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diff --git a/contrib/llvm/lib/Target/X86/X86WinEHState.cpp b/contrib/llvm/lib/Target/X86/X86WinEHState.cpp
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+//===-- X86WinEHState - Insert EH state updates for win32 exceptions ------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// All functions using an MSVC EH personality use an explicitly updated state
+// number stored in an exception registration stack object. The registration
+// object is linked into a thread-local chain of registrations stored at fs:00.
+// This pass adds the registration object and EH state updates.
+//
+//===----------------------------------------------------------------------===//
+
+#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"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/PatternMatch.h"
+#include "llvm/Pass.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/Cloning.h"
+#include "llvm/Transforms/Utils/Local.h"
+
+using namespace llvm;
+using namespace llvm::PatternMatch;
+
+#define DEBUG_TYPE "winehstate"
+
+namespace {
+class WinEHStatePass : public FunctionPass {
+public:
+ static char ID; // Pass identification, replacement for typeid.
+
+ WinEHStatePass() : FunctionPass(ID) {}
+
+ bool runOnFunction(Function &Fn) override;
+
+ bool doInitialization(Module &M) override;
+
+ bool doFinalization(Module &M) override;
+
+ void getAnalysisUsage(AnalysisUsage &AU) const override;
+
+ const char *getPassName() const override {
+ return "Windows 32-bit x86 EH state insertion";
+ }
+
+private:
+ void emitExceptionRegistrationRecord(Function *F);
+
+ 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 *getEHLinkRegistrationType();
+ Type *getSEHRegistrationType();
+ Type *getCXXEHRegistrationType();
+
+ // Per-module data.
+ Module *TheModule = 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;
+};
+}
+
+FunctionPass *llvm::createX86WinEHStatePass() { return new WinEHStatePass(); }
+
+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;
+ EHLinkRegistrationTy = nullptr;
+ CXXEHRegistrationTy = nullptr;
+ SEHRegistrationTy = nullptr;
+ FrameEscape = nullptr;
+ FrameRecover = nullptr;
+ FrameAddress = nullptr;
+ return false;
+}
+
+void WinEHStatePass::getAnalysisUsage(AnalysisUsage &AU) const {
+ // This pass should only insert a stack allocation, memory accesses, and
+ // framerecovers.
+ AU.setPreservesCFG();
+}
+
+bool WinEHStatePass::runOnFunction(Function &F) {
+ // If this is an outlined handler, don't do anything. We'll do state insertion
+ // for it in the parent.
+ StringRef WinEHParentName =
+ F.getFnAttribute("wineh-parent").getValueAsString();
+ if (WinEHParentName != F.getName() && !WinEHParentName.empty())
+ return false;
+
+ // Check the personality. Do nothing if this is not an MSVC personality.
+ LandingPadInst *LP = nullptr;
+ for (BasicBlock &BB : F) {
+ LP = BB.getLandingPadInst();
+ if (LP)
+ break;
+ }
+ if (!LP)
+ return false;
+ PersonalityFn =
+ dyn_cast<Function>(LP->getPersonalityFn()->stripPointerCasts());
+ if (!PersonalityFn)
+ return false;
+ Personality = classifyEHPersonality(PersonalityFn);
+ 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);
+
+ 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;
+ Personality = EHPersonality::Unknown;
+ return true;
+}
+
+/// Get the common EH registration subobject:
+/// typedef _EXCEPTION_DISPOSITION (*PEXCEPTION_ROUTINE)(
+/// _EXCEPTION_RECORD *, void *, _CONTEXT *, void *);
+/// struct EHRegistrationNode {
+/// EHRegistrationNode *Next;
+/// PEXCEPTION_ROUTINE Handler;
+/// };
+Type *WinEHStatePass::getEHLinkRegistrationType() {
+ if (EHLinkRegistrationTy)
+ return EHLinkRegistrationTy;
+ LLVMContext &Context = TheModule->getContext();
+ EHLinkRegistrationTy = StructType::create(Context, "EHRegistrationNode");
+ Type *FieldTys[] = {
+ EHLinkRegistrationTy->getPointerTo(0), // EHRegistrationNode *Next
+ Type::getInt8PtrTy(Context) // EXCEPTION_DISPOSITION (*Handler)(...)
+ };
+ EHLinkRegistrationTy->setBody(FieldTys, false);
+ return EHLinkRegistrationTy;
+}
+
+/// The __CxxFrameHandler3 registration node:
+/// struct CXXExceptionRegistration {
+/// void *SavedESP;
+/// EHRegistrationNode SubRecord;
+/// int32_t TryLevel;
+/// };
+Type *WinEHStatePass::getCXXEHRegistrationType() {
+ if (CXXEHRegistrationTy)
+ return CXXEHRegistrationTy;
+ LLVMContext &Context = TheModule->getContext();
+ Type *FieldTys[] = {
+ Type::getInt8PtrTy(Context), // void *SavedESP
+ getEHLinkRegistrationType(), // EHRegistrationNode SubRecord
+ Type::getInt32Ty(Context) // int32_t TryLevel
+ };
+ CXXEHRegistrationTy =
+ StructType::create(FieldTys, "CXXExceptionRegistration");
+ return CXXEHRegistrationTy;
+}
+
+/// The _except_handler3/4 registration node:
+/// struct EH4ExceptionRegistration {
+/// void *SavedESP;
+/// _EXCEPTION_POINTERS *ExceptionPointers;
+/// EHRegistrationNode SubRecord;
+/// int32_t EncodedScopeTable;
+/// int32_t TryLevel;
+/// };
+Type *WinEHStatePass::getSEHRegistrationType() {
+ if (SEHRegistrationTy)
+ return SEHRegistrationTy;
+ LLVMContext &Context = TheModule->getContext();
+ Type *FieldTys[] = {
+ Type::getInt8PtrTy(Context), // void *SavedESP
+ Type::getInt8PtrTy(Context), // void *ExceptionPointers
+ getEHLinkRegistrationType(), // EHRegistrationNode SubRecord
+ Type::getInt32Ty(Context), // int32_t EncodedScopeTable
+ Type::getInt32Ty(Context) // int32_t TryLevel
+ };
+ SEHRegistrationTy = StructType::create(FieldTys, "SEHExceptionRegistration");
+ return SEHRegistrationTy;
+}
+
+// Emit an exception registration record. These are stack allocations with the
+// common subobject of two pointers: the previous registration record (the old
+// fs:00) and the personality function for the current frame. The data before
+// and after that is personality function specific.
+void WinEHStatePass::emitExceptionRegistrationRecord(Function *F) {
+ assert(Personality == EHPersonality::MSVC_CXX ||
+ Personality == EHPersonality::MSVC_X86SEH);
+
+ StringRef PersonalityName = PersonalityFn->getName();
+ IRBuilder<> Builder(&F->getEntryBlock(), F->getEntryBlock().begin());
+ Type *Int8PtrType = Builder.getInt8PtrTy();
+ 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
+ StateFieldIndex = 2;
+ insertStateNumberStore(RegNode, Builder.GetInsertPoint(), -1);
+ // Handler = __ehhandler$F
+ Function *Trampoline = generateLSDAInEAXThunk(F);
+ 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 / -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);
+ 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");
+ }
+
+ // Insert an unlink before all returns.
+ for (BasicBlock &BB : *F) {
+ TerminatorInst *T = BB.getTerminator();
+ if (!isa<ReturnInst>(T))
+ continue;
+ Builder.SetInsertPoint(T);
+ unlinkExceptionRegistration(Builder);
+ }
+}
+
+Value *WinEHStatePass::emitEHLSDA(IRBuilder<> &Builder, Function *F) {
+ Value *FI8 = Builder.CreateBitCast(F, Type::getInt8PtrTy(F->getContext()));
+ return Builder.CreateCall(
+ Intrinsic::getDeclaration(TheModule, Intrinsic::x86_seh_lsda), FI8);
+}
+
+/// Generate a thunk that puts the LSDA of ParentFunc in EAX and then calls
+/// PersonalityFn, forwarding the parameters passed to PEXCEPTION_ROUTINE:
+/// typedef _EXCEPTION_DISPOSITION (*PEXCEPTION_ROUTINE)(
+/// _EXCEPTION_RECORD *, void *, _CONTEXT *, void *);
+/// We essentially want this code:
+/// movl $lsda, %eax
+/// jmpl ___CxxFrameHandler3
+Function *WinEHStatePass::generateLSDAInEAXThunk(Function *ParentFunc) {
+ LLVMContext &Context = ParentFunc->getContext();
+ Type *Int32Ty = Type::getInt32Ty(Context);
+ Type *Int8PtrType = Type::getInt8PtrTy(Context);
+ Type *ArgTys[5] = {Int8PtrType, Int8PtrType, Int8PtrType, Int8PtrType,
+ Int8PtrType};
+ FunctionType *TrampolineTy =
+ FunctionType::get(Int32Ty, makeArrayRef(&ArgTys[0], 4),
+ /*isVarArg=*/false);
+ FunctionType *TargetFuncTy =
+ FunctionType::get(Int32Ty, makeArrayRef(&ArgTys[0], 5),
+ /*isVarArg=*/false);
+ Function *Trampoline = Function::Create(
+ TrampolineTy, GlobalValue::InternalLinkage,
+ Twine("__ehhandler$") + ParentFunc->getName(), TheModule);
+ BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", Trampoline);
+ IRBuilder<> Builder(EntryBB);
+ Value *LSDA = emitEHLSDA(Builder, ParentFunc);
+ Value *CastPersonality =
+ Builder.CreateBitCast(PersonalityFn, TargetFuncTy->getPointerTo());
+ auto AI = Trampoline->arg_begin();
+ Value *Args[5] = {LSDA, AI++, AI++, AI++, AI++};
+ CallInst *Call = Builder.CreateCall(CastPersonality, Args);
+ // Can't use musttail due to prototype mismatch, but we can use tail.
+ Call->setTailCall(true);
+ // Set inreg so we pass it in EAX.
+ Call->addAttribute(1, Attribute::InReg);
+ Builder.CreateRet(Call);
+ return Trampoline;
+}
+
+void WinEHStatePass::linkExceptionRegistration(IRBuilder<> &Builder,
+ Value *Handler) {
+ Type *LinkTy = getEHLinkRegistrationType();
+ // Handler = Handler
+ Handler = Builder.CreateBitCast(Handler, Builder.getInt8PtrTy());
+ Builder.CreateStore(Handler, Builder.CreateStructGEP(LinkTy, Link, 1));
+ // Next = [fs:00]
+ Constant *FSZero =
+ Constant::getNullValue(LinkTy->getPointerTo()->getPointerTo(257));
+ Value *Next = Builder.CreateLoad(FSZero);
+ Builder.CreateStore(Next, Builder.CreateStructGEP(LinkTy, Link, 0));
+ // [fs:00] = Link
+ Builder.CreateStore(Link, FSZero);
+}
+
+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);
+ Link = GEP;
+ }
+ Type *LinkTy = getEHLinkRegistrationType();
+ // [fs:00] = Link->Next
+ Value *Next =
+ Builder.CreateLoad(Builder.CreateStructGEP(LinkTy, Link, 0));
+ Constant *FSZero =
+ 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);
+}
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