[project @ 2003-02-19 11:51:35 by simonmar]

[ghc-hetmet.git] / ghc / compiler / compMan / CompManager.lhs

diff --git a/ghc/compiler/compMan/CompManager.lhs b/ghc/compiler/compMan/CompManager.lhs
index 47afe26..84ff5ae 100644 (file)
--- a/ghc/compiler/compMan/CompManager.lhs
+++ b/ghc/compiler/compMan/CompManager.lhs
@@ -57,7 +57,7 @@ where
 #include "HsVersions.h"
 
 import DriverPipeline  ( CompResult(..), preprocess, compile, link )
-import DriverState     ( v_Output_file )
+import DriverState     ( v_Output_file, v_NoHsMain )
 import DriverPhases
 import DriverUtil
 import Finder
@@ -232,9 +232,9 @@ moduleNameToModule hpt mn = do
     _not_a_home_module -> do
          maybe_stuff <- findModule mn
          case maybe_stuff of
-           Nothing -> throwDyn (CmdLineError ("can't find module `"
+           Left _ -> throwDyn (CmdLineError ("can't find module `"
                                    ++ moduleNameUserString mn ++ "'"))
-           Just (m,_) -> return m
+           Right (m,_) -> return m
 
 cmGetContext :: CmState -> IO ([String],[String])
 cmGetContext CmState{ic=ic} = 
@@ -638,15 +638,22 @@ cmLoadModules cmstate1 dflags mg2unsorted
              -- clean up after ourselves
              cleanTempFilesExcept verb (ppFilesFromSummaries modsDone)
 
-             -- issue a warning for the confusing case where the user said '-o foo'
-             -- but we're not going to do any linking.
              ofile <- readIORef v_Output_file
-             when (ghci_mode == Batch && isJust ofile && not a_root_is_Main
+             no_hs_main <- readIORef v_NoHsMain
+
+             -- Issue a warning for the confusing case where the user
+             -- said '-o foo' but we're not going to do any linking.
+             -- We attempt linking if either (a) one of the modules is
+             -- called Main, or (b) the user said -no-hs-main, indicating
+             -- that main() is going to come from somewhere else.
+             --
+             let do_linking = a_root_is_Main || no_hs_main
+             when (ghci_mode == Batch && isJust ofile && not do_linking
                     && verb > 0) $
                 hPutStrLn stderr "Warning: output was redirected with -o, but no output will be generated\nbecause there is no Main module."
 
              -- link everything together
-              linkresult <- link ghci_mode dflags a_root_is_Main hpt3 
+              linkresult <- link ghci_mode dflags do_linking hpt3 
 
              cmLoadFinish Succeeded linkresult 
                           hpt3 modsDone ghci_mode pcs3
@@ -1166,11 +1173,9 @@ downsweep roots old_summaries
                        let old_summary = findModInSummaries old_summaries mod
                        summarise mod location old_summary
 
-                  Left _ -> 
-                       throwDyn (CmdLineError 
-                                   ("can't find module `" 
-                                     ++ showSDoc (ppr nm) ++ "' (while processing " 
-                                    ++ show currentMod ++ ")"))
+                  Left files -> do
+                       dflags <- getDynFlags
+                       throwDyn (noModError dflags currentMod nm files)
 
         -- loop invariant: env doesn't contain package modules
         loop :: [(FilePath,ModuleName)] -> ModuleEnv ModSummary -> IO [ModSummary]
@@ -1191,6 +1196,18 @@ downsweep roots old_summaries
                 loop new_imps (extendModuleEnvList env 
                                [ (ms_mod s, s) | s <- new_home_summaries ])
 
+-- ToDo: we don't have a proper line number for this error
+noModError dflags loc mod_nm files = ProgramError (showSDoc (
+  hang (text loc <> colon) 4 $
+    (text "Can't find module" <+> quotes (ppr mod_nm) $$ extra)
+  ))
+  where
+   extra
+    | verbosity dflags < 3 =
+        text "(use -v to see a list of the files searched for)"
+    | otherwise =
+        hang (ptext SLIT("locations searched:")) 4 (vcat (map text files))
+
 -----------------------------------------------------------------------------
 -- Summarising modules