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| author | Martin Sebor <msebor@redhat.com> | 2020-09-01 16:02:19 -0600 |
|---|---|---|
| committer | Martin Sebor <msebor@redhat.com> | 2020-09-01 16:03:25 -0600 |
| commit | 0c344a649d803a83ed35f629d292b98143935ffa (patch) | |
| tree | 069c12b4eb9f1263b68f13d0a2027908cb58204f /gcc/builtins.c | |
| parent | b1c59b31ef7adc832405209e9e2a77212284abd7 (diff) | |
| download | gcc-0c344a649d803a83ed35f629d292b98143935ffa.zip gcc-0c344a649d803a83ed35f629d292b98143935ffa.tar.gz gcc-0c344a649d803a83ed35f629d292b98143935ffa.tar.bz2 | |
Use the determined lower bound of the range of offsets in a PLUS_EXPR.
gcc/ChangeLog:
* builtins.c (compute_objsize): Only replace the upper bound
of a POINTER_PLUS offset when it's less than the lower bound.
gcc/testsuite/ChangeLog:
* gcc.dg/Wstringop-overflow.c: Remove xfails.
* gcc.dg/Wstringop-overflow-42.c: New test.
* gcc.dg/Wstringop-overread-4.c: New test.
Diffstat (limited to 'gcc/builtins.c')
| -rw-r--r-- | gcc/builtins.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/gcc/builtins.c b/gcc/builtins.c index bc35b07..97f1a18 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -4367,12 +4367,17 @@ compute_objsize (tree ptr, int ostype, access_ref *pref, offset to the maximum. */ offset_int orng[2]; tree off = gimple_assign_rhs2 (stmt); - if (!get_range (off, SIGNED, orng, rvals) - || !wi::les_p (orng[0], orng[1])) + if (!get_range (off, SIGNED, orng, rvals)) { orng[0] = wi::to_offset (TYPE_MIN_VALUE (ptrdiff_type_node)); orng[1] = wi::to_offset (TYPE_MAX_VALUE (ptrdiff_type_node)); } + else if (wi::lts_p (orng[1], orng[0])) + /* The upper bound is less than the lower bound when the integer + operand is the result of signed integer conversion to sizetype, + as in P + OFF + CST where OFF > 0. + Correct just the upper bound. */ + orng[1] = wi::to_offset (TYPE_MAX_VALUE (ptrdiff_type_node)); pref->offrng[0] += orng[0]; pref->offrng[1] += orng[1]; |