From a47d328ff345b05eb6fec4683ac04ac939064bfc Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Fri, 27 May 2011 15:32:30 -0400
Subject: [PATCH] re PR c++/47132 ([C++0x] decltype can't deduce some operator
 return types when defining an auto function's return)

	PR c++/47132
	* mangle.c (write_expression): Handle MODOP_EXPR.

From-SVN: r174357
---
 gcc/cp/ChangeLog                    |  3 +++
 gcc/cp/mangle.c                     |  9 +++++++++
 gcc/testsuite/ChangeLog             |  2 ++
 gcc/testsuite/g++.dg/abi/mangle47.C | 11 +++++++++++
 4 files changed, 25 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/abi/mangle47.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 7a579c6d004..9ccdee5a178 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 2011-05-27  Jason Merrill  <jason@redhat.com>
 
+	PR c++/47132
+	* mangle.c (write_expression): Handle MODOP_EXPR.
+
 	PR c++/47277
 	* parser.c (cp_parser_unqualified_id): Don't check
 	constructor_name_p for enums.
diff --git a/gcc/cp/mangle.c b/gcc/cp/mangle.c
index c1f3b44e905..27ef374597e 100644
--- a/gcc/cp/mangle.c
+++ b/gcc/cp/mangle.c
@@ -2599,6 +2599,15 @@ write_expression (tree expr)
       write_unqualified_id (fn);
       write_template_args (TREE_OPERAND (expr, 1));
     }
+  else if (TREE_CODE (expr) == MODOP_EXPR)
+    {
+      enum tree_code subop = TREE_CODE (TREE_OPERAND (expr, 1));
+      const char *name = (assignment_operator_name_info[(int) subop]
+			  .mangled_name);
+      write_string (name);
+      write_expression (TREE_OPERAND (expr, 0));
+      write_expression (TREE_OPERAND (expr, 2));
+    }
   else
     {
       int i, len;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index a9e31ce77fc..4c97a9f07df 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,7 @@
 2011-05-27  Jason Merrill  <jason@redhat.com>
 
+	* g++.dg/abi/mangle47.C: New.
+
 	PR c++/49176
 	* g++.dg/template/const5.C: New.
 
diff --git a/gcc/testsuite/g++.dg/abi/mangle47.C b/gcc/testsuite/g++.dg/abi/mangle47.C
new file mode 100644
index 00000000000..2c1b636dc05
--- /dev/null
+++ b/gcc/testsuite/g++.dg/abi/mangle47.C
@@ -0,0 +1,11 @@
+// PR c++/47132
+// { dg-options -std=c++0x }
+// { dg-final { scan-assembler "_Z1fIiEDToRfp_Li1EET_" } }
+
+template <typename T>
+auto f (T t) -> decltype(t |= 1);
+
+int main()
+{
+  f(1);
+}