/// AddLandingPadInfo - Extract the exception handling information from the
/// landingpad instruction and add them to the specified machine module info.
void llvm::AddLandingPadInfo(const LandingPadInst &I, MachineModuleInfo &MMI,
MachineBasicBlock *MBB) {
if (const auto *PF = dyn_cast<Function>(
I.getParent()->getParent()->getPersonalityFn()->stripPointerCasts()))
MMI.addPersonality(PF);
if (I.isCleanup())
MMI.addCleanup(MBB);
// FIXME: New EH - Add the clauses in reverse order. This isn't 100% correct,
// but we need to do it this way because of how the DWARF EH emitter
// processes the clauses.
for (unsigned i = I.getNumClauses(); i != 0; --i) {
Value *Val = I.getClause(i - 1);
if (I.isCatch(i - 1)) {
MMI.addCatchTypeInfo(MBB,
dyn_cast<GlobalValue>(Val->stripPointerCasts()));
} else {
// Add filters in a list.
Constant *CVal = cast<Constant>(Val);
SmallVector<const GlobalValue*, 4> FilterList;
for (User::op_iterator
II = CVal->op_begin(), IE = CVal->op_end(); II != IE; ++II)
FilterList.push_back(cast<GlobalValue>((*II)->stripPointerCasts()));
MMI.addFilterTypeInfo(MBB, FilterList);
}
}
}
/// setupFunctionContext - Allocate the function context on the stack and fill
/// it with all of the data that we know at this point.
Value *SjLjEHPrepare::setupFunctionContext(Function &F,
ArrayRef<LandingPadInst *> LPads) {
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.
const TargetLowering *TLI = TM->getTargetLowering();
unsigned Align =
TLI->getDataLayout()->getPrefTypeAlignment(FunctionContextTy);
FuncCtx = new AllocaInst(FunctionContextTy, nullptr, Align, "fn_context",
EntryBB->begin());
// Fill in the function context structure.
for (unsigned I = 0, E = LPads.size(); I != E; ++I) {
LandingPadInst *LPI = LPads[I];
IRBuilder<> Builder(LPI->getParent()->getFirstInsertionPt());
// Reference the __data field.
Value *FCData = Builder.CreateConstGEP2_32(FuncCtx, 0, 2, "__data");
// The exception values come back in context->__data[0].
Value *ExceptionAddr =
Builder.CreateConstGEP2_32(FCData, 0, 0, "exception_gep");
Value *ExnVal = Builder.CreateLoad(ExceptionAddr, true, "exn_val");
ExnVal = Builder.CreateIntToPtr(ExnVal, Builder.getInt8PtrTy());
Value *SelectorAddr =
Builder.CreateConstGEP2_32(FCData, 0, 1, "exn_selector_gep");
Value *SelVal = Builder.CreateLoad(SelectorAddr, true, "exn_selector_val");
substituteLPadValues(LPI, ExnVal, SelVal);
}
// Personality function
IRBuilder<> Builder(EntryBB->getTerminator());
if (!PersonalityFn)
PersonalityFn = LPads[0]->getPersonalityFn();
Value *PersonalityFieldPtr =
Builder.CreateConstGEP2_32(FuncCtx, 0, 3, "pers_fn_gep");
Builder.CreateStore(
Builder.CreateBitCast(PersonalityFn, Builder.getInt8PtrTy()),
PersonalityFieldPtr, /*isVolatile=*/true);
// LSDA address
Value *LSDA = Builder.CreateCall(LSDAAddrFn, "lsda_addr");
Value *LSDAFieldPtr = Builder.CreateConstGEP2_32(FuncCtx, 0, 4, "lsda_gep");
Builder.CreateStore(LSDA, LSDAFieldPtr, /*isVolatile=*/true);
return FuncCtx;
}
/// setupFunctionContext - Allocate the function context on the stack and fill
/// it with all of the data that we know at this point.
Value *SjLjEHPass::
setupFunctionContext(Function &F, ArrayRef<LandingPadInst*> LPads) {
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 =
TLI->getTargetData()->getPrefTypeAlignment(FunctionContextTy);
FuncCtx =
new AllocaInst(FunctionContextTy, 0, Align, "fn_context", EntryBB->begin());
// Fill in the function context structure.
Type *Int32Ty = Type::getInt32Ty(F.getContext());
Value *Zero = ConstantInt::get(Int32Ty, 0);
Value *One = ConstantInt::get(Int32Ty, 1);
Value *Two = ConstantInt::get(Int32Ty, 2);
Value *Three = ConstantInt::get(Int32Ty, 3);
Value *Four = ConstantInt::get(Int32Ty, 4);
Value *Idxs[2] = { Zero, 0 };
for (unsigned I = 0, E = LPads.size(); I != E; ++I) {
LandingPadInst *LPI = LPads[I];
IRBuilder<> Builder(LPI->getParent()->getFirstInsertionPt());
// Reference the __data field.
Idxs[1] = Two;
Value *FCData = Builder.CreateGEP(FuncCtx, Idxs, "__data");
// The exception values come back in context->__data[0].
Idxs[1] = Zero;
Value *ExceptionAddr = Builder.CreateGEP(FCData, Idxs, "exception_gep");
Value *ExnVal = Builder.CreateLoad(ExceptionAddr, true, "exn_val");
ExnVal = Builder.CreateIntToPtr(ExnVal, Type::getInt8PtrTy(F.getContext()));
Idxs[1] = One;
Value *SelectorAddr = Builder.CreateGEP(FCData, Idxs, "exn_selector_gep");
Value *SelVal = Builder.CreateLoad(SelectorAddr, true, "exn_selector_val");
substituteLPadValues(LPI, ExnVal, SelVal);
}
// Personality function
Idxs[1] = Three;
if (!PersonalityFn)
PersonalityFn = LPads[0]->getPersonalityFn();
Value *PersonalityFieldPtr =
GetElementPtrInst::Create(FuncCtx, Idxs, "pers_fn_gep",
EntryBB->getTerminator());
new StoreInst(PersonalityFn, PersonalityFieldPtr, true,
EntryBB->getTerminator());
// LSDA address
Value *LSDA = CallInst::Create(LSDAAddrFn, "lsda_addr",
EntryBB->getTerminator());
Idxs[1] = Four;
Value *LSDAFieldPtr = GetElementPtrInst::Create(FuncCtx, Idxs, "lsda_gep",
EntryBB->getTerminator());
new StoreInst(LSDA, LSDAFieldPtr, true, EntryBB->getTerminator());
return FuncCtx;
}
