Commit Graph

109 Commits

Author SHA1 Message Date
Alex Riesen
4629795816 Fix crash in t0020 (crlf conversion)
Reallocated wrong size.
Noticed on Ubuntu 7.04 probably because it has some malloc diagnostics in libc:
"git-read-tree --reset -u HEAD" aborted in the test. Valgrind sped up the
debugging greatly: took me 10 minutes.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-22 10:44:56 -07:00
Junio C Hamano
a5e92abde6 Fix funny types used in attribute value representation
It was bothering me a lot that I abused small integer values
casted to (void *) to represent non string values in
gitattributes.  This corrects it by making the type of attribute
values (const char *), and using the address of a few statically
allocated character buffer to denote true/false.  Unset attributes
are represented as having NULLs as their values.

Added in-header documentation to explain how git_checkattr()
routine should be called.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-18 16:17:13 -07:00
Junio C Hamano
515106fa13 Allow more than true/false to attributes.
This allows you to define three values (and possibly more) to
each attribute: true, false, and unset.

Typically the handlers that notice and act on attribute values
treat "unset" attribute to mean "do your default thing"
(e.g. crlf that is unset would trigger "guess from contents"),
so being able to override a setting to an unset state is
actually useful.

 - If you want to set the attribute value to true, have an entry
   in .gitattributes file that mentions the attribute name; e.g.

	*.o	binary

 - If you want to set the attribute value explicitly to false,
   use '-'; e.g.

	*.a	-diff

 - If you want to make the attribute value _unset_, perhaps to
   override an earlier entry, use '!'; e.g.

	*.a	-diff
	c.i.a	!diff

This also allows string values to attributes, with the natural
syntax:

	attrname=attrvalue

but you cannot use it, as nobody takes notice and acts on
it yet.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-17 01:04:59 -07:00
Junio C Hamano
e4aee10a2e Change attribute negation marker from '!' to '-'.
At the same time, we do not want to allow arbitrary strings for
attribute names, as we are likely to want to extend the syntax
later.  Allow only alnum, dash, underscore and dot for now.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-15 15:49:41 -07:00
Junio C Hamano
fc2d07b05f Define a built-in attribute macro "binary".
For binary files we would want to disable textual diff
generation and automatic crlf conversion.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-15 15:49:41 -07:00
Junio C Hamano
f48fd68887 attribute macro support
This adds "attribute macros" (for lack of better name).  So far,
we have low-level attributes such as crlf and diff, which are
defined in operational terms --- setting or unsetting them on a
particular path directly affects what is done to the path.  For
example, in order to decline diffs or crlf conversions on a
binary blob, no diffs on PostScript files, and treat all other
files normally, you would have something like these:

	*		diff crlf
	*.ps		!diff
	proprietary.o	!diff !crlf

That is fine as the operation goes, but gets unwieldy rather
rapidly, when we start adding more low-level attributes that are
defined in operational terms.  A near-term example of such an
attribute would be 'merge-3way' which would control if git
should attempt the usual 3-way file-level merge internally, or
leave merging to a specialized external program of user's
choice.  When it is added, we do _not_ want to force the users
to update the above to:

	*		diff crlf merge-3way
	*.ps		!diff
	proprietary.o	!diff !crlf !merge-3way

The way this patch solves this issue is to realize that the
attributes the user is assigning to paths are not defined in
terms of operations but in terms of what they are.

All of the three low-level attributes usually make sense for
most of the files that sane SCM users have git operate on (these
files are typically called "text').  Only a few cases, such as
binary blob, need exception to decline the "usual treatment
given to text files" -- and people mark them as "binary".

So this allows the $GIT_DIR/info/alternates and .gitattributes
at the toplevel of the project to also specify attributes that
assigns other attributes.  The syntax is '[attr]' followed by an
attribute name followed by a list of attribute names:

	[attr] binary	!diff !crlf !merge-3way

When "binary" attribute is set to a path, if the path has not
got diff/crlf/merge-3way attribute set or unset by other rules,
this rule unsets the three low-level attributes.

It is expected that the user level .gitattributes will be
expressed mostly in terms of attributes based on what the files
are, and the above sample would become like this:

	(built-in attribute configuration)
	[attr] binary	!diff !crlf !merge-3way
	*		diff crlf merge-3way

	(project specific .gitattributes)
	proprietary.o	binary

	(user preference $GIT_DIR/info/attributes)
	*.ps		!diff

There are a few caveats.

 * As described above, you can define these macros only in
   $GIT_DIR/info/attributes and toplevel .gitattributes.

 * There is no attempt to detect circular definition of macro
   attributes, and definitions are evaluated from bottom to top
   as usual to fill in other attributes that have not yet got
   values.  The following would work as expected:

	[attr] text	diff crlf
	[attr] ps	text !diff
	*.ps	ps

   while this would most likely not (I haven't tried):

	[attr] ps	text !diff
	[attr] text	diff crlf
	*.ps	ps

 * When a macro says "[attr] A B !C", saying that a path does
   not have attribute A does not let you tell anything about
   attributes B or C.  That is, given this:

	[attr] text	diff crlf
	[attr] ps	text !diff
	*.txt !ps

  path hello.txt, which would match "*.txt" pattern, would have
  "ps" attribute set to zero, but that does not make text
  attribute of hello.txt set to false (nor diff attribute set to
  true).

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-15 15:43:06 -07:00
Junio C Hamano
8c701249d2 Teach 'diff' about 'diff' attribute.
This makes paths that explicitly unset 'diff' attribute not to
produce "textual" diffs from 'git-diff' family.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-14 08:57:06 -07:00
Junio C Hamano
35ebfd6a0c Define 'crlf' attribute.
This defines the semantics of 'crlf' attribute as an example.
When a path has this attribute unset (i.e. '!crlf'), autocrlf
line-end conversion is not applied.

Eventually we would want to let users to build a pipeline of
processing to munge blob data to filesystem format (and in the
other direction) based on combination of attributes, and at that
point the mechanism in convert_to_{git,working_tree}() that
looks at 'crlf' attribute needs to be enhanced.  Perhaps the
existing 'crlf' would become the first step in the input chain,
and the last step in the output chain.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-14 08:57:06 -07:00
Junio C Hamano
d0bfd026a8 Add basic infrastructure to assign attributes to paths
This adds the basic infrastructure to assign attributes to
paths, in a way similar to what the exclusion mechanism does
based on $GIT_DIR/info/exclude and .gitignore files.

An attribute is just a simple string that does not contain any
whitespace.  They can be specified in $GIT_DIR/info/attributes
file, and .gitattributes file in each directory.

Each line in these files defines a pattern matching rule.
Similar to the exclusion mechanism, a later match overrides an
earlier match in the same file, and entries from .gitattributes
file in the same directory takes precedence over the ones from
parent directories.  Lines in $GIT_DIR/info/attributes file are
used as the lowest precedence default rules.

A line is either a comment (an empty line, or a line that begins
with a '#'), or a rule, which is a whitespace separated list of
tokens.  The first token on the line is a shell glob pattern.
The rest are names of attributes, each of which can optionally
be prefixed with '!'.  Such a line means "if a path matches this
glob, this attribute is set (or unset -- if the attribute name
is prefixed with '!').  For glob matching, the same "if the
pattern does not have a slash in it, the basename of the path is
matched with fnmatch(3) against the pattern, otherwise, the path
is matched with the pattern with FNM_PATHNAME" rule as the
exclusion mechanism is used.

This does not define what an attribute means.  Tying an
attribute to various effects it has on git operation for paths
that have it will be specified separately.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-14 08:57:06 -07:00