Start adding support for dllimport/dllexport on classes (PR11170)

This implements the central part of support for dllimport/dllexport on
classes: allowing the attribute on class declarations, inheriting it
to class members, and forcing emission of exported members. It's based
on Nico Rieck's patch from http://reviews.llvm.org/D1099.

This patch doesn't propagate dllexport to bases that are template
specializations, which is an interesting problem. It also doesn't
look at the rules when redeclaring classes with different attributes,
I'd like to do that separately.

Differential Revision: http://reviews.llvm.org/D3877

llvm-svn: 209908

1 files changed, 90 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/dllexport.cpp b/clang/test/CodeGenCXX/dllexport.cpp
index cd448049c64..df8524d03f0 100644
--- a/clang/test/CodeGenCXX/dllexport.cpp
+++ b/clang/test/CodeGenCXX/dllexport.cpp
@@ -3,6 +3,8 @@
 // RUN: %clang_cc1 -triple i686-windows-gnu    -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=GNU --check-prefix=G32 %s
 // RUN: %clang_cc1 -triple x86_64-windows-gnu  -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=GNU --check-prefix=G64 %s
 
+// RUN: %clang_cc1 -triple i686-pc-win32 -O1 -mconstructor-aliases -std=c++1y -emit-llvm -o - %s | FileCheck %s --check-prefix=MSC --check-prefix=M32
+
 // Helper structs to make templates more expressive.
 struct ImplicitInst_Exported {};
 struct ExplicitDecl_Exported {};
@@ -447,3 +449,91 @@ void __declspec(dllexport) precedenceRedecl1() {}
 // GNU-DAG: define dllexport void @_Z17precedenceRedecl2v()
 void __declspec(dllexport) precedenceRedecl2();
 void __declspec(dllimport) precedenceRedecl2() {}
+
+
+
+//===----------------------------------------------------------------------===//
+// Classes
+//===----------------------------------------------------------------------===//
+
+struct S {
+  void __declspec(dllexport) a() {}
+  // M32-DAG: define weak_odr dllexport x86_thiscallcc void @"\01?a@S@@QAEXXZ"
+
+  struct T {
+    void __declspec(dllexport) a() {}
+    // M32-DAG: define weak_odr dllexport x86_thiscallcc void @"\01?a@T@S@@QAEXXZ"
+  };
+};
+
+
+struct __declspec(dllexport) T {
+  // Copy assignment operator:
+  // M32-DAG: define weak_odr dllexport x86_thiscallcc nonnull %struct.T* @"\01??4T@@QAEAAU0@ABU0@@Z"
+
+  // Explicitly defaulted copy constructur:
+  T(const T&) = default;
+  // M32-DAG: define weak_odr dllexport x86_thiscallcc %struct.T* @"\01??0T@@QAE@ABU0@@Z"
+
+  void a() {}
+  // M32-DAG: define weak_odr dllexport x86_thiscallcc void @"\01?a@T@@QAEXXZ"
+
+  static int b;
+  // M32-DAG: @"\01?b@T@@2HA" = external dllexport global i32
+
+  static int c;
+  // M32-DAG: @"\01?c@T@@2HA" = dllexport global i32 0, align 4
+};
+
+USEVAR(T::b)
+int T::c;
+
+template <typename T> struct __declspec(dllexport) U { void foo() {} };
+// The U<int> specialization below must cause the following to be emitted:
+// M32-DAG: define weak_odr dllexport x86_thiscallcc void @"\01?foo@?$U@H@@QAEXXZ"
+// M32-DAG: define weak_odr dllexport x86_thiscallcc nonnull %struct.U* @"\01??4?$U@H@@QAEAAU0@ABU0@@Z"
+struct __declspec(dllexport) V : public U<int> { };
+
+
+struct __declspec(dllexport) W { virtual void foo() {} };
+// Default ctor:
+// M32-DAG: define weak_odr dllexport x86_thiscallcc %struct.W* @"\01??0W@@QAE@XZ"
+// Copy ctor:
+// M32-DAG: define weak_odr dllexport x86_thiscallcc %struct.W* @"\01??0W@@QAE@ABU0@@Z"
+// vftable:
+// M32-DAG: @"\01??_7W@@6B@" = weak_odr dllexport unnamed_addr constant [1 x i8*] [i8* bitcast (void (%struct.W*)* @"\01?foo@W@@UAEXXZ" to i8*)]
+
+struct __declspec(dllexport) X : public virtual W {};
+// vbtable:
+// M32-DAG: @"\01??_8X@@7B@" = weak_odr dllexport unnamed_addr constant [2 x i32] [i32 0, i32 4]
+
+struct __declspec(dllexport) Y {
+  // Move assignment operator:
+  // M32-DAG: define weak_odr dllexport x86_thiscallcc nonnull %struct.Y* @"\01??4Y@@QAEAAU0@$$QAU0@@Z"
+
+  int x;
+};
+
+struct __declspec(dllexport) Z { virtual ~Z() {} };
+// The scalar deleting dtor does not get exported:
+// M32-DAG: define linkonce_odr x86_thiscallcc void @"\01??_GZ@@UAEPAXI@Z"
+
+
+// The user-defined dtor does get exported:
+// M32-DAG: define weak_odr dllexport x86_thiscallcc void @"\01??1Z@@UAE@XZ"
+
+namespace DontUseDtorAlias {
+  struct __declspec(dllexport) A { ~A(); };
+  struct __declspec(dllexport) B : A { ~B(); };
+  A::~A() { }
+  B::~B() { }
+  // Emit a real definition of B's constructor; don't alias it to A's.
+  // M32-DAG: define dllexport x86_thiscallcc void @"\01??1B@DontUseDtorAlias@@QAE@XZ"
+}
+
+struct __declspec(dllexport) DefaultedCtorsDtors {
+  DefaultedCtorsDtors() = default;
+  // M32-DAG: define weak_odr dllexport x86_thiscallcc %struct.DefaultedCtorsDtors* @"\01??0DefaultedCtorsDtors@@QAE@XZ"
+  ~DefaultedCtorsDtors() = default;
+  // M32-DAG: define weak_odr dllexport x86_thiscallcc void @"\01??1DefaultedCtorsDtors@@QAE@XZ"
+};