[project @ 2006-01-03 16:15:37 by simonmar]

setContextAfterLoad: try to load a target if possible, otherwise load
the topmost module in the graph.  Previously we were loading the first
module in the list, which happened to be right a lot of the time, but
not always.

Fixes ticket #642

diff --git a/ghc/compiler/ghci/InteractiveUI.hs b/ghc/compiler/ghci/InteractiveUI.hs
index 3469421..0bf37dc 100644 (file)
--- a/ghc/compiler/ghci/InteractiveUI.hs
+++ b/ghc/compiler/ghci/InteractiveUI.hs
@@ -15,7 +15,8 @@ module InteractiveUI (
 
 -- The GHC interface
 import qualified GHC
-import GHC             ( Session, verbosity, dopt, DynFlag(..),
+import GHC             ( Session, verbosity, dopt, DynFlag(..), Target(..),
+                         TargetId(..),
                          mkModule, pprModule, Type, Module, SuccessFlag(..),
                          TyThing(..), Name, LoadHowMuch(..), Phase,
                          GhcException(..), showGhcException,
@@ -30,6 +31,7 @@ import OccName( pprOccName )
 import SrcLoc( isGoodSrcLoc, srcLocFile, srcLocLine, srcLocCol )
 
 -- Other random utilities
+import Digraph         ( flattenSCCs )
 import BasicTypes      ( failed, successIf )
 import Panic           ( panic, installSignalHandlers )
 import Config
@@ -592,7 +594,7 @@ changeDirectory dir = do
        io $ putStr "Warning: changing directory causes all loaded modules to be unloaded,\nbecause the search path has changed.\n"
   io (GHC.setTargets session [])
   io (GHC.load session LoadAllTargets)
-  setContextAfterLoad []
+  setContextAfterLoad session []
   io (GHC.workingDirectoryChanged session)
   dir <- expandPath dir
   io (setCurrentDirectory dir)
@@ -703,19 +705,39 @@ reloadModule m = do
 afterLoad ok session = do
   io (revertCAFs)  -- always revert CAFs on load.
   graph <- io (GHC.getModuleGraph session)
-  let mods = map GHC.ms_mod graph
-  mods' <- filterM (io . GHC.isLoaded session) mods
-  setContextAfterLoad mods'
-  modulesLoadedMsg ok mods'
+  graph' <- filterM (io . GHC.isLoaded session . GHC.ms_mod) graph
+  setContextAfterLoad session graph'
+  modulesLoadedMsg ok (map GHC.ms_mod graph')
 
-setContextAfterLoad [] = do
-  session <- getSession
+setContextAfterLoad session [] = do
   io (GHC.setContext session [] [prelude_mod])
-setContextAfterLoad (m:_) = do
-  session <- getSession
-  b <- io (GHC.moduleIsInterpreted session m)
-  if b then io (GHC.setContext session [m] []) 
-       else io (GHC.setContext session []  [prelude_mod,m])
+setContextAfterLoad session ms = do
+  -- load a target if one is available, otherwise load the topmost module.
+  targets <- io (GHC.getTargets session)
+  case [ m | Just m <- map (findTarget ms) targets ] of
+       []    -> 
+         let graph' = flattenSCCs (GHC.topSortModuleGraph True ms Nothing) in
+         load_this (last graph')         
+       (m:_) -> 
+         load_this m
+ where
+   findTarget ms t
+    = case filter (`matches` t) ms of
+       []    -> Nothing
+       (m:_) -> Just m
+
+   summary `matches` Target (TargetModule m) _
+       = GHC.ms_mod summary == m
+   summary `matches` Target (TargetFile f _) _ 
+       | Just f' <- GHC.ml_hs_file (GHC.ms_location summary)   = f == f'
+   summary `matches` target
+       = False
+
+   load_this summary | m <- GHC.ms_mod summary = do
+       b <- io (GHC.moduleIsInterpreted session m)
+       if b then io (GHC.setContext session [m] []) 
+                    else io (GHC.setContext session []  [prelude_mod,m])
+
 
 modulesLoadedMsg :: SuccessFlag -> [Module] -> GHCi ()
 modulesLoadedMsg ok mods = do