Bug#608902: FTBFS with binutils-gold or ld --no-add-needed (and ld --as-needed)

[Matthias Klose]

Package: petsc
Version: 3.1.dfsg-10
Severity: important
Tags: patch
User: ubuntu-devel at lists.ubuntu.com
Usertags: origin-ubuntu natty ubuntu-patch
User: debian-gcc at lists.debian.org
Usertags: ld-as-needed
User: peter.fritzsche at gmx.de
Usertags: no-add-needed

for the background, please see http://wiki.debian.org/ToolChain/DSOLinking

The package fails in the configury when built with -Wl,--no-add-needed

$ mpicxx -Wl,--no-add-needed -save-temps -o conftest hyp.c   -Wall 
-Wwrite-strings -Wno-strict-aliasing -g  -L/usr/lib -L/usr/lib -lHYPRE -llapack 
-lblas -L/usr/lib/openmpi/lib -L/usr/lib/gcc/x86_64-linux-gnu/4.5.2 -ldl -lmpi 
-lopen-rte -lopen-pal -lnsl -lutil -lgcc_s -lpthread -lmpi_f90 -lmpi_f77 
-lgfortran -lm -lm -lm -lm -L/usr/lib/openmpi/lib 
-L/usr/lib/gcc/x86_64-linux-gnu/4.5.2 -ldl -lmpi -lopen-rte -lopen-pal -lnsl 
-lutil -lgcc_s -lpthread -ldl
/usr/bin/ld: hyp.o: undefined reference to symbol 'HYPRE_IJMatrixCreate'
/usr/bin/ld: note: 'HYPRE_IJMatrixCreate' is defined in DSO 
/usr/lib64/libHYPRE_IJ_mv-2.4.0.so so try adding it to the linker command line
/usr/lib64/libHYPRE_IJ_mv-2.4.0.so: could not read symbols: Invalid operation
collect2: ld returned 1 exit status

libHYPRE_IJ_mv needs explict linking.

$ mpicxx -Wl,--as-needed -save-temps -o conftest hyp.c   -Wall -Wwrite-strings 
-Wno-strict-aliasing -g  -L/usr/lib -L/usr/lib -lHYPRE -llapack -lblas 
-L/usr/lib/openmpi/lib -L/usr/lib/gcc/x86_64-linux-gnu/4.5.2 -ldl -lmpi 
-lopen-rte -lopen-pal -lnsl -lutil -lgcc_s -lpthread -lmpi_f90 -lmpi_f77 
-lgfortran -lm -lm -lm -lm -L/usr/lib/openmpi/lib 
-L/usr/lib/gcc/x86_64-linux-gnu/4.5.2 -ldl -lmpi -lopen-rte -lopen-pal -lnsl 
-lutil -lgcc_s -lpthread -ldl
hyp.o: In function `main':
/scratch/packages/tmp/petsc-3.1.dfsg/hyp.c:16: undefined reference to 
`HYPRE_IJMatrixCreate'
collect2: ld returned 1 exit status

the reason is that libHYPRE.so is just a "dependency" library. Is there an easy 
way to add particular flags to link some libraries with? like
-Wl,--no-as-needed -lHYPRE -Wl,--as-needed ?

for now, I just added all HYPRE libs to work around this.

The last change in debian/rules fixes the link order and another build failure 
with ld --as-needed.

patch at:
http://launchpadlibrarian.net/61585886/petsc_3.1.dfsg-10_3.1.dfsg-10ubuntu1.diff.gz

the change to framework.py is unrelated, couldn't find another way to include 
the source and compiler flags in the log file.

There is another link failure in the mpi test, reported in #608901, not yet 
understood.