Bug#759038: Bug#765467: asis-programs: Version mismatch between GNAT 4.9.1 vs. ASIS 4.9
affects 759038 asis-programs
block 765467 by 759038
thanks
I have traced #765467 to a discrepancy between
debian/patches/ada-libgnatvsn.diff and
debian/patches/gcc-base-version.diff, which are patches applied to both
gcc-4.9 and gnat-4.9.
gcc-base-version.diff changes src/gcc/Makefile.in so that it builds
version.o with the flag -DBASEVER=$(FULLVER_s) (where FULLVER_s has the
value 4.9.1 and is introduced by this patch; upstream uses only
BASEVER_s). This is a recent change introduced for #759038.
ada-libgnatvsn.diff rebuilds version.o with -fPIC, so it can be included
into libgnatvsn.so.4.9, and passes -DBASEVER=$(BASEVER_s), like upstream
does. But the value of BASEVER_s is 4.9, not 4.9.1.
Consequently:
/usr/bin/gcc-4.9, linked statically with version.o, emits 4.9.1
/usr/bin/gnatpp, linked dynamically with version.o from libgnatvsn4.9,
expects 4.9.
I think the change made for #759038 should be reverted; as Matthias
said, we should use "4.9" consistently, not "4.9.1". I disagree with
Nicolas when he says that "gcc -dumpversion" should report 4.9.1; it
should report 4.9 instead because Debian only ever uses the tip of the
gcc-4_9-branch plus patches, and never exactly "4.9.1". Furthermore,
4.9.2 is looming on the horizon and will not change the format of ASIS
tree files, so 4.9 is really the version that should be in the tree
files.
Assuming this change is reverted, gnat1 will still emit "4.9.1" into the
tree files; this is the real issue. Linking gnat1 dynamically against
libgnatvsn.so.4.9 might be desirable but seems like a lot of work, and
also means that ada-libgnatvsn.diff would become even more intrusive
than it already is (and it is not upstreamable without a lot more work
because upstream supports many more cross-compiler configurations than
we do ATM).
In theory, gnat1 is linked statically with version.o, so emits whatever
is configured into version.o. Why gnat1 would emit "4.9.1" as reported
in #759038 escapes me ATM.
gcc-base-version.diff was introduced back in 2011 to change the
directories where various pieces of GCC are installed,
e.g. /usr/lib/gcc/$(target)/4.6.1 to /usr/lib/gcc/$(target)/4.6
(changing BASEVER from 4.6.1 to 4.6). At the same time, this patch
introduced FULLVER (value: 4.6.1). I am not sure why FULLVER is needed
at all nowadays. Why not remove FULLVER altogether?
--
Ludovic Brenta.
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