Two help messages given when "git add" notices the user gave it
nothing to add have been updated to use advise() API.
* hw/advice-add-nothing:
add: change advice config variables used by the add API
add: use advise function to display hints
advice.addNothing config variable is used to control the visibility of
two advice messages in the add library. This config variable is
replaced by two new variables, whose names are more clear and relevant
to the two cases.
Also add the two new variables to the documentation.
Signed-off-by: Heba Waly <heba.waly@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The effort to move "git-add--interactive" to C continues.
* js/patch-mode-in-others-in-c:
commit --interactive: make it work with the built-in `add -i`
built-in add -p: implement the "worktree" patch modes
built-in add -p: implement the "checkout" patch modes
built-in stash: use the built-in `git add -p` if so configured
legacy stash -p: respect the add.interactive.usebuiltin setting
built-in add -p: implement the "stash" and "reset" patch modes
built-in add -p: prepare for patch modes other than "stage"
Use the advise function in advice.c to display hints to the users, as
it provides a neat and a standard format for hint messages, i.e: the
text is colored in yellow and the line starts by the word "hint:".
Also this will enable us to control the messages using advice.*
configuration variables.
Signed-off-by: Heba Waly <heba.waly@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The effort to move "git-add--interactive" to C continues.
* js/add-p-in-c:
built-in add -p: show helpful hint when nothing can be staged
built-in add -p: only show the applicable parts of the help text
built-in add -p: implement the 'q' ("quit") command
built-in add -p: implement the '/' ("search regex") command
built-in add -p: implement the 'g' ("goto") command
built-in add -p: implement hunk editing
strbuf: add a helper function to call the editor "on an strbuf"
built-in add -p: coalesce hunks after splitting them
built-in add -p: implement the hunk splitting feature
built-in add -p: show different prompts for mode changes and deletions
built-in app -p: allow selecting a mode change as a "hunk"
built-in add -p: handle deleted empty files
built-in add -p: support multi-file diffs
built-in add -p: offer a helpful error message when hunk navigation failed
built-in add -p: color the prompt and the help text
built-in add -p: adjust hunk headers as needed
built-in add -p: show colored hunks by default
built-in add -i: wire up the new C code for the `patch` command
built-in add -i: start implementing the `patch` functionality in C
A few more commands learned the "--pathspec-from-file" command line
option.
* am/pathspec-f-f-checkout:
checkout, restore: support the --pathspec-from-file option
doc: restore: synchronize <pathspec> description
doc: checkout: synchronize <pathspec> description
doc: checkout: fix broken text reference
doc: checkout: remove duplicate synopsis
add: support the --pathspec-from-file option
cmd_add: prepare for next patch
This is a straight-forward port of 2f0896ec3a (restore: support
--patch, 2019-04-25) which added support for `git restore -p`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch teaches the built-in `git add -p` machinery all the tricks it
needs to know in order to act as the work horse for `git checkout -p`.
Apart from the minor changes (slightly reworded messages, different
`diff` and `apply --check` invocations), it requires a new function to
actually apply the changes, as `git checkout -p` is a bit special in
that respect: when the desired changes do not apply to the index, but
apply to the work tree, Git does not fail straight away, but asks the
user whether to apply the changes to the worktree at least.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As `git add` traditionally did not expose the `--patch=<mode>` modes via
command-line options, the scripted version of `git stash` had to call
`git add--interactive` directly.
But this prevents the built-in `add -p` from kicking in, as
`add--interactive` is the scripted version (which does not have a
"fall-back" to the built-in version).
So let's introduce support for internal switch for `git add` that the
scripted `git stash` can use to call the appropriate backend (scripted
or built-in, depending on `add.interactive.useBuiltin`).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `git stash` and `git reset` commands support a `--patch` option, and
both simply hand off to `git add -p` to perform that work. Let's teach
the built-in version of that command to be able to perform that work, too.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The Perl script backing `git add -p` is used not only for that command,
but also for `git stash -p`, `git reset -p` and `git checkout -p`.
In preparation for teaching the C version of `git add -p` to support
also the latter commands, let's abstract away what is "stage" specific
into a dedicated data structure describing the differences between the
patch modes.
Finally, please note that the Perl version tries to make sure that the
diffs are only generated for the modified files. This is not actually
necessary, as the calls to Git's diff machinery already perform that
work, and perform it well. This makes it unnecessary to port the
`FILTER` field of the `%patch_modes` struct, as well as the
`get_diff_reference()` function.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the previous steps, we re-implemented the main loop of `git add -i`
in C, and most of the commands.
Notably, we left out the actual functionality of `patch`, as the
relevant code makes up more than half of `git-add--interactive.perl`,
and is actually pretty independent of the rest of the commands.
With this commit, we start to tackle that `patch` part. For better
separation of concerns, we keep the code in a separate file,
`add-patch.c`. The new code is still guarded behind the
`add.interactive.useBuiltin` config setting, and for the moment,
it can only be called via `git add -p`.
The actual functionality follows the original implementation of
5cde71d64a (git-add --interactive, 2006-12-10), but not too closely
(for example, we use string offsets rather than copying strings around,
and after seeing whether the `k` and `j` commands are applicable, in the
C version we remember which previous/next hunk was undecided, and use it
rather than looking again when the user asked to jump).
As a further deviation from that commit, We also use a comma instead of
a slash to separate the available commands in the prompt, as the current
version of the Perl script does this, and we also add a line about the
question mark ("print help") to the help text.
While it is tempting to use this conversion of `git add -p` as an excuse
to work on `apply_all_patches()` so that it does _not_ want to read a
file from `stdin` or from a file, but accepts, say, an `strbuf` instead,
we will refrain from this particular rabbit hole at this stage.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Decisions taken for simplicity:
1) For now, `--pathspec-from-file` is declared incompatible with
`--interactive/--patch/--edit`, even when <file> is not `stdin`.
Such use case it not really expected. Also, it would require changes
to `interactive_add()` and `edit_patch()`.
2) It is not allowed to pass pathspec in both args and file.
Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some code blocks were moved down to be able to test for `pathspec.nr`
in the next patch. Blocks are moved as is without any changes. This
is done as separate patch to reduce the amount of diffs in next patch.
Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Unlike previous conversions to C, where we started with a built-in
helper, we start this conversion by adding an interception in the
`run_add_interactive()` function when the new opt-in
`add.interactive.useBuiltin` config knob is turned on (or the
corresponding environment variable `GIT_TEST_ADD_I_USE_BUILTIN`), and
calling the new internal API function `run_add_i()` that is implemented
directly in libgit.a.
At this point, the built-in version of `git add -i` only states that it
cannot do anything yet. In subsequent patches/patch series, the
`run_add_i()` function will gain more and more functionality, until it
is feature complete. The whole arc of the conversion can be found in the
PRs #170-175 at https://github.com/gitgitgadget/git.
The "--helper approach" can unfortunately not be used here: on Windows
we face the very specific problem that a `system()` call in
Perl seems to close `stdin` in the parent process when the spawned
process consumes even one character from `stdin`. Which prevents us from
implementing the main loop in C and still trying to hand off to the Perl
script.
The very real downside of the approach we have to take here is that the
test suite won't pass with `GIT_TEST_ADD_I_USE_BUILTIN=true` until the
conversion is complete (the `--helper` approach would have let it pass,
even at each of the incremental conversion steps).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous commit made 'git add' abort when given a repository that
doesn't have a commit checked out. However, the output upon failure
isn't appropriate:
% git add repo
warning: adding embedded git repository: repo
hint: You've added another git repository inside your current repository.
hint: [...]
error: unable to index file 'repo/'
fatal: adding files failed
The hint doesn't apply in this case, and the error message doesn't
tell the user why 'repo' couldn't be added to the index.
Provide better output by teaching add_to_index() to error when given a
git directory where HEAD can't be resolved. To avoid the embedded
repository warning and hint, call check_embedded_repo() only after
add_file_to_index() succeeds because, in general, its output doesn't
make sense if adding to the index fails.
Signed-off-by: Kyle Meyer <kyle@kyleam.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The assumption to work on the single "in-core index" instance has
been reduced from the library-ish part of the codebase.
* nd/the-index-final:
cache.h: flip NO_THE_INDEX_COMPATIBILITY_MACROS switch
read-cache.c: remove the_* from index_has_changes()
merge-recursive.c: remove implicit dependency on the_repository
merge-recursive.c: remove implicit dependency on the_index
sha1-name.c: remove implicit dependency on the_index
read-cache.c: replace update_index_if_able with repo_&
read-cache.c: kill read_index()
checkout: avoid the_index when possible
repository.c: replace hold_locked_index() with repo_hold_locked_index()
notes-utils.c: remove the_repository references
grep: use grep_opt->repo instead of explict repo argument
"git add --ignore-errors" did not work as advertised and instead
worked as an unintended synonym for "git add --renormalize", which
has been fixed.
* jk/add-ignore-errors-bit-assignment-fix:
add: use separate ADD_CACHE_RENORMALIZE flag
"git add -e" got confused when the change it wants to let the user
edit is smaller than the previous change that was left over in a
temporary file.
* js/add-e-clear-patch-before-stating:
add --edit: truncate the patch file
By default, index compat macros are off from now on, because they
could hide the_index dependency.
Only those in builtin can use it.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 9472935d81 (add: introduce "--renormalize", 2017-11-16) taught
git-add to pass HASH_RENORMALIZE to add_to_index(), which then passes
the flag along to index_path(). However, the flags taken by
add_to_index() and the ones taken by index_path() are distinct
namespaces. We cannot take HASH_* flags in add_to_index(), because they
overlap with the ADD_CACHE_* flags we already take (in this case,
HASH_RENORMALIZE conflicts with ADD_CACHE_IGNORE_ERRORS).
We can solve this by adding a new ADD_CACHE_RENORMALIZE flag, and using
it to set HASH_RENORMALIZE within add_to_index(). In order to make it
clear that these two flags come from distinct sets, let's also change
the name "newflags" in the function to "hash_flags".
Reported-by: Dmitriy Smirnov <dmitriy.smirnov@jetbrains.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If there is already a .git/ADD_EDIT.patch file, we fail to truncate it
properly, which could result in very funny errors.
Of course, this file should not be left lying around. But at least in
one case, there was a stale copy, larger than the current diff. So the
result was a corrupt diff.
Let's just truncate the file when we write it and not worry about it too
much.
Reported by J Wyman.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
"git add ':(attr:foo)'" is not supported and is supposed to be
rejected while the command line arguments are parsed, but we fail
to reject such a command line upfront.
* nd/attr-pathspec-fix:
add: do not accept pathspec magic 'attr'
During an "add", a call is made to run_diff_files() which calls
check_removed() for each index-entry. The preload_index() code
distributes some of the costs across multiple threads.
Because the files checked are restricted to pathspec, adding
individual files makes no measurable impact but on a Windows repo
with ~200K files, 'git add .' drops from 6.3 seconds to 3.3 seconds
for a 47% savings.
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Various codepaths in the core-ish part learn to work on an
arbitrary in-core index structure, not necessarily the default
instance "the_index".
* nd/the-index: (23 commits)
revision.c: reduce implicit dependency the_repository
revision.c: remove implicit dependency on the_index
ws.c: remove implicit dependency on the_index
tree-diff.c: remove implicit dependency on the_index
submodule.c: remove implicit dependency on the_index
line-range.c: remove implicit dependency on the_index
userdiff.c: remove implicit dependency on the_index
rerere.c: remove implicit dependency on the_index
sha1-file.c: remove implicit dependency on the_index
patch-ids.c: remove implicit dependency on the_index
merge.c: remove implicit dependency on the_index
merge-blobs.c: remove implicit dependency on the_index
ll-merge.c: remove implicit dependency on the_index
diff-lib.c: remove implicit dependency on the_index
read-cache.c: remove implicit dependency on the_index
diff.c: remove implicit dependency on the_index
grep.c: remove implicit dependency on the_index
diff.c: remove the_index dependency in textconv() functions
blame.c: rename "repo" argument to "r"
combine-diff.c: remove implicit dependency on the_index
...
"git add ':(attr:foo)'" is not supported and is supposed to be
rejected while the command line arguments are parsed, but we fail
to reject such a command line upfront.
* nd/attr-pathspec-fix:
add: do not accept pathspec magic 'attr'
Commit b0db704652 (pathspec: allow querying for attributes -
2017-03-13) adds new pathspec magic 'attr' but only with
match_pathspec(). "git add" has some pathspec related code that still
does not know about 'attr' and will bail out:
$ git add ':(attr:foo)'
fatal: BUG:dir.c:1584: unsupported magic 40
A better solution would be making this code support 'attr'. But I
don't know how much work is needed (I'm not familiar with this new
magic). For now, let's simply reject this magic with a friendlier
message:
$ git add ':(attr:foo)'
fatal: :(attr:foo): pathspec magic not supported by this command: 'attr'
Update t6135 so that the expected error message is from the
"graceful" rejection codepath, not "oops, we were supposed to reject
the request to trigger this magic" codepath.
Reported-by: smaudet@sebastianaudet.com
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The more library-ish parts of the codebase learned to work on the
in-core index-state instance that is passed in by their callers,
instead of always working on the singleton "the_index" instance.
* nd/no-the-index: (24 commits)
blame.c: remove implicit dependency on the_index
apply.c: remove implicit dependency on the_index
apply.c: make init_apply_state() take a struct repository
apply.c: pass struct apply_state to more functions
resolve-undo.c: use the right index instead of the_index
archive-*.c: use the right repository
archive.c: avoid access to the_index
grep: use the right index instead of the_index
attr: remove index from git_attr_set_direction()
entry.c: use the right index instead of the_index
submodule.c: use the right index instead of the_index
pathspec.c: use the right index instead of the_index
unpack-trees: avoid the_index in verify_absent()
unpack-trees: convert clear_ce_flags* to avoid the_index
unpack-trees: don't shadow global var the_index
unpack-trees: add a note about path invalidation
unpack-trees: remove 'extern' on function declaration
ls-files: correct index argument to get_convert_attr_ascii()
preload-index.c: use the right index instead of the_index
dir.c: remove an implicit dependency on the_index in pathspec code
...
The parse-options machinery learned to refrain from enclosing
placeholder string inside a "<bra" and "ket>" pair automatically
without PARSE_OPT_LITERAL_ARGHELP. Existing help text for option
arguments that are not formatted correctly have been identified and
fixed.
* rs/parse-opt-lithelp:
parse-options: automatically infer PARSE_OPT_LITERAL_ARGHELP
shortlog: correct option help for -w
send-pack: specify --force-with-lease argument help explicitly
pack-objects: specify --index-version argument help explicitly
difftool: remove angular brackets from argument help
add, update-index: fix --chmod argument help
push: use PARSE_OPT_LITERAL_ARGHELP instead of unbalanced brackets
Make the match_patchspec API and friends take an index_state instead
of assuming the_index in dir.c. All external call sites are converted
blindly to keep the patch simple and retain current behavior.
Individual call sites may receive further updates to use the right
index instead of the_index.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Parseopt wraps argument help strings in a pair of angular brackets by
default, to tell users that they need to replace it with an actual
value. This is useful in most cases, because most option arguments
are indeed single values of a certain type. The option
PARSE_OPT_LITERAL_ARGHELP needs to be used in option definitions with
arguments that have multiple parts or are literal strings.
Stop adding these angular brackets if special characters are present,
as they indicate that we don't deal with a simple placeholder. This
simplifies the code a bit and makes defining special options slightly
easier.
Remove the flag PARSE_OPT_LITERAL_ARGHELP in the cases where the new
and more cautious handling suffices.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Don't translate the argument specification for --chmod; "+x" and "-x"
are the literal strings that the commands accept.
Separate alternatives using a pipe character instead of a slash, for
consistency.
Use the flag PARSE_OPT_LITERAL_ARGHELP to prevent parseopt from adding a
pair of angular brackets around the argument help string, as that would
wrongly indicate that users need to replace the literal strings with
some kind of value.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code clean-up to adjust to a more recent lockfile API convention that
allows lockfile instances kept on the stack.
* ma/lockfile-cleanup:
lock_file: move static locks into functions
lock_file: make function-local locks non-static
refs.c: do not die if locking fails in `delete_pseudoref()`
refs.c: do not die if locking fails in `write_pseudoref()`
t/helper/test-write-cache: clean up lock-handling
Placing `struct lock_file`s on the stack used to be a bad idea, because
the temp- and lockfile-machinery would keep a pointer into the struct.
But after 076aa2cbd (tempfile: auto-allocate tempfiles on heap,
2017-09-05), we can safely have lockfiles on the stack. (This applies
even if a user returns early, leaving a locked lock behind.)
Each of these `struct lock_file`s is used from within a single function.
Move them into the respective functions to make the scope clearer and
drop the staticness.
For good measure, I have inspected these sites and come to believe that
they always release the lock, with the possible exception of bailing out
using `die()` or `exit()` or by returning from a `cmd_foo()`.
As pointed out by Jeff King, it would be bad if someone held on to a
`struct lock_file *` for some reason. After some grepping, I agree with
his findings: no-one appears to be doing that.
After this commit, the remaining occurrences of "static struct
lock_file" are locks that are used from within different functions. That
is, they need to remain static. (Short of more intrusive changes like
passing around pointers to non-static locks.)
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is more consistent with the project style. The majority of Git's
source files use dashes in preference to underscores in their file names.
Signed-off-by: Stefan Beller <sbeller@google.com>
Internal API clean-up to allow write_locked_index() optionally skip
writing the in-core index when it is not modified.
* ma/skip-writing-unchanged-index:
write_locked_index(): add flag to avoid writing unchanged index
We have several callers like
if (active_cache_changed && write_locked_index(...))
handle_error();
rollback_lock_file(...);
where the final rollback is needed because "!active_cache_changed"
shortcuts the if-expression. There are also a few variants of this,
including some if-else constructs that make it more clear when the
explicit rollback is really needed.
Teach `write_locked_index()` to take a new flag SKIP_IF_UNCHANGED and
simplify the callers. Leave the most complicated of the callers (in
builtin/update-index.c) unchanged. Rewriting it to use this new flag
would end up duplicating logic.
We could have made the new flag behave the other way round
("FORCE_WRITE"), but that could break existing users behind their backs.
Let's take the more conservative approach. We can still migrate existing
callers to use our new flag. Later we might even be able to flip the
default, possibly without entirely ignoring the risk to in-flight or
out-of-tree topics.
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
--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>
"git add --renormalize ." is a new and safer way to record the fact
that you are correcting the end-of-line convention and other
"convert_to_git()" glitches in the in-repository data.
* tb/add-renormalize:
add: introduce "--renormalize"
Make it safer to normalize the line endings in a repository.
Files that had been commited with CRLF will be commited with LF.
The old way to normalize a repo was like this:
# Make sure that there are not untracked files
$ echo "* text=auto" >.gitattributes
$ git read-tree --empty
$ git add .
$ git commit -m "Introduce end-of-line normalization"
The user must make sure that there are no untracked files,
otherwise they would have been added and tracked from now on.
The new "add --renormalize" does not add untracked files:
$ echo "* text=auto" >.gitattributes
$ git add --renormalize .
$ git commit -m "Introduce end-of-line normalization"
Note that "git add --renormalize <pathspec>" is the short form for
"git add -u --renormalize <pathspec>".
While at it, document that the same renormalization may be needed,
whenever a clean filter is added or changed.
Helped-By: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Remove the `DIFF_OPT_SET` macro and instead set the flags directly.
This conversion is done using the following semantic patch:
@@
expression E;
identifier fld;
@@
- DIFF_OPT_SET(&E, fld)
+ E.flags.fld = 1
@@
type T;
T *ptr;
identifier fld;
@@
- DIFF_OPT_SET(ptr, fld)
+ ptr->flags.fld = 1
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of explicitly setting the 'DIFF_OPT_OVERRIDE_SUBMODULE_CONFIG'
flag, use the 'DIFF_OPT_SET' macro.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
After run_diff_files, we throw away the rev_info struct,
including the pathspec that we copied into it, leaking the
memory. this is probably not a big deal in practice. We
usually only run this once per process, and the leak is
proportional to the pathspec list we're already holding in
memory.
But it's still a leak, and it pollutes leak-checker output,
making it harder to find important leaks.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code clean-up to avoid mixing values read from the .gitmodules file
and values read from the .git/config file.
* bw/submodule-config-cleanup:
submodule: remove gitmodules_config
unpack-trees: improve loading of .gitmodules
submodule-config: lazy-load a repository's .gitmodules file
submodule-config: move submodule-config functions to submodule-config.c
submodule-config: remove support for overlaying repository config
diff: stop allowing diff to have submodules configured in .git/config
submodule: remove submodule_config callback routine
unpack-trees: don't respect submodule.update
submodule: don't rely on overlayed config when setting diffopts
fetch: don't overlay config with submodule-config
submodule--helper: don't overlay config in update-clone
submodule--helper: don't overlay config in remote_submodule_branch
add, reset: ensure submodules can be added or reset
submodule: don't use submodule_from_name
t7411: check configuration parsing errors
In addition to adding the missing newline, add the x-ecutable bit
'mode change' character to the error message. This message now has
the same form as similar messages output by 'update-index'.
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
