Implement IsOverriderUsed. This can't be tested yet due to some other bugs :)
llvm-svn: 96897
diff --git a/clang/lib/CodeGen/CGVtable.cpp b/clang/lib/CodeGen/CGVtable.cpp
index 5ef44f1..93ed111 100644
--- a/clang/lib/CodeGen/CGVtable.cpp
+++ b/clang/lib/CodeGen/CGVtable.cpp
@@ -1288,9 +1288,54 @@
// If the base and the first base in the primary base chain have the same
// offsets, then this overrider will be used.
if (Base.getBaseOffset() == FirstBaseInPrimaryBaseChain.getBaseOffset())
+ return true;
+
+ // We know now that Base (or a direct or indirect base of it) is a primary
+ // base in part of the class hierarchy, but not a primary base in the most
+ // derived class.
+
+ // If the overrider is the first base in the primary base chain, we know
+ // that the overrider will be used.
+ if (Overrider.Method->getParent() == FirstBaseInPrimaryBaseChain.getBase())
return true;
- return true;
+ VtableBuilder::PrimaryBasesSetTy PrimaryBases;
+
+ const CXXRecordDecl *RD = FirstBaseInPrimaryBaseChain.getBase();
+ PrimaryBases.insert(RD);
+
+ // Now traverse the base chain, starting with the first base, until we find
+ // the base that is no longer a primary base.
+ while (true) {
+ const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
+ const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase();
+
+ if (!PrimaryBase)
+ break;
+
+ if (Layout.getPrimaryBaseWasVirtual()) {
+ assert(Layout.getVBaseClassOffset(PrimaryBase) == 0 &&
+ "Primary base should always be at offset 0!");
+
+ const ASTRecordLayout &MostDerivedClassLayout =
+ Context.getASTRecordLayout(MostDerivedClass);
+
+ // Now check if this is the primary base that is not a primary base in the
+ // most derived class.
+ if (MostDerivedClassLayout.getVBaseClassOffset(PrimaryBase) !=
+ FirstBaseInPrimaryBaseChain.getBaseOffset()) {
+ // We found it, stop walking the chain.
+ break;
+ }
+ } else {
+ assert(Layout.getBaseClassOffset(PrimaryBase) == 0 &&
+ "Primary base should always be at offset 0!");
+ }
+ }
+
+ // If the final overrider is an override of one of the primary bases,
+ // then we know that it will be used.
+ return OverridesMethodInPrimaryBase(Overrider.Method, PrimaryBases);
}
void