#include <ctype.h>
#include "syntax_tree.h"
#include "y.tab.h"

#define NODE_ARRAY_SIZE 1000
#define OBJ_STACK_SIZE 500

/* defined in pc.y (pc.c) */
extern void yyerror(char *);

struct node NodeArray[NODE_ARRAY_SIZE];
int NAp=0;

struct object ObjStack[OBJ_STACK_SIZE] = {
  { objFUNC, "STR2INT", 1, 0, 0 },
  { objFUNC, "INT2STR", 2, 0, 0 },
/*
  { objFUNC, "READ", 0, 0, 0 },
  { objFUNC, "WRITE", 1, 0, 0 },
*/
  { objFUNC, "READLN", 1, 0, 0 },
  { objFUNC, "WRITELN", -1, 0, 0 }
};
int lastGobjIndex=-1, OSp=4; /* OSp=6; */

char *ucase(char *s) {
  char *p;
  for(p = s; *p!=0; p++){
    *p = toupper(*p);
  }
  return s;
}

Tree mkNode(int type, Tree left, Tree right) {
  Tree p = &NodeArray[NAp++];
  p->type = type;
  p->left = left;
  p->right = right;
  p->third = NUL;
  return p;
}

Tree mkNode3(int type, Tree left, Tree right, Tree third) {
  Tree p = mkNode(type, left, right);
  p->third = third;
  return p;
}

Tree mkNum(int n) {
  Tree p = &NodeArray[NAp++];
  p->type = NUM;
  p->num = n;
  return p;
}

Tree mkStr(char *s) {
  Tree p = &NodeArray[NAp++];
  p->type = STR;
  p->str = s;
  return p;
}

Tree mkSym(char *name) {
  Tree p = &NodeArray[NAp++];
  p->type = SYM;
  p->name = ucase(name);
  p->obj = NUL;
  return p;
}

Obj pushFunc(char *name) {
  Obj p = &ObjStack[OSp];
  p->type = objFUNC;
  p->name = name;
  p->size = 0;
  lastGobjIndex = OSp++;
  return p;
}

void popScope() { OSp = lastGobjIndex+1; }

Obj pushGvar(char *name) {
  Obj p = &ObjStack[OSp];
  p->type = objGVAR;
  p->name = name;
  lastGobjIndex = OSp++;
  return p;
}

Obj pushGarr(char *name, int size) {
  Obj p = &ObjStack[OSp];
  p->type = objGARR;
  p->name = name;
  p->size = size;
  lastGobjIndex = OSp++;
  return p;
}

Obj pushLvar(char *name) {
  Obj p = &ObjStack[OSp++];
  p->type = objLVAR;
  p->name = name;
  p->scope = &ObjStack[lastGobjIndex];
  p->offset = p->scope->size++;
  return p;
}

Obj pushLarr(char *name, int size) {
  Obj p = &ObjStack[OSp++];
  p->type = objLARR;
  p->name = name;
  p->scope = &ObjStack[lastGobjIndex];
  p->offset = p->scope->size;
  p->scope->size += (p->size = size);
  return p;
}

Obj getObj(char *name) {
  int i;
  for (i=OSp-1; i>=0; i--) {
    if (strcmp(ObjStack[i].name, name)==0) return &ObjStack[i];
  }
  return NUL;
}