[PATCH rdma-core v2 3/3] configure: Add check for the presence of DRM headers

[Jason Gunthorpe]

On Thu, Feb 04, 2021 at 04:29:14PM -0800, Jianxin Xiong wrote:
> Compilation of pyverbs/dmabuf_alloc.c depends on a few DRM headers
> that are installed by either the kernel-header or the libdrm package.
> The installation is optional and the location is not unique.
> 
> Check the presence of the headers at both the standard locations and
> any location defined by custom libdrm installation. If the headers
> are missing, the dmabuf allocation routines are replaced by stubs that
> return suitable error to allow the related tests to skip.
> 
> Signed-off-by: Jianxin Xiong <jianxin.xiong at intel.com>
>  CMakeLists.txt              | 15 +++++++++++++++
>  pyverbs/CMakeLists.txt      | 14 ++++++++++++--
>  pyverbs/dmabuf_alloc.c      |  8 ++++----
>  pyverbs/dmabuf_alloc_stub.c | 39 +++++++++++++++++++++++++++++++++++++++
>  4 files changed, 70 insertions(+), 6 deletions(-)
>  create mode 100644 pyverbs/dmabuf_alloc_stub.c
> 
> diff --git a/CMakeLists.txt b/CMakeLists.txt
> index 4113423..95aec11 100644
> +++ b/CMakeLists.txt
> @@ -515,6 +515,21 @@ find_package(Systemd)
>  include_directories(${SYSTEMD_INCLUDE_DIRS})
>  RDMA_DoFixup("${SYSTEMD_FOUND}" "systemd/sd-daemon.h")
>  
> +# drm headers
> +
> +# First check the standard locations. The headers could have been installed
> +# by either the kernle-headers package or the libdrm package.
> +find_path(DRM_INCLUDE_DIRS "drm.h" PATH_SUFFIXES "drm" "libdrm")

Is there a reason not to just always call pkg_check_modules?

> +# Then check custom installation of libdrm
> +if (NOT DRM_INCLUDE_DIRS)
> +  pkg_check_modules(DRM libdrm)
> +endif()
> +
> +if (DRM_INCLUDE_DIRS)
> +  include_directories(${DRM_INCLUDE_DIRS})
> +endif()

This needs a hunk at the end:

if (NOT DRM_INCLUDE_DIRS)
  message(STATUS " DMABUF NOT supported (disabling some tests)")
endif()

>  #-------------------------
>  # Apply fixups
>  
> diff --git a/pyverbs/CMakeLists.txt b/pyverbs/CMakeLists.txt
> index 6fd7625..922253f 100644
> +++ b/pyverbs/CMakeLists.txt
> @@ -13,8 +13,6 @@ rdma_cython_module(pyverbs ""
>    cmid.pyx
>    cq.pyx
>    device.pyx
> -  dmabuf.pyx
> -  dmabuf_alloc.c
>    enums.pyx
>    mem_alloc.pyx
>    mr.pyx
> @@ -25,6 +23,18 @@ rdma_cython_module(pyverbs ""
>    xrcd.pyx
>  )
>  
> +if (DRM_INCLUDE_DIRS)
> +rdma_cython_module(pyverbs ""
> +  dmabuf.pyx
> +  dmabuf_alloc.c
> +)
> +else()
> +rdma_cython_module(pyverbs ""
> +  dmabuf.pyx
> +  dmabuf_alloc_stub.c
> +)
> +endif()

Like this:

if (DRM_INCLUDE_DIRS)
  set(DMABUF_ALLOC dmabuf_alloc.c)
else()
  set(DMABUF_ALLOC dmabuf_alloc_stbub.c)
endif()
rdma_cython_module(pyverbs ""
  dmabuf.pyx
  $(DMABUF_ALLOC)
)

Jason