compile-time crash with virtual inheritance

[ramosian-glider]

Originally reported on Google Code with ID 3

LLVM r159521

% cat tsan-bug.cc 
struct AAA              {  virtual long aaa (); };
struct BBB: virtual AAA { unsigned long bbb; };
struct CCC: virtual AAA { };
struct DDD: CCC, BBB { DDD (); };
DDD::DDD()  { }


% clang -O2 -c -fthread-sanitizer tsan-bug.cc 
clang: /home/kcc/llvm/lib/VMCore/Constants.cpp:1366: static llvm::Constant *llvm::ConstantExpr::getCast(unsigned
int, llvm::Constant *, llvm::Type *): Assertion `CastInst::castIsValid(opc, C, Ty)
&& "Invalid constantexpr cast!"' failed.


The assertion happens here: 

bool ThreadSanitizer::instrumentLoadOrStore(Instruction *I) {                     


...
  if (IsWrite && isVtableAccess(I)) {                                             


    Value *StoredValue = cast<StoreInst>(I)->getValueOperand();                   


    IRB.CreateCall2(TsanVptrUpdate,                                               


                    IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()),              


                    IRB.CreatePointerCast(StoredValue, IRB.getInt8PtrTy())); <<<<<<<<<<<<<<<<

The IR looks like this: 
  store i64 ptrtoint (i8** getelementptr inbounds ([9 x i8*]* @_ZTC3DDD8_3BBB, i64
0, i64 8) to i64), i64* %add.ptr.i, align 8, !tbaa !0

!0 = metadata !{metadata !"vtable pointer", metadata !1}


So, we have a store which is marked as "vtable pointer" but which is actually not a
pointer store.

Investigating. 

Reported by konstantin.s.serebryany on 2012-07-04 12:23:03

[ramosian-glider]

fixed by LLVM r159736.

Reported by konstantin.s.serebryany on 2012-07-05 09:11:04

• Status changed: Fixed

[ramosian-glider]

Adding Project:ThreadSanitizer as part of GitHub migration.

Reported by glider@google.com on 2015-07-30 09:21:29

• Labels added: ProjectThreadSanitizer