1 files changed, 108 insertions, 0 deletions
diff --git a/src/Haddock/GHC.hs b/src/Haddock/GHC.hs
new file mode 100644
index 00000000..b4b9dd3f
--- /dev/null
+++ b/src/Haddock/GHC.hs
@@ -0,0 +1,108 @@
+--
+-- Haddock - A Haskell Documentation Tool
+--
+-- (c) Simon Marlow 2003
+--
+
+
+module Haddock.GHC (
+  startGhc,
+  loadPackages,
+  tryParseStaticFlags,
+  parseGhcFlags,
+  module Haddock.GHC.Typecheck,
+  module Haddock.GHC.Utils
+) where
+
+
+import Haddock.GHC.Typecheck
+import Haddock.GHC.Utils
+import Haddock.Exception
+import Haddock.Options
+
+import Data.Foldable (foldlM)
+import Data.Maybe
+import Control.Monad
+
+import GHC
+import DynFlags hiding (Option)
+import Packages hiding (package)
+import StaticFlags
+
+
+-- | Start a GHC session with the -haddock flag set. Also turn off 
+-- compilation and linking.  
+startGhc :: String -> IO (Session, DynFlags)
+startGhc libDir = do
+  session <- newSession (Just libDir)
+  flags   <- getSessionDynFlags session
+  let flags' = dopt_set flags Opt_Haddock
+  let flags'' = flags' {
+      hscTarget = HscNothing,
+      ghcMode   = CompManager,
+      ghcLink   = NoLink
+    }
+  setSessionDynFlags session flags''
+  return (session, flags'')
+
+
+-- | Expose the list of packages to GHC. Then initialize GHC's package state
+-- and get the name of the actually loaded packages matching the supplied 
+-- list of packages. The matching packages might be newer versions of the 
+-- supplied ones. For each matching package, return its InstalledPackageInfo. 
+
+loadPackages :: Session -> [String] -> IO [InstalledPackageInfo]
+
+-- It would be better to try to get the "in scope" packages from GHC instead.
+-- This would make the -use-package flag unnecessary. But currently it 
+-- seems all you can get from the GHC api is all packages that are linked in 
+-- (i.e the closure of the "in scope" packages).
+
+loadPackages session pkgStrs = do
+
+  -- expose the packages 
+
+  dfs <- getSessionDynFlags session
+  let dfs' = dfs { packageFlags = packageFlags dfs ++ map ExposePackage pkgStrs }
+  setSessionDynFlags session dfs'
+
+  -- try to parse the packages and get their names, without versions
+  pkgNames <- mapM (handleParse . unpackPackageId . stringToPackageId) pkgStrs
+
+  -- init GHC's package state
+  (dfs'', depPackages) <- initPackages dfs'
+
+  -- compute the pkgIds of the loaded packages matching the 
+  -- supplied ones
+  
+  let depPkgs = map (fromJust . unpackPackageId) depPackages      
+      matchingPackages = [ mkPackageId pkg | pkg <- depPkgs, 
+                           pkgName pkg `elem` pkgNames ]
+
+  -- get InstalledPackageInfos for each package
+  let pkgInfos = map (getPackageDetails (pkgState dfs'')) matchingPackages
+
+  return pkgInfos
+  where
+    handleParse (Just pkg) = return (pkgName pkg)
+    handleParse Nothing = throwE "Could not parse package identifier"
+
+
+-- | Filter out the GHC specific flags and try to parse and set them as static 
+-- flags. Return a list of flags that couldn't be parsed. 
+tryParseStaticFlags flags = do
+  let ghcFlags = [ str | Flag_GhcFlag str <- flags ]
+  parseStaticFlags ghcFlags
+
+
+-- | Try to parse dynamic GHC flags
+parseGhcFlags session ghcFlags = do
+  dflags <- getSessionDynFlags session
+  foldlM parseFlag dflags (map words ghcFlags)
+  where 
+    -- try to parse a flag as either a dynamic or static GHC flag
+    parseFlag dynflags ghcFlag = do
+      (dynflags', rest) <- parseDynamicFlags dynflags ghcFlag
+      when (rest == ghcFlag) $
+          throwE ("Couldn't parse GHC flag: " ++ (unwords ghcFlag))           
+      return dynflags'