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>
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>
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>
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>
