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Re: PATCH: Bump version on mainline
"Joseph S. Myers" <email@example.com> writes:
> If the number of locations of the version number are to be reduced
> further, either the unique location should be gcc-common.texi or
> update_web_docs needs to be updated to generate whatever generated
> .texi file gets the version number when building online docs.
I have had the following idea for version numbers floating around in
my head for some time now. It attempts to address the following
0) We have the base version number in at least two places, version.c
1) The version number is propagated from version.c to several other
places by configure. This means that config.status has a
dependency on version.c, which in turn means that the daily bump of
the datestamp is another cause of having the entire world rebuilt
because you did a cvs update in your source directory.
2) The recommended practice for maintaining your own branch of GCC is
to modify the trailing part of the version string, leaving the
initial bit alone to identify the upstream version you branched
from. But then if you want to update to a newer version - say, if
you're tracking a release branch - you inevitably get a merge
conflict in version.c, which is irritating.
3) The mechanism for updating the datestamp is complicated and
fragile (it broke, for instance, when version_string was changed
from a char* to a char).
We create two files in the top-level config/ directory. They are
named DATESTAMP and GCC-BASE-VER. Their complete contents are,
respectively, "YYYYMMDD\n" and "X.Y[.Z]\n". For instance, today on
mainline they would read "20050227\n" and "4.1.0\n". (\n is a
newline, and the quotation marks are not in the file.)
version.c is then changed to read
const char version_string = BASE_VER " " DATESTAMP " (experimental)";
with the commentary above adjusted to match, and is now compiled as
version.o: version.c version.h $(srcdir)/../config/DATESTAMP \
$(CC) $(ALL_CFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \
-DBASE_VER="\"`cat $(srcdir)/../config/GCC-BASE-VER`\"" \
-DDATESTAMP="\"`cat $(srcdir)/../config/DATESTAMP`\"" \
-c $(srcdir)/version.c $(OUTPUT_OPTION)
Similarly, gcc-common.texi is now generated from gcc-common.texi.in
(this is necessary because texi2dvi does not support command line
@set) by the Makefile (not! by configure), doing something like
sed -e 's/@version@/$(shell cat $(srcdir)/../config/GCC-BASE-VER)/' \
$< > $@
And similarly with all the other places that need the version number.
I'd treat gcccbug.in as a special case - rename it to gccbug, and have
it determine the default version string at runtime via
"gcc --version | head -1" or equivalent.