diff options
| author | Martin Sebor <msebor@redhat.com> | 2018-06-25 20:33:28 +0000 |
|---|---|---|
| committer | Martin Sebor <msebor@gcc.gnu.org> | 2018-06-25 14:33:28 -0600 |
| commit | eec5f615cbad2de5ff10fbaa8c92f68cc5c6be00 (patch) | |
| tree | 6d97fc1ae9f1316ba96cf9579500332267bb075a /gcc/gimple-fold.c | |
| parent | 2bcd87a7b5bf793a00e99a5d7fdef4277afa7dc6 (diff) | |
| download | gcc-eec5f615cbad2de5ff10fbaa8c92f68cc5c6be00.zip gcc-eec5f615cbad2de5ff10fbaa8c92f68cc5c6be00.tar.gz gcc-eec5f615cbad2de5ff10fbaa8c92f68cc5c6be00.tar.bz2 | |
PR tree-optimization/85700 - Spurious -Wstringop-truncation warning with strncat
gcc/ChangeLog:
PR tree-optimization/85700
* gimple-fold.c (gimple_fold_builtin_strncat): Adjust comment.
* tree-ssa-strlen.c (is_strlen_related_p): Handle integer subtraction.
(maybe_diag_stxncpy_trunc): Distinguish strncat from strncpy.
gcc/testsuite/ChangeLog:
PR tree-optimization/85700
* gcc.dg/Wstringop-truncation-4.c: New test.
From-SVN: r262110
Diffstat (limited to 'gcc/gimple-fold.c')
| -rw-r--r-- | gcc/gimple-fold.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index a01bce7..b025935 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -2051,10 +2051,12 @@ gimple_fold_builtin_strncat (gimple_stmt_iterator *gsi) if (!nowarn && cmpsrc == 0) { tree fndecl = gimple_call_fndecl (stmt); - - /* To avoid certain truncation the specified bound should also - not be equal to (or less than) the length of the source. */ location_t loc = gimple_location (stmt); + + /* To avoid possible overflow the specified bound should also + not be equal to the length of the source, even when the size + of the destination is unknown (it's not an uncommon mistake + to specify as the bound to strncpy the length of the source). */ if (warning_at (loc, OPT_Wstringop_overflow_, "%G%qD specified bound %E equals source length", stmt, fndecl, len)) |