[project @ 2003-01-09 11:39:20 by simonmar]

[ghc-hetmet.git] / ghc / compiler / main / Finder.lhs

diff --git a/ghc/compiler/main/Finder.lhs b/ghc/compiler/main/Finder.lhs
index 8054e91..dc7e190 100644 (file)
--- a/ghc/compiler/main/Finder.lhs
+++ b/ghc/compiler/main/Finder.lhs
@@ -7,8 +7,11 @@
 module Finder (
     flushFinderCache,  -- :: IO ()
 
-    findModule,                -- :: ModuleName -> IO (Maybe (Module, ModLocation))
-    findPackageModule,  -- :: ModuleName -> IO (Maybe (Module, ModLocation))
+    findModule,                -- :: ModuleName 
+                       --   -> IO (Either [FilePath] (Module, ModLocation))
+
+    findPackageModule,  -- :: ModuleName
+                       --   -> IO (Either [FilePath] (Module, ModLocation))
 
     mkHomeModLocation, -- :: ModuleName -> String -> FilePath 
                        --      -> IO ModLocation
@@ -24,7 +27,6 @@ module Finder (
 
 import Module
 import UniqFM          ( filterUFM )
-import Packages                ( PackageConfig(..) )
 import HscTypes                ( Linkable(..), Unlinked(..) )
 import DriverState
 import DriverUtil      ( split_longest_prefix, splitFilename3 )
@@ -86,28 +88,32 @@ lookupFinderCache mod_name = do
 -- The ModLocation contains the names of all the files associated with
 -- that module: its source file, .hi file, object file, etc.
 
-findModule :: ModuleName -> IO (Maybe (Module, ModLocation))
+findModule :: ModuleName -> IO (Either [FilePath] (Module, ModLocation))
 findModule name = do
   r <- lookupFinderCache name
   case r of
-   Just result -> return (Just result)
+   Just result -> return (Right result)
    Nothing -> do  
        j <- maybeHomeModule name
        case j of
-        Just home_module -> return (Just home_module)
-        Nothing          -> findPackageMod name
-
-findPackageModule :: ModuleName -> IO (Maybe (Module, ModLocation))
+        Right home_module -> return (Right home_module)
+        Left home_files   -> do
+           r <- findPackageMod name
+           case r of
+               Right pkg_module -> return (Right pkg_module)
+               Left pkg_files   -> return (Left (home_files ++ pkg_files))
+
+findPackageModule :: ModuleName -> IO (Either [FilePath] (Module, ModLocation))
 findPackageModule name = do
   r <- lookupFinderCache name
   case r of
-   Just result -> return (Just result)
+   Just result -> return (Right result)
    Nothing     -> findPackageMod name
 
 hiBootExt = "hi-boot"
 hiBootVerExt = "hi-boot-" ++ cHscIfaceFileVersion
 
-maybeHomeModule :: ModuleName -> IO (Maybe (Module, ModLocation))
+maybeHomeModule :: ModuleName -> IO (Either [FilePath] (Module, ModLocation))
 maybeHomeModule mod_name = do
    home_path <- readIORef v_Import_paths
    hisuf     <- readIORef v_Hi_suf
@@ -142,7 +148,7 @@ maybeHomeModule mod_name = do
 -- -----------------------------------------------------------------------------
 -- Looking for a package module
 
-findPackageMod :: ModuleName -> IO (Maybe (Module, ModLocation))
+findPackageMod :: ModuleName -> IO (Either [FilePath] (Module, ModLocation))
 findPackageMod mod_name = do
   mode     <- readIORef v_GhcMode
   imp_dirs <- getPackageImportPath -- including the 'auto' ones
@@ -185,25 +191,28 @@ searchPathExts
        String -> String -> String -> IO (Module, ModLocation)  -- action
        )
      ] 
-  -> IO (Maybe (Module, ModLocation))
+  -> IO (Either [FilePath] (Module, ModLocation))
 
-searchPathExts path mod_name exts = search path
+searchPathExts path mod_name exts = search to_search
   where
     mod_str = moduleNameUserString mod_name
     basename = map (\c -> if c == '.' then '/' else c) mod_str
 
-    search [] = return Nothing
-    search (p:ps) = loop exts
-      where    
-       base | p == "."  = basename
-            | otherwise = p ++ '/':basename
-
-       loop [] = search ps
-       loop ((ext,fn):exts) = do
-           let file = base ++ '.':ext
-           b <- doesFileExist file
-           if b then Just `liftM` fn p basename ext
-                else loop exts
+    to_search :: [(FilePath, IO (Module,ModLocation))]
+    to_search = [ (file, fn p basename ext)
+               | p <- path, 
+                 (ext,fn) <- exts,
+                 let base | p == "."  = basename
+                          | otherwise = p ++ '/':basename
+                     file = base ++ '.':ext
+               ]
+
+    search [] = return (Left (map fst to_search))
+    search ((file, result) : rest) = do
+      b <- doesFileExist file
+      if b 
+       then Right `liftM` result
+       else search rest
 
 -- -----------------------------------------------------------------------------
 -- Building ModLocations