mesa: restore OpenCL support

Co-authored-by: Sandro <sandro.jaeckel@gmail.com>
Co-authored-by: Simon Bruder <simon@sbruder.de>

pkgs/development/libraries/mesa/default.nix

@@ -13,6 +13,8 @@
 , withValgrind ? !stdenv.isDarwin && lib.meta.availableOn stdenv.hostPlatform valgrind-light, valgrind-light
 , enableGalliumNine ? stdenv.isLinux
 , enableOSMesa ? stdenv.isLinux
+, enableOpenCL ? stdenv.isLinux && stdenv.isx86_64
+, libclc
 }:
 
 /** Packaging design:
@@ -53,7 +55,7 @@ self = stdenv.mkDerivation {
   #  ~35 MB in $drivers; watch https://launchpad.net/ubuntu/+source/mesa/+changelog
   patches = [
     ./missing-includes.patch # dev_t needs sys/stat.h, time_t needs time.h, etc.-- fixes build w/musl
-    ./opencl-install-dir.patch
+    ./opencl.patch
     ./disk_cache-include-dri-driver-path-in-cache-key.patch
     # Fix `-Werror=int-conversion` pthread warnings on musl.
     # TODO: Remove when https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6121 is merged and available
@@ -88,7 +90,8 @@ self = stdenv.mkDerivation {
 
   outputs = [ "out" "dev" "drivers" ]
     ++ lib.optional enableOSMesa "osmesa"
-    ++ lib.optional stdenv.isLinux "driversdev";
+    ++ lib.optional stdenv.isLinux "driversdev"
+    ++ lib.optional enableOpenCL "opencl";
 
   # TODO: Figure out how to enable opencl without having a runtime dependency on clang
   mesonFlags = [
@@ -118,6 +121,9 @@ self = stdenv.mkDerivation {
     "-Dmicrosoft-clc=disabled" # Only relevant on Windows (OpenCL 1.2 API on top of D3D12)
   ] ++ optionals stdenv.isLinux [
     "-Dglvnd=true"
+  ] ++ optionals enableOpenCL [
+    "-Dgallium-opencl=icd" # Enable the gallium OpenCL frontend
+    "-Dclang-libdir=${llvmPackages.clang-unwrapped.lib}/lib"
   ];
 
   buildInputs = with xorg; [
@@ -128,6 +134,7 @@ self = stdenv.mkDerivation {
   ] ++ lib.optionals (elem "wayland" eglPlatforms) [ wayland wayland-protocols ]
     ++ lib.optionals stdenv.isLinux [ libomxil-bellagio libva-minimal ]
     ++ lib.optionals stdenv.isDarwin [ libunwind ]
+    ++ lib.optionals enableOpenCL [ libclc llvmPackages.clang llvmPackages.clang-unwrapped ]
     ++ lib.optional withValgrind valgrind-light;
 
   depsBuildBuild = [ pkg-config ];
@@ -162,7 +169,7 @@ self = stdenv.mkDerivation {
 
     if [ -n "$(shopt -s nullglob; echo "$out"/lib/lib*_mesa*)" ]; then
       # Move other drivers to a separate output
-      mv $out/lib/lib*_mesa* $drivers/lib
+      mv -t $drivers/lib $out/lib/lib*_mesa*
     fi
 
     # Update search path used by glvnd
@@ -175,6 +182,17 @@ self = stdenv.mkDerivation {
     for js in $drivers/share/vulkan/icd.d/*.json; do
       substituteInPlace "$js" --replace "$out" "$drivers"
     done
+  '' + optionalString enableOpenCL ''
+    # Move OpenCL stuff
+    mkdir -p $opencl/lib
+    mv -t "$opencl/lib/"     \
+      $out/lib/gallium-pipe   \
+      $out/lib/libMesaOpenCL*
+
+    # We construct our own .icd file that contains an absolute path.
+    rm -r $out/etc/OpenCL
+    mkdir -p $opencl/etc/OpenCL/vendors/
+    echo $opencl/lib/libMesaOpenCL.so > $opencl/etc/OpenCL/vendors/mesa.icd
   '' + lib.optionalString enableOSMesa ''
     # move libOSMesa to $osmesa, as it's relatively big
     mkdir -p $osmesa/lib
@@ -209,7 +227,10 @@ self = stdenv.mkDerivation {
     done
   '';
 
-  NIX_CFLAGS_COMPILE = lib.optionalString stdenv.isDarwin "-fno-common";
+  NIX_CFLAGS_COMPILE = optionals stdenv.isDarwin [ "-fno-common" ] ++ lib.optionals enableOpenCL [
+    "-UPIPE_SEARCH_DIR"
+    "-DPIPE_SEARCH_DIR=\"${placeholder "opencl"}/lib/gallium-pipe\""
+  ];
 
   passthru = {
     inherit libdrm;

pkgs/development/libraries/mesa/opencl-install-dir.patch

@@ -1,12 +0,0 @@
-diff --git a/src/gallium/targets/opencl/meson.build b/src/gallium/targets/opencl/meson.build
-index 317ad8dab4a..5567308caf0 100644
---- a/src/gallium/targets/opencl/meson.build
-+++ b/src/gallium/targets/opencl/meson.build
-@@ -68,6 +68,6 @@ if with_opencl_icd
-     input : 'mesa.icd.in',
-     output : 'mesa.icd',
-     install : true,
--    install_dir : join_paths(get_option('sysconfdir'), 'OpenCL', 'vendors'),
-+    install_dir : join_paths(get_option('prefix'), 'etc', 'OpenCL', 'vendors'),
-   )
- endif

pkgs/development/libraries/mesa/opencl.patch

@@ -0,0 +1,70 @@
+diff --git a/meson_options.txt b/meson_options.txt
+index a7030aba31e..1d2d8814992 100644
+--- a/meson_options.txt
++++ b/meson_options.txt
+@@ -18,6 +18,12 @@
+ # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ # SOFTWARE.
+ 
++option(
++  'clang-libdir',
++  type : 'string',
++  value : '',
++  description : 'Locations to search for clang libraries.'
++)
+ option(
+   'platforms',
+   type : 'array',
+diff --git a/src/gallium/targets/opencl/meson.build b/src/gallium/targets/opencl/meson.build
+index b77826b6e1e..14fa9ba7177 100644
+--- a/src/gallium/targets/opencl/meson.build
++++ b/src/gallium/targets/opencl/meson.build
+@@ -30,6 +30,7 @@ if with_ld_version_script
+ endif
+ 
+ llvm_libdir = dep_llvm.get_variable(cmake : 'LLVM_LIBRARY_DIR', configtool: 'libdir')
++clang_libdir = get_option('clang-libdir')
+ opencl_libname = with_opencl_icd ? 'MesaOpenCL' : 'OpenCL'
+ 
+ polly_dep = null_dep
+@@ -60,19 +61,19 @@ else
+ endif
+ if not (dep_clang.found() and dep_clang_usable)
+   dep_clang = [
+-    cpp.find_library('clangCodeGen', dirs : llvm_libdir),
+-    cpp.find_library('clangFrontendTool', dirs : llvm_libdir),
+-    cpp.find_library('clangFrontend', dirs : llvm_libdir),
+-    cpp.find_library('clangDriver', dirs : llvm_libdir),
+-    cpp.find_library('clangSerialization', dirs : llvm_libdir),
+-    cpp.find_library('clangParse', dirs : llvm_libdir),
+-    cpp.find_library('clangSema', dirs : llvm_libdir),
+-    cpp.find_library('clangAnalysis', dirs : llvm_libdir),
+-    cpp.find_library('clangAST', dirs : llvm_libdir),
+-    cpp.find_library('clangASTMatchers', dirs : llvm_libdir),
+-    cpp.find_library('clangEdit', dirs : llvm_libdir),
+-    cpp.find_library('clangLex', dirs : llvm_libdir),
+-    cpp.find_library('clangBasic', dirs : llvm_libdir),
++    cpp.find_library('clangCodeGen', dirs : clang_libdir),
++    cpp.find_library('clangFrontendTool', dirs : clang_libdir),
++    cpp.find_library('clangFrontend', dirs : clang_libdir),
++    cpp.find_library('clangDriver', dirs : clang_libdir),
++    cpp.find_library('clangSerialization', dirs : clang_libdir),
++    cpp.find_library('clangParse', dirs : clang_libdir),
++    cpp.find_library('clangSema', dirs : clang_libdir),
++    cpp.find_library('clangAnalysis', dirs : clang_libdir),
++    cpp.find_library('clangAST', dirs : clang_libdir),
++    cpp.find_library('clangASTMatchers', dirs : clang_libdir),
++    cpp.find_library('clangEdit', dirs : clang_libdir),
++    cpp.find_library('clangLex', dirs : clang_libdir),
++    cpp.find_library('clangBasic', dirs : clang_libdir),
+     polly_dep, polly_isl_dep,
+   ]
+   # check clang once more
+@@ -120,6 +121,6 @@ if with_opencl_icd
+     input : 'mesa.icd.in',
+     output : 'mesa.icd',
+     install : true,
+-    install_dir : join_paths(get_option('sysconfdir'), 'OpenCL', 'vendors'),
++    install_dir : join_paths(get_option('prefix'), 'etc', 'OpenCL', 'vendors'),
+   )
+ endif