Add special support for haskeline

The library uses stuff in Setup.hs to determine whether or not it needs
to use -liconv. This patch replicates that logic in ghc-cabal. This
isn't pretty, and we should find a better way to do it, but it works
for now.

1 files changed, 82 insertions, 2 deletions

diff --git a/utils/ghc-cabal/ghc-cabal.hs b/utils/ghc-cabal/ghc-cabal.hs
index c806d3cf16..c19217e5e0 100644
--- a/utils/ghc-cabal/ghc-cabal.hs
+++ b/utils/ghc-cabal/ghc-cabal.hs
@@ -1,6 +1,7 @@
 
 module Main (main) where
 
+import Distribution.Compat.Exception
 import qualified Distribution.ModuleName as ModuleName
 import Distribution.PackageDescription
 import Distribution.PackageDescription.Configuration
@@ -9,9 +10,10 @@ import Distribution.Simple
 import Distribution.Simple.Configure
 import Distribution.Simple.LocalBuildInfo
 import Distribution.Simple.Program
-import Distribution.Simple.Utils (defaultPackageDesc)
+import Distribution.Simple.Utils (defaultPackageDesc, withTempFile)
 import Distribution.Simple.Build (writeAutogenFiles)
 import Distribution.Simple.Register (writeInstalledConfig)
+import Distribution.Simple.PackageIndex
 import Distribution.Text
 import Distribution.Verbosity
 import qualified Distribution.InstalledPackageInfo as Installed
@@ -19,6 +21,7 @@ import qualified Distribution.InstalledPackageInfo as Installed
 import qualified Distribution.Simple.PackageIndex as PackageIndex
          ( topologicalOrder, lookupPackageName, insert )
 
+import Control.Exception
 import Control.Monad
 import Data.Maybe
 import System.IO
@@ -148,7 +151,7 @@ doInstall ghcpkg ghcpkgconf directory distDir myDestDir myPrefix myLibdir myDocd
 generate :: [String] -> FilePath -> FilePath -> IO ()
 generate config_args distdir directory
  = withCurrentDirectory directory
- $ do let verbosity = verbose
+ $ do let verbosity = normal
       gpdFile <- defaultPackageDesc verbosity
       gpd <- readPackageDescription verbosity gpdFile
 
@@ -164,6 +167,17 @@ generate config_args distdir directory
       lbi <- getPersistBuildConfig distdir
       let pd0 = localPkgDescr lbi
 
+      -- Sigh, haskeline proper uses stuff in Setup.hs to handle whether
+      -- or not -liconv is used. We don't use Setup.hs, so we replicate
+      -- what it does here. We should do this better somehow.
+      when (display (pkgName (package pd0)) == "haskeline") $
+          case library pd0 of
+              Nothing -> fail "Can't happen: No haskeline library"
+              Just lib -> do
+                  d <- getCurrentDirectory
+                  print d
+                  maybeSetLibiconv verbosity (libBuildInfo lib) lbi
+
       hooked_bi <-
            if (buildType pd0 == Just Configure)
            then do
@@ -244,3 +258,69 @@ generate config_args distdir directory
       writeFile (distdir ++ "/package-data.mk") $ unlines xs
   where
      escape = foldr (\c xs -> if c == '#' then '\\':'#':xs else c:xs) []
+
+----------------------------------------------------------------------
+-- haskeline-specific hacks
+
+-- Sigh, haskeline proper uses stuff in Setup.hs to handle whether
+-- or not -liconv is used. We don't use Setup.hs, so we replicate
+-- what it does here. We should do this better somehow.
+
+-- Test whether compiling a c program that links against libiconv needs -liconv.
+maybeSetLibiconv :: Verbosity -> BuildInfo -> LocalBuildInfo -> IO ()
+maybeSetLibiconv verb bi lbi = do
+    let biWithIconv = addIconv bi
+    worksWithout <- tryCompile iconv_prog bi lbi verb
+    if worksWithout
+        then writeBuildInfo ""
+        else do
+    worksWith <- tryCompile iconv_prog biWithIconv lbi verb
+    if worksWith
+        then do
+            writeBuildInfo "iconv"
+        else fail "Unable to link against the iconv library."
+  where
+    -- Cabal (at least 1.6.0.1) won't parse an empty buildinfo file.
+    writeBuildInfo libs = writeFile "haskeline.buildinfo"
+                            $ unlines ["extra-libraries: " ++ libs]
+
+tryCompile :: String -> BuildInfo -> LocalBuildInfo -> Verbosity -> IO Bool
+tryCompile program bi lbi verb = flip catchIO processException $ flip catchExit processExit $ do
+    tempDir <- getTemporaryDirectory
+    withTempFile tempDir ".c" $ \fname h -> do
+        hPutStr h program
+        hClose h
+        -- TODO take verbosity from the args.
+        rawSystemProgramStdoutConf verb gccProgram (withPrograms lbi) (fname : args)
+        return True
+  where
+    processException :: IOException -> IO Bool
+    processException _ = return False
+    processExit = return . (==ExitSuccess)
+    -- Mimicing Distribution.Simple.Configure
+    deps = topologicalOrder (installedPkgs lbi)
+    args = concat
+                  [ ccOptions bi
+                  , cppOptions bi
+                  , ldOptions bi
+                  -- --extra-include-dirs and --extra-lib-dirs are included
+                  -- in the below fields.
+                  -- Also sometimes a dependency like rts points to a nonstandard
+                  -- include/lib directory where iconv can be found.
+                  , map ("-I" ++) (includeDirs bi ++ concatMap Installed.includeDirs deps)
+                  , map ("-L" ++) (extraLibDirs bi ++ concatMap Installed.libraryDirs deps)
+                  , map ("-l" ++) (extraLibs bi)
+                  ]
+
+addIconv :: BuildInfo -> BuildInfo
+addIconv bi = bi {extraLibs = "iconv" : extraLibs bi}
+
+iconv_prog :: String
+iconv_prog = unlines $
+    [ "#include <iconv.h>"
+    , "int main(void) {"
+    , "    iconv_t t = iconv_open(\"UTF-8\", \"UTF-8\");"
+    , "    return 0;"
+    , "}"
+    ]
+