Hi Martin,
On 6 December 2017 at 00:51, Jeff Law <l...@redhat.com> wrote: > On 12/05/2017 04:47 PM, Martin Sebor wrote: >> PR middle-end/82646 - bogus -Wstringop-overflow with >> -D_FORTIFY_SOURCE=2 on strncpy with range to a member array, >> >> The bug points out a false positive in a call to strncpy() when >> _FORTIFY_SOURCE is defined that doesn't exist otherwise. >> >> The problem is that __builtin_strncpy buffer overflow checking >> is done along with the expansion of the intrinsic in one place >> and __builtin___strncpy_chk is handled differently in another, >> and the two are out of sync. >> >> The attached patch corrects the choice of arguments used for >> overflow detection in __builtin___strncpy_chk and aligns >> the diagnostics between the two intrinsics. >> >> Martin >> >> gcc-82646.diff >> >> >> PR tree-optimization/82646 - bogus -Wstringop-overflow with >> -D_FORTIFY_SOURCE=2 on strncpy with range to a member array >> >> gcc/ChangeLog: >> >> PR tree-optimization/82646 >> * builtins.c (maybe_emit_chk_warning): Use size as the bound for >> strncpy, not maxlen. >> >> gcc/testsuite/ChangeLog: >> >> PR tree-optimization/82646 >> * gcc.dg/builtin-stringop-chk-1.c: Adjust. >> * gcc.dg/builtin-stringop-chk-9.c: New test. > OK. > The new test fails on 32 bits platforms (arm, x86_32, aarch64 ilp32): FAIL: gcc.dg/builtin-stringop-chk-9.c (test for warnings, line 125) FAIL: gcc.dg/builtin-stringop-chk-9.c (test for warnings, line 133) FAIL: gcc.dg/builtin-stringop-chk-9.c (test for warnings, line 141) FAIL: gcc.dg/builtin-stringop-chk-9.c (test for warnings, line 149) Christophe > [ Happy to see something easy fly by that isn't SVE related :-) ] > > jeff
