stdenv: implement crossOverlays

crossOverlays only apply to the packages being built, not the build
packages. It is useful when you don’t care what is used to build your
packages, just what is being built. The idea relies heavily on the
cross compiling infrastructure. Using this implies that we need to
create a cross stdenv.

8 files changed, 20 insertions, 15 deletions

diff --git a/pkgs/stdenv/cross/default.nix b/pkgs/stdenv/cross/default.nix
index daa9f66615c9e..a6063049a3ada 100644
--- a/pkgs/stdenv/cross/default.nix
+++ b/pkgs/stdenv/cross/default.nix
@@ -1,11 +1,14 @@
 { lib
-, localSystem, crossSystem, config, overlays
+, localSystem, crossSystem, config, overlays, crossOverlays ? []
 }:
 
 let
   bootStages = import ../. {
     inherit lib localSystem overlays;
-    crossSystem = null;
+
+    crossSystem = localSystem;
+    crossOverlays = [];
+
     # Ignore custom stdenvs when cross compiling for compatability
     config = builtins.removeAttrs config [ "replaceStdenv" ];
   };
@@ -33,7 +36,8 @@ in lib.init bootStages ++ [
 
   # Run Packages
   (buildPackages: {
-    inherit config overlays;
+    inherit config;
+    overlays = overlays ++ crossOverlays;
     selfBuild = false;
     stdenv = buildPackages.stdenv.override (old: rec {
       buildPlatform = localSystem;
@@ -48,7 +52,7 @@ in lib.init bootStages ++ [
 
       cc = if crossSystem.useiOSPrebuilt or false
              then buildPackages.darwin.iosSdkPkgs.clang
-           else if crossSystem.useAndroidPrebuilt
+           else if crossSystem.useAndroidPrebuilt or false
              then buildPackages.androidenv."androidndkPkgs_${crossSystem.ndkVer}".gcc
            else buildPackages.gcc;
 
@@ -56,6 +60,7 @@ in lib.init bootStages ++ [
         ++ lib.optionals
              (hostPlatform.isLinux && !buildPlatform.isLinux)
              [ buildPackages.patchelf buildPackages.paxctl ]
+        ++ lib.optional hostPlatform.isDarwin buildPackages.clang
         ++ lib.optional
              (let f = p: !p.isx86 || p.libc == "musl"; in f hostPlatform && !(f buildPlatform))
              buildPackages.updateAutotoolsGnuConfigScriptsHook
diff --git a/pkgs/stdenv/custom/default.nix b/pkgs/stdenv/custom/default.nix
index b6ea8685f8e64..e86face95195d 100644
--- a/pkgs/stdenv/custom/default.nix
+++ b/pkgs/stdenv/custom/default.nix
@@ -2,7 +2,7 @@
 , localSystem, crossSystem, config, overlays
 }:
 
-assert crossSystem == null;
+assert crossSystem == localSystem;
 
 let
   bootStages = import ../. {
diff --git a/pkgs/stdenv/darwin/default.nix b/pkgs/stdenv/darwin/default.nix
index 5fb410b64ebdc..b7d8e3ba5236b 100644
--- a/pkgs/stdenv/darwin/default.nix
+++ b/pkgs/stdenv/darwin/default.nix
@@ -1,5 +1,5 @@
 { lib
-, localSystem, crossSystem, config, overlays
+, localSystem, crossSystem, config, overlays, crossOverlays ? []
 
 # Allow passing in bootstrap files directly so we can test the stdenv bootstrap process when changing the bootstrap tools
 , bootstrapFiles ? let
@@ -16,7 +16,7 @@
   }
 }:
 
-assert crossSystem == null;
+assert crossSystem == localSystem;
 
 let
   inherit (localSystem) system platform;
diff --git a/pkgs/stdenv/default.nix b/pkgs/stdenv/default.nix
index 210e0439c0b84..c0bbe24e5219c 100644
--- a/pkgs/stdenv/default.nix
+++ b/pkgs/stdenv/default.nix
@@ -7,7 +7,7 @@
 { # Args just for stdenvs' usage
   lib
   # Args to pass on to the pkgset builder, too
-, localSystem, crossSystem, config, overlays
+, localSystem, crossSystem, config, overlays, crossOverlays ? []
 } @ args:
 
 let
@@ -36,7 +36,7 @@ let
 
   # Select the appropriate stages for the platform `system'.
 in
-  if crossSystem != null then stagesCross
+  if crossSystem != localSystem || crossOverlays != [] then stagesCross
   else if config ? replaceStdenv then stagesCustom
   else { # switch
     "i686-linux" = stagesLinux;
diff --git a/pkgs/stdenv/freebsd/default.nix b/pkgs/stdenv/freebsd/default.nix
index b3a6cedad8419..dbb4a0564558a 100644
--- a/pkgs/stdenv/freebsd/default.nix
+++ b/pkgs/stdenv/freebsd/default.nix
@@ -2,7 +2,7 @@
 , localSystem, crossSystem, config, overlays
 }:
 
-assert crossSystem == null;
+assert crossSystem == localSystem;
 let inherit (localSystem) system; in
 
 
diff --git a/pkgs/stdenv/linux/default.nix b/pkgs/stdenv/linux/default.nix
index 978beea692c6a..6d793999d904f 100644
--- a/pkgs/stdenv/linux/default.nix
+++ b/pkgs/stdenv/linux/default.nix
@@ -4,7 +4,7 @@
 # compiler and linker that do not search in default locations,
 # ensuring purity of components produced by it.
 { lib
-, localSystem, crossSystem, config, overlays
+, localSystem, crossSystem, config, overlays, crossOverlays ? []
 
 , bootstrapFiles ?
   let table = {
@@ -32,7 +32,7 @@
   in files
 }:
 
-assert crossSystem == null;
+assert crossSystem == localSystem;
 
 let
   inherit (localSystem) system platform;
diff --git a/pkgs/stdenv/native/default.nix b/pkgs/stdenv/native/default.nix
index 37795b11f6ddd..810cf16301f46 100644
--- a/pkgs/stdenv/native/default.nix
+++ b/pkgs/stdenv/native/default.nix
@@ -2,7 +2,7 @@
 , localSystem, crossSystem, config, overlays
 }:
 
-assert crossSystem == null;
+assert crossSystem == localSystem;
 
 let
   inherit (localSystem) system;
diff --git a/pkgs/stdenv/nix/default.nix b/pkgs/stdenv/nix/default.nix
index ffff8bdf51d48..a8311f49609aa 100644
--- a/pkgs/stdenv/nix/default.nix
+++ b/pkgs/stdenv/nix/default.nix
@@ -1,10 +1,10 @@
 { lib
-, crossSystem, config, overlays
+, crossSystem, localSystem, config, overlays
 , bootStages
 , ...
 }:
 
-assert crossSystem == null;
+assert crossSystem == localSystem;
 
 bootStages ++ [
   (prevStage: {