[project @ 2003-06-04 15:47:58 by simonmar]

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

diff --git a/ghc/compiler/main/DriverPhases.hs b/ghc/compiler/main/DriverPhases.hs
index 9c9794d..2efe293 100644 (file)
--- a/ghc/compiler/main/DriverPhases.hs
+++ b/ghc/compiler/main/DriverPhases.hs
@@ -1,5 +1,5 @@
 -----------------------------------------------------------------------------
--- $Id: DriverPhases.hs,v 1.24 2003/05/21 12:46:19 simonmar Exp $
+-- $Id: DriverPhases.hs,v 1.25 2003/06/04 15:47:59 simonmar Exp $
 --
 -- GHC Driver
 --
@@ -11,6 +11,7 @@
 
 module DriverPhases (
    Phase(..),
+   happensBefore,
    startPhase,         -- :: String -> Phase
    phaseInputExt,      -- :: Phase -> String
 
@@ -40,8 +41,7 @@ import DriverUtil
 -}
 
 data Phase 
-       = MkDependHS    -- haskell dependency generation
-       | Unlit
+       = Unlit
        | Cpp
        | HsPp
        | Hsc
@@ -58,6 +58,17 @@ data Phase
 #endif
   deriving (Eq, Show)
 
+-- Partial ordering on phases: we want to know which phases will occur before 
+-- which others.  This is used for sanity checking, to ensure that the
+-- pipeline will stop at some point (see DriverPipeline.runPipeline).
+x `happensBefore` y 
+       | x `elem` haskell_pipe = y `elem` tail (dropWhile (/= x) haskell_pipe)
+       | x `elem` c_pipe       = y `elem` tail (dropWhile (/= x) c_pipe)
+       | otherwise = False
+
+haskell_pipe = [Unlit,Cpp,HsPp,Hsc,HCc,Mangle,As,Ln]
+c_pipe       = [Cc,As,Ln]
+
 -- the first compilation phase for a given file is determined
 -- by its suffix.
 startPhase "lhs"   = Unlit
@@ -90,7 +101,6 @@ phaseInputExt SplitMangle = "split_s"        -- not really generated
 phaseInputExt As          = "s"
 phaseInputExt SplitAs     = "split_s"   -- not really generated
 phaseInputExt Ln          = "o"
-phaseInputExt MkDependHS  = "dep"
 #ifdef ILX
 phaseInputExt Ilx2Il      = "ilx"
 phaseInputExt Ilasm       = "il"