自学教程：C++ tempfree函数代码示例

Cell *cat(Node **a, int q)	/* a[0] cat a[1] */{	Cell *x, *y, *z;	int n1, n2;	char *s;	x = execute(a[0]);	y = execute(a[1]);	getsval(x);	getsval(y);	n1 = strlen(x->sval);	n2 = strlen(y->sval);	s = (char *) malloc(n1 + n2 + 1);	if (s == NULL)		ERROR "out of space concatenating %.15s... and %.15s...",			x->sval, y->sval FATAL;	strcpy(s, x->sval);	strcpy(s+n1, y->sval);	tempfree(y);	z = gettemp();	z->sval = s;	z->tval = STR;	tempfree(x);	return(z);}

Cell *intest(Node **a, int n)	/* a[0] is index (list), a[1] is symtab */{	Cell *x, *ap, *k;	Node *p;	char buf[RECSIZE];	char *s;	ap = execute(a[1]);	/* array name */	if (!isarr(ap)) {		dprintf( ("making %s into an array/n", ap->nval) );		if (freeable(ap))			xfree(ap->sval);		ap->tval &= ~(STR|NUM|DONTFREE);		ap->tval |= ARR;		ap->sval = (char *) makesymtab(NSYMTAB);	}	buf[0] = 0;	for (p = a[0]; p; p = p->nnext) {		x = execute(p);	/* expr */		s = getsval(x);		strcat(buf, s);		tempfree(x);		if (p->nnext)			strcat(buf, *SUBSEP);	}	k = lookup(buf, (Array *) ap->sval);	tempfree(ap);	if (k == NULL)		return(false);	else		return(true);}

Cell *instat(Node **a, int n)	/* for (a[0] in a[1]) a[2] */{	Cell *x, *vp, *arrayp, *cp, *ncp;	Array *tp;	int i;	vp = execute(a[0]);	arrayp = execute(a[1]);	if (!isarr(arrayp)) {		return true;	}	tp = (Array *) arrayp->sval;	tempfree(arrayp);	for (i = 0; i < tp->size; i++) {	/* this routine knows too much */		for (cp = tp->tab[i]; cp != NULL; cp = ncp) {			setsval(vp, cp->nval);			ncp = cp->cnext;			x = execute(a[2]);			if (isbreak(x)) {				tempfree(vp);				return true;			}			if (isnext(x) || isexit(x) || isret(x)) {				tempfree(vp);				return(x);			}			tempfree(x);		}	}	return true;}

Cell *ifstat(Node **a, int n)	/* if (a[0]) a[1]; else a[2] */{	Cell *x;	x = execute(a[0]);	if (istrue(x)) {		tempfree(x);		x = execute(a[1]);	} else if (a[2] != 0) {		tempfree(x);		x = execute(a[2]);	}	return(x);}

Cell *execute(Node *u)	/* execute a node of the parse tree */{	Cell *(*proc)(Node **, int);	Cell *x;	Node *a;	if (u == NULL)		return(true);	for (a = u; ; a = a->nnext) {		curnode = a;		if (isvalue(a)) {			x = (Cell *) (a->narg[0]);			if ((x->tval & FLD) && !donefld)				fldbld();			else if ((x->tval & REC) && !donerec)				recbld();			return(x);		}		if (notlegal(a->nobj))	/* probably a Cell* but too risky to print */			ERROR "illegal statement" FATAL;		proc = proctab[a->nobj-FIRSTTOKEN];		x = (*proc)(a->narg, a->nobj);		if ((x->tval & FLD) && !donefld)			fldbld();		else if ((x->tval & REC) && !donerec)			recbld();		if (isexpr(a))			return(x);		if (isjump(x))			return(x);		if (a->nnext == NULL)			return(x);		tempfree(x);	}}

Cell *printstat(Node **a, int n)	/* print a[0] */{	register Node *x;	register Cell *y;	FILE *fp;	if (a[1] == 0)	/* a[1] is redirection operator, a[2] is file */		fp = stdout;	else		fp = redirect((int)a[1], a[2]);	for (x = a[0]; x != NULL; x = x->nnext) {		y = execute(x);		fputs((char *)getsval(y), fp);		tempfree(y);		if (x->nnext == NULL)			fputs((char *)*ORS, fp);		else			fputs((char *)*OFS, fp);	}	if (a[1] != 0)		fflush(fp);	if (ferror(fp))		ERROR "write error on %s", filename(fp) FATAL;	return(true);}

Cell *dostat(Node **a, int n)	/* do a[0]; while(a[1]) */{	Cell *x;	for (;;) {		x = execute(a[0]);		if (isbreak(x))			return true;		if (isnext(x) || isnextfile(x) || isexit(x) || isret(x))			return(x);		tempfree(x);		x = execute(a[1]);		if (!istrue(x))			return(x);		tempfree(x);	}}

Cell *jump(Node **a, int n)	/* break, continue, next, nextfile, return */{	Cell *y;	switch (n) {	case EXIT:		if (a[0] != NULL) {			y = execute(a[0]);			errorflag = getfval(y);			tempfree(y);		}		longjmp(env, 1);	case RETURN:		if (a[0] != NULL) {			y = execute(a[0]);			if ((y->tval & (STR|NUM)) == (STR|NUM)) {				setsval(fp->retval, getsval(y));				fp->retval->fval = getfval(y);				fp->retval->tval |= NUM;			}			else if (y->tval & STR)				setsval(fp->retval, getsval(y));			else if (y->tval & NUM)				setfval(fp->retval, getfval(y));			else		/* can't happen */				ERROR "bad type variable %d", y->tval FATAL;			tempfree(y);		}		return(jret);	case NEXT:		return(jnext);	case NEXTFILE:		nextfile();		return(jnextfile);	case BREAK:		return(jbreak);	case CONTINUE:		return(jcont);	default:	/* can't happen */		ERROR "illegal jump type %d", n FATAL;	}	return 0;	/* not reached */}

Cell *matchop(Node **a, int n)	/* ~ and match() */{	Cell *x, *y;	char *s, *t;	int i;	fa *pfa;	int (*mf)(fa *, char *) = match, mode = 0;	if (n == MATCHFCN) {		mf = pmatch;		mode = 1;	}	x = execute(a[1]);	/* a[1] = target text */	s = getsval(x);	if (a[0] == 0)		/* a[1] == 0: already-compiled reg expr */		i = (*mf)((fa *) a[2], s);	else {		y = execute(a[2]);	/* a[2] = regular expr */		t = getsval(y);		pfa = makedfa(t, mode);		i = (*mf)(pfa, s);		tempfree(y);	}	tempfree(x);	if (n == MATCHFCN) {		int start = patbeg - s + 1;		if (patlen < 0)			start = 0;		setfval(rstartloc, (Awkfloat) start);		setfval(rlengthloc, (Awkfloat) patlen);		x = gettemp();		x->tval = NUM;		x->fval = start;		return x;	} else if ((n == MATCH && i == 1) || (n == NOTMATCH && i == 0))		return(true);	else		return(false);}