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Diffstat (limited to 'gnu/llvm/tools/clang/lib/CodeGen/CGCleanup.cpp')
| -rw-r--r-- | gnu/llvm/tools/clang/lib/CodeGen/CGCleanup.cpp | 1283 |
1 files changed, 0 insertions, 1283 deletions
diff --git a/gnu/llvm/tools/clang/lib/CodeGen/CGCleanup.cpp b/gnu/llvm/tools/clang/lib/CodeGen/CGCleanup.cpp deleted file mode 100644 index 3743d24f11f..00000000000 --- a/gnu/llvm/tools/clang/lib/CodeGen/CGCleanup.cpp +++ /dev/null @@ -1,1283 +0,0 @@ -//===--- CGCleanup.cpp - Bookkeeping and code emission for cleanups -------===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This file contains code dealing with the IR generation for cleanups -// and related information. -// -// A "cleanup" is a piece of code which needs to be executed whenever -// control transfers out of a particular scope. This can be -// conditionalized to occur only on exceptional control flow, only on -// normal control flow, or both. -// -//===----------------------------------------------------------------------===// - -#include "CGCleanup.h" -#include "CodeGenFunction.h" -#include "llvm/Support/SaveAndRestore.h" - -using namespace clang; -using namespace CodeGen; - -bool DominatingValue<RValue>::saved_type::needsSaving(RValue rv) { - if (rv.isScalar()) - return DominatingLLVMValue::needsSaving(rv.getScalarVal()); - if (rv.isAggregate()) - return DominatingLLVMValue::needsSaving(rv.getAggregatePointer()); - return true; -} - -DominatingValue<RValue>::saved_type -DominatingValue<RValue>::saved_type::save(CodeGenFunction &CGF, RValue rv) { - if (rv.isScalar()) { - llvm::Value *V = rv.getScalarVal(); - - // These automatically dominate and don't need to be saved. - if (!DominatingLLVMValue::needsSaving(V)) - return saved_type(V, ScalarLiteral); - - // Everything else needs an alloca. - Address addr = - CGF.CreateDefaultAlignTempAlloca(V->getType(), "saved-rvalue"); - CGF.Builder.CreateStore(V, addr); - return saved_type(addr.getPointer(), ScalarAddress); - } - - if (rv.isComplex()) { - CodeGenFunction::ComplexPairTy V = rv.getComplexVal(); - llvm::Type *ComplexTy = - llvm::StructType::get(V.first->getType(), V.second->getType()); - Address addr = CGF.CreateDefaultAlignTempAlloca(ComplexTy, "saved-complex"); - CGF.Builder.CreateStore(V.first, - CGF.Builder.CreateStructGEP(addr, 0, CharUnits())); - CharUnits offset = CharUnits::fromQuantity( - CGF.CGM.getDataLayout().getTypeAllocSize(V.first->getType())); - CGF.Builder.CreateStore(V.second, - CGF.Builder.CreateStructGEP(addr, 1, offset)); - return saved_type(addr.getPointer(), ComplexAddress); - } - - assert(rv.isAggregate()); - Address V = rv.getAggregateAddress(); // TODO: volatile? - if (!DominatingLLVMValue::needsSaving(V.getPointer())) - return saved_type(V.getPointer(), AggregateLiteral, - V.getAlignment().getQuantity()); - - Address addr = - CGF.CreateTempAlloca(V.getType(), CGF.getPointerAlign(), "saved-rvalue"); - CGF.Builder.CreateStore(V.getPointer(), addr); - return saved_type(addr.getPointer(), AggregateAddress, - V.getAlignment().getQuantity()); -} - -/// Given a saved r-value produced by SaveRValue, perform the code -/// necessary to restore it to usability at the current insertion -/// point. -RValue DominatingValue<RValue>::saved_type::restore(CodeGenFunction &CGF) { - auto getSavingAddress = [&](llvm::Value *value) { - auto alignment = cast<llvm::AllocaInst>(value)->getAlignment(); - return Address(value, CharUnits::fromQuantity(alignment)); - }; - switch (K) { - case ScalarLiteral: - return RValue::get(Value); - case ScalarAddress: - return RValue::get(CGF.Builder.CreateLoad(getSavingAddress(Value))); - case AggregateLiteral: - return RValue::getAggregate(Address(Value, CharUnits::fromQuantity(Align))); - case AggregateAddress: { - auto addr = CGF.Builder.CreateLoad(getSavingAddress(Value)); - return RValue::getAggregate(Address(addr, CharUnits::fromQuantity(Align))); - } - case ComplexAddress: { - Address address = getSavingAddress(Value); - llvm::Value *real = CGF.Builder.CreateLoad( - CGF.Builder.CreateStructGEP(address, 0, CharUnits())); - CharUnits offset = CharUnits::fromQuantity( - CGF.CGM.getDataLayout().getTypeAllocSize(real->getType())); - llvm::Value *imag = CGF.Builder.CreateLoad( - CGF.Builder.CreateStructGEP(address, 1, offset)); - return RValue::getComplex(real, imag); - } - } - - llvm_unreachable("bad saved r-value kind"); -} - -/// Push an entry of the given size onto this protected-scope stack. -char *EHScopeStack::allocate(size_t Size) { - Size = llvm::alignTo(Size, ScopeStackAlignment); - if (!StartOfBuffer) { - unsigned Capacity = 1024; - while (Capacity < Size) Capacity *= 2; - StartOfBuffer = new char[Capacity]; - StartOfData = EndOfBuffer = StartOfBuffer + Capacity; - } else if (static_cast<size_t>(StartOfData - StartOfBuffer) < Size) { - unsigned CurrentCapacity = EndOfBuffer - StartOfBuffer; - unsigned UsedCapacity = CurrentCapacity - (StartOfData - StartOfBuffer); - - unsigned NewCapacity = CurrentCapacity; - do { - NewCapacity *= 2; - } while (NewCapacity < UsedCapacity + Size); - - char *NewStartOfBuffer = new char[NewCapacity]; - char *NewEndOfBuffer = NewStartOfBuffer + NewCapacity; - char *NewStartOfData = NewEndOfBuffer - UsedCapacity; - memcpy(NewStartOfData, StartOfData, UsedCapacity); - delete [] StartOfBuffer; - StartOfBuffer = NewStartOfBuffer; - EndOfBuffer = NewEndOfBuffer; - StartOfData = NewStartOfData; - } - - assert(StartOfBuffer + Size <= StartOfData); - StartOfData -= Size; - return StartOfData; -} - -void EHScopeStack::deallocate(size_t Size) { - StartOfData += llvm::alignTo(Size, ScopeStackAlignment); -} - -bool EHScopeStack::containsOnlyLifetimeMarkers( - EHScopeStack::stable_iterator Old) const { - for (EHScopeStack::iterator it = begin(); stabilize(it) != Old; it++) { - EHCleanupScope *cleanup = dyn_cast<EHCleanupScope>(&*it); - if (!cleanup || !cleanup->isLifetimeMarker()) - return false; - } - - return true; -} - -bool EHScopeStack::requiresLandingPad() const { - for (stable_iterator si = getInnermostEHScope(); si != stable_end(); ) { - // Skip lifetime markers. - if (auto *cleanup = dyn_cast<EHCleanupScope>(&*find(si))) - if (cleanup->isLifetimeMarker()) { - si = cleanup->getEnclosingEHScope(); - continue; - } - return true; - } - - return false; -} - -EHScopeStack::stable_iterator -EHScopeStack::getInnermostActiveNormalCleanup() const { - for (stable_iterator si = getInnermostNormalCleanup(), se = stable_end(); - si != se; ) { - EHCleanupScope &cleanup = cast<EHCleanupScope>(*find(si)); - if (cleanup.isActive()) return si; - si = cleanup.getEnclosingNormalCleanup(); - } - return stable_end(); -} - - -void *EHScopeStack::pushCleanup(CleanupKind Kind, size_t Size) { - char *Buffer = allocate(EHCleanupScope::getSizeForCleanupSize(Size)); - bool IsNormalCleanup = Kind & NormalCleanup; - bool IsEHCleanup = Kind & EHCleanup; - bool IsActive = !(Kind & InactiveCleanup); - bool IsLifetimeMarker = Kind & LifetimeMarker; - EHCleanupScope *Scope = - new (Buffer) EHCleanupScope(IsNormalCleanup, - IsEHCleanup, - IsActive, - Size, - BranchFixups.size(), - InnermostNormalCleanup, - InnermostEHScope); - if (IsNormalCleanup) - InnermostNormalCleanup = stable_begin(); - if (IsEHCleanup) - InnermostEHScope = stable_begin(); - if (IsLifetimeMarker) - Scope->setLifetimeMarker(); - - return Scope->getCleanupBuffer(); -} - -void EHScopeStack::popCleanup() { - assert(!empty() && "popping exception stack when not empty"); - - assert(isa<EHCleanupScope>(*begin())); - EHCleanupScope &Cleanup = cast<EHCleanupScope>(*begin()); - InnermostNormalCleanup = Cleanup.getEnclosingNormalCleanup(); - InnermostEHScope = Cleanup.getEnclosingEHScope(); - deallocate(Cleanup.getAllocatedSize()); - - // Destroy the cleanup. - Cleanup.Destroy(); - - // Check whether we can shrink the branch-fixups stack. - if (!BranchFixups.empty()) { - // If we no longer have any normal cleanups, all the fixups are - // complete. - if (!hasNormalCleanups()) - BranchFixups.clear(); - - // Otherwise we can still trim out unnecessary nulls. - else - popNullFixups(); - } -} - -EHFilterScope *EHScopeStack::pushFilter(unsigned numFilters) { - assert(getInnermostEHScope() == stable_end()); - char *buffer = allocate(EHFilterScope::getSizeForNumFilters(numFilters)); - EHFilterScope *filter = new (buffer) EHFilterScope(numFilters); - InnermostEHScope = stable_begin(); - return filter; -} - -void EHScopeStack::popFilter() { - assert(!empty() && "popping exception stack when not empty"); - - EHFilterScope &filter = cast<EHFilterScope>(*begin()); - deallocate(EHFilterScope::getSizeForNumFilters(filter.getNumFilters())); - - InnermostEHScope = filter.getEnclosingEHScope(); -} - -EHCatchScope *EHScopeStack::pushCatch(unsigned numHandlers) { - char *buffer = allocate(EHCatchScope::getSizeForNumHandlers(numHandlers)); - EHCatchScope *scope = - new (buffer) EHCatchScope(numHandlers, InnermostEHScope); - InnermostEHScope = stable_begin(); - return scope; -} - -void EHScopeStack::pushTerminate() { - char *Buffer = allocate(EHTerminateScope::getSize()); - new (Buffer) EHTerminateScope(InnermostEHScope); - InnermostEHScope = stable_begin(); -} - -/// Remove any 'null' fixups on the stack. However, we can't pop more -/// fixups than the fixup depth on the innermost normal cleanup, or -/// else fixups that we try to add to that cleanup will end up in the -/// wrong place. We *could* try to shrink fixup depths, but that's -/// actually a lot of work for little benefit. -void EHScopeStack::popNullFixups() { - // We expect this to only be called when there's still an innermost - // normal cleanup; otherwise there really shouldn't be any fixups. - assert(hasNormalCleanups()); - - EHScopeStack::iterator it = find(InnermostNormalCleanup); - unsigned MinSize = cast<EHCleanupScope>(*it).getFixupDepth(); - assert(BranchFixups.size() >= MinSize && "fixup stack out of order"); - - while (BranchFixups.size() > MinSize && - BranchFixups.back().Destination == nullptr) - BranchFixups.pop_back(); -} - -Address CodeGenFunction::createCleanupActiveFlag() { - // Create a variable to decide whether the cleanup needs to be run. - Address active = CreateTempAllocaWithoutCast( - Builder.getInt1Ty(), CharUnits::One(), "cleanup.cond"); - - // Initialize it to false at a site that's guaranteed to be run - // before each evaluation. - setBeforeOutermostConditional(Builder.getFalse(), active); - - // Initialize it to true at the current location. - Builder.CreateStore(Builder.getTrue(), active); - - return active; -} - -void CodeGenFunction::initFullExprCleanupWithFlag(Address ActiveFlag) { - // Set that as the active flag in the cleanup. - EHCleanupScope &cleanup = cast<EHCleanupScope>(*EHStack.begin()); - assert(!cleanup.hasActiveFlag() && "cleanup already has active flag?"); - cleanup.setActiveFlag(ActiveFlag); - - if (cleanup.isNormalCleanup()) cleanup.setTestFlagInNormalCleanup(); - if (cleanup.isEHCleanup()) cleanup.setTestFlagInEHCleanup(); -} - -void EHScopeStack::Cleanup::anchor() {} - -static void createStoreInstBefore(llvm::Value *value, Address addr, - llvm::Instruction *beforeInst) { - auto store = new llvm::StoreInst(value, addr.getPointer(), beforeInst); - store->setAlignment(addr.getAlignment().getQuantity()); -} - -static llvm::LoadInst *createLoadInstBefore(Address addr, const Twine &name, - llvm::Instruction *beforeInst) { - auto load = new llvm::LoadInst(addr.getPointer(), name, beforeInst); - load->setAlignment(addr.getAlignment().getQuantity()); - return load; -} - -/// All the branch fixups on the EH stack have propagated out past the -/// outermost normal cleanup; resolve them all by adding cases to the -/// given switch instruction. -static void ResolveAllBranchFixups(CodeGenFunction &CGF, - llvm::SwitchInst *Switch, - llvm::BasicBlock *CleanupEntry) { - llvm::SmallPtrSet<llvm::BasicBlock*, 4> CasesAdded; - - for (unsigned I = 0, E = CGF.EHStack.getNumBranchFixups(); I != E; ++I) { - // Skip this fixup if its destination isn't set. - BranchFixup &Fixup = CGF.EHStack.getBranchFixup(I); - if (Fixup.Destination == nullptr) continue; - - // If there isn't an OptimisticBranchBlock, then InitialBranch is - // still pointing directly to its destination; forward it to the - // appropriate cleanup entry. This is required in the specific - // case of - // { std::string s; goto lbl; } - // lbl: - // i.e. where there's an unresolved fixup inside a single cleanup - // entry which we're currently popping. - if (Fixup.OptimisticBranchBlock == nullptr) { - createStoreInstBefore(CGF.Builder.getInt32(Fixup.DestinationIndex), - CGF.getNormalCleanupDestSlot(), - Fixup.InitialBranch); - Fixup.InitialBranch->setSuccessor(0, CleanupEntry); - } - - // Don't add this case to the switch statement twice. - if (!CasesAdded.insert(Fixup.Destination).second) - continue; - - Switch->addCase(CGF.Builder.getInt32(Fixup.DestinationIndex), - Fixup.Destination); - } - - CGF.EHStack.clearFixups(); -} - -/// Transitions the terminator of the given exit-block of a cleanup to -/// be a cleanup switch. -static llvm::SwitchInst *TransitionToCleanupSwitch(CodeGenFunction &CGF, - llvm::BasicBlock *Block) { - // If it's a branch, turn it into a switch whose default - // destination is its original target. - llvm::Instruction *Term = Block->getTerminator(); - assert(Term && "can't transition block without terminator"); - - if (llvm::BranchInst *Br = dyn_cast<llvm::BranchInst>(Term)) { - assert(Br->isUnconditional()); - auto Load = createLoadInstBefore(CGF.getNormalCleanupDestSlot(), - "cleanup.dest", Term); - llvm::SwitchInst *Switch = - llvm::SwitchInst::Create(Load, Br->getSuccessor(0), 4, Block); - Br->eraseFromParent(); - return Switch; - } else { - return cast<llvm::SwitchInst>(Term); - } -} - -void CodeGenFunction::ResolveBranchFixups(llvm::BasicBlock *Block) { - assert(Block && "resolving a null target block"); - if (!EHStack.getNumBranchFixups()) return; - - assert(EHStack.hasNormalCleanups() && - "branch fixups exist with no normal cleanups on stack"); - - llvm::SmallPtrSet<llvm::BasicBlock*, 4> ModifiedOptimisticBlocks; - bool ResolvedAny = false; - - for (unsigned I = 0, E = EHStack.getNumBranchFixups(); I != E; ++I) { - // Skip this fixup if its destination doesn't match. - BranchFixup &Fixup = EHStack.getBranchFixup(I); - if (Fixup.Destination != Block) continue; - - Fixup.Destination = nullptr; - ResolvedAny = true; - - // If it doesn't have an optimistic branch block, LatestBranch is - // already pointing to the right place. - llvm::BasicBlock *BranchBB = Fixup.OptimisticBranchBlock; - if (!BranchBB) - continue; - - // Don't process the same optimistic branch block twice. - if (!ModifiedOptimisticBlocks.insert(BranchBB).second) - continue; - - llvm::SwitchInst *Switch = TransitionToCleanupSwitch(*this, BranchBB); - - // Add a case to the switch. - Switch->addCase(Builder.getInt32(Fixup.DestinationIndex), Block); - } - - if (ResolvedAny) - EHStack.popNullFixups(); -} - -/// Pops cleanup blocks until the given savepoint is reached. -void CodeGenFunction::PopCleanupBlocks( - EHScopeStack::stable_iterator Old, - std::initializer_list<llvm::Value **> ValuesToReload) { - assert(Old.isValid()); - - bool HadBranches = false; - while (EHStack.stable_begin() != Old) { - EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.begin()); - HadBranches |= Scope.hasBranches(); - - // As long as Old strictly encloses the scope's enclosing normal - // cleanup, we're going to emit another normal cleanup which - // fallthrough can propagate through. - bool FallThroughIsBranchThrough = - Old.strictlyEncloses(Scope.getEnclosingNormalCleanup()); - - PopCleanupBlock(FallThroughIsBranchThrough); - } - - // If we didn't have any branches, the insertion point before cleanups must - // dominate the current insertion point and we don't need to reload any - // values. - if (!HadBranches) - return; - - // Spill and reload all values that the caller wants to be live at the current - // insertion point. - for (llvm::Value **ReloadedValue : ValuesToReload) { - auto *Inst = dyn_cast_or_null<llvm::Instruction>(*ReloadedValue); - if (!Inst) - continue; - - // Don't spill static allocas, they dominate all cleanups. These are created - // by binding a reference to a local variable or temporary. - auto *AI = dyn_cast<llvm::AllocaInst>(Inst); - if (AI && AI->isStaticAlloca()) - continue; - - Address Tmp = - CreateDefaultAlignTempAlloca(Inst->getType(), "tmp.exprcleanup"); - - // Find an insertion point after Inst and spill it to the temporary. - llvm::BasicBlock::iterator InsertBefore; - if (auto *Invoke = dyn_cast<llvm::InvokeInst>(Inst)) - InsertBefore = Invoke->getNormalDest()->getFirstInsertionPt(); - else - InsertBefore = std::next(Inst->getIterator()); - CGBuilderTy(CGM, &*InsertBefore).CreateStore(Inst, Tmp); - - // Reload the value at the current insertion point. - *ReloadedValue = Builder.CreateLoad(Tmp); - } -} - -/// Pops cleanup blocks until the given savepoint is reached, then add the -/// cleanups from the given savepoint in the lifetime-extended cleanups stack. -void CodeGenFunction::PopCleanupBlocks( - EHScopeStack::stable_iterator Old, size_t OldLifetimeExtendedSize, - std::initializer_list<llvm::Value **> ValuesToReload) { - PopCleanupBlocks(Old, ValuesToReload); - - // Move our deferred cleanups onto the EH stack. - for (size_t I = OldLifetimeExtendedSize, - E = LifetimeExtendedCleanupStack.size(); I != E; /**/) { - // Alignment should be guaranteed by the vptrs in the individual cleanups. - assert((I % alignof(LifetimeExtendedCleanupHeader) == 0) && - "misaligned cleanup stack entry"); - - LifetimeExtendedCleanupHeader &Header = - reinterpret_cast<LifetimeExtendedCleanupHeader&>( - LifetimeExtendedCleanupStack[I]); - I += sizeof(Header); - - EHStack.pushCopyOfCleanup(Header.getKind(), - &LifetimeExtendedCleanupStack[I], - Header.getSize()); - I += Header.getSize(); - - if (Header.isConditional()) { - Address ActiveFlag = - reinterpret_cast<Address &>(LifetimeExtendedCleanupStack[I]); - initFullExprCleanupWithFlag(ActiveFlag); - I += sizeof(ActiveFlag); - } - } - LifetimeExtendedCleanupStack.resize(OldLifetimeExtendedSize); -} - -static llvm::BasicBlock *CreateNormalEntry(CodeGenFunction &CGF, - EHCleanupScope &Scope) { - assert(Scope.isNormalCleanup()); - llvm::BasicBlock *Entry = Scope.getNormalBlock(); - if (!Entry) { - Entry = CGF.createBasicBlock("cleanup"); - Scope.setNormalBlock(Entry); - } - return Entry; -} - -/// Attempts to reduce a cleanup's entry block to a fallthrough. This -/// is basically llvm::MergeBlockIntoPredecessor, except -/// simplified/optimized for the tighter constraints on cleanup blocks. -/// -/// Returns the new block, whatever it is. -static llvm::BasicBlock *SimplifyCleanupEntry(CodeGenFunction &CGF, - llvm::BasicBlock *Entry) { - llvm::BasicBlock *Pred = Entry->getSinglePredecessor(); - if (!Pred) return Entry; - - llvm::BranchInst *Br = dyn_cast<llvm::BranchInst>(Pred->getTerminator()); - if (!Br || Br->isConditional()) return Entry; - assert(Br->getSuccessor(0) == Entry); - - // If we were previously inserting at the end of the cleanup entry - // block, we'll need to continue inserting at the end of the - // predecessor. - bool WasInsertBlock = CGF.Builder.GetInsertBlock() == Entry; - assert(!WasInsertBlock || CGF.Builder.GetInsertPoint() == Entry->end()); - - // Kill the branch. - Br->eraseFromParent(); - - // Replace all uses of the entry with the predecessor, in case there - // are phis in the cleanup. - Entry->replaceAllUsesWith(Pred); - - // Merge the blocks. - Pred->getInstList().splice(Pred->end(), Entry->getInstList()); - - // Kill the entry block. - Entry->eraseFromParent(); - - if (WasInsertBlock) - CGF.Builder.SetInsertPoint(Pred); - - return Pred; -} - -static void EmitCleanup(CodeGenFunction &CGF, - EHScopeStack::Cleanup *Fn, - EHScopeStack::Cleanup::Flags flags, - Address ActiveFlag) { - // If there's an active flag, load it and skip the cleanup if it's - // false. - llvm::BasicBlock *ContBB = nullptr; - if (ActiveFlag.isValid()) { - ContBB = CGF.createBasicBlock("cleanup.done"); - llvm::BasicBlock *CleanupBB = CGF.createBasicBlock("cleanup.action"); - llvm::Value *IsActive - = CGF.Builder.CreateLoad(ActiveFlag, "cleanup.is_active"); - CGF.Builder.CreateCondBr(IsActive, CleanupBB, ContBB); - CGF.EmitBlock(CleanupBB); - } - - // Ask the cleanup to emit itself. - Fn->Emit(CGF, flags); - assert(CGF.HaveInsertPoint() && "cleanup ended with no insertion point?"); - - // Emit the continuation block if there was an active flag. - if (ActiveFlag.isValid()) - CGF.EmitBlock(ContBB); -} - -static void ForwardPrebranchedFallthrough(llvm::BasicBlock *Exit, - llvm::BasicBlock *From, - llvm::BasicBlock *To) { - // Exit is the exit block of a cleanup, so it always terminates in - // an unconditional branch or a switch. - llvm::Instruction *Term = Exit->getTerminator(); - - if (llvm::BranchInst *Br = dyn_cast<llvm::BranchInst>(Term)) { - assert(Br->isUnconditional() && Br->getSuccessor(0) == From); - Br->setSuccessor(0, To); - } else { - llvm::SwitchInst *Switch = cast<llvm::SwitchInst>(Term); - for (unsigned I = 0, E = Switch->getNumSuccessors(); I != E; ++I) - if (Switch->getSuccessor(I) == From) - Switch->setSuccessor(I, To); - } -} - -/// We don't need a normal entry block for the given cleanup. -/// Optimistic fixup branches can cause these blocks to come into -/// existence anyway; if so, destroy it. -/// -/// The validity of this transformation is very much specific to the -/// exact ways in which we form branches to cleanup entries. -static void destroyOptimisticNormalEntry(CodeGenFunction &CGF, - EHCleanupScope &scope) { - llvm::BasicBlock *entry = scope.getNormalBlock(); - if (!entry) return; - - // Replace all the uses with unreachable. - llvm::BasicBlock *unreachableBB = CGF.getUnreachableBlock(); - for (llvm::BasicBlock::use_iterator - i = entry->use_begin(), e = entry->use_end(); i != e; ) { - llvm::Use &use = *i; - ++i; - - use.set(unreachableBB); - - // The only uses should be fixup switches. - llvm::SwitchInst *si = cast<llvm::SwitchInst>(use.getUser()); - if (si->getNumCases() == 1 && si->getDefaultDest() == unreachableBB) { - // Replace the switch with a branch. - llvm::BranchInst::Create(si->case_begin()->getCaseSuccessor(), si); - - // The switch operand is a load from the cleanup-dest alloca. - llvm::LoadInst *condition = cast<llvm::LoadInst>(si->getCondition()); - - // Destroy the switch. - si->eraseFromParent(); - - // Destroy the load. - assert(condition->getOperand(0) == CGF.NormalCleanupDest.getPointer()); - assert(condition->use_empty()); - condition->eraseFromParent(); - } - } - - assert(entry->use_empty()); - delete entry; -} - -/// Pops a cleanup block. If the block includes a normal cleanup, the -/// current insertion point is threaded through the cleanup, as are -/// any branch fixups on the cleanup. -void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough) { - assert(!EHStack.empty() && "cleanup stack is empty!"); - assert(isa<EHCleanupScope>(*EHStack.begin()) && "top not a cleanup!"); - EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.begin()); - assert(Scope.getFixupDepth() <= EHStack.getNumBranchFixups()); - - // Remember activation information. - bool IsActive = Scope.isActive(); - Address NormalActiveFlag = - Scope.shouldTestFlagInNormalCleanup() ? Scope.getActiveFlag() - : Address::invalid(); - Address EHActiveFlag = - Scope.shouldTestFlagInEHCleanup() ? Scope.getActiveFlag() - : Address::invalid(); - - // Check whether we need an EH cleanup. This is only true if we've - // generated a lazy EH cleanup block. - llvm::BasicBlock *EHEntry = Scope.getCachedEHDispatchBlock(); - assert(Scope.hasEHBranches() == (EHEntry != nullptr)); - bool RequiresEHCleanup = (EHEntry != nullptr); - EHScopeStack::stable_iterator EHParent = Scope.getEnclosingEHScope(); - - // Check the three conditions which might require a normal cleanup: - - // - whether there are branch fix-ups through this cleanup - unsigned FixupDepth = Scope.getFixupDepth(); - bool HasFixups = EHStack.getNumBranchFixups() != FixupDepth; - - // - whether there are branch-throughs or branch-afters - bool HasExistingBranches = Scope.hasBranches(); - - // - whether there's a fallthrough - llvm::BasicBlock *FallthroughSource = Builder.GetInsertBlock(); - bool HasFallthrough = (FallthroughSource != nullptr && IsActive); - - // Branch-through fall-throughs leave the insertion point set to the - // end of the last cleanup, which points to the current scope. The - // rest of IR gen doesn't need to worry about this; it only happens - // during the execution of PopCleanupBlocks(). - bool HasPrebranchedFallthrough = - (FallthroughSource && FallthroughSource->getTerminator()); - - // If this is a normal cleanup, then having a prebranched - // fallthrough implies that the fallthrough source unconditionally - // jumps here. - assert(!Scope.isNormalCleanup() || !HasPrebranchedFallthrough || - (Scope.getNormalBlock() && - FallthroughSource->getTerminator()->getSuccessor(0) - == Scope.getNormalBlock())); - - bool RequiresNormalCleanup = false; - if (Scope.isNormalCleanup() && - (HasFixups || HasExistingBranches || HasFallthrough)) { - RequiresNormalCleanup = true; - } - - // If we have a prebranched fallthrough into an inactive normal - // cleanup, rewrite it so that it leads to the appropriate place. - if (Scope.isNormalCleanup() && HasPrebranchedFallthrough && !IsActive) { - llvm::BasicBlock *prebranchDest; - - // If the prebranch is semantically branching through the next - // cleanup, just forward it to the next block, leaving the - // insertion point in the prebranched block. - if (FallthroughIsBranchThrough) { - EHScope &enclosing = *EHStack.find(Scope.getEnclosingNormalCleanup()); - prebranchDest = CreateNormalEntry(*this, cast<EHCleanupScope>(enclosing)); - - // Otherwise, we need to make a new block. If the normal cleanup - // isn't being used at all, we could actually reuse the normal - // entry block, but this is simpler, and it avoids conflicts with - // dead optimistic fixup branches. - } else { - prebranchDest = createBasicBlock("forwarded-prebranch"); - EmitBlock(prebranchDest); - } - - llvm::BasicBlock *normalEntry = Scope.getNormalBlock(); - assert(normalEntry && !normalEntry->use_empty()); - - ForwardPrebranchedFallthrough(FallthroughSource, - normalEntry, prebranchDest); - } - - // If we don't need the cleanup at all, we're done. - if (!RequiresNormalCleanup && !RequiresEHCleanup) { - destroyOptimisticNormalEntry(*this, Scope); - EHStack.popCleanup(); // safe because there are no fixups - assert(EHStack.getNumBranchFixups() == 0 || - EHStack.hasNormalCleanups()); - return; - } - - // Copy the cleanup emission data out. This uses either a stack - // array or malloc'd memory, depending on the size, which is - // behavior that SmallVector would provide, if we could use it - // here. Unfortunately, if you ask for a SmallVector<char>, the - // alignment isn't sufficient. - auto *CleanupSource = reinterpret_cast<char *>(Scope.getCleanupBuffer()); - llvm::AlignedCharArray<EHScopeStack::ScopeStackAlignment, 8 * sizeof(void *)> CleanupBufferStack; - std::unique_ptr<char[]> CleanupBufferHeap; - size_t CleanupSize = Scope.getCleanupSize(); - EHScopeStack::Cleanup *Fn; - - if (CleanupSize <= sizeof(CleanupBufferStack)) { - memcpy(CleanupBufferStack.buffer, CleanupSource, CleanupSize); - Fn = reinterpret_cast<EHScopeStack::Cleanup *>(CleanupBufferStack.buffer); - } else { - CleanupBufferHeap.reset(new char[CleanupSize]); - memcpy(CleanupBufferHeap.get(), CleanupSource, CleanupSize); - Fn = reinterpret_cast<EHScopeStack::Cleanup *>(CleanupBufferHeap.get()); - } - - EHScopeStack::Cleanup::Flags cleanupFlags; - if (Scope.isNormalCleanup()) - cleanupFlags.setIsNormalCleanupKind(); - if (Scope.isEHCleanup()) - cleanupFlags.setIsEHCleanupKind(); - - if (!RequiresNormalCleanup) { - destroyOptimisticNormalEntry(*this, Scope); - EHStack.popCleanup(); - } else { - // If we have a fallthrough and no other need for the cleanup, - // emit it directly. - if (HasFallthrough && !HasPrebranchedFallthrough && - !HasFixups && !HasExistingBranches) { - - destroyOptimisticNormalEntry(*this, Scope); - EHStack.popCleanup(); - - EmitCleanup(*this, Fn, cleanupFlags, NormalActiveFlag); - - // Otherwise, the best approach is to thread everything through - // the cleanup block and then try to clean up after ourselves. - } else { - // Force the entry block to exist. - llvm::BasicBlock *NormalEntry = CreateNormalEntry(*this, Scope); - - // I. Set up the fallthrough edge in. - - CGBuilderTy::InsertPoint savedInactiveFallthroughIP; - - // If there's a fallthrough, we need to store the cleanup - // destination index. For fall-throughs this is always zero. - if (HasFallthrough) { - if (!HasPrebranchedFallthrough) - Builder.CreateStore(Builder.getInt32(0), getNormalCleanupDestSlot()); - - // Otherwise, save and clear the IP if we don't have fallthrough - // because the cleanup is inactive. - } else if (FallthroughSource) { - assert(!IsActive && "source without fallthrough for active cleanup"); - savedInactiveFallthroughIP = Builder.saveAndClearIP(); - } - - // II. Emit the entry block. This implicitly branches to it if - // we have fallthrough. All the fixups and existing branches - // should already be branched to it. - EmitBlock(NormalEntry); - - // III. Figure out where we're going and build the cleanup - // epilogue. - - bool HasEnclosingCleanups = - (Scope.getEnclosingNormalCleanup() != EHStack.stable_end()); - - // Compute the branch-through dest if we need it: - // - if there are branch-throughs threaded through the scope - // - if fall-through is a branch-through - // - if there are fixups that will be optimistically forwarded - // to the enclosing cleanup - llvm::BasicBlock *BranchThroughDest = nullptr; - if (Scope.hasBranchThroughs() || - (FallthroughSource && FallthroughIsBranchThrough) || - (HasFixups && HasEnclosingCleanups)) { - assert(HasEnclosingCleanups); - EHScope &S = *EHStack.find(Scope.getEnclosingNormalCleanup()); - BranchThroughDest = CreateNormalEntry(*this, cast<EHCleanupScope>(S)); - } - - llvm::BasicBlock *FallthroughDest = nullptr; - SmallVector<llvm::Instruction*, 2> InstsToAppend; - - // If there's exactly one branch-after and no other threads, - // we can route it without a switch. - if (!Scope.hasBranchThroughs() && !HasFixups && !HasFallthrough && - Scope.getNumBranchAfters() == 1) { - assert(!BranchThroughDest || !IsActive); - - // Clean up the possibly dead store to the cleanup dest slot. - llvm::Instruction *NormalCleanupDestSlot = - cast<llvm::Instruction>(getNormalCleanupDestSlot().getPointer()); - if (NormalCleanupDestSlot->hasOneUse()) { - NormalCleanupDestSlot->user_back()->eraseFromParent(); - NormalCleanupDestSlot->eraseFromParent(); - NormalCleanupDest = Address::invalid(); - } - - llvm::BasicBlock *BranchAfter = Scope.getBranchAfterBlock(0); - InstsToAppend.push_back(llvm::BranchInst::Create(BranchAfter)); - - // Build a switch-out if we need it: - // - if there are branch-afters threaded through the scope - // - if fall-through is a branch-after - // - if there are fixups that have nowhere left to go and - // so must be immediately resolved - } else if (Scope.getNumBranchAfters() || - (HasFallthrough && !FallthroughIsBranchThrough) || - (HasFixups && !HasEnclosingCleanups)) { - - llvm::BasicBlock *Default = - (BranchThroughDest ? BranchThroughDest : getUnreachableBlock()); - - // TODO: base this on the number of branch-afters and fixups - const unsigned SwitchCapacity = 10; - - llvm::LoadInst *Load = - createLoadInstBefore(getNormalCleanupDestSlot(), "cleanup.dest", - nullptr); - llvm::SwitchInst *Switch = - llvm::SwitchInst::Create(Load, Default, SwitchCapacity); - - InstsToAppend.push_back(Load); - InstsToAppend.push_back(Switch); - - // Branch-after fallthrough. - if (FallthroughSource && !FallthroughIsBranchThrough) { - FallthroughDest = createBasicBlock("cleanup.cont"); - if (HasFallthrough) - Switch->addCase(Builder.getInt32(0), FallthroughDest); - } - - for (unsigned I = 0, E = Scope.getNumBranchAfters(); I != E; ++I) { - Switch->addCase(Scope.getBranchAfterIndex(I), - Scope.getBranchAfterBlock(I)); - } - - // If there aren't any enclosing cleanups, we can resolve all - // the fixups now. - if (HasFixups && !HasEnclosingCleanups) - ResolveAllBranchFixups(*this, Switch, NormalEntry); - } else { - // We should always have a branch-through destination in this case. - assert(BranchThroughDest); - InstsToAppend.push_back(llvm::BranchInst::Create(BranchThroughDest)); - } - - // IV. Pop the cleanup and emit it. - EHStack.popCleanup(); - assert(EHStack.hasNormalCleanups() == HasEnclosingCleanups); - - EmitCleanup(*this, Fn, cleanupFlags, NormalActiveFlag); - - // Append the prepared cleanup prologue from above. - llvm::BasicBlock *NormalExit = Builder.GetInsertBlock(); - for (unsigned I = 0, E = InstsToAppend.size(); I != E; ++I) - NormalExit->getInstList().push_back(InstsToAppend[I]); - - // Optimistically hope that any fixups will continue falling through. - for (unsigned I = FixupDepth, E = EHStack.getNumBranchFixups(); - I < E; ++I) { - BranchFixup &Fixup = EHStack.getBranchFixup(I); - if (!Fixup.Destination) continue; - if (!Fixup.OptimisticBranchBlock) { - createStoreInstBefore(Builder.getInt32(Fixup.DestinationIndex), - getNormalCleanupDestSlot(), - Fixup.InitialBranch); - Fixup.InitialBranch->setSuccessor(0, NormalEntry); - } - Fixup.OptimisticBranchBlock = NormalExit; - } - - // V. Set up the fallthrough edge out. - - // Case 1: a fallthrough source exists but doesn't branch to the - // cleanup because the cleanup is inactive. - if (!HasFallthrough && FallthroughSource) { - // Prebranched fallthrough was forwarded earlier. - // Non-prebranched fallthrough doesn't need to be forwarded. - // Either way, all we need to do is restore the IP we cleared before. - assert(!IsActive); - Builder.restoreIP(savedInactiveFallthroughIP); - - // Case 2: a fallthrough source exists and should branch to the - // cleanup, but we're not supposed to branch through to the next - // cleanup. - } else if (HasFallthrough && FallthroughDest) { - assert(!FallthroughIsBranchThrough); - EmitBlock(FallthroughDest); - - // Case 3: a fallthrough source exists and should branch to the - // cleanup and then through to the next. - } else if (HasFallthrough) { - // Everything is already set up for this. - - // Case 4: no fallthrough source exists. - } else { - Builder.ClearInsertionPoint(); - } - - // VI. Assorted cleaning. - - // Check whether we can merge NormalEntry into a single predecessor. - // This might invalidate (non-IR) pointers to NormalEntry. - llvm::BasicBlock *NewNormalEntry = - SimplifyCleanupEntry(*this, NormalEntry); - - // If it did invalidate those pointers, and NormalEntry was the same - // as NormalExit, go back and patch up the fixups. - if (NewNormalEntry != NormalEntry && NormalEntry == NormalExit) - for (unsigned I = FixupDepth, E = EHStack.getNumBranchFixups(); - I < E; ++I) - EHStack.getBranchFixup(I).OptimisticBranchBlock = NewNormalEntry; - } - } - - assert(EHStack.hasNormalCleanups() || EHStack.getNumBranchFixups() == 0); - - // Emit the EH cleanup if required. - if (RequiresEHCleanup) { - CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP(); - - EmitBlock(EHEntry); - - llvm::BasicBlock *NextAction = getEHDispatchBlock(EHParent); - - // Push a terminate scope or cleanupendpad scope around the potentially - // throwing cleanups. For funclet EH personalities, the cleanupendpad models - // program termination when cleanups throw. - bool PushedTerminate = false; - SaveAndRestore<llvm::Instruction *> RestoreCurrentFuncletPad( - CurrentFuncletPad); - llvm::CleanupPadInst *CPI = nullptr; - - const EHPersonality &Personality = EHPersonality::get(*this); - if (Personality.usesFuncletPads()) { - llvm::Value *ParentPad = CurrentFuncletPad; - if (!ParentPad) - ParentPad = llvm::ConstantTokenNone::get(CGM.getLLVMContext()); - CurrentFuncletPad = CPI = Builder.CreateCleanupPad(ParentPad); - } - - // Non-MSVC personalities need to terminate when an EH cleanup throws. - if (!Personality.isMSVCPersonality()) { - EHStack.pushTerminate(); - PushedTerminate = true; - } - - // We only actually emit the cleanup code if the cleanup is either - // active or was used before it was deactivated. - if (EHActiveFlag.isValid() || IsActive) { - cleanupFlags.setIsForEHCleanup(); - EmitCleanup(*this, Fn, cleanupFlags, EHActiveFlag); - } - - if (CPI) - Builder.CreateCleanupRet(CPI, NextAction); - else - Builder.CreateBr(NextAction); - - // Leave the terminate scope. - if (PushedTerminate) - EHStack.popTerminate(); - - Builder.restoreIP(SavedIP); - - SimplifyCleanupEntry(*this, EHEntry); - } -} - -/// isObviouslyBranchWithoutCleanups - Return true if a branch to the -/// specified destination obviously has no cleanups to run. 'false' is always -/// a conservatively correct answer for this method. -bool CodeGenFunction::isObviouslyBranchWithoutCleanups(JumpDest Dest) const { - assert(Dest.getScopeDepth().encloses(EHStack.stable_begin()) - && "stale jump destination"); - - // Calculate the innermost active normal cleanup. - EHScopeStack::stable_iterator TopCleanup = - EHStack.getInnermostActiveNormalCleanup(); - - // If we're not in an active normal cleanup scope, or if the - // destination scope is within the innermost active normal cleanup - // scope, we don't need to worry about fixups. - if (TopCleanup == EHStack.stable_end() || - TopCleanup.encloses(Dest.getScopeDepth())) // works for invalid - return true; - - // Otherwise, we might need some cleanups. - return false; -} - - -/// Terminate the current block by emitting a branch which might leave -/// the current cleanup-protected scope. The target scope may not yet -/// be known, in which case this will require a fixup. -/// -/// As a side-effect, this method clears the insertion point. -void CodeGenFunction::EmitBranchThroughCleanup(JumpDest Dest) { - assert(Dest.getScopeDepth().encloses(EHStack.stable_begin()) - && "stale jump destination"); - - if (!HaveInsertPoint()) - return; - - // Create the branch. - llvm::BranchInst *BI = Builder.CreateBr(Dest.getBlock()); - - // Calculate the innermost active normal cleanup. - EHScopeStack::stable_iterator - TopCleanup = EHStack.getInnermostActiveNormalCleanup(); - - // If we're not in an active normal cleanup scope, or if the - // destination scope is within the innermost active normal cleanup - // scope, we don't need to worry about fixups. - if (TopCleanup == EHStack.stable_end() || - TopCleanup.encloses(Dest.getScopeDepth())) { // works for invalid - Builder.ClearInsertionPoint(); - return; - } - - // If we can't resolve the destination cleanup scope, just add this - // to the current cleanup scope as a branch fixup. - if (!Dest.getScopeDepth().isValid()) { - BranchFixup &Fixup = EHStack.addBranchFixup(); - Fixup.Destination = Dest.getBlock(); - Fixup.DestinationIndex = Dest.getDestIndex(); - Fixup.InitialBranch = BI; - Fixup.OptimisticBranchBlock = nullptr; - - Builder.ClearInsertionPoint(); - return; - } - - // Otherwise, thread through all the normal cleanups in scope. - - // Store the index at the start. - llvm::ConstantInt *Index = Builder.getInt32(Dest.getDestIndex()); - createStoreInstBefore(Index, getNormalCleanupDestSlot(), BI); - - // Adjust BI to point to the first cleanup block. - { - EHCleanupScope &Scope = - cast<EHCleanupScope>(*EHStack.find(TopCleanup)); - BI->setSuccessor(0, CreateNormalEntry(*this, Scope)); - } - - // Add this destination to all the scopes involved. - EHScopeStack::stable_iterator I = TopCleanup; - EHScopeStack::stable_iterator E = Dest.getScopeDepth(); - if (E.strictlyEncloses(I)) { - while (true) { - EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(I)); - assert(Scope.isNormalCleanup()); - I = Scope.getEnclosingNormalCleanup(); - - // If this is the last cleanup we're propagating through, tell it - // that there's a resolved jump moving through it. - if (!E.strictlyEncloses(I)) { - Scope.addBranchAfter(Index, Dest.getBlock()); - break; - } - - // Otherwise, tell the scope that there's a jump propagating - // through it. If this isn't new information, all the rest of - // the work has been done before. - if (!Scope.addBranchThrough(Dest.getBlock())) - break; - } - } - - Builder.ClearInsertionPoint(); -} - -static bool IsUsedAsNormalCleanup(EHScopeStack &EHStack, - EHScopeStack::stable_iterator C) { - // If we needed a normal block for any reason, that counts. - if (cast<EHCleanupScope>(*EHStack.find(C)).getNormalBlock()) - return true; - - // Check whether any enclosed cleanups were needed. - for (EHScopeStack::stable_iterator - I = EHStack.getInnermostNormalCleanup(); - I != C; ) { - assert(C.strictlyEncloses(I)); - EHCleanupScope &S = cast<EHCleanupScope>(*EHStack.find(I)); - if (S.getNormalBlock()) return true; - I = S.getEnclosingNormalCleanup(); - } - - return false; -} - -static bool IsUsedAsEHCleanup(EHScopeStack &EHStack, - EHScopeStack::stable_iterator cleanup) { - // If we needed an EH block for any reason, that counts. - if (EHStack.find(cleanup)->hasEHBranches()) - return true; - - // Check whether any enclosed cleanups were needed. - for (EHScopeStack::stable_iterator - i = EHStack.getInnermostEHScope(); i != cleanup; ) { - assert(cleanup.strictlyEncloses(i)); - - EHScope &scope = *EHStack.find(i); - if (scope.hasEHBranches()) - return true; - - i = scope.getEnclosingEHScope(); - } - - return false; -} - -enum ForActivation_t { - ForActivation, - ForDeactivation -}; - -/// The given cleanup block is changing activation state. Configure a -/// cleanup variable if necessary. -/// -/// It would be good if we had some way of determining if there were -/// extra uses *after* the change-over point. -static void SetupCleanupBlockActivation(CodeGenFunction &CGF, - EHScopeStack::stable_iterator C, - ForActivation_t kind, - llvm::Instruction *dominatingIP) { - EHCleanupScope &Scope = cast<EHCleanupScope>(*CGF.EHStack.find(C)); - - // We always need the flag if we're activating the cleanup in a - // conditional context, because we have to assume that the current - // location doesn't necessarily dominate the cleanup's code. - bool isActivatedInConditional = - (kind == ForActivation && CGF.isInConditionalBranch()); - - bool needFlag = false; - - // Calculate whether the cleanup was used: - - // - as a normal cleanup - if (Scope.isNormalCleanup() && - (isActivatedInConditional || IsUsedAsNormalCleanup(CGF.EHStack, C))) { - Scope.setTestFlagInNormalCleanup(); - needFlag = true; - } - - // - as an EH cleanup - if (Scope.isEHCleanup() && - (isActivatedInConditional || IsUsedAsEHCleanup(CGF.EHStack, C))) { - Scope.setTestFlagInEHCleanup(); - needFlag = true; - } - - // If it hasn't yet been used as either, we're done. - if (!needFlag) return; - - Address var = Scope.getActiveFlag(); - if (!var.isValid()) { - var = CGF.CreateTempAlloca(CGF.Builder.getInt1Ty(), CharUnits::One(), - "cleanup.isactive"); - Scope.setActiveFlag(var); - - assert(dominatingIP && "no existing variable and no dominating IP!"); - - // Initialize to true or false depending on whether it was - // active up to this point. - llvm::Constant *value = CGF.Builder.getInt1(kind == ForDeactivation); - - // If we're in a conditional block, ignore the dominating IP and - // use the outermost conditional branch. - if (CGF.isInConditionalBranch()) { - CGF.setBeforeOutermostConditional(value, var); - } else { - createStoreInstBefore(value, var, dominatingIP); - } - } - - CGF.Builder.CreateStore(CGF.Builder.getInt1(kind == ForActivation), var); -} - -/// Activate a cleanup that was created in an inactivated state. -void CodeGenFunction::ActivateCleanupBlock(EHScopeStack::stable_iterator C, - llvm::Instruction *dominatingIP) { - assert(C != EHStack.stable_end() && "activating bottom of stack?"); - EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(C)); - assert(!Scope.isActive() && "double activation"); - - SetupCleanupBlockActivation(*this, C, ForActivation, dominatingIP); - - Scope.setActive(true); -} - -/// Deactive a cleanup that was created in an active state. -void CodeGenFunction::DeactivateCleanupBlock(EHScopeStack::stable_iterator C, - llvm::Instruction *dominatingIP) { - assert(C != EHStack.stable_end() && "deactivating bottom of stack?"); - EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(C)); - assert(Scope.isActive() && "double deactivation"); - - // If it's the top of the stack, just pop it, but do so only if it belongs - // to the current RunCleanupsScope. - if (C == EHStack.stable_begin() && - CurrentCleanupScopeDepth.strictlyEncloses(C)) { - // If it's a normal cleanup, we need to pretend that the - // fallthrough is unreachable. - CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP(); - PopCleanupBlock(); - Builder.restoreIP(SavedIP); - return; - } - - // Otherwise, follow the general case. - SetupCleanupBlockActivation(*this, C, ForDeactivation, dominatingIP); - - Scope.setActive(false); -} - -Address CodeGenFunction::getNormalCleanupDestSlot() { - if (!NormalCleanupDest.isValid()) - NormalCleanupDest = - CreateDefaultAlignTempAlloca(Builder.getInt32Ty(), "cleanup.dest.slot"); - return NormalCleanupDest; -} - -/// Emits all the code to cause the given temporary to be cleaned up. -void CodeGenFunction::EmitCXXTemporary(const CXXTemporary *Temporary, - QualType TempType, - Address Ptr) { - pushDestroy(NormalAndEHCleanup, Ptr, TempType, destroyCXXObject, - /*useEHCleanup*/ true); -} |