Earlier implementation had a major screw-up in the memory
management area. Rename/copy logic sometimes borrowed a pointer
to a structure without any provision for downstream to determine
which pointer is shared and which is not. This resulted in the
later clean-up code to sometimes double free such structure,
resulting in a segfault. This made -M and -C useless.
Another problem the earlier implementation had was that it
reordered the patches, and forced the logic to differentiate
renames and copies to depend on that particular order. This
problem was fixed by teaching rename/copy detection logic not to
do any reordering, and rename-copy differentiator not to depend
on the order of the patches. The diffs will leave rename/copy
detector in the same destination path order as the patch that
was fed into it. Some test vectors have been reordered to
accommodate this change.
It also adds a sanity check logic to the human-readable diff-raw
output to detect paths with embedded TAB and LF characters,
which cannot be expressed with that format. This idea came up
during a discussion with Chris Wedgwood.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
For later stages to reorder patches, pruning logic and rename detection
logic should not decide which delete to discard (because another entry
said it will take over the file as a rename) until the very end.
Also fix some tests that were assuming the earlier "last one is rename
or keep everything else is copy" semantics of diff-raw format, which no
longer is true.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This changes the diff-raw format again, following the mailing
list discussion. The new format explicitly expresses which one
is a rename and which one is a copy.
The documentation and tests are updated to match this change.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The rename/copy detection logic in earlier round was only good
enough to show patch output and discussion on the mailing list
about the diff-raw format updates revealed many problems with
it. This patch fixes all the ones known to me, without making
things I want to do later impossible, mostly related to patch
reordering.
(1) Earlier rename/copy detector determined which one is rename
and which one is copy too early, which made it impossible
to later introduce diffcore transformers to reorder
patches. This patch fixes it by moving that logic to the
very end of the processing.
(2) Earlier output routine diff_flush() was pruning all the
"no-change" entries indiscriminatingly. This was done due
to my false assumption that one of the requirements in the
diff-raw output was not to show such an entry (which
resulted in my incorrect comment about "diff-helper never
being able to be equivalent to built-in diff driver"). My
special thanks go to Linus for correcting me about this.
When we produce diff-raw output, for the downstream to be
able to tell renames from copies, sometimes it _is_
necessary to output "no-change" entries, and this patch
adds diffcore_prune() function for doing it.
(3) Earlier diff_filepair structure was trying to be not too
specific about rename/copy operations, but the purpose of
the structure was to record one or two paths, which _was_
indeed about rename/copy. This patch discards xfrm_msg
field which was trying to be generic for this wrong reason,
and introduces a couple of fields (rename_score and
rename_rank) that are explicitly specific to rename/copy
logic. One thing to note is that the information in a
single diff_filepair structure _still_ does not distinguish
renames from copies, and it is deliberately so. This is to
allow patches to be reordered in later stages.
(4) This patch also adds some tests about diff-raw format
output and makes sure that necessary "no-change" entries
appear on the output.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add <limits.h> to the include files handled by "cache.h", and remove
extraneous #include directives from various .c files. The rule is that
"cache.h" gets all the basic stuff, so that we'll have as few system
dependencies as possible.
This moves the path selection logic from individual programs to a new
diffcore transformer (diff-tree still needs to have its own for
performance reasons). Also the header printing code in diff-tree was
tweaked not to produce anything when pickaxe is in effect and there is
nothing interesting to report. An interesting example is the following
in the GIT archive itself:
$ git-whatchanged -p -C -S'or something in a real script'
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Update the diff-raw format as Linus and I discussed, except that
it does not use sequence of underscore '_' letters to express
nonexistence. All '0' mode is used for that purpose instead.
The new diff-raw format can express rename/copy, and the earlier
restriction that -M and -C _must_ be used with the patch format
output is no longer necessary. The patch makes -M and -C flags
independent of -p flag, so you need to say git-whatchanged -M -p
to get the diff/patch format.
Updated are both documentations and tests.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This does not actually supress the extra headers when pickaxe is
used, but prepares enough support for diff-tree to implement it.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This steals the "pickaxe" feature from JIT and make it available
to the bare Plumbing layer. From the command line, the user
gives a string he is intersted in.
Using the diff-core infrastructure previously introduced, it
filters the differences to limit the output only to the diffs
between <src> and <dst> where the string appears only in one but
not in the other. For example:
$ ./git-rev-list HEAD | ./git-diff-tree -Sdiff-tree-helper --stdin -M
would show the diffs that touch the string "diff-tree-helper".
In real software-archaeologist application, you would typically
look for a few to several lines of code and see where that code
came from.
The "pickaxe" module runs after "rename/copy detection" module,
so it even crosses the file rename boundary, as the above
example demonstrates.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This introduces the diff-core, the layer between the diff-tree
family and the external diff interface engine. The calls to the
interface diff-tree family uses (diff_change and diff_addremove)
have not changed and will not change. The purpose of the
diff-core layer is to provide an infrastructure to transform the
set of differences sent from the applications, before sending
them to the external diff interface.
The recently introduced rename detection code has been rewritten
to use the diff-core facility. When applications send in
separate creates and deletes, matching ones are transformed into
a single rename-and-edit diff, and sent out to the external diff
interface as such.
This patch also enhances the rename detection code further to be
able to detect copies. Currently this happens only as long as
copy sources appear as part of the modified files, but there
already is enough provision for callers to report unmodified
files to diff-core, so that they can be also used as copy source
candidates. Extending the callers this way will be done in a
separate patch.
Please see and marvel at how well this works by trying out the
newly added t/t4003-diff-rename-1.sh test script.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix various things that sparse complains about:
- use NULL instead of 0
- make sure we declare everything properly, or mark it static
- use proper function declarations ("fn(void)" instead of "fn()")
Sparse is always right.
Instead of swapping the arguments just before output, this patch
makes the swapping happen on the input side of the diff core,
when "reverse-diff" is in effect. This greatly simplifies the
logic, but more importantly it is necessary for upcoming "copy
detection" work.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This cleans up the way calls are made into the diff core from diff-tree
family and diff-helper. Earlier, these programs had "if
(generating_patch)" sprinkled all over the place, but those ugliness are
gone and handled uniformly from the diff core, even when not generating
patch format.
This also allowed diff-cache and diff-files to acquire -R
(reverse) option to generate diff in reverse. Users of
diff-tree can swap two trees easily so I did not add -R there.
[ Linus' note: I'll add -R to "diff-tree" too, since a "commit
diff" doesn't have another tree to switch around: the other
tree is always the parent(s) of the commit ]
Also -M<digits-as-mantissa> suggestion made by Linus has been
implemented.
Documentation updates are also included.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A bit of clean-up of diff.c which fixes up some comments and removes a
memory leak.
This also re-introduces the rename score debugging fprintf(), but leaves
it #idef'ed it out for normal use.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This rips out the rename detection engine from diff-helper and moves it
to the diff core, and updates the internal calling convention used by
diff-tree family into the diff core. In order to give the same option
name to diff-tree family as well as to diff-helper, I've changed the
earlier diff-helper '-r' option to '-M' (stands for Move; sorry but the
natural abbreviation 'r' for 'rename' is already taken for 'recursive').
Although I did a fair amount of test with the git-diff-tree with
existing rename commits in the core GIT repository, this should still be
considered beta (preview) release. This patch depends on the diff-delta
infrastructure just committed.
This implements almost everything I wanted to see in this series of
patch, except a few minor cleanups in the calling convention into diff
core, but that will be a separate cleanup patch.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds a framework and a stub implementation of rename
detection to diff-helper program.
The current stub code is just enough to detect pure renames in
diff-tree output and not fancier. The plan is perhaps to use
the same delta code when Nico's delta storage patch is merged
for similarity evaluation purposes.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This implements the output format suggested by Linus in
<Pine.LNX.4.58.0505161556260.18337@ppc970.osdl.org>, except the
imaginary diff option is spelled "diff --git" with double dashes as
suggested by Matthias Urlichs.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This updates the mode change strings to be a bit more machine
friendly. Although this might go against the spirit of
readability for human consumption, these mode bits strings are
shown only when unusual things (mode change, file creation and
deletion) happens, output normalized for machine consumption
would be permissible.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Petr Baudis <pasky@ucw.cz>
H. Peter Anvin mentioned that using SHA1_whatever as an
environment variable name is not nice and we should instead use
names starting with "GIT_" prefix to avoid conflicts. Here is
what this patch does:
* Renames the following environment variables:
New name Old Name
GIT_AUTHOR_DATE AUTHOR_DATE
GIT_AUTHOR_EMAIL AUTHOR_EMAIL
GIT_AUTHOR_NAME AUTHOR_NAME
GIT_COMMITTER_EMAIL COMMIT_AUTHOR_EMAIL
GIT_COMMITTER_NAME COMMIT_AUTHOR_NAME
GIT_ALTERNATE_OBJECT_DIRECTORIES SHA1_FILE_DIRECTORIES
GIT_OBJECT_DIRECTORY SHA1_FILE_DIRECTORY
* Introduces a compatibility macro, gitenv(), which does an
getenv() and if it fails calls gitenv_bc(), which in turn
picks up the value from old name while giving a warning about
using an old name.
* Changes all users of the environment variable to fetch
environment variable with the new name using gitenv().
* Updates the documentation and scripts shipped with Linus GIT
distribution.
The transition plan is as follows:
* We will keep the backward compatibility list used by gitenv()
for now, so the current scripts and user environments
continue to work as before. The users will get warnings when
they have old name but not new name in their environment to
the stderr.
* The Porcelain layers should start using new names. However,
just in case it ends up calling old Plumbing layer
implementation, they should also export old names, taking
values from the corresponding new names, during the
transition period.
* After a transition period, we would drop the compatibility
support and drop gitenv(). Revert the callers to directly
call getenv() but keep using the new names.
The last part is probably optional and the transition
duration needs to be set to a reasonable value.
Signed-off-by: Junio C Hamano <junkio@cox.net>
<JC> Editorial Note. We may want to include standard headers in one
of those headers everybody includes, e.g. cache.h, to reduce clutters,
but this commit is as Thomas posted to the GIT list.
Date: Sat, 7 May 2005 10:41:41 +0200
Signed-off-by: Thomas Glanzmann <sithglan@stud.uni-erlangen.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This patch updates the external diff interface engine for the change
to store the symbolic links in the cache, recently done by Kay
Sievers.
The main thing it does is when comparing with the work tree, it
prepares the counterpart to the blob being compared by doing a
readlink followed by sending that result to a temporary file to
be diffed.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This patch optimizes "diff-cache -p --cached" by avoiding to
inflate blobs into temporary files when the blob recorded in the
cache matches the corresponding file in the work tree. The file
in the work tree is passed as the comparison source in such a
case instead.
This optimization kicks in only when we have already read the
cache this optimization and this is deliberate. Especially,
diff-tree does not use this code, because changes are contained
in small number of files relative to the project size most of
the time, and reading cache is so expensive for a large project
that the cost of reading it outweighs the savings by not
inflating blobs.
Also this patch cleans up the structure passed from diff clients
by removing one unused structure member.
Signed-off-by: Junio C Hamano <junkio@cox.net>
(slightly updated from the version posted to the GIT mailing list
with small bugfixes).
This patch changes the git-apply-patch-script to exit non-zero when
the patch cannot be applied. Previously, the external diff driver
deliberately ignored the exit status of GIT_EXTERNAL_DIFF command,
which was a design mistake. It now stops the processing when
GIT_EXTERNAL_DIFF exits non-zero, so the damages from running
git-diff-* with git-apply-patch-script between two wrong trees can be
contained.
The "diff" command line generated by the built-in driver is changed to
always exit 0 in order to match this new behaviour. I know Pasky does
not use GIT_EXTERNAL_DIFF yet, so this change should not break Cogito,
either.
Signed-off-by: Junio C Hamano <junkio@cox.net>
It's silly, and it shouldn't matter, but every time I look at
the diffs, I ended up just worrying why "l/" and "k/" as the
prefixes.
Junio says it's a tribute to linux-kernel, but graciously also
said I can change it to something else. So make it "a/" and "b/"
until somebody else complains ;)
Linus says,
The fewer lines there are that don't usually tell a human
anything, the better. Dense is good.
This patch makes the default diff output more dense. This
removes the previous misguided attempt to be cg-patch
compatible.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When diff-cache -p and friends are interrupted, they can leave
their temporary files behind. Also when the external diff
program is killed instead of exiting (this usually happens when
piping the output to a pager, which can cause SIGPIPE when the
user quits viewing the diff early), they incorrectly died
without cleaning their temporary file.
This fixes these problems.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This changes the way the default arguments to diff are built when
diff-cache and friends are invoked with -p and there is no
GIT_EXTERNAL_DIFF environment variable. It attempts to be more cg-patch
friendly by:
- Showing diffs against /dev/null to denote added or removed
files;
- Showing file modes for existing files as a comment after the
diff label.
Unfortunately with this change GIT_DIFF_CMD customization cannot
be supported easily anymore, so it has been dropped.
GIT_DIFF_OPTS customization to change diffs from unified to
context is still there, though.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The "base" string already contains any finishing "/", so the way
to get the full pathname is to just concatenate the base and
path directly, with no extra slashes in between.
This introduces three public functions for diff-cache and friends can
use to call out to the GIT_EXTERNAL_DIFF program when they wish to.
A normal "add/remove/change" entry is turned into 7-parameter process
invocation of GIT_EXTERNAL_DIFF program as before. In addition, the
program can now be called with a single parameter when diff-cache and
friends want to report an unmerged path.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Introduce xmalloc and xrealloc to die gracefully with a descriptive
message when out of memory, rather than taking a SIGSEGV.
Signed-off-by: Christopher Li<chrislgit@chrisli.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This reworks the diff-tree-helper and show-diff to further make external
diff command interface simpler.
These commands now honor GIT_EXTERNAL_DIFF environment variable which
can point at an arbitrary program that takes 7 parameters:
name file1 file1-sha1 file1-mode file2 file2-sha1 file2-mode
The parameters for an external diff command are as follows:
name this invocation of the command is to emit diff
for the named cache/tree entry.
file1 pathname that holds the contents of the first
file. This can be a file inside the working
tree, or a temporary file created from the blob
object, or /dev/null. The command should not
attempt to unlink it -- the temporary is
unlinked by the caller.
file1-sha1 sha1 hash if file1 is a blob object, or "."
otherwise.
file1-mode mode bits for file1, or "." for a deleted file.
If GIT_EXTERNAL_DIFF environment variable is not set, the
default is to invoke diff with the set of parameters old
show-diff used to use. This built-in implementation honors the
GIT_DIFF_CMD and GIT_DIFF_OPTS environment variables as before.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With this patch, the non-core'ish part of show-diff command that
invokes an external "diff" comand to obtain patches is split
into a separate file. The next patch will introduce a new
command, diff-tree-helper, which uses this common diff interface
to format diff-tree and diff-cache output into a patch form.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
