Merging from trunk. I had to do two manual merges, quite trivial I think.

svn path=/nixpkgs/branches/stdenv-updates/; revision=18472

6 files changed, 71 insertions, 35 deletions

diff --git a/pkgs/lib/attrsets.nix b/pkgs/lib/attrsets.nix
index 4b2496c1987..4be944d8494 100644
--- a/pkgs/lib/attrsets.nix
+++ b/pkgs/lib/attrsets.nix
@@ -15,7 +15,7 @@ rec {
 
   /* Return an attribute from nested attribute sets.  For instance
      ["x" "y"] applied to some set e returns e.x.y, if it exists.  The
-     default value is returned otherwise.  */
+     default value is returned otherwise. */
   attrByPath = attrPath: default: e:
     let attr = head attrPath;
     in
@@ -200,7 +200,7 @@ rec {
 
   /* Does the same as the update operator '//' except that attributes are
      merged until the given pedicate is verified.  The predicate should
-     except 3 arguments which are the path to reach the attribute, a part of
+     accept 3 arguments which are the path to reach the attribute, a part of
      the first attribute set and a part of the second attribute set.  When
      the predicate is verified, the value of the first attribute set is
      replaced by the value of the second attribute set.
diff --git a/pkgs/lib/customisation.nix b/pkgs/lib/customisation.nix
new file mode 100644
index 00000000000..76d019a73c2
--- /dev/null
+++ b/pkgs/lib/customisation.nix
@@ -0,0 +1,61 @@
+let lib = import ./default.nix; in
+
+rec {
+
+
+  /* `overrideDerivation drv f' takes a derivation (i.e., the result
+     of a call to the builtin function `derivation') and returns a new
+     derivation in which the attributes of the original are overriden
+     according to the function `f'.  The function `f' is called with
+     the original derivation attributes.
+
+     `overrideDerivation' allows certain "ad-hoc" customisation
+     scenarios (e.g. in ~/.nixpkgs/config.nix).  For instance, if you
+     want to "patch" the derivation returned by a package function in
+     Nixpkgs to build another version than what the function itself
+     provides, you can do something like this:
+
+       mySed = overrideDerivation pkgs.gnused (oldAttrs: {
+         name = "sed-4.2.2-pre";
+         src = fetchurl {
+           url = ftp://alpha.gnu.org/gnu/sed/sed-4.2.2-pre.tar.bz2;
+           sha256 = "11nq06d131y4wmf3drm0yk502d2xc6n5qy82cg88rb9nqd2lj41k";
+         };
+         patches = [];
+       });
+
+     For another application, see build-support/vm, where this
+     function is used to build arbitrary derivations inside a QEMU
+     virtual machine. */
+     
+  overrideDerivation = drv: f:
+    let
+      # Filter out special attributes.
+      attrs = removeAttrs drv ["meta" "passthru" "outPath" "drvPath"];
+      newDrv = derivation (attrs // (f drv));
+    in newDrv //
+      { meta = if drv ? meta then drv.meta else {};
+        passthru = if drv ? passthru then drv.passthru else {};
+      };
+
+
+  # usage: (you can use override multiple times)
+  # let d = makeOverridable stdenv.mkDerivation { name = ..; buildInputs; }
+  #     noBuildInputs = d.override { buildInputs = []; }
+  #     additionalBuildInputs = d.override ( args : args // { buildInputs = args.buildInputs ++ [ additional ]; } )
+  makeOverridable = f: origArgs: f origArgs //
+    { override = newArgs:
+        makeOverridable f (origArgs // (if builtins.isFunction newArgs then newArgs origArgs else newArgs));
+      deepOverride = newArgs:
+        makeOverridable f ((lib.mapAttrs (deepOverride newArgs) origArgs) // newArgs);
+      origArgs = origArgs;
+    };
+
+
+  deepOverride = newArgs: name: x: if builtins.isAttrs x then (
+    if x ? deepOverride then (x.deepOverride newArgs) else
+    if x ? override then (x.override newArgs) else
+    x) else x;
+    
+        
+}
diff --git a/pkgs/lib/debug.nix b/pkgs/lib/debug.nix
index 4f757653bc0..5d411b864ec 100644
--- a/pkgs/lib/debug.nix
+++ b/pkgs/lib/debug.nix
@@ -1,6 +1,6 @@
 let lib = import ./default.nix;
 
-inherit (builtins) trace attrNamesToStr isAttrs isFunction isList head substring attrNames;
+inherit (builtins) trace attrNamesToStr isAttrs isFunction isList isInt isString head substring attrNames;
 
 in
 
@@ -37,7 +37,10 @@ rec {
       else if x == true then "x is boolean true"
       else if x == false then "x is boolean false"
       else if x == null then "x is null"
-      else "x is probably a string `${substring 0 50 x}...'";
+      else if isInt x then "x is an integer `${toString x}'"
+      else if isString x then "x is a string `${substring 0 50 x}...'"
+      else "x is probably a path `${substring 0 50 (toString x)}'";
+
   # trace the arguments passed to function and its result 
   traceCall  = n : f : a : let t = n2 : x : traceShowValMarked "${n} ${n2}:" x; in t "result" (f (t "arg 1" a));
   traceCall2 = n : f : a : b : let t = n2 : x : traceShowValMarked "${n} ${n2}:" x; in t "result" (f (t "arg 1" a) (t "arg 2" b));
diff --git a/pkgs/lib/default.nix b/pkgs/lib/default.nix
index 86c45fe8334..6276009ec19 100644
--- a/pkgs/lib/default.nix
+++ b/pkgs/lib/default.nix
@@ -16,6 +16,7 @@ let
   maintainers = import ./maintainers.nix;
   platforms = import ./platforms.nix;
   systems = import ./systems.nix;
+  customisation = import ./customisation.nix;
 
 in
   { inherit trivial lists strings stringsWithDeps attrsets sources options
@@ -26,3 +27,4 @@ in
   // trivial // lists // strings // stringsWithDeps // attrsets // sources
   // properties // options // types // meta // debug // misc // modules
   // systems
+  // customisation
diff --git a/pkgs/lib/maintainers.nix b/pkgs/lib/maintainers.nix
index 892b3e21044..9127c8c7308 100644
--- a/pkgs/lib/maintainers.nix
+++ b/pkgs/lib/maintainers.nix
@@ -8,6 +8,7 @@
   eelco = "Eelco Dolstra <e.dolstra@tudelft.nl>";
   ludo = "Ludovic Courtès <ludo@gnu.org>";
   marcweber = "Marc Weber <marco-oweber@gmx.de>";
+  pierron = "Nicolas B. Pierron <nixos@nbp.name>";
   raskin = "Michael Raskin <7c6f434c@mail.ru>";
   sander = "Sander van der Burg <s.vanderburg@tudelft.nl>";
   viric = "Lluís Batlle i Rossell <viriketo@gmail.com>";
diff --git a/pkgs/lib/misc.nix b/pkgs/lib/misc.nix
index ba7488ff70e..c1fee190268 100644
--- a/pkgs/lib/misc.nix
+++ b/pkgs/lib/misc.nix
@@ -9,23 +9,6 @@ with import ./strings.nix;
 
 rec {
 
-
-  # accumulates / merges all attr sets until null is fed.
-  # example: sumArgs id { a = 'a'; x = 'x'; } { y = 'y'; x = 'X'; } null
-  # result : { a = 'a'; x = 'X'; y = 'Y'; }
-  innerSumArgs = f : x : y : (if y == null then (f x)
-	else (innerSumArgs f (x // y)));
-  sumArgs = f : innerSumArgs f {};
-
-  # Advanced sumArgs version. Hm, twice as slow, I'm afraid.
-  # composedArgs id (x:x//{a="b";}) (x:x//{b=x.a + "c";}) null;
-  # {a="b" ; b="bc";};
-  innerComposedArgs = f : x : y : (if y==null then (f x)
-  	else (if (builtins.isAttrs y) then 
-		(innerComposedArgs f (x//y))
-	else (innerComposedArgs f (y x))));
-  composedArgs = f: innerComposedArgs f {};
-
   defaultMergeArg = x : y: if builtins.isAttrs y then
     y
   else 
@@ -105,14 +88,6 @@ rec {
   # }
   composedArgsAndFun = f: foldArgs defaultMerge f {};
 
-  # example a = pairMap (x : y : x + y) ["a" "b" "c" "d"];
-  # result: ["ab" "cd"]
-  innerPairMap = acc: f: l: 
-  	if l == [] then acc else
-	innerPairMap (acc ++ [(f (head l)(head (tail l)))])
-		f (tail (tail l));
-  pairMap = innerPairMap [];
-
   
   # shortcut for attrByPath ["name"] default attrs
   maybeAttr = name: default: attrs:
@@ -321,12 +296,6 @@ rec {
   flattenAttrs = set : map ( attr : builtins.getAttr attr set) (attrNames set);
   mapIf = cond : f :  fold ( x : l : if (cond x) then [(f x)] ++ l else l) [];
 
-  # pick attrs subset_attr_names and apply f 
-  subsetmap = f : attrs : subset_attr_names : 
-    listToAttrs (fold ( attr : r : if hasAttr attr attrs
-          then r ++ [ ( nameValuePair attr ( f (getAttr attr attrs) ) ) ] else r ) []
-      subset_attr_names );
-
   # prepareDerivationArgs tries to make writing configurable derivations easier
   # example:
   #  prepareDerivationArgs {