999 status_warning (status, "use of %s and %s together in %s format",
2000 _(s->name), _(t->name), fki->name);
2004 /* Give Y2K warnings. */
2005 if (warn_format_y2k)
2008 if (strchr (fci->flags2, '4') != 0)
2009 if (strchr (flag_chars, 'E') != 0)
2013 else if (strchr (fci->flags2, '3') != 0)
2015 else if (strchr (fci->flags2, '2') != 0)
2018 status_warning (status, "`%%%c' yields only last 2 digits of year in some locales",
2020 else if (y2k_level == 2)
2021 status_warning (status, "`%%%c' yields only last 2 digits of year", format_char);
2024 if (strchr (fci->flags2, '[') != 0)
2026 /* Skip over scan set, in case it happens to have '%' in it. */
2027 if (*format_chars == '^')
2029 /* Find closing bracket; if one is hit immediately, then
2030 it's part of the scan set rather than a terminator. */
2031 if (*format_chars == ']')
2033 while (*format_chars && *format_chars != ']')
2035 if (*format_chars != ']')
2036 /* The end of the format string was reached. */
2037 status_warning (status, "no closing `]' for `%%[' format");
2041 wanted_type_name = 0;
2042 if (fki->flags & (int) FMT_FLAG_ARG_CONVERT)
2044 wanted_type = (fci->types[length_chars_val].type
2045 ? *fci->types[length_chars_val].type : 0);
2046 wanted_type_name = fci->types[length_chars_val].name;
2047 wanted_type_std = fci->types[length_chars_val].std;
2048 if (wanted_type == 0)
2050 status_warning (status, "use of `%s' length modifier with `%c' type character",
2051 length_chars, format_char);
2052 /* Heuristic: skip one argument when an invalid length/type
2053 combination is encountered. */
2057 status_warning (status, "too few arguments for format");
2060 params = TREE_CHAIN (params);
2064 /* Warn if non-standard, provided it is more non-standard
2065 than the length and type characters that may already
2066 have been warned for. */
2067 && ADJ_STD (wanted_type_std) > ADJ_STD (length_chars_std)
2068 && ADJ_STD (wanted_type_std) > ADJ_STD (fci->std))
2070 if (ADJ_STD (wanted_type_std) > C_STD_VER)
2071 status_warning (status, "%s does not support the `%%%s%c' %s format",
2072 C_STD_NAME (wanted_type_std), length_chars,
2073 format_char, fki->name);
2077 /* Finally. . .check type of argument against desired type! */
2078 if (info->first_arg_num == 0)
2080 if ((fci->pointer_count == 0 && wanted_type == void_type_node)
2083 if (main_arg_num != 0)
2086 status_warning (status, "operand number specified with suppressed assignment");
2088 status_warning (status, "operand number specified for format taking no argument");
2093 if (main_arg_num != 0)
2095 arg_num = main_arg_num;
2096 params = main_arg_params;
2101 if (has_operand_number > 0)
2103 status_warning (status, "missing $ operand number in format");
2107 has_operand_number = 0;
2110 status_warning (status, "too few arguments for format");
2114 cur_param = TREE_VALUE (params);
2115 params = TREE_CHAIN (params);
2116 main_wanted_type.wanted_type = wanted_type;
2117 main_wanted_type.wanted_type_name = wanted_type_name;
2118 main_wanted_type.pointer_count = fci->pointer_count + aflag;
2119 main_wanted_type.char_lenient_flag = 0;
2120 if (strchr (fci->flags2, 'c') != 0)
2121 main_wanted_type.char_lenient_flag = 1;
2122 main_wanted_type.writing_in_flag = 0;
2123 main_wanted_type.reading_from_flag = 0;
2125 main_wanted_type.writing_in_flag = 1;
2128 if (strchr (fci->flags2, 'W') != 0)
2129 main_wanted_type.writing_in_flag = 1;
2130 if (strchr (fci->flags2, 'R') != 0)
2131 main_wanted_type.reading_from_flag = 1;
2133 main_wanted_type.name = NULL;
2134 main_wanted_type.param = cur_param;
2135 main_wanted_type.arg_num = arg_num;
2136 main_wanted_type.next = NULL;
2137 if (last_wanted_type != 0)
2138 last_wanted_type->next = &main_wanted_type;
2139 if (first_wanted_type == 0)
2140 first_wanted_type = &main_wanted_type;
2141 last_wanted_type = &main_wanted_type;
2144 if (first_wanted_type != 0)
2145 check_format_types (status, first_wanted_type);
2151 /* Check the argument types from a single format conversion (possibly
2152 including width and precision arguments). */
2154 check_format_types (status, types)
2156 format_wanted_type *types;
2158 for (; types != 0; types = types->next)
2167 cur_param = types->param;
2168 cur_type = TREE_TYPE (cur_param);
2169 if (cur_type == error_mark_node)
2172 wanted_type = types->wanted_type;
2173 arg_num = types->arg_num;
2175 /* The following should not occur here. */
2176 if (wanted_type == 0)
2178 if (wanted_type == void_type_node && types->pointer_count == 0)
2181 if (types->pointer_count == 0)
2182 wanted_type = (*lang_hooks.types.type_promotes_to) (wanted_type);
2184 STRIP_NOPS (cur_param);
2186 /* Check the types of any additional pointer arguments
2187 that precede the "real" argument. */
2188 for (i = 0; i < types->pointer_count; ++i)
2190 if (TREE_CODE (cur_type) == POINTER_TYPE)
2192 cur_type = TREE_TYPE (cur_type);
2193 if (cur_type == error_mark_node)
2196 /* Check for writing through a NULL pointer. */
2197 if (types->writing_in_flag
2200 && integer_zerop (cur_param))
2201 status_warning (status,
2202 "writing through null pointer (arg %d)",
2205 /* Check for reading through a NULL pointer. */
2206 if (types->reading_from_flag
2209 && integer_zerop (cur_param))
2210 status_warning (status,
2211 "reading through null pointer (arg %d)",
2214 if (cur_param != 0 && TREE_CODE (cur_param) == ADDR_EXPR)
2215 cur_param = TREE_OPERAND (cur_param, 0);
2219 /* See if this is an attempt to write into a const type with
2220 scanf or with printf "%n". Note: the writing in happens
2221 at the first indirection only, if for example
2222 void * const * is passed to scanf %p; passing
2223 const void ** is simply passing an incompatible type. */
2224 if (types->writing_in_flag
2226 && (TYPE_READONLY (cur_type)
2228 && (TREE_CODE_CLASS (TREE_CODE (cur_param)) == 'c'
2229 || (DECL_P (cur_param)
2230 && TREE_READONLY (cur_param))))))
2231 status_warning (status, "writing into constant object (arg %d)", arg_num);
2233 /* If there are extra type qualifiers beyond the first
2234 indirection, then this makes the types technically
2238 && (TYPE_READONLY (cur_type)
2239 || TYPE_VOLATILE (cur_type)
2240 || TYPE_RESTRICT (cur_type)))
2241 status_warning (status, "extra type qualifiers in format argument (arg %d)",
2247 if (types->pointer_count == 1)
2248 status_warning (status, "format argument is not a pointer (arg %d)", arg_num);
2250 status_warning (status, "format argument is not a pointer to a pointer (arg %d)", arg_num);
2255 if (i < types->pointer_count)
2258 orig_cur_type = cur_type;
2259 cur_type = TYPE_MAIN_VARIANT (cur_type);
2261 /* Check whether the argument type is a character type. This leniency
2262 only applies to certain formats, flagged with 'c'.
2264 if (types->char_lenient_flag)
2265 char_type_flag = (cur_type == char_type_node
2266 || cur_type == signed_char_type_node
2267 || cur_type == unsigned_char_type_node);
2269 /* Check the type of the "real" argument, if there's a type we want. */
2270 if (wanted_type == cur_type)
2272 /* If we want `void *', allow any pointer type.
2273 (Anything else would already have got a warning.)
2274 With -pedantic, only allow pointers to void and to character
2276 if (wanted_type == void_type_node
2277 && (!pedantic || (i == 1 && char_type_flag)))
2279 /* Don't warn about differences merely in signedness, unless
2280 -pedantic. With -pedantic, warn if the type is a pointer
2281 target and not a character type, and for character types at
2282 a second level of indirection. */
2283 if (TREE_CODE (wanted_type) == INTEGER_TYPE
2284 && TREE_CODE (cur_type) == INTEGER_TYPE
2285 && (! pedantic || i == 0 || (i == 1 && char_type_flag))
2286 && (TREE_UNSIGNED (wanted_type)
2287 ? wanted_type == c_common_unsigned_type (cur_type)
2288 : wanted_type == c_common_signed_type (cur_type)))
2290 /* Likewise, "signed char", "unsigned char" and "char" are
2291 equivalent but the above test won't consider them equivalent. */
2292 if (wanted_type == char_type_node
2293 && (! pedantic || i < 2)
2296 /* Now we have a type mismatch. */
2301 this = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (wanted_type)));
2303 if (TYPE_NAME (orig_cur_type) != 0
2304 && TREE_CODE (orig_cur_type) != INTEGER_TYPE
2305 && !(TREE_CODE (orig_cur_type) == POINTER_TYPE
2306 && TREE_CODE (TREE_TYPE (orig_cur_type)) == INTEGER_TYPE))
2308 if (TREE_CODE (TYPE_NAME (orig_cur_type)) == TYPE_DECL
2309 && DECL_NAME (TYPE_NAME (orig_cur_type)) != 0)
2310 that = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (orig_cur_type)));
2312 that = IDENTIFIER_POINTER (TYPE_NAME (orig_cur_type));
2315 /* A nameless type can't possibly match what the format wants.
2316 So there will be a warning for it.
2317 Make up a string to describe vaguely what it is. */
2320 if (TREE_CODE (orig_cur_type) == POINTER_TYPE)
2321 that = _("pointer");
2323 that = _("different type");
2326 /* Make the warning better in case of mismatch of int vs long. */
2327 if (TREE_CODE (orig_cur_type) == INTEGER_TYPE
2328 && TREE_CODE (wanted_type) == INTEGER_TYPE
2329 && TYPE_PRECISION (orig_cur_type) == TYPE_PRECISION (wanted_type)
2330 && TYPE_NAME (orig_cur_type) != 0
2331 && TREE_CODE (TYPE_NAME (orig_cur_type)) == TYPE_DECL)
2332 that = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (orig_cur_type)));
2334 if (strcmp (this, that) != 0)
2336 /* There may be a better name for the format, e.g. size_t,
2337 but we should allow for programs with a perverse typedef
2338 making size_t something other than what the compiler
2340 if (types->wanted_type_name != 0
2341 && strcmp (types->wanted_type_name, that) != 0)
2342 this = types->wanted_type_name;
2343 if (types->name != 0)
2344 status_warning (status, "%s is not type %s (arg %d)", types->name, this,
2347 status_warning (status, "%s format, %s arg (arg %d)", this, that, arg_num);
2353 /* Handle a "format" attribute; arguments as in
2354 struct attribute_spec.handler. */
2356 handle_format_attribute (node, name, args, flags, no_add_attrs)
2358 tree name ATTRIBUTE_UNUSED;
2364 function_format_info info;
2366 unsigned HOST_WIDE_INT arg_num;
2368 if (!decode_format_attr (args, &info, 0))
2370 *no_add_attrs = true;
2374 /* If a parameter list is specified, verify that the format_num
2375 argument is actually a string, in case the format attribute
2377 argument = TYPE_ARG_TYPES (type);
2380 for (arg_num = 1; argument != 0 && arg_num != info.format_num;
2381 ++arg_num, argument = TREE_CHAIN (argument))
2385 || TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE
2386 || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (argument)))
2389 if (!(flags & (int) ATTR_FLAG_BUILT_IN))
2390 error ("format string arg not a string type");
2391 *no_add_attrs = true;
2395 else if (info.first_arg_num != 0)
2397 /* Verify that first_arg_num points to the last arg,
2400 arg_num++, argument = TREE_CHAIN (argument);
2402 if (arg_num != info.first_arg_num)
2404 if (!(flags & (int) ATTR_FLAG_BUILT_IN))
2405 error ("args to be formatted is not '...'");
2406 *no_add_attrs = true;
2412 if (info.format_type == strftime_format_type && info.first_arg_num != 0)
2414 error ("strftime formats cannot format arguments");
2415 *no_add_attrs = true;
2419 /* If this is format type __asm_fprintf__, we have to initialize
2420 GCC's notion of HOST_WIDE_INT for checking %wd. */
2421 if (info.format_type == asm_fprintf_format_type)
2426 /* For this custom check to work, one must have issued:
2427 "typedef HOST_WIDE_INT __gcc_host_wide_int__;"
2428 in your source code prior to using this attribute. */
2431 format_kind_info *new_format_types;
2432 format_length_info *new_asm_fprintf_length_specs;
2434 if (!(hwi = maybe_get_identifier ("__gcc_host_wide_int__")))
2437 /* Create a new (writable) copy of asm_fprintf_length_specs. */
2438 new_asm_fprintf_length_specs =
2439 xmalloc (sizeof (asm_fprintf_length_specs));
2440 memcpy (new_asm_fprintf_length_specs, asm_fprintf_length_specs,
2441 sizeof (asm_fprintf_length_specs));
2443 /* Create a new (writable) copy of format_types. */
2444 new_format_types = xmalloc (sizeof (format_types_orig));
2445 memcpy (new_format_types, format_types_orig, sizeof (format_types_orig));
2447 /* Find the underlying type for HOST_WIDE_INT. */
2448 orig = DECL_ORIGINAL_TYPE (identifier_global_value (hwi));
2449 if (orig == long_integer_type_node)
2450 new_asm_fprintf_length_specs[1].index = FMT_LEN_l;
2451 else if (orig == long_long_integer_type_node)
2452 new_asm_fprintf_length_specs[1].index = FMT_LEN_ll;
2456 /* Assign the new data for use. */
2457 new_format_types[asm_fprintf_format_type].length_char_specs =
2458 new_asm_fprintf_length_specs;
2459 format_types = new_format_types;