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guile.m4 may need serial number
From: |
Mike Gran |
Subject: |
guile.m4 may need serial number |
Date: |
Thu, 27 Dec 2007 08:39:52 -0800 (PST) |
The automake manual recommends that .m4 files use a serial number for
versioning, so that it is possible to tell when an .m4 installed by aclocal is
updated.
<quote>
Because third-party macros defined in ‘*.m4’ files are naturally shared between
multiple
projects, some people like to version them. This makes it easier to tell which
of two M4
files is newer. Since at least 1996, the tradition is to use a ‘#serial’ line
for this.
A serial number should be a single line of the form
# serial version
where version is a version number containing only digits and dots. Usually
people use a
single integer, and they increment it each time they change the macro (hence
the name of
“serial”). Such a line should appear in the M4 file before any macro definition.
The ‘#’ must be the first character on the line, and it is OK to have extra
words after
the version, as in
#serial version garbage
Normally these serial numbers are completely ignored by aclocal and autoconf,
like
any genuine comment. However when using aclocal’s ‘--install’ feature, these
serial
numbers will modify the way aclocal selects the macros to install in the
package: if two
files with the same basename exists in your search path, and if at least one of
them use a
‘#serial’ line, aclocal will ignore the file that has the older ‘#serial’ line
(or the file that
has none).
</quote>
Thanks,
Mike Gran
- guile.m4 may need serial number,
Mike Gran <=