[MS ABI] Initialize "most general" member pointers which don't point at a vbase

The most general model has fields for the vbptr offset and the vbindex.
Don't initialize the vbptr offset if the vbindex is 0: we aren't
referencing an entity from a vbase.

Getting this wrong can make member pointer equality fail.

llvm-svn: 240043

diff --git a/clang/lib/CodeGen/MicrosoftCXXABI.cpp b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
index e19ad69..36d6953 100644 (file)
--- a/clang/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -2351,7 +2351,7 @@ MicrosoftCXXABI::EmitFullMemberPointer(llvm::Constant *FirstField,
 
   if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance)) {
     CharUnits Offs = CharUnits::Zero();
-    if (RD->getNumVBases())
+    if (VBTableIndex && RD->getNumVBases())
       Offs = getContext().getASTRecordLayout(RD).getVBPtrOffset();
     fields.push_back(llvm::ConstantInt::get(CGM.IntTy, Offs.getQuantity()));
   }

diff --git a/clang/test/CodeGenCXX/microsoft-abi-member-pointers.cpp b/clang/test/CodeGenCXX/microsoft-abi-member-pointers.cpp
index cf9da81..9525ffd 100644 (file)
--- a/clang/test/CodeGenCXX/microsoft-abi-member-pointers.cpp
+++ b/clang/test/CodeGenCXX/microsoft-abi-member-pointers.cpp
@@ -119,7 +119,7 @@ void (UnspecSingle::*us_f_mp)() = &UnspecSingle::foo;
 // CHECK: @"\01?v_f_mp@Const@@3P8Virtual@@AEXXZQ2@" =
 // CHECK:   global { i8*, i32, i32 } { i8* bitcast ({{.*}} @"\01?foo@Virtual@@QAEXXZ" to i8*), i32 0, i32 0 }, align 4
 // CHECK: @"\01?u_f_mp@Const@@3P8Unspecified@@AEXXZQ2@" =
-// CHECK:   global { i8*, i32, i32, i32 } { i8* bitcast ({{.*}} @"\01?foo@Unspecified@@QAEXXZ" to i8*), i32 0, i32 12, i32 0 }, align 4
+// CHECK:   global { i8*, i32, i32, i32 } { i8* bitcast ({{.*}} @"\01?foo@Unspecified@@QAEXXZ" to i8*), i32 0, i32 0, i32 0 }, align 4
 // CHECK: @"\01?us_f_mp@Const@@3P8UnspecSingle@@AEXXZQ2@" =
 // CHECK:   global { i8*, i32, i32, i32 } { i8* bitcast ({{.*}} @"\01?foo@UnspecSingle@@QAEXXZ" to i8*), i32 0, i32 0, i32 0 }, align 4
 }