Now that the submodule-config subsystem can lazily read the gitmodules
file we no longer need to explicitly pre-read the gitmodules by calling
'gitmodules_config()' so let's remove it.
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert grep to use 'struct repository' which enables recursing into
submodules to be handled in-process.
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert the flags for get_oid_with_context and friends to use "OID"
instead of "SHA1" in their names.

This transform was made by running the following one-liner on the
affected files:

  perl -pi -e 's/GET_SHA1/GET_OID/g'
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Now that all the callers of get_sha1 directly or indirectly use struct
object_id, rename the functions starting with get_sha1 to start with
get_oid.  Convert the internals in sha1_name.c to use struct object_id
as well, and eliminate explicit length checks where possible.  Convert a
use of 40 in get_oid_basic to GIT_SHA1_HEXSZ.

Outside of sha1_name.c and cache.h, this transition was made with the
following semantic patch:

@@
expression E1, E2;
@@
- get_sha1(E1, E2.hash)
+ get_oid(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1(E1, E2->hash)
+ get_oid(E1, E2)

@@
expression E1, E2;
@@
- get_sha1_committish(E1, E2.hash)
+ get_oid_committish(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1_committish(E1, E2->hash)
+ get_oid_committish(E1, E2)

@@
expression E1, E2;
@@
- get_sha1_treeish(E1, E2.hash)
+ get_oid_treeish(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1_treeish(E1, E2->hash)
+ get_oid_treeish(E1, E2)

@@
expression E1, E2;
@@
- get_sha1_commit(E1, E2.hash)
+ get_oid_commit(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1_commit(E1, E2->hash)
+ get_oid_commit(E1, E2)

@@
expression E1, E2;
@@
- get_sha1_tree(E1, E2.hash)
+ get_oid_tree(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1_tree(E1, E2->hash)
+ get_oid_tree(E1, E2)

@@
expression E1, E2;
@@
- get_sha1_blob(E1, E2.hash)
+ get_oid_blob(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1_blob(E1, E2->hash)
+ get_oid_blob(E1, E2)

@@
expression E1, E2, E3, E4;
@@
- get_sha1_with_context(E1, E2, E3.hash, E4)
+ get_oid_with_context(E1, E2, &E3, E4)

@@
expression E1, E2, E3, E4;
@@
- get_sha1_with_context(E1, E2, E3->hash, E4)
+ get_oid_with_context(E1, E2, E3, E4)
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Back in prehistoric times, our decision on whether or not to
show color by default relied on using a config callback that
either did or didn't load color config like color.diff.
When we introduced color.ui, we put it in the same boat:
commands had to manually respect it by using git_color_config()
or its git_color_default_config() convenience wrapper.

But in 4c7f1819 (make color.ui default to 'auto',
2013-06-10), that changed. Since then, we default color.ui
to auto in all programs, meaning that even plumbing commands
like "git diff-tree --pretty" might colorize the output.
Nobody seems to have complained in the intervening years,
presumably because the "is stdout a tty" check does a good
job of catching the right cases.

But that leaves an interesting curiosity: color.ui defaults
to auto even in plumbing, but you can't actually _disable_
the color via config. So if you really hate color and set
"color.ui" to false, diff-tree will still show color (but
porcelain like git-diff won't).  Nobody noticed that either,
probably because very few people disable color.

One could argue that the plumbing should _always_ disable
color unless an explicit --color option is given on the
command line. But in practice, this creates a lot of
complications for scripts which do want plumbing to show
user-visible output. They can't just pass "--color" blindly;
they need to check the user's config and decide what to
send.

Given that nobody has complained about the current behavior,
let's assume it's a good path, and follow it to its
conclusion: supporting color.ui everywhere.

Note that you can create havoc by setting color.ui=always in
your config, but that's more or less already the case. We
could disallow it entirely, but it is handy for one-offs
like:

  git -c color.ui=always foo >not-a-tty

when "foo" does not take a --color option itself.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert code that divides and rounds up to use DIV_ROUND_UP to make the
intent clearer and reduce the number of magic constants.
Signed-off-by: NRene Scharfe <l.s.r@web.de>
Reviewed-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Refactor calls to the grep machinery to always pass opt.ignore_case &
opt.extended_regexp_option instead of setting the equivalent regflags
bits.

The bug fixed when making -i work with -P in commit 9e3cbc59 ("log:
make --regexp-ignore-case work with --perl-regexp", 2017-05-20) was
really just plastering over the code smell which this change fixes.

The reason for adding the extensive commentary here is that I
discovered some subtle complexity in implementing this that really
should be called out explicitly to future readers.

Before this change we'd rely on the difference between
`extended_regexp_option` and `regflags` to serve as a membrane between
our preliminary parsing of grep.extendedRegexp and grep.patternType,
and what we decided to do internally.

Now that those two are the same thing, it's necessary to unset
`extended_regexp_option` just before we commit in cases where both of
those config variables are set. See 84befcd0 ("grep: add a
grep.patternType configuration setting", 2012-08-03) for the code and
documentation related to that.

The explanation of why the if/else branches in
grep_commit_pattern_type() are ordered the way they are exists in that
commit message, but I think it's worth calling this subtlety out
explicitly with a comment for future readers.

Even though grep_commit_pattern_type() is the only caller of
grep_set_pattern_type_option() it's simpler to reset the
extended_regexp_option flag in the latter, since 2/3 branches in the
former would otherwise need to reset it, this way we can do it in one
place.
Signed-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NVille Skyttä <ville.skytta@iki.fi>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert 'is_submodule_initialized()' to take a repository object and
while we're at it, lets rename the function to 'is_submodule_active()'
and remove the NEEDSWORK comment.
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert the remaining parts of grep to use struct object_id.
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In builtin/grep.c we parse the config before evaluating the command line
options. This makes the task of teaching grep to respect the new config
option 'submodule.recurse' very easy by just parsing that option.

As an alternative I had implemented a similar structure to treat
submodules as the fetch/push command have, including
* aligning the meaning of the 'recurse_submodules' to possible submodule
  values RECURSE_SUBMODULES_* as defined in submodule.h.
* having a callback to parse the value and
* reacting to the RECURSE_SUBMODULES_DEFAULT state that was the initial
  state.

However all this is not needed for a true boolean value, so let's keep
it simple. However this adds another place where "submodule.recurse" is
parsed.
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Skip the administrative overhead of using pthreads when only using one
thread. Instead take the non-threaded path which would be taken under
NO_PTHREADS.

The threading support was initially added in commit
5b594f45 ("Threaded grep", 2010-01-25) with a hardcoded compile-time
number of 8 threads. Later the number of threads was made configurable
in commit 89f09dd3 ("grep: add --threads=<num> option and
grep.threads configuration", 2015-12-15).

That change did not add any special handling for --threads=1. Now we
take a slightly faster path by skipping thread handling entirely when
1 thread is requested.
Signed-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Change the pattern compilation logic under threading so that grep
doesn't compile a pattern it never ends up using on the non-threaded
code path, only to compile it again N times for N threads which will
each use their own copy, ignoring the initially compiled pattern.

This redundant compilation dates back to the initial introduction of
the threaded grep in commit 5b594f45 ("Threaded grep",
2010-01-25).

There was never any reason for doing this redundant work other than an
oversight in the initial commit. Jeff King suggested on-list in
<20170414212325.fefrl3qdjigwyitd@sigill.intra.peff.net> that this
might be needed to check the pattern for sanity before threaded
execution commences.

That's not the case. The pattern is compiled under threading in
start_threads() before any concurrent execution has started by calling
pthread_create(), so if the pattern contains an error we still do the
right thing. I.e. die with one error before any threaded execution has
commenced, instead of e.g. spewing out an error for each N threads,
which could be a regression a change like this might inadvertently
introduce.

This change is not meant as an optimization, any performance gains
from this are in the hundreds to thousands of nanoseconds at most. If
we wanted more performance here we could just re-use the compiled
patterns in multiple threads (regcomp(3) is thread-safe), or partially
re-use them and the associated structures in the case of later PCRE
JIT changes.

Rather, it's just to make the code easier to reason about. It's
confusing to debug this under threading & non-threading when the
threading codepaths redundantly compile a pattern which is never used.

The reason the patterns are recompiled is as a side-effect of
duplicating the whole grep_opt structure, which is not thread safe,
writable, and munged during execution. The grep_opt structure then
points to the grep_pat structure where pattern or patterns are stored.

I looked into e.g. splitting the API into some "do & alloc threadsafe
stuff", "spawn thread", "do and alloc non-threadsafe stuff", but the
execution time of grep_opt_dup() & pattern compilation is trivial
compared to actually executing the grep, so there was no point. Even
with the more expensive JIT changes to follow the most expensive PCRE
patterns take something like 0.0X milliseconds to compile at most[1].

The undocumented --debug mode added in commit 17bf35a3 ("grep: teach
--debug option to dump the parse tree", 2012-09-13) still works
properly with this change. It only emits debugging info during pattern
compilation, which is now dumped by the pattern compiled just before
the first thread is started.

1. http://sljit.sourceforge.net/pcre.htmlSigned-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Change the grep_{lock,unlock} functions to assert that num_threads is
true, instead of only locking & unlocking the pthread mutex lock when
it is.

These functions are never called when num_threads isn't true, this
logic has gone through multiple iterations since the initial
introduction of grep threading in commit 5b594f45 ("Threaded grep",
2010-01-25), but ever since then they'd only be called if num_threads
was true, so this check made the code confusing to read.

Replace the check with an assertion, so that it's clear to the reader
that this code path is never taken unless we're spawning threads.
Signed-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add a warning about missing thread support when grep.threads or
--threads is set to a non 0 (default) or 1 (no parallelism) value
under NO_PTHREADS=YesPlease.

This is for consistency with the index-pack & pack-objects commands,
which also take a --threads option & are configurable via
pack.threads, and have long warned about the same under
NO_PTHREADS=YesPlease.
Signed-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add a die(...) to a default case for the switch statement selecting
between grep pattern types under --recurse-submodules.

Normally this would be caught by -Wswitch, but the grep_pattern_type
type is converted to int by going through parse_options(). Changing
the argument type passed to compile_submodule_options() won't work,
the value will just get coerced. The -Wswitch-default warning will
warn about it, but that produces a lot of noise across the codebase,
this potential issue would be drowned in that noise.

Thus catching this at runtime is the least bad option. This won't ever
trigger in practice, but if a new pattern type were to be added this
catches an otherwise silent bug during development.

See commit 0281e487 ("grep: optionally recurse into submodules",
2016-12-16) for the initial addition of this code.
Signed-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When a sha1 lookup returns the tree path via "struct
object_context", it just copies it into a fixed-size buffer.
This means the result can be truncated, and it means our
"struct object_context" consumes a lot of stack space.

Instead, let's allocate a string on the heap. Because most
callers don't care about this information, we'll avoid doing
it by default (so they don't all have to start calling
free() on the result). There are basically two options for
the caller to signal to us that it's interested:

  1. By setting a pointer to storage in the object_context.

  2. By passing a flag in another parameter.

Doing (1) would match the way that sha1_object_info_extended()
works. But it would mean that every caller would have to
initialize the object_context, which they don't currently
have to do.

This patch does (2), and adds a new bit to the function's
flags field. All of the callers that look at the "path"
field are updated to pass the new flag.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Make parse_object, parse_object_or_die, and parse_object_buffer take a
pointer to struct object_id.  Remove the temporary variables inserted
earlier, since they are no longer necessary.  Transform all of the
callers using the following semantic patch:

@@
expression E1;
@@
- parse_object(E1.hash)
+ parse_object(&E1)

@@
expression E1;
@@
- parse_object(E1->hash)
+ parse_object(E1)

@@
expression E1, E2;
@@
- parse_object_or_die(E1.hash, E2)
+ parse_object_or_die(&E1, E2)

@@
expression E1, E2;
@@
- parse_object_or_die(E1->hash, E2)
+ parse_object_or_die(E1, E2)

@@
expression E1, E2, E3, E4, E5;
@@
- parse_object_buffer(E1.hash, E2, E3, E4, E5)
+ parse_object_buffer(&E1, E2, E3, E4, E5)

@@
expression E1, E2, E3, E4, E5;
@@
- parse_object_buffer(E1->hash, E2, E3, E4, E5)
+ parse_object_buffer(E1, E2, E3, E4, E5)
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Change the cleanup phase for the grep command to free the pathspec
struct that's allocated earlier in the same block, and used just a few
lines earlier.

With "grep hi README.md" valgrind reports a loss of 239 bytes now,
down from 351.

The relevant --num-callers=40 --leak-check=full --show-leak-kinds=all
backtrace is:

    [...] 187 (112 direct, 75 indirect) bytes in 1 blocks are definitely lost in loss record 70 of 110
    [...]    at 0x4C2BBAF: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
    [...]    by 0x60B339: do_xmalloc (wrapper.c:59)
    [...]    by 0x60B2F6: xmalloc (wrapper.c:86)
    [...]    by 0x576B37: parse_pathspec (pathspec.c:652)
    [...]    by 0x4519F0: cmd_grep (grep.c:1215)
    [...]    by 0x4062EF: run_builtin (git.c:371)
    [...]    by 0x40544D: handle_builtin (git.c:572)
    [...]    by 0x4060A2: run_argv (git.c:624)
    [...]    by 0x4051C6: cmd_main (git.c:701)
    [...]    by 0x4C5901: main (common-main.c:43)
Signed-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Commit 0281e487 ("grep: optionally recurse into submodules")
added functions grep_submodule() and grep_submodule_launch() which
use "struct work_item" which is defined only when thread support
is available.

The original implementation of grep_submodule() used the "struct
work_item" in order to gain access to a strbuf to store its output which
was to be printed at a later point in time.  This differs from how both
grep_file() and grep_sha1() handle their output.  This patch eliminates
the reliance on the "struct work_item" and instead opts to use the
output function stored in the output field of the "struct grep_opt"
object directly, making it behave similarly to both grep_file() and
grep_sha1().
Reported-by: NRahul Bedarkar <rahul.bedarkar@imgtec.com>
Signed-off-by: NBrandon Williams <bmwill@google.com>
Reviewed-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio 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: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We need the gentle version in a later patch. As we have just one caller,
migrate the caller.
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert several functions to use struct object_id, and rename them so
that they no longer refer to SHA-1.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

git-grep has always disallowed grepping in a tree (as
opposed to the working directory) with both --untracked
and --no-index. But we traditionally did so by first
collecting the revs, and then complaining when any were
provided.

The --no-index option recently learned to detect revs
much earlier. This has two user-visible effects:

  - we don't bother to resolve revision names at all. So
    when there's a rev/path ambiguity, we always choose to
    treat it as a path.

  - likewise, when you do specify a revision without "--",
    the error you get is "no such path" and not "--untracked
    cannot be used with revs".

The rationale for doing this with --no-index is that it is
meant to be used outside a repository, and so parsing revs
at all does not make sense.

This patch gives --untracked the same treatment. While it
_is_ meant to be used in a repository, it is explicitly
about grepping the non-repository contents. Telling the user
"we found a rev, but you are not allowed to use revs" is
not really helpful compared to "we treated your argument as
a path, and could not find it".
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If we are using --no-index, then our arguments cannot be
revs in the first place. Not only is it pointless to
diagnose them, but if we are not in a repository, we should
not be trying to resolve any names.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We disallow the use of revisions with --no-index, but we
don't actually check and complain until well after we've
parsed the revisions.

This is the cause of a few problems:

 1. We shouldn't be calling get_sha1() at all when we aren't
    in a repository, as it might access the ref or object
    databases. For now, this should generally just return
    failure, but eventually it will become a BUG().

 2. When there's a "--" disambiguator and you're outside a
    repository, we'll complain early with "unable to resolve
    revision". But we can give a much more specific error.

 3. When there isn't a "--" disambiguator, we still do the
    normal rev/path checks. This is silly, as we know we
    cannot have any revs with --no-index. Everything we see
    must be a path.

    Outside of a repository this doesn't matter (since we
    know it won't resolve), but inside one, we may complain
    unnecessarily if a filename happens to also match a
    refname.

This patch skips the get_sha1() call entirely in the
no-index case, and behaves as if it failed (with the
exception of giving a better error message).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If we see "git grep pattern rev -- file" then we apply the
usual rev/pathspec disambiguation rules: any "rev" before
the "--" must be a revision, and we do not need to apply the
verify_non_filename() check.

But there are two bugs here:

  1. We keep a seen_dashdash flag to handle this case, but
     we set it in the same left-to-right pass over the
     arguments in which we parse "rev".

     So when we see "rev", we do not yet know that there is
     a "--", and we mistakenly complain if there is a
     matching file.

     We can fix this by making a preliminary pass over the
     arguments to find the "--", and only then checking the rev
     arguments.

  2. If we can't resolve "rev" but there isn't a dashdash,
     that's OK. We treat it like a path, and complain later
     if it doesn't exist.

     But if there _is_ a dashdash, then we know it must be a
     rev, and should treat it as such, complaining if it
     does not resolve. The current code instead ignores it
     and tries to treat it like a path.

This patch fixes both bugs, and tries to comment the parsing
flow a bit better.

It adds tests that cover the two bugs, but also some related
situations (which already worked, but this confirms that our
fixes did not break anything).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We loop over the arguments, but every branch of the loop
hits either a "continue" or a "break". Surely we can make
this simpler.

The final conditional is:

  if (arg is a rev) {
	  ... handle rev ...
	  continue;
  }
  break;

We can rewrite this as:

  if (arg is not a rev)
	  break;

  ... handle rev ...

That makes the flow a little bit simpler, and will make
things much easier to follow when we add more logic in
future patches.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When running a command of the form

  git grep --no-index pattern -- path

in the absence of a Git repository, an error message will be printed:

  fatal: BUG: setup_git_env called without repository

This is because "git grep" tries to interpret "--" as a rev. "git grep"
has always tried to first interpret "--" as a rev for at least a few
years, but this issue was upgraded from a pessimization to a bug in
commit 59332d13 ("Resurrect "git grep --no-index"", 2010-02-06), which
calls get_sha1 regardless of whether --no-index was specified. This bug
appeared to be benign until commit b1ef400e ("setup_git_env: avoid blind
fall-back to ".git"", 2016-10-20) when Git was taught to die in this
situation.  (This "git grep" bug appears to be one of the bugs that
commit b1ef400e is meant to flush out.)

Therefore, always interpret "--" as signaling the end of options,
instead of trying to interpret it as a rev first.
Signed-off-by: NJonathan Tan <jonathantanmy@google.com>
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Originally, we set up the threads for grep before parsing
the non-option arguments. In 53b8d931 (grep: disable
threading in non-worktree case, 2011-12-12), the thread code
got bumped lower in the function because it now needed to
know whether we got any revision arguments.

That put a big block of code in between the parsing of revs
and the parsing of pathspecs, both of which share some loop
variables. That makes it harder to read the code than the
original, where the shared loops were right next to each
other.

Let's bump the thread initialization until after all of the
parsing is done.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If a submodule was renamed at any point since it's inception then if you
were to try and grep on a commit prior to the submodule being moved, you
wouldn't be able to find a working directory for the submodule since the
path in the past is different from the current path.

This patch teaches grep to find the .git directory for a submodule in
the parents .git/modules/ directory in the event the path to the
submodule in the commit that is being searched differs from the state of
the currently checked out commit.  If found, the child process that is
spawned to grep the submodule will chdir into its gitdir instead of a
working directory.

In order to override the explicit setting of submodule child process's
gitdir environment variable (which was introduced in '10f5c526')
`GIT_DIR_ENVIORMENT` needs to be pushed onto child process's env_array.
This allows the searching of history from a submodule's gitdir, rather
than from a working directory.
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Teach grep to recursively search in submodules when provided with a
<tree> object. This allows grep to search a submodule based on the state
of the submodule that is present in a commit of the super project.

When grep is provided with a <tree> object, the name of the object is
prefixed to all output.  In order to provide uniformity of output
between the parent and child processes the option `--parent-basename`
has been added so that the child can preface all of it's output with the
name of the parent's object instead of the name of the commit SHA1 of
the submodule. This changes output from the command
`git grep -e. -l --recurse-submodules HEAD` from:

      HEAD:file
      <commit sha1 of submodule>:sub/file

to:

      HEAD:file
      HEAD:sub/file
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Allow grep to recognize submodules and recursively search for patterns in
each submodule.  This is done by forking off a process to recursively
call grep on each submodule.  The top level --super-prefix option is
used to pass a path to the submodule which can in turn be used to
prepend to output or in pathspec matching logic.

Recursion only occurs for submodules which have been initialized and
checked out by the parent project.  If a submodule hasn't been
initialized and checked out it is simply skipped.

In order to support the existing multi-threading infrastructure in grep,
output from each child process is captured in a strbuf so that it can be
later printed to the console in an ordered fashion.

To limit the number of theads that are created, each child process has
half the number of threads as its parents (minimum of 1), otherwise we
potentailly have a fork-bomb.
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio 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: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This reverts commit 4d552005 (grep: make it clear i-t-a entries are
ignored, 2015-12-27) and adds an alternative fix to maintain the -L
--cached behavior.

4d552005 caused 'git grep' to no longer find matches in new files in
the working tree where the corresponding index entry had the "intent to
add" bit set, despite the fact that these files are tracked.

The content in the index of a file for which the "intent to add" bit is
set is considered indeterminate and not empty. For most grep queries we
want these to behave the same, however for -L --cached (files without a
match) we don't want to respond positively for "intent to add" files as
their contents are indeterminate. This is in contrast to files with
empty contents in the index (no lines implies no matches for any grep
query expression) which should be reported in the output of a grep -L
--cached invocation.

Add tests to cover this case and a few related cases which previously
lacked coverage.
Helped-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NCharles Bailey <cbailey32@bloomberg.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>