From 302f5b54881b4505a6a04530f720f9aa5bdc4d4b Mon Sep 17 00:00:00 2001
From: Colin <colin@uninsane.org>
Date: Sun, 29 Dec 2024 09:56:52 +0000
Subject: [PATCH] mesa: fix cross compilation

this follows the same pattern as used for mesa's `intel-clc` build helper:

1. build `mesa-clc` for the build machine.
2. provide the native `mesa-clc` when cross-compiling mesa.

the meson changes for this have been upstreamed into the next release:

https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32719
---
 .../libraries/mesa/cross_clc.patch            | 90 +++++++++++++++++++
 pkgs/development/libraries/mesa/default.nix   |  6 ++
 2 files changed, 96 insertions(+)
 create mode 100644 pkgs/development/libraries/mesa/cross_clc.patch

diff --git a/pkgs/development/libraries/mesa/cross_clc.patch b/pkgs/development/libraries/mesa/cross_clc.patch
new file mode 100644
index 000000000000..cb29e57ec349
--- /dev/null
+++ b/pkgs/development/libraries/mesa/cross_clc.patch
@@ -0,0 +1,90 @@
+commit f063e9f74b45f34e4ac570a90901253bf8e64efd
+Author: Mary Guillemard <mary.guillemard@collabora.com>
+Date:   2024-12-02 09:11:35 +0100
+
+    meson: Add mesa-clc and install-mesa-clc options
+    
+    Due to the cross build issues in current meson, we adds new options to
+    allow mesa_clc and vtn_bindgen to be installed or searched on the
+    system.
+    
+    Signed-off-by: Mary Guillemard <mary.guillemard@collabora.com>
+    Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
+    Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
+    Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32719>
+
+diff --git a/meson.build b/meson.build
+index de9c9af53a1..e37325ec176 100644
+--- a/meson.build
++++ b/meson.build
+@@ -808,7 +808,7 @@ if with_gallium_rusticl or with_nouveau_vk or with_tools.contains('etnaviv')
+ endif
+ 
+ with_clover_spirv = with_gallium_clover and get_option('opencl-spirv')
+-with_clc = with_microsoft_clc or with_intel_clc or with_gallium_asahi or with_asahi_vk or with_gallium_rusticl or with_clover_spirv
++with_clc = get_option('mesa-clc') != 'auto' or with_microsoft_clc or with_intel_clc or with_gallium_asahi or with_asahi_vk or with_gallium_rusticl
+ 
+ dep_clc = null_dep
+ if with_gallium_clover or with_clc
+diff --git a/meson_options.txt b/meson_options.txt
+index 79ee65e6094..8f22b36e5fb 100644
+--- a/meson_options.txt
++++ b/meson_options.txt
+@@ -744,3 +744,20 @@ option(
+     'none', 'dri2'
+   ],
+ )
++
++option(
++  'mesa-clc',
++  type : 'combo',
++  value : 'auto',
++  choices : [
++    'enabled', 'system', 'auto'
++  ],
++  description : 'Build the mesa-clc compiler or use a system version.'
++)
++
++option(
++  'install-mesa-clc',
++  type : 'boolean',
++  value : false,
++  description : 'Install the mesa-clc compiler (if needed for cross builds).'
++)
+diff --git a/src/compiler/clc/meson.build b/src/compiler/clc/meson.build
+index 74767d08de2..4875d71ca21 100644
+--- a/src/compiler/clc/meson.build
++++ b/src/compiler/clc/meson.build
+@@ -117,15 +117,20 @@ idep_mesaclc = declare_dependency(
+   link_args : _idep_mesaclc_link_args,
+ )
+ 
+-prog_mesa_clc = executable(
+-  'mesa_clc',
+-  ['mesa_clc.c'],
+-  include_directories : [inc_include, inc_src],
+-  c_args : [pre_args, no_override_init_args],
+-  link_args : [ld_args_build_id],
+-  dependencies : [idep_mesaclc, dep_llvm, dep_spirv_tools, idep_getopt],
+-  # If we can run host binaries directly, just build mesa_clc for the host.
+-  # Most commonly this happens when doing a cross compile from an x86_64 build
+-  # machine to an x86 host
+-  native : not meson.can_run_host_binaries(),
+-)
++if get_option('mesa-clc') == 'system'
++  prog_mesa_clc = find_program('mesa_clc', native : true)
++else
++  prog_mesa_clc = executable(
++    'mesa_clc',
++    ['mesa_clc.c'],
++    include_directories : [inc_include, inc_src],
++    c_args : [pre_args, no_override_init_args],
++    link_args : [ld_args_build_id],
++    dependencies : [idep_mesaclc, dep_llvm, dep_spirv_tools, idep_getopt],
++    # If we can run host binaries directly, just build mesa_clc for the host.
++    # Most commonly this happens when doing a cross compile from an x86_64 build
++    # machine to an x86 host
++    native : not meson.can_run_host_binaries(),
++    install : get_option('install-mesa-clc'),
++  )
++endif
diff --git a/pkgs/development/libraries/mesa/default.nix b/pkgs/development/libraries/mesa/default.nix
index 37b96d30e867..633770b6862c 100644
--- a/pkgs/development/libraries/mesa/default.nix
+++ b/pkgs/development/libraries/mesa/default.nix
@@ -138,6 +138,9 @@ in stdenv.mkDerivation {
 
   patches = [
     ./opencl.patch
+    # cherry-picked from https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32719
+    # safe to remove for versions > 24.3.2
+    ./cross_clc.patch
   ];
 
   postPatch = ''
@@ -204,6 +207,7 @@ in stdenv.mkDerivation {
 
     # Enable Intel RT stuff when available
     (lib.mesonBool "install-intel-clc" true)
+    (lib.mesonBool "install-mesa-clc" true)
     (lib.mesonEnable "intel-rt" stdenv.hostPlatform.isx86_64)
     (lib.mesonOption "clang-libdir" "${lib.getLib llvmPackages.clang-unwrapped}/lib")
 
@@ -222,6 +226,7 @@ in stdenv.mkDerivation {
     (lib.mesonOption "video-codecs" "all")
   ] ++ lib.optionals needNativeCLC [
     (lib.mesonOption "intel-clc" "system")
+    (lib.mesonOption "mesa-clc" "system")
   ];
 
   strictDeps = true;
@@ -333,6 +338,7 @@ in stdenv.mkDerivation {
     echo $opencl/lib/libRusticlOpenCL.so > $opencl/etc/OpenCL/vendors/rusticl.icd
 
     moveToOutput bin/intel_clc $driversdev
+    moveToOutput bin/mesa_clc $driversdev
     moveToOutput lib/gallium-pipe $opencl
     moveToOutput "lib/lib*OpenCL*" $opencl
     moveToOutput "lib/libOSMesa*" $osmesa