| //===--- CodeGenFunction.cpp - Emit LLVM Code from ASTs for a Function ----===// |
| // |
| // 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 coordinates the per-function state used while generating code. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "CodeGenFunction.h" |
| #include "CGBlocks.h" |
| #include "CGCUDARuntime.h" |
| #include "CGCXXABI.h" |
| #include "CGCleanup.h" |
| #include "CGDebugInfo.h" |
| #include "CGOpenMPRuntime.h" |
| #include "CodeGenModule.h" |
| #include "CodeGenPGO.h" |
| #include "TargetInfo.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/ASTLambda.h" |
| #include "clang/AST/Attr.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclCXX.h" |
| #include "clang/AST/StmtCXX.h" |
| #include "clang/AST/StmtObjC.h" |
| #include "clang/Basic/Builtins.h" |
| #include "clang/Basic/CodeGenOptions.h" |
| #include "clang/Basic/TargetInfo.h" |
| #include "clang/CodeGen/CGFunctionInfo.h" |
| #include "clang/Frontend/FrontendDiagnostic.h" |
| #include "llvm/Frontend/OpenMP/OMPIRBuilder.h" |
| #include "llvm/IR/DataLayout.h" |
| #include "llvm/IR/Dominators.h" |
| #include "llvm/IR/FPEnv.h" |
| #include "llvm/IR/IntrinsicInst.h" |
| #include "llvm/IR/Intrinsics.h" |
| #include "llvm/IR/MDBuilder.h" |
| #include "llvm/IR/Operator.h" |
| #include "llvm/Transforms/Utils/PromoteMemToReg.h" |
| using namespace clang; |
| using namespace CodeGen; |
| |
| /// shouldEmitLifetimeMarkers - Decide whether we need emit the life-time |
| /// markers. |
| static bool shouldEmitLifetimeMarkers(const CodeGenOptions &CGOpts, |
| const LangOptions &LangOpts) { |
| if (CGOpts.DisableLifetimeMarkers) |
| return false; |
| |
| // Sanitizers may use markers. |
| if (CGOpts.SanitizeAddressUseAfterScope || |
| LangOpts.Sanitize.has(SanitizerKind::HWAddress) || |
| LangOpts.Sanitize.has(SanitizerKind::Memory)) |
| return true; |
| |
| // For now, only in optimized builds. |
| return CGOpts.OptimizationLevel != 0; |
| } |
| |
| CodeGenFunction::CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext) |
| : CodeGenTypeCache(cgm), CGM(cgm), Target(cgm.getTarget()), |
| Builder(cgm, cgm.getModule().getContext(), llvm::ConstantFolder(), |
| CGBuilderInserterTy(this)), |
| SanOpts(CGM.getLangOpts().Sanitize), CurFPFeatures(CGM.getLangOpts()), |
| DebugInfo(CGM.getModuleDebugInfo()), PGO(cgm), |
| ShouldEmitLifetimeMarkers( |
| shouldEmitLifetimeMarkers(CGM.getCodeGenOpts(), CGM.getLangOpts())) { |
| if (!suppressNewContext) |
| CGM.getCXXABI().getMangleContext().startNewFunction(); |
| |
| SetFastMathFlags(CurFPFeatures); |
| SetFPModel(); |
| } |
| |
| CodeGenFunction::~CodeGenFunction() { |
| assert(LifetimeExtendedCleanupStack.empty() && "failed to emit a cleanup"); |
| |
| if (getLangOpts().OpenMP && CurFn) |
| CGM.getOpenMPRuntime().functionFinished(*this); |
| |
| // If we have an OpenMPIRBuilder we want to finalize functions (incl. |
| // outlining etc) at some point. Doing it once the function codegen is done |
| // seems to be a reasonable spot. We do it here, as opposed to the deletion |
| // time of the CodeGenModule, because we have to ensure the IR has not yet |
| // been "emitted" to the outside, thus, modifications are still sensible. |
| if (CGM.getLangOpts().OpenMPIRBuilder) |
| CGM.getOpenMPRuntime().getOMPBuilder().finalize(); |
| } |
| |
| // Map the LangOption for exception behavior into |
| // the corresponding enum in the IR. |
| llvm::fp::ExceptionBehavior |
| clang::ToConstrainedExceptMD(LangOptions::FPExceptionModeKind Kind) { |
| |
| switch (Kind) { |
| case LangOptions::FPE_Ignore: return llvm::fp::ebIgnore; |
| case LangOptions::FPE_MayTrap: return llvm::fp::ebMayTrap; |
| case LangOptions::FPE_Strict: return llvm::fp::ebStrict; |
| } |
| llvm_unreachable("Unsupported FP Exception Behavior"); |
| } |
| |
| void CodeGenFunction::SetFPModel() { |
| llvm::RoundingMode RM = getLangOpts().getFPRoundingMode(); |
| auto fpExceptionBehavior = ToConstrainedExceptMD( |
| getLangOpts().getFPExceptionMode()); |
| |
| Builder.setDefaultConstrainedRounding(RM); |
| Builder.setDefaultConstrainedExcept(fpExceptionBehavior); |
| Builder.setIsFPConstrained(fpExceptionBehavior != llvm::fp::ebIgnore || |
| RM != llvm::RoundingMode::NearestTiesToEven); |
| } |
| |
| void CodeGenFunction::SetFastMathFlags(FPOptions FPFeatures) { |
| llvm::FastMathFlags FMF; |
| FMF.setAllowReassoc(FPFeatures.getAllowFPReassociate()); |
| FMF.setNoNaNs(FPFeatures.getNoHonorNaNs()); |
| FMF.setNoInfs(FPFeatures.getNoHonorInfs()); |
| FMF.setNoSignedZeros(FPFeatures.getNoSignedZero()); |
| FMF.setAllowReciprocal(FPFeatures.getAllowReciprocal()); |
| FMF.setApproxFunc(FPFeatures.getAllowApproxFunc()); |
| FMF.setAllowContract(FPFeatures.allowFPContractAcrossStatement()); |
| Builder.setFastMathFlags(FMF); |
| } |
| |
| CodeGenFunction::CGFPOptionsRAII::CGFPOptionsRAII(CodeGenFunction &CGF, |
| FPOptions FPFeatures) |
| : CGF(CGF), OldFPFeatures(CGF.CurFPFeatures) { |
| CGF.CurFPFeatures = FPFeatures; |
| |
| if (OldFPFeatures == FPFeatures) |
| return; |
| |
| FMFGuard.emplace(CGF.Builder); |
| |
| llvm::RoundingMode NewRoundingBehavior = |
| static_cast<llvm::RoundingMode>(FPFeatures.getRoundingMode()); |
| CGF.Builder.setDefaultConstrainedRounding(NewRoundingBehavior); |
| auto NewExceptionBehavior = |
| ToConstrainedExceptMD(static_cast<LangOptions::FPExceptionModeKind>( |
| FPFeatures.getFPExceptionMode())); |
| CGF.Builder.setDefaultConstrainedExcept(NewExceptionBehavior); |
| |
| CGF.SetFastMathFlags(FPFeatures); |
| |
| assert((CGF.CurFuncDecl == nullptr || CGF.Builder.getIsFPConstrained() || |
| isa<CXXConstructorDecl>(CGF.CurFuncDecl) || |
| isa<CXXDestructorDecl>(CGF.CurFuncDecl) || |
| (NewExceptionBehavior == llvm::fp::ebIgnore && |
| NewRoundingBehavior == llvm::RoundingMode::NearestTiesToEven)) && |
| "FPConstrained should be enabled on entire function"); |
| |
| auto mergeFnAttrValue = [&](StringRef Name, bool Value) { |
| auto OldValue = |
| CGF.CurFn->getFnAttribute(Name).getValueAsString() == "true"; |
| auto NewValue = OldValue & Value; |
| if (OldValue != NewValue) |
| CGF.CurFn->addFnAttr(Name, llvm::toStringRef(NewValue)); |
| }; |
| mergeFnAttrValue("no-infs-fp-math", FPFeatures.getNoHonorInfs()); |
| mergeFnAttrValue("no-nans-fp-math", FPFeatures.getNoHonorNaNs()); |
| mergeFnAttrValue("no-signed-zeros-fp-math", FPFeatures.getNoSignedZero()); |
| mergeFnAttrValue("unsafe-fp-math", FPFeatures.getAllowFPReassociate() && |
| FPFeatures.getAllowReciprocal() && |
| FPFeatures.getAllowApproxFunc() && |
| FPFeatures.getNoSignedZero()); |
| } |
| |
| CodeGenFunction::CGFPOptionsRAII::~CGFPOptionsRAII() { |
| CGF.CurFPFeatures = OldFPFeatures; |
| } |
| |
| LValue CodeGenFunction::MakeNaturalAlignAddrLValue(llvm::Value *V, QualType T) { |
| LValueBaseInfo BaseInfo; |
| TBAAAccessInfo TBAAInfo; |
| CharUnits Alignment = CGM.getNaturalTypeAlignment(T, &BaseInfo, &TBAAInfo); |
| return LValue::MakeAddr(Address(V, Alignment), T, getContext(), BaseInfo, |
| TBAAInfo); |
| } |
| |
| /// Given a value of type T* that may not be to a complete object, |
| /// construct an l-value with the natural pointee alignment of T. |
| LValue |
| CodeGenFunction::MakeNaturalAlignPointeeAddrLValue(llvm::Value *V, QualType T) { |
| LValueBaseInfo BaseInfo; |
| TBAAAccessInfo TBAAInfo; |
| CharUnits Align = CGM.getNaturalTypeAlignment(T, &BaseInfo, &TBAAInfo, |
| /* forPointeeType= */ true); |
| return MakeAddrLValue(Address(V, Align), T, BaseInfo, TBAAInfo); |
| } |
| |
| |
| llvm::Type *CodeGenFunction::ConvertTypeForMem(QualType T) { |
| return CGM.getTypes().ConvertTypeForMem(T); |
| } |
| |
| llvm::Type *CodeGenFunction::ConvertType(QualType T) { |
| return CGM.getTypes().ConvertType(T); |
| } |
| |
| TypeEvaluationKind CodeGenFunction::getEvaluationKind(QualType type) { |
| type = type.getCanonicalType(); |
| while (true) { |
| switch (type->getTypeClass()) { |
| #define TYPE(name, parent) |
| #define ABSTRACT_TYPE(name, parent) |
| #define NON_CANONICAL_TYPE(name, parent) case Type::name: |
| #define DEPENDENT_TYPE(name, parent) case Type::name: |
| #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(name, parent) case Type::name: |
| #include "clang/AST/TypeNodes.inc" |
| llvm_unreachable("non-canonical or dependent type in IR-generation"); |
| |
| case Type::Auto: |
| case Type::DeducedTemplateSpecialization: |
| llvm_unreachable("undeduced type in IR-generation"); |
| |
| // Various scalar types. |
| case Type::Builtin: |
| case Type::Pointer: |
| case Type::BlockPointer: |
| case Type::LValueReference: |
| case Type::RValueReference: |
| case Type::MemberPointer: |
| case Type::Vector: |
| case Type::ExtVector: |
| case Type::ConstantMatrix: |
| case Type::FunctionProto: |
| case Type::FunctionNoProto: |
| case Type::Enum: |
| case Type::ObjCObjectPointer: |
| case Type::Pipe: |
| case Type::ExtInt: |
| return TEK_Scalar; |
| |
| // Complexes. |
| case Type::Complex: |
| return TEK_Complex; |
| |
| // Arrays, records, and Objective-C objects. |
| case Type::ConstantArray: |
| case Type::IncompleteArray: |
| case Type::VariableArray: |
| case Type::Record: |
| case Type::ObjCObject: |
| case Type::ObjCInterface: |
| return TEK_Aggregate; |
| |
| // We operate on atomic values according to their underlying type. |
| case Type::Atomic: |
| type = cast<AtomicType>(type)->getValueType(); |
| continue; |
| } |
| llvm_unreachable("unknown type kind!"); |
| } |
| } |
| |
| llvm::DebugLoc CodeGenFunction::EmitReturnBlock() { |
| // For cleanliness, we try to avoid emitting the return block for |
| // simple cases. |
| llvm::BasicBlock *CurBB = Builder.GetInsertBlock(); |
| |
| if (CurBB) { |
| assert(!CurBB->getTerminator() && "Unexpected terminated block."); |
| |
| // We have a valid insert point, reuse it if it is empty or there are no |
| // explicit jumps to the return block. |
| if (CurBB->empty() || ReturnBlock.getBlock()->use_empty()) { |
| ReturnBlock.getBlock()->replaceAllUsesWith(CurBB); |
| delete ReturnBlock.getBlock(); |
| ReturnBlock = JumpDest(); |
| } else |
| EmitBlock(ReturnBlock.getBlock()); |
| return llvm::DebugLoc(); |
| } |
| |
| // Otherwise, if the return block is the target of a single direct |
| // branch then we can just put the code in that block instead. This |
| // cleans up functions which started with a unified return block. |
| if (ReturnBlock.getBlock()->hasOneUse()) { |
| llvm::BranchInst *BI = |
| dyn_cast<llvm::BranchInst>(*ReturnBlock.getBlock()->user_begin()); |
| if (BI && BI->isUnconditional() && |
| BI->getSuccessor(0) == ReturnBlock.getBlock()) { |
| // Record/return the DebugLoc of the simple 'return' expression to be used |
| // later by the actual 'ret' instruction. |
| llvm::DebugLoc Loc = BI->getDebugLoc(); |
| Builder.SetInsertPoint(BI->getParent()); |
| BI->eraseFromParent(); |
| delete ReturnBlock.getBlock(); |
| ReturnBlock = JumpDest(); |
| return Loc; |
| } |
| } |
| |
| // FIXME: We are at an unreachable point, there is no reason to emit the block |
| // unless it has uses. However, we still need a place to put the debug |
| // region.end for now. |
| |
| EmitBlock(ReturnBlock.getBlock()); |
| return llvm::DebugLoc(); |
| } |
| |
| static void EmitIfUsed(CodeGenFunction &CGF, llvm::BasicBlock *BB) { |
| if (!BB) return; |
| if (!BB->use_empty()) |
| return CGF.CurFn->getBasicBlockList().push_back(BB); |
| delete BB; |
| } |
| |
| void CodeGenFunction::FinishFunction(SourceLocation EndLoc) { |
| assert(BreakContinueStack.empty() && |
| "mismatched push/pop in break/continue stack!"); |
| |
| bool OnlySimpleReturnStmts = NumSimpleReturnExprs > 0 |
| && NumSimpleReturnExprs == NumReturnExprs |
| && ReturnBlock.getBlock()->use_empty(); |
| // Usually the return expression is evaluated before the cleanup |
| // code. If the function contains only a simple return statement, |
| // such as a constant, the location before the cleanup code becomes |
| // the last useful breakpoint in the function, because the simple |
| // return expression will be evaluated after the cleanup code. To be |
| // safe, set the debug location for cleanup code to the location of |
| // the return statement. Otherwise the cleanup code should be at the |
| // end of the function's lexical scope. |
| // |
| // If there are multiple branches to the return block, the branch |
| // instructions will get the location of the return statements and |
| // all will be fine. |
| if (CGDebugInfo *DI = getDebugInfo()) { |
| if (OnlySimpleReturnStmts) |
| DI->EmitLocation(Builder, LastStopPoint); |
| else |
| DI->EmitLocation(Builder, EndLoc); |
| } |
| |
| // Pop any cleanups that might have been associated with the |
| // parameters. Do this in whatever block we're currently in; it's |
| // important to do this before we enter the return block or return |
| // edges will be *really* confused. |
| bool HasCleanups = EHStack.stable_begin() != PrologueCleanupDepth; |
| bool HasOnlyLifetimeMarkers = |
| HasCleanups && EHStack.containsOnlyLifetimeMarkers(PrologueCleanupDepth); |
| bool EmitRetDbgLoc = !HasCleanups || HasOnlyLifetimeMarkers; |
| if (HasCleanups) { |
| // Make sure the line table doesn't jump back into the body for |
| // the ret after it's been at EndLoc. |
| Optional<ApplyDebugLocation> AL; |
| if (CGDebugInfo *DI = getDebugInfo()) { |
| if (OnlySimpleReturnStmts) |
| DI->EmitLocation(Builder, EndLoc); |
| else |
| // We may not have a valid end location. Try to apply it anyway, and |
| // fall back to an artificial location if needed. |
| AL = ApplyDebugLocation::CreateDefaultArtificial(*this, EndLoc); |
| } |
| |
| PopCleanupBlocks(PrologueCleanupDepth); |
| } |
| |
| // Emit function epilog (to return). |
| llvm::DebugLoc Loc = EmitReturnBlock(); |
| |
| if (ShouldInstrumentFunction()) { |
| if (CGM.getCodeGenOpts().InstrumentFunctions) |
| CurFn->addFnAttr("instrument-function-exit", "__cyg_profile_func_exit"); |
| if (CGM.getCodeGenOpts().InstrumentFunctionsAfterInlining) |
| CurFn->addFnAttr("instrument-function-exit-inlined", |
| "__cyg_profile_func_exit"); |
| } |
| |
| // Emit debug descriptor for function end. |
| if (CGDebugInfo *DI = getDebugInfo()) |
| DI->EmitFunctionEnd(Builder, CurFn); |
| |
| // Reset the debug location to that of the simple 'return' expression, if any |
| // rather than that of the end of the function's scope '}'. |
| ApplyDebugLocation AL(*this, Loc); |
| EmitFunctionEpilog(*CurFnInfo, EmitRetDbgLoc, EndLoc); |
| EmitEndEHSpec(CurCodeDecl); |
| |
| assert(EHStack.empty() && |
| "did not remove all scopes from cleanup stack!"); |
| |
| // If someone did an indirect goto, emit the indirect goto block at the end of |
| // the function. |
| if (IndirectBranch) { |
| EmitBlock(IndirectBranch->getParent()); |
| Builder.ClearInsertionPoint(); |
| } |
| |
| // If some of our locals escaped, insert a call to llvm.localescape in the |
| // entry block. |
| if (!EscapedLocals.empty()) { |
| // Invert the map from local to index into a simple vector. There should be |
| // no holes. |
| SmallVector<llvm::Value *, 4> EscapeArgs; |
| EscapeArgs.resize(EscapedLocals.size()); |
| for (auto &Pair : EscapedLocals) |
| EscapeArgs[Pair.second] = Pair.first; |
| llvm::Function *FrameEscapeFn = llvm::Intrinsic::getDeclaration( |
| &CGM.getModule(), llvm::Intrinsic::localescape); |
| CGBuilderTy(*this, AllocaInsertPt).CreateCall(FrameEscapeFn, EscapeArgs); |
| } |
| |
| // Remove the AllocaInsertPt instruction, which is just a convenience for us. |
| llvm::Instruction *Ptr = AllocaInsertPt; |
| AllocaInsertPt = nullptr; |
| Ptr->eraseFromParent(); |
| |
| // If someone took the address of a label but never did an indirect goto, we |
| // made a zero entry PHI node, which is illegal, zap it now. |
| if (IndirectBranch) { |
| llvm::PHINode *PN = cast<llvm::PHINode>(IndirectBranch->getAddress()); |
| if (PN->getNumIncomingValues() == 0) { |
| PN->replaceAllUsesWith(llvm::UndefValue::get(PN->getType())); |
| PN->eraseFromParent(); |
| } |
| } |
| |
| EmitIfUsed(*this, EHResumeBlock); |
| EmitIfUsed(*this, TerminateLandingPad); |
| EmitIfUsed(*this, TerminateHandler); |
| EmitIfUsed(*this, UnreachableBlock); |
| |
| for (const auto &FuncletAndParent : TerminateFunclets) |
| EmitIfUsed(*this, FuncletAndParent.second); |
| |
| if (CGM.getCodeGenOpts().EmitDeclMetadata) |
| EmitDeclMetadata(); |
| |
| for (SmallVectorImpl<std::pair<llvm::Instruction *, llvm::Value *> >::iterator |
| I = DeferredReplacements.begin(), |
| E = DeferredReplacements.end(); |
| I != E; ++I) { |
| I->first->replaceAllUsesWith(I->second); |
| I->first->eraseFromParent(); |
| } |
| |
| // Eliminate CleanupDestSlot alloca by replacing it with SSA values and |
| // PHIs if the current function is a coroutine. We don't do it for all |
| // functions as it may result in slight increase in numbers of instructions |
| // if compiled with no optimizations. We do it for coroutine as the lifetime |
| // of CleanupDestSlot alloca make correct coroutine frame building very |
| // difficult. |
| if (NormalCleanupDest.isValid() && isCoroutine()) { |
| llvm::DominatorTree DT(*CurFn); |
| llvm::PromoteMemToReg( |
| cast<llvm::AllocaInst>(NormalCleanupDest.getPointer()), DT); |
| NormalCleanupDest = Address::invalid(); |
| } |
| |
| // Scan function arguments for vector width. |
| for (llvm::Argument &A : CurFn->args()) |
| if (auto *VT = dyn_cast<llvm::VectorType>(A.getType())) |
| LargestVectorWidth = |
| std::max((uint64_t)LargestVectorWidth, |
| VT->getPrimitiveSizeInBits().getKnownMinSize()); |
| |
| // Update vector width based on return type. |
| if (auto *VT = dyn_cast<llvm::VectorType>(CurFn->getReturnType())) |
| LargestVectorWidth = |
| std::max((uint64_t)LargestVectorWidth, |
| VT->getPrimitiveSizeInBits().getKnownMinSize()); |
| |
| // Add the required-vector-width attribute. This contains the max width from: |
| // 1. min-vector-width attribute used in the source program. |
| // 2. Any builtins used that have a vector width specified. |
| // 3. Values passed in and out of inline assembly. |
| // 4. Width of vector arguments and return types for this function. |
| // 5. Width of vector aguments and return types for functions called by this |
| // function. |
| CurFn->addFnAttr("min-legal-vector-width", llvm::utostr(LargestVectorWidth)); |
| |
| // If we generated an unreachable return block, delete it now. |
| if (ReturnBlock.isValid() && ReturnBlock.getBlock()->use_empty()) { |
| Builder.ClearInsertionPoint(); |
| ReturnBlock.getBlock()->eraseFromParent(); |
| } |
| if (ReturnValue.isValid()) { |
| auto *RetAlloca = dyn_cast<llvm::AllocaInst>(ReturnValue.getPointer()); |
| if (RetAlloca && RetAlloca->use_empty()) { |
| RetAlloca->eraseFromParent(); |
| ReturnValue = Address::invalid(); |
| } |
| } |
| } |
| |
| /// ShouldInstrumentFunction - Return true if the current function should be |
| /// instrumented with __cyg_profile_func_* calls |
| bool CodeGenFunction::ShouldInstrumentFunction() { |
| if (!CGM.getCodeGenOpts().InstrumentFunctions && |
| !CGM.getCodeGenOpts().InstrumentFunctionsAfterInlining && |
| !CGM.getCodeGenOpts().InstrumentFunctionEntryBare) |
| return false; |
| if (!CurFuncDecl || CurFuncDecl->hasAttr<NoInstrumentFunctionAttr>()) |
| return false; |
| return true; |
| } |
| |
| /// ShouldXRayInstrument - Return true if the current function should be |
| /// instrumented with XRay nop sleds. |
| bool CodeGenFunction::ShouldXRayInstrumentFunction() const { |
| return CGM.getCodeGenOpts().XRayInstrumentFunctions; |
| } |
| |
| /// AlwaysEmitXRayCustomEvents - Return true if we should emit IR for calls to |
| /// the __xray_customevent(...) builtin calls, when doing XRay instrumentation. |
| bool CodeGenFunction::AlwaysEmitXRayCustomEvents() const { |
| return CGM.getCodeGenOpts().XRayInstrumentFunctions && |
| (CGM.getCodeGenOpts().XRayAlwaysEmitCustomEvents || |
| CGM.getCodeGenOpts().XRayInstrumentationBundle.Mask == |
| XRayInstrKind::Custom); |
| } |
| |
| bool CodeGenFunction::AlwaysEmitXRayTypedEvents() const { |
| return CGM.getCodeGenOpts().XRayInstrumentFunctions && |
| (CGM.getCodeGenOpts().XRayAlwaysEmitTypedEvents || |
| CGM.getCodeGenOpts().XRayInstrumentationBundle.Mask == |
| XRayInstrKind::Typed); |
| } |
| |
| llvm::Constant * |
| CodeGenFunction::EncodeAddrForUseInPrologue(llvm::Function *F, |
| llvm::Constant *Addr) { |
| // Addresses stored in prologue data can't require run-time fixups and must |
| // be PC-relative. Run-time fixups are undesirable because they necessitate |
| // writable text segments, which are unsafe. And absolute addresses are |
| // undesirable because they break PIE mode. |
| |
| // Add a layer of indirection through a private global. Taking its address |
| // won't result in a run-time fixup, even if Addr has linkonce_odr linkage. |
| auto *GV = new llvm::GlobalVariable(CGM.getModule(), Addr->getType(), |
| /*isConstant=*/true, |
| llvm::GlobalValue::PrivateLinkage, Addr); |
| |
| // Create a PC-relative address. |
| auto *GOTAsInt = llvm::ConstantExpr::getPtrToInt(GV, IntPtrTy); |
| auto *FuncAsInt = llvm::ConstantExpr::getPtrToInt(F, IntPtrTy); |
| auto *PCRelAsInt = llvm::ConstantExpr::getSub(GOTAsInt, FuncAsInt); |
| return (IntPtrTy == Int32Ty) |
| ? PCRelAsInt |
| : llvm::ConstantExpr::getTrunc(PCRelAsInt, Int32Ty); |
| } |
| |
| llvm::Value * |
| CodeGenFunction::DecodeAddrUsedInPrologue(llvm::Value *F, |
| llvm::Value *EncodedAddr) { |
| // Reconstruct the address of the global. |
| auto *PCRelAsInt = Builder.CreateSExt(EncodedAddr, IntPtrTy); |
| auto *FuncAsInt = Builder.CreatePtrToInt(F, IntPtrTy, "func_addr.int"); |
| auto *GOTAsInt = Builder.CreateAdd(PCRelAsInt, FuncAsInt, "global_addr.int"); |
| auto *GOTAddr = Builder.CreateIntToPtr(GOTAsInt, Int8PtrPtrTy, "global_addr"); |
| |
| // Load the original pointer through the global. |
| return Builder.CreateLoad(Address(GOTAddr, getPointerAlign()), |
| "decoded_addr"); |
| } |
| |
| void CodeGenFunction::EmitOpenCLKernelMetadata(const FunctionDecl *FD, |
| llvm::Function *Fn) |
| { |
| if (!FD->hasAttr<OpenCLKernelAttr>()) |
| return; |
| |
| llvm::LLVMContext &Context = getLLVMContext(); |
| |
| CGM.GenOpenCLArgMetadata(Fn, FD, this); |
| |
| if (const VecTypeHintAttr *A = FD->getAttr<VecTypeHintAttr>()) { |
| QualType HintQTy = A->getTypeHint(); |
| const ExtVectorType *HintEltQTy = HintQTy->getAs<ExtVectorType>(); |
| bool IsSignedInteger = |
| HintQTy->isSignedIntegerType() || |
| (HintEltQTy && HintEltQTy->getElementType()->isSignedIntegerType()); |
| llvm::Metadata *AttrMDArgs[] = { |
| llvm::ConstantAsMetadata::get(llvm::UndefValue::get( |
| CGM.getTypes().ConvertType(A->getTypeHint()))), |
| llvm::ConstantAsMetadata::get(llvm::ConstantInt::get( |
| llvm::IntegerType::get(Context, 32), |
| llvm::APInt(32, (uint64_t)(IsSignedInteger ? 1 : 0))))}; |
| Fn->setMetadata("vec_type_hint", llvm::MDNode::get(Context, AttrMDArgs)); |
| } |
| |
| if (const WorkGroupSizeHintAttr *A = FD->getAttr<WorkGroupSizeHintAttr>()) { |
| llvm::Metadata *AttrMDArgs[] = { |
| llvm::ConstantAsMetadata::get(Builder.getInt32(A->getXDim())), |
| llvm::ConstantAsMetadata::get(Builder.getInt32(A->getYDim())), |
| llvm::ConstantAsMetadata::get(Builder.getInt32(A->getZDim()))}; |
| Fn->setMetadata("work_group_size_hint", llvm::MDNode::get(Context, AttrMDArgs)); |
| } |
| |
| if (const ReqdWorkGroupSizeAttr *A = FD->getAttr<ReqdWorkGroupSizeAttr>()) { |
| llvm::Metadata *AttrMDArgs[] = { |
| llvm::ConstantAsMetadata::get(Builder.getInt32(A->getXDim())), |
| llvm::ConstantAsMetadata::get(Builder.getInt32(A->getYDim())), |
| llvm::ConstantAsMetadata::get(Builder.getInt32(A->getZDim()))}; |
| Fn->setMetadata("reqd_work_group_size", llvm::MDNode::get(Context, AttrMDArgs)); |
| } |
| |
| if (const OpenCLIntelReqdSubGroupSizeAttr *A = |
| FD->getAttr<OpenCLIntelReqdSubGroupSizeAttr>()) { |
| llvm::Metadata *AttrMDArgs[] = { |
| llvm::ConstantAsMetadata::get(Builder.getInt32(A->getSubGroupSize()))}; |
| Fn->setMetadata("intel_reqd_sub_group_size", |
| llvm::MDNode::get(Context, AttrMDArgs)); |
| } |
| } |
| |
| /// Determine whether the function F ends with a return stmt. |
| static bool endsWithReturn(const Decl* F) { |
| const Stmt *Body = nullptr; |
| if (auto *FD = dyn_cast_or_null<FunctionDecl>(F)) |
| Body = FD->getBody(); |
| else if (auto *OMD = dyn_cast_or_null<ObjCMethodDecl>(F)) |
| Body = OMD->getBody(); |
| |
| if (auto *CS = dyn_cast_or_null<CompoundStmt>(Body)) { |
| auto LastStmt = CS->body_rbegin(); |
| if (LastStmt != CS->body_rend()) |
| return isa<ReturnStmt>(*LastStmt); |
| } |
| return false; |
| } |
| |
| void CodeGenFunction::markAsIgnoreThreadCheckingAtRuntime(llvm::Function *Fn) { |
| if (SanOpts.has(SanitizerKind::Thread)) { |
| Fn->addFnAttr("sanitize_thread_no_checking_at_run_time"); |
| Fn->removeFnAttr(llvm::Attribute::SanitizeThread); |
| } |
| } |
| |
| /// Check if the return value of this function requires sanitization. |
| bool CodeGenFunction::requiresReturnValueCheck() const { |
| return requiresReturnValueNullabilityCheck() || |
| (SanOpts.has(SanitizerKind::ReturnsNonnullAttribute) && CurCodeDecl && |
| CurCodeDecl->getAttr<ReturnsNonNullAttr>()); |
| } |
| |
| static bool matchesStlAllocatorFn(const Decl *D, const ASTContext &Ctx) { |
| auto *MD = dyn_cast_or_null<CXXMethodDecl>(D); |
| if (!MD || !MD->getDeclName().getAsIdentifierInfo() || |
| !MD->getDeclName().getAsIdentifierInfo()->isStr("allocate") || |
| (MD->getNumParams() != 1 && MD->getNumParams() != 2)) |
| return false; |
| |
| if (MD->parameters()[0]->getType().getCanonicalType() != Ctx.getSizeType()) |
| return false; |
| |
| if (MD->getNumParams() == 2) { |
| auto *PT = MD->parameters()[1]->getType()->getAs<PointerType>(); |
| if (!PT || !PT->isVoidPointerType() || |
| !PT->getPointeeType().isConstQualified()) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| /// Return the UBSan prologue signature for \p FD if one is available. |
| static llvm::Constant *getPrologueSignature(CodeGenModule &CGM, |
| const FunctionDecl *FD) { |
| if (const auto *MD = dyn_cast<CXXMethodDecl>(FD)) |
| if (!MD->isStatic()) |
| return nullptr; |
| return CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM); |
| } |
| |
| void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy, |
| llvm::Function *Fn, |
| const CGFunctionInfo &FnInfo, |
| const FunctionArgList &Args, |
| SourceLocation Loc, |
| SourceLocation StartLoc) { |
| assert(!CurFn && |
| "Do not use a CodeGenFunction object for more than one function"); |
| |
| const Decl *D = GD.getDecl(); |
| |
| DidCallStackSave = false; |
| CurCodeDecl = D; |
| if (const auto *FD = dyn_cast_or_null<FunctionDecl>(D)) |
| if (FD->usesSEHTry()) |
| CurSEHParent = FD; |
| CurFuncDecl = (D ? D->getNonClosureContext() : nullptr); |
| FnRetTy = RetTy; |
| CurFn = Fn; |
| CurFnInfo = &FnInfo; |
| assert(CurFn->isDeclaration() && "Function already has body?"); |
| |
| // If this function has been blacklisted for any of the enabled sanitizers, |
| // disable the sanitizer for the function. |
| do { |
| #define SANITIZER(NAME, ID) \ |
| if (SanOpts.empty()) \ |
| break; \ |
| if (SanOpts.has(SanitizerKind::ID)) \ |
| if (CGM.isInSanitizerBlacklist(SanitizerKind::ID, Fn, Loc)) \ |
| SanOpts.set(SanitizerKind::ID, false); |
| |
| #include "clang/Basic/Sanitizers.def" |
| #undef SANITIZER |
| } while (0); |
| |
| if (D) { |
| // Apply the no_sanitize* attributes to SanOpts. |
| for (auto Attr : D->specific_attrs<NoSanitizeAttr>()) { |
| SanitizerMask mask = Attr->getMask(); |
| SanOpts.Mask &= ~mask; |
| if (mask & SanitizerKind::Address) |
| SanOpts.set(SanitizerKind::KernelAddress, false); |
| if (mask & SanitizerKind::KernelAddress) |
| SanOpts.set(SanitizerKind::Address, false); |
| if (mask & SanitizerKind::HWAddress) |
| SanOpts.set(SanitizerKind::KernelHWAddress, false); |
| if (mask & SanitizerKind::KernelHWAddress) |
| SanOpts.set(SanitizerKind::HWAddress, false); |
| } |
| } |
| |
| // Apply sanitizer attributes to the function. |
| if (SanOpts.hasOneOf(SanitizerKind::Address | SanitizerKind::KernelAddress)) |
| Fn->addFnAttr(llvm::Attribute::SanitizeAddress); |
| if (SanOpts.hasOneOf(SanitizerKind::HWAddress | SanitizerKind::KernelHWAddress)) |
| Fn->addFnAttr(llvm::Attribute::SanitizeHWAddress); |
| if (SanOpts.has(SanitizerKind::MemTag)) |
| Fn->addFnAttr(llvm::Attribute::SanitizeMemTag); |
| if (SanOpts.has(SanitizerKind::Thread)) |
| Fn->addFnAttr(llvm::Attribute::SanitizeThread); |
| if (SanOpts.hasOneOf(SanitizerKind::Memory | SanitizerKind::KernelMemory)) |
| Fn->addFnAttr(llvm::Attribute::SanitizeMemory); |
| if (SanOpts.has(SanitizerKind::SafeStack)) |
| Fn->addFnAttr(llvm::Attribute::SafeStack); |
| if (SanOpts.has(SanitizerKind::ShadowCallStack)) |
| Fn->addFnAttr(llvm::Attribute::ShadowCallStack); |
| |
| // Apply fuzzing attribute to the function. |
| if (SanOpts.hasOneOf(SanitizerKind::Fuzzer | SanitizerKind::FuzzerNoLink)) |
| Fn->addFnAttr(llvm::Attribute::OptForFuzzing); |
| |
| // Ignore TSan memory acesses from within ObjC/ObjC++ dealloc, initialize, |
| // .cxx_destruct, __destroy_helper_block_ and all of their calees at run time. |
| if (SanOpts.has(SanitizerKind::Thread)) { |
| if (const auto *OMD = dyn_cast_or_null<ObjCMethodDecl>(D)) { |
| IdentifierInfo *II = OMD->getSelector().getIdentifierInfoForSlot(0); |
| if (OMD->getMethodFamily() == OMF_dealloc || |
| OMD->getMethodFamily() == OMF_initialize || |
| (OMD->getSelector().isUnarySelector() && II->isStr(".cxx_destruct"))) { |
| markAsIgnoreThreadCheckingAtRuntime(Fn); |
| } |
| } |
| } |
| |
| // Ignore unrelated casts in STL allocate() since the allocator must cast |
| // from void* to T* before object initialization completes. Don't match on the |
| // namespace because not all allocators are in std:: |
| if (D && SanOpts.has(SanitizerKind::CFIUnrelatedCast)) { |
| if (matchesStlAllocatorFn(D, getContext())) |
| SanOpts.Mask &= ~SanitizerKind::CFIUnrelatedCast; |
| } |
| |
| // Ignore null checks in coroutine functions since the coroutines passes |
| // are not aware of how to move the extra UBSan instructions across the split |
| // coroutine boundaries. |
| if (D && SanOpts.has(SanitizerKind::Null)) |
| if (const auto *FD = dyn_cast<FunctionDecl>(D)) |
| if (FD->getBody() && |
| FD->getBody()->getStmtClass() == Stmt::CoroutineBodyStmtClass) |
| SanOpts.Mask &= ~SanitizerKind::Null; |
| |
| // Apply xray attributes to the function (as a string, for now) |
| if (const auto *XRayAttr = D ? D->getAttr<XRayInstrumentAttr>() : nullptr) { |
| if (CGM.getCodeGenOpts().XRayInstrumentationBundle.has( |
| XRayInstrKind::FunctionEntry) || |
| CGM.getCodeGenOpts().XRayInstrumentationBundle.has( |
| XRayInstrKind::FunctionExit)) { |
| if (XRayAttr->alwaysXRayInstrument() && ShouldXRayInstrumentFunction()) |
| Fn->addFnAttr("function-instrument", "xray-always"); |
| if (XRayAttr->neverXRayInstrument()) |
| Fn->addFnAttr("function-instrument", "xray-never"); |
| if (const auto *LogArgs = D->getAttr<XRayLogArgsAttr>()) |
| if (ShouldXRayInstrumentFunction()) |
| Fn->addFnAttr("xray-log-args", |
| llvm::utostr(LogArgs->getArgumentCount())); |
| } |
| } else { |
| if (ShouldXRayInstrumentFunction() && !CGM.imbueXRayAttrs(Fn, Loc)) |
| Fn->addFnAttr( |
| "xray-instruction-threshold", |
| llvm::itostr(CGM.getCodeGenOpts().XRayInstructionThreshold)); |
| } |
| |
| if (ShouldXRayInstrumentFunction()) { |
| if (CGM.getCodeGenOpts().XRayIgnoreLoops) |
| Fn->addFnAttr("xray-ignore-loops"); |
| |
| if (!CGM.getCodeGenOpts().XRayInstrumentationBundle.has( |
| XRayInstrKind::FunctionExit)) |
| Fn->addFnAttr("xray-skip-exit"); |
| |
| if (!CGM.getCodeGenOpts().XRayInstrumentationBundle.has( |
| XRayInstrKind::FunctionEntry)) |
| Fn->addFnAttr("xray-skip-entry"); |
| } |
| |
| unsigned Count, Offset; |
| if (const auto *Attr = |
| D ? D->getAttr<PatchableFunctionEntryAttr>() : nullptr) { |
| Count = Attr->getCount(); |
| Offset = Attr->getOffset(); |
| } else { |
| Count = CGM.getCodeGenOpts().PatchableFunctionEntryCount; |
| Offset = CGM.getCodeGenOpts().PatchableFunctionEntryOffset; |
| } |
| if (Count && Offset <= Count) { |
| Fn->addFnAttr("patchable-function-entry", std::to_string(Count - Offset)); |
| if (Offset) |
| Fn->addFnAttr("patchable-function-prefix", std::to_string(Offset)); |
| } |
| |
| // Add no-jump-tables value. |
| Fn->addFnAttr("no-jump-tables", |
| llvm::toStringRef(CGM.getCodeGenOpts().NoUseJumpTables)); |
| |
| // Add no-inline-line-tables value. |
| if (CGM.getCodeGenOpts().NoInlineLineTables) |
| Fn->addFnAttr("no-inline-line-tables"); |
| |
| // Add profile-sample-accurate value. |
| if (CGM.getCodeGenOpts().ProfileSampleAccurate) |
| Fn->addFnAttr("profile-sample-accurate"); |
| |
| if (!CGM.getCodeGenOpts().SampleProfileFile.empty()) |
| Fn->addFnAttr("use-sample-profile"); |
| |
| if (D && D->hasAttr<CFICanonicalJumpTableAttr>()) |
| Fn->addFnAttr("cfi-canonical-jump-table"); |
| |
| if (getLangOpts().OpenCL) { |
| // Add metadata for a kernel function. |
| if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D)) |
| EmitOpenCLKernelMetadata(FD, Fn); |
| } |
| |
| // If we are checking function types, emit a function type signature as |
| // prologue data. |
| if (getLangOpts().CPlusPlus && SanOpts.has(SanitizerKind::Function)) { |
| if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D)) { |
| if (llvm::Constant *PrologueSig = getPrologueSignature(CGM, FD)) { |
| // Remove any (C++17) exception specifications, to allow calling e.g. a |
| // noexcept function through a non-noexcept pointer. |
| auto ProtoTy = |
| getContext().getFunctionTypeWithExceptionSpec(FD->getType(), |
| EST_None); |
| llvm::Constant *FTRTTIConst = |
| CGM.GetAddrOfRTTIDescriptor(ProtoTy, /*ForEH=*/true); |
| llvm::Constant *FTRTTIConstEncoded = |
| EncodeAddrForUseInPrologue(Fn, FTRTTIConst); |
| llvm::Constant *PrologueStructElems[] = {PrologueSig, |
| FTRTTIConstEncoded}; |
| llvm::Constant *PrologueStructConst = |
| llvm::ConstantStruct::getAnon(PrologueStructElems, /*Packed=*/true); |
| Fn->setPrologueData(PrologueStructConst); |
| } |
| } |
| } |
| |
| // If we're checking nullability, we need to know whether we can check the |
| // return value. Initialize the flag to 'true' and refine it in EmitParmDecl. |
| if (SanOpts.has(SanitizerKind::NullabilityReturn)) { |
| auto Nullability = FnRetTy->getNullability(getContext()); |
| if (Nullability && *Nullability == NullabilityKind::NonNull) { |
| if (!(SanOpts.has(SanitizerKind::ReturnsNonnullAttribute) && |
| CurCodeDecl && CurCodeDecl->getAttr<ReturnsNonNullAttr>())) |
| RetValNullabilityPrecondition = |
| llvm::ConstantInt::getTrue(getLLVMContext()); |
| } |
| } |
| |
| // If we're in C++ mode and the function name is "main", it is guaranteed |
| // to be norecurse by the standard (3.6.1.3 "The function main shall not be |
| // used within a program"). |
| // |
| // OpenCL C 2.0 v2.2-11 s6.9.i: |
| // Recursion is not supported. |
| // |
| // SYCL v1.2.1 s3.10: |
| // kernels cannot include RTTI information, exception classes, |
| // recursive code, virtual functions or make use of C++ libraries that |
| // are not compiled for the device. |
| if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D)) { |
| if ((getLangOpts().CPlusPlus && FD->isMain()) || getLangOpts().OpenCL || |
| getLangOpts().SYCLIsDevice || |
| (getLangOpts().CUDA && FD->hasAttr<CUDAGlobalAttr>())) |
| Fn->addFnAttr(llvm::Attribute::NoRecurse); |
| } |
| |
| if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D)) { |
| Builder.setIsFPConstrained(FD->usesFPIntrin()); |
| if (FD->usesFPIntrin()) |
| Fn->addFnAttr(llvm::Attribute::StrictFP); |
| } |
| |
| // If a custom alignment is used, force realigning to this alignment on |
| // any main function which certainly will need it. |
| if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D)) |
| if ((FD->isMain() || FD->isMSVCRTEntryPoint()) && |
| CGM.getCodeGenOpts().StackAlignment) |
| Fn->addFnAttr("stackrealign"); |
| |
| llvm::BasicBlock *EntryBB = createBasicBlock("entry", CurFn); |
| |
| // Create a marker to make it easy to insert allocas into the entryblock |
| // later. Don't create this with the builder, because we don't want it |
| // folded. |
| llvm::Value *Undef = llvm::UndefValue::get(Int32Ty); |
| AllocaInsertPt = new llvm::BitCastInst(Undef, Int32Ty, "allocapt", EntryBB); |
| |
| ReturnBlock = getJumpDestInCurrentScope("return"); |
| |
| Builder.SetInsertPoint(EntryBB); |
| |
| // If we're checking the return value, allocate space for a pointer to a |
| // precise source location of the checked return statement. |
| if (requiresReturnValueCheck()) { |
| ReturnLocation = CreateDefaultAlignTempAlloca(Int8PtrTy, "return.sloc.ptr"); |
| InitTempAlloca(ReturnLocation, llvm::ConstantPointerNull::get(Int8PtrTy)); |
| } |
| |
| // Emit subprogram debug descriptor. |
| if (CGDebugInfo *DI = getDebugInfo()) { |
| // Reconstruct the type from the argument list so that implicit parameters, |
| // such as 'this' and 'vtt', show up in the debug info. Preserve the calling |
| // convention. |
| CallingConv CC = CallingConv::CC_C; |
| if (auto *FD = dyn_cast_or_null<FunctionDecl>(D)) |
| if (const auto *SrcFnTy = FD->getType()->getAs<FunctionType>()) |
| CC = SrcFnTy->getCallConv(); |
| SmallVector<QualType, 16> ArgTypes; |
| for (const VarDecl *VD : Args) |
| ArgTypes.push_back(VD->getType()); |
| QualType FnType = getContext().getFunctionType( |
| RetTy, ArgTypes, FunctionProtoType::ExtProtoInfo(CC)); |
| DI->EmitFunctionStart(GD, Loc, StartLoc, FnType, CurFn, CurFuncIsThunk, |
| Builder); |
| } |
| |
| if (ShouldInstrumentFunction()) { |
| if (CGM.getCodeGenOpts().InstrumentFunctions) |
| CurFn->addFnAttr("instrument-function-entry", "__cyg_profile_func_enter"); |
| if (CGM.getCodeGenOpts().InstrumentFunctionsAfterInlining) |
| CurFn->addFnAttr("instrument-function-entry-inlined", |
| "__cyg_profile_func_enter"); |
| if (CGM.getCodeGenOpts().InstrumentFunctionEntryBare) |
| CurFn->addFnAttr("instrument-function-entry-inlined", |
| "__cyg_profile_func_enter_bare"); |
| } |
| |
| // Since emitting the mcount call here impacts optimizations such as function |
| // inlining, we just add an attribute to insert a mcount call in backend. |
| // The attribute "counting-function" is set to mcount function name which is |
| // architecture dependent. |
| if (CGM.getCodeGenOpts().InstrumentForProfiling) { |
| // Calls to fentry/mcount should not be generated if function has |
| // the no_instrument_function attribute. |
| if (!CurFuncDecl || !CurFuncDecl->hasAttr<NoInstrumentFunctionAttr>()) { |
| if (CGM.getCodeGenOpts().CallFEntry) |
| Fn->addFnAttr("fentry-call", "true"); |
| else { |
| Fn->addFnAttr("instrument-function-entry-inlined", |
| getTarget().getMCountName()); |
| } |
| if (CGM.getCodeGenOpts().MNopMCount) { |
| if (!CGM.getCodeGenOpts().CallFEntry) |
| CGM.getDiags().Report(diag::err_opt_not_valid_without_opt) |
| << "-mnop-mcount" << "-mfentry"; |
| Fn->addFnAttr("mnop-mcount"); |
| } |
| |
| if (CGM.getCodeGenOpts().RecordMCount) { |
| if (!CGM.getCodeGenOpts().CallFEntry) |
| CGM.getDiags().Report(diag::err_opt_not_valid_without_opt) |
| << "-mrecord-mcount" << "-mfentry"; |
| Fn->addFnAttr("mrecord-mcount"); |
| } |
| } |
| } |
| |
| if (CGM.getCodeGenOpts().PackedStack) { |
| if (getContext().getTargetInfo().getTriple().getArch() != |
| llvm::Triple::systemz) |
| CGM.getDiags().Report(diag::err_opt_not_valid_on_target) |
| << "-mpacked-stack"; |
| Fn->addFnAttr("packed-stack"); |
| } |
| |
| if (RetTy->isVoidType()) { |
| // Void type; nothing to return. |
| ReturnValue = Address::invalid(); |
| |
| // Count the implicit return. |
| if (!endsWithReturn(D)) |
| ++NumReturnExprs; |
| } else if (CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect) { |
| // Indirect return; emit returned value directly into sret slot. |
| // This reduces code size, and affects correctness in C++. |
| auto AI = CurFn->arg_begin(); |
| if (CurFnInfo->getReturnInfo().isSRetAfterThis()) |
| ++AI; |
| ReturnValue = Address(&*AI, CurFnInfo->getReturnInfo().getIndirectAlign()); |
| if (!CurFnInfo->getReturnInfo().getIndirectByVal()) { |
| ReturnValuePointer = |
| CreateDefaultAlignTempAlloca(Int8PtrTy, "result.ptr"); |
| Builder.CreateStore(Builder.CreatePointerBitCastOrAddrSpaceCast( |
| ReturnValue.getPointer(), Int8PtrTy), |
| ReturnValuePointer); |
| } |
| } else if (CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::InAlloca && |
| !hasScalarEvaluationKind(CurFnInfo->getReturnType())) { |
| // Load the sret pointer from the argument struct and return into that. |
| unsigned Idx = CurFnInfo->getReturnInfo().getInAllocaFieldIndex(); |
| llvm::Function::arg_iterator EI = CurFn->arg_end(); |
| --EI; |
| llvm::Value *Addr = Builder.CreateStructGEP(nullptr, &*EI, Idx); |
| ReturnValuePointer = Address(Addr, getPointerAlign()); |
| Addr = Builder.CreateAlignedLoad(Addr, getPointerAlign(), "agg.result"); |
| ReturnValue = Address(Addr, CGM.getNaturalTypeAlignment(RetTy)); |
| } else { |
| ReturnValue = CreateIRTemp(RetTy, "retval"); |
| |
| // Tell the epilog emitter to autorelease the result. We do this |
| // now so that various specialized functions can suppress it |
| // during their IR-generation. |
| if (getLangOpts().ObjCAutoRefCount && |
| !CurFnInfo->isReturnsRetained() && |
| RetTy->isObjCRetainableType()) |
| AutoreleaseResult = true; |
| } |
| |
| EmitStartEHSpec(CurCodeDecl); |
| |
| PrologueCleanupDepth = EHStack.stable_begin(); |
| |
| // Emit OpenMP specific initialization of the device functions. |
| if (getLangOpts().OpenMP && CurCodeDecl) |
| CGM.getOpenMPRuntime().emitFunctionProlog(*this, CurCodeDecl); |
| |
| EmitFunctionProlog(*CurFnInfo, CurFn, Args); |
| |
| if (D && isa<CXXMethodDecl>(D) && cast<CXXMethodDecl>(D)->isInstance()) { |
| CGM.getCXXABI().EmitInstanceFunctionProlog(*this); |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(D); |
| if (MD->getParent()->isLambda() && |
| MD->getOverloadedOperator() == OO_Call) { |
| // We're in a lambda; figure out the captures. |
| MD->getParent()->getCaptureFields(LambdaCaptureFields, |
| LambdaThisCaptureField); |
| if (LambdaThisCaptureField) { |
| // If the lambda captures the object referred to by '*this' - either by |
| // value or by reference, make sure CXXThisValue points to the correct |
| // object. |
| |
| // Get the lvalue for the field (which is a copy of the enclosing object |
| // or contains the address of the enclosing object). |
| LValue ThisFieldLValue = EmitLValueForLambdaField(LambdaThisCaptureField); |
| if (!LambdaThisCaptureField->getType()->isPointerType()) { |
| // If the enclosing object was captured by value, just use its address. |
| CXXThisValue = ThisFieldLValue.getAddress(*this).getPointer(); |
| } else { |
| // Load the lvalue pointed to by the field, since '*this' was captured |
| // by reference. |
| CXXThisValue = |
| EmitLoadOfLValue(ThisFieldLValue, SourceLocation()).getScalarVal(); |
| } |
| } |
| for (auto *FD : MD->getParent()->fields()) { |
| if (FD->hasCapturedVLAType()) { |
| auto *ExprArg = EmitLoadOfLValue(EmitLValueForLambdaField(FD), |
| SourceLocation()).getScalarVal(); |
| auto VAT = FD->getCapturedVLAType(); |
| VLASizeMap[VAT->getSizeExpr()] = ExprArg; |
| } |
| } |
| } else { |
| // Not in a lambda; just use 'this' from the method. |
| // FIXME: Should we generate a new load for each use of 'this'? The |
| // fast register allocator would be happier... |
| CXXThisValue = CXXABIThisValue; |
| } |
| |
| // Check the 'this' pointer once per function, if it's available. |
| if (CXXABIThisValue) { |
| SanitizerSet SkippedChecks; |
| SkippedChecks.set(SanitizerKind::ObjectSize, true); |
| QualType ThisTy = MD->getThisType(); |
| |
| // If this is the call operator of a lambda with no capture-default, it |
| // may have a static invoker function, which may call this operator with |
| // a null 'this' pointer. |
| if (isLambdaCallOperator(MD) && |
| MD->getParent()->getLambdaCaptureDefault() == LCD_None) |
| SkippedChecks.set(SanitizerKind::Null, true); |
| |
| EmitTypeCheck(isa<CXXConstructorDecl>(MD) ? TCK_ConstructorCall |
| : TCK_MemberCall, |
| Loc, CXXABIThisValue, ThisTy, |
| getContext().getTypeAlignInChars(ThisTy->getPointeeType()), |
| SkippedChecks); |
| } |
| } |
| |
| // If any of the arguments have a variably modified type, make sure to |
| // emit the type size. |
| for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end(); |
| i != e; ++i) { |
| const VarDecl *VD = *i; |
| |
| // Dig out the type as written from ParmVarDecls; it's unclear whether |
| // the standard (C99 6.9.1p10) requires this, but we're following the |
| // precedent set by gcc. |
| QualType Ty; |
| if (const ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(VD)) |
| Ty = PVD->getOriginalType(); |
| else |
| Ty = VD->getType(); |
| |
| if (Ty->isVariablyModifiedType()) |
| EmitVariablyModifiedType(Ty); |
| } |
| // Emit a location at the end of the prologue. |
| if (CGDebugInfo *DI = getDebugInfo()) |
| DI->EmitLocation(Builder, StartLoc); |
| |
| // TODO: Do we need to handle this in two places like we do with |
| // target-features/target-cpu? |
| if (CurFuncDecl) |
| if (const auto *VecWidth = CurFuncDecl->getAttr<MinVectorWidthAttr>()) |
| LargestVectorWidth = VecWidth->getVectorWidth(); |
| } |
| |
| void CodeGenFunction::EmitFunctionBody(const Stmt *Body) { |
| incrementProfileCounter(Body); |
| if (const CompoundStmt *S = dyn_cast<CompoundStmt>(Body)) |
| EmitCompoundStmtWithoutScope(*S); |
| else |
| EmitStmt(Body); |
| } |
| |
| /// When instrumenting to collect profile data, the counts for some blocks |
| /// such as switch cases need to not include the fall-through counts, so |
| /// emit a branch around the instrumentation code. When not instrumenting, |
| /// this just calls EmitBlock(). |
| void CodeGenFunction::EmitBlockWithFallThrough(llvm::BasicBlock *BB, |
| const Stmt *S) { |
| llvm::BasicBlock *SkipCountBB = nullptr; |
| if (HaveInsertPoint() && CGM.getCodeGenOpts().hasProfileClangInstr()) { |
| // When instrumenting for profiling, the fallthrough to certain |
| // statements needs to skip over the instrumentation code so that we |
| // get an accurate count. |
| SkipCountBB = createBasicBlock("skipcount"); |
| EmitBranch(SkipCountBB); |
| } |
| EmitBlock(BB); |
| uint64_t CurrentCount = getCurrentProfileCount(); |
| incrementProfileCounter(S); |
| setCurrentProfileCount(getCurrentProfileCount() + CurrentCount); |
| if (SkipCountBB) |
| EmitBlock(SkipCountBB); |
| } |
| |
| /// Tries to mark the given function nounwind based on the |
| /// non-existence of any throwing calls within it. We believe this is |
| /// lightweight enough to do at -O0. |
| static void TryMarkNoThrow(llvm::Function *F) { |
| // LLVM treats 'nounwind' on a function as part of the type, so we |
| // can't do this on functions that can be overwritten. |
| if (F->isInterposable()) return; |
| |
| for (llvm::BasicBlock &BB : *F) |
| for (llvm::Instruction &I : BB) |
| if (I.mayThrow()) |
| return; |
| |
| F->setDoesNotThrow(); |
| } |
| |
| QualType CodeGenFunction::BuildFunctionArgList(GlobalDecl GD, |
| FunctionArgList &Args) { |
| const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); |
| QualType ResTy = FD->getReturnType(); |
| |
| const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD); |
| if (MD && MD->isInstance()) { |
| if (CGM.getCXXABI().HasThisReturn(GD)) |
| ResTy = MD->getThisType(); |
| else if (CGM.getCXXABI().hasMostDerivedReturn(GD)) |
| ResTy = CGM.getContext().VoidPtrTy; |
| CGM.getCXXABI().buildThisParam(*this, Args); |
| } |
| |
| // The base version of an inheriting constructor whose constructed base is a |
| // virtual base is not passed any arguments (because it doesn't actually call |
| // the inherited constructor). |
| bool PassedParams = true; |
| if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FD)) |
| if (auto Inherited = CD->getInheritedConstructor()) |
| PassedParams = |
| getTypes().inheritingCtorHasParams(Inherited, GD.getCtorType()); |
| |
| if (PassedParams) { |
| for (auto *Param : FD->parameters()) { |
| Args.push_back(Param); |
| if (!Param->hasAttr<PassObjectSizeAttr>()) |
| continue; |
| |
| auto *Implicit = ImplicitParamDecl::Create( |
| getContext(), Param->getDeclContext(), Param->getLocation(), |
| /*Id=*/nullptr, getContext().getSizeType(), ImplicitParamDecl::Other); |
| SizeArguments[Param] = Implicit; |
| Args.push_back(Implicit); |
| } |
| } |
| |
| if (MD && (isa<CXXConstructorDecl>(MD) || isa<CXXDestructorDecl>(MD))) |
| CGM.getCXXABI().addImplicitStructorParams(*this, ResTy, Args); |
| |
| return ResTy; |
| } |
| |
| static bool |
| shouldUseUndefinedBehaviorReturnOptimization(const FunctionDecl *FD, |
| const ASTContext &Context) { |
| QualType T = FD->getReturnType(); |
| // Avoid the optimization for functions that return a record type with a |
| // trivial destructor or another trivially copyable type. |
| if (const RecordType *RT = T.getCanonicalType()->getAs<RecordType>()) { |
| if (const auto *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) |
| return !ClassDecl->hasTrivialDestructor(); |
| } |
| return !T.isTriviallyCopyableType(Context); |
| } |
| |
| void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn, |
| const CGFunctionInfo &FnInfo) { |
| const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); |
| CurGD = GD; |
| |
| FunctionArgList Args; |
| QualType ResTy = BuildFunctionArgList(GD, Args); |
| |
| // Check if we should generate debug info for this function. |
| if (FD->hasAttr<NoDebugAttr>()) |
| DebugInfo = nullptr; // disable debug info indefinitely for this function |
| |
| // The function might not have a body if we're generating thunks for a |
| // function declaration. |
| SourceRange BodyRange; |
| if (Stmt *Body = FD->getBody()) |
| BodyRange = Body->getSourceRange(); |
| else |
| BodyRange = FD->getLocation(); |
| CurEHLocation = BodyRange.getEnd(); |
| |
| // Use the location of the start of the function to determine where |
| // the function definition is located. By default use the location |
| // of the declaration as the location for the subprogram. A function |
| // may lack a declaration in the source code if it is created by code |
| // gen. (examples: _GLOBAL__I_a, __cxx_global_array_dtor, thunk). |
| SourceLocation Loc = FD->getLocation(); |
| |
| // If this is a function specialization then use the pattern body |
| // as the location for the function. |
| if (const FunctionDecl *SpecDecl = FD->getTemplateInstantiationPattern()) |
| if (SpecDecl->hasBody(SpecDecl)) |
| Loc = SpecDecl->getLocation(); |
| |
| Stmt *Body = FD->getBody(); |
| |
| // Initialize helper which will detect jumps which can cause invalid lifetime |
| // markers. |
| if (Body && ShouldEmitLifetimeMarkers) |
| Bypasses.Init(Body); |
| |
| // Emit the standard function prologue. |
| StartFunction(GD, ResTy, Fn, FnInfo, Args, Loc, BodyRange.getBegin()); |
| |
| // Generate the body of the function. |
| PGO.assignRegionCounters(GD, CurFn); |
| if (isa<CXXDestructorDecl>(FD)) |
| EmitDestructorBody(Args); |
| else if (isa<CXXConstructorDecl>(FD)) |
| EmitConstructorBody(Args); |
| else if (getLangOpts().CUDA && |
| !getLangOpts().CUDAIsDevice && |
| FD->hasAttr<CUDAGlobalAttr>()) |
| CGM.getCUDARuntime().emitDeviceStub(*this, Args); |
| else if (isa<CXXMethodDecl>(FD) && |
| cast<CXXMethodDecl>(FD)->isLambdaStaticInvoker()) { |
| // The lambda static invoker function is special, because it forwards or |
| // clones the body of the function call operator (but is actually static). |
| EmitLambdaStaticInvokeBody(cast<CXXMethodDecl>(FD)); |
| } else if (FD->isDefaulted() && isa<CXXMethodDecl>(FD) && |
| (cast<CXXMethodDecl>(FD)->isCopyAssignmentOperator() || |
| cast<CXXMethodDecl>(FD)->isMoveAssignmentOperator())) { |
| // Implicit copy-assignment gets the same special treatment as implicit |
| // copy-constructors. |
| emitImplicitAssignmentOperatorBody(Args); |
| } else if (Body) { |
| EmitFunctionBody(Body); |
| } else |
| llvm_unreachable("no definition for emitted function"); |
| |
| // C++11 [stmt.return]p2: |
| // Flowing off the end of a function [...] results in undefined behavior in |
| // a value-returning function. |
| // C11 6.9.1p12: |
| // If the '}' that terminates a function is reached, and the value of the |
| // function call is used by the caller, the behavior is undefined. |
| if (getLangOpts().CPlusPlus && !FD->hasImplicitReturnZero() && !SawAsmBlock && |
| !FD->getReturnType()->isVoidType() && Builder.GetInsertBlock()) { |
| bool ShouldEmitUnreachable = |
| CGM.getCodeGenOpts().StrictReturn || |
| shouldUseUndefinedBehaviorReturnOptimization(FD, getContext()); |
| if (SanOpts.has(SanitizerKind::Return)) { |
| SanitizerScope SanScope(this); |
| llvm::Value *IsFalse = Builder.getFalse(); |
| EmitCheck(std::make_pair(IsFalse, SanitizerKind::Return), |
| SanitizerHandler::MissingReturn, |
| EmitCheckSourceLocation(FD->getLocation()), None); |
| } else if (ShouldEmitUnreachable) { |
| if (CGM.getCodeGenOpts().OptimizationLevel == 0) |
| EmitTrapCall(llvm::Intrinsic::trap); |
| } |
| if (SanOpts.has(SanitizerKind::Return) || ShouldEmitUnreachable) { |
| Builder.CreateUnreachable(); |
| Builder.ClearInsertionPoint(); |
| } |
| } |
| |
| // Emit the standard function epilogue. |
| FinishFunction(BodyRange.getEnd()); |
| |
| // If we haven't marked the function nothrow through other means, do |
| // a quick pass now to see if we can. |
| if (!CurFn->doesNotThrow()) |
| TryMarkNoThrow(CurFn); |
| } |
| |
| /// ContainsLabel - Return true if the statement contains a label in it. If |
| /// this statement is not executed normally, it not containing a label means |
| /// that we can just remove the code. |
| bool CodeGenFunction::ContainsLabel(const Stmt *S, bool IgnoreCaseStmts) { |
| // Null statement, not a label! |
| if (!S) return false; |
| |
| // If this is a label, we have to emit the code, consider something like: |
| // if (0) { ... foo: bar(); } goto foo; |
| // |
| // TODO: If anyone cared, we could track __label__'s, since we know that you |
| // can't jump to one from outside their declared region. |
| if (isa<LabelStmt>(S)) |
| return true; |
| |
| // If this is a case/default statement, and we haven't seen a switch, we have |
| // to emit the code. |
| if (isa<SwitchCase>(S) && !IgnoreCaseStmts) |
| return true; |
| |
| // If this is a switch statement, we want to ignore cases below it. |
| if (isa<SwitchStmt>(S)) |
| IgnoreCaseStmts = true; |
| |
| // Scan subexpressions for verboten labels. |
| for (const Stmt *SubStmt : S->children()) |
| if (ContainsLabel(SubStmt, IgnoreCaseStmts)) |
| return true; |
| |
| return false; |
| } |
| |
| /// containsBreak - Return true if the statement contains a break out of it. |
| /// If the statement (recursively) contains a switch or loop with a break |
| /// inside of it, this is fine. |
| bool CodeGenFunction::containsBreak(const Stmt *S) { |
| // Null statement, not a label! |
| if (!S) return false; |
| |
| // If this is a switch or loop that defines its own break scope, then we can |
| // include it and anything inside of it. |
| if (isa<SwitchStmt>(S) || isa<WhileStmt>(S) || isa<DoStmt>(S) || |
| isa<ForStmt>(S)) |
| return false; |
| |
| if (isa<BreakStmt>(S)) |
| return true; |
| |
| // Scan subexpressions for verboten breaks. |
| for (const Stmt *SubStmt : S->children()) |
| if (containsBreak(SubStmt)) |
| return true; |
| |
| return false; |
| } |
| |
| bool CodeGenFunction::mightAddDeclToScope(const Stmt *S) { |
| if (!S) return false; |
| |
| // Some statement kinds add a scope and thus never add a decl to the current |
| // scope. Note, this list is longer than the list of statements that might |
| // have an unscoped decl nested within them, but this way is conservatively |
| // correct even if more statement kinds are added. |
| if (isa<IfStmt>(S) || isa<SwitchStmt>(S) || isa<WhileStmt>(S) || |
| isa<DoStmt>(S) || isa<ForStmt>(S) || isa<CompoundStmt>(S) || |
| isa<CXXForRangeStmt>(S) || isa<CXXTryStmt>(S) || |
| isa<ObjCForCollectionStmt>(S) || isa<ObjCAtTryStmt>(S)) |
| return false; |
| |
| if (isa<DeclStmt>(S)) |
| return true; |
| |
| for (const Stmt *SubStmt : S->children()) |
| if (mightAddDeclToScope(SubStmt)) |
| return true; |
| |
| return false; |
| } |
| |
| /// ConstantFoldsToSimpleInteger - If the specified expression does not fold |
| /// to a constant, or if it does but contains a label, return false. If it |
| /// constant folds return true and set the boolean result in Result. |
| bool CodeGenFunction::ConstantFoldsToSimpleInteger(const Expr *Cond, |
| bool &ResultBool, |
| bool AllowLabels) { |
| llvm::APSInt ResultInt; |
| if (!ConstantFoldsToSimpleInteger(Cond, ResultInt, AllowLabels)) |
| return false; |
| |
| ResultBool = ResultInt.getBoolValue(); |
| return true; |
| } |
| |
| /// ConstantFoldsToSimpleInteger - If the specified expression does not fold |
| /// to a constant, or if it does but contains a label, return false. If it |
| /// constant folds return true and set the folded value. |
| bool CodeGenFunction::ConstantFoldsToSimpleInteger(const Expr *Cond, |
| llvm::APSInt &ResultInt, |
| bool AllowLabels) { |
| // FIXME: Rename and handle conversion of other evaluatable things |
| // to bool. |
| Expr::EvalResult Result; |
| if (!Cond->EvaluateAsInt(Result, getContext())) |
| return false; // Not foldable, not integer or not fully evaluatable. |
| |
| llvm::APSInt Int = Result.Val.getInt(); |
| if (!AllowLabels && CodeGenFunction::ContainsLabel(Cond)) |
| return false; // Contains a label. |
| |
| ResultInt = Int; |
| return true; |
| } |
| |
| /// EmitBranchOnBoolExpr - Emit a branch on a boolean condition (e.g. for an if |
| /// statement) to the specified blocks. Based on the condition, this might try |
| /// to simplify the codegen of the conditional based on the branch. |
| /// \param Weights The weights determined by the likelihood attributes. |
| void CodeGenFunction::EmitBranchOnBoolExpr(const Expr *Cond, |
| llvm::BasicBlock *TrueBlock, |
| llvm::BasicBlock *FalseBlock, |
| uint64_t TrueCount, |
| llvm::MDNode *Weights) { |
| Cond = Cond->IgnoreParens(); |
| |
| if (const BinaryOperator *CondBOp = dyn_cast<BinaryOperator>(Cond)) { |
| |
| // Handle X && Y in a condition. |
| if (CondBOp->getOpcode() == BO_LAnd) { |
| // If we have "1 && X", simplify the code. "0 && X" would have constant |
| // folded if the case was simple enough. |
| bool ConstantBool = false; |
| if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) && |
| ConstantBool) { |
| // br(1 && X) -> br(X). |
| incrementProfileCounter(CondBOp); |
| return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock, |
| TrueCount, Weights); |
| } |
| |
| // If we have "X && 1", simplify the code to use an uncond branch. |
| // "X && 0" would have been constant folded to 0. |
| if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) && |
| ConstantBool) { |
| // br(X && 1) -> br(X). |
| return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock, |
| TrueCount, Weights); |
| } |
| |
| // Emit the LHS as a conditional. If the LHS conditional is false, we |
| // want to jump to the FalseBlock. |
| llvm::BasicBlock *LHSTrue = createBasicBlock("land.lhs.true"); |
| // The counter tells us how often we evaluate RHS, and all of TrueCount |
| // can be propagated to that branch. |
| uint64_t RHSCount = getProfileCount(CondBOp->getRHS()); |
| |
| ConditionalEvaluation eval(*this); |
| { |
| ApplyDebugLocation DL(*this, Cond); |
| EmitBranchOnBoolExpr(CondBOp->getLHS(), LHSTrue, FalseBlock, RHSCount, |
| Weights); |
| EmitBlock(LHSTrue); |
| } |
| |
| incrementProfileCounter(CondBOp); |
| setCurrentProfileCount(getProfileCount(CondBOp->getRHS())); |
| |
| // Any temporaries created here are conditional. |
| eval.begin(*this); |
| EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock, TrueCount, |
| Weights); |
| eval.end(*this); |
| |
| return; |
| } |
| |
| if (CondBOp->getOpcode() == BO_LOr) { |
| // If we have "0 || X", simplify the code. "1 || X" would have constant |
| // folded if the case was simple enough. |
| bool ConstantBool = false; |
| if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) && |
| !ConstantBool) { |
| // br(0 || X) -> br(X). |
| incrementProfileCounter(CondBOp); |
| return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock, |
| TrueCount, Weights); |
| } |
| |
| // If we have "X || 0", simplify the code to use an uncond branch. |
| // "X || 1" would have been constant folded to 1. |
| if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) && |
| !ConstantBool) { |
| // br(X || 0) -> br(X). |
| return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock, |
| TrueCount, Weights); |
| } |
| |
| // Emit the LHS as a conditional. If the LHS conditional is true, we |
| // want to jump to the TrueBlock. |
| llvm::BasicBlock *LHSFalse = createBasicBlock("lor.lhs.false"); |
| // We have the count for entry to the RHS and for the whole expression |
| // being true, so we can divy up True count between the short circuit and |
| // the RHS. |
| uint64_t LHSCount = |
| getCurrentProfileCount() - getProfileCount(CondBOp->getRHS()); |
| uint64_t RHSCount = TrueCount - LHSCount; |
| |
| ConditionalEvaluation eval(*this); |
| { |
| ApplyDebugLocation DL(*this, Cond); |
| EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, LHSFalse, LHSCount, |
| Weights); |
| EmitBlock(LHSFalse); |
| } |
| |
| incrementProfileCounter(CondBOp); |
| setCurrentProfileCount(getProfileCount(CondBOp->getRHS())); |
| |
| // Any temporaries created here are conditional. |
| eval.begin(*this); |
| EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock, RHSCount, |
| Weights); |
| |
| eval.end(*this); |
| |
| return; |
| } |
| } |
| |
| if (const UnaryOperator *CondUOp = dyn_cast<UnaryOperator>(Cond)) { |
| // br(!x, t, f) -> br(x, f, t) |
| if (CondUOp->getOpcode() == UO_LNot) { |
| // Negate the count. |
| uint64_t FalseCount = getCurrentProfileCount() - TrueCount; |
| // Negate the condition and swap the destination blocks. |
| return EmitBranchOnBoolExpr(CondUOp->getSubExpr(), FalseBlock, TrueBlock, |
| FalseCount, Weights); |
| } |
| } |
| |
| if (const ConditionalOperator *CondOp = dyn_cast<ConditionalOperator>(Cond)) { |
| // br(c ? x : y, t, f) -> br(c, br(x, t, f), br(y, t, f)) |
| llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true"); |
| llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false"); |
| |
| ConditionalEvaluation cond(*this); |
| EmitBranchOnBoolExpr(CondOp->getCond(), LHSBlock, RHSBlock, |
| getProfileCount(CondOp), Weights); |
| |
| // When computing PGO branch weights, we only know the overall count for |
| // the true block. This code is essentially doing tail duplication of the |
| // naive code-gen, introducing new edges for which counts are not |
| // available. Divide the counts proportionally between the LHS and RHS of |
| // the conditional operator. |
| uint64_t LHSScaledTrueCount = 0; |
| if (TrueCount) { |
| double LHSRatio = |
| getProfileCount(CondOp) / (double)getCurrentProfileCount(); |
| LHSScaledTrueCount = TrueCount * LHSRatio; |
| } |
| |
| cond.begin(*this); |
| EmitBlock(LHSBlock); |
| incrementProfileCounter(CondOp); |
| { |
| ApplyDebugLocation DL(*this, Cond); |
| EmitBranchOnBoolExpr(CondOp->getLHS(), TrueBlock, FalseBlock, |
| LHSScaledTrueCount, Weights); |
| } |
| cond.end(*this); |
| |
| cond.begin(*this); |
| EmitBlock(RHSBlock); |
| EmitBranchOnBoolExpr(CondOp->getRHS(), TrueBlock, FalseBlock, |
| TrueCount - LHSScaledTrueCount, Weights); |
| cond.end(*this); |
| |
| return; |
| } |
| |
| if (const CXXThrowExpr *Throw = dyn_cast<CXXThrowExpr>(Cond)) { |
| // Conditional operator handling can give us a throw expression as a |
| // condition for a case like: |
| // br(c ? throw x : y, t, f) -> br(c, br(throw x, t, f), br(y, t, f) |
| // Fold this to: |
| // br(c, throw x, br(y, t, f)) |
| EmitCXXThrowExpr(Throw, /*KeepInsertionPoint*/false); |
| return; |
| } |
| |
| // If the branch has a condition wrapped by __builtin_unpredictable, |
| // create metadata that specifies that the branch is unpredictable. |
| // Don't bother if not optimizing because that metadata would not be used. |
| llvm::MDNode *Unpredictable = nullptr; |
| auto *Call = dyn_cast<CallExpr>(Cond->IgnoreImpCasts()); |
| if (Call && CGM.getCodeGenOpts().OptimizationLevel != 0) { |
| auto *FD = dyn_cast_or_null<FunctionDecl>(Call->getCalleeDecl()); |
| if (FD && FD->getBuiltinID() == Builtin::BI__builtin_unpredictable) { |
| llvm::MDBuilder MDHelper(getLLVMContext()); |
| Unpredictable = MDHelper.createUnpredictable(); |
| } |
| } |
| |
| // Create branch weights based on the number of times we get here and the |
| // number of times the condition should be true. |
| if (!Weights) { |
| uint64_t CurrentCount = std::max(getCurrentProfileCount(), TrueCount); |
| Weights = createProfileWeights(TrueCount, CurrentCount - TrueCount); |
| } |
| |
| // Emit the code with the fully general case. |
| llvm::Value *CondV; |
| { |
| ApplyDebugLocation DL(*this, Cond); |
| CondV = EvaluateExprAsBool(Cond); |
| } |
| Builder.CreateCondBr(CondV, TrueBlock, FalseBlock, Weights, Unpredictable); |
| } |
| |
| /// ErrorUnsupported - Print out an error that codegen doesn't support the |
| /// specified stmt yet. |
| void CodeGenFunction::ErrorUnsupported(const Stmt *S, const char *Type) { |
| CGM.ErrorUnsupported(S, Type); |
| } |
| |
| /// emitNonZeroVLAInit - Emit the "zero" initialization of a |
| /// variable-length array whose elements have a non-zero bit-pattern. |
| /// |
| /// \param baseType the inner-most element type of the array |
| /// \param src - a char* pointing to the bit-pattern for a single |
| /// base element of the array |
| /// \param sizeInChars - the total size of the VLA, in chars |
| static void emitNonZeroVLAInit(CodeGenFunction &CGF, QualType baseType, |
| Address dest, Address src, |
| llvm::Value *sizeInChars) { |
| CGBuilderTy &Builder = CGF.Builder; |
| |
| CharUnits baseSize = CGF.getContext().getTypeSizeInChars(baseType); |
| llvm::Value *baseSizeInChars |
| = llvm::ConstantInt::get(CGF.IntPtrTy, baseSize.getQuantity()); |
| |
| Address begin = |
| Builder.CreateElementBitCast(dest, CGF.Int8Ty, "vla.begin"); |
| llvm::Value *end = |
| Builder.CreateInBoundsGEP(begin.getPointer(), sizeInChars, "vla.end"); |
| |
| llvm::BasicBlock *originBB = CGF.Builder.GetInsertBlock(); |
| llvm::BasicBlock *loopBB = CGF.createBasicBlock("vla-init.loop"); |
| llvm::BasicBlock *contBB = CGF.createBasicBlock("vla-init.cont"); |
| |
| // Make a loop over the VLA. C99 guarantees that the VLA element |
| // count must be nonzero. |
| CGF.EmitBlock(loopBB); |
| |
| llvm::PHINode *cur = Builder.CreatePHI(begin.getType(), 2, "vla.cur"); |
| cur->addIncoming(begin.getPointer(), originBB); |
| |
| CharUnits curAlign = |
| dest.getAlignment().alignmentOfArrayElement(baseSize); |
| |
| // memcpy the individual element bit-pattern. |
| Builder.CreateMemCpy(Address(cur, curAlign), src, baseSizeInChars, |
| /*volatile*/ false); |
| |
| // Go to the next element. |
| llvm::Value *next = |
| Builder.CreateInBoundsGEP(CGF.Int8Ty, cur, baseSizeInChars, "vla.next"); |
| |
| // Leave if that's the end of the VLA. |
| llvm::Value *done = Builder.CreateICmpEQ(next, end, "vla-init.isdone"); |
| Builder.CreateCondBr(done, contBB, loopBB); |
| cur->addIncoming(next, loopBB); |
| |
| CGF.EmitBlock(contBB); |
| } |
| |
| void |
| CodeGenFunction::EmitNullInitialization(Address DestPtr, QualType Ty) { |
| // Ignore empty classes in C++. |
| if (getLangOpts().CPlusPlus) { |
| if (const RecordType *RT = Ty->getAs<RecordType>()) { |
| if (cast<CXXRecordDecl>(RT->getDecl())->isEmpty()) |
| return; |
| } |
| } |
| |
| // Cast the dest ptr to the appropriate i8 pointer type. |
| if (DestPtr.getElementType() != Int8Ty) |
| DestPtr = Builder.CreateElementBitCast(DestPtr, Int8Ty); |
| |
| // Get size and alignment info for this aggregate. |
| CharUnits size = getContext().getTypeSizeInChars(Ty); |
| |
| llvm::Value *SizeVal; |
| const VariableArrayType *vla; |
| |
| // Don't bother emitting a zero-byte memset. |
| if (size.isZero()) { |
| // But note that getTypeInfo returns 0 for a VLA. |
| if (const VariableArrayType *vlaType = |
| dyn_cast_or_null<VariableArrayType>( |
| getContext().getAsArrayType(Ty))) { |
| auto VlaSize = getVLASize(vlaType); |
| SizeVal = VlaSize.NumElts; |
| CharUnits eltSize = getContext().getTypeSizeInChars(VlaSize.Type); |
| if (!eltSize.isOne()) |
| SizeVal = Builder.CreateNUWMul(SizeVal, CGM.getSize(eltSize)); |
| vla = vlaType; |
| } else { |
| return; |
| } |
| } else { |
| SizeVal = CGM.getSize(size); |
| vla = nullptr; |
| } |
| |
| // If the type contains a pointer to data member we can't memset it to zero. |
| // Instead, create a null constant and copy it to the destination. |
| // TODO: there are other patterns besides zero that we can usefully memset, |
| // like -1, which happens to be the pattern used by member-pointers. |
| if (!CGM.getTypes().isZeroInitializable(Ty)) { |
| // For a VLA, emit a single element, then splat that over the VLA. |
| if (vla) Ty = getContext().getBaseElementType(vla); |
| |
| llvm::Constant *NullConstant = CGM.EmitNullConstant(Ty); |
| |
| llvm::GlobalVariable *NullVariable = |
| new llvm::GlobalVariable(CGM.getModule(), NullConstant->getType(), |
| /*isConstant=*/true, |
| llvm::GlobalVariable::PrivateLinkage, |
| NullConstant, Twine()); |
| CharUnits NullAlign = DestPtr.getAlignment(); |
| NullVariable->setAlignment(NullAlign.getAsAlign()); |
| Address SrcPtr(Builder.CreateBitCast(NullVariable, Builder.getInt8PtrTy()), |
| NullAlign); |
| |
| if (vla) return emitNonZeroVLAInit(*this, Ty, DestPtr, SrcPtr, SizeVal); |
| |
| // Get and call the appropriate llvm.memcpy overload. |
| Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, false); |
| return; |
| } |
| |
| // Otherwise, just memset the whole thing to zero. This is legal |
| // because in LLVM, all default initializers (other than the ones we just |
| // handled above) are guaranteed to have a bit pattern of all zeros. |
| Builder.CreateMemSet(DestPtr, Builder.getInt8(0), SizeVal, false); |
| } |
| |
| llvm::BlockAddress *CodeGenFunction::GetAddrOfLabel(const LabelDecl *L) { |
| // Make sure that there is a block for the indirect goto. |
| if (!IndirectBranch) |
| GetIndirectGotoBlock(); |
| |
| llvm::BasicBlock *BB = getJumpDestForLabel(L).getBlock(); |
| |
| // Make sure the indirect branch includes all of the address-taken blocks. |
| IndirectBranch->addDestination(BB); |
| return llvm::BlockAddress::get(CurFn, BB); |
| } |
| |
| llvm::BasicBlock *CodeGenFunction::GetIndirectGotoBlock() { |
| // If we already made the indirect branch for indirect goto, return its block. |
| if (IndirectBranch) return IndirectBranch->getParent(); |
| |
| CGBuilderTy TmpBuilder(*this, createBasicBlock("indirectgoto")); |
| |
| // Create the PHI node that indirect gotos will add entries to. |
| llvm::Value *DestVal = TmpBuilder.CreatePHI(Int8PtrTy, 0, |
| "indirect.goto.dest"); |
| |
| // Create the indirect branch instruction. |
| IndirectBranch = TmpBuilder.CreateIndirectBr(DestVal); |
| return IndirectBranch->getParent(); |
| } |
| |
| /// Computes the length of an array in elements, as well as the base |
| /// element type and a properly-typed first element pointer. |
| llvm::Value *CodeGenFunction::emitArrayLength(const ArrayType *origArrayType, |
| QualType &baseType, |
| Address &addr) { |
| const ArrayType *arrayType = origArrayType; |
| |
| // If it's a VLA, we have to load the stored size. Note that |
| // this is the size of the VLA in bytes, not its size in elements. |
| llvm::Value *numVLAElements = nullptr; |
| if (isa<VariableArrayType>(arrayType)) { |
| numVLAElements = getVLASize(cast<VariableArrayType>(arrayType)).NumElts; |
| |
| // Walk into all VLAs. This doesn't require changes to addr, |
| // which has type T* where T is the first non-VLA element type. |
| do { |
| QualType elementType = arrayType->getElementType(); |
| arrayType = getContext().getAsArrayType(elementType); |
| |
| // If we only have VLA components, 'addr' requires no adjustment. |
| if (!arrayType) { |
| baseType = elementType; |
| return numVLAElements; |
| } |
| } while (isa<VariableArrayType>(arrayType)); |
| |
| // We get out here only if we find a constant array type |
| // inside the VLA. |
| } |
| |
| // We have some number of constant-length arrays, so addr should |
| // have LLVM type [M x [N x [...]]]*. Build a GEP that walks |
| // down to the first element of addr. |
| SmallVector<llvm::Value*, 8> gepIndices; |
| |
| // GEP down to the array type. |
| llvm::ConstantInt *zero = Builder.getInt32(0); |
| gepIndices.push_back(zero); |
| |
| uint64_t countFromCLAs = 1; |
| QualType eltType; |
| |
| llvm::ArrayType *llvmArrayType = |
| dyn_cast<llvm::ArrayType>(addr.getElementType()); |
| while (llvmArrayType) { |
| assert(isa<ConstantArrayType>(arrayType)); |
| assert(cast<ConstantArrayType>(arrayType)->getSize().getZExtValue() |
| == llvmArrayType->getNumElements()); |
| |
| gepIndices.push_back(zero); |
| countFromCLAs *= llvmArrayType->getNumElements(); |
| eltType = arrayType->getElementType(); |
| |
| llvmArrayType = |
| dyn_cast<llvm::ArrayType>(llvmArrayType->getElementType()); |
| arrayType = getContext().getAsArrayType(arrayType->getElementType()); |
| assert((!llvmArrayType || arrayType) && |
| "LLVM and Clang types are out-of-synch"); |
| } |
| |
| if (arrayType) { |
| // From this point onwards, the Clang array type has been emitted |
| // as some other type (probably a packed struct). Compute the array |
| // size, and just emit the 'begin' expression as a bitcast. |
| while (arrayType) { |
| countFromCLAs *= |
| cast<ConstantArrayType>(arrayType)->getSize().getZExtValue(); |
| eltType = arrayType->getElementType(); |
| arrayType = getContext().getAsArrayType(eltType); |
| } |
| |
| llvm::Type *baseType = ConvertType(eltType); |
| addr = Builder.CreateElementBitCast(addr, baseType, "array.begin"); |
| } else { |
| // Create the actual GEP. |
| addr = Address(Builder.CreateInBoundsGEP(addr.getPointer(), |
| gepIndices, "array.begin"), |
| addr.getAlignment()); |
| } |
| |
| baseType = eltType; |
| |
| llvm::Value *numElements |
| = llvm::ConstantInt::get(SizeTy, countFromCLAs); |
| |
| // If we had any VLA dimensions, factor them in. |
| if (numVLAElements) |
| numElements = Builder.CreateNUWMul(numVLAElements, numElements); |
| |
| return numElements; |
| } |
| |
| CodeGenFunction::VlaSizePair CodeGenFunction::getVLASize(QualType type) { |
| const VariableArrayType *vla = getContext().getAsVariableArrayType(type); |
| assert(vla && "type was not a variable array type!"); |
| return getVLASize(vla); |
| } |
| |
| CodeGenFunction::VlaSizePair |
| CodeGenFunction::getVLASize(const VariableArrayType *type) { |
| // The number of elements so far; always size_t. |
| llvm::Value *numElements = nullptr; |
| |
| QualType elementType; |
| do { |
| elementType = type->getElementType(); |
| llvm::Value *vlaSize = VLASizeMap[type->getSizeExpr()]; |
| assert(vlaSize && "no size for VLA!"); |
| assert(vlaSize->getType() == SizeTy); |
| |
| if (!numElements) { |
| numElements = vlaSize; |
| } else { |
| // It's undefined behavior if this wraps around, so mark it that way. |
| // FIXME: Teach -fsanitize=undefined to trap this. |
| numElements = Builder.CreateNUWMul(numElements, vlaSize); |
| } |
| } while ((type = getContext().getAsVariableArrayType(elementType))); |
| |
| return { numElements, elementType }; |
| } |
| |
| CodeGenFunction::VlaSizePair |
| CodeGenFunction::getVLAElements1D(QualType type) { |
| const VariableArrayType *vla = getContext().getAsVariableArrayType(type); |
| assert(vla && "type was not a variable array type!"); |
| return getVLAElements1D(vla); |
| } |
| |
| CodeGenFunction::VlaSizePair |
| CodeGenFunction::getVLAElements1D(const VariableArrayType *Vla) { |
| llvm::Value *VlaSize = VLASizeMap[Vla->getSizeExpr()]; |
| assert(VlaSize && "no size for VLA!"); |
| assert(VlaSize->getType() == SizeTy); |
| return { VlaSize, Vla->getElementType() }; |
| } |
| |
| void CodeGenFunction::EmitVariablyModifiedType(QualType type) { |
| assert(type->isVariablyModifiedType() && |
| "Must pass variably modified type to EmitVLASizes!"); |
| |
| EnsureInsertPoint(); |
| |
| // We're going to walk down into the type and look for VLA |
| // expressions. |
| do { |
| assert(type->isVariablyModifiedType()); |
| |
| const Type *ty = type.getTypePtr(); |
| switch (ty->getTypeClass()) { |
| |
| #define TYPE(Class, Base) |
| #define ABSTRACT_TYPE(Class, Base) |
| #define NON_CANONICAL_TYPE(Class, Base) |
| #define DEPENDENT_TYPE(Class, Base) case Type::Class: |
| #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) |
| #include "clang/AST/TypeNodes.inc" |
| llvm_unreachable("unexpected dependent type!"); |
| |
| // These types are never variably-modified. |
| case Type::Builtin: |
| case Type::Complex: |
| case Type::Vector: |
| case Type::ExtVector: |
| case Type::ConstantMatrix: |
| case Type::Record: |
| case Type::Enum: |
| case Type::Elaborated: |
| case Type::TemplateSpecialization: |
| case Type::ObjCTypeParam: |
| case Type::ObjCObject: |
| case Type::ObjCInterface: |
| case Type::ObjCObjectPointer: |
| case Type::ExtInt: |
| llvm_unreachable("type class is never variably-modified!"); |
| |
| case Type::Adjusted: |
| type = cast<AdjustedType>(ty)->getAdjustedType(); |
| break; |
| |
| case Type::Decayed: |
| type = cast<DecayedType>(ty)->getPointeeType(); |
| break; |
| |
| case Type::Pointer: |
| type = cast<PointerType>(ty)->getPointeeType(); |
| break; |
| |
| case Type::BlockPointer: |
| type = cast<BlockPointerType>(ty)->getPointeeType(); |
| break; |
| |
| case Type::LValueReference: |
| case Type::RValueReference: |
| type = cast<ReferenceType>(ty)->getPointeeType(); |
| break; |
| |
| case Type::MemberPointer: |
| type = cast<MemberPointerType>(ty)->getPointeeType(); |
| break; |
| |
| case Type::ConstantArray: |
| case Type::IncompleteArray: |
| // Losing element qualification here is fine. |
| type = cast<ArrayType>(ty)->getElementType(); |
| break; |
| |
| case Type::VariableArray: { |
| // Losing element qualification here is fine. |
| const VariableArrayType *vat = cast<VariableArrayType>(ty); |
| |
| // Unknown size indication requires no size computation. |
| // Otherwise, evaluate and record it. |
| if (const Expr *size = vat->getSizeExpr()) { |
| // It's possible that we might have emitted this already, |
| // e.g. with a typedef and a pointer to it. |
| llvm::Value *&entry = VLASizeMap[size]; |
| if (!entry) { |
| llvm::Value *Size = EmitScalarExpr(size); |
| |
| // C11 6.7.6.2p5: |
| // If the size is an expression that is not an integer constant |
| // expression [...] each time it is evaluated it shall have a value |
| // greater than zero. |
| if (SanOpts.has(SanitizerKind::VLABound) && |
| size->getType()->isSignedIntegerType()) { |
| SanitizerScope SanScope(this); |
| llvm::Value *Zero = llvm::Constant::getNullValue(Size->getType()); |
| llvm::Constant *StaticArgs[] = { |
| EmitCheckSourceLocation(size->getBeginLoc()), |
| EmitCheckTypeDescriptor(size->getType())}; |
| EmitCheck(std::make_pair(Builder.CreateICmpSGT(Size, Zero), |
| SanitizerKind::VLABound), |
| SanitizerHandler::VLABoundNotPositive, StaticArgs, Size); |
| } |
| |
| // Always zexting here would be wrong if it weren't |
| // undefined behavior to have a negative bound. |
| entry = Builder.CreateIntCast(Size, SizeTy, /*signed*/ false); |
| } |
| } |
| type = vat->getElementType(); |
| break; |
| } |
| |
| case Type::FunctionProto: |
| case Type::FunctionNoProto: |
| type = cast<FunctionType>(ty)->getReturnType(); |
| break; |
| |
| case Type::Paren: |
| case Type::TypeOf: |
| case Type::UnaryTransform: |
| case Type::Attributed: |
| case Type::SubstTemplateTypeParm: |
| case Type::MacroQualified: |
| // Keep walking after single level desugaring. |
| type = type.getSingleStepDesugaredType(getContext()); |
| break; |
| |
| case Type::Typedef: |
| case Type::Decltype: |
| case Type::Auto: |
| case Type::DeducedTemplateSpecialization: |
| // Stop walking: nothing to do. |
| return; |
| |
| case Type::TypeOfExpr: |
| // Stop walking: emit typeof expression. |
| EmitIgnoredExpr(cast<TypeOfExprType>(ty)->getUnderlyingExpr()); |
| return; |
| |
| case Type::Atomic: |
| type = cast<AtomicType>(ty)->getValueType(); |
| break; |
| |
| case Type::Pipe: |
| type = cast<PipeType>(ty)->getElementType(); |
| break; |
| } |
| } while (type->isVariablyModifiedType()); |
| } |
| |
| Address CodeGenFunction::EmitVAListRef(const Expr* E) { |
| if (getContext().getBuiltinVaListType()->isArrayType()) |
| return EmitPointerWithAlignment(E); |
| return EmitLValue(E).getAddress(*this); |
| } |
| |
| Address CodeGenFunction::EmitMSVAListRef(const Expr *E) { |
| return EmitLValue(E).getAddress(*this); |
| } |
| |
| void CodeGenFunction::EmitDeclRefExprDbgValue(const DeclRefExpr *E, |
| const APValue &Init) { |
| assert(Init.hasValue() && "Invalid DeclRefExpr initializer!"); |
| if (CGDebugInfo *Dbg = getDebugInfo()) |
| if (CGM.getCodeGenOpts().hasReducedDebugInfo()) |
| Dbg->EmitGlobalVariable(E->getDecl(), Init); |
| } |
| |
| CodeGenFunction::PeepholeProtection |
| CodeGenFunction::protectFromPeepholes(RValue rvalue) { |
| // At the moment, the only aggressive peephole we do in IR gen |
| // is trunc(zext) folding, but if we add more, we can easily |
| // extend this protection. |
| |
| if (!rvalue.isScalar()) return PeepholeProtection(); |
| llvm::Value *value = rvalue.getScalarVal(); |
| if (!isa<llvm::ZExtInst>(value)) return PeepholeProtection(); |
| |
| // Just make an extra bitcast. |
| assert(HaveInsertPoint()); |
| llvm::Instruction *inst = new llvm::BitCastInst(value, value->getType(), "", |
| Builder.GetInsertBlock()); |
| |
| PeepholeProtection protection; |
| protection.Inst = inst; |
| return protection; |
| } |
| |
| void CodeGenFunction::unprotectFromPeepholes(PeepholeProtection protection) { |
| if (!protection.Inst) return; |
| |
| // In theory, we could try to duplicate the peepholes now, but whatever. |
| protection.Inst->eraseFromParent(); |
| } |
| |
| void CodeGenFunction::emitAlignmentAssumption(llvm::Value *PtrValue, |
| QualType Ty, SourceLocation Loc, |
| SourceLocation AssumptionLoc, |
| llvm::Value *Alignment, |
| llvm::Value *OffsetValue) { |
| if (Alignment->getType() != IntPtrTy) |
| Alignment = |
| Builder.CreateIntCast(Alignment, IntPtrTy, false, "casted.align"); |
| if (OffsetValue && OffsetValue->getType() != IntPtrTy) |
| OffsetValue = |
| Builder.CreateIntCast(OffsetValue, IntPtrTy, true, "casted.offset"); |
| llvm::Value *TheCheck = nullptr; |
| if (SanOpts.has(SanitizerKind::Alignment)) { |
| llvm::Value *PtrIntValue = |
| Builder.CreatePtrToInt(PtrValue, IntPtrTy, "ptrint"); |
| |
| if (OffsetValue) { |
| bool IsOffsetZero = false; |
| if (const auto *CI = dyn_cast<llvm::ConstantInt>(OffsetValue)) |
| IsOffsetZero = CI->isZero(); |
| |
| if (!IsOffsetZero) |
| PtrIntValue = Builder.CreateSub(PtrIntValue, OffsetValue, "offsetptr"); |
| } |
| |
| llvm::Value *Zero = llvm::ConstantInt::get(IntPtrTy, 0); |
| llvm::Value *Mask = |
| Builder.CreateSub(Alignment, llvm::ConstantInt::get(IntPtrTy, 1)); |
| llvm::Value *MaskedPtr = Builder.CreateAnd(PtrIntValue, Mask, "maskedptr"); |
| TheCheck = Builder.CreateICmpEQ(MaskedPtr, Zero, "maskcond"); |
| } |
| llvm::Instruction *Assumption = Builder.CreateAlignmentAssumption( |
| CGM.getDataLayout(), PtrValue, Alignment, OffsetValue); |
| |
| if (!SanOpts.has(SanitizerKind::Alignment)) |
| return; |
| emitAlignmentAssumptionCheck(PtrValue, Ty, Loc, AssumptionLoc, Alignment, |
| OffsetValue, TheCheck, Assumption); |
| } |
| |
| void CodeGenFunction::emitAlignmentAssumption(llvm::Value *PtrValue, |
| const Expr *E, |
| SourceLocation AssumptionLoc, |
| llvm::Value *Alignment, |
| llvm::Value *OffsetValue) { |
| if (auto *CE = dyn_cast<CastExpr>(E)) |
| E = CE->getSubExprAsWritten(); |
| QualType Ty = E->getType(); |
| SourceLocation Loc = E->getExprLoc(); |
| |
| emitAlignmentAssumption(PtrValue, Ty, Loc, AssumptionLoc, Alignment, |
| OffsetValue); |
| } |
| |
| llvm::Value *CodeGenFunction::EmitAnnotationCall(llvm::Function *AnnotationFn, |
| llvm::Value *AnnotatedVal, |
| StringRef AnnotationStr, |
| SourceLocation Location) { |
| llvm::Value *Args[4] = { |
| AnnotatedVal, |
| Builder.CreateBitCast(CGM.EmitAnnotationString(AnnotationStr), Int8PtrTy), |
| Builder.CreateBitCast(CGM.EmitAnnotationUnit(Location), Int8PtrTy), |
| CGM.EmitAnnotationLineNo(Location) |
| }; |
| return Builder.CreateCall(AnnotationFn, Args); |
| } |
| |
| void CodeGenFunction::EmitVarAnnotations(const VarDecl *D, llvm::Value *V) { |
| assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); |
| // FIXME We create a new bitcast for every annotation because that's what |
| // llvm-gcc was doing. |
| for (const auto *I : D->specific_attrs<AnnotateAttr>()) |
| EmitAnnotationCall(CGM.getIntrinsic(llvm::Intrinsic::var_annotation), |
| Builder.CreateBitCast(V, CGM.Int8PtrTy, V->getName()), |
| I->getAnnotation(), D->getLocation()); |
| } |
| |
| Address CodeGenFunction::EmitFieldAnnotations(const FieldDecl *D, |
| Address Addr) { |
| assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); |
| llvm::Value *V = Addr.getPointer(); |
| llvm::Type *VTy = V->getType(); |
| llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::ptr_annotation, |
| CGM.Int8PtrTy); |
| |
| for (const auto *I : D->specific_attrs<AnnotateAttr>()) { |
| // FIXME Always emit the cast inst so we can differentiate between |
| // annotation on the first field of a struct and annotation on the struct |
| // itself. |
| if (VTy != CGM.Int8PtrTy) |
| V = Builder.CreateBitCast(V, CGM.Int8PtrTy); |
| V = EmitAnnotationCall(F, V, I->getAnnotation(), D->getLocation()); |
| V = Builder.CreateBitCast(V, VTy); |
| } |
| |
| return Address(V, Addr.getAlignment()); |
| } |
| |
| CodeGenFunction::CGCapturedStmtInfo::~CGCapturedStmtInfo() { } |
| |
| CodeGenFunction::SanitizerScope::SanitizerScope(CodeGenFunction *CGF) |
| : CGF(CGF) { |
| assert(!CGF->IsSanitizerScope); |
| CGF->IsSanitizerScope = true; |
| } |
| |
| CodeGenFunction::SanitizerScope::~SanitizerScope() { |
| CGF->IsSanitizerScope = false; |
| } |
| |
| void CodeGenFunction::InsertHelper(llvm::Instruction *I, |
| const llvm::Twine &Name, |
| llvm::BasicBlock *BB, |
| llvm::BasicBlock::iterator InsertPt) const { |
| LoopStack.InsertHelper(I); |
| if (IsSanitizerScope) |
| CGM.getSanitizerMetadata()->disableSanitizerForInstruction(I); |
| } |
| |
| void CGBuilderInserter::InsertHelper( |
| llvm::Instruction *I, const llvm::Twine &Name, llvm::BasicBlock *BB, |
| llvm::BasicBlock::iterator InsertPt) const { |
| llvm::IRBuilderDefaultInserter::InsertHelper(I, Name, BB, InsertPt); |
| if (CGF) |
| CGF->InsertHelper(I, Name, BB, InsertPt); |
| } |
| |
| static bool hasRequiredFeatures(const SmallVectorImpl<StringRef> &ReqFeatures, |
| CodeGenModule &CGM, const FunctionDecl *FD, |
| std::string &FirstMissing) { |
| // If there aren't any required features listed then go ahead and return. |
| if (ReqFeatures.empty()) |
| return false; |
| |
| // Now build up the set of caller features and verify that all the required |
| // features are there. |
| llvm::StringMap<bool> CallerFeatureMap; |
| CGM.getContext().getFunctionFeatureMap(CallerFeatureMap, FD); |
| |
| // If we have at least one of the features in the feature list return |
| // true, otherwise return false. |
| return std::all_of( |
| ReqFeatures.begin(), ReqFeatures.end(), [&](StringRef Feature) { |
| SmallVector<StringRef, 1> OrFeatures; |
| Feature.split(OrFeatures, '|'); |
| return llvm::any_of(OrFeatures, [&](StringRef Feature) { |
| if (!CallerFeatureMap.lookup(Feature)) { |
| FirstMissing = Feature.str(); |
| return false; |
| } |
| return true; |
| }); |
| }); |
| } |
| |
| // Emits an error if we don't have a valid set of target features for the |
| // called function. |
| void CodeGenFunction::checkTargetFeatures(const CallExpr *E, |
| const FunctionDecl *TargetDecl) { |
| return checkTargetFeatures(E->getBeginLoc(), TargetDecl); |
| } |
| |
| // Emits an error if we don't have a valid set of target features for the |
| // called function. |
| void CodeGenFunction::checkTargetFeatures(SourceLocation Loc, |
| const FunctionDecl *TargetDecl) { |
| // Early exit if this is an indirect call. |
| if (!TargetDecl) |
| return; |
| |
| // Get the current enclosing function if it exists. If it doesn't |
| // we can't check the target features anyhow. |
| const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(CurCodeDecl); |
| if (!FD) |
| return; |
| |
| // Grab the required features for the call. For a builtin this is listed in |
| // the td file with the default cpu, for an always_inline function this is any |
| // listed cpu and any listed features. |
| unsigned BuiltinID = TargetDecl->getBuiltinID(); |
| std::string MissingFeature; |
| if (BuiltinID) { |
| SmallVector<StringRef, 1> ReqFeatures; |
| const char *FeatureList = |
| CGM.getContext().BuiltinInfo.getRequiredFeatures(BuiltinID); |
| // Return if the builtin doesn't have any required features. |
| if (!FeatureList || StringRef(FeatureList) == "") |
| return; |
| StringRef(FeatureList).split(ReqFeatures, ','); |
| if (!hasRequiredFeatures(ReqFeatures, CGM, FD, MissingFeature)) |
| CGM.getDiags().Report(Loc, diag::err_builtin_needs_feature) |
| << TargetDecl->getDeclName() |
| << CGM.getContext().BuiltinInfo.getRequiredFeatures(BuiltinID); |
| |
| } else if (!TargetDecl->isMultiVersion() && |
| TargetDecl->hasAttr<TargetAttr>()) { |
| // Get the required features for the callee. |
| |
| const TargetAttr *TD = TargetDecl->getAttr<TargetAttr>(); |
| ParsedTargetAttr ParsedAttr = |
| CGM.getContext().filterFunctionTargetAttrs(TD); |
| |
| SmallVector<StringRef, 1> ReqFeatures; |
| llvm::StringMap<bool> CalleeFeatureMap; |
| CGM.getContext().getFunctionFeatureMap(CalleeFeatureMap, TargetDecl); |
| |
| for (const auto &F : ParsedAttr.Features) { |
| if (F[0] == '+' && CalleeFeatureMap.lookup(F.substr(1))) |
| ReqFeatures.push_back(StringRef(F).substr(1)); |
| } |
| |
| for (const auto &F : CalleeFeatureMap) { |
| // Only positive features are "required". |
| if (F.getValue()) |
| ReqFeatures.push_back(F.getKey()); |
| } |
| if (!hasRequiredFeatures(ReqFeatures, CGM, FD, MissingFeature)) |
| CGM.getDiags().Report(Loc, diag::err_function_needs_feature) |
| << FD->getDeclName() << TargetDecl->getDeclName() << MissingFeature; |
| } |
| } |
| |
| void CodeGenFunction::EmitSanitizerStatReport(llvm::SanitizerStatKind SSK) { |
| if (!CGM.getCodeGenOpts().SanitizeStats) |
| return; |
| |
| llvm::IRBuilder<> IRB(Builder.GetInsertBlock(), Builder.GetInsertPoint()); |
| IRB.SetCurrentDebugLocation(Builder.getCurrentDebugLocation()); |
| CGM.getSanStats().create(IRB, SSK); |
| } |
| |
| llvm::Value * |
| CodeGenFunction::FormResolverCondition(const MultiVersionResolverOption &RO) { |
| llvm::Value *Condition = nullptr; |
| |
| if (!RO.Conditions.Architecture.empty()) |
| Condition = EmitX86CpuIs(RO.Conditions.Architecture); |
| |
| if (!RO.Conditions.Features.empty()) { |
| llvm::Value *FeatureCond = EmitX86CpuSupports(RO.Conditions.Features); |
| Condition = |
| Condition ? Builder.CreateAnd(Condition, FeatureCond) : FeatureCond; |
| } |
| return Condition; |
| } |
| |
| static void CreateMultiVersionResolverReturn(CodeGenModule &CGM, |
| llvm::Function *Resolver, |
| CGBuilderTy &Builder, |
| llvm::Function *FuncToReturn, |
| bool SupportsIFunc) { |
| if (SupportsIFunc) { |
| Builder.CreateRet(FuncToReturn); |
| return; |
| } |
| |
| llvm::SmallVector<llvm::Value *, 10> Args; |
| llvm::for_each(Resolver->args(), |
| [&](llvm::Argument &Arg) { Args.push_back(&Arg); }); |
| |
| llvm::CallInst *Result = Builder.CreateCall(FuncToReturn, Args); |
| Result->setTailCallKind(llvm::CallInst::TCK_MustTail); |
| |
| if (Resolver->getReturnType()->isVoidTy()) |
| Builder.CreateRetVoid(); |
| else |
| Builder.CreateRet(Result); |
| } |
| |
| void CodeGenFunction::EmitMultiVersionResolver( |
| llvm::Function *Resolver, ArrayRef<MultiVersionResolverOption> Options) { |
| assert(getContext().getTargetInfo().getTriple().isX86() && |
| "Only implemented for x86 targets"); |
| |
| bool SupportsIFunc = getContext().getTargetInfo().supportsIFunc(); |
| |
| // Main function's basic block. |
| llvm::BasicBlock *CurBlock = createBasicBlock("resolver_entry", Resolver); |
| Builder.SetInsertPoint(CurBlock); |
| EmitX86CpuInit(); |
| |
| for (const MultiVersionResolverOption &RO : Options) { |
| Builder.SetInsertPoint(CurBlock); |
| llvm::Value *Condition = FormResolverCondition(RO); |
| |
| // The 'default' or 'generic' case. |
| if (!Condition) { |
| assert(&RO == Options.end() - 1 && |
| "Default or Generic case must be last"); |
| CreateMultiVersionResolverReturn(CGM, Resolver, Builder, RO.Function, |
| SupportsIFunc); |
| return; |
| } |
| |
| llvm::BasicBlock *RetBlock = createBasicBlock("resolver_return", Resolver); |
| CGBuilderTy RetBuilder(*this, RetBlock); |
| CreateMultiVersionResolverReturn(CGM, Resolver, RetBuilder, RO.Function, |
| SupportsIFunc); |
| CurBlock = createBasicBlock("resolver_else", Resolver); |
| Builder.CreateCondBr(Condition, RetBlock, CurBlock); |
| } |
| |
| // If no generic/default, emit an unreachable. |
| Builder.SetInsertPoint(CurBlock); |
| llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap); |
| TrapCall->setDoesNotReturn(); |
| TrapCall->setDoesNotThrow(); |
| Builder.CreateUnreachable(); |
| Builder.ClearInsertionPoint(); |
| } |
| |
| // Loc - where the diagnostic will point, where in the source code this |
| // alignment has failed. |
| // SecondaryLoc - if present (will be present if sufficiently different from |
| // Loc), the diagnostic will additionally point a "Note:" to this location. |
| // It should be the location where the __attribute__((assume_aligned)) |
| // was written e.g. |
| void CodeGenFunction::emitAlignmentAssumptionCheck( |
| llvm::Value *Ptr, QualType Ty, SourceLocation Loc, |
| SourceLocation SecondaryLoc, llvm::Value *Alignment, |
| llvm::Value *OffsetValue, llvm::Value *TheCheck, |
| llvm::Instruction *Assumption) { |
| assert(Assumption && isa<llvm::CallInst>(Assumption) && |
| cast<llvm::CallInst>(Assumption)->getCalledOperand() == |
| llvm::Intrinsic::getDeclaration( |
| Builder.GetInsertBlock()->getParent()->getParent(), |
| llvm::Intrinsic::assume) && |
| "Assumption should be a call to llvm.assume()."); |
| assert(&(Builder.GetInsertBlock()->back()) == Assumption && |
| "Assumption should be the last instruction of the basic block, " |
| "since the basic block is still being generated."); |
| |
| if (!SanOpts.has(SanitizerKind::Alignment)) |
| return; |
| |
| // Don't check pointers to volatile data. The behavior here is implementation- |
| // defined. |
| if (Ty->getPointeeType().isVolatileQualified()) |
| return; |
| |
| // We need to temorairly remove the assumption so we can insert the |
| // sanitizer check before it, else the check will be dropped by optimizations. |
| Assumption->removeFromParent(); |
| |
| { |
| SanitizerScope SanScope(this); |
| |
| if (!OffsetValue) |
| OffsetValue = Builder.getInt1(0); // no offset. |
| |
| llvm::Constant *StaticData[] = {EmitCheckSourceLocation(Loc), |
| EmitCheckSourceLocation(SecondaryLoc), |
| EmitCheckTypeDescriptor(Ty)}; |
| llvm::Value *DynamicData[] = {EmitCheckValue(Ptr), |
| EmitCheckValue(Alignment), |
| EmitCheckValue(OffsetValue)}; |
| EmitCheck({std::make_pair(TheCheck, SanitizerKind::Alignment)}, |
| SanitizerHandler::AlignmentAssumption, StaticData, DynamicData); |
| } |
| |
| // We are now in the (new, empty) "cont" basic block. |
| // Reintroduce the assumption. |
| Builder.Insert(Assumption); |
| // FIXME: Assumption still has it's original basic block as it's Parent. |
| } |
| |
| llvm::DebugLoc CodeGenFunction::SourceLocToDebugLoc(SourceLocation Location) { |
| if (CGDebugInfo *DI = getDebugInfo()) |
| return DI->SourceLocToDebugLoc(Location); |
| |
| return llvm::DebugLoc(); |
| } |