util.c

根据编译器的基本原理

/****************************************************/
/* 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:
	case TR:
	case FAL:
	case AND:
	case NOT:
	case INT:
	case BOOL:
	case STRING:
	case DO:
	case WHILE:
      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 GT: fprintf(listing,">\n"); break;
	case NGT: fprintf(listing,"<=\n"); break;
	case NLT: fprintf(listing,">=\n"); break;
	case COMMA: fprintf(listing,",\n"); break;
	case SQUOTE: fprintf(listing,"'\n"); break;
    case NUM:
      fprintf(listing,
          "NUM, val= %s\n",tokenString);
      break;
    case ID:
      fprintf(listing,
          "ID, name= %s\n",tokenString);
      break;
	case STR:
	  fprintf(listing,
		  "STRING, val=%s\n",tokenString);
	  break;
    case ERROR1:
      fprintf(listing,
          "LEXICAL ERROR-illegal character: %s\n",tokenString);
      break;
	case ERROR2:
	  fprintf(listing,
		  "LEXICAL ERROR-right bracket of a string is lost: %s",tokenString);
	  break;
	case ERROR3:
	  fprintf(listing,
		  "LEXICAL ERROR-right delimiter of a comment is lost.\n");
	  break;
    default: /* should never happen */
      fprintf(listing,"Unknown token: %d\n",token);
  }
}

/* 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;
	}
	t->tempname="";
	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;
	}
	t->tempname="";
	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;
			
			case WhileK:	fprintf(listing,"Do while\n"); break;
			case IntK:		fprintf(listing,"Int:\n"); break;
			case BoolK:		fprintf(listing,"Bool:\n"); break;
			case StringK:	fprintf(listing,"String:\n"); break;
			default:		fprintf(listing,"Unknown ExpNode kind\n"); break;
			}
		}
		else if (tree->nodekind==ExpK)
		{ 
			switch (tree->kind.exp) 
			{
			case OpK:
				fprintf(listing,"Op: ");
				switch(tree->attr.op)
				{
				case LT:		fprintf(listing,"<\n"); break;
				case EQ:		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 OR:		fprintf(listing,"or\n"); break;
				case AND:		fprintf(listing,"and\n"); break;
				case NOT:		fprintf(listing,"not\n"); break;
				case GT:		fprintf(listing,">\n"); break;
				case NGT:		fprintf(listing,"<=\n"); break;
				case NLT:		fprintf(listing,">=\n"); break;
				default:
					fprintf(listing,"Unknown ExpNode kind\n");
					break;
				}
				break;
			case ConstK:	fprintf(listing,"Const: %d\n",tree->attr.val); break;
			case IdK:		fprintf(listing,"Id: %s\n",tree->attr.name); break;
			case StrK:		fprintf(listing,"String: '%s'\n",tree->attr.str); break;
			case BK:		fprintf(listing,"Bool: %d\n",tree->attr.val); 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;
}