[petsc-dev] PETSC_UNUSED broken needs repair

[Barry Smith]

  It happily sets the attribute even though the attribute does not exist.


TEST configureUnused from PETSc.Configure(/export/home/petsc/petsc-dev-3/config/PETSc/Configure.py:528)
TESTING: configureUnused from PETSc.Configure(/export/home/petsc/petsc-dev-3/config/PETSc/Configure.py:528)
  Sees if __attribute((unused)) is supported
        Pushing language Cxx
sh: /export/home/petsc/soft/mpich2-1.2.1p1/bin/mpicxx -c -o /tmp/petsc-VAqamh/PETSc.Configure/conftest.o -I/tmp/petsc-VAqamh/config.setCompilers -I/tmp/petsc-VAqamh/config.compilers -I/tmp/petsc-VAqamh/config.functions -I/tmp/petsc-VAqamh/config.types -I/tmp/petsc-VAqamh/PETSc.utilities.missing -I/tmp/petsc-VAqamh/config.libraries -I/tmp/petsc-VAqamh/PETSc.Configure -I/tmp/petsc-VAqamh/PETSc.utilities.scalarTypes  -g     /tmp/petsc-VAqamh/PETSc.Configure/conftest.cc 
Executing: /export/home/petsc/soft/mpich2-1.2.1p1/bin/mpicxx -c -o /tmp/petsc-VAqamh/PETSc.Configure/conftest.o -I/tmp/petsc-VAqamh/config.setCompilers -I/tmp/petsc-VAqamh/config.compilers -I/tmp/petsc-VAqamh/config.functions -I/tmp/petsc-VAqamh/config.types -I/tmp/petsc-VAqamh/PETSc.utilities.missing -I/tmp/petsc-VAqamh/config.libraries -I/tmp/petsc-VAqamh/PETSc.Configure -I/tmp/petsc-VAqamh/PETSc.utilities.scalarTypes  -g     /tmp/petsc-VAqamh/PETSc.Configure/conftest.cc 
sh: 
Possible ERROR while running compiler: error message = {"/tmp/petsc-VAqamh/PETSc.Configure/conftest.cc", line 3: Warning: attribute unused is unsupported and will be skipped..
1 Warning(s) detected.
}
Source:
#include "confdefs.h"
#include "conffix.h"
__attribute((unused)) static int myfunc(void){ return 1;}

int main() {
int i = myfunc();
;
  return 0;
}
                Pushing language CXX
                Popping language CXX
sh: /export/home/petsc/soft/mpich2-1.2.1p1/bin/mpicxx  -o /tmp/petsc-VAqamh/PETSc.Configure/conftest    -g  /tmp/petsc-VAqamh/PETSc.Configure/conftest.o  -ldl 
Executing: /export/home/petsc/soft/mpich2-1.2.1p1/bin/mpicxx  -o /tmp/petsc-VAqamh/PETSc.Configure/conftest    -g  /tmp/petsc-VAqamh/PETSc.Configure/conftest.o  -ldl 
sh: 
        Defined "UNUSED" to "__attribute((unused))"
        Popping language Cxx