1 files changed, 304 insertions, 0 deletions
diff --git a/krebs/5pkgs/writers.nix b/krebs/5pkgs/writers.nix
new file mode 100644
index 000000000..6e33a6507
--- /dev/null
+++ b/krebs/5pkgs/writers.nix
@@ -0,0 +1,304 @@
+{ pkgs, ... }:
+with import <stockholm/lib>;
+{
+  nixpkgs.config.packageOverrides = _: {
+    execve = name: { filename, argv ? null, envp ? {}, destination ? "" }: let
+    in pkgs.writeC name { inherit destination; } /* c */ ''
+      #include <unistd.h>
+
+      static char *const filename = ${toC filename};
+
+      ${if argv == null
+        then /* Propagate arguments */ /* c */ ''
+          #define MAIN_ARGS int argc, char **argv
+        ''
+        else /* Provide fixed arguments */ /* c */ ''
+          #define MAIN_ARGS void
+          static char *const argv[] = ${toC (argv ++ [null])};
+        ''}
+
+      static char *const envp[] = ${toC (
+        mapAttrsToList (k: v: "${k}=${v}") envp ++ [null]
+      )};
+
+      int main (MAIN_ARGS) {
+        execve(filename, argv, envp);
+        return -1;
+      }
+    '';
+
+    execveBin = name: cfg:
+      pkgs.execve name (cfg // { destination = "/bin/${name}"; });
+
+    makeScriptWriter = interpreter: name: text:
+      assert (with types; either absolute-pathname filename).check name;
+      pkgs.writeOut (baseNameOf name) {
+        ${optionalString (types.absolute-pathname.check name) name} = {
+          executable = true;
+          text = "#! ${interpreter}\n${text}";
+        };
+      };
+
+    writeBash = name: text:
+      assert (with types; either absolute-pathname filename).check name;
+      pkgs.writeOut (baseNameOf name) {
+        ${optionalString (types.absolute-pathname.check name) name} = {
+          check = pkgs.writeDash "shellcheck.sh" ''
+            ${pkgs.haskellPackages.ShellCheck}/bin/shellcheck "$1" || :
+          '';
+          executable = true;
+          text = "#! ${pkgs.bash}/bin/bash\n${text}";
+        };
+      };
+
+    writeBashBin = name:
+      assert types.filename.check name;
+      pkgs.writeBash "/bin/${name}";
+
+    writeC = name: { destination ? "" }: text: pkgs.runCommand name {
+      inherit text;
+      passAsFile = [ "text" ];
+    } /* sh */ ''
+      PATH=${makeBinPath (with pkgs; [
+        binutils
+        coreutils
+        gcc
+      ])}
+      exe=$out${destination}
+      mkdir -p "$(dirname "$exe")"
+      gcc -O -Wall -o "$exe" -x c "$textPath"
+      strip --strip-unneeded "$exe"
+    '';
+
+    writeDash = pkgs.makeScriptWriter "${pkgs.dash}/bin/dash";
+
+    writeDashBin = name:
+      assert types.filename.check name;
+      pkgs.writeDash "/bin/${name}";
+
+    writeEximConfig = name: text: pkgs.runCommand name {
+      inherit text;
+      passAsFile = [ "text" ];
+    } /* sh */ ''
+      # TODO validate exim config even with config.nix.useChroot == true
+      # currently doing so will fail because "user exim was not found"
+      #${pkgs.exim}/bin/exim -C "$textPath" -bV >/dev/null
+      mv "$textPath" $out
+    '';
+
+    writeOut = name: specs0:
+    let
+      writers.link =
+        { path
+        , link
+        }:
+        assert path == "" || types.absolute-pathname.check path;
+        assert types.package.check link;
+        {
+          install = /* sh */ ''
+            ${optionalString (dirOf path != "/") /* sh */ ''
+              ${pkgs.coreutils}/bin/mkdir -p $out${dirOf path}
+            ''}
+            ${pkgs.coreutils}/bin/ln -s ${link} $out${path}
+          '';
+        };
+
+      writers.text =
+        { path
+        , check ? null
+        , executable ? false
+        , mode ? if executable then "0755" else "0644"
+        , text
+        }:
+        assert path == "" || types.absolute-pathname.check path;
+        assert types.bool.check executable;
+        assert types.file-mode.check mode;
+        rec {
+          var = "file_${hashString "sha1" path}";
+          val = text;
+          install = /* sh */ ''
+            ${optionalString (check != null) /* sh */ ''
+              ${check} ''$${var}Path
+            ''}
+            ${pkgs.coreutils}/bin/install \
+                -m ${mode} \
+                -D \
+                ''$${var}Path $out${path}
+          '';
+        };
+
+      write = spec: writers.${spec.type} (removeAttrs spec ["type"]);
+
+      specs =
+        mapAttrsToList
+          (path: spec: let
+            known-types = [ "link" "text" ];
+            found-types = attrNames (getAttrs known-types spec);
+            type = assert length found-types == 1; head found-types;
+          in spec // { inherit path type; })
+          specs0;
+
+      files = map write specs;
+
+      filevars = genAttrs' (filter (hasAttr "var") files)
+                           (spec: nameValuePair spec.var spec.val);
+
+      env = filevars // { passAsFile = attrNames filevars; };
+    in
+      pkgs.runCommand name env /* sh */ ''
+        set -efu
+        ${concatMapStringsSep "\n" (getAttr "install") files}
+      '';
+
+    writeHaskell =
+      k:
+      let
+        k' = parseDrvName k;
+        name = k'.name;
+        version = if k'.version != "" then k'.version else "0";
+      in
+      { base-depends ? ["base"]
+      , executables ? {}
+      , ghc-options ? ["-Wall" "-O3" "-threaded" "-rtsopts"]
+      , haskellPackages ? pkgs.haskellPackages
+      , library ? null
+      , license ? "WTFPL"
+      }:
+      let
+        isExecutable = executables != {};
+        isLibrary = library != null;
+
+        cabal-file = pkgs.writeText "${name}-${version}.cabal" /* cabal */ ''
+          build-type: Simple
+          cabal-version: >= 1.2
+          name: ${name}
+          version: ${version}
+          ${concatStringsSep "\n" (mapAttrsToList exe-section executables)}
+          ${optionalString isLibrary (lib-section library)}
+        '';
+
+        exe-install =
+          exe-name:
+          { file ? pkgs.writeText "${name}-${exe-name}.hs" text
+          , relpath ? "${exe-name}.hs"
+          , text
+          , ... }:
+          if types.filename.check exe-name
+            then /* sh */ "install -D ${file} $out/${relpath}"
+            else throw "argument ‘exe-name’ is not a ${types.filename.name}";
+
+        exe-section =
+          exe-name:
+          { build-depends ? base-depends ++ extra-depends
+          , extra-depends ? []
+          , file ? pkgs.writeText "${name}-${exe-name}.hs" text
+          , relpath ? "${exe-name}.hs"
+          , text
+          , ... }: /* cabal */ ''
+            executable ${exe-name}
+              build-depends: ${concatStringsSep "," build-depends}
+              ghc-options: ${toString ghc-options}
+              main-is: ${relpath}
+          '';
+
+        get-depends =
+          { build-depends ? base-depends ++ extra-depends
+          , extra-depends ? []
+          , ...
+          }:
+          build-depends;
+
+        lib-install =
+          { exposed-modules
+          , ... }:
+          concatStringsSep "\n" (mapAttrsToList mod-install exposed-modules);
+
+        lib-section =
+          { build-depends ? base-depends ++ extra-depends
+          , extra-depends ? []
+          , exposed-modules
+          , ... }: /* cabal */ ''
+            library
+              build-depends: ${concatStringsSep "," build-depends}
+              ghc-options: ${toString ghc-options}
+              exposed-modules: ${concatStringsSep "," (attrNames exposed-modules)}
+          '';
+
+        mod-install =
+          mod-name:
+          { file ? pkgs.writeText "${name}-${mod-name}.hs" text
+          , relpath ? "${replaceStrings ["."] ["/"] mod-name}.hs"
+          , text
+          , ... }:
+          if types.haskell.modid.check mod-name
+            then /* sh */ "install -D ${file} $out/${relpath}"
+            else throw "argument ‘mod-name’ is not a ${types.haskell.modid.name}";
+      in
+        haskellPackages.mkDerivation {
+          inherit isExecutable isLibrary license version;
+          executableHaskellDepends =
+            attrVals
+              (concatMap get-depends (attrValues executables))
+              haskellPackages;
+          libraryHaskellDepends =
+            attrVals
+              (optionals isLibrary (get-depends library))
+              haskellPackages;
+          pname = name;
+          src = pkgs.runCommand "${name}-${version}-src" {} /* sh */ ''
+            install -D ${cabal-file} $out/${cabal-file.name}
+            ${optionalString isLibrary (lib-install library)}
+            ${concatStringsSep "\n" (mapAttrsToList exe-install executables)}
+          '';
+        };
+
+    writeJq = name: text: pkgs.runCommand name {
+      inherit text;
+      passAsFile = [ "text" ];
+    } /* sh */ ''
+      name=${assert types.filename.check name; name}
+
+      # syntax check
+      ${pkgs.jq}/bin/jq -f "$textPath" -n
+
+      cp "$textPath" "$out"
+    '';
+
+    writeJSON = name: value: pkgs.writeText name (toJSON value);
+
+    writeNixFromCabal =
+      trace (toString [
+        "The function `writeNixFromCabal` has been deprecated in favour of"
+        "`writeHaskell`."
+      ])
+      (name: path: pkgs.runCommand name {} /* sh */ ''
+        ${pkgs.cabal2nix}/bin/cabal2nix ${path} > $out
+      '');
+
+    writePython2 = name: text: pkgs.runCommand name {
+      inherit text;
+      passAsFile = [ "text" ];
+    } /* sh */ ''
+      name=${assert types.filename.check name; name}
+
+      # syntax check
+      ${pkgs.python2}/bin/python -m py_compile "$textPath"
+
+      cp "$textPath" "$out"
+    '';
+
+    writePython3 = name: text: pkgs.runCommand name {
+      inherit text;
+      passAsFile = [ "text" ];
+    } /* sh */ ''
+      name=${assert types.filename.check name; name}
+
+      # syntax check
+      ${pkgs.python3}/bin/python -m py_compile "$textPath"
+
+      cp "$textPath" "$out"
+    '';
+
+    writeSed = pkgs.makeScriptWriter "${pkgs.gnused}/bin/sed -f";
+  };
+}