cabal-read: import from stockholm

1 files changed, 39 insertions, 0 deletions

diff --git a/pkgs/simple/cabal-read.nix b/pkgs/simple/cabal-read.nix
new file mode 100644
index 0000000..03b42ef
--- /dev/null
+++ b/pkgs/simple/cabal-read.nix
@@ -0,0 +1,39 @@
+{ writeHaskellPackage }:
+
+# Because `sed -n 's/.*\<ghc-options:\s\+\(.*\)/\1/p'` is too simple.
+writeHaskellPackage "cabal-read" {
+  executables.ghc-options = {
+    extra-depends = ["Cabal"];
+    text = /* haskell */ ''
+      {-# LANGUAGE CPP #-}
+      module Main (main) where
+      import Data.List
+      import Data.Maybe
+      import Distribution.Compiler
+      import Distribution.PackageDescription.Parsec
+      import Distribution.Types.BuildInfo
+      import Distribution.Types.CondTree
+      import Distribution.Types.Executable
+      import Distribution.Types.GenericPackageDescription
+      import Distribution.Types.UnqualComponentName
+      import Distribution.Verbosity
+      import System.Environment
+      main :: IO ()
+      main = do
+          [path, name] <- getArgs
+
+          desc <- readGenericPackageDescription normal path
+
+          case lookup (mkUnqualComponentName name) (condExecutables desc) of
+            Just exe ->
+              putStrLn . intercalate " " . fromMaybe [] . lookup GHC
+      #if MIN_VERSION_Cabal(3,0,0)
+                       . perCompilerFlavorToList
+      #endif
+                       . options . buildInfo . condTreeData $ exe
+
+            Nothing ->
+              error ("executable " <> name <> " not found in " <> path)
+    '';
+  };
+}