From 226c0ddd0d63dd6c8dde497c755af2ad1f02e0c1 Mon Sep 17 00:00:00 2001 From: Dan Jacques Date: Tue, 10 Apr 2018 11:05:44 -0400 Subject: [PATCH] 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: Dan Jacques Thanks-to: Robbie Iannucci Thanks-to: Junio C Hamano Signed-off-by: Junio C Hamano --- Makefile | 28 ++++- 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, 253 insertions(+), 39 deletions(-) diff --git a/Makefile b/Makefile index 55684d1735..44bad53231 100644 --- a/Makefile +++ b/Makefile @@ -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 diff --git a/cache.h b/cache.h index bbaf5c349a..bc6636b7df 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 7d716d5a54..b2e5a86dff 100644 --- a/common-main.c +++ b/common-main.c @@ -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); diff --git a/config.mak.uname b/config.mak.uname index 6a1d0de0cc..e1cfe5e5ed 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 ce192a2d64..38d52d90a2 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 +#endif + +#if defined(HAVE_BSD_KERN_PROC_SYSCTL) +#include +#include +#include +#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 ff0b48048a..2522453cda 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 db727ea020..6b64d5c2e8 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 3a89893712..48432f9fb8 100644 --- a/git.c +++ b/git.c @@ -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); diff --git a/t/t0061-run-command.sh b/t/t0061-run-command.sh index d03149be9f..c887ed5b45 100755 --- a/t/t0061-run-command.sh +++ b/t/t0061-run-command.sh @@ -145,7 +145,7 @@ test_trace () { expect="$1" shift GIT_TRACE=1 test-tool run-command "$@" 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 } -- 2.43.2