pkgs/build-support/cabal: stabilize shared linking support

We cannot pass the --{enable,disable}-executable-dynamic flags to GHC
versions prior to 7.4.x.

Building shared libraries via --{enable,disable}-shared is possible in theory
with GHC 6.12.x or later, but doesn't work in practice because our GHC 6.10.x
builds don't provide shared versions of their base libraries. This could
probably be fixed, but it's probably not worth the effort.

1 files changed, 32 insertions, 16 deletions

diff --git a/pkgs/build-support/cabal/default.nix b/pkgs/build-support/cabal/default.nix
index fb3b6b99c4f4..9b6d8c4e80ed 100644
--- a/pkgs/build-support/cabal/default.nix
+++ b/pkgs/build-support/cabal/default.nix
@@ -4,11 +4,26 @@
 , enableLibraryProfiling ? false
 , enableSharedLibraries ? false
 , enableSharedExecutables ? false
-, enableCheckPhase ? true
+, enableCheckPhase ? stdenv.lib.versionOlder "7.4" ghc.version
 }:
 
-# The Cabal library shipped with GHC versions older than 7.x doesn't accept the --enable-tests configure flag.
-assert enableCheckPhase -> stdenv.lib.versionOlder "7" ghc.ghcVersion;
+let
+  enableFeature         = stdenv.lib.enableFeature;
+  versionOlder          = stdenv.lib.versionOlder;
+  optional              = stdenv.lib.optional;
+  optionals             = stdenv.lib.optionals;
+  optionalString        = stdenv.lib.optionalString;
+  filter                = stdenv.lib.filter;
+in
+
+# Cabal shipped with GHC 6.12.4 or earlier doesn't know the "--enable-tests configure" flag.
+assert enableCheckPhase -> versionOlder "7" ghc.version;
+
+# GHC prior to 7.4.x doesn't know the "--enable-executable-dynamic" flag.
+assert enableSharedExecutables -> versionOlder "7.4" ghc.version;
+
+# Our GHC 6.10.x builds do not provide sharable versions of their core libraries.
+assert enableSharedLibraries -> versionOlder "6.12" ghc.version;
 
 {
   mkDerivation =
@@ -25,8 +40,8 @@ assert enableCheckPhase -> stdenv.lib.versionOlder "7" ghc.ghcVersion;
         # in the interest of keeping hashes stable.
         postprocess =
           x : (removeAttrs x internalAttrs) // {
-                buildInputs           = stdenv.lib.filter (y : ! (y == null)) x.buildInputs;
-                propagatedBuildInputs = stdenv.lib.filter (y : ! (y == null)) x.propagatedBuildInputs;
+                buildInputs           = filter (y : ! (y == null)) x.buildInputs;
+                propagatedBuildInputs = filter (y : ! (y == null)) x.propagatedBuildInputs;
                 doCheck               = enableCheckPhase && x.doCheck;
               };
 
@@ -69,7 +84,7 @@ assert enableCheckPhase -> stdenv.lib.versionOlder "7" ghc.ghcVersion;
             # but often propagatedBuildInputs is preferable anyway
             buildInputs = [ghc Cabal] ++ self.extraBuildInputs;
             extraBuildInputs = self.buildTools ++
-                               (stdenv.lib.optionals self.doCheck self.testDepends) ++
+                               (optionals self.doCheck self.testDepends) ++
                                (if self.pkgconfigDepends == [] then [] else [pkgconfig]) ++
                                (if self.isLibrary then [] else self.buildDepends ++ self.extraLibraries ++ self.pkgconfigDepends);
 
@@ -105,8 +120,8 @@ assert enableCheckPhase -> stdenv.lib.versionOlder "7" ghc.ghcVersion;
             jailbreak = false;
 
             # pass the '--enable-split-objs' flag to cabal in the configure stage
-            enableSplitObjs = !(  stdenv.isDarwin         # http://hackage.haskell.org/trac/ghc/ticket/4013
-                               || stdenv.lib.versionOlder "7.6.99" ghc.ghcVersion  # -fsplit-ojbs is broken in 7.7 snapshot
+            enableSplitObjs = !(  stdenv.isDarwin                       # http://hackage.haskell.org/trac/ghc/ticket/4013
+                               || versionOlder "7.6.99" ghc.version     # -fsplit-ojbs is broken in 7.7 snapshot
                                );
 
             # pass the '--enable-tests' flag to cabal in the configure stage
@@ -122,21 +137,22 @@ assert enableCheckPhase -> stdenv.lib.versionOlder "7" ghc.ghcVersion;
             inherit enableSharedExecutables;
 
             extraConfigureFlags = [
-              (stdenv.lib.enableFeature enableLibraryProfiling "library-profiling")
-              (stdenv.lib.enableFeature self.enableSharedLibraries "shared")
-              (stdenv.lib.enableFeature self.enableSharedExecutables "executable-dynamic")
-              (stdenv.lib.enableFeature self.enableSplitObjs "split-objs")
-            ] ++ stdenv.lib.optional (stdenv.lib.versionOlder "7" ghc.ghcVersion) (stdenv.lib.enableFeature self.doCheck "tests");
+              (enableFeature self.enableSplitObjs "split-objs")
+              (enableFeature enableLibraryProfiling "library-profiling")
+              (enableFeature self.enableSharedLibraries "shared")
+              (optional (versionOlder "7.4" ghc.version) (enableFeature self.enableSharedExecutables "executable-dynamic"))
+              (optional (versionOlder "7" ghc.version) (enableFeature self.doCheck "tests"))
+            ];
 
             # GHC needs the locale configured during the Haddock phase.
             LANG = "en_US.UTF-8";
-            LOCALE_ARCHIVE = lib.optionalString stdenv.isLinux "${glibcLocales}/lib/locale/locale-archive";
+            LOCALE_ARCHIVE = optionalString stdenv.isLinux "${glibcLocales}/lib/locale/locale-archive";
 
             # compiles Setup and configures
             configurePhase = ''
               eval "$preConfigure"
 
-              ${lib.optionalString self.jailbreak "${jailbreakCabal}/bin/jailbreak-cabal ${self.pname}.cabal"}
+              ${optionalString self.jailbreak "${jailbreakCabal}/bin/jailbreak-cabal ${self.pname}.cabal"}
 
               for i in Setup.hs Setup.lhs; do
                 test -f $i && ghc --make $i
@@ -175,7 +191,7 @@ assert enableCheckPhase -> stdenv.lib.versionOlder "7" ghc.ghcVersion;
               eval "$postBuild"
             '';
 
-            checkPhase = stdenv.lib.optional self.doCheck ''
+            checkPhase = optional self.doCheck ''
               eval "$preCheck"
 
               ./Setup test ${self.testTarget}