diff options
Diffstat (limited to 'lib/CodeGen/SjLjEHPrepare.cpp')
| -rw-r--r-- | lib/CodeGen/SjLjEHPrepare.cpp | 67 |
1 files changed, 36 insertions, 31 deletions
diff --git a/lib/CodeGen/SjLjEHPrepare.cpp b/lib/CodeGen/SjLjEHPrepare.cpp index 8d4d1b2..059e8d6 100644 --- a/lib/CodeGen/SjLjEHPrepare.cpp +++ b/lib/CodeGen/SjLjEHPrepare.cpp @@ -44,7 +44,6 @@ namespace { const Type *FunctionContextTy; Constant *RegisterFn; Constant *UnregisterFn; - Constant *ResumeFn; Constant *BuiltinSetjmpFn; Constant *FrameAddrFn; Constant *LSDAAddrFn; @@ -67,8 +66,8 @@ namespace { } private: - void markInvokeCallSite(InvokeInst *II, unsigned InvokeNo, - Value *CallSite, + void insertCallSiteStore(Instruction *I, int Number, Value *CallSite); + void markInvokeCallSite(InvokeInst *II, int InvokeNo, Value *CallSite, SwitchInst *CatchSwitch); void splitLiveRangesLiveAcrossInvokes(SmallVector<InvokeInst*,16> &Invokes); bool insertSjLjEHSupport(Function &F); @@ -107,11 +106,6 @@ 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); BuiltinSetjmpFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_setjmp); LSDAAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_lsda); @@ -123,12 +117,22 @@ bool SjLjEHPass::doInitialization(Module &M) { 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, +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()), @@ -145,8 +149,11 @@ void SjLjEHPass::markInvokeCallSite(InvokeInst *II, unsigned InvokeNo, } } - // Insert a store of the invoke num before the invoke - 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); // Add a switch case to our unwind block. @@ -272,8 +279,8 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { 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) + // 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. @@ -283,6 +290,7 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { } else if (UnwindInst *UI = dyn_cast<UnwindInst>(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; @@ -478,24 +486,21 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { for (unsigned i = 0, e = Invokes.size(); i != e; ++i) markInvokeCallSite(Invokes[i], i+1, CallSite, DispatchSwitch); - // 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<UnreachableInst>(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<CallInst>(--I)) { - if (CI->getCalledFunction() == ResumeFn) { - Value *NegativeOne = Constant::getAllOnesValue(Int32Ty); - new StoreInst(NegativeOne, CallSite, true, I); // volatile - } + // 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? |