[project @ 2003-11-05 14:51:53 by simonpj]

[ghc-hetmet.git] / ghc / compiler / typecheck / TcRnMonad.lhs

diff --git a/ghc/compiler/typecheck/TcRnMonad.lhs b/ghc/compiler/typecheck/TcRnMonad.lhs
index 4d2e8bf..de3390c 100644 (file)
--- a/ghc/compiler/typecheck/TcRnMonad.lhs
+++ b/ghc/compiler/typecheck/TcRnMonad.lhs
@@ -38,7 +38,7 @@ import Bag            ( emptyBag )
 import Outputable
 import UniqSupply      ( UniqSupply, mkSplitUniqSupply, uniqFromSupply, splitUniqSupply )
 import Unique          ( Unique )
-import CmdLineOpts     ( DynFlags, DynFlag(..), dopt, opt_PprStyle_Debug )
+import CmdLineOpts     ( DynFlags, DynFlag(..), dopt, opt_PprStyle_Debug, dopt_set )
 import Bag             ( snocBag, unionBags )
 import Panic           ( showException )
  
@@ -92,7 +92,8 @@ initTc hsc_env mod do_this
                tcg_deprecs  = NoDeprecs,
                tcg_insts    = [],
                tcg_rules    = [],
-               tcg_fords    = []
+               tcg_fords    = [],
+               tcg_keep     = emptyNameSet
             } ;
             lcl_env = TcLclEnv {
                tcl_errs       = errs_var,
@@ -225,6 +226,10 @@ getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
 doptM :: DynFlag -> TcRnIf gbl lcl Bool
 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
 
+setOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
+setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
+                        env { env_top = top { hsc_dflags = dopt_set (hsc_dflags top) flag}} )
+
 ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl ()    -- Do it flag is true
 ifOptM flag thing_inside = do { b <- doptM flag; 
                                if b then thing_inside else return () }
@@ -403,6 +408,20 @@ addMessages (m_warns, m_errs)
         (warns, errs) <- readMutVar errs_var ;
         writeMutVar errs_var (warns `unionBags` m_warns,
                               errs  `unionBags` m_errs) }
+
+discardWarnings :: TcRn a -> TcRn a
+-- Ignore warnings inside the thing inside;
+-- used to ignore-unused-variable warnings inside derived code
+-- With -dppr-debug, the effects is switched off, so you can still see
+-- what warnings derived code would give
+discardWarnings thing_inside
+  | opt_PprStyle_Debug = thing_inside
+  | otherwise
+  = do { errs_var <- newMutVar emptyMessages
+       ; result <- setErrsVar errs_var thing_inside
+       ; (_warns, errs) <- readMutVar errs_var
+       ; addMessages (emptyBag, errs)
+       ; return result }
 \end{code}