From: Jason Merrill <jason@redhat.com>
Date: Mon, 25 Jun 2012 20:37:14 +0000 (-0400)
Subject: re PR c++/52988 (std::async not executed on function returning nullptr_t)
X-Git-Tag: releases/gcc-4.6.4~474
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a05069d8ad6ef7c7a7c9a3353c278d5ee91c3290;p=thirdparty%2Fgcc.git

re PR c++/52988 (std::async not executed on function returning nullptr_t)

	PR c++/52988
	* typeck.c (decay_conversion): Don't discard side-effects from
	expressions of nullptr_t.

From-SVN: r188953
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 87870dfcf745..c53875116798 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2012-06-25  Jason Merrill  <jason@redhat.com>
+
+	PR c++/52988
+	* typeck.c (decay_conversion): Don't discard side-effects from
+	expressions of nullptr_t.
+
 2012-04-04  Steve Ellcey <sje@cup.hp.com>
 
 	Backported from mainline.
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index deb895111b62..b2a08a3b9e8c 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -1822,7 +1822,7 @@ decay_conversion (tree exp)
   if (error_operand_p (exp))
     return error_mark_node;
 
-  if (NULLPTR_TYPE_P (type))
+  if (NULLPTR_TYPE_P (type) && !TREE_SIDE_EFFECTS (exp))
     return nullptr_node;
 
   /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index a4fb57c915cb..33920f8651a2 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2012-06-25  Jason Merrill  <jason@redhat.com>
+
+	PR c++/52988
+	* g++.dg/cpp0x/nullptr28.C: New.
+
 2012-06-19  Kaz Kojima  <kkojima@gcc.gnu.org>
 
 	* gcc.dg/stack-usage-1.c: Remove dg-options line for sh targets
diff --git a/gcc/testsuite/g++.dg/cpp0x/nullptr28.C b/gcc/testsuite/g++.dg/cpp0x/nullptr28.C
new file mode 100644
index 000000000000..05fbe57b1971
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/nullptr28.C
@@ -0,0 +1,16 @@
+// { dg-do run { target c++11 } }
+
+typedef decltype(nullptr) nullptr_t;
+
+int i;
+nullptr_t n;
+const nullptr_t& f() { ++i; return n; }
+
+nullptr_t g() { return f(); }
+
+int main()
+{
+  g();
+  if (i != 1)
+    __builtin_abort ();
+}