C++ ABI change: destroy value arguments in caller.

        * calls.c (initialize_argument_information): Pass the address of
        the TARGET_EXPR temporary rather than storing it into another.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@48983 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 38 insertions, 0 deletions

diff --git a/gcc/testsuite/g++.dg/init/elide1.C b/gcc/testsuite/g++.dg/init/elide1.C
new file mode 100644
index 00000000000..24e81e387e5
--- /dev/null
+++ b/gcc/testsuite/g++.dg/init/elide1.C
@@ -0,0 +1,38 @@
+// { dg-do run }
+
+// Test that the destructor for a temporary passed by value isn't run
+// until end of full-expression, as per [class.copy]:
+
+// Whenever a temporary class object is copied using a copy  constructor,
+// and  this  object  and  the copy have the same cv-unqualified type, an
+// implementation is permitted to treat the original and the copy as  two
+// different  ways of referring to the same object and not perform a copy
+// at all, even if the class copy constructor  or  destructor  have  side
+// effects....                                       In these cases,  the
+// object  is  destroyed  at the later of times when the original and the
+// copy would have been destroyed without the optimization.
+
+// Here, the temporary would be destroyed later than the parm, so either we
+// must suppress the optimization in this case or destroy value parms in the
+// caller.
+
+int d;
+
+struct A {
+  A () { }
+  A (const A&) { }
+  ~A() { ++d; }
+};
+
+void f (A a) { }
+
+int main ()
+{
+  int r;
+  f (A ()), r = d;
+
+  if (r < d && d)
+    return 0;
+  else
+    return 1;
+}