From 3299ead8e9ff3d65ff133518d4df84dc2a424c72 Mon Sep 17 00:00:00 2001
From: Erik Pilkington <erik.pilkington@gmail.com>
Date: Tue, 2 Apr 2019 19:48:07 +0000
Subject: [PATCH] [CodeGen] Fix a regression by emitting lambda expressions in
 EmitLValue

This ability was removed in r351487, but it's needed when a lambda appears as an
OpaqueValueExpr subexpression of a PseudoObjectExpr.

rdar://49030379

Differential revision: https://reviews.llvm.org/D60099

llvm-svn: 357515
---
 clang/lib/CodeGen/CGExpr.cpp                       |  2 +
 clang/test/CodeGenObjCXX/property-lvalue-lambda.mm | 47 ++++++++++++++++++++++
 2 files changed, 49 insertions(+)
 create mode 100644 clang/test/CodeGenObjCXX/property-lvalue-lambda.mm

diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index f19af33..80a40df 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -1294,6 +1294,8 @@ LValue CodeGenFunction::EmitLValue(const Expr *E) {
     return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
   case Expr::CXXUuidofExprClass:
     return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
+  case Expr::LambdaExprClass:
+    return EmitAggExprToLValue(E);
 
   case Expr::ExprWithCleanupsClass: {
     const auto *cleanups = cast<ExprWithCleanups>(E);
diff --git a/clang/test/CodeGenObjCXX/property-lvalue-lambda.mm b/clang/test/CodeGenObjCXX/property-lvalue-lambda.mm
new file mode 100644
index 0000000..4bc6ca6
--- /dev/null
+++ b/clang/test/CodeGenObjCXX/property-lvalue-lambda.mm
@@ -0,0 +1,47 @@
+// RUN: %clang_cc1 -fblocks -disable-llvm-passes -triple x86_64-apple-darwin10 -std=c++17 -emit-llvm -o - %s | FileCheck %s
+
+typedef void (^blk_t)();
+typedef void (*fnptr_t)();
+
+@interface X
+@property blk_t blk;
+@property fnptr_t fnptr;
+@end
+
+template <class T>
+blk_t operator+(blk_t lhs, T) { return lhs; }
+
+template <class T>
+fnptr_t operator+(fnptr_t lhs, T) { return lhs; }
+
+// CHECK-LABEL: define void @_Z2t1P1X
+void t1(X *x) {
+  // Check that we call lambda.operator blk_t(), and that we send that result to
+  // the setter.
+
+  // CHECK: [[CALL:%.*]] = call void ()* @"_ZZ2t1P1XENK3$_0cvU13block_pointerFvvEEv"
+  // CHECK: call void{{.*}}@objc_msgSend{{.*}}({{.*}} void ()* [[CALL]])
+  x.blk = [] {};
+
+  // CHECK: [[CALL2:%.*]] = call void ()* @"_ZZ2t1P1XENK3$_1cvPFvvEEv"
+  // CHECK: call void{{.*}}@objc_msgSend{{.*}}({{.*}} void ()* [[CALL2]])
+  x.fnptr = [] {};
+}
+
+// CHECK-LABEL: define void @_Z2t2P1X
+void t2(X *x) {
+  // Test the case when the lambda isn't unique. (see OpaqueValueExpr::isUnique)
+  // FIXME: This asserts if the lambda isn't trivially copy/movable.
+
+  // [x setBlk: operator+([x blk], [] {})]
+
+  // CHECK: call void{{.*}}@objc_msgSend{{.*}}
+  // CHECK: [[PLUS:%.*]] = call void ()* @"_ZplIZ2t2P1XE3$_2EU13block_pointerFvvES4_T_"
+  // CHECK: call void{{.*}}@objc_msgSend{{.*}}({{.*}} [[PLUS]])
+  x.blk += [] {};
+
+  // CHECK: call void{{.*}}@objc_msgSend{{.*}}
+  // CHECK: [[PLUS:%.*]] = call void ()* @"_ZplIZ2t2P1XE3$_3EPFvvES4_T_"
+  // CHECK: call void{{.*}}@objc_msgSend{{.*}}({{.*}} [[PLUS]])
+  x.fnptr += [] {};
+}
-- 
2.7.4