stdenv: remove unix kernel family

System predicate patterns can now be specified as a list of OR'd
attribute sets.

lib/systems/inspect.nix

@@ -1,8 +1,9 @@
 with import ./parse.nix;
 with import ../attrsets.nix;
+with import ../lists.nix;
 
 rec {
-  patterns = {
+  patterns = rec {
     "32bit"      = { cpu = { bits = 32; }; };
     "64bit"      = { cpu = { bits = 64; }; };
     i686         = { cpu = cpuTypes.i686; };
@@ -13,8 +14,8 @@ rec {
     BigEndian    = { cpu = { significantByte = significantBytes.bigEndian; }; };
     LittleEndian = { cpu = { significantByte = significantBytes.littleEndian; }; };
 
-    Unix         = { kernel = { families = { inherit (kernelFamilies) unix; }; }; };
     BSD          = { kernel = { families = { inherit (kernelFamilies) bsd; }; }; };
+    Unix         = [ BSD Linux SunOS Hurd Cygwin ];
 
     Darwin       = { kernel = kernels.darwin; };
     Linux        = { kernel = kernels.linux; };
@@ -27,11 +28,15 @@ rec {
     Cygwin       = { kernel = kernels.windows; abi = abis.cygnus; };
     MinGW        = { kernel = kernels.windows; abi = abis.gnu; };
 
-    Arm32        = recursiveUpdate patterns.Arm patterns."32bit";
-    Arm64        = recursiveUpdate patterns.Arm patterns."64bit";
+    Arm32        = recursiveUpdate Arm patterns."32bit";
+    Arm64        = recursiveUpdate Arm patterns."64bit";
   };
 
+  matchAnyAttrs = patterns:
+    if builtins.isList patterns then attrs: any (pattern: matchAttrs pattern attrs) patterns
+    else matchAttrs patterns;
+
   predicates = mapAttrs'
-    (name: value: nameValuePair ("is" + name) (matchAttrs value))
+    (name: value: nameValuePair ("is" + name) (matchAnyAttrs value))
     patterns;
 }

lib/systems/parse.nix

@@ -68,21 +68,20 @@ rec {
   isKernelFamily = isType "kernel-family";
   kernelFamilies = setTypes "kernel-family" {
     bsd = {};
-    unix = {};
   };
 
   isKernel = x: isType "kernel" x;
   kernels = with execFormats; with kernelFamilies; setTypesAssert "kernel"
     (x: isExecFormat x.execFormat && all isKernelFamily (attrValues x.families))
   {
-    darwin  = { execFormat = macho;   families = { inherit unix; }; };
-    freebsd = { execFormat = elf;     families = { inherit unix bsd; }; };
-    hurd    = { execFormat = elf;     families = { inherit unix; }; };
-    linux   = { execFormat = elf;     families = { inherit unix; }; };
-    netbsd  = { execFormat = elf;     families = { inherit unix bsd; }; };
-    none    = { execFormat = unknown; families = { inherit unix; }; };
-    openbsd = { execFormat = elf;     families = { inherit unix bsd; }; };
-    solaris = { execFormat = elf;     families = { inherit unix; }; };
+    darwin  = { execFormat = macho;   families = { }; };
+    freebsd = { execFormat = elf;     families = { inherit bsd; }; };
+    hurd    = { execFormat = elf;     families = { }; };
+    linux   = { execFormat = elf;     families = { }; };
+    netbsd  = { execFormat = elf;     families = { inherit bsd; }; };
+    none    = { execFormat = unknown; families = { }; };
+    openbsd = { execFormat = elf;     families = { inherit bsd; }; };
+    solaris = { execFormat = elf;     families = { }; };
     windows = { execFormat = pe;      families = { }; };
   } // { # aliases
     # TODO(@Ericson2314): Handle these Darwin version suffixes more generally.