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2016-04-14Merge branch 'sb/submodule-path-misc-bugs' into sb/submodule-initJunio C Hamano1-36/+36
"git submodule" reports the paths of submodules the command recurses into, but this was incorrect when the command was not run from the root level of the superproject. Any further comments? Otherwise will merge to 'next'. * sb/submodule-path-misc-bugs: (600 commits) t7407: make expectation as clear as possible submodule update: test recursive path reporting from subdirectory submodule update: align reporting path for custom command execution submodule status: correct path handling in recursive submodules submodule update --init: correct path handling in recursive submodules submodule foreach: correct path display in recursive submodules Git 2.8 Documentation: fix git-p4 AsciiDoc formatting mingw: skip some tests in t9115 due to file name issues t1300: fix the new --show-origin tests on Windows t1300-repo-config: make it resilient to being run via 'sh -x' config --show-origin: report paths with forward slashes submodule: fix regression for deinit without submodules l10n: pt_PT: Update and add new translations l10n: ca.po: update translation Git 2.8-rc4 Documentation: fix broken linkgit to git-config Documentation: use ASCII quotation marks in git-p4 Revert "config.mak.uname: use clang for Mac OS X 10.6" git-compat-util: st_add4: work around gcc 4.2.x compiler crash ...
2016-03-04Merge branch 'sb/submodule-parallel-fetch'Junio C Hamano1-21/+3
Simplify the two callback functions that are triggered when the child process terminates to avoid misuse of the child-process structure that has already been cleaned up. * sb/submodule-parallel-fetch: run-command: do not pass child process data into callbacks
2016-03-01run_processes_parallel: rename parameters for the callbacksStefan Beller1-2/+2
The refs code has a similar pattern of passing around 'struct strbuf *err', which is strictly used for error reporting. This is not the case here, as the strbuf is used to accumulate all the output (whether it is error or not) for the user. Rename it to 'out'. Suggested-by: Jonathan Nieder <jrnieder@gmail.com> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-03-01run_processes_parallel: treat output of children as byte arrayStefan Beller1-4/+4
We do not want the output to be interrupted by a NUL byte, so we cannot use raw fputs. Introduce strbuf_write to avoid having long arguments in run-command.c. Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-03-01run-command: do not pass child process data into callbacksStefan Beller1-21/+3
The expected way to pass data into the callback is to pass them via the customizable callback pointer. The error reporting in default_{start_failure, task_finished} is not user friendly enough, that we want to encourage using the child data for such purposes. Furthermore the struct child data is cleaned by the run-command API, before we access them in the callbacks, leading to use-after-free situations. Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-26Merge branch 'jk/epipe-in-async'Junio C Hamano1-0/+10
Handling of errors while writing into our internal asynchronous process has been made more robust, which reduces flakiness in our tests. * jk/epipe-in-async: t5504: handle expected output from SIGPIPE death test_must_fail: report number of unexpected signal fetch-pack: ignore SIGPIPE in sideband demuxer write_or_die: handle EPIPE in async threads
2016-02-26Merge branch 'jk/tighten-alloc'Junio C Hamano1-35/+25
Update various codepaths to avoid manually-counted malloc(). * jk/tighten-alloc: (22 commits) ewah: convert to REALLOC_ARRAY, etc convert ewah/bitmap code to use xmalloc diff_populate_gitlink: use a strbuf transport_anonymize_url: use xstrfmt git-compat-util: drop mempcpy compat code sequencer: simplify memory allocation of get_message test-path-utils: fix normalize_path_copy output buffer size fetch-pack: simplify add_sought_entry fast-import: simplify allocation in start_packfile write_untracked_extension: use FLEX_ALLOC helper prepare_{git,shell}_cmd: use argv_array use st_add and st_mult for allocation size computation convert trivial cases to FLEX_ARRAY macros use xmallocz to avoid size arithmetic convert trivial cases to ALLOC_ARRAY convert manual allocations to argv_array argv-array: add detach function add helpers for allocating flex-array structs harden REALLOC_ARRAY and xcalloc against size_t overflow tree-diff: catch integer overflow in combine_diff_path allocation ...
2016-02-25write_or_die: handle EPIPE in async threadsJeff King1-0/+10
When write_or_die() sees EPIPE, it treats it specially by converting it into a SIGPIPE death. We obviously cannot ignore it, as the write has failed and the caller expects us to die. But likewise, we cannot just call die(), because printing any message at all would be a nuisance during normal operations. However, this is a problem if write_or_die() is called from a thread. Our raised signal ends up killing the whole process, when logically we just need to kill the thread (after all, if we are ignoring SIGPIPE, there is good reason to think that the main thread is expecting to handle it). Inside an async thread, the die() code already does the right thing, because we use our custom die_async() routine, which calls pthread_join(). So ideally we would piggy-back on that, and simply call: die_quietly_with_code(141); or similar. But refactoring the die code to do this is surprisingly non-trivial. The die_routines themselves handle both printing and the decision of the exit code. Every one of them would have to be modified to take new parameters for the code, and to tell us to be quiet. Instead, we can just teach write_or_die() to check for the async case and handle it specially. We do have to build an interface to abstract the async exit, but it's simple and self-contained. If we had many call-sites that wanted to do this die_quietly_with_code(), this approach wouldn't scale as well, but we don't. This is the only place where do this weird exit trick. 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 King1-35/+25
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>
2016-01-20Merge branch 'nd/clear-gitenv-upon-use-of-alias'Junio C Hamano1-1/+1
d95138e6 (setup: set env $GIT_WORK_TREE when work tree is set, like $GIT_DIR, 2015-06-26) attempted to work around a glitch in alias handling by overwriting GIT_WORK_TREE environment variable to affect subprocesses when set_git_work_tree() gets called, which resulted in a rather unpleasant regression to "clone" and "init". Try to address the same issue by always restoring the environment and respawning the real underlying command when handling alias. * nd/clear-gitenv-upon-use-of-alias: run-command: don't warn on SIGPIPE deaths git.c: make sure we do not leak GIT_* to alias scripts setup.c: re-fix d95138e (setup: set env $GIT_WORK_TREE when .. git.c: make it clear save_env() is for alias handling only
2015-12-29run-command: don't warn on SIGPIPE deathsJeff King1-1/+1
When git executes a sub-command, we print a warning if the command dies due to a signal, but make an exception for "uninteresting" cases like SIGINT and SIGQUIT (since the user presumably just hit ^C). We should make a similar exception for SIGPIPE, because it's an expected and uninteresting return in most cases; it generally means the user quit the pager before git had finished generating all output. This used to be very hard to trigger in practice, because: 1. We only complain if we see a real SIGPIPE death, not the shell-induced 141 exit code. This means that anything we run via the shell does not trigger the warning, which includes most non-trivial aliases. 2. The common case for SIGPIPE is the user quitting the pager before git has finished generating all output. But if the user triggers a pager with "-p", we redirect the git wrapper's stderr to that pager, too. Since the pager is dead, it means that the message goes nowhere. 3. You can see it if you run your own pager, like "git foo | head". But that only happens if "foo" is a non-builtin (so it doesn't work with "log", for example). However, it may become more common after 86d26f2, which teaches alias to re-exec builtins rather than running them in the same process. This case doesn't trigger (1), as we don't need a shell to run a git command. It doesn't trigger (2), because the pager is not started by the original git, but by the inner re-exec of git. And it doesn't trigger (3), because builtins are treated more like non-builtins in this case. Given how flaky this message already is (e.g., you cannot even know whether you will see it, as git optimizes out some shell invocations behind the scenes based on the contents of the command!), and that it is unlikely to ever provide useful information, let's suppress it for all cases of SIGPIPE. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-12-16run-command: add an asynchronous parallel child processorStefan Beller1-0/+335
This allows to run external commands in parallel with ordered output on stderr. If we run external commands in parallel we cannot pipe the output directly to the our stdout/err as it would mix up. So each process's output will flow through a pipe, which we buffer. One subprocess can be directly piped to out stdout/err for a low latency feedback to the user. Example: Let's assume we have 5 submodules A,B,C,D,E and each fetch takes a different amount of time as the different submodules vary in size, then the output of fetches in sequential order might look like this: time --> output: |---A---| |-B-| |-------C-------| |-D-| |-E-| When we schedule these submodules into maximal two parallel processes, a schedule and sample output over time may look like this: process 1: |---A---| |-D-| |-E-| process 2: |-B-| |-------C-------| output: |---A---|B|---C-------|DE So A will be perceived as it would run normally in the single child version. As B has finished by the time A is done, we can dump its whole progress buffer on stderr, such that it looks like it finished in no time. Once that is done, C is determined to be the visible child and its progress will be reported in real time. So this way of output is really good for human consumption, as it only changes the timing, not the actual output. For machine consumption the output needs to be prepared in the tasks, by either having a prefix per line or per block to indicate whose tasks output is displayed, because the output order may not follow the original sequential ordering: |----A----| |--B--| |-C-| will be scheduled to be all parallel: process 1: |----A----| process 2: |--B--| process 3: |-C-| output: |----A----|CB This happens because C finished before B did, so it will be queued for output before B. To detect when a child has finished executing, we check interleaved with other actions (such as checking the liveliness of children or starting new processes) whether the stderr pipe still exists. Once a child closed its stderr stream, we assume it is terminating very soon, and use `finish_command()` from the single external process execution interface to collect the exit status. By maintaining the strong assumption of stderr being open until the very end of a child process, we can avoid other hassle such as an implementation using `waitpid(-1)`, which is not implemented in Windows. Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-11-03Merge branch 'rs/daemon-plug-child-leak'Junio C Hamano1-6/+9
"git daemon" uses "run_command()" without "finish_command()", so it needs to release resources itself, which it forgot to do. * rs/daemon-plug-child-leak: daemon: plug memory leak run-command: factor out child_process_clear()
2015-11-02run-command: factor out child_process_clear()René Scharfe1-6/+9
Avoid duplication by moving the code to release allocated memory for arguments and environment to its own function, child_process_clear(). Export it to provide a counterpart to child_process_init(). Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-10-07Merge branch 'ti/glibc-stdio-mutex-from-signal-handler'Junio C Hamano1-8/+17
Allocation related functions and stdio are unsafe things to call inside a signal handler, and indeed killing the pager can cause glibc to deadlock waiting on allocation mutex as our signal handler tries to free() some data structures in wait_for_pager(). Reduce these unsafe calls. * ti/glibc-stdio-mutex-from-signal-handler: pager: don't use unsafe functions in signal handlers
2015-10-05Merge branch 'jk/async-pkt-line'Junio C Hamano1-1/+15
The debugging infrastructure for pkt-line based communication has been improved to mark the side-band communication specifically. * jk/async-pkt-line: pkt-line: show packets in async processes as "sideband" run-command: provide in_async query function
2015-09-04pager: don't use unsafe functions in signal handlersTakashi Iwai1-8/+17
Since the commit a3da8821208d (pager: do wait_for_pager on signal death), we call wait_for_pager() in the pager's signal handler. The recent bug report revealed that this causes a deadlock in glibc at aborting "git log" [*1*]. When this happens, git process is left unterminated, and it can't be killed by SIGTERM but only by SIGKILL. The problem is that wait_for_pager() function does more than waiting for pager process's termination, but it does cleanups and printing errors. Unfortunately, the functions that may be used in a signal handler are very limited [*2*]. Particularly, malloc(), free() and the variants can't be used in a signal handler because they take a mutex internally in glibc. This was the cause of the deadlock above. Other than the direct calls of malloc/free, many functions calling malloc/free can't be used. strerror() is such one, either. Also the usage of fflush() and printf() in a signal handler is bad, although it seems working so far. In a safer side, we should avoid them, too. This patch tries to reduce the calls of such functions in signal handlers. wait_for_signal() takes a flag and avoids the unsafe calls. Also, finish_command_in_signal() is introduced for the same reason. There the free() calls are removed, and only waits for the children without whining at errors. [*1*] https://bugzilla.opensuse.org/show_bug.cgi?id=942297 [*2*] http://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html#tag_15_04_03 Signed-off-by: Takashi Iwai <tiwai@suse.de> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-01run-command: provide in_async query functionJeff King1-1/+15
It's not easy for arbitrary code to find out whether it is running in an async process or not. A top-level function which is fed to start_async() can know (you just pass down an argument saying "you are async"). But that function may call other global functions, and we would not want to have to pass the information all the way through the call stack. Nor can we simply set a global variable, as those may be shared between async threads and the main thread (if the platform supports pthreads). We need pthread tricks _or_ a global variable, depending on how start_async is implemented. The callers don't have enough information to do this right, so let's provide a simple query function that does. Fortunately we can reuse the existing infrastructure to make the pthread case simple (and even simplify die_async() by using our new function). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-25Merge branch 'jk/long-error-messages'Junio C Hamano1-15/+2
The codepath to produce error messages had a hard-coded limit to the size of the message, primarily to avoid memory allocation while calling die(). * jk/long-error-messages: vreportf: avoid intermediate buffer vreportf: report to arbitrary filehandles
2015-08-11vreportf: report to arbitrary filehandlesJeff King1-15/+2
The vreportf function always goes to stderr, but run-command wants child errors to go to the parent's original stderr. To solve this, commit a5487dd duplicates the stderr fd and installs die and error handlers to direct the output appropriately (which later turned into the vwritef function). This has two downsides, though: - we make multiple calls to write(), which contradicts the "write at once" logic from d048a96 (print warning/error/fatal messages in one shot, 2007-11-09). - the custom handlers basically duplicate the normal handlers. They're only a few lines of code, but we should not have to repeat the magic "exit(128)", for example. We can solve the first by using fdopen() on the duplicated descriptor. We can't pass this to vreportf, but we could introduce a new vreportf_to to handle it. However, to fix the second problem, we instead introduce a new "set_error_handle" function, which lets the normal vreportf calls output to a handle besides stderr. Thus we can get rid of our custom handlers entirely, and just ask the regular handlers to output to our new descriptor. And as vwritef has no more callers, it can just go away. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-10find_hook: keep our own static bufferJeff King1-4/+6
The find_hook function returns the results of git_path, which is a static buffer shared by other path-related calls. Returning such a buffer is slightly dangerous, because it can be overwritten by seemingly unrelated functions. Let's at least keep our _own_ static buffer, so you can only get in trouble by calling find_hook in quick succession, which is less likely to happen and more obvious to notice. While we're at it, let's add some documentation of the function's limitations. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-11Merge branch 'nd/multiple-work-trees'Junio C Hamano1-2/+2
A replacement for contrib/workdir/git-new-workdir that does not rely on symbolic links and make sharing of objects and refs safer by making the borrowee and borrowers aware of each other. * nd/multiple-work-trees: (41 commits) prune --worktrees: fix expire vs worktree existence condition t1501: fix test with split index t2026: fix broken &&-chain t2026 needs procondition SANITY git-checkout.txt: a note about multiple checkout support for submodules checkout: add --ignore-other-wortrees checkout: pass whole struct to parse_branchname_arg instead of individual flags git-common-dir: make "modules/" per-working-directory directory checkout: do not fail if target is an empty directory t2025: add a test to make sure grafts is working from a linked checkout checkout: don't require a work tree when checking out into a new one git_path(): keep "info/sparse-checkout" per work-tree count-objects: report unused files in $GIT_DIR/worktrees/... gc: support prune --worktrees gc: factor out gc.pruneexpire parsing code gc: style change -- no SP before closing parenthesis checkout: clean up half-prepared directories in --to mode checkout: reject if the branch is already checked out elsewhere prune: strategies for linked checkouts checkout: support checking out into a new working directory ...
2015-03-25Merge branch 'jk/run-command-capture'Junio C Hamano1-1/+22
The run-command interface was easy to abuse and make a pipe for us to read from the process, wait for the process to finish and then attempt to read its output, which is a pattern that lead to a deadlock. Fix such uses by introducing a helper to do this correctly (i.e. we need to read first and then wait the process to finish) and also add code to prevent such abuse in the run-command helper. * jk/run-command-capture: run-command: forbid using run_command with piped output trailer: use capture_command submodule: use capture_command wt-status: use capture_command run-command: introduce capture_command helper wt_status: fix signedness mismatch in strbuf_read call wt-status: don't flush before running "submodule status"
2015-03-22run-command: forbid using run_command with piped outputJeff King1-1/+6
Because run_command both spawns and wait()s for the command before returning control to the caller, any reads from the pipes we open must necessarily happen after wait() returns. This can lead to deadlock, as the child process may block on writing to us while we are blocked waiting for it to exit. Worse, it only happens when the child fills the pipe buffer, which means that the problem may come and go depending on the platform and the size of the output produced by the child. Let's detect and flag this dangerous construct so that we can catch potential bugs early in the test suite rather than having them happen in the field. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-22run-command: introduce capture_command helperJeff King1-0/+16
Something as simple as reading the stdout from a command turns out to be rather hard to do right. Doing: cmd.out = -1; run_command(&cmd); strbuf_read(&buf, cmd.out, 0); can result in deadlock if the child process produces a large amount of output. What happens is: 1. The parent spawns the child with its stdout connected to a pipe, of which the parent is the sole reader. 2. The parent calls wait(), blocking until the child exits. 3. The child writes to stdout. If it writes more data than the OS pipe buffer can hold, the write() call will block. This is a deadlock; the parent is waiting for the child to exit, and the child is waiting for the parent to call read(). So we might try instead: start_command(&cmd); strbuf_read(&buf, cmd.out, 0); finish_command(&cmd); But that is not quite right either. We are examining cmd.out and running finish_command whether start_command succeeded or not, which is wrong. Moreover, these snippets do not do any error handling. If our read() fails, we must make sure to still call finish_command (to reap the child process). And both snippets failed to close the cmd.out descriptor, which they must do (provided start_command succeeded). Let's introduce a run-command helper that can make this a bit simpler for callers to get right. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-10git-compat-util.h: move SHELL_PATH default into headerKyle J. McKay1-4/+0
If SHELL_PATH is not defined we use "/bin/sh". However, run-command.c is not the only file that needs to use the default value so move it into a common header. Signed-off-by: Kyle J. McKay <mackyle@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-22Merge branch 'jc/hook-cleanup'Junio C Hamano1-17/+0
Remove unused code. * jc/hook-cleanup: run-command.c: retire unused run_hook_with_custom_index()
2014-12-01path.c: make get_pathname() call sites return const char *Nguyễn Thái Ngọc Duy1-2/+2
Before the previous commit, get_pathname returns an array of PATH_MAX length. Even if git_path() and similar functions does not use the whole array, git_path() caller can, in theory. After the commit, get_pathname() may return a buffer that has just enough room for the returned string and git_path() caller should never write beyond that. Make git_path(), mkpath() and git_path_submodule() return a const buffer to make sure callers do not write in it at all. This could have been part of the previous commit, but the "const" conversion is too much distraction from the core changes in path.c. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-01run-command.c: retire unused run_hook_with_custom_index()Junio C Hamano1-17/+0
This was originally meant to be used to rewrite run_commit_hook() that only special cases the GIT_INDEX_FILE environment, but the run_hook_ve() refactoring done earlier made the implementation of run_commit_hook() thin and clean enough. Nobody uses this, so retire it as an unfinished clean-up made unnecessary. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-11-10run-command: use void to declare that functions take no parametersRené Scharfe1-2/+2
Explicitly declare that git_atexit_dispatch() and git_atexit_clear() take no parameters instead of leaving their parameter list empty and thus unspecified. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-24Merge branch 'eb/no-pthreads'Junio C Hamano1-0/+40
Allow us build with NO_PTHREADS=NoThanks compilation option. * eb/no-pthreads: Handle atexit list internaly for unthreaded builds pack-objects: set number of threads before checking and warning index-pack: fix compilation with NO_PTHREADS
2014-10-19Handle atexit list internaly for unthreaded buildsEtienne Buira1-0/+40
Wrap atexit()s calls on unthreaded builds to handle callback list internally. This is needed because on unthreaded builds, asyncs inherits parent's atexit() list, that gets run as soon as the async exit()s (and again at the end of async's parent process). That led to remove temporary files too early. Also remove a by-atexit-callback guard against this kind of issue in clone.c, as this patch makes it redundant. Fixes test 5537 (temporary shallow file vanished before unpack-objects could open it) BTW remove an unused variable in shallow.c. Helped-by: Duy Nguyen <pclouds@gmail.com> Helped-by: Andreas Schwab <schwab@linux-m68k.org> Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Etienne Buira <etienne.buira@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-19run-command: add env_array, an optional argv_array for envRené Scharfe1-0/+6
Similar to args, add a struct argv_array member to struct child_process that simplifies specifying the environment for children. It is freed automatically by finish_command() or if start_command() encounters an error. Suggested-by: Jeff King <peff@peff.net> Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-20run-command: inline prepare_run_command_v_opt()René Scharfe1-16/+8
Merge prepare_run_command_v_opt() and its only caller. This removes a pointer indirection and allows to initialize the struct child_process using CHILD_PROCESS_INIT. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-20run-command: call run_command_v_opt_cd_env() instead of duplicating itRené Scharfe1-3/+1
Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-20run-command: introduce child_process_init()René Scharfe1-0/+6
Add a helper function for initializing those struct child_process variables for which the macro CHILD_PROCESS_INIT can't be used. Suggested-by: Jeff King <peff@peff.net> Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-20run-command: introduce CHILD_PROCESS_INITRené Scharfe1-2/+1
Most struct child_process variables are cleared using memset first after declaration. Provide a macro, CHILD_PROCESS_INIT, that can be used to initialize them statically instead. That's shorter, doesn't require a function call and is slightly more readable (especially given that we already have STRBUF_INIT, ARGV_ARRAY_INIT etc.). Helped-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-07-30Merge branch 'sk/mingw-uni-fix-more'Junio C Hamano1-8/+2
Most of these are battle-tested in msysgit and are needed to complete what has been merged to 'master' already. * sk/mingw-uni-fix-more: Win32: enable color output in Windows cmd.exe Win32: patch Windows environment on startup Win32: keep the environment sorted Win32: use low-level memory allocation during initialization Win32: reduce environment array reallocations Win32: don't copy the environment twice when spawning child processes Win32: factor out environment block creation Win32: unify environment function names Win32: unify environment case-sensitivity Win32: fix environment memory leaks Win32: Unicode environment (incoming) Win32: Unicode environment (outgoing) Revert "Windows: teach getenv to do a case-sensitive search" tests: do not pass iso8859-1 encoded parameter
2014-07-21Win32: don't copy the environment twice when spawning child processesKarsten Blees1-8/+2
When spawning child processes via start_command(), the environment and all environment entries are copied twice. First by make_augmented_environ / copy_environ to merge with child_process.env. Then a second time by make_environment_block to create a sorted environment block string as required by CreateProcess. Move the merge logic to make_environment_block so that we only need to copy the environment once. This changes semantics of the env parameter: it now expects a delta (such as child_process.env) rather than a full environment. This is not a problem as the parameter is only used by start_command() (all other callers previously passed char **environ, and now pass NULL). The merge logic no longer xstrdup()s the environment strings, so do_putenv must not free them. Add a parameter to distinguish this from normal putenv. Remove the now unused make_augmented_environ / free_environ API. Signed-off-by: Karsten Blees <blees@dcon.de> Signed-off-by: Stepan Kasal <kasal@ucw.cz> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-07-17run-command: use internal argv_array of struct child_process in run_hook_ve()René Scharfe1-11/+4
Use the existing argv_array member instead of providing our own. This way we don't have to initialize or clean it up explicitly. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-05-15run-command: store an optional argv_arrayJeff King1-1/+8
All child_process structs need to point to an argv. For flexibility, we do not mandate the use of a dynamic argv_array. However, because the child_process does not own the memory, this can make memory management with a separate argv_array difficult. For example, if a function calls start_command but not finish_command, the argv memory must persist. The code needs to arrange to clean up the argv_array separately after finish_command runs. As a result, some of our code in this situation just leaks the memory. To help such cases, this patch adds a built-in argv_array to the child_process, which gets cleaned up automatically (both in finish_command and when start_command fails). Callers may use it if they choose, but can continue to use the raw argv if they wish. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-03-18commit: fix patch hunk editing with "commit -p -m"Benoit Pierre1-12/+32
Don't change git environment: move the GIT_EDITOR=":" override to the hook command subprocess, like it's already done for GIT_INDEX_FILE. Signed-off-by: Benoit Pierre <benoit.pierre@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-10-31run-command: trivial style fixesFelipe Contreras1-8/+5
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-22Merge branch 'tr/fd-gotcha-fixes'Junio C Hamano1-1/+4
Two places we did not check return value (expected to be a file descriptor) correctly. * tr/fd-gotcha-fixes: run-command: dup_devnull(): guard against syscalls failing git_mkstemps: correctly test return value of open()
2013-07-12run-command: dup_devnull(): guard against syscalls failingThomas Rast1-1/+4
dup_devnull() did not check the return values of open() and dup2(). Fix this omission. Signed-off-by: Thomas Rast <trast@inf.ethz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-08mingw: rename WIN32 cpp macro to GIT_WINDOWS_NATIVEJonathan Nieder1-5/+5
Throughout git, it is assumed that the WIN32 preprocessor symbol is defined on native Windows setups (mingw and msvc) and not on Cygwin. On Cygwin, most of the time git can pretend this is just another Unix machine, and Windows-specific magic is generally counterproductive. Unfortunately Cygwin *does* define the WIN32 symbol in some headers. Best to rely on a new git-specific symbol GIT_WINDOWS_NATIVE instead, defined as follows: #if defined(WIN32) && !defined(__CYGWIN__) # define GIT_WINDOWS_NATIVE #endif After this change, it should be possible to drop the CYGWIN_V15_WIN32API setting without any negative effect. [rj: %s/WINDOWS_NATIVE/GIT_WINDOWS_NATIVE/g ] Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-19Merge branch 'jk/a-thread-only-dies-once'Junio C Hamano1-0/+11
A regression fix for the logic to detect die() handler triggering itself recursively. * jk/a-thread-only-dies-once: run-command: use thread-aware die_is_recursing routine usage: allow pluggable die-recursion checks
2013-04-16run-command: use thread-aware die_is_recursing routineJeff King1-0/+11
If we die from an async thread, we do not actually exit the program, but just kill the thread. This confuses the static counter in usage.c's default die_is_recursing function; it updates the counter once for the thread death, and then when the main program calls die() itself, it erroneously thinks we are recursing. The end result is that we print "recursion detected in die handler" instead of the real error in such a case (the easiest way to trigger this is having a remote connection hang up while running a sideband demultiplexer). This patch solves it by using a per-thread counter when the async_die function is installed; we detect recursion in each thread (including the main one), but they do not step on each other's toes. Other threaded code does not need to worry about this, as they do not install specialized die handlers; they just let a die() from a sub-thread take down the whole program. Since we are overriding the default recursion-check function, there is an interesting corner case that is not a problem, but bears some explanation. Imagine the main thread calls die(), and then in the die_routine starts an async call. We will switch to using thread-local storage, which starts at 0, for the main thread's counter, even though the original counter was actually at 1. That's OK, though, for two reasons: 1. It would miss only the first level of recursion, and would still find recursive failures inside the async helper. 2. We do not currently and are not likely to start doing anything as heavyweight as starting an async routine from within a die routine or helper function. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-21run-command: always set failed_errno in start_commandJeff King1-2/+3
When we fail to fork, we set the failed_errno variable to the value of errno so it is not clobbered by later syscalls. However, we do so in a conditional, and it is hard to see later under what conditions the variable has a valid value. Instead of setting it only when fork fails, let's just always set it after forking. This is more obvious for human readers (as we are no longer setting it as a side effect of a strerror call), and it is more obvious to gcc, which no longer generates a spurious -Wuninitialized warning. It also happens to match what the WIN32 half of the #ifdef does. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-07Merge branch 'sb/run-command-fd-error-reporting'Junio C Hamano1-2/+6
* sb/run-command-fd-error-reporting: run-command: be more informative about what failed
2013-02-01run-command: be more informative about what failedStephen Boyd1-2/+6
While debugging an error with verify_signed_buffer() the error messages from run-command weren't very useful: error: cannot create pipe for gpg: Too many open files error: could not run gpg. because they didn't indicate *which* pipe couldn't be created. Print which pipe failed to be created in the error message so we can more easily debug similar problems in the future. For example, the above error now prints: error: cannot create standard error pipe for gpg: Too many open files error: could not run gpg. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-01-14hooks: Add function to check if a hook existsAaron Schrab1-2/+13
Create find_hook() function to determine if a given hook exists and is executable. If it is, the path to the script will be returned, otherwise NULL is returned. This encapsulates the tests that are used to check for the existence of a hook in one place, making it easier to modify those checks if that is found to be necessary. This also makes it simple for places that can use a hook to check if a hook exists before doing, possibly lengthy, setup work which would be pointless if no such hook is present. The returned value is left as a static value from get_pathname() rather than a duplicate because it is anticipated that the return value will either be used as a boolean, immediately added to an argv_array list which would result in it being duplicated at that point, or used to actually run the command without much intervening work. Callers which need to hold onto the returned value for a longer time are expected to duplicate the return value themselves. Signed-off-by: Aaron Schrab <aaron@schrab.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-01-06run-command: encode signal death as a positive integerJeff King1-1/+1
When a sub-command dies due to a signal, we encode the signal number into the numeric exit status as "signal - 128". This is easy to identify (versus a regular positive error code), and when cast to an unsigned integer (e.g., by feeding it to exit), matches what a POSIX shell would return when reporting a signal death in $? or through its own exit code. So we have a negative value inside the code, but once it passes across an exit() barrier, it looks positive (and any code we receive from a sub-shell will have the positive form). E.g., death by SIGPIPE (signal 13) will look like -115 to us in inside git, but will end up as 141 when we call exit() with it. And a program killed by SIGPIPE but run via the shell will come to us with an exit code of 141. Unfortunately, this means that when the "use_shell" option is set, we need to be on the lookout for _both_ forms. We might or might not have actually invoked the shell (because we optimize out some useless shell calls). If we didn't invoke the shell, we will will see the sub-process's signal death directly, and run-command converts it into a negative value. But if we did invoke the shell, we will see the shell's 128+signal exit status. To be thorough, we would need to check both, or cast the value to an unsigned char (after checking that it is not -1, which is a magic error value). Fortunately, most callsites do not care at all whether the exit was from a code or from a signal; they merely check for a non-zero status, and sometimes propagate the error via exit(). But for the callers that do care, we can make life slightly easier by just using the consistent positive form. This actually fixes two minor bugs: 1. In launch_editor, we check whether the editor died from SIGINT or SIGQUIT. But we checked only the negative form, meaning that we would fail to notice a signal death exit code which was propagated through the shell. 2. In handle_alias, we assume that a negative return value from run_command means that errno tells us something interesting (like a fork failure, or ENOENT). Otherwise, we simply propagate the exit code. Negative signal death codes confuse us, and we print a useless "unable to run alias 'foo': Success" message. By encoding signal deaths using the positive form, the existing code just propagates it as it would a normal non-zero exit code. The downside is that callers of run_command can no longer differentiate between a signal received directly by the sub-process, and one propagated. However, no caller currently cares, and since we already optimize out some calls to the shell under the hood, that distinction is not something that should be relied upon by callers. Fix the same logic in t/test-terminal.perl for consistency [jc: raised by Jonathan in the discussion]. Signed-off-by: Jeff King <peff@peff.net> Acked-by: Johannes Sixt <j6t@kdbg.org> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-01-05fix compilation with NO_PTHREADSJeff King1-1/+1
Commit 1327452 cleaned up an unused parameter from wait_or_whine, but forgot to update a caller that is inside "#ifdef NO_PTHREADS". Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-12-02run-command: do not warn about child death from terminalJeff King1-1/+2
SIGINT and SIGQUIT are not generally interesting signals to the user, since they are typically caused by them hitting "^C" or otherwise telling their terminal to send the signal. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-12-02run-command: drop silent_exec_failure arg from wait_or_whineJeff King1-4/+3
We do not actually use this parameter; instead we complain from the child itself (for fork/exec) or from start_command (if we are using spawn on Windows). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-10-25Merge branch 'jk/no-more-pre-exec-callback'Jeff King1-10/+0
Removes a workaround for buggy version of less older than version 406. * jk/no-more-pre-exec-callback: pager: drop "wait for output to run less" hack
2012-09-20Merge branch 'dg/run-command-child-cleanup' into maintJunio C Hamano1-6/+7
* dg/run-command-child-cleanup: run-command.c: fix broken list iteration in clear_child_for_cleanup
2012-09-14Merge branch 'dg/run-command-child-cleanup'Junio C Hamano1-6/+7
The code to wait for subprocess and remove it from our internal queue wasn't quite right. * dg/run-command-child-cleanup: run-command.c: fix broken list iteration in clear_child_for_cleanup
2012-09-11Merge branch 'jc/maint-sane-execvp-notdir' into maint-1.7.11Junio C Hamano1-0/+2
* jc/maint-sane-execvp-notdir: sane_execvp(): ignore non-directory on $PATH
2012-09-11run-command.c: fix broken list iteration in clear_child_for_cleanupDavid Gould1-6/+7
Iterate through children_to_clean using 'next' fields but with an extra level of indirection. This allows us to update the chain when we remove a child and saves us managing several variables around the loop mechanism. Signed-off-by: David Gould <david@optimisefitness.com> Acked-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-09-03Merge branch 'jc/maint-sane-execvp-notdir'Junio C Hamano1-0/+2
"git foo" errored out with "Not a directory" when the user had a non directory on $PATH, and worse yet it masked an alias "foo" to run. * jc/maint-sane-execvp-notdir: sane_execvp(): ignore non-directory on $PATH
2012-07-31sane_execvp(): ignore non-directory on $PATHJunio C Hamano1-0/+2
When you have a non-directory on your PATH, a funny thing happens: $ PATH=$PATH:/bin/sh git foo fatal: cannot exec 'git-foo': Not a directory? Worse yet, as real commands always take precedence over aliases, this behaviour interacts rather badly with them: $ PATH=$PATH:/bin/sh git -c alias.foo=show git foo -s fatal: cannot exec 'git-foo': Not a directory? This is because an ENOTDIR error from the underlying execvp(2) is reported back to the caller of our sane_execvp() wrapper as-is. Translating it to ENOENT, just like the case where we _might_ have the command in an unreadable directory, fixes it. Without an alias, we would get git: 'foo' is not a git command. See 'git --help'. and we use the 'foo' alias when it is available, of course. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-06-05pager: drop "wait for output to run less" hackJeff King1-10/+0
Commit 35ce862 (pager: Work around window resizing bug in 'less', 2007-01-24) causes git's pager sub-process to wait to receive input after forking but before exec-ing the pager. To handle this, run-command had to grow a "pre-exec callback" feature. Unfortunately, this feature does not work at all on Windows (where we do not fork), and interacts poorly with run-command's parent notification system. Its use should be discouraged. The bug in less was fixed in version 406, which was released in June 2007. It is probably safe at this point to remove our workaround. That lets us rip out the preexec_cb feature entirely. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-04-20Merge branch 'js/spawn-via-shell-path-fix'Junio C Hamano1-0/+4
Mops up an unfortunate fallout from bw/spawn-via-shell-path topic. By Johannes Sixt * js/spawn-via-shell-path-fix: Do not use SHELL_PATH from build system in prepare_shell_cmd on Windows
2012-04-20Merge branch 'jk/run-command-eacces'Junio C Hamano1-2/+64
When PATH contains an unreadable directory, alias expansion code did not kick in, and failed with an error that said "git-subcmd" was not found. By Jeff King (1) and Ramsay Jones (1) * jk/run-command-eacces: run-command: treat inaccessible directories as ENOENT compat/mingw.[ch]: Change return type of exec functions to int
2012-04-17Do not use SHELL_PATH from build system in prepare_shell_cmd on WindowsJohannes Sixt1-0/+4
The recent change to use SHELL_PATH instead of "sh" to spawn shell commands is not suited for Windows: - The default setting, "/bin/sh", does not work when git has to run the shell because it is a POSIX style path, but not a proper Windows style path. - If it worked, it would hard-code a position in the files system where the shell is expected, making git (more precisely, the POSIX toolset that is needed alongside git) non-relocatable. But we cannot sacrifice relocatability on Windows. - Apart from that, even though the Makefile leaves SHELL_PATH set to "/bin/sh" for the Windows builds, the build system passes a mangled path to the compiler, and something like "D:/Src/msysgit/bin/sh" is used, which is doubly bad because it points to where /bin/sh resolves to on the system where git was built. - Finally, the system's CreateProcess() function that is used under mingw.c's hood does not work with forward slashes and cannot find the shell. Undo the earlier change on Windows. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-04-05run-command: treat inaccessible directories as ENOENTJeff King1-2/+64
When execvp reports EACCES, it can be one of two things: 1. We found a file to execute, but did not have permissions to do so. 2. We did not have permissions to look in some directory in the $PATH. In the former case, we want to consider this a permissions problem and report it to the user as such (since getting this for something like "git foo" is likely a configuration error). In the latter case, there is a good chance that the inaccessible directory does not contain anything of interest. Reporting "permission denied" is confusing to the user (and prevents our usual "did you mean...?" lookup). It also prevents git from trying alias lookup, since we do so only when an external command does not exist (not when it exists but has an error). This patch detects EACCES from execvp, checks whether we are in case (2), and if so converts errno to ENOENT. This behavior matches that of "bash" (but not of simpler shells that use execvp more directly, like "dash"). Test stolen from Junio. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-04-03Use SHELL_PATH from build system in run_command.c:prepare_shell_cmdBen Walton1-1/+5
During the testing of the 1.7.10 rc series on Solaris for OpenCSW, it was discovered that t7006-pager was failing due to finding a bad "sh" in PATH after a call to execvp("sh", ...). This call was setup by run_command.c:prepare_shell_cmd. The PATH in use at the time saw /opt/csw/bin given precedence to traditional Solaris paths such as /usr/bin and /usr/xpg4/bin. A package named schilyutils (Joerg Schilling's utilities) was installed on the build system and it delivered a modified version of the traditional Solaris /usr/bin/sh as /opt/csw/bin/sh. This version of sh suffers from many of the same problems as /usr/bin/sh. The command-specific pager test failed due to the broken "sh" handling ^ as a pipe character. It tried to fork two processes when it encountered "sed s/^/foo:/" as the pager command. This problem was entirely dependent on the PATH of the user at runtime. Possible fixes for this issue are: 1. Use the standard system() or popen() which both launch a POSIX shell on Solaris as long as _POSIX_SOURCE is defined. 2. The git wrapper could prepend SANE_TOOL_PATH to PATH thus forcing all unqualified commands run to use the known good tools on the system. 3. The run_command.c:prepare_shell_command() could use the same SHELL_PATH that is in the #! line of all all scripts and not rely on PATH to find the sh to run. Option 1 would preclude opening a bidirectional pipe to a filter script and would also break git for Windows as cmd.exe is spawned from system() (cf. v1.7.5-rc0~144^2, "alias: use run_command api to execute aliases, 2011-01-07). Option 2 is not friendly to users as it would negate their ability to use tools of their choice in many cases. Alternately, injecting SANE_TOOL_PATH such that it takes precedence over /bin and /usr/bin (and anything with lower precedence than those paths) as git-sh-setup.sh does would not solve the problem either as the user environment could still allow a bad sh to be found. (Many OpenCSW users will have /opt/csw/bin leading their PATH and some subset would have schilyutils installed.) Option 3 allows us to use a known good shell while still honouring the users' PATH for the utilities being run. Thus, it solves the problem while not negatively impacting either users or git's ability to run external commands in convenient ways. Essentially, the shell is a special case of tool that should not rely on SANE_TOOL_PATH and must be called explicitly. With this patch applied, any code path leading to run_command.c:prepare_shell_cmd can count on using the same sane shell that all shell scripts in the git suite use. Both the build system and run_command.c will default this shell to /bin/sh unless overridden. Signed-off-by: Ben Walton <bwalton@artsci.utoronto.ca> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-01-08dashed externals: kill children on exitClemens Buchacher1-0/+1
Several git commands are so-called dashed externals, that is commands executed as a child process of the git wrapper command. If the git wrapper is killed by a signal, the child process will continue to run. This is different from internal commands, which always die with the git wrapper command. Enable the recently introduced cleanup mechanism for child processes in order to make dashed externals act more in line with internal commands. Signed-off-by: Clemens Buchacher <drizzd@aon.at> Acked-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-01-08run-command: optionally kill children on exitJeff King1-0/+68
When we spawn a helper process, it should generally be done and finish_command called before we exit. However, if we exit abnormally due to an early return or a signal, the helper may continue to run in our absence. In the best case, this may simply be wasted CPU cycles or a few stray messages on a terminal. But it could also mean a process that the user thought was aborted continues to run to completion (e.g., a push's pack-objects helper will complete the push, even though you killed the push process). This patch provides infrastructure for run-command to keep track of PIDs to be killed, and clean them on signal reception or input, just as we do with tempfiles. PIDs can be added in two ways: 1. If NO_PTHREADS is defined, async helper processes are automatically marked. By definition this code must be ready to die when the parent dies, since it may be implemented as a thread of the parent process. 2. If the run-command caller specifies the "clean_on_exit" option. This is not the default, as there are cases where it is OK for the child to outlive us (e.g., when spawning a pager). PIDs are cleared from the kill-list automatically during wait_or_whine, which is called from finish_command and finish_async. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Clemens Buchacher <drizzd@aon.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-10-05Merge branch 'jk/argv-array'Junio C Hamano1-10/+8
* jk/argv-array: run_hook: use argv_array API checkout: use argv_array API bisect: use argv_array API quote: provide sq_dequote_to_argv_array refactor argv_array into generic code quote.h: fix bogus comment add sha1_array API docs
2011-09-14run_hook: use argv_array APIJeff King1-10/+8
This was a pretty straightforward use, so it really doesn't save that many lines. Still, perhaps it's a little bit more readable. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-08-01notice error exit from pagerClemens Buchacher1-9/+6
If the pager fails to run, git produces no output, e.g.: $ GIT_PAGER=not-a-command git log The error reporting fails for two reasons: (1) start_command: There is a mechanism that detects errors during execvp introduced in 2b541bf8 (start_command: detect execvp failures early). The child writes one byte to a pipe only if execvp fails. The parent waits for either EOF, when the successful execvp automatically closes the pipe (see FD_CLOEXEC in fcntl(1)), or it reads a single byte, in which case it knows that the execvp failed. This mechanism is incompatible with the workaround introduced in 35ce8622 (pager: Work around window resizing bug in 'less'), which waits for input from the parent before the exec. Since both the parent and the child are waiting for input from each other, that would result in a deadlock. In order to avoid that, the mechanism is disabled by closing the child_notifier file descriptor. (2) finish_command: The parent correctly detects the 127 exit status from the child, but the error output goes nowhere, since by that time it is already being redirected to the child. No simple solution for (1) comes to mind. Number (2) can be solved by not sending error output to the pager. Not redirecting error output to the pager can result in the pager overwriting error output with standard output, however. Since there is no reliable way to handle error reporting in the parent, produce the output in the child instead. Signed-off-by: Clemens Buchacher <drizzd@aon.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-07-31error_routine: use parent's stderr if exec failsClemens Buchacher1-8/+7
The new process's error output may be redirected elsewhere, but if the exec fails, output should still go to the parent's stderr. This has already been done for the die_routine. Do the same for error_routine. Signed-off-by: Clemens Buchacher <drizzd@aon.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-04-20run-command: handle short writes and EINTR in die_childJonathan Nieder1-6/+9
If start_command fails after forking and before exec finishes, there is not much use in noticing an I/O error on top of that. finish_command will notice that the child exited with nonzero status anyway. So as noted in v1.7.0.3~20^2 (run-command.c: fix build warnings on Ubuntu, 2010-01-30) and v1.7.5-rc0~29^2 (2011-03-16), it is safe to ignore errors from write in this codepath. Even so, the result from write contains useful information: it tells us if the write was cancelled by a signal (EINTR) or was only partially completed (e.g., when writing to an almost-full pipe). Let's use write_in_full to loop until the desired number of bytes have been written (still ignoring errors if that fails). As a happy side effect, the assignment to a dummy variable to appease gcc -D_FORTIFY_SOURCE is no longer needed. xwrite and write_in_full check the return value from write(2). Noticed with gcc -Wunused-but-set-variable. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-04-18Revert "run-command: prettify -D_FORTIFY_SOURCE workaround"Junio C Hamano1-11/+6
This reverts commit ebec842773932e6f853acac70c80f84209b5f83e, which somehow mistakenly thought that any non-zero return from write(2) is an error.
2011-03-17run-command: prettify -D_FORTIFY_SOURCE workaroundJonathan Nieder1-6/+11
Current gcc + glibc with -D_FORTIFY_SOURCE try very aggressively to protect against a programming style which uses write(...) without checking the return value for errors. Even the usual hint of casting to (void) does not suppress the warning. Sometimes when there is an output error, especially right before exit, there really is nothing to be done. The obvious solution, adopted in v1.7.0.3~20^2 (run-command.c: fix build warnings on Ubuntu, 2010-01-30), is to save the return value to a dummy variable: ssize_t dummy; dummy = write(...); But that (1) is ugly and (2) triggers -Wunused-but-set-variable warnings with gcc-4.6 -Wall, so we are not much better off than when we started. Instead, use an "if" statement with an empty body to make the intent clear. if (write(...)) ; /* yes, yes, there was an error. */ Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Improved-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-02-07start_command: flush buffers in the WIN32 code path as wellJohannes Sixt1-1/+1
The POSIX code path did The Right Thing already, but we have to do the same on Windows. This bug caused failures in t5526-fetch-submodules, where the output of 'git fetch --recurse-submodules' was in the wrong order. Debugged-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-06-21Merge branch 'js/async-thread'Junio C Hamano1-18/+57
* js/async-thread: fast-import: die_nicely() back to vsnprintf (reverts part of ebaa79f) Enable threaded async procedures whenever pthreads is available Dying in an async procedure should only exit the thread, not the process. Reimplement async procedures using pthreads Windows: more pthreads functions Fix signature of fcntl() compatibility dummy Make report() from usage.c public as vreportf() and use it. Modernize t5530-upload-pack-error. Conflicts: http-backend.c
2010-05-20start_command: close cmd->err descriptor when fork/spawn failsbert Dvornik1-0/+2
Fix the problem where the cmd->err passed into start_command wasn't being properly closed when certain types of errors occurr. (Compare the affected code with the clean shutdown code later in the function.) On Windows, this problem would be triggered if mingw_spawnvpe() failed, which would happen if the command to be executed was malformed (e.g. a text file that didn't start with a #! line). If cmd->err was a pipe, the failure to close it could result in a hang while the other side was waiting (forever) for either input or pipe close, e.g. while trying to shove the output into the side band. On msysGit, this problem was causing a hang in t5516-fetch-push. [J6t: With a slight adjustment of the test case, the hang is also observed on Linux.] Signed-off-by: bert Dvornik <dvornik+git@gmail.com> Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-04-11Merge branch 'jl/maint-submodule-gitfile-awareness'Junio C Hamano1-3/+1
* jl/maint-submodule-gitfile-awareness: Windows: start_command: Support non-NULL dir in struct child_process
2010-04-11Windows: start_command: Support non-NULL dir in struct child_processJohannes Sixt1-3/+1
A caller of start_command can set the member 'dir' to a directory to request that the child process starts with that directory as CWD. The first user of this feature was added recently in eee49b6 (Teach diff --submodule and status to handle .git files in submodules). On Windows, we have been lazy and had not implemented support for this feature, yet. This fixes the shortcoming. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-03-10Enable threaded async procedures whenever pthreads is availableJohannes Sixt1-5/+5
Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-03-07Merge branch 'mw/maint-gcc-warns-unused-write'Junio C Hamano1-4/+6
* mw/maint-gcc-warns-unused-write: run-command.c: fix build warnings on Ubuntu
2010-03-07Dying in an async procedure should only exit the thread, not the process.Johannes Sixt1-0/+34
Async procedures are intended as helpers that perform a very restricted task, and the caller usually has to manage them in a larger context. Conceptually, the async procedure is not concerned with the "bigger picture" in whose context it is run. When it dies, it is not supposed to destroy this "bigger picture", but rather only its own limit view of the world. On POSIX, the async procedure is run in its own process, and exiting this process naturally had only these limited effects. On Windows (or when ASYNC_AS_THREAD is set), calling die() exited the whole process, destroying the caller (the "big picture") as well. This fixes it to exit only the thread. Without ASYNC_AS_THREAD, one particular effect of exiting the async procedure process is that it automatically closes file descriptors, most notably the writable end of the pipe that the async procedure writes to. The async API already requires that the async procedure closes the pipe ends when it exits normally. But for calls to die() no requirements are imposed. In the non-threaded case the pipe ends are closed implicitly by the exiting process, but in the threaded case, the die routine must take care of closing them. Now t5530-upload-pack-error.sh passes on Windows. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-03-07Reimplement async procedures using pthreadsJohannes Sixt1-18/+23
On Windows, async procedures have always been run in threads, and the implementation used Windows specific APIs. Rewrite the code to use pthreads. A new configuration option is introduced so that the threaded implementation can also be used on POSIX systems. Since this option is intended only as playground on POSIX, but is mandatory on Windows, the option is not documented. One detail is that on POSIX it is necessary to set FD_CLOEXEC on the pipe handles. On Windows, this is not needed because pipe handles are not inherited to child processes, and the new calls to set_cloexec() are effectively no-ops. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-03-03run-command.c: fix build warnings on UbuntuMichael Wookey1-4/+6
Building git on Ubuntu 9.10 warns that the return value of write(2) isn't checked. These warnings were introduced in commits: 2b541bf8 ("start_command: detect execvp failures early") a5487ddf ("start_command: report child process setup errors to the parent's stderr") GCC details: $ gcc --version gcc (Ubuntu 4.4.1-4ubuntu9) 4.4.1 Silence the warnings by reading (but not making use of) the return value of write(2). Signed-off-by: Michael Wookey <michaelwookey@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-05Merge branch 'sp/maint-push-sideband' into sp/push-sidebandJunio C Hamano1-13/+77
* sp/maint-push-sideband: receive-pack: Send hook output over side band #2 receive-pack: Wrap status reports inside side-band-64k receive-pack: Refactor how capabilities are shown to the client send-pack: demultiplex a sideband stream with status data run-command: support custom fd-set in async run-command: Allow stderr to be a caller supplied pipe Update git fsck --full short description to mention packs Conflicts: run-command.c
2010-02-05run-command: support custom fd-set in asyncErik Faye-Lund1-13/+70
This patch adds the possibility to supply a set of non-0 file descriptors for async process communication instead of the default-created pipe. Additionally, we now support bi-directional communiction with the async procedure, by giving the async function both read and write file descriptors. To retain compatiblity and similar "API feel" with start_command, we require start_async callers to set .out = -1 to get a readable file descriptor. If either of .in or .out is 0, we supply no file descriptor to the async process. [sp: Note: Erik started this patch, and a huge bulk of it is his work. All bugs were introduced later by Shawn.] Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-05run-command: Allow stderr to be a caller supplied pipeShawn O. Pearce1-0/+8
Like .out, .err may now be set to a file descriptor > 0, which is a writable pipe/socket/file that the child's stderr will be redirected into. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-20Merge branch 'js/exec-error-report'Junio C Hamano1-46/+131
* js/exec-error-report: Improve error message when a transport helper was not found start_command: detect execvp failures early run-command: move wait_or_whine earlier start_command: report child process setup errors to the parent's stderr Conflicts: Makefile
2010-01-18Merge branch 'js/windows'Junio C Hamano1-40/+31
* js/windows: Do not use date.c:tm_to_time_t() from compat/mingw.c MSVC: Windows-native implementation for subset of Pthreads API MSVC: Fix an "incompatible pointer types" compiler warning Windows: avoid the "dup dance" when spawning a child process Windows: simplify the pipe(2) implementation Windows: boost startup by avoiding a static dependency on shell32.dll Windows: disable Python
2010-01-16Windows: avoid the "dup dance" when spawning a child processJohannes Sixt1-40/+31
When stdin, stdout, or stderr must be redirected for a child process that on Windows is spawned using one of the spawn() functions of Microsoft's C runtime, then there is no choice other than to 1. make a backup copy of fd 0,1,2 with dup 2. dup2 the redirection source fd into 0,1,2 3. spawn 4. dup2 the backup back into 0,1,2 5. close the backup copy and the redirection source We used this idiom as well -- but we are not using the spawn() functions anymore! Instead, we have our own implementation. We had hardcoded that stdin, stdout, and stderr of the child process were inherited from the parent's fds 0, 1, and 2. But we can actually specify any fd. With this patch, the fds to inherit are passed from start_command()'s WIN32 section to our spawn implementation. This way, we can avoid the backup copies of the fds. The backup copies were a bug waiting to surface: The OS handles underlying the dup()ed fds were inherited by the child process (but were not associated with a file descriptor in the child). Consequently, the file or pipe represented by the OS handle remained open even after the backup copy was closed in the parent process until the child exited. Since our implementation of pipe() creates non-inheritable OS handles, we still dup() file descriptors in start_command() because dup() happens to create inheritable duplicates. (A nice side effect is that the fd cleanup in start_command is the same for Windows and Unix and remains unchanged.) Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10start_command: detect execvp failures earlyJohannes Sixt1-1/+46
Previously, failures during execvp could be detected only by finish_command. However, in some situations it is beneficial for the parent process to know earlier that the child process will not run. The idea to use a pipe to signal failures to the parent process and the test case were lifted from patches by Ilari Liusvaara. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10run-command: move wait_or_whine earlierJohannes Sixt1-42/+42
We want to reuse it from start_command. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10start_command: report child process setup errors to the parent's stderrJohannes Sixt1-3/+43
When the child process's environment is set up in start_command(), error messages were written to wherever the parent redirected the child's stderr channel. However, even if the parent redirected the child's stderr, errors during this setup process, including the exec itself, are usually an indication of a problem in the parent's environment. Therefore, the error messages should go to the parent's stderr. Redirection of the child's error messages is usually only used to redirect hook error messages during client-server exchanges. In these cases, hook setup errors could be regarded as information leak. This patch makes a copy of stderr if necessary and uses a special die routine that is used for all die() calls in the child that sends the errors messages to the parent's stderr. The trace call that reported a failed execvp is removed (because it writes to stderr) and replaced by die_errno() with special treatment of ENOENT. The improvement in the error message can be seen with this sequence: mkdir .git/hooks/pre-commit git commit Previously, the error message was error: cannot run .git/hooks/pre-commit: No such file or directory and now it is fatal: cannot exec '.git/hooks/pre-commit': Permission denied Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-05run-command: optimize out useless shell callsJeff King1-9/+11
If there are no metacharacters in the program to be run, we can just skip running the shell entirely and directly exec the program. The metacharacter test is pulled verbatim from launch_editor, which already implements this optimization. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-01run-command: add "use shell" optionJeff King1-0/+47
Many callsites run "sh -c $CMD" to run $CMD. We can make it a little simpler for them by factoring out the munging of argv. For simple cases with no arguments, this doesn't help much, but: 1. For cases with arguments, we save the caller from having to build the appropriate shell snippet. 2. We can later optimize to avoid the shell when there are no metacharacters in the program. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-18Test for WIN32 instead of __MINGW32_Frank Li1-4/+4
The code which is conditional on MinGW32 is actually conditional on Windows. Use the WIN32 symbol, which is defined by the MINGW32 and MSVC environments, but not by Cygwin. Define SNPRINTF_SIZE_CORR=1 for MSVC too, as its vsnprintf function does not add NUL at the end of the buffer if the result fits the buffer size exactly. Signed-off-by: Frank Li <lznuaa@gmail.com> Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-18Fix __stdcall placement and function prototypeFrank Li1-1/+1
MSVC requires __stdcall to be between the functions return value and the function name, and that the function pointer type is in the form of return_type (WINAPI *function_name)(arguments...) Signed-off-by: Frank Li <lznuaa@gmail.com> Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-18Avoid declaration after statementFrank Li1-0/+2
MSVC does not understand this C99 style. Signed-off-by: Frank Li <lznuaa@gmail.com> Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-11start_command: do not clobber cmd->env on Windows code pathJohannes Sixt1-5/+2
Previously, it would not be possible to call start_command twice for the same struct child_process that has env set. The fix is achieved by moving the loop that modifies the environment block into a helper function. This also allows us to make two other helper functions static. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-08-10Merge branch 'js/run-command-updates'Junio C Hamano1-46/+59
* js/run-command-updates: api-run-command.txt: describe error behavior of run_command functions run-command.c: squelch a "use before assignment" warning receive-pack: remove unnecessary run_status report run_command: report failure to execute the program, but optionally don't run_command: encode deadly signal number in the return value run_command: report system call errors instead of returning error codes run_command: return exit code as positive value MinGW: simplify waitpid() emulation macros
2009-08-04run-command.c: squelch a "use before assignment" warningDavid Soria Parra1-1/+1
i686-apple-darwin9-gcc-4.0.1 (GCC) 4.0.1 (Apple Inc. build 5490) compiler (and probably others) mistakenly thinks variable failed_errno is used before assigned. Work it around by giving it a fake initialization. Signed-off-by: David Soria Parra <dsp@php.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-06run_command: report failure to execute the program, but optionally don'tJohannes Sixt1-4/+8
In the case where a program was not found, it was still the task of the caller to report an error to the user. Usually, this is an interesting case but only few callers actually reported a specific error (though many call sites report a generic error message regardless of the cause). With this change the error is reported by run_command, but since there is one call site in git.c that does not want that, an option is added to struct child_process, which is used to turn the error off. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-06run_command: encode deadly signal number in the return valueJohannes Sixt1-1/+8
We now write the signal number in the error message if the program terminated by a signal. The negative return value is constructed such that after truncation to 8 bits it looks like a POSIX shell's $?: $ echo 0000 | { git upload-pack .; echo $? >&2; } | : error: git-upload-pack died of signal 13 141 Previously, the exit code was 255 instead of 141. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-06run_command: report system call errors instead of returning error codesJohannes Sixt1-40/+49
The motivation for this change is that system call failures are serious errors that should be reported to the user, but only few callers took the burden to decode the error codes that the functions returned into error messages. If at all, then only an unspecific error message was given. A prominent example is this: $ git upload-pack . | : fatal: unable to run 'git-upload-pack' In this example, git-upload-pack, the external command invoked through the git wrapper, dies due to SIGPIPE, but the git wrapper does not bother to report the real cause. In fact, this very error message is copied to the syslog if git-daemon's client aborts the connection early. With this change, system call failures are reported immediately after the failure and only a generic failure code is returned to the caller. In the above example the error is now to the point: $ git upload-pack . | : error: git-upload-pack died of signal Note that there is no error report if the invoked program terminated with a non-zero exit code, because it is reasonable to expect that the invoked program has already reported an error. (But many run_command call sites nevertheless write a generic error message.) There was one special return code that was used to identify the case where run_command failed because the requested program could not be exec'd. This special case is now treated like a system call failure with errno set to ENOENT. No error is reported in this case, because the call site in git.c expects this as a normal result. Therefore, the callers that carefully decoded the return value still check for this condition. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-05run_command: return exit code as positive valueJohannes Sixt1-8/+1
As a general guideline, functions in git's code return zero to indicate success and negative values to indicate failure. The run_command family of functions followed this guideline. But there are actually two different kinds of failure: - failures of system calls; - non-zero exit code of the program that was run. Usually, a non-zero exit code of the program is a failure and means a failure to the caller. Except that sometimes it does not. For example, the exit code of merge programs (e.g. external merge drivers) conveys information about how the merge failed, and not all exit calls are actually failures. Furthermore, the return value of run_command is sometimes used as exit code by the caller. This change arranges that the exit code of the program is returned as a positive value, which can now be regarded as the "result" of the function. System call failures continue to be reported as negative values. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-06-27Convert existing die(..., strerror(errno)) to die_errno()Thomas Rast1-2/+2
Change calls to die(..., strerror(errno)) to use the new die_errno(). In the process, also make slight style adjustments: at least state _something_ about the function that failed (instead of just printing the pathname), and put paths in single quotes. Signed-off-by: Thomas Rast <trast@student.ethz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-05-01Fix a bunch of pointer declarations (codestyle)Felipe Contreras1-1/+1
Essentially; s/type* /type */ as per the coding guidelines. Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-02-03Merge branch 'jk/maint-cleanup-after-exec-failure'Junio C Hamano1-4/+14
* jk/maint-cleanup-after-exec-failure: git: use run_command() to execute dashed externals run_command(): help callers distinguish errors run_command(): handle missing command errors more gracefully git: s/run_command/run_builtin/
2009-01-28run_command(): handle missing command errors more gracefullyJeff King1-4/+14
When run_command() was asked to run a non-existant command, its behavior varied depending on the platform: - on POSIX systems, we would fork, and then after the execvp call failed, we could call die(), which prints a message to stderr and exits with code 128. - on Windows, we do a PATH lookup, realize the program isn't there, and then return ERR_RUN_COMMAND_FORK The goal of this patch is to make it clear to callers that the specific error was a missing command. To do this, we will return the error code ERR_RUN_COMMAND_EXEC, which is already defined in run-command.h, checked for in several places, but never actually gets set. The new behavior is: - on POSIX systems, we exit the forked process with code 127 (the same as the shell uses to report missing commands). The parent process recognizes this code and returns an EXEC error. The stderr message is silenced, since the caller may be speculatively trying to run a command. Instead, we use trace_printf so that somebody interested in debugging can see the error that occured. - on Windows, we check errno, which is already set correctly by mingw_spawnvpe, and report an EXEC error instead of a FORK error Thus it is safe to speculatively run a command: int r = run_command_v_opt(argv, 0); if (r == -ERR_RUN_COMMAND_EXEC) /* oops, it wasn't found; try something else */ else /* we failed for some other reason, error is in r */ Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-17run_hook(): allow more than 9 hook argumentsStephan Beyer1-9/+9
This is done using the ALLOC_GROW macro. Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-17run_hook(): check the executability of the hook before filling argvStephan Beyer1-3/+3
Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-17Move run_hook() from builtin-commit.c into run-command.c (libgit)Stephan Beyer1-0/+45
A function that runs a hook is used in several Git commands. builtin-commit.c has the one that is most general for cases without piping. The one in builtin-gc.c prints some useful warnings. This patch moves a merged version of these variants into libgit and lets the other builtins use this libified run_hook(). The run_hook() function used in receive-pack.c feeds the standard input of the pre-receive or post-receive hooks. This function is renamed to run_receive_hook() because the libified run_hook() cannot handle this. Mentored-by: Daniel Barkalow <barkalow@iabervon.org> Mentored-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-10-02run-command.c: remove run_command_v_opt_cd()Nanako Shiraishi1-8/+0
This function is not used anywhere. Johannes Sixt <johannes.sixt@telecom.at>: > Future callers can use run_command_v_opt_cd_env() instead. Signed-off-by: Nanako Shiraishi <nanako3@lavabit.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-08-19Merge branch 'jk/pager-swap'Junio C Hamano1-0/+2
* jk/pager-swap: spawn pager via run_command interface run-command: add pre-exec callback
2008-08-04Add output flushing before fork()Anders Melchiorsen1-0/+1
This adds fflush(NULL) before fork() in start_command(), to keep the generic interface safe. A remaining use of fork() with no flushing is in a comment in show_tree(). Rewrite that comment to use start_command(). Signed-off-by: Anders Melchiorsen <mail@cup.kalibalik.dk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-03Flush output in start_asyncAnders Melchiorsen1-0/+3
This prevents double output in case stdout is redirected. Signed-off-by: Anders Melchiorsen <mail@cup.kalibalik.dk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-28run-command (Windows): Run dashless "git <cmd>"Steffen Prohaska1-7/+4
We prefer running the dashless form, and POSIX side already does so; we should use it in MinGW's start_command(), too. Signed-off-by: Steffen Prohaska <prohaska@zib.de> Acked-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-25run-command: add pre-exec callbackJeff King1-0/+2
This is a function provided by the caller which is called _after_ the process is forked, but before the spawned program is executed. On platforms (like mingw) where subprocesses are forked and executed in a single call, the preexec callback is simply ignored. This will be used in the following patch to do some setup for 'less' that must happen in the forked child. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-07Merge branch 'qq/maint'Junio C Hamano1-0/+2
* qq/maint: run_command(): respect GIT_TRACE Conflicts: run-command.c
2008-07-07run_command(): respect GIT_TRACEJohannes Schindelin1-0/+2
When GIT_TRACE is set, the user is most likely wanting to see an external command that is about to be executed. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-26Windows: Implement a custom spawnve().Johannes Sixt1-1/+1
The problem with Windows's own implementation is that it tries to be clever when a console program is invoked from a GUI application: In this case it sometimes automatically allocates a new console window. As a consequence, the IO channels of the spawned program are directed to the console, but the invoking application listens on channels that are now directed to nowhere. In this implementation we use the lowlevel facilities of CreateProcess(), which offers a flag to tell the system not to open a console. As a side effect, only stdin, stdout, and stderr channels will be accessible from C programs that are spawned. Other channels (file handles, pipe handles, etc.) are still inherited by the spawned program, but it doesn't get enough information to access them. Johannes Schindelin integrated path quoting and unified the various *execv* and *spawnv* helpers. Eric Raible suggested to also quote '{'. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2008-06-26Windows: Implement asynchronous functions as threads.Johannes Sixt1-1/+28
In upload-pack we must explicitly close the output channel of rev-list. (On Unix, the channel is closed automatically because process that runs rev-list terminates.) Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2008-06-23Windows: Implement start_command().Johannes Sixt1-14/+83
On Windows, we have spawnv() variants to run a child process instead of fork()/exec(). In order to attach pipe ends to stdin, stdout, and stderr, we have to use this idiom: save1 = dup(1); dup2(pipe[1], 1); spawnv(); dup2(save1, 1); close(pipe[1]); assuming that the descriptors created by pipe() are not inheritable. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2008-03-05run-command: Redirect stderr to a pipe before redirecting stdout to stderrChristian Couder1-7/+7
With this patch, in the 'start_command' function after forking we now take care of stderr in the child process before stdout. This way if 'start_command' is called with a 'child_process' argument like this: .err = -1; .stdout_to_stderr = 1; then stderr will be redirected to a pipe before stdout is redirected to stderr. So we can now get the process' stdout from the pipe (as well as its stderr). Earlier such a call would have redirected stdout to stderr before stderr was itself redirected, and therefore stdout would not have followed stderr, which would not have been very useful anyway. Update documentation in 'api-run-command.txt' accordingly. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Acked-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-23start_command(), if .in/.out > 0, closes file descriptors, not the callersJohannes Sixt1-2/+20
Callers of start_command() can set the members .in and .out of struct child_process to a value > 0 to specify that this descriptor is used as the stdin or stdout of the child process. Previously, if start_command() was successful, this descriptor was closed upon return. Here we now make sure that the descriptor is also closed in case of failures. All callers are updated not to close the file descriptor themselves after start_command() was called. Note that earlier run_gpg_verify() of git-verify-tag set .out = 1, which worked because start_command() treated this as a special case, but now this is incorrect because it closes the descriptor. The intent here is to inherit stdout to the child, which is achieved by .out = 0. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-23start_command(), .in/.out/.err = -1: Callers must close the file descriptorJohannes Sixt1-6/+0
By setting .in, .out, or .err members of struct child_process to -1, the callers of start_command() can request that a pipe is allocated that talks to the child process and one end is returned by replacing -1 with the file descriptor. Previously, a flag was set (for .in and .out, but not .err) to signal finish_command() to close the pipe end that start_command() had handed out, so it was optional for callers to close the pipe, and many already do so. Now we make it mandatory to close the pipe. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-11-11run-command: Support sending stderr to /dev/nullShawn O. Pearce1-2/+4
Some callers may wish to redirect stderr to /dev/null in some contexts, such as if they are executing a command only to get the exit status and don't want users to see whatever output it may produce as a side-effect of computing that exit status. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-21Add infrastructure to run a function asynchronously.Johannes Sixt1-8/+43
This adds start_async() and finish_async(), which runs a function asynchronously. Communication with the caller happens only via pipes. For this reason, this implementation forks off a child process that runs the function. [sp: Style nit fixed by removing unnecessary block on if condition inside of start_async()] Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-21Have start_command() create a pipe to read the stderr of the child.Johannes Sixt1-2/+24
This adds another stanza that allocates a pipe that is connected to the child's stderr and that the caller can read from. In order to request this pipe, the caller sets cmd->err to -1. The implementation is not exactly modeled after the stdout case: For stdout the caller can supply an existing file descriptor, but this facility is nowhere needed in the stderr case. Additionally, the caller is required to close cmd->err. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-05-23Allow environment variables to be unset in the processes started by run_commandAlex Riesen1-2/+6
To unset a variable, just specify its name, without "=". For example: const char *env[] = {"GIT_DIR=.git", "PWD", NULL}; const char *argv[] = {"git-ls-files", "-s", NULL}; int err = run_command_v_opt_cd_env(argv, RUN_GIT_CMD, ".", env); The PWD will be unset before executing git-ls-files. Signed-off-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-23Add ability to specify environment extension to run_commandAlex Riesen1-1/+15
There is no way to specify and override for the environment: there'd be no user for it yet. Signed-off-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-23Add run_command_v_opt_cd: chdir into a directory before execAlex Riesen1-5/+22
It can make code simplier (no need to preserve cwd) and safer (no chance the cwd of the current process is accidentally forgotten). Signed-off-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12Teach run-command to redirect stdout to /dev/nullShawn O. Pearce1-8/+18
Some run-command callers may wish to just discard any data that is sent to stdout from the child. This is a lot like our existing no_stdin support, we just open /dev/null and duplicate the descriptor into position. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12Teach run-command about stdout redirectionShawn O. Pearce1-1/+29
Some potential callers of the run_command family of functions need to control not only the stdin redirection of the child, but also the stdout redirection of the child. This can now be setup much like the already existing stdin redirection. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12Simplify closing two fds at once in run-command.cShawn O. Pearce1-6/+9
I started hacking on a change to add stdout redirection support to the run_command family, but found I was using a lot of close calls on two pipes in an array (such as for pipe). So I'm doing a tiny bit of refactoring first to make the next set of changes clearer. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-11Teach run_command how to setup a stdin pipeShawn O. Pearce1-1/+34
Sometimes callers trying to use run_command to execute a child process will want to setup a pipe or file descriptor to redirect into the child's stdin. This idea is completely stolen from builtin-bundle's fork_with_pipe, written by Johannes Schindelin. All credit (and blame) should lie with Dscho. ;-) Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-11Split run_command into two halves (start/finish)Shawn O. Pearce1-7/+19
If the calling process wants to send data to stdin of a child process it will need to arrange for a pipe and get the child process running, feed data to it, then wait for the child process to finish. So we split the run function into two halves, allowing callers to first start the child then later finish it. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-11Start defining a more sophisticated run_commandShawn O. Pearce1-7/+18
There are a number of places where we do some variation of fork()+exec() but we also need to setup redirection in the process, much like what run_command does for us already with its option flags. It would be nice to reuse more of the run_command logic, especially as that non-fork API helps us to port to odd platforms like Win32. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-11Remove unused run_command variantsShawn O. Pearce1-45/+0
We don't actually use these va_list based variants of run_command anymore. I'm removing them before I make further improvements. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-30Use /dev/null for update hook stdin.Shawn O. Pearce1-3/+3
Currently the update hook invoked by receive-pack has its stdin connected to the pushing client. The hook shouldn't attempt to read from this stream, and doing so may consume data that was meant for receive-pack. Instead we should give the update hook /dev/null as its stdin, ensuring that it always receives EOF and doesn't disrupt the protocol if it attempts to read any data. The post-update hook is similar, as it gets invoked with /dev/null on stdin to prevent the hook from reading data from the client. Previously we had invoked it with stdout also connected to /dev/null, throwing away anything on stdout, to prevent client protocol errors. Instead we should redirect stdout to stderr, like we do with the update hook. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-30Redirect update hook stdout to stderr.Shawn O. Pearce1-6/+26
If an update hook outputs to stdout then that output will be sent back over the wire to the push client as though it were part of the git protocol. This tends to cause protocol errors on the client end of the connection, as the hook output is not expected in that context. Most hook developers work around this by making sure their hook outputs everything to stderr. But hooks shouldn't need to perform such special behavior. Instead we can just dup stderr to stdout prior to invoking the update hook. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-30Remove unnecessary argc parameter from run_command_v.Shawn O. Pearce1-4/+4
The argc parameter is never used by the run_command_v family of functions. Instead they require that the passed argv[] be NULL terminated so they can rely on the operating system's execvp function to correctly pass the arguments to the new process. Making the caller pass the argc is just confusing, as the caller could be mislead into believing that the argc might take precendece over the argv, or that the argv does not need to be NULL terminated. So goodbye argc. Don't come back. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-20simplify inclusion of system header files.Junio C Hamano1-1/+0
This is a mechanical clean-up of the way *.c files include system header files. (1) sources under compat/, platform sha-1 implementations, and xdelta code are exempt from the following rules; (2) the first #include must be "git-compat-util.h" or one of our own header file that includes it first (e.g. config.h, builtin.h, pkt-line.h); (3) system headers that are included in "git-compat-util.h" need not be included in individual C source files. (4) "git-compat-util.h" does not have to include subsystem specific header files (e.g. expat.h). Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-08-15use appropriate typedefsDavid Rientjes1-4/+4
Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-05Const tightening.Junio C Hamano1-3/+3
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>
2006-01-13Exec git programs without using PATH.Michal Ostrowski1-2/+7
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>
2005-12-07Clean up file descriptors when calling hooks.Daniel Barkalow1-2/+13
When calling post-update hook, don't leave stdin and stdout connected to the pushing connection. Signed-off-by: Daniel Barkalow <barkalow@iabervon.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-08-02receive-pack hooks updates.Junio C Hamano1-7/+5
The earlier one conflated update and post-update hooks for no good reason. Correct that ugly hack. Now post-update hooks will take the list of successfully updated refs. Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-07-31[PATCH] Added hook in git-receive-packJosef Weidendorfer1-0/+60
Just before updating a ref, $GIT_DIR/hooks/update refname old-sha1 new-sha1 is called if executable. The hook can decline the ref to be updated by exiting with a non-zero status, or allow it to be updated by exiting with a zero status. The mechanism also allows e.g sending of a mail with pushed commits on the remote repository. Documentation update with an example hook is included. jc: The credits of the basic idea and initial implementation go to Josef, but I ended up rewriting major parts of his patch, so bugs are all mine. Also I changed the semantics for the hook from his original version (which were post-update hook) so that the hook can optionally decline to update the ref, and also can be used to implement the overall cleanups. The latter was primarily to implement a suggestion from Linus that calling update-server-info should be made optional. Signed-off-by: Junio C Hamano <junkio@cox.net>