Use the approach originally used in commit f91b3c1d (Add options to
build with system utility libraries, 2006-10-19) for all other
third-party libraries. Create a "cm_bzlib.h" header wrapper that
robustly includes the header from the bzip2 library chosen for the CMake
build (either builtin or system version). Include the header wrapper
anywhere we need the API provided by <bzlib.h>.
We cannot suppress PGI compiler warnings completely because even with
the "-w" flag the compiler still writes a message containing "compilation
completed with warnings" to stderr.
A warning is triggered by expressions like
test ? NULL : ptr_to_const_char
test ? ".." : ptr_to_const_char
that the PGI compiler handles incorrectly. It chooses the pointer type
of the first option (either void* or char*) and warns about conversion
of the second without a cast. Flip the expression logic to
!test ? ptr_to_const_char : NULL
!test ? ptr_to_const_char : ".."
to help the compiler choose the proper result type.
Brad King