[llvm] r236359 - Re-land "[WinEH] Add an EH registration and state insertion pass for 32-bit x86"

Mehdi Amini mehdi.amini at apple.com
Tue May 5 15:56:34 PDT 2015


Hi Reid,

You relanded this in r236508 (for some reason I can’t find the email for it?) and it breaks our ASAN bot:

=================================================================
==8942==ERROR: AddressSanitizer: heap-use-after-free on address 0x60b00000a358 at pc 0x0001179973f2 bp 0x7fff564a1f70 sp 0x7fff564a1f68
READ of size 8 at 0x60b00000a358 thread T0
    #0 0x1179973f1 in llvm::Value::use_begin() const Value.h:264
    #1 0x1153a51bf in llvm::Value::hasNUses(unsigned int) const Value.cpp:97
    #2 0x11425508a in (anonymous namespace)::WinEHPrepare::prepareExceptionHandlers(llvm::Function&, llvm::SmallVectorImpl<llvm::LandingPadInst*>&) WinEHPrepare.cpp:924
    #3 0x1142474fe in (anonymous namespace)::WinEHPrepare::runOnFunction(llvm::Function&) WinEHPrepare.cpp:370
    #4 0x114e575f2 in llvm::FPPassManager::runOnFunction(llvm::Function&) LegacyPassManager.cpp:1537
    #5 0x114e58c85 in llvm::FPPassManager::runOnModule(llvm::Module&) LegacyPassManager.cpp:1557
    #6 0x114e5d2c0 in (anonymous namespace)::MPPassManager::runOnModule(llvm::Module&) LegacyPassManager.cpp:1615
    #7 0x114e5a0a7 in llvm::legacy::PassManagerImpl::run(llvm::Module&) LegacyPassManager.cpp:1722
    #8 0x114e6012e in llvm::legacy::PassManager::run(llvm::Module&) LegacyPassManager.cpp:1755
    #9 0x109761abc in compileModule(char**, llvm::LLVMContext&) llc.cpp:377
    #10 0x109754760 in main llc.cpp:201

0x60b00000a358 is located 40 bytes inside of 112-byte region [0x60b00000a330,0x60b00000a3a0)
freed by thread T0 here:
    #0 0x11f1c8879 in wrap__ZdlPv 
    #1 0x1153a11c0 in llvm::User::operator delete(void*) User.cpp:76
    #2 0x114cd892e in llvm::AllocaInst::~AllocaInst() Instructions.cpp:886
    #3 0x1142096ac in llvm::ilist_node_traits<llvm::Instruction>::deleteNode(llvm::Instruction*) ilist.h:113
    #4 0x11420944c in llvm::iplist<llvm::Instruction, llvm::ilist_traits<llvm::Instruction> >::erase(llvm::ilist_iterator<llvm::Instruction>) ilist.h:466
    #5 0x114ca27e4 in llvm::Instruction::eraseFromParent() Instruction.cpp:66
    #6 0x118c64cee in rewriteSingleStoreAlloca(llvm::AllocaInst*, (anonymous namespace)::AllocaInfo&, (anonymous namespace)::LargeBlockInfo&, llvm::DominatorTree&, llvm::AliasSetTracker*) PromoteMemoryToRegister.cpp:417
    #7 0x118c5af72 in (anonymous namespace)::PromoteMem2Reg::run() PromoteMemoryToRegister.cpp:550
    #8 0x118c58b7e in llvm::PromoteMemToReg(llvm::ArrayRef<llvm::AllocaInst*>, llvm::DominatorTree&, llvm::AliasSetTracker*, llvm::AssumptionCache*) PromoteMemoryToRegister.cpp:987
    #9 0x114255366 in (anonymous namespace)::WinEHPrepare::prepareExceptionHandlers(llvm::Function&, llvm::SmallVectorImpl<llvm::LandingPadInst*>&) WinEHPrepare.cpp:927
    #10 0x1142474fe in (anonymous namespace)::WinEHPrepare::runOnFunction(llvm::Function&) WinEHPrepare.cpp:370
    #11 0x114e575f2 in llvm::FPPassManager::runOnFunction(llvm::Function&) LegacyPassManager.cpp:1537
    #12 0x114e58c85 in llvm::FPPassManager::runOnModule(llvm::Module&) LegacyPassManager.cpp:1557
    #13 0x114e5d2c0 in (anonymous namespace)::MPPassManager::runOnModule(llvm::Module&) LegacyPassManager.cpp:1615
    #14 0x114e5a0a7 in llvm::legacy::PassManagerImpl::run(llvm::Module&) LegacyPassManager.cpp:1722
    #15 0x114e6012e in llvm::legacy::PassManager::run(llvm::Module&) LegacyPassManager.cpp:1755
    #16 0x109761abc in compileModule(char**, llvm::LLVMContext&) llc.cpp:377
    #17 0x109754760 in main llc.cpp:201

previously allocated by thread T0 here:
    #0 0x11f1c82f9 in wrap__Znwm
    #1 0x1153a0c61 in llvm::User::operator new(unsigned long, unsigned int) User.cpp:57
    #2 0x1147777e2 in llvm::UnaryInstruction::operator new(unsigned long) InstrTypes.h:101
    #3 0x11424a60f in (anonymous namespace)::WinEHPrepare::prepareExceptionHandlers(llvm::Function&, llvm::SmallVectorImpl<llvm::LandingPadInst*>&) WinEHPrepare.cpp:698
    #4 0x1142474fe in (anonymous namespace)::WinEHPrepare::runOnFunction(llvm::Function&) WinEHPrepare.cpp:370
    #5 0x114e575f2 in llvm::FPPassManager::runOnFunction(llvm::Function&) LegacyPassManager.cpp:1537
    #6 0x114e58c85 in llvm::FPPassManager::runOnModule(llvm::Module&) LegacyPassManager.cpp:1557
    #7 0x114e5d2c0 in (anonymous namespace)::MPPassManager::runOnModule(llvm::Module&) LegacyPassManager.cpp:1615
    #8 0x114e5a0a7 in llvm::legacy::PassManagerImpl::run(llvm::Module&) LegacyPassManager.cpp:1722
    #9 0x114e6012e in llvm::legacy::PassManager::run(llvm::Module&) LegacyPassManager.cpp:1755
    #10 0x109761abc in compileModule(char**, llvm::LLVMContext&) llc.cpp:377
    #11 0x109754760 in main llc.cpp:201


Thanks,

Mehdi




> On May 1, 2015, at 3:40 PM, Reid Kleckner <reid at kleckner.net> wrote:
> 
> Author: rnk
> Date: Fri May  1 17:40:25 2015
> New Revision: 236359
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=236359&view=rev
> Log:
> Re-land "[WinEH] Add an EH registration and state insertion pass for 32-bit x86"
> 
> This reverts commit r236340.
> 
> Added:
>    llvm/trunk/lib/Target/X86/X86WinEHState.cpp
>    llvm/trunk/test/CodeGen/X86/win32-eh.ll
> Modified:
>    llvm/trunk/include/llvm/MC/MCAsmInfo.h
>    llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
>    llvm/trunk/lib/CodeGen/WinEHPrepare.cpp
>    llvm/trunk/lib/Target/X86/CMakeLists.txt
>    llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
>    llvm/trunk/lib/Target/X86/X86.h
>    llvm/trunk/lib/Target/X86/X86TargetMachine.cpp
>    llvm/trunk/test/CodeGen/X86/inalloca-invoke.ll
> 
> Modified: llvm/trunk/include/llvm/MC/MCAsmInfo.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCAsmInfo.h?rev=236359&r1=236358&r2=236359&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/MC/MCAsmInfo.h (original)
> +++ llvm/trunk/include/llvm/MC/MCAsmInfo.h Fri May  1 17:40:25 2015
> @@ -37,6 +37,7 @@ enum class EncodingType {
>   ARM,     /// Windows NT (Windows on ARM)
>   CE,      /// Windows CE ARM, PowerPC, SH3, SH4
>   Itanium, /// Windows x64, Windows Itanium (IA-64)
> +  X86,     /// Windows x86, uses no CFI, just EH tables
>   MIPS = Alpha,
> };
> }
> @@ -506,12 +507,13 @@ public:
>   /// frame information to unwind.
>   bool usesCFIForEH() const {
>     return (ExceptionsType == ExceptionHandling::DwarfCFI ||
> -            ExceptionsType == ExceptionHandling::ARM ||
> -            ExceptionsType == ExceptionHandling::WinEH);
> +            ExceptionsType == ExceptionHandling::ARM || usesWindowsCFI());
>   }
> 
>   bool usesWindowsCFI() const {
> -    return ExceptionsType == ExceptionHandling::WinEH;
> +    return ExceptionsType == ExceptionHandling::WinEH &&
> +           (WinEHEncodingType != WinEH::EncodingType::Invalid &&
> +            WinEHEncodingType != WinEH::EncodingType::X86);
>   }
> 
>   bool doesDwarfUseRelocationsAcrossSections() const {
> 
> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinter.cpp?rev=236359&r1=236358&r2=236359&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinter.cpp (original)
> +++ llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinter.cpp Fri May  1 17:40:25 2015
> @@ -266,6 +266,8 @@ bool AsmPrinter::doInitialization(Module
>   case ExceptionHandling::WinEH:
>     switch (MAI->getWinEHEncodingType()) {
>     default: llvm_unreachable("unsupported unwinding information encoding");
> +    case WinEH::EncodingType::Invalid:
> +      break;
>     case WinEH::EncodingType::Itanium:
>       ES = new Win64Exception(this);
>       break;
> 
> Modified: llvm/trunk/lib/CodeGen/WinEHPrepare.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/WinEHPrepare.cpp?rev=236359&r1=236358&r2=236359&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/WinEHPrepare.cpp (original)
> +++ llvm/trunk/lib/CodeGen/WinEHPrepare.cpp Fri May  1 17:40:25 2015
> @@ -8,9 +8,11 @@
> //===----------------------------------------------------------------------===//
> //
> // This pass lowers LLVM IR exception handling into something closer to what the
> -// backend wants. It snifs the personality function to see which kind of
> -// preparation is necessary. If the personality function uses the Itanium LSDA,
> -// this pass delegates to the DWARF EH preparation pass.
> +// backend wants for functions using a personality function from a runtime
> +// provided by MSVC. Functions with other personality functions are left alone
> +// and may be prepared by other passes. In particular, all supported MSVC
> +// personality functions require cleanup code to be outlined, and the C++
> +// personality requires catch handler code to be outlined.
> //
> //===----------------------------------------------------------------------===//
> 
> @@ -31,7 +33,6 @@
> #include "llvm/IR/Module.h"
> #include "llvm/IR/PatternMatch.h"
> #include "llvm/Pass.h"
> -#include "llvm/Support/CommandLine.h"
> #include "llvm/Support/Debug.h"
> #include "llvm/Support/raw_ostream.h"
> #include "llvm/Transforms/Utils/BasicBlockUtils.h"
> @@ -922,7 +923,7 @@ bool WinEHPrepare::prepareExceptionHandl
>   if (SEHExceptionCodeSlot) {
>     if (SEHExceptionCodeSlot->hasNUses(0))
>       SEHExceptionCodeSlot->eraseFromParent();
> -    else
> +    else if (isAllocaPromotable(SEHExceptionCodeSlot))
>       PromoteMemToReg(SEHExceptionCodeSlot, *DT);
>   }
> 
> 
> Modified: llvm/trunk/lib/Target/X86/CMakeLists.txt
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/CMakeLists.txt?rev=236359&r1=236358&r2=236359&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/X86/CMakeLists.txt (original)
> +++ llvm/trunk/lib/Target/X86/CMakeLists.txt Fri May  1 17:40:25 2015
> @@ -32,6 +32,7 @@ set(sources
>   X86TargetTransformInfo.cpp
>   X86VZeroUpper.cpp
>   X86FixupLEAs.cpp
> +  X86WinEHState.cpp
>   )
> 
> if( CMAKE_CL_64 )
> 
> Modified: llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp?rev=236359&r1=236358&r2=236359&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp (original)
> +++ llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp Fri May  1 17:40:25 2015
> @@ -132,9 +132,10 @@ X86MCAsmInfoMicrosoft::X86MCAsmInfoMicro
>     PrivateLabelPrefix = ".L";
>     PointerSize = 8;
>     WinEHEncodingType = WinEH::EncodingType::Itanium;
> -    ExceptionsType = ExceptionHandling::WinEH;
>   }
> 
> +  ExceptionsType = ExceptionHandling::WinEH;
> +
>   AssemblerDialect = AsmWriterFlavor;
> 
>   TextAlignFillValue = 0x90;
> 
> Modified: llvm/trunk/lib/Target/X86/X86.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86.h?rev=236359&r1=236358&r2=236359&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/X86/X86.h (original)
> +++ llvm/trunk/lib/Target/X86/X86.h Fri May  1 17:40:25 2015
> @@ -69,6 +69,12 @@ FunctionPass *createX86FixupLEAs();
> /// esp-relative movs with pushes.
> FunctionPass *createX86CallFrameOptimization();
> 
> +/// createX86WinEHStatePass - Return an IR pass that inserts EH registration
> +/// stack objects and explicit EH state updates. This pass must run after EH
> +/// preparation, which does Windows-specific but architecture-neutral
> +/// preparation.
> +FunctionPass *createX86WinEHStatePass();
> +
> } // End llvm namespace
> 
> #endif
> 
> Modified: llvm/trunk/lib/Target/X86/X86TargetMachine.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86TargetMachine.cpp?rev=236359&r1=236358&r2=236359&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/X86/X86TargetMachine.cpp (original)
> +++ llvm/trunk/lib/Target/X86/X86TargetMachine.cpp Fri May  1 17:40:25 2015
> @@ -185,6 +185,7 @@ public:
>   void addIRPasses() override;
>   bool addInstSelector() override;
>   bool addILPOpts() override;
> +  bool addPreISel() override;
>   void addPreRegAlloc() override;
>   void addPostRegAlloc() override;
>   void addPreEmitPass() override;
> @@ -220,6 +221,14 @@ bool X86PassConfig::addILPOpts() {
>   return true;
> }
> 
> +bool X86PassConfig::addPreISel() {
> +  // Only add this pass for 32-bit x86.
> +  Triple TT(TM->getTargetTriple());
> +  if (TT.getArch() == Triple::x86)
> +    addPass(createX86WinEHStatePass());
> +  return true;
> +}
> +
> void X86PassConfig::addPreRegAlloc() {
>   addPass(createX86CallFrameOptimization());
> }
> 
> Added: llvm/trunk/lib/Target/X86/X86WinEHState.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86WinEHState.cpp?rev=236359&view=auto
> ==============================================================================
> --- llvm/trunk/lib/Target/X86/X86WinEHState.cpp (added)
> +++ llvm/trunk/lib/Target/X86/X86WinEHState.cpp Fri May  1 17:40:25 2015
> @@ -0,0 +1,317 @@
> +//===-- 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/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 *RegNode,
> +                                 Value *Handler);
> +  void unlinkExceptionRegistration(IRBuilder<> &Builder, Value *RegNode);
> +
> +  // Module-level type getters.
> +  Type *getEHRegistrationType();
> +  Type *getSEH3RegistrationType();
> +  Type *getSEH4RegistrationType();
> +  Type *getCXXEH3RegistrationType();
> +
> +  // Per-module data.
> +  Module *TheModule = nullptr;
> +  StructType *EHRegistrationTy = nullptr;
> +  StructType *CXXEH3RegistrationTy = nullptr;
> +  StructType *SEH3RegistrationTy = nullptr;
> +  StructType *SEH4RegistrationTy = nullptr;
> +
> +  // Per-function state
> +  EHPersonality Personality = EHPersonality::Unknown;
> +  Function *PersonalityFn = nullptr;
> +};
> +}
> +
> +FunctionPass *llvm::createX86WinEHStatePass() { return new WinEHStatePass(); }
> +
> +char WinEHStatePass::ID = 0;
> +
> +bool WinEHStatePass::doInitialization(Module &M) {
> +  TheModule = &M;
> +  return false;
> +}
> +
> +bool WinEHStatePass::doFinalization(Module &M) {
> +  assert(TheModule == &M);
> +  TheModule = nullptr;
> +  EHRegistrationTy = nullptr;
> +  CXXEH3RegistrationTy = nullptr;
> +  SEH3RegistrationTy = nullptr;
> +  SEH4RegistrationTy = 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) {
> +  // 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;
> +
> +  emitExceptionRegistrationRecord(&F);
> +  // FIXME: State insertion.
> +
> +  // Reset per-function state.
> +  PersonalityFn = nullptr;
> +  Personality = EHPersonality::Unknown;
> +  return true;
> +}
> +
> +/// Get the common EH registration subobject:
> +///   struct EHRegistrationNode {
> +///     EHRegistrationNode *Next;
> +///     EXCEPTION_DISPOSITION (*Handler)(...);
> +///   };
> +Type *WinEHStatePass::getEHRegistrationType() {
> +  if (EHRegistrationTy)
> +    return EHRegistrationTy;
> +  LLVMContext &Context = TheModule->getContext();
> +  EHRegistrationTy = StructType::create(Context, "EHRegistrationNode");
> +  Type *FieldTys[] = {
> +      EHRegistrationTy->getPointerTo(0), // EHRegistrationNode *Next
> +      Type::getInt8PtrTy(Context) // EXCEPTION_DISPOSITION (*Handler)(...)
> +  };
> +  EHRegistrationTy->setBody(FieldTys, false);
> +  return EHRegistrationTy;
> +}
> +
> +/// The __CxxFrameHandler3 registration node:
> +///   struct CXXExceptionRegistration {
> +///     void *SavedESP;
> +///     EHRegistrationNode SubRecord;
> +///     int32_t TryLevel;
> +///   };
> +Type *WinEHStatePass::getCXXEH3RegistrationType() {
> +  if (CXXEH3RegistrationTy)
> +    return CXXEH3RegistrationTy;
> +  LLVMContext &Context = TheModule->getContext();
> +  Type *FieldTys[] = {
> +      Type::getInt8PtrTy(Context), // void *SavedESP
> +      getEHRegistrationType(),     // EHRegistrationNode SubRecord
> +      Type::getInt32Ty(Context)    // int32_t TryLevel
> +  };
> +  CXXEH3RegistrationTy =
> +      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;
> +}
> +
> +/// The _except_handler4 registration node:
> +///   struct EH4ExceptionRegistration {
> +///     void *SavedESP;
> +///     _EXCEPTION_POINTERS *ExceptionPointers;
> +///     EHRegistrationNode SubRecord;
> +///     int32_t EncodedScopeTable;
> +///     int32_t TryLevel;
> +///   };
> +Type *WinEHStatePass::getSEH4RegistrationType() {
> +  if (SEH4RegistrationTy)
> +    return SEH4RegistrationTy;
> +  LLVMContext &Context = TheModule->getContext();
> +  Type *FieldTys[] = {
> +      Type::getInt8PtrTy(Context), // void *SavedESP
> +      Type::getInt8PtrTy(Context), // void *ExceptionPointers
> +      getEHRegistrationType(),     // EHRegistrationNode SubRecord
> +      Type::getInt32Ty(Context),   // int32_t EncodedScopeTable
> +      Type::getInt32Ty(Context)    // int32_t TryLevel
> +  };
> +  SEH4RegistrationTy = StructType::create(FieldTys, "EH4ExceptionRegistration");
> +  return SEH4RegistrationTy;
> +}
> +
> +// 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();
> +  Value *SubRecord = nullptr;
> +  if (PersonalityName == "__CxxFrameHandler3") {
> +    Type *RegNodeTy = getCXXEH3RegistrationType();
> +    Value *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));
> +    // FIXME: 'Personality' is incorrect here. We need to generate a trampoline
> +    // that effectively gets the LSDA.
> +    SubRecord = Builder.CreateStructGEP(RegNodeTy, RegNode, 1);
> +    linkExceptionRegistration(Builder, SubRecord, PersonalityFn);
> +  } 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));
> +    // FIXME: Generalize llvm.eh.sjljl.lsda for this.
> +    // ScopeTable = nullptr
> +    Builder.CreateStore(Constant::getNullValue(Int8PtrType),
> +                        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);
> +    // 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: Generalize llvm.eh.sjljl.lsda for this, and then do the stack
> +    // cookie xor.
> +    // ScopeTable = nullptr
> +    Builder.CreateStore(Builder.getInt32(0),
> +                        Builder.CreateStructGEP(RegNodeTy, RegNode, 3));
> +    SubRecord = Builder.CreateStructGEP(RegNodeTy, RegNode, 2);
> +    linkExceptionRegistration(Builder, SubRecord, PersonalityFn);
> +  } else {
> +    llvm_unreachable("unexpected personality function");
> +  }
> +
> +  // FIXME: 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);
> +  }
> +}
> +
> +void WinEHStatePass::linkExceptionRegistration(IRBuilder<> &Builder,
> +                                               Value *RegNode, Value *Handler) {
> +  Type *RegNodeTy = getEHRegistrationType();
> +  // Handler = Handler
> +  Handler = Builder.CreateBitCast(Handler, Builder.getInt8PtrTy());
> +  Builder.CreateStore(Handler, Builder.CreateStructGEP(RegNodeTy, RegNode, 1));
> +  // Next = [fs:00]
> +  Constant *FSZero =
> +      Constant::getNullValue(RegNodeTy->getPointerTo()->getPointerTo(257));
> +  Value *Next = Builder.CreateLoad(FSZero);
> +  Builder.CreateStore(Next, Builder.CreateStructGEP(RegNodeTy, RegNode, 0));
> +  // [fs:00] = RegNode
> +  Builder.CreateStore(RegNode, 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)) {
> +    GEP = cast<GetElementPtrInst>(GEP->clone());
> +    Builder.Insert(GEP);
> +    RegNode = GEP;
> +  }
> +  Type *RegNodeTy = getEHRegistrationType();
> +  // [fs:00] = RegNode->Next
> +  Value *Next =
> +      Builder.CreateLoad(Builder.CreateStructGEP(RegNodeTy, RegNode, 0));
> +  Constant *FSZero =
> +      Constant::getNullValue(RegNodeTy->getPointerTo()->getPointerTo(257));
> +  Builder.CreateStore(Next, FSZero);
> +}
> 
> Modified: llvm/trunk/test/CodeGen/X86/inalloca-invoke.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/inalloca-invoke.ll?rev=236359&r1=236358&r2=236359&view=diff
> ==============================================================================
> --- llvm/trunk/test/CodeGen/X86/inalloca-invoke.ll (original)
> +++ llvm/trunk/test/CodeGen/X86/inalloca-invoke.ll Fri May  1 17:40:25 2015
> @@ -4,6 +4,7 @@
> 
> %frame.reverse = type { %Iter, %Iter }
> 
> +declare i32 @pers(...)
> declare void @llvm.stackrestore(i8*)
> declare i8* @llvm.stacksave()
> declare void @begin(%Iter* sret)
> @@ -22,8 +23,7 @@ blah:
> 
> ; CHECK:  calll   __chkstk
> ; CHECK:  movl %esp, %[[beg:[^ ]*]]
> -; CHECK:  movl %esp, %[[end:[^ ]*]]
> -; CHECK:  addl $12, %[[end]]
> +; CHECK:  leal 12(%[[beg]]), %[[end:[^ ]*]]
> 
>   call void @begin(%Iter* sret %temp.lvalue)
> ; CHECK:  calll _begin
> @@ -49,7 +49,7 @@ invoke.cont5:
>   ret i32 0
> 
> lpad:                                             ; preds = %invoke.cont, %entry
> -  %lp = landingpad { i8*, i32 } personality i8* null
> +  %lp = landingpad { i8*, i32 } personality i32 (...)* @pers
>           cleanup
>   unreachable
> }
> 
> Added: llvm/trunk/test/CodeGen/X86/win32-eh.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/win32-eh.ll?rev=236359&view=auto
> ==============================================================================
> --- llvm/trunk/test/CodeGen/X86/win32-eh.ll (added)
> +++ llvm/trunk/test/CodeGen/X86/win32-eh.ll Fri May  1 17:40:25 2015
> @@ -0,0 +1,77 @@
> +; RUN: llc -mtriple=i686-pc-windows-msvc < %s | FileCheck %s
> +
> +declare void @may_throw_or_crash()
> +declare i32 @_except_handler3(...)
> +declare i32 @_except_handler4(...)
> +declare i32 @__CxxFrameHandler3(...)
> +declare void @llvm.eh.begincatch(i8*, i8*)
> +declare void @llvm.eh.endcatch()
> +
> +define void @use_except_handler3() {
> +  invoke void @may_throw_or_crash()
> +      to label %cont unwind label %catchall
> +cont:
> +  ret void
> +catchall:
> +  landingpad { i8*, i32 } personality i32 (...)* @_except_handler3
> +      catch i8* null
> +  br label %cont
> +}
> +
> +; CHECK-LABEL: _use_except_handler3:
> +; CHECK: subl ${{[0-9]+}}, %esp
> +; CHECK: movl %fs:0, %[[next:[^ ,]*]]
> +; CHECK: movl %[[next]], (%esp)
> +; CHECK: leal (%esp), %[[node:[^ ,]*]]
> +; CHECK: movl %[[node]], %fs:0
> +; CHECK: calll _may_throw_or_crash
> +; CHECK: movl (%esp), %[[next:[^ ,]*]]
> +; CHECK: movl %[[next]], %fs:0
> +; CHECK: retl
> +
> +define void @use_except_handler4() {
> +  invoke void @may_throw_or_crash()
> +      to label %cont unwind label %catchall
> +cont:
> +  ret void
> +catchall:
> +  landingpad { i8*, i32 } personality i32 (...)* @_except_handler4
> +      catch i8* null
> +  br label %cont
> +}
> +
> +; CHECK-LABEL: _use_except_handler4:
> +; CHECK: subl ${{[0-9]+}}, %esp
> +; CHECK: leal 8(%esp), %[[node:[^ ,]*]]
> +; CHECK: movl %fs:0, %[[next:[^ ,]*]]
> +; CHECK: movl %[[next]], 8(%esp)
> +; CHECK: movl %[[node]], %fs:0
> +; CHECK: calll _may_throw_or_crash
> +; CHECK: movl 8(%esp), %[[next:[^ ,]*]]
> +; CHECK: movl %[[next]], %fs:0
> +; CHECK: retl
> +
> +define void @use_CxxFrameHandler3() {
> +  invoke void @may_throw_or_crash()
> +      to label %cont unwind label %catchall
> +cont:
> +  ret void
> +catchall:
> +  %ehvals = landingpad { i8*, i32 } personality i32 (...)* @__CxxFrameHandler3
> +      catch i8* null
> +  %ehptr = extractvalue { i8*, i32 } %ehvals, 0
> +  call void @llvm.eh.begincatch(i8* %ehptr, i8* null)
> +  call void @llvm.eh.endcatch()
> +  br label %cont
> +}
> +
> +; CHECK-LABEL: _use_CxxFrameHandler3:
> +; CHECK: subl ${{[0-9]+}}, %esp
> +; CHECK: leal 4(%esp), %[[node:[^ ,]*]]
> +; CHECK: movl %fs:0, %[[next:[^ ,]*]]
> +; CHECK: movl %[[next]], 4(%esp)
> +; CHECK: movl %[[node]], %fs:0
> +; CHECK: calll _may_throw_or_crash
> +; CHECK: movl 4(%esp), %[[next:[^ ,]*]]
> +; CHECK: movl %[[next]], %fs:0
> +; CHECK: retl
> 
> 
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