void ScopeStack::jumpToStatement(std::vector<JumpTarget> &targets,
Statement *loopOrSwitchStatement) {
for (auto it = targets.rbegin(), end = targets.rend(); it != end; ++it) {
if (it->targetStatement == loopOrSwitchStatement) {
runCleanups(it->cleanupScope, it->targetBlock);
return;
}
}
assert(false && "Target for labeled break not found.");
}
void ScopeStack::jumpToLabel(Loc loc, Identifier *labelName) {
// If we have already seen that label, branch to it, executing any cleanups
// as necessary.
auto it = labelTargets.find(labelName);
if (it != labelTargets.end()) {
runCleanups(it->second.cleanupScope, it->second.targetBlock);
return;
}
llvm::BasicBlock *target = llvm::BasicBlock::Create(
irs->context(), "goto.unresolved", irs->topfunc());
irs->ir->CreateBr(target);
currentUnresolvedGotos().emplace_back(loc, irs->scopebb(), target, labelName);
}
llvm::BasicBlock *ScopeStack::emitLandingPad() {
// save and rewrite scope
IRScope savedIRScope = irs->scope();
llvm::BasicBlock *beginBB =
llvm::BasicBlock::Create(irs->context(), "landingPad", irs->topfunc());
irs->scope() = IRScope(beginBB);
llvm::LandingPadInst *landingPad = createLandingPadInst(irs);
// Stash away the exception object pointer and selector value into their
// stack slots.
llvm::Value *ehPtr = DtoExtractValue(landingPad, 0);
irs->ir->CreateStore(ehPtr, irs->func()->getOrCreateEhPtrSlot());
llvm::Value *ehSelector = DtoExtractValue(landingPad, 1);
if (!irs->func()->ehSelectorSlot) {
irs->func()->ehSelectorSlot =
DtoRawAlloca(ehSelector->getType(), 0, "eh.selector");
}
irs->ir->CreateStore(ehSelector, irs->func()->ehSelectorSlot);
// Add landingpad clauses, emit finallys and 'if' chain to catch the
// exception.
CleanupCursor lastCleanup = currentCleanupScope();
for (auto it = catchScopes.rbegin(), end = catchScopes.rend(); it != end;
++it) {
// Insert any cleanups in between the last catch we ran (i.e. tested for
// and found that the type does not match) and this one.
assert(lastCleanup >= it->cleanupScope);
if (lastCleanup > it->cleanupScope) {
landingPad->setCleanup(true);
llvm::BasicBlock *afterCleanupBB = llvm::BasicBlock::Create(
irs->context(), beginBB->getName() + llvm::Twine(".after.cleanup"),
irs->topfunc());
runCleanups(lastCleanup, it->cleanupScope, afterCleanupBB);
irs->scope() = IRScope(afterCleanupBB);
lastCleanup = it->cleanupScope;
}
// Add the ClassInfo reference to the landingpad instruction so it is
// emitted to the EH tables.
landingPad->addClause(it->classInfoPtr);
llvm::BasicBlock *mismatchBB = llvm::BasicBlock::Create(
irs->context(), beginBB->getName() + llvm::Twine(".mismatch"),
irs->topfunc());
// "Call" llvm.eh.typeid.for, which gives us the eh selector value to
// compare the landing pad selector value with.
llvm::Value *ehTypeId =
irs->ir->CreateCall(GET_INTRINSIC_DECL(eh_typeid_for),
DtoBitCast(it->classInfoPtr, getVoidPtrType()));
// Compare the selector value from the unwinder against the expected
// one and branch accordingly.
irs->ir->CreateCondBr(
irs->ir->CreateICmpEQ(irs->ir->CreateLoad(irs->func()->ehSelectorSlot),
ehTypeId),
it->bodyBlock, mismatchBB);
irs->scope() = IRScope(mismatchBB);
}
// No catch matched. Execute all finallys and resume unwinding.
if (lastCleanup > 0) {
landingPad->setCleanup(true);
runCleanups(lastCleanup, 0, irs->func()->getOrCreateResumeUnwindBlock());
} else if (!catchScopes.empty()) {
// Directly convert the last mismatch branch into a branch to the
// unwind resume block.
irs->scopebb()->replaceAllUsesWith(
irs->func()->getOrCreateResumeUnwindBlock());
irs->scopebb()->eraseFromParent();
} else {
irs->ir->CreateBr(irs->func()->getOrCreateResumeUnwindBlock());
}
irs->scope() = savedIRScope;
return beginBB;
}
void ScopeStack::jumpToClosest(std::vector<JumpTarget> &targets) {
assert(!targets.empty() &&
"Encountered break/continue but no loop in scope.");
JumpTarget &t = targets.back();
runCleanups(t.cleanupScope, t.targetBlock);
}
void ScopeStack::runAllCleanups(llvm::BasicBlock *continueWith) {
runCleanups(0, continueWith);
}
llvm::BasicBlock *TryCatchFinallyScopes::emitLandingPad() {
#if LDC_LLVM_VER >= 308
if (useMSVCEH()) {
assert(currentCleanupScope() > 0);
return emitLandingPadMSVC(currentCleanupScope() - 1);
}
#endif
// save and rewrite scope
IRScope savedIRScope = irs.scope();
// insert landing pads at the end of the function, in emission order,
// to improve human-readability of the IR
llvm::BasicBlock *beginBB = irs.insertBBBefore(nullptr, "landingPad");
irs.scope() = IRScope(beginBB);
llvm::LandingPadInst *landingPad = createLandingPadInst(irs);
// Stash away the exception object pointer and selector value into their
// stack slots.
llvm::Value *ehPtr = DtoExtractValue(landingPad, 0);
irs.ir->CreateStore(ehPtr, getOrCreateEhPtrSlot());
llvm::Value *ehSelector = DtoExtractValue(landingPad, 1);
if (!ehSelectorSlot)
ehSelectorSlot = DtoRawAlloca(ehSelector->getType(), 0, "eh.selector");
irs.ir->CreateStore(ehSelector, ehSelectorSlot);
// Add landingpad clauses, emit finallys and 'if' chain to catch the
// exception.
CleanupCursor lastCleanup = currentCleanupScope();
for (auto it = tryCatchScopes.rbegin(), end = tryCatchScopes.rend();
it != end; ++it) {
const auto &tryCatchScope = *it;
// Insert any cleanups in between the previous (inner-more) try-catch scope
// and this one.
const auto newCleanup = tryCatchScope.getCleanupScope();
assert(lastCleanup >= newCleanup);
if (lastCleanup > newCleanup) {
landingPad->setCleanup(true);
llvm::BasicBlock *afterCleanupBB =
irs.insertBB(beginBB->getName() + llvm::Twine(".after.cleanup"));
runCleanups(lastCleanup, newCleanup, afterCleanupBB);
irs.scope() = IRScope(afterCleanupBB);
lastCleanup = newCleanup;
}
for (const auto &cb : tryCatchScope.getCatchBlocks()) {
// Add the ClassInfo reference to the landingpad instruction so it is
// emitted to the EH tables.
landingPad->addClause(cb.classInfoPtr);
llvm::BasicBlock *mismatchBB =
irs.insertBB(beginBB->getName() + llvm::Twine(".mismatch"));
// "Call" llvm.eh.typeid.for, which gives us the eh selector value to
// compare the landing pad selector value with.
llvm::Value *ehTypeId =
irs.ir->CreateCall(GET_INTRINSIC_DECL(eh_typeid_for),
DtoBitCast(cb.classInfoPtr, getVoidPtrType()));
// Compare the selector value from the unwinder against the expected
// one and branch accordingly.
irs.ir->CreateCondBr(
irs.ir->CreateICmpEQ(irs.ir->CreateLoad(ehSelectorSlot), ehTypeId),
cb.bodyBB, mismatchBB, cb.branchWeights);
irs.scope() = IRScope(mismatchBB);
}
}
// No catch matched. Execute all finallys and resume unwinding.
auto resumeUnwindBlock = getOrCreateResumeUnwindBlock();
if (lastCleanup > 0) {
landingPad->setCleanup(true);
runCleanups(lastCleanup, 0, resumeUnwindBlock);
} else if (!tryCatchScopes.empty()) {
// Directly convert the last mismatch branch into a branch to the
// unwind resume block.
irs.scopebb()->replaceAllUsesWith(resumeUnwindBlock);
irs.scopebb()->eraseFromParent();
} else {
irs.ir->CreateBr(resumeUnwindBlock);
}
irs.scope() = savedIRScope;
return beginBB;
}
void TryCatchFinallyScopes::runCleanups(CleanupCursor targetScope,
llvm::BasicBlock *continueWith) {
runCleanups(currentCleanupScope(), targetScope, continueWith);
}
