r306175 - Revert "[MS] Don't statically initialize dllimport member function pointers"

[Reid Kleckner via cfe-commits]

Author: rnk
Date: Fri Jun 23 17:39:01 2017
New Revision: 306175

URL: http://llvm.org/viewvc/llvm-project?rev=306175&view=rev
Log:
Revert "[MS] Don't statically initialize dllimport member function pointers"

This reverts commit r306137. It has problems on code like this:

  struct __declspec(dllimport) Foo {
    int a;
    int get_a() { return a; }
  };
  template <int (Foo::*Getter)()> struct HasValue {
    int operator()(Foo *p) { return (p->*Getter)(); }
  };
  int main() {
    Foo f;
    f.a = 3;
    int x = HasValue<&Foo::get_a>()(&f);
  }

Removed:
    cfe/trunk/test/CodeGenCXX/dllimport-memptr-global.cpp
Modified:
    cfe/trunk/lib/AST/ExprConstant.cpp

Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=306175&r1=306174&r2=306175&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Fri Jun 23 17:39:01 2017
@@ -1665,19 +1665,6 @@ static bool CheckLValueConstantExpressio
   return true;
 }
 
-/// Member pointers are constant expressions unless they point to a
-/// non-virtual dllimport member function.
-static bool CheckMemberPointerConstantExpression(EvalInfo &Info,
-                                                 SourceLocation Loc,
-                                                 QualType Type,
-                                                 const APValue &Value) {
-  const ValueDecl *Member = Value.getMemberPointerDecl();
-  const auto *FD = dyn_cast_or_null<CXXMethodDecl>(Member);
-  if (!FD)
-    return true;
-  return FD->isVirtual() || !FD->hasAttr<DLLImportAttr>();
-}
-
 /// Check that this core constant expression is of literal type, and if not,
 /// produce an appropriate diagnostic.
 static bool CheckLiteralType(EvalInfo &Info, const Expr *E,
@@ -1770,9 +1757,6 @@ static bool CheckConstantExpression(Eval
     return CheckLValueConstantExpression(Info, DiagLoc, Type, LVal);
   }
 
-  if (Value.isMemberPointer())
-    return CheckMemberPointerConstantExpression(Info, DiagLoc, Type, Value);
-
   // Everything else is fine.
   return true;
 }

Removed: cfe/trunk/test/CodeGenCXX/dllimport-memptr-global.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/dllimport-memptr-global.cpp?rev=306174&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenCXX/dllimport-memptr-global.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/dllimport-memptr-global.cpp (removed)
@@ -1,58 +0,0 @@
-// Also check that -Wglobal-constructors does the right thing. Strictly
-// speaking, this is a Sema test, but this avoids test case duplication.
-// RUN: %clang_cc1 -Wglobal-constructors %s -verify -triple i686-windows-msvc -fms-extensions -std=c++11
-//
-// RUN: %clang_cc1 %s -emit-llvm -o - -triple i686-windows-msvc -fms-extensions -std=c++11 | FileCheck %s
-
-struct __declspec(dllimport) Single {
-  void nonvirt();
-  virtual void virt();
-};
-
-struct A { int a; };
-struct B { int b; };
-struct __declspec(dllimport) Multi : A, B {
-  void nonvirt();
-  virtual void virt();
-};
-
-struct __declspec(dllimport) Virtual : virtual A {
-  void nonvirt();
-  virtual void virt();
-};
-
-struct General;
-static_assert(sizeof(void (General::*)()) == 16, "force general memptr model");
-struct __declspec(dllimport) General {
-  void nonvirt();
-  virtual void virt();
-};
-
-auto mp_single_nv = &Single::nonvirt; // expected-warning {{global constructor}}
-auto mp_multi_nv = &Multi::nonvirt; // expected-warning {{global constructor}}
-auto mp_virtual_nv = &Virtual::nonvirt; // expected-warning {{global constructor}}
-auto mp_general_nv = &General::nonvirt; // expected-warning {{global constructor}}
-
-auto mp_single_v = &Single::virt;
-auto mp_multi_v = &Multi::virt;
-auto mp_virtual_v = &Virtual::virt;
-auto mp_general_v = &General::virt;
-
-// All of the non-virtual globals need dynamic initializers.
-
-// CHECK: @"\01?mp_single_nv@@3P8Single@@AEXXZQ1@" = global i8* null, align 4
-// CHECK: @"\01?mp_multi_nv@@3P8Multi@@AEXXZQ1@" = global { i8*, i32 } zeroinitializer, align 4
-// CHECK: @"\01?mp_virtual_nv@@3P8Virtual@@AEXXZQ1@" = global { i8*, i32, i32 } zeroinitializer, align 4
-// CHECK: @"\01?mp_general_nv@@3P8General@@AEXXZQ1@" = global { i8*, i32, i32, i32 } zeroinitializer, align 4
-
-// CHECK: @"\01?mp_single_v@@3P8Single@@AEXXZQ1@" = global i8* bitcast (void (%struct.Single*, ...)* @"\01??_9Single@@$BA at AE" to i8*), align 4
-// CHECK: @"\01?mp_multi_v@@3P8Multi@@AEXXZQ1@" = global { i8*, i32 } { i8* bitcast (void (%struct.Multi*, ...)* @"\01??_9Multi@@$BA at AE" to i8*), i32 0 }, align 4
-// CHECK: @"\01?mp_virtual_v@@3P8Virtual@@AEXXZQ1@" = global { i8*, i32, i32 } { i8* bitcast (void (%struct.Virtual*, ...)* @"\01??_9Virtual@@$BA at AE" to i8*), i32 0, i32 0 }, align 4
-// CHECK: @"\01?mp_general_v@@3P8General@@AEXXZQ1@" = global { i8*, i32, i32, i32 } { i8* bitcast (void (%struct.General*, ...)* @"\01??_9General@@$BA at AE" to i8*), i32 0, i32 0, i32 0 }, align 4
-
-// CHECK: define internal void @_GLOBAL__sub_I{{.*}}() {{.*}} {
-// CHECK:   call void @"\01??__Emp_single_nv@@YAXXZ"()
-// CHECK:   call void @"\01??__Emp_multi_nv@@YAXXZ"()
-// CHECK:   call void @"\01??__Emp_virtual_nv@@YAXXZ"()
-// CHECK:   call void @"\01??__Emp_general_nv@@YAXXZ"()
-// CHECK: }