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2016-11-29common-main: stop munging argv[0] pathJeff King
Since 650c44925 (common-main: call git_extract_argv0_path(), 2016-07-01), the argv[0] that is seen in cmd_main() of individual programs is always the basename of the executable, as common-main strips off the full path. This can produce confusing results for git-daemon, which wants to re-exec itself. For instance, if the program was originally run as "/usr/lib/git/git-daemon", it will try just re-execing "git-daemon", which will find the first instance in $PATH. If git's exec-path has not been prepended to $PATH, we may find the git-daemon from a different version (or no git-daemon at all). Normally this isn't a problem. Git commands are run as "git daemon", the git wrapper puts the exec-path at the front of $PATH, and argv[0] is already "daemon" anyway. But running git-daemon via its full exec-path, while not really a recommended method, did work prior to 650c44925. Let's make it work again. The real goal of 650c44925 was not to munge argv[0], but to reliably set the argv0_path global. The only reason it munges at all is that one caller, the git.c wrapper, piggy-backed on that computation to find the command basename. Instead, let's leave argv[0] untouched in common-main, and have git.c do its own basename computation. While we're at it, let's drop the return value from git_extract_argv0_path(). It was only ever used in this one callsite, and its dual purposes is what led to this confusion in the first place. Note that by changing the interface, the compiler can confirm for us that there are no other callers storing the return value. But the compiler can't tell us whether any of the cmd_main() functions (besides git.c) were relying on the basename munging. However, we can observe that prior to 650c44925, no other cmd_main() functions did that munging, and no new cmd_main() functions have been introduced since then. So we can't be regressing any of those cases. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-22prepare_{git,shell}_cmd: use argv_arrayJeff King
These functions transform an existing argv into one suitable for exec-ing or spawning via git or a shell. We can use an argv_array in each to avoid dealing with manual counting and allocation. This also makes the memory allocation more clear and fixes some leaks. In prepare_shell_cmd, we would sometimes allocate a new string with "$@" in it and sometimes not, meaning the caller could not correctly free it. On the non-Windows side, we are in a child process which will exec() or exit() immediately, so the leak isn't a big deal. On Windows, though, we use spawn() from the parent process, and leak a string for each shell command we run. On top of that, the Windows code did not free the allocated argv array at all (but does for the prepare_git_cmd case!). By switching both of these functions to write into an argv_array, we can consistently free the result as appropriate. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-01system_path(): always return free'able memory to the callerJunio C Hamano
The function sometimes returns a newly allocated string and sometimes returns a borrowed string, the latter of which the callers must not free(). The existing callers all assume that the return value belongs to the callee and most of them copy it with strdup() when they want to keep it around. They end up leaking the returned copy when the callee returned a new string because they cannot tell if they should free it. Change the contract between the callers and system_path() to make the returned string owned by the callers; they are responsible for freeing it when done, but they do not have to make their own copy to store it away. Adjust the callers to make sure they do not leak the returned string once they are done, but do not bother freeing it just before dying, exiting or exec'ing other program to avoid unnecessary churn. Reported-by: Alexander Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-19Add the LAST_ARG_MUST_BE_NULL macroRamsay Jones
The sentinel function attribute is not understood by versions of the gcc compiler prior to v4.0. At present, for earlier versions of gcc, the build issues 108 warnings related to the unknown attribute. In order to suppress the warnings, we conditionally define the LAST_ARG_MUST_BE_NULL macro to provide the sentinel attribute for gcc v4.0 and newer. Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-10use "sentinel" function attribute for variadic listsJeff King
This attribute can help gcc notice when callers forget to add a NULL sentinel to the end of the function. This is our first use of the sentinel attribute, but we shouldn't need to #ifdef for other compilers, as __attribute__ is already a no-op on non-gcc-compatible compilers. Suggested-by: Bert Wesarg <bert.wesarg@googlemail.com> More-Spots-Found-By: Matt Kraai <kraai@ftbfs.org> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-26Refactor git_set_argv0_path() to git_extract_argv0_path()Steve Haslam
This commit moves the code that computes the dirname of argv[0] from git.c's main() to git_set_argv0_path() and renames the function to git_extract_argv0_path(). This makes the code in git.c's main less cluttered, and we can use the dirname computation from other main() functions too. [ spr: - split Steve's original commit and wrote new commit message. - Integrated Johannes Schindelin's cca1704897e7fdb182f68d4c48a437c5d7bc5203 while rebasing onto master. ] Signed-off-by: Steve Haslam <shaslam@lastminute.com> Signed-off-by: Steffen Prohaska <prohaska@zib.de> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-29Refactor, adding prepare_git_cmd(const char **argv)Steffen Prohaska
prepare_git_cmd(const char **argv) adds a first entry "git" to the array argv. The new array is allocated on the heap. It's the caller's responsibility to release it with free(). The code was already present in execv_git_cmd() but could not be used from outside. Now it can also be called for preparing the command list in the MinGW codepath in run-command.c. Signed-off-by: Steffen Prohaska <prohaska@zib.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-26Record the command invocation path earlyJohannes Sixt
We will need the command invocation path in system_path(). This path was passed to setup_path(), but system_path() can be called earlier, for example via: main commit_pager_choice setup_pager git_config git_etc_gitconfig system_path Therefore, we introduce git_set_argv0_path() and call it as soon as possible. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-13Move code interpreting path relative to exec-dir to new function system_path()Steffen Prohaska
Expanding system paths relative to git_exec_path can be used for creating an installation that can be moved to a different directory without re-compiling. We use this approach for template_dir and the system wide gitconfig. The Windows installer (msysgit) is an example for such a setup. This commit moves common code to a new function system_path(). System paths that are to be interpreted relative to git_exec_path are passed to system_path() and the return value is used instead of the original path. system_path() prefixes a relative path with git_exec_path and leaves absolute paths unmodified. For example, we now write template_dir = system_path(DEFAULT_GIT_TEMPLATE_DIR); [j6t: moved from path.c to exec_cmd.c] Signed-off-by: Steffen Prohaska <prohaska@zib.de> Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-10-30use only the $PATH for exec'ing git commandsScott R Parish
We need to correctly set up $PATH for non-c based git commands. Since we already do this, we can just use that $PATH and execvp, instead of looping over the paths with execve. This patch adds a setup_path() function to exec_cmd.c, which sets the $PATH order correctly for our search order. execv_git_cmd() is stripped down to setting up argv and calling execvp(). git.c's main() only only needs to call setup_path(). Signed-off-by: Scott R Parish <srp@srparish.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-10-30"current_exec_path" is a misleading name, use "argv_exec_path"Scott R Parish
Signed-off-by: Scott R Parish <srp@srparish.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-04-29Make macros to prevent double-inclusion in headers consistent.Junio C Hamano
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-05Const tightening.Junio C Hamano
Mark Wooding noticed there was a type mismatch warning in git.c; this patch does things slightly differently (mostly tightening const) and was what I was holding onto, waiting for the setup-revisions change to be merged into the master branch. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-01-14Exec git programs without using PATH.Michal Ostrowski
The git suite may not be in PATH (and thus programs such as git-send-pack could not exec git-rev-list). Thus there is a need for logic that will locate these programs. Modifying PATH is not desirable as it result in behavior differing from the user's intentions, as we may end up prepending "/usr/bin" to PATH. - git C programs will use exec*_git_cmd() APIs to exec sub-commands. - exec*_git_cmd() will execute a git program by searching for it in the following directories: 1. --exec-path (as used by "git") 2. The GIT_EXEC_PATH environment variable. 3. $(gitexecdir) as set in Makefile (default value $(bindir)). - git wrapper will modify PATH as before to enable shell scripts to invoke "git-foo" commands. Ideally, shell scripts should use the git wrapper to become independent of PATH, and then modifying PATH will not be necessary. [jc: with minor updates after a brief review.] Signed-off-by: Michal Ostrowski <mostrows@watson.ibm.com> Signed-off-by: Junio C Hamano <junkio@cox.net>