From e541ea3a61a3331e39d5a90387472126453293bd Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Tue, 12 May 2009 21:28:12 +0000
Subject: [PATCH] implement l-value codegen of comma expr

llvm-svn: 71595
---
 clang/lib/CodeGen/CGExpr.cpp |  6 ++++++
 clang/test/CodeGen/exprs.c   | 12 ++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 8ff2080efa33..06d8d974b081 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -1108,6 +1108,12 @@ RValue CodeGenFunction::EmitCallExpr(const CallExpr *E) {
 }
 
 LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
+  // Comma expressions just emit their LHS then their RHS as an l-value.
+  if (E->getOpcode() == BinaryOperator::Comma) {
+    EmitAnyExpr(E->getLHS());
+    return EmitLValue(E->getRHS());
+  }
+  
   // Can only get l-value for binary operator expressions which are a
   // simple assignment of aggregate type.
   if (E->getOpcode() != BinaryOperator::Assign)
diff --git a/clang/test/CodeGen/exprs.c b/clang/test/CodeGen/exprs.c
index ad3e4e095686..36cfff9e8a69 100644
--- a/clang/test/CodeGen/exprs.c
+++ b/clang/test/CodeGen/exprs.c
@@ -104,3 +104,15 @@ void f7() {
 int f8() {
   return ({ foo(); }).Y;
 }
+
+// rdar://6880558
+struct S;
+struct C {
+  int i;
+  struct S *tab[];
+};
+struct S { struct C c; };
+void f9(struct S *x) {
+  foo(((void)1, x->c).tab[0]);
+}
+