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Author SHA1 Message Date
Jeff King
650c449250 common-main: call git_extract_argv0_path()
Every program which links against libgit.a must call this
function, or risk hitting an assert() in system_path() that
checks whether we have configured argv0_path (though only
when RUNTIME_PREFIX is defined, so essentially only on
Windows).

Looking at the diff, you can see that putting it into the
common main() saves us having to do it individually in each
of the external commands. But what you can't see are the
cases where we _should_ have been doing so, but weren't
(e.g., git-credential-store, and all of the t/helper test
programs).

This has been an accident-waiting-to-happen for a long time,
but wasn't triggered until recently because it involves one
of those programs actually calling system_path(). That
happened with git-credential-store in v2.8.0 with ae5f677
(lazily load core.sharedrepository, 2016-03-11). The
program:

  - takes a lock file, which...

  - opens a tempfile, which...

  - calls adjust_shared_perm to fix permissions, which...

  - lazy-loads the config (as of ae5f677), which...

  - calls system_path() to find the location of
    /etc/gitconfig

On systems with RUNTIME_PREFIX, this means credential-store
reliably hits that assert() and cannot be used.

We never noticed in the test suite, because we set
GIT_CONFIG_NOSYSTEM there, which skips the system_path()
lookup entirely.  But if we were to tweak git_config() to
find /etc/gitconfig even when we aren't going to open it,
then the test suite shows multiple failures (for
credential-store, and for some other test helpers). I didn't
include that tweak here because it's way too specific to
this particular call to be worth carrying around what is
essentially dead code.

The implementation is fairly straightforward, with one
exception: there is exactly one caller (git.c) that actually
cares about the result of the function, and not the
side-effect of setting up argv0_path. We can accommodate
that by simply replacing the value of argv[0] in the array
we hand down to cmd_main().

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 15:09:10 -07:00
Jeff King
3f2e2297b9 add an extra level of indirection to main()
There are certain startup tasks that we expect every git
process to do. In some cases this is just to improve the
quality of the program (e.g., setting up gettext()). In
others it is a requirement for using certain functions in
libgit.a (e.g., system_path() expects that you have called
git_extract_argv0_path()).

Most commands are builtins and are covered by the git.c
version of main(). However, there are still a few external
commands that use their own main(). Each of these has to
remember to include the correct startup sequence, and we are
not always consistent.

Rather than just fix the inconsistencies, let's make this
harder to get wrong by providing a common main() that can
run this standard startup.

We basically have two options to do this:

 - the compat/mingw.h file already does something like this by
   adding a #define that replaces the definition of main with a
   wrapper that calls mingw_startup().

   The upside is that the code in each program doesn't need
   to be changed at all; it's rewritten on the fly by the
   preprocessor.

   The downside is that it may make debugging of the startup
   sequence a bit more confusing, as the preprocessor is
   quietly inserting new code.

 - the builtin functions are all of the form cmd_foo(),
   and git.c's main() calls them.

   This is much more explicit, which may make things more
   obvious to somebody reading the code. It's also more
   flexible (because of course we have to figure out _which_
   cmd_foo() to call).

   The downside is that each of the builtins must define
   cmd_foo(), instead of just main().

This patch chooses the latter option, preferring the more
explicit approach, even though it is more invasive. We
introduce a new file common-main.c, with the "real" main. It
expects to call cmd_main() from whatever other objects it is
linked against.

We link common-main.o against anything that links against
libgit.a, since we know that such programs will need to do
this setup. Note that common-main.o can't actually go inside
libgit.a, as the linker would not pick up its main()
function automatically (it has no callers).

The rest of the patch is just adjusting all of the various
external programs (mostly in t/helper) to use cmd_main().
I've provided a global declaration for cmd_main(), which
means that all of the programs also need to match its
signature. In particular, many functions need to switch to
"const char **" instead of "char **" for argv. This effect
ripples out to a few other variables and functions, as well.

This makes the patch even more invasive, but the end result
is much better. We should be treating argv strings as const
anyway, and now all programs conform to the same signature
(which also matches the way builtins are defined).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 15:09:10 -07:00
Junio C Hamano
8f309aeb82 strbuf: introduce strbuf_getline_{lf,nul}()
The strbuf_getline() interface allows a byte other than LF or NUL as
the line terminator, but this is only because I wrote these
codepaths anticipating that there might be a value other than NUL
and LF that could be useful when I introduced line_termination long
time ago.  No useful caller that uses other value has emerged.

By now, it is clear that the interface is overly broad without a
good reason.  Many codepaths have hardcoded preference to read
either LF terminated or NUL terminated records from their input, and
then call strbuf_getline() with LF or NUL as the third parameter.

This step introduces two thin wrappers around strbuf_getline(),
namely, strbuf_getline_lf() and strbuf_getline_nul(), and
mechanically rewrites these call sites to call either one of
them.  The changes contained in this patch are:

 * introduction of these two functions in strbuf.[ch]

 * mechanical conversion of all callers to strbuf_getline() with
   either '\n' or '\0' as the third parameter to instead call the
   respective thin wrapper.

After this step, output from "git grep 'strbuf_getline('" would
become a lot smaller.  An interim goal of this series is to make
this an empty set, so that we can have strbuf_getline_crlf() take
over the shorter name strbuf_getline().

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-01-15 10:12:51 -08:00
Michael Haggerty
fb58c8d507 refs: move the remaining ref module declarations to refs.h
Some functions from the refs module were still declared in cache.h.
Move them to refs.h.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 13:17:12 -07:00
René Scharfe
d318027932 run-command: introduce CHILD_PROCESS_INIT
Most struct child_process variables are cleared using memset first after
declaration.  Provide a macro, CHILD_PROCESS_INIT, that can be used to
initialize them statically instead.  That's shorter, doesn't require a
function call and is slightly more readable (especially given that we
already have STRBUF_INIT, ARGV_ARRAY_INIT etc.).

Helped-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-20 09:53:37 -07:00
René Scharfe
1cefa14325 remote-testsvn: use internal argv_array of struct child_process in cmd_import()
Use the existing argv_array member instead of providing our own.  This
way we don't have to initialize or clean it up explicitly.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-07-18 12:50:03 -07:00
Rohit Mani
2c5495f7b6 use strchrnul() in place of strchr() and strlen()
Avoid scanning strings twice, once with strchr() and then with
strlen(), by using strchrnul().

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Rohit Mani <rohit.mani@outlook.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-03-10 08:35:30 -07:00
Christian Couder
5955654823 replace {pre,suf}fixcmp() with {starts,ends}_with()
Leaving only the function definitions and declarations so that any
new topic in flight can still make use of the old functions, replace
existing uses of the prefixcmp() and suffixcmp() with new API
functions.

The change can be recreated by mechanically applying this:

    $ git grep -l -e prefixcmp -e suffixcmp -- \*.c |
      grep -v strbuf\\.c |
      xargs perl -pi -e '
        s|!prefixcmp\(|starts_with\(|g;
        s|prefixcmp\(|!starts_with\(|g;
        s|!suffixcmp\(|ends_with\(|g;
        s|suffixcmp\(|!ends_with\(|g;
      '

on the result of preparatory changes in this series.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-05 14:13:21 -08:00
Ramsay Jones
84d32bf767 sparse: Fix mingw_main() argument number/type errors
Sparse issues 68 errors (two errors for each main() function) such
as the following:

      SP git.c
  git.c:510:5: error: too many arguments for function mingw_main
  git.c:510:5: error: symbol 'mingw_main' redeclared with different type \
    (originally declared at git.c:510) - different argument counts

The errors are caused by the 'main' macro used by the MinGW build
to provide a replacement main() function. The original main function
is effectively renamed to 'mingw_main' and is called from the new
main function. The replacement main is used to execute certain actions
common to all git programs on MinGW (e.g. ensure the standard I/O
streams are in binary mode).

In order to suppress the errors, we change the macro to include the
parameters in the declaration of the mingw_main function.

Unfortunately, this change provokes both sparse and gcc to complain
about 9 calls to mingw_main(), such as the following:

      CC git.o
  git.c: In function 'main':
  git.c:510: warning: passing argument 2 of 'mingw_main' from \
    incompatible pointer type
  git.c:510: note: expected 'const char **' but argument is of \
    type 'char **'

In order to suppress these warnings, since both of the main
functions need to be declared with the same prototype, we
change the declaration of the 9 main functions, thus:

    int main(int argc, char **argv)

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-28 12:32:08 -07:00
Jeff King
bfae342c97 remote-testsvn: fix unitialized variable
In remote-test-svn, there is a parse_rev_note function to
parse lines of the form "Revision-number" from notes. If it
finds such a line and parses it, it returns 0, copying the
value into a "struct rev_note". If it finds an entry that is
garbled or out of range, it returns -1 to signal an error.

However, if it does not find any "Revision-number" line at
all, it returns success but does not put anything into the
rev_note. So upon a successful return, the rev_note may or
may not be initialized, and the caller has no way of
knowing.

gcc does not usually catch the use of the unitialized
variable because the conditional assignment happens in a
separate function from the point of use. However, when
compiling with -O3, gcc will inline parse_rev_note and
notice the problem.

We can fix it by returning "-1" when no note is found (so on
a zero return, we always found a valid value).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-12-15 10:43:11 -08:00
Florian Achleitner
5bfc76b5b2 remote-svn: add marks-file regeneration
fast-import mark files are stored outside the object database and are
therefore not fetched and can be lost somehow else.  marks provide a
svn revision --> git sha1 mapping, while the notes that are attached
to each commit when it is imported provide a git sha1 --> svn revision
mapping.

If the marks file is not available or not plausible, regenerate it by
walking through the notes tree.  , i.e.  The plausibility check tests
if the highest revision in the marks file matches the revision of the
top ref. It doesn't ensure that the mark file is completely correct.
This could only be done with an effort equal to unconditional
regeneration.

Signed-off-by: Florian Achleitner <florian.achleitner.2.6.31@gmail.com>
Acked-by: David Michael Barr <b@rr-dav.id.au>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-10-07 14:10:17 -07:00
Florian Achleitner
8e43a1d010 remote-svn: add incremental import
Search for a note attached to the ref to update and read it's
'Revision-number:'-line. Start import from the next svn revision.

If there is no next revision in the svn repo, svnrdump terminates with
a message on stderr an non-zero return value. This looks a little
weird, but there is no other way to know whether there is a new
revision in the svn repo.

On the start of an incremental import, the parent of the first commit
in the fast-import stream is set to the branch name to update. All
following commits specify their parent by a mark number. Previous mark
files are currently not reused.

Signed-off-by: Florian Achleitner <florian.achleitner.2.6.31@gmail.com>
Acked-by: David Michael Barr <b@rr-dav.id.au>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-10-07 14:10:17 -07:00
Florian Achleitner
8d7cd8eb3b remote-svn: Activate import/export-marks for fast-import
Enable import and export of a marks file by sending the appropriate
feature commands to fast-import before sending data.

Signed-off-by: Florian Achleitner <florian.achleitner.2.6.31@gmail.com>
Acked-by: David Michael Barr <b@rr-dav.id.au>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-10-07 14:10:17 -07:00
Florian Achleitner
f6529de9f4 Allow reading svn dumps from files via file:// urls
For testing as well as for importing large, already available dumps,
it's useful to bypass svnrdump and replay the svndump from a file
directly.

Add support for file:// urls in the remote url, e.g.

  svn::file:///path/to/dump

When the remote helper finds an url starting with file:// it tries to
open that file instead of invoking svnrdump.

Signed-off-by: Florian Achleitner <florian.achleitner.2.6.31@gmail.com>
Acked-by: David Michael Barr <b@rr-dav.id.au>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-10-07 14:10:17 -07:00
Florian Achleitner
68f64ff8b4 Implement a remote helper for svn in C
Enable basic fetching from subversion repositories. When processing
remote URLs starting with testsvn::, git invokes this remote-helper.
It starts svnrdump to extract revisions from the subversion repository
in the 'dump file format', and converts them to a git-fast-import stream
using the functions of vcs-svn/.

Imported refs are created in a private namespace at
refs/svn/<remote-name>/master.  The revision history is imported
linearly (no branch detection) and completely, i.e. from revision 0 to
HEAD.

The 'bidi-import' capability is used. The remote-helper expects data
from fast-import on its stdin. It buffers a batch of 'import' command
lines in a string_list before starting to process them.

Signed-off-by: Florian Achleitner <florian.achleitner.2.6.31@gmail.com>
Acked-by: David Michael Barr <b@rr-dav.id.au>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-10-07 14:10:16 -07:00