MS ABI: Don't ICE for pointers to pointers to members of incomplete classes

CodeGen would try to come up with an LLVM IR type for a pointer to
member type on the way to forming an LLVM IR type for a pointer to
pointer to member type.

However, if the pointer to member representation has not been locked in yet,
we would not be able to come up with a pointer to member IR type.

In these cases, make the pointer to member type an incomplete type.
This will make the pointer to pointer to member type a pointer to an
incomplete type.  If the class eventually obtains an inheritance model,
we will make the pointer to member type represent the actual inheritance
model.

Differential Revision: http://reviews.llvm.org/D5373

llvm-svn: 218084

5 files changed, 31 insertions, 14 deletions

diff --git a/clang/lib/CodeGen/CGCXXABI.h b/clang/lib/CodeGen/CGCXXABI.h
index b7ce0b07e57..f021e886c02 100644
--- a/clang/lib/CodeGen/CGCXXABI.h
+++ b/clang/lib/CodeGen/CGCXXABI.h
@@ -161,6 +161,10 @@ public:
     return true;
   }
 
+  virtual bool isTypeInfoCalculable(QualType Ty) const {
+    return !Ty->isIncompleteType();
+  }
+
   /// Create a null member pointer of the given type.
   virtual llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT);
 
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index f49e9ec1267..9f359185381 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -79,6 +79,17 @@ CodeGenFunction::~CodeGenFunction() {
   }
 }
 
+LValue CodeGenFunction::MakeNaturalAlignAddrLValue(llvm::Value *V, QualType T) {
+  CharUnits Alignment;
+  if (CGM.getCXXABI().isTypeInfoCalculable(T)) {
+    Alignment = getContext().getTypeAlignInChars(T);
+    unsigned MaxAlign = getContext().getLangOpts().MaxTypeAlign;
+    if (MaxAlign && Alignment.getQuantity() > MaxAlign &&
+        !getContext().isAlignmentRequired(T))
+      Alignment = CharUnits::fromQuantity(MaxAlign);
+  }
+  return LValue::MakeAddr(V, T, Alignment, getContext(), CGM.getTBAAInfo(T));
+}
 
 llvm::Type *CodeGenFunction::ConvertTypeForMem(QualType T) {
   return CGM.getTypes().ConvertTypeForMem(T);
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index b67860cab18..eebdbf34a8e 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -1401,18 +1401,7 @@ public:
                             CGM.getTBAAInfo(T));
   }
 
-  LValue MakeNaturalAlignAddrLValue(llvm::Value *V, QualType T) {
-    CharUnits Alignment;
-    if (!T->isIncompleteType()) {
-      Alignment = getContext().getTypeAlignInChars(T);
-      unsigned MaxAlign = getContext().getLangOpts().MaxTypeAlign;
-      if (MaxAlign && Alignment.getQuantity() > MaxAlign &&
-          !getContext().isAlignmentRequired(T))
-        Alignment = CharUnits::fromQuantity(MaxAlign);
-    }
-    return LValue::MakeAddr(V, T, Alignment, getContext(),
-                            CGM.getTBAAInfo(T));
-  }
+  LValue MakeNaturalAlignAddrLValue(llvm::Value *V, QualType T);
 
   /// CreateTempAlloca - This creates a alloca and inserts it into the entry
   /// block. The caller is responsible for setting an appropriate alignment on
diff --git a/clang/lib/CodeGen/CodeGenTypes.cpp b/clang/lib/CodeGen/CodeGenTypes.cpp
index 1f39eb88c01..1404dfd7a9d 100644
--- a/clang/lib/CodeGen/CodeGenTypes.cpp
+++ b/clang/lib/CodeGen/CodeGenTypes.cpp
@@ -81,7 +81,7 @@ void CodeGenTypes::addRecordTypeName(const RecordDecl *RD,
 /// ConvertType in that it is used to convert to the memory representation for
 /// a type.  For example, the scalar representation for _Bool is i1, but the
 /// memory representation is usually i8 or i32, depending on the target.
-llvm::Type *CodeGenTypes::ConvertTypeForMem(QualType T){
+llvm::Type *CodeGenTypes::ConvertTypeForMem(QualType T) {
   llvm::Type *R = ConvertType(T);
 
   // If this is a non-bool type, don't map it.
@@ -587,6 +587,8 @@ llvm::Type *CodeGenTypes::ConvertType(QualType T) {
   }
 
   case Type::MemberPointer: {
+    if (!getCXXABI().isMemberPointerConvertible(cast<MemberPointerType>(Ty)))
+      return llvm::StructType::create(getLLVMContext());
     ResultType = 
       getCXXABI().ConvertMemberPointerType(cast<MemberPointerType>(Ty));
     break;
diff --git a/clang/lib/CodeGen/MicrosoftCXXABI.cpp b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
index 36392bc5ed0..dd6a4580d49 100644
--- a/clang/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -488,7 +488,18 @@ public:
 
   bool isMemberPointerConvertible(const MemberPointerType *MPT) const override {
     const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
-    return RD->getAttr<MSInheritanceAttr>() != nullptr;
+    return RD->hasAttr<MSInheritanceAttr>();
+  }
+
+  virtual bool isTypeInfoCalculable(QualType Ty) const {
+    if (!CGCXXABI::isTypeInfoCalculable(Ty))
+      return false;
+    if (const auto *MPT = Ty->getAs<MemberPointerType>()) {
+      const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
+      if (!RD->hasAttr<MSInheritanceAttr>())
+        return false;
+    }
+    return true;
   }
 
   llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT) override;