util.c

1.小型编译器 2。支持整数

/****************************************************/
/* File: util.c                                     */
/* Utility function implementation                  */
/* for the TINY compiler                            */
/* Compiler Construction: Principles and Practice   */
/* Kenneth C. Louden                                */
/****************************************************/

#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 ASSIGN: 
			fprintf(listing,":=\n"); 
			break;
    	case LT: 
			fprintf(listing,"<\n"); 
			break;
    	case EQ: 
			fprintf(listing,"=\n"); 
			break;
    	case LPAREN: 
			fprintf(listing,"(\n"); 
			break;
    	case RPAREN: 
			fprintf(listing,")\n"); 
			break;
    	case SEMI: 
			fprintf(listing,";\n"); 
			break;
    	case PLUS: 
			fprintf(listing,"+\n"); 
			break;
    	case MINUS: 
			fprintf(listing,"-\n"); 
			break;
    	case TIMES: 
			fprintf(listing,"*\n"); 
			break;
    	case OVER: 
			fprintf(listing,"/\n"); 
			break;
    	case ENDFILE: 
			fprintf(listing,"EOF\n"); 
			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);
			break;
  	}
}

/* Function newStmtNode creates a new statement
 * node 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->kind.stmt = kind;
    	t->lineno = lineno;
  	}
  	return t;
}

/* Function newExpNode creates a new expression 
 * node for syntax tree construction
 */
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->kind.exp = kind;
    	t->lineno = lineno;
    	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 = (char*)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 int 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;
}