rcsrev.c

早期freebsd实现

/*
 *                     RCS revision number handling
 */

/* Copyright (C) 1982, 1988, 1989 Walter Tichy
   Copyright 1990, 1991 by Paul Eggert
   Distributed under license by the Free Software Foundation, Inc.

This file is part of RCS.

RCS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

RCS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with RCS; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

Report problems and direct all questions to:

    [e-mail]

*/




/* $Log: rcsrev.c,v $
 * Revision 5.3  1991/08/19  03:13:55  eggert
 * Add `-r$', `-rB.'.  Remove botches like `<now>' from messages.  Tune.
 *
 * Revision 5.2  1991/04/21  11:58:28  eggert
 * Add tiprev().
 *
 * Revision 5.1  1991/02/25  07:12:43  eggert
 * Avoid overflow when comparing revision numbers.
 *
 * Revision 5.0  1990/08/22  08:13:43  eggert
 * Remove compile-time limits; use malloc instead.
 * Ansify and Posixate.  Tune.
 * Remove possibility of an internal error.  Remove lint.
 *
 * Revision 4.5  89/05/01  15:13:22  narten
 * changed copyright header to reflect current distribution rules
 * 
 * Revision 4.4  87/12/18  11:45:22  narten
 * more lint cleanups. Also, the NOTREACHED comment is no longer necessary, 
 * since there's now a return value there with a value. (Guy Harris)
 * 
 * Revision 4.3  87/10/18  10:38:42  narten
 * Updating version numbers. Changes relative to version 1.1 actually 
 * relative to 4.1
 * 
 * Revision 1.3  87/09/24  14:00:37  narten
 * Sources now pass through lint (if you ignore printf/sprintf/fprintf 
 * warnings)
 * 
 * Revision 1.2  87/03/27  14:22:37  jenkins
 * Port to suns
 * 
 * Revision 4.1  83/03/25  21:10:45  wft
 * Only changed $Header to $Id.
 * 
 * Revision 3.4  82/12/04  13:24:08  wft
 * Replaced getdelta() with gettree().
 *
 * Revision 3.3  82/11/28  21:33:15  wft
 * fixed compartial() and compnum() for nil-parameters; fixed nils
 * in error messages. Testprogram output shortenend.
 *
 * Revision 3.2  82/10/18  21:19:47  wft
 * renamed compnum->cmpnum, compnumfld->cmpnumfld,
 * numericrevno->numricrevno.
 *
 * Revision 3.1  82/10/11  19:46:09  wft
 * changed expandsym() to check for source==nil; returns zero length string
 * in that case.
 */



/*
#define REVTEST
*/
/* version REVTEST is for testing the routines that generate a sequence
 * of delta numbers needed to regenerate a given delta.
 */

#include "rcsbase.h"

libId(revId, "$Id: rcsrev.c,v 5.3 1991/08/19 03:13:55 eggert Exp $")

static char const *branchtip P((char const*));
static struct hshentry *genbranch P((struct hshentry const*,char const*,unsigned,char const*,char const*,char const*,struct hshentries**));



	unsigned
countnumflds(s)
	char const *s;
/* Given a pointer s to a dotted number (date or revision number),
 * countnumflds returns the number of digitfields in s.
 */
{
	register char const *sp;
	register unsigned count;
        if ((sp=s)==nil) return(0);
        if (*sp == '\0') return(0);
        count = 1;
	do {
                if (*sp++ == '.') count++;
	} while (*sp);
        return(count);
}

	void
getbranchno(revno,branchno)
	char const *revno;
	struct buf *branchno;
/* Given a non-nil revision number revno, getbranchno copies the number of the branch
 * on which revno is into branchno. If revno itself is a branch number,
 * it is copied unchanged.
 */
{
	register unsigned numflds;
	register char *tp;

	bufscpy(branchno, revno);
        numflds=countnumflds(revno);
	if (!(numflds & 1)) {
		tp = branchno->string;
		while (--numflds)
			while (*tp++ != '.')
				;
                *(tp-1)='\0';
        }
}



int cmpnum(num1, num2)
	char const *num1, *num2;
/* compares the two dotted numbers num1 and num2 lexicographically
 * by field. Individual fields are compared numerically.
 * returns <0, 0, >0 if num1<num2, num1==num2, and num1>num2, resp.
 * omitted fields are assumed to be higher than the existing ones.
*/
{
	register char const *s1, *s2;
	register size_t d1, d2;
	register int r;

        s1=num1==nil?"":num1;
        s2=num2==nil?"":num2;

	for (;;) {
		/* Give precedence to shorter one.  */
		if (!*s1)
			return (unsigned char)*s2;
		if (!*s2)
			return -1;

		/* Strip leading zeros, then find number of digits.  */
		while (*s1=='0') ++s1;  for (d1=0; isdigit(s1[d1]); d1++) ;
		while (*s2=='0') ++s2;  for (d2=0; isdigit(s2[d2]); d2++) ;

		/* Do not convert to integer; it might overflow!  */
		if (d1 != d2)
			return d1<d2 ? -1 : 1;
		if ((r = memcmp(s1, s2, d1)))
			return r;
		s1 += d1;
		s2 += d1;

                /* skip '.' */
		if (*s1) s1++;
		if (*s2) s2++;
	}
}



int cmpnumfld(num1, num2, fld)
	char const *num1, *num2;
	unsigned fld;
/* Compare the two dotted numbers at field fld.
 * num1 and num2 must have at least fld fields.
 * fld must be positive.
*/
{
	register char const *s1, *s2;
	register size_t d1, d2;

	s1 = num1;
	s2 = num2;
        /* skip fld-1 fields */
	while (--fld) {
		while (*s1++ != '.')
			;
		while (*s2++ != '.')
			;
	}
        /* Now s1 and s2 point to the beginning of the respective fields */
	while (*s1=='0') ++s1;  for (d1=0; isdigit(s1[d1]); d1++) ;
	while (*s2=='0') ++s2;  for (d2=0; isdigit(s2[d2]); d2++) ;

	return d1<d2 ? -1 : d1==d2 ? memcmp(s1,s2,d1) : 1;
}


	static void
cantfindbranch(revno, date, author, state)
	char const *revno, date[datesize], *author, *state;
{
	char datebuf[datesize];

	error("No revision on branch %s has%s%s%s%s%s%s.",
		revno,
		date ? " a date before " : "",
		date ? date2str(date,datebuf) : "",
		author ? " and author "+(date?0:4) : "",
		author ? author : "",
		state ? " and state "+(date||author?0:4) : "",
		state ? state : ""
	);
}

	static void
absent(revno, field)
	char const *revno;
	unsigned field;
{
	struct buf t;
	bufautobegin(&t);
	error("%s %s absent", field&1?"revision":"branch",
		partialno(&t,revno,field)
	);
	bufautoend(&t);
}


	int
compartial(num1, num2, length)
	char const *num1, *num2;
	unsigned length;

/*   compare the first "length" fields of two dot numbers;
     the omitted field is considered to be larger than any number  */
/*   restriction:  at least one number has length or more fields   */

{
	register char const *s1, *s2;
	register size_t d1, d2;
	register int r;

        s1 = num1;      s2 = num2;
	if (!s1) return 1;
	if (!s2) return -1;

	for (;;) {
	    if (!*s1) return 1;
	    if (!*s2) return -1;

	    while (*s1=='0') ++s1;  for (d1=0; isdigit(s1[d1]); d1++) ;
	    while (*s2=='0') ++s2;  for (d2=0; isdigit(s2[d2]); d2++) ;

	    if (d1 != d2)
		    return d1<d2 ? -1 : 1;
	    if ((r = memcmp(s1, s2, d1)))
		    return r;
	    s1 += d1;
	    s2 += d1;

	    if (*s1 == '.') s1++;
            if (*s2 == '.') s2++;

	    if ( --length == 0 ) return 0;
	}
}


char * partialno(rev1,rev2,length)
	struct buf *rev1;
	char const *rev2;
	register unsigned length;
/* Function: Copies length fields of revision number rev2 into rev1.
 * Return rev1's string.
 */
{
	register char *r1;

	bufscpy(rev1, rev2);
	r1 = rev1->string;
        while (length) {
		while (*r1!='.' && *r1)
			++r1;
		++r1;
                length--;
        }
        /* eliminate last '.'*/
        *(r1-1)='\0';
	return rev1->string;
}




	static void
store1(store, next)
	struct hshentries ***store;
	struct hshentry *next;
/*
 * Allocate a new list node that addresses NEXT.
 * Append it to the list that **STORE is the end pointer of.
 */
{
	register struct hshentries *p;

	p = ftalloc(struct hshentries);
	p->first = next;
	**store = p;
	*store = &p->rest;
}

struct hshentry * genrevs(revno,date,author,state,store)
	char const *revno, *date, *author, *state;
	struct hshentries **store;
/* Function: finds the deltas needed for reconstructing the
 * revision given by revno, date, author, and state, and stores pointers
 * to these deltas into a list whose starting address is given by store.
 * The last delta (target delta) is returned.
 * If the proper delta could not be found, nil is returned.
 */
{
	unsigned length;
        register struct hshentry * next;
        int result;
	char const *branchnum;
	struct buf t;
	char datebuf[datesize];

	bufautobegin(&t);

	if (!(next = Head)) {
		error("RCS file empty");
		goto norev;
        }

        length = countnumflds(revno);

        if (length >= 1) {
                /* at least one field; find branch exactly */
		while ((result=cmpnumfld(revno,next->num,1)) < 0) {
			store1(&store, next);
                        next = next->next;
			if (!next) {
			    error("branch number %s too low", partialno(&t,revno,1));
			    goto norev;
			}
                }

		if (result>0) {
			absent(revno, 1);
			goto norev;
		}
        }
        if (length<=1){
                /* pick latest one on given branch */
                branchnum = next->num; /* works even for empty revno*/
                while ((next!=nil) &&
                       (cmpnumfld(branchnum,next->num,1)==0) &&
                       !(
                        (date==nil?1:(cmpnum(date,next->date)>=0)) &&
                        (author==nil?1:(strcmp(author,next->author)==0)) &&
                        (state ==nil?1:(strcmp(state, next->state) ==0))
                        )
                       )
		{
			store1(&store, next);
                        next=next->next;
                }
                if ((next==nil) ||
                    (cmpnumfld(branchnum,next->num,1)!=0))/*overshot*/ {
			cantfindbranch(
				length ? revno : partialno(&t,branchnum,1),
				date, author, state
			);
			goto norev;
                } else {
			store1(&store, next);