expr_t parse_multi_expr(tokenizer_t t) {
char * filename = cur_tok(t).filename;
int line = cur_tok(t).line_num;
expr_t e = parse_unary_expr(t);
while((cur_tok(t).kind == TOK_MUL)|(cur_tok(t).kind == TOK_DIV)|(cur_tok(t).kind == TOK_REM)) {
op_kind_t op = parse_multi_oper(t);
expr_t e0 = parse_unary_expr(t);
e = mk_expr_bin_op(filename, line, op, e, e0);
}
return e;
}
// multi-rest ::= '*' primary expr (multi-rest)
// '/' primary expr (multi-rest)
// '%' primary expr (multi-rest)
//
// assuming the first primary expr and operator has already been parsed
// this parses the 'rest' of the expression
Expr*
parse_mult_rest(Parser& p, Token_stream& ts, Token const* tok, Expr* e1)
{
// look for the next operand
if (Expr* e2 = parse_unary_expr(p, ts)) {
// if there is another operator after the primary expr
// and it is a multiplicative operator
// then consume it.
// the expr so far becomes the lhs operand
// and we recurse until there are no more multiplicative operators.
if (Token const* t = ts.next()) {
if (is_mult_op(t->kind()))
return parse_mult_rest(p, ts, ts.advance(), p.on_binary(tok, e1, e2));
// return once we're done eating up multiplicative operators
else
return p.on_binary(tok, e1, e2);
}
else
return p.on_binary(tok, e1, e2);
}
error("Expected expression after multiplicative expr: ");
print(e1);
print(tok);
print("\n");
return nullptr;
}
// not ::= ! unary expr
Expr*
parse_not(Parser& p, Token_stream& ts)
{
// eat the not tok
Token const* tok = ts.advance();
assert(tok->kind() == bang_tok);
if (Expr* e = parse_unary_expr(p, ts))
return p.on_unary(tok, e);
error("Expected primary expr after '!'.");
return nullptr;
}
expr_t parse_mult_expr(tokenizer_t t){
expr_t expr_left, expr_right;
expr_left = parse_unary_expr(t);
struct token tok = cur_tok(t);
// relational-operator
while(tok.kind == TOK_MUL || tok.kind == TOK_DIV || tok.kind == TOK_REM){
eat_it(t, TOK_ANY); // なんでも食べる
expr_right = parse_unary_expr(t);
op_kind_t op_kind;
if(tok.kind == TOK_MUL) op_kind = op_kind_mult;
if(tok.kind == TOK_DIV) op_kind = op_kind_div;
if(tok.kind == TOK_REM) op_kind = op_kind_rem;
expr_left = mk_expr_bin_op(t->filename, t->line,
op_kind, expr_left, expr_right); // left にたたんでいく
tok = cur_tok(t);
}
return expr_left;
}
expr_t parse_op_expr(tokenizer_t t)
{
// struct token tok = cur_tok(t);
expr_t expr;
if(cur_tok(t).kind == TOK_BANG){
eat_it(t, TOK_BANG);
expr = parse_unary_expr(t);
return mk_expr_un_op(t->filename, t->line, op_kind_logneg, expr);
}else if(cur_tok(t).kind == TOK_PLUS){
eat_it(t, TOK_PLUS);
expr = parse_unary_expr(t);
return mk_expr_un_op(t->filename, t->line, op_kind_un_plus, expr);
}else if(cur_tok(t).kind == TOK_MINUS){
eat_it(t, TOK_MINUS);
expr = parse_unary_expr(t);
return mk_expr_un_op(t->filename, t->line, op_kind_un_minus, expr);
}else{
syntax_error(t, "error: parse_op_expr (expected TOK_BANG, TOK_PLUS, TOK_MINUS)");
return NULL;
// exit
}
// }
}
// factor ::= factor '*' primary expr
// factor '/' primary expr
// factor '%' primary expr
// primary expr
//
// or
// factor ::= primary expr (multi-rest)
Expr*
parse_mult_expr(Parser& p, Token_stream& ts)
{
if (Expr* e1 = parse_unary_expr(p, ts)) {
if (Token const* tok = ts.next()) {
switch (tok->kind()) {
case star_tok: return parse_mult_rest(p, ts, ts.expect(star_tok), e1);
case fslash_tok: return parse_mult_rest(p, ts, ts.expect(fslash_tok), e1);
case mod_tok: return parse_mult_rest(p, ts, ts.expect(mod_tok), e1);
// anything else and we consider e1 a lone primary expr
default:
return e1;
}
}
// if it is only the primary expr
else
return e1;
}
return nullptr;
}
expr_t parse_unary_expr(tokenizer_t t) {
char * filename = cur_tok(t).filename;
int line = cur_tok(t).line_num;
char * f =(char *)safe_malloc(sizeof(char) * 50) ;
if(cur_tok(t).kind == TOK_INT_LITERAL) {
strcpy(f, cur_tok(t).num);
f = (char *)realloc(f, sizeof(char) * strlen(f) + 1);
eat_it(t, TOK_INT_LITERAL);
return mk_expr_int_literal(filename, line, f);
}
else if(cur_tok(t).kind == TOK_ID) {
strcpy(f, parse_identifier(t));
f = (char *)realloc(f, sizeof(char) * strlen(f) + 1);
if(cur_tok(t).kind == TOK_LPAREN) {
eat_it(t, TOK_LPAREN);
expr_list_t args = parse_arg_expr_list(t);
eat_it(t, TOK_RPAREN);
return mk_expr_call(filename, line, f, args);
}
else {
return mk_expr_id(filename, line, f);
}
}
else if(cur_tok(t).kind == TOK_LPAREN) {
eat_it(t, TOK_LPAREN);
expr_t e = parse_expr(t);
eat_it(t, TOK_RPAREN);
return mk_expr_paren(filename, line, e);
}
else if((cur_tok(t).kind == TOK_PLUS)|(cur_tok(t).kind == TOK_MINUS)|(cur_tok(t).kind == TOK_BANG)) {
op_kind_t op = parse_unary_oper(t);
expr_t exp = parse_unary_expr(t);
return mk_expr_un_op(filename, line, op, exp);
}
else {
printf("exit_5\n");
exit(1);
}
}
static int
parse_multiplicative_expr(int need_eval, cfg_cond_value_t *prv)
{
return parse_unary_expr(need_eval, prv);
}
