From: jason <jason@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon, 21 Mar 2016 21:13:06 +0000 (+0000)
Subject: 	PR c++/70285
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=bf64d98ab39b387d879f03ca7d691015a218821a;p=thirdparty%2Fgcc.git

	PR c++/70285
	* cp-gimplify.c (cp_fold) [COND_EXPR]: Handle bit-fields.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@234384 138bc75d-0d04-0410-961f-82ee72b054a4
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index cd98a53b0ac4..3912395c8963 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2016-03-21  Jason Merrill  <jason@redhat.com>
+
+	PR c++/70285
+	* cp-gimplify.c (cp_fold) [COND_EXPR]: Handle bit-fields.
+
 2016-03-18  Jason Merrill  <jason@redhat.com>
 
 	PR c++/70139
diff --git a/gcc/cp/cp-gimplify.c b/gcc/cp/cp-gimplify.c
index 6a767fa13a4e..9bf248216b8d 100644
--- a/gcc/cp/cp-gimplify.c
+++ b/gcc/cp/cp-gimplify.c
@@ -2130,6 +2130,12 @@ cp_fold (tree x)
       else
 	x = fold (x);
 
+      /* A COND_EXPR might have incompatible types in branches if one or both
+	 arms are bitfields.  If folding exposed such a branch, fix it up.  */
+      if (TREE_CODE (x) != code)
+	if (tree type = is_bitfield_expr_with_lowered_type (x))
+	  x = fold_convert (type, x);
+
       break;
 
     case CALL_EXPR:
diff --git a/gcc/testsuite/g++.dg/other/bitfield5.C b/gcc/testsuite/g++.dg/other/bitfield5.C
new file mode 100644
index 000000000000..b8cd4dd206a3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/other/bitfield5.C
@@ -0,0 +1,15 @@
+// PR c++/70285
+
+int a;
+
+struct S
+{
+  int i:8;
+} b;
+
+int
+fn1 (bool x)
+{
+  (&fn1 ? b.i : a) = 42;
+  return (&fn1 ? b.i : a);
+}