//===----------------------------------------------------------------------===//
#include "X86.h"
-#include "llvm/Analysis/LibCallSemantics.h"
+#include "llvm/Analysis/CFG.h"
+#include "llvm/Analysis/EHPersonalities.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/WinEHFuncInfo.h"
#define DEBUG_TYPE "winehstate"
+namespace llvm { void initializeWinEHStatePassPass(PassRegistry &); }
+
namespace {
class WinEHStatePass : public FunctionPass {
public:
static char ID; // Pass identification, replacement for typeid.
- WinEHStatePass() : FunctionPass(ID) {}
+ WinEHStatePass() : FunctionPass(ID) {
+ initializeWinEHStatePassPass(*PassRegistry::getPassRegistry());
+ }
bool runOnFunction(Function &Fn) override;
void linkExceptionRegistration(IRBuilder<> &Builder, Function *Handler);
void unlinkExceptionRegistration(IRBuilder<> &Builder);
- void addCXXStateStores(Function &F, MachineModuleInfo &MMI);
- void addSEHStateStores(Function &F, MachineModuleInfo &MMI);
- void addCXXStateStoresToFunclet(Value *ParentRegNode, WinEHFuncInfo &FuncInfo,
- Function &F, int BaseState);
+ void addStateStores(Function &F, WinEHFuncInfo &FuncInfo);
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();
char WinEHStatePass::ID = 0;
+INITIALIZE_PASS(WinEHStatePass, "x86-winehstate",
+ "Insert stores for EH state numbers", false, false)
+
bool WinEHStatePass::doInitialization(Module &M) {
TheModule = &M;
- FrameEscape = Intrinsic::getDeclaration(TheModule, Intrinsic::frameescape);
- FrameRecover = Intrinsic::getDeclaration(TheModule, Intrinsic::framerecover);
+ FrameEscape = Intrinsic::getDeclaration(TheModule, Intrinsic::localescape);
+ FrameRecover = Intrinsic::getDeclaration(TheModule, Intrinsic::localrecover);
FrameAddress = Intrinsic::getDeclaration(TheModule, Intrinsic::frameaddress);
return false;
}
void WinEHStatePass::getAnalysisUsage(AnalysisUsage &AU) const {
// This pass should only insert a stack allocation, memory accesses, and
- // framerecovers.
+ // localrecovers.
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.
+ // Check the personality. Do nothing if this personality doesn't use funclets.
if (!F.hasPersonalityFn())
return false;
PersonalityFn =
if (!PersonalityFn)
return false;
Personality = classifyEHPersonality(PersonalityFn);
- if (!isMSVCEHPersonality(Personality))
+ if (!isFuncletEHPersonality(Personality))
+ return false;
+
+ // Skip this function if there are no EH pads and we aren't using IR-level
+ // outlining.
+ bool HasPads = false;
+ for (BasicBlock &BB : F) {
+ if (BB.isEHPad()) {
+ HasPads = true;
+ break;
+ }
+ }
+ if (!HasPads)
return false;
// Disable frame pointer elimination in this function.
emitExceptionRegistrationRecord(&F);
- auto *MMIPtr = getAnalysisIfAvailable<MachineModuleInfo>();
- assert(MMIPtr && "MachineModuleInfo should always be available");
- MachineModuleInfo &MMI = *MMIPtr;
- switch (Personality) {
- default: llvm_unreachable("unexpected personality function");
- case EHPersonality::MSVC_CXX: addCXXStateStores(F, MMI); break;
- case EHPersonality::MSVC_X86SEH: addSEHStateStores(F, MMI); break;
- }
+ // The state numbers calculated here in IR must agree with what we calculate
+ // later on for the MachineFunction. In particular, if an IR pass deletes an
+ // unreachable EH pad after this point before machine CFG construction, we
+ // will be in trouble. If this assumption is ever broken, we should turn the
+ // numbers into an immutable analysis pass.
+ WinEHFuncInfo FuncInfo;
+ addStateStores(F, FuncInfo);
// Reset per-function state.
PersonalityFn = nullptr;
Builder.CreateStore(SP, Builder.CreateStructGEP(RegNodeTy, RegNode, 0));
// TryLevel = -1
StateFieldIndex = 2;
- insertStateNumberStore(RegNode, Builder.GetInsertPoint(), -1);
+ insertStateNumberStore(RegNode, &*Builder.GetInsertPoint(), -1);
// Handler = __ehhandler$F
Function *Trampoline = generateLSDAInEAXThunk(F);
Link = Builder.CreateStructGEP(RegNodeTy, RegNode, 1);
Builder.CreateStore(SP, Builder.CreateStructGEP(RegNodeTy, RegNode, 0));
// TryLevel = -2 / -1
StateFieldIndex = 4;
- insertStateNumberStore(RegNode, Builder.GetInsertPoint(),
+ insertStateNumberStore(RegNode, &*Builder.GetInsertPoint(),
UseStackGuard ? -2 : -1);
// ScopeTable = llvm.x86.seh.lsda(F)
Value *FI8 = Builder.CreateBitCast(F, Int8PtrType);
FunctionType *TargetFuncTy =
FunctionType::get(Int32Ty, makeArrayRef(&ArgTys[0], 5),
/*isVarArg=*/false);
- Function *Trampoline = Function::Create(
- TrampolineTy, GlobalValue::InternalLinkage,
- Twine("__ehhandler$") + ParentFunc->getName(), TheModule);
+ Function *Trampoline =
+ Function::Create(TrampolineTy, GlobalValue::InternalLinkage,
+ Twine("__ehhandler$") + GlobalValue::getRealLinkageName(
+ 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++};
+ 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);
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::addStateStores(Function &F, WinEHFuncInfo &FuncInfo) {
+ // Mark the registration node. The backend needs to know which alloca it is so
+ // that it can recover the original frame pointer.
+ IRBuilder<> Builder(RegNode->getParent(), std::next(RegNode->getIterator()));
+ Value *RegNodeI8 = Builder.CreateBitCast(RegNode, Builder.getInt8PtrTy());
+ Builder.CreateCall(
+ Intrinsic::getDeclaration(TheModule, Intrinsic::x86_seh_ehregnode),
+ {RegNodeI8});
+
+ // Calculate state numbers.
+ if (isAsynchronousEHPersonality(Personality))
+ calculateSEHStateNumbers(&F, FuncInfo);
+ else
+ calculateWinCXXEHStateNumbers(&F, FuncInfo);
-void WinEHStatePass::addCXXStateStoresToFunclet(Value *ParentRegNode,
- WinEHFuncInfo &FuncInfo,
- Function &F, int BaseState) {
// Iterate all the instructions and emit state number stores.
+ DenseMap<BasicBlock *, ColorVector> BlockColors = colorEHFunclets(F);
for (BasicBlock &BB : F) {
+ // Figure out what state we should assign calls in this block.
+ int BaseState = -1;
+ auto &BBColors = BlockColors[&BB];
+
+ assert(BBColors.size() == 1 &&
+ "multi-color BB not removed by preparation");
+ BasicBlock *FuncletEntryBB = BBColors.front();
+ if (auto *FuncletPad =
+ dyn_cast<FuncletPadInst>(FuncletEntryBB->getFirstNonPHI())) {
+ auto BaseStateI = FuncInfo.FuncletBaseStateMap.find(FuncletPad);
+ if (BaseStateI != FuncInfo.FuncletBaseStateMap.end())
+ BaseState = BaseStateI->second;
+ }
+
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);
+ insertStateNumberStore(RegNode, 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);
- }
- }
- }
-}
-
-/// Assign every distinct landingpad a unique state number for SEH. Unlike C++
-/// EH, we can use this very simple algorithm while C++ EH cannot because catch
-/// handlers aren't outlined and the runtime doesn't have to figure out which
-/// catch handler frame to unwind to.
-/// FIXME: __finally blocks are outlined, so this approach may break down there.
-void WinEHStatePass::addSEHStateStores(Function &F, MachineModuleInfo &MMI) {
- WinEHFuncInfo &FuncInfo = MMI.getWinEHFuncInfo(&F);
-
- // Remember and return the index that we used. We save it in WinEHFuncInfo so
- // that we can lower llvm.x86.seh.exceptioninfo later in filter functions
- // without too much trouble.
- int RegNodeEscapeIndex = escapeRegNode(F);
- FuncInfo.EHRegNodeEscapeIndex = RegNodeEscapeIndex;
-
- // Iterate all the instructions and emit state number stores.
- int CurState = 0;
- SmallPtrSet<BasicBlock *, 4> ExceptBlocks;
- for (BasicBlock &BB : F) {
- for (auto I = BB.begin(), E = BB.end(); I != E; ++I) {
- if (auto *CI = dyn_cast<CallInst>(I)) {
- auto *Intrin = dyn_cast<IntrinsicInst>(CI);
- if (Intrin) {
- // Calls that "don't throw" are considered to be able to throw asynch
- // exceptions, but intrinsics cannot.
- continue;
- }
- insertStateNumberStore(RegNode, CI, -1);
- } else if (auto *II = dyn_cast<InvokeInst>(I)) {
- // Look up the state number of the landingpad this unwinds to.
- LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst();
- auto InsertionPair =
- FuncInfo.LandingPadStateMap.insert(std::make_pair(LPI, CurState));
- auto Iter = InsertionPair.first;
- int &State = Iter->second;
- bool Inserted = InsertionPair.second;
- if (Inserted) {
- // Each action consumes a state number.
- auto *EHActions = cast<IntrinsicInst>(LPI->getNextNode());
- SmallVector<std::unique_ptr<ActionHandler>, 4> ActionList;
- parseEHActions(EHActions, ActionList);
- assert(!ActionList.empty());
- CurState += ActionList.size();
- State += ActionList.size() - 1;
-
- // Remember all the __except block targets.
- for (auto &Handler : ActionList) {
- if (auto *CH = dyn_cast<CatchHandler>(Handler.get())) {
- auto *BA = cast<BlockAddress>(CH->getHandlerBlockOrFunc());
- ExceptBlocks.insert(BA->getBasicBlock());
- }
- }
- }
+ assert(FuncInfo.InvokeStateMap.count(II) && "invoke has no state!");
+ int State = FuncInfo.InvokeStateMap[II];
insertStateNumberStore(RegNode, II, State);
}
}
}
-
- // Insert llvm.stackrestore into each __except block.
- Function *StackRestore =
- Intrinsic::getDeclaration(TheModule, Intrinsic::stackrestore);
- for (BasicBlock *ExceptBB : ExceptBlocks) {
- IRBuilder<> Builder(ExceptBB->begin());
- Value *SP =
- Builder.CreateLoad(Builder.CreateStructGEP(RegNodeTy, RegNode, 0));
- Builder.CreateCall(StackRestore, {SP});
- }
}
void WinEHStatePass::insertStateNumberStore(Value *ParentRegNode,
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