/*----------------------------------------------------------------------*/
static ast_statement_t *parse_if(parse_state_t *p) {
token_t *token;
ast_statement_t *statement;
/* if */
token = next_token(p);
EXPECT(token, TK_IF, "'if' expected");
statement = ALLOC(sizeof(ast_statement_t));
BZERO(statement);
statement->tag = AST_STATEMENT_IF;
/* if predicate / block */
statement->u.if_.condition = parse_logical_expression(p);
statement->u.if_.if_block = parse_statement_list(p);
/* else? */
token = peek_token(p);
if (test_token(token, TK_ELSE)) {
next_token(p);
/* else block */
statement->u.if_.else_block = parse_statement_list(p);
} else {
statement->u.if_.else_block = NULL;
}
/* end */
token = next_token(p);
EXPECT(token, TK_END, "'end' expected");
return statement;
}
void cx_parser::parse_case_label(cx_symtab_node* p_function_id, const cx_type *p_expr_type) {
get_token_append();
bool sign_flag(false);
if (token_in(token, tokenlist_unary_ops)) {
sign_flag = true;
get_token_append();
}
switch (token) {
case tc_identifier:
if (!search_all(p_token->string__())) {
cx_error(err_undefined_identifier);
}
get_token_append();
break;
case tc_number:
if (p_token->type() != ty_integer) cx_error(err_invalid_constant);
get_token_append();
break;
case tc_string:
if (sign_flag || (strlen(p_token->string__()) != 3)) {
cx_error(err_invalid_constant);
}
break;
default:
break;
}
conditional_get_token_append(tc_colon, err_missing_colon);
parse_statement_list(p_function_id, tc_BREAK);
}
/** parse_compound parse compounded statements.
*
* {
* <statements>;
* }
*
* @param p_function_id : ptr to this statements function Id.
*/
void cx_parser::parse_compound(cx_symtab_node* p_function_id) {
get_token_append();
parse_statement_list(p_function_id, tc_right_bracket);
// if ((p_function_id->defn.routine.which == func_std_iterator)) return;
conditional_get_token_append(tc_right_bracket, err_missing_right_bracket);
}
/*
parse_statement_list
Recursively parses a valid statement
Parameters: none
Return: none
*/
void parse_statement_list(Tree &cst){
cst.add_branch_node("statement_list");
if(!(curr_token -> type).compare("closed_block")){
// ε production, do nothing
}
else{
parse_statement(cst);
parse_statement_list(cst);
}
cst.kill_all_children();
}
/*
parse_block
Matches a block of code
Parameters: none
Return: none
*/
void parse_block(Tree &cst){
cst.add_branch_node("block");
if(!(curr_token -> type).compare("open_block")) {
match("{", cst);
parse_statement_list(cst);
match("}", cst);
}
else{
std::cout << "Invalid block declaration on line " << curr_token -> line_number << std::endl;
exit(EXIT_FAILURE);
}
cst.kill_all_children();
}
/*----------------------------------------------------------------------*/
void parse(parse_input_t *parse_in, parse_output_t *parse_out) {
parse_state_t parse_state;
parse_state_t *p = &parse_state;
p->in = parse_in;
p->out = parse_out;
p->out->error = 0;
p->token_index = 0;
if (setjmp(p->jmpbuf)) {
return;
}
p->out->first_statement = parse_statement_list(p);
}
/** parse_DO parse do/while statement.
*
* do
* <statement>;
* while(<expression>);
*
* @param p_function_id : ptr to this statements function Id.
*/
void cx_parser::parse_DO(cx_symtab_node* p_function_id) {
int break_point = put_location_marker();
get_token_append(); //do
parse_statement_list(p_function_id, tc_WHILE);
conditional_get_token_append(tc_WHILE, err_missing_WHILE);
conditional_get_token_append(tc_left_paren, err_missing_left_paren);
check_boolean(parse_expression());
conditional_get_token_append(tc_right_paren, err_missing_right_paren);
fixup_location_marker(break_point);
}
/*----------------------------------------------------------------------*/
static ast_statement_t *parse_for(parse_state_t *p) {
token_t *token;
ast_statement_t *statement_for;
ast_statement_t **next_statement;
statement_for = ALLOC(sizeof(ast_statement_t));
BZERO(statement_for);
statement_for->tag = AST_STATEMENT_FOR;
statement_for->u.for_.initialize = NULL;
statement_for->u.for_.condition = NULL;
statement_for->u.for_.increment = NULL;
/* for */
token = next_token(p);
EXPECT(token, TK_FOR, "'for' expected");
/* init statements */
next_statement = &statement_for->u.for_.initialize;
for (;;) {
token = peek_token(p);
if (test_token(token, TK_SEMICOLON)) {
next_token(p);
break;
}
*next_statement = parse_statement(p);
if (*next_statement == NULL) {
error(p, "statement expected");
}
next_statement = &((*next_statement)->next);
*next_statement = NULL;
token = peek_token(p);
if (test_token(token, TK_SEMICOLON)) {
next_token(p);
break;
} else if (test_token(token, TK_COMMA)) {
next_token(p);
} else {
error(p, "';' or ',' expected");
}
}
/* conditional */
token = peek_token(p);
if (test_token(token, TK_SEMICOLON)) {
next_token(p);
} else {
statement_for->u.for_.condition = parse_logical_expression(p);
if (statement_for->u.for_.condition == NULL) {
error(p, "conditional expression expected");
}
token = peek_token(p);
EXPECT(token, TK_SEMICOLON, "';' expected");
next_token(p);
}
/* increment statements */
next_statement = &statement_for->u.for_.increment;
for (;;) {
token = peek_token(p);
if (test_token(token, TK_DO)) {
next_token(p);
break;
}
*next_statement = parse_statement(p);
if (*next_statement == NULL) {
error(p, "increment statement or 'do' expected");
}
next_statement = &((*next_statement)->next);
*next_statement = NULL;
token = peek_token(p);
if (test_token(token, TK_DO)) {
next_token(p);
break;
} else if (test_token(token, TK_COMMA)) {
next_token(p);
} else {
error(p, "'do' or ',' expected");
}
}
/* block */
statement_for->u.for_.block = parse_statement_list(p);
/* end */
token = next_token(p);
EXPECT(token, TK_END, "'end' expected");
return statement_for;
}
/*----------------------------------------------------------------------*/
static ast_statement_t *parse_define_function(parse_state_t *p) {
token_t *token;
ast_statement_t *statement;
ast_function_parameter_t *parameter = NULL;
ast_function_parameter_t *prev_parameter = NULL;
statement = ALLOC(sizeof(ast_statement_t));
BZERO(statement);
statement->tag = AST_STATEMENT_DEFINE_FUNCTION;
/* function keyword */
token = next_token(p);
EXPECT(token, TK_FUNCTION, "'function' expected");
/* function name */
token = next_token(p);
EXPECT(token, TK_IDENTIFIER, "function name expected");
statement->u.define_function.name_token = token;
/* function parameters */
token = peek_token(p);
if (test_token(token, TK_LBRACKET)) { /* opening bracket? */
next_token(p);
for (;;) {
token = peek_token(p);
if (token == NULL || token->type != TK_IDENTIFIER)
break;
next_token(p);
prev_parameter = parameter;
parameter = ALLOC(sizeof(ast_function_parameter_t));
if (prev_parameter == NULL) {
statement->u.define_function.first_parameter = parameter;
} else {
prev_parameter->next = parameter;
}
/* parameter name */
parameter->identifier_token = token;
/* colon before parameter type */
token = next_token(p);
EXPECT(token, TK_COLON, "':' expected");
/* parameter type */
token = next_token(p);
EXPECT(token, TK_IDENTIFIER, "parameter type expected");
parameter->type_token = token;
/* comma? */
token = peek_token(p);
if (!test_token(token, TK_COMMA))
break;
next_token(p);
}
/* closing bracket */
token = next_token(p);
EXPECT(token, TK_RBRACKET, "')' expected");
}
/* colon before return type? */
token = peek_token(p);
if (test_token(token, TK_COLON)) {
next_token(p);
/* return type */
token = next_token(p);
statement->u.define_function.return_type_token = token;
EXPECT(token, TK_IDENTIFIER, "return type expected");
}
/* function body statement list */
statement->u.define_function.block = parse_statement_list(p);
/* end */
token = next_token(p);
EXPECT(token, TK_END, "'end' expected");
return statement;
}