void CGObjCRuntime::EmitTryCatchStmt(CodeGenFunction &CGF,
const ObjCAtTryStmt &S,
llvm::Constant *beginCatchFn,
llvm::Constant *endCatchFn,
llvm::Constant *exceptionRethrowFn) {
// Jump destination for falling out of catch bodies.
CodeGenFunction::JumpDest Cont;
if (S.getNumCatchStmts())
Cont = CGF.getJumpDestInCurrentScope("eh.cont");
CodeGenFunction::FinallyInfo FinallyInfo;
if (const ObjCAtFinallyStmt *Finally = S.getFinallyStmt())
FinallyInfo.enter(CGF, Finally->getFinallyBody(),
beginCatchFn, endCatchFn, exceptionRethrowFn);
SmallVector<CatchHandler, 8> Handlers;
// Enter the catch, if there is one.
if (S.getNumCatchStmts()) {
for (unsigned I = 0, N = S.getNumCatchStmts(); I != N; ++I) {
const ObjCAtCatchStmt *CatchStmt = S.getCatchStmt(I);
const VarDecl *CatchDecl = CatchStmt->getCatchParamDecl();
Handlers.push_back(CatchHandler());
CatchHandler &Handler = Handlers.back();
Handler.Variable = CatchDecl;
Handler.Body = CatchStmt->getCatchBody();
Handler.Block = CGF.createBasicBlock("catch");
// @catch(...) always matches.
if (!CatchDecl) {
Handler.TypeInfo = nullptr; // catch-all
// Don't consider any other catches.
break;
}
Handler.TypeInfo = GetEHType(CatchDecl->getType());
}
EHCatchScope *Catch = CGF.EHStack.pushCatch(Handlers.size());
for (unsigned I = 0, E = Handlers.size(); I != E; ++I)
Catch->setHandler(I, Handlers[I].TypeInfo, Handlers[I].Block);
}
// Emit the try body.
CGF.EmitStmt(S.getTryBody());
// Leave the try.
if (S.getNumCatchStmts())
CGF.popCatchScope();
// Remember where we were.
CGBuilderTy::InsertPoint SavedIP = CGF.Builder.saveAndClearIP();
// Emit the handlers.
for (unsigned I = 0, E = Handlers.size(); I != E; ++I) {
CatchHandler &Handler = Handlers[I];
CGF.EmitBlock(Handler.Block);
llvm::Value *RawExn = CGF.getExceptionFromSlot();
// Enter the catch.
llvm::Value *Exn = RawExn;
if (beginCatchFn)
Exn = CGF.EmitNounwindRuntimeCall(beginCatchFn, RawExn, "exn.adjusted");
CodeGenFunction::LexicalScope cleanups(CGF, Handler.Body->getSourceRange());
if (endCatchFn) {
// Add a cleanup to leave the catch.
bool EndCatchMightThrow = (Handler.Variable == nullptr);
CGF.EHStack.pushCleanup<CallObjCEndCatch>(NormalAndEHCleanup,
EndCatchMightThrow,
endCatchFn);
}
// Bind the catch parameter if it exists.
if (const VarDecl *CatchParam = Handler.Variable) {
llvm::Type *CatchType = CGF.ConvertType(CatchParam->getType());
llvm::Value *CastExn = CGF.Builder.CreateBitCast(Exn, CatchType);
CGF.EmitAutoVarDecl(*CatchParam);
EmitInitOfCatchParam(CGF, CastExn, CatchParam);
}
CGF.ObjCEHValueStack.push_back(Exn);
CGF.EmitStmt(Handler.Body);
CGF.ObjCEHValueStack.pop_back();
// Leave any cleanups associated with the catch.
cleanups.ForceCleanup();
CGF.EmitBranchThroughCleanup(Cont);
}
// Go back to the try-statement fallthrough.
CGF.Builder.restoreIP(SavedIP);
// Pop out of the finally.
if (S.getFinallyStmt())
FinallyInfo.exit(CGF);
if (Cont.isValid())
CGF.EmitBlock(Cont.getBlock());
}
