unifdef.c

				incomment = CHAR_LITERAL;
				linestate = LS_DIRTY;
				cp += 1;
			} else if (strncmp(cp, "\"", 1) == 0) {
				incomment = STRING_LITERAL;
				linestate = LS_DIRTY;
				cp += 1;
			} else if (strncmp(cp, "\n", 1) == 0) {
				linestate = LS_START;
				cp += 1;
			} else if (strchr(" \r\t", *cp) != NULL) {
				cp += 1;
			} else
				return (cp);
			continue;
		case CXX_COMMENT:
			if (strncmp(cp, "\n", 1) == 0) {
				incomment = NO_COMMENT;
				linestate = LS_START;
			}
			cp += 1;
			continue;
		case CHAR_LITERAL:
		case STRING_LITERAL:
			if ((incomment == CHAR_LITERAL && cp[0] == '\'') ||
			    (incomment == STRING_LITERAL && cp[0] == '\"')) {
				incomment = NO_COMMENT;
				cp += 1;
			} else if (cp[0] == '\\') {
				if (cp[1] == '\0')
					cp += 1;
				else
					cp += 2;
			} else if (strncmp(cp, "\n", 1) == 0) {
				if (incomment == CHAR_LITERAL)
					error("unterminated char literal");
				else
					error("unterminated string literal");
			} else
				cp += 1;
			continue;
		case C_COMMENT:
			if (strncmp(cp, "*\\\r\n", 4) == 0) {
				incomment = FINISHING_COMMENT;
				cp += 4;
			} else if (strncmp(cp, "*\\\n", 3) == 0) {
				incomment = FINISHING_COMMENT;
				cp += 3;
			} else if (strncmp(cp, "*/", 2) == 0) {
				incomment = NO_COMMENT;
				cp += 2;
			} else
				cp += 1;
			continue;
		case STARTING_COMMENT:
			if (*cp == '*') {
				incomment = C_COMMENT;
				cp += 1;
			} else if (*cp == '/') {
				incomment = CXX_COMMENT;
				cp += 1;
			} else {
				incomment = NO_COMMENT;
				linestate = LS_DIRTY;
			}
			continue;
		case FINISHING_COMMENT:
			if (*cp == '/') {
				incomment = NO_COMMENT;
				cp += 1;
			} else
				incomment = C_COMMENT;
			continue;
		default:
			abort(); /* bug */
		}
	return (cp);
}

/*
 * Skip macro arguments.
 */
static const char *
skipargs(const char *cp)
{
	const char *ocp = cp;
	int level = 0;
	cp = skipcomment(cp);
	if (*cp != '(')
		return (cp);
	do {
		if (*cp == '(')
			level++;
		if (*cp == ')')
			level--;
		cp = skipcomment(cp+1);
	} while (level != 0 && *cp != '\0');
	if (level == 0)
		return (cp);
	else
	/* Rewind and re-detect the syntax error later. */
		return (ocp);
}

/*
 * Skip over an identifier.
 */
static const char *
skipsym(const char *cp)
{
	while (!endsym(*cp))
		++cp;
	return (cp);
}

/*
 * Look for the symbol in the symbol table. If it is found, we return
 * the symbol table index, else we return -1.
 */
static int
findsym(const char *str)
{
	const char *cp;
	int symind;

	cp = skipsym(str);
	if (cp == str)
		return (-1);
	if (symlist) {
		if (symdepth && firstsym)
			printf("%s%3d", zerosyms ? "" : "\n", depth);
		firstsym = zerosyms = false;
		printf("%s%.*s%s",
		    symdepth ? " " : "",
		    (int)(cp-str), str,
		    symdepth ? "" : "\n");
		/* we don't care about the value of the symbol */
		return (0);
	}
	for (symind = 0; symind < nsyms; ++symind) {
		if (strlcmp(symname[symind], str, cp-str) == 0) {
			debug("findsym %s %s", symname[symind],
			    value[symind] ? value[symind] : "");
			return (symind);
		}
	}
	return (-1);
}

/*
 * Add a symbol to the symbol table.
 */
static void
addsym(bool ignorethis, bool definethis, char *sym)
{
	int symind;
	char *val;

	symind = findsym(sym);
	if (symind < 0) {
		if (nsyms >= MAXSYMS)
			errx(2, "too many symbols");
		symind = nsyms++;
	}
	symname[symind] = sym;
	ignore[symind] = ignorethis;
	val = sym + (skipsym(sym) - sym);
	if (definethis) {
		if (*val == '=') {
			value[symind] = val+1;
			*val = '\0';
		} else if (*val == '\0')
			value[symind] = "1";
		else
			usage();
	} else {
		if (*val != '\0')
			usage();
		value[symind] = NULL;
	}
	debug("addsym %s=%s", symname[symind],
	    value[symind] ? value[symind] : "undef");
}

/*
 * Compare s with n characters of t.
 * The same as strncmp() except that it checks that s[n] == '\0'.
 */
static int
strlcmp(const char *s, const char *t, size_t n)
{
	while (n-- && *t != '\0')
		if (*s != *t)
			return ((unsigned char)*s - (unsigned char)*t);
		else
			++s, ++t;
	return ((unsigned char)*s);
}

/*
 * Diagnostics.
 */
static void
debug(const char *msg, ...)
{
	va_list ap;

	if (debugging) {
		va_start(ap, msg);
		vwarnx(msg, ap);
		va_end(ap);
	}
}

static void
error(const char *msg)
{
	if (depth == 0)
		warnx("%s: %d: %s", filename, linenum, msg);
	else
		warnx("%s: %d: %s (#if line %d depth %d)",
		    filename, linenum, msg, stifline[depth], depth);
	closeout();
	errx(2, "output may be truncated");
}