We are diagnosing operator delete (this_3(D)); A::f (this_3(D)); *this_3(D) ={v} CLOBBER;
where the CLOBBER appears at the end of the DTOR for C++11 and later. The following avoids this by simply never diagnosing clobbers as use-after-free. Bootstrap and regtest running on x86_64-unknown-linux-gnu, I'm going to push this if it succeeds. Richard. * gimple-ssa-warn-access.cc (pass_waccess::check_pointer_uses): Do not diagnose clobbers. * g++.dg/warn/Wuse-after-free3.C: Remove expected duplicate diagnostic. --- gcc/gimple-ssa-warn-access.cc | 4 ++++ gcc/testsuite/g++.dg/warn/Wuse-after-free3.C | 3 +-- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/gcc/gimple-ssa-warn-access.cc b/gcc/gimple-ssa-warn-access.cc index ed5499ca7fb..88d44690ade 100644 --- a/gcc/gimple-ssa-warn-access.cc +++ b/gcc/gimple-ssa-warn-access.cc @@ -4189,6 +4189,10 @@ pass_waccess::check_pointer_uses (gimple *stmt, tree ptr, if (use_stmt == stmt || is_gimple_debug (use_stmt)) continue; + /* A clobber isn't a use. */ + if (gimple_clobber_p (use_stmt)) + continue; + if (realloc_lhs) { /* Check to see if USE_STMT is a mismatched deallocation diff --git a/gcc/testsuite/g++.dg/warn/Wuse-after-free3.C b/gcc/testsuite/g++.dg/warn/Wuse-after-free3.C index 1862ac8b09d..e5b157865bf 100644 --- a/gcc/testsuite/g++.dg/warn/Wuse-after-free3.C +++ b/gcc/testsuite/g++.dg/warn/Wuse-after-free3.C @@ -1,7 +1,6 @@ // PR target/104213 // { dg-do compile } // { dg-options "-Wuse-after-free" } -// FIXME: We should not output the warning twice. struct A { @@ -13,4 +12,4 @@ A::~A () { operator delete (this); f (); // { dg-warning "used after" } -} // { dg-warning "used after" } +} -- 2.35.3