Re: [PATCH dwarves v2] Respect CMAKE_INSTALL_LIBDIR

["Olson, Matthew" <matthew.olson@intel.com>]

On Mon, Nov 25, 2024 at 07:19:53PM +0000, Alan Maguire wrote:
> On 25/11/2024 18:47, Ben Olson wrote:
> > This patch changes the `cmake` configuration to honor `CMAKE_INSTALL_LIBDIR`
> > and use either `lib` or `lib64` by default so that installations match the
> > conventional placement of libraries.
> > For example, it will now install `libdwarves.so` into `${PREFIX}/lib` or
> > `${PREFIX}/lib64`, depending on the distribution.
> > 
> > Signed-off-by: Brandon Kammerdiener <brandon.kammerdiener@intel.com>
> > Signed-off-by: Ben Olson <matthew.olson@intel.com>
> > Cc: Alan Maguire <alan.maguire@oracle.com>
> 
> Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
> Tested-by: Alan Maguire <alan.maguire@oracle.com>
> 
> (tested on Oracle Linux which uses lib64 for libraries; specifying cmake
> with no arguments did the right thing and "make install" installed into
> /usr/local/lib64 as expected; nice!)
> 
> One small nit I noticed, sorry missed this last time - the README
> has another reference to -D__LIB:
> 
> "    Ex. cmake -D__LIB=lib -DBUILD_SHARED_LIBS=OFF .."
> 
> I think we should probably remove that reference also, right?

Ach, you're right! Missed that. I'll add that in a v3.

> 
> > ---
> > 
> > Changes in v2:
> >   - Included the proper built-in CMake module
> >   - Made commit message distro-agnostic
> > 
> >  CMakeLists.txt | 19 ++++++-------------
> >  README         |  3 +--
> >  2 files changed, 7 insertions(+), 15 deletions(-)
> > 
> > diff --git a/CMakeLists.txt b/CMakeLists.txt
> > index 8ca1bf2..1d0dadf 100644
> > --- a/CMakeLists.txt
> > +++ b/CMakeLists.txt
> > @@ -21,18 +21,9 @@ else()
> >  	LINK_DIRECTORIES(${LIBBPF_LIBRARY_DIRS})
> >  endif()
> >  
> > -# Try to parse this later, Helio just showed me a KDE4 example to support
> > -# x86-64 builds.
> > -# the following are directories where stuff will be installed to
> > -set(__LIB "" CACHE STRING "Define suffix of directory name (32/64)" )
> > -
> > -macro(_set_fancy _var _value _comment)
> > -	if (NOT DEFINED ${_var})
> > -		set(${_var} ${_value})
> > -	else (NOT DEFINED ${_var})
> > -		set(${_var} "${${_var}}" CACHE PATH "${_comment}")
> > -	endif (NOT DEFINED ${_var})
> > -endmacro(_set_fancy)
> > +# Use the standard library installation directory
> > +include(GNUInstallDirs)
> > +set(CMAKE_INSTALL_LIBDIR "lib" CACHE STRING "libdir name")
> >  
> >  # where to look first for cmake modules,
> >  # before ${CMAKE_ROOT}/Modules/ is checked
> > @@ -84,7 +75,9 @@ if(NOT LIBBPF_FOUND AND NOT EXISTS "${PROJECT_SOURCE_DIR}/lib/bpf/src/btf.h")
> >  	message(FATAL_ERROR "The submodules were not downloaded! GIT_SUBMODULE was turned off or failed. Please update submodules and try again.")
> >  endif()
> >  
> > -_set_fancy(LIB_INSTALL_DIR "${EXEC_INSTALL_PREFIX}${CMAKE_INSTALL_PREFIX}/${__LIB}" "libdir")
> > +if (NOT DEFINED LIB_INSTALL_DIR)
> > +    set(LIB_INSTALL_DIR "${EXEC_INSTALL_PREFIX}${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}")
> > +endif()
> >  
> >  # libbpf uses reallocarray, which is not available in all versions of glibc
> >  # libbpf's include/tools/libc_compat.h provides implementation, but needs
> > diff --git a/README b/README
> > index f9aeef7..0627872 100644
> > --- a/README
> > +++ b/README
> > @@ -3,8 +3,7 @@ Build instructions:
> >  1. install cmake
> >  2. mkdir build
> >  3. cd build
> > -4. cmake -D__LIB=lib ..
> > -5. make install
> > +4. make install
> >  
> >  cmake Options:
> >    -DBUILD_SHARED_LIBS
>