Implement proper support for generating code for compound literals in

C++, which means:
  - binding the temporary as needed in Sema, so that we generate the
  appropriate call to the destructor, and
  - emitting the compound literal into the appropriate location for
  the aggregate, rather than trying to emit it as a temporary and
  memcpy() it.

Fixes PR10138 / <rdar://problem/9615901>.

llvm-svn: 133235

3 files changed, 38 insertions, 5 deletions

diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index c1ead814b9a..694316983e8 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -91,9 +91,7 @@ public:
   void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); }
   void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); }
   void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); }
-  void VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
-    EmitAggLoadOfLValue(E);
-  }
+  void VisitCompoundLiteralExpr(CompoundLiteralExpr *E);
   void VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
     EmitAggLoadOfLValue(E);
   }
@@ -247,6 +245,13 @@ void AggExprEmitter::VisitOpaqueValueExpr(OpaqueValueExpr *e) {
   EmitFinalDestCopy(e, CGF.getOpaqueLValueMapping(e));
 }
 
+void
+AggExprEmitter::VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
+  AggValueSlot Slot = EnsureSlot(E->getType());
+  CGF.EmitAggExpr(E->getInitializer(), Slot);
+}
+
+
 void AggExprEmitter::VisitCastExpr(CastExpr *E) {
   switch (E->getCastKind()) {
   case CK_Dynamic: {
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index fe11c7e4fea..2d8ed17b708 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -5309,8 +5309,9 @@ Sema::BuildCompoundLiteralExpr(SourceLocation LParenLoc, TypeSourceInfo *TInfo,
   // In C, compound literals are l-values for some reason.
   ExprValueKind VK = getLangOptions().CPlusPlus ? VK_RValue : VK_LValue;
 
-  return Owned(new (Context) CompoundLiteralExpr(LParenLoc, TInfo, literalType,
-                                                 VK, literalExpr, isFileScope));
+  return MaybeBindToTemporary(
+           new (Context) CompoundLiteralExpr(LParenLoc, TInfo, literalType,
+                                             VK, literalExpr, isFileScope));
 }
 
 ExprResult
diff --git a/clang/test/CodeGenCXX/compound-literals.cpp b/clang/test/CodeGenCXX/compound-literals.cpp
new file mode 100644
index 00000000000..cd44e97c674
--- /dev/null
+++ b/clang/test/CodeGenCXX/compound-literals.cpp
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -emit-llvm -o - %s | FileCheck %s
+
+struct X {
+  X();
+  X(const X&);
+  X(const char*);
+  ~X();
+};
+
+struct Y { 
+  int i;
+  X x;
+};
+
+// CHECK: define i32 @_Z1fv()
+int f() {
+  // CHECK: [[LVALUE:%[a-z0-9.]+]] = alloca
+  // CHECK-NEXT: [[I:%[a-z0-9]+]] = getelementptr inbounds {{.*}}* [[LVALUE]], i32 0, i32 0
+  // CHECK-NEXT: store i32 17, i32* [[I]]
+  // CHECK-NEXT: [[X:%[a-z0-9]+]] = getelementptr inbounds {{.*}} [[LVALUE]], i32 0, i32 1
+  // CHECK-NEXT: call void @_ZN1XC1EPKc({{.*}}[[X]]
+  // CHECK-NEXT: [[I:%[a-z0-9]+]] = getelementptr inbounds {{.*}} [[LVALUE]], i32 0, i32 0
+  // CHECK-NEXT: [[RESULT:%[a-z0-9]+]] = load i32*
+  // CHECK-NEXT: call void @_ZN1YD1Ev
+  // CHECK-NEXT: ret i32 [[RESULT]]
+  return ((Y){17, "seventeen"}).i;
+}