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>
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 order to use the submodule-config subsystem, callers first need to
initialize it by calling 'repo_read_gitmodules()' or
'gitmodules_config()' (which just redirects to
'repo_read_gitmodules()'). There are a couple of callers who need to
load an explicit revision of the repository's .gitmodules file (grep) or
need to modify the .gitmodules file so they would need to load it before
modify the file (checkout), but the majority of callers are simply
reading the .gitmodules file present in the working tree. For the
common case it would be nice to avoid the boilerplate of initializing
the submodule-config system before using it, so instead let's perform
lazy-loading of the submodule-config system.
Remove the calls to reading the gitmodules file from ls-files to show
that lazy-loading the .gitmodules file works.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Migrate the functions used to initialize the submodule-config to
submodule-config.c so that the callback routine used in the
initialization process can be static and prevent it from being used
outside of initializing the submodule-config through the main API.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Exit early when asked to prune an index that contains no entries to
begin with. This avoids pointer arithmetic on istate->cache, which is
possibly NULL in that case.
Found with Clang's UBSan.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Simplify the code for moving members inside of an array and make it more
robust by using the helper macro MOVE_ARRAY. It calculates the size
based on the specified number of elements for us and supports NULL
pointers when that number is zero. Raw memmove(3) calls with NULL can
cause the compiler to (over-eagerly) optimize out later NULL checks.
This patch was generated with contrib/coccinelle/array.cocci and spatch
(Coccinelle).
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert ls-files to use a repository struct and recurse submodules
inprocess.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* bw/ls-files-sans-the-index:
ls-files: factor out tag calculation
ls-files: factor out debug info into a function
ls-files: convert show_files to take an index
ls-files: convert show_ce_entry to take an index
ls-files: convert prune_cache to take an index
ls-files: convert ce_excluded to take an index
ls-files: convert show_ru_info to take an index
ls-files: convert show_other_files to take an index
ls-files: convert show_killed_files to take an index
ls-files: convert write_eolinfo to take an index
ls-files: convert overlay_tree_on_cache to take an index
tree: convert read_tree to take an index parameter
convert: convert renormalize_buffer to take an index
convert: convert convert_to_git to take an index
convert: convert convert_to_git_filter_fd to take an index
convert: convert crlf_to_git to take an index
convert: convert get_cached_convert_stats_ascii to take an index
* 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
alias: use the early config machinery to expand aliases
t7006: demonstrate a problem with aliases in subdirectories
t1308: relax the test verifying that empty alias values are disallowed
help: use early config when autocorrecting aliases
config: report correct line number upon error
discover_git_directory(): avoid setting invalid git_dir
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>
Simplify parse_pathspec() codepath and stop it from looking at the
default in-core index.
* bw/pathspec-sans-the-index:
pathspec: convert find_pathspecs_matching_against_index to take an index
pathspec: remove PATHSPEC_STRIP_SUBMODULE_SLASH_CHEAP
ls-files: prevent prune_cache from overeagerly pruning submodules
pathspec: remove PATHSPEC_STRIP_SUBMODULE_SLASH_EXPENSIVE flag
submodule: add die_in_unpopulated_submodule function
pathspec: provide a more descriptive die message
Conversion from uchar[20] to struct object_id continues.
* bc/object-id: (53 commits)
object: convert parse_object* to take struct object_id
tree: convert parse_tree_indirect to struct object_id
sequencer: convert do_recursive_merge to struct object_id
diff-lib: convert do_diff_cache to struct object_id
builtin/ls-tree: convert to struct object_id
merge: convert checkout_fast_forward to struct object_id
sequencer: convert fast_forward_to to struct object_id
builtin/ls-files: convert overlay_tree_on_cache to object_id
builtin/read-tree: convert to struct object_id
sha1_name: convert internals of peel_onion to object_id
upload-pack: convert remaining parse_object callers to object_id
revision: convert remaining parse_object callers to object_id
revision: rename add_pending_sha1 to add_pending_oid
http-push: convert process_ls_object and descendants to object_id
refs/files-backend: convert many internals to struct object_id
refs: convert struct ref_update to use struct object_id
ref-filter: convert some static functions to struct object_id
Convert struct ref_array_item to struct object_id
Convert the verify_pack callback to struct object_id
Convert lookup_tag to struct object_id
...
Since (ae8d08242 pathspec: pass directory indicator to
match_pathspec_item()) the path matching logic has been able to cope
with submodules without needing to strip off a trailing slash if a path
refers to a submodule.
ls-files is the only caller of 'parse_pathspec()' which relies on the
behavior of the PATHSPEC_STRIP_SUBMODULE_SLASH_CHEAP flag because it
uses the result to construct a common prefix of all provided pathspecs
which is then used to prune the index of all entries which don't have
that prefix. Since submodules entries in the index don't have a
trailing slash 'prune_cache()' will be overeager and prune a submodule
'sub' if the common prefix is 'sub/'. To correct this behavior, only
prune entries which don't match up to, but not including, a trailing
slash of the common prefix.
This is in preparation to remove the
PATHSPEC_STRIP_SUBMODULE_SLASH_CHEAP flag in a later patch.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert parse_tree_indirect to take a pointer to struct object_id.
Update all the callers. This transformation was achieved using the
following semantic patch and manual updates to the declaration and
definition. Update builtin/checkout.c manually as well, since it uses a
ternary expression not handled by the semantic patch.
@@
expression E1;
@@
- parse_tree_indirect(E1.hash)
+ parse_tree_indirect(&E1)
@@
expression E1;
@@
- parse_tree_indirect(E1->hash)
+ parse_tree_indirect(E1)
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is another caller of parse_tree_indirect.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Don't assume that the current working directory is the root of the
repository. Correctly generate the path for the recursing child
processes by building it from the work_tree() root instead. Otherwise if
we run ls-files using --git-dir or --work-tree it will not work
correctly as it attempts to change directory into a potentially invalid
location. Best case, it doesn't exist and we produce an error. Worst
case we cd into the wrong location and unknown behavior occurs.
Add a new test which highlights this possibility.
Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since commit e77aa336f1 ("ls-files: optionally recurse into
submodules", 2016-10-07) ls-files has known how to recurse into
submodules when displaying files.
Unfortunately this fails for certain cases, including when nesting more
than one submodule, called from within a submodule that itself has
submodules, or when the GIT_DIR environemnt variable is set.
Prior to commit b58a68c1c1 ("setup: allow for prefix to be passed to
git commands", 2017-03-17) this resulted in an error indicating that
--prefix and --super-prefix were incompatible.
After this commit, instead, the process loops forever with a GIT_DIR set
to the parent and continuously reads the parent submodule files and
recursing forever.
Fix this by preparing the environment properly for submodules when
setting up the child process. This is similar to how other commands such
as grep behave.
This was not caught by the original tests because the scenario is
avoided if the submodules are created separately and not stored as the
standard method of putting the submodule git directory under
.git/modules/<name>. We can update the test to show the failure by the
addition of "git submodule absorbgitdirs" to the test case. However,
note that this new test would run forever without the necessary fix in
this patch.
Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When using the --recurse-submodules flag with a relative pathspec which
includes "..", an error is produced inside the child process spawned for a
submodule. When creating the pathspec struct in the child, the ".." is
interpreted to mean "go up a directory" which causes an error stating that the
path ".." is outside of the repository.
While it is true that ".." is outside the scope of the submodule, it is
confusing to a user who originally invoked the command where ".." was indeed
still inside the scope of the superproject. Since the child process launched
for the submodule has some context that it is operating underneath a
superproject, this error could be avoided.
This patch fixes the bug by passing the 'prefix' to the child process. Now
each child process that works on a submodule has two points of reference to the
superproject: (1) the 'super_prefix' which is the path from the root of the
superproject down to root of the submodule and (2) the 'prefix' which is the
path from the root of the superproject down to the directory where the user
invoked the git command.
With these two pieces of information a child process can correctly interpret
the pathspecs provided by the user as well as being able to properly format its
output relative to the directory the user invoked the original command from.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
prune_cache() first identifies those entries at the start of the sorted
array that can be discarded. Then it moves the rest of the entries up.
Last it identifies the unwanted trailing entries among the moved ones
and cuts them off.
Change the order: Identify both start *and* end of the range to keep
first and then move only those entries to the top. The resulting code
is slightly shorter and a bit more efficient.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Reviewed-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function prune_cache() relies on the fact that it is only called on
max_prefix and sneakily uses the matching global variable max_prefix_len
directly. Tighten its interface by passing both the string and its
length as parameters. While at it move the NULL check into the function
to collect all cache-pruning related logic in one place.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Reviewed-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git ls-files" learned "--recurse-submodules" option that can be
used to get a listing of tracked files across submodules (i.e. this
only works with "--cached" option, not for listing untracked or
ignored files). This would be a useful tool to sit on the upstream
side of a pipe that is read with xargs to work on all working tree
files from the top-level superproject.
* bw/ls-files-recurse-submodules:
ls-files: add pathspec matching for submodules
ls-files: pass through safe options for --recurse-submodules
ls-files: optionally recurse into submodules
git: make super-prefix option
Pathspecs can be a bit tricky when trying to apply them to submodules.
The main challenge is that the pathspecs will be with respect to the
superproject and not with respect to paths in the submodule. The
approach this patch takes is to pass in the identical pathspec from the
superproject to the submodule in addition to the submodule-prefix, which
is the path from the root of the superproject to the submodule, and then
we can compare an entry in the submodule prepended with the
submodule-prefix to the pathspec in order to determine if there is a
match.
This patch also permits the pathspec logic to perform a prefix match against
submodules since a pathspec could refer to a file inside of a submodule.
Due to limitations in the wildmatch logic, a prefix match is only done
literally. If any wildcard character is encountered we'll simply punt
and produce a false positive match. More accurate matching will be done
once inside the submodule. This is due to the superproject not knowing
what files could exist in the submodule.
Signed-off-by: Brandon Williams <bmwill@google.com>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Pass through some known-safe options when recursing into submodules.
(--cached, -v, -t, -z, --debug, --eol)
Signed-off-by: Brandon Williams <bmwill@google.com>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Allow ls-files to recognize submodules in order to retrieve a list of
files from a repository's submodules. This is done by forking off a
process to recursively call ls-files on all submodules. Use top-level
--super-prefix option to pass a path to the submodule which it can
use to prepend to output or pathspec matching logic.
Signed-off-by: Brandon Williams <bmwill@google.com>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert struct cache_entry to use struct object_id by applying the
following semantic patch and the object_id transforms from contrib, plus
the actual change to the struct:
@@
struct cache_entry E1;
@@
- E1.sha1
+ E1.oid.hash
@@
struct cache_entry *E1;
@@
- E1->sha1
+ E1->oid.hash
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The vast majority of error messages in Git's source code which report a
bug use the convention to prefix the message with "BUG:".
As part of cleaning up merge-recursive to stop die()ing except in case of
detected bugs, let's just make the remainder of the bug reports consistent
with the de facto rule.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Various clean-ups to the command line option parsing.
* jk/options-cleanup:
apply, ls-files: simplify "-z" parsing
checkout-index: disallow "--no-stage" option
checkout-index: handle "--no-index" option
checkout-index: handle "--no-prefix" option
checkout-index: simplify "-z" option parsing
give "nbuf" strbuf a more meaningful name
As a short option, we cannot handle negation. Thus a callback
handling "unset" is overkill, and we can just use OPT_SET_INT
instead to handle setting the option.
Anybody who adds "--nul" synonym to this later would need to be
careful not to break "--no-nul", which should mean that lines are
terminated with LF at the end.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When working in a cross-platform environment, a user may want to
check if text files are stored normalized in the repository and
if .gitattributes are set appropriately.
Make it possible to let Git show the line endings in the index and
in the working tree and the effective text/eol attributes.
The end of line ("eolinfo") are shown like this:
"-text" binary (or with bare CR) file
"none" text file without any EOL
"lf" text file with LF
"crlf" text file with CRLF
"mixed" text file with mixed line endings.
The effective text/eol attribute is one of these:
"", "-text", "text", "text=auto", "text eol=lf", "text eol=crlf"
git ls-files --eol gives an output like this:
i/none w/none attr/text=auto t/t5100/empty
i/-text w/-text attr/-text t/test-binary-2.png
i/lf w/lf attr/text eol=lf t/t5100/rfc2047-info-0007
i/lf w/crlf attr/text eol=crlf doit.bat
i/mixed w/mixed attr/ locale/XX.po
to show what eol convention is used in the data in the index ('i'),
and in the working tree ('w'), and what attribute is in effect,
for each path that is shown.
Add test cases in t0027.
Helped-By: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Even though multiplication is commutative, the order of arguments
should be xcalloc(nmemb, size). ps_matched is an array of 1-byte
element whose size is the same as the number of pathspec elements.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The expected call sequence is for the caller to use match_pathspec()
repeatedly on a set of pathspecs, accumulating the "hits" in a
separate array, and then call this function to diagnose a pathspec
that never matched anything, as that can indicate a typo from the
command line, e.g. "git commit Maekfile".
Many builtin commands use this function from builtin/ls-files.c,
which is not a very healthy arrangement. ls-files might have been
the first command to feel the need for such a helper, but the need
is shared by everybody who uses the "match and then report" pattern.
Move it to dir.c where match_pathspec() is defined.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch puts the usage info strings that were not already in docopt-
like format into docopt-like format, which will be a litle easier for
end users and a lot easier for translators. Changes include:
- Placing angle brackets around fill-in-the-blank parameters
- Putting dashes in multiword parameter names
- Adding spaces to [-f|--foobar] to make [-f | --foobar]
- Replacing <foobar>* with [<foobar>...]
Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Reviewed-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch activates the DO_MATCH_DIRECTORY code in m_p_i(), which
makes "git diff HEAD submodule/" and "git diff HEAD submodule" produce
the same output. Previously only the version without trailing slash
returns the difference (if any).
That's the effect of new ce_path_match(). dir_path_match() is not
executed by the new tests. And it should not introduce regressions.
Previously if path "dir/" is passed in with pathspec "dir/", they
obviously match. With new dir_path_match(), the path becomes
_directory_ "dir" vs pathspec "dir/", which is not executed by the old
code path in m_p_i(). The new code path is executed and produces the
same result.
The other case is pathspec "dir" and path "dir/" is now turned to
"dir" (with DO_MATCH_DIRECTORY). Still the same result before or after
the patch.
So why change? Because of the next patch about clean.c.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
