[Bug target/104213] [12 Regression] bogus use-after-free in virtual dtor with -ffat-lto-objects on ARM

[mpolacek at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104213

--- Comment #8 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
I've tried

diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 22d3dd1e2ad..c2a0f0c24e2 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -17319,6 +17319,7 @@ finish_constructor_body (void)
            DECL_RESULT (current_function_decl), val);
       /* Return the address of the object.  */
       exprstmt = build_stmt (input_location, RETURN_EXPR, val);
+      suppress_warning (exprstmt, OPT_Wuse_after_free);
       add_stmt (exprstmt);
     }
 }
@@ -17412,6 +17413,7 @@ finish_destructor_body (void)
            DECL_RESULT (current_function_decl), val);
       /* Return the address of the object.  */
       exprstmt = build_stmt (input_location, RETURN_EXPR, val);
+      suppress_warning (exprstmt, OPT_Wuse_after_free);
       add_stmt (exprstmt);
     }
 }
diff --git a/gcc/cp/optimize.cc b/gcc/cp/optimize.cc
index 4ad3f1dc9aa..51393710526 100644
--- a/gcc/cp/optimize.cc
+++ b/gcc/cp/optimize.cc
@@ -168,6 +168,7 @@ build_delete_destructor_body (tree delete_dtor, tree
complete_dtor)
       tree val = DECL_ARGUMENTS (delete_dtor);
       val = build2 (MODIFY_EXPR, TREE_TYPE (val),
                     DECL_RESULT (delete_dtor), val);
+      suppress_warning (val, OPT_Wuse_after_free);
       add_stmt (build_stmt (0, RETURN_EXPR, val));
     }
 }

the last hunk should have done the trick but the suppress_warning bits don't
survive gimplification, it seems.