[MS ABI] Error instead of generating bad vftables for certain virtual hierarchies (PR18967)
Erroring out until we fix the bug means we don't have to keep chasing down
this same miscompile in a bunch of different places.
Differential Revision: http://llvm-reviews.chandlerc.com/D2890
llvm-svn: 202331
diff --git a/clang/lib/AST/VTableBuilder.cpp b/clang/lib/AST/VTableBuilder.cpp
index e0e30a1..8efd9c0 100644
--- a/clang/lib/AST/VTableBuilder.cpp
+++ b/clang/lib/AST/VTableBuilder.cpp
@@ -2560,10 +2560,47 @@
const CXXRecordDecl *LastVBase,
BasesSetVectorTy &VisitedBases);
+ void CheckBadVirtualInheritanceHierarchy() {
+ // We fail at this-adjustment for virtual methods inherited from
+ // non-virtual bases that overrides a method in a virtual base.
+ if (Context.getLangOpts().DumpVTableLayouts)
+ return;
+ for (CXXRecordDecl::base_class_const_iterator BI =
+ MostDerivedClass->bases_begin(), BE = MostDerivedClass->bases_end();
+ BI != BE; ++BI) {
+ const CXXRecordDecl *Base = BI->getType()->getAsCXXRecordDecl();
+ if (BI->isVirtual())
+ continue;
+ for (CXXRecordDecl::method_iterator I = Base->method_begin(),
+ E = Base->method_end(); I != E; ++I) {
+ const CXXMethodDecl *Method = *I;
+ if (!Method->isVirtual())
+ continue;
+ if (isa<CXXDestructorDecl>(Method))
+ continue;
+ OverriddenMethodsSetTy OverriddenMethods;
+ ComputeAllOverriddenMethods(Method, OverriddenMethods);
+ for (OverriddenMethodsSetTy::const_iterator I =
+ OverriddenMethods.begin(),
+ E = OverriddenMethods.end(); I != E; ++I) {
+ const CXXMethodDecl *Overridden = *I;
+ if (Base->isVirtuallyDerivedFrom(Overridden->getParent())) {
+ ErrorUnsupported("classes with non-virtual base "
+ "classes that override methods in virtual bases",
+ BI->getLocStart());
+ return;
+ }
+ }
+ }
+ }
+ }
+
void LayoutVFTable() {
// FIXME: add support for RTTI when we have proper LLVM support for symbols
// pointing to the middle of a section.
+ CheckBadVirtualInheritanceHierarchy();
+
BasesSetVectorTy VisitedBases;
AddMethods(BaseSubobject(MostDerivedClass, CharUnits::Zero()), 0, 0,
VisitedBases);