git/exec-cmd.c

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#include "cache.h"
#include "exec-cmd.h"
#include "quote.h"
#include "strvec.h"
#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);
Compute prefix at runtime if RUNTIME_PREFIX is set This commit adds support for relocatable binaries (called RUNTIME_PREFIX). Such binaries can be moved together with the system configuration files to a different directory, as long as the relative paths from the binary to the configuration files is preserved. This functionality is essential on Windows where we deliver git binaries with an installer that allows to freely choose the installation location. If RUNTIME_PREFIX is unset we use the static prefix. This will be the default on Unix. Thus, the behavior on Unix will remain identical to the old implementation, which used to add the prefix in the Makefile. If RUNTIME_PREFIX is set the prefix is computed from the location of the executable. In this case, system_path() tries to strip known directories that executables can be located in from the path of the executable. If the path is successfully stripped it is used as the prefix. For example, if the executable is "/msysgit/bin/git" and BINDIR is "bin", then the prefix computed is "/msysgit". If the runtime prefix computation fails, we fall back to the static prefix specified in the makefile. This can be the case if the executable is not installed at a known location. Note that our test system sets GIT_CONFIG_NOSYSTEM to tell git to ignore global configuration files during testing. Hence testing does not trigger the fall back. Note that RUNTIME_PREFIX only works on Windows, though adding support on Unix should not be too hard. The implementation requires argv0_path to be set to an absolute path. argv0_path must point to the directory of the executable. We use assert() to verify this in debug builds. On Windows, the wrapper for main() (see compat/mingw.h) guarantees that argv0_path is correctly initialized. On Unix, further work is required before RUNTIME_PREFIX can be enabled. Signed-off-by: Steffen Prohaska <prohaska@zib.de> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-18 12:00:14 +00:00
#ifdef RUNTIME_PREFIX
/**
* 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(executable_dirname);
assert(is_absolute_path(executable_dirname));
Compute prefix at runtime if RUNTIME_PREFIX is set This commit adds support for relocatable binaries (called RUNTIME_PREFIX). Such binaries can be moved together with the system configuration files to a different directory, as long as the relative paths from the binary to the configuration files is preserved. This functionality is essential on Windows where we deliver git binaries with an installer that allows to freely choose the installation location. If RUNTIME_PREFIX is unset we use the static prefix. This will be the default on Unix. Thus, the behavior on Unix will remain identical to the old implementation, which used to add the prefix in the Makefile. If RUNTIME_PREFIX is set the prefix is computed from the location of the executable. In this case, system_path() tries to strip known directories that executables can be located in from the path of the executable. If the path is successfully stripped it is used as the prefix. For example, if the executable is "/msysgit/bin/git" and BINDIR is "bin", then the prefix computed is "/msysgit". If the runtime prefix computation fails, we fall back to the static prefix specified in the makefile. This can be the case if the executable is not installed at a known location. Note that our test system sets GIT_CONFIG_NOSYSTEM to tell git to ignore global configuration files during testing. Hence testing does not trigger the fall back. Note that RUNTIME_PREFIX only works on Windows, though adding support on Unix should not be too hard. The implementation requires argv0_path to be set to an absolute path. argv0_path must point to the directory of the executable. We use assert() to verify this in debug builds. On Windows, the wrapper for main() (see compat/mingw.h) guarantees that argv0_path is correctly initialized. On Unix, further work is required before RUNTIME_PREFIX can be enabled. Signed-off-by: Steffen Prohaska <prohaska@zib.de> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-18 12:00:14 +00:00
if (!prefix &&
!(prefix = strip_path_suffix(executable_dirname, GIT_EXEC_PATH)) &&
!(prefix = strip_path_suffix(executable_dirname, BINDIR)) &&
!(prefix = strip_path_suffix(executable_dirname, "git"))) {
prefix = FALLBACK_RUNTIME_PREFIX;
trace_printf("RUNTIME_PREFIX requested, "
Compute prefix at runtime if RUNTIME_PREFIX is set This commit adds support for relocatable binaries (called RUNTIME_PREFIX). Such binaries can be moved together with the system configuration files to a different directory, as long as the relative paths from the binary to the configuration files is preserved. This functionality is essential on Windows where we deliver git binaries with an installer that allows to freely choose the installation location. If RUNTIME_PREFIX is unset we use the static prefix. This will be the default on Unix. Thus, the behavior on Unix will remain identical to the old implementation, which used to add the prefix in the Makefile. If RUNTIME_PREFIX is set the prefix is computed from the location of the executable. In this case, system_path() tries to strip known directories that executables can be located in from the path of the executable. If the path is successfully stripped it is used as the prefix. For example, if the executable is "/msysgit/bin/git" and BINDIR is "bin", then the prefix computed is "/msysgit". If the runtime prefix computation fails, we fall back to the static prefix specified in the makefile. This can be the case if the executable is not installed at a known location. Note that our test system sets GIT_CONFIG_NOSYSTEM to tell git to ignore global configuration files during testing. Hence testing does not trigger the fall back. Note that RUNTIME_PREFIX only works on Windows, though adding support on Unix should not be too hard. The implementation requires argv0_path to be set to an absolute path. argv0_path must point to the directory of the executable. We use assert() to verify this in debug builds. On Windows, the wrapper for main() (see compat/mingw.h) guarantees that argv0_path is correctly initialized. On Unix, further work is required before RUNTIME_PREFIX can be enabled. Signed-off-by: Steffen Prohaska <prohaska@zib.de> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-18 12:00:14 +00:00
"but prefix computation failed. "
"Using static fallback '%s'.\n", prefix);
}
return prefix;
}
/*
* 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 -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 */
#ifdef HAVE_WPGMPTR
/*
* Resolves the executable path by using the global variable _wpgmptr.
*
* Returns 0 on success, -1 on failure.
*/
static int git_get_exec_path_wpgmptr(struct strbuf *buf)
{
int len = wcslen(_wpgmptr) * 3 + 1;
strbuf_grow(buf, len);
len = xwcstoutf(buf->buf, _wpgmptr, len);
if (len < 0)
return -1;
buf->len += len;
return 0;
}
#endif /* HAVE_WPGMPTR */
/*
* 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 */
#ifdef HAVE_WPGMPTR
git_get_exec_path_wpgmptr(buf) &&
#endif /* HAVE_WPGMPTR */
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;
}
trace2_cmd_path(buf->buf);
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)
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 FALLBACK_RUNTIME_PREFIX;
}
/*
* 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 UNUSED)
{
}
#endif /* RUNTIME_PREFIX */
char *system_path(const char *path)
{
struct strbuf d = STRBUF_INIT;
if (is_absolute_path(path))
return xstrdup(path);
Compute prefix at runtime if RUNTIME_PREFIX is set This commit adds support for relocatable binaries (called RUNTIME_PREFIX). Such binaries can be moved together with the system configuration files to a different directory, as long as the relative paths from the binary to the configuration files is preserved. This functionality is essential on Windows where we deliver git binaries with an installer that allows to freely choose the installation location. If RUNTIME_PREFIX is unset we use the static prefix. This will be the default on Unix. Thus, the behavior on Unix will remain identical to the old implementation, which used to add the prefix in the Makefile. If RUNTIME_PREFIX is set the prefix is computed from the location of the executable. In this case, system_path() tries to strip known directories that executables can be located in from the path of the executable. If the path is successfully stripped it is used as the prefix. For example, if the executable is "/msysgit/bin/git" and BINDIR is "bin", then the prefix computed is "/msysgit". If the runtime prefix computation fails, we fall back to the static prefix specified in the makefile. This can be the case if the executable is not installed at a known location. Note that our test system sets GIT_CONFIG_NOSYSTEM to tell git to ignore global configuration files during testing. Hence testing does not trigger the fall back. Note that RUNTIME_PREFIX only works on Windows, though adding support on Unix should not be too hard. The implementation requires argv0_path to be set to an absolute path. argv0_path must point to the directory of the executable. We use assert() to verify this in debug builds. On Windows, the wrapper for main() (see compat/mingw.h) guarantees that argv0_path is correctly initialized. On Unix, further work is required before RUNTIME_PREFIX can be enabled. Signed-off-by: Steffen Prohaska <prohaska@zib.de> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-18 12:00:14 +00:00
strbuf_addf(&d, "%s/%s", system_prefix(), path);
return strbuf_detach(&d, NULL);
}
static const char *exec_path_value;
void git_set_exec_path(const char *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. */
const char *git_exec_path(void)
{
if (!exec_path_value) {
const char *env = getenv(EXEC_PATH_ENVIRONMENT);
if (env && *env)
exec_path_value = xstrdup(env);
else
exec_path_value = system_path(GIT_EXEC_PATH);
}
return exec_path_value;
}
static void add_path(struct strbuf *out, const char *path)
{
if (path && *path) {
strbuf_add_absolute_path(out, path);
strbuf_addch(out, PATH_SEP);
}
}
void setup_path(void)
{
const char *exec_path = git_exec_path();
const char *old_path = getenv("PATH");
struct strbuf new_path = STRBUF_INIT;
git_set_exec_path(exec_path);
add_path(&new_path, exec_path);
if (old_path)
strbuf_addstr(&new_path, old_path);
else
strbuf_addstr(&new_path, _PATH_DEFPATH);
setenv("PATH", new_path.buf, 1);
strbuf_release(&new_path);
}
const char **prepare_git_cmd(struct strvec *out, const char **argv)
{
strvec_push(out, "git");
strvec_pushv(out, argv);
return out->v;
}
int execv_git_cmd(const char **argv)
{
struct strvec nargv = STRVEC_INIT;
prepare_git_cmd(&nargv, argv);
trace_argv_printf(nargv.v, "trace: exec:");
/* execvp() can only ever return if it fails */
sane_execvp("git", (char **)nargv.v);
trace_printf("trace: exec failed: %s\n", strerror(errno));
strvec_clear(&nargv);
return -1;
}
int execl_git_cmd(const char *cmd, ...)
{
int argc;
const char *argv[MAX_ARGS + 1];
const char *arg;
va_list param;
va_start(param, cmd);
argv[0] = cmd;
argc = 1;
while (argc < MAX_ARGS) {
arg = argv[argc++] = va_arg(param, char *);
if (!arg)
break;
}
va_end(param);
if (MAX_ARGS <= argc)
return error(_("too many args to run %s"), cmd);
argv[argc] = NULL;
return execv_git_cmd(argv);
}