Enable Git to resolve its own binary location using a variety of OS-specific and generic methods, including:
- procfs via "/proc/self/exe" (Linux)
- _NSGetExecutablePath (Darwin)
- KERN_PROC_PATHNAME sysctl on BSDs.
- argv0, if absolute (all, including Windows).
This is used to enable RUNTIME_PREFIX support for non-Windows systems, notably Linux and Darwin. When configured with RUNTIME_PREFIX, Git will do a best-effort resolution of its executable path and automatically use this as its "exec_path" for relative helper and data lookups, unless explicitly overridden.
Small incidental formatting cleanup of "exec_cmd.c".
Signed-off-by: Dan Jacques <dnj@google.com>
Thanks-to: Robbie Iannucci <iannucci@google.com>
Thanks-to: Junio C Hamano <gitster@pobox.com>
---
Makefile | 30 ++++++-
cache.h | 1 +
common-main.c | 4 +-
config.mak.uname | 7 ++
exec_cmd.c | 236 +++++++++++++++++++++++++++++++++++++++++++------
exec_cmd.h | 4 +-
gettext.c | 8 +-
git.c | 2 +-
t/t0061-run-command.sh | 2 +-
9 files changed, 254 insertions(+), 40 deletions(-)
Show changes to 9 files +254 −40
Makefile, cache.h, common-main.c, config.mak.uname, exec_cmd.c, exec_cmd.h, gettext.c, git.c, t/t0061-run-command.sh
diff --git a/Makefile b/Makefile
index 033a55505..f84e816cf 100644
--- a/Makefile
+++ b/Makefile
@@ -441,6 +441,18 @@ all::
# can be moved to arbitrary filesystem locations. RUNTIME_PREFIX also causes
# Perl scripts to use a modified entry point header allowing them to resolve
# support files at runtime.
+#
+# When using RUNTIME_PREFIX, define HAVE_BSD_KERN_PROC_SYSCTL if your platform
+# supports the KERN_PROC BSD sysctl function.
+#
+# When using RUNTIME_PREFIX, define PROCFS_EXECUTABLE_PATH if your platform
+# mounts a "procfs" filesystem capable of resolving the path of the current
+# executable. If defined, this must be the canonical path for the "procfs"
+# current executable path.
+#
+# When using RUNTIME_PREFIX, define HAVE_NS_GET_EXECUTABLE_PATH if your platform
+# supports calling _NSGetExecutablePath to retrieve the path of the running
+# executable.
GIT-VERSION-FILE: FORCE
@$(SHELL_PATH) ./GIT-VERSION-GEN
@@ -1664,10 +1676,23 @@ ifdef HAVE_BSD_SYSCTL
BASIC_CFLAGS += -DHAVE_BSD_SYSCTL
endif
+ifdef HAVE_BSD_KERN_PROC_SYSCTL
+ BASIC_CFLAGS += -DHAVE_BSD_KERN_PROC_SYSCTL
+endif
+
ifdef HAVE_GETDELIM
BASIC_CFLAGS += -DHAVE_GETDELIM
endif
+ifneq ($(PROCFS_EXECUTABLE_PATH),)
+ procfs_executable_path_SQ = $(subst ','\'',$(PROCFS_EXECUTABLE_PATH))
+ BASIC_CFLAGS += '-DPROCFS_EXECUTABLE_PATH="$(procfs_executable_path_SQ)"'
+endif
+
+ifdef HAVE_NS_GET_EXECUTABLE_PATH
+ BASIC_CFLAGS += -DHAVE_NS_GET_EXECUTABLE_PATH
+endif
+
ifeq ($(TCLTK_PATH),)
NO_TCLTK = NoThanks
endif
@@ -1772,7 +1797,7 @@ PERLLIB_EXTRA_SQ = $(subst ','\'',$(PERLLIB_EXTRA))
# RUNTIME_PREFIX's resolution logic requires resource paths to be expressed
# relative to each other and share an installation path.
#
-# This is a dependnecy in:
+# This is a dependency in:
# - Git's binary RUNTIME_PREFIX logic in (see "exec_cmd.c").
# - The runtime prefix Perl header (see
# "perl/header_templates/runtime_prefix.template.pl").
@@ -2216,6 +2241,7 @@ endif
exec_cmd.sp exec_cmd.s exec_cmd.o: GIT-PREFIX
exec_cmd.sp exec_cmd.s exec_cmd.o: EXTRA_CPPFLAGS = \
'-DGIT_EXEC_PATH="$(gitexecdir_SQ)"' \
+ '-DGIT_LOCALE_PATH="$(localedir_relative_SQ)"' \
'-DBINDIR="$(bindir_relative_SQ)"' \
'-DPREFIX="$(prefix_SQ)"'
@@ -2233,7 +2259,7 @@ attr.sp attr.s attr.o: EXTRA_CPPFLAGS = \
gettext.sp gettext.s gettext.o: GIT-PREFIX
gettext.sp gettext.s gettext.o: EXTRA_CPPFLAGS = \
- -DGIT_LOCALE_PATH='"$(localedir_SQ)"'
+ -DGIT_LOCALE_PATH='"$(localedir_relative_SQ)"'
http-push.sp http.sp http-walker.sp remote-curl.sp imap-send.sp: SPARSE_FLAGS += \
-DCURL_DISABLE_TYPECHECK
diff --git a/cache.h b/cache.h
index a61b2d3f0..d8c55d72b 100644
--- a/cache.h
+++ b/cache.h
@@ -428,6 +428,7 @@ static inline enum object_type object_type(unsigned int mode)
#define GIT_ICASE_PATHSPECS_ENVIRONMENT "GIT_ICASE_PATHSPECS"
#define GIT_QUARANTINE_ENVIRONMENT "GIT_QUARANTINE_PATH"
#define GIT_OPTIONAL_LOCKS_ENVIRONMENT "GIT_OPTIONAL_LOCKS"
+#define GIT_TEXT_DOMAIN_DIR_ENVIRONMENT "GIT_TEXTDOMAINDIR"
/*
* Environment variable used in handshaking the wire protocol.
diff --git a/common-main.c b/common-main.c
index 6a689007e..6516a1f89 100644
--- a/common-main.c
+++ b/common-main.c
@@ -32,12 +32,12 @@ int main(int argc, const char **argv)
*/
sanitize_stdfds();
+ git_resolve_executable_dir(argv[0]);
+
git_setup_gettext();
attr_start();
- git_extract_argv0_path(argv[0]);
-
restore_sigpipe_to_default();
return cmd_main(argc, argv);
diff --git a/config.mak.uname b/config.mak.uname
index 6a1d0de0c..e1cfe5e5e 100644
--- a/config.mak.uname
+++ b/config.mak.uname
@@ -37,6 +37,7 @@ ifeq ($(uname_S),Linux)
HAVE_GETDELIM = YesPlease
SANE_TEXT_GREP=-a
FREAD_READS_DIRECTORIES = UnfortunatelyYes
+ PROCFS_EXECUTABLE_PATH = /proc/self/exe
endif
ifeq ($(uname_S),GNU/kFreeBSD)
HAVE_ALLOCA_H = YesPlease
@@ -111,6 +112,7 @@ ifeq ($(uname_S),Darwin)
BASIC_CFLAGS += -DPROTECT_HFS_DEFAULT=1
HAVE_BSD_SYSCTL = YesPlease
FREAD_READS_DIRECTORIES = UnfortunatelyYes
+ HAVE_NS_GET_EXECUTABLE_PATH = YesPlease
endif
ifeq ($(uname_S),SunOS)
NEEDS_SOCKET = YesPlease
@@ -205,6 +207,7 @@ ifeq ($(uname_S),FreeBSD)
HAVE_PATHS_H = YesPlease
GMTIME_UNRELIABLE_ERRORS = UnfortunatelyYes
HAVE_BSD_SYSCTL = YesPlease
+ HAVE_BSD_KERN_PROC_SYSCTL = YesPlease
PAGER_ENV = LESS=FRX LV=-c MORE=FRX
FREAD_READS_DIRECTORIES = UnfortunatelyYes
endif
@@ -217,6 +220,8 @@ ifeq ($(uname_S),OpenBSD)
BASIC_LDFLAGS += -L/usr/local/lib
HAVE_PATHS_H = YesPlease
HAVE_BSD_SYSCTL = YesPlease
+ HAVE_BSD_KERN_PROC_SYSCTL = YesPlease
+ PROCFS_EXECUTABLE_PATH = /proc/curproc/file
endif
ifeq ($(uname_S),MirBSD)
NO_STRCASESTR = YesPlease
@@ -235,6 +240,8 @@ ifeq ($(uname_S),NetBSD)
USE_ST_TIMESPEC = YesPlease
HAVE_PATHS_H = YesPlease
HAVE_BSD_SYSCTL = YesPlease
+ HAVE_BSD_KERN_PROC_SYSCTL = YesPlease
+ PROCFS_EXECUTABLE_PATH = /proc/curproc/exe
endif
ifeq ($(uname_S),AIX)
DEFAULT_PAGER = more
diff --git a/exec_cmd.c b/exec_cmd.c
index ce192a2d6..38d52d90a 100644
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -2,24 +2,52 @@
#include "exec_cmd.h"
#include "quote.h"
#include "argv-array.h"
-#define MAX_ARGS 32
-static const char *argv_exec_path;
+#if defined(RUNTIME_PREFIX)
+
+#if defined(HAVE_NS_GET_EXECUTABLE_PATH)
+#include <mach-o/dyld.h>
+#endif
+
+#if defined(HAVE_BSD_KERN_PROC_SYSCTL)
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/sysctl.h>
+#endif
+
+#endif /* RUNTIME_PREFIX */
+
+#define MAX_ARGS 32
+
+static const char *system_prefix(void);
#ifdef RUNTIME_PREFIX
-static const char *argv0_path;
+
+/**
+ * When using a runtime prefix, Git dynamically resolves paths relative to its
+ * executable.
+ *
+ * The method for determining the path of the executable is highly
+ * platform-specific.
+ */
+
+/**
+ * Path to the current Git executable. Resolved on startup by
+ * 'git_resolve_executable_dir'.
+ */
+static const char *executable_dirname;
static const char *system_prefix(void)
{
static const char *prefix;
- assert(argv0_path);
- assert(is_absolute_path(argv0_path));
+ assert(executable_dirname);
+ assert(is_absolute_path(executable_dirname));
if (!prefix &&
- !(prefix = strip_path_suffix(argv0_path, GIT_EXEC_PATH)) &&
- !(prefix = strip_path_suffix(argv0_path, BINDIR)) &&
- !(prefix = strip_path_suffix(argv0_path, "git"))) {
+ !(prefix = strip_path_suffix(executable_dirname, GIT_EXEC_PATH)) &&
+ !(prefix = strip_path_suffix(executable_dirname, BINDIR)) &&
+ !(prefix = strip_path_suffix(executable_dirname, "git"))) {
prefix = PREFIX;
trace_printf("RUNTIME_PREFIX requested, "
"but prefix computation failed. "
@@ -28,27 +56,179 @@ static const char *system_prefix(void)
return prefix;
}
-void git_extract_argv0_path(const char *argv0)
+/*
+ * Resolves the executable path from argv[0], only if it is absolute.
+ *
+ * Returns 0 on success, -1 on failure.
+ */
+static int git_get_exec_path_from_argv0(struct strbuf *buf, const char *argv0)
{
const char *slash;
if (!argv0 || !*argv0)
- return;
+ return -1;
slash = find_last_dir_sep(argv0);
+ if (slash) {
+ trace_printf("trace: resolved executable path from argv0: %s\n",
+ argv0);
+ strbuf_add_absolute_path(buf, argv0);
+ return 0;
+ }
+ return -1;
+}
+#ifdef PROCFS_EXECUTABLE_PATH
+/*
+ * Resolves the executable path by examining a procfs symlink.
+ *
+ * Returns 0 on success, -1 on failure.
+ */
+static int git_get_exec_path_procfs(struct strbuf *buf)
+{
+ if (strbuf_realpath(buf, PROCFS_EXECUTABLE_PATH, 0)) {
+ trace_printf(
+ "trace: resolved executable path from procfs: %s\n",
+ buf->buf);
+ return 0;
+ }
+ return -1;
+}
+#endif /* PROCFS_EXECUTABLE_PATH */
+
+#ifdef HAVE_BSD_KERN_PROC_SYSCTL
+/*
+ * Resolves the executable path using KERN_PROC_PATHNAME BSD sysctl.
+ *
+ * Returns 0 on success, -1 on failure.
+ */
+static int git_get_exec_path_bsd_sysctl(struct strbuf *buf)
+{
+ int mib[4];
+ char path[MAXPATHLEN];
+ size_t cb = sizeof(path);
+
+ mib[0] = CTL_KERN;
+ mib[1] = KERN_PROC;
+ mib[2] = KERN_PROC_PATHNAME;
+ mib[3] = -1;
+ if (!sysctl(mib, 4, path, &cb, NULL, 0)) {
+ trace_printf(
+ "trace: resolved executable path from sysctl: %s\n",
+ path);
+ strbuf_addstr(buf, path);
+ return 0;
+ }
+ return -1;
+}
+#endif /* HAVE_BSD_KERN_PROC_SYSCTL */
+
+#ifdef HAVE_NS_GET_EXECUTABLE_PATH
+/*
+ * Resolves the executable path by querying Darwin application stack.
+ *
+ * Returns 0 on success, -1 on failure.
+ */
+static int git_get_exec_path_darwin(struct strbuf *buf)
+{
+ char path[PATH_MAX];
+ uint32_t size = sizeof(path);
+ if (!_NSGetExecutablePath(path, &size)) {
+ trace_printf(
+ "trace: resolved executable path from Darwin stack: %s\n",
+ path);
+ strbuf_addstr(buf, path);
+ return 0;
+ }
+ return -1;
+}
+#endif /* HAVE_NS_GET_EXECUTABLE_PATH */
+
+/*
+ * Resolves the absolute path of the current executable.
+ *
+ * Returns 0 on success, -1 on failure.
+ */
+static int git_get_exec_path(struct strbuf *buf, const char *argv0)
+{
+ /*
+ * Identifying the executable path is operating system specific.
+ * Selectively employ all available methods in order of preference,
+ * preferring highly-available authoritative methods over
+ * selectively-available or non-authoritative methods.
+ *
+ * All cases fall back on resolving against argv[0] if there isn't a
+ * better functional method. However, note that argv[0] can be
+ * used-supplied on many operating systems, and is not authoritative
+ * in those cases.
+ *
+ * Each of these functions returns 0 on success, so evaluation will stop
+ * after the first successful method.
+ */
+ if (
+#ifdef HAVE_BSD_KERN_PROC_SYSCTL
+ git_get_exec_path_bsd_sysctl(buf) &&
+#endif /* HAVE_BSD_KERN_PROC_SYSCTL */
+
+#ifdef HAVE_NS_GET_EXECUTABLE_PATH
+ git_get_exec_path_darwin(buf) &&
+#endif /* HAVE_NS_GET_EXECUTABLE_PATH */
+
+#ifdef PROCFS_EXECUTABLE_PATH
+ git_get_exec_path_procfs(buf) &&
+#endif /* PROCFS_EXECUTABLE_PATH */
+
+ git_get_exec_path_from_argv0(buf, argv0)) {
+ return -1;
+ }
+
+ if (strbuf_normalize_path(buf)) {
+ trace_printf("trace: could not normalize path: %s\n", buf->buf);
+ return -1;
+ }
+
+ return 0;
+}
+
+void git_resolve_executable_dir(const char *argv0)
+{
+ struct strbuf buf = STRBUF_INIT;
+ char *resolved;
+ const char *slash;
+
+ if (git_get_exec_path(&buf, argv0)) {
+ trace_printf(
+ "trace: could not determine executable path from: %s\n",
+ argv0);
+ strbuf_release(&buf);
+ return;
+ }
+
+ resolved = strbuf_detach(&buf, NULL);
+ slash = find_last_dir_sep(resolved);
if (slash)
- argv0_path = xstrndup(argv0, slash - argv0);
+ resolved[slash - resolved] = '\0';
+
+ executable_dirname = resolved;
+ trace_printf("trace: resolved executable dir: %s\n",
+ executable_dirname);
}
#else
+/*
+ * When not using a runtime prefix, Git uses a hard-coded path.
+ */
static const char *system_prefix(void)
{
return PREFIX;
}
-void git_extract_argv0_path(const char *argv0)
+/*
+ * This is called during initialization, but No work needs to be done here when
+ * runtime prefix is not being used.
+ */
+void git_resolve_executable_dir(const char *argv0)
{
}
@@ -65,32 +245,28 @@ char *system_path(const char *path)
return strbuf_detach(&d, NULL);
}
-void git_set_argv_exec_path(const char *exec_path)
+static const char *exec_path_value;
+
+void git_set_exec_path(const char *exec_path)
{
- argv_exec_path = exec_path;
+ exec_path_value = exec_path;
/*
* Propagate this setting to external programs.
*/
setenv(EXEC_PATH_ENVIRONMENT, exec_path, 1);
}
-
-/* Returns the highest-priority, location to look for git programs. */
+/* Returns the highest-priority location to look for git programs. */
const char *git_exec_path(void)
{
- static char *cached_exec_path;
-
- if (argv_exec_path)
- return argv_exec_path;
-
- if (!cached_exec_path) {
+ if (!exec_path_value) {
const char *env = getenv(EXEC_PATH_ENVIRONMENT);
if (env && *env)
- cached_exec_path = xstrdup(env);
+ exec_path_value = xstrdup(env);
else
- cached_exec_path = system_path(GIT_EXEC_PATH);
+ exec_path_value = system_path(GIT_EXEC_PATH);
}
- return cached_exec_path;
+ return exec_path_value;
}
static void add_path(struct strbuf *out, const char *path)
@@ -103,10 +279,12 @@ static void add_path(struct strbuf *out, const char *path)
void setup_path(void)
{
+ const char *exec_path = git_exec_path();
const char *old_path = getenv("PATH");
struct strbuf new_path = STRBUF_INIT;
- add_path(&new_path, git_exec_path());
+ git_set_exec_path(exec_path);
+ add_path(&new_path, exec_path);
if (old_path)
strbuf_addstr(&new_path, old_path);
@@ -125,7 +303,8 @@ const char **prepare_git_cmd(struct argv_array *out, const char **argv)
return out->argv;
}
-int execv_git_cmd(const char **argv) {
+int execv_git_cmd(const char **argv)
+{
struct argv_array nargv = ARGV_ARRAY_INIT;
prepare_git_cmd(&nargv, argv);
@@ -140,8 +319,7 @@ int execv_git_cmd(const char **argv) {
return -1;
}
-
-int execl_git_cmd(const char *cmd,...)
+int execl_git_cmd(const char *cmd, ...)
{
int argc;
const char *argv[MAX_ARGS + 1];
diff --git a/exec_cmd.h b/exec_cmd.h
index ff0b48048..2522453cd 100644
--- a/exec_cmd.h
+++ b/exec_cmd.h
@@ -3,8 +3,8 @@
struct argv_array;
-extern void git_set_argv_exec_path(const char *exec_path);
-extern void git_extract_argv0_path(const char *path);
+extern void git_set_exec_path(const char *exec_path);
+extern void git_resolve_executable_dir(const char *path);
extern const char *git_exec_path(void);
extern void setup_path(void);
extern const char **prepare_git_cmd(struct argv_array *out, const char **argv);
diff --git a/gettext.c b/gettext.c
index db727ea02..6b64d5c2e 100644
--- a/gettext.c
+++ b/gettext.c
@@ -2,7 +2,8 @@
* Copyright (c) 2010 Ævar Arnfjörð Bjarmason
*/
-#include "git-compat-util.h"
+#include "cache.h"
+#include "exec_cmd.h"
#include "gettext.h"
#include "strbuf.h"
#include "utf8.h"
@@ -157,10 +158,11 @@ static void init_gettext_charset(const char *domain)
void git_setup_gettext(void)
{
- const char *podir = getenv("GIT_TEXTDOMAINDIR");
+ const char *podir = getenv(GIT_TEXT_DOMAIN_DIR_ENVIRONMENT);
if (!podir)
- podir = GIT_LOCALE_PATH;
+ podir = system_path(GIT_LOCALE_PATH);
+
bindtextdomain("git", podir);
setlocale(LC_MESSAGES, "");
setlocale(LC_TIME, "");
diff --git a/git.c b/git.c
index ceaa58ef4..ab2042d5c 100644
--- a/git.c
+++ b/git.c
@@ -65,7 +65,7 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
*/
if (skip_prefix(cmd, "--exec-path", &cmd)) {
if (*cmd == '=')
- git_set_argv_exec_path(cmd + 1);
+ git_set_exec_path(cmd + 1);
else {
puts(git_exec_path());
exit(0);
diff --git a/t/t0061-run-command.sh b/t/t0061-run-command.sh
index 24c92b6cd..1009595d6 100755
--- a/t/t0061-run-command.sh
+++ b/t/t0061-run-command.sh
@@ -145,7 +145,7 @@ test_trace () {
expect="$1"
shift
GIT_TRACE=1 test-run-command "$@" run-command true 2>&1 >/dev/null | \
- sed 's/.* run_command: //' >actual &&
+ sed -e 's/.* run_command: //' -e '/trace: .*/d' >actual &&
echo "$expect true" >expect &&
test_cmp expect actual
}
Dan Jacques
