X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fmain%2FDynFlags.hs;h=cf1d7e9bedb3e64b5ad4fa0953e51634d6575ff0;hb=a47d62f78621bb35f4ba73cd3817f33fda95fa72;hp=bb8555ef65b528247aecdd955717c885b4a1d194;hpb=3998d13f096efb302cf83865b611746765596754;p=ghc-hetmet.git

diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs
index bb8555e..cf1d7e9 100644
--- a/compiler/main/DynFlags.hs
+++ b/compiler/main/DynFlags.hs
@@ -1,14 +1,12 @@
 
------------------------------------------------------------------------------
---
+-- |
 -- Dynamic flags
 --
 --
 -- (c) The University of Glasgow 2005
 --
------------------------------------------------------------------------------
 
--- | Most flags are dynamic flags, which means they can change from
+-- Most flags are dynamic flags, which means they can change from
 -- compilation to compilation using @OPTIONS_GHC@ pragmas, and in a
 -- multi-session GHC each session can be using different dynamic
 -- flags.  Dynamic flags can also be set at the prompt in GHCi.
@@ -310,7 +308,7 @@ data DynFlags = DynFlags {
   stgToDo               :: Maybe [StgToDo],  -- similarly
   hscTarget             :: HscTarget,
   hscOutName            :: String,      -- ^ Name of the output file
-  extCoreName           :: String,      -- ^ Name of the .core output file
+  extCoreName           :: String,      -- ^ Name of the .hcr output file
   verbosity             :: Int,         -- ^ Verbosity level: see "DynFlags#verbosity_levels"
   optLevel              :: Int,         -- ^ Optimisation level
   simplPhases           :: Int,         -- ^ Number of simplifier phases
@@ -331,7 +329,7 @@ data DynFlags = DynFlags {
 
   dphBackend            :: DPHBackend,
 
-  thisPackage           :: PackageId,
+  thisPackage           :: PackageId,   -- ^ name of package currently being compiled
 
   -- ways
   wayNames              :: [WayName],   -- ^ Way flags from the command line
@@ -578,7 +576,7 @@ defaultDynFlags =
         ghcUsagePath            = panic "defaultDynFlags: No ghciUsagePath",
         ghciUsagePath           = panic "defaultDynFlags: No ghciUsagePath",
         topDir                  = panic "defaultDynFlags: No topDir",
-        systemPackageConfig     = panic "defaultDynFlags: No systemPackageConfig",
+        systemPackageConfig     = panic  "no systemPackageConfig: call GHC.setSessionDynFlags",
         pgm_L                   = panic "defaultDynFlags: No pgm_L",
         pgm_P                   = panic "defaultDynFlags: No pgm_P",
         pgm_F                   = panic "defaultDynFlags: No pgm_F",
@@ -803,7 +801,16 @@ optLevelFlags
 
     , ([2],     Opt_LiberateCase)
     , ([2],     Opt_SpecConstr)
-    , ([2],     Opt_StaticArgumentTransformation)
+
+--     , ([2],     Opt_StaticArgumentTransformation)
+-- Max writes: I think it's probably best not to enable SAT with -O2 for the
+-- 6.10 release. The version of SAT in HEAD at the moment doesn't incorporate
+-- several improvements to the heuristics, and I'm concerned that without
+-- those changes SAT will interfere with some attempts to write "high
+-- performance Haskell", as we saw in some posts on Haskell-Cafe earlier
+-- this year. In particular, the version in HEAD lacks the tail call
+-- criterion, so many things that look like reasonable loops will be
+-- turned into functions with extra (unneccesary) thunk creation.
 
     , ([0,1,2], Opt_DoLambdaEtaExpansion)
                 -- This one is important for a tiresome reason:
@@ -1691,8 +1698,15 @@ glasgowExtsFlags = [
 -- -----------------------------------------------------------------------------
 -- Parsing the dynamic flags.
 
-parseDynamicFlags :: DynFlags -> [Located String]
-                  -> IO (DynFlags, [Located String], [Located String])
+-- | Parse dynamic flags from a list of command line argument.  Returns the
+-- the parsed 'DynFlags', the left-over arguments, and a list of warnings.
+-- Throws a 'UsageError' if errors occurred during parsing (such as unknown
+-- flags or missing arguments).
+parseDynamicFlags :: Monad m =>
+                     DynFlags -> [Located String]
+                  -> m (DynFlags, [Located String], [Located String])
+                     -- ^ Updated 'DynFlags', left-over arguments, and
+                     -- list of warnings.
 parseDynamicFlags dflags args = do
   -- XXX Legacy support code
   -- We used to accept things like