Reland 192220 "Abstract out parts of thunk emission code, add support for simple thunks when using -cxx-abi microsoft" with relaxed assertions

llvm-svn: 192285
diff --git a/clang/test/CodeGenCXX/microsoft-abi-thunks.cpp b/clang/test/CodeGenCXX/microsoft-abi-thunks.cpp
new file mode 100644
index 0000000..091ef32
--- /dev/null
+++ b/clang/test/CodeGenCXX/microsoft-abi-thunks.cpp
@@ -0,0 +1,118 @@
+// RUN: %clang_cc1 -fno-rtti -emit-llvm %s -o - -cxx-abi microsoft -triple=i386-pc-win32 >%t 2>&1
+// RUN: FileCheck --check-prefix=MANGLING %s < %t
+// RUN: FileCheck --check-prefix=XMANGLING %s < %t
+// RUN: FileCheck --check-prefix=CODEGEN %s < %t
+// RUN: %clang_cc1 -fno-rtti -emit-llvm %s -o - -cxx-abi microsoft -triple=x86_64-pc-win32 2>&1 | FileCheck --check-prefix=MANGLING-X64 %s
+
+void foo(void *);
+
+struct A {
+  virtual ~A();
+  virtual void public_f();
+  // Make sure we don't emit unneeded thunks:
+  // XMANGLING-NOT: @"\01?public_f@A@@QAEXXZ"
+ protected:
+  virtual void protected_f();
+ private:
+  virtual void private_f();
+};
+
+struct B {
+  virtual ~B();
+  virtual void public_f();
+ protected:
+  virtual void protected_f();
+ private:
+  virtual void private_f();
+};
+
+
+struct C : A, B {
+  C();
+
+  virtual ~C();
+  // MANGLING-DAG: @"\01??1C@@UAE@XZ"
+  // MANGLING-DAG: @"\01??_GC@@UAEPAXI@Z"
+  // MANGLING-DAG: @"\01??_EC@@W3AEPAXI@Z"
+  // MANGLING-X64-DAG: @"\01??1C@@UEAA@XZ"
+  // MANGLING-X64-DAG: @"\01??_GC@@UEAAPEAXI@Z"
+  // MANGLING-X64-DAG: @"\01??_EC@@W7EAAPEAXI@Z"
+
+  // Overrides public_f() of two subobjects with distinct vfptrs, thus needs a thunk.
+  virtual void public_f();
+  // MANGLING-DAG: @"\01?public_f@C@@UAEXXZ"
+  // MANGLING-DAG: @"\01?public_f@C@@W3AEXXZ"
+  // MANGLING-X64-DAG: @"\01?public_f@C@@UEAAXXZ"
+  // MANGLING-X64-DAG: @"\01?public_f@C@@W7EAAXXZ"
+ protected:
+  virtual void protected_f();
+  // MANGLING-DAG: @"\01?protected_f@C@@MAEXXZ"
+  // MANGLING-DAG: @"\01?protected_f@C@@O3AEXXZ"
+  // MANGLING-X64-DAG: @"\01?protected_f@C@@MEAAXXZ"
+  // MANGLING-X64-DAG: @"\01?protected_f@C@@O7EAAXXZ"
+
+ private:
+  virtual void private_f();
+  // MANGLING-DAG: @"\01?private_f@C@@EAEXXZ"
+  // MANGLING-DAG: @"\01?private_f@C@@G3AEXXZ"
+  // MANGLING-X64-DAG: @"\01?private_f@C@@EEAAXXZ"
+  // MANGLING-X64-DAG: @"\01?private_f@C@@G7EAAXXZ"
+};
+
+C::C() {}  // Emits vftable and forces thunk generation.
+
+// CODEGEN: define weak x86_thiscallcc void @"\01??_EC@@W3AEPAXI@Z"(%struct.C* %this, i32 %should_call_delete)
+// CODEGEN:   getelementptr inbounds i8* {{.*}}, i64 -4
+// FIXME: should actually call _EC, not _GC.
+// CODEGEN:   call x86_thiscallcc void @"\01??_GC@@UAEPAXI@Z"
+// CODEGEN: ret
+
+// CODEGEN: define weak x86_thiscallcc void @"\01?public_f@C@@W3AEXXZ"(%struct.C*
+// CODEGEN:   getelementptr inbounds i8* {{.*}}, i64 -4
+// CODEGEN:   call x86_thiscallcc void @"\01?public_f@C@@UAEXXZ"(%struct.C*
+// CODEGEN: ret
+
+void zoo(C* obj) {
+  delete obj;
+}
+
+struct D {
+  virtual B* goo();
+};
+
+struct E : D {
+  virtual C* goo();
+  // MANGLING-DAG: @"\01?goo@E@@UAEPAUC@@XZ"
+  // MANGLING-DAG: @"\01?goo@E@@QAEPAUB@@XZ"
+  // MANGLING-X64-DAG: @"\01?goo@E@@UEAAPEAUC@@XZ"
+  // MANGLING-X64-DAG: @"\01?goo@E@@QEAAPEAUB@@XZ"
+};
+
+E e;  // Emits vftable and forces thunk generation.
+
+// CODEGEN: define weak x86_thiscallcc %struct.C* @"\01?goo@E@@QAEPAUB@@XZ"
+// CODEGEN:   call x86_thiscallcc %struct.C* @"\01?goo@E@@UAEPAUC@@XZ"
+// CODEGEN:   getelementptr inbounds i8* {{.*}}, i64 4
+// CODEGEN: ret
+
+struct F : virtual A, virtual B {
+  virtual ~F();
+};
+
+F f;  // Just make sure we don't crash, e.g. mangling the complete dtor.
+
+struct G : C { };
+
+struct H : E {
+  virtual G* goo();
+  // MANGLING-DAG: @"\01?goo@H@@UAEPAUG@@XZ"
+  // MANGLING-DAG: @"\01?goo@H@@QAEPAUB@@XZ"
+  // MANGLING-DAG: @"\01?goo@H@@QAEPAUC@@XZ"
+  // MANGLING-X64-DAG: @"\01?goo@H@@UEAAPEAUG@@XZ"
+  // MANGLING-X64-DAG: @"\01?goo@H@@QEAAPEAUB@@XZ"
+  // MANGLING-X64-DAG: @"\01?goo@H@@QEAAPEAUC@@XZ"
+};
+
+H h;
+
+// FIXME: Write vtordisp adjusting thunk tests