symbol.c

来自「a compiler in java that parses and creat」· C语言 代码 · 共 42 行

#include "global.h"

#define STRMAX 999	/* size of lexeme array */
#define SYMMAX 100	/* size of symtable */

char lexemes [STRMAX];

/* las used position in lexemes */
int lastchar = -1;

struct entry symtable[SYMMAX];

/* last used position in symtable */
int lastentry = 0;

/* returns the position of entry for s */
int lookup(char s[]) {	
	int p;
	for( p=lastentry; p>0;  p-=1 ) 
		if(strcmp(symtable[p].lexptr, s) == 0)
			return p;
	return 0;
}

/* returns position of entry for s */
int insert(char s[], int tok) {
	int len;
	/* strlen computes length of s */
	len = strlen(s);
	if(lastentry + 1 > SYMMAX)
		error(" Symbol Table Full ");
	if(lastchar + len + 1 >= STRMAX )
		error(" Lexemes Array Full ");
	lastentry = lastentry + 1;
	symtable[lastentry].token = tok;
	symtable[lastentry].lexptr = &lexemes[lastchar + 1];
	lastchar = lastchar + len + 1;
	strcpy(symtable[lastentry].lexptr, s);
	return lastentry;
}