Revert "Revert r199416, "MS ABI: Improve selection of an inheritance model""

This reverts commit r199475 (which reverted r199416) with fixes for the
breakages.

We wouldn't lock an inheritance model if we saw a pointer-to-member
formed as a result of the address-of operator.

llvm-svn: 199482

1 files changed, 50 insertions, 39 deletions

diff --git a/clang/lib/CodeGen/MicrosoftCXXABI.cpp b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
index 32f8ab2fb5d..875591d0df9 100644
--- a/clang/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -1322,25 +1322,29 @@ void MicrosoftCXXABI::EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
 }
 
 // Member pointer helpers.
-static bool hasVBPtrOffsetField(MSInheritanceModel Inheritance) {
-  return Inheritance == MSIM_Unspecified;
+static bool hasVBPtrOffsetField(MSInheritanceAttr::Spelling Inheritance) {
+  return Inheritance == MSInheritanceAttr::Keyword_unspecified_inheritance;
 }
 
 static bool hasOnlyOneField(bool IsMemberFunction,
-                            MSInheritanceModel Inheritance) {
-  return Inheritance <= MSIM_SinglePolymorphic ||
-      (!IsMemberFunction && Inheritance <= MSIM_MultiplePolymorphic);
+                            MSInheritanceAttr::Spelling Inheritance) {
+  if (IsMemberFunction)
+    return Inheritance <= MSInheritanceAttr::Keyword_single_inheritance;
+  return Inheritance <= MSInheritanceAttr::Keyword_multiple_inheritance;
 }
 
 // Only member pointers to functions need a this adjustment, since it can be
 // combined with the field offset for data pointers.
-static bool hasNonVirtualBaseAdjustmentField(bool IsMemberFunction,
-                                             MSInheritanceModel Inheritance) {
-  return (IsMemberFunction && Inheritance >= MSIM_Multiple);
+static bool
+hasNonVirtualBaseAdjustmentField(bool IsMemberFunction,
+                                 MSInheritanceAttr::Spelling Inheritance) {
+  return IsMemberFunction &&
+         Inheritance >= MSInheritanceAttr::Keyword_multiple_inheritance;
 }
 
-static bool hasVirtualBaseAdjustmentField(MSInheritanceModel Inheritance) {
-  return Inheritance >= MSIM_Virtual;
+static bool
+hasVirtualBaseAdjustmentField(MSInheritanceAttr::Spelling Inheritance) {
+  return Inheritance >= MSInheritanceAttr::Keyword_virtual_inheritance;
 }
 
 // Use zero for the field offset of a null data member pointer if we can
@@ -1349,8 +1353,10 @@ static bool hasVirtualBaseAdjustmentField(MSInheritanceModel Inheritance) {
 // use zero for null.  If there are multiple fields, we can use zero even if it
 // is a valid field offset because null-ness testing will check the other
 // fields.
-static bool nullFieldOffsetIsZero(MSInheritanceModel Inheritance) {
-  return Inheritance != MSIM_Multiple && Inheritance != MSIM_Single;
+static bool nullFieldOffsetIsZero(const CXXRecordDecl *RD) {
+  return RD->getMSInheritanceModel() >=
+             MSInheritanceAttr::Keyword_virtual_inheritance ||
+         (RD->hasDefinition() && RD->isPolymorphic());
 }
 
 bool MicrosoftCXXABI::isZeroInitializable(const MemberPointerType *MPT) {
@@ -1362,16 +1368,16 @@ bool MicrosoftCXXABI::isZeroInitializable(const MemberPointerType *MPT) {
   // The virtual base adjustment field is always -1 for null, so if we have one
   // we can't zero initialize.  The field offset is sometimes also -1 if 0 is a
   // valid field offset.
-  const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl();
-  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
+  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
+  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
   return (!hasVirtualBaseAdjustmentField(Inheritance) &&
-          nullFieldOffsetIsZero(Inheritance));
+          nullFieldOffsetIsZero(RD));
 }
 
 llvm::Type *
 MicrosoftCXXABI::ConvertMemberPointerType(const MemberPointerType *MPT) {
-  const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl();
-  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
+  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
+  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
   llvm::SmallVector<llvm::Type *, 4> fields;
   if (MPT->isMemberFunctionPointer())
     fields.push_back(CGM.VoidPtrTy);  // FunctionPointerOrVirtualThunk
@@ -1395,13 +1401,13 @@ void MicrosoftCXXABI::
 GetNullMemberPointerFields(const MemberPointerType *MPT,
                            llvm::SmallVectorImpl<llvm::Constant *> &fields) {
   assert(fields.empty());
-  const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl();
-  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
+  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
+  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
   if (MPT->isMemberFunctionPointer()) {
     // FunctionPointerOrVirtualThunk
     fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy));
   } else {
-    if (nullFieldOffsetIsZero(Inheritance))
+    if (nullFieldOffsetIsZero(RD))
       fields.push_back(getZeroInt());  // FieldOffset
     else
       fields.push_back(getAllOnesInt());  // FieldOffset
@@ -1433,7 +1439,7 @@ MicrosoftCXXABI::EmitFullMemberPointer(llvm::Constant *FirstField,
                                        const CXXRecordDecl *RD,
                                        CharUnits NonVirtualBaseAdjustment)
 {
-  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
+  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
 
   // Single inheritance class member pointer are represented as scalars instead
   // of aggregates.
@@ -1464,7 +1470,7 @@ MicrosoftCXXABI::EmitFullMemberPointer(llvm::Constant *FirstField,
 llvm::Constant *
 MicrosoftCXXABI::EmitMemberDataPointer(const MemberPointerType *MPT,
                                        CharUnits offset) {
-  const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl();
+  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
   llvm::Constant *FirstField =
     llvm::ConstantInt::get(CGM.IntTy, offset.getQuantity());
   return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/false, RD,
@@ -1487,8 +1493,8 @@ llvm::Constant *MicrosoftCXXABI::EmitMemberPointer(const APValue &MP,
   // FIXME PR15713: Support virtual inheritance paths.
 
   if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MPD))
-    return BuildMemberPointer(MPT->getClass()->getAsCXXRecordDecl(),
-                              MD, ThisAdjustment);
+    return BuildMemberPointer(MPT->getMostRecentCXXRecordDecl(), MD,
+                              ThisAdjustment);
 
   CharUnits FieldOffset =
     getContext().toCharUnitsFromBits(getContext().getFieldOffset(MPD));
@@ -1501,6 +1507,7 @@ MicrosoftCXXABI::BuildMemberPointer(const CXXRecordDecl *RD,
                                     CharUnits NonVirtualBaseAdjustment) {
   assert(MD->isInstance() && "Member function must not be static!");
   MD = MD->getCanonicalDecl();
+  RD = RD->getMostRecentDecl();
   CodeGenTypes &Types = CGM.getTypes();
 
   llvm::Constant *FirstField;
@@ -1578,8 +1585,8 @@ MicrosoftCXXABI::EmitMemberPointerComparison(CodeGenFunction &CGF,
 
   // If this is a single field member pointer (single inheritance), this is a
   // single icmp.
-  const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl();
-  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
+  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
+  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
   if (hasOnlyOneField(MPT->isMemberFunctionPointer(), Inheritance))
     return Builder.CreateICmp(Eq, L, R);
 
@@ -1760,8 +1767,8 @@ MicrosoftCXXABI::EmitMemberDataPointerAddress(CodeGenFunction &CGF,
   llvm::Type *PType =
       CGF.ConvertTypeForMem(MPT->getPointeeType())->getPointerTo(AS);
   CGBuilderTy &Builder = CGF.Builder;
-  const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl();
-  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
+  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
+  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
 
   // Extract the fields we need, regardless of model.  We'll apply them if we
   // have them.
@@ -1795,9 +1802,9 @@ MicrosoftCXXABI::EmitMemberDataPointerAddress(CodeGenFunction &CGF,
   return Builder.CreateBitCast(Addr, PType);
 }
 
-static MSInheritanceModel
+static MSInheritanceAttr::Spelling
 getInheritanceFromMemptr(const MemberPointerType *MPT) {
-  return MPT->getClass()->getAsCXXRecordDecl()->getMSInheritanceModel();
+  return MPT->getMostRecentCXXRecordDecl()->getMSInheritanceModel();
 }
 
 llvm::Value *
@@ -1817,15 +1824,17 @@ MicrosoftCXXABI::EmitMemberPointerConversion(CodeGenFunction &CGF,
   const MemberPointerType *SrcTy =
     E->getSubExpr()->getType()->castAs<MemberPointerType>();
   const MemberPointerType *DstTy = E->getType()->castAs<MemberPointerType>();
-  MSInheritanceModel SrcInheritance = getInheritanceFromMemptr(SrcTy);
-  MSInheritanceModel DstInheritance = getInheritanceFromMemptr(DstTy);
   bool IsFunc = SrcTy->isMemberFunctionPointer();
 
   // If the classes use the same null representation, reinterpret_cast is a nop.
   bool IsReinterpret = E->getCastKind() == CK_ReinterpretMemberPointer;
-  if (IsReinterpret && (IsFunc ||
-                        nullFieldOffsetIsZero(SrcInheritance) ==
-                        nullFieldOffsetIsZero(DstInheritance)))
+  if (IsReinterpret && IsFunc)
+    return Src;
+
+  CXXRecordDecl *SrcRD = SrcTy->getMostRecentCXXRecordDecl();
+  CXXRecordDecl *DstRD = DstTy->getMostRecentCXXRecordDecl();
+  if (IsReinterpret &&
+      nullFieldOffsetIsZero(SrcRD) == nullFieldOffsetIsZero(DstRD))
     return Src;
 
   CGBuilderTy &Builder = CGF.Builder;
@@ -1854,6 +1863,7 @@ MicrosoftCXXABI::EmitMemberPointerConversion(CodeGenFunction &CGF,
   llvm::Value *NonVirtualBaseAdjustment = 0;
   llvm::Value *VirtualBaseAdjustmentOffset = 0;
   llvm::Value *VBPtrOffset = 0;
+  MSInheritanceAttr::Spelling SrcInheritance = SrcRD->getMSInheritanceModel();
   if (!hasOnlyOneField(IsFunc, SrcInheritance)) {
     // We need to extract values.
     unsigned I = 0;
@@ -1884,6 +1894,7 @@ MicrosoftCXXABI::EmitMemberPointerConversion(CodeGenFunction &CGF,
   // FIXME PR15713: Support conversions through virtually derived classes.
 
   // Recompose dst from the null struct and the adjusted fields from src.
+  MSInheritanceAttr::Spelling DstInheritance = DstRD->getMSInheritanceModel();
   llvm::Value *Dst;
   if (hasOnlyOneField(IsFunc, DstInheritance)) {
     Dst = FirstField;
@@ -1929,8 +1940,8 @@ MicrosoftCXXABI::EmitMemberPointerConversion(const CastExpr *E,
   if (E->getCastKind() == CK_ReinterpretMemberPointer)
     return Src;
 
-  MSInheritanceModel SrcInheritance = getInheritanceFromMemptr(SrcTy);
-  MSInheritanceModel DstInheritance = getInheritanceFromMemptr(DstTy);
+  MSInheritanceAttr::Spelling SrcInheritance = getInheritanceFromMemptr(SrcTy);
+  MSInheritanceAttr::Spelling DstInheritance = getInheritanceFromMemptr(DstTy);
 
   // Decompose src.
   llvm::Constant *FirstField = Src;
@@ -1991,13 +2002,13 @@ MicrosoftCXXABI::EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF,
   assert(MPT->isMemberFunctionPointer());
   const FunctionProtoType *FPT =
     MPT->getPointeeType()->castAs<FunctionProtoType>();
-  const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl();
+  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
   llvm::FunctionType *FTy =
     CGM.getTypes().GetFunctionType(
       CGM.getTypes().arrangeCXXMethodType(RD, FPT));
   CGBuilderTy &Builder = CGF.Builder;
 
-  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
+  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
 
   // Extract the fields we need, regardless of model.  We'll apply them if we
   // have them.