diff --git a/src/check_expr.cpp b/src/check_expr.cpp index 67cf50a75..6ff43ecab 100644 --- a/src/check_expr.cpp +++ b/src/check_expr.cpp @@ -6263,6 +6263,34 @@ void check_try_split_types(CheckerContext *c, Operand *x, String const &name, Ty } +void check_try_expr_no_value_error(CheckerContext *c, String const &name, Operand const &x, Type *type_hint) { + // TODO(bill): better error message + gbString t = type_to_string(x.type); + error(x.expr, "'%.*s' does not return a value, value is of type %s", LIT(name), t); + if (is_type_union(type_deref(x.type))) { + Type *bsrc = base_type(type_deref(x.type)); + gbString th = nullptr; + if (type_hint != nullptr) { + GB_ASSERT(bsrc->kind == Type_Union); + for_array(i, bsrc->Union.variants) { + Type *vt = bsrc->Union.variants[i]; + if (are_types_identical(vt, type_hint)) { + th = type_to_string(type_hint); + break; + } + } + } + gbString expr_str = expr_to_string(x.expr); + if (th != nullptr) { + error_line("\tSuggestion: was a type assertion such as %s.(%s) or %s.? wanted?\n", expr_str, th, expr_str); + } else { + error_line("\tSuggestion: was a type assertion such as %s.(T) or %s.? wanted?\n", expr_str, expr_str); + } + gb_string_free(th); + gb_string_free(expr_str); + } + gb_string_free(t); +} ExprKind check_try_expr(CheckerContext *c, Operand *o, Ast *node, Type *type_hint) { String name = str_lit("try"); @@ -6288,45 +6316,49 @@ ExprKind check_try_expr(CheckerContext *c, Operand *o, Ast *node, Type *type_hin if (c->curr_proc_sig == nullptr) { error(node, "'%.*s' can only be used within a procedure", LIT(name)); } - Type *proc_type = base_type(c->curr_proc_sig); - GB_ASSERT(proc_type->kind == Type_Proc); - Type *result_type = proc_type->Proc.results; - if (result_type == nullptr) { - error(node, "'%.*s' requires the current procedure to have at least one return value", LIT(name)); + + if (right_type == nullptr) { + check_try_expr_no_value_error(c, name, x, type_hint); } else { - GB_ASSERT(result_type->kind == Type_Tuple); + Type *proc_type = base_type(c->curr_proc_sig); + GB_ASSERT(proc_type->kind == Type_Proc); + Type *result_type = proc_type->Proc.results; + if (result_type == nullptr) { + error(node, "'%.*s' requires the current procedure to have at least one return value", LIT(name)); + } else { + GB_ASSERT(result_type->kind == Type_Tuple); - auto const &vars = result_type->Tuple.variables; - Type *end_type = vars[vars.count-1]->type; + auto const &vars = result_type->Tuple.variables; + Type *end_type = vars[vars.count-1]->type; - if (vars.count > 1) { - if (!proc_type->Proc.has_named_results) { - error(node, "'%.*s' within a procedure with more than 1 return value requires that the return values are named, allowing for early return", LIT(name)); + if (vars.count > 1) { + if (!proc_type->Proc.has_named_results) { + error(node, "'%.*s' within a procedure with more than 1 return value requires that the return values are named, allowing for early return", LIT(name)); + } } - } - Operand rhs = {}; - rhs.type = right_type; - rhs.mode = Addressing_Value; + Operand rhs = {}; + rhs.type = right_type; + rhs.mode = Addressing_Value; - // TODO(bill): better error message - if (!check_is_assignable_to(c, &rhs, end_type)) { - gbString a = type_to_string(right_type); - gbString b = type_to_string(end_type); - gbString ret_type = type_to_string(result_type); - error(node, "Cannot assign end value of type '%s' to '%s' in '%.*s'", a, b, LIT(name)); - if (vars.count == 1) { - error_line("\tProcedure return value type: %s\n", ret_type); - } else { - error_line("\tProcedure return value types: (%s)\n", ret_type); + // TODO(bill): better error message + if (!check_is_assignable_to(c, &rhs, end_type)) { + gbString a = type_to_string(right_type); + gbString b = type_to_string(end_type); + gbString ret_type = type_to_string(result_type); + error(node, "Cannot assign end value of type '%s' to '%s' in '%.*s'", a, b, LIT(name)); + if (vars.count == 1) { + error_line("\tProcedure return value type: %s\n", ret_type); + } else { + error_line("\tProcedure return value types: (%s)\n", ret_type); + } + gb_string_free(ret_type); + gb_string_free(b); + gb_string_free(a); } - gb_string_free(ret_type); - gb_string_free(b); - gb_string_free(a); } } - if (left_type != nullptr) { o->mode = Addressing_Value; o->type = left_type; @@ -6367,8 +6399,7 @@ ExprKind check_try_else_expr(CheckerContext *c, Operand *o, Ast *node, Type *typ if (left_type != nullptr) { check_assignment(c, &y, left_type, name); } else { - // TODO(bill): better error message - error(node, "'%.*s' does not return a value", LIT(name)); + check_try_expr_no_value_error(c, name, x, type_hint); } if (left_type == nullptr) {