Use 'GhcMonad' in DriverPipeline. Also haddockify a bit while we're at it.

[ghc-hetmet.git] / compiler / main / DynFlags.hs

diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs
index 14842b1..fbfda3c 100644 (file)
--- 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.
@@ -83,7 +81,7 @@ import Panic
 import UniqFM           ( UniqFM )
 import Util
 import Maybes           ( orElse )
-import SrcLoc           ( SrcSpan )
+import SrcLoc
 import FastString
 import Outputable
 import {-# SOURCE #-} ErrUtils ( Severity(..), Message, mkLocMessage )
@@ -202,7 +200,7 @@ data DynFlag
    | Opt_TemplateHaskell
    | Opt_QuasiQuotes
    | Opt_ImplicitParams
-   | Opt_Generics
+   | Opt_Generics                      -- "Derivable type classes"
    | Opt_ImplicitPrelude
    | Opt_ScopedTypeVariables
    | Opt_UnboxedTuples
@@ -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",
@@ -1645,12 +1643,13 @@ xFlags = [
   ( "PackageImports",                   Opt_PackageImports, const Supported )
   ]
 
-impliedFlags :: [(DynFlag, [DynFlag])]
-impliedFlags = [
-   ( Opt_GADTs,               [Opt_RelaxedPolyRec] )    -- We want type-sig variables to
-                                                        --      be completely rigid for GADTs
- , ( Opt_ScopedTypeVariables, [Opt_RelaxedPolyRec] )    -- Ditto for scoped type variables; see
-                                                        --      Note [Scoped tyvars] in TcBinds
+impliedFlags :: [(DynFlag, DynFlag)]
+impliedFlags
+  = [ (Opt_GADTs,               Opt_RelaxedPolyRec)  -- We want type-sig variables to
+                                                     --      be completely rigid for GADTs
+
+    , (Opt_ScopedTypeVariables, Opt_RelaxedPolyRec)  -- Ditto for scoped type variables; see
+                                                     --      Note [Scoped tyvars] in TcBinds
   ]
 
 glasgowExtsFlags :: [DynFlag]
@@ -1690,7 +1689,15 @@ glasgowExtsFlags = [
 -- -----------------------------------------------------------------------------
 -- Parsing the dynamic flags.
 
-parseDynamicFlags :: DynFlags -> [String] -> IO (DynFlags, [String], [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
@@ -1699,14 +1706,13 @@ parseDynamicFlags dflags args = do
   --     optdep -f -optdepdepend
   --     optdep -f -optdep depend
   -- but the spaces trip up proper argument handling. So get rid of them.
-  let f ("-optdep" : x : xs) = ("-optdep" ++ x) : f xs
+  let f (L p "-optdep" : L _ x : xs) = (L p ("-optdep" ++ x)) : f xs
       f (x : xs) = x : f xs
       f xs = xs
       args' = f args
   let ((leftover, errs, warns), dflags')
           = runCmdLine (processArgs dynamic_flags args') dflags
-  when (not (null errs)) $ do
-    ghcError (UsageError (unlines errs))
+  when (not (null errs)) $ ghcError $ errorsToGhcException errs
   return (dflags', leftover, warns)
 
 type DynP = CmdLineP DynFlags
@@ -1718,10 +1724,13 @@ upd f = do
 
 --------------------------
 setDynFlag, unSetDynFlag :: DynFlag -> DynP ()
-setDynFlag f = upd (\dfs -> foldl dopt_set (dopt_set dfs f) deps)
+setDynFlag f = do { upd (\dfs -> dopt_set dfs f)
+                 ; mapM_ setDynFlag deps }
   where
-    deps = [ d | (f', ds) <- impliedFlags, f' == f, d <- ds ]
+    deps = [ d | (f', d) <- impliedFlags, f' == f ]
         -- When you set f, set the ones it implies
+       -- NB: use setDynFlag recursively, in case the implied flags
+       --     implies further flags
         -- When you un-set f, however, we don't un-set the things it implies
         --      (except for -fno-glasgow-exts, which is treated specially)