Revert "Verifier: Check for incompatible bit piece expressions"

This reverts commit r234698.

This caused a use-after-free: `QueuedBitPieceExpressions` holds onto
references to `DbgInfoIntrinsic`s and references them past where they're
deleted (this is because the verifier is run as a function pass, and
then `verifyTypeRefs()` is called during `doFinalization()`).

I'll include a reduced crasher for `llc` when I recommit the check.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234717 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Duncan P. N. Exon Smith 2015-04-13 00:06:28 +00:00
parent b7239d3aa5
commit ea8c159524
4 changed files with 32 additions and 90 deletions

View File

@ -735,6 +735,9 @@ public:
/// \brief Check if this is an inlined function argument.
bool isInlinedFnArgument(const Function *CurFn);
/// \brief Return the size reported by the variable's type.
unsigned getSizeInBits(const DITypeIdentifierMap &Map);
void printExtendedName(raw_ostream &OS) const;
};

View File

@ -1535,7 +1535,15 @@ void DebugLocEntry::finalize(const AsmPrinter &AP,
Offset += PieceOffset-Offset;
}
Offset += PieceSize;
#ifndef NDEBUG
DIVariable Var = Piece.getVariable();
unsigned VarSize = Var.getSizeInBits(TypeIdentifierMap);
assert(PieceSize+PieceOffset <= VarSize
&& "piece is larger than or outside of variable");
assert(PieceSize != VarSize
&& "piece covers entire variable");
#endif
emitDebugLocValue(AP, TypeIdentifierMap, Streamer, Piece, PieceOffset);
}
} else {

View File

@ -33,6 +33,19 @@
using namespace llvm;
using namespace llvm::dwarf;
/// \brief Return the size reported by the variable's type.
unsigned DIVariable::getSizeInBits(const DITypeIdentifierMap &Map) {
DIType Ty = getType().resolve(Map);
// Follow derived types until we reach a type that
// reports back a size.
while (isa<MDDerivedType>(Ty) && !Ty.getSizeInBits()) {
DIDerivedType DT = cast<MDDerivedType>(Ty);
Ty = DT.getTypeDerivedFrom().resolve(Map);
}
assert(Ty.getSizeInBits() && "type with size 0");
return Ty.getSizeInBits();
}
//===----------------------------------------------------------------------===//
// Simple Descriptor Constructors and other Methods
//===----------------------------------------------------------------------===//

View File

@ -178,11 +178,8 @@ class Verifier : public InstVisitor<Verifier>, VerifierSupport {
/// \brief Keep track of the metadata nodes that have been checked already.
SmallPtrSet<const Metadata *, 32> MDNodes;
/// \brief Track unresolved string-based type references.
SmallDenseMap<const MDString *, const MDNode *, 32> UnresolvedTypeRefs;
/// \brief Track queue of bit piece expressions to verify.
SmallVector<const DbgInfoIntrinsic *, 32> QueuedBitPieceExpressions;
/// \brief Track string-based type references.
SmallDenseMap<const MDString *, const MDNode *, 32> TypeRefs;
/// \brief The personality function referenced by the LandingPadInsts.
/// All LandingPadInsts within the same function must use the same
@ -410,9 +407,6 @@ private:
// Module-level debug info verification...
void verifyTypeRefs();
template <class MapTy>
void verifyBitPieceExpression(const DbgInfoIntrinsic &I,
const MapTy &TypeRefs);
void visitUnresolvedTypeRef(const MDString *S, const MDNode *N);
};
} // End anonymous namespace
@ -708,7 +702,7 @@ bool Verifier::isValidUUID(const MDNode &N, const Metadata *MD) {
// Keep track of names of types referenced via UUID so we can check that they
// actually exist.
UnresolvedTypeRefs.insert(std::make_pair(S, &N));
TypeRefs.insert(std::make_pair(S, &N));
return true;
}
@ -3377,11 +3371,6 @@ void Verifier::visitDbgIntrinsic(StringRef Kind, DbgIntrinsicTy &DII) {
"invalid llvm.dbg." + Kind + " intrinsic expression", &DII,
DII.getRawExpression());
// Queue up bit piece expressions to be verified once we can resolve
// typerefs.
if (DII.getExpression()->isValid() && DII.getExpression()->isBitPiece())
QueuedBitPieceExpressions.push_back(&DII);
// Ignore broken !dbg attachments; they're checked elsewhere.
if (MDNode *N = DII.getDebugLoc().getAsMDNode())
if (!isa<MDLocation>(N))
@ -3397,66 +3386,6 @@ void Verifier::visitDbgIntrinsic(StringRef Kind, DbgIntrinsicTy &DII) {
BB ? BB->getParent() : nullptr, Var, VarIA, Loc, LocIA);
}
template <class MapTy>
static uint64_t getVariableSize(const MDLocalVariable &V, const MapTy &Map) {
// Be careful of broken types (checked elsewhere).
const Metadata *RawType = V.getRawType();
while (RawType) {
// Try to get the size directly.
if (auto *T = dyn_cast<MDType>(RawType))
if (uint64_t Size = T->getSizeInBits())
return Size;
if (auto *DT = dyn_cast<MDDerivedType>(RawType)) {
// Look at the base type.
RawType = DT->getRawBaseType();
continue;
}
if (auto *S = dyn_cast<MDString>(RawType)) {
// Don't error on missing types (checked elsewhere).
RawType = Map.lookup(S);
continue;
}
// Missing type or size.
break;
}
// Fail gracefully.
return 0;
}
template <class MapTy>
void Verifier::verifyBitPieceExpression(const DbgInfoIntrinsic &I,
const MapTy &TypeRefs) {
MDLocalVariable *V;
MDExpression *E;
if (auto *DVI = dyn_cast<DbgValueInst>(&I)) {
V = DVI->getVariable();
E = DVI->getExpression();
} else {
auto *DDI = cast<DbgDeclareInst>(&I);
V = DDI->getVariable();
E = DDI->getExpression();
}
assert(V && E->isValid() && E->isBitPiece() &&
"Expected valid bitpieces here");
// If there's no size, the type is broken, but that should be checked
// elsewhere.
uint64_t VarSize = getVariableSize(*V, TypeRefs);
if (!VarSize)
return;
unsigned PieceSize = E->getBitPieceSize();
unsigned PieceOffset = E->getBitPieceOffset();
Assert(PieceSize + PieceOffset <= VarSize,
"piece is larger than or outside of variable", &I, V, E);
Assert(PieceSize != VarSize, "piece covers entire variable", &I, V, E);
}
void Verifier::visitUnresolvedTypeRef(const MDString *S, const MDNode *N) {
// This is in its own function so we get an error for each bad type ref (not
// just the first).
@ -3468,29 +3397,18 @@ void Verifier::verifyTypeRefs() {
if (!CUs)
return;
// Visit all the compile units again to map the type references.
SmallDenseMap<const MDString *, const MDType *, 32> TypeRefs;
// Visit all the compile units again to check the type references.
for (auto *CU : CUs->operands())
if (auto Ts = cast<MDCompileUnit>(CU)->getRetainedTypes())
for (MDType *Op : Ts)
if (auto *T = dyn_cast<MDCompositeType>(Op))
if (auto *S = T->getRawIdentifier()) {
UnresolvedTypeRefs.erase(S);
TypeRefs.insert(std::make_pair(S, T));
}
// Verify debug intrinsic bit piece expressions.
for (auto *DII : QueuedBitPieceExpressions)
verifyBitPieceExpression(*DII, TypeRefs);
// Return early if all typerefs were resolved.
if (UnresolvedTypeRefs.empty())
TypeRefs.erase(T->getRawIdentifier());
if (TypeRefs.empty())
return;
// Sort the unresolved references by name so the output is deterministic.
typedef std::pair<const MDString *, const MDNode *> TypeRef;
SmallVector<TypeRef, 32> Unresolved(UnresolvedTypeRefs.begin(),
UnresolvedTypeRefs.end());
SmallVector<TypeRef, 32> Unresolved(TypeRefs.begin(), TypeRefs.end());
std::sort(Unresolved.begin(), Unresolved.end(),
[](const TypeRef &LHS, const TypeRef &RHS) {
return LHS.first->getString() < RHS.first->getString();