co.c

早期freebsd实现

                        if (!rmworkfile()) continue;

                /* skip description */
                getdesc(false); /* don't echo*/

		locker_expansion = 0 < lockflag;
		joinfilename = buildrevision(
			gendeltas, targetdelta,
			join&&tostdout ? (FILE*)0 : neworkptr,
			Expand!=OLD_EXPAND
		);
#		if !large_memory
			if (fcopy == neworkptr)
				fcopy = 0;  /* Don't close it twice.  */
#		endif
		if_advise_access(changelock && gendeltas->first!=targetdelta,
			finptr, MADV_SEQUENTIAL
		);

		if (!donerewrite(changelock))
			continue;

		newdate = targetdelta->date;
		if (join) {
			newdate = 0;
			if (!joinfilename) {
				aflush(neworkptr);
				joinfilename = neworkfilename;
			}
			if (!buildjoin(joinfilename))
				continue;
		}
        }
	if (!tostdout) {
	    r = 0;
	    if (mtimeflag && newdate) {
		if (!join)
		    aflush(neworkptr);
		r = setfiledate(neworkfilename, newdate);
	    }
	    if (r == 0) {
		ignoreints();
		r = chnamemod(&neworkptr, neworkfilename, workfilename,
		  WORKMODE(RCSstat.st_mode,
		    !(Expand==VAL_EXPAND || lockflag<=0&&StrictLocks)
		  )
		);
		keepdirtemp(neworkfilename);
		restoreints();
	    }
	    if (r != 0) {
		eerror(workfilename);
		error("see %s", neworkfilename);
		continue;
	    }
	    diagnose("done\n");
	}
        } while (cleanup(),
                 ++argv, --argc >=1);

	tempunlink();
	Ofclose(workstdout);
	exitmain(exitstatus);

}       /* end of main (co) */

	static void
cleanup()
{
	if (nerror) exitstatus = EXIT_FAILURE;
	Izclose(&finptr);
	Ozclose(&frewrite);
#	if !large_memory
		if (fcopy!=workstdout) Ozclose(&fcopy);
#	endif
	if (neworkptr!=workstdout) Ozclose(&neworkptr);
	dirtempunlink();
}

#if lint
#	define exiterr coExit
#endif
	exiting void
exiterr()
{
	dirtempunlink();
	tempunlink();
	_exit(EXIT_FAILURE);
}


/*****************************************************************
 * The following routines are auxiliary routines
 *****************************************************************/

	static int
rmworkfile()
/* Function: prepares to remove workfilename, if it exists, and if
 * it is read-only.
 * Otherwise (file writable):
 *   if !quietmode asks the user whether to really delete it (default: fail);
 *   otherwise failure.
 * Returns true if permission is gotten.
 */
{
	if (workstat.st_mode&(S_IWUSR|S_IWGRP|S_IWOTH) && !forceflag) {
	    /* File is writable */
	    if (!yesorno(false, "writable %s exists%s; remove it? [ny](n): ",
			workfilename,
			myself(workstat.st_uid) ? "" : ", and you do not own it"
	    )) {
		error(!quietflag && ttystdin()
			? "checkout aborted"
			: "writable %s exists; checkout aborted", workfilename);
		return false;
            }
        }
	/* Actual unlink is done later by caller. */
	return true;
}


	static int
rmlock(delta)
	struct hshentry const *delta;
/* Function: removes the lock held by caller on delta.
 * Returns -1 if someone else holds the lock,
 * 0 if there is no lock on delta,
 * and 1 if a lock was found and removed.
 */
{       register struct lock * next, * trail;
	char const *num;
        struct lock dummy;
        int whomatch, nummatch;

        num=delta->num;
        dummy.nextlock=next=Locks;
        trail = &dummy;
        while (next!=nil) {
		whomatch = strcmp(getcaller(), next->login);
                nummatch=strcmp(num,next->delta->num);
                if ((whomatch==0) && (nummatch==0)) break;
			/*found a lock on delta by caller*/
                if ((whomatch!=0)&&(nummatch==0)) {
                    error("revision %s locked by %s; use co -r or rcs -u",num,next->login);
                    return -1;
                }
                trail=next;
                next=next->nextlock;
        }
        if (next!=nil) {
                /*found one; delete it */
                trail->nextlock=next->nextlock;
                Locks=dummy.nextlock;
                next->delta->lockedby=nil; /* reset locked-by */
                return 1; /*success*/
        } else  return 0; /*no lock on delta*/
}




/*****************************************************************
 * The rest of the routines are for handling joins
 *****************************************************************/


	static char const *
addjoin(joinrev)
	char *joinrev;
/* Add joinrev's number to joinlist, yielding address of char past joinrev,
 * or nil if no such revision exists.
 */
{
	register char *j;
	register struct hshentry const *d;
	char terminator;
	struct buf numrev;
	struct hshentries *joindeltas;

	j = joinrev;
	for (;;) {
	    switch (*j++) {
		default:
		    continue;
		case 0:
		case ' ': case '\t': case '\n':
		case ':': case ',': case ';':
		    break;
	    }
	    break;
	}
	terminator = *--j;
	*j = 0;
	bufautobegin(&numrev);
	d = 0;
	if (expandsym(joinrev, &numrev))
	    d = genrevs(numrev.string,(char*)nil,(char*)nil,(char*)nil,&joindeltas);
	bufautoend(&numrev);
	*j = terminator;
	if (d) {
		joinlist[++lastjoin] = d->num;
		return j;
	}
	return nil;
}

	static int
preparejoin()
/* Function: Parses a join list pointed to by join and places pointers to the
 * revision numbers into joinlist.
 */
{
	register char const *j;

        j=join;
        lastjoin= -1;
        for (;;) {
                while ((*j==' ')||(*j=='\t')||(*j==',')) j++;
                if (*j=='\0') break;
                if (lastjoin>=joinlength-2) {
                        error("too many joins");
                        return(false);
                }
		if (!(j = addjoin(j))) return false;
                while ((*j==' ') || (*j=='\t')) j++;
                if (*j == ':') {
                        j++;
                        while((*j==' ') || (*j=='\t')) j++;
                        if (*j!='\0') {
				if (!(j = addjoin(j))) return false;
                        } else {
                                error("join pair incomplete");
                                return false;
                        }
                } else {
                        if (lastjoin==0) { /* first pair */
                                /* common ancestor missing */
                                joinlist[1]=joinlist[0];
                                lastjoin=1;
                                /*derive common ancestor*/
				if (!(joinlist[0] = getancestor(targetdelta->num,joinlist[1])))
                                       return false;
                        } else {
                                error("join pair incomplete");
                                return false;
                        }
                }
        }
        if (lastjoin<1) {
                error("empty join");
                return false;
        } else  return true;
}



	static char const *
getancestor(r1, r2)
	char const *r1, *r2;
/* Yield the common ancestor of r1 and r2 if successful, nil otherwise.
 * Work reliably only if r1 and r2 are not branch numbers.
 */
{
	static struct buf t1, t2;

	unsigned l1, l2, l3;
	char const *r;

	l1 = countnumflds(r1);
	l2 = countnumflds(r2);
	if ((2<l1 || 2<l2)  &&  cmpnum(r1,r2)!=0) {
	    /* not on main trunk or identical */
	    l3 = 0;
	    while (cmpnumfld(r1, r2, l3+1)==0 && cmpnumfld(r1, r2, l3+2)==0)
		l3 += 2;
	    /* This will terminate since r1 and r2 are not the same; see above. */
	    if (l3==0) {
		/* no common prefix; common ancestor on main trunk */
		VOID partialno(&t1, r1, l1>2 ? (unsigned)2 : l1);
		VOID partialno(&t2, r2, l2>2 ? (unsigned)2 : l2);
		r = cmpnum(t1.string,t2.string)<0 ? t1.string : t2.string;
		if (cmpnum(r,r1)!=0 && cmpnum(r,r2)!=0)
			return r;
	    } else if (cmpnumfld(r1, r2, l3+1)!=0)
			return partialno(&t1,r1,l3);
	}
	error("common ancestor of %s and %s undefined", r1, r2);
	return nil;
}



	static int
buildjoin(initialfile)
	char const *initialfile;
/* Function: merge pairs of elements in joinlist into initialfile
 * If workstdout is set, copy result to stdout.
 * All unlinking of initialfile, rev2, and rev3 should be done by tempunlink().
 */
{
	struct buf commarg;
	struct buf subs;
	char const *rev2, *rev3;
        int i;
	char const *cov[10], *mergev[12];
	char const **p;

	bufautobegin(&commarg);
	bufautobegin(&subs);
	rev2 = maketemp(0);
	rev3 = maketemp(3); /* buildrevision() may use 1 and 2 */

	cov[0] = nil;
	/* cov[1] setup below */
	cov[2] = CO;
	/* cov[3] setup below */
	p = &cov[4];
	if (expandarg) *p++ = expandarg;
	if (suffixarg) *p++ = suffixarg;
	if (versionarg) *p++ = versionarg;
	*p++ = quietarg;
	*p++ = RCSfilename;
	*p = nil;

	mergev[0] = nil;
	mergev[1] = nil;
	mergev[2] = MERGE;
	mergev[3] = mergev[5] = "-L";
	/* rest of mergev setup below */

        i=0;
        while (i<lastjoin) {
                /*prepare marker for merge*/
                if (i==0)
			bufscpy(&subs, targetdelta->num);
		else {
			bufscat(&subs, ",");
			bufscat(&subs, joinlist[i-2]);
			bufscat(&subs, ":");
			bufscat(&subs, joinlist[i-1]);
		}
		diagnose("revision %s\n",joinlist[i]);
		bufscpy(&commarg, "-p");
		bufscat(&commarg, joinlist[i]);
		cov[1] = rev2;
		cov[3] = commarg.string;
		if (runv(cov))
			goto badmerge;
		diagnose("revision %s\n",joinlist[i+1]);
		bufscpy(&commarg, "-p");
		bufscat(&commarg, joinlist[i+1]);
		cov[1] = rev3;
		cov[3] = commarg.string;
		if (runv(cov))
			goto badmerge;
		diagnose("merging...\n");
		mergev[4] = subs.string;
		mergev[6] = joinlist[i+1];
		p = &mergev[7];
		if (quietflag) *p++ = quietarg;
		if (lastjoin<=i+2 && workstdout) *p++ = "-p";
		*p++ = initialfile;
		*p++ = rev2;
		*p++ = rev3;
		*p = nil;
		switch (runv(mergev)) {
		    case DIFF_FAILURE: case DIFF_SUCCESS:
			break;
		    default:
			goto badmerge;
		}
                i=i+2;
        }
	bufautoend(&commarg);
	bufautoend(&subs);
        return true;

    badmerge:
	nerror++;
	bufautoend(&commarg);
	bufautoend(&subs);
	return false;
}