Move getMainFun to TcRnDriver, trim DynFlags imports

compiler/main/DynFlags.hs

@@ -31,7 +31,6 @@ module DynFlags (
         dopt_set, dopt_unset,           -- DynFlags -> DynFlag -> DynFlags
         getOpts,                        -- DynFlags -> (DynFlags -> [a]) -> [a]
         getVerbFlag,
-        getMainFun,
         updOptLevel,
         setTmpDir,
         setPackageName,
@@ -69,9 +68,7 @@ import Platform
 #endif
 import Module
 import PackageConfig
-import PrelNames        ( mAIN, main_RDR_Unqual )
-import RdrName          ( RdrName, mkRdrUnqual )
-import OccName          ( mkVarOccFS )
+import PrelNames        ( mAIN )
 #if defined(i386_TARGET_ARCH) || (!defined(mingw32_TARGET_OS) && !defined(darwin_TARGET_OS))
 import StaticFlags      ( opt_Static )
 #endif
@@ -2104,13 +2101,6 @@ setMainIs arg
   where
     (main_mod, main_fn) = splitLongestPrefix arg (== '.')
 
--- | Get the unqualified name of the function to use as the \"main\" for the main module.
--- Either returns the default name or the one configured on the command line with -main-is
-getMainFun :: DynFlags -> RdrName
-getMainFun dflags = case (mainFunIs dflags) of
-    Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
-    Nothing -> main_RDR_Unqual
-
 -----------------------------------------------------------------------------
 -- Paths & Libraries
 

compiler/typecheck/TcRnDriver.lhs

@@ -34,7 +34,6 @@ import DynFlags
 import StaticFlags
 import HsSyn
 import RdrHsSyn
-
 import PrelNames
 import RdrName
 import TcHsSyn
@@ -944,6 +943,12 @@ check_main dflags tcg_env
     pp_main_fn | main_fn == main_RDR_Unqual = ptext (sLit "function") <+> quotes (ppr main_fn)
 	       | otherwise                  = ptext (sLit "main function") <+> quotes (ppr main_fn)
 	       
+-- | Get the unqualified name of the function to use as the \"main\" for the main module.
+-- Either returns the default name or the one configured on the command line with -main-is
+getMainFun :: DynFlags -> RdrName
+getMainFun dflags = case (mainFunIs dflags) of
+    Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn))
+    Nothing -> main_RDR_Unqual
 \end{code}
 
 Note [Root-main Id]