Add CodeGenModule::ComputeThunkAdjustment, which Eli wrote.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@90401 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGClass.cpp b/lib/CodeGen/CGClass.cpp
index b3c2b98..fd2afe7 100644
--- a/lib/CodeGen/CGClass.cpp
+++ b/lib/CodeGen/CGClass.cpp
@@ -112,6 +112,42 @@
return NonVirtualOffset;
}
+// FIXME: This probably belongs in CGVtable, but it relies on
+// the static function ComputeNonVirtualBaseClassOffset, so we should make that
+// a CodeGenModule member function as well.
+ThunkAdjustment
+CodeGenModule::ComputeThunkAdjustment(const CXXRecordDecl *ClassDecl,
+ const CXXRecordDecl *BaseClassDecl) {
+ CXXBasePaths Paths(/*FindAmbiguities=*/false,
+ /*RecordPaths=*/true, /*DetectVirtual=*/false);
+ if (!const_cast<CXXRecordDecl *>(ClassDecl)->
+ isDerivedFrom(const_cast<CXXRecordDecl *>(BaseClassDecl), Paths)) {
+ assert(false && "Class must be derived from the passed in base class!");
+ return ThunkAdjustment();
+ }
+
+ unsigned Start = 0;
+ uint64_t VirtualOffset = 0;
+
+ const CXXBasePath &Path = Paths.front();
+ const CXXRecordDecl *VBase = 0;
+ for (unsigned i = 0, e = Path.size(); i != e; ++i) {
+ const CXXBasePathElement& Element = Path[i];
+ if (Element.Base->isVirtual()) {
+ Start = i+1;
+ QualType VBaseType = Element.Base->getType();
+ VBase = cast<CXXRecordDecl>(VBaseType->getAs<RecordType>()->getDecl());
+ }
+ }
+ if (VBase)
+ VirtualOffset =
+ getVtableInfo().getVirtualBaseOffsetIndex(ClassDecl, BaseClassDecl);
+
+ uint64_t Offset =
+ ComputeNonVirtualBaseClassOffset(getContext(), Paths, Start);
+ return ThunkAdjustment(Offset, VirtualOffset);
+}
+
llvm::Value *
CodeGenFunction::GetAddressOfBaseClass(llvm::Value *Value,
const CXXRecordDecl *ClassDecl,
diff --git a/lib/CodeGen/CodeGenModule.h b/lib/CodeGen/CodeGenModule.h
index e5bd3e2..9746570 100644
--- a/lib/CodeGen/CodeGenModule.h
+++ b/lib/CodeGen/CodeGenModule.h
@@ -232,7 +232,7 @@
/// GenerateRTTINonClass - Generate the rtti information for the given
/// non-class type.
llvm::Constant *GenerateRTTI(QualType Ty);
-
+
/// BuildThunk - Build a thunk for the given method.
llvm::Constant *BuildThunk(const CXXMethodDecl *MD, bool Extern,
const ThunkAdjustment &ThisAdjustment);
@@ -252,6 +252,11 @@
llvm::Constant *GetCXXBaseClassOffset(const CXXRecordDecl *ClassDecl,
const CXXRecordDecl *BaseClassDecl);
+ /// ComputeThunkAdjustment - Returns the two parts required to compute the
+ /// offset for an object.
+ ThunkAdjustment ComputeThunkAdjustment(const CXXRecordDecl *ClassDecl,
+ const CXXRecordDecl *BaseClassDecl);
+
/// GetStringForStringLiteral - Return the appropriate bytes for a string
/// literal, properly padded to match the literal type. If only the address of
/// a constant is needed consider using GetAddrOfConstantStringLiteral.