root/usr.bin/cvs/diff.c
/*      $OpenBSD: diff.c,v 1.164 2021/10/24 21:24:16 deraadt Exp $      */
/*
 * Copyright (c) 2008 Tobias Stoeckmann <tobias@openbsd.org>
 * Copyright (c) 2006 Joris Vink <joris@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/stat.h>
#include <sys/time.h>

#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "cvs.h"
#include "diff.h"
#include "remote.h"

void    cvs_diff_local(struct cvs_file *);

static int       dflags = 0;
static int       Nflag = 0;
static int       force_head = 0;
static char     *koptstr;
static char     *rev1 = NULL;
static char     *rev2 = NULL;
static time_t    date1 = -1;
static time_t    date2 = -1;
static char     *dateflag1 = NULL;
static char     *dateflag2 = NULL;

struct cvs_cmd cvs_cmd_diff = {
        CVS_OP_DIFF, CVS_USE_WDIR, "diff",
        { "di", "dif" },
        "Show differences between revisions",
        "[-abcdilNnpRuw] [[-D date] [-r rev] [-D date2 | -r rev2]] "
        "[-k mode] [file ...]",
        "abcfC:dD:ik:lNnpr:RuU:w",
        NULL,
        cvs_diff
};

struct cvs_cmd cvs_cmd_rdiff = {
        CVS_OP_RDIFF, 0, "rdiff",
        { "patch", "pa" },
        "Show differences between revisions",
        "[-flR] [-c | -u] [-s | -t] [-V ver] -D date | -r rev\n"
        "[-D date2 | -r rev2] [-k mode] module ...",
        "cfD:k:lr:RuV:",
        NULL,
        cvs_diff
};

int
cvs_diff(int argc, char **argv)
{
        int ch, flags;
        char *arg = ".";
        const char *errstr;
        struct cvs_recursion cr;

        flags = CR_RECURSE_DIRS;
        strlcpy(diffargs, cvs_cmdop == CVS_OP_DIFF ? "diff" : "rdiff",
            sizeof(diffargs));

        while ((ch = getopt(argc, argv, cvs_cmdop == CVS_OP_DIFF ?
            cvs_cmd_diff.cmd_opts : cvs_cmd_rdiff.cmd_opts)) != -1) {
                switch (ch) {
                case 'a':
                        strlcat(diffargs, " -a", sizeof(diffargs));
                        dflags |= D_FORCEASCII;
                        break;
                case 'b':
                        strlcat(diffargs, " -b", sizeof(diffargs));
                        dflags |= D_FOLDBLANKS;
                        break;
                case 'c':
                        strlcat(diffargs, " -c", sizeof(diffargs));
                        diff_format = D_CONTEXT;
                        break;
                case 'C':
                        diff_context = strtonum(optarg, 0, INT_MAX, &errstr);
                        if (errstr != NULL)
                                fatal("context lines %s: %s", errstr, optarg);
                        strlcat(diffargs, " -C ", sizeof(diffargs));
                        strlcat(diffargs, optarg, sizeof(diffargs));
                        diff_format = D_CONTEXT;
                        break;
                case 'd':
                        strlcat(diffargs, " -d", sizeof(diffargs));
                        dflags |= D_MINIMAL;
                        break;
                case 'D':
                        if (date1 == -1 && rev1 == NULL) {
                                if ((date1 = date_parse(optarg)) == -1)
                                        fatal("invalid date: %s", optarg);
                                dateflag1 = optarg;
                        } else if (date2 == -1 && rev2 == NULL) {
                                if ((date2 = date_parse(optarg)) == -1)
                                        fatal("invalid date: %s", optarg);
                                dateflag2 = optarg;
                        } else {
                                fatal("no more than 2 revisions/dates can"
                                    " be specified");
                        }
                        break;
                case 'f':
                        force_head = 1;
                        break;
                case 'i':
                        strlcat(diffargs, " -i", sizeof(diffargs));
                        dflags |= D_IGNORECASE;
                        break;
                case 'k':
                        koptstr = optarg;
                        kflag = rcs_kflag_get(koptstr);
                        if (RCS_KWEXP_INVAL(kflag)) {
                                cvs_log(LP_ERR,
                                    "invalid RCS keyword expansion mode");
                                fatal("%s", cvs_cmdop == CVS_OP_DIFF ?
                                    cvs_cmd_diff.cmd_synopsis :
                                    cvs_cmd_rdiff.cmd_synopsis);
                        }
                        break;
                case 'l':
                        flags &= ~CR_RECURSE_DIRS;
                        break;
                case 'n':
                        strlcat(diffargs, " -n", sizeof(diffargs));
                        diff_format = D_RCSDIFF;
                        break;
                case 'N':
                        strlcat(diffargs, " -N", sizeof(diffargs));
                        Nflag = 1;
                        break;
                case 'p':
                        strlcat(diffargs, " -p", sizeof(diffargs));
                        dflags |= D_PROTOTYPE;
                        break;
                case 'R':
                        flags |= CR_RECURSE_DIRS;
                        break;
                case 'r':
                        if (date1 == -1 && rev1 == NULL) {
                                rev1 = optarg;
                        } else if (date2 == -1 && rev2 == NULL) {
                                rev2 = optarg;
                        } else {
                                fatal("no more than 2 revisions/dates can"
                                    " be specified");
                        }
                        break;
                case 't':
                        strlcat(diffargs, " -t", sizeof(diffargs));
                        dflags |= D_EXPANDTABS;
                        break;
                case 'u':
                        strlcat(diffargs, " -u", sizeof(diffargs));
                        diff_format = D_UNIFIED;
                        break;
                case 'U':
                        diff_context = strtonum(optarg, 0, INT_MAX, &errstr);
                        if (errstr != NULL)
                                fatal("context lines %s: %s", errstr, optarg);
                        strlcat(diffargs, " -U ", sizeof(diffargs));
                        strlcat(diffargs, optarg, sizeof(diffargs));
                        diff_format = D_UNIFIED;
                        break;
                case 'V':
                        fatal("the -V option is obsolete "
                            "and should not be used");
                case 'w':
                        strlcat(diffargs, " -w", sizeof(diffargs));
                        dflags |= D_IGNOREBLANKS;
                        break;
                default:
                        fatal("%s", cvs_cmdop == CVS_OP_DIFF ?
                            cvs_cmd_diff.cmd_synopsis :
                            cvs_cmd_rdiff.cmd_synopsis);
                }
        }

        argc -= optind;
        argv += optind;

        cr.enterdir = NULL;
        cr.leavedir = NULL;

        if (cvs_cmdop == CVS_OP_RDIFF) {
                if (rev1 == NULL && rev2 == NULL && dateflag1 == NULL &&
                    dateflag2 == NULL)
                        fatal("must specify at least one revision/date!");

                if (!argc)
                        fatal("%s", cvs_cmd_rdiff.cmd_synopsis);

                if (!diff_format) {
                        strlcat(diffargs, " -c", sizeof(diffargs));
                        diff_format = D_CONTEXT;
                }

                flags |= CR_REPO;
        }

        if (cvsroot_is_remote()) {
                cvs_client_connect_to_server();
                cr.fileproc = cvs_client_sendfile;

                if (!(flags & CR_RECURSE_DIRS))
                        cvs_client_send_request("Argument -l");

                if (kflag)
                        cvs_client_send_request("Argument -k%s", koptstr);

                switch (diff_format) {
                case D_CONTEXT:
                        if (cvs_cmdop == CVS_OP_RDIFF)
                                cvs_client_send_request("Argument -c");
                        else {
                                cvs_client_send_request("Argument -C %d",
                                    diff_context);
                        }
                        break;
                case D_RCSDIFF:
                        cvs_client_send_request("Argument -n");
                        break;
                case D_UNIFIED:
                        if (cvs_cmdop == CVS_OP_RDIFF || diff_context == 3)
                                cvs_client_send_request("Argument -u");
                        else {
                                cvs_client_send_request("Argument -U %d",
                                    diff_context);
                        }
                        break;
                default:
                        break;
                }

                if (Nflag == 1)
                        cvs_client_send_request("Argument -N");

                if (dflags & D_PROTOTYPE)
                        cvs_client_send_request("Argument -p");

                if (rev1 != NULL)
                        cvs_client_send_request("Argument -r%s", rev1);
                if (rev2 != NULL)
                        cvs_client_send_request("Argument -r%s", rev2);

                if (dateflag1 != NULL)
                        cvs_client_send_request("Argument -D%s", dateflag1);
                if (dateflag2 != NULL)
                        cvs_client_send_request("Argument -D%s", dateflag2);
        } else {
                if (cvs_cmdop == CVS_OP_RDIFF &&
                    chdir(current_cvsroot->cr_dir) == -1)
                        fatal("cvs_diff: %s", strerror(errno));

                cr.fileproc = cvs_diff_local;
        }

        cr.flags = flags;

        diff_rev1 = diff_rev2 = NULL;

        if (cvs_cmdop == CVS_OP_DIFF || cvsroot_is_local()) {
                if (argc > 0)
                        cvs_file_run(argc, argv, &cr);
                else
                        cvs_file_run(1, &arg, &cr);
        }

        if (cvsroot_is_remote()) {
                cvs_client_send_files(argv, argc);
                cvs_client_senddir(".");

                cvs_client_send_request((cvs_cmdop == CVS_OP_RDIFF) ?
                    "rdiff" : "diff");

                cvs_client_get_responses();
        }

        return (0);
}

void
cvs_diff_local(struct cvs_file *cf)
{
        BUF *b1;
        int fd1, fd2;
        struct stat st;
        struct timeval tv[2], tv2[2];
        struct tm datetm;
        char rbuf[CVS_REV_BUFSZ], tbuf[CVS_TIME_BUFSZ], *p1, *p2;

        b1 = NULL;
        fd1 = fd2 = -1;
        p1 = p2 = NULL;

        cvs_log(LP_TRACE, "cvs_diff_local(%s)", cf->file_path);

        if (cf->file_type == CVS_DIR) {
                if (verbosity > 1)
                        cvs_log(LP_ERR, "Diffing inside %s", cf->file_path);
                return;
        }

        cvs_file_classify(cf, cvs_directory_tag);

        if (cvs_cmdop == CVS_OP_DIFF) {
                if (cf->file_ent == NULL) {
                        cvs_log(LP_ERR, "I know nothing about %s",
                            cf->file_path);
                        return;
                }

                switch (cf->file_ent->ce_status) {
                case CVS_ENT_ADDED:
                        if (Nflag == 0) {
                                cvs_log(LP_ERR, "%s is a new entry, no "
                                    "comparison available", cf->file_path);
                                return;
                        }
                        if (!(cf->file_flags & FILE_ON_DISK)) {
                                cvs_log(LP_ERR, "cannot find %s",
                                    cf->file_path);
                                return;
                        }
                        break;
                case CVS_ENT_REMOVED:
                        if (Nflag == 0) {
                                cvs_log(LP_ERR, "%s was removed, no "
                                    "comparison available", cf->file_path);
                                return;
                        }
                        if (cf->file_rcs == NULL) {
                                cvs_log(LP_ERR, "cannot find RCS file for %s",
                                    cf->file_path);
                                return;
                        }
                        break;
                default:
                        if (!(cf->file_flags & FILE_ON_DISK)) {
                                cvs_printf("? %s\n", cf->file_path);
                                return;
                        }

                        if (cf->file_rcs == NULL) {
                                cvs_log(LP_ERR, "cannot find RCS file for %s",
                                    cf->file_path);
                                return;
                        }
                        break;
                }
        }

        if (cf->file_status == FILE_UPTODATE && rev1 == NULL && rev2 == NULL &&
            date1 == -1 && date2 == -1)
                return;

        if (cf->file_rcs != NULL && cf->file_rcs->rf_head == NULL) {
                cvs_log(LP_ERR, "no head revision in RCS file for %s\n",
                    cf->file_path);
                return;
        }

        if (kflag && cf->file_rcs != NULL)
                rcs_kwexp_set(cf->file_rcs, kflag);

        if (cf->file_rcs == NULL)
                diff_rev1 = NULL;
        else if (rev1 != NULL || date1 != -1) {
                cvs_specified_date = date1;
                diff_rev1 = rcs_translate_tag(rev1, cf->file_rcs);
                if (diff_rev1 == NULL && cvs_cmdop == CVS_OP_DIFF) {
                        if (rev1 != NULL) {
                                cvs_log(LP_ERR, "tag %s not in file %s", rev1,
                                    cf->file_path);
                                goto cleanup;
                        } else if (Nflag) {
                                diff_rev1 = NULL;
                        } else {
                                gmtime_r(&cvs_specified_date, &datetm);
                                strftime(tbuf, sizeof(tbuf),
                                    "%Y.%m.%d.%H.%M.%S", &datetm);
                                cvs_log(LP_ERR, "no revision for date %s in "
                                    "file %s", tbuf, cf->file_path);
                                goto cleanup;
                        }
                } else if (diff_rev1 == NULL && cvs_cmdop == CVS_OP_RDIFF &&
                    force_head) {
                        /* -f is not allowed for unknown symbols */
                        if ((diff_rev1 = rcsnum_parse(rev1)) == NULL)
                                fatal("no such tag %s", rev1);
                        free(diff_rev1);

                        diff_rev1 = cf->file_rcs->rf_head;
                }
                cvs_specified_date = -1;
        } else if (cvs_cmdop == CVS_OP_DIFF) {
                if (cf->file_ent->ce_status == CVS_ENT_ADDED)
                        diff_rev1 = NULL;
                else
                        diff_rev1 = cf->file_ent->ce_rev;
        }

        if (cf->file_rcs == NULL)
                diff_rev2 = NULL;
        else if (rev2 != NULL || date2 != -1) {
                cvs_specified_date = date2;
                diff_rev2 = rcs_translate_tag(rev2, cf->file_rcs);
                if (diff_rev2 == NULL && cvs_cmdop == CVS_OP_DIFF) {
                        if (rev2 != NULL) {
                                cvs_log(LP_ERR, "tag %s not in file %s", rev2,
                                    cf->file_path);
                                goto cleanup;
                        } else if (Nflag) {
                                diff_rev2 = NULL;
                        } else {
                                gmtime_r(&cvs_specified_date, &datetm);
                                strftime(tbuf, sizeof(tbuf),
                                    "%Y.%m.%d.%H.%M.%S", &datetm);
                                cvs_log(LP_ERR, "no revision for date %s in "
                                    "file %s", tbuf, cf->file_path);
                                goto cleanup;
                        }
                } else if (diff_rev2 == NULL && cvs_cmdop == CVS_OP_RDIFF &&
                    force_head) {
                        /* -f is not allowed for unknown symbols */
                        if ((diff_rev2 = rcsnum_parse(rev2)) == NULL)
                                fatal("no such tag %s", rev2);
                        free(diff_rev2);

                        diff_rev2 = cf->file_rcs->rf_head;
                }
                cvs_specified_date = -1;
        } else if (cvs_cmdop == CVS_OP_RDIFF)
                diff_rev2 = cf->file_rcs->rf_head;
        else if (cf->file_ent->ce_status == CVS_ENT_REMOVED)
                diff_rev2 = NULL;

        if (diff_rev1 != NULL && diff_rev2 != NULL &&
            rcsnum_cmp(diff_rev1, diff_rev2, 0) == 0)
                goto cleanup;

        switch (cvs_cmdop) {
        case CVS_OP_DIFF:
                if (cf->file_status == FILE_UPTODATE) {
                        if (diff_rev2 == NULL &&
                            !rcsnum_cmp(diff_rev1, cf->file_rcsrev, 0))
                                goto cleanup;
                }
                break;
        case CVS_OP_RDIFF:
                if (diff_rev1 == NULL && diff_rev2 == NULL)
                        goto cleanup;
                break;
        }

        cvs_printf("Index: %s\n", cf->file_path);
        if (cvs_cmdop == CVS_OP_DIFF)
                cvs_printf("%s\nRCS file: %s\n", RCS_DIFF_DIV,
                    cf->file_rcs != NULL ? cf->file_rpath : cf->file_path);

        if (diff_rev1 != NULL) {
                if (cvs_cmdop == CVS_OP_DIFF && diff_rev1 != NULL) {
                        (void)rcsnum_tostr(diff_rev1, rbuf, sizeof(rbuf));
                        cvs_printf("retrieving revision %s\n", rbuf);
                }

                tv[0].tv_sec = rcs_rev_getdate(cf->file_rcs, diff_rev1);
                tv[0].tv_usec = 0;
                tv[1] = tv[0];

                (void)xasprintf(&p1, "%s/diff1.XXXXXXXXXX", cvs_tmpdir);
                fd1 = rcs_rev_write_stmp(cf->file_rcs, diff_rev1, p1, 0);
                if (futimes(fd1, tv) == -1)
                        fatal("cvs_diff_local: utimes failed");
        }

        if (diff_rev2 != NULL) {
                if (cvs_cmdop == CVS_OP_DIFF && rev2 != NULL) {
                        (void)rcsnum_tostr(diff_rev2, rbuf, sizeof(rbuf));
                        cvs_printf("retrieving revision %s\n", rbuf);
                }

                tv2[0].tv_sec = rcs_rev_getdate(cf->file_rcs, diff_rev2);
                tv2[0].tv_usec = 0;
                tv2[1] = tv2[0];

                (void)xasprintf(&p2, "%s/diff2.XXXXXXXXXX", cvs_tmpdir);
                fd2 = rcs_rev_write_stmp(cf->file_rcs, diff_rev2, p2, 0);
                if (futimes(fd2, tv2) == -1)
                        fatal("cvs_diff_local: utimes failed");
        } else if (cvs_cmdop == CVS_OP_DIFF &&
            (cf->file_flags & FILE_ON_DISK) &&
            cf->file_ent->ce_status != CVS_ENT_REMOVED) {
                (void)xasprintf(&p2, "%s/diff2.XXXXXXXXXX", cvs_tmpdir);
                if (cvs_server_active == 1 && cf->fd == -1) {
                        tv2[0].tv_sec = rcs_rev_getdate(cf->file_rcs,
                            cf->file_ent->ce_rev);
                        tv2[0].tv_usec = 0;
                        tv2[1] = tv2[0];

                        fd2 = rcs_rev_write_stmp(cf->file_rcs,
                            cf->file_ent->ce_rev, p2, 0);
                        if (futimes(fd2, tv2) == -1)
                                fatal("cvs_diff_local: futimes failed");
                } else {
                        if (fstat(cf->fd, &st) == -1)
                                fatal("fstat failed %s", strerror(errno));
                        b1 = buf_load_fd(cf->fd);

                        tv2[0].tv_sec = st.st_mtime;
                        tv2[0].tv_usec = 0;
                        tv2[1] = tv2[0];

                        fd2 = buf_write_stmp(b1, p2, tv2);
                        buf_free(b1);
                }
        }

        switch (cvs_cmdop) {
        case CVS_OP_DIFF:
                cvs_printf("%s", diffargs);

                if (rev1 != NULL && diff_rev1 != NULL) {
                        (void)rcsnum_tostr(diff_rev1, rbuf, sizeof(rbuf));
                        cvs_printf(" -r%s", rbuf);

                        if (rev2 != NULL && diff_rev2 != NULL) {
                                (void)rcsnum_tostr(diff_rev2, rbuf,
                                    sizeof(rbuf));
                                cvs_printf(" -r%s", rbuf);
                        }
                }

                if (diff_rev2 == NULL)
                        cvs_printf(" %s", cf->file_path);
                cvs_printf("\n");
                break;
        case CVS_OP_RDIFF:
                cvs_printf("diff ");
                switch (diff_format) {
                case D_CONTEXT:
                        cvs_printf("-c ");
                        break;
                case D_RCSDIFF:
                        cvs_printf("-n ");
                        break;
                case D_UNIFIED:
                        cvs_printf("-u ");
                        break;
                default:
                        break;
                }
                if (diff_rev1 == NULL) {
                        cvs_printf("%s ", CVS_PATH_DEVNULL);
                } else {
                        (void)rcsnum_tostr(diff_rev1, rbuf, sizeof(rbuf));
                        cvs_printf("%s:%s ", cf->file_path, rbuf);
                }

                if (diff_rev2 == NULL) {
                        cvs_printf("%s:removed\n", cf->file_path);
                } else {
                        (void)rcsnum_tostr(diff_rev2 != NULL ? diff_rev2 :
                            cf->file_rcs->rf_head, rbuf, sizeof(rbuf));
                        cvs_printf("%s:%s\n", cf->file_path, rbuf);
                }
                break;
        }

        if (fd1 == -1) {
                if ((fd1 = open(CVS_PATH_DEVNULL, O_RDONLY)) == -1)
                        fatal("cannot open %s", CVS_PATH_DEVNULL);
        }
        if (fd2 == -1) {
                if ((fd2 = open(CVS_PATH_DEVNULL, O_RDONLY)) == -1)
                        fatal("cannot open %s", CVS_PATH_DEVNULL);
        }

        if (diffreg(p1 != NULL ? cf->file_path : CVS_PATH_DEVNULL,
            p2 != NULL ? cf->file_path : CVS_PATH_DEVNULL, fd1, fd2, NULL,
            dflags) == D_ERROR)
                fatal("cvs_diff_local: failed to get RCS patch");

        close(fd1);
        close(fd2);

        worklist_run(&temp_files, worklist_unlink);

        free(p1);
        free(p2);

cleanup:
        if (diff_rev1 != NULL &&
            (cf->file_rcs == NULL || diff_rev1 != cf->file_rcs->rf_head) &&
            (cf->file_ent == NULL || diff_rev1 != cf->file_ent->ce_rev))
                free(diff_rev1);
        diff_rev1 = NULL;

        if (diff_rev2 != NULL &&
            (cf->file_rcs == NULL || diff_rev2 != cf->file_rcs->rf_head))
                free(diff_rev2);
        diff_rev2 = NULL;
}