/*----------------------------------------------------------------------*/
static ast_statement_t *parse_statement(parse_state_t *p) {
token_t *token;
token = peek_token(p);
if (token == NULL) {
return NULL;
} else if (test_token(token, TK_ELSE) ||
test_token(token, TK_END)) {
return NULL;
} else if (test_token(token, TK_VAR)) {
return parse_declare_var(p);
} else if (test_token(token, TK_FUNCTION)) {
return parse_define_function(p);
} else if (test_token(token, TK_RETURN)) {
return parse_return(p);
} else if (test_token(token, TK_IF)) {
return parse_if(p);
} else if (test_token(token, TK_FOR)) {
return parse_for(p);
} else if (test_token(token, TK_IDENTIFIER)) {
return parse_assignment(p);
}
next_token(p);
error(p, "statement expected");
return NULL; /* unreachable */
}
struct instruction *parse_instruction(void)
{
struct expr *expr;
struct instruction *res;
switch (lookahead[0]->type)
{
case WHILE: return parse_while();
case DO: return parse_do();
case IDENTIFIER: case LPAREN:
expr = parse_expression();
switch(lookahead[0]->type)
{
case ASSIGN: return parse_assignment_instr(expr);
case EOL:
if (expr->exprtype != funcalltype)
{
if (expr->exprtype == binopexprtype
&& expr->val.binopexpr.op == EQ)
{
error(expr->pos, "unexpected =, did you mean <- ?");
exit(1);
}
else
syntaxerror("expected instruction, not expression");
}
eat(EOL);
res = funcallinstr(expr->val.funcall.fun_ident,
expr->val.funcall.args, expr->pos);
free(expr);
return res;
default:
next();
syntaxerror("unexpected %s", tok->val);
return parse_instruction();
}
case RETURN:
eat(RETURN);
if (lookahead[0]->type == EOL)
{
eat(EOL);
return return_stmt(NULL);
}
else
{
expr = parse_expression(); eat(EOL);
return return_stmt(expr);
}
case FOR: return parse_for();
case IF: return parse_if();
case SWITCH: return parse_switch();
case ENDOFFILE: return NULL;
default:
next();
syntaxerror("expected instruction, not %s", tok->val);
return parse_instruction();
}
}
/* parse a compound- or a simple-command
* (pipeline and lists are done outside this)
* ----------------------------------------------------------------------- */
union node *parse_command(struct parser *p, int tempflags) {
enum tok_flag tok;
union node *command;
union node **rptr;
tok = parse_gettok(p, tempflags);
switch(tok) {
/* T_FOR begins an iteration statement */
case T_FOR:
command = parse_for(p);
break;
/* T_IF begins a case match statement */
case T_CASE:
command = parse_case(p);
break;
/* T_IF begins a conditional statement */
case T_IF:
command = parse_if(p);
break;
/* T_WHILE/T_UNTIL begin a for-loop statement */
case T_WHILE:
case T_UNTIL:
command = parse_loop(p);
break;
/* T_LP/T_BEGIN start a grouping compound */
case T_LP:
case T_BEGIN:
p->pushback++;
command = parse_grouping(p);
break;
/* handle simple commands */
case T_NAME:
case T_WORD:
case T_REDIR:
case T_ASSIGN:
p->pushback++;
command = parse_simple_command(p);
break;
/* it wasn't a compound command, return now */
default:
p->pushback++;
return NULL;
}
if(command) {
/* they all can have redirections, so parse these now */
rptr = &command->ncmd.rdir;
/*
* in the case of a simple command there are maybe already
* redirections in the list (because in a simple command they
* can appear between arguments), so skip to the end of the list.
*/
while(*rptr)
tree_next(rptr);
while(parse_gettok(p, P_DEFAULT) & T_REDIR)
tree_move(p->tree, rptr);
}
p->pushback++;
return command;
}
/** Parse statement.
*
* @param parse Parser object.
* @return New syntax tree node.
*/
stree_stat_t *parse_stat(parse_t *parse)
{
stree_stat_t *stat;
stree_vdecl_t *vdecl_s;
stree_if_t *if_s;
stree_switch_t *switch_s;
stree_while_t *while_s;
stree_for_t *for_s;
stree_raise_t *raise_s;
stree_break_t *break_s;
stree_return_t *return_s;
stree_wef_t *wef_s;
stree_exps_t *exp_s;
#ifdef DEBUG_PARSE_TRACE
printf("Parse statement.\n");
#endif
switch (lcur_lc(parse)) {
case lc_var:
vdecl_s = parse_vdecl(parse);
stat = stree_stat_new(st_vdecl);
stat->u.vdecl_s = vdecl_s;
break;
case lc_if:
if_s = parse_if(parse);
stat = stree_stat_new(st_if);
stat->u.if_s = if_s;
break;
case lc_switch:
switch_s = parse_switch(parse);
stat = stree_stat_new(st_switch);
stat->u.switch_s = switch_s;
break;
case lc_while:
while_s = parse_while(parse);
stat = stree_stat_new(st_while);
stat->u.while_s = while_s;
break;
case lc_for:
for_s = parse_for(parse);
stat = stree_stat_new(st_for);
stat->u.for_s = for_s;
break;
case lc_raise:
raise_s = parse_raise(parse);
stat = stree_stat_new(st_raise);
stat->u.raise_s = raise_s;
break;
case lc_break:
break_s = parse_break(parse);
stat = stree_stat_new(st_break);
stat->u.break_s = break_s;
break;
case lc_return:
return_s = parse_return(parse);
stat = stree_stat_new(st_return);
stat->u.return_s = return_s;
break;
case lc_do:
case lc_with:
wef_s = parse_wef(parse);
stat = stree_stat_new(st_wef);
stat->u.wef_s = wef_s;
break;
default:
exp_s = parse_exps(parse);
stat = stree_stat_new(st_exps);
stat->u.exp_s = exp_s;
break;
}
#ifdef DEBUG_PARSE_TRACE
printf("Parsed statement %p\n", stat);
#endif
return stat;
}
