diff options
Diffstat (limited to 'lib/CodeGen/SjLjEHPrepare.cpp')
| -rw-r--r-- | lib/CodeGen/SjLjEHPrepare.cpp | 64 |
1 files changed, 50 insertions, 14 deletions
diff --git a/lib/CodeGen/SjLjEHPrepare.cpp b/lib/CodeGen/SjLjEHPrepare.cpp index 059e8d6..ce50568 100644 --- a/lib/CodeGen/SjLjEHPrepare.cpp +++ b/lib/CodeGen/SjLjEHPrepare.cpp @@ -46,6 +46,8 @@ namespace { Constant *UnregisterFn; Constant *BuiltinSetjmpFn; Constant *FrameAddrFn; + Constant *StackAddrFn; + Constant *StackRestoreFn; Constant *LSDAAddrFn; Value *PersonalityFn; Constant *SelectorFn; @@ -107,6 +109,8 @@ bool SjLjEHPass::doInitialization(Module &M) { 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); @@ -294,14 +298,22 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { // If we don't have any invokes or unwinds, there's nothing to do. if (Unwinds.empty() && Invokes.empty()) return false; - // Find the eh.selector.* and eh.exception calls. 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. + // 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; - for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { + 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) { @@ -309,7 +321,11 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { 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); } } } @@ -419,7 +435,7 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { // Populate the Function Context // 1. LSDA address // 2. Personality function address - // 3. jmpbuf (save FP and call eh.sjlj.setjmp) + // 3. jmpbuf (save SP, FP and call eh.sjlj.setjmp) // LSDA address Idxs[0] = Zero; @@ -440,31 +456,41 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { new StoreInst(PersonalityFn, PersonalityFieldPtr, true, EntryBB->getTerminator()); - // Save the frame pointer. + // Save the frame pointer. Idxs[1] = ConstantInt::get(Int32Ty, 5); - Value *FieldPtr + Value *JBufPtr = 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", + 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, ElemPtr, true, EntryBB->getTerminator()); - // Call the setjmp instrinsic. It fills in the rest of the jmpbuf + 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, FieldPtr, + 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 + // check the return value of the setjmp. non-zero goes to dispatcher. Value *IsNormal = new ICmpInst(EntryBB->getTerminator(), ICmpInst::ICMP_EQ, DispatchVal, Zero, "notunwind"); @@ -509,6 +535,16 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { 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) |