From: Jason Merrill <jason@redhat.com>
Date: Wed, 5 Oct 2016 22:58:55 +0000 (-0400)
Subject: PR c++/54293 - binding reference to member of temporary
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=5794b9f622dce668aa92ebabdf26abd0e799c665;p=gcc.git

PR c++/54293 - binding reference to member of temporary

	* call.c (reference_binding): Fix binding to member of temporary.

From-SVN: r240819
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index f8752a6911c..569d696546d 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 2016-10-05  Jason Merrill  <jason@redhat.com>
 
+	PR c++/54293
+	* call.c (reference_binding): Fix binding to member of temporary.
+
 	* call.c (extend_ref_init_temps): Fix TARGET_EXPR handling.
 
 	* parser.c (cp_parser_skip_to_end_of_statement): Add missing break.
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index c33341813cf..dac1337cc49 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -1539,15 +1539,20 @@ reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags,
 	gl_kind = clk_rvalueref;
     }
   else if (expr)
-    {
-      gl_kind = lvalue_kind (expr);
-      if (gl_kind & clk_class)
-	/* A class prvalue is not a glvalue.  */
-	gl_kind = clk_none;
-    }
+    gl_kind = lvalue_kind (expr);
+  else if (CLASS_TYPE_P (from)
+	   || TREE_CODE (from) == ARRAY_TYPE)
+    gl_kind = clk_class;
   else
     gl_kind = clk_none;
-  is_lvalue = gl_kind && !(gl_kind & clk_rvalueref);
+
+  /* Don't allow a class prvalue when LOOKUP_NO_TEMP_BIND.  */
+  if ((flags & LOOKUP_NO_TEMP_BIND)
+      && (gl_kind & clk_class))
+    gl_kind = clk_none;
+
+  /* Same mask as real_lvalue_p.  */
+  is_lvalue = gl_kind && !(gl_kind & (clk_rvalueref|clk_class));
 
   tfrom = from;
   if ((gl_kind & clk_bitfield) != 0)
@@ -1569,11 +1574,7 @@ reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags,
      [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
      const and rvalue references to rvalues of compatible class type.
      We should also do direct bindings for non-class xvalues.  */
-  if (related_p
-      && (gl_kind
-	  || (!(flags & LOOKUP_NO_TEMP_BIND)
-	      && (CLASS_TYPE_P (from)
-		  || TREE_CODE (from) == ARRAY_TYPE))))
+  if (related_p && gl_kind)
     {
       /* [dcl.init.ref]
 
diff --git a/gcc/testsuite/g++.dg/init/ref19.C b/gcc/testsuite/g++.dg/init/ref19.C
index ed78c939ba6..d583e939fdb 100644
--- a/gcc/testsuite/g++.dg/init/ref19.C
+++ b/gcc/testsuite/g++.dg/init/ref19.C
@@ -11,7 +11,11 @@ struct A
 
 int main()
 {
-  const int &r = A().i;
+  {
+    const int &r = A().i;
+    if (d != 0)
+      return 1;
+  }
   if (d != 1)
     return 1;
 }