When a patch consists mostly of moving blocks of code around, it can
be quite tedious to ensure that the blocks are moved verbatim, and not
undesirably modified in the move. To that end, color blocks that are
moved within the same patch differently. For example (OM, del, add,
and NM are different colors):
[OM] -void sensitive_stuff(void)
[OM] -{
[OM] - if (!is_authorized_user())
[OM] - die("unauthorized");
[OM] - sensitive_stuff(spanning,
[OM] - multiple,
[OM] - lines);
[OM] -}
void another_function()
{
[del] - printf("foo");
[add] + printf("bar");
}
[NM] +void sensitive_stuff(void)
[NM] +{
[NM] + if (!is_authorized_user())
[NM] + die("unauthorized");
[NM] + sensitive_stuff(spanning,
[NM] + multiple,
[NM] + lines);
[NM] +}
However adjacent blocks may be problematic. For example, in this
potentially malicious patch, the swapping of blocks can be spotted:
[OM] -void sensitive_stuff(void)
[OM] -{
[OMA] - if (!is_authorized_user())
[OMA] - die("unauthorized");
[OM] - sensitive_stuff(spanning,
[OM] - multiple,
[OM] - lines);
[OMA] -}
void another_function()
{
[del] - printf("foo");
[add] + printf("bar");
}
[NM] +void sensitive_stuff(void)
[NM] +{
[NMA] + sensitive_stuff(spanning,
[NMA] + multiple,
[NMA] + lines);
[NM] + if (!is_authorized_user())
[NM] + die("unauthorized");
[NMA] +}
If the moved code is larger, it is easier to hide some permutation in the
code, which is why some alternative coloring is needed.
This patch implements the first mode:
* basic alternating 'Zebra' mode
This conveys all information needed to the user. Defer customization to
later patches.
First I implemented an alternative design, which would try to fingerprint
a line by its neighbors to detect if we are in a block or at the boundary.
This idea iss error prone as it inspected each line and its neighboring
lines to determine if the line was (a) moved and (b) if was deep inside
a hunk by having matching neighboring lines. This is unreliable as the
we can construct hunks which have equal neighbors that just exceed the
number of lines inspected. (Think of 'AXYZBXYZCXYZD..' with each letter
as a line, that is permutated to AXYZCXYZBXYZD..').
Instead this provides a dynamic programming greedy algorithm that finds
the largest moved hunk and then has several modes on highlighting bounds.
A note on the options '--submodule=diff' and '--color-words/--word-diff':
In the conversion to use emit_line in the prior patches both submodules
as well as word diff output carefully chose to call emit_line with sign=0.
All output with sign=0 is ignored for move detection purposes in this
patch, such that no weird looking output will be generated for these
cases. This leads to another thought: We could pass on '--color-moved' to
submodules such that they color up moved lines for themselves. If we'd do
so only line moves within a repository boundary are marked up.
It is useful to have moved lines colored, but there are annoying corner
cases, such as a single line moved, that is very common. For example
in a typical patch of C code, we have closing braces that end statement
blocks or functions.
While it is technically true that these lines are moved as they show up
elsewhere, it is harmful for the review as the reviewers attention is
drawn to such a minor side annoyance.
For now let's have a simple solution of hardcoding the number of
moved lines to be at least 3 before coloring them. Note, that the
length is applied across all blocks to find the 'lonely' blocks
that pollute new code, but do not interfere with a permutated
block where each permutation has less lines than 3.
Helped-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new option 'emitted_symbols' in the struct diff_options which
controls whether all output is buffered up until all output is available.
It is set internally in diff.c when necessary.
We'll have a new struct 'emitted_string' in diff.c which will be used to
buffer each line. The emitted_string will duplicate the memory of the
line to buffer as that is easiest to reason about for now. In a future
patch we may want to decrease the memory usage by not duplicating all
output for buffering but rather we may want to store offsets into the
file or in case of hunk descriptions such as the similarity score, we
could just store the relevant number and reproduce the text later on.
This approach was chosen as a first step because it is quite simple
compared to the alternative with less memory footprint.
emit_diff_symbol factors out the emission part and depending on the
diff_options->emitted_symbols the emission will be performed directly
when calling emit_diff_symbol or after the whole process is done, i.e.
by buffering we have add the possibility for a second pass over the
whole output before doing the actual output.
In 6440d34 (2012-03-14, diff: tweak a _copy_ of diff_options with
word-diff) we introduced a duplicate diff options struct for word
emissions as we may have different regex settings in there.
When buffering the output, we need to operate on just one buffer,
so we have to copy back the emissions of the word buffer into the
main buffer.
Unconditionally enable output via buffer in this patch as it yields
a great opportunity for testing, i.e. all the diff tests from the
test suite pass without having reordering issues (i.e. only parts
of the output got buffered, and we forgot to buffer other parts).
The test suite passes, which gives confidence that we converted all
functions to use emit_string for output.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The word diffing is not line oriented and would need some serious
effort to be transformed into a line oriented approach, so
just go with a symbol DIFF_SYMBOL_WORD_DIFF that is a partial line.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We call print_stat_summary from builtin/apply, so we still
need the version with a file pointer, so introduce
print_stat_summary_0 that uses emit_string machinery and
keep print_stat_summary with the same arguments around.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As the submodule process is no longer attached to the same file pointer
'o->file' as the superprojects process, there is a different result in
color.c::check_auto_color. That is why we need to pass coloring explicitly,
such that the submodule coloring decision will be made by the child process
processing the submodule. Only DIFF_SYMBOL_SUBMODULE_PIPETHROUGH contains
color, the other symbols are for embedding the submodule output into the
superprojects output.
Remove the colors from the function signatures, as all the coloring
decisions will be made either inside the child process or the final
emit_diff_symbol, but not in the functions driving the submodule diff.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
we could save a little bit of memory when buffering in a later mode
by just passing the inner part ("%s and %s", file1, file 2), but
those a just a few bytes, so instead let's reuse the implementation from
DIFF_SYMBOL_HEADER and keep the whole line around.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The header is constructed lazily including line breaks, so just emit
the raw string as is.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have to use fprintf instead of emit_line, because we want to emit the
tab after the color. This is important for ancient versions of gnu patch
AFAICT, although we probably do not want to feed colored output to the
patch utility, such that it would not matter if the trailing tab is
colored. Keep the corner case as-is though.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The context marker use the exact same output pattern, so reuse it.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a new flags field to emit_diff_symbol, that will be used by
context lines for:
* white space rules that are applicable (The first 12 bits)
Take a note in cahe.c as well, when this ws rules are extended we have
to fix the bits in the flags field.
* how the rules are evaluated (actually this double encodes the sign
of the line, but the code is easier to keep this way, bits 13,14,15)
* if the line a blank line at EOF (bit 16)
The check if new lines need to be marked up as extra lines at the end of
file, is now done unconditionally. That should be ok, as
'new_blank_line_at_eof' has a quick early return.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a later patch we want to buffer all output before emitting it as a
new feature ("markup moved lines") conceptually cannot be implemented
in a single pass over the output.
There are different approaches to buffer all output such as:
* Buffering on the char level, i.e. we'd have a char[] which would
grow at approximately 80 characters a line. This would keep the
output completely unstructured, but might be very easy to implement,
such as redirecting all output to a temporary file and working off
that. The later passes over the buffer are quite complicated though,
because we have to parse back any output and then decide if it should
be modified.
* Buffer on a line level. As the output is mostly line oriented already,
this would make sense, but it still is a bit awkward as we'd have to
make sense of it again by looking at the first characters of a line
to decide what part of a diff a line is.
* Buffer semantically. Imagine there is a formal grammar for the diff
output and we'd keep the symbols of this grammar around. This keeps
the highest level of structure in the buffered data, such that the
actual memory requirements are less than say the first option. Instead
of buffering the characters of the line, we'll buffer what we intend
to do plus additional information for the specifics. An output of
diff --git a/new.txt b/new.txt
index fa69b07..412428c 100644
Binary files a/new.txt and b/new.txt differ
could be buffered as
DIFF_SYMBOL_DIFF_START + new.txt
DIFF_SYMBOL_INDEX_MODE + fa69b07 412428c "non-executable" flag
DIFF_SYMBOL_BINARY_FILES + new.txt
This and the following patches introduce the third option of buffering
by first moving any output to emit_diff_symbol, and then introducing the
buffering in this function.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a later patch we want to do more things before and after all filepairs
are flushed. So factor flushing out all file pairs into its own function
that the new code can be plugged in easily.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The emit_hunk_header() function is responsible for assembling a
hunk header and calling emit_line() to send the hunk header
to the output file. Its only caller fn_out_consume() needs
to prepare for a case where the function emits an incomplete
line and add the terminating LF.
Instead make sure emit_hunk_header() to always send a
completed line to emit_line().
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We already have dereferenced 'p->two' into a local variable 'two'.
Use that.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A common pattern to free a piece of memory and assign NULL to the
pointer that used to point at it has been replaced with a new
FREE_AND_NULL() macro.
* ab/free-and-null:
*.[ch] refactoring: make use of the FREE_AND_NULL() macro
coccinelle: make use of the "expression" FREE_AND_NULL() rule
coccinelle: add a rule to make "expression" code use FREE_AND_NULL()
coccinelle: make use of the "type" FREE_AND_NULL() rule
coccinelle: add a rule to make "type" code use FREE_AND_NULL()
git-compat-util: add a FREE_AND_NULL() wrapper around free(ptr); ptr = NULL
Fix configuration codepath to pay proper attention to commondir
that is used in multi-worktree situation, and isolate config API
into its own header file.
* 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
Code clean-up.
* 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
Apply the result of the just-added coccinelle rule. This manually
excludes a few occurrences, mostly things that resulted in many
FREE_AND_NULL() on one line, that'll be manually fixed in a subsequent
change.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio 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: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We often try to open a file for reading whose existence is
optional, and silently ignore errors from open/fopen; report such
errors if they are not due to missing files.
* nd/fopen-errors:
mingw_fopen: report ENOENT for invalid file names
mingw: verify that paths are not mistaken for remote nicknames
log: fix memory leak in open_next_file()
rerere.c: move error_errno() closer to the source system call
print errno when reporting a system call error
wrapper.c: make warn_on_inaccessible() static
wrapper.c: add and use fopen_or_warn()
wrapper.c: add and use warn_on_fopen_errors()
config.mak.uname: set FREAD_READS_DIRECTORIES for Darwin, too
config.mak.uname: set FREAD_READS_DIRECTORIES for Linux and FreeBSD
clone: use xfopen() instead of fopen()
use xfopen() in more places
git_fopen: fix a sparse 'not declared' warning
The internal logic used in "git blame" has been libified to make it
easier to use by cgit.
* js/blame-lib: (29 commits)
blame: move entry prepend to libgit
blame: move scoreboard setup to libgit
blame: move scoreboard-related methods to libgit
blame: move fake-commit-related methods to libgit
blame: move origin-related methods to libgit
blame: move core structures to header
blame: create entry prepend function
blame: create scoreboard setup function
blame: create scoreboard init function
blame: rework methods that determine 'final' commit
blame: wrap blame_sort and compare_blame_final
blame: move progress updates to a scoreboard callback
blame: make sanity_check use a callback in scoreboard
blame: move no_whole_file_rename flag to scoreboard
blame: move xdl_opts flags to scoreboard
blame: move show_root flag to scoreboard
blame: move reverse flag to scoreboard
blame: move contents_from to scoreboard
blame: move copy/move thresholds to scoreboard
blame: move stat counters to scoreboard
...
Make the "indent" heuristics the default in "diff" and diff.indentHeuristics
configuration variable an escape hatch for those who do no want it.
* mb/diff-default-to-indent-heuristics:
add--interactive: drop diff.indentHeuristic handling
diff: enable indent heuristic by default
diff: have the diff-* builtins configure diff before initializing revisions
diff: make the indent heuristic part of diff's basic configuration
Convert diff_change to take a struct object_id. In addition convert the
function pointer type 'change_fn_t' to also take a struct object_id.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert diff_addremove to take a struct object_id. In addtion convert
the function pointer type 'add_remove_fn_t' to also take a struct
object_id.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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
...
xfopen()
- provides error details
- explains error on reading, or writing, or whatever operation
- has l10n support
- prints file name in the error
Some of these are missing in the places that are replaced with xfopen(),
which is a clear win. In some other places, it's just less code (not as
clearly a win as the previous case but still is).
The only slight regresssion is in remote-testsvn, where we don't report
the file class (marks files) in the error messages anymore. But since
this is a _test_ svn remote transport, I'm not too concerned.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
textconv_object is used in places other than blame.c and should be moved
to a more appropriate location. Other textconv related functions are
located in diff.c so that seems as good a place as any.
Signed-off-by: Jeff Smith <whydoubt@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The feature was included in v2.11 (released 2016-11-29) and we got no
negative feedback. Quite the opposite, all feedback we got was positive.
Turn it on by default. Users who dislike the feature can turn it off
by setting diff.indentHeuristic (which also configures plumbing commands,
see prior patches).
The change to t/t4051-diff-function-context.sh is needed because the
heuristic shifts the changed hunk in the patch. To get the same result
regardless of the heuristic configuration, we modify the test file
differently: We insert a completely new line after line 2, instead of
simply duplicating it.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Marc Branchaud <marcnarc@xiplink.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This heuristic was originally introduced as an experimental feature,
and therefore part of the UI configuration.
But the user often sees diffs generated by plumbing commands like
diff-tree. Moving the indent heuristic into diff's basic configuration
prepares the way for diff plumbing commands to respect the setting.
The heuristic itself merely makes the diffs more aesthetically
pleasing, without changing their correctness. Scripts that rely on
the diff plumbing commands should not care whether or not the heuristic
is employed.
Signed-off-by: Marc Branchaud <marcnarc@xiplink.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert as many instances of unsigned char [20] as possible. Update the
callers of notes_cache_get and notes_cache_put to use the new interface.
Among the functions updated are callers of
lookup_commit_reference_gently, which we will soon convert.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Conversion from unsigned char [40] to struct object_id continues.
* bc/object-id:
Documentation: update and rename api-sha1-array.txt
Rename sha1_array to oid_array
Convert sha1_array_for_each_unique and for_each_abbrev to object_id
Convert sha1_array_lookup to take struct object_id
Convert remaining callers of sha1_array_lookup to object_id
Make sha1_array_append take a struct object_id *
sha1-array: convert internal storage for struct sha1_array to object_id
builtin/pull: convert to struct object_id
submodule: convert check_for_new_submodule_commits to object_id
sha1_name: convert disambiguate_hint_fn to take object_id
sha1_name: convert struct disambiguate_state to object_id
test-sha1-array: convert most code to struct object_id
parse-options-cb: convert sha1_array_append caller to struct object_id
fsck: convert init_skiplist to struct object_id
builtin/receive-pack: convert portions to struct object_id
builtin/pull: convert portions to struct object_id
builtin/diff: convert to struct object_id
Convert GIT_SHA1_RAWSZ used for allocation to GIT_MAX_RAWSZ
Convert GIT_SHA1_HEXSZ used for allocation to GIT_MAX_HEXSZ
Define new hash-size constants for allocating memory
To generate a patch id, we format the diff header into a
fixed-size buffer, and then feed the result to our sha1
computation. The fixed buffer has size '4*PATH_MAX + 20',
which in theory accommodates the four filenames plus some
extra data. Except:
1. The filenames may not be constrained to PATH_MAX. The
static value may not be a real limit on the current
filesystem. Moreover, we may compute patch-ids for
names stored only in git, without touching the current
filesystem at all.
2. The 20 bytes is not nearly enough to cover the
extra content we put in the buffer.
As a result, the data we feed to the sha1 computation may be
truncated, and it's possible that a commit with a very long
filename could erroneously collide in the patch-id space
with another commit. For instance, if one commit modified
"really-long-filename/foo" and another modified "bar" in the
same directory.
In practice this is unlikely. Because the filenames are
repeated, and because there's a single cutoff at the end of
the buffer, the offending filename would have to be on the
order of four times larger than PATH_MAX.
We could fix this by moving to a strbuf. However, we can
observe that the purpose of formatting this in the first
place is to feed it to git_SHA1_Update(). So instead, let's
just feed each part of the formatted string directly. This
actually ends up more readable, and we can even factor out
some duplicated bits from the various conditional branches.
Technically this may change the output of patch-id for very
long filenames, but it's not worth making an exception for
this in the --stable output. It was a bug, and one that only
affected an unlikely set of paths. And anyway, the exact
value would have varied from platform to platform depending
on the value of PATH_MAX, so there is no "stable" value.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since we will likely be introducing a new hash function at some point,
and that hash function might be longer than 40 hex characters, use the
constant GIT_MAX_HEXSZ, which is designed to be suitable for
allocations, instead of GIT_SHA1_HEXSZ. This will ease the transition
down the line by distinguishing between places where we need to allocate
memory suitable for the largest hash from those where we need to handle
the current hash.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The prefix_filename() function returns a pointer to static
storage, which makes it easy to use dangerously. We already
fixed one buggy caller in hash-object recently, and the
calls in apply.c are suspicious (I didn't dig in enough to
confirm that there is a bug, but we call the function once
in apply_all_patches() and then again indirectly from
parse_chunk()).
Let's make it harder to get wrong by allocating the return
value. For simplicity, we'll do this even when the prefix is
empty (and we could just return the original file pointer).
That will cause us to allocate sometimes when we wouldn't
otherwise need to, but this function isn't called in
performance critical code-paths (and it already _might_
allocate on any given call, so a caller that cares about
performance is questionable anyway).
The downside is that the callers need to remember to free()
the result to avoid leaking. Most of them already used
xstrdup() on the result, so we know they are OK. The
remainder have been converted to use free() as appropriate.
I considered retaining a prefix_filename_unsafe() for cases
where we know the static lifetime is OK (and handling the
cleanup is awkward). This is only a handful of cases,
though, and it's not worth the mental energy in worrying
about whether the "unsafe" variant is OK to use in any
situation.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
