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Diffstat (limited to 'contrib/llvm/lib/CodeGen/SjLjEHPrepare.cpp')
| -rw-r--r-- | contrib/llvm/lib/CodeGen/SjLjEHPrepare.cpp | 592 |
1 files changed, 592 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/SjLjEHPrepare.cpp b/contrib/llvm/lib/CodeGen/SjLjEHPrepare.cpp new file mode 100644 index 0000000..13e1454 --- /dev/null +++ b/contrib/llvm/lib/CodeGen/SjLjEHPrepare.cpp @@ -0,0 +1,592 @@ +//===- SjLjEHPass.cpp - Eliminate Invoke & Unwind instructions -----------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This transformation is designed for use by code generators which use SjLj +// based exception handling. +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "sjljehprepare" +#include "llvm/Transforms/Scalar.h" +#include "llvm/Constants.h" +#include "llvm/DerivedTypes.h" +#include "llvm/Instructions.h" +#include "llvm/Intrinsics.h" +#include "llvm/LLVMContext.h" +#include "llvm/Module.h" +#include "llvm/Pass.h" +#include "llvm/ADT/SmallVector.h" +#include "llvm/ADT/Statistic.h" +#include "llvm/CodeGen/Passes.h" +#include "llvm/Support/Debug.h" +#include "llvm/Target/TargetLowering.h" +#include "llvm/Transforms/Utils/BasicBlockUtils.h" +#include "llvm/Transforms/Utils/Local.h" +#include <set> +using namespace llvm; + +STATISTIC(NumInvokes, "Number of invokes replaced"); +STATISTIC(NumUnwinds, "Number of unwinds replaced"); +STATISTIC(NumSpilled, "Number of registers live across unwind edges"); + +namespace { + class SjLjEHPass : public FunctionPass { + + const TargetLowering *TLI; + + const Type *FunctionContextTy; + Constant *RegisterFn; + Constant *UnregisterFn; + Constant *BuiltinSetjmpFn; + Constant *FrameAddrFn; + Constant *StackAddrFn; + Constant *StackRestoreFn; + Constant *LSDAAddrFn; + Value *PersonalityFn; + Constant *SelectorFn; + Constant *ExceptionFn; + Constant *CallSiteFn; + Constant *DispatchSetupFn; + + Value *CallSite; + public: + static char ID; // Pass identification, replacement for typeid + explicit SjLjEHPass(const TargetLowering *tli = NULL) + : FunctionPass(ID), TLI(tli) { } + bool doInitialization(Module &M); + bool runOnFunction(Function &F); + + virtual void getAnalysisUsage(AnalysisUsage &AU) const { } + const char *getPassName() const { + return "SJLJ Exception Handling preparation"; + } + + private: + void insertCallSiteStore(Instruction *I, int Number, Value *CallSite); + void markInvokeCallSite(InvokeInst *II, int InvokeNo, Value *CallSite, + SwitchInst *CatchSwitch); + void splitLiveRangesAcrossInvokes(SmallVector<InvokeInst*,16> &Invokes); + bool insertSjLjEHSupport(Function &F); + }; +} // end anonymous namespace + +char SjLjEHPass::ID = 0; + +// Public Interface To the SjLjEHPass pass. +FunctionPass *llvm::createSjLjEHPass(const TargetLowering *TLI) { + return new SjLjEHPass(TLI); +} +// doInitialization - Set up decalarations and types needed to process +// exceptions. +bool SjLjEHPass::doInitialization(Module &M) { + // Build the function context structure. + // builtin_setjmp uses a five word jbuf + const Type *VoidPtrTy = + Type::getInt8PtrTy(M.getContext()); + const Type *Int32Ty = Type::getInt32Ty(M.getContext()); + FunctionContextTy = + StructType::get(M.getContext(), + VoidPtrTy, // __prev + Int32Ty, // call_site + ArrayType::get(Int32Ty, 4), // __data + VoidPtrTy, // __personality + VoidPtrTy, // __lsda + ArrayType::get(VoidPtrTy, 5), // __jbuf + NULL); + RegisterFn = M.getOrInsertFunction("_Unwind_SjLj_Register", + Type::getVoidTy(M.getContext()), + PointerType::getUnqual(FunctionContextTy), + (Type *)0); + UnregisterFn = + M.getOrInsertFunction("_Unwind_SjLj_Unregister", + Type::getVoidTy(M.getContext()), + PointerType::getUnqual(FunctionContextTy), + (Type *)0); + FrameAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::frameaddress); + StackAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::stacksave); + StackRestoreFn = Intrinsic::getDeclaration(&M, Intrinsic::stackrestore); + BuiltinSetjmpFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_setjmp); + LSDAAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_lsda); + SelectorFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_selector); + ExceptionFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_exception); + CallSiteFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_callsite); + DispatchSetupFn + = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_dispatch_setup); + PersonalityFn = 0; + + return true; +} + +/// insertCallSiteStore - Insert a store of the call-site value to the +/// function context +void SjLjEHPass::insertCallSiteStore(Instruction *I, int Number, + Value *CallSite) { + ConstantInt *CallSiteNoC = ConstantInt::get(Type::getInt32Ty(I->getContext()), + Number); + // Insert a store of the call-site number + new StoreInst(CallSiteNoC, CallSite, true, I); // volatile +} + +/// markInvokeCallSite - Insert code to mark the call_site for this invoke +void SjLjEHPass::markInvokeCallSite(InvokeInst *II, int InvokeNo, + Value *CallSite, + SwitchInst *CatchSwitch) { + ConstantInt *CallSiteNoC= ConstantInt::get(Type::getInt32Ty(II->getContext()), + InvokeNo); + // The runtime comes back to the dispatcher with the call_site - 1 in + // the context. Odd, but there it is. + ConstantInt *SwitchValC = ConstantInt::get(Type::getInt32Ty(II->getContext()), + InvokeNo - 1); + + // If the unwind edge has phi nodes, split the edge. + if (isa<PHINode>(II->getUnwindDest()->begin())) { + SplitCriticalEdge(II, 1, this); + + // If there are any phi nodes left, they must have a single predecessor. + while (PHINode *PN = dyn_cast<PHINode>(II->getUnwindDest()->begin())) { + PN->replaceAllUsesWith(PN->getIncomingValue(0)); + PN->eraseFromParent(); + } + } + + // Insert the store of the call site value + insertCallSiteStore(II, InvokeNo, CallSite); + + // Record the call site value for the back end so it stays associated with + // the invoke. + CallInst::Create(CallSiteFn, CallSiteNoC, "", II); + + // Add a switch case to our unwind block. + CatchSwitch->addCase(SwitchValC, II->getUnwindDest()); + // We still want this to look like an invoke so we emit the LSDA properly, + // so we don't transform the invoke into a call here. +} + +/// MarkBlocksLiveIn - Insert BB and all of its predescessors into LiveBBs until +/// we reach blocks we've already seen. +static void MarkBlocksLiveIn(BasicBlock *BB, std::set<BasicBlock*> &LiveBBs) { + if (!LiveBBs.insert(BB).second) return; // already been here. + + for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) + MarkBlocksLiveIn(*PI, LiveBBs); +} + +/// splitLiveRangesAcrossInvokes - Each value that is live across an unwind edge +/// we spill into a stack location, guaranteeing that there is nothing live +/// across the unwind edge. This process also splits all critical edges +/// coming out of invoke's. +/// FIXME: Move this function to a common utility file (Local.cpp?) so +/// both SjLj and LowerInvoke can use it. +void SjLjEHPass:: +splitLiveRangesAcrossInvokes(SmallVector<InvokeInst*,16> &Invokes) { + // First step, split all critical edges from invoke instructions. + for (unsigned i = 0, e = Invokes.size(); i != e; ++i) { + InvokeInst *II = Invokes[i]; + SplitCriticalEdge(II, 0, this); + SplitCriticalEdge(II, 1, this); + assert(!isa<PHINode>(II->getNormalDest()) && + !isa<PHINode>(II->getUnwindDest()) && + "critical edge splitting left single entry phi nodes?"); + } + + Function *F = Invokes.back()->getParent()->getParent(); + + // To avoid having to handle incoming arguments specially, we lower each arg + // to a copy instruction in the entry block. This ensures that the argument + // value itself cannot be live across the entry block. + BasicBlock::iterator AfterAllocaInsertPt = F->begin()->begin(); + while (isa<AllocaInst>(AfterAllocaInsertPt) && + isa<ConstantInt>(cast<AllocaInst>(AfterAllocaInsertPt)->getArraySize())) + ++AfterAllocaInsertPt; + for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end(); + AI != E; ++AI) { + const Type *Ty = AI->getType(); + // Aggregate types can't be cast, but are legal argument types, so we have + // to handle them differently. We use an extract/insert pair as a + // lightweight method to achieve the same goal. + if (isa<StructType>(Ty) || isa<ArrayType>(Ty) || isa<VectorType>(Ty)) { + Instruction *EI = ExtractValueInst::Create(AI, 0, "",AfterAllocaInsertPt); + Instruction *NI = InsertValueInst::Create(AI, EI, 0); + NI->insertAfter(EI); + AI->replaceAllUsesWith(NI); + // Set the operand of the instructions back to the AllocaInst. + EI->setOperand(0, AI); + NI->setOperand(0, AI); + } else { + // This is always a no-op cast because we're casting AI to AI->getType() + // so src and destination types are identical. BitCast is the only + // possibility. + CastInst *NC = new BitCastInst( + AI, AI->getType(), AI->getName()+".tmp", AfterAllocaInsertPt); + AI->replaceAllUsesWith(NC); + // Set the operand of the cast instruction back to the AllocaInst. + // Normally it's forbidden to replace a CastInst's operand because it + // could cause the opcode to reflect an illegal conversion. However, + // we're replacing it here with the same value it was constructed with. + // We do this because the above replaceAllUsesWith() clobbered the + // operand, but we want this one to remain. + NC->setOperand(0, AI); + } + } + + // Finally, scan the code looking for instructions with bad live ranges. + for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) + for (BasicBlock::iterator II = BB->begin(), E = BB->end(); II != E; ++II) { + // Ignore obvious cases we don't have to handle. In particular, most + // instructions either have no uses or only have a single use inside the + // current block. Ignore them quickly. + Instruction *Inst = II; + if (Inst->use_empty()) continue; + if (Inst->hasOneUse() && + cast<Instruction>(Inst->use_back())->getParent() == BB && + !isa<PHINode>(Inst->use_back())) continue; + + // If this is an alloca in the entry block, it's not a real register + // value. + if (AllocaInst *AI = dyn_cast<AllocaInst>(Inst)) + if (isa<ConstantInt>(AI->getArraySize()) && BB == F->begin()) + continue; + + // Avoid iterator invalidation by copying users to a temporary vector. + SmallVector<Instruction*,16> Users; + for (Value::use_iterator UI = Inst->use_begin(), E = Inst->use_end(); + UI != E; ++UI) { + Instruction *User = cast<Instruction>(*UI); + if (User->getParent() != BB || isa<PHINode>(User)) + Users.push_back(User); + } + + // Find all of the blocks that this value is live in. + std::set<BasicBlock*> LiveBBs; + LiveBBs.insert(Inst->getParent()); + while (!Users.empty()) { + Instruction *U = Users.back(); + Users.pop_back(); + + if (!isa<PHINode>(U)) { + MarkBlocksLiveIn(U->getParent(), LiveBBs); + } else { + // Uses for a PHI node occur in their predecessor block. + PHINode *PN = cast<PHINode>(U); + for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) + if (PN->getIncomingValue(i) == Inst) + MarkBlocksLiveIn(PN->getIncomingBlock(i), LiveBBs); + } + } + + // Now that we know all of the blocks that this thing is live in, see if + // it includes any of the unwind locations. + bool NeedsSpill = false; + for (unsigned i = 0, e = Invokes.size(); i != e; ++i) { + BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest(); + if (UnwindBlock != BB && LiveBBs.count(UnwindBlock)) { + NeedsSpill = true; + } + } + + // If we decided we need a spill, do it. + // FIXME: Spilling this way is overkill, as it forces all uses of + // the value to be reloaded from the stack slot, even those that aren't + // in the unwind blocks. We should be more selective. + if (NeedsSpill) { + ++NumSpilled; + DemoteRegToStack(*Inst, true); + } + } +} + +bool SjLjEHPass::insertSjLjEHSupport(Function &F) { + SmallVector<ReturnInst*,16> Returns; + SmallVector<UnwindInst*,16> Unwinds; + SmallVector<InvokeInst*,16> Invokes; + + // Look through the terminators of the basic blocks to find invokes, returns + // and unwinds. + for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { + if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) { + // Remember all return instructions in case we insert an invoke into this + // function. + Returns.push_back(RI); + } else if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) { + Invokes.push_back(II); + } else if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) { + Unwinds.push_back(UI); + } + } + + NumInvokes += Invokes.size(); + NumUnwinds += Unwinds.size(); + + // If we don't have any invokes, there's nothing to do. + if (Invokes.empty()) return false; + + // Find the eh.selector.*, eh.exception and alloca calls. + // + // Remember any allocas() that aren't in the entry block, as the + // jmpbuf saved SP will need to be updated for them. + // + // We'll use the first eh.selector to determine the right personality + // function to use. For SJLJ, we always use the same personality for the + // whole function, not on a per-selector basis. + // FIXME: That's a bit ugly. Better way? + SmallVector<CallInst*,16> EH_Selectors; + SmallVector<CallInst*,16> EH_Exceptions; + SmallVector<Instruction*,16> JmpbufUpdatePoints; + + // Note: Skip the entry block since there's nothing there that interests + // us. eh.selector and eh.exception shouldn't ever be there, and we + // want to disregard any allocas that are there. + for (Function::iterator BB = F.begin(), E = F.end(); ++BB != E;) { + for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { + if (CallInst *CI = dyn_cast<CallInst>(I)) { + if (CI->getCalledFunction() == SelectorFn) { + if (!PersonalityFn) PersonalityFn = CI->getArgOperand(1); + EH_Selectors.push_back(CI); + } else if (CI->getCalledFunction() == ExceptionFn) { + EH_Exceptions.push_back(CI); + } else if (CI->getCalledFunction() == StackRestoreFn) { + JmpbufUpdatePoints.push_back(CI); + } + } else if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) { + JmpbufUpdatePoints.push_back(AI); + } + } + } + + // If we don't have any eh.selector calls, we can't determine the personality + // function. Without a personality function, we can't process exceptions. + if (!PersonalityFn) return false; + + // We have invokes, so we need to add register/unregister calls to get this + // function onto the global unwind stack. + // + // First thing we need to do is scan the whole function for values that are + // live across unwind edges. Each value that is live across an unwind edge we + // spill into a stack location, guaranteeing that there is nothing live across + // the unwind edge. This process also splits all critical edges coming out of + // invoke's. + splitLiveRangesAcrossInvokes(Invokes); + + BasicBlock *EntryBB = F.begin(); + // Create an alloca for the incoming jump buffer ptr and the new jump buffer + // that needs to be restored on all exits from the function. This is an + // alloca because the value needs to be added to the global context list. + unsigned Align = 4; // FIXME: Should be a TLI check? + AllocaInst *FunctionContext = + new AllocaInst(FunctionContextTy, 0, Align, + "fcn_context", F.begin()->begin()); + + Value *Idxs[2]; + const Type *Int32Ty = Type::getInt32Ty(F.getContext()); + Value *Zero = ConstantInt::get(Int32Ty, 0); + // We need to also keep around a reference to the call_site field + Idxs[0] = Zero; + Idxs[1] = ConstantInt::get(Int32Ty, 1); + CallSite = GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2, + "call_site", + EntryBB->getTerminator()); + + // The exception selector comes back in context->data[1] + Idxs[1] = ConstantInt::get(Int32Ty, 2); + Value *FCData = GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2, + "fc_data", + EntryBB->getTerminator()); + Idxs[1] = ConstantInt::get(Int32Ty, 1); + Value *SelectorAddr = GetElementPtrInst::Create(FCData, Idxs, Idxs+2, + "exc_selector_gep", + EntryBB->getTerminator()); + // The exception value comes back in context->data[0] + Idxs[1] = Zero; + Value *ExceptionAddr = GetElementPtrInst::Create(FCData, Idxs, Idxs+2, + "exception_gep", + EntryBB->getTerminator()); + + // The result of the eh.selector call will be replaced with a a reference to + // the selector value returned in the function context. We leave the selector + // itself so the EH analysis later can use it. + for (int i = 0, e = EH_Selectors.size(); i < e; ++i) { + CallInst *I = EH_Selectors[i]; + Value *SelectorVal = new LoadInst(SelectorAddr, "select_val", true, I); + I->replaceAllUsesWith(SelectorVal); + } + + // eh.exception calls are replaced with references to the proper location in + // the context. Unlike eh.selector, the eh.exception calls are removed + // entirely. + for (int i = 0, e = EH_Exceptions.size(); i < e; ++i) { + CallInst *I = EH_Exceptions[i]; + // Possible for there to be duplicates, so check to make sure the + // instruction hasn't already been removed. + if (!I->getParent()) continue; + Value *Val = new LoadInst(ExceptionAddr, "exception", true, I); + const Type *Ty = Type::getInt8PtrTy(F.getContext()); + Val = CastInst::Create(Instruction::IntToPtr, Val, Ty, "", I); + + I->replaceAllUsesWith(Val); + I->eraseFromParent(); + } + + // The entry block changes to have the eh.sjlj.setjmp, with a conditional + // branch to a dispatch block for non-zero returns. If we return normally, + // we're not handling an exception and just register the function context and + // continue. + + // Create the dispatch block. The dispatch block is basically a big switch + // statement that goes to all of the invoke landing pads. + BasicBlock *DispatchBlock = + BasicBlock::Create(F.getContext(), "eh.sjlj.setjmp.catch", &F); + + // Add a call to dispatch_setup at the start of the dispatch block. This is + // expanded to any target-specific setup that needs to be done. + Value *SetupArg = + CastInst::Create(Instruction::BitCast, FunctionContext, + Type::getInt8PtrTy(F.getContext()), "", + DispatchBlock); + CallInst::Create(DispatchSetupFn, SetupArg, "", DispatchBlock); + + // Insert a load of the callsite in the dispatch block, and a switch on its + // value. By default, we go to a block that just does an unwind (which is the + // correct action for a standard call). + BasicBlock *UnwindBlock = + BasicBlock::Create(F.getContext(), "unwindbb", &F); + Unwinds.push_back(new UnwindInst(F.getContext(), UnwindBlock)); + + Value *DispatchLoad = new LoadInst(CallSite, "invoke.num", true, + DispatchBlock); + SwitchInst *DispatchSwitch = + SwitchInst::Create(DispatchLoad, UnwindBlock, Invokes.size(), + DispatchBlock); + // Split the entry block to insert the conditional branch for the setjmp. + BasicBlock *ContBlock = EntryBB->splitBasicBlock(EntryBB->getTerminator(), + "eh.sjlj.setjmp.cont"); + + // Populate the Function Context + // 1. LSDA address + // 2. Personality function address + // 3. jmpbuf (save SP, FP and call eh.sjlj.setjmp) + + // LSDA address + Idxs[0] = Zero; + Idxs[1] = ConstantInt::get(Int32Ty, 4); + Value *LSDAFieldPtr = + GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2, + "lsda_gep", + EntryBB->getTerminator()); + Value *LSDA = CallInst::Create(LSDAAddrFn, "lsda_addr", + EntryBB->getTerminator()); + new StoreInst(LSDA, LSDAFieldPtr, true, EntryBB->getTerminator()); + + Idxs[1] = ConstantInt::get(Int32Ty, 3); + Value *PersonalityFieldPtr = + GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2, + "lsda_gep", + EntryBB->getTerminator()); + new StoreInst(PersonalityFn, PersonalityFieldPtr, true, + EntryBB->getTerminator()); + + // Save the frame pointer. + Idxs[1] = ConstantInt::get(Int32Ty, 5); + Value *JBufPtr + = GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2, + "jbuf_gep", + EntryBB->getTerminator()); + Idxs[1] = ConstantInt::get(Int32Ty, 0); + Value *FramePtr = + GetElementPtrInst::Create(JBufPtr, Idxs, Idxs+2, "jbuf_fp_gep", + EntryBB->getTerminator()); + + Value *Val = CallInst::Create(FrameAddrFn, + ConstantInt::get(Int32Ty, 0), + "fp", + EntryBB->getTerminator()); + new StoreInst(Val, FramePtr, true, EntryBB->getTerminator()); + + // Save the stack pointer. + Idxs[1] = ConstantInt::get(Int32Ty, 2); + Value *StackPtr = + GetElementPtrInst::Create(JBufPtr, Idxs, Idxs+2, "jbuf_sp_gep", + EntryBB->getTerminator()); + + Val = CallInst::Create(StackAddrFn, "sp", EntryBB->getTerminator()); + new StoreInst(Val, StackPtr, true, EntryBB->getTerminator()); + + // Call the setjmp instrinsic. It fills in the rest of the jmpbuf. + Value *SetjmpArg = + CastInst::Create(Instruction::BitCast, JBufPtr, + Type::getInt8PtrTy(F.getContext()), "", + EntryBB->getTerminator()); + Value *DispatchVal = CallInst::Create(BuiltinSetjmpFn, SetjmpArg, + "dispatch", + EntryBB->getTerminator()); + // check the return value of the setjmp. non-zero goes to dispatcher. + Value *IsNormal = new ICmpInst(EntryBB->getTerminator(), + ICmpInst::ICMP_EQ, DispatchVal, Zero, + "notunwind"); + // Nuke the uncond branch. + EntryBB->getTerminator()->eraseFromParent(); + + // Put in a new condbranch in its place. + BranchInst::Create(ContBlock, DispatchBlock, IsNormal, EntryBB); + + // Register the function context and make sure it's known to not throw + CallInst *Register = + CallInst::Create(RegisterFn, FunctionContext, "", + ContBlock->getTerminator()); + Register->setDoesNotThrow(); + + // At this point, we are all set up, update the invoke instructions to mark + // their call_site values, and fill in the dispatch switch accordingly. + for (unsigned i = 0, e = Invokes.size(); i != e; ++i) + markInvokeCallSite(Invokes[i], i+1, CallSite, DispatchSwitch); + + // Mark call instructions that aren't nounwind as no-action (call_site == + // -1). Skip the entry block, as prior to then, no function context has been + // created for this function and any unexpected exceptions thrown will go + // directly to the caller's context, which is what we want anyway, so no need + // to do anything here. + for (Function::iterator BB = F.begin(), E = F.end(); ++BB != E;) { + for (BasicBlock::iterator I = BB->begin(), end = BB->end(); I != end; ++I) + if (CallInst *CI = dyn_cast<CallInst>(I)) { + // Ignore calls to the EH builtins (eh.selector, eh.exception) + Constant *Callee = CI->getCalledFunction(); + if (Callee != SelectorFn && Callee != ExceptionFn + && !CI->doesNotThrow()) + insertCallSiteStore(CI, -1, CallSite); + } + } + + // Replace all unwinds with a branch to the unwind handler. + // ??? Should this ever happen with sjlj exceptions? + for (unsigned i = 0, e = Unwinds.size(); i != e; ++i) { + BranchInst::Create(UnwindBlock, Unwinds[i]); + Unwinds[i]->eraseFromParent(); + } + + // Following any allocas not in the entry block, update the saved SP in the + // jmpbuf to the new value. + for (unsigned i = 0, e = JmpbufUpdatePoints.size(); i != e; ++i) { + Instruction *AI = JmpbufUpdatePoints[i]; + Instruction *StackAddr = CallInst::Create(StackAddrFn, "sp"); + StackAddr->insertAfter(AI); + Instruction *StoreStackAddr = new StoreInst(StackAddr, StackPtr, true); + StoreStackAddr->insertAfter(StackAddr); + } + + // Finally, for any returns from this function, if this function contains an + // invoke, add a call to unregister the function context. + for (unsigned i = 0, e = Returns.size(); i != e; ++i) + CallInst::Create(UnregisterFn, FunctionContext, "", Returns[i]); + + return true; +} + +bool SjLjEHPass::runOnFunction(Function &F) { + bool Res = insertSjLjEHSupport(F); + return Res; +} |
