Commit 226c0ddd authored by Dan Jacques's avatar Dan Jacques Committed by Junio C Hamano

exec_cmd: RUNTIME_PREFIX on some POSIX systems

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: default avatarDan Jacques <dnj@google.com>
Thanks-to: Robbie Iannucci <iannucci@google.com>
Thanks-to: Junio C Hamano <gitster@pobox.com>
Signed-off-by: default avatarJunio C Hamano <gitster@pobox.com>
parent 07d90ead
......@@ -448,6 +448,18 @@ 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
@$(SHELL_PATH) ./GIT-VERSION-GEN
......@@ -1674,10 +1686,23 @@ ifdef HAVE_BSD_SYSCTL
BASIC_CFLAGS += -DHAVE_BSD_SYSCTL
endif
ifdef HAVE_BSD_KERN_PROC_SYSCTL
BASIC_CFLAGS += -DHAVE_BSD_KERN_PROC_SYSCTL
endif
ifdef HAVE_GETDELIM
BASIC_CFLAGS += -DHAVE_GETDELIM
endif
ifneq ($(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
......@@ -2226,6 +2251,7 @@ 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)"'
......@@ -2243,7 +2269,7 @@ 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
......
......@@ -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.
......
......@@ -32,14 +32,14 @@ int main(int argc, const char **argv)
*/
sanitize_stdfds();
git_resolve_executable_dir(argv[0]);
git_setup_gettext();
initialize_the_repository();
attr_start();
git_extract_argv0_path(argv[0]);
restore_sigpipe_to_default();
return cmd_main(argc, argv);
......
......@@ -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
......
......@@ -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];
......
......@@ -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);
......
......@@ -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, "");
......
......@@ -83,7 +83,7 @@ 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);
......
......@@ -145,7 +145,7 @@ test_trace () {
expect="$1"
shift
GIT_TRACE=1 test-tool run-command "$@" 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
}
......
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