X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FSjLjEHPrepare.cpp;h=65a33da93afe7cb3d5bd44024ba3d10b3f1dc095;hb=7332e6ee25378e19c0f621c80c32b283b07f428a;hp=91a85c07196ce76f397d73216e80bfee41d8b0fe;hpb=8fc3b6903ac555e21d6c64c34f9815781e68c88b;p=oota-llvm.git diff --git a/lib/CodeGen/SjLjEHPrepare.cpp b/lib/CodeGen/SjLjEHPrepare.cpp index 91a85c07196..65a33da93af 100644 --- a/lib/CodeGen/SjLjEHPrepare.cpp +++ b/lib/CodeGen/SjLjEHPrepare.cpp @@ -21,17 +21,14 @@ #include "llvm/LLVMContext.h" #include "llvm/Module.h" #include "llvm/Pass.h" -#include "llvm/CodeGen/Passes.h" -#include "llvm/Transforms/Utils/BasicBlockUtils.h" -#include "llvm/Transforms/Utils/Local.h" -#include "llvm/ADT/DenseMap.h" -#include "llvm/ADT/Statistic.h" #include "llvm/ADT/SmallVector.h" -#include "llvm/Support/CommandLine.h" -#include "llvm/Support/Compiler.h" +#include "llvm/ADT/Statistic.h" +#include "llvm/CodeGen/Passes.h" #include "llvm/Support/Debug.h" -#include "llvm/Support/raw_ostream.h" #include "llvm/Target/TargetLowering.h" +#include "llvm/Transforms/Utils/BasicBlockUtils.h" +#include "llvm/Transforms/Utils/Local.h" +#include using namespace llvm; STATISTIC(NumInvokes, "Number of invokes replaced"); @@ -39,27 +36,29 @@ STATISTIC(NumUnwinds, "Number of unwinds replaced"); STATISTIC(NumSpilled, "Number of registers live across unwind edges"); namespace { - class VISIBILITY_HIDDEN SjLjEHPass : public FunctionPass { + class SjLjEHPass : public FunctionPass { const TargetLowering *TLI; const Type *FunctionContextTy; Constant *RegisterFn; Constant *UnregisterFn; - Constant *ResumeFn; Constant *BuiltinSetjmpFn; Constant *FrameAddrFn; + Constant *StackAddrFn; + Constant *StackRestoreFn; Constant *LSDAAddrFn; Value *PersonalityFn; - Constant *Selector32Fn; - Constant *Selector64Fn; + 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) { } + : FunctionPass(ID), TLI(tli) { } bool doInitialization(Module &M); bool runOnFunction(Function &F); @@ -69,9 +68,10 @@ namespace { } private: - void markInvokeCallSite(InvokeInst *II, unsigned InvokeNo, - Value *CallSite); - void splitLiveRangesLiveAcrossInvokes(SmallVector &Invokes); + void insertCallSiteStore(Instruction *I, int Number, Value *CallSite); + void markInvokeCallSite(InvokeInst *II, int InvokeNo, Value *CallSite, + SwitchInst *CatchSwitch); + void splitLiveRangesAcrossInvokes(SmallVector &Invokes); bool insertSjLjEHSupport(Function &F); }; } // end anonymous namespace @@ -82,17 +82,15 @@ char SjLjEHPass::ID = 0; FunctionPass *llvm::createSjLjEHPass(const TargetLowering *TLI) { return new SjLjEHPass(TLI); } -// doInitialization - Make sure that there is a prototype for abort in the -// current module. +// 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 = - PointerType::getUnqual(Type::getInt8Ty(M.getContext())); - const Type *Int32Ty = Type::getInt32Ty(M.getContext()); + Type *VoidPtrTy = Type::getInt8PtrTy(M.getContext()); + Type *Int32Ty = Type::getInt32Ty(M.getContext()); FunctionContextTy = - StructType::get(M.getContext(), - VoidPtrTy, // __prev + StructType::get(VoidPtrTy, // __prev Int32Ty, // call_site ArrayType::get(Int32Ty, 4), // __data VoidPtrTy, // __personality @@ -108,26 +106,41 @@ bool SjLjEHPass::doInitialization(Module &M) { Type::getVoidTy(M.getContext()), PointerType::getUnqual(FunctionContextTy), (Type *)0); - ResumeFn = - M.getOrInsertFunction("_Unwind_SjLj_Resume", - Type::getVoidTy(M.getContext()), - VoidPtrTy, - (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); - Selector32Fn = Intrinsic::getDeclaration(&M, Intrinsic::eh_selector_i32); - Selector64Fn = Intrinsic::getDeclaration(&M, Intrinsic::eh_selector_i64); + 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, unsigned InvokeNo, - Value *CallSite) { +void SjLjEHPass::markInvokeCallSite(InvokeInst *II, int InvokeNo, + Value *CallSite, + SwitchInst *CatchSwitch) { ConstantInt *CallSiteNoC= ConstantInt::get(Type::getInt32Ty(II->getContext()), - InvokeNo); + 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(II->getUnwindDest()->begin())) { @@ -140,13 +153,17 @@ void SjLjEHPass::markInvokeCallSite(InvokeInst *II, unsigned InvokeNo, } } - // Insert a store of the invoke num before the invoke and store zero into the - // location afterward. - new StoreInst(CallSiteNoC, CallSite, true, II); // volatile + // 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); - // We still want this to look like an invoke so we emit the LSDA properly - // FIXME: ??? Or will this cause strangeness with mis-matched IDs like - // when it was in the front end? + // 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 @@ -162,8 +179,10 @@ static void MarkBlocksLiveIn(BasicBlock *BB, std::set &LiveBBs) { /// 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:: -splitLiveRangesLiveAcrossInvokes(SmallVector &Invokes) { +splitLiveRangesAcrossInvokes(SmallVector &Invokes) { // First step, split all critical edges from invoke instructions. for (unsigned i = 0, e = Invokes.size(); i != e; ++i) { InvokeInst *II = Invokes[i]; @@ -185,16 +204,33 @@ splitLiveRangesLiveAcrossInvokes(SmallVector &Invokes) { ++AfterAllocaInsertPt; for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end(); AI != E; ++AI) { - // 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); - // Normally its is 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 to simply - // make NC its user. - NC->setOperand(0, 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(Ty) || isa(Ty) || isa(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. @@ -253,6 +289,9 @@ splitLiveRangesLiveAcrossInvokes(SmallVector &Invokes) { } // 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); @@ -266,8 +305,8 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { SmallVector 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) + // and unwinds. + for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { if (ReturnInst *RI = dyn_cast(BB->getTerminator())) { // Remember all return instructions in case we insert an invoke into this // function. @@ -277,253 +316,269 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { } else if (UnwindInst *UI = dyn_cast(BB->getTerminator())) { Unwinds.push_back(UI); } - // If we don't have any invokes or unwinds, there's nothing to do. - if (Unwinds.empty() && Invokes.empty()) return false; + } NumInvokes += Invokes.size(); NumUnwinds += Unwinds.size(); - - if (!Invokes.empty()) { - // We have invokes, so we need to add register/unregister calls to get - // this function onto the global unwind stack. - - 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()); - - // Find the eh.selector.* and eh.exception calls. We'll use the first - // ex.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 EH_Selectors; - SmallVector EH_Exceptions; - for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { - for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { - if (CallInst *CI = dyn_cast(I)) { - if (CI->getCalledFunction() == Selector32Fn || - CI->getCalledFunction() == Selector64Fn) { - if (!PersonalityFn) PersonalityFn = CI->getOperand(2); - EH_Selectors.push_back(CI); - } else if (CI->getCalledFunction() == ExceptionFn) { - EH_Exceptions.push_back(CI); - } + // 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 EH_Selectors; + SmallVector EH_Exceptions; + SmallVector 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(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(I)) { + JmpbufUpdatePoints.push_back(AI); } } - // 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); - Type *Ty = PointerType::getUnqual(Type::getInt8Ty(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); - - // Insert a load in the Catch 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"); + // 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); + } - // Populate the Function Context - // 1. LSDA address - // 2. Personality function address - // 3. jmpbuf (save FP and call eh.sjlj.setjmp) + // 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(); + } - // 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", + // 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); + + // Insert a load of the callsite in the dispatch block, and a switch on its + // value. By default, we issue a trap statement. + BasicBlock *TrapBlock = + BasicBlock::Create(F.getContext(), "trapbb", &F); + CallInst::Create(Intrinsic::getDeclaration(F.getParent(), Intrinsic::trap), + "", TrapBlock); + new UnreachableInst(F.getContext(), TrapBlock); + + Value *DispatchLoad = new LoadInst(CallSite, "invoke.num", true, + DispatchBlock); + SwitchInst *DispatchSwitch = + SwitchInst::Create(DispatchLoad, TrapBlock, 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()); - new StoreInst(PersonalityFn, PersonalityFieldPtr, true, - EntryBB->getTerminator()); - - // Save the frame pointer. - Idxs[1] = ConstantInt::get(Int32Ty, 5); - Value *FieldPtr - = GetElementPtrInst::Create(FunctionContext, Idxs, Idxs+2, - "jbuf_gep", - EntryBB->getTerminator()); - Idxs[1] = ConstantInt::get(Int32Ty, 0); - Value *ElemPtr = - GetElementPtrInst::Create(FieldPtr, Idxs, Idxs+2, "jbuf_fp_gep", + 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()); - - Value *Val = CallInst::Create(FrameAddrFn, - ConstantInt::get(Int32Ty, 0), - "fp", - EntryBB->getTerminator()); - new StoreInst(Val, ElemPtr, true, EntryBB->getTerminator()); - // Call the setjmp instrinsic. It fills in the rest of the jmpbuf - Value *SetjmpArg = - CastInst::Create(Instruction::BitCast, FieldPtr, - Type::getInt8Ty(F.getContext())->getPointerTo(), "", - 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. - DenseMap PadSites; - unsigned NextCallSiteValue = 1; - for (SmallVector::iterator I = Invokes.begin(), - E = Invokes.end(); I < E; ++I) { - unsigned CallSiteValue; - BasicBlock *LandingPad = (*I)->getSuccessor(1); - // landing pads can be shared. If we see a landing pad again, we - // want to make sure to use the same call site index so the dispatch - // will go to the right place. - CallSiteValue = PadSites[LandingPad]; - if (!CallSiteValue) { - CallSiteValue = NextCallSiteValue++; - PadSites[LandingPad] = CallSiteValue; - // Add a switch case to our unwind block. 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((*I)->getContext()), - CallSiteValue - 1); - DispatchSwitch->addCase(SwitchValC, (*I)->getUnwindDest()); - } - markInvokeCallSite(*I, CallSiteValue, CallSite); - } - - // The front end has likely added calls to _Unwind_Resume. We need - // to find those calls and mark the call_site as -1 immediately prior. - // resume is a noreturn function, so any block that has a call to it - // should end in an 'unreachable' instruction with the call immediately - // prior. That's how we'll search. - // ??? There's got to be a better way. this is fugly. - for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) - if ((dyn_cast(BB->getTerminator()))) { - BasicBlock::iterator I = BB->getTerminator(); - // Check the previous instruction and see if it's a resume call - if (I == BB->begin()) continue; - if (CallInst *CI = dyn_cast(--I)) { - if (CI->getCalledFunction() == ResumeFn) { - Value *NegativeOne = Constant::getAllOnesValue(Int32Ty); - new StoreInst(NegativeOne, CallSite, true, I); // volatile - } - } + 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()); + + // Add a call to dispatch_setup after the setjmp call. This is expanded to any + // target-specific setup that needs to be done. + CallInst::Create(DispatchSetupFn, DispatchVal, "", 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(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(); - } + // 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(TrapBlock, Unwinds[i]); + Unwinds[i]->eraseFromParent(); + } - // 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. - splitLiveRangesLiveAcrossInvokes(Invokes); - - // 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]); + // 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; }