@matheusbsbs / matheus-bagliano / commits / 226c0ddd0d

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 <dnj@google.com> Thanks-to: Robbie Iannucci <iannucci@google.com> Thanks-to: Junio C Hamano <gitster@pobox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Dan Jacques committed Apr 10, 2018 at 11:05 UTC 226c0ddd0d63dd6c8dde497c755af2ad1f02e0c1
9 files changed +253 -39
Makefile
+27 -1
@@ -448,6 +448,18 @@ all::
448 # can be moved to arbitrary filesystem locations. RUNTIME_PREFIX also causes
449 # Perl scripts to use a modified entry point header allowing them to resolve
450 # support files at runtime.
451 +#
452 +# When using RUNTIME_PREFIX, define HAVE_BSD_KERN_PROC_SYSCTL if your platform
453 +# supports the KERN_PROC BSD sysctl function.
454 +#
455 +# When using RUNTIME_PREFIX, define PROCFS_EXECUTABLE_PATH if your platform
456 +# mounts a "procfs" filesystem capable of resolving the path of the current
457 +# executable. If defined, this must be the canonical path for the "procfs"
458 +# current executable path.
459 +#
460 +# When using RUNTIME_PREFIX, define HAVE_NS_GET_EXECUTABLE_PATH if your platform
461 +# supports calling _NSGetExecutablePath to retrieve the path of the running
462 +# executable.
463
464 GIT-VERSION-FILE: FORCE
465 @$(SHELL_PATH) ./GIT-VERSION-GEN
@@ -1674,10 +1686,23 @@ ifdef HAVE_BSD_SYSCTL
1686 BASIC_CFLAGS += -DHAVE_BSD_SYSCTL
1687 endif
1688
1689 +ifdef HAVE_BSD_KERN_PROC_SYSCTL
1690 + BASIC_CFLAGS += -DHAVE_BSD_KERN_PROC_SYSCTL
1691 +endif
1692 +
1693 ifdef HAVE_GETDELIM
1694 BASIC_CFLAGS += -DHAVE_GETDELIM
1695 endif
1696
1697 +ifneq ($(PROCFS_EXECUTABLE_PATH),)
1698 + procfs_executable_path_SQ = $(subst ','\'',$(PROCFS_EXECUTABLE_PATH))
1699 + BASIC_CFLAGS += '-DPROCFS_EXECUTABLE_PATH="$(procfs_executable_path_SQ)"'
1700 +endif
1701 +
1702 +ifdef HAVE_NS_GET_EXECUTABLE_PATH
1703 + BASIC_CFLAGS += -DHAVE_NS_GET_EXECUTABLE_PATH
1704 +endif
1705 +
1706 ifeq ($(TCLTK_PATH),)
1707 NO_TCLTK = NoThanks
1708 endif
@@ -2226,6 +2251,7 @@ endif
2251 exec_cmd.sp exec_cmd.s exec_cmd.o: GIT-PREFIX
2252 exec_cmd.sp exec_cmd.s exec_cmd.o: EXTRA_CPPFLAGS = \
2253 '-DGIT_EXEC_PATH="$(gitexecdir_SQ)"' \
2254 + '-DGIT_LOCALE_PATH="$(localedir_relative_SQ)"' \
2255 '-DBINDIR="$(bindir_relative_SQ)"' \
2256 '-DPREFIX="$(prefix_SQ)"'
2257
@@ -2243,7 +2269,7 @@ attr.sp attr.s attr.o: EXTRA_CPPFLAGS = \
2269
2270 gettext.sp gettext.s gettext.o: GIT-PREFIX
2271 gettext.sp gettext.s gettext.o: EXTRA_CPPFLAGS = \
2246 - -DGIT_LOCALE_PATH='"$(localedir_SQ)"'
2272 + -DGIT_LOCALE_PATH='"$(localedir_relative_SQ)"'
2273
2274 http-push.sp http.sp http-walker.sp remote-curl.sp imap-send.sp: SPARSE_FLAGS += \
2275 -DCURL_DISABLE_TYPECHECK
cache.h
+1
@@ -428,6 +428,7 @@ static inline enum object_type object_type(unsigned int mode)
428 #define GIT_ICASE_PATHSPECS_ENVIRONMENT "GIT_ICASE_PATHSPECS"
429 #define GIT_QUARANTINE_ENVIRONMENT "GIT_QUARANTINE_PATH"
430 #define GIT_OPTIONAL_LOCKS_ENVIRONMENT "GIT_OPTIONAL_LOCKS"
431 +#define GIT_TEXT_DOMAIN_DIR_ENVIRONMENT "GIT_TEXTDOMAINDIR"
432
433 /*
434 * Environment variable used in handshaking the wire protocol.
common-main.c
+2 -2
@@ -32,14 +32,14 @@ int main(int argc, const char **argv)
32 */
33 sanitize_stdfds();
34
35 + git_resolve_executable_dir(argv[0]);
36 +
37 git_setup_gettext();
38
39 initialize_the_repository();
40
41 attr_start();
42
41 - git_extract_argv0_path(argv[0]);
42 -
43 restore_sigpipe_to_default();
44
45 return cmd_main(argc, argv);
config.mak.uname
+7
@@ -37,6 +37,7 @@ ifeq ($(uname_S),Linux)
37 HAVE_GETDELIM = YesPlease
38 SANE_TEXT_GREP=-a
39 FREAD_READS_DIRECTORIES = UnfortunatelyYes
40 + PROCFS_EXECUTABLE_PATH = /proc/self/exe
41 endif
42 ifeq ($(uname_S),GNU/kFreeBSD)
43 HAVE_ALLOCA_H = YesPlease
@@ -111,6 +112,7 @@ ifeq ($(uname_S),Darwin)
112 BASIC_CFLAGS += -DPROTECT_HFS_DEFAULT=1
113 HAVE_BSD_SYSCTL = YesPlease
114 FREAD_READS_DIRECTORIES = UnfortunatelyYes
115 + HAVE_NS_GET_EXECUTABLE_PATH = YesPlease
116 endif
117 ifeq ($(uname_S),SunOS)
118 NEEDS_SOCKET = YesPlease
@@ -205,6 +207,7 @@ ifeq ($(uname_S),FreeBSD)
207 HAVE_PATHS_H = YesPlease
208 GMTIME_UNRELIABLE_ERRORS = UnfortunatelyYes
209 HAVE_BSD_SYSCTL = YesPlease
210 + HAVE_BSD_KERN_PROC_SYSCTL = YesPlease
211 PAGER_ENV = LESS=FRX LV=-c MORE=FRX
212 FREAD_READS_DIRECTORIES = UnfortunatelyYes
213 endif
@@ -217,6 +220,8 @@ ifeq ($(uname_S),OpenBSD)
220 BASIC_LDFLAGS += -L/usr/local/lib
221 HAVE_PATHS_H = YesPlease
222 HAVE_BSD_SYSCTL = YesPlease
223 + HAVE_BSD_KERN_PROC_SYSCTL = YesPlease
224 + PROCFS_EXECUTABLE_PATH = /proc/curproc/file
225 endif
226 ifeq ($(uname_S),MirBSD)
227 NO_STRCASESTR = YesPlease
@@ -235,6 +240,8 @@ ifeq ($(uname_S),NetBSD)
240 USE_ST_TIMESPEC = YesPlease
241 HAVE_PATHS_H = YesPlease
242 HAVE_BSD_SYSCTL = YesPlease
243 + HAVE_BSD_KERN_PROC_SYSCTL = YesPlease
244 + PROCFS_EXECUTABLE_PATH = /proc/curproc/exe
245 endif
246 ifeq ($(uname_S),AIX)
247 DEFAULT_PAGER = more
exec_cmd.c
+207 -29
@@ -2,24 +2,52 @@
2 #include "exec_cmd.h"
3 #include "quote.h"
4 #include "argv-array.h"
5 -#define MAX_ARGS 32
5
7 -static const char *argv_exec_path;
6 +#if defined(RUNTIME_PREFIX)
7 +
8 +#if defined(HAVE_NS_GET_EXECUTABLE_PATH)
9 +#include <mach-o/dyld.h>
10 +#endif
11 +
12 +#if defined(HAVE_BSD_KERN_PROC_SYSCTL)
13 +#include <sys/param.h>
14 +#include <sys/types.h>
15 +#include <sys/sysctl.h>
16 +#endif
17 +
18 +#endif /* RUNTIME_PREFIX */
19 +
20 +#define MAX_ARGS 32
21 +
22 +static const char *system_prefix(void);
23
24 #ifdef RUNTIME_PREFIX
10 -static const char *argv0_path;
25 +
26 +/**
27 + * When using a runtime prefix, Git dynamically resolves paths relative to its
28 + * executable.
29 + *
30 + * The method for determining the path of the executable is highly
31 + * platform-specific.
32 + */
33 +
34 +/**
35 + * Path to the current Git executable. Resolved on startup by
36 + * 'git_resolve_executable_dir'.
37 + */
38 +static const char *executable_dirname;
39
40 static const char *system_prefix(void)
41 {
42 static const char *prefix;
43
16 - assert(argv0_path);
17 - assert(is_absolute_path(argv0_path));
44 + assert(executable_dirname);
45 + assert(is_absolute_path(executable_dirname));
46
47 if (!prefix &&
20 - !(prefix = strip_path_suffix(argv0_path, GIT_EXEC_PATH)) &&
21 - !(prefix = strip_path_suffix(argv0_path, BINDIR)) &&
22 - !(prefix = strip_path_suffix(argv0_path, "git"))) {
48 + !(prefix = strip_path_suffix(executable_dirname, GIT_EXEC_PATH)) &&
49 + !(prefix = strip_path_suffix(executable_dirname, BINDIR)) &&
50 + !(prefix = strip_path_suffix(executable_dirname, "git"))) {
51 prefix = PREFIX;
52 trace_printf("RUNTIME_PREFIX requested, "
53 "but prefix computation failed. "
@@ -28,27 +56,179 @@ static const char *system_prefix(void)
56 return prefix;
57 }
58
31 -void git_extract_argv0_path(const char *argv0)
59 +/*
60 + * Resolves the executable path from argv[0], only if it is absolute.
61 + *
62 + * Returns 0 on success, -1 on failure.
63 + */
64 +static int git_get_exec_path_from_argv0(struct strbuf *buf, const char *argv0)
65 {
66 const char *slash;
67
68 if (!argv0 || !*argv0)
36 - return;
69 + return -1;
70
71 slash = find_last_dir_sep(argv0);
72 + if (slash) {
73 + trace_printf("trace: resolved executable path from argv0: %s\n",
74 + argv0);
75 + strbuf_add_absolute_path(buf, argv0);
76 + return 0;
77 + }
78 + return -1;
79 +}
80
81 +#ifdef PROCFS_EXECUTABLE_PATH
82 +/*
83 + * Resolves the executable path by examining a procfs symlink.
84 + *
85 + * Returns 0 on success, -1 on failure.
86 + */
87 +static int git_get_exec_path_procfs(struct strbuf *buf)
88 +{
89 + if (strbuf_realpath(buf, PROCFS_EXECUTABLE_PATH, 0)) {
90 + trace_printf(
91 + "trace: resolved executable path from procfs: %s\n",
92 + buf->buf);
93 + return 0;
94 + }
95 + return -1;
96 +}
97 +#endif /* PROCFS_EXECUTABLE_PATH */
98 +
99 +#ifdef HAVE_BSD_KERN_PROC_SYSCTL
100 +/*
101 + * Resolves the executable path using KERN_PROC_PATHNAME BSD sysctl.
102 + *
103 + * Returns 0 on success, -1 on failure.
104 + */
105 +static int git_get_exec_path_bsd_sysctl(struct strbuf *buf)
106 +{
107 + int mib[4];
108 + char path[MAXPATHLEN];
109 + size_t cb = sizeof(path);
110 +
111 + mib[0] = CTL_KERN;
112 + mib[1] = KERN_PROC;
113 + mib[2] = KERN_PROC_PATHNAME;
114 + mib[3] = -1;
115 + if (!sysctl(mib, 4, path, &cb, NULL, 0)) {
116 + trace_printf(
117 + "trace: resolved executable path from sysctl: %s\n",
118 + path);
119 + strbuf_addstr(buf, path);
120 + return 0;
121 + }
122 + return -1;
123 +}
124 +#endif /* HAVE_BSD_KERN_PROC_SYSCTL */
125 +
126 +#ifdef HAVE_NS_GET_EXECUTABLE_PATH
127 +/*
128 + * Resolves the executable path by querying Darwin application stack.
129 + *
130 + * Returns 0 on success, -1 on failure.
131 + */
132 +static int git_get_exec_path_darwin(struct strbuf *buf)
133 +{
134 + char path[PATH_MAX];
135 + uint32_t size = sizeof(path);
136 + if (!_NSGetExecutablePath(path, &size)) {
137 + trace_printf(
138 + "trace: resolved executable path from Darwin stack: %s\n",
139 + path);
140 + strbuf_addstr(buf, path);
141 + return 0;
142 + }
143 + return -1;
144 +}
145 +#endif /* HAVE_NS_GET_EXECUTABLE_PATH */
146 +
147 +/*
148 + * Resolves the absolute path of the current executable.
149 + *
150 + * Returns 0 on success, -1 on failure.
151 + */
152 +static int git_get_exec_path(struct strbuf *buf, const char *argv0)
153 +{
154 + /*
155 + * Identifying the executable path is operating system specific.
156 + * Selectively employ all available methods in order of preference,
157 + * preferring highly-available authoritative methods over
158 + * selectively-available or non-authoritative methods.
159 + *
160 + * All cases fall back on resolving against argv[0] if there isn't a
161 + * better functional method. However, note that argv[0] can be
162 + * used-supplied on many operating systems, and is not authoritative
163 + * in those cases.
164 + *
165 + * Each of these functions returns 0 on success, so evaluation will stop
166 + * after the first successful method.
167 + */
168 + if (
169 +#ifdef HAVE_BSD_KERN_PROC_SYSCTL
170 + git_get_exec_path_bsd_sysctl(buf) &&
171 +#endif /* HAVE_BSD_KERN_PROC_SYSCTL */
172 +
173 +#ifdef HAVE_NS_GET_EXECUTABLE_PATH
174 + git_get_exec_path_darwin(buf) &&
175 +#endif /* HAVE_NS_GET_EXECUTABLE_PATH */
176 +
177 +#ifdef PROCFS_EXECUTABLE_PATH
178 + git_get_exec_path_procfs(buf) &&
179 +#endif /* PROCFS_EXECUTABLE_PATH */
180 +
181 + git_get_exec_path_from_argv0(buf, argv0)) {
182 + return -1;
183 + }
184 +
185 + if (strbuf_normalize_path(buf)) {
186 + trace_printf("trace: could not normalize path: %s\n", buf->buf);
187 + return -1;
188 + }
189 +
190 + return 0;
191 +}
192 +
193 +void git_resolve_executable_dir(const char *argv0)
194 +{
195 + struct strbuf buf = STRBUF_INIT;
196 + char *resolved;
197 + const char *slash;
198 +
199 + if (git_get_exec_path(&buf, argv0)) {
200 + trace_printf(
201 + "trace: could not determine executable path from: %s\n",
202 + argv0);
203 + strbuf_release(&buf);
204 + return;
205 + }
206 +
207 + resolved = strbuf_detach(&buf, NULL);
208 + slash = find_last_dir_sep(resolved);
209 if (slash)
41 - argv0_path = xstrndup(argv0, slash - argv0);
210 + resolved[slash - resolved] = '\0';
211 +
212 + executable_dirname = resolved;
213 + trace_printf("trace: resolved executable dir: %s\n",
214 + executable_dirname);
215 }
216
217 #else
218
219 +/*
220 + * When not using a runtime prefix, Git uses a hard-coded path.
221 + */
222 static const char *system_prefix(void)
223 {
224 return PREFIX;
225 }
226
51 -void git_extract_argv0_path(const char *argv0)
227 +/*
228 + * This is called during initialization, but No work needs to be done here when
229 + * runtime prefix is not being used.
230 + */
231 +void git_resolve_executable_dir(const char *argv0)
232 {
233 }
234
@@ -65,32 +245,28 @@ char *system_path(const char *path)
245 return strbuf_detach(&d, NULL);
246 }
247
68 -void git_set_argv_exec_path(const char *exec_path)
248 +static const char *exec_path_value;
249 +
250 +void git_set_exec_path(const char *exec_path)
251 {
70 - argv_exec_path = exec_path;
252 + exec_path_value = exec_path;
253 /*
254 * Propagate this setting to external programs.
255 */
256 setenv(EXEC_PATH_ENVIRONMENT, exec_path, 1);
257 }
258
77 -
78 -/* Returns the highest-priority, location to look for git programs. */
259 +/* Returns the highest-priority location to look for git programs. */
260 const char *git_exec_path(void)
261 {
81 - static char *cached_exec_path;
82 -
83 - if (argv_exec_path)
84 - return argv_exec_path;
85 -
86 - if (!cached_exec_path) {
262 + if (!exec_path_value) {
263 const char *env = getenv(EXEC_PATH_ENVIRONMENT);
264 if (env && *env)
89 - cached_exec_path = xstrdup(env);
265 + exec_path_value = xstrdup(env);
266 else
91 - cached_exec_path = system_path(GIT_EXEC_PATH);
267 + exec_path_value = system_path(GIT_EXEC_PATH);
268 }
93 - return cached_exec_path;
269 + return exec_path_value;
270 }
271
272 static void add_path(struct strbuf *out, const char *path)
@@ -103,10 +279,12 @@ static void add_path(struct strbuf *out, const char *path)
279
280 void setup_path(void)
281 {
282 + const char *exec_path = git_exec_path();
283 const char *old_path = getenv("PATH");
284 struct strbuf new_path = STRBUF_INIT;
285
109 - add_path(&new_path, git_exec_path());
286 + git_set_exec_path(exec_path);
287 + add_path(&new_path, exec_path);
288
289 if (old_path)
290 strbuf_addstr(&new_path, old_path);
@@ -125,7 +303,8 @@ const char **prepare_git_cmd(struct argv_array *out, const char **argv)
303 return out->argv;
304 }
305
128 -int execv_git_cmd(const char **argv) {
306 +int execv_git_cmd(const char **argv)
307 +{
308 struct argv_array nargv = ARGV_ARRAY_INIT;
309
310 prepare_git_cmd(&nargv, argv);
@@ -140,8 +319,7 @@ int execv_git_cmd(const char **argv) {
319 return -1;
320 }
321
143 -
144 -int execl_git_cmd(const char *cmd,...)
322 +int execl_git_cmd(const char *cmd, ...)
323 {
324 int argc;
325 const char *argv[MAX_ARGS + 1];
exec_cmd.h
+2 -2
@@ -3,8 +3,8 @@
3
4 struct argv_array;
5
6 -extern void git_set_argv_exec_path(const char *exec_path);
7 -extern void git_extract_argv0_path(const char *path);
6 +extern void git_set_exec_path(const char *exec_path);
7 +extern void git_resolve_executable_dir(const char *path);
8 extern const char *git_exec_path(void);
9 extern void setup_path(void);
10 extern const char **prepare_git_cmd(struct argv_array *out, const char **argv);
gettext.c
+5 -3
@@ -2,7 +2,8 @@
2 * Copyright (c) 2010 Ævar Arnfjörð Bjarmason
3 */
4
5 -#include "git-compat-util.h"
5 +#include "cache.h"
6 +#include "exec_cmd.h"
7 #include "gettext.h"
8 #include "strbuf.h"
9 #include "utf8.h"
@@ -157,10 +158,11 @@ static void init_gettext_charset(const char *domain)
158
159 void git_setup_gettext(void)
160 {
160 - const char *podir = getenv("GIT_TEXTDOMAINDIR");
161 + const char *podir = getenv(GIT_TEXT_DOMAIN_DIR_ENVIRONMENT);
162
163 if (!podir)
163 - podir = GIT_LOCALE_PATH;
164 + podir = system_path(GIT_LOCALE_PATH);
165 +
166 bindtextdomain("git", podir);
167 setlocale(LC_MESSAGES, "");
168 setlocale(LC_TIME, "");
git.c
+1 -1
@@ -83,7 +83,7 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
83 */
84 if (skip_prefix(cmd, "--exec-path", &cmd)) {
85 if (*cmd == '=')
86 - git_set_argv_exec_path(cmd + 1);
86 + git_set_exec_path(cmd + 1);
87 else {
88 puts(git_exec_path());
89 exit(0);
t/t0061-run-command.sh
+1 -1
@@ -145,7 +145,7 @@ test_trace () {
145 expect="$1"
146 shift
147 GIT_TRACE=1 test-tool run-command "$@" run-command true 2>&1 >/dev/null | \
148 - sed 's/.* run_command: //' >actual &&
148 + sed -e 's/.* run_command: //' -e '/trace: .*/d' >actual &&
149 echo "$expect true" >expect &&
150 test_cmp expect actual
151 }