Merging more distcc derivations, at the style of ccache

These allow building a Masquerade PATH for distccd, or overriding
stdenv to use distcc.

pkgs/development/tools/misc/distcc/default.nix

@@ -1,13 +1,12 @@
-{ stdenv, fetchurl, popt, avahi, pkgconfig, python, gtk
+{ stdenv, fetchurl, popt, avahi, pkgconfig, python, gtk, runCommand, gcc
 , sysconfDir ? ""   # set this parameter to override the default value $out/etc
 , static ? false
 }:
 
-let name    = "distcc";
-    version = "3.1";
-in
-
-stdenv.mkDerivation {
+let
+name    = "distcc";
+version = "3.1";
+distcc = stdenv.mkDerivation {
   name = "${name}-${version}";
   src = fetchurl {
     url = "http://distcc.googlecode.com/files/${name}-${version}.tar.bz2";
@@ -36,6 +35,32 @@ stdenv.mkDerivation {
   # The test suite fails because it uses hard-coded paths, i.e. /usr/bin/gcc.
   doCheck = false;
 
+  passthru = {
+    # A derivation that provides gcc and g++ commands, but that
+    # will end up calling distcc for the given cacheDir
+    links = extraConfig : (runCommand "distcc-links"
+        { inherit (gcc) langC langCC; }
+      ''
+        mkdir -p $out/bin
+        if [ $langC -eq 1 ]; then
+          cat > $out/bin/gcc << EOF
+          #!/bin/sh
+          ${extraConfig}
+          exec ${distcc}/bin/distcc gcc "\$@"
+        EOF
+          chmod +x $out/bin/gcc
+        fi
+        if [ $langCC -eq 1 ]; then
+          cat > $out/bin/g++ << EOF
+          #!/bin/sh
+          ${extraConfig}
+          exec ${distcc}/bin/distcc g++ "\$@"
+        EOF
+          chmod +x $out/bin/g++
+        fi
+      '');
+  };
+
   meta = {
     description = "a fast, free distributed C/C++ compiler";
     homepage = "http://distcc.org";
@@ -44,4 +69,6 @@ stdenv.mkDerivation {
     platforms = stdenv.lib.platforms.linux;
     maintainers = [ stdenv.lib.maintainers.simons ];
   };
-}
+};
+in
+distcc

pkgs/development/tools/misc/distcc/masq.nix

@@ -0,0 +1,41 @@
+{ stdenv, gccRaw, binutils }:
+
+stdenv.mkDerivation {
+  name = "distcc-masq-${gccRaw.name}";
+
+  phases = [ "installPhase" ];
+  installPhase = ''
+    ensureDir $out/bin
+
+    bin=${gccRaw}/bin
+
+    shopt -s nullglob
+    if [ -f $bin/gcc ]; then
+      ln -s $bin/gcc $out/bin
+    else
+      for a in $bin/*-gcc; do
+        ln -s $bin/*-gcc $out/bin/gcc
+        ln -s $bin/*-gcc $out/bin/cc
+      done
+    fi
+
+    if [ -f $bin/g++ ]; then
+      ln -s $bin/g++ $out/bin
+    else
+      for a in $bin/*-g++; do
+        ln -sf $bin/*-g++ $out/bin/g++
+        ln -sf $bin/*-g++ $out/bin/c++
+      done
+    fi
+
+    bbin=${binutils}/bin
+    if [ -f $bbin/as ]; then
+      ln -s $bbin/as $out/bin
+    else
+      for a in $bbin/*-as; do
+        ln -sf $bbin/*-as $out/bin/as
+      done
+    fi
+    
+  '';
+}

pkgs/top-level/all-packages.nix

@@ -3075,6 +3075,28 @@ let
 
   distcc = callPackage ../development/tools/misc/distcc { };
 
+  # distccWrapper: wrapper that works as gcc or g++
+  # It can be used by setting in nixpkgs config like this, for example:
+  #    replaceStdenv = { pkgs }: pkgs.distccStdenv;
+  # But if you build in chroot, a default 'nix' will create
+  # a new net namespace, and won't have network access.
+  # You can use an override in packageOverrides to set extraConfig:
+  #    packageOverrides = pkgs: {
+  #     distccWrapper = pkgs.distccWrapper.override {
+  #       extraConfig = ''
+  #         DISTCC_HOSTS="myhost1 myhost2"
+  #       '';
+  #     };
+  #
+  distccWrapper = makeOverridable ({ extraConfig ? "" }:
+     wrapGCC (distcc.links extraConfig)) {};
+  distccStdenv = lowPrio (overrideGCC stdenv distccWrapper);
+
+  distccMasquerade = callPackage ../development/tools/misc/distcc/masq.nix {
+    gccRaw = gcc.gcc;
+    binutils = binutils;
+  };
+
   docutils = builderDefsPackage (import ../development/tools/documentation/docutils) {
     inherit python pil makeWrapper;
   };