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C++ PATCH for c++/52988 (omitted calls with nullptr)
- From: Jason Merrill <jason at redhat dot com>
- To: gcc-patches List <gcc-patches at gcc dot gnu dot org>, Jonathan Wakely <jwakely dot gcc at gmail dot com>
- Date: Mon, 25 Jun 2012 13:41:06 -0400
- Subject: C++ PATCH for c++/52988 (omitted calls with nullptr)
We were assuming that any expression of nullptr_t was equivalent to
nullptr, but that isn't valid if the expression has side-effects...
Tested x86_64-pc-linux-gnu, applying to 4.6, 4.7, trunk.
commit c716e8680864db1312338691de7d2618efec1c3f
Author: Jason Merrill <jason@redhat.com>
Date: Mon Jun 25 13:06:15 2012 -0400
PR c++/52988
* typeck.c (decay_conversion): Don't discard side-effects from
expressions of nullptr_t.
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 945266b..971f386 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -1843,7 +1843,7 @@ decay_conversion (tree exp, tsubst_flags_t complain)
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/g++.dg/cpp0x/nullptr28.C b/gcc/testsuite/g++.dg/cpp0x/nullptr28.C
new file mode 100644
index 0000000..05fbe57
--- /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 ();
+}