1 /* Copyright (C) 2016-2017 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"
65 #include "tree-ssa-propagate.h"
71 #include "stor-layout.h"
79 #include "substring-locations.h"
80 #include "diagnostic.h"
82 /* The likely worst case value of MB_LEN_MAX for the target, large enough
83 for UTF-8. Ideally, this would be obtained by a target hook if it were
84 to be used for optimization but it's good enough as is for warnings. */
85 #define target_mb_len_max() 6
87 /* The maximum number of bytes a single non-string directive can result
88 in. This is the result of printf("%.*Lf", INT_MAX, -LDBL_MAX) for
89 LDBL_MAX_10_EXP of 4932. */
90 #define IEEE_MAX_10_EXP 4932
91 #define target_dir_max() (target_int_max () + IEEE_MAX_10_EXP + 2)
95 const pass_data pass_data_sprintf_length
= {
96 GIMPLE_PASS
, // pass type
97 "printf-return-value", // pass name
98 OPTGROUP_NONE
, // optinfo_flags
100 PROP_cfg
, // properties_required
101 0, // properties_provided
102 0, // properties_destroyed
103 0, // properties_start
104 0, // properties_finish
107 /* Set to the warning level for the current function which is equal
108 either to warn_format_trunc for bounded functions or to
109 warn_format_overflow otherwise. */
111 static int warn_level
;
113 struct format_result
;
115 class pass_sprintf_length
: public gimple_opt_pass
117 bool fold_return_value
;
120 pass_sprintf_length (gcc::context
*ctxt
)
121 : gimple_opt_pass (pass_data_sprintf_length
, ctxt
),
122 fold_return_value (false)
125 opt_pass
* clone () { return new pass_sprintf_length (m_ctxt
); }
127 virtual bool gate (function
*);
129 virtual unsigned int execute (function
*);
131 void set_pass_param (unsigned int n
, bool param
)
134 fold_return_value
= param
;
137 bool handle_gimple_call (gimple_stmt_iterator
*);
140 bool compute_format_length (call_info
&, format_result
*);
144 pass_sprintf_length::gate (function
*)
146 /* Run the pass iff -Warn-format-overflow or -Warn-format-truncation
147 is specified and either not optimizing and the pass is being invoked
148 early, or when optimizing and the pass is being invoked during
149 optimization (i.e., "late"). */
150 return ((warn_format_overflow
> 0
151 || warn_format_trunc
> 0
152 || flag_printf_return_value
)
153 && (optimize
> 0) == fold_return_value
);
156 /* The minimum, maximum, likely, and unlikely maximum number of bytes
157 of output either a formatting function or an individual directive
162 /* The absolute minimum number of bytes. The result of a successful
163 conversion is guaranteed to be no less than this. (An erroneous
164 conversion can be indicated by MIN > HOST_WIDE_INT_MAX.) */
165 unsigned HOST_WIDE_INT min
;
166 /* The likely maximum result that is used in diagnostics. In most
167 cases MAX is the same as the worst case UNLIKELY result. */
168 unsigned HOST_WIDE_INT max
;
169 /* The likely result used to trigger diagnostics. For conversions
170 that result in a range of bytes [MIN, MAX], LIKELY is somewhere
172 unsigned HOST_WIDE_INT likely
;
173 /* In rare cases (e.g., for nultibyte characters) UNLIKELY gives
174 the worst cases maximum result of a directive. In most cases
175 UNLIKELY == MAX. UNLIKELY is used to control the return value
176 optimization but not in diagnostics. */
177 unsigned HOST_WIDE_INT unlikely
;
180 /* The result of a call to a formatted function. */
184 /* Range of characters written by the formatted function.
185 Setting the minimum to HOST_WIDE_INT_MAX disables all
186 length tracking for the remainder of the format string. */
189 /* True when the range above is obtained from known values of
190 directive arguments, or bounds on the amount of output such
191 as width and precision, and not the result of heuristics that
192 depend on warning levels. It's used to issue stricter diagnostics
193 in cases where strings of unknown lengths are bounded by the arrays
194 they are determined to refer to. KNOWNRANGE must not be used for
195 the return value optimization. */
198 /* True if no individual directive resulted in more than 4095 bytes
199 of output (the total NUMBER_CHARS_{MIN,MAX} might be greater).
200 Implementations are not required to handle directives that produce
201 more than 4K bytes (leading to undefined behavior) and so when one
202 is found it disables the return value optimization. */
205 /* True when a floating point directive has been seen in the format
209 /* True when an intermediate result has caused a warning. Used to
210 avoid issuing duplicate warnings while finishing the processing
211 of a call. WARNED also disables the return value optimization. */
214 /* Preincrement the number of output characters by 1. */
215 format_result
& operator++ ()
220 /* Postincrement the number of output characters by 1. */
221 format_result
operator++ (int)
223 format_result
prev (*this);
228 /* Increment the number of output characters by N. */
229 format_result
& operator+= (unsigned HOST_WIDE_INT
);
233 format_result::operator+= (unsigned HOST_WIDE_INT n
)
235 gcc_assert (n
< HOST_WIDE_INT_MAX
);
237 if (range
.min
< HOST_WIDE_INT_MAX
)
240 if (range
.max
< HOST_WIDE_INT_MAX
)
243 if (range
.likely
< HOST_WIDE_INT_MAX
)
246 if (range
.unlikely
< HOST_WIDE_INT_MAX
)
252 /* Return the value of INT_MIN for the target. */
254 static inline HOST_WIDE_INT
257 return tree_to_shwi (TYPE_MIN_VALUE (integer_type_node
));
260 /* Return the value of INT_MAX for the target. */
262 static inline unsigned HOST_WIDE_INT
265 return tree_to_uhwi (TYPE_MAX_VALUE (integer_type_node
));
268 /* Return the value of SIZE_MAX for the target. */
270 static inline unsigned HOST_WIDE_INT
273 return tree_to_uhwi (TYPE_MAX_VALUE (size_type_node
));
276 /* Return the constant initial value of DECL if available or DECL
277 otherwise. Same as the synonymous function in c/c-typeck.c. */
280 decl_constant_value (tree decl
)
282 if (/* Don't change a variable array bound or initial value to a constant
283 in a place where a variable is invalid. Note that DECL_INITIAL
284 isn't valid for a PARM_DECL. */
285 current_function_decl
!= 0
286 && TREE_CODE (decl
) != PARM_DECL
287 && !TREE_THIS_VOLATILE (decl
)
288 && TREE_READONLY (decl
)
289 && DECL_INITIAL (decl
) != 0
290 && TREE_CODE (DECL_INITIAL (decl
)) != ERROR_MARK
291 /* This is invalid if initial value is not constant.
292 If it has either a function call, a memory reference,
293 or a variable, then re-evaluating it could give different results. */
294 && TREE_CONSTANT (DECL_INITIAL (decl
))
295 /* Check for cases where this is sub-optimal, even though valid. */
296 && TREE_CODE (DECL_INITIAL (decl
)) != CONSTRUCTOR
)
297 return DECL_INITIAL (decl
);
301 /* Given FORMAT, set *PLOC to the source location of the format string
302 and return the format string if it is known or null otherwise. */
305 get_format_string (tree format
, location_t
*ploc
)
309 /* Pull out a constant value if the front end didn't. */
310 format
= decl_constant_value (format
);
314 if (integer_zerop (format
))
316 /* FIXME: Diagnose null format string if it hasn't been diagnosed
317 by -Wformat (the latter diagnoses only nul pointer constants,
318 this pass can do better). */
322 HOST_WIDE_INT offset
= 0;
324 if (TREE_CODE (format
) == POINTER_PLUS_EXPR
)
326 tree arg0
= TREE_OPERAND (format
, 0);
327 tree arg1
= TREE_OPERAND (format
, 1);
331 if (TREE_CODE (arg1
) != INTEGER_CST
)
336 /* POINTER_PLUS_EXPR offsets are to be interpreted signed. */
337 if (!cst_and_fits_in_hwi (arg1
))
340 offset
= int_cst_value (arg1
);
343 if (TREE_CODE (format
) != ADDR_EXPR
)
346 *ploc
= EXPR_LOC_OR_LOC (format
, input_location
);
348 format
= TREE_OPERAND (format
, 0);
350 if (TREE_CODE (format
) == ARRAY_REF
351 && tree_fits_shwi_p (TREE_OPERAND (format
, 1))
352 && (offset
+= tree_to_shwi (TREE_OPERAND (format
, 1))) >= 0)
353 format
= TREE_OPERAND (format
, 0);
359 tree array_size
= NULL_TREE
;
362 && TREE_CODE (TREE_TYPE (format
)) == ARRAY_TYPE
363 && (array_init
= decl_constant_value (format
)) != format
364 && TREE_CODE (array_init
) == STRING_CST
)
366 /* Extract the string constant initializer. Note that this may
367 include a trailing NUL character that is not in the array (e.g.
368 const char a[3] = "foo";). */
369 array_size
= DECL_SIZE_UNIT (format
);
373 if (TREE_CODE (format
) != STRING_CST
)
376 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (format
))) != char_type_node
)
378 /* Wide format string. */
382 const char *fmtstr
= TREE_STRING_POINTER (format
);
383 unsigned fmtlen
= TREE_STRING_LENGTH (format
);
387 /* Variable length arrays can't be initialized. */
388 gcc_assert (TREE_CODE (array_size
) == INTEGER_CST
);
390 if (tree_fits_shwi_p (array_size
))
392 HOST_WIDE_INT array_size_value
= tree_to_shwi (array_size
);
393 if (array_size_value
> 0
394 && array_size_value
== (int) array_size_value
395 && fmtlen
> array_size_value
)
396 fmtlen
= array_size_value
;
401 if (offset
>= fmtlen
)
408 if (fmtlen
< 1 || fmtstr
[--fmtlen
] != 0)
410 /* FIXME: Diagnose an unterminated format string if it hasn't been
411 diagnosed by -Wformat. Similarly to a null format pointer,
412 -Wformay diagnoses only nul pointer constants, this pass can
420 /* The format_warning_at_substring function is not used here in a way
421 that makes using attribute format viable. Suppress the warning. */
423 #pragma GCC diagnostic push
424 #pragma GCC diagnostic ignored "-Wsuggest-attribute=format"
426 /* For convenience and brevity. */
429 (* const fmtwarn
) (const substring_loc
&, const source_range
*,
430 const char *, int, const char *, ...)
431 = format_warning_at_substring
;
433 /* Format length modifiers. */
438 FMT_LEN_hh
, // char argument
441 FMT_LEN_ll
, // long long
442 FMT_LEN_L
, // long double (and GNU long long)
444 FMT_LEN_t
, // ptrdiff_t
445 FMT_LEN_j
// intmax_t
449 /* Description of the result of conversion either of a single directive
450 or the whole format string. */
454 /* Construct a FMTRESULT object with all counters initialized
455 to MIN. KNOWNRANGE is set when MIN is valid. */
456 fmtresult (unsigned HOST_WIDE_INT min
= HOST_WIDE_INT_MAX
)
457 : argmin (), argmax (),
458 knownrange (min
< HOST_WIDE_INT_MAX
),
464 range
.unlikely
= min
;
467 /* Construct a FMTRESULT object with MIN, MAX, and LIKELY counters.
468 KNOWNRANGE is set when both MIN and MAX are valid. */
469 fmtresult (unsigned HOST_WIDE_INT min
, unsigned HOST_WIDE_INT max
,
470 unsigned HOST_WIDE_INT likely
= HOST_WIDE_INT_MAX
)
471 : argmin (), argmax (),
472 knownrange (min
< HOST_WIDE_INT_MAX
&& max
< HOST_WIDE_INT_MAX
),
477 range
.likely
= max
< likely
? min
: likely
;
478 range
.unlikely
= max
;
481 /* Adjust result upward to reflect the RANGE of values the specified
482 width or precision is known to be in. */
483 fmtresult
& adjust_for_width_or_precision (const HOST_WIDE_INT
[2],
485 unsigned = 0, unsigned = 0);
487 /* Return the maximum number of decimal digits a value of TYPE
488 formats as on output. */
489 static unsigned type_max_digits (tree
, int);
491 /* The range a directive's argument is in. */
494 /* The minimum and maximum number of bytes that a directive
495 results in on output for an argument in the range above. */
498 /* True when the range above is obtained from a known value of
499 a directive's argument or its bounds and not the result of
500 heuristics that depend on warning levels. */
503 /* True when the argument is a null pointer. */
507 /* Adjust result upward to reflect the range ADJUST of values the
508 specified width or precision is known to be in. When non-null,
509 TYPE denotes the type of the directive whose result is being
510 adjusted, BASE gives the base of the directive (octal, decimal,
511 or hex), and ADJ denotes the additional adjustment to the LIKELY
512 counter that may need to be added when ADJUST is a range. */
515 fmtresult::adjust_for_width_or_precision (const HOST_WIDE_INT adjust
[2],
516 tree type
/* = NULL_TREE */,
517 unsigned base
/* = 0 */,
518 unsigned adj
/* = 0 */)
520 bool minadjusted
= false;
522 /* Adjust the minimum and likely counters. */
525 if (range
.min
< (unsigned HOST_WIDE_INT
)adjust
[0])
527 range
.min
= adjust
[0];
531 /* Adjust the likely counter. */
532 if (range
.likely
< range
.min
)
533 range
.likely
= range
.min
;
535 else if (adjust
[0] == target_int_min ()
536 && (unsigned HOST_WIDE_INT
)adjust
[1] == target_int_max ())
539 /* Adjust the maximum counter. */
542 if (range
.max
< (unsigned HOST_WIDE_INT
)adjust
[1])
544 range
.max
= adjust
[1];
546 /* Set KNOWNRANGE if both the minimum and maximum have been
547 adjusted. Otherwise leave it at what it was before. */
548 knownrange
= minadjusted
;
552 if (warn_level
> 1 && type
)
554 /* For large non-constant width or precision whose range spans
555 the maximum number of digits produced by the directive for
556 any argument, set the likely number of bytes to be at most
557 the number digits plus other adjustment determined by the
558 caller (one for sign or two for the hexadecimal "0x"
560 unsigned dirdigs
= type_max_digits (type
, base
);
561 if (adjust
[0] < dirdigs
&& dirdigs
< adjust
[1]
562 && range
.likely
< dirdigs
)
563 range
.likely
= dirdigs
+ adj
;
565 else if (range
.likely
< (range
.min
? range
.min
: 1))
567 /* Conservatively, set LIKELY to at least MIN but no less than
568 1 unless MAX is zero. */
569 range
.likely
= (range
.min
571 : range
.max
&& (range
.max
< HOST_WIDE_INT_MAX
572 || warn_level
> 1) ? 1 : 0);
575 /* Finally adjust the unlikely counter to be at least as large as
577 if (range
.unlikely
< range
.max
)
578 range
.unlikely
= range
.max
;
583 /* Return the maximum number of digits a value of TYPE formats in
584 BASE on output, not counting base prefix . */
587 fmtresult::type_max_digits (tree type
, int base
)
589 unsigned prec
= TYPE_PRECISION (type
);
591 return (prec
+ 2) / 3;
596 /* Decimal approximation: yields 3, 5, 10, and 20 for precision
597 of 8, 16, 32, and 64 bits. */
598 return prec
* 301 / 1000 + 1;
602 get_int_range (tree
, tree
, HOST_WIDE_INT
*, HOST_WIDE_INT
*,
603 bool, HOST_WIDE_INT
);
605 /* Description of a format directive. A directive is either a plain
606 string or a conversion specification that starts with '%'. */
610 /* The 1-based directive number (for debugging). */
613 /* The first character of the directive and its length. */
617 /* A bitmap of flags, one for each character. */
618 unsigned flags
[256 / sizeof (int)];
620 /* The range of values of the specified width, or -1 if not specified. */
621 HOST_WIDE_INT width
[2];
622 /* The range of values of the specified precision, or -1 if not
624 HOST_WIDE_INT prec
[2];
626 /* Length modifier. */
627 format_lengths modifier
;
629 /* Format specifier character. */
632 /* The argument of the directive or null when the directive doesn't
633 take one or when none is available (such as for vararg functions). */
636 /* Format conversion function that given a directive and an argument
637 returns the formatting result. */
638 fmtresult (*fmtfunc
) (const directive
&, tree
);
640 /* Return True when a the format flag CHR has been used. */
641 bool get_flag (char chr
) const
643 unsigned char c
= chr
& 0xff;
644 return (flags
[c
/ (CHAR_BIT
* sizeof *flags
)]
645 & (1U << (c
% (CHAR_BIT
* sizeof *flags
))));
648 /* Make a record of the format flag CHR having been used. */
649 void set_flag (char chr
)
651 unsigned char c
= chr
& 0xff;
652 flags
[c
/ (CHAR_BIT
* sizeof *flags
)]
653 |= (1U << (c
% (CHAR_BIT
* sizeof *flags
)));
656 /* Reset the format flag CHR. */
657 void clear_flag (char chr
)
659 unsigned char c
= chr
& 0xff;
660 flags
[c
/ (CHAR_BIT
* sizeof *flags
)]
661 &= ~(1U << (c
% (CHAR_BIT
* sizeof *flags
)));
664 /* Set both bounds of the width range to VAL. */
665 void set_width (HOST_WIDE_INT val
)
667 width
[0] = width
[1] = val
;
670 /* Set the width range according to ARG, with both bounds being
671 no less than 0. For a constant ARG set both bounds to its value
672 or 0, whichever is greater. For a non-constant ARG in some range
673 set width to its range adjusting each bound to -1 if it's less.
674 For an indeterminate ARG set width to [0, INT_MAX]. */
675 void set_width (tree arg
)
677 get_int_range (arg
, integer_type_node
, width
, width
+ 1, true, 0);
680 /* Set both bounds of the precision range to VAL. */
681 void set_precision (HOST_WIDE_INT val
)
683 prec
[0] = prec
[1] = val
;
686 /* Set the precision range according to ARG, with both bounds being
687 no less than -1. For a constant ARG set both bounds to its value
688 or -1 whichever is greater. For a non-constant ARG in some range
689 set precision to its range adjusting each bound to -1 if it's less.
690 For an indeterminate ARG set precision to [-1, INT_MAX]. */
691 void set_precision (tree arg
)
693 get_int_range (arg
, integer_type_node
, prec
, prec
+ 1, false, -1);
697 /* Return the logarithm of X in BASE. */
700 ilog (unsigned HOST_WIDE_INT x
, int base
)
711 /* Return the number of bytes resulting from converting into a string
712 the INTEGER_CST tree node X in BASE with a minimum of PREC digits.
713 PLUS indicates whether 1 for a plus sign should be added for positive
714 numbers, and PREFIX whether the length of an octal ('O') or hexadecimal
715 ('0x') prefix should be added for nonzero numbers. Return -1 if X cannot
719 tree_digits (tree x
, int base
, HOST_WIDE_INT prec
, bool plus
, bool prefix
)
721 unsigned HOST_WIDE_INT absval
;
725 if (TYPE_UNSIGNED (TREE_TYPE (x
)))
727 if (tree_fits_uhwi_p (x
))
729 absval
= tree_to_uhwi (x
);
737 if (tree_fits_shwi_p (x
))
739 HOST_WIDE_INT i
= tree_to_shwi (x
);
740 if (HOST_WIDE_INT_MIN
== i
)
742 /* Avoid undefined behavior due to negating a minimum. */
743 absval
= HOST_WIDE_INT_MAX
;
761 int ndigs
= ilog (absval
, base
);
763 res
+= prec
< ndigs
? ndigs
: prec
;
765 if (prefix
&& absval
)
776 /* Given the formatting result described by RES and NAVAIL, the number
777 of available in the destination, return the range of bytes remaining
778 in the destination. */
780 static inline result_range
781 bytes_remaining (unsigned HOST_WIDE_INT navail
, const format_result
&res
)
785 if (HOST_WIDE_INT_MAX
<= navail
)
787 range
.min
= range
.max
= range
.likely
= range
.unlikely
= navail
;
791 /* The lower bound of the available range is the available size
792 minus the maximum output size, and the upper bound is the size
793 minus the minimum. */
794 range
.max
= res
.range
.min
< navail
? navail
- res
.range
.min
: 0;
796 range
.likely
= res
.range
.likely
< navail
? navail
- res
.range
.likely
: 0;
798 if (res
.range
.max
< HOST_WIDE_INT_MAX
)
799 range
.min
= res
.range
.max
< navail
? navail
- res
.range
.max
: 0;
801 range
.min
= range
.likely
;
803 range
.unlikely
= (res
.range
.unlikely
< navail
804 ? navail
- res
.range
.unlikely
: 0);
809 /* Description of a call to a formatted function. */
811 struct pass_sprintf_length::call_info
813 /* Function call statement. */
816 /* Function called. */
819 /* Called built-in function code. */
820 built_in_function fncode
;
822 /* Format argument and format string extracted from it. */
826 /* The location of the format argument. */
829 /* The destination object size for __builtin___xxx_chk functions
830 typically determined by __builtin_object_size, or -1 if unknown. */
831 unsigned HOST_WIDE_INT objsize
;
833 /* Number of the first variable argument. */
834 unsigned HOST_WIDE_INT argidx
;
836 /* True for functions like snprintf that specify the size of
837 the destination, false for others like sprintf that don't. */
840 /* True for bounded functions like snprintf that specify a zero-size
841 buffer as a request to compute the size of output without actually
842 writing any. NOWRITE is cleared in response to the %n directive
843 which has side-effects similar to writing output. */
846 /* Return true if the called function's return value is used. */
847 bool retval_used () const
849 return gimple_get_lhs (callstmt
);
852 /* Return the warning option corresponding to the called function. */
855 return bounded
? OPT_Wformat_truncation_
: OPT_Wformat_overflow_
;
859 /* Return the result of formatting a no-op directive (such as '%n'). */
862 format_none (const directive
&, tree
)
868 /* Return the result of formatting the '%%' directive. */
871 format_percent (const directive
&, tree
)
878 /* Compute intmax_type_node and uintmax_type_node similarly to how
879 tree.c builds size_type_node. */
882 build_intmax_type_nodes (tree
*pintmax
, tree
*puintmax
)
884 if (strcmp (UINTMAX_TYPE
, "unsigned int") == 0)
886 *pintmax
= integer_type_node
;
887 *puintmax
= unsigned_type_node
;
889 else if (strcmp (UINTMAX_TYPE
, "long unsigned int") == 0)
891 *pintmax
= long_integer_type_node
;
892 *puintmax
= long_unsigned_type_node
;
894 else if (strcmp (UINTMAX_TYPE
, "long long unsigned int") == 0)
896 *pintmax
= long_long_integer_type_node
;
897 *puintmax
= long_long_unsigned_type_node
;
901 for (int i
= 0; i
< NUM_INT_N_ENTS
; i
++)
902 if (int_n_enabled_p
[i
])
905 sprintf (name
, "__int%d unsigned", int_n_data
[i
].bitsize
);
907 if (strcmp (name
, UINTMAX_TYPE
) == 0)
909 *pintmax
= int_n_trees
[i
].signed_type
;
910 *puintmax
= int_n_trees
[i
].unsigned_type
;
918 /* Determine the range [*PMIN, *PMAX] that the expression ARG of TYPE
919 is in. Return true when the range is a subrange of that of TYPE.
920 Whn ARG is null it is as if it had the full range of TYPE.
921 When ABSOLUTE is true the range reflects the absolute value of
922 the argument. When ABSOLUTE is false, negative bounds of
923 the determined range are replaced with NEGBOUND. */
926 get_int_range (tree arg
, tree type
, HOST_WIDE_INT
*pmin
, HOST_WIDE_INT
*pmax
,
927 bool absolute
, HOST_WIDE_INT negbound
)
929 bool knownrange
= false;
933 *pmin
= (TYPE_UNSIGNED (type
)
934 ? tree_to_uhwi (TYPE_MIN_VALUE (type
))
935 : tree_to_shwi (TYPE_MIN_VALUE (type
)));
936 *pmax
= tree_to_uhwi (TYPE_MAX_VALUE (type
));
938 else if (TREE_CODE (arg
) == INTEGER_CST
)
940 /* For a constant argument return its value adjusted as specified
941 by NEGATIVE and NEGBOUND and return true to indicate that the
943 *pmin
= tree_fits_shwi_p (arg
) ? tree_to_shwi (arg
) : tree_to_uhwi (arg
);
949 /* True if the argument's range cannot be determined. */
952 type
= TREE_TYPE (arg
);
954 if (TREE_CODE (arg
) == SSA_NAME
955 && TREE_CODE (type
) == INTEGER_TYPE
)
957 /* Try to determine the range of values of the integer argument. */
959 enum value_range_type range_type
= get_range_info (arg
, &min
, &max
);
960 if (range_type
== VR_RANGE
)
962 HOST_WIDE_INT type_min
963 = (TYPE_UNSIGNED (type
)
964 ? tree_to_uhwi (TYPE_MIN_VALUE (type
))
965 : tree_to_shwi (TYPE_MIN_VALUE (type
)));
967 HOST_WIDE_INT type_max
= tree_to_uhwi (TYPE_MAX_VALUE (type
));
969 *pmin
= min
.to_shwi ();
970 *pmax
= max
.to_shwi ();
972 /* Return true if the adjusted range is a subrange of
973 the full range of the argument's type. */
974 knownrange
= type_min
< *pmin
|| *pmax
< type_max
;
980 /* Handle an argument with an unknown range as if none had been
983 return get_int_range (NULL_TREE
, type
, pmin
, pmax
, absolute
, negbound
);
986 /* Adjust each bound as specified by ABSOLUTE and NEGBOUND. */
992 *pmin
= *pmax
= -*pmin
;
995 HOST_WIDE_INT tmp
= -*pmin
;
1002 else if (*pmin
< negbound
)
1008 /* With the range [*ARGMIN, *ARGMAX] of an integer directive's actual
1009 argument, due to the conversion from either *ARGMIN or *ARGMAX to
1010 the type of the directive's formal argument it's possible for both
1011 to result in the same number of bytes or a range of bytes that's
1012 less than the number of bytes that would result from formatting
1013 some other value in the range [*ARGMIN, *ARGMAX]. This can be
1014 determined by checking for the actual argument being in the range
1015 of the type of the directive. If it isn't it must be assumed to
1016 take on the full range of the directive's type.
1017 Return true when the range has been adjusted to the full unsigned
1018 range of DIRTYPE, or [0, DIRTYPE_MAX], and false otherwise. */
1021 adjust_range_for_overflow (tree dirtype
, tree
*argmin
, tree
*argmax
)
1023 tree argtype
= TREE_TYPE (*argmin
);
1024 unsigned argprec
= TYPE_PRECISION (argtype
);
1025 unsigned dirprec
= TYPE_PRECISION (dirtype
);
1027 /* If the actual argument and the directive's argument have the same
1028 precision and sign there can be no overflow and so there is nothing
1030 if (argprec
== dirprec
&& TYPE_SIGN (argtype
) == TYPE_SIGN (dirtype
))
1033 /* The logic below was inspired/lifted from the CONVERT_EXPR_CODE_P
1034 branch in the extract_range_from_unary_expr function in tree-vrp.c. */
1036 if (TREE_CODE (*argmin
) == INTEGER_CST
1037 && TREE_CODE (*argmax
) == INTEGER_CST
1038 && (dirprec
>= argprec
1039 || integer_zerop (int_const_binop (RSHIFT_EXPR
,
1040 int_const_binop (MINUS_EXPR
,
1043 size_int (dirprec
)))))
1045 *argmin
= force_fit_type (dirtype
, wi::to_widest (*argmin
), 0, false);
1046 *argmax
= force_fit_type (dirtype
, wi::to_widest (*argmax
), 0, false);
1048 /* If *ARGMIN is still less than *ARGMAX the conversion above
1049 is safe. Otherwise, it has overflowed and would be unsafe. */
1050 if (tree_int_cst_le (*argmin
, *argmax
))
1054 tree dirmin
= TYPE_MIN_VALUE (dirtype
);
1055 tree dirmax
= TYPE_MAX_VALUE (dirtype
);
1057 if (TYPE_UNSIGNED (dirtype
))
1064 *argmin
= integer_zero_node
;
1071 /* Return a range representing the minimum and maximum number of bytes
1072 that the format directive DIR will output for any argument given
1073 the WIDTH and PRECISION (extracted from DIR). This function is
1074 used when the directive argument or its value isn't known. */
1077 format_integer (const directive
&dir
, tree arg
)
1079 tree intmax_type_node
;
1080 tree uintmax_type_node
;
1082 /* Base to format the number in. */
1085 /* True when a conversion is preceded by a prefix indicating the base
1086 of the argument (octal or hexadecimal). */
1087 bool maybebase
= dir
.get_flag ('#');
1089 /* True when a signed conversion is preceded by a sign or space. */
1090 bool maybesign
= false;
1092 /* True for signed conversions (i.e., 'd' and 'i'). */
1095 switch (dir
.specifier
)
1099 /* Space and '+' are only meaningful for signed conversions. */
1100 maybesign
= dir
.get_flag (' ') | dir
.get_flag ('+');
1118 /* The type of the "formal" argument expected by the directive. */
1119 tree dirtype
= NULL_TREE
;
1121 /* Determine the expected type of the argument from the length
1123 switch (dir
.modifier
)
1126 if (dir
.specifier
== 'p')
1127 dirtype
= ptr_type_node
;
1129 dirtype
= sign
? integer_type_node
: unsigned_type_node
;
1133 dirtype
= sign
? short_integer_type_node
: short_unsigned_type_node
;
1137 dirtype
= sign
? signed_char_type_node
: unsigned_char_type_node
;
1141 dirtype
= sign
? long_integer_type_node
: long_unsigned_type_node
;
1147 ? long_long_integer_type_node
1148 : long_long_unsigned_type_node
);
1152 dirtype
= signed_or_unsigned_type_for (!sign
, size_type_node
);
1156 dirtype
= signed_or_unsigned_type_for (!sign
, ptrdiff_type_node
);
1160 build_intmax_type_nodes (&intmax_type_node
, &uintmax_type_node
);
1161 dirtype
= sign
? intmax_type_node
: uintmax_type_node
;
1165 return fmtresult ();
1168 /* The type of the argument to the directive, either deduced from
1169 the actual non-constant argument if one is known, or from
1170 the directive itself when none has been provided because it's
1172 tree argtype
= NULL_TREE
;
1176 /* When the argument has not been provided, use the type of
1177 the directive's argument as an approximation. This will
1178 result in false positives for directives like %i with
1179 arguments with smaller precision (such as short or char). */
1182 else if (TREE_CODE (arg
) == INTEGER_CST
)
1184 /* When a constant argument has been provided use its value
1185 rather than type to determine the length of the output. */
1188 if ((dir
.prec
[0] <= 0 && dir
.prec
[1] >= 0) && integer_zerop (arg
))
1190 /* As a special case, a precision of zero with a zero argument
1191 results in zero bytes except in base 8 when the '#' flag is
1192 specified, and for signed conversions in base 8 and 10 when
1193 flags when either the space or '+' flag has been specified
1194 when it results in just one byte (with width having the normal
1195 effect). This must extend to the case of a specified precision
1196 with an unknown value because it can be zero. */
1197 res
.range
.min
= ((base
== 8 && dir
.get_flag ('#')) || maybesign
);
1198 if (res
.range
.min
== 0 && dir
.prec
[0] != dir
.prec
[1])
1201 res
.range
.likely
= 1;
1205 res
.range
.max
= res
.range
.min
;
1206 res
.range
.likely
= res
.range
.min
;
1211 /* Convert the argument to the type of the directive. */
1212 arg
= fold_convert (dirtype
, arg
);
1214 res
.range
.min
= tree_digits (arg
, base
, dir
.prec
[0],
1215 maybesign
, maybebase
);
1216 if (dir
.prec
[0] == dir
.prec
[1])
1217 res
.range
.max
= res
.range
.min
;
1219 res
.range
.max
= tree_digits (arg
, base
, dir
.prec
[1],
1220 maybesign
, maybebase
);
1221 res
.range
.likely
= res
.range
.min
;
1224 res
.range
.unlikely
= res
.range
.max
;
1226 /* Bump up the counters if WIDTH is greater than LEN. */
1227 res
.adjust_for_width_or_precision (dir
.width
, dirtype
, base
,
1228 (sign
| maybebase
) + (base
== 16));
1229 /* Bump up the counters again if PRECision is greater still. */
1230 res
.adjust_for_width_or_precision (dir
.prec
, dirtype
, base
,
1231 (sign
| maybebase
) + (base
== 16));
1235 else if (TREE_CODE (TREE_TYPE (arg
)) == INTEGER_TYPE
1236 || TREE_CODE (TREE_TYPE (arg
)) == POINTER_TYPE
)
1237 /* Determine the type of the provided non-constant argument. */
1238 argtype
= TREE_TYPE (arg
);
1240 /* Don't bother with invalid arguments since they likely would
1241 have already been diagnosed, and disable any further checking
1242 of the format string by returning [-1, -1]. */
1243 return fmtresult ();
1247 /* Using either the range the non-constant argument is in, or its
1248 type (either "formal" or actual), create a range of values that
1249 constrain the length of output given the warning level. */
1250 tree argmin
= NULL_TREE
;
1251 tree argmax
= NULL_TREE
;
1254 && TREE_CODE (arg
) == SSA_NAME
1255 && TREE_CODE (argtype
) == INTEGER_TYPE
)
1257 /* Try to determine the range of values of the integer argument
1258 (range information is not available for pointers). */
1260 enum value_range_type range_type
= get_range_info (arg
, &min
, &max
);
1261 if (range_type
== VR_RANGE
)
1263 argmin
= build_int_cst (argtype
, wi::fits_uhwi_p (min
)
1264 ? min
.to_uhwi () : min
.to_shwi ());
1265 argmax
= build_int_cst (argtype
, wi::fits_uhwi_p (max
)
1266 ? max
.to_uhwi () : max
.to_shwi ());
1268 /* Set KNOWNRANGE if the argument is in a known subrange
1269 of the directive's type (KNOWNRANGE may be reset below). */
1271 = (!tree_int_cst_equal (TYPE_MIN_VALUE (dirtype
), argmin
)
1272 || !tree_int_cst_equal (TYPE_MAX_VALUE (dirtype
), argmax
));
1274 res
.argmin
= argmin
;
1275 res
.argmax
= argmax
;
1277 else if (range_type
== VR_ANTI_RANGE
)
1279 /* Handle anti-ranges if/when bug 71690 is resolved. */
1281 else if (range_type
== VR_VARYING
)
1283 /* The argument here may be the result of promoting the actual
1284 argument to int. Try to determine the type of the actual
1285 argument before promotion and narrow down its range that
1287 gimple
*def
= SSA_NAME_DEF_STMT (arg
);
1288 if (is_gimple_assign (def
))
1290 tree_code code
= gimple_assign_rhs_code (def
);
1291 if (code
== INTEGER_CST
)
1293 arg
= gimple_assign_rhs1 (def
);
1294 return format_integer (dir
, arg
);
1297 if (code
== NOP_EXPR
)
1299 tree type
= TREE_TYPE (gimple_assign_rhs1 (def
));
1300 if (TREE_CODE (type
) == INTEGER_TYPE
1301 || TREE_CODE (type
) == POINTER_TYPE
)
1310 /* For an unknown argument (e.g., one passed to a vararg function)
1311 or one whose value range cannot be determined, create a T_MIN
1312 constant if the argument's type is signed and T_MAX otherwise,
1313 and use those to compute the range of bytes that the directive
1314 can output. When precision may be zero, use zero as the minimum
1315 since it results in no bytes on output (unless width is specified
1316 to be greater than 0). */
1317 bool zero
= dir
.prec
[0] <= 0 && dir
.prec
[1] >= 0;
1318 argmin
= build_int_cst (argtype
, !zero
);
1320 int typeprec
= TYPE_PRECISION (dirtype
);
1321 int argprec
= TYPE_PRECISION (argtype
);
1323 if (argprec
< typeprec
)
1325 if (POINTER_TYPE_P (argtype
))
1326 argmax
= build_all_ones_cst (argtype
);
1327 else if (TYPE_UNSIGNED (argtype
))
1328 argmax
= TYPE_MAX_VALUE (argtype
);
1330 argmax
= TYPE_MIN_VALUE (argtype
);
1334 if (POINTER_TYPE_P (dirtype
))
1335 argmax
= build_all_ones_cst (dirtype
);
1336 else if (TYPE_UNSIGNED (dirtype
))
1337 argmax
= TYPE_MAX_VALUE (dirtype
);
1339 argmax
= TYPE_MIN_VALUE (dirtype
);
1342 res
.argmin
= argmin
;
1343 res
.argmax
= argmax
;
1346 if (tree_int_cst_lt (argmax
, argmin
))
1353 /* Clear KNOWNRANGE if the range has been adjusted to the maximum
1354 of the directive. If it has been cleared then since ARGMIN and/or
1355 ARGMAX have been adjusted also adjust the corresponding ARGMIN and
1356 ARGMAX in the result to include in diagnostics. */
1357 if (adjust_range_for_overflow (dirtype
, &argmin
, &argmax
))
1359 res
.knownrange
= false;
1360 res
.argmin
= argmin
;
1361 res
.argmax
= argmax
;
1364 /* Recursively compute the minimum and maximum from the known range,
1365 taking care to swap them if the lower bound results in longer
1366 output than the upper bound (e.g., in the range [-1, 0]. */
1368 if (TYPE_UNSIGNED (dirtype
))
1370 /* For unsigned conversions/directives, use the minimum (i.e., 0
1371 or 1) and maximum to compute the shortest and longest output,
1373 res
.range
.min
= format_integer (dir
, argmin
).range
.min
;
1374 res
.range
.max
= format_integer (dir
, argmax
).range
.max
;
1378 /* For signed conversions/directives, use the maximum (i.e., 0)
1379 to compute the shortest output and the minimum (i.e., TYPE_MIN)
1380 to compute the longest output. This is important when precision
1381 is specified but unknown because otherwise both output lengths
1382 would reflect the largest possible precision (i.e., INT_MAX). */
1383 res
.range
.min
= format_integer (dir
, argmax
).range
.min
;
1384 res
.range
.max
= format_integer (dir
, argmin
).range
.max
;
1387 if (res
.range
.max
< res
.range
.min
)
1389 unsigned HOST_WIDE_INT tmp
= res
.range
.max
;
1390 res
.range
.max
= res
.range
.min
;
1391 res
.range
.min
= tmp
;
1394 res
.range
.likely
= res
.knownrange
? res
.range
.max
: res
.range
.min
;
1395 res
.range
.unlikely
= res
.range
.max
;
1396 res
.adjust_for_width_or_precision (dir
.width
, dirtype
, base
,
1397 (sign
| maybebase
) + (base
== 16));
1398 res
.adjust_for_width_or_precision (dir
.prec
, dirtype
, base
,
1399 (sign
| maybebase
) + (base
== 16));
1404 /* Return the number of bytes that a format directive consisting of FLAGS,
1405 PRECision, format SPECification, and MPFR rounding specifier RNDSPEC,
1406 would result for argument X under ideal conditions (i.e., if PREC
1407 weren't excessive). MPFR 3.1 allocates large amounts of memory for
1408 values of PREC with large magnitude and can fail (see MPFR bug #21056).
1409 This function works around those problems. */
1411 static unsigned HOST_WIDE_INT
1412 get_mpfr_format_length (mpfr_ptr x
, const char *flags
, HOST_WIDE_INT prec
,
1413 char spec
, char rndspec
)
1417 HOST_WIDE_INT len
= strlen (flags
);
1420 memcpy (fmtstr
+ 1, flags
, len
);
1421 memcpy (fmtstr
+ 1 + len
, ".*R", 3);
1422 fmtstr
[len
+ 4] = rndspec
;
1423 fmtstr
[len
+ 5] = spec
;
1424 fmtstr
[len
+ 6] = '\0';
1426 spec
= TOUPPER (spec
);
1427 if (spec
== 'E' || spec
== 'F')
1429 /* For %e, specify the precision explicitly since mpfr_sprintf
1430 does its own thing just to be different (see MPFR bug 21088). */
1436 /* Avoid passing negative precisions with larger magnitude to MPFR
1437 to avoid exposing its bugs. (A negative precision is supposed
1443 HOST_WIDE_INT p
= prec
;
1447 /* For G/g, precision gives the maximum number of significant
1448 digits which is bounded by LDBL_MAX_10_EXP, or, for a 128
1449 bit IEEE extended precision, 4932. Using twice as much
1450 here should be more than sufficient for any real format. */
1451 if ((IEEE_MAX_10_EXP
* 2) < prec
)
1452 prec
= IEEE_MAX_10_EXP
* 2;
1457 /* Cap precision arbitrarily at 1KB and add the difference
1458 (if any) to the MPFR result. */
1463 len
= mpfr_snprintf (NULL
, 0, fmtstr
, (int)p
, x
);
1465 /* Handle the unlikely (impossible?) error by returning more than
1466 the maximum dictated by the function's return type. */
1468 return target_dir_max () + 1;
1470 /* Adjust the return value by the difference. */
1477 /* Return the number of bytes to format using the format specifier
1478 SPEC and the precision PREC the largest value in the real floating
1481 static unsigned HOST_WIDE_INT
1482 format_floating_max (tree type
, char spec
, HOST_WIDE_INT prec
)
1484 machine_mode mode
= TYPE_MODE (type
);
1486 /* IBM Extended mode. */
1487 if (MODE_COMPOSITE_P (mode
))
1490 /* Get the real type format desription for the target. */
1491 const real_format
*rfmt
= REAL_MODE_FORMAT (mode
);
1494 real_maxval (&rv
, 0, mode
);
1496 /* Convert the GCC real value representation with the precision
1497 of the real type to the mpfr_t format with the GCC default
1498 round-to-nearest mode. */
1500 mpfr_init2 (x
, rfmt
->p
);
1501 mpfr_from_real (x
, &rv
, GMP_RNDN
);
1503 /* Return a value one greater to account for the leading minus sign. */
1504 return 1 + get_mpfr_format_length (x
, "", prec
, spec
, 'D');
1507 /* Return a range representing the minimum and maximum number of bytes
1508 that the directive DIR will output for any argument. This function
1509 is used when the directive argument or its value isn't known. */
1512 format_floating (const directive
&dir
)
1516 switch (dir
.modifier
)
1520 type
= double_type_node
;
1524 type
= long_double_type_node
;
1528 type
= long_double_type_node
;
1532 return fmtresult ();
1535 /* The minimum and maximum number of bytes produced by the directive. */
1538 /* The minimum output as determined by flags. It's always at least 1.
1539 When plus or space are set the output is preceded by either a sign
1541 int flagmin
= (1 /* for the first digit */
1542 + (dir
.get_flag ('+') | dir
.get_flag (' ')));
1544 /* When the pound flag is set the decimal point is included in output
1545 regardless of precision. Whether or not a decimal point is included
1546 otherwise depends on the specification and precision. */
1547 bool radix
= dir
.get_flag ('#');
1549 switch (dir
.specifier
)
1554 HOST_WIDE_INT minprec
= 6 + !radix
/* decimal point */;
1555 if (dir
.prec
[0] <= 0)
1557 else if (dir
.prec
[0] > 0)
1558 minprec
= dir
.prec
[0] + !radix
/* decimal point */;
1560 res
.range
.min
= (2 /* 0x */
1566 res
.range
.max
= format_floating_max (type
, 'a', dir
.prec
[1]);
1567 res
.range
.likely
= res
.range
.min
;
1569 /* The unlikely maximum accounts for the longest multibyte
1570 decimal point character. */
1571 res
.range
.unlikely
= res
.range
.max
;
1572 if (dir
.prec
[0] != dir
.prec
[1]
1573 || dir
.prec
[0] == -1 || dir
.prec
[0] > 0)
1574 res
.range
.unlikely
+= target_mb_len_max () - 1;
1582 /* The minimum output is "[-+]1.234567e+00" regardless
1583 of the value of the actual argument. */
1584 HOST_WIDE_INT minprec
= 6 + !radix
/* decimal point */;
1585 if ((dir
.prec
[0] < 0 && dir
.prec
[1] > -1) || dir
.prec
[0] == 0)
1587 else if (dir
.prec
[0] > 0)
1588 minprec
= dir
.prec
[0] + !radix
/* decimal point */;
1590 res
.range
.min
= (flagmin
1594 /* MPFR uses a precision of 16 by default for some reason.
1595 Set it to the C default of 6. */
1596 int maxprec
= dir
.prec
[1] < 0 ? 6 : dir
.prec
[1];
1597 res
.range
.max
= format_floating_max (type
, 'e', maxprec
);
1599 res
.range
.likely
= res
.range
.min
;
1601 /* The unlikely maximum accounts for the longest multibyte
1602 decimal point character. */
1603 if (dir
.prec
[0] != dir
.prec
[1]
1604 || dir
.prec
[0] == -1 || dir
.prec
[0] > 0)
1605 res
.range
.unlikely
= res
.range
.max
+ target_mb_len_max () -1;
1607 res
.range
.unlikely
= res
.range
.max
;
1614 /* The lower bound when precision isn't specified is 8 bytes
1615 ("1.23456" since precision is taken to be 6). When precision
1616 is zero, the lower bound is 1 byte (e.g., "1"). Otherwise,
1617 when precision is greater than zero, then the lower bound
1618 is 2 plus precision (plus flags). */
1619 HOST_WIDE_INT minprec
= 0;
1620 if (dir
.prec
[0] < 0)
1621 minprec
= dir
.prec
[1] < 0 ? 6 + !radix
/* decimal point */ : 0;
1622 else if (dir
.prec
[0])
1623 minprec
= dir
.prec
[0] + !radix
/* decimal point */;
1625 res
.range
.min
= flagmin
+ radix
+ minprec
;
1627 /* Compute the upper bound for -TYPE_MAX. */
1628 res
.range
.max
= format_floating_max (type
, 'f', dir
.prec
[1]);
1630 res
.range
.likely
= res
.range
.min
;
1632 /* The unlikely maximum accounts for the longest multibyte
1633 decimal point character. */
1634 if (dir
.prec
[0] != dir
.prec
[1]
1635 || dir
.prec
[0] == -1 || dir
.prec
[0] > 0)
1636 res
.range
.unlikely
= res
.range
.max
+ target_mb_len_max () - 1;
1643 /* The %g output depends on precision and the exponent of
1644 the argument. Since the value of the argument isn't known
1645 the lower bound on the range of bytes (not counting flags
1647 res
.range
.min
= flagmin
;
1648 res
.range
.max
= format_floating_max (type
, 'g', dir
.prec
[1]);
1649 res
.range
.likely
= res
.range
.max
;
1651 /* The unlikely maximum accounts for the longest multibyte
1652 decimal point character. */
1653 res
.range
.unlikely
= res
.range
.max
+ target_mb_len_max () - 1;
1658 return fmtresult ();
1661 /* Bump up the byte counters if WIDTH is greater. */
1662 res
.adjust_for_width_or_precision (dir
.width
);
1666 /* Return a range representing the minimum and maximum number of bytes
1667 that the directive DIR will write on output for the floating argument
1671 format_floating (const directive
&dir
, tree arg
)
1673 if (!arg
|| TREE_CODE (arg
) != REAL_CST
)
1674 return format_floating (dir
);
1676 HOST_WIDE_INT prec
[] = { dir
.prec
[0], dir
.prec
[1] };
1678 if (TOUPPER (dir
.specifier
) == 'A')
1680 /* For %a, leave the minimum precision unspecified to let
1681 MFPR trim trailing zeros (as it and many other systems
1682 including Glibc happen to do) and set the maximum
1683 precision to reflect what it would be with trailing zeros
1684 present (as Solaris and derived systems do). */
1690 = REAL_MODE_FORMAT (TYPE_MODE (TREE_TYPE (arg
)))->p
;
1692 /* The precision of the IEEE 754 double format is 53.
1693 The precision of all other GCC binary double formats
1695 prec
[1] = fmtprec
<= 56 ? 13 : 15;
1699 /* The minimum and maximum number of bytes produced by the directive. */
1702 /* Get the real type format desription for the target. */
1703 const REAL_VALUE_TYPE
*rvp
= TREE_REAL_CST_PTR (arg
);
1704 const real_format
*rfmt
= REAL_MODE_FORMAT (TYPE_MODE (TREE_TYPE (arg
)));
1707 char *pfmt
= fmtstr
;
1710 for (const char *pf
= "-+ #0"; *pf
; ++pf
)
1711 if (dir
.get_flag (*pf
))
1717 /* Set up an array to easily iterate over. */
1718 unsigned HOST_WIDE_INT
* const minmax
[] = {
1719 &res
.range
.min
, &res
.range
.max
1722 for (int i
= 0; i
!= sizeof minmax
/ sizeof *minmax
; ++i
)
1724 /* Convert the GCC real value representation with the precision
1725 of the real type to the mpfr_t format rounding down in the
1726 first iteration that computes the minimm and up in the second
1727 that computes the maximum. This order is arbibtrary because
1728 rounding in either direction can result in longer output. */
1730 mpfr_init2 (mpfrval
, rfmt
->p
);
1731 mpfr_from_real (mpfrval
, rvp
, i
? GMP_RNDU
: GMP_RNDD
);
1733 /* Use the MPFR rounding specifier to round down in the first
1734 iteration and then up. In most but not all cases this will
1735 result in the same number of bytes. */
1736 char rndspec
= "DU"[i
];
1738 /* Format it and store the result in the corresponding member
1739 of the result struct. */
1740 *minmax
[i
] = get_mpfr_format_length (mpfrval
, fmtstr
, prec
[i
],
1741 dir
.specifier
, rndspec
);
1745 /* Make sure the minimum is less than the maximum (MPFR rounding
1746 in the call to mpfr_snprintf can result in the reverse. */
1747 if (res
.range
.max
< res
.range
.min
)
1749 unsigned HOST_WIDE_INT tmp
= res
.range
.min
;
1750 res
.range
.min
= res
.range
.max
;
1751 res
.range
.max
= tmp
;
1754 res
.knownrange
= true;
1756 /* For the same floating point constant use the longer output
1757 as the likely maximum since with round to nearest either is
1759 res
.range
.likely
= res
.range
.max
;
1760 res
.range
.unlikely
= res
.range
.max
;
1762 if (res
.range
.max
> 2 && (prec
[0] != 0 || prec
[1] != 0))
1764 /* Unless the precision is zero output longer than 2 bytes may
1765 include the decimal point which must be a single character
1766 up to MB_LEN_MAX in length. This is overly conservative
1767 since in some conversions some constants result in no decimal
1768 point (e.g., in %g). */
1769 res
.range
.unlikely
+= target_mb_len_max () - 1;
1772 res
.adjust_for_width_or_precision (dir
.width
);
1776 /* Return a FMTRESULT struct set to the lengths of the shortest and longest
1777 strings referenced by the expression STR, or (-1, -1) when not known.
1778 Used by the format_string function below. */
1781 get_string_length (tree str
)
1784 return fmtresult ();
1786 if (tree slen
= c_strlen (str
, 1))
1788 /* Simply return the length of the string. */
1789 fmtresult
res (tree_to_shwi (slen
));
1793 /* Determine the length of the shortest and longest string referenced
1794 by STR. Strings of unknown lengths are bounded by the sizes of
1795 arrays that subexpressions of STR may refer to. Pointers that
1796 aren't known to point any such arrays result in LENRANGE[1] set
1799 get_range_strlen (str
, lenrange
);
1801 if (lenrange
[0] || lenrange
[1])
1804 = (tree_fits_uhwi_p (lenrange
[0])
1805 ? tree_to_uhwi (lenrange
[0])
1809 = (tree_fits_uhwi_p (lenrange
[1])
1810 ? tree_to_uhwi (lenrange
[1])
1811 : HOST_WIDE_INT_M1U
);
1813 /* get_range_strlen() returns the target value of SIZE_MAX for
1814 strings of unknown length. Bump it up to HOST_WIDE_INT_M1U
1815 which may be bigger. */
1816 if ((unsigned HOST_WIDE_INT
)min
== target_size_max ())
1817 min
= HOST_WIDE_INT_M1U
;
1818 if ((unsigned HOST_WIDE_INT
)max
== target_size_max ())
1819 max
= HOST_WIDE_INT_M1U
;
1821 fmtresult
res (min
, max
);
1823 /* Set RES.KNOWNRANGE to true if and only if all strings referenced
1824 by STR are known to be bounded (though not necessarily by their
1825 actual length but perhaps by their maximum possible length). */
1826 if (res
.range
.max
< target_int_max ())
1828 res
.knownrange
= true;
1829 /* When the the length of the longest string is known and not
1830 excessive use it as the likely length of the string(s). */
1831 res
.range
.likely
= res
.range
.max
;
1835 /* When the upper bound is unknown (as assumed to be excessive)
1836 set the likely length to the greater of 1 and the length of
1837 the shortest string. */
1838 res
.range
.likely
= res
.range
.min
? res
.range
.min
: warn_level
> 1;
1841 res
.range
.unlikely
= res
.range
.max
;
1846 return get_string_length (NULL_TREE
);
1849 /* Return the minimum and maximum number of characters formatted
1850 by the '%c' format directives and its wide character form for
1851 the argument ARG. ARG can be null (for functions such as
1855 format_character (const directive
&dir
, tree arg
)
1859 res
.knownrange
= true;
1861 if (dir
.modifier
== FMT_LEN_l
)
1863 /* A wide character can result in as few as zero bytes. */
1866 HOST_WIDE_INT min
, max
;
1867 if (get_int_range (arg
, integer_type_node
, &min
, &max
, false, 0))
1869 if (min
== 0 && max
== 0)
1871 /* The NUL wide character results in no bytes. */
1873 res
.range
.likely
= 0;
1874 res
.range
.unlikely
= 0;
1876 else if (min
> 0 && min
< 128)
1878 /* A wide character in the ASCII range most likely results
1879 in a single byte, and only unlikely in up to MB_LEN_MAX. */
1881 res
.range
.likely
= 1;
1882 res
.range
.unlikely
= target_mb_len_max ();
1886 /* A wide character outside the ASCII range likely results
1887 in up to two bytes, and only unlikely in up to MB_LEN_MAX. */
1888 res
.range
.max
= target_mb_len_max ();
1889 res
.range
.likely
= 2;
1890 res
.range
.unlikely
= res
.range
.max
;
1895 /* An unknown wide character is treated the same as a wide
1896 character outside the ASCII range. */
1897 res
.range
.max
= target_mb_len_max ();
1898 res
.range
.likely
= 2;
1899 res
.range
.unlikely
= res
.range
.max
;
1904 /* A plain '%c' directive. Its ouput is exactly 1. */
1905 res
.range
.min
= res
.range
.max
= 1;
1906 res
.range
.likely
= res
.range
.unlikely
= 1;
1907 res
.knownrange
= true;
1910 /* Bump up the byte counters if WIDTH is greater. */
1911 return res
.adjust_for_width_or_precision (dir
.width
);
1914 /* Return the minimum and maximum number of characters formatted
1915 by the '%s' format directive and its wide character form for
1916 the argument ARG. ARG can be null (for functions such as
1920 format_string (const directive
&dir
, tree arg
)
1924 /* Compute the range the argument's length can be in. */
1925 fmtresult slen
= get_string_length (arg
);
1926 if (slen
.range
.min
== slen
.range
.max
1927 && slen
.range
.min
< HOST_WIDE_INT_MAX
)
1929 /* The argument is either a string constant or it refers
1930 to one of a number of strings of the same length. */
1932 /* A '%s' directive with a string argument with constant length. */
1933 res
.range
= slen
.range
;
1935 if (dir
.modifier
== FMT_LEN_l
)
1937 /* In the worst case the length of output of a wide string S
1938 is bounded by MB_LEN_MAX * wcslen (S). */
1939 res
.range
.max
*= target_mb_len_max ();
1940 res
.range
.unlikely
= res
.range
.max
;
1941 /* It's likely that the the total length is not more that
1943 res
.range
.likely
= res
.range
.min
* 2;
1945 if (dir
.prec
[1] >= 0
1946 && (unsigned HOST_WIDE_INT
)dir
.prec
[1] < res
.range
.max
)
1948 res
.range
.max
= dir
.prec
[1];
1949 res
.range
.likely
= dir
.prec
[1];
1950 res
.range
.unlikely
= dir
.prec
[1];
1953 if (dir
.prec
[0] < 0 && dir
.prec
[1] > -1)
1955 else if (dir
.prec
[0] >= 0)
1956 res
.range
.likely
= dir
.prec
[0];
1958 /* Even a non-empty wide character string need not convert into
1964 res
.knownrange
= true;
1966 if (dir
.prec
[0] < 0 && dir
.prec
[1] > -1)
1968 else if ((unsigned HOST_WIDE_INT
)dir
.prec
[0] < res
.range
.min
)
1969 res
.range
.min
= dir
.prec
[0];
1971 if ((unsigned HOST_WIDE_INT
)dir
.prec
[1] < res
.range
.max
)
1973 res
.range
.max
= dir
.prec
[1];
1974 res
.range
.likely
= dir
.prec
[1];
1975 res
.range
.unlikely
= dir
.prec
[1];
1979 else if (arg
&& integer_zerop (arg
))
1981 /* Handle null pointer argument. */
1989 /* For a '%s' and '%ls' directive with a non-constant string,
1990 the minimum number of characters is the greater of WIDTH
1991 and either 0 in mode 1 or the smaller of PRECISION and 1
1992 in mode 2, and the maximum is PRECISION or -1 to disable
1995 if (dir
.prec
[0] >= 0)
1997 if (slen
.range
.min
>= target_int_max ())
1999 else if ((unsigned HOST_WIDE_INT
)dir
.prec
[0] < slen
.range
.min
)
2001 slen
.range
.min
= dir
.prec
[0];
2002 slen
.range
.likely
= slen
.range
.min
;
2005 if ((unsigned HOST_WIDE_INT
)dir
.prec
[1] < slen
.range
.max
2006 || slen
.range
.max
>= target_int_max ())
2008 slen
.range
.max
= dir
.prec
[1];
2009 slen
.range
.likely
= slen
.range
.max
;
2012 else if (slen
.range
.min
>= target_int_max ())
2015 slen
.range
.max
= HOST_WIDE_INT_MAX
;
2016 /* At level one strings of unknown length are assumed to be
2017 empty, while at level 1 they are assumed to be one byte
2019 slen
.range
.likely
= warn_level
> 1;
2022 slen
.range
.unlikely
= slen
.range
.max
;
2024 res
.range
= slen
.range
;
2025 res
.knownrange
= slen
.knownrange
;
2028 /* Bump up the byte counters if WIDTH is greater. */
2029 return res
.adjust_for_width_or_precision (dir
.width
);
2032 /* Format plain string (part of the format string itself). */
2035 format_plain (const directive
&dir
, tree
)
2037 fmtresult
res (dir
.len
);
2041 /* Return true if the RESULT of a directive in a call describe by INFO
2042 should be diagnosed given the AVAILable space in the destination. */
2045 should_warn_p (const pass_sprintf_length::call_info
&info
,
2046 const result_range
&avail
, const result_range
&result
)
2048 if (result
.max
<= avail
.min
)
2050 /* The least amount of space remaining in the destination is big
2051 enough for the longest output. */
2057 if (warn_format_trunc
== 1 && result
.min
<= avail
.max
2058 && info
.retval_used ())
2060 /* The likely amount of space remaining in the destination is big
2061 enough for the least output and the return value is used. */
2065 if (warn_format_trunc
== 1 && result
.likely
<= avail
.likely
2066 && !info
.retval_used ())
2068 /* The likely amount of space remaining in the destination is big
2069 enough for the likely output and the return value is unused. */
2073 if (warn_format_trunc
== 2
2074 && result
.likely
<= avail
.min
2075 && (result
.max
<= avail
.min
2076 || result
.max
> HOST_WIDE_INT_MAX
))
2078 /* The minimum amount of space remaining in the destination is big
2079 enough for the longest output. */
2085 if (warn_level
== 1 && result
.likely
<= avail
.likely
)
2087 /* The likely amount of space remaining in the destination is big
2088 enough for the likely output. */
2093 && result
.likely
<= avail
.min
2094 && (result
.max
<= avail
.min
2095 || result
.max
> HOST_WIDE_INT_MAX
))
2097 /* The minimum amount of space remaining in the destination is big
2098 enough for the longest output. */
2106 /* At format string location describe by DIRLOC in a call described
2107 by INFO, issue a warning for a directive DIR whose output may be
2108 in excess of the available space AVAIL_RANGE in the destination
2109 given the formatting result FMTRES. This function does nothing
2110 except decide whether to issue a warning for a possible write
2111 past the end or truncation and, if so, format the warning.
2112 Return true if a warning has been issued. */
2115 maybe_warn (substring_loc
&dirloc
, source_range
*pargrange
,
2116 const pass_sprintf_length::call_info
&info
,
2117 const result_range
&avail_range
, const result_range
&res
,
2118 const directive
&dir
)
2120 if (!should_warn_p (info
, avail_range
, res
))
2123 /* A warning will definitely be issued below. */
2125 /* The maximum byte count to reference in the warning. Larger counts
2126 imply that the upper bound is unknown (and could be anywhere between
2127 RES.MIN + 1 and SIZE_MAX / 2) are printed as "N or more bytes" rather
2128 than "between N and X" where X is some huge number. */
2129 unsigned HOST_WIDE_INT maxbytes
= target_dir_max ();
2131 /* True when there is enough room in the destination for the least
2132 amount of a directive's output but not enough for its likely or
2134 bool maybe
= (res
.min
<= avail_range
.max
2135 && (avail_range
.min
< res
.likely
2136 || (res
.max
< HOST_WIDE_INT_MAX
2137 && avail_range
.min
< res
.max
)));
2139 if (avail_range
.min
== avail_range
.max
)
2141 /* The size of the destination region is exact. */
2142 unsigned HOST_WIDE_INT navail
= avail_range
.max
;
2144 if (*dir
.beg
!= '%')
2146 /* For plain character directives (i.e., the format string itself)
2147 but not others, point the caret at the first character that's
2148 past the end of the destination. */
2149 dirloc
.set_caret_index (dirloc
.get_caret_idx () + navail
);
2152 if (*dir
.beg
== '\0')
2154 /* This is the terminating nul. */
2155 gcc_assert (res
.min
== 1 && res
.min
== res
.max
);
2160 ? G_("%qE output may be truncated before the last format "
2162 : G_("%qE output truncated before the last format character"))
2164 ? G_("%qE may write a terminating nul past the end "
2165 "of the destination")
2166 : G_("%qE writing a terminating nul past the end "
2167 "of the destination")));
2169 return fmtwarn (dirloc
, NULL
, NULL
, info
.warnopt (), fmtstr
,
2173 if (res
.min
== res
.max
)
2179 ? G_("%<%.*s%> directive output may be truncated writing "
2180 "%wu byte into a region of size %wu")
2181 : G_("%<%.*s%> directive output truncated writing "
2182 "%wu byte into a region of size %wu"))
2183 : G_("%<%.*s%> directive writing %wu byte "
2184 "into a region of size %wu"))
2187 ? G_("%<%.*s%> directive output may be truncated writing "
2188 "%wu bytes into a region of size %wu")
2189 : G_("%<%.*s%> directive output truncated writing "
2190 "%wu bytes into a region of size %wu"))
2191 : G_("%<%.*s%> directive writing %wu bytes "
2192 "into a region of size %wu")));
2193 return fmtwarn (dirloc
, pargrange
, NULL
,
2194 info
.warnopt (), fmtstr
,
2195 dir
.len
, dir
.beg
, res
.min
,
2199 if (res
.min
== 0 && res
.max
< maxbytes
)
2204 ? G_("%<%.*s%> directive output may be truncated writing "
2205 "up to %wu bytes into a region of size %wu")
2206 : G_("%<%.*s%> directive output truncated writing "
2207 "up to %wu bytes into a region of size %wu"))
2208 : G_("%<%.*s%> directive writing up to %wu bytes "
2209 "into a region of size %wu"));
2210 return fmtwarn (dirloc
, pargrange
, NULL
,
2211 info
.warnopt (), fmtstr
,
2216 if (res
.min
== 0 && maxbytes
<= res
.max
)
2218 /* This is a special case to avoid issuing the potentially
2220 writing 0 or more bytes into a region of size 0. */
2224 ? G_("%<%.*s%> directive output may be truncated writing "
2225 "likely %wu or more bytes into a region of size %wu")
2226 : G_("%<%.*s%> directive output truncated writing "
2227 "likely %wu or more bytes into a region of size %wu"))
2228 : G_("%<%.*s%> directive writing likely %wu or more bytes "
2229 "into a region of size %wu"));
2230 return fmtwarn (dirloc
, pargrange
, NULL
,
2231 info
.warnopt (), fmtstr
,
2233 res
.likely
, navail
);
2236 if (res
.max
< maxbytes
)
2241 ? G_("%<%.*s%> directive output may be truncated writing "
2242 "between %wu and %wu bytes into a region of size %wu")
2243 : G_("%<%.*s%> directive output truncated writing "
2244 "between %wu and %wu bytes into a region of size %wu"))
2245 : G_("%<%.*s%> directive writing between %wu and "
2246 "%wu bytes into a region of size %wu"));
2247 return fmtwarn (dirloc
, pargrange
, NULL
,
2248 info
.warnopt (), fmtstr
,
2257 ? G_("%<%.*s%> directive output may be truncated writing "
2258 "%wu or more bytes into a region of size %wu")
2259 : G_("%<%.*s%> directive output truncated writing "
2260 "%wu or more bytes into a region of size %wu"))
2261 : G_("%<%.*s%> directive writing %wu or more bytes "
2262 "into a region of size %wu"));
2263 return fmtwarn (dirloc
, pargrange
, NULL
,
2264 info
.warnopt (), fmtstr
,
2269 /* The size of the destination region is a range. */
2271 if (*dir
.beg
!= '%')
2273 unsigned HOST_WIDE_INT navail
= avail_range
.max
;
2275 /* For plain character directives (i.e., the format string itself)
2276 but not others, point the caret at the first character that's
2277 past the end of the destination. */
2278 dirloc
.set_caret_index (dirloc
.get_caret_idx () + navail
);
2281 if (*dir
.beg
== '\0')
2283 gcc_assert (res
.min
== 1 && res
.min
== res
.max
);
2288 ? G_("%qE output may be truncated before the last format "
2290 : G_("%qE output truncated before the last format character"))
2292 ? G_("%qE may write a terminating nul past the end "
2293 "of the destination")
2294 : G_("%qE writing a terminating nul past the end "
2295 "of the destination")));
2297 return fmtwarn (dirloc
, NULL
, NULL
, info
.warnopt (), fmtstr
,
2301 if (res
.min
== res
.max
)
2307 ? G_("%<%.*s%> directive output may be truncated writing "
2308 "%wu byte into a region of size between %wu and %wu")
2309 : G_("%<%.*s%> directive output truncated writing "
2310 "%wu byte into a region of size between %wu and %wu"))
2311 : G_("%<%.*s%> directive writing %wu byte "
2312 "into a region of size between %wu and %wu"))
2315 ? G_("%<%.*s%> directive output may be truncated writing "
2316 "%wu bytes into a region of size between %wu and %wu")
2317 : G_("%<%.*s%> directive output truncated writing "
2318 "%wu bytes into a region of size between %wu and %wu"))
2319 : G_("%<%.*s%> directive writing %wu bytes "
2320 "into a region of size between %wu and %wu")));
2322 return fmtwarn (dirloc
, pargrange
, NULL
,
2323 info
.warnopt (), fmtstr
,
2324 dir
.len
, dir
.beg
, res
.min
,
2325 avail_range
.min
, avail_range
.max
);
2328 if (res
.min
== 0 && res
.max
< maxbytes
)
2333 ? G_("%<%.*s%> directive output may be truncated writing "
2334 "up to %wu bytes into a region of size between "
2336 : G_("%<%.*s%> directive output truncated writing "
2337 "up to %wu bytes into a region of size between "
2339 : G_("%<%.*s%> directive writing up to %wu bytes "
2340 "into a region of size between %wu and %wu"));
2341 return fmtwarn (dirloc
, pargrange
, NULL
,
2342 info
.warnopt (), fmtstr
,
2343 dir
.len
, dir
.beg
, res
.max
,
2344 avail_range
.min
, avail_range
.max
);
2347 if (res
.min
== 0 && maxbytes
<= res
.max
)
2349 /* This is a special case to avoid issuing the potentially confusing
2351 writing 0 or more bytes into a region of size between 0 and N. */
2355 ? G_("%<%.*s%> directive output may be truncated writing "
2356 "likely %wu or more bytes into a region of size between "
2358 : G_("%<%.*s%> directive output truncated writing likely "
2359 "%wu or more bytes into a region of size between "
2361 : G_("%<%.*s%> directive writing likely %wu or more bytes "
2362 "into a region of size between %wu and %wu"));
2363 return fmtwarn (dirloc
, pargrange
, NULL
,
2364 info
.warnopt (), fmtstr
,
2365 dir
.len
, dir
.beg
, res
.likely
,
2366 avail_range
.min
, avail_range
.max
);
2369 if (res
.max
< maxbytes
)
2374 ? G_("%<%.*s%> directive output may be truncated writing "
2375 "between %wu and %wu bytes into a region of size "
2376 "between %wu and %wu")
2377 : G_("%<%.*s%> directive output truncated writing "
2378 "between %wu and %wu bytes into a region of size "
2379 "between %wu and %wu"))
2380 : G_("%<%.*s%> directive writing between %wu and "
2381 "%wu bytes into a region of size between %wu and %wu"));
2382 return fmtwarn (dirloc
, pargrange
, NULL
,
2383 info
.warnopt (), fmtstr
,
2386 avail_range
.min
, avail_range
.max
);
2392 ? G_("%<%.*s%> directive output may be truncated writing "
2393 "%wu or more bytes into a region of size between "
2395 : G_("%<%.*s%> directive output truncated writing "
2396 "%wu or more bytes into a region of size between "
2398 : G_("%<%.*s%> directive writing %wu or more bytes "
2399 "into a region of size between %wu and %wu"));
2400 return fmtwarn (dirloc
, pargrange
, NULL
,
2401 info
.warnopt (), fmtstr
,
2404 avail_range
.min
, avail_range
.max
);
2407 /* Compute the length of the output resulting from the directive DIR
2408 in a call described by INFO and update the overall result of the call
2409 in *RES. Return true if the directive has been handled. */
2412 format_directive (const pass_sprintf_length::call_info
&info
,
2413 format_result
*res
, const directive
&dir
)
2415 /* Offset of the beginning of the directive from the beginning
2416 of the format string. */
2417 size_t offset
= dir
.beg
- info
.fmtstr
;
2418 size_t start
= offset
;
2419 size_t length
= offset
+ dir
.len
- !!dir
.len
;
2421 /* Create a location for the whole directive from the % to the format
2423 substring_loc
dirloc (info
.fmtloc
, TREE_TYPE (info
.format
),
2424 offset
, start
, length
);
2426 /* Also create a location range for the argument if possible.
2427 This doesn't work for integer literals or function calls. */
2428 source_range argrange
;
2429 source_range
*pargrange
;
2430 if (dir
.arg
&& CAN_HAVE_LOCATION_P (dir
.arg
))
2432 argrange
= EXPR_LOCATION_RANGE (dir
.arg
);
2433 pargrange
= &argrange
;
2438 /* Bail when there is no function to compute the output length,
2439 or when minimum length checking has been disabled. */
2440 if (!dir
.fmtfunc
|| res
->range
.min
>= HOST_WIDE_INT_MAX
)
2443 /* Compute the range of lengths of the formatted output. */
2444 fmtresult fmtres
= dir
.fmtfunc (dir
, dir
.arg
);
2446 /* Record whether the output of all directives is known to be
2447 bounded by some maximum, implying that their arguments are
2448 either known exactly or determined to be in a known range
2449 or, for strings, limited by the upper bounds of the arrays
2451 res
->knownrange
&= fmtres
.knownrange
;
2453 if (!fmtres
.knownrange
)
2455 /* Only when the range is known, check it against the host value
2456 of INT_MAX + (the number of bytes of the "%.*Lf" directive with
2457 INT_MAX precision, which is the longest possible output of any
2458 single directive). That's the largest valid byte count (though
2459 not valid call to a printf-like function because it can never
2460 return such a count). Otherwise, the range doesn't correspond
2461 to known values of the argument. */
2462 if (fmtres
.range
.max
> target_dir_max ())
2464 /* Normalize the MAX counter to avoid having to deal with it
2465 later. The counter can be less than HOST_WIDE_INT_M1U
2466 when compiling for an ILP32 target on an LP64 host. */
2467 fmtres
.range
.max
= HOST_WIDE_INT_M1U
;
2468 /* Disable exact and maximum length checking after a failure
2469 to determine the maximum number of characters (for example
2470 for wide characters or wide character strings) but continue
2471 tracking the minimum number of characters. */
2472 res
->range
.max
= HOST_WIDE_INT_M1U
;
2475 if (fmtres
.range
.min
> target_dir_max ())
2477 /* Disable exact length checking after a failure to determine
2478 even the minimum number of characters (it shouldn't happen
2479 except in an error) but keep tracking the minimum and maximum
2480 number of characters. */
2485 int dirlen
= dir
.len
;
2489 fmtwarn (dirloc
, pargrange
, NULL
, info
.warnopt (),
2490 "%<%.*s%> directive argument is null",
2493 /* Don't bother processing the rest of the format string. */
2495 res
->range
.min
= HOST_WIDE_INT_M1U
;
2496 res
->range
.max
= HOST_WIDE_INT_M1U
;
2500 /* Compute the number of available bytes in the destination. There
2501 must always be at least one byte of space for the terminating
2502 NUL that's appended after the format string has been processed. */
2503 result_range avail_range
= bytes_remaining (info
.objsize
, *res
);
2505 bool warned
= res
->warned
;
2508 warned
= maybe_warn (dirloc
, pargrange
, info
, avail_range
,
2511 /* Bump up the total maximum if it isn't too big. */
2512 if (res
->range
.max
< HOST_WIDE_INT_MAX
2513 && fmtres
.range
.max
< HOST_WIDE_INT_MAX
)
2514 res
->range
.max
+= fmtres
.range
.max
;
2516 /* Raise the total unlikely maximum by the larger of the maximum
2517 and the unlikely maximum. It doesn't matter if the unlikely
2518 maximum overflows. */
2519 if (fmtres
.range
.max
< fmtres
.range
.unlikely
)
2520 res
->range
.unlikely
+= fmtres
.range
.unlikely
;
2522 res
->range
.unlikely
+= fmtres
.range
.max
;
2524 res
->range
.min
+= fmtres
.range
.min
;
2525 res
->range
.likely
+= fmtres
.range
.likely
;
2527 /* Has the minimum directive output length exceeded the maximum
2528 of 4095 bytes required to be supported? */
2529 bool minunder4k
= fmtres
.range
.min
< 4096;
2530 bool maxunder4k
= fmtres
.range
.max
< 4096;
2531 /* Clear UNDER4K in the overall result if the maximum has exceeded
2532 the 4k (this is necessary to avoid the return valuye optimization
2533 that may not be safe in the maximum case). */
2535 res
->under4k
= false;
2538 /* Only warn at level 2. */
2541 || (!maxunder4k
&& fmtres
.range
.max
< HOST_WIDE_INT_MAX
)))
2543 /* The directive output may be longer than the maximum required
2544 to be handled by an implementation according to 7.21.6.1, p15
2545 of C11. Warn on this only at level 2 but remember this and
2546 prevent folding the return value when done. This allows for
2547 the possibility of the actual libc call failing due to ENOMEM
2548 (like Glibc does under some conditions). */
2550 if (fmtres
.range
.min
== fmtres
.range
.max
)
2551 warned
= fmtwarn (dirloc
, pargrange
, NULL
,
2553 "%<%.*s%> directive output of %wu bytes exceeds "
2554 "minimum required size of 4095",
2555 dirlen
, dir
.beg
, fmtres
.range
.min
);
2560 ? G_("%<%.*s%> directive output between %wu and %wu "
2561 "bytes may exceed minimum required size of 4095")
2562 : G_("%<%.*s%> directive output between %wu and %wu "
2563 "bytes exceeds minimum required size of 4095"));
2565 warned
= fmtwarn (dirloc
, pargrange
, NULL
,
2566 info
.warnopt (), fmtstr
,
2568 fmtres
.range
.min
, fmtres
.range
.max
);
2572 /* Has the likely and maximum directive output exceeded INT_MAX? */
2573 bool likelyximax
= *dir
.beg
&& res
->range
.likely
> target_int_max ();
2574 bool maxximax
= *dir
.beg
&& res
->range
.max
> target_int_max ();
2577 /* Warn for the likely output size at level 1. */
2579 /* But only warn for the maximum at level 2. */
2582 && fmtres
.range
.max
< HOST_WIDE_INT_MAX
)))
2584 /* The directive output causes the total length of output
2585 to exceed INT_MAX bytes. */
2587 if (fmtres
.range
.min
== fmtres
.range
.max
)
2588 warned
= fmtwarn (dirloc
, pargrange
, NULL
, info
.warnopt (),
2589 "%<%.*s%> directive output of %wu bytes causes "
2590 "result to exceed %<INT_MAX%>",
2591 dirlen
, dir
.beg
, fmtres
.range
.min
);
2595 = (fmtres
.range
.min
> target_int_max ()
2596 ? G_ ("%<%.*s%> directive output between %wu and %wu "
2597 "bytes causes result to exceed %<INT_MAX%>")
2598 : G_ ("%<%.*s%> directive output between %wu and %wu "
2599 "bytes may cause result to exceed %<INT_MAX%>"));
2600 warned
= fmtwarn (dirloc
, pargrange
, NULL
,
2601 info
.warnopt (), fmtstr
,
2603 fmtres
.range
.min
, fmtres
.range
.max
);
2607 if (warned
&& fmtres
.range
.min
< fmtres
.range
.likely
2608 && fmtres
.range
.likely
< fmtres
.range
.max
)
2610 inform (info
.fmtloc
,
2611 (1 == fmtres
.range
.likely
2612 ? G_("assuming directive output of %wu byte")
2613 : G_("assuming directive output of %wu bytes")),
2614 fmtres
.range
.likely
);
2617 if (warned
&& fmtres
.argmin
)
2619 if (fmtres
.argmin
== fmtres
.argmax
)
2620 inform (info
.fmtloc
, "directive argument %qE", fmtres
.argmin
);
2621 else if (fmtres
.knownrange
)
2622 inform (info
.fmtloc
, "directive argument in the range [%E, %E]",
2623 fmtres
.argmin
, fmtres
.argmax
);
2625 inform (info
.fmtloc
,
2626 "using the range [%E, %E] for directive argument",
2627 fmtres
.argmin
, fmtres
.argmax
);
2630 res
->warned
|= warned
;
2632 if (!dir
.beg
[0] && res
->warned
&& info
.objsize
< HOST_WIDE_INT_MAX
)
2634 /* If a warning has been issued for buffer overflow or truncation
2635 (but not otherwise) help the user figure out how big a buffer
2638 location_t callloc
= gimple_location (info
.callstmt
);
2640 unsigned HOST_WIDE_INT min
= res
->range
.min
;
2641 unsigned HOST_WIDE_INT max
= res
->range
.max
;
2646 ? G_("%qE output %wu byte into a destination of size %wu")
2647 : G_("%qE output %wu bytes into a destination of size %wu")),
2648 info
.func
, min
, info
.objsize
);
2649 else if (max
< HOST_WIDE_INT_MAX
)
2651 "%qE output between %wu and %wu bytes into "
2652 "a destination of size %wu",
2653 info
.func
, min
, max
, info
.objsize
);
2654 else if (min
< res
->range
.likely
&& res
->range
.likely
< max
)
2656 "%qE output %wu or more bytes (assuming %wu) into "
2657 "a destination of size %wu",
2658 info
.func
, min
, res
->range
.likely
, info
.objsize
);
2661 "%qE output %wu or more bytes into a destination of size %wu",
2662 info
.func
, min
, info
.objsize
);
2665 if (dump_file
&& *dir
.beg
)
2667 fprintf (dump_file
, " Result: %lli, %lli, %lli, %lli "
2668 "(%lli, %lli, %lli, %lli)\n",
2669 (long long)fmtres
.range
.min
,
2670 (long long)fmtres
.range
.likely
,
2671 (long long)fmtres
.range
.max
,
2672 (long long)fmtres
.range
.unlikely
,
2673 (long long)res
->range
.min
,
2674 (long long)res
->range
.likely
,
2675 (long long)res
->range
.max
,
2676 (long long)res
->range
.unlikely
);
2682 #pragma GCC diagnostic pop
2684 /* Parse a format directive in function call described by INFO starting
2685 at STR and populate DIR structure. Bump up *ARGNO by the number of
2686 arguments extracted for the directive. Return the length of
2690 parse_directive (pass_sprintf_length::call_info
&info
,
2691 directive
&dir
, format_result
*res
,
2692 const char *str
, unsigned *argno
)
2694 const char *pcnt
= strchr (str
, '%');
2697 if (size_t len
= pcnt
? pcnt
- str
: *str
? strlen (str
) : 1)
2699 /* This directive is either a plain string or the terminating nul
2700 (which isn't really a directive but it simplifies things to
2701 handle it as if it were). */
2703 dir
.fmtfunc
= format_plain
;
2707 fprintf (dump_file
, " Directive %u at offset %llu: \"%.*s\", "
2710 (unsigned long long)(size_t)(dir
.beg
- info
.fmtstr
),
2711 (int)dir
.len
, dir
.beg
, (unsigned long long)dir
.len
);
2717 const char *pf
= pcnt
+ 1;
2719 /* POSIX numbered argument index or zero when none. */
2720 unsigned dollar
= 0;
2722 /* With and precision. -1 when not specified, HOST_WIDE_INT_MIN
2723 when given by a va_list argument, and a non-negative value
2724 when specified in the format string itself. */
2725 HOST_WIDE_INT width
= -1;
2726 HOST_WIDE_INT precision
= -1;
2728 /* Width specified via the asterisk. Need not be INTEGER_CST.
2729 For vararg functions set to void_node. */
2730 tree star_width
= NULL_TREE
;
2732 /* Width specified via the asterisk. Need not be INTEGER_CST.
2733 For vararg functions set to void_node. */
2734 tree star_precision
= NULL_TREE
;
2738 /* This could be either a POSIX positional argument, the '0'
2739 flag, or a width, depending on what follows. Store it as
2740 width and sort it out later after the next character has
2743 width
= strtol (pf
, &end
, 10);
2746 else if ('*' == *pf
)
2748 /* Similarly to the block above, this could be either a POSIX
2749 positional argument or a width, depending on what follows. */
2750 if (*argno
< gimple_call_num_args (info
.callstmt
))
2751 star_width
= gimple_call_arg (info
.callstmt
, (*argno
)++);
2753 star_width
= void_node
;
2759 /* Handle the POSIX dollar sign which references the 1-based
2760 positional argument number. */
2762 dollar
= width
+ info
.argidx
;
2764 && TREE_CODE (star_width
) == INTEGER_CST
)
2765 dollar
= width
+ tree_to_shwi (star_width
);
2767 /* Bail when the numbered argument is out of range (it will
2768 have already been diagnosed by -Wformat). */
2770 || dollar
== info
.argidx
2771 || dollar
> gimple_call_num_args (info
.callstmt
))
2776 star_width
= NULL_TREE
;
2781 if (dollar
|| !star_width
)
2787 /* The '0' that has been interpreted as a width above is
2788 actually a flag. Reset HAVE_WIDTH, set the '0' flag,
2789 and continue processing other flags. */
2795 /* (Non-zero) width has been seen. The next character
2796 is either a period or a digit. */
2797 goto start_precision
;
2800 /* When either '$' has been seen, or width has not been seen,
2801 the next field is the optional flags followed by an optional
2811 dir
.set_flag (*pf
++);
2823 width
= strtol (pf
, &end
, 10);
2826 else if ('*' == *pf
)
2828 if (*argno
< gimple_call_num_args (info
.callstmt
))
2829 star_width
= gimple_call_arg (info
.callstmt
, (*argno
)++);
2832 /* This is (likely) a va_list. It could also be an invalid
2833 call with insufficient arguments. */
2834 star_width
= void_node
;
2838 else if ('\'' == *pf
)
2840 /* The POSIX apostrophe indicating a numeric grouping
2841 in the current locale. Even though it's possible to
2842 estimate the upper bound on the size of the output
2843 based on the number of digits it probably isn't worth
2857 precision
= strtol (pf
, &end
, 10);
2860 else if ('*' == *pf
)
2862 if (*argno
< gimple_call_num_args (info
.callstmt
))
2863 star_precision
= gimple_call_arg (info
.callstmt
, (*argno
)++);
2866 /* This is (likely) a va_list. It could also be an invalid
2867 call with insufficient arguments. */
2868 star_precision
= void_node
;
2874 /* The decimal precision or the asterisk are optional.
2875 When neither is dirified it's taken to be zero. */
2886 dir
.modifier
= FMT_LEN_hh
;
2889 dir
.modifier
= FMT_LEN_h
;
2894 dir
.modifier
= FMT_LEN_j
;
2899 dir
.modifier
= FMT_LEN_L
;
2907 dir
.modifier
= FMT_LEN_ll
;
2910 dir
.modifier
= FMT_LEN_l
;
2915 dir
.modifier
= FMT_LEN_t
;
2920 dir
.modifier
= FMT_LEN_z
;
2927 /* Handle a sole '%' character the same as "%%" but since it's
2928 undefined prevent the result from being folded. */
2931 res
->range
.min
= res
->range
.max
= HOST_WIDE_INT_M1U
;
2934 dir
.fmtfunc
= format_percent
;
2945 res
->floating
= true;
2946 dir
.fmtfunc
= format_floating
;
2955 dir
.fmtfunc
= format_integer
;
2959 /* The %p output is implementation-defined. It's possible
2960 to determine this format but due to extensions (edirially
2961 those of the Linux kernel -- see bug 78512) the first %p
2962 in the format string disables any further processing. */
2966 /* %n has side-effects even when nothing is actually printed to
2968 info
.nowrite
= false;
2969 dir
.fmtfunc
= format_none
;
2973 dir
.fmtfunc
= format_character
;
2978 dir
.fmtfunc
= format_string
;
2982 /* Unknown conversion specification. */
2986 dir
.specifier
= *pf
++;
2990 if (TREE_CODE (TREE_TYPE (star_width
)) == INTEGER_TYPE
)
2991 dir
.set_width (star_width
);
2994 /* Width specified by a va_list takes on the range [0, -INT_MIN]
2995 (width is the absolute value of that specified). */
2997 dir
.width
[1] = target_int_max () + 1;
3001 dir
.set_width (width
);
3005 if (TREE_CODE (TREE_TYPE (star_precision
)) == INTEGER_TYPE
)
3006 dir
.set_precision (star_precision
);
3009 /* Precision specified by a va_list takes on the range [-1, INT_MAX]
3010 (unlike width, negative precision is ignored). */
3012 dir
.prec
[1] = target_int_max ();
3016 dir
.set_precision (precision
);
3018 /* Extract the argument if the directive takes one and if it's
3019 available (e.g., the function doesn't take a va_list). Treat
3020 missing arguments the same as va_list, even though they will
3021 have likely already been diagnosed by -Wformat. */
3022 if (dir
.specifier
!= '%'
3023 && *argno
< gimple_call_num_args (info
.callstmt
))
3024 dir
.arg
= gimple_call_arg (info
.callstmt
, dollar
? dollar
: (*argno
)++);
3026 /* Return the length of the format directive. */
3027 dir
.len
= pf
- pcnt
;
3031 fprintf (dump_file
, " Directive %u at offset %llu: \"%.*s\"",
3032 dir
.dirno
, (unsigned long long)(size_t)(dir
.beg
- info
.fmtstr
),
3033 (int)dir
.len
, dir
.beg
);
3036 if (dir
.width
[0] == dir
.width
[1])
3037 fprintf (dump_file
, ", width = %lli", (long long)dir
.width
[0]);
3039 fprintf (dump_file
, ", width in range [%lli, %lli]",
3040 (long long)dir
.width
[0], (long long)dir
.width
[1]);
3045 if (dir
.prec
[0] == dir
.prec
[1])
3046 fprintf (dump_file
, ", precision = %lli", (long long)dir
.prec
[0]);
3048 fprintf (dump_file
, ", precision in range [%lli, %lli]",
3049 (long long)dir
.prec
[0], (long long)dir
.prec
[1]);
3051 fputc ('\n', dump_file
);
3057 /* Compute the length of the output resulting from the call to a formatted
3058 output function described by INFO and store the result of the call in
3059 *RES. Issue warnings for detected past the end writes. Return true
3060 if the complete format string has been processed and *RES can be relied
3061 on, false otherwise (e.g., when a unknown or unhandled directive was seen
3062 that caused the processing to be terminated early). */
3065 pass_sprintf_length::compute_format_length (call_info
&info
,
3070 location_t callloc
= gimple_location (info
.callstmt
);
3071 fprintf (dump_file
, "%s:%i: ",
3072 LOCATION_FILE (callloc
), LOCATION_LINE (callloc
));
3073 print_generic_expr (dump_file
, info
.func
, dump_flags
);
3075 fprintf (dump_file
, ": objsize = %llu, fmtstr = \"%s\"\n",
3076 (unsigned long long)info
.objsize
, info
.fmtstr
);
3079 /* Reset the minimum and maximum byte counters. */
3080 res
->range
.min
= res
->range
.max
= 0;
3082 /* No directive has been seen yet so the length of output is bounded
3083 by the known range [0, 0] (with no conversion producing more than
3084 4K bytes) until determined otherwise. */
3085 res
->knownrange
= true;
3086 res
->under4k
= true;
3087 res
->floating
= false;
3088 res
->warned
= false;
3090 /* 1-based directive counter. */
3093 /* The variadic argument counter. */
3094 unsigned argno
= info
.argidx
;
3096 for (const char *pf
= info
.fmtstr
; ; ++dirno
)
3098 directive dir
= directive ();
3101 size_t n
= parse_directive (info
, dir
, res
, pf
, &argno
);
3103 /* Return failure if the format function fails. */
3104 if (!format_directive (info
, res
, dir
))
3107 /* Return success the directive is zero bytes long and it's
3108 the last think in the format string (i.e., it's the terminating
3109 nul, which isn't really a directive but handling it as one makes
3117 /* The complete format string was processed (with or without warnings). */
3121 /* Return the size of the object referenced by the expression DEST if
3122 available, or -1 otherwise. */
3124 static unsigned HOST_WIDE_INT
3125 get_destination_size (tree dest
)
3127 /* Initialize object size info before trying to compute it. */
3128 init_object_sizes ();
3130 /* Use __builtin_object_size to determine the size of the destination
3131 object. When optimizing, determine the smallest object (such as
3132 a member array as opposed to the whole enclosing object), otherwise
3133 use type-zero object size to determine the size of the enclosing
3134 object (the function fails without optimization in this type). */
3135 int ost
= optimize
> 0;
3136 unsigned HOST_WIDE_INT size
;
3137 if (compute_builtin_object_size (dest
, ost
, &size
))
3140 return HOST_WIDE_INT_M1U
;
3143 /* Given a suitable result RES of a call to a formatted output function
3144 described by INFO, substitute the result for the return value of
3145 the call. The result is suitable if the number of bytes it represents
3146 is known and exact. A result that isn't suitable for substitution may
3147 have its range set to the range of return values, if that is known.
3148 Return true if the call is removed and gsi_next should not be performed
3152 try_substitute_return_value (gimple_stmt_iterator
*gsi
,
3153 const pass_sprintf_length::call_info
&info
,
3154 const format_result
&res
)
3156 tree lhs
= gimple_get_lhs (info
.callstmt
);
3158 /* Set to true when the entire call has been removed. */
3159 bool removed
= false;
3161 /* The minimum return value. */
3162 unsigned HOST_WIDE_INT minretval
= res
.range
.min
;
3164 /* The maximum return value is in most cases bounded by RES.RANGE.MAX
3165 but in cases involving multibyte characters could be as large as
3166 RES.RANGE.UNLIKELY. */
3167 unsigned HOST_WIDE_INT maxretval
3168 = res
.range
.unlikely
< res
.range
.max
? res
.range
.max
: res
.range
.unlikely
;
3170 /* Adjust the number of bytes which includes the terminating nul
3171 to reflect the return value of the function which does not.
3172 Because the valid range of the function is [INT_MIN, INT_MAX],
3173 a valid range before the adjustment below is [0, INT_MAX + 1]
3174 (the functions only return negative values on error or undefined
3176 if (minretval
<= target_int_max () + 1)
3178 if (maxretval
<= target_int_max () + 1)
3181 /* Avoid the return value optimization when the behavior of the call
3182 is undefined either because any directive may have produced 4K or
3183 more of output, or the return value exceeds INT_MAX, or because
3184 the output overflows the destination object (but leave it enabled
3185 when the function is bounded because then the behavior is well-
3188 && minretval
== maxretval
3189 && (info
.bounded
|| minretval
< info
.objsize
)
3190 && minretval
<= target_int_max ()
3191 /* Not prepared to handle possibly throwing calls here; they shouldn't
3192 appear in non-artificial testcases, except when the __*_chk routines
3193 are badly declared. */
3194 && !stmt_ends_bb_p (info
.callstmt
))
3196 tree cst
= build_int_cst (integer_type_node
, minretval
);
3198 if (lhs
== NULL_TREE
3201 /* Remove the call to the bounded function with a zero size
3202 (e.g., snprintf(0, 0, "%i", 123)) if there is no lhs. */
3203 unlink_stmt_vdef (info
.callstmt
);
3204 gsi_remove (gsi
, true);
3207 else if (info
.nowrite
)
3209 /* Replace the call to the bounded function with a zero size
3210 (e.g., snprintf(0, 0, "%i", 123) with the constant result
3212 if (!update_call_from_tree (gsi
, cst
))
3213 gimplify_and_update_call_from_tree (gsi
, cst
);
3214 gimple
*callstmt
= gsi_stmt (*gsi
);
3215 update_stmt (callstmt
);
3219 /* Replace the left-hand side of the call with the constant
3220 result of the formatted function. */
3221 gimple_call_set_lhs (info
.callstmt
, NULL_TREE
);
3222 gimple
*g
= gimple_build_assign (lhs
, cst
);
3223 gsi_insert_after (gsi
, g
, GSI_NEW_STMT
);
3224 update_stmt (info
.callstmt
);
3230 fprintf (dump_file
, " Removing call statement.");
3233 fprintf (dump_file
, " Substituting ");
3234 print_generic_expr (dump_file
, cst
, dump_flags
);
3235 fprintf (dump_file
, " for %s.\n",
3236 info
.nowrite
? "statement" : "return value");
3242 bool setrange
= false;
3244 if ((info
.bounded
|| maxretval
< info
.objsize
)
3246 && (minretval
< target_int_max ()
3247 && maxretval
< target_int_max ()))
3249 /* If the result is in a valid range bounded by the size of
3250 the destination set it so that it can be used for subsequent
3252 int prec
= TYPE_PRECISION (integer_type_node
);
3254 wide_int min
= wi::shwi (minretval
, prec
);
3255 wide_int max
= wi::shwi (maxretval
, prec
);
3256 set_range_info (lhs
, VR_RANGE
, min
, max
);
3263 const char *inbounds
3264 = (minretval
< info
.objsize
3265 ? (maxretval
< info
.objsize
3266 ? "in" : "potentially out-of")
3269 const char *what
= setrange
? "Setting" : "Discarding";
3270 if (minretval
!= maxretval
)
3272 " %s %s-bounds return value range [%llu, %llu].\n",
3274 (unsigned long long)minretval
,
3275 (unsigned long long)maxretval
);
3277 fprintf (dump_file
, " %s %s-bounds return value %llu.\n",
3278 what
, inbounds
, (unsigned long long)minretval
);
3283 fputc ('\n', dump_file
);
3288 /* Determine if a GIMPLE CALL is to one of the sprintf-like built-in
3289 functions and if so, handle it. Return true if the call is removed
3290 and gsi_next should not be performed in the caller. */
3293 pass_sprintf_length::handle_gimple_call (gimple_stmt_iterator
*gsi
)
3295 call_info info
= call_info ();
3297 info
.callstmt
= gsi_stmt (*gsi
);
3298 if (!gimple_call_builtin_p (info
.callstmt
, BUILT_IN_NORMAL
))
3301 info
.func
= gimple_call_fndecl (info
.callstmt
);
3302 info
.fncode
= DECL_FUNCTION_CODE (info
.func
);
3304 /* The size of the destination as in snprintf(dest, size, ...). */
3305 unsigned HOST_WIDE_INT dstsize
= HOST_WIDE_INT_M1U
;
3307 /* The size of the destination determined by __builtin_object_size. */
3308 unsigned HOST_WIDE_INT objsize
= HOST_WIDE_INT_M1U
;
3310 /* Buffer size argument number (snprintf and vsnprintf). */
3311 unsigned HOST_WIDE_INT idx_dstsize
= HOST_WIDE_INT_M1U
;
3313 /* Object size argument number (snprintf_chk and vsnprintf_chk). */
3314 unsigned HOST_WIDE_INT idx_objsize
= HOST_WIDE_INT_M1U
;
3316 /* Format string argument number (valid for all functions). */
3317 unsigned idx_format
;
3319 switch (info
.fncode
)
3321 case BUILT_IN_SPRINTF
:
3323 // __builtin_sprintf (dst, format, ...)
3328 case BUILT_IN_SPRINTF_CHK
:
3330 // __builtin___sprintf_chk (dst, ost, objsize, format, ...)
3336 case BUILT_IN_SNPRINTF
:
3338 // __builtin_snprintf (dst, size, format, ...)
3342 info
.bounded
= true;
3345 case BUILT_IN_SNPRINTF_CHK
:
3347 // __builtin___snprintf_chk (dst, size, ost, objsize, format, ...)
3352 info
.bounded
= true;
3355 case BUILT_IN_VSNPRINTF
:
3357 // __builtin_vsprintf (dst, size, format, va)
3361 info
.bounded
= true;
3364 case BUILT_IN_VSNPRINTF_CHK
:
3366 // __builtin___vsnprintf_chk (dst, size, ost, objsize, format, va)
3371 info
.bounded
= true;
3374 case BUILT_IN_VSPRINTF
:
3376 // __builtin_vsprintf (dst, format, va)
3381 case BUILT_IN_VSPRINTF_CHK
:
3383 // __builtin___vsprintf_chk (dst, ost, objsize, format, va)
3393 /* Set the global warning level for this function. */
3394 warn_level
= info
.bounded
? warn_format_trunc
: warn_format_overflow
;
3396 /* The first argument is a pointer to the destination. */
3397 tree dstptr
= gimple_call_arg (info
.callstmt
, 0);
3399 info
.format
= gimple_call_arg (info
.callstmt
, idx_format
);
3401 if (idx_dstsize
== HOST_WIDE_INT_M1U
)
3403 /* For non-bounded functions like sprintf, determine the size
3404 of the destination from the object or pointer passed to it
3405 as the first argument. */
3406 dstsize
= get_destination_size (dstptr
);
3408 else if (tree size
= gimple_call_arg (info
.callstmt
, idx_dstsize
))
3410 /* For bounded functions try to get the size argument. */
3412 if (TREE_CODE (size
) == INTEGER_CST
)
3414 dstsize
= tree_to_uhwi (size
);
3415 /* No object can be larger than SIZE_MAX bytes (half the address
3416 space) on the target.
3417 The functions are defined only for output of at most INT_MAX
3418 bytes. Specifying a bound in excess of that limit effectively
3419 defeats the bounds checking (and on some implementations such
3420 as Solaris cause the function to fail with EINVAL). */
3421 if (dstsize
> target_size_max () / 2)
3423 /* Avoid warning if -Wstringop-overflow is specified since
3424 it also warns for the same thing though only for the
3425 checking built-ins. */
3426 if ((idx_objsize
== HOST_WIDE_INT_M1U
3427 || !warn_stringop_overflow
))
3428 warning_at (gimple_location (info
.callstmt
), info
.warnopt (),
3429 "specified bound %wu exceeds maximum object size "
3431 dstsize
, target_size_max () / 2);
3433 else if (dstsize
> target_int_max ())
3434 warning_at (gimple_location (info
.callstmt
), info
.warnopt (),
3435 "specified bound %wu exceeds %<INT_MAX %>",
3438 else if (TREE_CODE (size
) == SSA_NAME
)
3440 /* Try to determine the range of values of the argument
3441 and use the greater of the two at -Wformat-level 1 and
3442 the smaller of them at level 2. */
3444 enum value_range_type range_type
3445 = get_range_info (size
, &min
, &max
);
3446 if (range_type
== VR_RANGE
)
3450 ? wi::fits_uhwi_p (max
) ? max
.to_uhwi () : max
.to_shwi ()
3451 : wi::fits_uhwi_p (min
) ? min
.to_uhwi () : min
.to_shwi ());
3456 if (idx_objsize
!= HOST_WIDE_INT_M1U
)
3457 if (tree size
= gimple_call_arg (info
.callstmt
, idx_objsize
))
3458 if (tree_fits_uhwi_p (size
))
3459 objsize
= tree_to_uhwi (size
);
3461 if (info
.bounded
&& !dstsize
)
3463 /* As a special case, when the explicitly specified destination
3464 size argument (to a bounded function like snprintf) is zero
3465 it is a request to determine the number of bytes on output
3466 without actually producing any. Pretend the size is
3467 unlimited in this case. */
3468 info
.objsize
= HOST_WIDE_INT_MAX
;
3469 info
.nowrite
= true;
3473 /* For calls to non-bounded functions or to those of bounded
3474 functions with a non-zero size, warn if the destination
3476 if (integer_zerop (dstptr
))
3478 /* This is diagnosed with -Wformat only when the null is a constant
3479 pointer. The warning here diagnoses instances where the pointer
3481 location_t loc
= gimple_location (info
.callstmt
);
3482 warning_at (EXPR_LOC_OR_LOC (dstptr
, loc
),
3483 info
.warnopt (), "null destination pointer");
3487 /* Set the object size to the smaller of the two arguments
3488 of both have been specified and they're not equal. */
3489 info
.objsize
= dstsize
< objsize
? dstsize
: objsize
;
3492 && dstsize
< target_size_max () / 2 && objsize
< dstsize
3493 /* Avoid warning if -Wstringop-overflow is specified since
3494 it also warns for the same thing though only for the
3495 checking built-ins. */
3496 && (idx_objsize
== HOST_WIDE_INT_M1U
3497 || !warn_stringop_overflow
))
3499 warning_at (gimple_location (info
.callstmt
), info
.warnopt (),
3500 "specified bound %wu exceeds the size %wu "
3501 "of the destination object", dstsize
, objsize
);
3505 if (integer_zerop (info
.format
))
3507 /* This is diagnosed with -Wformat only when the null is a constant
3508 pointer. The warning here diagnoses instances where the pointer
3510 location_t loc
= gimple_location (info
.callstmt
);
3511 warning_at (EXPR_LOC_OR_LOC (info
.format
, loc
),
3512 info
.warnopt (), "null format string");
3516 info
.fmtstr
= get_format_string (info
.format
, &info
.fmtloc
);
3520 /* The result is the number of bytes output by the formatted function,
3521 including the terminating NUL. */
3522 format_result res
= format_result ();
3524 bool success
= compute_format_length (info
, &res
);
3526 /* When optimizing and the printf return value optimization is enabled,
3527 attempt to substitute the computed result for the return value of
3528 the call. Avoid this optimization when -frounding-math is in effect
3529 and the format string contains a floating point directive. */
3532 && flag_printf_return_value
3533 && (!flag_rounding_math
|| !res
.floating
))
3534 return try_substitute_return_value (gsi
, info
, res
);
3539 /* Execute the pass for function FUN. */
3542 pass_sprintf_length::execute (function
*fun
)
3545 FOR_EACH_BB_FN (bb
, fun
)
3547 for (gimple_stmt_iterator si
= gsi_start_bb (bb
); !gsi_end_p (si
); )
3549 /* Iterate over statements, looking for function calls. */
3550 gimple
*stmt
= gsi_stmt (si
);
3552 if (is_gimple_call (stmt
) && handle_gimple_call (&si
))
3553 /* If handle_gimple_call returns true, the iterator is
3554 already pointing to the next statement. */
3561 /* Clean up object size info. */
3562 fini_object_sizes ();
3567 } /* Unnamed namespace. */
3569 /* Return a pointer to a pass object newly constructed from the context
3573 make_pass_sprintf_length (gcc::context
*ctxt
)
3575 return new pass_sprintf_length (ctxt
);