From 4c88e719ddaa64ea71ece335250b69e4142a74ee Mon Sep 17 00:00:00 2001
From: Mikhail Maltsev <mikhail.maltsev@arm.com>
Date: Wed, 14 Feb 2018 11:34:25 +0000
Subject: [PATCH] [Sema] Fix decltype of static data members

Summary:
According to the C++11 standard [dcl.type.simple]p4:
  The type denoted by decltype(e) is defined as follows:
  - if e is an unparenthesized id-expression or an unparenthesized
    class member access (5.2.5), decltype(e) is the type of the entity
    named by e.

Currently Clang handles the 'member access' case incorrectly for
static data members (decltype returns T& instead of T). This patch
fixes the issue.

Reviewers: faisalv, rsmith, rogfer01

Reviewed By: rogfer01

Subscribers: rogfer01, cfe-commits

Differential Revision: https://reviews.llvm.org/D42969

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@325117 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaType.cpp                                      | 5 +++--
 .../dcl.dcl/dcl.spec/dcl.type/dcl.type.simple/p4-cxx0x.cpp | 7 ++++++-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 8f3b359fde..e323b31f8e 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -7868,8 +7868,9 @@ static QualType getDecltypeForExpr(Sema &S, Expr *E) {
     if (const ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl()))
       return VD->getType();
   } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
-    if (const FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
-      return FD->getType();
+    if (const ValueDecl *VD = ME->getMemberDecl())
+      if (isa<FieldDecl>(VD) || isa<VarDecl>(VD))
+        return VD->getType();
   } else if (const ObjCIvarRefExpr *IR = dyn_cast<ObjCIvarRefExpr>(E)) {
     return IR->getDecl()->getType();
   } else if (const ObjCPropertyRefExpr *PR = dyn_cast<ObjCPropertyRefExpr>(E)) {
diff --git a/test/CXX/dcl.dcl/dcl.spec/dcl.type/dcl.type.simple/p4-cxx0x.cpp b/test/CXX/dcl.dcl/dcl.spec/dcl.type/dcl.type.simple/p4-cxx0x.cpp
index 53227ea37c..ee952aeaf0 100644
--- a/test/CXX/dcl.dcl/dcl.spec/dcl.type/dcl.type.simple/p4-cxx0x.cpp
+++ b/test/CXX/dcl.dcl/dcl.spec/dcl.type/dcl.type.simple/p4-cxx0x.cpp
@@ -12,13 +12,18 @@ struct is_same<T, T> {
 
 const int&& foo();
 int i;
-struct A { double x; };
+struct A {
+  double x;
+  static int y;
+};
 const A* a = new A();
 
 static_assert(is_same<decltype(foo()), const int&&>::value, "");
 static_assert(is_same<decltype(i), int>::value, "");
 static_assert(is_same<decltype(a->x), double>::value, "");
 static_assert(is_same<decltype((a->x)), const double&>::value, "");
+static_assert(is_same<decltype(a->y), int>::value, "");
+static_assert(is_same<decltype((a->y)), int&>::value, "");
 static_assert(is_same<decltype(static_cast<int&&>(i)), int&&>::value, "");
 
 int f0(int); // expected-note{{possible target}}
-- 
2.40.0