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diff: refactor compare_files
Break out a good chunk of the body of compare_files into a new function compare_prepped_files. This simplifies indenting and code slightly. * src/diff.c (compare_prepped_files): New function, taken from compare_files. (compare_files): Use it.
This commit is contained in:
Paul Eggert
parent
5d30da7a5b
commit
77ac458934
430
src/diff.c
430
src/diff.c
@ -1150,6 +1150,228 @@ dir_p (struct comparison const *pcmp, int f)
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return pcmp->file[f].detype == DE_DIR;
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}
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/* Compare two files with parent comparison PARENT.
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The two files are described by CMP, which has been prepped to contain
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the files' detypes and possibly descriptors and stat results.
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If the files need to be opened, use OPEN_FLAGS. */
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static int
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compare_prepped_files (struct comparison const *parent,
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struct comparison *cmp, int open_flags)
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{
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/* If neither file "exists", there's nothing to compare. */
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if (cmp->file[0].desc == NONEXISTENT && cmp->file[1].desc == NONEXISTENT)
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return EXIT_SUCCESS;
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bool same_files = (cmp->file[0].desc != NONEXISTENT
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&& cmp->file[1].desc != NONEXISTENT
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&& cmp->file[0].detype == cmp->file[1].detype
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&& same_file (&cmp->file[0].stat, &cmp->file[1].stat));
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/* If the two named files are actually the same physical file.
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we know they are identical without actually reading them. */
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if (same_files & no_diff_means_no_output)
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return EXIT_SUCCESS;
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bool toplevel = parent == &noparent;
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/* Comapre the two hierarchies if both files are directories, or if
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diff is recursive and one file is a directory and the other
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pretends to be a directory full of empty files. But don't
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compare dir contents one level down unless -r was specified. */
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if (dir_p (cmp, 0) & dir_p (cmp, 1)
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|| (recursive
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&& ((new_file & dir_p (cmp, 1)
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&& cmp->file[0].desc == NONEXISTENT)
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|| (((new_file | unidirectional_new_file) & dir_p (cmp, 0))
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&& cmp->file[1].desc == NONEXISTENT))))
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{
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if (output_style == OUTPUT_IFDEF)
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fatal ("-D option not supported with directories");
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if (recursive | toplevel)
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return diff_dirs (cmp);
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else
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{
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/* See POSIX 1003.1-2017 for this format. */
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message ("Common subdirectories: %s and %s\n",
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squote (0, cmp->file[0].name),
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squote (1, cmp->file[1].name));
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return EXIT_SUCCESS;
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}
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}
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/* Fail if only one file exists. */
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if ((cmp->file[0].desc == NONEXISTENT
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&& ! (new_file | unidirectional_new_file))
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|| (cmp->file[1].desc == NONEXISTENT && !new_file))
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{
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bool existing = cmp->file[0].desc == NONEXISTENT;
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char const *dname = parent->file[existing].name;
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char const *bname = last_component (cmp->file[existing].name);
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/* See POSIX 1003.1-2017 for this format. */
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message ("Only in %s: %s\n", squote (0, dname), squote (1, bname));
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return EXIT_FAILURE;
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}
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/* If the two files have different types, do not compare them.
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Simply report the type difference. However, at the top level,
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do this only if one file is a symlink and the other is not. */
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if (toplevel
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? (cmp->file[0].detype == DE_LNK) != (cmp->file[1].detype == DE_LNK)
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: cmp->file[0].detype != cmp->file[1].detype)
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{
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char const *ftype[2];
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for (int f = 0; f < 2; f++)
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{
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static char const *const file_type_msgid[] = {
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[DE_FIFO] = N_("fifo"),
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[DE_CHR ] = N_("character special file"),
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[DE_BLK ] = N_("block special file"),
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[DE_REG ] = N_("regular file"),
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[DE_LNK ] = N_("symbolic link"),
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[DE_SOCK] = N_("socket"),
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[DE_WHT ] = N_("whiteout"),
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};
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ftype[f] = (((cmp->file[f].detype
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< sizeof file_type_msgid / sizeof *file_type_msgid)
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&& file_type_msgid[cmp->file[f].detype])
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? _(file_type_msgid[cmp->file[f].detype])
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: file_type (&cmp->file[f].stat));
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}
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/* POSIX 1003.1-2017 says any message will do, so long as it
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contains the file names. */
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message ("File %s is a %s while file %s is a %s\n",
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file_label[0] ? file_label[0] : squote (0, cmp->file[0].name),
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ftype[0],
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file_label[1] ? file_label[1] : squote (1, cmp->file[1].name),
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ftype[1]);
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return EXIT_FAILURE;
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}
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/* If both files are symlinks, compare symlink contents. */
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if (cmp->file[0].detype == DE_LNK)
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{
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/* We get here only if we are not dereferencing symlinks. */
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dassert (no_dereference_symlinks);
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int status = EXIT_SUCCESS;
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char *link_value[2]; link_value[1] = nullptr;
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char linkbuf[2][128];
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for (bool f = false; ; f = true)
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{
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int dirfd = parent->file[f].desc;
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char const *name = cmp->file[f].name;
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char const *nm = dirfd < 0 ? name : last_component (name);
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link_value[f] = careadlinkat (dirfd, nm,
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linkbuf[f], sizeof linkbuf[f],
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nullptr, readlinkat);
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if (!link_value[f])
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{
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perror_with_name (cmp->file[f].name);
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status = EXIT_TROUBLE;
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break;
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}
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if (f)
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{
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status = (STREQ (link_value[0], link_value[f])
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? EXIT_SUCCESS : EXIT_FAILURE);
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break;
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}
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}
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if (status == EXIT_FAILURE)
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message ("Symbolic links %s -> %s and %s -> %s differ\n",
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quote_n (0, cmp->file[0].name), quote_n (1, link_value[0]),
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quote_n (2, cmp->file[1].name), quote_n (3, link_value[1]));
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for (int f = 0; f < 2; f++)
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if (link_value[f] != linkbuf[f])
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free (link_value[f]);
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return status;
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}
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/* If the files are special files and we are not at the top level,
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compare their device numbers. */
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if (!toplevel
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&& (cmp->file[0].detype == DE_CHR || cmp->file[0].detype == DE_BLK))
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{
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intmax_t num[] = {
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major (cmp->file[0].stat.st_rdev),
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minor (cmp->file[0].stat.st_rdev),
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major (cmp->file[1].stat.st_rdev),
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minor (cmp->file[1].stat.st_rdev)
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};
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enum { n_num = sizeof num / sizeof *num };
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char numbuf[n_num][INT_BUFSIZE_BOUND (intmax_t)];
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for (int i = 0; i < n_num; i++)
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sprintf (numbuf[i], "%"PRIdMAX, num[i]);
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message ((cmp->file[0].detype == DE_CHR
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? ("Character special files %s (%s, %s)"
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" and %s (%s, %s) differ\n")
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: ("Block special files %s (%s, %s)"
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" and %s (%s, %s) differ\n")),
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quote_n (0, cmp->file[0].name), numbuf[0], numbuf[1],
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quote_n (2, cmp->file[1].name), numbuf[2], numbuf[3]);
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return EXIT_FAILURE;
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}
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if (files_can_be_treated_as_binary
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&& cmp->file[0].detype == DE_REG
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&& cmp->file[1].detype == DE_REG
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&& cmp->file[0].stat.st_size != cmp->file[1].stat.st_size
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&& 0 <= cmp->file[0].stat.st_size
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&& 0 <= cmp->file[1].stat.st_size)
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{
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message ("Files %s and %s differ\n",
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file_label[0] ? file_label[0] : squote (0, cmp->file[0].name),
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file_label[1] ? file_label[1] : squote (1, cmp->file[1].name));
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return EXIT_FAILURE;
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}
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/* Both files exist and neither is a directory or a symbolic link.
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Open the files and record their descriptors,
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if they are not already open. */
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int status = EXIT_SUCCESS;
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for (int f = 0; f < 2; f++)
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if (cmp->file[f].desc == UNOPENED)
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{
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if (f && same_files)
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cmp->file[f].desc = cmp->file[0].desc;
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else
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{
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int dirfd = parent->file[f].desc;
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char const *name = cmp->file[f].name;
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char const *nm = dirfd < 0 ? name : last_component (name);
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cmp->file[f].desc = openat (dirfd, nm, open_flags);
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if (cmp->file[f].desc < 0)
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{
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perror_with_name (name);
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status = EXIT_TROUBLE;
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}
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}
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}
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else if (cmp->file[f].desc == OPEN_FAILED)
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{
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error (0, cmp->file[f].openerr, "%s", squote (0, cmp->file[f].name));
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status = EXIT_TROUBLE;
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}
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/* Compare the files' contents, if no error was found. */
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if (status != EXIT_SUCCESS)
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return status;
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return diff_2_files (cmp);
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}
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/* Compare two files (or dirs) with parent comparison PARENT
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and names and directory entry types NAME0, DETYPE0 and NAME1, DETYPE1.
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(If PARENT == &NOPARENT, then the first name is just NAME0, etc.)
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@ -1394,212 +1616,8 @@ compare_files (struct comparison const *parent,
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status = EXIT_TROUBLE;
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}
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bool same_files;
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if (status != EXIT_SUCCESS)
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{
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/* An error has already been reported. */
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}
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else if (cmp.file[0].desc == NONEXISTENT
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&& cmp.file[1].desc == NONEXISTENT)
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{
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/* Neither file "exists", so there's nothing to compare. */
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}
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else if ((same_files
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= (cmp.file[0].desc != NONEXISTENT
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&& cmp.file[1].desc != NONEXISTENT
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&& cmp.file[0].detype == cmp.file[1].detype
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&& same_file (&cmp.file[0].stat, &cmp.file[1].stat)))
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&& no_diff_means_no_output)
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{
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/* The two named files are actually the same physical file.
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We know they are identical without actually reading them. */
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}
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else if (dir_p (&cmp, 0) & dir_p (&cmp, 1)
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|| (recursive
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&& ((new_file & dir_p (&cmp, 1)
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&& cmp.file[0].desc == NONEXISTENT)
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|| (((new_file | unidirectional_new_file) & dir_p (&cmp, 0))
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&& cmp.file[1].desc == NONEXISTENT))))
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{
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if (output_style == OUTPUT_IFDEF)
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fatal ("-D option not supported with directories");
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/* Either both files are directories, or diff is recursive and
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one file is a directory and the other pretends to be a
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directory full of empty files. Compare the two hierarchies. */
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if (! (recursive | toplevel))
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{
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/* But don't compare dir contents one level down
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unless -r was specified.
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See POSIX 1003.1-2017 for this format. */
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message ("Common subdirectories: %s and %s\n",
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squote (0, cmp.file[0].name),
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squote (1, cmp.file[1].name));
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}
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else
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status = diff_dirs (&cmp);
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}
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else if ((cmp.file[0].desc == NONEXISTENT
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&& ! (new_file | unidirectional_new_file))
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|| (cmp.file[1].desc == NONEXISTENT && !new_file))
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{
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/* Only one file exists. See POSIX 1003.1-2017 for this format. */
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char const *dname = parent->file[cmp.file[0].desc == NONEXISTENT].name;
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message ("Only in %s: %s\n", squote (0, dname), squote (1, name0));
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status = EXIT_FAILURE;
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}
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else if (cmp.file[0].detype != cmp.file[1].detype
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&& (!toplevel
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|| cmp.file[0].detype == DE_LNK
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|| cmp.file[1].detype == DE_LNK))
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{
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/* The two files have different types and are not to be compared. */
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char const *ftype[2];
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for (int f = 0; f < 2; f++)
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{
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static char const *const file_type_msgid[] = {
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[DE_FIFO] = N_("fifo"),
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[DE_CHR ] = N_("character special file"),
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[DE_BLK ] = N_("block special file"),
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[DE_REG ] = N_("regular file"),
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[DE_LNK ] = N_("symbolic link"),
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[DE_SOCK] = N_("socket"),
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[DE_WHT ] = N_("whiteout"),
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};
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ftype[f] = (((cmp.file[f].detype
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< sizeof file_type_msgid / sizeof *file_type_msgid)
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&& file_type_msgid[cmp.file[f].detype])
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? _(file_type_msgid[cmp.file[f].detype])
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: file_type (&cmp.file[f].stat));
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}
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/* POSIX 1003.1-2017 says any message will do, so long as it
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contains the file names. */
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message ("File %s is a %s while file %s is a %s\n",
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file_label[0] ? file_label[0] : squote (0, cmp.file[0].name),
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ftype[0],
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file_label[1] ? file_label[1] : squote (1, cmp.file[1].name),
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ftype[1]);
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/* This is a difference. */
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status = EXIT_FAILURE;
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}
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else if (cmp.file[0].detype == DE_LNK)
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{
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/* We get here only if we are not dereferencing symlinks. */
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dassert (no_dereference_symlinks);
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/* Compare the values of the symbolic links. */
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char *link_value[2]; link_value[1] = nullptr;
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char linkbuf[2][128];
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for (bool f = false; ; f = true)
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{
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int dirfd = parent->file[f].desc;
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char const *name = cmp.file[f].name;
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char const *nm = dirfd < 0 ? name : last_component (name);
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link_value[f] = careadlinkat (dirfd, nm,
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linkbuf[f], sizeof linkbuf[f],
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nullptr, readlinkat);
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if (!link_value[f])
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{
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perror_with_name (cmp.file[f].name);
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status = EXIT_TROUBLE;
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break;
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}
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if (f)
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{
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status = (STREQ (link_value[0], link_value[f])
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? EXIT_SUCCESS : EXIT_FAILURE);
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break;
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}
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}
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if (status == EXIT_FAILURE)
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message ("Symbolic links %s -> %s and %s -> %s differ\n",
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quote_n (0, cmp.file[0].name), quote_n (1, link_value[0]),
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quote_n (2, cmp.file[1].name), quote_n (3, link_value[1]));
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for (int f = 0; f < 2; f++)
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if (link_value[f] != linkbuf[f])
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free (link_value[f]);
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}
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else if (!toplevel
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&& (cmp.file[0].detype == DE_CHR || cmp.file[0].detype == DE_BLK))
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{
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intmax_t num[] = {
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major (cmp.file[0].stat.st_rdev),
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minor (cmp.file[0].stat.st_rdev),
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major (cmp.file[1].stat.st_rdev),
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minor (cmp.file[1].stat.st_rdev)
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};
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enum { n_num = sizeof num / sizeof *num };
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char numbuf[n_num][INT_BUFSIZE_BOUND (intmax_t)];
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for (int i = 0; i < n_num; i++)
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sprintf (numbuf[i], "%"PRIdMAX, num[i]);
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message ((cmp.file[0].detype == DE_CHR
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? ("Character special files %s (%s, %s)"
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" and %s (%s, %s) differ\n")
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: ("Block special files %s (%s, %s)"
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" and %s (%s, %s) differ\n")),
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quote_n (0, cmp.file[0].name), numbuf[0], numbuf[1],
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quote_n (2, cmp.file[1].name), numbuf[2], numbuf[3]);
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status = EXIT_FAILURE;
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}
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else if (files_can_be_treated_as_binary
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&& cmp.file[0].detype == DE_REG
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&& cmp.file[1].detype == DE_REG
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&& cmp.file[0].stat.st_size != cmp.file[1].stat.st_size
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&& 0 <= cmp.file[0].stat.st_size
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&& 0 <= cmp.file[1].stat.st_size)
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{
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message ("Files %s and %s differ\n",
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file_label[0] ? file_label[0] : squote (0, cmp.file[0].name),
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file_label[1] ? file_label[1] : squote (1, cmp.file[1].name));
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status = EXIT_FAILURE;
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}
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else
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{
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/* Both exist and neither is a directory or a symbolic link. */
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/* Open the files and record their descriptors, if they are not
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already open. */
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for (int f = 0; f < 2; f++)
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if (cmp.file[f].desc == UNOPENED)
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{
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if (f && same_files)
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cmp.file[f].desc = cmp.file[0].desc;
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else
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{
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int dirfd = parent->file[f].desc;
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char const *name = cmp.file[f].name;
|
||||
char const *nm = dirfd < 0 ? name : last_component (name);
|
||||
cmp.file[f].desc = openat (dirfd, nm, O_RDONLY | oflags);
|
||||
if (cmp.file[f].desc < 0)
|
||||
{
|
||||
perror_with_name (name);
|
||||
status = EXIT_TROUBLE;
|
||||
}
|
||||
}
|
||||
}
|
||||
else if (cmp.file[f].desc == OPEN_FAILED)
|
||||
{
|
||||
error (0, cmp.file[f].openerr, "%s",
|
||||
squote (0, cmp.file[f].name));
|
||||
status = EXIT_TROUBLE;
|
||||
}
|
||||
|
||||
/* Compare the files, if no error was found. */
|
||||
|
||||
if (status == EXIT_SUCCESS)
|
||||
status = diff_2_files (&cmp);
|
||||
}
|
||||
|
||||
if (status == EXIT_SUCCESS)
|
||||
status = compare_prepped_files (parent, &cmp, O_RDONLY | oflags);
|
||||
|
||||
/* Close any input files. */
|
||||
for (int f = 0; f < 2; f++)
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user