X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=compiler%2Fmain%2FDynFlags.hs;h=9c25251b8e38954ef3d094bdf81505fdd0db4534;hb=5c9424bb4f530c315d1dde2c53ebb1adfd3a2da4;hp=df9efcbde2b45f53677f5e39c5a6cee7ceb786f9;hpb=dddfba386d413d575c1d0be2a26f0cf1417fa5b6;p=ghc-hetmet.git

diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs
index df9efcb..9c25251 100644
--- a/compiler/main/DynFlags.hs
+++ b/compiler/main/DynFlags.hs
@@ -430,6 +430,19 @@ data DynFlags = DynFlags {
   haddockOptions :: Maybe String
  }
 
+-- | The target code type of the compilation (if any).
+--
+-- 'HscNothing' can be used to avoid generating any output, however, note
+-- that:
+--
+--  * This will not run the desugaring step, thus no warnings generated in
+--    this step will be output.  In particular, this includes warnings
+--    related to pattern matching.
+--
+--  * At the moment switching from 'HscNothing' to 'HscInterpreted' without
+--    unloading first is not safe.  To unload use
+--    @GHC.setTargets [] >> GHC.load LoadAllTargets@.
+--
 data HscTarget
   = HscC
   | HscAsm