void statement(LIST *S, int level) {
LIST *list;
ATTR *E = (ATTR*)malloc(sizeof(ATTR));
debug(level,"STATEMENT");
if(token == ID) {
assignment_stat(S, level+1);
} else if(token == TK_IF) {
if_stat(S, level+1);
backpatch(S, int2string(nextquad()));
} else if(token == TK_DO) {
while_stat(S, level+1);
S->next = NULL;
} else if(token == TK_EXIT) {
exit_stat(level+1);
list = makelist(int2string(nextquad()));
list->exitflag = 1;
genquad("jump", "_", "_", "_");
S->next = merge(S->next, list);
} else if(token == TK_RETURN) {
return_stat(E, level+1);
S->next = NULL;
} else if(token == TK_PRINT) {
print_stat(level+1);
S->next = NULL;
} else if(token == TK_CALL) {
call_stat(level+1);
S->next = NULL;
} else {
S->next = NULL;
}
}
int statement()
{
int es = 0;
if (es == 0 && strcmp(token, "if") == 0) es = if_stat();//<IF语句>
if (es == 0 && strcmp(token, "while") == 0) es = while_stat();//<while语句>
if (es == 0 && strcmp(token, "for") == 0) es = for_stat();//<for语句>
//可在此处添加do语句调用
if (es == 0 && strcmp(token, "read") == 0) es = read_stat();//<read语句>
if (es == 0 && strcmp(token, "write") == 0) es = write_stat();//<write语句>
if (es == 0 && strcmp(token, "{") == 0) es = compound_stat();//<复合语句>
if (es == 0 && (strcmp(token, "ID") == 0 || strcmp(token, "NUM") == 0 || strcmp(token, "(") == 0)) es = expression_stat();//<表达式语句>
return(es);
}
void stat(){
if (lookahead == INTEGER || lookahead == STRING || lookahead == BOOLEAN || lookahead == TABLE)
def_stat();
else if (lookahead == ID)
assign_stat();
else if (lookahead == IF)
if_stat();
else if (lookahead == WHILE)
while_stat();
else if (lookahead == READ)
read_stat();
else //(lookahead == WRITE)
write_stat();
}
/*Genera il codice per il nodo stat_list e crea lo scope del programma*/
Code stat_list(Pnode stat_list_node){
//Definisco la variabile che contiene il codice da ritornare
Code stat_list_code;
stat_list_code.head = NULL;
stat_list_code.tail = NULL;
stat_list_code.size = 0;
//Creo l'ambiente del programma
push_environment();
//Punto al primo stat
Pnode stat_node = stat_list_node->child;
//Ciclo lungo tutti gli stat_node
while (stat_node!=NULL){
//Creo il codice dello stat_node
Code stat_code;
switch (stat_node->type){
case(N_DEF_STAT): stat_code = def_stat(stat_node);break;
case(N_ASSIGN_STAT): stat_code = assign_stat(stat_node);break;
case(N_IF_STAT): stat_code = if_stat(stat_node);break;
case(N_WHILE_STAT): stat_code = while_stat(stat_node);break;
case(N_READ_STAT): stat_code = read_stat(stat_node);break;
case(N_WRITE_STAT): stat_code = write_stat(stat_node);break;
}
//Appendo il codice a stat_list_code
stat_list_code = appcode(stat_list_code,stat_code);
//Punto al fratello successivo
stat_node = stat_node->brother;
}
//Appendo il codice per fare il pop dell'environment a stat_list_code
if(numobj_in_current_env()!=0)
stat_list_code = appcode(stat_list_code,makecode1(T_POP,numobj_in_current_env()));
//elimino l'ambiente creato (elimina già le variabili dall'ambiente)
pop_environment();
return stat_list_code;
}
Code stat(Pnode p)
{
switch (p->type)
{
case N_DEF_STAT:
return def_stat(p);
case N_ASSIGN_STAT:
return assign_stat(p);
case N_IF_STAT:
return if_stat(p);
case N_WHILE_STAT:
return while_stat(p);
case N_READ_STAT:
return read_stat(p);
case N_WRITE_STAT:
return write_stat(p);
default:
noderror(p);
}
return endcode();
}
