diff options
Diffstat (limited to 'contrib/llvm/lib/Target/X86/X86WinEHState.cpp')
-rw-r--r-- | contrib/llvm/lib/Target/X86/X86WinEHState.cpp | 311 |
1 files changed, 209 insertions, 102 deletions
diff --git a/contrib/llvm/lib/Target/X86/X86WinEHState.cpp b/contrib/llvm/lib/Target/X86/X86WinEHState.cpp index 4efaada..ce69ea7 100644 --- a/contrib/llvm/lib/Target/X86/X86WinEHState.cpp +++ b/contrib/llvm/lib/Target/X86/X86WinEHState.cpp @@ -16,6 +16,7 @@ #include "X86.h" #include "llvm/Analysis/LibCallSemantics.h" +#include "llvm/CodeGen/MachineModuleInfo.h" #include "llvm/CodeGen/Passes.h" #include "llvm/CodeGen/WinEHFuncInfo.h" #include "llvm/IR/Dominators.h" @@ -59,30 +60,49 @@ public: private: void emitExceptionRegistrationRecord(Function *F); - void linkExceptionRegistration(IRBuilder<> &Builder, Value *RegNode, - Value *Handler); - void unlinkExceptionRegistration(IRBuilder<> &Builder, Value *RegNode); + void linkExceptionRegistration(IRBuilder<> &Builder, Value *Handler); + void unlinkExceptionRegistration(IRBuilder<> &Builder); + void addCXXStateStores(Function &F, MachineModuleInfo &MMI); + void addCXXStateStoresToFunclet(Value *ParentRegNode, WinEHFuncInfo &FuncInfo, + Function &F, int BaseState); + void insertStateNumberStore(Value *ParentRegNode, Instruction *IP, int State); Value *emitEHLSDA(IRBuilder<> &Builder, Function *F); Function *generateLSDAInEAXThunk(Function *ParentFunc); + int escapeRegNode(Function &F); + // Module-level type getters. - Type *getEHRegistrationType(); - Type *getSEH3RegistrationType(); - Type *getSEH4RegistrationType(); - Type *getCXXEH3RegistrationType(); + Type *getEHLinkRegistrationType(); + Type *getSEHRegistrationType(); + Type *getCXXEHRegistrationType(); // Per-module data. Module *TheModule = nullptr; - StructType *EHRegistrationTy = nullptr; - StructType *CXXEH3RegistrationTy = nullptr; - StructType *SEH3RegistrationTy = nullptr; - StructType *SEH4RegistrationTy = nullptr; + StructType *EHLinkRegistrationTy = nullptr; + StructType *CXXEHRegistrationTy = nullptr; + StructType *SEHRegistrationTy = nullptr; + Function *FrameRecover = nullptr; + Function *FrameAddress = nullptr; + Function *FrameEscape = nullptr; // Per-function state EHPersonality Personality = EHPersonality::Unknown; Function *PersonalityFn = nullptr; + + /// The stack allocation containing all EH data, including the link in the + /// fs:00 chain and the current state. + AllocaInst *RegNode = nullptr; + + /// Struct type of RegNode. Used for GEPing. + Type *RegNodeTy = nullptr; + + /// The index of the state field of RegNode. + int StateFieldIndex = ~0U; + + /// The linked list node subobject inside of RegNode. + Value *Link = nullptr; }; } @@ -92,16 +112,21 @@ char WinEHStatePass::ID = 0; bool WinEHStatePass::doInitialization(Module &M) { TheModule = &M; + FrameEscape = Intrinsic::getDeclaration(TheModule, Intrinsic::frameescape); + FrameRecover = Intrinsic::getDeclaration(TheModule, Intrinsic::framerecover); + FrameAddress = Intrinsic::getDeclaration(TheModule, Intrinsic::frameaddress); return false; } bool WinEHStatePass::doFinalization(Module &M) { assert(TheModule == &M); TheModule = nullptr; - EHRegistrationTy = nullptr; - CXXEH3RegistrationTy = nullptr; - SEH3RegistrationTy = nullptr; - SEH4RegistrationTy = nullptr; + EHLinkRegistrationTy = nullptr; + CXXEHRegistrationTy = nullptr; + SEHRegistrationTy = nullptr; + FrameEscape = nullptr; + FrameRecover = nullptr; + FrameAddress = nullptr; return false; } @@ -136,8 +161,19 @@ bool WinEHStatePass::runOnFunction(Function &F) { if (!isMSVCEHPersonality(Personality)) return false; + // Disable frame pointer elimination in this function. + // FIXME: Do the nested handlers need to keep the parent ebp in ebp, or can we + // use an arbitrary register? + F.addFnAttr("no-frame-pointer-elim", "true"); + emitExceptionRegistrationRecord(&F); - // FIXME: State insertion. + + auto *MMIPtr = getAnalysisIfAvailable<MachineModuleInfo>(); + assert(MMIPtr && "MachineModuleInfo should always be available"); + MachineModuleInfo &MMI = *MMIPtr; + if (Personality == EHPersonality::MSVC_CXX) { + addCXXStateStores(F, MMI); + } // Reset per-function state. PersonalityFn = nullptr; @@ -152,17 +188,17 @@ bool WinEHStatePass::runOnFunction(Function &F) { /// EHRegistrationNode *Next; /// PEXCEPTION_ROUTINE Handler; /// }; -Type *WinEHStatePass::getEHRegistrationType() { - if (EHRegistrationTy) - return EHRegistrationTy; +Type *WinEHStatePass::getEHLinkRegistrationType() { + if (EHLinkRegistrationTy) + return EHLinkRegistrationTy; LLVMContext &Context = TheModule->getContext(); - EHRegistrationTy = StructType::create(Context, "EHRegistrationNode"); + EHLinkRegistrationTy = StructType::create(Context, "EHRegistrationNode"); Type *FieldTys[] = { - EHRegistrationTy->getPointerTo(0), // EHRegistrationNode *Next + EHLinkRegistrationTy->getPointerTo(0), // EHRegistrationNode *Next Type::getInt8PtrTy(Context) // EXCEPTION_DISPOSITION (*Handler)(...) }; - EHRegistrationTy->setBody(FieldTys, false); - return EHRegistrationTy; + EHLinkRegistrationTy->setBody(FieldTys, false); + return EHLinkRegistrationTy; } /// The __CxxFrameHandler3 registration node: @@ -171,40 +207,21 @@ Type *WinEHStatePass::getEHRegistrationType() { /// EHRegistrationNode SubRecord; /// int32_t TryLevel; /// }; -Type *WinEHStatePass::getCXXEH3RegistrationType() { - if (CXXEH3RegistrationTy) - return CXXEH3RegistrationTy; +Type *WinEHStatePass::getCXXEHRegistrationType() { + if (CXXEHRegistrationTy) + return CXXEHRegistrationTy; LLVMContext &Context = TheModule->getContext(); Type *FieldTys[] = { Type::getInt8PtrTy(Context), // void *SavedESP - getEHRegistrationType(), // EHRegistrationNode SubRecord + getEHLinkRegistrationType(), // EHRegistrationNode SubRecord Type::getInt32Ty(Context) // int32_t TryLevel }; - CXXEH3RegistrationTy = + CXXEHRegistrationTy = StructType::create(FieldTys, "CXXExceptionRegistration"); - return CXXEH3RegistrationTy; -} - -/// The _except_handler3 registration node: -/// struct EH3ExceptionRegistration { -/// EHRegistrationNode SubRecord; -/// void *ScopeTable; -/// int32_t TryLevel; -/// }; -Type *WinEHStatePass::getSEH3RegistrationType() { - if (SEH3RegistrationTy) - return SEH3RegistrationTy; - LLVMContext &Context = TheModule->getContext(); - Type *FieldTys[] = { - getEHRegistrationType(), // EHRegistrationNode SubRecord - Type::getInt8PtrTy(Context), // void *ScopeTable - Type::getInt32Ty(Context) // int32_t TryLevel - }; - SEH3RegistrationTy = StructType::create(FieldTys, "EH3ExceptionRegistration"); - return SEH3RegistrationTy; + return CXXEHRegistrationTy; } -/// The _except_handler4 registration node: +/// The _except_handler3/4 registration node: /// struct EH4ExceptionRegistration { /// void *SavedESP; /// _EXCEPTION_POINTERS *ExceptionPointers; @@ -212,19 +229,19 @@ Type *WinEHStatePass::getSEH3RegistrationType() { /// int32_t EncodedScopeTable; /// int32_t TryLevel; /// }; -Type *WinEHStatePass::getSEH4RegistrationType() { - if (SEH4RegistrationTy) - return SEH4RegistrationTy; +Type *WinEHStatePass::getSEHRegistrationType() { + if (SEHRegistrationTy) + return SEHRegistrationTy; LLVMContext &Context = TheModule->getContext(); Type *FieldTys[] = { Type::getInt8PtrTy(Context), // void *SavedESP Type::getInt8PtrTy(Context), // void *ExceptionPointers - getEHRegistrationType(), // EHRegistrationNode SubRecord + getEHLinkRegistrationType(), // EHRegistrationNode SubRecord Type::getInt32Ty(Context), // int32_t EncodedScopeTable Type::getInt32Ty(Context) // int32_t TryLevel }; - SEH4RegistrationTy = StructType::create(FieldTys, "EH4ExceptionRegistration"); - return SEH4RegistrationTy; + SEHRegistrationTy = StructType::create(FieldTys, "SEHExceptionRegistration"); + return SEHRegistrationTy; } // Emit an exception registration record. These are stack allocations with the @@ -238,62 +255,63 @@ void WinEHStatePass::emitExceptionRegistrationRecord(Function *F) { StringRef PersonalityName = PersonalityFn->getName(); IRBuilder<> Builder(&F->getEntryBlock(), F->getEntryBlock().begin()); Type *Int8PtrType = Builder.getInt8PtrTy(); - Value *SubRecord = nullptr; - if (PersonalityName == "__CxxFrameHandler3") { - Type *RegNodeTy = getCXXEH3RegistrationType(); - Value *RegNode = Builder.CreateAlloca(RegNodeTy); + if (Personality == EHPersonality::MSVC_CXX) { + RegNodeTy = getCXXEHRegistrationType(); + RegNode = Builder.CreateAlloca(RegNodeTy); // FIXME: We can skip this in -GS- mode, when we figure that out. // SavedESP = llvm.stacksave() Value *SP = Builder.CreateCall( Intrinsic::getDeclaration(TheModule, Intrinsic::stacksave), {}); Builder.CreateStore(SP, Builder.CreateStructGEP(RegNodeTy, RegNode, 0)); // TryLevel = -1 - Builder.CreateStore(Builder.getInt32(-1), - Builder.CreateStructGEP(RegNodeTy, RegNode, 2)); + StateFieldIndex = 2; + insertStateNumberStore(RegNode, Builder.GetInsertPoint(), -1); // Handler = __ehhandler$F Function *Trampoline = generateLSDAInEAXThunk(F); - SubRecord = Builder.CreateStructGEP(RegNodeTy, RegNode, 1); - linkExceptionRegistration(Builder, SubRecord, Trampoline); - } else if (PersonalityName == "_except_handler3") { - Type *RegNodeTy = getSEH3RegistrationType(); - Value *RegNode = Builder.CreateAlloca(RegNodeTy); - // TryLevel = -1 - Builder.CreateStore(Builder.getInt32(-1), - Builder.CreateStructGEP(RegNodeTy, RegNode, 2)); - // ScopeTable = llvm.x86.seh.lsda(F) - Value *LSDA = emitEHLSDA(Builder, F); - Builder.CreateStore(LSDA, Builder.CreateStructGEP(RegNodeTy, RegNode, 1)); - SubRecord = Builder.CreateStructGEP(RegNodeTy, RegNode, 0); - linkExceptionRegistration(Builder, SubRecord, PersonalityFn); - } else if (PersonalityName == "_except_handler4") { - Type *RegNodeTy = getSEH4RegistrationType(); - Value *RegNode = Builder.CreateAlloca(RegNodeTy); + Link = Builder.CreateStructGEP(RegNodeTy, RegNode, 1); + linkExceptionRegistration(Builder, Trampoline); + } else if (Personality == EHPersonality::MSVC_X86SEH) { + // If _except_handler4 is in use, some additional guard checks and prologue + // stuff is required. + bool UseStackGuard = (PersonalityName == "_except_handler4"); + RegNodeTy = getSEHRegistrationType(); + RegNode = Builder.CreateAlloca(RegNodeTy); // SavedESP = llvm.stacksave() Value *SP = Builder.CreateCall( Intrinsic::getDeclaration(TheModule, Intrinsic::stacksave), {}); Builder.CreateStore(SP, Builder.CreateStructGEP(RegNodeTy, RegNode, 0)); - // TryLevel = -2 - Builder.CreateStore(Builder.getInt32(-2), - Builder.CreateStructGEP(RegNodeTy, RegNode, 4)); - // FIXME: XOR the LSDA with __security_cookie. + // TryLevel = -2 / -1 + StateFieldIndex = 4; + insertStateNumberStore(RegNode, Builder.GetInsertPoint(), + UseStackGuard ? -2 : -1); // ScopeTable = llvm.x86.seh.lsda(F) Value *FI8 = Builder.CreateBitCast(F, Int8PtrType); Value *LSDA = Builder.CreateCall( Intrinsic::getDeclaration(TheModule, Intrinsic::x86_seh_lsda), FI8); - Builder.CreateStore(LSDA, Builder.CreateStructGEP(RegNodeTy, RegNode, 1)); - SubRecord = Builder.CreateStructGEP(RegNodeTy, RegNode, 2); - linkExceptionRegistration(Builder, SubRecord, PersonalityFn); + Type *Int32Ty = Type::getInt32Ty(TheModule->getContext()); + LSDA = Builder.CreatePtrToInt(LSDA, Int32Ty); + // If using _except_handler4, xor the address of the table with + // __security_cookie. + if (UseStackGuard) { + Value *Cookie = + TheModule->getOrInsertGlobal("__security_cookie", Int32Ty); + Value *Val = Builder.CreateLoad(Int32Ty, Cookie); + LSDA = Builder.CreateXor(LSDA, Val); + } + Builder.CreateStore(LSDA, Builder.CreateStructGEP(RegNodeTy, RegNode, 3)); + Link = Builder.CreateStructGEP(RegNodeTy, RegNode, 2); + linkExceptionRegistration(Builder, PersonalityFn); } else { llvm_unreachable("unexpected personality function"); } - // FIXME: Insert an unlink before all returns. + // Insert an unlink before all returns. for (BasicBlock &BB : *F) { TerminatorInst *T = BB.getTerminator(); if (!isa<ReturnInst>(T)) continue; Builder.SetInsertPoint(T); - unlinkExceptionRegistration(Builder, SubRecord); + unlinkExceptionRegistration(Builder); } } @@ -342,33 +360,122 @@ Function *WinEHStatePass::generateLSDAInEAXThunk(Function *ParentFunc) { } void WinEHStatePass::linkExceptionRegistration(IRBuilder<> &Builder, - Value *RegNode, Value *Handler) { - Type *RegNodeTy = getEHRegistrationType(); + Value *Handler) { + Type *LinkTy = getEHLinkRegistrationType(); // Handler = Handler Handler = Builder.CreateBitCast(Handler, Builder.getInt8PtrTy()); - Builder.CreateStore(Handler, Builder.CreateStructGEP(RegNodeTy, RegNode, 1)); + Builder.CreateStore(Handler, Builder.CreateStructGEP(LinkTy, Link, 1)); // Next = [fs:00] Constant *FSZero = - Constant::getNullValue(RegNodeTy->getPointerTo()->getPointerTo(257)); + Constant::getNullValue(LinkTy->getPointerTo()->getPointerTo(257)); Value *Next = Builder.CreateLoad(FSZero); - Builder.CreateStore(Next, Builder.CreateStructGEP(RegNodeTy, RegNode, 0)); - // [fs:00] = RegNode - Builder.CreateStore(RegNode, FSZero); + Builder.CreateStore(Next, Builder.CreateStructGEP(LinkTy, Link, 0)); + // [fs:00] = Link + Builder.CreateStore(Link, FSZero); } -void WinEHStatePass::unlinkExceptionRegistration(IRBuilder<> &Builder, - Value *RegNode) { - // Clone RegNode into the current BB for better address mode folding. - if (auto *GEP = dyn_cast<GetElementPtrInst>(RegNode)) { +void WinEHStatePass::unlinkExceptionRegistration(IRBuilder<> &Builder) { + // Clone Link into the current BB for better address mode folding. + if (auto *GEP = dyn_cast<GetElementPtrInst>(Link)) { GEP = cast<GetElementPtrInst>(GEP->clone()); Builder.Insert(GEP); - RegNode = GEP; + Link = GEP; } - Type *RegNodeTy = getEHRegistrationType(); - // [fs:00] = RegNode->Next + Type *LinkTy = getEHLinkRegistrationType(); + // [fs:00] = Link->Next Value *Next = - Builder.CreateLoad(Builder.CreateStructGEP(RegNodeTy, RegNode, 0)); + Builder.CreateLoad(Builder.CreateStructGEP(LinkTy, Link, 0)); Constant *FSZero = - Constant::getNullValue(RegNodeTy->getPointerTo()->getPointerTo(257)); + Constant::getNullValue(LinkTy->getPointerTo()->getPointerTo(257)); Builder.CreateStore(Next, FSZero); } + +void WinEHStatePass::addCXXStateStores(Function &F, MachineModuleInfo &MMI) { + WinEHFuncInfo &FuncInfo = MMI.getWinEHFuncInfo(&F); + calculateWinCXXEHStateNumbers(&F, FuncInfo); + + // The base state for the parent is -1. + addCXXStateStoresToFunclet(RegNode, FuncInfo, F, -1); + + // Set up RegNodeEscapeIndex + int RegNodeEscapeIndex = escapeRegNode(F); + + // Only insert stores in catch handlers. + Constant *FI8 = + ConstantExpr::getBitCast(&F, Type::getInt8PtrTy(TheModule->getContext())); + for (auto P : FuncInfo.HandlerBaseState) { + Function *Handler = const_cast<Function *>(P.first); + int BaseState = P.second; + IRBuilder<> Builder(&Handler->getEntryBlock(), + Handler->getEntryBlock().begin()); + // FIXME: Find and reuse such a call if present. + Value *ParentFP = Builder.CreateCall(FrameAddress, {Builder.getInt32(1)}); + Value *RecoveredRegNode = Builder.CreateCall( + FrameRecover, {FI8, ParentFP, Builder.getInt32(RegNodeEscapeIndex)}); + RecoveredRegNode = + Builder.CreateBitCast(RecoveredRegNode, RegNodeTy->getPointerTo(0)); + addCXXStateStoresToFunclet(RecoveredRegNode, FuncInfo, *Handler, BaseState); + } +} + +/// Escape RegNode so that we can access it from child handlers. Find the call +/// to frameescape, if any, in the entry block and append RegNode to the list +/// of arguments. +int WinEHStatePass::escapeRegNode(Function &F) { + // Find the call to frameescape and extract its arguments. + IntrinsicInst *EscapeCall = nullptr; + for (Instruction &I : F.getEntryBlock()) { + IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I); + if (II && II->getIntrinsicID() == Intrinsic::frameescape) { + EscapeCall = II; + break; + } + } + SmallVector<Value *, 8> Args; + if (EscapeCall) { + auto Ops = EscapeCall->arg_operands(); + Args.append(Ops.begin(), Ops.end()); + } + Args.push_back(RegNode); + + // Replace the call (if it exists) with new one. Otherwise, insert at the end + // of the entry block. + IRBuilder<> Builder(&F.getEntryBlock(), + EscapeCall ? EscapeCall : F.getEntryBlock().end()); + Builder.CreateCall(FrameEscape, Args); + if (EscapeCall) + EscapeCall->eraseFromParent(); + return Args.size() - 1; +} + +void WinEHStatePass::addCXXStateStoresToFunclet(Value *ParentRegNode, + WinEHFuncInfo &FuncInfo, + Function &F, int BaseState) { + // Iterate all the instructions and emit state number stores. + for (BasicBlock &BB : F) { + for (Instruction &I : BB) { + if (auto *CI = dyn_cast<CallInst>(&I)) { + // Possibly throwing call instructions have no actions to take after + // an unwind. Ensure they are in the -1 state. + if (CI->doesNotThrow()) + continue; + insertStateNumberStore(ParentRegNode, CI, BaseState); + } else if (auto *II = dyn_cast<InvokeInst>(&I)) { + // Look up the state number of the landingpad this unwinds to. + LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst(); + // FIXME: Why does this assertion fail? + //assert(FuncInfo.LandingPadStateMap.count(LPI) && "LP has no state!"); + int State = FuncInfo.LandingPadStateMap[LPI]; + insertStateNumberStore(ParentRegNode, II, State); + } + } + } +} + +void WinEHStatePass::insertStateNumberStore(Value *ParentRegNode, + Instruction *IP, int State) { + IRBuilder<> Builder(IP); + Value *StateField = + Builder.CreateStructGEP(RegNodeTy, ParentRegNode, StateFieldIndex); + Builder.CreateStore(Builder.getInt32(State), StateField); +} |