82static const unsigned Read = 1;
83static const unsigned Write = 2;
84static const unsigned Callee = 4;
85static const unsigned Branchee = 8;
116 Value *findValue(
Value *V,
bool OffsetOk)
const;
128 std::string Messages;
133 :
Mod(
Mod),
DL(
DL), AA(AA), AC(AC), DT(DT), TLI(TLI),
134 MessagesStr(Messages) {}
137 for (
const Value *V : Vs) {
140 if (isa<Instruction>(V)) {
141 MessagesStr << *
V <<
'\n';
143 V->printAsOperand(MessagesStr,
true,
Mod);
153 void CheckFailed(
const Twine &Message) { MessagesStr << Message <<
'\n'; }
159 template <
typename T1,
typename... Ts>
160 void CheckFailed(
const Twine &Message,
const T1 &V1,
const Ts &... Vs) {
161 CheckFailed(Message);
162 WriteValues({V1, Vs...});
168#define Check(C, ...) \
171 CheckFailed(__VA_ARGS__); \
179 Check(
F.hasName() ||
F.hasLocalLinkage(),
180 "Unusual: Unnamed function with non-local linkage", &
F);
189 nullptr, MemRef::Callee);
191 if (
Function *
F = dyn_cast<Function>(findValue(Callee,
193 Check(
I.getCallingConv() ==
F->getCallingConv(),
194 "Undefined behavior: Caller and callee calling convention differ",
198 unsigned NumActualArgs =
I.arg_size();
200 Check(FT->isVarArg() ? FT->getNumParams() <= NumActualArgs
201 : FT->getNumParams() == NumActualArgs,
202 "Undefined behavior: Call argument count mismatches callee "
206 Check(FT->getReturnType() ==
I.getType(),
207 "Undefined behavior: Call return type mismatches "
208 "callee return type",
214 auto AI =
I.arg_begin(), AE =
I.arg_end();
215 for (; AI != AE; ++AI) {
220 "Undefined behavior: Call argument type mismatches "
221 "callee parameter type",
230 for (
auto *BI =
I.arg_begin(); BI != AE; ++BI, ++ArgNo) {
240 if (
I.doesNotAccessMemory(ArgNo))
242 if (AI != BI && (*BI)->getType()->isPointerTy()) {
246 "Unusual: noalias argument aliases another argument", &
I);
256 visitMemoryReference(
I, Loc,
DL->getABITypeAlign(Ty), Ty,
257 MemRef::Read | MemRef::Write);
263 if (
const auto *CI = dyn_cast<CallInst>(&
I)) {
264 if (CI->isTailCall()) {
267 for (
Value *Arg :
I.args()) {
272 Value *Obj = findValue(Arg,
true);
273 Check(!isa<AllocaInst>(Obj),
274 "Undefined behavior: Call with \"tail\" keyword references "
282 switch (II->getIntrinsicID()) {
288 case Intrinsic::memcpy: {
300 dyn_cast<ConstantInt>(findValue(MCI->
getLength(),
302 if (
Len->getValue().isIntN(32))
306 "Undefined behavior: memcpy source and destination overlap", &
I);
309 case Intrinsic::memcpy_inline: {
323 "Undefined behavior: memcpy source and destination overlap", &
I);
326 case Intrinsic::memmove: {
334 case Intrinsic::memset: {
340 case Intrinsic::memset_inline: {
347 case Intrinsic::vastart:
348 Check(
I.getParent()->getParent()->isVarArg(),
349 "Undefined behavior: va_start called in a non-varargs function",
353 std::nullopt,
nullptr, MemRef::Read | MemRef::Write);
355 case Intrinsic::vacopy:
357 std::nullopt,
nullptr, MemRef::Write);
359 std::nullopt,
nullptr, MemRef::Read);
361 case Intrinsic::vaend:
363 std::nullopt,
nullptr, MemRef::Read | MemRef::Write);
366 case Intrinsic::stackrestore:
371 std::nullopt,
nullptr, MemRef::Read | MemRef::Write);
373 case Intrinsic::get_active_lane_mask:
374 if (
auto *TripCount = dyn_cast<ConstantInt>(
I.getArgOperand(1)))
375 Check(!TripCount->isZero(),
376 "get_active_lane_mask: operand #2 "
377 "must be greater than 0",
385 Check(!
F->doesNotReturn(),
386 "Unusual: Return statement in function with noreturn attribute", &
I);
388 if (
Value *V =
I.getReturnValue()) {
389 Value *Obj = findValue(V,
true);
390 Check(!isa<AllocaInst>(Obj),
"Unusual: Returning alloca value", &
I);
406 "Undefined behavior: Null pointer dereference", &
I);
408 "Undefined behavior: Undef pointer dereference", &
I);
411 "Unusual: All-ones pointer dereference", &
I);
414 "Unusual: Address one pointer dereference", &
I);
416 if (Flags & MemRef::Write) {
418 Check(!GV->isConstant(),
"Undefined behavior: Write to read-only memory",
422 "Undefined behavior: Write to text section", &
I);
424 if (Flags & MemRef::Read) {
428 "Undefined behavior: Load from block address", &
I);
430 if (Flags & MemRef::Callee) {
432 "Undefined behavior: Call to block address", &
I);
434 if (Flags & MemRef::Branchee) {
437 "Undefined behavior: Branch to non-blockaddress", &
I);
452 Type *ATy = AI->getAllocatedType();
453 if (!AI->isArrayAllocation() && ATy->
isSized())
454 BaseSize =
DL->getTypeAllocSize(ATy);
455 BaseAlign = AI->getAlign();
459 if (GV->hasDefinitiveInitializer()) {
460 Type *GTy = GV->getValueType();
462 BaseSize =
DL->getTypeAllocSize(GTy);
463 BaseAlign = GV->getAlign();
464 if (!BaseAlign && GTy->
isSized())
465 BaseAlign =
DL->getABITypeAlign(GTy);
473 "Undefined behavior: Buffer overflow", &
I);
478 Align =
DL->getABITypeAlign(Ty);
479 if (BaseAlign &&
Align)
481 "Undefined behavior: Memory reference address is misaligned", &
I);
492 I.getOperand(0)->getType(), MemRef::Write);
496 Check(!isa<UndefValue>(
I.getOperand(0)) || !isa<UndefValue>(
I.getOperand(1)),
497 "Undefined result: xor(undef, undef)", &
I);
501 Check(!isa<UndefValue>(
I.getOperand(0)) || !isa<UndefValue>(
I.getOperand(1)),
502 "Undefined result: sub(undef, undef)", &
I);
506 if (
ConstantInt *CI = dyn_cast<ConstantInt>(findValue(
I.getOperand(1),
508 Check(CI->getValue().ult(cast<IntegerType>(
I.getType())->getBitWidth()),
509 "Undefined result: Shift count out of range", &
I);
514 dyn_cast<ConstantInt>(findValue(
I.getOperand(1),
false)))
515 Check(CI->getValue().ult(cast<IntegerType>(
I.getType())->getBitWidth()),
516 "Undefined result: Shift count out of range", &
I);
521 dyn_cast<ConstantInt>(findValue(
I.getOperand(1),
false)))
522 Check(CI->getValue().ult(cast<IntegerType>(
I.getType())->getBitWidth()),
523 "Undefined result: Shift count out of range", &
I);
529 if (isa<UndefValue>(V))
532 VectorType *VecTy = dyn_cast<VectorType>(V->getType());
544 if (
C->isZeroValue())
549 for (
unsigned I = 0,
N = cast<FixedVectorType>(VecTy)->getNumElements();
552 if (isa<UndefValue>(Elem))
564 Check(!
isZero(
I.getOperand(1),
I.getModule()->getDataLayout(), DT, AC),
565 "Undefined behavior: Division by zero", &
I);
569 Check(!
isZero(
I.getOperand(1),
I.getModule()->getDataLayout(), DT, AC),
570 "Undefined behavior: Division by zero", &
I);
574 Check(!
isZero(
I.getOperand(1),
I.getModule()->getDataLayout(), DT, AC),
575 "Undefined behavior: Division by zero", &
I);
579 Check(!
isZero(
I.getOperand(1),
I.getModule()->getDataLayout(), DT, AC),
580 "Undefined behavior: Division by zero", &
I);
584 if (isa<ConstantInt>(
I.getArraySize()))
586 Check(&
I.getParent()->getParent()->getEntryBlock() ==
I.getParent(),
587 "Pessimization: Static alloca outside of entry block", &
I);
594 MemRef::Read | MemRef::Write);
599 std::nullopt,
nullptr, MemRef::Branchee);
601 Check(
I.getNumDestinations() != 0,
602 "Undefined behavior: indirectbr with no destinations", &
I);
606 if (
ConstantInt *CI = dyn_cast<ConstantInt>(findValue(
I.getIndexOperand(),
610 cast<FixedVectorType>(
I.getVectorOperandType())->getNumElements()),
611 "Undefined result: extractelement index out of range", &
I);
615 if (
ConstantInt *CI = dyn_cast<ConstantInt>(findValue(
I.getOperand(2),
617 Check(CI->getValue().ult(
618 cast<FixedVectorType>(
I.getType())->getNumElements()),
619 "Undefined result: insertelement index out of range", &
I);
624 Check(&
I == &
I.getParent()->front() ||
625 std::prev(
I.getIterator())->mayHaveSideEffects(),
626 "Unusual: unreachable immediately preceded by instruction without "
638Value *Lint::findValue(
Value *V,
bool OffsetOk)
const {
640 return findValueImpl(V, OffsetOk, Visited);
644Value *Lint::findValueImpl(
Value *V,
bool OffsetOk,
647 if (!Visited.
insert(V).second)
656 if (
LoadInst *L = dyn_cast<LoadInst>(V)) {
661 if (!VisitedBlocks.
insert(BB).second)
665 return findValueImpl(U, OffsetOk, Visited);
666 if (BBI != BB->
begin())
673 }
else if (
PHINode *PN = dyn_cast<PHINode>(V)) {
674 if (
Value *W = PN->hasConstantValue())
675 return findValueImpl(W, OffsetOk, Visited);
676 }
else if (
CastInst *CI = dyn_cast<CastInst>(V)) {
677 if (CI->isNoopCast(*
DL))
678 return findValueImpl(CI->getOperand(0), OffsetOk, Visited);
683 return findValueImpl(W, OffsetOk, Visited);
684 }
else if (
ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
688 CE->getOperand(0)->getType(),
CE->getType(),
690 return findValueImpl(
CE->getOperand(0), OffsetOk, Visited);
695 if (
Instruction *Inst = dyn_cast<Instruction>(V)) {
697 return findValueImpl(W, OffsetOk, Visited);
698 }
else if (
auto *
C = dyn_cast<Constant>(V)) {
701 return findValueImpl(W, OffsetOk, Visited);
708 auto *
Mod =
F.getParent();
709 auto *
DL = &
F.getParent()->getDataLayout();
714 Lint L(
Mod,
DL, AA, AC, DT, TLI);
716 dbgs() << L.MessagesStr.str();
728 assert(!
F.isDeclaration() &&
"Cannot lint external functions");
748 if (!
F.isDeclaration())
MachineBasicBlock MachineBasicBlock::iterator DebugLoc DL
This file implements a class to represent arbitrary precision integral constant values and operations...
This is the interface for LLVM's primary stateless and local alias analysis.
This file contains the declarations for the subclasses of Constant, which represent the different fla...
static bool isZero(Value *V, const DataLayout &DL, DominatorTree *DT, AssumptionCache *AC)
This file provides utility analysis objects describing memory locations.
Module.h This file contains the declarations for the Module class.
FunctionAnalysisManager FAM
This header defines various interfaces for pass management in LLVM.
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
This is the interface for a metadata-based scoped no-alias analysis.
This file defines the SmallPtrSet class.
This is the interface for a metadata-based TBAA.
A manager for alias analyses.
void registerFunctionAnalysis()
Register a specific AA result.
AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB)
The main low level interface to the alias analysis implementation.
uint64_t getLimitedValue(uint64_t Limit=UINT64_MAX) const
If this value is smaller than the specified limit, return it, otherwise return the limit value.
The possible results of an alias query.
@ PartialAlias
The two locations alias, but only due to a partial overlap.
@ MustAlias
The two locations precisely alias each other.
an instruction to allocate memory on the stack
A container for analyses that lazily runs them and caches their results.
bool registerPass(PassBuilderT &&PassBuilder)
Register an analysis pass with the manager.
PassT::Result & getResult(IRUnitT &IR, ExtraArgTs... ExtraArgs)
Get the result of an analysis pass for a given IR unit.
This class represents an incoming formal argument to a Function.
bool hasNoAliasAttr() const
Return true if this argument has the noalias attribute.
bool onlyReadsMemory() const
Return true if this argument has the readonly or readnone attribute.
Type * getParamStructRetType() const
If this is an sret argument, return its type.
bool hasStructRetAttr() const
Return true if this argument has the sret attribute.
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory),...
A function analysis which provides an AssumptionCache.
A cache of @llvm.assume calls within a function.
bool hasParamAttr(unsigned ArgNo, Attribute::AttrKind Kind) const
Return true if the attribute exists for the given argument.
AttributeSet getAttributes(unsigned Index) const
The attributes for the specified index are returned.
Analysis pass providing a never-invalidated alias analysis result.
LLVM Basic Block Representation.
iterator begin()
Instruction iterator methods.
const BasicBlock * getUniquePredecessor() const
Return the predecessor of this block if it has a unique predecessor block.
InstListType::iterator iterator
Instruction iterators...
Base class for all callable instructions (InvokeInst and CallInst) Holds everything related to callin...
This is the base class for all instructions that perform data casts.
static bool isNoopCast(Instruction::CastOps Opcode, Type *SrcTy, Type *DstTy, const DataLayout &DL)
A no-op cast is one that can be effected without changing any bits.
A constant value that is initialized with an expression using other constant values.
This is the shared class of boolean and integer constants.
const APInt & getValue() const
Return the constant as an APInt value reference.
This is an important base class in LLVM.
A parsed version of the target data layout string in and methods for querying it.
Analysis pass which computes a DominatorTree.
Concrete subclass of DominatorTreeBase that is used to compute a normal dominator tree.
Indirect Branch Instruction.
This instruction inserts a single (scalar) element into a VectorType value.
Base class for instruction visitors.
RetTy visitIndirectBrInst(IndirectBrInst &I)
RetTy visitExtractElementInst(ExtractElementInst &I)
RetTy visitCallBase(CallBase &I)
void visitFunction(Function &F)
RetTy visitUnreachableInst(UnreachableInst &I)
RetTy visitReturnInst(ReturnInst &I)
RetTy visitStoreInst(StoreInst &I)
RetTy visitInsertElementInst(InsertElementInst &I)
RetTy visitAllocaInst(AllocaInst &I)
RetTy visitLoadInst(LoadInst &I)
RetTy visitVAArgInst(VAArgInst &I)
A wrapper class for inspecting calls to intrinsic functions.
PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM)
An instruction for reading from memory.
static LocationSize precise(uint64_t Value)
TypeSize getValue() const
static constexpr LocationSize afterPointer()
Any location after the base pointer (but still within the underlying object).
This class wraps the llvm.memcpy.inline intrinsic.
ConstantInt * getLength() const
This class wraps the llvm.memcpy intrinsic.
Value * getLength() const
Value * getDest() const
This is just like getRawDest, but it strips off any cast instructions (including addrspacecast) that ...
MaybeAlign getDestAlign() const
This class wraps the llvm.memmove intrinsic.
This class wraps the llvm.memset.inline intrinsic.
This class wraps the llvm.memset and llvm.memset.inline intrinsics.
MaybeAlign getSourceAlign() const
Value * getSource() const
This is just like getRawSource, but it strips off any cast instructions that feed it,...
Representation for a specific memory location.
static MemoryLocation get(const LoadInst *LI)
Return a location with information about the memory reference by the given instruction.
static MemoryLocation getForSource(const MemTransferInst *MTI)
Return a location representing the source of a memory transfer.
LocationSize Size
The maximum size of the location, in address-units, or UnknownSize if the size is not known.
static MemoryLocation getAfter(const Value *Ptr, const AAMDNodes &AATags=AAMDNodes())
Return a location that may access any location after Ptr, while remaining within the underlying objec...
const Value * Ptr
The address of the start of the location.
static MemoryLocation getForDest(const MemIntrinsic *MI)
Return a location representing the destination of a memory set or transfer.
static MemoryLocation getForArgument(const CallBase *Call, unsigned ArgIdx, const TargetLibraryInfo *TLI)
Return a location representing a particular argument of a call.
A Module instance is used to store all the information related to an LLVM module.
A set of analyses that are preserved following a run of a transformation pass.
static PreservedAnalyses all()
Construct a special preserved set that preserves all passes.
Return a value (possibly void), from a function.
Analysis pass providing a never-invalidated alias analysis result.
A templated base class for SmallPtrSet which provides the typesafe interface that is common across al...
std::pair< iterator, bool > insert(PtrType Ptr)
Inserts Ptr if and only if there is no element in the container equal to Ptr.
SmallPtrSet - This class implements a set which is optimized for holding SmallSize or less elements.
An instruction for storing to memory.
Analysis pass providing the TargetLibraryInfo.
Provides information about what library functions are available for the current target.
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Analysis pass providing a never-invalidated alias analysis result.
The instances of the Type class are immutable: once they are created, they are never changed.
bool isPointerTy() const
True if this is an instance of PointerType.
bool isSized(SmallPtrSetImpl< Type * > *Visited=nullptr) const
Return true if it makes sense to take the size of this type.
static UndefValue * get(Type *T)
Static factory methods - Return an 'undef' object of the specified type.
This function has undefined behavior.
This class represents the va_arg llvm instruction, which returns an argument of the specified type gi...
LLVM Value Representation.
Type * getType() const
All values are typed, get the type of this value.
A raw_ostream that writes to an std::string.
@ C
The default llvm calling convention, compatible with C.
@ CE
Windows NT (Windows on ARM)
This is an optimization pass for GlobalISel generic memory operations.
Value * GetPointerBaseWithConstantOffset(Value *Ptr, int64_t &Offset, const DataLayout &DL, bool AllowNonInbounds=true)
Analyze the specified pointer to see if it can be expressed as a base pointer plus a constant offset.
const Value * getUnderlyingObject(const Value *V, unsigned MaxLookup=6)
This method strips off any GEP address adjustments and pointer casts from the specified value,...
Value * FindAvailableLoadedValue(LoadInst *Load, BasicBlock *ScanBB, BasicBlock::iterator &ScanFrom, unsigned MaxInstsToScan=DefMaxInstsToScan, AAResults *AA=nullptr, bool *IsLoadCSE=nullptr, unsigned *NumScanedInst=nullptr)
Scan backwards to see if we have the value of the given load available locally within a small number ...
Value * simplifyInstruction(Instruction *I, const SimplifyQuery &Q)
See if we can compute a simplified version of this instruction.
Constant * ConstantFoldConstant(const Constant *C, const DataLayout &DL, const TargetLibraryInfo *TLI=nullptr)
ConstantFoldConstant - Fold the constant using the specified DataLayout.
Value * FindInsertedValue(Value *V, ArrayRef< unsigned > idx_range, Instruction *InsertBefore=nullptr)
Given an aggregate and an sequence of indices, see if the scalar value indexed is already around as a...
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
void lintModule(const Module &M)
Lint a module.
cl::opt< unsigned > DefMaxInstsToScan
The default number of maximum instructions to scan in the block, used by FindAvailableLoadedValue().
@ Mod
The access may modify the value stored in memory.
void computeKnownBits(const Value *V, KnownBits &Known, const DataLayout &DL, unsigned Depth=0, AssumptionCache *AC=nullptr, const Instruction *CxtI=nullptr, const DominatorTree *DT=nullptr, bool UseInstrInfo=true)
Determine which bits of V are known to be either zero or one and return them in the KnownZero/KnownOn...
Align commonAlignment(Align A, uint64_t Offset)
Returns the alignment that satisfies both alignments.
void lintFunction(const Function &F)
lintFunction - Check a function for errors, printing messages on stderr.
This struct is a compact representation of a valid (non-zero power of two) alignment.
bool isZero() const
Returns true if value is all zero.
This struct is a compact representation of a valid (power of two) or undefined (0) alignment.