mesa-clc: native host build of mesa_clc + vtn_bindgen2 for cross builds

A Redox cross build cannot run the target shader-precompile tools on the host,
so build them natively once and feed them to the cross Mesa via
-Dmesa-clc=system -Dprecomp-compiler=system. Native meson build against
llvm-native's CLEAN host LLVM/Clang (the redoxer toolchain's llvm-config emits
-I<toolchain>/include, which holds Redox target libc headers that poison host
g++), host system deps (libdrm/expat/zlib/zstd), and our host-built
SPIRV-Tools/LLVMSPIRVLib/libclc (pkg-config with absolute .pc prefixes; native
pkg-config, not the cross wrapper). Driver-agnostic tools, so iris-only (no
amdgpu-LLVM needed); they serve radeonsi/radv in the cross build too.

local/recipes/dev/mesa-clc/recipe.toml

@@ -0,0 +1,119 @@
+[package]
+name = "mesa-clc"
+# NATIVE (host) build of Mesa's build-time shader compilers: mesa_clc,
+# vtn_bindgen2 and the driver precomp tools (intel_clc, ...). The cross Mesa
+# build cannot run Redox target binaries on the host, so it consumes these via
+# -Dmesa-clc=system -Dprecomp-compiler=system. Version tracks Mesa.
+version = "26.1.4"
+description = "Native host build of Mesa's mesa_clc / vtn_bindgen2 / precomp shader tools, consumed by the cross Mesa build (-Dmesa-clc=system -Dprecomp-compiler=system)."
+
+[source]
+tar = "https://gitlab.freedesktop.org/mesa/mesa/-/archive/mesa-26.1.4/mesa-mesa-26.1.4.tar.gz"
+blake3 = "2299cd27430592c9a4a21c6345e74d5df278f4cd5839875ffd75abc3c1e988f9"
+upstream = "https://gitlab.freedesktop.org/mesa/mesa"
+
+[build]
+template = "custom"
+# Host toolchain LLVM/clang (all-five targets) + our host-built SPIRV/libclc are
+# reused; the Manjaro host supplies the common build deps (libdrm, expat, zlib,
+# python). llvm-native provides a host clang/LLVM dev tree if the toolchain one
+# is insufficient. spirv-* / libclc are staged so native pkg-config resolves them.
+dependencies = [
+    "llvm-native",
+    "spirv-tools",
+    "spirv-llvm-translator",
+    "libclc",
+]
+dev-dependencies = [
+    "llvm-native.dev",
+    "llvm-native.runtime",
+]
+script = '''
+DYNAMIC_INIT
+
+# NATIVE build: drop every cross-compile flag so host gcc/g++ target the host.
+unset LDFLAGS CFLAGS CXXFLAGS CPPFLAGS
+export CC=/usr/bin/gcc
+export CXX=/usr/bin/g++
+
+# Use llvm-native's CLEAN host LLVM/Clang (staged in the sysroot at usr/bin).
+# Do NOT use the redoxer toolchain's llvm-config: its includedir
+# (<toolchain>/include) also holds the Redox *target* libc headers
+# (features.h/stdlib.h without __GLIBC_USE) next to the llvm headers, and
+# `llvm-config --cxxflags` emits `-I<that dir>`, which shadows host glibc and
+# breaks the native g++ compile (host libstdc++ os_defines.h fails on
+# __GLIBC_USE). llvm-native's includedir is clean (llvm headers only). mesa_clc/
+# vtn_bindgen2 are driver-agnostic, so an X86-only host LLVM is sufficient.
+export PATH="${COOKBOOK_SYSROOT}/usr/bin:${PATH}"
+export LD_LIBRARY_PATH="${COOKBOOK_SYSROOT}/usr/lib:${LD_LIBRARY_PATH:-}"
+
+# DYNAMIC_INIT points pkg-config at the CROSS wrapper (sysroot-only) via
+# PKG_CONFIG / PKG_CONFIG_LIBDIR / PKG_CONFIG_SYSROOT_DIR. This is a NATIVE build,
+# so override to the host pkg-config and let it search BOTH the host system dirs
+# (libzstd/libdrm/expat from Manjaro /usr) AND the staged sysroot (our host-built
+# SPIRV-Tools/LLVMSPIRVLib/libclc). We rewrite the staged .pc prefixes to the
+# absolute sysroot path and drop PKG_CONFIG_SYSROOT_DIR so host .pc (prefix=/usr)
+# are not re-rooted.
+export PKG_CONFIG=/usr/bin/pkg-config
+unset PKG_CONFIG_SYSROOT_DIR
+unset PKG_CONFIG_PATH
+export PKG_CONFIG_LIBDIR="${COOKBOOK_SYSROOT}/usr/lib/pkgconfig:/usr/lib/pkgconfig:/usr/share/pkgconfig"
+for _pc in "${COOKBOOK_SYSROOT}"/usr/lib/pkgconfig/*.pc; do
+    [ -f "$_pc" ] || continue
+    sed -i "s|^prefix=/usr\$|prefix=${COOKBOOK_SYSROOT}/usr|" "$_pc"
+done
+# Do NOT add a global -I${COOKBOOK_SYSROOT}/usr/include: that would inject the
+# Redox relibc headers (features.h/stdlib.h without __GLIBC_USE) ahead of the
+# host glibc/libstdc++ headers and break the native compile. pkg-config (with
+# the absolute .pc prefixes above) and llvm-config supply the correct per-
+# dependency include/lib paths for LLVMSPIRVLib/SPIRV-Tools/libclc/LLVM.
+
+# Configure a NATIVE mesa restricted to the shader compilers. No window-system
+# platforms / GL runtime — we only need the clc/precomp tool executables.
+meson setup build-clc "${COOKBOOK_SOURCE}" \
+    --buildtype=release \
+    --prefix=/usr \
+    -Dmesa-clc=enabled \
+    -Dinstall-mesa-clc=true \
+    -Dprecomp-compiler=enabled \
+    -Dinstall-precomp-compiler=true \
+    -Dgallium-drivers=iris \
+    -Dvulkan-drivers=intel \
+    -Dllvm=enabled \
+    -Dshared-llvm=enabled \
+    -Dplatforms= \
+    -Degl=disabled \
+    -Dglx=disabled \
+    -Dgbm=disabled \
+    -Dgles1=disabled \
+    -Dgles2=disabled \
+    -Dopengl=true \
+    -Dshared-glapi=enabled \
+    -Dvideo-codecs= \
+    -Dgallium-va=disabled \
+    -Dgallium-extra-hud=false \
+    -Dvalgrind=disabled \
+    -Dlibunwind=disabled \
+    -Dzstd=enabled \
+    -Dshader-cache=disabled
+
+# Build the tool executables by their ninja output paths (ninja targets are
+# paths, not bare names). intel_clc is only present when the intel driver's clc
+# path is configured — build it only if it is a known target.
+_targets="src/compiler/clc/mesa_clc src/compiler/spirv/vtn_bindgen2"
+if ninja -C build-clc -t targets all 2>/dev/null | grep -q "src/intel/compiler/intel_clc:"; then
+    _targets="$_targets src/intel/compiler/intel_clc"
+fi
+ninja -C build-clc $_targets
+
+# Stage every tool executable we built into usr/bin.
+mkdir -p "${COOKBOOK_STAGE}/usr/bin"
+for t in $_targets; do
+    if [ -x "build-clc/$t" ]; then
+        cp "build-clc/$t" "${COOKBOOK_STAGE}/usr/bin/"
+    else
+        echo "mesa-clc: WARN target build-clc/$t not found after build"
+    fi
+done
+ls -la "${COOKBOOK_STAGE}/usr/bin/"
+'''

recipes/dev/mesa-clc

@@ -0,0 +1 @@
+../../local/recipes/dev/mesa-clc