re PR c++/13684 (local static object variable constructed once but ctors and dtors called multiple times on same memory when called in multiple threads)

        PR c++/13684
        * cp/decl.c (expand_static_init): Use thread-safety API.
        (register_dtor_fn): Return the call, don't expand it.
        * cp/tree.c (add_stmt_to_compound): New fn.
        (stabilize_call): Use it.
        * gimplify.c (gimplify_cleanup_point_expr): Handle CLEANUP_EH_ONLY.
        (gimple_push_cleanup): Add eh_only parm.
        (gimplify_target_expr): Pass it.
        * c.opt (-fno-threadsafe-statics): New option.
        * c-opts.c (c_common_handle_option): Handle it.
        * c-common.h (flag_threadsafe_statics): Declare it.
        * c-common.c (flag_threadsafe_statics): Record it.
        * doc/invoke.texi: Document it.
        * tsystem.h (_GNU_SOURCE): Define.
        * gthr-posix.h (__gthread_recursive_mutex_t): New typedef.
        (__GTHREAD_RECURSIVE_MUTEX_INIT): New macro.
        (__GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION): New macro.
        (__gthread_recursive_mutex_init_function): New fn.
        (__gthread_recursive_mutex_lock): New fn.
        (__gthread_recursive_mutex_trylock): New fn.
        (__gthread_recursive_mutex_unlock): New fn.
        * gthr-solaris.h, gthr-single.h, gthr-dce.h: Likewise.
        * gthr-win32.h, gthr-vxworks.h: Likewise.
        * gthr.h: Document.

        * libsupc++/guard.cc (static_mutex): Internal class implementing a
        recursive mutex which controls initialization of local statics.
        (__gnu_cxx::recursive_init): New exception class.
        (__cxa_guard_acquire): Deal with locking and recursion detection.
        (acquire_1, __cxa_guard_abort, __cxa_guard_release): Likewise.

From-SVN: r86687

1 files changed, 14 insertions, 6 deletions

diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index 4bdadad..9933467 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -2254,6 +2254,19 @@ stabilize_expr (tree exp, tree* initp)
   return exp;
 }
 
+/* Add NEW, an expression whose value we don't care about, after the
+   similar expression ORIG.  */
+
+tree
+add_stmt_to_compound (tree orig, tree new)
+{
+  if (!new || !TREE_SIDE_EFFECTS (new))
+    return orig;
+  if (!orig || !TREE_SIDE_EFFECTS (orig))
+    return new;
+  return build2 (COMPOUND_EXPR, void_type_node, orig, new);
+}
+
 /* Like stabilize_expr, but for a call whose args we want to
    pre-evaluate.  */
 
@@ -2275,12 +2288,7 @@ stabilize_call (tree call, tree *initp)
       {
 	tree init;
 	TREE_VALUE (t) = stabilize_expr (TREE_VALUE (t), &init);
-	if (!init)
-	  /* Nothing.  */;
-	else if (inits)
-	  inits = build2 (COMPOUND_EXPR, void_type_node, inits, init);
-	else
-	  inits = init;
+	inits = add_stmt_to_compound (inits, init);
       }
 
   *initp = inits;