tools/findunref/findunref.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Finds all unreferenced files in a source tree that do not match a list of
 * permitted pathnames.
 */

#include <ctype.h>
#include <errno.h>
#include <fnmatch.h>
#include <ftw.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/types.h>

/*
 * Pathname set: a simple datatype for storing pathname pattern globs and
 * for checking whether a given pathname is matched by a pattern glob in
 * the set.
 */
typedef struct {
    char        **paths;
    unsigned int    npath;
    unsigned int    maxpaths;
} pnset_t;

/*
 * Data associated with the current SCM manifest.
 */
typedef struct scmdata {
    pnset_t     *manifest;
    char        metapath[MAXPATHLEN];
    char        root[MAXPATHLEN];
    unsigned int    rootlen;
    boolean_t   rootwarn;
} scmdata_t;

/*
 * Hooks used to check if a given unreferenced file is known to an SCM
 * (currently Git, Mercurial and TeamWare).
 */
typedef int checkscm_func_t(const char *, const struct FTW *);
typedef void chdirscm_func_t(const char *);

typedef struct {
    const char  *name;
    checkscm_func_t *checkfunc;
    chdirscm_func_t *chdirfunc;
} scm_t;

static checkscm_func_t check_tw, check_scmdata;
static chdirscm_func_t chdir_hg, chdir_git;
static int  pnset_add(pnset_t *, const char *);
static int  pnset_check(const pnset_t *, const char *);
static void pnset_empty(pnset_t *);
static void pnset_free(pnset_t *);
static int  checkpath(const char *, const struct stat *, int, struct FTW *);
static pnset_t  *make_exset(const char *);
static void warn(const char *, ...);
static void die(const char *, ...);

static const scm_t scms[] = {
    { "tw",     check_tw,   NULL        },
    { "teamware",   check_tw,   NULL        },
    { "hg",     check_scmdata,  chdir_hg    },
    { "mercurial",  check_scmdata,  chdir_hg    },
    { "git",    check_scmdata,  chdir_git   },
    { NULL,     NULL,       NULL        }
};

static const scm_t  *scm;
static scmdata_t    scmdata;
static time_t       tstamp;     /* timestamp to compare files to */
static pnset_t      *exsetp;    /* pathname globs to ignore */
static const char   *progname;

int
main(int argc, char *argv[])
{
    int c;
    char path[MAXPATHLEN];
    char subtree[MAXPATHLEN] = "./";
    char *tstampfile = ".build.tstamp";
    struct stat tsstat;

    progname = strrchr(argv[0], '/');
    if (progname == NULL)
        progname = argv[0];
    else
        progname++;

    while ((c = getopt(argc, argv, "as:t:S:")) != EOF) {
        switch (c) {
        case 'a':
            /* for compatibility; now the default */
            break;

        case 's':
            (void) strlcat(subtree, optarg, MAXPATHLEN);
            break;

        case 't':
            tstampfile = optarg;
            break;

        case 'S':
            for (scm = scms; scm->name != NULL; scm++) {
                if (strcmp(scm->name, optarg) == 0)
                    break;
            }
            if (scm->name == NULL)
                die("unsupported SCM `%s'\n", optarg);
            break;

        default:
        case '?':
            goto usage;
        }
    }

    argc -= optind;
    argv += optind;

    if (argc != 2) {
usage:      (void) fprintf(stderr, "usage: %s [-s <subtree>] "
            "[-t <tstampfile>] [-S hg|tw|git] <srcroot> <exceptfile>\n",
            progname);
        return (EXIT_FAILURE);
    }

    /*
     * Interpret a relative timestamp path as relative to srcroot.
     */
    if (tstampfile[0] == '/')
        (void) strlcpy(path, tstampfile, MAXPATHLEN);
    else
        (void) snprintf(path, MAXPATHLEN, "%s/%s", argv[0], tstampfile);

    if (stat(path, &tsstat) == -1)
        die("cannot stat timestamp file \"%s\"", path);
    tstamp = tsstat.st_mtime;

    /*
     * Create the exception pathname set.
     */
    exsetp = make_exset(argv[1]);
    if (exsetp == NULL)
        die("cannot make exception pathname set\n");

    /*
     * Walk the specified subtree of the tree rooted at argv[0].
     */
    if (chdir(argv[0]) == -1)
        die("cannot change directory to \"%s\"", argv[0]);

    if (nftw(subtree, checkpath, 100, FTW_PHYS) != 0)
        die("cannot walk tree rooted at \"%s\"\n", argv[0]);

    pnset_empty(exsetp);
    return (EXIT_SUCCESS);
}

/*
 * Load and return a pnset for the manifest for the Mercurial repo at `hgroot'.
 */
static pnset_t *
hg_manifest(const char *hgroot)
{
    FILE    *fp = NULL;
    char    *hgcmd = NULL;
    char    *newline;
    pnset_t *pnsetp;
    char    path[MAXPATHLEN];

    pnsetp = calloc(sizeof (pnset_t), 1);
    if (pnsetp == NULL ||
        asprintf(&hgcmd, "hg manifest -R %s", hgroot) == -1)
        goto fail;

    fp = popen(hgcmd, "r");
    if (fp == NULL)
        goto fail;

    while (fgets(path, sizeof (path), fp) != NULL) {
        newline = strrchr(path, '\n');
        if (newline != NULL)
            *newline = '\0';

        if (pnset_add(pnsetp, path) == 0)
            goto fail;
    }

    (void) pclose(fp);
    free(hgcmd);
    return (pnsetp);
fail:
    warn("cannot load hg manifest at %s", hgroot);
    if (fp != NULL)
        (void) pclose(fp);
    free(hgcmd);
    pnset_free(pnsetp);
    return (NULL);
}

/*
 * Load and return a pnset for the manifest for the Git repo at `gitroot'.
 */
static pnset_t *
git_manifest(const char *gitroot)
{
    FILE    *fp = NULL;
    char    *gitcmd = NULL;
    char    *newline;
    pnset_t *pnsetp;
    char    path[MAXPATHLEN];

    pnsetp = calloc(sizeof (pnset_t), 1);
    if (pnsetp == NULL ||
        asprintf(&gitcmd, "git --git-dir=%s/.git ls-files", gitroot) == -1)
        goto fail;

    fp = popen(gitcmd, "r");
    if (fp == NULL)
        goto fail;

    while (fgets(path, sizeof (path), fp) != NULL) {
        newline = strrchr(path, '\n');
        if (newline != NULL)
            *newline = '\0';

        if (pnset_add(pnsetp, path) == 0)
            goto fail;
    }

    (void) pclose(fp);
    free(gitcmd);
    return (pnsetp);
fail:
    warn("cannot load git manifest at %s", gitroot);
    if (fp != NULL)
        (void) pclose(fp);
    free(gitcmd);
    pnset_free(pnsetp);
    return (NULL);
}

/*
 * If necessary, change our active manifest to be appropriate for `path'.
 */
static void
chdir_scmdata(const char *path, const char *meta,
    pnset_t *(*manifest_func)(const char *path))
{
    char scmpath[MAXPATHLEN];
    char basepath[MAXPATHLEN];
    char *slash;

    (void) snprintf(scmpath, MAXPATHLEN, "%s/%s", path, meta);

    /*
     * Change our active manifest if any one of the following is true:
     *
     *   1. No manifest is loaded.  Find the nearest SCM root to load from.
     *
     *   2. A manifest is loaded, but we've moved into a directory with
     *  its own metadata directory (e.g., usr/closed).  Load from its
     *  root.
     *
     *   3. A manifest is loaded, but no longer applies (e.g., the manifest
     *  under usr/closed is loaded, but we've moved to usr/src).
     */
    if (scmdata.manifest == NULL ||
        (strcmp(scmpath, scmdata.metapath) != 0 &&
        access(scmpath, X_OK) == 0) ||
        strncmp(path, scmdata.root, scmdata.rootlen - 1) != 0) {
        pnset_free(scmdata.manifest);
        scmdata.manifest = NULL;

        (void) strlcpy(basepath, path, MAXPATHLEN);

        /*
         * Walk up the directory tree looking for metadata
         * subdirectories.
         */
        while (access(scmpath, X_OK) == -1) {
            slash = strrchr(basepath, '/');
            if (slash == NULL) {
                if (!scmdata.rootwarn) {
                    warn("no metadata directory "
                        "for \"%s\"\n", path);
                    scmdata.rootwarn = B_TRUE;
                }
                return;
            }
            *slash = '\0';
            (void) snprintf(scmpath, MAXPATHLEN, "%s/%s", basepath,
                meta);
        }

        /*
         * We found a directory with an SCM metadata directory; record
         * it and load its manifest.
         */
        (void) strlcpy(scmdata.metapath, scmpath, MAXPATHLEN);
        (void) strlcpy(scmdata.root, basepath, MAXPATHLEN);
        scmdata.manifest = manifest_func(scmdata.root);

        /*
         * The logic in check_scmdata() depends on scmdata.root having
         * a single trailing slash, so only add it if it's missing.
         */
        if (scmdata.root[strlen(scmdata.root) - 1] != '/')
            (void) strlcat(scmdata.root, "/", MAXPATHLEN);
        scmdata.rootlen = strlen(scmdata.root);
    }
}

/*
 * If necessary, change our active manifest to be appropriate for `path'.
 */
static void
chdir_git(const char *path)
{
    chdir_scmdata(path, ".git", git_manifest);
}

static void
chdir_hg(const char *path)
{
    chdir_scmdata(path, ".hg", hg_manifest);
}

/* ARGSUSED */
static int
check_scmdata(const char *path, const struct FTW *ftwp)
{
    /*
     * The manifest paths are relative to the manifest root; skip past it.
     */
    path += scmdata.rootlen;

    return (scmdata.manifest != NULL && pnset_check(scmdata.manifest,
        path));
}

/*
 * Check if a file is under TeamWare control by checking for its corresponding
 * SCCS "s-dot" file.
 */
static int
check_tw(const char *path, const struct FTW *ftwp)
{
    char sccspath[MAXPATHLEN];

    (void) snprintf(sccspath, MAXPATHLEN, "%.*s/SCCS/s.%s", ftwp->base,
        path, path + ftwp->base);

    return (access(sccspath, F_OK) == 0);
}

/*
 * Using `exceptfile' and a built-in list of exceptions, build and return a
 * pnset_t consisting of all of the pathnames globs which are allowed to be
 * unreferenced in the source tree.
 */
static pnset_t *
make_exset(const char *exceptfile)
{
    FILE        *fp;
    char        line[MAXPATHLEN];
    char        *newline;
    pnset_t     *pnsetp;
    unsigned int    i;

    pnsetp = calloc(sizeof (pnset_t), 1);
    if (pnsetp == NULL)
        return (NULL);

    /*
     * Add any exceptions from the file.
     */
    fp = fopen(exceptfile, "r");
    if (fp == NULL) {
        warn("cannot open exception file \"%s\"", exceptfile);
        goto fail;
    }

    while (fgets(line, sizeof (line), fp) != NULL) {
        newline = strrchr(line, '\n');
        if (newline != NULL)
            *newline = '\0';

        for (i = 0; isspace(line[i]); i++)
            ;

        if (line[i] == '#' || line[i] == '\0')
            continue;

        if (pnset_add(pnsetp, line) == 0) {
            (void) fclose(fp);
            goto fail;
        }
    }

    (void) fclose(fp);
    return (pnsetp);
fail:
    pnset_free(pnsetp);
    return (NULL);
}

/*
 * FTW callback: print `path' if it's older than `tstamp' and not in `exsetp'.
 */
static int
checkpath(const char *path, const struct stat *statp, int type,
    struct FTW *ftwp)
{
    switch (type) {
    case FTW_F:
        /*
         * Skip if the file is referenced or in the exception list.
         */
        if (statp->st_atime >= tstamp || pnset_check(exsetp, path))
            return (0);

        /*
         * If requested, restrict ourselves to unreferenced files
         * under SCM control.
         */
        if (scm == NULL || scm->checkfunc(path, ftwp))
            (void) puts(path);
        return (0);

    case FTW_D:
        /*
         * Prune any directories in the exception list.
         */
        if (pnset_check(exsetp, path)) {
            ftwp->quit = FTW_PRUNE;
            return (0);
        }

        /*
         * If necessary, advise the SCM logic of our new directory.
         */
        if (scm != NULL && scm->chdirfunc != NULL)
            scm->chdirfunc(path);

        return (0);

    case FTW_DNR:
        warn("cannot read \"%s\"", path);
        return (0);

    case FTW_NS:
        warn("cannot stat \"%s\"", path);
        return (0);

    default:
        break;
    }

    return (0);
}

/*
 * Add `path' to the pnset_t pointed to by `pnsetp'.
 */
static int
pnset_add(pnset_t *pnsetp, const char *path)
{
    char **newpaths;
    unsigned int maxpaths;

    if (pnsetp->npath == pnsetp->maxpaths) {
        maxpaths = (pnsetp->maxpaths == 0) ? 512 : pnsetp->maxpaths * 2;
        newpaths = realloc(pnsetp->paths, sizeof (char *) * maxpaths);
        if (newpaths == NULL)
            return (0);
        pnsetp->paths = newpaths;
        pnsetp->maxpaths = maxpaths;
    }

    pnsetp->paths[pnsetp->npath] = strdup(path);
    if (pnsetp->paths[pnsetp->npath] == NULL)
        return (0);

    pnsetp->npath++;
    return (1);
}

/*
 * Check `path' against the pnset_t pointed to by `pnsetp'.
 */
static int
pnset_check(const pnset_t *pnsetp, const char *path)
{
    unsigned int i;

    for (i = 0; i < pnsetp->npath; i++) {
        if (fnmatch(pnsetp->paths[i], path, 0) == 0)
            return (1);
    }
    return (0);
}

/*
 * Empty the pnset_t pointed to by `pnsetp'.
 */
static void
pnset_empty(pnset_t *pnsetp)
{
    while (pnsetp->npath-- != 0)
        free(pnsetp->paths[pnsetp->npath]);

    free(pnsetp->paths);
    pnsetp->maxpaths = 0;
}

/*
 * Free the pnset_t pointed to by `pnsetp'.
 */
static void
pnset_free(pnset_t *pnsetp)
{
    if (pnsetp != NULL) {
        pnset_empty(pnsetp);
        free(pnsetp);
    }
}

/* PRINTFLIKE1 */
static void
warn(const char *format, ...)
{
    va_list alist;
    char *errstr = strerror(errno);

    if (errstr == NULL)
        errstr = "<unknown error>";

    (void) fprintf(stderr, "%s: ", progname);

    va_start(alist, format);
    (void) vfprintf(stderr, format, alist);
    va_end(alist);

    if (strrchr(format, '\n') == NULL)
        (void) fprintf(stderr, ": %s\n", errstr);
}

/* PRINTFLIKE1 */
static void
die(const char *format, ...)
{
    va_list alist;
    char *errstr = strerror(errno);

    if (errstr == NULL)
        errstr = "<unknown error>";

    (void) fprintf(stderr, "%s: fatal: ", progname);

    va_start(alist, format);
    (void) vfprintf(stderr, format, alist);
    va_end(alist);

    if (strrchr(format, '\n') == NULL)
        (void) fprintf(stderr, ": %s\n", errstr);

    exit(EXIT_FAILURE);
}