Revert r69771, I missed some (obvious) details. :/

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69773 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 49 insertions, 16 deletions

diff --git a/lib/CodeGen/CGObjCMac.cpp b/lib/CodeGen/CGObjCMac.cpp
index c62a9055dc..e0f4492513 100644
--- a/lib/CodeGen/CGObjCMac.cpp
+++ b/lib/CodeGen/CGObjCMac.cpp
@@ -4220,29 +4220,62 @@ llvm::GlobalVariable * CGObjCNonFragileABIMac::BuildClassMetaData(
   return GV;
 }
 
+/// countInheritedIvars - count number of ivars in class and its super class(s)
+///
+static int countInheritedIvars(const ObjCInterfaceDecl *OI, 
+                               ASTContext &Context) {
+  int count = 0;
+  if (!OI)
+    return 0;
+  const ObjCInterfaceDecl *SuperClass = OI->getSuperClass();
+  if (SuperClass)
+    count += countInheritedIvars(SuperClass, Context);
+  for (ObjCInterfaceDecl::ivar_iterator I = OI->ivar_begin(),
+       E = OI->ivar_end(); I != E; ++I)
+    ++count;
+  // look into properties.
+  for (ObjCInterfaceDecl::prop_iterator I = OI->prop_begin(Context),
+       E = OI->prop_end(Context); I != E; ++I) {
+    if ((*I)->getPropertyIvarDecl())
+      ++count;
+  }
+  return count;
+}
+
 void CGObjCNonFragileABIMac::GetClassSizeInfo(const ObjCInterfaceDecl *OID,
                                               uint32_t &InstanceStart,
                                               uint32_t &InstanceSize) {
   assert(!OID->isForwardDecl() && "Invalid interface decl!");
   const llvm::StructLayout *Layout = GetInterfaceDeclStructLayout(OID);
     
+  int countSuperClassIvars = countInheritedIvars(OID->getSuperClass(),
+                                                 CGM.getContext());
   const RecordDecl *RD = CGM.getContext().addRecordToClass(OID);
-  
-  // Field 0 is always the superclass record (which may be empty).
-  RecordDecl::field_iterator fi = RD->field_begin(CGM.getContext());
-  RecordDecl::field_iterator fe = RD->field_end(CGM.getContext());
-  assert(fi != fe && "class record should never be empty!");
-
-  InstanceStart = CGM.getContext().getTypeSize((*fi)->getType()) / 8;
-
-  // We report the size of the instance as the offset following the
-  // last ivar (which is, of course, not the actual size).
-  std::advance(fi, std::distance(fi, fe) - 1);
-  const FieldDecl *LastField = *fi;
-  uint64_t Offset = GetIvarBaseOffset(Layout, LastField);
-  // Add size of type (rounded to next byte).
-  InstanceSize = (Offset + 
-                  (CGM.getContext().getTypeSize(LastField->getType()) + 7) / 8);
+  RecordDecl::field_iterator firstField = RD->field_begin(CGM.getContext());
+  RecordDecl::field_iterator lastField = RD->field_end(CGM.getContext());
+  while (countSuperClassIvars-- > 0) {
+    lastField = firstField;
+    ++firstField;
+  }
+    
+  for (RecordDecl::field_iterator e = RD->field_end(CGM.getContext()),
+         ifield = firstField; ifield != e; ++ifield)
+    lastField = ifield;
+    
+  InstanceStart = InstanceSize = 0;
+  if (lastField != RD->field_end(CGM.getContext())) {
+    FieldDecl *Field = *lastField;
+    const llvm::Type *FieldTy =
+      CGM.getTypes().ConvertTypeForMem(Field->getType());
+    unsigned Size = CGM.getTargetData().getTypePaddedSize(FieldTy);
+    InstanceSize = GetIvarBaseOffset(Layout, Field) + Size;
+    if (firstField == RD->field_end(CGM.getContext()))
+      InstanceStart = InstanceSize;
+    else {
+      Field = *firstField;
+      InstanceStart =  GetIvarBaseOffset(Layout, Field);
+    }
+  }
 }
 
 void CGObjCNonFragileABIMac::GenerateClass(const ObjCImplementationDecl *ID) {