In some situations it is useful to know if the given repository
is a submodule of another repository.
Add the flag --show-superproject-working-tree to git-rev-parse
to make it easy to find out if there is a superproject. When no
superproject exists, the output will be empty.
Signed-off-by: Stefan Beller <sbeller@xxxxxxxxxx>
---
> I can accept "it is not an error to ask for the root of the
> superproject's working tree when we do not have any---that is one
> way to ask if we have a superproject or not". But if that is the
> case, the code can stay the same, but the documentation should say
> so, something like...
*this patch*
* Documentation shamelessly stolen from Junio.
Thanks,
Stefan
Documentation/git-rev-parse.txt | 6 +++
builtin/rev-parse.c | 7 ++++
submodule.c | 82 +++++++++++++++++++++++++++++++++++++++++
submodule.h | 8 ++++
t/t1500-rev-parse.sh | 14 +++++++
5 files changed, 117 insertions(+)
diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt
index 91c02b8c85..c40c470448 100644
--- a/Documentation/git-rev-parse.txt
+++ b/Documentation/git-rev-parse.txt
@@ -261,6 +261,12 @@ print a message to stderr and exit with nonzero status.
--show-toplevel::
Show the absolute path of the top-level directory.
+--show-superproject-working-tree
+ Show the absolute path of the root of the superproject's
+ working tree (if exists) that uses the current repository as
+ its submodule. Outputs nothing if the current repository is
+ not used as a submodule by any project.
+
--shared-index-path::
Show the path to the shared index file in split index mode, or
empty if not in split-index mode.
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index e08677e559..2549643267 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -12,6 +12,7 @@
#include "diff.h"
#include "revision.h"
#include "split-index.h"
+#include "submodule.h"
#define DO_REVS 1
#define DO_NOREV 2
@@ -779,6 +780,12 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
puts(work_tree);
continue;
}
+ if (!strcmp(arg, "--show-superproject-working-tree")) {
+ const char *superproject = get_superproject_working_tree();
+ if (superproject)
+ puts(superproject);
+ continue;
+ }
if (!strcmp(arg, "--show-prefix")) {
if (prefix)
puts(prefix);
diff --git a/submodule.c b/submodule.c
index 3b98766a6b..bb405653fd 100644
--- a/submodule.c
+++ b/submodule.c
@@ -1514,3 +1514,85 @@ void absorb_git_dir_into_superproject(const char *prefix,
strbuf_release(&sb);
}
}
+
+const char *get_superproject_working_tree(void)
+{
+ struct child_process cp = CHILD_PROCESS_INIT;
+ struct strbuf sb = STRBUF_INIT;
+ const char *one_up = real_path_if_valid("../");
+ const char *cwd = xgetcwd();
+ const char *ret = NULL;
+ const char *subpath;
+ int code;
+ ssize_t len;
+
+ if (!is_inside_work_tree())
+ /*
+ * FIXME:
+ * We might have a superproject, but it is harder
+ * to determine.
+ */
+ return NULL;
+
+ if (!one_up)
+ return NULL;
+
+ subpath = relative_path(cwd, one_up, &sb);
+
+ prepare_submodule_repo_env(&cp.env_array);
+ argv_array_pop(&cp.env_array);
+
+ argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
+ "ls-files", "-z", "--stage", "--full-name", "--",
+ subpath, NULL);
+ strbuf_reset(&sb);
+
+ cp.no_stdin = 1;
+ cp.no_stderr = 1;
+ cp.out = -1;
+ cp.git_cmd = 1;
+
+ if (start_command(&cp))
+ die(_("could not start ls-files in .."));
+
+ len = strbuf_read(&sb, cp.out, PATH_MAX);
+ close(cp.out);
+
+ if (starts_with(sb.buf, "160000")) {
+ int super_sub_len;
+ int cwd_len = strlen(cwd);
+ char *super_sub, *super_wt;
+
+ /*
+ * There is a superproject having this repo as a submodule.
+ * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
+ * We're only interested in the name after the tab.
+ */
+ super_sub = strchr(sb.buf, '\t') + 1;
+ super_sub_len = sb.buf + sb.len - super_sub - 1;
+
+ if (super_sub_len > cwd_len ||
+ strcmp(&cwd[cwd_len - super_sub_len], super_sub))
+ die (_("BUG: returned path string doesn't match cwd?"));
+
+ super_wt = xstrdup(cwd);
+ super_wt[cwd_len - super_sub_len] = '\0';
+
+ ret = real_path(super_wt);
+ free(super_wt);
+ }
+ strbuf_release(&sb);
+
+ code = finish_command(&cp);
+
+ if (code == 128)
+ /* '../' is not a git repository */
+ return NULL;
+ if (code == 0 && len == 0)
+ /* There is an unrelated git repository at '../' */
+ return NULL;
+ if (code)
+ die(_("ls-tree returned unexpected return code %d"), code);
+
+ return ret;
+}
diff --git a/submodule.h b/submodule.h
index 05ab674f06..c8a0c9cb29 100644
--- a/submodule.h
+++ b/submodule.h
@@ -93,4 +93,12 @@ extern void prepare_submodule_repo_env(struct argv_array *out);
extern void absorb_git_dir_into_superproject(const char *prefix,
const char *path,
unsigned flags);
+
+/*
+ * Return the absolute path of the working tree of the superproject, which this
+ * project is a submodule of. If this repository is not a submodule of
+ * another repository, return NULL.
+ */
+extern const char *get_superproject_working_tree(void);
+
#endif
diff --git a/t/t1500-rev-parse.sh b/t/t1500-rev-parse.sh
index 9ed8b8ccba..03d3c7f6d6 100755
--- a/t/t1500-rev-parse.sh
+++ b/t/t1500-rev-parse.sh
@@ -116,4 +116,18 @@ test_expect_success 'git-path inside sub-dir' '
test_cmp expect actual
'
+test_expect_success 'showing the superproject correctly' '
+ git rev-parse --show-superproject-working-tree >out &&
+ test_must_be_empty out &&
+
+ test_create_repo super &&
+ test_commit -C super test_commit &&
+ test_create_repo sub &&
+ test_commit -C sub test_commit &&
+ git -C super submodule add ../sub dir/sub &&
+ echo $(pwd)/super >expect &&
+ git -C super/dir/sub rev-parse --show-superproject-working-tree >out &&
+ test_cmp expect out
+'
+
test_done
--
2.12.0.190.g6e60aba09d.dirty