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2018-05-23Merge branch 'tg/worktree-add-existing-branch'Libravatar Junio C Hamano1-27/+74
"git worktree add" learned to check out an existing branch. * tg/worktree-add-existing-branch: worktree: teach "add" to check out existing branches worktree: factor out dwim_branch function worktree: improve message when creating a new worktree worktree: remove extra members from struct add_opts
2018-05-08Merge branch 'sb/worktree-remove-opt-force'Libravatar Junio C Hamano1-2/+3
"git worktree remove" learned that "-f" is a shorthand for "--force" option, just like for "git worktree add". * sb/worktree-remove-opt-force: worktree: accept -f as short for --force for removal
2018-04-30worktree: teach "add" to check out existing branchesLibravatar Thomas Gummerer1-2/+11
Currently 'git worktree add <path>' creates a new branch named after the basename of the path by default. If a branch with that name already exists, the command refuses to do anything, unless the '--force' option is given. However we can do a little better than that, and check the branch out if it is not checked out anywhere else. This will help users who just want to check an existing branch out into a new worktree, and save a few keystrokes. As the current behaviour is to simply 'die()' when a branch with the name of the basename of the path already exists, there are no backwards compatibility worries here. We will still 'die()' if the branch is checked out in another worktree, unless the --force flag is passed. Helped-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com> Reviewed-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-30worktree: factor out dwim_branch functionLibravatar Thomas Gummerer1-11/+18
Factor out a dwim_branch function, which takes care of the dwim'ery in 'git worktree add <path>'. It's not too much code currently, but we're adding a new kind of dwim in a subsequent patch, at which point it makes more sense to have it as a separate function. Factor it out now to reduce the patch noise in the next patch. Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com> Reviewed-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-30worktree: improve message when creating a new worktreeLibravatar Thomas Gummerer1-2/+36
Currently 'git worktree add' produces output like the following: Preparing ../foo (identifier foo) HEAD is now at 26da330922 <title> The '../foo' is the path where the worktree is created, which the user has just given on the command line. The identifier is an internal implementation detail, which is not particularly relevant for the user and indeed isn't mentioned explicitly anywhere in the man page. Instead of this message, print a message that gives the user a bit more detail of what exactly 'git worktree' is doing. There are various dwim modes which perform some magic under the hood, which should be helpful to users. Just from the output of the command it is not always visible to users what exactly has happened. Help the users a bit more by modifying the "Preparing ..." message and adding some additional information of what 'git worktree add' did under the hood, while not displaying the identifier anymore. Currently there are several different cases: - 'git worktree add -b ...' or 'git worktree add <path>', both of which create a new branch, either through the user explicitly requesting it, or through 'git worktree add' implicitly creating it. This will end up with the following output: Preparing worktree (new branch '<branch>') HEAD is now at 26da330922 <title> - 'git worktree add -B ...', which may either create a new branch if the branch with the given name does not exist yet, or resets an existing branch to the current HEAD, or the commit-ish given. Depending on which action is taken, we'll end up with the following output: Preparing worktree (resetting branch '<branch>'; was at caa68db14) HEAD is now at 26da330922 <title> or: Preparing worktree (new branch '<branch>') HEAD is now at 26da330922 <title> - 'git worktree add --detach' or 'git worktree add <path> <commit-ish>', both of which create a new worktree with a detached HEAD, for which we will print the following output: Preparing worktree (detached HEAD 26da330922) HEAD is now at 26da330922 <title> - 'git worktree add <path> <local-branch>', which checks out the branch and prints the following output: Preparing worktree (checking out '<local-branch>') HEAD is now at 47007d5 <title> Additionally currently the "Preparing ..." line is printed to stderr, while the "HEAD is now at ..." line is printed to stdout by 'git reset --hard', which is used internally by 'git worktree add'. Fix this inconsistency by printing the "Preparing ..." message to stdout as well. As "Preparing ..." is not an error, stdout also seems like the more appropriate output stream. Helped-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com> Reviewed-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-30worktree: remove extra members from struct add_optsLibravatar Thomas Gummerer1-17/+16
There are two members of 'struct add_opts', which are only used inside the 'add()' function, but being part of 'struct add_opts' they are needlessly also passed to the 'add_worktree' function. Make them local to the 'add()' function to make it clearer where they are used. Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com> Reviewed-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-18worktree: accept -f as short for --force for removalLibravatar Stefan Beller1-2/+3
Many commands support a "--force" option, frequently abbreviated as "-f", however, "git worktree remove"'s hand-rolled OPT_BOOL forgets to recognize the short form, despite git-worktree.txt documenting "-f" as supported. Replace OPT_BOOL with OPT__FORCE, which provides "-f" for free, and makes 'remove' consistent with 'add' option parsing (which also specifies the PARSE_OPT_NOCOMPLETE flag). Helped-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-10Merge branch 'nd/worktree-prune'Libravatar Junio C Hamano1-9/+2
The way "git worktree prune" worked internally has been simplified, by assuming how "git worktree move" moves an existing worktree to a different place. * nd/worktree-prune: worktree prune: improve prune logic when worktree is moved worktree: delete dead code gc.txt: more details about what gc does
2018-04-10Merge branch 'bc/object-id'Libravatar Junio C Hamano1-2/+2
Conversion from uchar[20] to struct object_id continues. * bc/object-id: (36 commits) convert: convert to struct object_id sha1_file: introduce a constant for max header length Convert lookup_replace_object to struct object_id sha1_file: convert read_sha1_file to struct object_id sha1_file: convert read_object_with_reference to object_id tree-walk: convert tree entry functions to object_id streaming: convert istream internals to struct object_id tree-walk: convert get_tree_entry_follow_symlinks internals to object_id builtin/notes: convert static functions to object_id builtin/fmt-merge-msg: convert remaining code to object_id sha1_file: convert sha1_object_info* to object_id Convert remaining callers of sha1_object_info_extended to object_id packfile: convert unpack_entry to struct object_id sha1_file: convert retry_bad_packed_offset to struct object_id sha1_file: convert assert_sha1_type to object_id builtin/mktree: convert to struct object_id streaming: convert open_istream to use struct object_id sha1_file: convert check_sha1_signature to struct object_id sha1_file: convert read_loose_object to use struct object_id builtin/index-pack: convert struct ref_delta_entry to object_id ...
2018-03-15worktree prune: improve prune logic when worktree is movedLibravatar Nguyễn Thái Ngọc Duy1-1/+2
Automatic detection of worktree relocation by a user (via 'mv', for instance) was removed by 618244e160 (worktree: stop supporting moving worktrees manually - 2016-01-22). Prior to that, .git/worktrees/<tag>/gitdir was updated whenever the worktree was accessed in order to let the pruning logic know that the worktree was "active" even if it disappeared for a while (due to being located on removable media, for instance). "git worktree move" has come so we don't really need this, but since it's easy to do, perhaps we could keep supporting manual worktree move a bit longer. Notice that when a worktree is active, the "index" file should be updated pretty often in common case. The logic is updated to check for index mtime to see if the worktree is alive. The old logic of checking gitdir's mtime is dropped because nobody updates it anyway. The new corner case is, if the index file does not exist, we immediately remove the stale worktree. But if the "index" file does not exist, you may have a bigger problem. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-15worktree: delete dead codeLibravatar Nguyễn Thái Ngọc Duy1-8/+0
This "link" was a feature in early iterations of multiple worktree functionality for some reason it was dropped [1]. Since nobody creates this "link", there's no need to check it. This is mostly used to let the user moves a worktree manually [2]. If you move a worktree within the same file system, this hard link count lets us know the worktree is still there even if we don't know where it is. We support 'worktree move' now and don't need this anymore. [1] last appearance in v4 message-id: 1393675983-3232-25-git-send-email-pclouds@gmail.com and the reason in v5 was "revisit later", message-id: 1394246900-31535-1-git-send-email-pclouds@gmail.com [2] 23af91d102 (prune: strategies for linked checkouts - 2014-11-30) Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-14Merge branch 'nd/parseopt-completion'Libravatar Junio C Hamano1-1/+3
Teach parse-options API an option to help the completion script, and make use of the mechanism in command line completion. * nd/parseopt-completion: (45 commits) completion: more subcommands in _git_notes() completion: complete --{reuse,reedit}-message= for all notes subcmds completion: simplify _git_notes completion: don't set PARSE_OPT_NOCOMPLETE on --rerere-autoupdate completion: use __gitcomp_builtin in _git_worktree completion: use __gitcomp_builtin in _git_tag completion: use __gitcomp_builtin in _git_status completion: use __gitcomp_builtin in _git_show_branch completion: use __gitcomp_builtin in _git_rm completion: use __gitcomp_builtin in _git_revert completion: use __gitcomp_builtin in _git_reset completion: use __gitcomp_builtin in _git_replace remote: force completing --mirror= instead of --mirror completion: use __gitcomp_builtin in _git_remote completion: use __gitcomp_builtin in _git_push completion: use __gitcomp_builtin in _git_pull completion: use __gitcomp_builtin in _git_notes completion: use __gitcomp_builtin in _git_name_rev completion: use __gitcomp_builtin in _git_mv completion: use __gitcomp_builtin in _git_merge_base ...
2018-03-14Merge branch 'nd/worktree-move'Libravatar Junio C Hamano1-0/+220
"git worktree" learned move and remove subcommands. * nd/worktree-move: t2028: fix minor error and issues in newly-added "worktree move" tests worktree remove: allow it when $GIT_WORK_TREE is already gone worktree remove: new command worktree move: refuse to move worktrees with submodules worktree move: accept destination as directory worktree move: new command worktree.c: add update_worktree_location() worktree.c: add validate_worktree()
2018-03-14Convert find_unique_abbrev* to struct object_idLibravatar brian m. carlson1-2/+2
Convert find_unique_abbrev and find_unique_abbrev_r to each take a pointer to struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-28Merge branch 'es/worktree-add-post-checkout-hook'Libravatar Junio C Hamano1-3/+17
"git worktree add" learned to run the post-checkout hook, just like "git clone" runs it upon the initial checkout. * es/worktree-add-post-checkout-hook: worktree: add: fix 'post-checkout' not knowing new worktree location
2018-02-15Merge branch 'jc/worktree-add-short-help'Libravatar Junio C Hamano1-1/+1
Error message fix. * jc/worktree-add-short-help: worktree: say that "add" takes an arbitrary commit in short-help
2018-02-15worktree: add: fix 'post-checkout' not knowing new worktree locationLibravatar Eric Sunshine1-3/+17
Although "git worktree add" learned to run the 'post-checkout' hook in ade546be47 (worktree: invoke post-checkout hook, 2017-12-07), it neglected to change to the directory of the newly-created worktree before running the hook. Instead, the hook runs within the directory from which the "git worktree add" command itself was invoked, which effectively neuters the hook since it knows nothing about the new worktree directory. Further, ade546be47 failed to sanitize the environment before running the hook, which means that user-assigned values of GIT_DIR and GIT_WORK_TREE could mislead the hook about the location of the new worktree. In the case of "git worktree add" being run from a bare repository, the GIT_DIR="." assigned by Git itself leaks into the hook's environment and breaks Git commands; this is so even when the working directory is correctly changed to the new worktree before the hook runs since ".", relative to the new worktree directory, does not point at the bare repository. Fix these problems by (1) changing to the new worktree's directory before running the hook, and (2) sanitizing the environment of GIT_DIR and GIT_WORK_TREE so hooks can't be confused by misleading values. Enhance the t2025 'post-checkout' tests to verify that the hook is indeed run within the correct directory and that Git commands invoked by the hook compute Git-dir and top-level worktree locations correctly. While at it, also add two new tests: (1) verify that the hook is run within the correct directory even when the new worktree is created from a sibling worktree (as opposed to the main worktree); (2) verify that the hook is provided with correct context when the new worktree is created from a bare repository (test provided by Lars Schneider). Implementation Notes: Rather than sanitizing the environment of GIT_DIR and GIT_WORK_TREE, an alternative would be to set them explicitly, as is already done for other Git commands run internally by "git worktree add". This patch opts instead to sanitize the environment in order to clearly document that the worktree is fully functional by the time the hook is run, thus does not require special environmental overrides. The hook is run manually, rather than via run_hook_le(), since it needs to change the working directory to that of the worktree, and run_hook_le() does not provide such functionality. As this is a one-off case, adding 'run_hook' overloads which allow the directory to be set does not seem warranted at this time. Reported-by: Lars Schneider <larsxschneider@gmail.com> Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-12worktree remove: allow it when $GIT_WORK_TREE is already goneLibravatar Nguyễn Thái Ngọc Duy1-5/+7
"git worktree remove" basically consists of two things - delete $GIT_WORK_TREE - delete $GIT_DIR (which is $SUPER_GIT_DIR/worktrees/something) If $GIT_WORK_TREE is already gone for some reason, we should be able to finish the job by deleting $GIT_DIR. Two notes: - $GIT_WORK_TREE _can_ be missing if the worktree is locked. In that case we must not delete $GIT_DIR because the real $GIT_WORK_TREE may be in a usb stick somewhere. This is already handled because we check for lock first. - validate_worktree() is still called because it may do more checks in future (and it already does something else, like checking main worktree, but that's irrelevant in this case) Noticed-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-12worktree remove: new commandLibravatar Nguyễn Thái Ngọc Duy1-1/+133
This command allows to delete a worktree. Like 'move' you cannot remove the main worktree, or one with submodules inside [1]. For deleting $GIT_WORK_TREE, Untracked files or any staged entries are considered precious and therefore prevent removal by default. Ignored files are not precious. When it comes to deleting $GIT_DIR, there's no "clean" check because there should not be any valuable data in there, except: - HEAD reflog. There is nothing we can do about this until somebody steps up and implements the ref graveyard. - Detached HEAD. Technically it can still be recovered. Although it may be nice to warn about orphan commits like 'git checkout' does. [1] We do 'git status' with --ignore-submodules=all for safety anyway. But this needs a closer look by submodule people before we can allow deletion. For example, if a submodule is totally clean, but its repo not absorbed to the main .git dir, then deleting worktree also deletes the valuable .submodule repo too. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-12worktree move: refuse to move worktrees with submodulesLibravatar Nguyễn Thái Ngọc Duy1-0/+23
Submodules contains .git files with relative paths. After a worktree move, these files need to be updated or they may point to nowhere. This is a bandage patch to make sure "worktree move" don't break people's worktrees by accident. When .git file update code is in place, this validate_no_submodules() could be removed. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-12worktree move: accept destination as directoryLibravatar Nguyễn Thái Ngọc Duy1-1/+10
Similar to "mv a b/", which is actually "mv a b/a", we extract basename of source worktree and create a directory of the same name at destination if dst path is a directory. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-12worktree move: new commandLibravatar Nguyễn Thái Ngọc Duy1-0/+53
This command allows to relocate linked worktrees. Main worktree cannot (yet) be moved. There are two options to move the main worktree, but both have complications, so it's not implemented yet. Anyway the options are: - convert the main worktree to a linked one and move it away, leave the git repository where it is. The repo essentially becomes bare after this move. - move the repository with the main worktree. The tricky part is make sure all file descriptors to the repository are closed, or it may fail on Windows. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-09completion: use __gitcomp_builtin in _git_worktreeLibravatar Nguyễn Thái Ngọc Duy1-1/+1
The new completable options for "worktree add" are: --checkout --guess-remote --lock --track Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-09parse-options: let OPT__FORCE take optional flags argumentLibravatar Nguyễn Thái Ngọc Duy1-1/+3
--force option is most likely hidden from command line completion for safety reasons. This is done by adding an extra flag PARSE_OPT_NOCOMPLETE. Update OPT__FORCE() to accept additional flags. Actual flag change comes later depending on individual commands. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-01-17worktree: say that "add" takes an arbitrary commit in short-helpLibravatar Junio C Hamano1-1/+1
c4738aed ("worktree: add can be created from any commit-ish", 2017-11-26) taught "git worktree add" to start a new worktree with an arbitrary commit-ish checked out, not limited to a tip of a branch. "git worktree --help" was updated to describe this, but we forgot to update "git worktree -h". Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-27Merge branch 'es/worktree-checkout-hook'Libravatar Junio C Hamano1-6/+16
"git worktree add" learned to run the post-checkout hook, just like "git checkout" does, after the initial checkout. * es/worktree-checkout-hook: worktree: invoke post-checkout hook (unless --no-checkout)
2017-12-07worktree: invoke post-checkout hook (unless --no-checkout)Libravatar Eric Sunshine1-6/+16
git-clone and git-checkout both invoke the post-checkout hook following a successful checkout, yet git-worktree neglects to do so even though it too "checks out" the worktree. Fix this oversight. Implementation note: The newly-created worktree may reference a branch or be detached. In the latter case, a commit lookup is performed, though the result is used only in a boolean sense to (a) determine if the commit actually exists, and (b) assign either the branch name or commit ID to HEAD. Since the post-commit hook needs to know the ID of the checked-out commit, the lookup now needs to be done in all cases, rather than only when detached. Consequently, a new boolean is needed to handle (b) since the lookup result itself can no longer perform that role. Reported-by: Matthew K Gumbel <matthew.k.gumbel@intel.com> Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-06add worktree.guessRemote config optionLibravatar Thomas Gummerer1-2/+12
Some users might want to have the --guess-remote option introduced in the previous commit on by default, so they don't have to type it out every time they create a new worktree. Add a config option worktree.guessRemote that allows users to configure the default behaviour for themselves. Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-06worktree: add --guess-remote flag to add subcommandLibravatar Thomas Gummerer1-0/+10
Currently 'git worktree add <path>' creates a new branch named after the basename of the <path>, that matches the HEAD of whichever worktree we were on when calling "git worktree add <path>". It's sometimes useful to have 'git worktree add <path> behave more like the dwim machinery in 'git checkout <new-branch>', i.e. check if the new branch name, derived from the basename of the <path>, uniquely matches the branch name of a remote-tracking branch, and if so check out that branch and set the upstream to the remote-tracking branch. Add a new --guess-remote option that enables exactly that behaviour. Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-27worktree: make add <path> <branch> dwimLibravatar Thomas Gummerer1-0/+16
Currently 'git worktree add <path> <branch>', errors out when 'branch' is not a local branch. It has no additional dwim'ing features that one might expect. Make it behave more like 'git checkout <branch>' when the branch doesn't exist locally, but a remote tracking branch uniquely matches the desired branch name, i.e. create a new branch from the remote tracking branch and set the upstream to the remote tracking branch. As 'git worktree add' currently just dies in this situation, there are no backwards compatibility worries when introducing this feature. Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-27worktree: add --[no-]track option to the add subcommandLibravatar Thomas Gummerer1-0/+8
Currently 'git worktree add' sets up tracking branches if '<branch>' is a remote tracking branch, and doesn't set them up otherwise, as is the default for 'git branch'. This may or may not be what the user wants. Allow overriding this behaviour with a --[no-]track flag that gets passed through to 'git branch'. We already respect branch.autoSetupMerge, as 'git worktree' just calls 'git branch' internally. Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16worktree: convert struct worktree to object_idLibravatar brian m. carlson1-3/+3
Convert the head_sha1 member to be head_oid instead. This is required to convert resolve_ref_unsafe. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-27worktree: check the result of read_in_full()Libravatar Jeff King1-1/+18
We try to read "len" bytes into a buffer and just assume that it happened correctly. In practice this should usually be the case, since we just stat'd the file to get the length. But we could be fooled by transient errors or by other processes racily truncating the file. Let's be more careful. There's a slim chance this could catch a real error, but it also prevents people and tools from getting worried while reading the code. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-27worktree: use xsize_t to access file sizeLibravatar Jeff King1-2/+3
To read the "gitdir" file into memory, we stat the file and allocate a buffer. But we store the size in an "int", which may be truncated. We should use a size_t and xsize_t(), which will detect truncation. An overflow is unlikely for a "gitdir" file, but it's a good practice to model. Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-08add UNLEAK annotation for reducing leak false positivesLibravatar Jeff King1-0/+2
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>
2017-06-24Merge branch 'ab/free-and-null'Libravatar Junio C Hamano1-4/+2
A common pattern to free a piece of memory and assign NULL to the pointer that used to point at it has been replaced with a new FREE_AND_NULL() macro. * ab/free-and-null: *.[ch] refactoring: make use of the FREE_AND_NULL() macro coccinelle: make use of the "expression" FREE_AND_NULL() rule coccinelle: add a rule to make "expression" code use FREE_AND_NULL() coccinelle: make use of the "type" FREE_AND_NULL() rule coccinelle: add a rule to make "type" code use FREE_AND_NULL() git-compat-util: add a FREE_AND_NULL() wrapper around free(ptr); ptr = NULL
2017-06-24Merge branch 'bw/config-h'Libravatar Junio C Hamano1-0/+1
Fix configuration codepath to pay proper attention to commondir that is used in multi-worktree situation, and isolate config API into its own header file. * bw/config-h: config: don't implicitly use gitdir or commondir config: respect commondir setup: teach discover_git_directory to respect the commondir config: don't include config.h by default config: remove git_config_iter config: create config.h
2017-06-16*.[ch] refactoring: make use of the FREE_AND_NULL() macroLibravatar Ævar Arnfjörð Bjarmason1-4/+2
Replace occurrences of `free(ptr); ptr = NULL` which weren't caught by the coccinelle rule. These fall into two categories: - free/NULL assignments one after the other which coccinelle all put on one line, which is functionally equivalent code, but very ugly. - manually spotted occurrences where the NULL assignment isn't right after the free() call. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-15config: don't include config.h by defaultLibravatar Brandon Williams1-0/+1
Stop including config.h by default in cache.h. Instead only include config.h in those files which require use of the config system. Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-29Merge branch 'js/plug-leaks'Libravatar Junio C Hamano1-3/+5
Fix memory leaks pointed out by Coverity (and people). * js/plug-leaks: (26 commits) checkout: fix memory leak submodule_uses_worktrees(): plug memory leak show_worktree(): plug memory leak name-rev: avoid leaking memory in the `deref` case remote: plug memory leak in match_explicit() add_reflog_for_walk: avoid memory leak shallow: avoid memory leak line-log: avoid memory leak receive-pack: plug memory leak in update() fast-export: avoid leaking memory in handle_tag() mktree: plug memory leaks reported by Coverity pack-redundant: plug memory leak setup_discovered_git_dir(): plug memory leak setup_bare_git_dir(): help static analysis split_commit_in_progress(): simplify & fix memory leak checkout: fix memory leak cat-file: fix memory leak mailinfo & mailsplit: check for EOF while parsing status: close file descriptor after reading git-rebase-todo difftool: address a couple of resource/memory leaks ...
2017-05-16Merge branch 'js/larger-timestamps'Libravatar Junio C Hamano1-2/+2
Some platforms have ulong that is smaller than time_t, and our historical use of ulong for timestamp would mean they cannot represent some timestamp that the platform allows. Invent a separate and dedicated timestamp_t (so that we can distingiuish timestamps and a vanilla ulongs, which along is already a good move), and then declare uintmax_t is the type to be used as the timestamp_t. * js/larger-timestamps: archive-tar: fix a sparse 'constant too large' warning use uintmax_t for timestamps date.c: abort if the system time cannot handle one of our timestamps timestamp_t: a new data type for timestamps PRItime: introduce a new "printf format" for timestamps parse_timestamp(): specify explicitly where we parse timestamps t0006 & t5000: skip "far in the future" test when time_t is too limited t0006 & t5000: prepare for 64-bit timestamps ref-filter: avoid using `unsigned long` for catch-all data type
2017-05-08show_worktree(): plug memory leakLibravatar Johannes Schindelin1-3/+5
The buffer allocated by shorten_unambiguous_ref() needs to be released. Discovered by Coverity. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-27timestamp_t: a new data type for timestampsLibravatar Johannes Schindelin1-2/+2
Git's source code assumes that unsigned long is at least as precise as time_t. Which is incorrect, and causes a lot of problems, in particular where unsigned long is only 32-bit (notably on Windows, even in 64-bit versions). So let's just use a more appropriate data type instead. In preparation for this, we introduce the new `timestamp_t` data type. By necessity, this is a very, very large patch, as it has to replace all timestamps' data type in one go. As we will use a data type that is not necessarily identical to `time_t`, we need to be very careful to use `time_t` whenever we interact with the system functions, and `timestamp_t` everywhere else. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-26Merge branch 'nd/worktree-add-lock'Libravatar Junio C Hamano1-4/+11
Allow to lock a worktree immediately after it's created. This helps prevent a race between "git worktree add; git worktree lock" and "git worktree prune". * nd/worktree-add-lock: worktree add: add --lock option
2017-04-26Merge branch 'jk/war-on-git-path'Libravatar Junio C Hamano1-4/+2
While handy, "git_path()" is a dangerous function to use as a callsite that uses it safely one day can be broken by changes to other code that calls it. Reduction of its use continues. * jk/war-on-git-path: am: drop "dir" parameter from am_state_init replace strbuf_addstr(git_path()) with git_path_buf() replace xstrdup(git_path(...)) with git_pathdup(...) use git_path_* helper functions branch: add edit_description() helper bisect: add git_path_bisect_terms helper
2017-04-20replace strbuf_addstr(git_path()) with git_path_buf()Libravatar Jeff King1-4/+2
Writing directly into the strbuf avoids a useless copy of the data, and dropping calls to git_path() makes it easier to audit for dangerous calls. Note that git_path() does an implicit strbuf_reset(), but in each of these cases we were either already doing that reset, or writing into a fresh strbuf anyway. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-20worktree add: add --lock optionLibravatar Nguyễn Thái Ngọc Duy1-4/+11
As explained in the document. This option has an advantage over the command sequence "git worktree add && git worktree lock": there will be no gap that somebody can accidentally "prune" the new worktree (or soon, explicitly "worktree remove" it). "worktree add" does keep a lock on while it's preparing the worktree. If --lock is specified, this lock remains after the worktree is created. Suggested-by: David Taylor <David.Taylor@dell.com> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-21prefix_filename: return newly allocated stringLibravatar Jeff King1-1/+2
The prefix_filename() function returns a pointer to static storage, which makes it easy to use dangerously. We already fixed one buggy caller in hash-object recently, and the calls in apply.c are suspicious (I didn't dig in enough to confirm that there is a bug, but we call the function once in apply_all_patches() and then again indirectly from parse_chunk()). Let's make it harder to get wrong by allocating the return value. For simplicity, we'll do this even when the prefix is empty (and we could just return the original file pointer). That will cause us to allocate sometimes when we wouldn't otherwise need to, but this function isn't called in performance critical code-paths (and it already _might_ allocate on any given call, so a caller that cares about performance is questionable anyway). The downside is that the callers need to remember to free() the result to avoid leaking. Most of them already used xstrdup() on the result, so we know they are OK. The remainder have been converted to use free() as appropriate. I considered retaining a prefix_filename_unsafe() for cases where we know the static lifetime is OK (and handling the cleanup is awkward). This is only a handful of cases, though, and it's not worth the mental energy in worrying about whether the "unsafe" variant is OK to use in any situation. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-21prefix_filename: drop length parameterLibravatar Jeff King1-1/+1
This function takes the prefix as a ptr/len pair, but in every caller the length is exactly strlen(ptr). Let's simplify the interface and just take the string. This saves callers specifying it (and in some cases handling a NULL prefix). In a handful of cases we had the length already without calling strlen, so this is technically slower. But it's not likely to matter (after all, if the prefix is non-empty we'll allocate and copy it into a buffer anyway). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-10Merge branch 'ps/worktree-prune-help-fix'Libravatar Junio C Hamano1-2/+2
Incorrect usage help message for "git worktree prune" has been fixed. * ps/worktree-prune-help-fix: worktree: fix option descriptions for `prune`