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| author | Martin Sebor <msebor@redhat.com> | 2018-06-12 17:14:31 +0000 |
|---|---|---|
| committer | Martin Sebor <msebor@gcc.gnu.org> | 2018-06-12 11:14:31 -0600 |
| commit | bb0f14ae684a38a44aaf42b312c213aedaa74103 (patch) | |
| tree | 7e041b94bbe264ea9855d679e7299cd8a1f4281d /gcc/c-family/c-warn.c | |
| parent | 132afeecc3f5adc88a029f9d1e11ca6d64ab3e8b (diff) | |
| download | gcc-bb0f14ae684a38a44aaf42b312c213aedaa74103.zip gcc-bb0f14ae684a38a44aaf42b312c213aedaa74103.tar.gz gcc-bb0f14ae684a38a44aaf42b312c213aedaa74103.tar.bz2 | |
PR c/85931 - -Wsizeof-pointer-memaccess for strncpy with size of source
gcc/c-family/ChangeLog:
PR c/85931
* c-warn.c (sizeof_pointer_memaccess_warning): Avoid warning when
sizeof source and destination yields the same value.
gcc/ChangeLog:
PR c/85931
* fold-const.c (operand_equal_p): Handle SAVE_EXPR.
gcc/testsuite/ChangeLog:
PR c/85931
* gcc.dg/Wstringop-truncation-3.c: New test.
From-SVN: r261515
Diffstat (limited to 'gcc/c-family/c-warn.c')
| -rw-r--r-- | gcc/c-family/c-warn.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/gcc/c-family/c-warn.c b/gcc/c-family/c-warn.c index 859d72b..95ac09d 100644 --- a/gcc/c-family/c-warn.c +++ b/gcc/c-family/c-warn.c @@ -792,13 +792,26 @@ sizeof_pointer_memaccess_warning (location_t *sizeof_arg_loc, tree callee, { /* The argument type may be an array. Diagnose bounded string copy functions that specify the bound in terms of the source - argument rather than the destination. */ + argument rather than the destination unless they are equal + to one another. Handle constant sizes and also try to handle + sizeof expressions involving VLAs. */ if (strop && !cmp && fncode != BUILT_IN_STRNDUP && src) { tem = tree_strip_nop_conversions (src); if (TREE_CODE (tem) == ADDR_EXPR) tem = TREE_OPERAND (tem, 0); - if (operand_equal_p (tem, sizeof_arg[idx], OEP_ADDRESS_OF)) + + tree d = tree_strip_nop_conversions (dest); + if (TREE_CODE (d) == ADDR_EXPR) + d = TREE_OPERAND (d, 0); + + tree dstsz = TYPE_SIZE_UNIT (TREE_TYPE (d)); + tree srcsz = TYPE_SIZE_UNIT (TREE_TYPE (tem)); + + if ((!dstsz + || !srcsz + || !operand_equal_p (dstsz, srcsz, OEP_LEXICOGRAPHIC)) + && operand_equal_p (tem, sizeof_arg[idx], OEP_ADDRESS_OF)) warning_at (sizeof_arg_loc[idx], OPT_Wsizeof_pointer_memaccess, "argument to %<sizeof%> in %qD call is the same " "expression as the source; did you mean to use " |