[project @ 2003-07-21 14:33:19 by simonmar]

[ghc-hetmet.git] / ghc / compiler / rename / RnEnv.lhs

diff --git a/ghc/compiler/rename/RnEnv.lhs b/ghc/compiler/rename/RnEnv.lhs
index 68b09c6..255356c 100644 (file)
--- a/ghc/compiler/rename/RnEnv.lhs
+++ b/ghc/compiler/rename/RnEnv.lhs
@@ -39,8 +39,9 @@ import Module         ( Module, ModuleName, moduleName, mkHomeModule,
 import PrelNames       ( mkUnboundName, intTyConName, 
                          boolTyConName, funTyConName,
                          unpackCStringName, unpackCStringFoldrName, unpackCStringUtf8Name,
-                         eqStringName, printName, 
-                         bindIOName, returnIOName, failIOName, thenIOName
+                         eqStringName, printName, integerTyConName,
+                         bindIOName, returnIOName, failIOName, thenIOName,
+                         rOOT_MAIN_Name
                        )
 #ifdef GHCI    
 import DsMeta          ( templateHaskellNames, qTyConName )
@@ -70,11 +71,24 @@ newTopBinder mod rdr_name loc
   | Just name <- isExact_maybe rdr_name
   = returnM name
 
-  | otherwise
-  = ASSERT( not (isOrig rdr_name) || rdrNameModule rdr_name == moduleName mod )
+  | isOrig rdr_name
+  = ASSERT( rdr_mod == moduleName mod || rdr_mod == rOOT_MAIN_Name )
        -- When reading External Core we get Orig names as binders, 
        -- but they should agree with the module gotten from the monad
-    newGlobalName mod (rdrNameOcc rdr_name) loc
+       --
+       -- Except for the ":Main.main = ..." definition inserted into 
+       -- the Main module
+       --
+       -- Because of this latter case, we take the module from the RdrName,
+       -- not from the environment.  In principle, it'd be fine to have an
+       -- arbitrary mixture of external core definitions in a single module,
+       -- (apart from module-initialisation issues, perhaps).
+    newGlobalName (mkHomeModule rdr_mod) (rdrNameOcc rdr_name) loc
+
+  | otherwise
+  = newGlobalName mod (rdrNameOcc rdr_name) loc
+  where
+    rdr_mod = rdrNameModule rdr_name
 
 newGlobalName :: Module -> OccName -> SrcLoc -> TcRn m Name
 newGlobalName mod occ loc
@@ -564,9 +578,15 @@ mentioned explicitly, but which might be needed by the type checker.
 implicitStmtFVs source_fvs     -- Compiling a statement
   = stmt_fvs `plusFV` implicitModuleFVs source_fvs
   where
-    stmt_fvs = mkFVs [printName, bindIOName, thenIOName, returnIOName, failIOName]
+    stmt_fvs = mkFVs [printName, bindIOName, thenIOName, returnIOName, failIOName, 
+                     integerTyConName]
                -- These are all needed implicitly when compiling a statement
                -- See TcModule.tc_stmts
+       -- Reason for integerTyConName: consider this in GHCi
+       --      ghci>  []
+       -- We get an ambigous constraint (Show a), which we now default just like
+       -- numeric types... but unless we have the instance decl for Integer we 
+       -- won't find a valid default!
 
 implicitModuleFVs source_fvs
   = mkTemplateHaskellFVs source_fvs    `plusFV`