git/builtin/show-ref.c

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#include "builtin.h"
Honor core.precomposeUnicode in more places On Mac's HFS where git sets core.precomposeUnicode to true automatically by git init/clone, when a user creates a simple unicode refname (in NFC format) such as españa: $ git branch españa different commands would display the branch name differently. For example, git branch, git log --decorate, and git fast-export all used 65 73 70 61 c3 b1 61 (or "espa\xc3\xb1a") (NFC form) while show-ref would use 65 73 70 61 6e cc 83 61 (or "espan\xcc\x83a") (NFD form). A stress test for git filter-repo was tripped up by this inconsistency, though digging in I found that the problems could compound; for example, if the user ran $ git pack-refs --all and then tried to check out the branch, they would be met with: $ git checkout españa error: pathspec 'españa' did not match any file(s) known to git $ git checkout españa -- fatal: invalid reference: españa $ git branch españa * master Note that the user could run the `git branch` command first and copy and paste the `españa` portion of the output and still see the same two errors. Also, if the user added --no-prune to the pack-refs command, then they would see three branches: master, españa, and españa (those last two are NFC vs. NFD forms, even if they render the same). Further, if the user had the `españa` branch checked out before running `git pack-refs --all`, the user would be greeted with (note that I'm trimming trailing output with an ellipsis): $ git rev-parse HEAD fatal: ambiguous argument 'HEAD': unknown revision or path... $ git status On branch españa No commits yet... Or worse, if the user didn't check this stuff first, running `git commit` will create a new commit with all changes of all of history being squashed into it. In addition to pack-refs, one could also get into this state with upload-pack or anything that calls either pack-refs or upload-pack (e.g. gc or clone). Add code in a few places (pack-refs, show-ref, upload-pack) to check and honor the setting of core.precomposeUnicode to avoid these bugs. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-25 22:58:54 +08:00
#include "config.h"
#include "gettext.h"
#include "hex.h"
builtin/show-ref: add new mode to check for reference existence While we have multiple ways to show the value of a given reference, we do not have any way to check whether a reference exists at all. While commands like git-rev-parse(1) or git-show-ref(1) can be used to check for reference existence in case the reference resolves to something sane, neither of them can be used to check for existence in some other scenarios where the reference does not resolve cleanly: - References which have an invalid name cannot be resolved. - References to nonexistent objects cannot be resolved. - Dangling symrefs can be resolved via git-symbolic-ref(1), but this requires the caller to special case existence checks depending on whether or not a reference is symbolic or direct. Furthermore, git-rev-list(1) and other commands do not let the caller distinguish easily between an actually missing reference and a generic error. Taken together, this seems like sufficient motivation to introduce a separate plumbing command to explicitly check for the existence of a reference without trying to resolve its contents. This new command comes in the form of `git show-ref --exists`. This new mode will exit successfully when the reference exists, with a specific exit code of 2 when it does not exist, or with 1 when there has been a generic error. Note that the only way to properly implement this command is by using the internal `refs_read_raw_ref()` function. While the public function `refs_resolve_ref_unsafe()` can be made to behave in the same way by passing various flags, it does not provide any way to obtain the errno with which the reference backend failed when reading the reference. As such, it becomes impossible for us to distinguish generic errors from the explicit case where the reference wasn't found. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-31 16:16:54 +08:00
#include "refs/refs-internal.h"
#include "object-name.h"
#include "object-store-ll.h"
Add "git show-ref" builtin command It's kind of like "git peek-remote", but works only locally (and thus avoids the whole overhead of git_connect()) and has some extra verification features. For example, it allows you to filter the results, and to choose whether you want the tag dereferencing or not. You can also use it to just test whether a particular ref exists. For example: git show-ref master will show all references called "master", whether tags or heads or anything else, and regardless of how deep in the reference naming hierarchy they are (so it would show "refs/heads/master" but also "refs/remote/other-repo/master"). When using the "--verify" flag, the command requires an exact ref path: git show-ref --verify refs/heads/master will only match the exact branch called "master". If nothing matches, show-ref will return an error code of 1, and in the case of verification, it will show an error message. For scripting, you can ask it to be quiet with the "--quiet" flag, which allows you to do things like git-show-ref --quiet --verify -- "refs/heads/$headname" || echo "$headname is not a valid branch" to check whether a particular branch exists or not (notice how we don't actually want to show any results, and we want to use the full refname for it in order to not trigger the problem with ambiguous partial matches). To show only tags, or only proper branch heads, use "--tags" and/or "--heads" respectively (using both means that it shows tags _and_ heads, but not other random references under the refs/ subdirectory). To do automatic tag object dereferencing, use the "-d" or "--dereference" flag, so you can do git show-ref --tags --dereference to get a listing of all tags together with what they dereference. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-16 02:19:32 +08:00
#include "object.h"
#include "string-list.h"
#include "parse-options.h"
Add "git show-ref" builtin command It's kind of like "git peek-remote", but works only locally (and thus avoids the whole overhead of git_connect()) and has some extra verification features. For example, it allows you to filter the results, and to choose whether you want the tag dereferencing or not. You can also use it to just test whether a particular ref exists. For example: git show-ref master will show all references called "master", whether tags or heads or anything else, and regardless of how deep in the reference naming hierarchy they are (so it would show "refs/heads/master" but also "refs/remote/other-repo/master"). When using the "--verify" flag, the command requires an exact ref path: git show-ref --verify refs/heads/master will only match the exact branch called "master". If nothing matches, show-ref will return an error code of 1, and in the case of verification, it will show an error message. For scripting, you can ask it to be quiet with the "--quiet" flag, which allows you to do things like git-show-ref --quiet --verify -- "refs/heads/$headname" || echo "$headname is not a valid branch" to check whether a particular branch exists or not (notice how we don't actually want to show any results, and we want to use the full refname for it in order to not trigger the problem with ambiguous partial matches). To show only tags, or only proper branch heads, use "--tags" and/or "--heads" respectively (using both means that it shows tags _and_ heads, but not other random references under the refs/ subdirectory). To do automatic tag object dereferencing, use the "-d" or "--dereference" flag, so you can do git show-ref --tags --dereference to get a listing of all tags together with what they dereference. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-16 02:19:32 +08:00
static const char * const show_ref_usage[] = {
N_("git show-ref [--head] [-d | --dereference]\n"
" [-s | --hash[=<n>]] [--abbrev[=<n>]] [--branches] [--tags]\n"
" [--] [<pattern>...]"),
N_("git show-ref --verify [-q | --quiet] [-d | --dereference]\n"
" [-s | --hash[=<n>]] [--abbrev[=<n>]]\n"
" [--] [<ref>...]"),
N_("git show-ref --exclude-existing[=<pattern>]"),
builtin/show-ref: add new mode to check for reference existence While we have multiple ways to show the value of a given reference, we do not have any way to check whether a reference exists at all. While commands like git-rev-parse(1) or git-show-ref(1) can be used to check for reference existence in case the reference resolves to something sane, neither of them can be used to check for existence in some other scenarios where the reference does not resolve cleanly: - References which have an invalid name cannot be resolved. - References to nonexistent objects cannot be resolved. - Dangling symrefs can be resolved via git-symbolic-ref(1), but this requires the caller to special case existence checks depending on whether or not a reference is symbolic or direct. Furthermore, git-rev-list(1) and other commands do not let the caller distinguish easily between an actually missing reference and a generic error. Taken together, this seems like sufficient motivation to introduce a separate plumbing command to explicitly check for the existence of a reference without trying to resolve its contents. This new command comes in the form of `git show-ref --exists`. This new mode will exit successfully when the reference exists, with a specific exit code of 2 when it does not exist, or with 1 when there has been a generic error. Note that the only way to properly implement this command is by using the internal `refs_read_raw_ref()` function. While the public function `refs_resolve_ref_unsafe()` can be made to behave in the same way by passing various flags, it does not provide any way to obtain the errno with which the reference backend failed when reading the reference. As such, it becomes impossible for us to distinguish generic errors from the explicit case where the reference wasn't found. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-31 16:16:54 +08:00
N_("git show-ref --exists <ref>"),
NULL
};
Add "git show-ref" builtin command It's kind of like "git peek-remote", but works only locally (and thus avoids the whole overhead of git_connect()) and has some extra verification features. For example, it allows you to filter the results, and to choose whether you want the tag dereferencing or not. You can also use it to just test whether a particular ref exists. For example: git show-ref master will show all references called "master", whether tags or heads or anything else, and regardless of how deep in the reference naming hierarchy they are (so it would show "refs/heads/master" but also "refs/remote/other-repo/master"). When using the "--verify" flag, the command requires an exact ref path: git show-ref --verify refs/heads/master will only match the exact branch called "master". If nothing matches, show-ref will return an error code of 1, and in the case of verification, it will show an error message. For scripting, you can ask it to be quiet with the "--quiet" flag, which allows you to do things like git-show-ref --quiet --verify -- "refs/heads/$headname" || echo "$headname is not a valid branch" to check whether a particular branch exists or not (notice how we don't actually want to show any results, and we want to use the full refname for it in order to not trigger the problem with ambiguous partial matches). To show only tags, or only proper branch heads, use "--tags" and/or "--heads" respectively (using both means that it shows tags _and_ heads, but not other random references under the refs/ subdirectory). To do automatic tag object dereferencing, use the "-d" or "--dereference" flag, so you can do git show-ref --tags --dereference to get a listing of all tags together with what they dereference. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-16 02:19:32 +08:00
struct show_one_options {
int quiet;
int hash_only;
int abbrev;
int deref_tags;
};
static void show_one(const struct show_one_options *opts,
const char *refname, const struct object_id *oid)
{
const char *hex;
struct object_id peeled;
if (!repo_has_object_file(the_repository, oid))
die("git show-ref: bad ref %s (%s)", refname,
oid_to_hex(oid));
if (opts->quiet)
return;
hex = repo_find_unique_abbrev(the_repository, oid, opts->abbrev);
if (opts->hash_only)
printf("%s\n", hex);
else
printf("%s %s\n", hex, refname);
if (!opts->deref_tags)
return;
refs: switch peel_ref() to peel_iterated_oid() The peel_ref() interface is confusing and error-prone: - it's typically used by ref iteration callbacks that have both a refname and oid. But since they pass only the refname, we may load the ref value from the filesystem again. This is inefficient, but also means we are open to a race if somebody simultaneously updates the ref. E.g., this: int some_ref_cb(const char *refname, const struct object_id *oid, ...) { if (!peel_ref(refname, &peeled)) printf("%s peels to %s", oid_to_hex(oid), oid_to_hex(&peeled); } could print nonsense. It is correct to say "refname peels to..." (you may see the "before" value or the "after" value, either of which is consistent), but mentioning both oids may be mixing before/after values. Worse, whether this is possible depends on whether the optimization to read from the current iterator value kicks in. So it is actually not possible with: for_each_ref(some_ref_cb); but it _is_ possible with: head_ref(some_ref_cb); which does not use the iterator mechanism (though in practice, HEAD should never peel to anything, so this may not be triggerable). - it must take a fully-qualified refname for the read_ref_full() code path to work. Yet we routinely pass it partial refnames from callbacks to for_each_tag_ref(), etc. This happens to work when iterating because there we do not call read_ref_full() at all, and only use the passed refname to check if it is the same as the iterator. But the requirements for the function parameters are quite unclear. Instead of taking a refname, let's instead take an oid. That fixes both problems. It's a little funny for a "ref" function not to involve refs at all. The key thing is that it's optimizing under the hood based on having access to the ref iterator. So let's change the name to make it clear why you'd want this function versus just peel_object(). There are two other directions I considered but rejected: - we could pass the peel information into the each_ref_fn callback. However, we don't know if the caller actually wants it or not. For packed-refs, providing it is essentially free. But for loose refs, we actually have to peel the object, which would be wasteful in most cases. We could likewise pass in a flag to the callback indicating whether the peeled information is known, but that complicates those callbacks, as they then have to decide whether to manually peel themselves. Plus it requires changing the interface of every callback, whether they care about peeling or not, and there are many of them. - we could make a function to return the peeled value of the current iterated ref (computing it if necessary), and BUG() otherwise. I.e.: int peel_current_iterated_ref(struct object_id *out); Each of the current callers is an each_ref_fn callback, so they'd mostly be happy. But: - we use those callbacks with functions like head_ref(), which do not use the iteration code. So we'd need to handle the fallback case there, anyway. - it's possible that a caller would want to call into generic code that sometimes is used during iteration and sometimes not. This encapsulates the logic to do the fast thing when possible, and fallback when necessary. The implementation is mostly obvious, but I want to call out a few things in the patch: - the test-tool coverage for peel_ref() is now meaningless, as it all collapses to a single peel_object() call (arguably they were pretty uninteresting before; the tricky part of that function is the fast-path we see during iteration, but these calls didn't trigger that). I've just dropped it entirely, though note that some other tests relied on the tags we created; I've moved that creation to the tests where it matters. - we no longer need to take a ref_store parameter, since we'd never look up a ref now. We do still rely on a global "current iterator" variable which _could_ be kept per-ref-store. But in practice this is only useful if there are multiple recursive iterations, at which point the more appropriate solution is probably a stack of iterators. No caller used the actual ref-store parameter anyway (they all call the wrapper that passes the_repository). - the original only kicked in the optimization when the "refname" pointer matched (i.e., not string comparison). We do likewise with the "oid" parameter here, but fall back to doing an actual oideq() call. This in theory lets us kick in the optimization more often, though in practice no current caller cares. It should never be wrong, though (peeling is a property of an object, so two refs pointing to the same object would peel identically). - the original took care not to touch the peeled out-parameter unless we found something to put in it. But no caller cares about this, and anyway, it is enforced by peel_object() itself (and even in the optimized iterator case, that's where we eventually end up). We can shorten the code and avoid an extra copy by just passing the out-parameter through the stack. Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-21 03:44:43 +08:00
if (!peel_iterated_oid(oid, &peeled)) {
hex = repo_find_unique_abbrev(the_repository, &peeled, opts->abbrev);
printf("%s %s^{}\n", hex, refname);
}
}
struct show_ref_data {
const struct show_one_options *show_one_opts;
const char **patterns;
int found_match;
int show_head;
};
static int show_ref(const char *refname, const struct object_id *oid,
int flag UNUSED, void *cbdata)
Add "git show-ref" builtin command It's kind of like "git peek-remote", but works only locally (and thus avoids the whole overhead of git_connect()) and has some extra verification features. For example, it allows you to filter the results, and to choose whether you want the tag dereferencing or not. You can also use it to just test whether a particular ref exists. For example: git show-ref master will show all references called "master", whether tags or heads or anything else, and regardless of how deep in the reference naming hierarchy they are (so it would show "refs/heads/master" but also "refs/remote/other-repo/master"). When using the "--verify" flag, the command requires an exact ref path: git show-ref --verify refs/heads/master will only match the exact branch called "master". If nothing matches, show-ref will return an error code of 1, and in the case of verification, it will show an error message. For scripting, you can ask it to be quiet with the "--quiet" flag, which allows you to do things like git-show-ref --quiet --verify -- "refs/heads/$headname" || echo "$headname is not a valid branch" to check whether a particular branch exists or not (notice how we don't actually want to show any results, and we want to use the full refname for it in order to not trigger the problem with ambiguous partial matches). To show only tags, or only proper branch heads, use "--tags" and/or "--heads" respectively (using both means that it shows tags _and_ heads, but not other random references under the refs/ subdirectory). To do automatic tag object dereferencing, use the "-d" or "--dereference" flag, so you can do git show-ref --tags --dereference to get a listing of all tags together with what they dereference. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-16 02:19:32 +08:00
{
struct show_ref_data *data = cbdata;
if (data->show_head && !strcmp(refname, "HEAD"))
goto match;
if (data->patterns) {
Add "git show-ref" builtin command It's kind of like "git peek-remote", but works only locally (and thus avoids the whole overhead of git_connect()) and has some extra verification features. For example, it allows you to filter the results, and to choose whether you want the tag dereferencing or not. You can also use it to just test whether a particular ref exists. For example: git show-ref master will show all references called "master", whether tags or heads or anything else, and regardless of how deep in the reference naming hierarchy they are (so it would show "refs/heads/master" but also "refs/remote/other-repo/master"). When using the "--verify" flag, the command requires an exact ref path: git show-ref --verify refs/heads/master will only match the exact branch called "master". If nothing matches, show-ref will return an error code of 1, and in the case of verification, it will show an error message. For scripting, you can ask it to be quiet with the "--quiet" flag, which allows you to do things like git-show-ref --quiet --verify -- "refs/heads/$headname" || echo "$headname is not a valid branch" to check whether a particular branch exists or not (notice how we don't actually want to show any results, and we want to use the full refname for it in order to not trigger the problem with ambiguous partial matches). To show only tags, or only proper branch heads, use "--tags" and/or "--heads" respectively (using both means that it shows tags _and_ heads, but not other random references under the refs/ subdirectory). To do automatic tag object dereferencing, use the "-d" or "--dereference" flag, so you can do git show-ref --tags --dereference to get a listing of all tags together with what they dereference. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-16 02:19:32 +08:00
int reflen = strlen(refname);
const char **p = data->patterns, *m;
Add "git show-ref" builtin command It's kind of like "git peek-remote", but works only locally (and thus avoids the whole overhead of git_connect()) and has some extra verification features. For example, it allows you to filter the results, and to choose whether you want the tag dereferencing or not. You can also use it to just test whether a particular ref exists. For example: git show-ref master will show all references called "master", whether tags or heads or anything else, and regardless of how deep in the reference naming hierarchy they are (so it would show "refs/heads/master" but also "refs/remote/other-repo/master"). When using the "--verify" flag, the command requires an exact ref path: git show-ref --verify refs/heads/master will only match the exact branch called "master". If nothing matches, show-ref will return an error code of 1, and in the case of verification, it will show an error message. For scripting, you can ask it to be quiet with the "--quiet" flag, which allows you to do things like git-show-ref --quiet --verify -- "refs/heads/$headname" || echo "$headname is not a valid branch" to check whether a particular branch exists or not (notice how we don't actually want to show any results, and we want to use the full refname for it in order to not trigger the problem with ambiguous partial matches). To show only tags, or only proper branch heads, use "--tags" and/or "--heads" respectively (using both means that it shows tags _and_ heads, but not other random references under the refs/ subdirectory). To do automatic tag object dereferencing, use the "-d" or "--dereference" flag, so you can do git show-ref --tags --dereference to get a listing of all tags together with what they dereference. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-16 02:19:32 +08:00
while ((m = *p++) != NULL) {
int len = strlen(m);
if (len > reflen)
continue;
if (memcmp(m, refname + reflen - len, len))
continue;
if (len == reflen)
goto match;
if (refname[reflen - len - 1] == '/')
goto match;
}
return 0;
}
match:
data->found_match++;
show_one(data->show_one_opts, refname, oid);
Add "git show-ref" builtin command It's kind of like "git peek-remote", but works only locally (and thus avoids the whole overhead of git_connect()) and has some extra verification features. For example, it allows you to filter the results, and to choose whether you want the tag dereferencing or not. You can also use it to just test whether a particular ref exists. For example: git show-ref master will show all references called "master", whether tags or heads or anything else, and regardless of how deep in the reference naming hierarchy they are (so it would show "refs/heads/master" but also "refs/remote/other-repo/master"). When using the "--verify" flag, the command requires an exact ref path: git show-ref --verify refs/heads/master will only match the exact branch called "master". If nothing matches, show-ref will return an error code of 1, and in the case of verification, it will show an error message. For scripting, you can ask it to be quiet with the "--quiet" flag, which allows you to do things like git-show-ref --quiet --verify -- "refs/heads/$headname" || echo "$headname is not a valid branch" to check whether a particular branch exists or not (notice how we don't actually want to show any results, and we want to use the full refname for it in order to not trigger the problem with ambiguous partial matches). To show only tags, or only proper branch heads, use "--tags" and/or "--heads" respectively (using both means that it shows tags _and_ heads, but not other random references under the refs/ subdirectory). To do automatic tag object dereferencing, use the "-d" or "--dereference" flag, so you can do git show-ref --tags --dereference to get a listing of all tags together with what they dereference. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-16 02:19:32 +08:00
return 0;
}
static int add_existing(const char *refname,
const struct object_id *oid UNUSED,
int flag UNUSED, void *cbdata)
{
struct string_list *list = (struct string_list *)cbdata;
string_list_insert(list, refname);
return 0;
}
struct exclude_existing_options {
/*
* We need an explicit `enabled` field because it is perfectly valid
* for `pattern` to be `NULL` even if `--exclude-existing` was given.
*/
int enabled;
const char *pattern;
};
/*
* read "^(?:<anything>\s)?<refname>(?:\^\{\})?$" from the standard input,
* and
* (1) strip "^{}" at the end of line if any;
* (2) ignore if match is provided and does not head-match refname;
* (3) warn if refname is not a well-formed refname and skip;
* (4) ignore if refname is a ref that exists in the local repository;
* (5) otherwise output the line.
*/
static int cmd_show_ref__exclude_existing(const struct exclude_existing_options *opts)
{
struct string_list existing_refs = STRING_LIST_INIT_DUP;
char buf[1024];
int patternlen = opts->pattern ? strlen(opts->pattern) : 0;
for_each_ref(add_existing, &existing_refs);
while (fgets(buf, sizeof(buf), stdin)) {
char *ref;
int len = strlen(buf);
if (len > 0 && buf[len - 1] == '\n')
buf[--len] = '\0';
if (3 <= len && !strcmp(buf + len - 3, "^{}")) {
len -= 3;
buf[len] = '\0';
}
for (ref = buf + len; buf < ref; ref--)
if (isspace(ref[-1]))
break;
if (opts->pattern) {
int reflen = buf + len - ref;
if (reflen < patternlen)
continue;
if (strncmp(ref, opts->pattern, patternlen))
continue;
}
if (check_refname_format(ref, 0)) {
warning("ref '%s' ignored", ref);
continue;
}
if (!string_list_has_string(&existing_refs, ref)) {
printf("%s\n", buf);
}
}
string_list_clear(&existing_refs, 0);
return 0;
}
static int cmd_show_ref__verify(const struct show_one_options *show_one_opts,
const char **refs)
{
if (!refs || !*refs)
die("--verify requires a reference");
while (*refs) {
struct object_id oid;
if ((starts_with(*refs, "refs/") || refname_is_safe(*refs)) &&
!read_ref(*refs, &oid)) {
show_one(show_one_opts, *refs, &oid);
}
else if (!show_one_opts->quiet)
die("'%s' - not a valid ref", *refs);
else
return 1;
refs++;
}
return 0;
}
struct patterns_options {
int show_head;
int branches_only;
int tags_only;
};
static int cmd_show_ref__patterns(const struct patterns_options *opts,
const struct show_one_options *show_one_opts,
const char **patterns)
{
struct show_ref_data show_ref_data = {
.show_one_opts = show_one_opts,
.show_head = opts->show_head,
};
if (patterns && *patterns)
show_ref_data.patterns = patterns;
if (opts->show_head)
head_ref(show_ref, &show_ref_data);
if (opts->branches_only || opts->tags_only) {
if (opts->branches_only)
for_each_fullref_in("refs/heads/", show_ref, &show_ref_data);
if (opts->tags_only)
for_each_fullref_in("refs/tags/", show_ref, &show_ref_data);
} else {
for_each_ref(show_ref, &show_ref_data);
}
if (!show_ref_data.found_match)
return 1;
return 0;
}
builtin/show-ref: add new mode to check for reference existence While we have multiple ways to show the value of a given reference, we do not have any way to check whether a reference exists at all. While commands like git-rev-parse(1) or git-show-ref(1) can be used to check for reference existence in case the reference resolves to something sane, neither of them can be used to check for existence in some other scenarios where the reference does not resolve cleanly: - References which have an invalid name cannot be resolved. - References to nonexistent objects cannot be resolved. - Dangling symrefs can be resolved via git-symbolic-ref(1), but this requires the caller to special case existence checks depending on whether or not a reference is symbolic or direct. Furthermore, git-rev-list(1) and other commands do not let the caller distinguish easily between an actually missing reference and a generic error. Taken together, this seems like sufficient motivation to introduce a separate plumbing command to explicitly check for the existence of a reference without trying to resolve its contents. This new command comes in the form of `git show-ref --exists`. This new mode will exit successfully when the reference exists, with a specific exit code of 2 when it does not exist, or with 1 when there has been a generic error. Note that the only way to properly implement this command is by using the internal `refs_read_raw_ref()` function. While the public function `refs_resolve_ref_unsafe()` can be made to behave in the same way by passing various flags, it does not provide any way to obtain the errno with which the reference backend failed when reading the reference. As such, it becomes impossible for us to distinguish generic errors from the explicit case where the reference wasn't found. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-31 16:16:54 +08:00
static int cmd_show_ref__exists(const char **refs)
{
struct strbuf unused_referent = STRBUF_INIT;
struct object_id unused_oid;
unsigned int unused_type;
int failure_errno = 0;
const char *ref;
int ret = 0;
if (!refs || !*refs)
die("--exists requires a reference");
ref = *refs++;
if (*refs)
die("--exists requires exactly one reference");
if (refs_read_raw_ref(get_main_ref_store(the_repository), ref,
&unused_oid, &unused_referent, &unused_type,
&failure_errno)) {
if (failure_errno == ENOENT || failure_errno == EISDIR) {
builtin/show-ref: add new mode to check for reference existence While we have multiple ways to show the value of a given reference, we do not have any way to check whether a reference exists at all. While commands like git-rev-parse(1) or git-show-ref(1) can be used to check for reference existence in case the reference resolves to something sane, neither of them can be used to check for existence in some other scenarios where the reference does not resolve cleanly: - References which have an invalid name cannot be resolved. - References to nonexistent objects cannot be resolved. - Dangling symrefs can be resolved via git-symbolic-ref(1), but this requires the caller to special case existence checks depending on whether or not a reference is symbolic or direct. Furthermore, git-rev-list(1) and other commands do not let the caller distinguish easily between an actually missing reference and a generic error. Taken together, this seems like sufficient motivation to introduce a separate plumbing command to explicitly check for the existence of a reference without trying to resolve its contents. This new command comes in the form of `git show-ref --exists`. This new mode will exit successfully when the reference exists, with a specific exit code of 2 when it does not exist, or with 1 when there has been a generic error. Note that the only way to properly implement this command is by using the internal `refs_read_raw_ref()` function. While the public function `refs_resolve_ref_unsafe()` can be made to behave in the same way by passing various flags, it does not provide any way to obtain the errno with which the reference backend failed when reading the reference. As such, it becomes impossible for us to distinguish generic errors from the explicit case where the reference wasn't found. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-31 16:16:54 +08:00
error(_("reference does not exist"));
ret = 2;
} else {
errno = failure_errno;
error_errno(_("failed to look up reference"));
ret = 1;
}
goto out;
}
out:
strbuf_release(&unused_referent);
return ret;
}
static int hash_callback(const struct option *opt, const char *arg, int unset)
{
struct show_one_options *opts = opt->value;
struct option abbrev_opt = *opt;
opts->hash_only = 1;
/* Use full length SHA1 if no argument */
if (!arg)
return 0;
abbrev_opt.value = &opts->abbrev;
return parse_opt_abbrev_cb(&abbrev_opt, arg, unset);
}
static int exclude_existing_callback(const struct option *opt, const char *arg,
int unset)
{
struct exclude_existing_options *opts = opt->value;
assert NOARG/NONEG behavior of parse-options callbacks When we define a parse-options callback, the flags we put in the option struct must match what the callback expects. For example, a callback which does not handle the "unset" parameter should only be used with PARSE_OPT_NONEG. But since the callback and the option struct are not defined next to each other, it's easy to get this wrong (as earlier patches in this series show). Fortunately, the compiler can help us here: compiling with -Wunused-parameters can show us which callbacks ignore their "unset" parameters (and likewise, ones that ignore "arg" expect to be triggered with PARSE_OPT_NOARG). But after we've inspected a callback and determined that all of its callers use the right flags, what do we do next? We'd like to silence the compiler warning, but do so in a way that will catch any wrong calls in the future. We can do that by actually checking those variables and asserting that they match our expectations. Because this is such a common pattern, we'll introduce some helper macros. The resulting messages aren't as descriptive as we could make them, but the file/line information from BUG() is enough to identify the problem (and anyway, the point is that these should never be seen). Each of the annotated callbacks in this patch triggers -Wunused-parameters, and was manually inspected to make sure all callers use the correct options (so none of these BUGs should be triggerable). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-05 14:45:42 +08:00
BUG_ON_OPT_NEG(unset);
opts->enabled = 1;
opts->pattern = arg;
return 0;
}
Add "git show-ref" builtin command It's kind of like "git peek-remote", but works only locally (and thus avoids the whole overhead of git_connect()) and has some extra verification features. For example, it allows you to filter the results, and to choose whether you want the tag dereferencing or not. You can also use it to just test whether a particular ref exists. For example: git show-ref master will show all references called "master", whether tags or heads or anything else, and regardless of how deep in the reference naming hierarchy they are (so it would show "refs/heads/master" but also "refs/remote/other-repo/master"). When using the "--verify" flag, the command requires an exact ref path: git show-ref --verify refs/heads/master will only match the exact branch called "master". If nothing matches, show-ref will return an error code of 1, and in the case of verification, it will show an error message. For scripting, you can ask it to be quiet with the "--quiet" flag, which allows you to do things like git-show-ref --quiet --verify -- "refs/heads/$headname" || echo "$headname is not a valid branch" to check whether a particular branch exists or not (notice how we don't actually want to show any results, and we want to use the full refname for it in order to not trigger the problem with ambiguous partial matches). To show only tags, or only proper branch heads, use "--tags" and/or "--heads" respectively (using both means that it shows tags _and_ heads, but not other random references under the refs/ subdirectory). To do automatic tag object dereferencing, use the "-d" or "--dereference" flag, so you can do git show-ref --tags --dereference to get a listing of all tags together with what they dereference. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-16 02:19:32 +08:00
int cmd_show_ref(int argc, const char **argv, const char *prefix)
{
struct exclude_existing_options exclude_existing_opts = {0};
struct patterns_options patterns_opts = {0};
struct show_one_options show_one_opts = {0};
builtin/show-ref: add new mode to check for reference existence While we have multiple ways to show the value of a given reference, we do not have any way to check whether a reference exists at all. While commands like git-rev-parse(1) or git-show-ref(1) can be used to check for reference existence in case the reference resolves to something sane, neither of them can be used to check for existence in some other scenarios where the reference does not resolve cleanly: - References which have an invalid name cannot be resolved. - References to nonexistent objects cannot be resolved. - Dangling symrefs can be resolved via git-symbolic-ref(1), but this requires the caller to special case existence checks depending on whether or not a reference is symbolic or direct. Furthermore, git-rev-list(1) and other commands do not let the caller distinguish easily between an actually missing reference and a generic error. Taken together, this seems like sufficient motivation to introduce a separate plumbing command to explicitly check for the existence of a reference without trying to resolve its contents. This new command comes in the form of `git show-ref --exists`. This new mode will exit successfully when the reference exists, with a specific exit code of 2 when it does not exist, or with 1 when there has been a generic error. Note that the only way to properly implement this command is by using the internal `refs_read_raw_ref()` function. While the public function `refs_resolve_ref_unsafe()` can be made to behave in the same way by passing various flags, it does not provide any way to obtain the errno with which the reference backend failed when reading the reference. As such, it becomes impossible for us to distinguish generic errors from the explicit case where the reference wasn't found. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-31 16:16:54 +08:00
int verify = 0, exists = 0;
const struct option show_ref_options[] = {
OPT_BOOL(0, "tags", &patterns_opts.tags_only, N_("only show tags (can be combined with branches)")),
OPT_BOOL(0, "branches", &patterns_opts.branches_only, N_("only show branches (can be combined with tags)")),
OPT_HIDDEN_BOOL(0, "heads", &patterns_opts.branches_only,
N_("deprecated synonym for --branches")),
builtin/show-ref: add new mode to check for reference existence While we have multiple ways to show the value of a given reference, we do not have any way to check whether a reference exists at all. While commands like git-rev-parse(1) or git-show-ref(1) can be used to check for reference existence in case the reference resolves to something sane, neither of them can be used to check for existence in some other scenarios where the reference does not resolve cleanly: - References which have an invalid name cannot be resolved. - References to nonexistent objects cannot be resolved. - Dangling symrefs can be resolved via git-symbolic-ref(1), but this requires the caller to special case existence checks depending on whether or not a reference is symbolic or direct. Furthermore, git-rev-list(1) and other commands do not let the caller distinguish easily between an actually missing reference and a generic error. Taken together, this seems like sufficient motivation to introduce a separate plumbing command to explicitly check for the existence of a reference without trying to resolve its contents. This new command comes in the form of `git show-ref --exists`. This new mode will exit successfully when the reference exists, with a specific exit code of 2 when it does not exist, or with 1 when there has been a generic error. Note that the only way to properly implement this command is by using the internal `refs_read_raw_ref()` function. While the public function `refs_resolve_ref_unsafe()` can be made to behave in the same way by passing various flags, it does not provide any way to obtain the errno with which the reference backend failed when reading the reference. As such, it becomes impossible for us to distinguish generic errors from the explicit case where the reference wasn't found. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-31 16:16:54 +08:00
OPT_BOOL(0, "exists", &exists, N_("check for reference existence without resolving")),
OPT_BOOL(0, "verify", &verify, N_("stricter reference checking, "
"requires exact ref path")),
OPT_HIDDEN_BOOL('h', NULL, &patterns_opts.show_head,
N_("show the HEAD reference, even if it would be filtered out")),
OPT_BOOL(0, "head", &patterns_opts.show_head,
N_("show the HEAD reference, even if it would be filtered out")),
OPT_BOOL('d', "dereference", &show_one_opts.deref_tags,
N_("dereference tags into object IDs")),
OPT_CALLBACK_F('s', "hash", &show_one_opts, N_("n"),
N_("only show SHA1 hash using <n> digits"),
PARSE_OPT_OPTARG, &hash_callback),
OPT__ABBREV(&show_one_opts.abbrev),
OPT__QUIET(&show_one_opts.quiet,
N_("do not print results to stdout (useful with --verify)")),
OPT_CALLBACK_F(0, "exclude-existing", &exclude_existing_opts,
N_("pattern"), N_("show refs from stdin that aren't in local repository"),
PARSE_OPT_OPTARG | PARSE_OPT_NONEG, exclude_existing_callback),
OPT_END()
};
Honor core.precomposeUnicode in more places On Mac's HFS where git sets core.precomposeUnicode to true automatically by git init/clone, when a user creates a simple unicode refname (in NFC format) such as españa: $ git branch españa different commands would display the branch name differently. For example, git branch, git log --decorate, and git fast-export all used 65 73 70 61 c3 b1 61 (or "espa\xc3\xb1a") (NFC form) while show-ref would use 65 73 70 61 6e cc 83 61 (or "espan\xcc\x83a") (NFD form). A stress test for git filter-repo was tripped up by this inconsistency, though digging in I found that the problems could compound; for example, if the user ran $ git pack-refs --all and then tried to check out the branch, they would be met with: $ git checkout españa error: pathspec 'españa' did not match any file(s) known to git $ git checkout españa -- fatal: invalid reference: españa $ git branch españa * master Note that the user could run the `git branch` command first and copy and paste the `españa` portion of the output and still see the same two errors. Also, if the user added --no-prune to the pack-refs command, then they would see three branches: master, españa, and españa (those last two are NFC vs. NFD forms, even if they render the same). Further, if the user had the `españa` branch checked out before running `git pack-refs --all`, the user would be greeted with (note that I'm trimming trailing output with an ellipsis): $ git rev-parse HEAD fatal: ambiguous argument 'HEAD': unknown revision or path... $ git status On branch españa No commits yet... Or worse, if the user didn't check this stuff first, running `git commit` will create a new commit with all changes of all of history being squashed into it. In addition to pack-refs, one could also get into this state with upload-pack or anything that calls either pack-refs or upload-pack (e.g. gc or clone). Add code in a few places (pack-refs, show-ref, upload-pack) to check and honor the setting of core.precomposeUnicode to avoid these bugs. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-25 22:58:54 +08:00
git_config(git_default_config, NULL);
argc = parse_options(argc, argv, prefix, show_ref_options,
show_ref_usage, 0);
Add "git show-ref" builtin command It's kind of like "git peek-remote", but works only locally (and thus avoids the whole overhead of git_connect()) and has some extra verification features. For example, it allows you to filter the results, and to choose whether you want the tag dereferencing or not. You can also use it to just test whether a particular ref exists. For example: git show-ref master will show all references called "master", whether tags or heads or anything else, and regardless of how deep in the reference naming hierarchy they are (so it would show "refs/heads/master" but also "refs/remote/other-repo/master"). When using the "--verify" flag, the command requires an exact ref path: git show-ref --verify refs/heads/master will only match the exact branch called "master". If nothing matches, show-ref will return an error code of 1, and in the case of verification, it will show an error message. For scripting, you can ask it to be quiet with the "--quiet" flag, which allows you to do things like git-show-ref --quiet --verify -- "refs/heads/$headname" || echo "$headname is not a valid branch" to check whether a particular branch exists or not (notice how we don't actually want to show any results, and we want to use the full refname for it in order to not trigger the problem with ambiguous partial matches). To show only tags, or only proper branch heads, use "--tags" and/or "--heads" respectively (using both means that it shows tags _and_ heads, but not other random references under the refs/ subdirectory). To do automatic tag object dereferencing, use the "-d" or "--dereference" flag, so you can do git show-ref --tags --dereference to get a listing of all tags together with what they dereference. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-16 02:19:32 +08:00
die_for_incompatible_opt3(exclude_existing_opts.enabled, "--exclude-existing",
verify, "--verify",
exists, "--exists");
if (exclude_existing_opts.enabled)
return cmd_show_ref__exclude_existing(&exclude_existing_opts);
else if (verify)
return cmd_show_ref__verify(&show_one_opts, argv);
builtin/show-ref: add new mode to check for reference existence While we have multiple ways to show the value of a given reference, we do not have any way to check whether a reference exists at all. While commands like git-rev-parse(1) or git-show-ref(1) can be used to check for reference existence in case the reference resolves to something sane, neither of them can be used to check for existence in some other scenarios where the reference does not resolve cleanly: - References which have an invalid name cannot be resolved. - References to nonexistent objects cannot be resolved. - Dangling symrefs can be resolved via git-symbolic-ref(1), but this requires the caller to special case existence checks depending on whether or not a reference is symbolic or direct. Furthermore, git-rev-list(1) and other commands do not let the caller distinguish easily between an actually missing reference and a generic error. Taken together, this seems like sufficient motivation to introduce a separate plumbing command to explicitly check for the existence of a reference without trying to resolve its contents. This new command comes in the form of `git show-ref --exists`. This new mode will exit successfully when the reference exists, with a specific exit code of 2 when it does not exist, or with 1 when there has been a generic error. Note that the only way to properly implement this command is by using the internal `refs_read_raw_ref()` function. While the public function `refs_resolve_ref_unsafe()` can be made to behave in the same way by passing various flags, it does not provide any way to obtain the errno with which the reference backend failed when reading the reference. As such, it becomes impossible for us to distinguish generic errors from the explicit case where the reference wasn't found. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-31 16:16:54 +08:00
else if (exists)
return cmd_show_ref__exists(argv);
else
return cmd_show_ref__patterns(&patterns_opts, &show_one_opts, argv);
Add "git show-ref" builtin command It's kind of like "git peek-remote", but works only locally (and thus avoids the whole overhead of git_connect()) and has some extra verification features. For example, it allows you to filter the results, and to choose whether you want the tag dereferencing or not. You can also use it to just test whether a particular ref exists. For example: git show-ref master will show all references called "master", whether tags or heads or anything else, and regardless of how deep in the reference naming hierarchy they are (so it would show "refs/heads/master" but also "refs/remote/other-repo/master"). When using the "--verify" flag, the command requires an exact ref path: git show-ref --verify refs/heads/master will only match the exact branch called "master". If nothing matches, show-ref will return an error code of 1, and in the case of verification, it will show an error message. For scripting, you can ask it to be quiet with the "--quiet" flag, which allows you to do things like git-show-ref --quiet --verify -- "refs/heads/$headname" || echo "$headname is not a valid branch" to check whether a particular branch exists or not (notice how we don't actually want to show any results, and we want to use the full refname for it in order to not trigger the problem with ambiguous partial matches). To show only tags, or only proper branch heads, use "--tags" and/or "--heads" respectively (using both means that it shows tags _and_ heads, but not other random references under the refs/ subdirectory). To do automatic tag object dereferencing, use the "-d" or "--dereference" flag, so you can do git show-ref --tags --dereference to get a listing of all tags together with what they dereference. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-16 02:19:32 +08:00
}