| //===-- Value.cpp - Implement the Value class -----------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the Value, ValueHandle, and User classes. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/IR/Value.h" |
| #include "LLVMContextImpl.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/SmallString.h" |
| #include "llvm/ADT/SetVector.h" |
| #include "llvm/IR/Constant.h" |
| #include "llvm/IR/Constants.h" |
| #include "llvm/IR/DataLayout.h" |
| #include "llvm/IR/DerivedTypes.h" |
| #include "llvm/IR/DerivedUser.h" |
| #include "llvm/IR/GetElementPtrTypeIterator.h" |
| #include "llvm/IR/InstrTypes.h" |
| #include "llvm/IR/Instructions.h" |
| #include "llvm/IR/IntrinsicInst.h" |
| #include "llvm/IR/Module.h" |
| #include "llvm/IR/Operator.h" |
| #include "llvm/IR/Statepoint.h" |
| #include "llvm/IR/ValueHandle.h" |
| #include "llvm/IR/ValueSymbolTable.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/ManagedStatic.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include <algorithm> |
| |
| using namespace llvm; |
| |
| static cl::opt<unsigned> NonGlobalValueMaxNameSize( |
| "non-global-value-max-name-size", cl::Hidden, cl::init(1024), |
| cl::desc("Maximum size for the name of non-global values.")); |
| |
| //===----------------------------------------------------------------------===// |
| // Value Class |
| //===----------------------------------------------------------------------===// |
| static inline Type *checkType(Type *Ty) { |
| assert(Ty && "Value defined with a null type: Error!"); |
| return Ty; |
| } |
| |
| Value::Value(Type *ty, unsigned scid) |
| : VTy(checkType(ty)), UseList(nullptr), SubclassID(scid), |
| HasValueHandle(0), SubclassOptionalData(0), SubclassData(0), |
| NumUserOperands(0), IsUsedByMD(false), HasName(false) { |
| static_assert(ConstantFirstVal == 0, "!(SubclassID < ConstantFirstVal)"); |
| // FIXME: Why isn't this in the subclass gunk?? |
| // Note, we cannot call isa<CallInst> before the CallInst has been |
| // constructed. |
| if (SubclassID == Instruction::Call || SubclassID == Instruction::Invoke || |
| SubclassID == Instruction::CallBr) |
| assert((VTy->isFirstClassType() || VTy->isVoidTy() || VTy->isStructTy()) && |
| "invalid CallInst type!"); |
| else if (SubclassID != BasicBlockVal && |
| (/*SubclassID < ConstantFirstVal ||*/ SubclassID > ConstantLastVal)) |
| assert((VTy->isFirstClassType() || VTy->isVoidTy()) && |
| "Cannot create non-first-class values except for constants!"); |
| static_assert(sizeof(Value) == 2 * sizeof(void *) + 2 * sizeof(unsigned), |
| "Value too big"); |
| } |
| |
| Value::~Value() { |
| // Notify all ValueHandles (if present) that this value is going away. |
| if (HasValueHandle) |
| ValueHandleBase::ValueIsDeleted(this); |
| if (isUsedByMetadata()) |
| ValueAsMetadata::handleDeletion(this); |
| |
| #ifndef NDEBUG // Only in -g mode... |
| // Check to make sure that there are no uses of this value that are still |
| // around when the value is destroyed. If there are, then we have a dangling |
| // reference and something is wrong. This code is here to print out where |
| // the value is still being referenced. |
| // |
| if (!use_empty()) { |
| dbgs() << "While deleting: " << *VTy << " %" << getName() << "\n"; |
| for (auto *U : users()) |
| dbgs() << "Use still stuck around after Def is destroyed:" << *U << "\n"; |
| } |
| #endif |
| assert(use_empty() && "Uses remain when a value is destroyed!"); |
| |
| // If this value is named, destroy the name. This should not be in a symtab |
| // at this point. |
| destroyValueName(); |
| } |
| |
| void Value::deleteValue() { |
| switch (getValueID()) { |
| #define HANDLE_VALUE(Name) \ |
| case Value::Name##Val: \ |
| delete static_cast<Name *>(this); \ |
| break; |
| #define HANDLE_MEMORY_VALUE(Name) \ |
| case Value::Name##Val: \ |
| static_cast<DerivedUser *>(this)->DeleteValue( \ |
| static_cast<DerivedUser *>(this)); \ |
| break; |
| #define HANDLE_INSTRUCTION(Name) /* nothing */ |
| #include "llvm/IR/Value.def" |
| |
| #define HANDLE_INST(N, OPC, CLASS) \ |
| case Value::InstructionVal + Instruction::OPC: \ |
| delete static_cast<CLASS *>(this); \ |
| break; |
| #define HANDLE_USER_INST(N, OPC, CLASS) |
| #include "llvm/IR/Instruction.def" |
| |
| default: |
| llvm_unreachable("attempting to delete unknown value kind"); |
| } |
| } |
| |
| void Value::destroyValueName() { |
| ValueName *Name = getValueName(); |
| if (Name) |
| Name->Destroy(); |
| setValueName(nullptr); |
| } |
| |
| bool Value::hasNUses(unsigned N) const { |
| return hasNItems(use_begin(), use_end(), N); |
| } |
| |
| bool Value::hasNUsesOrMore(unsigned N) const { |
| return hasNItemsOrMore(use_begin(), use_end(), N); |
| } |
| |
| bool Value::isUsedInBasicBlock(const BasicBlock *BB) const { |
| // This can be computed either by scanning the instructions in BB, or by |
| // scanning the use list of this Value. Both lists can be very long, but |
| // usually one is quite short. |
| // |
| // Scan both lists simultaneously until one is exhausted. This limits the |
| // search to the shorter list. |
| BasicBlock::const_iterator BI = BB->begin(), BE = BB->end(); |
| const_user_iterator UI = user_begin(), UE = user_end(); |
| for (; BI != BE && UI != UE; ++BI, ++UI) { |
| // Scan basic block: Check if this Value is used by the instruction at BI. |
| if (is_contained(BI->operands(), this)) |
| return true; |
| // Scan use list: Check if the use at UI is in BB. |
| const auto *User = dyn_cast<Instruction>(*UI); |
| if (User && User->getParent() == BB) |
| return true; |
| } |
| return false; |
| } |
| |
| unsigned Value::getNumUses() const { |
| return (unsigned)std::distance(use_begin(), use_end()); |
| } |
| |
| static bool getSymTab(Value *V, ValueSymbolTable *&ST) { |
| ST = nullptr; |
| if (Instruction *I = dyn_cast<Instruction>(V)) { |
| if (BasicBlock *P = I->getParent()) |
| if (Function *PP = P->getParent()) |
| ST = PP->getValueSymbolTable(); |
| } else if (BasicBlock *BB = dyn_cast<BasicBlock>(V)) { |
| if (Function *P = BB->getParent()) |
| ST = P->getValueSymbolTable(); |
| } else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) { |
| if (Module *P = GV->getParent()) |
| ST = &P->getValueSymbolTable(); |
| } else if (Argument *A = dyn_cast<Argument>(V)) { |
| if (Function *P = A->getParent()) |
| ST = P->getValueSymbolTable(); |
| } else { |
| assert(isa<Constant>(V) && "Unknown value type!"); |
| return true; // no name is setable for this. |
| } |
| return false; |
| } |
| |
| ValueName *Value::getValueName() const { |
| if (!HasName) return nullptr; |
| |
| LLVMContext &Ctx = getContext(); |
| auto I = Ctx.pImpl->ValueNames.find(this); |
| assert(I != Ctx.pImpl->ValueNames.end() && |
| "No name entry found!"); |
| |
| return I->second; |
| } |
| |
| void Value::setValueName(ValueName *VN) { |
| LLVMContext &Ctx = getContext(); |
| |
| assert(HasName == Ctx.pImpl->ValueNames.count(this) && |
| "HasName bit out of sync!"); |
| |
| if (!VN) { |
| if (HasName) |
| Ctx.pImpl->ValueNames.erase(this); |
| HasName = false; |
| return; |
| } |
| |
| HasName = true; |
| Ctx.pImpl->ValueNames[this] = VN; |
| } |
| |
| StringRef Value::getName() const { |
| // Make sure the empty string is still a C string. For historical reasons, |
| // some clients want to call .data() on the result and expect it to be null |
| // terminated. |
| if (!hasName()) |
| return StringRef("", 0); |
| return getValueName()->getKey(); |
| } |
| |
| void Value::setNameImpl(const Twine &NewName) { |
| // Fast-path: LLVMContext can be set to strip out non-GlobalValue names |
| if (getContext().shouldDiscardValueNames() && !isa<GlobalValue>(this)) |
| return; |
| |
| // Fast path for common IRBuilder case of setName("") when there is no name. |
| if (NewName.isTriviallyEmpty() && !hasName()) |
| return; |
| |
| SmallString<256> NameData; |
| StringRef NameRef = NewName.toStringRef(NameData); |
| assert(NameRef.find_first_of(0) == StringRef::npos && |
| "Null bytes are not allowed in names"); |
| |
| // Name isn't changing? |
| if (getName() == NameRef) |
| return; |
| |
| // Cap the size of non-GlobalValue names. |
| if (NameRef.size() > NonGlobalValueMaxNameSize && !isa<GlobalValue>(this)) |
| NameRef = |
| NameRef.substr(0, std::max(1u, (unsigned)NonGlobalValueMaxNameSize)); |
| |
| assert(!getType()->isVoidTy() && "Cannot assign a name to void values!"); |
| |
| // Get the symbol table to update for this object. |
| ValueSymbolTable *ST; |
| if (getSymTab(this, ST)) |
| return; // Cannot set a name on this value (e.g. constant). |
| |
| if (!ST) { // No symbol table to update? Just do the change. |
| if (NameRef.empty()) { |
| // Free the name for this value. |
| destroyValueName(); |
| return; |
| } |
| |
| // NOTE: Could optimize for the case the name is shrinking to not deallocate |
| // then reallocated. |
| destroyValueName(); |
| |
| // Create the new name. |
| setValueName(ValueName::Create(NameRef)); |
| getValueName()->setValue(this); |
| return; |
| } |
| |
| // NOTE: Could optimize for the case the name is shrinking to not deallocate |
| // then reallocated. |
| if (hasName()) { |
| // Remove old name. |
| ST->removeValueName(getValueName()); |
| destroyValueName(); |
| |
| if (NameRef.empty()) |
| return; |
| } |
| |
| // Name is changing to something new. |
| setValueName(ST->createValueName(NameRef, this)); |
| } |
| |
| void Value::setName(const Twine &NewName) { |
| setNameImpl(NewName); |
| if (Function *F = dyn_cast<Function>(this)) |
| F->recalculateIntrinsicID(); |
| } |
| |
| void Value::takeName(Value *V) { |
| ValueSymbolTable *ST = nullptr; |
| // If this value has a name, drop it. |
| if (hasName()) { |
| // Get the symtab this is in. |
| if (getSymTab(this, ST)) { |
| // We can't set a name on this value, but we need to clear V's name if |
| // it has one. |
| if (V->hasName()) V->setName(""); |
| return; // Cannot set a name on this value (e.g. constant). |
| } |
| |
| // Remove old name. |
| if (ST) |
| ST->removeValueName(getValueName()); |
| destroyValueName(); |
| } |
| |
| // Now we know that this has no name. |
| |
| // If V has no name either, we're done. |
| if (!V->hasName()) return; |
| |
| // Get this's symtab if we didn't before. |
| if (!ST) { |
| if (getSymTab(this, ST)) { |
| // Clear V's name. |
| V->setName(""); |
| return; // Cannot set a name on this value (e.g. constant). |
| } |
| } |
| |
| // Get V's ST, this should always succed, because V has a name. |
| ValueSymbolTable *VST; |
| bool Failure = getSymTab(V, VST); |
| assert(!Failure && "V has a name, so it should have a ST!"); (void)Failure; |
| |
| // If these values are both in the same symtab, we can do this very fast. |
| // This works even if both values have no symtab yet. |
| if (ST == VST) { |
| // Take the name! |
| setValueName(V->getValueName()); |
| V->setValueName(nullptr); |
| getValueName()->setValue(this); |
| return; |
| } |
| |
| // Otherwise, things are slightly more complex. Remove V's name from VST and |
| // then reinsert it into ST. |
| |
| if (VST) |
| VST->removeValueName(V->getValueName()); |
| setValueName(V->getValueName()); |
| V->setValueName(nullptr); |
| getValueName()->setValue(this); |
| |
| if (ST) |
| ST->reinsertValue(this); |
| } |
| |
| void Value::assertModuleIsMaterializedImpl() const { |
| #ifndef NDEBUG |
| const GlobalValue *GV = dyn_cast<GlobalValue>(this); |
| if (!GV) |
| return; |
| const Module *M = GV->getParent(); |
| if (!M) |
| return; |
| assert(M->isMaterialized()); |
| #endif |
| } |
| |
| #ifndef NDEBUG |
| static bool contains(SmallPtrSetImpl<ConstantExpr *> &Cache, ConstantExpr *Expr, |
| Constant *C) { |
| if (!Cache.insert(Expr).second) |
| return false; |
| |
| for (auto &O : Expr->operands()) { |
| if (O == C) |
| return true; |
| auto *CE = dyn_cast<ConstantExpr>(O); |
| if (!CE) |
| continue; |
| if (contains(Cache, CE, C)) |
| return true; |
| } |
| return false; |
| } |
| |
| static bool contains(Value *Expr, Value *V) { |
| if (Expr == V) |
| return true; |
| |
| auto *C = dyn_cast<Constant>(V); |
| if (!C) |
| return false; |
| |
| auto *CE = dyn_cast<ConstantExpr>(Expr); |
| if (!CE) |
| return false; |
| |
| SmallPtrSet<ConstantExpr *, 4> Cache; |
| return contains(Cache, CE, C); |
| } |
| #endif // NDEBUG |
| |
| void Value::doRAUW(Value *New, ReplaceMetadataUses ReplaceMetaUses) { |
| assert(New && "Value::replaceAllUsesWith(<null>) is invalid!"); |
| assert(!contains(New, this) && |
| "this->replaceAllUsesWith(expr(this)) is NOT valid!"); |
| assert(New->getType() == getType() && |
| "replaceAllUses of value with new value of different type!"); |
| |
| // Notify all ValueHandles (if present) that this value is going away. |
| if (HasValueHandle) |
| ValueHandleBase::ValueIsRAUWd(this, New); |
| if (ReplaceMetaUses == ReplaceMetadataUses::Yes && isUsedByMetadata()) |
| ValueAsMetadata::handleRAUW(this, New); |
| |
| while (!materialized_use_empty()) { |
| Use &U = *UseList; |
| // Must handle Constants specially, we cannot call replaceUsesOfWith on a |
| // constant because they are uniqued. |
| if (auto *C = dyn_cast<Constant>(U.getUser())) { |
| if (!isa<GlobalValue>(C)) { |
| C->handleOperandChange(this, New); |
| continue; |
| } |
| } |
| |
| U.set(New); |
| } |
| |
| if (BasicBlock *BB = dyn_cast<BasicBlock>(this)) |
| BB->replaceSuccessorsPhiUsesWith(cast<BasicBlock>(New)); |
| } |
| |
| void Value::replaceAllUsesWith(Value *New) { |
| doRAUW(New, ReplaceMetadataUses::Yes); |
| } |
| |
| void Value::replaceNonMetadataUsesWith(Value *New) { |
| doRAUW(New, ReplaceMetadataUses::No); |
| } |
| |
| // Like replaceAllUsesWith except it does not handle constants or basic blocks. |
| // This routine leaves uses within BB. |
| void Value::replaceUsesOutsideBlock(Value *New, BasicBlock *BB) { |
| assert(New && "Value::replaceUsesOutsideBlock(<null>, BB) is invalid!"); |
| assert(!contains(New, this) && |
| "this->replaceUsesOutsideBlock(expr(this), BB) is NOT valid!"); |
| assert(New->getType() == getType() && |
| "replaceUses of value with new value of different type!"); |
| assert(BB && "Basic block that may contain a use of 'New' must be defined\n"); |
| |
| replaceUsesWithIf(New, [BB](Use &U) { |
| auto *I = dyn_cast<Instruction>(U.getUser()); |
| // Don't replace if it's an instruction in the BB basic block. |
| return !I || I->getParent() != BB; |
| }); |
| } |
| |
| namespace { |
| // Various metrics for how much to strip off of pointers. |
| enum PointerStripKind { |
| PSK_ZeroIndices, |
| PSK_ZeroIndicesAndAliases, |
| PSK_ZeroIndicesSameRepresentation, |
| PSK_ZeroIndicesAndInvariantGroups, |
| PSK_InBoundsConstantIndices, |
| PSK_InBounds |
| }; |
| |
| template <PointerStripKind StripKind> |
| static const Value *stripPointerCastsAndOffsets(const Value *V) { |
| if (!V->getType()->isPointerTy()) |
| return V; |
| |
| // Even though we don't look through PHI nodes, we could be called on an |
| // instruction in an unreachable block, which may be on a cycle. |
| SmallPtrSet<const Value *, 4> Visited; |
| |
| Visited.insert(V); |
| do { |
| if (auto *GEP = dyn_cast<GEPOperator>(V)) { |
| switch (StripKind) { |
| case PSK_ZeroIndices: |
| case PSK_ZeroIndicesAndAliases: |
| case PSK_ZeroIndicesSameRepresentation: |
| case PSK_ZeroIndicesAndInvariantGroups: |
| if (!GEP->hasAllZeroIndices()) |
| return V; |
| break; |
| case PSK_InBoundsConstantIndices: |
| if (!GEP->hasAllConstantIndices()) |
| return V; |
| LLVM_FALLTHROUGH; |
| case PSK_InBounds: |
| if (!GEP->isInBounds()) |
| return V; |
| break; |
| } |
| V = GEP->getPointerOperand(); |
| } else if (Operator::getOpcode(V) == Instruction::BitCast) { |
| V = cast<Operator>(V)->getOperand(0); |
| } else if (StripKind != PSK_ZeroIndicesSameRepresentation && |
| Operator::getOpcode(V) == Instruction::AddrSpaceCast) { |
| // TODO: If we know an address space cast will not change the |
| // representation we could look through it here as well. |
| V = cast<Operator>(V)->getOperand(0); |
| } else if (StripKind == PSK_ZeroIndicesAndAliases && isa<GlobalAlias>(V)) { |
| V = cast<GlobalAlias>(V)->getAliasee(); |
| } else { |
| if (const auto *Call = dyn_cast<CallBase>(V)) { |
| if (const Value *RV = Call->getReturnedArgOperand()) { |
| V = RV; |
| continue; |
| } |
| // The result of launder.invariant.group must alias it's argument, |
| // but it can't be marked with returned attribute, that's why it needs |
| // special case. |
| if (StripKind == PSK_ZeroIndicesAndInvariantGroups && |
| (Call->getIntrinsicID() == Intrinsic::launder_invariant_group || |
| Call->getIntrinsicID() == Intrinsic::strip_invariant_group)) { |
| V = Call->getArgOperand(0); |
| continue; |
| } |
| } |
| return V; |
| } |
| assert(V->getType()->isPointerTy() && "Unexpected operand type!"); |
| } while (Visited.insert(V).second); |
| |
| return V; |
| } |
| } // end anonymous namespace |
| |
| const Value *Value::stripPointerCasts() const { |
| return stripPointerCastsAndOffsets<PSK_ZeroIndices>(this); |
| } |
| |
| const Value *Value::stripPointerCastsAndAliases() const { |
| return stripPointerCastsAndOffsets<PSK_ZeroIndicesAndAliases>(this); |
| } |
| |
| const Value *Value::stripPointerCastsSameRepresentation() const { |
| return stripPointerCastsAndOffsets<PSK_ZeroIndicesSameRepresentation>(this); |
| } |
| |
| const Value *Value::stripInBoundsConstantOffsets() const { |
| return stripPointerCastsAndOffsets<PSK_InBoundsConstantIndices>(this); |
| } |
| |
| const Value *Value::stripPointerCastsAndInvariantGroups() const { |
| return stripPointerCastsAndOffsets<PSK_ZeroIndicesAndInvariantGroups>(this); |
| } |
| |
| const Value * |
| Value::stripAndAccumulateConstantOffsets(const DataLayout &DL, APInt &Offset, |
| bool AllowNonInbounds) const { |
| if (!getType()->isPtrOrPtrVectorTy()) |
| return this; |
| |
| unsigned BitWidth = Offset.getBitWidth(); |
| assert(BitWidth == DL.getIndexTypeSizeInBits(getType()) && |
| "The offset bit width does not match the DL specification."); |
| |
| // Even though we don't look through PHI nodes, we could be called on an |
| // instruction in an unreachable block, which may be on a cycle. |
| SmallPtrSet<const Value *, 4> Visited; |
| Visited.insert(this); |
| const Value *V = this; |
| do { |
| if (auto *GEP = dyn_cast<GEPOperator>(V)) { |
| // If in-bounds was requested, we do not strip non-in-bounds GEPs. |
| if (!AllowNonInbounds && !GEP->isInBounds()) |
| return V; |
| |
| // If one of the values we have visited is an addrspacecast, then |
| // the pointer type of this GEP may be different from the type |
| // of the Ptr parameter which was passed to this function. This |
| // means when we construct GEPOffset, we need to use the size |
| // of GEP's pointer type rather than the size of the original |
| // pointer type. |
| APInt GEPOffset(DL.getIndexTypeSizeInBits(V->getType()), 0); |
| if (!GEP->accumulateConstantOffset(DL, GEPOffset)) |
| return V; |
| |
| // Stop traversal if the pointer offset wouldn't fit in the bit-width |
| // provided by the Offset argument. This can happen due to AddrSpaceCast |
| // stripping. |
| if (GEPOffset.getMinSignedBits() > BitWidth) |
| return V; |
| |
| Offset += GEPOffset.sextOrTrunc(BitWidth); |
| V = GEP->getPointerOperand(); |
| } else if (Operator::getOpcode(V) == Instruction::BitCast || |
| Operator::getOpcode(V) == Instruction::AddrSpaceCast) { |
| V = cast<Operator>(V)->getOperand(0); |
| } else if (auto *GA = dyn_cast<GlobalAlias>(V)) { |
| if (!GA->isInterposable()) |
| V = GA->getAliasee(); |
| } else if (const auto *Call = dyn_cast<CallBase>(V)) { |
| if (const Value *RV = Call->getReturnedArgOperand()) |
| V = RV; |
| } |
| assert(V->getType()->isPtrOrPtrVectorTy() && "Unexpected operand type!"); |
| } while (Visited.insert(V).second); |
| |
| return V; |
| } |
| |
| const Value *Value::stripInBoundsOffsets() const { |
| return stripPointerCastsAndOffsets<PSK_InBounds>(this); |
| } |
| |
| uint64_t Value::getPointerDereferenceableBytes(const DataLayout &DL, |
| bool &CanBeNull) const { |
| assert(getType()->isPointerTy() && "must be pointer"); |
| |
| uint64_t DerefBytes = 0; |
| CanBeNull = false; |
| if (const Argument *A = dyn_cast<Argument>(this)) { |
| DerefBytes = A->getDereferenceableBytes(); |
| if (DerefBytes == 0 && (A->hasByValAttr() || A->hasStructRetAttr())) { |
| Type *PT = cast<PointerType>(A->getType())->getElementType(); |
| if (PT->isSized()) |
| DerefBytes = DL.getTypeStoreSize(PT); |
| } |
| if (DerefBytes == 0) { |
| DerefBytes = A->getDereferenceableOrNullBytes(); |
| CanBeNull = true; |
| } |
| } else if (const auto *Call = dyn_cast<CallBase>(this)) { |
| DerefBytes = Call->getDereferenceableBytes(AttributeList::ReturnIndex); |
| if (DerefBytes == 0) { |
| DerefBytes = |
| Call->getDereferenceableOrNullBytes(AttributeList::ReturnIndex); |
| CanBeNull = true; |
| } |
| } else if (const LoadInst *LI = dyn_cast<LoadInst>(this)) { |
| if (MDNode *MD = LI->getMetadata(LLVMContext::MD_dereferenceable)) { |
| ConstantInt *CI = mdconst::extract<ConstantInt>(MD->getOperand(0)); |
| DerefBytes = CI->getLimitedValue(); |
| } |
| if (DerefBytes == 0) { |
| if (MDNode *MD = |
| LI->getMetadata(LLVMContext::MD_dereferenceable_or_null)) { |
| ConstantInt *CI = mdconst::extract<ConstantInt>(MD->getOperand(0)); |
| DerefBytes = CI->getLimitedValue(); |
| } |
| CanBeNull = true; |
| } |
| } else if (auto *IP = dyn_cast<IntToPtrInst>(this)) { |
| if (MDNode *MD = IP->getMetadata(LLVMContext::MD_dereferenceable)) { |
| ConstantInt *CI = mdconst::extract<ConstantInt>(MD->getOperand(0)); |
| DerefBytes = CI->getLimitedValue(); |
| } |
| if (DerefBytes == 0) { |
| if (MDNode *MD = |
| IP->getMetadata(LLVMContext::MD_dereferenceable_or_null)) { |
| ConstantInt *CI = mdconst::extract<ConstantInt>(MD->getOperand(0)); |
| DerefBytes = CI->getLimitedValue(); |
| } |
| CanBeNull = true; |
| } |
| } else if (auto *AI = dyn_cast<AllocaInst>(this)) { |
| if (!AI->isArrayAllocation()) { |
| DerefBytes = DL.getTypeStoreSize(AI->getAllocatedType()); |
| CanBeNull = false; |
| } |
| } else if (auto *GV = dyn_cast<GlobalVariable>(this)) { |
| if (GV->getValueType()->isSized() && !GV->hasExternalWeakLinkage()) { |
| // TODO: Don't outright reject hasExternalWeakLinkage but set the |
| // CanBeNull flag. |
| DerefBytes = DL.getTypeStoreSize(GV->getValueType()); |
| CanBeNull = false; |
| } |
| } |
| return DerefBytes; |
| } |
| |
| MaybeAlign Value::getPointerAlignment(const DataLayout &DL) const { |
| assert(getType()->isPointerTy() && "must be pointer"); |
| if (auto *GO = dyn_cast<GlobalObject>(this)) { |
| if (isa<Function>(GO)) { |
| const MaybeAlign FunctionPtrAlign = DL.getFunctionPtrAlign(); |
| switch (DL.getFunctionPtrAlignType()) { |
| case DataLayout::FunctionPtrAlignType::Independent: |
| return FunctionPtrAlign; |
| case DataLayout::FunctionPtrAlignType::MultipleOfFunctionAlign: |
| return std::max(FunctionPtrAlign, MaybeAlign(GO->getAlignment())); |
| } |
| llvm_unreachable("Unhandled FunctionPtrAlignType"); |
| } |
| const MaybeAlign Alignment(GO->getAlignment()); |
| if (!Alignment) { |
| if (auto *GVar = dyn_cast<GlobalVariable>(GO)) { |
| Type *ObjectType = GVar->getValueType(); |
| if (ObjectType->isSized()) { |
| // If the object is defined in the current Module, we'll be giving |
| // it the preferred alignment. Otherwise, we have to assume that it |
| // may only have the minimum ABI alignment. |
| if (GVar->isStrongDefinitionForLinker()) |
| return MaybeAlign(DL.getPreferredAlignment(GVar)); |
| else |
| return Align(DL.getABITypeAlignment(ObjectType)); |
| } |
| } |
| } |
| return Alignment; |
| } else if (const Argument *A = dyn_cast<Argument>(this)) { |
| const MaybeAlign Alignment(A->getParamAlignment()); |
| if (!Alignment && A->hasStructRetAttr()) { |
| // An sret parameter has at least the ABI alignment of the return type. |
| Type *EltTy = cast<PointerType>(A->getType())->getElementType(); |
| if (EltTy->isSized()) |
| return Align(DL.getABITypeAlignment(EltTy)); |
| } |
| return Alignment; |
| } else if (const AllocaInst *AI = dyn_cast<AllocaInst>(this)) { |
| const MaybeAlign Alignment(AI->getAlignment()); |
| if (!Alignment) { |
| Type *AllocatedType = AI->getAllocatedType(); |
| if (AllocatedType->isSized()) |
| return MaybeAlign(DL.getPrefTypeAlignment(AllocatedType)); |
| } |
| return Alignment; |
| } else if (const auto *Call = dyn_cast<CallBase>(this)) { |
| const MaybeAlign Alignment(Call->getRetAlignment()); |
| if (!Alignment && Call->getCalledFunction()) |
| return MaybeAlign( |
| Call->getCalledFunction()->getAttributes().getRetAlignment()); |
| return Alignment; |
| } else if (const LoadInst *LI = dyn_cast<LoadInst>(this)) { |
| if (MDNode *MD = LI->getMetadata(LLVMContext::MD_align)) { |
| ConstantInt *CI = mdconst::extract<ConstantInt>(MD->getOperand(0)); |
| return MaybeAlign(CI->getLimitedValue()); |
| } |
| } |
| return llvm::None; |
| } |
| |
| const Value *Value::DoPHITranslation(const BasicBlock *CurBB, |
| const BasicBlock *PredBB) const { |
| auto *PN = dyn_cast<PHINode>(this); |
| if (PN && PN->getParent() == CurBB) |
| return PN->getIncomingValueForBlock(PredBB); |
| return this; |
| } |
| |
| LLVMContext &Value::getContext() const { return VTy->getContext(); } |
| |
| void Value::reverseUseList() { |
| if (!UseList || !UseList->Next) |
| // No need to reverse 0 or 1 uses. |
| return; |
| |
| Use *Head = UseList; |
| Use *Current = UseList->Next; |
| Head->Next = nullptr; |
| while (Current) { |
| Use *Next = Current->Next; |
| Current->Next = Head; |
| Head->setPrev(&Current->Next); |
| Head = Current; |
| Current = Next; |
| } |
| UseList = Head; |
| Head->setPrev(&UseList); |
| } |
| |
| bool Value::isSwiftError() const { |
| auto *Arg = dyn_cast<Argument>(this); |
| if (Arg) |
| return Arg->hasSwiftErrorAttr(); |
| auto *Alloca = dyn_cast<AllocaInst>(this); |
| if (!Alloca) |
| return false; |
| return Alloca->isSwiftError(); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // ValueHandleBase Class |
| //===----------------------------------------------------------------------===// |
| |
| void ValueHandleBase::AddToExistingUseList(ValueHandleBase **List) { |
| assert(List && "Handle list is null?"); |
| |
| // Splice ourselves into the list. |
| Next = *List; |
| *List = this; |
| setPrevPtr(List); |
| if (Next) { |
| Next->setPrevPtr(&Next); |
| assert(getValPtr() == Next->getValPtr() && "Added to wrong list?"); |
| } |
| } |
| |
| void ValueHandleBase::AddToExistingUseListAfter(ValueHandleBase *List) { |
| assert(List && "Must insert after existing node"); |
| |
| Next = List->Next; |
| setPrevPtr(&List->Next); |
| List->Next = this; |
| if (Next) |
| Next->setPrevPtr(&Next); |
| } |
| |
| void ValueHandleBase::AddToUseList() { |
| assert(getValPtr() && "Null pointer doesn't have a use list!"); |
| |
| LLVMContextImpl *pImpl = getValPtr()->getContext().pImpl; |
| |
| if (getValPtr()->HasValueHandle) { |
| // If this value already has a ValueHandle, then it must be in the |
| // ValueHandles map already. |
| ValueHandleBase *&Entry = pImpl->ValueHandles[getValPtr()]; |
| assert(Entry && "Value doesn't have any handles?"); |
| AddToExistingUseList(&Entry); |
| return; |
| } |
| |
| // Ok, it doesn't have any handles yet, so we must insert it into the |
| // DenseMap. However, doing this insertion could cause the DenseMap to |
| // reallocate itself, which would invalidate all of the PrevP pointers that |
| // point into the old table. Handle this by checking for reallocation and |
| // updating the stale pointers only if needed. |
| DenseMap<Value*, ValueHandleBase*> &Handles = pImpl->ValueHandles; |
| const void *OldBucketPtr = Handles.getPointerIntoBucketsArray(); |
| |
| ValueHandleBase *&Entry = Handles[getValPtr()]; |
| assert(!Entry && "Value really did already have handles?"); |
| AddToExistingUseList(&Entry); |
| getValPtr()->HasValueHandle = true; |
| |
| // If reallocation didn't happen or if this was the first insertion, don't |
| // walk the table. |
| if (Handles.isPointerIntoBucketsArray(OldBucketPtr) || |
| Handles.size() == 1) { |
| return; |
| } |
| |
| // Okay, reallocation did happen. Fix the Prev Pointers. |
| for (DenseMap<Value*, ValueHandleBase*>::iterator I = Handles.begin(), |
| E = Handles.end(); I != E; ++I) { |
| assert(I->second && I->first == I->second->getValPtr() && |
| "List invariant broken!"); |
| I->second->setPrevPtr(&I->second); |
| } |
| } |
| |
| void ValueHandleBase::RemoveFromUseList() { |
| assert(getValPtr() && getValPtr()->HasValueHandle && |
| "Pointer doesn't have a use list!"); |
| |
| // Unlink this from its use list. |
| ValueHandleBase **PrevPtr = getPrevPtr(); |
| assert(*PrevPtr == this && "List invariant broken"); |
| |
| *PrevPtr = Next; |
| if (Next) { |
| assert(Next->getPrevPtr() == &Next && "List invariant broken"); |
| Next->setPrevPtr(PrevPtr); |
| return; |
| } |
| |
| // If the Next pointer was null, then it is possible that this was the last |
| // ValueHandle watching VP. If so, delete its entry from the ValueHandles |
| // map. |
| LLVMContextImpl *pImpl = getValPtr()->getContext().pImpl; |
| DenseMap<Value*, ValueHandleBase*> &Handles = pImpl->ValueHandles; |
| if (Handles.isPointerIntoBucketsArray(PrevPtr)) { |
| Handles.erase(getValPtr()); |
| getValPtr()->HasValueHandle = false; |
| } |
| } |
| |
| void ValueHandleBase::ValueIsDeleted(Value *V) { |
| assert(V->HasValueHandle && "Should only be called if ValueHandles present"); |
| |
| // Get the linked list base, which is guaranteed to exist since the |
| // HasValueHandle flag is set. |
| LLVMContextImpl *pImpl = V->getContext().pImpl; |
| ValueHandleBase *Entry = pImpl->ValueHandles[V]; |
| assert(Entry && "Value bit set but no entries exist"); |
| |
| // We use a local ValueHandleBase as an iterator so that ValueHandles can add |
| // and remove themselves from the list without breaking our iteration. This |
| // is not really an AssertingVH; we just have to give ValueHandleBase a kind. |
| // Note that we deliberately do not the support the case when dropping a value |
| // handle results in a new value handle being permanently added to the list |
| // (as might occur in theory for CallbackVH's): the new value handle will not |
| // be processed and the checking code will mete out righteous punishment if |
| // the handle is still present once we have finished processing all the other |
| // value handles (it is fine to momentarily add then remove a value handle). |
| for (ValueHandleBase Iterator(Assert, *Entry); Entry; Entry = Iterator.Next) { |
| Iterator.RemoveFromUseList(); |
| Iterator.AddToExistingUseListAfter(Entry); |
| assert(Entry->Next == &Iterator && "Loop invariant broken."); |
| |
| switch (Entry->getKind()) { |
| case Assert: |
| break; |
| case Weak: |
| case WeakTracking: |
| // WeakTracking and Weak just go to null, which unlinks them |
| // from the list. |
| Entry->operator=(nullptr); |
| break; |
| case Callback: |
| // Forward to the subclass's implementation. |
| static_cast<CallbackVH*>(Entry)->deleted(); |
| break; |
| } |
| } |
| |
| // All callbacks, weak references, and assertingVHs should be dropped by now. |
| if (V->HasValueHandle) { |
| #ifndef NDEBUG // Only in +Asserts mode... |
| dbgs() << "While deleting: " << *V->getType() << " %" << V->getName() |
| << "\n"; |
| if (pImpl->ValueHandles[V]->getKind() == Assert) |
| llvm_unreachable("An asserting value handle still pointed to this" |
| " value!"); |
| |
| #endif |
| llvm_unreachable("All references to V were not removed?"); |
| } |
| } |
| |
| void ValueHandleBase::ValueIsRAUWd(Value *Old, Value *New) { |
| assert(Old->HasValueHandle &&"Should only be called if ValueHandles present"); |
| assert(Old != New && "Changing value into itself!"); |
| assert(Old->getType() == New->getType() && |
| "replaceAllUses of value with new value of different type!"); |
| |
| // Get the linked list base, which is guaranteed to exist since the |
| // HasValueHandle flag is set. |
| LLVMContextImpl *pImpl = Old->getContext().pImpl; |
| ValueHandleBase *Entry = pImpl->ValueHandles[Old]; |
| |
| assert(Entry && "Value bit set but no entries exist"); |
| |
| // We use a local ValueHandleBase as an iterator so that |
| // ValueHandles can add and remove themselves from the list without |
| // breaking our iteration. This is not really an AssertingVH; we |
| // just have to give ValueHandleBase some kind. |
| for (ValueHandleBase Iterator(Assert, *Entry); Entry; Entry = Iterator.Next) { |
| Iterator.RemoveFromUseList(); |
| Iterator.AddToExistingUseListAfter(Entry); |
| assert(Entry->Next == &Iterator && "Loop invariant broken."); |
| |
| switch (Entry->getKind()) { |
| case Assert: |
| case Weak: |
| // Asserting and Weak handles do not follow RAUW implicitly. |
| break; |
| case WeakTracking: |
| // Weak goes to the new value, which will unlink it from Old's list. |
| Entry->operator=(New); |
| break; |
| case Callback: |
| // Forward to the subclass's implementation. |
| static_cast<CallbackVH*>(Entry)->allUsesReplacedWith(New); |
| break; |
| } |
| } |
| |
| #ifndef NDEBUG |
| // If any new weak value handles were added while processing the |
| // list, then complain about it now. |
| if (Old->HasValueHandle) |
| for (Entry = pImpl->ValueHandles[Old]; Entry; Entry = Entry->Next) |
| switch (Entry->getKind()) { |
| case WeakTracking: |
| dbgs() << "After RAUW from " << *Old->getType() << " %" |
| << Old->getName() << " to " << *New->getType() << " %" |
| << New->getName() << "\n"; |
| llvm_unreachable( |
| "A weak tracking value handle still pointed to the old value!\n"); |
| default: |
| break; |
| } |
| #endif |
| } |
| |
| // Pin the vtable to this file. |
| void CallbackVH::anchor() {} |