1 /* Copyright (C) 2016-2020 Free Software Foundation, Inc.
2 Contributed by Martin Sebor <msebor@redhat.com>.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 /* This file implements the printf-return-value pass. The pass does
21 two things: 1) it analyzes calls to formatted output functions like
22 sprintf looking for possible buffer overflows and calls to bounded
23 functions like snprintf for early truncation (and under the control
24 of the -Wformat-length option issues warnings), and 2) under the
25 control of the -fprintf-return-value option it folds the return
26 value of safe calls into constants, making it possible to eliminate
27 code that depends on the value of those constants.
29 For all functions (bounded or not) the pass uses the size of the
30 destination object. That means that it will diagnose calls to
31 snprintf not on the basis of the size specified by the function's
32 second argument but rathger on the basis of the size the first
33 argument points to (if possible). For bound-checking built-ins
34 like __builtin___snprintf_chk the pass uses the size typically
35 determined by __builtin_object_size and passed to the built-in
36 by the Glibc inline wrapper.
38 The pass handles all forms standard sprintf format directives,
39 including character, integer, floating point, pointer, and strings,
40 with the standard C flags, widths, and precisions. For integers
41 and strings it computes the length of output itself. For floating
42 point it uses MPFR to fornmat known constants with up and down
43 rounding and uses the resulting range of output lengths. For
44 strings it uses the length of string literals and the sizes of
45 character arrays that a character pointer may point to as a bound
46 on the longest string. */
50 #include "coretypes.h"
54 #include "tree-pass.h"
56 #include "gimple-fold.h"
57 #include "gimple-pretty-print.h"
58 #include "diagnostic-core.h"
59 #include "fold-const.h"
60 #include "gimple-iterator.h"
62 #include "tree-object-size.h"
64 #include "tree-ssa-propagate.h"
67 #include "tree-scalar-evolution.h"
68 #include "tree-ssa-loop.h"
70 #include "langhooks.h"
74 #include "stor-layout.h"
82 #include "substring-locations.h"
83 #include "diagnostic.h"
85 #include "alloc-pool.h"
86 #include "vr-values.h"
87 #include "tree-ssa-strlen.h"
90 /* The likely worst case value of MB_LEN_MAX for the target, large enough
91 for UTF-8. Ideally, this would be obtained by a target hook if it were
92 to be used for optimization but it's good enough as is for warnings. */
93 #define target_mb_len_max() 6
95 /* The maximum number of bytes a single non-string directive can result
96 in. This is the result of printf("%.*Lf", INT_MAX, -LDBL_MAX) for
97 LDBL_MAX_10_EXP of 4932. */
98 #define IEEE_MAX_10_EXP 4932
99 #define target_dir_max() (target_int_max () + IEEE_MAX_10_EXP + 2)
103 /* Set to the warning level for the current function which is equal
104 either to warn_format_trunc for bounded functions or to
105 warn_format_overflow otherwise. */
107 static int warn_level
;
109 /* The minimum, maximum, likely, and unlikely maximum number of bytes
110 of output either a formatting function or an individual directive
115 /* The absolute minimum number of bytes. The result of a successful
116 conversion is guaranteed to be no less than this. (An erroneous
117 conversion can be indicated by MIN > HOST_WIDE_INT_MAX.) */
118 unsigned HOST_WIDE_INT min
;
119 /* The likely maximum result that is used in diagnostics. In most
120 cases MAX is the same as the worst case UNLIKELY result. */
121 unsigned HOST_WIDE_INT max
;
122 /* The likely result used to trigger diagnostics. For conversions
123 that result in a range of bytes [MIN, MAX], LIKELY is somewhere
125 unsigned HOST_WIDE_INT likely
;
126 /* In rare cases (e.g., for nultibyte characters) UNLIKELY gives
127 the worst cases maximum result of a directive. In most cases
128 UNLIKELY == MAX. UNLIKELY is used to control the return value
129 optimization but not in diagnostics. */
130 unsigned HOST_WIDE_INT unlikely
;
133 /* Return the value of INT_MIN for the target. */
135 static inline HOST_WIDE_INT
138 return tree_to_shwi (TYPE_MIN_VALUE (integer_type_node
));
141 /* Return the value of INT_MAX for the target. */
143 static inline unsigned HOST_WIDE_INT
146 return tree_to_uhwi (TYPE_MAX_VALUE (integer_type_node
));
149 /* Return the value of SIZE_MAX for the target. */
151 static inline unsigned HOST_WIDE_INT
154 return tree_to_uhwi (TYPE_MAX_VALUE (size_type_node
));
157 /* A straightforward mapping from the execution character set to the host
158 character set indexed by execution character. */
160 static char target_to_host_charmap
[256];
162 /* Initialize a mapping from the execution character set to the host
166 init_target_to_host_charmap ()
168 /* If the percent sign is non-zero the mapping has already been
170 if (target_to_host_charmap
['%'])
173 /* Initialize the target_percent character (done elsewhere). */
174 if (!init_target_chars ())
177 /* The subset of the source character set used by printf conversion
178 specifications (strictly speaking, not all letters are used but
179 they are included here for the sake of simplicity). The dollar
180 sign must be included even though it's not in the basic source
182 const char srcset
[] = " 0123456789!\"#%&'()*+,-./:;<=>?[\\]^_{|}~$"
183 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
185 /* Set the mapping for all characters to some ordinary value (i,e.,
186 not none used in printf conversion specifications) and overwrite
187 those that are used by conversion specifications with their
188 corresponding values. */
189 memset (target_to_host_charmap
+ 1, '?', sizeof target_to_host_charmap
- 1);
191 /* Are the two sets of characters the same? */
192 bool all_same_p
= true;
194 for (const char *pc
= srcset
; *pc
; ++pc
)
196 /* Slice off the high end bits in case target characters are
197 signed. All values are expected to be non-nul, otherwise
198 there's a problem. */
199 if (unsigned char tc
= lang_hooks
.to_target_charset (*pc
))
201 target_to_host_charmap
[tc
] = *pc
;
210 /* Set the first element to a non-zero value if the mapping
211 is 1-to-1, otherwise leave it clear (NUL is assumed to be
212 the same in both character sets). */
213 target_to_host_charmap
[0] = all_same_p
;
218 /* Return the host source character corresponding to the character
219 CH in the execution character set if one exists, or some innocuous
220 (non-special, non-nul) source character otherwise. */
222 static inline unsigned char
223 target_to_host (unsigned char ch
)
225 return target_to_host_charmap
[ch
];
228 /* Convert an initial substring of the string TARGSTR consisting of
229 characters in the execution character set into a string in the
230 source character set on the host and store up to HOSTSZ characters
231 in the buffer pointed to by HOSTR. Return HOSTR. */
234 target_to_host (char *hostr
, size_t hostsz
, const char *targstr
)
236 /* Make sure the buffer is reasonably big. */
237 gcc_assert (hostsz
> 4);
239 /* The interesting subset of source and execution characters are
240 the same so no conversion is necessary. However, truncate
241 overlong strings just like the translated strings are. */
242 if (target_to_host_charmap
['\0'] == 1)
244 size_t len
= strlen (targstr
);
247 memcpy (hostr
, targstr
, hostsz
- 4);
248 strcpy (hostr
+ hostsz
- 4, "...");
251 memcpy (hostr
, targstr
, len
+ 1);
255 /* Convert the initial substring of TARGSTR to the corresponding
256 characters in the host set, appending "..." if TARGSTR is too
257 long to fit. Using the static buffer assumes the function is
258 not called in between sequence points (which it isn't). */
259 for (char *ph
= hostr
; ; ++targstr
)
261 *ph
++ = target_to_host (*targstr
);
265 if (size_t (ph
- hostr
) == hostsz
)
267 strcpy (ph
- 4, "...");
275 /* Convert the sequence of decimal digits in the execution character
276 starting at *PS to a HOST_WIDE_INT, analogously to strtol. Return
277 the result and set *PS to one past the last converted character.
278 On range error set ERANGE to the digit that caused it. */
280 static inline HOST_WIDE_INT
281 target_strtowi (const char **ps
, const char **erange
)
283 unsigned HOST_WIDE_INT val
= 0;
286 unsigned char c
= target_to_host (**ps
);
291 /* Check for overflow. */
292 if (val
> ((unsigned HOST_WIDE_INT
) HOST_WIDE_INT_MAX
- c
) / 10LU)
294 val
= HOST_WIDE_INT_MAX
;
297 /* Skip the remaining digits. */
299 c
= target_to_host (*++*ps
);
313 /* Given FORMAT, set *PLOC to the source location of the format string
314 and return the format string if it is known or null otherwise. */
317 get_format_string (tree format
, location_t
*ploc
)
319 *ploc
= EXPR_LOC_OR_LOC (format
, input_location
);
321 return c_getstr (format
);
324 /* For convenience and brevity, shorter named entrypoints of
325 format_string_diagnostic_t::emit_warning_va and
326 format_string_diagnostic_t::emit_warning_n_va.
327 These have to be functions with the attribute so that exgettext
331 ATTRIBUTE_GCC_DIAG (5, 6)
332 fmtwarn (const substring_loc
&fmt_loc
, location_t param_loc
,
333 const char *corrected_substring
, int opt
, const char *gmsgid
, ...)
335 format_string_diagnostic_t
diag (fmt_loc
, NULL
, param_loc
, NULL
,
336 corrected_substring
);
338 va_start (ap
, gmsgid
);
339 bool warned
= diag
.emit_warning_va (opt
, gmsgid
, &ap
);
346 ATTRIBUTE_GCC_DIAG (6, 8) ATTRIBUTE_GCC_DIAG (7, 8)
347 fmtwarn_n (const substring_loc
&fmt_loc
, location_t param_loc
,
348 const char *corrected_substring
, int opt
, unsigned HOST_WIDE_INT n
,
349 const char *singular_gmsgid
, const char *plural_gmsgid
, ...)
351 format_string_diagnostic_t
diag (fmt_loc
, NULL
, param_loc
, NULL
,
352 corrected_substring
);
354 va_start (ap
, plural_gmsgid
);
355 bool warned
= diag
.emit_warning_n_va (opt
, n
, singular_gmsgid
, plural_gmsgid
,
362 /* Format length modifiers. */
367 FMT_LEN_hh
, // char argument
370 FMT_LEN_ll
, // long long
371 FMT_LEN_L
, // long double (and GNU long long)
373 FMT_LEN_t
, // ptrdiff_t
374 FMT_LEN_j
// intmax_t
378 /* Description of the result of conversion either of a single directive
379 or the whole format string. */
384 /* Construct a FMTRESULT object with all counters initialized
385 to MIN. KNOWNRANGE is set when MIN is valid. */
386 fmtresult (unsigned HOST_WIDE_INT min
= HOST_WIDE_INT_MAX
)
387 : argmin (), argmax (), dst_offset (HOST_WIDE_INT_MIN
), nonstr (),
388 knownrange (min
< HOST_WIDE_INT_MAX
),
394 range
.unlikely
= min
;
397 /* Construct a FMTRESULT object with MIN, MAX, and LIKELY counters.
398 KNOWNRANGE is set when both MIN and MAX are valid. */
399 fmtresult (unsigned HOST_WIDE_INT min
, unsigned HOST_WIDE_INT max
,
400 unsigned HOST_WIDE_INT likely
= HOST_WIDE_INT_MAX
)
401 : argmin (), argmax (), dst_offset (HOST_WIDE_INT_MIN
), nonstr (),
402 knownrange (min
< HOST_WIDE_INT_MAX
&& max
< HOST_WIDE_INT_MAX
),
407 range
.likely
= max
< likely
? min
: likely
;
408 range
.unlikely
= max
;
411 /* Adjust result upward to reflect the RANGE of values the specified
412 width or precision is known to be in. */
413 fmtresult
& adjust_for_width_or_precision (const HOST_WIDE_INT
[2],
415 unsigned = 0, unsigned = 0);
417 /* Return the maximum number of decimal digits a value of TYPE
418 formats as on output. */
419 static unsigned type_max_digits (tree
, int);
421 /* The range a directive's argument is in. */
424 /* The starting offset into the destination of the formatted function
425 call of the %s argument that points into (aliases with) the same
426 destination array. */
427 HOST_WIDE_INT dst_offset
;
429 /* The minimum and maximum number of bytes that a directive
430 results in on output for an argument in the range above. */
433 /* Non-nul when the argument of a string directive is not a nul
434 terminated string. */
437 /* True when the range above is obtained from a known value of
438 a directive's argument or its bounds and not the result of
439 heuristics that depend on warning levels. */
442 /* True for a directive that may fail (such as wide character
446 /* True when the argument is a null pointer. */
450 /* Adjust result upward to reflect the range ADJUST of values the
451 specified width or precision is known to be in. When non-null,
452 TYPE denotes the type of the directive whose result is being
453 adjusted, BASE gives the base of the directive (octal, decimal,
454 or hex), and ADJ denotes the additional adjustment to the LIKELY
455 counter that may need to be added when ADJUST is a range. */
458 fmtresult::adjust_for_width_or_precision (const HOST_WIDE_INT adjust
[2],
459 tree type
/* = NULL_TREE */,
460 unsigned base
/* = 0 */,
461 unsigned adj
/* = 0 */)
463 bool minadjusted
= false;
465 /* Adjust the minimum and likely counters. */
468 if (range
.min
< (unsigned HOST_WIDE_INT
)adjust
[0])
470 range
.min
= adjust
[0];
474 /* Adjust the likely counter. */
475 if (range
.likely
< range
.min
)
476 range
.likely
= range
.min
;
478 else if (adjust
[0] == target_int_min ()
479 && (unsigned HOST_WIDE_INT
)adjust
[1] == target_int_max ())
482 /* Adjust the maximum counter. */
485 if (range
.max
< (unsigned HOST_WIDE_INT
)adjust
[1])
487 range
.max
= adjust
[1];
489 /* Set KNOWNRANGE if both the minimum and maximum have been
490 adjusted. Otherwise leave it at what it was before. */
491 knownrange
= minadjusted
;
495 if (warn_level
> 1 && type
)
497 /* For large non-constant width or precision whose range spans
498 the maximum number of digits produced by the directive for
499 any argument, set the likely number of bytes to be at most
500 the number digits plus other adjustment determined by the
501 caller (one for sign or two for the hexadecimal "0x"
503 unsigned dirdigs
= type_max_digits (type
, base
);
504 if (adjust
[0] < dirdigs
&& dirdigs
< adjust
[1]
505 && range
.likely
< dirdigs
)
506 range
.likely
= dirdigs
+ adj
;
508 else if (range
.likely
< (range
.min
? range
.min
: 1))
510 /* Conservatively, set LIKELY to at least MIN but no less than
511 1 unless MAX is zero. */
512 range
.likely
= (range
.min
514 : range
.max
&& (range
.max
< HOST_WIDE_INT_MAX
515 || warn_level
> 1) ? 1 : 0);
518 /* Finally adjust the unlikely counter to be at least as large as
520 if (range
.unlikely
< range
.max
)
521 range
.unlikely
= range
.max
;
526 /* Return the maximum number of digits a value of TYPE formats in
527 BASE on output, not counting base prefix . */
530 fmtresult::type_max_digits (tree type
, int base
)
532 unsigned prec
= TYPE_PRECISION (type
);
536 return (prec
+ 2) / 3;
538 /* Decimal approximation: yields 3, 5, 10, and 20 for precision
539 of 8, 16, 32, and 64 bits. */
540 return prec
* 301 / 1000 + 1;
549 get_int_range (tree
, HOST_WIDE_INT
*, HOST_WIDE_INT
*, bool, HOST_WIDE_INT
,
554 /* Description of a format directive. A directive is either a plain
555 string or a conversion specification that starts with '%'. */
559 directive (const call_info
*inf
, unsigned dno
)
560 : info (inf
), dirno (dno
), argno (), beg (), len (), flags (),
561 width (), prec (), modifier (), specifier (), arg (), fmtfunc ()
564 /* Reference to the info structure describing the call that this
565 directive is a part of. */
566 const call_info
*info
;
568 /* The 1-based directive number (for debugging). */
571 /* The zero-based argument number of the directive's argument ARG in
572 the function's argument list. */
575 /* The first character of the directive and its length. */
579 /* A bitmap of flags, one for each character. */
580 unsigned flags
[256 / sizeof (int)];
582 /* The range of values of the specified width, or -1 if not specified. */
583 HOST_WIDE_INT width
[2];
584 /* The range of values of the specified precision, or -1 if not
586 HOST_WIDE_INT prec
[2];
588 /* Length modifier. */
589 format_lengths modifier
;
591 /* Format specifier character. */
594 /* The argument of the directive or null when the directive doesn't
595 take one or when none is available (such as for vararg functions). */
598 /* Format conversion function that given a directive and an argument
599 returns the formatting result. */
600 fmtresult (*fmtfunc
) (const directive
&, tree
, const vr_values
*);
602 /* Return True when a the format flag CHR has been used. */
603 bool get_flag (char chr
) const
605 unsigned char c
= chr
& 0xff;
606 return (flags
[c
/ (CHAR_BIT
* sizeof *flags
)]
607 & (1U << (c
% (CHAR_BIT
* sizeof *flags
))));
610 /* Make a record of the format flag CHR having been used. */
611 void set_flag (char chr
)
613 unsigned char c
= chr
& 0xff;
614 flags
[c
/ (CHAR_BIT
* sizeof *flags
)]
615 |= (1U << (c
% (CHAR_BIT
* sizeof *flags
)));
618 /* Reset the format flag CHR. */
619 void clear_flag (char chr
)
621 unsigned char c
= chr
& 0xff;
622 flags
[c
/ (CHAR_BIT
* sizeof *flags
)]
623 &= ~(1U << (c
% (CHAR_BIT
* sizeof *flags
)));
626 /* Set both bounds of the width range to VAL. */
627 void set_width (HOST_WIDE_INT val
)
629 width
[0] = width
[1] = val
;
632 /* Set the width range according to ARG, with both bounds being
633 no less than 0. For a constant ARG set both bounds to its value
634 or 0, whichever is greater. For a non-constant ARG in some range
635 set width to its range adjusting each bound to -1 if it's less.
636 For an indeterminate ARG set width to [0, INT_MAX]. */
637 void set_width (tree arg
, const vr_values
*vr
)
639 get_int_range (arg
, width
, width
+ 1, true, 0, vr
);
642 /* Set both bounds of the precision range to VAL. */
643 void set_precision (HOST_WIDE_INT val
)
645 prec
[0] = prec
[1] = val
;
648 /* Set the precision range according to ARG, with both bounds being
649 no less than -1. For a constant ARG set both bounds to its value
650 or -1 whichever is greater. For a non-constant ARG in some range
651 set precision to its range adjusting each bound to -1 if it's less.
652 For an indeterminate ARG set precision to [-1, INT_MAX]. */
653 void set_precision (tree arg
, const vr_values
*vr
)
655 get_int_range (arg
, prec
, prec
+ 1, false, -1, vr
);
658 /* Return true if both width and precision are known to be
659 either constant or in some range, false otherwise. */
660 bool known_width_and_precision () const
662 return ((width
[1] < 0
663 || (unsigned HOST_WIDE_INT
)width
[1] <= target_int_max ())
665 || (unsigned HOST_WIDE_INT
)prec
[1] < target_int_max ()));
669 /* The result of a call to a formatted function. */
674 : range (), aliases (), alias_count (), knownrange (), posunder4k (),
675 floating (), warned () { /* No-op. */ }
679 XDELETEVEC (aliases
);
682 /* Range of characters written by the formatted function.
683 Setting the minimum to HOST_WIDE_INT_MAX disables all
684 length tracking for the remainder of the format string. */
689 directive dir
; /* The directive that aliases the destination. */
690 HOST_WIDE_INT offset
; /* The offset at which it aliases it. */
691 result_range range
; /* The raw result of the directive. */
694 /* An array of directives whose pointer argument aliases a part
695 of the destination object of the formatted function. */
697 unsigned alias_count
;
699 /* True when the range above is obtained from known values of
700 directive arguments, or bounds on the amount of output such
701 as width and precision, and not the result of heuristics that
702 depend on warning levels. It's used to issue stricter diagnostics
703 in cases where strings of unknown lengths are bounded by the arrays
704 they are determined to refer to. KNOWNRANGE must not be used for
705 the return value optimization. */
708 /* True if no individual directive could fail or result in more than
709 4095 bytes of output (the total NUMBER_CHARS_{MIN,MAX} might be
710 greater). Implementations are not required to handle directives
711 that produce more than 4K bytes (leading to undefined behavior)
712 and so when one is found it disables the return value optimization.
713 Similarly, directives that can fail (such as wide character
714 directives) disable the optimization. */
717 /* True when a floating point directive has been seen in the format
721 /* True when an intermediate result has caused a warning. Used to
722 avoid issuing duplicate warnings while finishing the processing
723 of a call. WARNED also disables the return value optimization. */
726 /* Preincrement the number of output characters by 1. */
727 format_result
& operator++ ()
732 /* Postincrement the number of output characters by 1. */
733 format_result
operator++ (int)
735 format_result
prev (*this);
740 /* Increment the number of output characters by N. */
741 format_result
& operator+= (unsigned HOST_WIDE_INT
);
743 /* Add a directive to the sequence of those with potentially aliasing
745 void append_alias (const directive
&, HOST_WIDE_INT
, const result_range
&);
748 /* Not copyable or assignable. */
749 format_result (format_result
&);
750 void operator= (format_result
&);
754 format_result::operator+= (unsigned HOST_WIDE_INT n
)
756 gcc_assert (n
< HOST_WIDE_INT_MAX
);
758 if (range
.min
< HOST_WIDE_INT_MAX
)
761 if (range
.max
< HOST_WIDE_INT_MAX
)
764 if (range
.likely
< HOST_WIDE_INT_MAX
)
767 if (range
.unlikely
< HOST_WIDE_INT_MAX
)
774 format_result::append_alias (const directive
&d
, HOST_WIDE_INT off
,
775 const result_range
&resrng
)
777 unsigned cnt
= alias_count
+ 1;
778 alias_info
*ar
= XNEWVEC (alias_info
, cnt
);
780 for (unsigned i
= 0; i
!= alias_count
; ++i
)
783 ar
[alias_count
].dir
= d
;
784 ar
[alias_count
].offset
= off
;
785 ar
[alias_count
].range
= resrng
;
787 XDELETEVEC (aliases
);
793 /* Return the logarithm of X in BASE. */
796 ilog (unsigned HOST_WIDE_INT x
, int base
)
807 /* Return the number of bytes resulting from converting into a string
808 the INTEGER_CST tree node X in BASE with a minimum of PREC digits.
809 PLUS indicates whether 1 for a plus sign should be added for positive
810 numbers, and PREFIX whether the length of an octal ('O') or hexadecimal
811 ('0x') prefix should be added for nonzero numbers. Return -1 if X cannot
815 tree_digits (tree x
, int base
, HOST_WIDE_INT prec
, bool plus
, bool prefix
)
817 unsigned HOST_WIDE_INT absval
;
821 if (TYPE_UNSIGNED (TREE_TYPE (x
)))
823 if (tree_fits_uhwi_p (x
))
825 absval
= tree_to_uhwi (x
);
833 if (tree_fits_shwi_p (x
))
835 HOST_WIDE_INT i
= tree_to_shwi (x
);
836 if (HOST_WIDE_INT_MIN
== i
)
838 /* Avoid undefined behavior due to negating a minimum. */
839 absval
= HOST_WIDE_INT_MAX
;
857 int ndigs
= ilog (absval
, base
);
859 res
+= prec
< ndigs
? ndigs
: prec
;
861 /* Adjust a non-zero value for the base prefix, either hexadecimal,
862 or, unless precision has resulted in a leading zero, also octal. */
863 if (prefix
&& absval
&& (base
== 16 || prec
<= ndigs
))
874 /* Description of a call to a formatted function. */
878 /* Function call statement. */
881 /* Function called. */
884 /* Called built-in function code. */
885 built_in_function fncode
;
887 /* The "origin" of the destination pointer argument, which is either
888 the DECL of the destination buffer being written into or a pointer
889 that points to it, plus some offset. */
892 /* For a destination pointing to a struct array member, the offset of
894 HOST_WIDE_INT dst_field
;
896 /* The offset into the destination buffer. */
897 HOST_WIDE_INT dst_offset
;
899 /* Format argument and format string extracted from it. */
903 /* The location of the format argument. */
906 /* The destination object size for __builtin___xxx_chk functions
907 typically determined by __builtin_object_size, or -1 if unknown. */
908 unsigned HOST_WIDE_INT objsize
;
910 /* Number of the first variable argument. */
911 unsigned HOST_WIDE_INT argidx
;
913 /* True for functions like snprintf that specify the size of
914 the destination, false for others like sprintf that don't. */
917 /* True for bounded functions like snprintf that specify a zero-size
918 buffer as a request to compute the size of output without actually
919 writing any. NOWRITE is cleared in response to the %n directive
920 which has side-effects similar to writing output. */
923 /* Return true if the called function's return value is used. */
924 bool retval_used () const
926 return gimple_get_lhs (callstmt
);
929 /* Return the warning option corresponding to the called function. */
932 return bounded
? OPT_Wformat_truncation_
: OPT_Wformat_overflow_
;
935 /* Return true for calls to file formatted functions. */
936 bool is_file_func () const
938 return (fncode
== BUILT_IN_FPRINTF
939 || fncode
== BUILT_IN_FPRINTF_CHK
940 || fncode
== BUILT_IN_FPRINTF_UNLOCKED
941 || fncode
== BUILT_IN_VFPRINTF
942 || fncode
== BUILT_IN_VFPRINTF_CHK
);
945 /* Return true for calls to string formatted functions. */
946 bool is_string_func () const
948 return (fncode
== BUILT_IN_SPRINTF
949 || fncode
== BUILT_IN_SPRINTF_CHK
950 || fncode
== BUILT_IN_SNPRINTF
951 || fncode
== BUILT_IN_SNPRINTF_CHK
952 || fncode
== BUILT_IN_VSPRINTF
953 || fncode
== BUILT_IN_VSPRINTF_CHK
954 || fncode
== BUILT_IN_VSNPRINTF
955 || fncode
== BUILT_IN_VSNPRINTF_CHK
);
959 /* Return the result of formatting a no-op directive (such as '%n'). */
962 format_none (const directive
&, tree
, const vr_values
*)
968 /* Return the result of formatting the '%%' directive. */
971 format_percent (const directive
&, tree
, const vr_values
*)
978 /* Compute intmax_type_node and uintmax_type_node similarly to how
979 tree.c builds size_type_node. */
982 build_intmax_type_nodes (tree
*pintmax
, tree
*puintmax
)
984 if (strcmp (UINTMAX_TYPE
, "unsigned int") == 0)
986 *pintmax
= integer_type_node
;
987 *puintmax
= unsigned_type_node
;
989 else if (strcmp (UINTMAX_TYPE
, "long unsigned int") == 0)
991 *pintmax
= long_integer_type_node
;
992 *puintmax
= long_unsigned_type_node
;
994 else if (strcmp (UINTMAX_TYPE
, "long long unsigned int") == 0)
996 *pintmax
= long_long_integer_type_node
;
997 *puintmax
= long_long_unsigned_type_node
;
1001 for (int i
= 0; i
< NUM_INT_N_ENTS
; i
++)
1002 if (int_n_enabled_p
[i
])
1004 char name
[50], altname
[50];
1005 sprintf (name
, "__int%d unsigned", int_n_data
[i
].bitsize
);
1006 sprintf (altname
, "__int%d__ unsigned", int_n_data
[i
].bitsize
);
1008 if (strcmp (name
, UINTMAX_TYPE
) == 0
1009 || strcmp (altname
, UINTMAX_TYPE
) == 0)
1011 *pintmax
= int_n_trees
[i
].signed_type
;
1012 *puintmax
= int_n_trees
[i
].unsigned_type
;
1020 /* Determine the range [*PMIN, *PMAX] that the expression ARG is
1021 in and that is representable in type int.
1022 Return true when the range is a subrange of that of int.
1023 When ARG is null it is as if it had the full range of int.
1024 When ABSOLUTE is true the range reflects the absolute value of
1025 the argument. When ABSOLUTE is false, negative bounds of
1026 the determined range are replaced with NEGBOUND. */
1029 get_int_range (tree arg
, HOST_WIDE_INT
*pmin
, HOST_WIDE_INT
*pmax
,
1030 bool absolute
, HOST_WIDE_INT negbound
,
1031 const class vr_values
*vr_values
)
1033 /* The type of the result. */
1034 const_tree type
= integer_type_node
;
1036 bool knownrange
= false;
1040 *pmin
= tree_to_shwi (TYPE_MIN_VALUE (type
));
1041 *pmax
= tree_to_shwi (TYPE_MAX_VALUE (type
));
1043 else if (TREE_CODE (arg
) == INTEGER_CST
1044 && TYPE_PRECISION (TREE_TYPE (arg
)) <= TYPE_PRECISION (type
))
1046 /* For a constant argument return its value adjusted as specified
1047 by NEGATIVE and NEGBOUND and return true to indicate that the
1049 *pmin
= tree_fits_shwi_p (arg
) ? tree_to_shwi (arg
) : tree_to_uhwi (arg
);
1055 /* True if the argument's range cannot be determined. */
1056 bool unknown
= true;
1058 tree argtype
= TREE_TYPE (arg
);
1060 /* Ignore invalid arguments with greater precision that that
1061 of the expected type (e.g., in sprintf("%*i", 12LL, i)).
1062 They will have been detected and diagnosed by -Wformat and
1063 so it's not important to complicate this code to try to deal
1065 if (TREE_CODE (arg
) == SSA_NAME
1066 && INTEGRAL_TYPE_P (argtype
)
1067 && TYPE_PRECISION (argtype
) <= TYPE_PRECISION (type
))
1069 /* Try to determine the range of values of the integer argument. */
1070 const value_range_equiv
*vr
1071 = CONST_CAST (class vr_values
*, vr_values
)->get_value_range (arg
);
1073 if (range_int_cst_p (vr
))
1075 HOST_WIDE_INT type_min
1076 = (TYPE_UNSIGNED (argtype
)
1077 ? tree_to_uhwi (TYPE_MIN_VALUE (argtype
))
1078 : tree_to_shwi (TYPE_MIN_VALUE (argtype
)));
1080 HOST_WIDE_INT type_max
= tree_to_uhwi (TYPE_MAX_VALUE (argtype
));
1082 *pmin
= TREE_INT_CST_LOW (vr
->min ());
1083 *pmax
= TREE_INT_CST_LOW (vr
->max ());
1087 /* Return true if the adjusted range is a subrange of
1088 the full range of the argument's type. *PMAX may
1089 be less than *PMIN when the argument is unsigned
1090 and its upper bound is in excess of TYPE_MAX. In
1091 that (invalid) case disregard the range and use that
1092 of the expected type instead. */
1093 knownrange
= type_min
< *pmin
|| *pmax
< type_max
;
1100 /* Handle an argument with an unknown range as if none had been
1103 return get_int_range (NULL_TREE
, pmin
, pmax
, absolute
,
1104 negbound
, vr_values
);
1107 /* Adjust each bound as specified by ABSOLUTE and NEGBOUND. */
1113 *pmin
= *pmax
= -*pmin
;
1116 /* Make sure signed overlow is avoided. */
1117 gcc_assert (*pmin
!= HOST_WIDE_INT_MIN
);
1119 HOST_WIDE_INT tmp
= -*pmin
;
1126 else if (*pmin
< negbound
)
1132 /* With the range [*ARGMIN, *ARGMAX] of an integer directive's actual
1133 argument, due to the conversion from either *ARGMIN or *ARGMAX to
1134 the type of the directive's formal argument it's possible for both
1135 to result in the same number of bytes or a range of bytes that's
1136 less than the number of bytes that would result from formatting
1137 some other value in the range [*ARGMIN, *ARGMAX]. This can be
1138 determined by checking for the actual argument being in the range
1139 of the type of the directive. If it isn't it must be assumed to
1140 take on the full range of the directive's type.
1141 Return true when the range has been adjusted to the full range
1142 of DIRTYPE, and false otherwise. */
1145 adjust_range_for_overflow (tree dirtype
, tree
*argmin
, tree
*argmax
)
1147 tree argtype
= TREE_TYPE (*argmin
);
1148 unsigned argprec
= TYPE_PRECISION (argtype
);
1149 unsigned dirprec
= TYPE_PRECISION (dirtype
);
1151 /* If the actual argument and the directive's argument have the same
1152 precision and sign there can be no overflow and so there is nothing
1154 if (argprec
== dirprec
&& TYPE_SIGN (argtype
) == TYPE_SIGN (dirtype
))
1157 /* The logic below was inspired/lifted from the CONVERT_EXPR_CODE_P
1158 branch in the extract_range_from_unary_expr function in tree-vrp.c. */
1160 if (TREE_CODE (*argmin
) == INTEGER_CST
1161 && TREE_CODE (*argmax
) == INTEGER_CST
1162 && (dirprec
>= argprec
1163 || integer_zerop (int_const_binop (RSHIFT_EXPR
,
1164 int_const_binop (MINUS_EXPR
,
1167 size_int (dirprec
)))))
1169 *argmin
= force_fit_type (dirtype
, wi::to_widest (*argmin
), 0, false);
1170 *argmax
= force_fit_type (dirtype
, wi::to_widest (*argmax
), 0, false);
1172 /* If *ARGMIN is still less than *ARGMAX the conversion above
1173 is safe. Otherwise, it has overflowed and would be unsafe. */
1174 if (tree_int_cst_le (*argmin
, *argmax
))
1178 *argmin
= TYPE_MIN_VALUE (dirtype
);
1179 *argmax
= TYPE_MAX_VALUE (dirtype
);
1183 /* Return a range representing the minimum and maximum number of bytes
1184 that the format directive DIR will output for any argument given
1185 the WIDTH and PRECISION (extracted from DIR). This function is
1186 used when the directive argument or its value isn't known. */
1189 format_integer (const directive
&dir
, tree arg
, const vr_values
*vr_values
)
1191 tree intmax_type_node
;
1192 tree uintmax_type_node
;
1194 /* Base to format the number in. */
1197 /* True when a conversion is preceded by a prefix indicating the base
1198 of the argument (octal or hexadecimal). */
1199 bool maybebase
= dir
.get_flag ('#');
1201 /* True when a signed conversion is preceded by a sign or space. */
1202 bool maybesign
= false;
1204 /* True for signed conversions (i.e., 'd' and 'i'). */
1207 switch (dir
.specifier
)
1211 /* Space and '+' are only meaningful for signed conversions. */
1212 maybesign
= dir
.get_flag (' ') | dir
.get_flag ('+');
1230 /* The type of the "formal" argument expected by the directive. */
1231 tree dirtype
= NULL_TREE
;
1233 /* Determine the expected type of the argument from the length
1235 switch (dir
.modifier
)
1238 if (dir
.specifier
== 'p')
1239 dirtype
= ptr_type_node
;
1241 dirtype
= sign
? integer_type_node
: unsigned_type_node
;
1245 dirtype
= sign
? short_integer_type_node
: short_unsigned_type_node
;
1249 dirtype
= sign
? signed_char_type_node
: unsigned_char_type_node
;
1253 dirtype
= sign
? long_integer_type_node
: long_unsigned_type_node
;
1259 ? long_long_integer_type_node
1260 : long_long_unsigned_type_node
);
1264 dirtype
= signed_or_unsigned_type_for (!sign
, size_type_node
);
1268 dirtype
= signed_or_unsigned_type_for (!sign
, ptrdiff_type_node
);
1272 build_intmax_type_nodes (&intmax_type_node
, &uintmax_type_node
);
1273 dirtype
= sign
? intmax_type_node
: uintmax_type_node
;
1277 return fmtresult ();
1280 /* The type of the argument to the directive, either deduced from
1281 the actual non-constant argument if one is known, or from
1282 the directive itself when none has been provided because it's
1284 tree argtype
= NULL_TREE
;
1288 /* When the argument has not been provided, use the type of
1289 the directive's argument as an approximation. This will
1290 result in false positives for directives like %i with
1291 arguments with smaller precision (such as short or char). */
1294 else if (TREE_CODE (arg
) == INTEGER_CST
)
1296 /* When a constant argument has been provided use its value
1297 rather than type to determine the length of the output. */
1300 if ((dir
.prec
[0] <= 0 && dir
.prec
[1] >= 0) && integer_zerop (arg
))
1302 /* As a special case, a precision of zero with a zero argument
1303 results in zero bytes except in base 8 when the '#' flag is
1304 specified, and for signed conversions in base 8 and 10 when
1305 either the space or '+' flag has been specified and it results
1306 in just one byte (with width having the normal effect). This
1307 must extend to the case of a specified precision with
1308 an unknown value because it can be zero. */
1309 res
.range
.min
= ((base
== 8 && dir
.get_flag ('#')) || maybesign
);
1310 if (res
.range
.min
== 0 && dir
.prec
[0] != dir
.prec
[1])
1313 res
.range
.likely
= 1;
1317 res
.range
.max
= res
.range
.min
;
1318 res
.range
.likely
= res
.range
.min
;
1323 /* Convert the argument to the type of the directive. */
1324 arg
= fold_convert (dirtype
, arg
);
1326 res
.range
.min
= tree_digits (arg
, base
, dir
.prec
[0],
1327 maybesign
, maybebase
);
1328 if (dir
.prec
[0] == dir
.prec
[1])
1329 res
.range
.max
= res
.range
.min
;
1331 res
.range
.max
= tree_digits (arg
, base
, dir
.prec
[1],
1332 maybesign
, maybebase
);
1333 res
.range
.likely
= res
.range
.min
;
1334 res
.knownrange
= true;
1337 res
.range
.unlikely
= res
.range
.max
;
1339 /* Bump up the counters if WIDTH is greater than LEN. */
1340 res
.adjust_for_width_or_precision (dir
.width
, dirtype
, base
,
1341 (sign
| maybebase
) + (base
== 16));
1342 /* Bump up the counters again if PRECision is greater still. */
1343 res
.adjust_for_width_or_precision (dir
.prec
, dirtype
, base
,
1344 (sign
| maybebase
) + (base
== 16));
1348 else if (INTEGRAL_TYPE_P (TREE_TYPE (arg
))
1349 || TREE_CODE (TREE_TYPE (arg
)) == POINTER_TYPE
)
1350 /* Determine the type of the provided non-constant argument. */
1351 argtype
= TREE_TYPE (arg
);
1353 /* Don't bother with invalid arguments since they likely would
1354 have already been diagnosed, and disable any further checking
1355 of the format string by returning [-1, -1]. */
1356 return fmtresult ();
1360 /* Using either the range the non-constant argument is in, or its
1361 type (either "formal" or actual), create a range of values that
1362 constrain the length of output given the warning level. */
1363 tree argmin
= NULL_TREE
;
1364 tree argmax
= NULL_TREE
;
1367 && TREE_CODE (arg
) == SSA_NAME
1368 && INTEGRAL_TYPE_P (argtype
))
1370 /* Try to determine the range of values of the integer argument
1371 (range information is not available for pointers). */
1372 const value_range_equiv
*vr
1373 = CONST_CAST (class vr_values
*, vr_values
)->get_value_range (arg
);
1375 if (range_int_cst_p (vr
))
1377 argmin
= vr
->min ();
1378 argmax
= vr
->max ();
1380 /* Set KNOWNRANGE if the argument is in a known subrange
1381 of the directive's type and neither width nor precision
1382 is unknown. (KNOWNRANGE may be reset below). */
1384 = ((!tree_int_cst_equal (TYPE_MIN_VALUE (dirtype
), argmin
)
1385 || !tree_int_cst_equal (TYPE_MAX_VALUE (dirtype
), argmax
))
1386 && dir
.known_width_and_precision ());
1388 res
.argmin
= argmin
;
1389 res
.argmax
= argmax
;
1391 else if (vr
->kind () == VR_ANTI_RANGE
)
1393 /* Handle anti-ranges if/when bug 71690 is resolved. */
1395 else if (vr
->varying_p () || vr
->undefined_p ())
1397 /* The argument here may be the result of promoting the actual
1398 argument to int. Try to determine the type of the actual
1399 argument before promotion and narrow down its range that
1401 gimple
*def
= SSA_NAME_DEF_STMT (arg
);
1402 if (is_gimple_assign (def
))
1404 tree_code code
= gimple_assign_rhs_code (def
);
1405 if (code
== INTEGER_CST
)
1407 arg
= gimple_assign_rhs1 (def
);
1408 return format_integer (dir
, arg
, vr_values
);
1411 if (code
== NOP_EXPR
)
1413 tree type
= TREE_TYPE (gimple_assign_rhs1 (def
));
1414 if (INTEGRAL_TYPE_P (type
)
1415 || TREE_CODE (type
) == POINTER_TYPE
)
1424 if (TREE_CODE (argtype
) == POINTER_TYPE
)
1426 argmin
= build_int_cst (pointer_sized_int_node
, 0);
1427 argmax
= build_all_ones_cst (pointer_sized_int_node
);
1431 argmin
= TYPE_MIN_VALUE (argtype
);
1432 argmax
= TYPE_MAX_VALUE (argtype
);
1436 /* Clear KNOWNRANGE if the range has been adjusted to the maximum
1437 of the directive. If it has been cleared then since ARGMIN and/or
1438 ARGMAX have been adjusted also adjust the corresponding ARGMIN and
1439 ARGMAX in the result to include in diagnostics. */
1440 if (adjust_range_for_overflow (dirtype
, &argmin
, &argmax
))
1442 res
.knownrange
= false;
1443 res
.argmin
= argmin
;
1444 res
.argmax
= argmax
;
1447 /* Recursively compute the minimum and maximum from the known range. */
1448 if (TYPE_UNSIGNED (dirtype
) || tree_int_cst_sgn (argmin
) >= 0)
1450 /* For unsigned conversions/directives or signed when
1451 the minimum is positive, use the minimum and maximum to compute
1452 the shortest and longest output, respectively. */
1453 res
.range
.min
= format_integer (dir
, argmin
, vr_values
).range
.min
;
1454 res
.range
.max
= format_integer (dir
, argmax
, vr_values
).range
.max
;
1456 else if (tree_int_cst_sgn (argmax
) < 0)
1458 /* For signed conversions/directives if maximum is negative,
1459 use the minimum as the longest output and maximum as the
1461 res
.range
.min
= format_integer (dir
, argmax
, vr_values
).range
.min
;
1462 res
.range
.max
= format_integer (dir
, argmin
, vr_values
).range
.max
;
1466 /* Otherwise, 0 is inside of the range and minimum negative. Use 0
1467 as the shortest output and for the longest output compute the
1468 length of the output of both minimum and maximum and pick the
1470 unsigned HOST_WIDE_INT max1
1471 = format_integer (dir
, argmin
, vr_values
).range
.max
;
1472 unsigned HOST_WIDE_INT max2
1473 = format_integer (dir
, argmax
, vr_values
).range
.max
;
1475 = format_integer (dir
, integer_zero_node
, vr_values
).range
.min
;
1476 res
.range
.max
= MAX (max1
, max2
);
1479 /* If the range is known, use the maximum as the likely length. */
1481 res
.range
.likely
= res
.range
.max
;
1484 /* Otherwise, use the minimum. Except for the case where for %#x or
1485 %#o the minimum is just for a single value in the range (0) and
1486 for all other values it is something longer, like 0x1 or 01.
1487 Use the length for value 1 in that case instead as the likely
1489 res
.range
.likely
= res
.range
.min
;
1492 && (tree_int_cst_sgn (argmin
) < 0 || tree_int_cst_sgn (argmax
) > 0))
1494 if (res
.range
.min
== 1)
1495 res
.range
.likely
+= base
== 8 ? 1 : 2;
1496 else if (res
.range
.min
== 2
1498 && (dir
.width
[0] == 2 || dir
.prec
[0] == 2))
1503 res
.range
.unlikely
= res
.range
.max
;
1504 res
.adjust_for_width_or_precision (dir
.width
, dirtype
, base
,
1505 (sign
| maybebase
) + (base
== 16));
1506 res
.adjust_for_width_or_precision (dir
.prec
, dirtype
, base
,
1507 (sign
| maybebase
) + (base
== 16));
1512 /* Return the number of bytes that a format directive consisting of FLAGS,
1513 PRECision, format SPECification, and MPFR rounding specifier RNDSPEC,
1514 would result for argument X under ideal conditions (i.e., if PREC
1515 weren't excessive). MPFR 3.1 allocates large amounts of memory for
1516 values of PREC with large magnitude and can fail (see MPFR bug #21056).
1517 This function works around those problems. */
1519 static unsigned HOST_WIDE_INT
1520 get_mpfr_format_length (mpfr_ptr x
, const char *flags
, HOST_WIDE_INT prec
,
1521 char spec
, char rndspec
)
1525 HOST_WIDE_INT len
= strlen (flags
);
1528 memcpy (fmtstr
+ 1, flags
, len
);
1529 memcpy (fmtstr
+ 1 + len
, ".*R", 3);
1530 fmtstr
[len
+ 4] = rndspec
;
1531 fmtstr
[len
+ 5] = spec
;
1532 fmtstr
[len
+ 6] = '\0';
1534 spec
= TOUPPER (spec
);
1535 if (spec
== 'E' || spec
== 'F')
1537 /* For %e, specify the precision explicitly since mpfr_sprintf
1538 does its own thing just to be different (see MPFR bug 21088). */
1544 /* Avoid passing negative precisions with larger magnitude to MPFR
1545 to avoid exposing its bugs. (A negative precision is supposed
1551 HOST_WIDE_INT p
= prec
;
1553 if (spec
== 'G' && !strchr (flags
, '#'))
1555 /* For G/g without the pound flag, precision gives the maximum number
1556 of significant digits which is bounded by LDBL_MAX_10_EXP, or, for
1557 a 128 bit IEEE extended precision, 4932. Using twice as much here
1558 should be more than sufficient for any real format. */
1559 if ((IEEE_MAX_10_EXP
* 2) < prec
)
1560 prec
= IEEE_MAX_10_EXP
* 2;
1565 /* Cap precision arbitrarily at 1KB and add the difference
1566 (if any) to the MPFR result. */
1571 len
= mpfr_snprintf (NULL
, 0, fmtstr
, (int)p
, x
);
1573 /* Handle the unlikely (impossible?) error by returning more than
1574 the maximum dictated by the function's return type. */
1576 return target_dir_max () + 1;
1578 /* Adjust the return value by the difference. */
1585 /* Return the number of bytes to format using the format specifier
1586 SPEC and the precision PREC the largest value in the real floating
1589 static unsigned HOST_WIDE_INT
1590 format_floating_max (tree type
, char spec
, HOST_WIDE_INT prec
)
1592 machine_mode mode
= TYPE_MODE (type
);
1594 /* IBM Extended mode. */
1595 if (MODE_COMPOSITE_P (mode
))
1598 /* Get the real type format desription for the target. */
1599 const real_format
*rfmt
= REAL_MODE_FORMAT (mode
);
1602 real_maxval (&rv
, 0, mode
);
1604 /* Convert the GCC real value representation with the precision
1605 of the real type to the mpfr_t format with the GCC default
1606 round-to-nearest mode. */
1608 mpfr_init2 (x
, rfmt
->p
);
1609 mpfr_from_real (x
, &rv
, MPFR_RNDN
);
1611 /* Return a value one greater to account for the leading minus sign. */
1612 unsigned HOST_WIDE_INT r
1613 = 1 + get_mpfr_format_length (x
, "", prec
, spec
, 'D');
1618 /* Return a range representing the minimum and maximum number of bytes
1619 that the directive DIR will output for any argument. PREC gives
1620 the adjusted precision range to account for negative precisions
1621 meaning the default 6. This function is used when the directive
1622 argument or its value isn't known. */
1625 format_floating (const directive
&dir
, const HOST_WIDE_INT prec
[2])
1629 switch (dir
.modifier
)
1633 type
= double_type_node
;
1637 type
= long_double_type_node
;
1641 type
= long_double_type_node
;
1645 return fmtresult ();
1648 /* The minimum and maximum number of bytes produced by the directive. */
1651 /* The minimum output as determined by flags. It's always at least 1.
1652 When plus or space are set the output is preceded by either a sign
1654 unsigned flagmin
= (1 /* for the first digit */
1655 + (dir
.get_flag ('+') | dir
.get_flag (' ')));
1657 /* The minimum is 3 for "inf" and "nan" for all specifiers, plus 1
1658 for the plus sign/space with the '+' and ' ' flags, respectively,
1659 unless reduced below. */
1660 res
.range
.min
= 2 + flagmin
;
1662 /* When the pound flag is set the decimal point is included in output
1663 regardless of precision. Whether or not a decimal point is included
1664 otherwise depends on the specification and precision. */
1665 bool radix
= dir
.get_flag ('#');
1667 switch (dir
.specifier
)
1672 HOST_WIDE_INT minprec
= 6 + !radix
/* decimal point */;
1673 if (dir
.prec
[0] <= 0)
1675 else if (dir
.prec
[0] > 0)
1676 minprec
= dir
.prec
[0] + !radix
/* decimal point */;
1678 res
.range
.likely
= (2 /* 0x */
1684 res
.range
.max
= format_floating_max (type
, 'a', prec
[1]);
1686 /* The unlikely maximum accounts for the longest multibyte
1687 decimal point character. */
1688 res
.range
.unlikely
= res
.range
.max
;
1689 if (dir
.prec
[1] > 0)
1690 res
.range
.unlikely
+= target_mb_len_max () - 1;
1698 /* Minimum output attributable to precision and, when it's
1699 non-zero, decimal point. */
1700 HOST_WIDE_INT minprec
= prec
[0] ? prec
[0] + !radix
: 0;
1702 /* The likely minimum output is "[-+]1.234567e+00" regardless
1703 of the value of the actual argument. */
1704 res
.range
.likely
= (flagmin
1709 res
.range
.max
= format_floating_max (type
, 'e', prec
[1]);
1711 /* The unlikely maximum accounts for the longest multibyte
1712 decimal point character. */
1713 if (dir
.prec
[0] != dir
.prec
[1]
1714 || dir
.prec
[0] == -1 || dir
.prec
[0] > 0)
1715 res
.range
.unlikely
= res
.range
.max
+ target_mb_len_max () -1;
1717 res
.range
.unlikely
= res
.range
.max
;
1724 /* Minimum output attributable to precision and, when it's non-zero,
1726 HOST_WIDE_INT minprec
= prec
[0] ? prec
[0] + !radix
: 0;
1728 /* For finite numbers (i.e., not infinity or NaN) the lower bound
1729 when precision isn't specified is 8 bytes ("1.23456" since
1730 precision is taken to be 6). When precision is zero, the lower
1731 bound is 1 byte (e.g., "1"). Otherwise, when precision is greater
1732 than zero, then the lower bound is 2 plus precision (plus flags).
1733 But in all cases, the lower bound is no greater than 3. */
1734 unsigned HOST_WIDE_INT min
= flagmin
+ radix
+ minprec
;
1735 if (min
< res
.range
.min
)
1736 res
.range
.min
= min
;
1738 /* Compute the upper bound for -TYPE_MAX. */
1739 res
.range
.max
= format_floating_max (type
, 'f', prec
[1]);
1741 /* The minimum output with unknown precision is a single byte
1742 (e.g., "0") but the more likely output is 3 bytes ("0.0"). */
1743 if (dir
.prec
[0] < 0 && dir
.prec
[1] > 0)
1744 res
.range
.likely
= 3;
1746 res
.range
.likely
= min
;
1748 /* The unlikely maximum accounts for the longest multibyte
1749 decimal point character. */
1750 if (dir
.prec
[0] != dir
.prec
[1]
1751 || dir
.prec
[0] == -1 || dir
.prec
[0] > 0)
1752 res
.range
.unlikely
= res
.range
.max
+ target_mb_len_max () - 1;
1759 /* The %g output depends on precision and the exponent of
1760 the argument. Since the value of the argument isn't known
1761 the lower bound on the range of bytes (not counting flags
1762 or width) is 1 plus radix (i.e., either "0" or "0." for
1763 "%g" and "%#g", respectively, with a zero argument). */
1764 unsigned HOST_WIDE_INT min
= flagmin
+ radix
;
1765 if (min
< res
.range
.min
)
1766 res
.range
.min
= min
;
1769 HOST_WIDE_INT maxprec
= dir
.prec
[1];
1770 if (radix
&& maxprec
)
1772 /* When the pound flag (radix) is set, trailing zeros aren't
1773 trimmed and so the longest output is the same as for %e,
1774 except with precision minus 1 (as specified in C11). */
1778 else if (maxprec
< 0)
1784 res
.range
.max
= format_floating_max (type
, spec
, maxprec
);
1786 /* The likely output is either the maximum computed above
1787 minus 1 (assuming the maximum is positive) when precision
1788 is known (or unspecified), or the same minimum as for %e
1789 (which is computed for a non-negative argument). Unlike
1790 for the other specifiers above the likely output isn't
1791 the minimum because for %g that's 1 which is unlikely. */
1793 || (unsigned HOST_WIDE_INT
)dir
.prec
[1] < target_int_max ())
1794 res
.range
.likely
= res
.range
.max
- 1;
1797 HOST_WIDE_INT minprec
= 6 + !radix
/* decimal point */;
1798 res
.range
.likely
= (flagmin
1804 /* The unlikely maximum accounts for the longest multibyte
1805 decimal point character. */
1806 res
.range
.unlikely
= res
.range
.max
+ target_mb_len_max () - 1;
1811 return fmtresult ();
1814 /* Bump up the byte counters if WIDTH is greater. */
1815 res
.adjust_for_width_or_precision (dir
.width
);
1819 /* Return a range representing the minimum and maximum number of bytes
1820 that the directive DIR will write on output for the floating argument
1824 format_floating (const directive
&dir
, tree arg
, const vr_values
*)
1826 HOST_WIDE_INT prec
[] = { dir
.prec
[0], dir
.prec
[1] };
1827 tree type
= (dir
.modifier
== FMT_LEN_L
|| dir
.modifier
== FMT_LEN_ll
1828 ? long_double_type_node
: double_type_node
);
1830 /* For an indeterminate precision the lower bound must be assumed
1832 if (TOUPPER (dir
.specifier
) == 'A')
1834 /* Get the number of fractional decimal digits needed to represent
1835 the argument without a loss of accuracy. */
1837 = REAL_MODE_FORMAT (TYPE_MODE (type
))->p
;
1839 /* The precision of the IEEE 754 double format is 53.
1840 The precision of all other GCC binary double formats
1842 unsigned maxprec
= fmtprec
<= 56 ? 13 : 15;
1844 /* For %a, leave the minimum precision unspecified to let
1845 MFPR trim trailing zeros (as it and many other systems
1846 including Glibc happen to do) and set the maximum
1847 precision to reflect what it would be with trailing zeros
1848 present (as Solaris and derived systems do). */
1849 if (dir
.prec
[1] < 0)
1851 /* Both bounds are negative implies that precision has
1852 not been specified. */
1856 else if (dir
.prec
[0] < 0)
1858 /* With a negative lower bound and a non-negative upper
1859 bound set the minimum precision to zero and the maximum
1860 to the greater of the maximum precision (i.e., with
1861 trailing zeros present) and the specified upper bound. */
1863 prec
[1] = dir
.prec
[1] < maxprec
? maxprec
: dir
.prec
[1];
1866 else if (dir
.prec
[0] < 0)
1868 if (dir
.prec
[1] < 0)
1870 /* A precision in a strictly negative range is ignored and
1871 the default of 6 is used instead. */
1872 prec
[0] = prec
[1] = 6;
1876 /* For a precision in a partly negative range, the lower bound
1877 must be assumed to be zero and the new upper bound is the
1878 greater of 6 (the default precision used when the specified
1879 precision is negative) and the upper bound of the specified
1882 prec
[1] = dir
.prec
[1] < 6 ? 6 : dir
.prec
[1];
1887 || TREE_CODE (arg
) != REAL_CST
1888 || !useless_type_conversion_p (type
, TREE_TYPE (arg
)))
1889 return format_floating (dir
, prec
);
1891 /* The minimum and maximum number of bytes produced by the directive. */
1894 /* Get the real type format desription for the target. */
1895 const REAL_VALUE_TYPE
*rvp
= TREE_REAL_CST_PTR (arg
);
1896 const real_format
*rfmt
= REAL_MODE_FORMAT (TYPE_MODE (TREE_TYPE (arg
)));
1898 if (!real_isfinite (rvp
))
1900 /* The format for Infinity and NaN is "[-]inf"/"[-]infinity"
1901 and "[-]nan" with the choice being implementation-defined
1902 but not locale dependent. */
1903 bool sign
= dir
.get_flag ('+') || real_isneg (rvp
);
1904 res
.range
.min
= 3 + sign
;
1906 res
.range
.likely
= res
.range
.min
;
1907 res
.range
.max
= res
.range
.min
;
1908 /* The unlikely maximum is "[-/+]infinity" or "[-/+][qs]nan".
1909 For NaN, the C/POSIX standards specify two formats:
1912 "[-/+]nan(n-char-sequence)"
1913 No known printf implementation outputs the latter format but AIX
1914 outputs QNaN and SNaN for quiet and signalling NaN, respectively,
1915 so the unlikely maximum reflects that. */
1916 res
.range
.unlikely
= sign
+ (real_isinf (rvp
) ? 8 : 4);
1918 /* The range for infinity and NaN is known unless either width
1919 or precision is unknown. Width has the same effect regardless
1920 of whether the argument is finite. Precision is either ignored
1921 (e.g., Glibc) or can have an effect on the short vs long format
1922 such as inf/infinity (e.g., Solaris). */
1923 res
.knownrange
= dir
.known_width_and_precision ();
1925 /* Adjust the range for width but ignore precision. */
1926 res
.adjust_for_width_or_precision (dir
.width
);
1932 char *pfmt
= fmtstr
;
1935 for (const char *pf
= "-+ #0"; *pf
; ++pf
)
1936 if (dir
.get_flag (*pf
))
1942 /* Set up an array to easily iterate over. */
1943 unsigned HOST_WIDE_INT
* const minmax
[] = {
1944 &res
.range
.min
, &res
.range
.max
1947 for (int i
= 0; i
!= sizeof minmax
/ sizeof *minmax
; ++i
)
1949 /* Convert the GCC real value representation with the precision
1950 of the real type to the mpfr_t format rounding down in the
1951 first iteration that computes the minimm and up in the second
1952 that computes the maximum. This order is arbibtrary because
1953 rounding in either direction can result in longer output. */
1955 mpfr_init2 (mpfrval
, rfmt
->p
);
1956 mpfr_from_real (mpfrval
, rvp
, i
? MPFR_RNDU
: MPFR_RNDD
);
1958 /* Use the MPFR rounding specifier to round down in the first
1959 iteration and then up. In most but not all cases this will
1960 result in the same number of bytes. */
1961 char rndspec
= "DU"[i
];
1963 /* Format it and store the result in the corresponding member
1964 of the result struct. */
1965 *minmax
[i
] = get_mpfr_format_length (mpfrval
, fmtstr
, prec
[i
],
1966 dir
.specifier
, rndspec
);
1967 mpfr_clear (mpfrval
);
1971 /* Make sure the minimum is less than the maximum (MPFR rounding
1972 in the call to mpfr_snprintf can result in the reverse. */
1973 if (res
.range
.max
< res
.range
.min
)
1975 unsigned HOST_WIDE_INT tmp
= res
.range
.min
;
1976 res
.range
.min
= res
.range
.max
;
1977 res
.range
.max
= tmp
;
1980 /* The range is known unless either width or precision is unknown. */
1981 res
.knownrange
= dir
.known_width_and_precision ();
1983 /* For the same floating point constant, unless width or precision
1984 is unknown, use the longer output as the likely maximum since
1985 with round to nearest either is equally likely. Otheriwse, when
1986 precision is unknown, use the greater of the minimum and 3 as
1987 the likely output (for "0.0" since zero precision is unlikely). */
1989 res
.range
.likely
= res
.range
.max
;
1990 else if (res
.range
.min
< 3
1992 && (unsigned HOST_WIDE_INT
)dir
.prec
[1] == target_int_max ())
1993 res
.range
.likely
= 3;
1995 res
.range
.likely
= res
.range
.min
;
1997 res
.range
.unlikely
= res
.range
.max
;
1999 if (res
.range
.max
> 2 && (prec
[0] != 0 || prec
[1] != 0))
2001 /* Unless the precision is zero output longer than 2 bytes may
2002 include the decimal point which must be a single character
2003 up to MB_LEN_MAX in length. This is overly conservative
2004 since in some conversions some constants result in no decimal
2005 point (e.g., in %g). */
2006 res
.range
.unlikely
+= target_mb_len_max () - 1;
2009 res
.adjust_for_width_or_precision (dir
.width
);
2013 /* Return a FMTRESULT struct set to the lengths of the shortest and longest
2014 strings referenced by the expression STR, or (-1, -1) when not known.
2015 Used by the format_string function below. */
2018 get_string_length (tree str
, unsigned eltsize
, const vr_values
*vr
)
2021 return fmtresult ();
2023 /* Try to determine the dynamic string length first.
2024 Set MAXBOUND to an arbitrary non-null non-integer node as a request
2025 to have it set to the length of the longest string in a PHI. */
2026 c_strlen_data lendata
= { };
2027 lendata
.maxbound
= str
;
2029 get_range_strlen_dynamic (str
, &lendata
, vr
);
2032 /* Determine the length of the shortest and longest string referenced
2033 by STR. Strings of unknown lengths are bounded by the sizes of
2034 arrays that subexpressions of STR may refer to. Pointers that
2035 aren't known to point any such arrays result in LENDATA.MAXLEN
2037 get_range_strlen (str
, &lendata
, eltsize
);
2040 /* If LENDATA.MAXBOUND is not equal to .MINLEN it corresponds to the bound
2041 of the largest array STR refers to, if known, or it's set to SIZE_MAX
2044 /* Return the default result when nothing is known about the string. */
2045 if ((lendata
.maxbound
&& !tree_fits_uhwi_p (lendata
.maxbound
))
2046 || !tree_fits_uhwi_p (lendata
.maxlen
))
2049 res
.nonstr
= lendata
.decl
;
2053 unsigned HOST_WIDE_INT lenmax
= tree_to_uhwi (max_object_size ()) - 2;
2054 if (integer_zerop (lendata
.minlen
)
2055 && (!lendata
.maxbound
|| lenmax
<= tree_to_uhwi (lendata
.maxbound
))
2056 && lenmax
<= tree_to_uhwi (lendata
.maxlen
))
2059 res
.nonstr
= lendata
.decl
;
2064 = (tree_fits_uhwi_p (lendata
.minlen
)
2065 ? tree_to_uhwi (lendata
.minlen
)
2069 = (lendata
.maxbound
&& tree_fits_uhwi_p (lendata
.maxbound
)
2070 ? tree_to_uhwi (lendata
.maxbound
)
2071 : HOST_WIDE_INT_M1U
);
2073 const bool unbounded
= integer_all_onesp (lendata
.maxlen
);
2075 /* Set the max/likely counters to unbounded when a minimum is known
2076 but the maximum length isn't bounded. This implies that STR is
2077 a conditional expression involving a string of known length and
2078 and an expression of unknown/unbounded length. */
2080 && (unsigned HOST_WIDE_INT
)min
< HOST_WIDE_INT_M1U
2082 max
= HOST_WIDE_INT_M1U
;
2084 /* get_range_strlen() returns the target value of SIZE_MAX for
2085 strings of unknown length. Bump it up to HOST_WIDE_INT_M1U
2086 which may be bigger. */
2087 if ((unsigned HOST_WIDE_INT
)min
== target_size_max ())
2088 min
= HOST_WIDE_INT_M1U
;
2089 if ((unsigned HOST_WIDE_INT
)max
== target_size_max ())
2090 max
= HOST_WIDE_INT_M1U
;
2092 fmtresult
res (min
, max
);
2093 res
.nonstr
= lendata
.decl
;
2095 /* Set RES.KNOWNRANGE to true if and only if all strings referenced
2096 by STR are known to be bounded (though not necessarily by their
2097 actual length but perhaps by their maximum possible length). */
2098 if (res
.range
.max
< target_int_max ())
2100 res
.knownrange
= true;
2101 /* When the length of the longest string is known and not
2102 excessive use it as the likely length of the string(s). */
2103 res
.range
.likely
= res
.range
.max
;
2107 /* When the upper bound is unknown (it can be zero or excessive)
2108 set the likely length to the greater of 1. If MAXBOUND is
2109 known, also reset the length of the lower bound to zero. */
2110 res
.range
.likely
= res
.range
.min
? res
.range
.min
: warn_level
> 1;
2111 if (lendata
.maxbound
&& !integer_all_onesp (lendata
.maxbound
))
2115 res
.range
.unlikely
= unbounded
? HOST_WIDE_INT_MAX
: res
.range
.max
;
2120 /* Return the minimum and maximum number of characters formatted
2121 by the '%c' format directives and its wide character form for
2122 the argument ARG. ARG can be null (for functions such as
2126 format_character (const directive
&dir
, tree arg
, const vr_values
*vr_values
)
2130 res
.knownrange
= true;
2132 if (dir
.specifier
== 'C'
2133 || dir
.modifier
== FMT_LEN_l
)
2135 /* A wide character can result in as few as zero bytes. */
2138 HOST_WIDE_INT min
, max
;
2139 if (get_int_range (arg
, &min
, &max
, false, 0, vr_values
))
2141 if (min
== 0 && max
== 0)
2143 /* The NUL wide character results in no bytes. */
2145 res
.range
.likely
= 0;
2146 res
.range
.unlikely
= 0;
2148 else if (min
>= 0 && min
< 128)
2150 /* Be conservative if the target execution character set
2151 is not a 1-to-1 mapping to the source character set or
2152 if the source set is not ASCII. */
2153 bool one_2_one_ascii
2154 = (target_to_host_charmap
[0] == 1 && target_to_host ('a') == 97);
2156 /* A wide character in the ASCII range most likely results
2157 in a single byte, and only unlikely in up to MB_LEN_MAX. */
2158 res
.range
.max
= one_2_one_ascii
? 1 : target_mb_len_max ();;
2159 res
.range
.likely
= 1;
2160 res
.range
.unlikely
= target_mb_len_max ();
2161 res
.mayfail
= !one_2_one_ascii
;
2165 /* A wide character outside the ASCII range likely results
2166 in up to two bytes, and only unlikely in up to MB_LEN_MAX. */
2167 res
.range
.max
= target_mb_len_max ();
2168 res
.range
.likely
= 2;
2169 res
.range
.unlikely
= res
.range
.max
;
2170 /* Converting such a character may fail. */
2176 /* An unknown wide character is treated the same as a wide
2177 character outside the ASCII range. */
2178 res
.range
.max
= target_mb_len_max ();
2179 res
.range
.likely
= 2;
2180 res
.range
.unlikely
= res
.range
.max
;
2186 /* A plain '%c' directive. Its ouput is exactly 1. */
2187 res
.range
.min
= res
.range
.max
= 1;
2188 res
.range
.likely
= res
.range
.unlikely
= 1;
2189 res
.knownrange
= true;
2192 /* Bump up the byte counters if WIDTH is greater. */
2193 return res
.adjust_for_width_or_precision (dir
.width
);
2196 /* Determine the offset *INDEX of the first byte of an array element of
2197 TYPE (possibly recursively) into which the byte offset OFF points.
2198 On success set *INDEX to the offset of the first byte and return type.
2199 Otherwise, if no such element can be found, return null. */
2202 array_elt_at_offset (tree type
, HOST_WIDE_INT off
, HOST_WIDE_INT
*index
)
2204 gcc_assert (TREE_CODE (type
) == ARRAY_TYPE
);
2207 while (TREE_CODE (TREE_TYPE (eltype
)) == ARRAY_TYPE
)
2208 eltype
= TREE_TYPE (eltype
);
2210 if (TYPE_MODE (TREE_TYPE (eltype
)) != TYPE_MODE (char_type_node
))
2211 eltype
= TREE_TYPE (eltype
);
2219 HOST_WIDE_INT typsz
= int_size_in_bytes (type
);
2220 HOST_WIDE_INT eltsz
= int_size_in_bytes (eltype
);
2221 if (off
< typsz
* eltsz
)
2223 *index
= (off
/ eltsz
) * eltsz
;
2224 return TREE_CODE (eltype
) == ARRAY_TYPE
? TREE_TYPE (eltype
) : eltype
;
2230 /* Determine the offset *INDEX of the first byte of a struct member of TYPE
2231 (possibly recursively) into which the byte offset OFF points. On success
2232 set *INDEX to the offset of the first byte and return true. Otherwise,
2233 if no such member can be found, return false. */
2236 field_at_offset (tree type
, HOST_WIDE_INT off
, HOST_WIDE_INT
*index
)
2238 gcc_assert (RECORD_OR_UNION_TYPE_P (type
));
2240 for (tree fld
= TYPE_FIELDS (type
); fld
; fld
= TREE_CHAIN (fld
))
2242 if (TREE_CODE (fld
) != FIELD_DECL
|| DECL_ARTIFICIAL (fld
))
2245 tree fldtype
= TREE_TYPE (fld
);
2246 HOST_WIDE_INT fldoff
= int_byte_position (fld
);
2248 /* If the size is not available the field is a flexible array
2249 member. Treat this case as success. */
2250 tree typesize
= TYPE_SIZE_UNIT (fldtype
);
2251 HOST_WIDE_INT fldsize
= (tree_fits_uhwi_p (typesize
)
2252 ? tree_to_uhwi (typesize
)
2255 if (fldoff
+ fldsize
< off
)
2258 if (TREE_CODE (fldtype
) == ARRAY_TYPE
)
2260 HOST_WIDE_INT idx
= 0;
2261 if (tree ft
= array_elt_at_offset (fldtype
, off
, &idx
))
2271 if (RECORD_OR_UNION_TYPE_P (fldtype
))
2274 return field_at_offset (fldtype
, off
- fldoff
, index
);
2284 /* For an expression X of pointer type, recursively try to find the same
2285 origin (object or pointer) as Y it references and return such an X.
2286 When X refers to a struct member, set *FLDOFF to the offset of the
2287 member from the beginning of the "most derived" object. */
2290 get_origin_and_offset (tree x
, HOST_WIDE_INT
*fldoff
, HOST_WIDE_INT
*off
)
2295 switch (TREE_CODE (x
))
2298 x
= TREE_OPERAND (x
, 0);
2299 return get_origin_and_offset (x
, fldoff
, off
);
2303 tree offset
= TREE_OPERAND (x
, 1);
2304 HOST_WIDE_INT idx
= (tree_fits_uhwi_p (offset
)
2305 ? tree_to_uhwi (offset
) : HOST_WIDE_INT_MAX
);
2307 tree eltype
= TREE_TYPE (x
);
2308 if (TREE_CODE (eltype
) == INTEGER_TYPE
)
2313 else if (idx
< HOST_WIDE_INT_MAX
)
2314 *fldoff
+= idx
* int_size_in_bytes (eltype
);
2318 x
= TREE_OPERAND (x
, 0);
2319 return get_origin_and_offset (x
, fldoff
, NULL
);
2325 tree offset
= TREE_OPERAND (x
, 1);
2326 *off
= (tree_fits_uhwi_p (offset
)
2327 ? tree_to_uhwi (offset
) : HOST_WIDE_INT_MAX
);
2330 x
= TREE_OPERAND (x
, 0);
2335 = (TREE_CODE (x
) == ADDR_EXPR
2336 ? TREE_TYPE (TREE_OPERAND (x
, 0)) : TREE_TYPE (TREE_TYPE (x
)));
2338 /* The byte offset of the most basic struct member the byte
2339 offset *OFF corresponds to, or for a (multidimensional)
2340 array member, the byte offset of the array element. */
2341 HOST_WIDE_INT index
= 0;
2343 if ((RECORD_OR_UNION_TYPE_P (xtype
)
2344 && field_at_offset (xtype
, *off
, &index
))
2345 || (TREE_CODE (xtype
) == ARRAY_TYPE
2346 && TREE_CODE (TREE_TYPE (xtype
)) == ARRAY_TYPE
2347 && array_elt_at_offset (xtype
, *off
, &index
)))
2354 return get_origin_and_offset (x
, fldoff
, NULL
);
2358 tree fld
= TREE_OPERAND (x
, 1);
2359 *fldoff
+= int_byte_position (fld
);
2361 get_origin_and_offset (fld
, fldoff
, off
);
2362 x
= TREE_OPERAND (x
, 0);
2363 return get_origin_and_offset (x
, fldoff
, off
);
2368 gimple
*def
= SSA_NAME_DEF_STMT (x
);
2369 if (is_gimple_assign (def
))
2371 tree_code code
= gimple_assign_rhs_code (def
);
2372 if (code
== ADDR_EXPR
)
2374 x
= gimple_assign_rhs1 (def
);
2375 return get_origin_and_offset (x
, fldoff
, off
);
2378 if (code
== POINTER_PLUS_EXPR
)
2380 tree offset
= gimple_assign_rhs2 (def
);
2382 *off
= (tree_fits_uhwi_p (offset
)
2383 ? tree_to_uhwi (offset
) : HOST_WIDE_INT_MAX
);
2385 x
= gimple_assign_rhs1 (def
);
2386 return get_origin_and_offset (x
, fldoff
, NULL
);
2388 else if (code
== VAR_DECL
)
2390 x
= gimple_assign_rhs1 (def
);
2391 return get_origin_and_offset (x
, fldoff
, off
);
2394 else if (gimple_nop_p (def
) && SSA_NAME_VAR (x
))
2395 x
= SSA_NAME_VAR (x
);
2405 /* If ARG refers to the same (sub)object or array element as described
2406 by DST and DST_FLD, return the byte offset into the struct member or
2407 array element referenced by ARG. Otherwise return HOST_WIDE_INT_MIN
2408 to indicate that ARG and DST do not refer to the same object. */
2410 static HOST_WIDE_INT
2411 alias_offset (tree arg
, tree dst
, HOST_WIDE_INT dst_fld
)
2413 /* See if the argument refers to the same base object as the destination
2414 of the formatted function call, and if so, try to determine if they
2416 if (!arg
|| !dst
|| !ptr_derefs_may_alias_p (arg
, dst
))
2417 return HOST_WIDE_INT_MIN
;
2419 /* The two arguments may refer to the same object. If they both refer
2420 to a struct member, see if the members are one and the same. */
2421 HOST_WIDE_INT arg_off
= 0, arg_fld
= 0;
2423 tree arg_orig
= get_origin_and_offset (arg
, &arg_fld
, &arg_off
);
2425 if (arg_orig
== dst
&& arg_fld
== dst_fld
)
2428 return HOST_WIDE_INT_MIN
;
2431 /* Return the minimum and maximum number of characters formatted
2432 by the '%s' format directive and its wide character form for
2433 the argument ARG. ARG can be null (for functions such as
2437 format_string (const directive
&dir
, tree arg
, const vr_values
*vr_values
)
2443 /* See if ARG might alias the destination of the call with
2444 DST_ORIGIN and DST_FIELD. If so, store the starting offset
2445 so that the overlap can be determined for certain later,
2446 when the amount of output of the call (including subsequent
2447 directives) has been computed. Otherwise, store HWI_MIN. */
2448 res
.dst_offset
= alias_offset (arg
, dir
.info
->dst_origin
,
2449 dir
.info
->dst_field
);
2452 /* Compute the range the argument's length can be in. */
2454 if (dir
.specifier
== 'S' || dir
.modifier
== FMT_LEN_l
)
2456 /* Get a node for a C type that will be the same size
2457 as a wchar_t on the target. */
2458 tree node
= get_typenode_from_name (MODIFIED_WCHAR_TYPE
);
2460 /* Now that we have a suitable node, get the number of
2461 bytes it occupies. */
2462 count_by
= int_size_in_bytes (node
);
2463 gcc_checking_assert (count_by
== 2 || count_by
== 4);
2466 fmtresult slen
= get_string_length (arg
, count_by
, vr_values
);
2467 if (slen
.range
.min
== slen
.range
.max
2468 && slen
.range
.min
< HOST_WIDE_INT_MAX
)
2470 /* The argument is either a string constant or it refers
2471 to one of a number of strings of the same length. */
2473 /* A '%s' directive with a string argument with constant length. */
2474 res
.range
= slen
.range
;
2476 if (dir
.specifier
== 'S'
2477 || dir
.modifier
== FMT_LEN_l
)
2479 /* In the worst case the length of output of a wide string S
2480 is bounded by MB_LEN_MAX * wcslen (S). */
2481 res
.range
.max
*= target_mb_len_max ();
2482 res
.range
.unlikely
= res
.range
.max
;
2483 /* It's likely that the total length is not more that
2485 res
.range
.likely
= res
.range
.min
* 2;
2487 if (dir
.prec
[1] >= 0
2488 && (unsigned HOST_WIDE_INT
)dir
.prec
[1] < res
.range
.max
)
2490 res
.range
.max
= dir
.prec
[1];
2491 res
.range
.likely
= dir
.prec
[1];
2492 res
.range
.unlikely
= dir
.prec
[1];
2495 if (dir
.prec
[0] < 0 && dir
.prec
[1] > -1)
2497 else if (dir
.prec
[0] >= 0)
2498 res
.range
.likely
= dir
.prec
[0];
2500 /* Even a non-empty wide character string need not convert into
2504 /* A non-empty wide character conversion may fail. */
2505 if (slen
.range
.max
> 0)
2510 res
.knownrange
= true;
2512 if (dir
.prec
[0] < 0 && dir
.prec
[1] > -1)
2514 else if ((unsigned HOST_WIDE_INT
)dir
.prec
[0] < res
.range
.min
)
2515 res
.range
.min
= dir
.prec
[0];
2517 if ((unsigned HOST_WIDE_INT
)dir
.prec
[1] < res
.range
.max
)
2519 res
.range
.max
= dir
.prec
[1];
2520 res
.range
.likely
= dir
.prec
[1];
2521 res
.range
.unlikely
= dir
.prec
[1];
2525 else if (arg
&& integer_zerop (arg
))
2527 /* Handle null pointer argument. */
2535 /* For a '%s' and '%ls' directive with a non-constant string (either
2536 one of a number of strings of known length or an unknown string)
2537 the minimum number of characters is lesser of PRECISION[0] and
2538 the length of the shortest known string or zero, and the maximum
2539 is the lessser of the length of the longest known string or
2540 PTRDIFF_MAX and PRECISION[1]. The likely length is either
2541 the minimum at level 1 and the greater of the minimum and 1
2542 at level 2. This result is adjust upward for width (if it's
2545 if (dir
.specifier
== 'S'
2546 || dir
.modifier
== FMT_LEN_l
)
2548 /* A wide character converts to as few as zero bytes. */
2550 if (slen
.range
.max
< target_int_max ())
2551 slen
.range
.max
*= target_mb_len_max ();
2553 if (slen
.range
.likely
< target_int_max ())
2554 slen
.range
.likely
*= 2;
2556 if (slen
.range
.likely
< target_int_max ())
2557 slen
.range
.unlikely
*= target_mb_len_max ();
2559 /* A non-empty wide character conversion may fail. */
2560 if (slen
.range
.max
> 0)
2564 res
.range
= slen
.range
;
2566 if (dir
.prec
[0] >= 0)
2568 /* Adjust the minimum to zero if the string length is unknown,
2569 or at most the lower bound of the precision otherwise. */
2570 if (slen
.range
.min
>= target_int_max ())
2572 else if ((unsigned HOST_WIDE_INT
)dir
.prec
[0] < slen
.range
.min
)
2573 res
.range
.min
= dir
.prec
[0];
2575 /* Make both maxima no greater than the upper bound of precision. */
2576 if ((unsigned HOST_WIDE_INT
)dir
.prec
[1] < slen
.range
.max
2577 || slen
.range
.max
>= target_int_max ())
2579 res
.range
.max
= dir
.prec
[1];
2580 res
.range
.unlikely
= dir
.prec
[1];
2583 /* If precision is constant, set the likely counter to the lesser
2584 of it and the maximum string length. Otherwise, if the lower
2585 bound of precision is greater than zero, set the likely counter
2586 to the minimum. Otherwise set it to zero or one based on
2587 the warning level. */
2588 if (dir
.prec
[0] == dir
.prec
[1])
2590 = ((unsigned HOST_WIDE_INT
)dir
.prec
[0] < slen
.range
.max
2591 ? dir
.prec
[0] : slen
.range
.max
);
2592 else if (dir
.prec
[0] > 0)
2593 res
.range
.likely
= res
.range
.min
;
2595 res
.range
.likely
= warn_level
> 1;
2597 else if (dir
.prec
[1] >= 0)
2600 if ((unsigned HOST_WIDE_INT
)dir
.prec
[1] < slen
.range
.max
)
2601 res
.range
.max
= dir
.prec
[1];
2602 res
.range
.likely
= dir
.prec
[1] ? warn_level
> 1 : 0;
2603 if ((unsigned HOST_WIDE_INT
)dir
.prec
[1] < slen
.range
.unlikely
)
2604 res
.range
.unlikely
= dir
.prec
[1];
2606 else if (slen
.range
.min
>= target_int_max ())
2609 res
.range
.max
= HOST_WIDE_INT_MAX
;
2610 /* At level 1 strings of unknown length are assumed to be
2611 empty, while at level 1 they are assumed to be one byte
2613 res
.range
.likely
= warn_level
> 1;
2614 res
.range
.unlikely
= HOST_WIDE_INT_MAX
;
2618 /* A string of unknown length unconstrained by precision is
2619 assumed to be empty at level 1 and just one character long
2620 at higher levels. */
2621 if (res
.range
.likely
>= target_int_max ())
2622 res
.range
.likely
= warn_level
> 1;
2626 /* If the argument isn't a nul-terminated string and the number
2627 of bytes on output isn't bounded by precision, set NONSTR. */
2628 if (slen
.nonstr
&& slen
.range
.min
< (unsigned HOST_WIDE_INT
)dir
.prec
[0])
2629 res
.nonstr
= slen
.nonstr
;
2631 /* Bump up the byte counters if WIDTH is greater. */
2632 return res
.adjust_for_width_or_precision (dir
.width
);
2635 /* Format plain string (part of the format string itself). */
2638 format_plain (const directive
&dir
, tree
, const vr_values
*)
2640 fmtresult
res (dir
.len
);
2644 /* Return true if the RESULT of a directive in a call describe by INFO
2645 should be diagnosed given the AVAILable space in the destination. */
2648 should_warn_p (const call_info
&info
,
2649 const result_range
&avail
, const result_range
&result
)
2651 if (result
.max
<= avail
.min
)
2653 /* The least amount of space remaining in the destination is big
2654 enough for the longest output. */
2660 if (warn_format_trunc
== 1 && result
.min
<= avail
.max
2661 && info
.retval_used ())
2663 /* The likely amount of space remaining in the destination is big
2664 enough for the least output and the return value is used. */
2668 if (warn_format_trunc
== 1 && result
.likely
<= avail
.likely
2669 && !info
.retval_used ())
2671 /* The likely amount of space remaining in the destination is big
2672 enough for the likely output and the return value is unused. */
2676 if (warn_format_trunc
== 2
2677 && result
.likely
<= avail
.min
2678 && (result
.max
<= avail
.min
2679 || result
.max
> HOST_WIDE_INT_MAX
))
2681 /* The minimum amount of space remaining in the destination is big
2682 enough for the longest output. */
2688 if (warn_level
== 1 && result
.likely
<= avail
.likely
)
2690 /* The likely amount of space remaining in the destination is big
2691 enough for the likely output. */
2696 && result
.likely
<= avail
.min
2697 && (result
.max
<= avail
.min
2698 || result
.max
> HOST_WIDE_INT_MAX
))
2700 /* The minimum amount of space remaining in the destination is big
2701 enough for the longest output. */
2709 /* At format string location describe by DIRLOC in a call described
2710 by INFO, issue a warning for a directive DIR whose output may be
2711 in excess of the available space AVAIL_RANGE in the destination
2712 given the formatting result FMTRES. This function does nothing
2713 except decide whether to issue a warning for a possible write
2714 past the end or truncation and, if so, format the warning.
2715 Return true if a warning has been issued. */
2718 maybe_warn (substring_loc
&dirloc
, location_t argloc
,
2719 const call_info
&info
,
2720 const result_range
&avail_range
, const result_range
&res
,
2721 const directive
&dir
)
2723 if (!should_warn_p (info
, avail_range
, res
))
2726 /* A warning will definitely be issued below. */
2728 /* The maximum byte count to reference in the warning. Larger counts
2729 imply that the upper bound is unknown (and could be anywhere between
2730 RES.MIN + 1 and SIZE_MAX / 2) are printed as "N or more bytes" rather
2731 than "between N and X" where X is some huge number. */
2732 unsigned HOST_WIDE_INT maxbytes
= target_dir_max ();
2734 /* True when there is enough room in the destination for the least
2735 amount of a directive's output but not enough for its likely or
2737 bool maybe
= (res
.min
<= avail_range
.max
2738 && (avail_range
.min
< res
.likely
2739 || (res
.max
< HOST_WIDE_INT_MAX
2740 && avail_range
.min
< res
.max
)));
2742 /* Buffer for the directive in the host character set (used when
2743 the source character set is different). */
2746 if (avail_range
.min
== avail_range
.max
)
2748 /* The size of the destination region is exact. */
2749 unsigned HOST_WIDE_INT navail
= avail_range
.max
;
2751 if (target_to_host (*dir
.beg
) != '%')
2753 /* For plain character directives (i.e., the format string itself)
2754 but not others, point the caret at the first character that's
2755 past the end of the destination. */
2756 if (navail
< dir
.len
)
2757 dirloc
.set_caret_index (dirloc
.get_caret_idx () + navail
);
2760 if (*dir
.beg
== '\0')
2762 /* This is the terminating nul. */
2763 gcc_assert (res
.min
== 1 && res
.min
== res
.max
);
2765 return fmtwarn (dirloc
, UNKNOWN_LOCATION
, NULL
, info
.warnopt (),
2768 ? G_("%qE output may be truncated before the "
2769 "last format character")
2770 : G_("%qE output truncated before the last "
2771 "format character"))
2773 ? G_("%qE may write a terminating nul past the "
2774 "end of the destination")
2775 : G_("%qE writing a terminating nul past the "
2776 "end of the destination")),
2780 if (res
.min
== res
.max
)
2782 const char *d
= target_to_host (hostdir
, sizeof hostdir
, dir
.beg
);
2784 return fmtwarn_n (dirloc
, argloc
, NULL
, info
.warnopt (), res
.min
,
2785 "%<%.*s%> directive writing %wu byte into a "
2786 "region of size %wu",
2787 "%<%.*s%> directive writing %wu bytes into a "
2788 "region of size %wu",
2789 (int) dir
.len
, d
, res
.min
, navail
);
2791 return fmtwarn_n (dirloc
, argloc
, NULL
, info
.warnopt (), res
.min
,
2792 "%<%.*s%> directive output may be truncated "
2793 "writing %wu byte into a region of size %wu",
2794 "%<%.*s%> directive output may be truncated "
2795 "writing %wu bytes into a region of size %wu",
2796 (int) dir
.len
, d
, res
.min
, navail
);
2798 return fmtwarn_n (dirloc
, argloc
, NULL
, info
.warnopt (), res
.min
,
2799 "%<%.*s%> directive output truncated writing "
2800 "%wu byte into a region of size %wu",
2801 "%<%.*s%> directive output truncated writing "
2802 "%wu bytes into a region of size %wu",
2803 (int) dir
.len
, d
, res
.min
, navail
);
2805 if (res
.min
== 0 && res
.max
< maxbytes
)
2806 return fmtwarn (dirloc
, argloc
, NULL
,
2810 ? G_("%<%.*s%> directive output may be truncated "
2811 "writing up to %wu bytes into a region of "
2813 : G_("%<%.*s%> directive output truncated writing "
2814 "up to %wu bytes into a region of size %wu"))
2815 : G_("%<%.*s%> directive writing up to %wu bytes "
2816 "into a region of size %wu"), (int) dir
.len
,
2817 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
2820 if (res
.min
== 0 && maxbytes
<= res
.max
)
2821 /* This is a special case to avoid issuing the potentially
2823 writing 0 or more bytes into a region of size 0. */
2824 return fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
2827 ? G_("%<%.*s%> directive output may be truncated "
2828 "writing likely %wu or more bytes into a "
2829 "region of size %wu")
2830 : G_("%<%.*s%> directive output truncated writing "
2831 "likely %wu or more bytes into a region of "
2833 : G_("%<%.*s%> directive writing likely %wu or more "
2834 "bytes into a region of size %wu"), (int) dir
.len
,
2835 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
2836 res
.likely
, navail
);
2838 if (res
.max
< maxbytes
)
2839 return fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
2842 ? G_("%<%.*s%> directive output may be truncated "
2843 "writing between %wu and %wu bytes into a "
2844 "region of size %wu")
2845 : G_("%<%.*s%> directive output truncated "
2846 "writing between %wu and %wu bytes into a "
2847 "region of size %wu"))
2848 : G_("%<%.*s%> directive writing between %wu and "
2849 "%wu bytes into a region of size %wu"),
2851 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
2852 res
.min
, res
.max
, navail
);
2854 return fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
2857 ? G_("%<%.*s%> directive output may be truncated "
2858 "writing %wu or more bytes into a region of "
2860 : G_("%<%.*s%> directive output truncated writing "
2861 "%wu or more bytes into a region of size %wu"))
2862 : G_("%<%.*s%> directive writing %wu or more bytes "
2863 "into a region of size %wu"), (int) dir
.len
,
2864 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
2868 /* The size of the destination region is a range. */
2870 if (target_to_host (*dir
.beg
) != '%')
2872 unsigned HOST_WIDE_INT navail
= avail_range
.max
;
2874 /* For plain character directives (i.e., the format string itself)
2875 but not others, point the caret at the first character that's
2876 past the end of the destination. */
2877 if (navail
< dir
.len
)
2878 dirloc
.set_caret_index (dirloc
.get_caret_idx () + navail
);
2881 if (*dir
.beg
== '\0')
2883 gcc_assert (res
.min
== 1 && res
.min
== res
.max
);
2885 return fmtwarn (dirloc
, UNKNOWN_LOCATION
, NULL
, info
.warnopt (),
2888 ? G_("%qE output may be truncated before the last "
2890 : G_("%qE output truncated before the last format "
2893 ? G_("%qE may write a terminating nul past the end "
2894 "of the destination")
2895 : G_("%qE writing a terminating nul past the end "
2896 "of the destination")), info
.func
);
2899 if (res
.min
== res
.max
)
2901 const char *d
= target_to_host (hostdir
, sizeof hostdir
, dir
.beg
);
2903 return fmtwarn_n (dirloc
, argloc
, NULL
, info
.warnopt (), res
.min
,
2904 "%<%.*s%> directive writing %wu byte into a region "
2905 "of size between %wu and %wu",
2906 "%<%.*s%> directive writing %wu bytes into a region "
2907 "of size between %wu and %wu", (int) dir
.len
, d
,
2908 res
.min
, avail_range
.min
, avail_range
.max
);
2910 return fmtwarn_n (dirloc
, argloc
, NULL
, info
.warnopt (), res
.min
,
2911 "%<%.*s%> directive output may be truncated writing "
2912 "%wu byte into a region of size between %wu and %wu",
2913 "%<%.*s%> directive output may be truncated writing "
2914 "%wu bytes into a region of size between %wu and "
2915 "%wu", (int) dir
.len
, d
, res
.min
, avail_range
.min
,
2918 return fmtwarn_n (dirloc
, argloc
, NULL
, info
.warnopt (), res
.min
,
2919 "%<%.*s%> directive output truncated writing %wu "
2920 "byte into a region of size between %wu and %wu",
2921 "%<%.*s%> directive output truncated writing %wu "
2922 "bytes into a region of size between %wu and %wu",
2923 (int) dir
.len
, d
, res
.min
, avail_range
.min
,
2927 if (res
.min
== 0 && res
.max
< maxbytes
)
2928 return fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
2931 ? G_("%<%.*s%> directive output may be truncated "
2932 "writing up to %wu bytes into a region of size "
2933 "between %wu and %wu")
2934 : G_("%<%.*s%> directive output truncated writing "
2935 "up to %wu bytes into a region of size between "
2937 : G_("%<%.*s%> directive writing up to %wu bytes "
2938 "into a region of size between %wu and %wu"),
2940 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
2941 res
.max
, avail_range
.min
, avail_range
.max
);
2943 if (res
.min
== 0 && maxbytes
<= res
.max
)
2944 /* This is a special case to avoid issuing the potentially confusing
2946 writing 0 or more bytes into a region of size between 0 and N. */
2947 return fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
2950 ? G_("%<%.*s%> directive output may be truncated "
2951 "writing likely %wu or more bytes into a region "
2952 "of size between %wu and %wu")
2953 : G_("%<%.*s%> directive output truncated writing "
2954 "likely %wu or more bytes into a region of size "
2955 "between %wu and %wu"))
2956 : G_("%<%.*s%> directive writing likely %wu or more bytes "
2957 "into a region of size between %wu and %wu"),
2959 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
2960 res
.likely
, avail_range
.min
, avail_range
.max
);
2962 if (res
.max
< maxbytes
)
2963 return fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
2966 ? G_("%<%.*s%> directive output may be truncated "
2967 "writing between %wu and %wu bytes into a region "
2968 "of size between %wu and %wu")
2969 : G_("%<%.*s%> directive output truncated writing "
2970 "between %wu and %wu bytes into a region of size "
2971 "between %wu and %wu"))
2972 : G_("%<%.*s%> directive writing between %wu and "
2973 "%wu bytes into a region of size between %wu and "
2974 "%wu"), (int) dir
.len
,
2975 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
2976 res
.min
, res
.max
, avail_range
.min
, avail_range
.max
);
2978 return fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
2981 ? G_("%<%.*s%> directive output may be truncated writing "
2982 "%wu or more bytes into a region of size between "
2984 : G_("%<%.*s%> directive output truncated writing "
2985 "%wu or more bytes into a region of size between "
2987 : G_("%<%.*s%> directive writing %wu or more bytes "
2988 "into a region of size between %wu and %wu"),
2990 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
2991 res
.min
, avail_range
.min
, avail_range
.max
);
2994 /* Given the formatting result described by RES and NAVAIL, the number
2995 of available in the destination, return the range of bytes remaining
2996 in the destination. */
2998 static inline result_range
2999 bytes_remaining (unsigned HOST_WIDE_INT navail
, const format_result
&res
)
3003 if (HOST_WIDE_INT_MAX
<= navail
)
3005 range
.min
= range
.max
= range
.likely
= range
.unlikely
= navail
;
3009 /* The lower bound of the available range is the available size
3010 minus the maximum output size, and the upper bound is the size
3011 minus the minimum. */
3012 range
.max
= res
.range
.min
< navail
? navail
- res
.range
.min
: 0;
3014 range
.likely
= res
.range
.likely
< navail
? navail
- res
.range
.likely
: 0;
3016 if (res
.range
.max
< HOST_WIDE_INT_MAX
)
3017 range
.min
= res
.range
.max
< navail
? navail
- res
.range
.max
: 0;
3019 range
.min
= range
.likely
;
3021 range
.unlikely
= (res
.range
.unlikely
< navail
3022 ? navail
- res
.range
.unlikely
: 0);
3027 /* Compute the length of the output resulting from the directive DIR
3028 in a call described by INFO and update the overall result of the call
3029 in *RES. Return true if the directive has been handled. */
3032 format_directive (const call_info
&info
,
3033 format_result
*res
, const directive
&dir
,
3034 const class vr_values
*vr_values
)
3036 /* Offset of the beginning of the directive from the beginning
3037 of the format string. */
3038 size_t offset
= dir
.beg
- info
.fmtstr
;
3039 size_t start
= offset
;
3040 size_t length
= offset
+ dir
.len
- !!dir
.len
;
3042 /* Create a location for the whole directive from the % to the format
3044 substring_loc
dirloc (info
.fmtloc
, TREE_TYPE (info
.format
),
3045 offset
, start
, length
);
3047 /* Also get the location of the argument if possible.
3048 This doesn't work for integer literals or function calls. */
3049 location_t argloc
= UNKNOWN_LOCATION
;
3051 argloc
= EXPR_LOCATION (dir
.arg
);
3053 /* Bail when there is no function to compute the output length,
3054 or when minimum length checking has been disabled. */
3055 if (!dir
.fmtfunc
|| res
->range
.min
>= HOST_WIDE_INT_MAX
)
3058 /* Compute the range of lengths of the formatted output. */
3059 fmtresult fmtres
= dir
.fmtfunc (dir
, dir
.arg
, vr_values
);
3061 /* Record whether the output of all directives is known to be
3062 bounded by some maximum, implying that their arguments are
3063 either known exactly or determined to be in a known range
3064 or, for strings, limited by the upper bounds of the arrays
3066 res
->knownrange
&= fmtres
.knownrange
;
3068 if (!fmtres
.knownrange
)
3070 /* Only when the range is known, check it against the host value
3071 of INT_MAX + (the number of bytes of the "%.*Lf" directive with
3072 INT_MAX precision, which is the longest possible output of any
3073 single directive). That's the largest valid byte count (though
3074 not valid call to a printf-like function because it can never
3075 return such a count). Otherwise, the range doesn't correspond
3076 to known values of the argument. */
3077 if (fmtres
.range
.max
> target_dir_max ())
3079 /* Normalize the MAX counter to avoid having to deal with it
3080 later. The counter can be less than HOST_WIDE_INT_M1U
3081 when compiling for an ILP32 target on an LP64 host. */
3082 fmtres
.range
.max
= HOST_WIDE_INT_M1U
;
3083 /* Disable exact and maximum length checking after a failure
3084 to determine the maximum number of characters (for example
3085 for wide characters or wide character strings) but continue
3086 tracking the minimum number of characters. */
3087 res
->range
.max
= HOST_WIDE_INT_M1U
;
3090 if (fmtres
.range
.min
> target_dir_max ())
3092 /* Disable exact length checking after a failure to determine
3093 even the minimum number of characters (it shouldn't happen
3094 except in an error) but keep tracking the minimum and maximum
3095 number of characters. */
3100 /* Buffer for the directive in the host character set (used when
3101 the source character set is different). */
3104 int dirlen
= dir
.len
;
3108 fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
3109 "%G%<%.*s%> directive argument is null",
3110 info
.callstmt
, dirlen
,
3111 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
));
3113 /* Don't bother processing the rest of the format string. */
3115 res
->range
.min
= HOST_WIDE_INT_M1U
;
3116 res
->range
.max
= HOST_WIDE_INT_M1U
;
3120 /* Compute the number of available bytes in the destination. There
3121 must always be at least one byte of space for the terminating
3122 NUL that's appended after the format string has been processed. */
3123 result_range avail_range
= bytes_remaining (info
.objsize
, *res
);
3125 /* If the argument aliases a part of the destination of the formatted
3126 call at offset FMTRES.DST_OFFSET append the directive and its result
3127 to the set of aliases for later processing. */
3128 if (fmtres
.dst_offset
!= HOST_WIDE_INT_MIN
)
3129 res
->append_alias (dir
, fmtres
.dst_offset
, fmtres
.range
);
3131 bool warned
= res
->warned
;
3134 warned
= maybe_warn (dirloc
, argloc
, info
, avail_range
,
3137 /* Bump up the total maximum if it isn't too big. */
3138 if (res
->range
.max
< HOST_WIDE_INT_MAX
3139 && fmtres
.range
.max
< HOST_WIDE_INT_MAX
)
3140 res
->range
.max
+= fmtres
.range
.max
;
3142 /* Raise the total unlikely maximum by the larger of the maximum
3143 and the unlikely maximum. */
3144 unsigned HOST_WIDE_INT save
= res
->range
.unlikely
;
3145 if (fmtres
.range
.max
< fmtres
.range
.unlikely
)
3146 res
->range
.unlikely
+= fmtres
.range
.unlikely
;
3148 res
->range
.unlikely
+= fmtres
.range
.max
;
3150 if (res
->range
.unlikely
< save
)
3151 res
->range
.unlikely
= HOST_WIDE_INT_M1U
;
3153 res
->range
.min
+= fmtres
.range
.min
;
3154 res
->range
.likely
+= fmtres
.range
.likely
;
3156 /* Has the minimum directive output length exceeded the maximum
3157 of 4095 bytes required to be supported? */
3158 bool minunder4k
= fmtres
.range
.min
< 4096;
3159 bool maxunder4k
= fmtres
.range
.max
< 4096;
3160 /* Clear POSUNDER4K in the overall result if the maximum has exceeded
3161 the 4k (this is necessary to avoid the return value optimization
3162 that may not be safe in the maximum case). */
3164 res
->posunder4k
= false;
3165 /* Also clear POSUNDER4K if the directive may fail. */
3167 res
->posunder4k
= false;
3170 /* Only warn at level 2. */
3172 /* Only warn for string functions. */
3173 && info
.is_string_func ()
3175 || (!maxunder4k
&& fmtres
.range
.max
< HOST_WIDE_INT_MAX
)))
3177 /* The directive output may be longer than the maximum required
3178 to be handled by an implementation according to 7.21.6.1, p15
3179 of C11. Warn on this only at level 2 but remember this and
3180 prevent folding the return value when done. This allows for
3181 the possibility of the actual libc call failing due to ENOMEM
3182 (like Glibc does with very large precision or width).
3183 Issue the "may exceed" warning only for string functions and
3184 not for fprintf or printf. */
3186 if (fmtres
.range
.min
== fmtres
.range
.max
)
3187 warned
= fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
3188 "%<%.*s%> directive output of %wu bytes exceeds "
3189 "minimum required size of 4095", dirlen
,
3190 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
3192 else if (!minunder4k
)
3193 warned
= fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
3194 "%<%.*s%> directive output between %wu and %wu "
3195 "bytes exceeds minimum required size of 4095",
3197 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
3198 fmtres
.range
.min
, fmtres
.range
.max
);
3199 else if (!info
.retval_used () && info
.is_string_func ())
3200 warned
= fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
3201 "%<%.*s%> directive output between %wu and %wu "
3202 "bytes may exceed minimum required size of "
3205 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
3206 fmtres
.range
.min
, fmtres
.range
.max
);
3209 /* Has the likely and maximum directive output exceeded INT_MAX? */
3210 bool likelyximax
= *dir
.beg
&& res
->range
.likely
> target_int_max ();
3211 /* Don't consider the maximum to be in excess when it's the result
3212 of a string of unknown length (i.e., whose maximum has been set
3213 to be greater than or equal to HOST_WIDE_INT_MAX. */
3214 bool maxximax
= (*dir
.beg
3215 && res
->range
.max
> target_int_max ()
3216 && res
->range
.max
< HOST_WIDE_INT_MAX
);
3219 /* Warn for the likely output size at level 1. */
3221 /* But only warn for the maximum at level 2. */
3224 && fmtres
.range
.max
< HOST_WIDE_INT_MAX
)))
3226 if (fmtres
.range
.min
> target_int_max ())
3228 /* The directive output exceeds INT_MAX bytes. */
3229 if (fmtres
.range
.min
== fmtres
.range
.max
)
3230 warned
= fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
3231 "%<%.*s%> directive output of %wu bytes exceeds "
3232 "%<INT_MAX%>", dirlen
,
3233 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
3236 warned
= fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
3237 "%<%.*s%> directive output between %wu and "
3238 "%wu bytes exceeds %<INT_MAX%>", dirlen
,
3239 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
3240 fmtres
.range
.min
, fmtres
.range
.max
);
3242 else if (res
->range
.min
> target_int_max ())
3244 /* The directive output is under INT_MAX but causes the result
3245 to exceed INT_MAX bytes. */
3246 if (fmtres
.range
.min
== fmtres
.range
.max
)
3247 warned
= fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
3248 "%<%.*s%> directive output of %wu bytes causes "
3249 "result to exceed %<INT_MAX%>", dirlen
,
3250 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
3253 warned
= fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
3254 "%<%.*s%> directive output between %wu and "
3255 "%wu bytes causes result to exceed %<INT_MAX%>",
3257 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
3258 fmtres
.range
.min
, fmtres
.range
.max
);
3260 else if ((!info
.retval_used () || !info
.bounded
)
3261 && (info
.is_string_func ()))
3262 /* Warn for calls to string functions that either aren't bounded
3263 (sprintf) or whose return value isn't used. */
3264 warned
= fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
3265 "%<%.*s%> directive output between %wu and "
3266 "%wu bytes may cause result to exceed "
3267 "%<INT_MAX%>", dirlen
,
3268 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
),
3269 fmtres
.range
.min
, fmtres
.range
.max
);
3272 if (!warned
&& fmtres
.nonstr
)
3274 warned
= fmtwarn (dirloc
, argloc
, NULL
, info
.warnopt (),
3275 "%<%.*s%> directive argument is not a nul-terminated "
3278 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
));
3279 if (warned
&& DECL_P (fmtres
.nonstr
))
3280 inform (DECL_SOURCE_LOCATION (fmtres
.nonstr
),
3281 "referenced argument declared here");
3285 if (warned
&& fmtres
.range
.min
< fmtres
.range
.likely
3286 && fmtres
.range
.likely
< fmtres
.range
.max
)
3287 inform_n (info
.fmtloc
, fmtres
.range
.likely
,
3288 "assuming directive output of %wu byte",
3289 "assuming directive output of %wu bytes",
3290 fmtres
.range
.likely
);
3292 if (warned
&& fmtres
.argmin
)
3294 if (fmtres
.argmin
== fmtres
.argmax
)
3295 inform (info
.fmtloc
, "directive argument %qE", fmtres
.argmin
);
3296 else if (fmtres
.knownrange
)
3297 inform (info
.fmtloc
, "directive argument in the range [%E, %E]",
3298 fmtres
.argmin
, fmtres
.argmax
);
3300 inform (info
.fmtloc
,
3301 "using the range [%E, %E] for directive argument",
3302 fmtres
.argmin
, fmtres
.argmax
);
3305 res
->warned
|= warned
;
3307 if (!dir
.beg
[0] && res
->warned
)
3309 location_t callloc
= gimple_location (info
.callstmt
);
3311 unsigned HOST_WIDE_INT min
= res
->range
.min
;
3312 unsigned HOST_WIDE_INT max
= res
->range
.max
;
3314 if (info
.objsize
< HOST_WIDE_INT_MAX
)
3316 /* If a warning has been issued for buffer overflow or truncation
3317 help the user figure out how big a buffer they need. */
3320 inform_n (callloc
, min
,
3321 "%qE output %wu byte into a destination of size %wu",
3322 "%qE output %wu bytes into a destination of size %wu",
3323 info
.func
, min
, info
.objsize
);
3324 else if (max
< HOST_WIDE_INT_MAX
)
3326 "%qE output between %wu and %wu bytes into "
3327 "a destination of size %wu",
3328 info
.func
, min
, max
, info
.objsize
);
3329 else if (min
< res
->range
.likely
&& res
->range
.likely
< max
)
3331 "%qE output %wu or more bytes (assuming %wu) into "
3332 "a destination of size %wu",
3333 info
.func
, min
, res
->range
.likely
, info
.objsize
);
3336 "%qE output %wu or more bytes into a destination of size "
3338 info
.func
, min
, info
.objsize
);
3340 else if (!info
.is_string_func ())
3342 /* If the warning is for a file function like fprintf
3343 of printf with no destination size just print the computed
3346 inform_n (callloc
, min
,
3347 "%qE output %wu byte", "%qE output %wu bytes",
3349 else if (max
< HOST_WIDE_INT_MAX
)
3351 "%qE output between %wu and %wu bytes",
3352 info
.func
, min
, max
);
3353 else if (min
< res
->range
.likely
&& res
->range
.likely
< max
)
3355 "%qE output %wu or more bytes (assuming %wu)",
3356 info
.func
, min
, res
->range
.likely
);
3359 "%qE output %wu or more bytes",
3364 if (dump_file
&& *dir
.beg
)
3368 HOST_WIDE_INT_PRINT_DEC
", " HOST_WIDE_INT_PRINT_DEC
", "
3369 HOST_WIDE_INT_PRINT_DEC
", " HOST_WIDE_INT_PRINT_DEC
" ("
3370 HOST_WIDE_INT_PRINT_DEC
", " HOST_WIDE_INT_PRINT_DEC
", "
3371 HOST_WIDE_INT_PRINT_DEC
", " HOST_WIDE_INT_PRINT_DEC
")\n",
3372 fmtres
.range
.min
, fmtres
.range
.likely
,
3373 fmtres
.range
.max
, fmtres
.range
.unlikely
,
3374 res
->range
.min
, res
->range
.likely
,
3375 res
->range
.max
, res
->range
.unlikely
);
3381 /* Parse a format directive in function call described by INFO starting
3382 at STR and populate DIR structure. Bump up *ARGNO by the number of
3383 arguments extracted for the directive. Return the length of
3387 parse_directive (call_info
&info
,
3388 directive
&dir
, format_result
*res
,
3389 const char *str
, unsigned *argno
,
3390 const vr_values
*vr_values
)
3392 const char *pcnt
= strchr (str
, target_percent
);
3395 if (size_t len
= pcnt
? pcnt
- str
: *str
? strlen (str
) : 1)
3397 /* This directive is either a plain string or the terminating nul
3398 (which isn't really a directive but it simplifies things to
3399 handle it as if it were). */
3401 dir
.fmtfunc
= format_plain
;
3405 fprintf (dump_file
, " Directive %u at offset "
3406 HOST_WIDE_INT_PRINT_UNSIGNED
": \"%.*s\", "
3407 "length = " HOST_WIDE_INT_PRINT_UNSIGNED
"\n",
3409 (unsigned HOST_WIDE_INT
)(size_t)(dir
.beg
- info
.fmtstr
),
3410 (int)dir
.len
, dir
.beg
, (unsigned HOST_WIDE_INT
) dir
.len
);
3416 /* Set the directive argument's number to correspond to its position
3417 in the formatted function call's argument list. */
3420 const char *pf
= pcnt
+ 1;
3422 /* POSIX numbered argument index or zero when none. */
3423 HOST_WIDE_INT dollar
= 0;
3425 /* With and precision. -1 when not specified, HOST_WIDE_INT_MIN
3426 when given by a va_list argument, and a non-negative value
3427 when specified in the format string itself. */
3428 HOST_WIDE_INT width
= -1;
3429 HOST_WIDE_INT precision
= -1;
3431 /* Pointers to the beginning of the width and precision decimal
3432 string (if any) within the directive. */
3433 const char *pwidth
= 0;
3434 const char *pprec
= 0;
3436 /* When the value of the decimal string that specifies width or
3437 precision is out of range, points to the digit that causes
3438 the value to exceed the limit. */
3439 const char *werange
= NULL
;
3440 const char *perange
= NULL
;
3442 /* Width specified via the asterisk. Need not be INTEGER_CST.
3443 For vararg functions set to void_node. */
3444 tree star_width
= NULL_TREE
;
3446 /* Width specified via the asterisk. Need not be INTEGER_CST.
3447 For vararg functions set to void_node. */
3448 tree star_precision
= NULL_TREE
;
3450 if (ISDIGIT (target_to_host (*pf
)))
3452 /* This could be either a POSIX positional argument, the '0'
3453 flag, or a width, depending on what follows. Store it as
3454 width and sort it out later after the next character has
3457 width
= target_strtowi (&pf
, &werange
);
3459 else if (target_to_host (*pf
) == '*')
3461 /* Similarly to the block above, this could be either a POSIX
3462 positional argument or a width, depending on what follows. */
3463 if (*argno
< gimple_call_num_args (info
.callstmt
))
3464 star_width
= gimple_call_arg (info
.callstmt
, (*argno
)++);
3466 star_width
= void_node
;
3470 if (target_to_host (*pf
) == '$')
3472 /* Handle the POSIX dollar sign which references the 1-based
3473 positional argument number. */
3475 dollar
= width
+ info
.argidx
;
3477 && TREE_CODE (star_width
) == INTEGER_CST
3478 && (TYPE_PRECISION (TREE_TYPE (star_width
))
3479 <= TYPE_PRECISION (integer_type_node
)))
3480 dollar
= width
+ tree_to_shwi (star_width
);
3482 /* Bail when the numbered argument is out of range (it will
3483 have already been diagnosed by -Wformat). */
3485 || dollar
== (int)info
.argidx
3486 || dollar
> gimple_call_num_args (info
.callstmt
))
3491 star_width
= NULL_TREE
;
3496 if (dollar
|| !star_width
)
3502 /* The '0' that has been interpreted as a width above is
3503 actually a flag. Reset HAVE_WIDTH, set the '0' flag,
3504 and continue processing other flags. */
3510 /* (Non-zero) width has been seen. The next character
3511 is either a period or a digit. */
3512 goto start_precision
;
3515 /* When either '$' has been seen, or width has not been seen,
3516 the next field is the optional flags followed by an optional
3519 switch (target_to_host (*pf
))
3526 dir
.set_flag (target_to_host (*pf
++));
3535 if (ISDIGIT (target_to_host (*pf
)))
3539 width
= target_strtowi (&pf
, &werange
);
3541 else if (target_to_host (*pf
) == '*')
3543 if (*argno
< gimple_call_num_args (info
.callstmt
))
3544 star_width
= gimple_call_arg (info
.callstmt
, (*argno
)++);
3547 /* This is (likely) a va_list. It could also be an invalid
3548 call with insufficient arguments. */
3549 star_width
= void_node
;
3553 else if (target_to_host (*pf
) == '\'')
3555 /* The POSIX apostrophe indicating a numeric grouping
3556 in the current locale. Even though it's possible to
3557 estimate the upper bound on the size of the output
3558 based on the number of digits it probably isn't worth
3565 if (target_to_host (*pf
) == '.')
3569 if (ISDIGIT (target_to_host (*pf
)))
3572 precision
= target_strtowi (&pf
, &perange
);
3574 else if (target_to_host (*pf
) == '*')
3576 if (*argno
< gimple_call_num_args (info
.callstmt
))
3577 star_precision
= gimple_call_arg (info
.callstmt
, (*argno
)++);
3580 /* This is (likely) a va_list. It could also be an invalid
3581 call with insufficient arguments. */
3582 star_precision
= void_node
;
3588 /* The decimal precision or the asterisk are optional.
3589 When neither is dirified it's taken to be zero. */
3594 switch (target_to_host (*pf
))
3597 if (target_to_host (pf
[1]) == 'h')
3600 dir
.modifier
= FMT_LEN_hh
;
3603 dir
.modifier
= FMT_LEN_h
;
3608 dir
.modifier
= FMT_LEN_j
;
3613 dir
.modifier
= FMT_LEN_L
;
3618 if (target_to_host (pf
[1]) == 'l')
3621 dir
.modifier
= FMT_LEN_ll
;
3624 dir
.modifier
= FMT_LEN_l
;
3629 dir
.modifier
= FMT_LEN_t
;
3634 dir
.modifier
= FMT_LEN_z
;
3639 switch (target_to_host (*pf
))
3641 /* Handle a sole '%' character the same as "%%" but since it's
3642 undefined prevent the result from being folded. */
3645 res
->range
.min
= res
->range
.max
= HOST_WIDE_INT_M1U
;
3648 dir
.fmtfunc
= format_percent
;
3659 res
->floating
= true;
3660 dir
.fmtfunc
= format_floating
;
3669 dir
.fmtfunc
= format_integer
;
3673 /* The %p output is implementation-defined. It's possible
3674 to determine this format but due to extensions (edirially
3675 those of the Linux kernel -- see bug 78512) the first %p
3676 in the format string disables any further processing. */
3680 /* %n has side-effects even when nothing is actually printed to
3682 info
.nowrite
= false;
3683 dir
.fmtfunc
= format_none
;
3688 /* POSIX wide character and C/POSIX narrow character. */
3689 dir
.fmtfunc
= format_character
;
3694 /* POSIX wide string and C/POSIX narrow character string. */
3695 dir
.fmtfunc
= format_string
;
3699 /* Unknown conversion specification. */
3703 dir
.specifier
= target_to_host (*pf
++);
3705 /* Store the length of the format directive. */
3706 dir
.len
= pf
- pcnt
;
3708 /* Buffer for the directive in the host character set (used when
3709 the source character set is different). */
3714 if (INTEGRAL_TYPE_P (TREE_TYPE (star_width
)))
3715 dir
.set_width (star_width
, vr_values
);
3718 /* Width specified by a va_list takes on the range [0, -INT_MIN]
3719 (width is the absolute value of that specified). */
3721 dir
.width
[1] = target_int_max () + 1;
3726 if (width
== HOST_WIDE_INT_MAX
&& werange
)
3728 size_t begin
= dir
.beg
- info
.fmtstr
+ (pwidth
- pcnt
);
3729 size_t caret
= begin
+ (werange
- pcnt
);
3730 size_t end
= pf
- info
.fmtstr
- 1;
3732 /* Create a location for the width part of the directive,
3733 pointing the caret at the first out-of-range digit. */
3734 substring_loc
dirloc (info
.fmtloc
, TREE_TYPE (info
.format
),
3737 fmtwarn (dirloc
, UNKNOWN_LOCATION
, NULL
, info
.warnopt (),
3738 "%<%.*s%> directive width out of range", (int) dir
.len
,
3739 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
));
3742 dir
.set_width (width
);
3747 if (INTEGRAL_TYPE_P (TREE_TYPE (star_precision
)))
3748 dir
.set_precision (star_precision
, vr_values
);
3751 /* Precision specified by a va_list takes on the range [-1, INT_MAX]
3752 (unlike width, negative precision is ignored). */
3754 dir
.prec
[1] = target_int_max ();
3759 if (precision
== HOST_WIDE_INT_MAX
&& perange
)
3761 size_t begin
= dir
.beg
- info
.fmtstr
+ (pprec
- pcnt
) - 1;
3762 size_t caret
= dir
.beg
- info
.fmtstr
+ (perange
- pcnt
) - 1;
3763 size_t end
= pf
- info
.fmtstr
- 2;
3765 /* Create a location for the precision part of the directive,
3766 including the leading period, pointing the caret at the first
3767 out-of-range digit . */
3768 substring_loc
dirloc (info
.fmtloc
, TREE_TYPE (info
.format
),
3771 fmtwarn (dirloc
, UNKNOWN_LOCATION
, NULL
, info
.warnopt (),
3772 "%<%.*s%> directive precision out of range", (int) dir
.len
,
3773 target_to_host (hostdir
, sizeof hostdir
, dir
.beg
));
3776 dir
.set_precision (precision
);
3779 /* Extract the argument if the directive takes one and if it's
3780 available (e.g., the function doesn't take a va_list). Treat
3781 missing arguments the same as va_list, even though they will
3782 have likely already been diagnosed by -Wformat. */
3783 if (dir
.specifier
!= '%'
3784 && *argno
< gimple_call_num_args (info
.callstmt
))
3785 dir
.arg
= gimple_call_arg (info
.callstmt
, dollar
? dollar
: (*argno
)++);
3790 " Directive %u at offset " HOST_WIDE_INT_PRINT_UNSIGNED
3793 (unsigned HOST_WIDE_INT
)(size_t)(dir
.beg
- info
.fmtstr
),
3794 (int)dir
.len
, dir
.beg
);
3797 if (dir
.width
[0] == dir
.width
[1])
3798 fprintf (dump_file
, ", width = " HOST_WIDE_INT_PRINT_DEC
,
3802 ", width in range [" HOST_WIDE_INT_PRINT_DEC
3803 ", " HOST_WIDE_INT_PRINT_DEC
"]",
3804 dir
.width
[0], dir
.width
[1]);
3809 if (dir
.prec
[0] == dir
.prec
[1])
3810 fprintf (dump_file
, ", precision = " HOST_WIDE_INT_PRINT_DEC
,
3814 ", precision in range [" HOST_WIDE_INT_PRINT_DEC
3815 HOST_WIDE_INT_PRINT_DEC
"]",
3816 dir
.prec
[0], dir
.prec
[1]);
3818 fputc ('\n', dump_file
);
3824 /* Diagnose overlap between destination and %s directive arguments. */
3827 maybe_warn_overlap (call_info
&info
, format_result
*res
)
3829 /* Two vectors of 1-based indices corresponding to either certainly
3830 or possibly aliasing arguments. */
3831 auto_vec
<int, 16> aliasarg
[2];
3833 /* Go through the array of potentially aliasing directives and collect
3834 argument numbers of those that do or may overlap the destination
3835 object given the full result. */
3836 for (unsigned i
= 0; i
!= res
->alias_count
; ++i
)
3838 const format_result::alias_info
&alias
= res
->aliases
[i
];
3840 enum { possible
= -1, none
= 0, certain
= 1 } overlap
= none
;
3842 /* If the precision is zero there is no overlap. (This only
3843 considers %s directives and ignores %n.) */
3844 if (alias
.dir
.prec
[0] == 0 && alias
.dir
.prec
[1] == 0)
3847 if (alias
.offset
== HOST_WIDE_INT_MAX
3848 || info
.dst_offset
== HOST_WIDE_INT_MAX
)
3850 else if (alias
.offset
== info
.dst_offset
)
3851 overlap
= alias
.dir
.prec
[0] == 0 ? possible
: certain
;
3854 /* Determine overlap from the range of output and offsets
3855 into the same destination as the source, and rule out
3856 impossible overlap. */
3857 unsigned HOST_WIDE_INT albeg
= alias
.offset
;
3858 unsigned HOST_WIDE_INT dstbeg
= info
.dst_offset
;
3860 unsigned HOST_WIDE_INT alend
= albeg
+ alias
.range
.min
;
3861 unsigned HOST_WIDE_INT dstend
= dstbeg
+ res
->range
.min
- 1;
3863 if ((albeg
<= dstbeg
&& alend
> dstbeg
)
3864 || (albeg
>= dstbeg
&& albeg
< dstend
))
3868 alend
= albeg
+ alias
.range
.max
;
3870 alend
= HOST_WIDE_INT_M1U
;
3872 dstend
= dstbeg
+ res
->range
.max
- 1;
3873 if (dstend
< dstbeg
)
3874 dstend
= HOST_WIDE_INT_M1U
;
3876 if ((albeg
>= dstbeg
&& albeg
<= dstend
)
3877 || (alend
>= dstbeg
&& alend
<= dstend
))
3882 if (overlap
== none
)
3885 /* Append the 1-based argument number. */
3886 aliasarg
[overlap
!= certain
].safe_push (alias
.dir
.argno
+ 1);
3888 /* Disable any kind of optimization. */
3889 res
->range
.unlikely
= HOST_WIDE_INT_M1U
;
3892 tree arg0
= gimple_call_arg (info
.callstmt
, 0);
3893 location_t loc
= gimple_location (info
.callstmt
);
3895 bool aliaswarn
= false;
3897 unsigned ncertain
= aliasarg
[0].length ();
3898 unsigned npossible
= aliasarg
[1].length ();
3899 if (ncertain
&& npossible
)
3901 /* If there are multiple arguments that overlap, some certainly
3902 and some possibly, handle both sets in a single diagnostic. */
3904 = warning_at (loc
, OPT_Wrestrict
,
3905 "%qE arguments %Z and maybe %Z overlap destination "
3907 info
.func
, aliasarg
[0].address (), ncertain
,
3908 aliasarg
[1].address (), npossible
,
3913 /* There is only one set of two or more arguments and they all
3914 certainly overlap the destination. */
3916 = warning_n (loc
, OPT_Wrestrict
, ncertain
,
3917 "%qE argument %Z overlaps destination object %qE",
3918 "%qE arguments %Z overlap destination object %qE",
3919 info
.func
, aliasarg
[0].address (), ncertain
,
3924 /* There is only one set of two or more arguments and they all
3925 may overlap (but need not). */
3927 = warning_n (loc
, OPT_Wrestrict
, npossible
,
3928 "%qE argument %Z may overlap destination object %qE",
3929 "%qE arguments %Z may overlap destination object %qE",
3930 info
.func
, aliasarg
[1].address (), npossible
,
3938 if (info
.dst_origin
!= arg0
)
3940 /* If its location is different from the first argument of the call
3941 point either at the destination object itself or at the expression
3942 that was used to determine the overlap. */
3943 loc
= (DECL_P (info
.dst_origin
)
3944 ? DECL_SOURCE_LOCATION (info
.dst_origin
)
3945 : EXPR_LOCATION (info
.dst_origin
));
3946 if (loc
!= UNKNOWN_LOCATION
)
3948 "destination object referenced by %<restrict%>-qualified "
3949 "argument 1 was declared here");
3954 /* Compute the length of the output resulting from the call to a formatted
3955 output function described by INFO and store the result of the call in
3956 *RES. Issue warnings for detected past the end writes. Return true
3957 if the complete format string has been processed and *RES can be relied
3958 on, false otherwise (e.g., when a unknown or unhandled directive was seen
3959 that caused the processing to be terminated early). */
3962 compute_format_length (call_info
&info
, format_result
*res
, const vr_values
*vr
)
3966 location_t callloc
= gimple_location (info
.callstmt
);
3967 fprintf (dump_file
, "%s:%i: ",
3968 LOCATION_FILE (callloc
), LOCATION_LINE (callloc
));
3969 print_generic_expr (dump_file
, info
.func
, dump_flags
);
3972 ": objsize = " HOST_WIDE_INT_PRINT_UNSIGNED
3973 ", fmtstr = \"%s\"\n",
3974 info
.objsize
, info
.fmtstr
);
3977 /* Reset the minimum and maximum byte counters. */
3978 res
->range
.min
= res
->range
.max
= 0;
3980 /* No directive has been seen yet so the length of output is bounded
3981 by the known range [0, 0] (with no conversion resulting in a failure
3982 or producing more than 4K bytes) until determined otherwise. */
3983 res
->knownrange
= true;
3984 res
->floating
= false;
3985 res
->warned
= false;
3987 /* 1-based directive counter. */
3990 /* The variadic argument counter. */
3991 unsigned argno
= info
.argidx
;
3993 bool success
= true;
3995 for (const char *pf
= info
.fmtstr
; ; ++dirno
)
3997 directive
dir (&info
, dirno
);
3999 size_t n
= parse_directive (info
, dir
, res
, pf
, &argno
, vr
);
4001 /* Return failure if the format function fails. */
4002 if (!format_directive (info
, res
, dir
, vr
))
4005 /* Return success when the directive is zero bytes long and it's
4006 the last thing in the format string (i.e., it's the terminating
4007 nul, which isn't really a directive but handling it as one makes
4011 success
= *pf
== '\0';
4018 maybe_warn_overlap (info
, res
);
4020 /* The complete format string was processed (with or without warnings). */
4024 /* Return the size of the object referenced by the expression DEST if
4025 available, or the maximum possible size otherwise. */
4027 static unsigned HOST_WIDE_INT
4028 get_destination_size (tree dest
)
4030 /* When there is no destination return the maximum. */
4032 return HOST_WIDE_INT_MAX
;
4034 /* Initialize object size info before trying to compute it. */
4035 init_object_sizes ();
4037 /* Use __builtin_object_size to determine the size of the destination
4038 object. When optimizing, determine the smallest object (such as
4039 a member array as opposed to the whole enclosing object), otherwise
4040 use type-zero object size to determine the size of the enclosing
4041 object (the function fails without optimization in this type). */
4042 int ost
= optimize
> 0;
4043 unsigned HOST_WIDE_INT size
;
4044 if (compute_builtin_object_size (dest
, ost
, &size
))
4047 return HOST_WIDE_INT_MAX
;
4050 /* Return true if the call described by INFO with result RES safe to
4051 optimize (i.e., no undefined behavior), and set RETVAL to the range
4052 of its return values. */
4055 is_call_safe (const call_info
&info
,
4056 const format_result
&res
, bool under4k
,
4057 unsigned HOST_WIDE_INT retval
[2])
4059 if (under4k
&& !res
.posunder4k
)
4062 /* The minimum return value. */
4063 retval
[0] = res
.range
.min
;
4065 /* The maximum return value is in most cases bounded by RES.RANGE.MAX
4066 but in cases involving multibyte characters could be as large as
4067 RES.RANGE.UNLIKELY. */
4069 = res
.range
.unlikely
< res
.range
.max
? res
.range
.max
: res
.range
.unlikely
;
4071 /* Adjust the number of bytes which includes the terminating nul
4072 to reflect the return value of the function which does not.
4073 Because the valid range of the function is [INT_MIN, INT_MAX],
4074 a valid range before the adjustment below is [0, INT_MAX + 1]
4075 (the functions only return negative values on error or undefined
4077 if (retval
[0] <= target_int_max () + 1)
4079 if (retval
[1] <= target_int_max () + 1)
4082 /* Avoid the return value optimization when the behavior of the call
4083 is undefined either because any directive may have produced 4K or
4084 more of output, or the return value exceeds INT_MAX, or because
4085 the output overflows the destination object (but leave it enabled
4086 when the function is bounded because then the behavior is well-
4088 if (retval
[0] == retval
[1]
4089 && (info
.bounded
|| retval
[0] < info
.objsize
)
4090 && retval
[0] <= target_int_max ())
4093 if ((info
.bounded
|| retval
[1] < info
.objsize
)
4094 && (retval
[0] < target_int_max ()
4095 && retval
[1] < target_int_max ()))
4098 if (!under4k
&& (info
.bounded
|| retval
[0] < info
.objsize
))
4104 /* Given a suitable result RES of a call to a formatted output function
4105 described by INFO, substitute the result for the return value of
4106 the call. The result is suitable if the number of bytes it represents
4107 is known and exact. A result that isn't suitable for substitution may
4108 have its range set to the range of return values, if that is known.
4109 Return true if the call is removed and gsi_next should not be performed
4113 try_substitute_return_value (gimple_stmt_iterator
*gsi
,
4114 const call_info
&info
,
4115 const format_result
&res
)
4117 tree lhs
= gimple_get_lhs (info
.callstmt
);
4119 /* Set to true when the entire call has been removed. */
4120 bool removed
= false;
4122 /* The minimum and maximum return value. */
4123 unsigned HOST_WIDE_INT retval
[2] = {0};
4124 bool safe
= is_call_safe (info
, res
, true, retval
);
4127 && retval
[0] == retval
[1]
4128 /* Not prepared to handle possibly throwing calls here; they shouldn't
4129 appear in non-artificial testcases, except when the __*_chk routines
4130 are badly declared. */
4131 && !stmt_ends_bb_p (info
.callstmt
))
4133 tree cst
= build_int_cst (lhs
? TREE_TYPE (lhs
) : integer_type_node
,
4136 if (lhs
== NULL_TREE
&& info
.nowrite
)
4138 /* Remove the call to the bounded function with a zero size
4139 (e.g., snprintf(0, 0, "%i", 123)) if there is no lhs. */
4140 unlink_stmt_vdef (info
.callstmt
);
4141 gsi_remove (gsi
, true);
4144 else if (info
.nowrite
)
4146 /* Replace the call to the bounded function with a zero size
4147 (e.g., snprintf(0, 0, "%i", 123) with the constant result
4149 if (!update_call_from_tree (gsi
, cst
))
4150 gimplify_and_update_call_from_tree (gsi
, cst
);
4151 gimple
*callstmt
= gsi_stmt (*gsi
);
4152 update_stmt (callstmt
);
4156 /* Replace the left-hand side of the call with the constant
4157 result of the formatted function. */
4158 gimple_call_set_lhs (info
.callstmt
, NULL_TREE
);
4159 gimple
*g
= gimple_build_assign (lhs
, cst
);
4160 gsi_insert_after (gsi
, g
, GSI_NEW_STMT
);
4161 update_stmt (info
.callstmt
);
4167 fprintf (dump_file
, " Removing call statement.");
4170 fprintf (dump_file
, " Substituting ");
4171 print_generic_expr (dump_file
, cst
, dump_flags
);
4172 fprintf (dump_file
, " for %s.\n",
4173 info
.nowrite
? "statement" : "return value");
4177 else if (lhs
&& types_compatible_p (TREE_TYPE (lhs
), integer_type_node
))
4179 bool setrange
= false;
4182 && (info
.bounded
|| retval
[1] < info
.objsize
)
4183 && (retval
[0] < target_int_max ()
4184 && retval
[1] < target_int_max ()))
4186 /* If the result is in a valid range bounded by the size of
4187 the destination set it so that it can be used for subsequent
4189 int prec
= TYPE_PRECISION (integer_type_node
);
4191 wide_int min
= wi::shwi (retval
[0], prec
);
4192 wide_int max
= wi::shwi (retval
[1], prec
);
4193 set_range_info (lhs
, VR_RANGE
, min
, max
);
4200 const char *inbounds
4201 = (retval
[0] < info
.objsize
4202 ? (retval
[1] < info
.objsize
4203 ? "in" : "potentially out-of")
4206 const char *what
= setrange
? "Setting" : "Discarding";
4207 if (retval
[0] != retval
[1])
4209 " %s %s-bounds return value range ["
4210 HOST_WIDE_INT_PRINT_UNSIGNED
", "
4211 HOST_WIDE_INT_PRINT_UNSIGNED
"].\n",
4212 what
, inbounds
, retval
[0], retval
[1]);
4214 fprintf (dump_file
, " %s %s-bounds return value "
4215 HOST_WIDE_INT_PRINT_UNSIGNED
".\n",
4216 what
, inbounds
, retval
[0]);
4221 fputc ('\n', dump_file
);
4226 /* Try to simplify a s{,n}printf call described by INFO with result
4227 RES by replacing it with a simpler and presumably more efficient
4228 call (such as strcpy). */
4231 try_simplify_call (gimple_stmt_iterator
*gsi
,
4232 const call_info
&info
,
4233 const format_result
&res
)
4235 unsigned HOST_WIDE_INT dummy
[2];
4236 if (!is_call_safe (info
, res
, info
.retval_used (), dummy
))
4239 switch (info
.fncode
)
4241 case BUILT_IN_SNPRINTF
:
4242 return gimple_fold_builtin_snprintf (gsi
);
4244 case BUILT_IN_SPRINTF
:
4245 return gimple_fold_builtin_sprintf (gsi
);
4254 /* Return the zero-based index of the format string argument of a printf
4255 like function and set *IDX_ARGS to the first format argument. When
4256 no such index exists return UINT_MAX. */
4259 get_user_idx_format (tree fndecl
, unsigned *idx_args
)
4261 tree attrs
= lookup_attribute ("format", DECL_ATTRIBUTES (fndecl
));
4263 attrs
= lookup_attribute ("format", TYPE_ATTRIBUTES (TREE_TYPE (fndecl
)));
4268 attrs
= TREE_VALUE (attrs
);
4270 tree archetype
= TREE_VALUE (attrs
);
4271 if (strcmp ("printf", IDENTIFIER_POINTER (archetype
)))
4274 attrs
= TREE_CHAIN (attrs
);
4275 tree fmtarg
= TREE_VALUE (attrs
);
4277 attrs
= TREE_CHAIN (attrs
);
4278 tree elliparg
= TREE_VALUE (attrs
);
4280 /* Attribute argument indices are 1-based but we use zero-based. */
4281 *idx_args
= tree_to_uhwi (elliparg
) - 1;
4282 return tree_to_uhwi (fmtarg
) - 1;
4285 } /* Unnamed namespace. */
4287 /* Determine if a GIMPLE call at *GSI is to one of the sprintf-like built-in
4288 functions and if so, handle it. Return true if the call is removed and
4289 gsi_next should not be performed in the caller. */
4292 handle_printf_call (gimple_stmt_iterator
*gsi
, const vr_values
*vr_values
)
4294 init_target_to_host_charmap ();
4296 call_info info
= call_info ();
4298 info
.callstmt
= gsi_stmt (*gsi
);
4299 info
.func
= gimple_call_fndecl (info
.callstmt
);
4303 /* Format string argument number (valid for all functions). */
4304 unsigned idx_format
= UINT_MAX
;
4305 if (gimple_call_builtin_p (info
.callstmt
, BUILT_IN_NORMAL
))
4306 info
.fncode
= DECL_FUNCTION_CODE (info
.func
);
4310 idx_format
= get_user_idx_format (info
.func
, &idx_args
);
4311 if (idx_format
== UINT_MAX
4312 || idx_format
>= gimple_call_num_args (info
.callstmt
)
4313 || idx_args
> gimple_call_num_args (info
.callstmt
)
4314 || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (info
.callstmt
,
4317 info
.fncode
= BUILT_IN_NONE
;
4318 info
.argidx
= idx_args
;
4321 /* The size of the destination as in snprintf(dest, size, ...). */
4322 unsigned HOST_WIDE_INT dstsize
= HOST_WIDE_INT_M1U
;
4324 /* The size of the destination determined by __builtin_object_size. */
4325 unsigned HOST_WIDE_INT objsize
= HOST_WIDE_INT_M1U
;
4327 /* Zero-based buffer size argument number (snprintf and vsnprintf). */
4328 unsigned idx_dstsize
= UINT_MAX
;
4330 /* Object size argument number (snprintf_chk and vsnprintf_chk). */
4331 unsigned idx_objsize
= UINT_MAX
;
4333 /* Destinaton argument number (valid for sprintf functions only). */
4334 unsigned idx_dstptr
= 0;
4336 switch (info
.fncode
)
4339 // User-defined function with attribute format (printf).
4343 case BUILT_IN_FPRINTF
:
4345 // __builtin_fprintf (FILE*, format, ...)
4351 case BUILT_IN_FPRINTF_CHK
:
4353 // __builtin_fprintf_chk (FILE*, ost, format, ...)
4359 case BUILT_IN_FPRINTF_UNLOCKED
:
4361 // __builtin_fprintf_unnlocked (FILE*, format, ...)
4367 case BUILT_IN_PRINTF
:
4369 // __builtin_printf (format, ...)
4375 case BUILT_IN_PRINTF_CHK
:
4377 // __builtin_printf_chk (ost, format, ...)
4383 case BUILT_IN_PRINTF_UNLOCKED
:
4385 // __builtin_printf (format, ...)
4391 case BUILT_IN_SPRINTF
:
4393 // __builtin_sprintf (dst, format, ...)
4398 case BUILT_IN_SPRINTF_CHK
:
4400 // __builtin___sprintf_chk (dst, ost, objsize, format, ...)
4406 case BUILT_IN_SNPRINTF
:
4408 // __builtin_snprintf (dst, size, format, ...)
4412 info
.bounded
= true;
4415 case BUILT_IN_SNPRINTF_CHK
:
4417 // __builtin___snprintf_chk (dst, size, ost, objsize, format, ...)
4422 info
.bounded
= true;
4425 case BUILT_IN_VFPRINTF
:
4427 // __builtin_vprintf (FILE*, format, va_list)
4433 case BUILT_IN_VFPRINTF_CHK
:
4435 // __builtin___vfprintf_chk (FILE*, ost, format, va_list)
4441 case BUILT_IN_VPRINTF
:
4443 // __builtin_vprintf (format, va_list)
4449 case BUILT_IN_VPRINTF_CHK
:
4451 // __builtin___vprintf_chk (ost, format, va_list)
4457 case BUILT_IN_VSNPRINTF
:
4459 // __builtin_vsprintf (dst, size, format, va)
4463 info
.bounded
= true;
4466 case BUILT_IN_VSNPRINTF_CHK
:
4468 // __builtin___vsnprintf_chk (dst, size, ost, objsize, format, va)
4473 info
.bounded
= true;
4476 case BUILT_IN_VSPRINTF
:
4478 // __builtin_vsprintf (dst, format, va)
4483 case BUILT_IN_VSPRINTF_CHK
:
4485 // __builtin___vsprintf_chk (dst, ost, objsize, format, va)
4495 /* Set the global warning level for this function. */
4496 warn_level
= info
.bounded
? warn_format_trunc
: warn_format_overflow
;
4498 /* For all string functions the first argument is a pointer to
4500 tree dstptr
= (idx_dstptr
< gimple_call_num_args (info
.callstmt
)
4501 ? gimple_call_arg (info
.callstmt
, 0) : NULL_TREE
);
4503 info
.format
= gimple_call_arg (info
.callstmt
, idx_format
);
4505 /* True when the destination size is constant as opposed to the lower
4506 or upper bound of a range. */
4507 bool dstsize_cst_p
= true;
4508 bool posunder4k
= true;
4510 if (idx_dstsize
== UINT_MAX
)
4512 /* For non-bounded functions like sprintf, determine the size
4513 of the destination from the object or pointer passed to it
4514 as the first argument. */
4515 dstsize
= get_destination_size (dstptr
);
4517 else if (tree size
= gimple_call_arg (info
.callstmt
, idx_dstsize
))
4519 /* For bounded functions try to get the size argument. */
4521 if (TREE_CODE (size
) == INTEGER_CST
)
4523 dstsize
= tree_to_uhwi (size
);
4524 /* No object can be larger than SIZE_MAX bytes (half the address
4525 space) on the target.
4526 The functions are defined only for output of at most INT_MAX
4527 bytes. Specifying a bound in excess of that limit effectively
4528 defeats the bounds checking (and on some implementations such
4529 as Solaris cause the function to fail with EINVAL). */
4530 if (dstsize
> target_size_max () / 2)
4532 /* Avoid warning if -Wstringop-overflow is specified since
4533 it also warns for the same thing though only for the
4534 checking built-ins. */
4535 if ((idx_objsize
== UINT_MAX
4536 || !warn_stringop_overflow
))
4537 warning_at (gimple_location (info
.callstmt
), info
.warnopt (),
4538 "specified bound %wu exceeds maximum object size "
4540 dstsize
, target_size_max () / 2);
4541 /* POSIX requires snprintf to fail if DSTSIZE is greater
4542 than INT_MAX. Even though not all POSIX implementations
4543 conform to the requirement, avoid folding in this case. */
4546 else if (dstsize
> target_int_max ())
4548 warning_at (gimple_location (info
.callstmt
), info
.warnopt (),
4549 "specified bound %wu exceeds %<INT_MAX%>",
4551 /* POSIX requires snprintf to fail if DSTSIZE is greater
4552 than INT_MAX. Avoid folding in that case. */
4556 else if (TREE_CODE (size
) == SSA_NAME
)
4558 /* Try to determine the range of values of the argument
4559 and use the greater of the two at level 1 and the smaller
4560 of them at level 2. */
4561 const value_range_equiv
*vr
4562 = CONST_CAST (class vr_values
*, vr_values
)->get_value_range (size
);
4564 if (range_int_cst_p (vr
))
4566 unsigned HOST_WIDE_INT minsize
= TREE_INT_CST_LOW (vr
->min ());
4567 unsigned HOST_WIDE_INT maxsize
= TREE_INT_CST_LOW (vr
->max ());
4568 dstsize
= warn_level
< 2 ? maxsize
: minsize
;
4570 if (minsize
> target_int_max ())
4571 warning_at (gimple_location (info
.callstmt
), info
.warnopt (),
4572 "specified bound range [%wu, %wu] exceeds "
4576 /* POSIX requires snprintf to fail if DSTSIZE is greater
4577 than INT_MAX. Avoid folding if that's possible. */
4578 if (maxsize
> target_int_max ())
4581 else if (vr
->varying_p ())
4583 /* POSIX requires snprintf to fail if DSTSIZE is greater
4584 than INT_MAX. Since SIZE's range is unknown, avoid
4589 /* The destination size is not constant. If the function is
4590 bounded (e.g., snprintf) a lower bound of zero doesn't
4591 necessarily imply it can be eliminated. */
4592 dstsize_cst_p
= false;
4596 if (idx_objsize
!= UINT_MAX
)
4597 if (tree size
= gimple_call_arg (info
.callstmt
, idx_objsize
))
4598 if (tree_fits_uhwi_p (size
))
4599 objsize
= tree_to_uhwi (size
);
4601 if (info
.bounded
&& !dstsize
)
4603 /* As a special case, when the explicitly specified destination
4604 size argument (to a bounded function like snprintf) is zero
4605 it is a request to determine the number of bytes on output
4606 without actually producing any. Pretend the size is
4607 unlimited in this case. */
4608 info
.objsize
= HOST_WIDE_INT_MAX
;
4609 info
.nowrite
= dstsize_cst_p
;
4613 /* For calls to non-bounded functions or to those of bounded
4614 functions with a non-zero size, warn if the destination
4616 if (dstptr
&& integer_zerop (dstptr
))
4618 /* This is diagnosed with -Wformat only when the null is a constant
4619 pointer. The warning here diagnoses instances where the pointer
4621 location_t loc
= gimple_location (info
.callstmt
);
4622 warning_at (EXPR_LOC_OR_LOC (dstptr
, loc
),
4623 info
.warnopt (), "%Gnull destination pointer",
4628 /* Set the object size to the smaller of the two arguments
4629 of both have been specified and they're not equal. */
4630 info
.objsize
= dstsize
< objsize
? dstsize
: objsize
;
4633 && dstsize
< target_size_max () / 2 && objsize
< dstsize
4634 /* Avoid warning if -Wstringop-overflow is specified since
4635 it also warns for the same thing though only for the
4636 checking built-ins. */
4637 && (idx_objsize
== UINT_MAX
4638 || !warn_stringop_overflow
))
4640 warning_at (gimple_location (info
.callstmt
), info
.warnopt (),
4641 "specified bound %wu exceeds the size %wu "
4642 "of the destination object", dstsize
, objsize
);
4646 /* Determine if the format argument may be null and warn if not
4647 and if the argument is null. */
4648 if (integer_zerop (info
.format
)
4649 && gimple_call_builtin_p (info
.callstmt
, BUILT_IN_NORMAL
))
4651 location_t loc
= gimple_location (info
.callstmt
);
4652 warning_at (EXPR_LOC_OR_LOC (info
.format
, loc
),
4653 info
.warnopt (), "%Gnull format string",
4658 info
.fmtstr
= get_format_string (info
.format
, &info
.fmtloc
);
4664 /* Compute the origin of the destination pointer and its offset
4665 from the base object/pointer if possible. */
4666 info
.dst_offset
= 0;
4667 info
.dst_origin
= get_origin_and_offset (dstptr
, &info
.dst_field
,
4671 /* The result is the number of bytes output by the formatted function,
4672 including the terminating NUL. */
4675 /* I/O functions with no destination argument (i.e., all forms of fprintf
4676 and printf) may fail under any conditions. Others (i.e., all forms of
4677 sprintf) may only fail under specific conditions determined for each
4678 directive. Clear POSUNDER4K for the former set of functions and set
4679 it to true for the latter (it can only be cleared later, but it is
4680 never set to true again). */
4681 res
.posunder4k
= posunder4k
&& dstptr
;
4683 bool success
= compute_format_length (info
, &res
, vr_values
);
4685 gimple_set_no_warning (info
.callstmt
, true);
4687 /* When optimizing and the printf return value optimization is enabled,
4688 attempt to substitute the computed result for the return value of
4689 the call. Avoid this optimization when -frounding-math is in effect
4690 and the format string contains a floating point directive. */
4691 bool call_removed
= false;
4692 if (success
&& optimize
> 0)
4694 /* Save a copy of the iterator pointing at the call. The iterator
4695 may change to point past the call in try_substitute_return_value
4696 but the original value is needed in try_simplify_call. */
4697 gimple_stmt_iterator gsi_call
= *gsi
;
4699 if (flag_printf_return_value
4700 && (!flag_rounding_math
|| !res
.floating
))
4701 call_removed
= try_substitute_return_value (gsi
, info
, res
);
4704 try_simplify_call (&gsi_call
, info
, res
);
4707 return call_removed
;