//===----------------------------------------------------------------------===//
#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"
void linkExceptionRegistration(IRBuilder<> &Builder, Function *Handler);
void unlinkExceptionRegistration(IRBuilder<> &Builder);
- void addCXXStateStores(Function &F, WinEHFuncInfo &FuncInfo);
- void addSEHStateStores(Function &F, WinEHFuncInfo &FuncInfo);
- void addStateStoresToFunclet(Value *ParentRegNode, WinEHFuncInfo &FuncInfo,
- Function &F, int BaseState);
+ void addStateStores(Function &F, WinEHFuncInfo &FuncInfo);
void insertStateNumberStore(Value *ParentRegNode, Instruction *IP, int State);
- void insertRestoreFrame(BasicBlock *BB);
Value *emitEHLSDA(IRBuilder<> &Builder, Function *F);
Function *generateLSDAInEAXThunk(Function *ParentFunc);
- int escapeRegNode(Function &F);
-
// Module-level type getters.
Type *getEHLinkRegistrationType();
Type *getSEHRegistrationType();
Function *FrameRecover = nullptr;
Function *FrameAddress = nullptr;
Function *FrameEscape = nullptr;
- Function *RestoreFrame = nullptr;
// Per-function state
EHPersonality Personality = EHPersonality::Unknown;
FrameEscape = Intrinsic::getDeclaration(TheModule, Intrinsic::localescape);
FrameRecover = Intrinsic::getDeclaration(TheModule, Intrinsic::localrecover);
FrameAddress = Intrinsic::getDeclaration(TheModule, Intrinsic::frameaddress);
- RestoreFrame =
- Intrinsic::getDeclaration(TheModule, Intrinsic::x86_seh_restoreframe);
return false;
}
}
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 personality doesn't use funclets.
if (!F.hasPersonalityFn())
return false;
// Skip this function if there are no EH pads and we aren't using IR-level
// outlining.
- if (WinEHParentName.empty()) {
- bool HasPads = false;
- for (BasicBlock &BB : F) {
- if (BB.isEHPad()) {
- HasPads = true;
- break;
- }
+ bool HasPads = false;
+ for (BasicBlock &BB : F) {
+ if (BB.isEHPad()) {
+ HasPads = true;
+ break;
}
- if (!HasPads)
- return false;
}
+ if (!HasPads)
+ 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
emitExceptionRegistrationRecord(&F);
- auto *MMI = getAnalysisIfAvailable<MachineModuleInfo>();
- // If MMI is null, create our own WinEHFuncInfo. This only happens in opt
- // tests.
- std::unique_ptr<WinEHFuncInfo> FuncInfoPtr;
- if (!MMI)
- FuncInfoPtr.reset(new WinEHFuncInfo());
- WinEHFuncInfo &FuncInfo =
- *(MMI ? &MMI->getWinEHFuncInfo(&F) : FuncInfoPtr.get());
-
- FuncInfo.EHRegNode = RegNode;
-
- switch (Personality) {
- default: llvm_unreachable("unexpected personality function");
- case EHPersonality::MSVC_CXX:
- addCXXStateStores(F, FuncInfo);
- break;
- case EHPersonality::MSVC_X86SEH:
- addSEHStateStores(F, FuncInfo);
- 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);
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, WinEHFuncInfo &FuncInfo) {
- calculateWinCXXEHStateNumbers(&F, FuncInfo);
-
- // The base state for the parent is -1.
- addStateStoresToFunclet(RegNode, FuncInfo, F, -1);
-
- // Set up RegNodeEscapeIndex
- int RegNodeEscapeIndex = escapeRegNode(F);
- FuncInfo.EHRegNodeEscapeIndex = RegNodeEscapeIndex;
-}
-
-/// Escape RegNode so that we can access it from child handlers. Find the call
-/// to localescape, if any, in the entry block and append RegNode to the list
-/// of arguments.
-int WinEHStatePass::escapeRegNode(Function &F) {
- // Find the call to localescape and extract its arguments.
- IntrinsicInst *EscapeCall = nullptr;
- for (Instruction &I : F.getEntryBlock()) {
- IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I);
- if (II && II->getIntrinsicID() == Intrinsic::localescape) {
- 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.
- Instruction *InsertPt = EscapeCall;
- if (!EscapeCall)
- InsertPt = F.getEntryBlock().getTerminator();
- IRBuilder<> Builder(&F.getEntryBlock(), InsertPt);
- Builder.CreateCall(FrameEscape, Args);
- if (EscapeCall)
- EscapeCall->eraseFromParent();
- return Args.size() - 1;
-}
-
-void WinEHStatePass::insertRestoreFrame(BasicBlock *BB) {
- Instruction *Start = BB->getFirstInsertionPt();
- if (match(Start, m_Intrinsic<Intrinsic::x86_seh_restoreframe>()))
- return;
- IRBuilder<> Builder(Start);
- Builder.CreateCall(RestoreFrame, {});
-}
+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::addStateStoresToFunclet(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.
- Instruction *PadInst = II->getUnwindDest()->getFirstNonPHI();
- // FIXME: Why does this assertion fail?
- //assert(FuncInfo.EHPadStateMap.count(PadInst) && "EH Pad has no state!");
- int State = FuncInfo.EHPadStateMap[PadInst];
- 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, WinEHFuncInfo &FuncInfo) {
- // Remember and return the index that we used. We save it in WinEHFuncInfo so
- // that we can lower llvm.x86.seh.recoverfp later in filter functions without
- // too much trouble.
- int RegNodeEscapeIndex = escapeRegNode(F);
- FuncInfo.EHRegNodeEscapeIndex = RegNodeEscapeIndex;
-
- // If this funciton uses the new EH IR, use the explicit state numbering
- // algorithm and return early.
- bool UsesLPads = false;
- for (BasicBlock &BB : F) {
- if (BB.isLandingPad()) {
- UsesLPads = true;
- break;
- }
- }
- if (!UsesLPads) {
- calculateSEHStateNumbers(&F, FuncInfo);
- addStateStoresToFunclet(RegNode, FuncInfo, F, -1);
- return;
- }
- // FIXME: Delete the rest of this code and clean things up when new EH is
- // done.
-
- // 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.EHPadStateMap.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());
-#ifndef NDEBUG
- for (BasicBlock *Pred : predecessors(BA->getBasicBlock()))
- assert(Pred->isLandingPad() &&
- "WinEHPrepare failed to split block");
-#endif
- ExceptBlocks.insert(BA->getBasicBlock());
- }
- }
- }
+ assert(FuncInfo.InvokeStateMap.count(II) && "invoke has no state!");
+ int State = FuncInfo.InvokeStateMap[II];
insertStateNumberStore(RegNode, II, State);
}
}
}
-
- // Insert llvm.x86.seh.restoreframe() into each __except block.
- Function *RestoreFrame =
- Intrinsic::getDeclaration(TheModule, Intrinsic::x86_seh_restoreframe);
- for (BasicBlock *ExceptBB : ExceptBlocks) {
- IRBuilder<> Builder(ExceptBB->begin());
- Builder.CreateCall(RestoreFrame, {});
- }
}
void WinEHStatePass::insertStateNumberStore(Value *ParentRegNode,
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