Commit Graph

383 Commits

Author SHA1 Message Date
Dragan Simic 4ca7a3fd26 diff --stat: set the width defaults in a helper function
Extract the commonly used initialization of the --stat-width=<width>,
--stat-name-width=<width> and --stat-graph-with=<width> parameters to their
internal default values into a helper function, to avoid repeating the same
initialization code in a few places.

Add a couple of tests to additionally cover existing configuration options
diff.statNameWidth=<width> and diff.statGraphWidth=<width> when used by
git-merge to generate --stat outputs.  This closes the gap that existed
previously in the --stat tests, and reduces the chances for having any
regressions introduced by this commit.

While there, perform a small bunch of minor wording tweaks in the improved
unit test, to improve its test-level consistency a bit.

Signed-off-by: Dragan Simic <dsimic@manjaro.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-09-29 15:46:06 -07:00
Jeff King 5cc6b2d70b diff: drop useless "status" parameter from diff_result_code()
Many programs use diff_result_code() to get a user-visible program exit
code from a diff result (e.g., checking opts.found_changes if
--exit-code was requested).

This function also takes a "status" parameter, which seems at first
glance that it could be used to propagate an error encountered when
computing the diff. But it doesn't work that way:

  - negative values are passed through as-is, but are not appropriate as
    program exit codes

  - when --exit-code or --check is in effect, we _ignore_ the passed-in
    status completely. So a failed diff which did not have a chance to
    set opts.found_changes would erroneously report "success, no
    changes" instead of propagating the error.

After recent cleanups, neither of these bugs is possible to trigger, as
every caller just passes in "0". So rather than fixing them, we can
simply drop the useless parameter instead.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-21 15:33:24 -07:00
Jeff King 25bd3acd04 diff: drop useless return from run_diff_{files,index} functions
Neither of these functions ever returns a value other than zero.
Instead, they expect unrecoverable errors to exit immediately, and
things like "--exit-code" are stored inside the diff_options struct to
be handled later via diff_result_code().

Some callers do check the return values, but many don't bother. Let's
drop the useless return values, which are misleading callers about how
the functions work. This could be seen as a step in the wrong direction,
as we might want to eventually "lib-ify" these to more cleanly return
errors up the stack, in which case we'd have to add the return values
back in. But there are some benefits to doing this now:

  1. In the current code, somebody could accidentally add a "return -1"
     to one of the functions, which would be erroneously ignored by many
     callers. By removing the return code, the compiler can notice the
     mismatch and force the developer to decide what to do.

     Obviously the other option here is that we could start consistently
     checking the error code in every caller. But it would be dead code,
     and we wouldn't get any compile-time help in catching new cases.

  2. It communicates the situation to callers, who may want to choose a
     different function. These functions are really thin wrappers for
     doing git-diff-files and git-diff-index within the process. But
     callers who care about recovering from an error here are probably
     better off using the underlying library functions, many of
     which do return errors.

If somebody eventually wants to teach these functions to propagate
errors, they'll have to switch back to returning a value, effectively
reverting this patch. But at least then they will be starting with a
level playing field: they know that they will need to inspect each
caller to see how it should handle the error.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-21 15:33:24 -07:00
Junio C Hamano b3d1c85d48 Merge branch 'gc/config-context'
Reduce reliance on a global state in the config reading API.

* gc/config-context:
  config: pass source to config_parser_event_fn_t
  config: add kvi.path, use it to evaluate includes
  config.c: remove config_reader from configsets
  config: pass kvi to die_bad_number()
  trace2: plumb config kvi
  config.c: pass ctx with CLI config
  config: pass ctx with config files
  config.c: pass ctx in configsets
  config: add ctx arg to config_fn_t
  urlmatch.h: use config_fn_t type
  config: inline git_color_default_config
2023-07-06 11:54:48 -07:00
Glen Choo a4e7e317f8 config: add ctx arg to config_fn_t
Add a new "const struct config_context *ctx" arg to config_fn_t to hold
additional information about the config iteration operation.
config_context has a "struct key_value_info kvi" member that holds
metadata about the config source being read (e.g. what kind of config
source it is, the filename, etc). In this series, we're only interested
in .kvi, so we could have just used "struct key_value_info" as an arg,
but config_context makes it possible to add/adjust members in the future
without changing the config_fn_t signature. We could also consider other
ways of organizing the args (e.g. moving the config name and value into
config_context or key_value_info), but in my experiments, the
incremental benefit doesn't justify the added complexity (e.g. a
config_fn_t will sometimes invoke another config_fn_t but with a
different config value).

In subsequent commits, the .kvi member will replace the global "struct
config_reader" in config.c, making config iteration a global-free
operation. It requires much more work for the machinery to provide
meaningful values of .kvi, so for now, merely change the signature and
call sites, pass NULL as a placeholder value, and don't rely on the arg
in any meaningful way.

Most of the changes are performed by
contrib/coccinelle/config_fn_ctx.pending.cocci, which, for every
config_fn_t:

- Modifies the signature to accept "const struct config_context *ctx"
- Passes "ctx" to any inner config_fn_t, if needed
- Adds UNUSED attributes to "ctx", if needed

Most config_fn_t instances are easily identified by seeing if they are
called by the various config functions. Most of the remaining ones are
manually named in the .cocci patch. Manual cleanups are still needed,
but the majority of it is trivial; it's either adjusting config_fn_t
that the .cocci patch didn't catch, or adding forward declarations of
"struct config_context ctx" to make the signatures make sense.

The non-trivial changes are in cases where we are invoking a config_fn_t
outside of config machinery, and we now need to decide what value of
"ctx" to pass. These cases are:

- trace2/tr2_cfg.c:tr2_cfg_set_fl()

  This is indirectly called by git_config_set() so that the trace2
  machinery can notice the new config values and update its settings
  using the tr2 config parsing function, i.e. tr2_cfg_cb().

- builtin/checkout.c:checkout_main()

  This calls git_xmerge_config() as a shorthand for parsing a CLI arg.
  This might be worth refactoring away in the future, since
  git_xmerge_config() can call git_default_config(), which can do much
  more than just parsing.

Handle them by creating a KVI_INIT macro that initializes "struct
key_value_info" to a reasonable default, and use that to construct the
"ctx" arg.

Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-28 14:06:39 -07:00
Elijah Newren df6e874496 diff.h: remove unnecessary include of oidset.h
This also made it clear that several .c files depended upon various
things that oidset included, but had omitted the direct #include for
those headers.  Add those now.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-21 13:39:53 -07:00
Elijah Newren eaa966db79 diff.h: move declaration for global in diff.c from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-21 13:39:53 -07:00
Junio C Hamano de00f4b7f3 Merge branch 'jk/log-follow-with-non-literal-pathspec'
"git [-c log.follow=true] log [--follow] ':(glob)f**'" used to barf.

* jk/log-follow-with-non-literal-pathspec:
  diff: detect pathspec magic not supported by --follow
  diff: factor out --follow pathspec check
  pathspec: factor out magic-to-name function
2023-06-20 15:53:13 -07:00
Jeff King 9eac5954e8 diff: factor out --follow pathspec check
In --follow mode, we require exactly one pathspec. We check this
condition in two places:

  - in diff_setup_done(), we complain if --follow is used with an
    inapropriate pathspec

  - in git-log's revision "tweak" function, we enable log.follow only if
    the pathspec allows it

The duplication isn't a big deal right now, since the logic is so
simple. But in preparation for it becoming more complex, let's pull it
into a shared function.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-03 10:34:25 +09:00
Junio C Hamano ccd12a3d6c Merge branch 'en/header-split-cache-h-part-2'
More header clean-up.

* en/header-split-cache-h-part-2: (22 commits)
  reftable: ensure git-compat-util.h is the first (indirect) include
  diff.h: reduce unnecessary includes
  object-store.h: reduce unnecessary includes
  commit.h: reduce unnecessary includes
  fsmonitor: reduce includes of cache.h
  cache.h: remove unnecessary headers
  treewide: remove cache.h inclusion due to previous changes
  cache,tree: move basic name compare functions from read-cache to tree
  cache,tree: move cmp_cache_name_compare from tree.[ch] to read-cache.c
  hash-ll.h: split out of hash.h to remove dependency on repository.h
  tree-diff.c: move S_DIFFTREE_IFXMIN_NEQ define from cache.h
  dir.h: move DTYPE defines from cache.h
  versioncmp.h: move declarations for versioncmp.c functions from cache.h
  ws.h: move declarations for ws.c functions from cache.h
  match-trees.h: move declarations for match-trees.c functions from cache.h
  pkt-line.h: move declarations for pkt-line.c functions from cache.h
  base85.h: move declarations for base85.c functions from cache.h
  copy.h: move declarations for copy.c functions from cache.h
  server-info.h: move declarations for server-info.c functions from cache.h
  packfile.h: move pack_window and pack_entry from cache.h
  ...
2023-05-09 16:45:46 -07:00
Elijah Newren 0e312eaa12 diff.h: reduce unnecessary includes
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-24 12:47:33 -07:00
Junio C Hamano 72871b198f Merge branch 'ab/remove-implicit-use-of-the-repository'
Code clean-up around the use of the_repository.

* ab/remove-implicit-use-of-the-repository:
  libs: use "struct repository *" argument, not "the_repository"
  post-cocci: adjust comments for recent repo_* migration
  cocci: apply the "revision.h" part of "the_repository.pending"
  cocci: apply the "rerere.h" part of "the_repository.pending"
  cocci: apply the "refs.h" part of "the_repository.pending"
  cocci: apply the "promisor-remote.h" part of "the_repository.pending"
  cocci: apply the "packfile.h" part of "the_repository.pending"
  cocci: apply the "pretty.h" part of "the_repository.pending"
  cocci: apply the "object-store.h" part of "the_repository.pending"
  cocci: apply the "diff.h" part of "the_repository.pending"
  cocci: apply the "commit.h" part of "the_repository.pending"
  cocci: apply the "commit-reach.h" part of "the_repository.pending"
  cocci: apply the "cache.h" part of "the_repository.pending"
  cocci: add missing "the_repository" macros to "pending"
  cocci: sort "the_repository" rules by header
  cocci: fix incorrect & verbose "the_repository" rules
  cocci: remove dead rule from "the_repository.pending.cocci"
2023-04-06 13:38:30 -07:00
Junio C Hamano e7dca80692 Merge branch 'ab/remove-implicit-use-of-the-repository' into en/header-split-cache-h
* ab/remove-implicit-use-of-the-repository:
  libs: use "struct repository *" argument, not "the_repository"
  post-cocci: adjust comments for recent repo_* migration
  cocci: apply the "revision.h" part of "the_repository.pending"
  cocci: apply the "rerere.h" part of "the_repository.pending"
  cocci: apply the "refs.h" part of "the_repository.pending"
  cocci: apply the "promisor-remote.h" part of "the_repository.pending"
  cocci: apply the "packfile.h" part of "the_repository.pending"
  cocci: apply the "pretty.h" part of "the_repository.pending"
  cocci: apply the "object-store.h" part of "the_repository.pending"
  cocci: apply the "diff.h" part of "the_repository.pending"
  cocci: apply the "commit.h" part of "the_repository.pending"
  cocci: apply the "commit-reach.h" part of "the_repository.pending"
  cocci: apply the "cache.h" part of "the_repository.pending"
  cocci: add missing "the_repository" macros to "pending"
  cocci: sort "the_repository" rules by header
  cocci: fix incorrect & verbose "the_repository" rules
  cocci: remove dead rule from "the_repository.pending.cocci"
2023-04-04 08:25:52 -07:00
Ævar Arnfjörð Bjarmason c7c33f50bd post-cocci: adjust comments for recent repo_* migration
In preceding commits we changed many calls to macros that were
providing a "the_repository" argument to invoke corresponding repo_*()
function instead. Let's follow-up and adjust references to those in
comments, which coccinelle didn't (and inherently can't) catch.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-28 07:36:46 -07:00
Ævar Arnfjörð Bjarmason 085390328f cocci: apply the "diff.h" part of "the_repository.pending"
Apply the part of "the_repository.pending.cocci" pertaining to
"diff.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-28 07:36:45 -07:00
Junio C Hamano 15108de2fa Merge branch 'jk/format-patch-ignore-noprefix'
"git format-patch" honors the src/dst prefixes set to nonstandard
values with configuration variables like "diff.noprefix", causing
receiving end of the patch that expects the standard -p1 format to
break.  Teach "format-patch" to ignore end-user configuration and
always use the standard prefixes.

This is a backward compatibility breaking change.

* jk/format-patch-ignore-noprefix:
  rebase: prefer --default-prefix to --{src,dst}-prefix for format-patch
  format-patch: add format.noprefix option
  format-patch: do not respect diff.noprefix
  diff: add --default-prefix option
  t4013: add tests for diff prefix options
  diff: factor out src/dst prefix setup
2023-03-21 14:18:55 -07:00
Junio C Hamano 88cc8ed8bc Merge branch 'en/header-cleanup'
Code clean-up to clarify the rule that "git-compat-util.h" must be
the first to be included.

* en/header-cleanup:
  diff.h: remove unnecessary include of object.h
  Remove unnecessary includes of builtin.h
  treewide: replace cache.h with more direct headers, where possible
  replace-object.h: move read_replace_refs declaration from cache.h to here
  object-store.h: move struct object_info from cache.h
  dir.h: refactor to no longer need to include cache.h
  object.h: stop depending on cache.h; make cache.h depend on object.h
  ident.h: move ident-related declarations out of cache.h
  pretty.h: move has_non_ascii() declaration from commit.h
  cache.h: remove dependence on hex.h; make other files include it explicitly
  hex.h: move some hex-related declarations from cache.h
  hash.h: move some oid-related declarations from cache.h
  alloc.h: move ALLOC_GROW() functions from cache.h
  treewide: remove unnecessary cache.h includes in source files
  treewide: remove unnecessary cache.h includes
  treewide: remove unnecessary git-compat-util.h includes in headers
  treewide: ensure one of the appropriate headers is sourced first
2023-03-17 14:03:09 -07:00
Jeff King 6799aadfdf diff: factor out src/dst prefix setup
We directly manipulate diffopt's a_prefix and b_prefix to set up either
the default "a/foo" prefix or the "--no-prefix" variant. Although this
is only a few lines, it's worth pulling these into their own functions.
That lets us avoid one repetition already in this patch, but will also
give us a cleaner interface for callers which want to tweak this
setting.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-09 08:32:17 -08:00
Junio C Hamano ece8dc97ae Merge branch 'jc/diff-algo-attribute'
The "diff" drivers specified by the "diff" attribute attached to
paths can now specify which algorithm (e.g. histogram) to use.

* jc/diff-algo-attribute:
  diff: teach diff to read algorithm from diff driver
  diff: consolidate diff algorithm option parsing
2023-02-27 10:08:56 -08:00
Elijah Newren f524970185 diff.h: remove unnecessary include of object.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-23 17:25:30 -08:00
Elijah Newren a64215b6cd object.h: stop depending on cache.h; make cache.h depend on object.h
Things should be able to depend on object.h without pulling in all of
cache.h.  Move an enum to allow this.

Note that a couple files previously depended on things brought in
through cache.h indirectly (revision.h -> commit.h -> object.h ->
cache.h).  As such, this change requires making existing dependencies
more explicit in half a dozen files.  The inclusion of strbuf.h in
some headers if of particular note: these headers directly embedded a
strbuf in some new structs, meaning they should have been including
strbuf.h all along but were indirectly getting the necessary
definitions.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-23 17:25:29 -08:00
John Cai a4cf900ee7 diff: teach diff to read algorithm from diff driver
It can be useful to specify diff algorithms per file type. For example,
one may want to use the minimal diff algorithm for .json files, another
for .c files, etc.

The diff machinery already checks attributes for a diff driver. Teach
the diff driver parser a new type "algorithm" to look for in the
config, which will be used if a driver has been specified through the
attributes.

Enforce precedence of the diff algorithm by favoring the command line
option, then looking at the driver attributes & config combination, then
finally the diff.algorithm config.

To enforce precedence order, use a new `ignore_driver_algorithm` member
during options parsing to indicate the diff algorithm was set via command
line args.

Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-21 09:29:10 -08:00
Junio C Hamano ab91f6b7c4 Merge branch 'rs/diff-parseopts'
The way the diff machinery prepares the options array for the
parse_options API has been refactored to avoid resource leaks.

* rs/diff-parseopts:
  diff: remove parseopts member from struct diff_options
  diff: use add_diff_options() in diff_opt_parse()
  diff: factor out add_diff_options()
2022-12-19 11:46:17 +09:00
René Scharfe 189e97bc4b diff: remove parseopts member from struct diff_options
repo_diff_setup() builds the struct option array with git diff's command
line options and stores a pointer to it in the parseopts member of
struct diff_options.  The array is freed by diff_setup_done(), but not
by release_revisions().  Thus calling only repo_diff_setup() and
release_revisions() leaks that array.

We could free it in release_revisions() as well to plug that leak, but
there is a better way: Only build it when needed.  Absorb
prep_parse_options() into the last place that uses the parseopts member
of struct diff_options, add_diff_parseopts(), and get rid of said
member.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-12-02 08:25:30 +09:00
René Scharfe c5630c4868 diff: factor out add_diff_options()
Add a function for appending the parseopts member of struct diff_options
to a struct option array.  Use it in two sites instead of accessing the
parseopts member directly.  Decoupling callers from diff internals like
that allows us to change the latter.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-12-02 08:25:29 +09:00
Jerry Zhang 51276c1832 patch-id: use stable patch-id for rebases
Git doesn't persist patch-ids during the rebase process, so there is
no need to specifically invoke the unstable variant. Use the stable
logic for all internal patch-id calculations to minimize the number of
code paths and improve test coverage.

Signed-off-by: Jerry Zhang <jerry@skydio.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-24 15:44:19 -07:00
Junio C Hamano 9a160990ef Merge branch 'js/diff-filter-negation-fix'
"git diff --diff-filter=aR" is now parsed correctly.

* js/diff-filter-negation-fix:
  diff-filter: be more careful when looking for negative bits
  diff.c: move the diff filter bits definitions up a bit
  docs(diff): lose incorrect claim about `diff-files --diff-filter=A`
2022-02-16 15:14:30 -08:00
Elijah Newren 95433eeed9 diff: add ability to insert additional headers for paths
When additional headers are provided, we need to
  * add diff_filepairs to diff_queued_diff for each paths in the
    additional headers map which, unless that path is part of
    another diff_filepair already found in diff_queued_diff
  * format the headers (colorization, line_prefix for --graph)
  * make sure the various codepaths that attempt to return early
    if there are "no changes" take into account the headers that
    need to be shown.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-02 10:02:28 -08:00
Johannes Schindelin 75408ca949 diff-filter: be more careful when looking for negative bits
The `--diff-filter=<bits>` option allows to filter the diff by certain
criteria, for example `R` to only show renamed files. It also supports
negating a filter via a down-cased letter, i.e. `r` to show _everything
but_ renamed files.

However, the code is a bit overzealous when trying to figure out whether
`git diff` should start with all diff-filters turned on because the user
provided a lower-case letter: if the `--diff-filter` argument starts
with an upper-case letter, we must not start with all bits turned on.

Even worse, it is possible to specify the diff filters in multiple,
separate options, e.g. `--diff-filter=AM [...] --diff-filter=m`.

Let's accumulate the include/exclude filters independently, and only
special-case the "only exclude filters were specified" case after
parsing the options altogether.

Note: The code replaced by this commit took pains to avoid setting any
unused bits of `options->filter`. That was unnecessary, though, as all
accesses happen via the `filter_bit_tst()` function using specific bits,
and setting the unused bits has no effect. Therefore, we can simplify
the code by using `~0` (or in this instance, `~<unwanted-bit>`).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-28 10:18:18 -08:00
Ævar Arnfjörð Bjarmason a47fcbe6e4 diff.h: move pickaxe fields together again
Move the pickaxe and pickaxe_opts fields next to each other again. In
a past life they'd been on adjacent lines, but when they got moved
from a global variable to the diff_options struct in 6b5ee137e5 (Diff
clean-up., 2005-09-21) they got split apart.

That split made sense at the time, the "char*" and "int" (flags)
options were being grouped, but we've long since abandoned that
pattern in the diff_options struct, and now it makes more sense to
group these together again.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-11 12:47:31 +09:00
Ævar Arnfjörð Bjarmason d26ec88009 pickaxe: die when --find-object and --pickaxe-all are combined
Neither the --pickaxe-all documentation nor --find-object's has ever
suggested that you can combine the two. See f506b8e8b5 (git log/diff:
add -G<regexp> that greps in the patch text, 2010-08-23) and
15af58c1ad (diffcore: add a pickaxe option to find a specific blob,
2018-01-04).

But we've silently tolerated it, which makes the logic in
diffcore_pickaxe() harder to reason about. Let's assert that we won't
have the two combined.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-11 12:47:31 +09:00
Ævar Arnfjörð Bjarmason 188e9e28c5 pickaxe: die when -G and --pickaxe-regex are combined
When the -G and --pickaxe-regex options are combined we simply ignore
the --pickaxe-regex option. Let's die instead as suggested by our
documentation, since -G is always a regex.

When --pickaxe-regex was added in d01d8c6782 (Support for pickaxe
matching regular expressions, 2006-03-29) only the -S option
existed. Then when -G was added in f506b8e8b5 (git log/diff: add
-G<regexp> that greps in the patch text, 2010-08-23) neither the
documentation for --pickaxe-regex was updated accordingly, nor was
something like this assertion added.

Since 5bc3f0b567 (diffcore-pickaxe doc: document -S and -G properly,
2013-05-31) we've claimed that --pickaxe-regex should only be used
with -S, but have silently tolerated combining it with -G, let's die
instead.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-11 12:47:31 +09:00
Junio C Hamano 845d6030f8 Merge branch 'jc/diffcore-rotate'
"git {diff,log} --{skip,rotate}-to=<path>" allows the user to
discard diff output for early paths or move them to the end of the
output.

* jc/diffcore-rotate:
  diff: --{rotate,skip}-to=<path>
2021-02-25 16:43:30 -08:00
Junio C Hamano 1eb4136ac2 diff: --{rotate,skip}-to=<path>
In the implementation of "git difftool", there is a case where the
user wants to start viewing the diffs at a specific path and
continue on to the rest, optionally wrapping around to the
beginning.  Since it is somewhat cumbersome to implement such a
feature as a post-processing step of "git diff" output, let's
support it internally with two new options.

 - "git diff --rotate-to=C", when the resulting patch would show
   paths A B C D E without the option, would "rotate" the paths to
   shows patch to C D E A B instead.  It is an error when there is
   no patch for C is shown.

 - "git diff --skip-to=C" would instead "skip" the paths before C,
   and shows patch to C D E.  Again, it is an error when there is no
   patch for C is shown.

 - "git log [-p]" also accepts these two options, but it is not an
   error if there is no change to the specified path.  Instead, the
   set of output paths are rotated or skipped to the specified path
   or the first path that sorts after the specified path.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-16 09:30:42 -08:00
Ævar Arnfjörð Bjarmason e900d494dc diff: add an API for deferred freeing
Add a diff_free() function to free anything we may have allocated in
the "diff_options" struct, and the ability to make calling it a noop
by setting "no_free" in "diff_options".

This is required because when e.g. "git diff" is run we'll allocate
things in that struct, use the diff machinery once, and then exit.

But if we run e.g. "git log -p" we're going to re-use what we
allocated across multiple diff_flush() calls, and only want to free
things at the end.

We've thus ended up with features like the recently added "diff -I"[1]
where we'll leak memory. As it turns out it could have simply used the
pattern established in 6ea57703f6 (log: prepare log/log-tree to reuse
the diffopt.close_file attribute, 2016-06-22).

Manually adding more such flags to things log_tree_commit() every time
we need to allocate something would be tedious. Let's instead move
that fclose() code it to a new diff_free(), in anticipation of freeing
more things in that function in follow-up commits.

Some functions such as log_tree_commit() need an idiom of optionally
retaining a previous "no_free", as they may either free the memory
themselves, or their caller may do so. I'm keeping that idiom in
log_show_early() for good measure, even though I don't think it's
currently called in this manner. It also gets passed an existing
"struct rev_info", so future callers may want to set the "no_free"
flag.

This change is a bit hard to read because while the freeing pattern
we're introducing isn't unusual, the "file" member is a special
snowflake. We usually don't want to fclose() it. This is because
"file" is usually stdout, in which case we don't want to fclose()
it. We only want to opt-in to closing it when we e.g. open a file on
the filesystem. Thus the opt-in "close_file" flag.

So the API in general just needs a "no_free" flag to defer freeing,
but the "file" member still needs its "close_file" flag. This is made
more confusing because while refactoring this code we could replace
some "close_file=0" with "no_free=1", whereas others need to set both
flags.

This is because there were some cases where an existing "close_file=0"
meant "let's defer deallocation", and others where it meant "we don't
want to close this file handle at all".

1. 296d4a94e7 (diff: add -I<regex> that ignores matching changes,
   2020-10-20)

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-11 09:21:05 -08:00
Junio C Hamano 0806279428 Merge branch 'sj/untracked-files-in-submodule-directory-is-not-dirty'
"git diff" showed a submodule working tree with untracked cruft as
"Submodule commit <objectname>-dirty", but a natural expectation is
that the "-dirty" indicator would align with "git describe --dirty",
which does not consider having untracked files in the working tree
as source of dirtiness.  The inconsistency has been fixed.

* sj/untracked-files-in-submodule-directory-is-not-dirty:
  diff: do not show submodule with untracked files as "-dirty"
2021-01-25 14:19:18 -08:00
Sangeeta Jain 8ef9312464 diff: do not show submodule with untracked files as "-dirty"
Git diff reports a submodule directory as -dirty even when there are
only untracked files in the submodule directory. This is inconsistent
with what `git describe --dirty` says when run in the submodule
directory in that state.

Make `--ignore-submodules=untracked` the default for `git diff` when
there is no configuration variable or command line option, so that the
command would not give '-dirty' suffix to a submodule whose working
tree has untracked files, to make it consistent with `git
describe --dirty` that is run in the submodule working tree.

And also make `--ignore-submodules=none` the default for `git status`
so that the user doesn't end up deleting a submodule that has
uncommitted (untracked) files.

Signed-off-by: Sangeeta Jain <sangunb09@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-08 14:27:35 -08:00
Junio C Hamano 1ae0949a03 Merge branch 'mk/diff-ignore-regex'
"git diff" family of commands learned the "-I<regex>" option to
ignore hunks whose changed lines all match the given pattern.

* mk/diff-ignore-regex:
  diff: add -I<regex> that ignores matching changes
  merge-base, xdiff: zero out xpparam_t structures
2020-11-02 13:17:44 -08:00
Junio C Hamano b6fb70c985 Merge branch 'dl/diff-merge-base'
"git diff A...B" learned "git diff --merge-base A B", which is a
longer short-hand to say the same thing.

* dl/diff-merge-base:
  contrib/completion: complete `git diff --merge-base`
  builtin/diff-tree: learn --merge-base
  builtin/diff-index: learn --merge-base
  t4068: add --merge-base tests
  diff-lib: define diff_get_merge_base()
  diff-lib: accept option flags in run_diff_index()
  contrib/completion: extract common diff/difftool options
  git-diff.txt: backtick quote command text
  git-diff-index.txt: make --cached description a proper sentence
  t4068: remove unnecessary >tmp
2020-11-02 13:17:39 -08:00
Michał Kępień 296d4a94e7 diff: add -I<regex> that ignores matching changes
Add a new diff option that enables ignoring changes whose all lines
(changed, removed, and added) match a given regular expression.  This is
similar to the -I/--ignore-matching-lines option in standalone diff
utilities and can be used e.g. to ignore changes which only affect code
comments or to look for unrelated changes in commits containing a large
number of automatically applied modifications (e.g. a tree-wide string
replacement).  The difference between -G/-S and the new -I option is
that the latter filters output on a per-change basis.

Use the 'ignore' field of xdchange_t for marking a change as ignored or
not.  Since the same field is used by --ignore-blank-lines, identical
hunk emitting rules apply for --ignore-blank-lines and -I.  These two
options can also be used together in the same git invocation (they are
complementary to each other).

Rename xdl_mark_ignorable() to xdl_mark_ignorable_lines(), to indicate
that it is logically a "sibling" of xdl_mark_ignorable_regex() rather
than its "parent".

Signed-off-by: Michał Kępień <michal@isc.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-20 12:53:26 -07:00
Junio C Hamano 34415c76c8 Merge branch 'so/combine-diff-simplify'
Code simplification.

* so/combine-diff-simplify:
  diff: get rid of redundant 'dense' argument
2020-10-05 14:01:51 -07:00
Junio C Hamano 288ed98bf7 Merge branch 'tb/bloom-improvements'
"git commit-graph write" learned to limit the number of bloom
filters that are computed from scratch with the --max-new-filters
option.

* tb/bloom-improvements:
  commit-graph: introduce 'commitGraph.maxNewFilters'
  builtin/commit-graph.c: introduce '--max-new-filters=<n>'
  commit-graph: rename 'split_commit_graph_opts'
  bloom: encode out-of-bounds filters as non-empty
  bloom/diff: properly short-circuit on max_changes
  bloom: use provided 'struct bloom_filter_settings'
  bloom: split 'get_bloom_filter()' in two
  commit-graph.c: store maximum changed paths
  commit-graph: respect 'commitGraph.readChangedPaths'
  t/helper/test-read-graph.c: prepare repo settings
  commit-graph: pass a 'struct repository *' in more places
  t4216: use an '&&'-chain
  commit-graph: introduce 'get_bloom_filter_settings()'
2020-09-29 14:01:20 -07:00
Sergey Organov d01141de5a diff: get rid of redundant 'dense' argument
Get rid of 'dense' argument that is redundant for every function that has
'struct rev_info *rev' argument as well, as the value of 'dense' passed is
always taken from 'rev->dense_combined_merges' field.

The only place where this was not the case is in 'submodule.c' where
'diff_tree_combined_merge()' was called with '1' for 'dense' argument. However,
at that call the 'revs' instance used is local to the function, and we now just
set 'revs->dense_combined_merges' to 1 in this local instance.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-29 11:54:53 -07:00
Denton Liu 0f5a1d449b builtin/diff-index: learn --merge-base
There is currently no easy way to take the diff between the working tree
or index and the merge base between an arbitrary commit and HEAD. Even
diff's `...` notation doesn't allow this because it only works between
commits. However, the ability to do this would be desirable to a user
who would like to see all the changes they've made on a branch plus
uncommitted changes without taking into account changes made in the
upstream branch.

Teach diff-index and diff (with one commit) the --merge-base option
which allows a user to use the merge base of a commit and HEAD as the
"before" side.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-20 21:30:26 -07:00
Denton Liu 177a830268 diff-lib: define diff_get_merge_base()
In a future commit, we will be using this function to implement
--merge-base functionality in various diff commands.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-20 21:30:26 -07:00
Denton Liu 4c3fe82ef1 diff-lib: accept option flags in run_diff_index()
In a future commit, we will teach run_diff_index() to accept more
options via flag bits. For now, change `cached` into a flag in the
`option` bitfield. The behaviour should remain exactly the same.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-20 21:30:26 -07:00
Derrick Stolee b16a827764 bloom/diff: properly short-circuit on max_changes
Commit e3696980 (diff: halt tree-diff early after max_changes,
2020-03-30) intended to create a mechanism to short-circuit a diff
calculation after a certain number of paths were modified. By
incrementing a "num_changes" counter throughout the recursive
ll_diff_tree_paths(), this was supposed to match the number of changes
that would be written into the changed-path Bloom filters.
Unfortunately, this was not implemented correctly and instead misses
simple cases like file modifications. This then does not stop very
large changed-path filters from being written (unless they add or remove
many files).

To start, change the implementation in ll_diff_tree_paths() to instead
use the global diff_queue_diff struct's 'nr' member as the count. This
is a way to simplify the logic instead of making more mistakes in the
complicated diff code.

This has a drawback: the diff_queue_diff struct only lists the paths
corresponding to blob changes, not their leading directories. Thus,
get_or_compute_bloom_filter() needs an additional check to see if the
hashmap with the leading directories becomes too large.

One reason why this was not caught by test cases was that the test in
t4216-log-bloom.sh that was supposed to check this "too many changes"
condition only checked this on the initial commit of a repository. The
old logic counted these values correctly. Update this test in a few
ways:

1. Use GIT_TEST_BLOOM_SETTINGS_MAX_CHANGED_PATHS to reduce the limit,
   allowing smaller commits to engage with this logic.

2. Create several interesting cases of edits, adds, removes, and mode
   changes (in the second commit). By testing both sides of the
   inequality with the *_MAX_CHANGED_PATHS variable, we can see that
   the count is exactly correct, so none of these changes are missed
   or over-counted.

3. Use the trace2 data value filter_found_large to verify that these
   commits are on the correct side of the limit.

Another way to verify the behavior is correct is through performance
tests. By testing on my local copies of the Git repository and the Linux
kernel repository, I could measure the effect of these short-circuits
when computing a fresh commit-graph file with changed-path Bloom filters
using the command

  GIT_TEST_BLOOM_SETTINGS_MAX_CHANGED_PATHS=N time \
    git commit-graph write --reachable --changed-paths

and reporting the wall time and resulting commit-graph size.

For Git, the results are

|        |      N=1       |       N=10     |      N=512     |
|--------|----------------|----------------|----------------|
| HEAD~1 | 10.90s  9.18MB | 11.11s  9.34MB | 11.31s  9.35MB |
| HEAD   |  9.21s  8.62MB | 11.11s  9.29MB | 11.29s  9.34MB |

For Linux, the results are

|        |       N=1      |     N=20      |     N=512     |
|--------|----------------|---------------|---------------|
| HEAD~1 | 61.28s  64.3MB | 76.9s  72.6MB | 77.6s  72.6MB |
| HEAD   | 49.44s  56.3MB | 68.7s  65.9MB | 69.2s  65.9MB |

Naturally, the improvement becomes much less as the limit grows, as
fewer commits satisfy the short-circuit.

Reported-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-17 09:31:25 -07:00
Eric Sunshine 72a7239016 diff-lib: tighten show_interdiff()'s interface
To compute and show an interdiff, show_interdiff() needs only the two
OID's to compare and a diffopts, yet it expects callers to supply an
entire rev_info. The demand for rev_info is not only overkill, but also
places unnecessary burden on potential future callers which might not
otherwise have a rev_info at hand. Address this by tightening its
signature to require only the items it needs instead of a full rev_info.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-08 15:03:27 -07:00
Eric Sunshine cdffbdc217 diff: move show_interdiff() from its own file to diff-lib
show_interdiff() is a relatively small function and not likely to grow
larger or more complicated. Rather than dedicating an entire source file
to it, relocate it to diff-lib.c which houses other "take two things and
compare them" functions meant to be re-used but not so low-level as to
reside in the core diff implementation.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-08 15:03:26 -07:00
SZEDER Gábor 0ee3cb888d diff.h: drop diff_tree_oid() & friends' return value
ll_diff_tree_oid() has only ever returned 0 [1], so it's return value
is basically useless.  It's only caller diff_tree_oid() has only ever
returned the return value of ll_diff_tree_oid() as-is [2], so its
return value is just as useless.  Most of diff_tree_oid()'s callers
simply ignore its return value, except:

  - diff_root_tree_oid() is a thin wrapper around diff_tree_oid() and
    returns with its return value, but all of diff_root_tree_oid()'s
    callers ignore its return value.

  - rev_compare_tree() and rev_same_tree_as_empty() do look at the
    return value in a condition, but, since the return value is always
    0, the former's < 0 condition is never fulfilled, while the
    latter's >= 0 condition is always fulfilled.

So let's drop the return value of ll_diff_tree_oid(), diff_tree_oid()
and diff_root_tree_oid(), and drop those conditions from
rev_compare_tree() and rev_same_tree_as_empty() as well.

[1] ll_diff_tree_oid() and its ancestors have been returning only 0
    ever since it was introduced as diff_tree() in 9174026cfe (Add
    "diff-tree" program to show which files have changed between two
    trees., 2005-04-09).
[2] diff_tree_oid() traces back to diff-tree.c:main() in 9174026cfe as
    well.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-08 12:28:49 -07:00