Function try_call

cranelift/frontend/src/frontend.rs:1947–2032

()

    #[test]
    fn try_call() {
        let mut sig = Signature::new(CallConv::SystemV);
        sig.params.push(AbiParam::new(I8));
        sig.returns.push(AbiParam::new(I32));
        let mut fn_ctx = FunctionBuilderContext::new();
        let mut func = Function::with_name_signature(UserFuncName::testcase("sample"), sig);

        let sig0 = func.import_signature(Signature::new(CallConv::SystemV));
        let name = func.declare_imported_user_function(UserExternalName::new(0, 0));
        let fn0 = func.import_function(ExtFuncData {
            name: ExternalName::User(name),
            signature: sig0,
            colocated: false,
            patchable: false,
        });

        let mut builder = FunctionBuilder::new(&mut func, &mut fn_ctx);

        let block0 = builder.create_block();
        let block1 = builder.create_block();
        let block2 = builder.create_block();
        let block3 = builder.create_block();

        let my_var = builder.declare_var(I32);

        builder.switch_to_block(block0);
        let branch_val = builder.append_block_param(block0, I8);
        builder.ins().brif(branch_val, block1, &[], block2, &[]);

        builder.switch_to_block(block1);
        let one = builder.ins().iconst(I32, 1);
        builder.def_var(my_var, one);

        let normal_return = BlockCall::new(block3, [], &mut builder.func.dfg.value_lists);
        let exception_table = builder
            .func
            .dfg
            .exception_tables
            .push(ExceptionTableData::new(sig0, normal_return, []));
        builder.ins().try_call(fn0, &[], exception_table);

        builder.switch_to_block(block2);
        let two = builder.ins().iconst(I32, 2);
        builder.def_var(my_var, two);

        let normal_return = BlockCall::new(block3, [], &mut builder.func.dfg.value_lists);
        let exception_table = builder
            .func
            .dfg
            .exception_tables
            .push(ExceptionTableData::new(sig0, normal_return, []));
        builder.ins().try_call(fn0, &[], exception_table);

        builder.switch_to_block(block3);
        let ret_val = builder.use_var(my_var);
        builder.ins().return_(&[ret_val]);

        builder.seal_all_blocks();