util.c

tiny 编译器程序的设计 修改了原作者的程序 现在能生成中间代码

/****************************************************/
/* File: util.c                                     */
/* Utility function implementation                  */
/* for the C_Minus compiler                         */
/****************************************************/

#include "globals.h"
#include "util.h"


/* procedure printToken prints a token 
 * and its lexeme to the listing file
 */
void printToken(TokenType token, const char* tokenString )
{ switch (token)
  { case IF:
    case THEN:
    case ELSE:
    case END:
    case REPEAT:
    case  UNTIL:
    case READ:
    case WRITE:
         fprintf(listing,"reserved word: %s\n",tokenString);
         break;
    case PLUS: fprintf(listing,"+\n"); break;
    case MINUS: fprintf(listing,"-\n"); break;
    case LPAREN: fprintf(listing,"(\n"); break;
    case RPAREN: fprintf(listing,")\n"); break;
    case LT: fprintf(listing,"<\n"); break;
    case EQ: fprintf(listing,"=\n"); break;
    case ASSIGN: fprintf(listing,":=\n"); break;
    case SEMI: fprintf(listing,";\n"); break;
    case ENDFILE: fprintf(listing,"EOF\n"); break;
    case TIMES: fprintf(listing,"*\n",tokenString); break;
    case OVER: fprintf(listing,"/\n",tokenString); break;
    case NUM: 
         fprintf(listing,"NUM, val= %s\n",tokenString); break;
    case ID: 
         fprintf(listing,"ID, name= %s\n",tokenString); break;
    case ERROR:
        fprintf(listing,"ERROR: %s\n",tokenString); break;
    default: /* should never happen */
      fprintf(listing,"Unknown token: %d\n",token);
  }
}

/* function newstmtNode creates a new treenode
 * for syntax tree construction
 */

TreeNode * newStmtNode(StmtKind kind)
{ TreeNode * t = (TreeNode *) malloc(sizeof(TreeNode));
  int i;
  if (t==NULL)
    fprintf(listing,"Out of memory error at line %d\n",lineno);
  else{
    for(i=0;i<MAXCHILDREN;i++) t->child[i] = NULL;
    t->sibling = NULL;
    t->nodekind = StmtK;
    t->lineno = lineno;
    t->kind.stmt = kind;
  }
  return t;
}

TreeNode * newExpNode(ExpKind kind)
{ TreeNode * t = (TreeNode *) malloc(sizeof(TreeNode));
  int i;
  if (t==NULL)
    fprintf(listing,"Out of memory error at line %d\n",lineno);
  else {
    for (i=0;i<MAXCHILDREN;i++) t->child[i] = NULL;
    t->sibling = NULL;
    t->nodekind = ExpK;
    t->lineno = lineno;
    t->kind.exp = kind;
    t->type=Void;
  }
  return t;
}


/* function copyString allocates and makes a new
 * copy of an existing string
 */
char * copyString(char * s)
{ int n;
  char * t;
  if (s==NULL) return NULL;
  n = strlen(s)+1;
  t = malloc(n);
  if (t==NULL)
    fprintf(listing,"Out of memory error at line %d\n",lineno);
  else strcpy(t,s);
  return t;
}

/* variable indentno is used by printTree to
 * store current number of spaces to indent
 */
static indentno = 0;

/* macros to increase/decrease indentation */
#define INDENT indentno+=2
#define UNINDENT indentno-=2

/* printSpaces indents by printing spaces */
static void printSpaces(void)
{ int i;
  for (i=0;i<indentno;i++)
    fprintf(listing," ");
}

/* procedure printTree prints a syntax tree to the 
 * listing file using indentation to indicate subtrees
 */
void printTree(TreeNode * tree)
{ int i;
  INDENT;
  while (tree != NULL) {
	printSpaces();
    if(tree->nodekind==StmtK)
     { switch (tree ->kind.stmt) 
        {
         case IfK:
          fprintf(listing,"If\n");
          break;
		 case RepeatK:
		  fprintf(listing,"Repeat\n");
		   break;
         case AssignK:
          fprintf(listing,"Assign to:%s\n",tree->attr.name);
          break;
         case ReadK:
          fprintf(listing,"Read:%s\n",tree->attr.name);
          break;
         case WriteK:
          fprintf(listing,"Write\n");
          break;
	 default:
            fprintf(listing,"Unknown,ExpNode kind\n");
            break;	
         }
    }
     else if(tree->nodekind==ExpK)
    { 
        switch(tree->kind.exp){
         case OpK:
			fprintf(listing,"Op:");
                        printToken(tree->attr.op,'\0');
			break;
	 case ConstK:
		     fprintf(listing,"const:%d\n",tree->attr.val);
			break;
         case IdK:
		    fprintf(listing,"ID: %s\n",tree->attr.name);
			break;
		
     
        default:
          fprintf(listing,"Unknown EXpNode kind\n");
          break;
      }
}
    else fprintf(listing,"Unknown node kind\n");
    for (i=0;i<MAXCHILDREN;i++)
         printTree(tree->child[i]);
    tree = tree->sibling;
  }
  UNINDENT;
}