/*
 * File : chiaa.c
 * Last Modified: 14 December 2002
 *
 *
 */


typeptr empty_node (){
// returns an empty node with its left and right pointers as NULL

        typeptr t1 = (typeptr) malloc(sizeof(typenode));
        t1->left = NULL;
        t1->right = NULL;

        return t1;
}


typeptr new_node(char *info, myType t){
//returns a new node of type t

        typeptr t1 = empty_node();

        t1->info.c = (char*)malloc(strlen(info)+1);
        strcpy(t1->info.c,info);
        t1->type = t;

        return t1;
}

typeptr new_int_node(int info) {
//returns a new node of type NUMBER

        typeptr t1 = empty_node();

        t1->info.i = info;
        t1->type = NUMBER;

        return t1;
}

typeptr new_dummy_node() {
//returns a new dummy node with "." filled in its info field

        typeptr t1= empty_node();

        t1->type = DUMMY;
        t1->info.c = ".";
}

typeptr join_child_node(typeptr t1, typeptr t2, typeptr t3) {
//return pointer to the root node that points the left subtree t2 and right subtree t3

        t1->left = t2;
        t1->right = t3;
        return t1;
}


void print_tree (typeptr t) {
//prints the abstract syntax tree formed

        if (t != NULL) {
                if ((t->type == STR) || (t->type == NUMOPER) || (t->type == TYPE) || (t->type == LOGOPER)
                     || (t->type == ASSIGNOPER) || (t->type == DUMMY) || (t->type == RESWORD))
                        printf("%s ", t->info.c);
                if (t->type == NUMBER)
                        printf("%d ", t->info.i);
                if (t->left != NULL || t->right != NULL) {
                        printf("\n( ");
                        print_tree(t->left);
                        print_tree(t->right);
                        printf(")");
                }
        }
        return ;
}

int isLeaf(typeptr t){
//return 1 if the node is leaf node, otherwise 0

        if (t->left==NULL && t->right==NULL)
                return 1;
        else
                return 0;
}

void generate(typeptr t){
//generate equivalent interpreted code from the abstract syntax tree

        int leftCount,rightCount;
        int leftlabel, rightlabel, slabel,scount;

        if (t == NULL) return;
        switch(t->type) {
                case DUMMY:
                        generate(t->left);
                        generate(t->right);
                        break;
                case TYPE:
                        //printf("Procedure %s: \n",t->left->info.c);
                        if (t->left->type == ASSIGNOPER)
                                generate(t->left);
                        generate(t->right);
                        break;
                case ASSIGNOPER:
                        generate(t->right);
                        printf("STORE R1, %s\n",t->left->info.c);
                        break;
                case STR:
                        if (isLeaf(t))
                                printf("LOAD %s, R1\n",t->info.c);
                        break;
                case NUMBER:
                        if (isLeaf(t))
                                printf("LOAD #%d, R1\n",t->info.i);
                        break;
                case LOGOPER:
                        if (strcmp(t->info.c,"<") == 0) {
                                scount = count++;
                                generate(t->left);
                                printf("STORE R1, temp%d\n",scount);
                                generate(t->right);
                                printf("L temp%d, R1\n",scount);
                        }

                        if (strcmp(t->info.c,"<=") == 0) {
                                scount = count++;
                                generate(t->left);
                                printf("STORE R1, temp%d\n",scount);
                                generate(t->right);
                                printf("LE temp%d, R1\n",scount);
                        }

                        if (strcmp(t->info.c,">") == 0) {
                                scount = count++;
                                generate(t->left);
                                printf("STORE R1, temp%d\n",scount);
                                generate(t->right);
                                printf("G temp%d, R1\n",scount);
                        }

                        if (strcmp(t->info.c,">=") == 0) {
                                scount = count++;
                                generate(t->left);
                                printf("STORE R1, temp%d\n",scount);
                                generate(t->right);
                                printf("GE temp%d, R1\n",scount);
                        }

                        if (strcmp(t->info.c,"!=") == 0) {
                                scount = count++;
                                generate(t->left);
                                printf("STORE R1, temp%d\n",scount);
                                generate(t->right);
                                printf("NE temp%d, R1\n",scount);
                        }

                        if (strcmp(t->info.c,"==") == 0) {
                                scount = count++;
                                generate(t->left);
                                printf("STORE R1, temp%d\n",scount);
                                generate(t->right);
                                printf("CMP temp%d, R1\n",scount);
                        }

                        if (strcmp(t->info.c,"AND") == 0) {
                                scount = count++;
                                generate(t->left);
                                printf("STORE R1, temp%d\n",scount);
                                generate(t->right);
                                printf("AND R1, temp%d\n",scount);
                        }

                        if (strcmp(t->info.c,"OR") == 0) {
                                scount = count++;
                                generate(t->left);
                                printf("STORE R1, temp%d\n",scount);
                                generate(t->right);
                                printf("OR R1, temp%d\n",scount);
                        }

                        if (strcmp(t->info.c,"NOT") == 0) {
                                scount = count++;
                                generate(t->left);
                                printf("NOT R1\n");
                        }


                        break;
                case RESWORD:
                        slabel = label;

                        if (strcmp(t->info.c,"IF") == 0) {
                                if (t->right->type == DUMMY){
                                        if (t->right->left != NULL){
                                                leftlabel = label++;
                                                slabel = leftlabel;
                                        }
                                        if (t->right->right != NULL)
                                                rightlabel = label++;
                                }

                                generate(t->left);
                                printf("IFFALSE GOTO Label%d\n",slabel);
                                if (t->right->type != DUMMY){
                                        generate(t->right);
                                        printf("Label%d:\n",slabel);
                                }
                                else{
                                        generate(t->right->left);
                                        printf("GOTO Label%d\n",rightlabel);
                                        printf("Label%d:\n",leftlabel);
                                        generate(t->right->right);
                                        printf("Label%d:\n",rightlabel);
                                }
                        }

                        if (strcmp(t->info.c,"WHILE") == 0) {
                                leftlabel = label++;
                                rightlabel = label++;

                                printf("LABEL%d:\n",leftlabel);
                                generate(t->left);
                                printf("IFFALSE GOTO Label%d\n",rightlabel);
                                generate(t->right);
                                printf("GOTO Label%d\n",leftlabel);
                                printf("LABEL%d:\n",rightlabel);
                        }

                        if (strcmp(t->info.c,"DO") == 0) {
                                slabel = label++;
                                printf("LABEL%d:\n",slabel);
                                generate(t->right);
                                generate(t->left);
                                printf("IFTRUE GOTO Label%d\n",slabel);
                        }

                        if (strcmp(t->info.c,"FOR") == 0) {
                                slabel = label++;
                                if (t->left->left != NULL)
                                        generate(t->left->left);
                                printf("Label%d:\n",slabel);
                                generate(t->right);
                                if (t->left->type == DUMMY){
                                        if (t->left->right != NULL){
                                                if (t->left->right->right != NULL)
                                                        generate(t->left->right->right);
                                                if (t->left->right->left != NULL){
                                                        generate(t->left->right->left);
                                                        printf("IFTRUE GOTO Label%d\n",slabel);
                                                }
                                                else {
                                                        printf("GOTO Label%d\n",slabel);
                                                }
                                        }
                                }
                        }

                        break;
                case NUMOPER:
                        if (!isLeaf(t->left) || !isLeaf(t->right))
                                leftCount = count++;
                        if (!isLeaf(t->right))
                                rightCount = count++;

                        generate(t->left);
                        if (!isLeaf(t->left) || !isLeaf(t->right))
                                printf("STORE R1, Temp%d\n",leftCount);

                        if (!isLeaf(t->right)){
                                generate(t->right);
                                printf("STORE R1, Temp%d\n",rightCount);
                        }

                        if (!isLeaf(t->left) || !isLeaf(t->right))
                                printf("LOAD Temp%d, R1\n",leftCount);

                        if (strcmp(t->info.c,"+") == 0)
                                if (!isLeaf(t->right))
                                        printf("ADD Temp%d, R1\n",rightCount);
                                else
                                        if (t->right->type == STR)
                                                printf("ADD %s, R1\n",t->right->info.c);
                                        else
                                                printf("ADD #%d, R1\n",t->right->info.i);

                        if (strcmp(t->info.c,"-") == 0){
                                if (!isLeaf(t->right)){
                                        printf("NEG Temp%d\n",rightCount);
                                        printf("ADD Temp%d, R1\n",rightCount);
                                }
                                else
                                        if (t->right->type == STR){
                                                printf("NEG %s\n",t->right->info.c);
                                                printf("ADD %s, R1\n",t->right->info.c);
                                        }
                                        else{
                                                printf("NEG #%d\n",t->right->info.i);
                                                printf("ADD #%d, R1\n",t->right->info.i);
                                        }
                        }

                        if (strcmp(t->info.c,"*") == 0)
                                if (!isLeaf(t->right))
                                        printf("MULT Temp%d, R1\n",rightCount);
                                else
                                        if (t->right->type == STR)
                                                printf("MULT %s, R1\n",t->right->info.c);
                                        else
                                                printf("MULT #%d, R1\n",t->right->info.i);
                        if (strcmp(t->info.c,"/") == 0)
                                if (!isLeaf(t->right))
                                        printf("DIV R1, Temp%d\n",rightCount);
                                else
                                        if (t->right->type == STR)
                                                printf("DIV R1, %s\n",t->right->info.c);
                                        else
                                                printf("DIV R1, #%d\n",t->right->info.i);

                        if (strcmp(t->info.c,"%") == 0)
                                if (!isLeaf(t->right))
                                        printf("MOD R1, Temp%d\n",rightCount);
                                else
                                        if (t->right->type == STR)
                                                printf("MOD R1, %s\n",t->right->info.c);
                                        else
                                                printf("MOD R1, #%d\n",t->right->info.i);

                        break;
        }
        return;
}