wrapCC, wrapBintools: move expand-response-params bootstrapping out

The cc and bintools wrapper contained ad hoc bootstrapping logic for
expand-response-params (which was callPackage-ed in a let binding). This
lead to the strange situation that the bootstrapping logic related to
expand-response-params is split between the wrapper derivations (where
it is duplicated) and the actual stdenv bootstrapping.

To clean this up, the wrappers simply should take expand-response-params
as an ordinary input: They need an adjacent expand-response-params (i.e.
one that runs on their host platform), but don't care about the how.
Providing this is only problematic during stdenv bootstrapping where we
have to pull it from the previous stage at times.

pkgs/build-support/bintools-wrapper/default.nix

@@ -29,7 +29,7 @@
 , isGNU ? bintools.isGNU or false
 , isLLVM ? bintools.isLLVM or false
 , isCCTools ? bintools.isCCTools or false
-, buildPackages ? {}
+, expand-response-params
 , targetPackages ? {}
 , useMacosReexportHack ? false
 , wrapGas ? false
@@ -132,10 +132,6 @@ let
     else if hasSuffix "pc-gnu" targetPlatform.config then "ld.so.1"
     else "";
 
-  expand-response-params =
-    optionalString (buildPackages ? stdenv && buildPackages.stdenv.hasCC && buildPackages.stdenv.cc != "/dev/null")
-    (import ../expand-response-params { inherit (buildPackages) stdenv; });
-
 in
 
 stdenvNoCC.mkDerivation {
@@ -419,6 +415,7 @@ stdenvNoCC.mkDerivation {
 
   env = {
     # for substitution in utils.bash
+    # TODO(@sternenseemann): invent something cleaner than passing in "" in case of absence
     expandResponseParams = "${expand-response-params}/bin/expand-response-params";
     # TODO(@sternenseemann): rename env var via stdenv rebuild
     shell = (getBin runtimeShell + runtimeShell.shellPath or "");

pkgs/build-support/cc-wrapper/default.nix

@@ -16,7 +16,7 @@
 , extraTools ? [], extraPackages ? [], extraBuildCommands ? ""
 , nixSupport ? {}
 , isGNU ? false, isClang ? cc.isClang or false, isCcache ? cc.isCcache or false, gnugrep ? null
-, buildPackages ? {}
+, expand-response-params
 , libcxx ? null
 
 # Whether or not to add `-B` and `-L` to `nix-support/cc-{c,ld}flags`
@@ -113,9 +113,6 @@ let
   # unstable implementation detail, however.
   suffixSalt = replaceStrings ["-" "."] ["_" "_"] targetPlatform.config;
 
-  expand-response-params =
-    optionalString ((buildPackages.stdenv.hasCC or false) && buildPackages.stdenv.cc != "/dev/null") (import ../expand-response-params { inherit (buildPackages) stdenv; });
-
   useGccForLibs = useCcForLibs
     && libcxx == null
     && !targetPlatform.isDarwin
@@ -298,6 +295,9 @@ stdenvNoCC.mkDerivation {
         '(${concatStringsSep " " (map (pkg: "\"${pkg}\"") pkgs)}))
     '';
 
+    # Expose expand-response-params we are /actually/ using. In stdenv
+    # bootstrapping, expand-response-params usually comes from an earlier stage,
+    # so it is important to expose this for reference checking.
     inherit expand-response-params;
 
     inherit nixSupport;
@@ -739,6 +739,7 @@ stdenvNoCC.mkDerivation {
     inherit isClang;
 
     # for substitution in utils.bash
+    # TODO(@sternenseemann): invent something cleaner than passing in "" in case of absence
     expandResponseParams = "${expand-response-params}/bin/expand-response-params";
     # TODO(@sternenseemann): rename env var via stdenv rebuild
     shell = getBin runtimeShell + runtimeShell.shellPath or "";

pkgs/stdenv/darwin/default.nix

@@ -76,9 +76,9 @@ let
         nativeTools = false;
         nativeLibc = false;
 
-        buildPackages = lib.optionalAttrs (prevStage ? stdenv) {
-          inherit (prevStage) stdenv;
-        };
+        expand-response-params = lib.optionalString
+          (prevStage.stdenv.hasCC or false && prevStage.stdenv.cc != "/dev/null")
+          prevStage.expand-response-params;
 
         extraPackages = [
           prevStage.llvmPackages.compiler-rt
@@ -254,7 +254,7 @@ in
           nativeTools = false;
           nativeLibc = false;
 
-          buildPackages = { };
+          expand-response-params = "";
           libc = selfDarwin.Libsystem;
 
           inherit lib;
@@ -841,9 +841,7 @@ in
 
         # Rewrap binutils so it uses the rebuilt Libsystem.
         binutils = superDarwin.binutils.override {
-          buildPackages = {
-            inherit (prevStage) stdenv;
-          };
+          inherit (prevStage) expand-response-params;
           libc = selfDarwin.Libsystem;
         } // {
           passthru = { inherit (prevStage.bintools.passthru) isFromBootstrapFiles; };
@@ -1048,9 +1046,7 @@ in
         };
 
         binutils = superDarwin.binutils.override {
-          buildPackages = {
-            inherit (prevStage) stdenv;
-          };
+          inherit (prevStage) expand-response-params;
 
           bintools = selfDarwin.binutils-unwrapped;
           libc = selfDarwin.Libsystem;
@@ -1087,9 +1083,7 @@ in
               nativeTools = false;
               nativeLibc = false;
 
-              buildPackages = {
-                inherit (prevStage) stdenv;
-              };
+              inherit (prevStage) expand-response-params;
 
               extraPackages = [
                 self.llvmPackages.compiler-rt

pkgs/stdenv/linux/default.nix

@@ -185,9 +185,9 @@ let
           name = "${name}-gcc-wrapper";
           nativeTools = false;
           nativeLibc = false;
-          buildPackages = lib.optionalAttrs (prevStage ? stdenv) {
-            inherit (prevStage) stdenv;
-          };
+          expand-response-params = lib.optionalString
+            (prevStage.stdenv.hasCC or false && prevStage.stdenv.cc != "/dev/null")
+            prevStage.expand-response-params;
           cc = prevStage.gcc-unwrapped;
           bintools = prevStage.binutils;
           isGNU = true;
@@ -261,7 +261,7 @@ in
         name = "bootstrap-stage0-binutils-wrapper";
         nativeTools = false;
         nativeLibc = false;
-        buildPackages = { };
+        expand-response-params = "";
         libc = getLibc self;
         inherit lib;
         inherit (self) stdenvNoCC coreutils gnugrep;
@@ -557,9 +557,7 @@ in
       # Since this is the first fresh build of binutils since stage2, our own runtimeShell will be used.
       binutils = super.binutils.override {
         # Build expand-response-params with last stage like below
-        buildPackages = {
-          inherit (prevStage) stdenv;
-        };
+        inherit (prevStage) expand-response-params;
       };
 
       # To allow users' overrides inhibit dependencies too heavy for
@@ -570,9 +568,7 @@ in
         nativeTools = false;
         nativeLibc = false;
         isGNU = true;
-        buildPackages = {
-          inherit (prevStage) stdenv;
-        };
+        inherit (prevStage) expand-response-params;
         cc = prevStage.gcc-unwrapped;
         bintools = self.binutils;
         libc = getLibc self;
@@ -654,7 +650,9 @@ in
         # More complicated cases
         ++ (map (x: getOutput x (getLibc prevStage)) [ "out" "dev" "bin" ] )
         ++  [ linuxHeaders # propagated from .dev
-            binutils gcc gcc.cc gcc.cc.lib gcc.expand-response-params gcc.cc.libgcc glibc.passthru.libgcc
+              binutils gcc gcc.cc gcc.cc.lib
+              gcc.expand-response-params # != (prevStage.)expand-response-params
+              gcc.cc.libgcc glibc.passthru.libgcc
           ]
         ++ lib.optionals (localSystem.libc == "musl") [ fortify-headers ]
         ++ [ prevStage.updateAutotoolsGnuConfigScriptsHook prevStage.gnu-config ]

pkgs/top-level/all-packages.nix

@@ -656,6 +656,8 @@ with pkgs;
 
   evhz = callPackage ../tools/misc/evhz { };
 
+  expand-response-params = callPackage ../build-support/expand-response-params { };
+
   expressvpn = callPackage ../applications/networking/expressvpn { };
 
   faq = callPackage ../development/tools/faq { };