diff --git a/prism/config.yml b/prism/config.yml index a0abb98ef7..8551c95b1f 100644 --- a/prism/config.yml +++ b/prism/config.yml @@ -104,6 +104,14 @@ errors: - EXPECT_STRING_CONTENT - EXPECT_WHEN_DELIMITER - EXPRESSION_BARE_HASH + - EXPRESSION_NOT_WRITABLE + - EXPRESSION_NOT_WRITABLE_ENCODING + - EXPRESSION_NOT_WRITABLE_FALSE + - EXPRESSION_NOT_WRITABLE_FILE + - EXPRESSION_NOT_WRITABLE_LINE + - EXPRESSION_NOT_WRITABLE_NIL + - EXPRESSION_NOT_WRITABLE_SELF + - EXPRESSION_NOT_WRITABLE_TRUE - FLOAT_PARSE - FOR_COLLECTION - FOR_IN diff --git a/prism/prism.c b/prism/prism.c index 91d27f566d..695734d0a3 100644 --- a/prism/prism.c +++ b/prism/prism.c @@ -12945,6 +12945,32 @@ parse_write(pm_parser_t *parser, pm_node_t *target, pm_token_t *operator, pm_nod } } +/** + * Certain expressions are not writable, but in order to provide a better + * experience we give a specific error message. In order to maintain as much + * information in the tree as possible, we replace them with local variable + * writes. + */ +static pm_node_t * +parse_unwriteable_write(pm_parser_t *parser, pm_node_t *target, const pm_token_t *equals, pm_node_t *value) { + switch (PM_NODE_TYPE(target)) { + case PM_SOURCE_ENCODING_NODE: pm_parser_err_token(parser, equals, PM_ERR_EXPRESSION_NOT_WRITABLE_ENCODING); break; + case PM_FALSE_NODE: pm_parser_err_token(parser, equals, PM_ERR_EXPRESSION_NOT_WRITABLE_FALSE); break; + case PM_SOURCE_FILE_NODE: pm_parser_err_token(parser, equals, PM_ERR_EXPRESSION_NOT_WRITABLE_FILE); break; + case PM_SOURCE_LINE_NODE: pm_parser_err_token(parser, equals, PM_ERR_EXPRESSION_NOT_WRITABLE_LINE); break; + case PM_NIL_NODE: pm_parser_err_token(parser, equals, PM_ERR_EXPRESSION_NOT_WRITABLE_NIL); break; + case PM_SELF_NODE: pm_parser_err_token(parser, equals, PM_ERR_EXPRESSION_NOT_WRITABLE_SELF); break; + case PM_TRUE_NODE: pm_parser_err_token(parser, equals, PM_ERR_EXPRESSION_NOT_WRITABLE_TRUE); break; + default: break; + } + + pm_constant_id_t name = pm_parser_constant_id_location(parser, target->location.start, target->location.end); + pm_local_variable_write_node_t *result = pm_local_variable_write_node_create(parser, name, 0, value, &target->location, equals); + + pm_node_destroy(parser, target); + return (pm_node_t *) result; +} + /** * Parse a list of targets for assignment. This is used in the case of a for * loop or a multi-assignment. For example, in the following code: @@ -19357,13 +19383,25 @@ parse_expression_infix(pm_parser_t *parser, pm_node_t *node, pm_binding_power_t pm_node_t *value = parse_assignment_values(parser, previous_binding_power, PM_BINDING_POWER_MULTI_ASSIGNMENT + 1, accepts_command_call, PM_ERR_EXPECT_EXPRESSION_AFTER_EQUAL); return parse_write(parser, (pm_node_t *) multi_target, &token, value); } - default: + case PM_SOURCE_ENCODING_NODE: + case PM_FALSE_NODE: + case PM_SOURCE_FILE_NODE: + case PM_SOURCE_LINE_NODE: + case PM_NIL_NODE: + case PM_SELF_NODE: + case PM_TRUE_NODE: { + // In these special cases, we have specific error messages + // and we will replace them with local variable writes. parser_lex(parser); - - // In this case we have an = sign, but we don't know what it's for. We - // need to treat it as an error. For now, we'll mark it as an error - // and just skip right past it. - pm_parser_err_token(parser, &token, PM_ERR_EXPECT_EXPRESSION_AFTER_EQUAL); + pm_node_t *value = parse_assignment_values(parser, previous_binding_power, binding_power, accepts_command_call, PM_ERR_EXPECT_EXPRESSION_AFTER_EQUAL); + return parse_unwriteable_write(parser, node, &token, value); + } + default: + // In this case we have an = sign, but we don't know what + // it's for. We need to treat it as an error. We'll mark it + // as an error and skip past it. + parser_lex(parser); + pm_parser_err_token(parser, &token, PM_ERR_EXPRESSION_NOT_WRITABLE); return node; } } diff --git a/prism/templates/src/diagnostic.c.erb b/prism/templates/src/diagnostic.c.erb index 97ad451890..42f8024551 100644 --- a/prism/templates/src/diagnostic.c.erb +++ b/prism/templates/src/diagnostic.c.erb @@ -188,6 +188,14 @@ static const pm_diagnostic_data_t diagnostic_messages[PM_DIAGNOSTIC_ID_MAX] = { [PM_ERR_EXPECT_STRING_CONTENT] = { "expected string content after opening string delimiter", PM_ERROR_LEVEL_SYNTAX }, [PM_ERR_EXPECT_WHEN_DELIMITER] = { "expected a delimiter after the predicates of a `when` clause", PM_ERROR_LEVEL_SYNTAX }, [PM_ERR_EXPRESSION_BARE_HASH] = { "unexpected bare hash in expression", PM_ERROR_LEVEL_SYNTAX }, + [PM_ERR_EXPRESSION_NOT_WRITABLE] = { "unexpected '='; target cannot be written", PM_ERROR_LEVEL_SYNTAX }, + [PM_ERR_EXPRESSION_NOT_WRITABLE_ENCODING] = { "Can't assign to __ENCODING__", PM_ERROR_LEVEL_SYNTAX }, + [PM_ERR_EXPRESSION_NOT_WRITABLE_FALSE] = { "Can't assign to false", PM_ERROR_LEVEL_SYNTAX }, + [PM_ERR_EXPRESSION_NOT_WRITABLE_FILE] = { "Can't assign to __FILE__", PM_ERROR_LEVEL_SYNTAX }, + [PM_ERR_EXPRESSION_NOT_WRITABLE_LINE] = { "Can't assign to __LINE__", PM_ERROR_LEVEL_SYNTAX }, + [PM_ERR_EXPRESSION_NOT_WRITABLE_NIL] = { "Can't assign to nil", PM_ERROR_LEVEL_SYNTAX }, + [PM_ERR_EXPRESSION_NOT_WRITABLE_SELF] = { "Can't change the value of self", PM_ERROR_LEVEL_SYNTAX }, + [PM_ERR_EXPRESSION_NOT_WRITABLE_TRUE] = { "Can't assign to true", PM_ERROR_LEVEL_SYNTAX }, [PM_ERR_FLOAT_PARSE] = { "could not parse the float '%.*s'", PM_ERROR_LEVEL_SYNTAX }, [PM_ERR_FOR_COLLECTION] = { "expected a collection after the `in` in a `for` statement", PM_ERROR_LEVEL_SYNTAX }, [PM_ERR_FOR_INDEX] = { "expected an index after `for`", PM_ERROR_LEVEL_SYNTAX },