Revert "[WinEH] Add an EH registration and state insertion pass for 32-bit x86"

This reverts commit r236339, it breaks the win32 clang-cl self-host.

llvm-svn: 236340
This commit is contained in:
Reid Kleckner 2015-05-01 20:14:04 +00:00
parent 4856fc61b4
commit 2747d3d55a
10 changed files with 12 additions and 428 deletions

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@ -37,7 +37,6 @@ 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,
};
}
@ -507,13 +506,12 @@ public:
/// frame information to unwind.
bool usesCFIForEH() const {
return (ExceptionsType == ExceptionHandling::DwarfCFI ||
ExceptionsType == ExceptionHandling::ARM || usesWindowsCFI());
ExceptionsType == ExceptionHandling::ARM ||
ExceptionsType == ExceptionHandling::WinEH);
}
bool usesWindowsCFI() const {
return ExceptionsType == ExceptionHandling::WinEH &&
(WinEHEncodingType != WinEH::EncodingType::Invalid &&
WinEHEncodingType != WinEH::EncodingType::X86);
return ExceptionsType == ExceptionHandling::WinEH;
}
bool doesDwarfUseRelocationsAcrossSections() const {

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@ -266,8 +266,6 @@ bool AsmPrinter::doInitialization(Module &M) {
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;

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@ -8,11 +8,9 @@
//===----------------------------------------------------------------------===//
//
// This pass lowers LLVM IR exception handling into something closer to what the
// 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.
// 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.
//
//===----------------------------------------------------------------------===//
@ -33,6 +31,7 @@
#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"
@ -923,7 +922,7 @@ bool WinEHPrepare::prepareExceptionHandlers(
if (SEHExceptionCodeSlot) {
if (SEHExceptionCodeSlot->hasNUses(0))
SEHExceptionCodeSlot->eraseFromParent();
else if (isAllocaPromotable(SEHExceptionCodeSlot))
else
PromoteMemToReg(SEHExceptionCodeSlot, *DT);
}

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@ -32,7 +32,6 @@ set(sources
X86TargetTransformInfo.cpp
X86VZeroUpper.cpp
X86FixupLEAs.cpp
X86WinEHState.cpp
)
if( CMAKE_CL_64 )

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@ -132,10 +132,9 @@ X86MCAsmInfoMicrosoft::X86MCAsmInfoMicrosoft(const Triple &Triple) {
PrivateLabelPrefix = ".L";
PointerSize = 8;
WinEHEncodingType = WinEH::EncodingType::Itanium;
ExceptionsType = ExceptionHandling::WinEH;
}
ExceptionsType = ExceptionHandling::WinEH;
AssemblerDialect = AsmWriterFlavor;
TextAlignFillValue = 0x90;

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@ -69,12 +69,6 @@ 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

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@ -185,7 +185,6 @@ public:
void addIRPasses() override;
bool addInstSelector() override;
bool addILPOpts() override;
bool addPreISel() override;
void addPreRegAlloc() override;
void addPostRegAlloc() override;
void addPreEmitPass() override;
@ -221,14 +220,6 @@ 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());
}

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@ -1,317 +0,0 @@
//===-- 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);
}

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@ -4,7 +4,6 @@
%frame.reverse = type { %Iter, %Iter }
declare i32 @pers(...)
declare void @llvm.stackrestore(i8*)
declare i8* @llvm.stacksave()
declare void @begin(%Iter* sret)
@ -23,7 +22,8 @@ blah:
; CHECK: calll __chkstk
; CHECK: movl %esp, %[[beg:[^ ]*]]
; CHECK: leal 12(%[[beg]]), %[[end:[^ ]*]]
; CHECK: movl %esp, %[[end:[^ ]*]]
; CHECK: addl $12, %[[end]]
call void @begin(%Iter* sret %temp.lvalue)
; CHECK: calll _begin
@ -49,7 +49,7 @@ invoke.cont5: ; preds = %invoke.cont
ret i32 0
lpad: ; preds = %invoke.cont, %entry
%lp = landingpad { i8*, i32 } personality i32 (...)* @pers
%lp = landingpad { i8*, i32 } personality i8* null
cleanup
unreachable
}

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@ -1,77 +0,0 @@
; 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