MS ABI: Update the thunk linkage computation
As suggested by Reid:
- class has GVA_Internal linkage -> internal
- thunk has return adjustment -> weak_odr, to handle evil corner case [1]
- all other normal methods -> linkonce_odr
1. Evil corner case:
struct Incomplete;
struct A { int a; virtual A *bar(); };
struct B { int b; virtual B *foo(Incomplete); };
struct C : A, B { int c; virtual C *foo(Incomplete); };
C c;
Here, the thunk for C::foo() will be emitted when C::foo() is defined, which
might be in a different translation unit, so it needs to be weak_odr.
Differential Revision: http://reviews.llvm.org/D3992
llvm-svn: 210368
diff --git a/clang/test/CodeGenCXX/microsoft-abi-thunks.cpp b/clang/test/CodeGenCXX/microsoft-abi-thunks.cpp
index 2be642c..c755b30 100644
--- a/clang/test/CodeGenCXX/microsoft-abi-thunks.cpp
+++ b/clang/test/CodeGenCXX/microsoft-abi-thunks.cpp
@@ -61,13 +61,13 @@
C::C() {} // Emits vftable and forces thunk generation.
-// CODEGEN-LABEL: define weak x86_thiscallcc void @"\01??_EC@@W3AEPAXI@Z"(%struct.C* %this, i32 %should_call_delete)
+// CODEGEN-LABEL: define linkonce_odr x86_thiscallcc void @"\01??_EC@@W3AEPAXI@Z"(%struct.C* %this, i32 %should_call_delete)
// CODEGEN: getelementptr i8* {{.*}}, i32 -4
// FIXME: should actually call _EC, not _GC.
// CODEGEN: call x86_thiscallcc void @"\01??_GC@@UAEPAXI@Z"
// CODEGEN: ret
-// CODEGEN-LABEL: define weak x86_thiscallcc void @"\01?public_f@C@@W3AEXXZ"(%struct.C*
+// CODEGEN-LABEL: define linkonce_odr x86_thiscallcc void @"\01?public_f@C@@W3AEXXZ"(%struct.C*
// CODEGEN: getelementptr i8* {{.*}}, i32 -4
// CODEGEN: call x86_thiscallcc void @"\01?public_f@C@@UAEXXZ"(%struct.C*
// CODEGEN: ret
@@ -91,7 +91,7 @@
E::E() {} // Emits vftable and forces thunk generation.
-// CODEGEN-LABEL: define weak x86_thiscallcc %struct.C* @"\01?goo@E@@QAEPAUB@@XZ"
+// CODEGEN-LABEL: define weak_odr x86_thiscallcc %struct.C* @"\01?goo@E@@QAEPAUB@@XZ"
// CODEGEN: call x86_thiscallcc %struct.C* @"\01?goo@E@@UAEPAUC@@XZ"
// CODEGEN: getelementptr inbounds i8* {{.*}}, i32 4
// CODEGEN: ret
@@ -124,7 +124,7 @@
I::I() {} // Emits vftable and forces thunk generation.
-// CODEGEN-LABEL: define weak x86_thiscallcc %struct.{{[BF]}}* @"\01?goo@I@@QAEPAUB@@XZ"
+// CODEGEN-LABEL: define weak_odr x86_thiscallcc %struct.{{[BF]}}* @"\01?goo@I@@QAEPAUB@@XZ"
// CODEGEN: %[[ORIG_RET:.*]] = call x86_thiscallcc %struct.F* @"\01?goo@I@@UAEPAUF@@XZ"
// CODEGEN: %[[ORIG_RET_i8:.*]] = bitcast %struct.F* %[[ORIG_RET]] to i8*
// CODEGEN: %[[VBPTR_i8:.*]] = getelementptr inbounds i8* %[[ORIG_RET_i8]], i32 4
@@ -152,3 +152,14 @@
};
C c;
}
+
+namespace {
+struct E : D {
+ E();
+ virtual C* goo();
+};
+E::E() {}
+E e;
+// Class with internal linkage has internal linkage thunks.
+// CODEGEN: define internal x86_thiscallcc %struct.C* @"\01?goo@E@?A@@QAEPAUB@@XZ"
+}