Read depend packages from *.cabal, and adjust compiler package flags.

Cabal.hs

@@ -2,6 +2,7 @@
 
 module Cabal (initializeGHC) where
 
+import CabalApi (dependPackages)
 import Control.Applicative
 import Control.Exception
 import Control.Monad
@@ -29,7 +30,7 @@ initializeGHC :: Options -> FilePath -> [String] -> Bool -> Ghc (FilePath,LogRea
 initializeGHC opt fileName ghcOptions logging = withCabal ||> withoutCabal
   where
     withoutCabal = do
-        logReader <- initSession opt ghcOptions importDirs logging
+        logReader <- initSession opt ghcOptions importDirs Nothing logging
         return (fileName,logReader)
     withCabal = do
         (owdir,cdir,cfile) <- liftIO getDirs
@@ -42,7 +43,8 @@ initializeGHC opt fileName ghcOptions logging = withCabal ||> withoutCabal
             idirs = case hsSourceDirs of
                 []   -> [cdir,owdir]
                 dirs -> map (cdir </>) dirs ++ [owdir]
-        logReader <- initSession opt gopts idirs logging
+        depPkgs   <- liftIO $ dependPackages cfile
+        logReader <- initSession opt gopts idirs (Just depPkgs) logging
         return (fileName,logReader)
     addX = ("-X" ++)
 

CabalApi.hs

@@ -0,0 +1,39 @@
+module CabalApi (dependPackages) where
+
+import Data.Maybe (maybeToList)
+import Data.Set (fromList, toList)
+
+import Distribution.Verbosity (silent)
+import Distribution.Package (Dependency(Dependency), PackageName(PackageName))
+import Distribution.PackageDescription
+  (GenericPackageDescription,
+   condLibrary, condExecutables, condTestSuites, condBenchmarks,
+   CondTree, condTreeConstraints)
+import Distribution.PackageDescription.Parse (readPackageDescription)
+
+----------------------------------------------------------------
+
+parseGenericDescription :: FilePath -> IO GenericPackageDescription
+parseGenericDescription =  readPackageDescription silent
+
+getDepsOfPairs :: [(a1, CondTree v [b] a)] -> [b]
+getDepsOfPairs =  concatMap (condTreeConstraints . snd)
+
+allDependsOfDescription :: GenericPackageDescription -> [Dependency]
+allDependsOfDescription pd =
+  concat [depLib, depExe, depTests, depBench]
+  where
+    depLib   = concatMap condTreeConstraints (maybeToList . condLibrary $ pd)
+    depExe   = getDepsOfPairs . condExecutables $ pd
+    depTests = getDepsOfPairs . condTestSuites  $ pd
+    depBench = getDepsOfPairs . condBenchmarks  $ pd
+
+getDependencyPackageName :: Dependency -> String
+getDependencyPackageName (Dependency (PackageName n) _) = n
+
+dependPackages :: FilePath -> IO [String]
+dependPackages =
+  fmap (toList . fromList
+        . map getDependencyPackageName
+        . allDependsOfDescription)
+  . parseGenericDescription

GHCApi.hs

@@ -31,29 +31,33 @@ initSession0 :: Options -> Ghc [PackageId]
 initSession0 opt = getSessionDynFlags >>=
   (>>= setSessionDynFlags) . setGhcFlags opt
 
-initSession :: Options -> [String] -> [FilePath] -> Bool -> Ghc LogReader
+initSession :: Options -> [String] -> [FilePath] -> Maybe [String] -> Bool -> Ghc LogReader
-initSession opt cmdOpts idirs logging = do
+initSession opt cmdOpts idirs mayPkgs logging = do
     dflags <- getSessionDynFlags
     let opts = map noLoc cmdOpts
     (dflags',_,_) <- parseDynamicFlags dflags opts
-    (dflags'',readLog) <- liftIO . (>>= setLogger logging) . setGhcFlags opt . setFlags opt dflags' $ idirs
+    (dflags'',readLog) <- liftIO . (>>= setLogger logging)
+                          . setGhcFlags opt . setFlags opt dflags' idirs $ mayPkgs
     _ <- setSessionDynFlags dflags''
     return readLog
 
 ----------------------------------------------------------------
 
-setFlags :: Options -> DynFlags -> [FilePath] -> DynFlags
+setFlags :: Options -> DynFlags -> [FilePath] -> Maybe [String] -> DynFlags
-setFlags opt d idirs
+setFlags opt d idirs mayPkgs
   | expandSplice opt = dopt_set d' Opt_D_dump_splices
   | otherwise        = d'
   where
-    d' = d {
+    d' = maySetExpose $ d {
-        packageFlags = ghcPackage : packageFlags d
+        importPaths = idirs
-      , importPaths = idirs
       , ghcLink = LinkInMemory
       , hscTarget = HscInterpreted
       , flags = flags d
       }
+    -- Do hide-all only when depend packages specified
+    maySetExpose df = maybe df (\x -> (dopt_set df Opt_HideAllPackages) {
+                                   packageFlags = map ExposePackage x ++ packageFlags df
+                                   }) mayPkgs
 
 ghcPackage :: PackageFlag
 ghcPackage = ExposePackage "ghc"

ghc-mod.cabal

@@ -28,6 +28,7 @@ Data-Files:             Makefile ghc.el ghc-func.el ghc-doc.el ghc-comp.el
 Executable ghc-mod
   Main-Is:              GHCMod.hs
   Other-Modules:        Browse
+                        CabalApi
                         Cabal
                         CabalDev
                         Check
@@ -45,6 +46,7 @@ Executable ghc-mod
   GHC-Options:          -Wall
   Build-Depends:        base >= 4.0 && < 5
                       , Cabal
+                      , containers
                       , convertible
                       , directory
                       , filepath