meson: Make target-agnostic

The cross file is added in the `mkDerivation`. It isn't nice putting
build tool-specific stuff here, but our current architecture gives us
little alternative.

pkgs/development/tools/build-managers/meson/default.nix

@@ -3,20 +3,8 @@
 , stdenv
 , writeTextDir
 , substituteAll
-, targetPackages
 }:
 
-let
-  # See https://mesonbuild.com/Reference-tables.html#cpu-families
-  cpuFamilies = {
-    aarch64  = "aarch64";
-    armv5tel = "arm";
-    armv6l   = "arm";
-    armv7l   = "arm";
-    i686     = "x86";
-    x86_64   = "x86_64";
-  };
-in
 python3Packages.buildPythonApplication rec {
   pname = "meson";
   version = "0.54.0";
@@ -70,27 +58,11 @@ python3Packages.buildPythonApplication rec {
 
   setupHook = ./setup-hook.sh;
 
-  crossFile = writeTextDir "cross-file.conf" ''
-    [binaries]
-    pkgconfig = 'pkg-config'
-
-    [properties]
-    needs_exe_wrapper = true
-
-    [host_machine]
-    system = '${targetPackages.stdenv.targetPlatform.parsed.kernel.name}'
-    cpu_family = '${cpuFamilies.${targetPackages.stdenv.targetPlatform.parsed.cpu.name}}'
-    cpu = '${targetPackages.stdenv.targetPlatform.parsed.cpu.name}'
-    endian = ${if targetPackages.stdenv.targetPlatform.isLittleEndian then "'little'" else "'big'"}
-  '';
-
   # 0.45 update enabled tests but they are failing
   doCheck = false;
   # checkInputs = [ ninja pkgconfig ];
   # checkPhase = "python ./run_project_tests.py";
 
-  isCross = stdenv.targetPlatform != stdenv.hostPlatform;
-
   meta = with lib; {
     homepage = "https://mesonbuild.com";
     description = "SCons-like build system that use python as a front-end language and Ninja as a building backend";

pkgs/development/tools/build-managers/meson/setup-hook.sh

@@ -5,11 +5,6 @@ mesonConfigurePhase() {
         mesonFlags="--prefix=$prefix $mesonFlags"
     fi
 
-    # Build release by default.
-    if [ -n "@isCross@" ]; then
-      crossMesonFlags="--cross-file=@crossFile@/cross-file.conf"
-    fi
-
     # See multiple-outputs.sh and meson’s coredata.py
     mesonFlags="\
         --libdir=${!outputLib}/lib --libexecdir=${!outputLib}/libexec \

pkgs/stdenv/generic/make-derivation.nix

@@ -49,6 +49,7 @@ in rec {
     # Configure Phase
     , configureFlags ? []
     , cmakeFlags ? []
+    , mesonFlags ? []
     , # Target is not included by default because most programs don't care.
       # Including it then would cause needless mass rebuilds.
       #
@@ -252,6 +253,34 @@ in rec {
           ++ lib.optional (stdenv.buildPlatform.uname.system != null) "-DCMAKE_HOST_SYSTEM_NAME=${stdenv.buildPlatform.uname.system}"
           ++ lib.optional (stdenv.buildPlatform.uname.processor != null) "-DCMAKE_HOST_SYSTEM_PROCESSOR=${stdenv.buildPlatform.uname.processor}"
           ++ lib.optional (stdenv.buildPlatform.uname.release != null) "-DCMAKE_HOST_SYSTEM_VERSION=${stdenv.buildPlatform.uname.release}";
+
+          mesonFlags = if mesonFlags == null then null else let
+            # See https://mesonbuild.com/Reference-tables.html#cpu-families
+            cpuFamilies = {
+              aarch64  = "aarch64";
+              armv5tel = "arm";
+              armv6l   = "arm";
+              armv7l   = "arm";
+              i686     = "x86";
+              x86_64   = "x86_64";
+            };
+            crossFile = builtins.toFile "cross-file.conf" (''
+              [properties]
+              needs_exe_wrapper = true
+
+              [host_machine]
+              system = '${stdenv.targetPlatform.parsed.kernel.name}'
+              cpu_family = '${cpuFamilies.${stdenv.targetPlatform.parsed.cpu.name}}'
+              cpu = '${stdenv.targetPlatform.parsed.cpu.name}'
+              endian = ${if stdenv.targetPlatform.isLittleEndian then "'little'" else "'big'"}
+            ''
+            # TODO should have target prefix too, issue #86077
+            + ''
+
+              [binaries]
+              pkgconfig = 'pkg-config'
+            '');
+          in [ "--cross-file=${crossFile}" ] ++ mesonFlags;
         } // lib.optionalAttrs (attrs.enableParallelBuilding or false) {
           enableParallelChecking = attrs.enableParallelChecking or true;
         } // lib.optionalAttrs (hardeningDisable != [] || hardeningEnable != []) {