Re: [PATCH v2 2/2] rev-parse: add option for absolute or relative path formatting
From: Johannes Schindelin <hidden>
Date: 2020-11-09 14:46:22
Hi brian, On Fri, 9 Oct 2020, brian m. carlson wrote:
git rev-parse has several options which print various paths. Some of these paths are printed relative to the current working directory, and some are absolute. Normally, this is not a problem, but there are times when one wants paths entirely in one format or another. This can be done trivially if the paths are canonical, but canonicalizing paths is not possible on some shell scripting environments which lack realpath(1) and also in Go, which lacks functions that properly canonicalize paths on Windows. To help out the scripter, let's provide an option which turns most of the paths printed by git rev-parse to be either relative to the current working directory or absolute and canonical. Document which options are affected and which are not so that users are not confused. This approach is cleaner and tidier than providing duplicates of existing options which are either relative or absolute. Note that if the user needs both forms, it is possible to pass an additional option in the middle of the command line which changes the behavior of subsequent operations.
Good.
quoted hunk ↗ jump to hunk
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c index ed200c8af1..ec62b4cd16 100644 --- a/builtin/rev-parse.c +++ b/builtin/rev-parse.c@@ -583,6 +583,76 @@ static void handle_ref_opt(const char *pattern, const char *prefix) clear_ref_exclusion(&ref_excludes); } +enum format_type { + /* We would like a relative path. */ + FORMAT_RELATIVE, + /* We would like a canonical absolute path. */ + FORMAT_CANONICAL, + /* We would like the default behavior. */ + FORMAT_DEFAULT, +}; + +enum default_type { + /* Our default is a relative path. */ + DEFAULT_RELATIVE, + /* Our default is a relative path if there's a shared root. */ + DEFAULT_RELATIVE_IF_SHARED, + /* Our default is a canonical absolute path. */ + DEFAULT_CANONICAL, + /* Our default is not to modify the item. */ + DEFAULT_UNMODIFIED, +};
I wonder whether it would make sense to consolidate these two enums into a single one.
quoted hunk ↗ jump to hunk
+static void print_path(const char *path, const char *prefix, enum format_type format, enum default_type def) +{ + char *cwd = NULL; + /* + * We don't ever produce a relative path if prefix is NULL, so set the + * prefix to the current directory so that we can produce a relative + * path whenever possible. If we're using RELATIVE_IF_SHARED mode, then + * we want an absolute path unless the two share a common prefix, so don't + * set it in that case, since doing so causes a relative path to always + * be produced if possible. + */ + if (!prefix && (format != FORMAT_DEFAULT || def != DEFAULT_RELATIVE_IF_SHARED)) + prefix = cwd = xgetcwd(); + if (format == FORMAT_DEFAULT && def == DEFAULT_UNMODIFIED) { + puts(path); + } else if (format == FORMAT_RELATIVE || + (format == FORMAT_DEFAULT && def == DEFAULT_RELATIVE)) { + /* + * In order for relative_path to work as expected, we need to + * make sure that both paths are absolute paths. If we don't, + * we can end up with an unexpected absolute path that the user + * didn't want. + */ + struct strbuf buf = STRBUF_INIT, realbuf = STRBUF_INIT, prefixbuf = STRBUF_INIT; + if (!is_absolute_path(path)) { + if (!strbuf_realpath_missing(&realbuf, path)) + die(_("Unable to resolve path '%s'"), path); + path = realbuf.buf; + } + if (!is_absolute_path(prefix)) { + if (!strbuf_realpath_missing(&prefixbuf, prefix)) + die(_("Unable to resolve path '%s'"), path); + prefix = prefixbuf.buf; + } + puts(relative_path(path, prefix, &buf)); + strbuf_release(&buf); + } else if (format == FORMAT_DEFAULT && def == DEFAULT_RELATIVE_IF_SHARED) { + struct strbuf buf = STRBUF_INIT; + puts(relative_path(path, prefix, &buf)); + strbuf_release(&buf); + } else { + struct strbuf buf = STRBUF_INIT; + if (!strbuf_realpath_missing(&buf, path)) + die(_("Unable to resolve path '%s'"), path); + puts(buf.buf); + strbuf_release(&buf); + } + free(cwd); +} + int cmd_rev_parse(int argc, const char **argv, const char *prefix) { int i, as_is = 0, verify = 0, quiet = 0, revs_count = 0, type = 0;@@ -595,6 +665,7 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix) struct object_context unused; struct strbuf buf = STRBUF_INIT; const int hexsz = the_hash_algo->hexsz; + enum format_type format = FORMAT_DEFAULT; if (argc > 1 && !strcmp("--parseopt", argv[1])) return cmd_parseopt(argc - 1, argv + 1, prefix);@@ -650,8 +721,7 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix) if (!argv[i + 1]) die("--git-path requires an argument"); strbuf_reset(&buf); - puts(relative_path(git_path("%s", argv[i + 1]), - prefix, &buf)); + print_path(git_path("%s", argv[i + 1]), prefix, format, DEFAULT_RELATIVE_IF_SHARED);
One thing that the original code did was to reuse the same `strbuf`. Not sure whether this matters in practice.
quoted hunk ↗ jump to hunk
i++; continue; }@@ -683,6 +753,16 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix) show_file(arg, 0); continue; } + if (opt_with_value(arg, "--path-format", &arg)) { + if (!strcmp(arg, "absolute")) { + format = FORMAT_CANONICAL; + } else if (!strcmp(arg, "relative")) { + format = FORMAT_RELATIVE; + } else { + die("unknown argument to --path-format: %s", arg); + } + continue; + } if (!strcmp(arg, "--default")) { def = argv[++i]; if (!def)@@ -803,7 +883,7 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix) if (!strcmp(arg, "--show-toplevel")) { const char *work_tree = get_git_work_tree(); if (work_tree) - puts(work_tree); + print_path(work_tree, prefix, format, DEFAULT_CANONICAL);
The way `print_path()`'s code is structured, it is not immediately obvious to me whether the patch changes behavior here. I _suspect_ that we're now calling `strbuf_realpath_missing()` and react to its return value, which is different from before. Wouldn't make `DEFAULT_UNMODIFIED` make more sense here?
quoted hunk ↗ jump to hunk
else die("this operation must be run in a work tree"); continue;@@ -811,7 +891,7 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix) if (!strcmp(arg, "--show-superproject-working-tree")) { struct strbuf superproject = STRBUF_INIT; if (get_superproject_working_tree(&superproject)) - puts(superproject.buf); + print_path(superproject.buf, prefix, format, DEFAULT_CANONICAL);
Shouldn't this be `DEFAULT_UNMODIFIED`?
quoted hunk ↗ jump to hunk
strbuf_release(&superproject); continue; }@@ -846,16 +926,18 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix) const char *gitdir = getenv(GIT_DIR_ENVIRONMENT); char *cwd; int len; + enum format_type wanted = format; if (arg[2] == 'g') { /* --git-dir */ if (gitdir) { - puts(gitdir); + print_path(gitdir, prefix, format, DEFAULT_UNMODIFIED); continue; } if (!prefix) { - puts(".git"); + print_path(".git", prefix, format, DEFAULT_UNMODIFIED); continue; } } else { /* --absolute-git-dir */ + wanted = FORMAT_CANONICAL; if (!gitdir && !prefix) gitdir = ".git"; if (gitdir) {@@ -868,14 +950,14 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix) } cwd = xgetcwd(); len = strlen(cwd); - printf("%s%s.git\n", cwd, len && cwd[len-1] != '/' ? "/" : ""); + strbuf_reset(&buf); + strbuf_addf(&buf, "%s%s.git", cwd, len && cwd[len-1] != '/' ? "/" : "");
So `DEFAULT_CANONICAL` ensures a trailing `/`? I do not see that in
`print_path()`'s implementation, and also, I would love to see a different
name for that ("canonical", from my Java past, suggests something like
"real path" to me).
Thanks,
Dscho
quoted hunk ↗ jump to hunk
free(cwd); + print_path(buf.buf, prefix, wanted, DEFAULT_CANONICAL); continue; } if (!strcmp(arg, "--git-common-dir")) { - strbuf_reset(&buf); - puts(relative_path(get_git_common_dir(), - prefix, &buf)); + print_path(get_git_common_dir(), prefix, format, DEFAULT_RELATIVE_IF_SHARED); continue; } if (!strcmp(arg, "--is-inside-git-dir")) {@@ -905,8 +987,7 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix) if (the_index.split_index) { const struct object_id *oid = &the_index.split_index->base_oid; const char *path = git_path("sharedindex.%s", oid_to_hex(oid)); - strbuf_reset(&buf); - puts(relative_path(path, prefix, &buf)); + print_path(path, prefix, format, DEFAULT_RELATIVE); } continue; }diff --git a/t/t1500-rev-parse.sh b/t/t1500-rev-parse.sh index 408b97d5af..51d7d40ec1 100755 --- a/t/t1500-rev-parse.sh +++ b/t/t1500-rev-parse.sh@@ -3,6 +3,16 @@ test_description='test git rev-parse' . ./test-lib.sh +test_one () { + dir="$1" && + expect="$2" && + shift && + shift && + echo "$expect" >expect && + git -C "$dir" rev-parse "$@" >actual && + test_cmp expect actual +} + # usage: [options] label is-bare is-inside-git is-inside-work prefix git-dir absolute-git-dir test_rev_parse () { d=@@ -60,7 +70,13 @@ ROOT=$(pwd) test_expect_success 'setup' ' mkdir -p sub/dir work && - cp -R .git repo.git + cp -R .git repo.git && + git checkout -B main && + test_commit abc && + git checkout -b side && + test_commit def && + git checkout main && + git worktree add worktree side ' test_rev_parse toplevel false false true '' .git "$ROOT/.git"@@ -88,6 +104,45 @@ test_rev_parse -C work -g ../repo.git -b t 'GIT_DIR=../repo.git, core.bare = tru test_rev_parse -C work -g ../repo.git -b u 'GIT_DIR=../repo.git, core.bare undefined' false false true '' +test_expect_success 'rev-parse --path-format=absolute' ' + test_one "." "$ROOT/.git" --path-format=absolute --git-dir && + test_one "." "$ROOT/.git" --path-format=absolute --git-common-dir && + test_one "sub/dir" "$ROOT/.git" --path-format=absolute --git-dir && + test_one "sub/dir" "$ROOT/.git" --path-format=absolute --git-common-dir && + test_one "worktree" "$ROOT/.git/worktrees/worktree" --path-format=absolute --git-dir && + test_one "worktree" "$ROOT/.git" --path-format=absolute --git-common-dir && + test_one "." "$ROOT" --path-format=absolute --show-toplevel && + test_one "." "$ROOT/.git/objects" --path-format=absolute --git-path objects && + test_one "." "$ROOT/.git/objects/foo/bar/baz" --path-format=absolute --git-path objects/foo/bar/baz +' + +test_expect_success 'rev-parse --path-format=relative' ' + test_one "." ".git" --path-format=relative --git-dir && + test_one "." ".git" --path-format=relative --git-common-dir && + test_one "sub/dir" "../../.git" --path-format=relative --git-dir && + test_one "sub/dir" "../../.git" --path-format=relative --git-common-dir && + test_one "worktree" "../.git/worktrees/worktree" --path-format=relative --git-dir && + test_one "worktree" "../.git" --path-format=relative --git-common-dir && + test_one "." "./" --path-format=relative --show-toplevel && + test_one "." ".git/objects" --path-format=relative --git-path objects && + test_one "." ".git/objects/foo/bar/baz" --path-format=relative --git-path objects/foo/bar/baz +' + +test_expect_success '--path-format=relative does not affect --absolute-git-dir' ' + git rev-parse --path-format=relative --absolute-git-dir >actual && + echo "$ROOT/.git" >expect && + test_cmp expect actual +' + +test_expect_success '--path-format can change in the middle of the command line' ' + git rev-parse --path-format=absolute --git-dir --path-format=relative --git-path objects/foo/bar >actual && + cat >expect <<-EOF && + $ROOT/.git + .git/objects/foo/bar + EOF + test_cmp expect actual +' + test_expect_success 'git-common-dir from worktree root' ' echo .git >expect && git rev-parse --git-common-dir >actual &&