summaryrefslogtreecommitdiff
path: root/git-compat-util.h
AgeCommit message (Collapse)Author
2019-02-14Merge branch 'nd/fileno-may-be-macro'Junio C Hamano
* nd/fileno-may-be-macro: git-compat-util: work around fileno(fp) that is a macro
2019-02-12git-compat-util: work around fileno(fp) that is a macroDuy Nguyen
On various BSD's, fileno(fp) is implemented as a macro that directly accesses the fields in the FILE * object, which breaks a function that accepts a "void *fp" parameter and calls fileno(fp) and expect it to work. Work it around by adding a compile-time knob FILENO_IS_A_MACRO that inserts a real helper function in the middle of the callchain. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-18Merge branch 'rb/hpe'Junio C Hamano
Portability updates for the HPE NonStop platform. * rb/hpe: compat/regex/regcomp.c: define intptr_t and uintptr_t on NonStop git-compat-util.h: add FLOSS headers for HPE NonStop config.mak.uname: support for modern HPE NonStop config. transport-helper: drop read/write errno checks transport-helper: use xread instead of read
2019-01-14Merge branch 'nd/indentation-fix'Junio C Hamano
Code cleanup. * nd/indentation-fix: Indent code with TABs
2019-01-14Merge branch 'tb/use-common-win32-pathfuncs-on-cygwin'Junio C Hamano
Cygwin update. * tb/use-common-win32-pathfuncs-on-cygwin: git clone <url> C:\cygwin\home\USER\repo' is working (again)
2019-01-03git-compat-util.h: add FLOSS headers for HPE NonStopRandall S. Becker
The HPE NonStop (a.k.a. __TANDEM) platform cannot build git without using the FLOSS package supplied by HPE. The convenient location for including the relevant headers is in this file. The NSIG define is also not defined on __TANDEM, so we define it here as 100 if it is not defined only for __TANDEM builds. Signed-off-by: Randall S. Becker <rsbecker@nexbridge.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-26git clone <url> C:\cygwin\home\USER\repo' is working (again)Torsten Bögershausen
A regression for cygwin users was introduced with commit 05b458c, "real_path: resolve symlinks by hand". In the the commit message we read: The current implementation of real_path uses chdir() in order to resolve symlinks. Unfortunately this isn't thread-safe as chdir() affects a process as a whole... The old (and non-thread-save) OS calls chdir()/pwd() had been replaced by a string operation. The cygwin layer "knows" that "C:\cygwin" is an absolute path, but the new string operation does not. "git clone <url> C:\cygwin\home\USER\repo" fails like this: fatal: Invalid path '/home/USER/repo/C:\cygwin\home\USER\repo' The solution is to implement has_dos_drive_prefix(), skip_dos_drive_prefix() is_dir_sep(), offset_1st_component() and convert_slashes() for cygwin in the same way as it is done in 'Git for Windows' in compat/mingw.[ch] Extract the needed code into compat/win32/path-utils.[ch] and use it for cygwin as well. Reported-by: Steven Penny <svnpenn@gmail.com> Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-09Indent code with TABsNguyễn Thái Ngọc Duy
We indent with TABs and sometimes for fine alignment, TABs followed by spaces, but never all spaces (unless the indentation is less than 8 columns). Indenting with spaces slips through in some places. Fix them. Imported code and compat/ are left alone on purpose. The former should remain as close as upstream as possible. The latter pretty much has separate maintainers, it's up to them to decide. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-21Merge branch 'cc/delta-islands'Junio C Hamano
A few issues in the implementation of "delta-islands" feature has been corrected. * cc/delta-islands: pack-objects: fix off-by-one in delta-island tree-depth computation pack-objects: zero-initialize tree_depth/layer arrays pack-objects: fix tree_depth and layer invariants
2018-11-21pack-objects: zero-initialize tree_depth/layer arraysJeff King
Commit 108f530385 (pack-objects: move tree_depth into 'struct packing_data', 2018-08-16) started maintaining a tree_depth array that matches the "objects" array. We extend the array when: 1. The objects array is extended, in which case we use realloc to extend the tree_depth array. 2. A caller asks to store a tree_depth for object N, and this is the first such request; we create the array from scratch and store the value for N. In the latter case, though, we use regular xmalloc(), and the depth values for any objects besides N is undefined. This happens to not trigger a bug with the current code, but the reasons are quite subtle: - we never ask about the depth for any object with index i < N. This is because we store the depth immediately for all trees and blobs. So any such "i" must be a non-tree, and therefore we will never need to care about its depth (in fact, we really only care about the depth of trees). - there are no objects at this point with index i > N, because we always fill in the depth for a tree immediately after its object entry is created (we may still allocate uninitialized depth entries, but they'll be initialized by packlist_alloc() when it initializes the entry in the "objects" array). So it works, but only by chance. To be defensive, let's zero the array, which matches the "unset" values which would be handed out by oe_tree_depth() already. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-14git-compat-util: prefer poll.h to sys/poll.hĐoàn Trần Công Danh
POSIX specifies that <poll.h> is the correct header for poll(2) whereas <sys/poll.h> is only needed for some old libc. Let's follow the POSIX way by default. This effectively eliminates musl's warning: warning redirecting incorrect #include <sys/poll.h> to <poll.h> Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-31config: allow for platform-specific core.* config settingsJohannes Schindelin
In the Git for Windows project, we have ample precendent for config settings that apply to Windows, and to Windows only. Let's formalize this concept by introducing a platform_core_config() function that can be #define'd in a platform-specific manner. This will allow us to contain platform-specific code better, as the corresponding variables no longer need to be exported so that they can be defined in environment.c and be set in config.c Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-30Merge branch 'cb/khash-maybe-unused-function'Junio C Hamano
Build fix. * cb/khash-maybe-unused-function: khash: silence -Wunused-function for delta-islands commit-slabs: move MAYBE_UNUSED out
2018-10-26Merge branch 'js/mingw-default-ident'Junio C Hamano
The logic to select the default user name and e-mail on Windows has been improved. * js/mingw-default-ident: mingw: use domain information for default email getpwuid(mingw): provide a better default for the user name getpwuid(mingw): initialize the structure only once
2018-10-24commit-slabs: move MAYBE_UNUSED outCarlo Marcelo Arenas Belón
after 36da893114 ("config.mak.dev: enable -Wunused-function", 2018-10-18) it is expected to be used to prevent -Wunused-function warnings for code that was macro generated Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-16mingw: use domain information for default emailJohannes Schindelin
When a user is registered in a Windows domain, it is really easy to obtain the email address. So let's do that. Suggested by Lutz Roeder. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-04mingw: bump the minimum Windows version to VistaJohannes Schindelin
Quite some time ago, a last plea to the XP users out there who want to see Windows XP support in Git for Windows, asking them to get engaged and help, vanished into the depths of the universe. We tried for a long time to play nice with the last remaining XP users who somehow manage to build Git from source, but a recent update of mingw-w64 (7.0.0.5233.e0c09544 -> 7.0.0.5245.edf66197) finally dropped the last sign of XP support, and Git for Windows' SDK is no longer able to build core Git's `master` branch as a consequence. (Git for Windows' `master` branch already bumped the minimum Windows version to Vista a while ago, so it is fine.) It is time to require Windows Vista or later to build Git from source. This, incidentally, lets us use quite a few nice new APIs. It also means that we no longer need the inet_pton() and inet_ntop() emulation, which is nice. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-04mingw: set _WIN32_WINNT explicitly for Git for WindowsJohannes Schindelin
Previously, we only ever declared a target Windows version if compiling with Visual C. Which meant that we were relying on the MinGW headers to guess which Windows version we want to target... Let's be explicit about it, in particular because we actually want to bump the target Windows version to Vista (which we will do in the next commit). Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-20Merge branch 'js/typofixes'Junio C Hamano
Comment update. * js/typofixes: remote-curl: remove spurious period git-compat-util.h: fix typo
2018-08-08git-compat-util.h: fix typoJohannes Schindelin
The words "save" and "safe" are both very wonderful words, each with their own set of meanings. Let's not confuse them with one another save on occasion of a pun. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-26automatically ban strcpy()Jeff King
There are a few standard C functions (like strcpy) which are easy to misuse. E.g.: char path[PATH_MAX]; strcpy(path, arg); may overflow the "path" buffer. Sometimes there's an earlier constraint on the size of "arg", but even in such a case it's hard to verify that the code is correct. If the size really is unbounded, you're better off using a dynamic helper like strbuf: struct strbuf path = STRBUF_INIT; strbuf_addstr(path, arg); or if it really is bounded, then use xsnprintf to show your expectation (and get a run-time assertion): char path[PATH_MAX]; xsnprintf(path, sizeof(path), "%s", arg); which makes further auditing easier. We'd usually catch undesirable code like this in a review, but there's no automated enforcement. Adding that enforcement can help us be more consistent and save effort (and a round-trip) during review. This patch teaches the compiler to report an error when it sees strcpy (and will become a model for banning a few other functions). This has a few advantages over a separate linting tool: 1. We know it's run as part of a build cycle, so it's hard to ignore. Whereas an external linter is an extra step the developer needs to remember to do. 2. Likewise, it's basically free since the compiler is parsing the code anyway. 3. We know it's robust against false positives (unlike a grep-based linter). The two big disadvantages are: 1. We'll only check code that is actually compiled, so it may miss code that isn't triggered on your particular system. But since presumably people don't add new code without compiling it (and if they do, the banned function list is the least of their worries), we really only care about failing to clean up old code when adding new functions to the list. And that's easy enough to address with a manual audit when adding a new function (which is what I did for the functions here). 2. If this ends up generating false positives, it's going to be harder to disable (as opposed to a separate linter, which may have mechanisms for overriding a particular case). But the intent is to only ban functions which are obviously bad, and for which we accept using an alternative even when this particular use isn't buggy (e.g., the xsnprintf alternative above). The implementation here is simple: we'll define a macro for the banned function which replaces it with a reference to a descriptively named but undeclared identifier. Replacing it with any invalid code would work (since we just want to break compilation). But ideally we'd meet these goals: - it should be portable; ideally this would trigger everywhere, and does not need to be part of a DEVELOPER=1 setup (because unlike warnings which may depend on the compiler or system, this is a clear indicator of something wrong in the code). - it should generate a readable error that gives the developer a clue what happened - it should avoid generating too much other cruft that makes it hard to see the actual error - it should mention the original callsite in the error The output with this patch looks like this (using gcc 7, on a checkout with 022d2ac1f3 reverted, which removed the final strcpy from blame.c): CC builtin/blame.o In file included from ./git-compat-util.h:1246, from ./cache.h:4, from builtin/blame.c:8: builtin/blame.c: In function ‘cmd_blame’: ./banned.h:11:22: error: ‘sorry_strcpy_is_a_banned_function’ undeclared (first use in this function) #define BANNED(func) sorry_##func##_is_a_banned_function ^~~~~~ ./banned.h:14:21: note: in expansion of macro ‘BANNED’ #define strcpy(x,y) BANNED(strcpy) ^~~~~~ builtin/blame.c:1074:4: note: in expansion of macro ‘strcpy’ strcpy(repeated_meta_color, GIT_COLOR_CYAN); ^~~~~~ ./banned.h:11:22: note: each undeclared identifier is reported only once for each function it appears in #define BANNED(func) sorry_##func##_is_a_banned_function ^~~~~~ ./banned.h:14:21: note: in expansion of macro ‘BANNED’ #define strcpy(x,y) BANNED(strcpy) ^~~~~~ builtin/blame.c:1074:4: note: in expansion of macro ‘strcpy’ strcpy(repeated_meta_color, GIT_COLOR_CYAN); ^~~~~~ This prominently shows the phrase "strcpy is a banned function", along with the original callsite in blame.c and the location of the ban code in banned.h. Which should be enough to get even a developer seeing this for the first time pointed in the right direction. This doesn't match our ideals perfectly, but it's a pretty good balance. A few alternatives I tried: 1. Instead of using an undeclared variable, using an undeclared function. This shortens the message, because the "each undeclared identifier" message is not needed (and as you can see above, it triggers a separate mention of each of the expansion points). But it doesn't actually stop compilation unless you use -Werror=implicit-function-declaration in your CFLAGS. This is the case for DEVELOPER=1, but not for a default build (on the other hand, we'd eventually produce a link error pointing to the correct source line with the descriptive name). 2. The linux kernel uses a similar mechanism in its BUILD_BUG_ON_MSG(), where they actually declare the function but do so with gcc's error attribute. But that's not portable to other compilers (and it also runs afoul of our error() macro). We could make a gcc-specific technique and fallback on other compilers, but it's probably not worth the complexity. It also isn't significantly shorter than the error message shown above. 3. We could drop the BANNED() macro, which would shorten the number of lines in the error. But curiously, removing it (and just expanding strcpy directly to the bogus identifier) causes gcc _not_ to report the original line of code. So this strategy seems to be an acceptable mix of information, portability, simplicity, and robustness, without _too_ much extra clutter. I also tested it with clang, and it looks as good (actually, slightly less cluttered than with gcc). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-30Merge branch 'js/use-bug-macro'Junio C Hamano
Developer support update, by using BUG() macro instead of die() to mark codepaths that should not happen more clearly. * js/use-bug-macro: BUG_exit_code: fix sparse "symbol not declared" warning Convert remaining die*(BUG) messages Replace all die("BUG: ...") calls by BUG() ones run-command: use BUG() to report bugs, not die() test-tool: help verifying BUG() code paths
2018-05-29Sync with Git 2.17.1Junio C Hamano
* maint: (25 commits) Git 2.17.1 Git 2.16.4 Git 2.15.2 Git 2.14.4 Git 2.13.7 fsck: complain when .gitmodules is a symlink index-pack: check .gitmodules files with --strict unpack-objects: call fsck_finish() after fscking objects fsck: call fsck_finish() after fscking objects fsck: check .gitmodules content fsck: handle promisor objects in .gitmodules check fsck: detect gitmodules files fsck: actually fsck blob data fsck: simplify ".git" check index-pack: make fsck error message more specific verify_path: disallow symlinks in .gitmodules update-index: stat updated files earlier verify_dotfile: mention case-insensitivity in comment verify_path: drop clever fallthrough skip_prefix: add case-insensitive variant ...
2018-05-23Merge branch 'nd/repack-keep-pack'Junio C Hamano
"git gc" in a large repository takes a lot of time as it considers to repack all objects into one pack by default. The command has been taught to pretend as if the largest existing packfile is marked with ".keep" so that it is left untouched while objects in other packs and loose ones are repacked. * nd/repack-keep-pack: pack-objects: show some progress when counting kept objects gc --auto: exclude base pack if not enough mem to "repack -ad" gc: handle a corner case in gc.bigPackThreshold gc: add gc.bigPackThreshold config gc: add --keep-largest-pack option repack: add --keep-pack option t7700: have closing quote of a test at the beginning of line
2018-05-22Sync with Git 2.16.4Junio C Hamano
* maint-2.16: Git 2.16.4 Git 2.15.2 Git 2.14.4 Git 2.13.7 verify_path: disallow symlinks in .gitmodules update-index: stat updated files earlier verify_dotfile: mention case-insensitivity in comment verify_path: drop clever fallthrough skip_prefix: add case-insensitive variant is_{hfs,ntfs}_dotgitmodules: add tests is_ntfs_dotgit: match other .git files is_hfs_dotgit: match other .git files is_ntfs_dotgit: use a size_t for traversing string submodule-config: verify submodule names as paths
2018-05-22Sync with Git 2.15.2Junio C Hamano
* maint-2.15: Git 2.15.2 Git 2.14.4 Git 2.13.7 verify_path: disallow symlinks in .gitmodules update-index: stat updated files earlier verify_dotfile: mention case-insensitivity in comment verify_path: drop clever fallthrough skip_prefix: add case-insensitive variant is_{hfs,ntfs}_dotgitmodules: add tests is_ntfs_dotgit: match other .git files is_hfs_dotgit: match other .git files is_ntfs_dotgit: use a size_t for traversing string submodule-config: verify submodule names as paths
2018-05-22Sync with Git 2.14.4Junio C Hamano
* maint-2.14: Git 2.14.4 Git 2.13.7 verify_path: disallow symlinks in .gitmodules update-index: stat updated files earlier verify_dotfile: mention case-insensitivity in comment verify_path: drop clever fallthrough skip_prefix: add case-insensitive variant is_{hfs,ntfs}_dotgitmodules: add tests is_ntfs_dotgit: match other .git files is_hfs_dotgit: match other .git files is_ntfs_dotgit: use a size_t for traversing string submodule-config: verify submodule names as paths
2018-05-22Sync with Git 2.13.7Junio C Hamano
* maint-2.13: Git 2.13.7 verify_path: disallow symlinks in .gitmodules update-index: stat updated files earlier verify_dotfile: mention case-insensitivity in comment verify_path: drop clever fallthrough skip_prefix: add case-insensitive variant is_{hfs,ntfs}_dotgitmodules: add tests is_ntfs_dotgit: match other .git files is_hfs_dotgit: match other .git files is_ntfs_dotgit: use a size_t for traversing string submodule-config: verify submodule names as paths
2018-05-22skip_prefix: add case-insensitive variantJeff King
We have the convenient skip_prefix() helper, but if you want to do case-insensitive matching, you're stuck doing it by hand. We could add an extra parameter to the function to let callers ask for this, but the function is small and somewhat performance-critical. Let's just re-implement it for the case-insensitive version. Signed-off-by: Jeff King <peff@peff.net>
2018-05-10BUG_exit_code: fix sparse "symbol not declared" warningRamsay Jones
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-08Merge branch 'ls/checkout-encoding'Junio C Hamano
The new "checkout-encoding" attribute can ask Git to convert the contents to the specified encoding when checking out to the working tree (and the other way around when checking in). * ls/checkout-encoding: convert: add round trip check based on 'core.checkRoundtripEncoding' convert: add tracing for 'working-tree-encoding' attribute convert: check for detectable errors in UTF encodings convert: add 'working-tree-encoding' attribute utf8: add function to detect a missing UTF-16/32 BOM utf8: add function to detect prohibited UTF-16/32 BOM utf8: teach same_encoding() alternative UTF encoding names strbuf: add a case insensitive starts_with() strbuf: add xstrdup_toupper() strbuf: remove unnecessary NUL assignment in xstrdup_tolower()
2018-05-06Convert remaining die*(BUG) messagesJohannes Schindelin
These were not caught by the previous commit, as they did not match the regular expression. While at it, remove the localization from one instance: we never want BUG() messages to be translated, as they target Git developers, not the end user (hence it would be quite unhelpful to not only burden the translators, but then even end up with a bug report in a language that no core Git contributor understands). Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-16gc --auto: exclude base pack if not enough mem to "repack -ad"Nguyễn Thái Ngọc Duy
pack-objects could be a big memory hog especially on large repos, everybody knows that. The suggestion to stick a .keep file on the giant base pack to avoid this problem is also known for a long time. Recent patches add an option to do just this, but it has to be either configured or activated manually. This patch lets `git gc --auto` activate this mode automatically when it thinks `repack -ad` will use a lot of memory and start affecting the system due to swapping or flushing OS cache. gc --auto decides to do this based on an estimation of pack-objects memory usage, which is quite accurate at least for the heap part, and whether that fits in half of system memory (the assumption here is for desktop environment where there are many other applications running). This mechanism only kicks in if gc.bigBasePackThreshold is not configured. If it is, it is assumed that the user already knows what they want. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-09strbuf: add a case insensitive starts_with()Lars Schneider
Check in a case insensitive manner if one string is a prefix of another string. This function is used in a subsequent commit. Signed-off-by: Lars Schneider <larsxschneider@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-22wrapper: rename 'template' variablesBrandon Williams
Rename C++ keyword in order to bring the codebase closer to being able to be compiled with a C++ compiler. Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-12git-compat-util: introduce skip_to_optional_arg()Christian Couder
We often accept both a "--key" option and a "--key=<val>" option. These options currently are parsed using something like: if (!strcmp(arg, "--key")) { /* do something */ } else if (skip_prefix(arg, "--key=", &arg)) { /* do something with arg */ } which is a bit cumbersome compared to just: if (skip_to_optional_arg(arg, "--key", &arg)) { /* do something with arg */ } This also introduces skip_to_optional_arg_default() for the few cases where something different should be done when the first argument is exactly "--key" than when it is exactly "--key=". In general it is better for UI consistency and simplicity if "--key" and "--key=" do the same thing though, so that using skip_to_optional_arg() should be encouraged compared to skip_to_optional_arg_default(). Note that these functions can be used to parse any "key=value" string where "key" is also considered as valid, not just command line options. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-29Merge branch 'rj/no-sign-compare'Junio C Hamano
Many codepaths have been updated to squelch -Wsign-compare warnings. * rj/no-sign-compare: ALLOC_GROW: avoid -Wsign-compare warnings cache.h: hex2chr() - avoid -Wsign-compare warnings commit-slab.h: avoid -Wsign-compare warnings git-compat-util.h: xsize_t() - avoid -Wsign-compare warnings
2017-09-22git-compat-util.h: xsize_t() - avoid -Wsign-compare warningsRamsay Jones
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-20git-compat-util: make UNLEAK less error-proneJonathan Tan
Commit 0e5bba5 ("add UNLEAK annotation for reducing leak false positives", 2017-09-08) introduced an UNLEAK macro to be used as "UNLEAK(var);", but its existing definitions leave semicolons that act as empty statements, which will lead to syntax errors, e.g. if (condition) UNLEAK(var); else something_else(var); would be broken with two statements between if (condition) and else. Lose the excess semicolon from the end of the macro replacement text. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-08add UNLEAK annotation for reducing leak false positivesJeff King
It's a common pattern in git commands to allocate some memory that should last for the lifetime of the program and then not bother to free it, relying on the OS to throw it away. This keeps the code simple, and it's fast (we don't waste time traversing structures or calling free at the end of the program). But it also triggers warnings from memory-leak checkers like valgrind or LSAN. They know that the memory was still allocated at program exit, but they don't know _when_ the leaked memory stopped being useful. If it was early in the program, then it's probably a real and important leak. But if it was used right up until program exit, it's not an interesting leak and we'd like to suppress it so that we can see the real leaks. This patch introduces an UNLEAK() macro that lets us do so. To understand its design, let's first look at some of the alternatives. Unfortunately the suppression systems offered by leak-checking tools don't quite do what we want. A leak-checker basically knows two things: 1. Which blocks were allocated via malloc, and the callstack during the allocation. 2. Which blocks were left un-freed at the end of the program (and which are unreachable, but more on that later). Their suppressions work by mentioning the function or callstack of a particular allocation, and marking it as OK to leak. So imagine you have code like this: int cmd_foo(...) { /* this allocates some memory */ char *p = some_function(); printf("%s", p); return 0; } You can say "ignore allocations from some_function(), they're not leaks". But that's not right. That function may be called elsewhere, too, and we would potentially want to know about those leaks. So you can say "ignore the callstack when main calls some_function". That works, but your annotations are brittle. In this case it's only two functions, but you can imagine that the actual allocation is much deeper. If any of the intermediate code changes, you have to update the suppression. What we _really_ want to say is that "the value assigned to p at the end of the function is not a real leak". But leak-checkers can't understand that; they don't know about "p" in the first place. However, we can do something a little bit tricky if we make some assumptions about how leak-checkers work. They generally don't just report all un-freed blocks. That would report even globals which are still accessible when the leak-check is run. Instead they take some set of memory (like BSS) as a root and mark it as "reachable". Then they scan the reachable blocks for anything that looks like a pointer to a malloc'd block, and consider that block reachable. And then they scan those blocks, and so on, transitively marking anything reachable from a global as "not leaked" (or at least leaked in a different category). So we can mark the value of "p" as reachable by putting it into a variable with program lifetime. One way to do that is to just mark "p" as static. But that actually affects the run-time behavior if the function is called twice (you aren't likely to call main() twice, but some of our cmd_*() functions are called from other commands). Instead, we can trick the leak-checker by putting the value into _any_ reachable bytes. This patch keeps a global linked-list of bytes copied from "unleaked" variables. That list is reachable even at program exit, which confers recursive reachability on whatever values we unleak. In other words, you can do: int cmd_foo(...) { char *p = some_function(); printf("%s", p); UNLEAK(p); return 0; } to annotate "p" and suppress the leak report. But wait, couldn't we just say "free(p)"? In this toy example, yes. But UNLEAK()'s byte-copying strategy has several advantages over actually freeing the memory: 1. It's recursive across structures. In many cases our "p" is not just a pointer, but a complex struct whose fields may have been allocated by a sub-function. And in some cases (e.g., dir_struct) we don't even have a function which knows how to free all of the struct members. By marking the struct itself as reachable, that confers reachability on any pointers it contains (including those found in embedded structs, or reachable by walking heap blocks recursively. 2. It works on cases where we're not sure if the value is allocated or not. For example: char *p = argc > 1 ? argv[1] : some_function(); It's safe to use UNLEAK(p) here, because it's not freeing any memory. In the case that we're pointing to argv here, the reachability checker will just ignore our bytes. 3. Likewise, it works even if the variable has _already_ been freed. We're just copying the pointer bytes. If the block has been freed, the leak-checker will skip over those bytes as uninteresting. 4. Because it's not actually freeing memory, you can UNLEAK() before we are finished accessing the variable. This is helpful in cases like this: char *p = some_function(); return another_function(p); Writing this with free() requires: int ret; char *p = some_function(); ret = another_function(p); free(p); return ret; But with unleak we can just write: char *p = some_function(); UNLEAK(p); return another_function(p); This patch adds the UNLEAK() macro and enables it automatically when Git is compiled with SANITIZE=leak. In normal builds it's a noop, so we pay no runtime cost. It also adds some UNLEAK() annotations to show off how the feature works. On top of other recent leak fixes, these are enough to get t0000 and t0001 to pass when compiled with LSAN. Note the case in commit.c which actually converts a strbuf_release() into an UNLEAK. This code was already non-leaky, but the free didn't do anything useful, since we're exiting. Converting it to an annotation means that non-leak-checking builds pay no runtime cost. The cost is minimal enough that it's probably not worth going on a crusade to convert these kinds of frees to UNLEAKS. I did it here for consistency with the "sb" leak (though it would have been equally correct to go the other way, and turn them both into strbuf_release() calls). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-08-23pack: move release_pack_memory()Jonathan Tan
The function unuse_one_window() needs to be temporarily made global. Its scope will be restored to static in a subsequent commit. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-08-23Merge branch 'rs/move-array' into maintJunio C Hamano
Code clean-up. * rs/move-array: ls-files: don't try to prune an empty index apply: use COPY_ARRAY and MOVE_ARRAY in update_image() use MOVE_ARRAY add MOVE_ARRAY
2017-08-11Merge branch 'rs/move-array'Junio C Hamano
Code clean-up. * rs/move-array: ls-files: don't try to prune an empty index apply: use COPY_ARRAY and MOVE_ARRAY in update_image() use MOVE_ARRAY add MOVE_ARRAY
2017-07-18Merge branch 'tb/push-to-cygwin-unc-path'Junio C Hamano
On Cygwin, similar to Windows, "git push //server/share/repository" ought to mean a repository on a network share that can be accessed locally, but this did not work correctly due to stripping the double slashes at the beginning. This may need to be heavily tested before it gets unleashed to the wild, as the change is at a fairly low-level code and would affect not just the code to decide if the push destination is local. There may be unexpected fallouts in the path normalization. * tb/push-to-cygwin-unc-path: cygwin: allow pushing to UNC paths
2017-07-17add MOVE_ARRAYRené Scharfe
Similar to COPY_ARRAY (introduced in 60566cbb58), add a safe and convenient helper for moving potentially overlapping ranges of array entries. It infers the element size, multiplies automatically and safely to get the size in bytes, does a basic type safety check by comparing element sizes and unlike memmove(3) it supports NULL pointers iff 0 elements are to be moved. Also add a semantic patch to demonstrate the helper's intended usage. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-07-05cygwin: allow pushing to UNC pathsTorsten Bögershausen
cygwin can use an UNC path like //server/share/repo $ cd //server/share/dir $ mkdir test $ cd test $ git init --bare However, when we try to push from a local Git repository to this repo, there is a problem: Git converts the leading "//" into a single "/". As cygwin handles an UNC path so well, Git can support them better: - Introduce cygwin_offset_1st_component() which keeps the leading "//", similar to what Git for Windows does. - Move CYGWIN out of the POSIX in the tests for path normalization in t0060 Signed-off-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-15git-compat-util: add a FREE_AND_NULL() wrapper around free(ptr); ptr = NULLÆvar Arnfjörð Bjarmason
Add a FREE_AND_NULL() wrapper marco for the common pattern of freeing a pointer and assigning NULL to it right afterwards. The implementation is similar to the (currently unused) XDL_PTRFREE macro in xdiff/xmacros.h added in commit 3443546f6e ("Use a *real* built-in diff generator", 2006-03-24). The only difference is that free() is called unconditionally, see [1]. See [2] for a suggested alternative which does this via a function instead of a macro. As covered in replies to that message, while it's a viable approach, it would introduce caveats which this approach doesn't have, so that potential change is left to a future follow-up change. This merely allows us to translate exactly what we're doing now to a less verbose & idiomatic form using a macro, while guaranteeing that we don't introduce any functional changes. 1. <alpine.DEB.2.20.1608301948310.129229@virtualbox> (http://public-inbox.org/git/alpine.DEB.2.20.1608301948310.129229@virtualbox/) 2. <20170610032143.GA7880@starla> (https://public-inbox.org/git/20170610032143.GA7880@starla/) Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-13Merge branch 'nd/fopen-errors'Junio C Hamano
We often try to open a file for reading whose existence is optional, and silently ignore errors from open/fopen; report such errors if they are not due to missing files. * nd/fopen-errors: mingw_fopen: report ENOENT for invalid file names mingw: verify that paths are not mistaken for remote nicknames log: fix memory leak in open_next_file() rerere.c: move error_errno() closer to the source system call print errno when reporting a system call error wrapper.c: make warn_on_inaccessible() static wrapper.c: add and use fopen_or_warn() wrapper.c: add and use warn_on_fopen_errors() config.mak.uname: set FREAD_READS_DIRECTORIES for Darwin, too config.mak.uname: set FREAD_READS_DIRECTORIES for Linux and FreeBSD clone: use xfopen() instead of fopen() use xfopen() in more places git_fopen: fix a sparse 'not declared' warning
2017-06-13Merge branch 'jc/noent-notdir'Junio C Hamano
Our code often opens a path to an optional file, to work on its contents when we can successfully open it. We can ignore a failure to open if such an optional file does not exist, but we do want to report a failure in opening for other reasons (e.g. we got an I/O error, or the file is there, but we lack the permission to open). The exact errors we need to ignore are ENOENT (obviously) and ENOTDIR (less obvious). Instead of repeating comparison of errno with these two constants, introduce a helper function to do so. * jc/noent-notdir: treewide: use is_missing_file_error() where ENOENT and ENOTDIR are checked compat-util: is_missing_file_error()
2017-06-13Merge branch 'bw/forking-and-threading' into maintJunio C Hamano
The "run-command" API implementation has been made more robust against dead-locking in a threaded environment. * bw/forking-and-threading: usage.c: drop set_error_handle() run-command: restrict PATH search to executable files run-command: expose is_executable function run-command: block signals between fork and execve run-command: add note about forking and threading run-command: handle dup2 and close errors in child run-command: eliminate calls to error handling functions in child run-command: don't die in child when duping /dev/null run-command: prepare child environment before forking string-list: add string_list_remove function run-command: use the async-signal-safe execv instead of execvp run-command: prepare command before forking t0061: run_command executes scripts without a #! line t5550: use write_script to generate post-update hook