https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104213
--- Comment #12 from Marek Polacek <mpolacek at gcc dot gnu.org> --- Removing the COMPARISON_CLASS_P check regresses uninit-pr74762.C. So how about diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc index 22d3dd1e2ad..6534a7fd320 100644 --- a/gcc/cp/decl.cc +++ b/gcc/cp/decl.cc @@ -17315,6 +17315,7 @@ finish_constructor_body (void) add_stmt (build_stmt (input_location, LABEL_EXPR, cdtor_label)); val = DECL_ARGUMENTS (current_function_decl); + suppress_warning (val, OPT_Wuse_after_free); val = build2 (MODIFY_EXPR, TREE_TYPE (val), DECL_RESULT (current_function_decl), val); /* Return the address of the object. */ @@ -17408,6 +17409,7 @@ finish_destructor_body (void) tree val; val = DECL_ARGUMENTS (current_function_decl); + suppress_warning (val, OPT_Wuse_after_free); val = build2 (MODIFY_EXPR, TREE_TYPE (val), DECL_RESULT (current_function_decl), val); /* Return the address of the object. */ diff --git a/gcc/cp/optimize.cc b/gcc/cp/optimize.cc index 4ad3f1dc9aa..13ab8b7361e 100644 --- a/gcc/cp/optimize.cc +++ b/gcc/cp/optimize.cc @@ -166,6 +166,7 @@ build_delete_destructor_body (tree delete_dtor, tree complete_dtor) if (targetm.cxx.cdtor_returns_this ()) { tree val = DECL_ARGUMENTS (delete_dtor); + suppress_warning (val, OPT_Wuse_after_free); val = build2 (MODIFY_EXPR, TREE_TYPE (val), DECL_RESULT (delete_dtor), val); add_stmt (build_stmt (0, RETURN_EXPR, val)); diff --git a/gcc/gimple-ssa-warn-access.cc b/gcc/gimple-ssa-warn-access.cc index 8bc33eeb6fa..f39092ec416 100644 --- a/gcc/gimple-ssa-warn-access.cc +++ b/gcc/gimple-ssa-warn-access.cc @@ -3880,9 +3880,19 @@ pass_waccess::warn_invalid_pointer (tree ref, gimple *use_stmt, bool maybe, bool equality /* = false */) { /* Avoid printing the unhelpful "<unknown>" in the diagnostics. */ - if (ref && TREE_CODE (ref) == SSA_NAME - && (!SSA_NAME_VAR (ref) || DECL_ARTIFICIAL (SSA_NAME_VAR (ref)))) - ref = NULL_TREE; + if (ref && TREE_CODE (ref) == SSA_NAME) + { + tree var = SSA_NAME_VAR (ref); + if (!var) + ref = NULL_TREE; + else if (DECL_ARTIFICIAL (var)) + { + /* Don't warn for cases like when a cdtor returns 'this' on ARM. */ + if (warning_suppressed_p (var, OPT_Wuse_after_free)) + return; + ref = NULL_TREE; + } + } location_t use_loc = gimple_location (use_stmt); if (use_loc == UNKNOWN_LOCATION) I guess I can test & post it.