From 3f92868b7e1fb0b9e49e9407ff3f2c0e7f8d07ea Mon Sep 17 00:00:00 2001
From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Mon, 26 Sep 2016 23:56:57 +0000
Subject: [PATCH] P0145R3 (C++17 evaluation order tweaks): evaluate the base
 expression before the pointer-to-member expression in calls through .* and
 ->* expressions.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@282457 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGExprCXX.cpp            |  6 +++---
 test/CodeGenCXX/cxx1z-eval-order.cpp | 32 ++++++++++++++--------------
 2 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp
index e607c3c153..1dfe437c33 100644
--- a/lib/CodeGen/CGExprCXX.cpp
+++ b/lib/CodeGen/CGExprCXX.cpp
@@ -301,9 +301,6 @@ CodeGenFunction::EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
   const CXXRecordDecl *RD = 
     cast<CXXRecordDecl>(MPT->getClass()->getAs<RecordType>()->getDecl());
 
-  // Get the member function pointer.
-  llvm::Value *MemFnPtr = EmitScalarExpr(MemFnExpr);
-
   // Emit the 'this' pointer.
   Address This = Address::invalid();
   if (BO->getOpcode() == BO_PtrMemI)
@@ -314,6 +311,9 @@ CodeGenFunction::EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
   EmitTypeCheck(TCK_MemberCall, E->getExprLoc(), This.getPointer(),
                 QualType(MPT->getClass(), 0));
 
+  // Get the member function pointer.
+  llvm::Value *MemFnPtr = EmitScalarExpr(MemFnExpr);
+
   // Ask the ABI to load the callee.  Note that This is modified.
   llvm::Value *ThisPtrForCall = nullptr;
   llvm::Value *Callee =
diff --git a/test/CodeGenCXX/cxx1z-eval-order.cpp b/test/CodeGenCXX/cxx1z-eval-order.cpp
index 3531891d38..655f9a5ee0 100644
--- a/test/CodeGenCXX/cxx1z-eval-order.cpp
+++ b/test/CodeGenCXX/cxx1z-eval-order.cpp
@@ -125,35 +125,35 @@ void alloc_before_init() {
 // CHECK: }
 }
 
-#if 0
-// CHECKDISABLED-LABEL: define {{.*}}@{{.*}}dotstar_lhs_before_rhs{{.*}}(
+
+// CHECK-LABEL: define {{.*}}@{{.*}}dotstar_lhs_before_rhs{{.*}}(
 int dotstar_lhs_before_rhs() {
-  // CHECKDISABLED: call {{.*}}@{{.*}}make_a{{.*}}(
-  // CHECKDISABLED: call {{.*}}@{{.*}}make_mem_ptr_a{{.*}}(
+  // CHECK: call {{.*}}@{{.*}}make_a{{.*}}(
+  // CHECK: call {{.*}}@{{.*}}make_mem_ptr_a{{.*}}(
   int a = make_a().*make_mem_ptr_a();
 
-  // CHECKDISABLED: call {{.*}}@{{.*}}make_a_ptr{{.*}}(
-  // CHECKDISABLED: call {{.*}}@{{.*}}make_mem_ptr_a{{.*}}(
+  // CHECK: call {{.*}}@{{.*}}make_a_ptr{{.*}}(
+  // CHECK: call {{.*}}@{{.*}}make_mem_ptr_a{{.*}}(
   int b = make_a_ptr()->*make_mem_ptr_a();
 
-  // CHECKDISABLED: call {{.*}}@{{.*}}make_c{{.*}}(
-  // CHECKDISABLED: call {{.*}}@{{.*}}make_b{{.*}}(
+  // CHECK: call {{.*}}@{{.*}}make_c{{.*}}(
+  // CHECK: call {{.*}}@{{.*}}make_b{{.*}}(
   make_c()->*make_b();
 
-  // CHECKDISABLED: call {{.*}}@{{.*}}make_a{{.*}}(
-  // CHECKDISABLED: call {{.*}}@{{.*}}make_mem_fn_ptr_a{{.*}}(
-  // CHECKDISABLED: call
+  // CHECK: call {{.*}}@{{.*}}make_a{{.*}}(
+  // CHECK: call {{.*}}@{{.*}}make_mem_fn_ptr_a{{.*}}(
+  // CHECK: call
   (make_a().*make_mem_fn_ptr_a())();
 
-  // CHECKDISABLED: call {{.*}}@{{.*}}make_a_ptr{{.*}}(
-  // CHECKDISABLED: call {{.*}}@{{.*}}make_mem_fn_ptr_a{{.*}}(
-  // CHECKDISABLED: call
+  // CHECK: call {{.*}}@{{.*}}make_a_ptr{{.*}}(
+  // CHECK: call {{.*}}@{{.*}}make_mem_fn_ptr_a{{.*}}(
+  // CHECK: call
   (make_a_ptr()->*make_mem_fn_ptr_a())();
 
   return a + b;
-// CHECKDISABLED: }
+// CHECK: }
 }
-#endif
+
 #if 0
 // CHECKDISABLED-LABEL: define {{.*}}@{{.*}}assign_lhs_before_rhs{{.*}}(
 void assign_rhs_before_lhs() {
-- 
2.40.0