Don't preprocess .s files

One important reason is that gcc 4.8.1 sometimes crashes:

  http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60436

Another reason is that preprocessing assembly files unnecessarily
slows down compilation.

3 files changed, 29 insertions, 24 deletions

diff --git a/compiler/main/DriverPhases.hs b/compiler/main/DriverPhases.hs
index c406f6ad0d..2981269d54 100644
--- a/compiler/main/DriverPhases.hs
+++ b/compiler/main/DriverPhases.hs
@@ -82,7 +82,7 @@ data Phase
         | HCc           -- Haskellised C (as opposed to vanilla C) compilation
         | Splitter      -- Assembly file splitter (part of '-split-objs')
         | SplitAs       -- Assembler for split assembly files (part of '-split-objs')
-        | As            -- Assembler for regular assembly files
+        | As Bool       -- Assembler for regular assembly files (Bool: with-cpp)
         | LlvmOpt       -- Run LLVM opt tool over llvm assembly
         | LlvmLlc       -- LLVM bitcode to native assembly
         | LlvmMangle    -- Fix up TNTC by processing assembly produced by LLVM
@@ -119,7 +119,7 @@ eqPhase Cobjcpp     Cobjcpp    = True
 eqPhase HCc         HCc        = True
 eqPhase Splitter    Splitter   = True
 eqPhase SplitAs     SplitAs    = True
-eqPhase As          As         = True
+eqPhase (As x)      (As y)     = x == y
 eqPhase LlvmOpt     LlvmOpt    = True
 eqPhase LlvmLlc     LlvmLlc    = True
 eqPhase LlvmMangle  LlvmMangle = True
@@ -150,21 +150,21 @@ nextPhase dflags p
       Splitter   -> SplitAs
       LlvmOpt    -> LlvmLlc
       LlvmLlc    -> LlvmMangle
-      LlvmMangle -> As
+      LlvmMangle -> As False
       SplitAs    -> MergeStub
-      As         -> MergeStub
-      Ccpp       -> As
-      Cc         -> As
-      Cobjc      -> As
-      Cobjcpp    -> As
+      As _       -> MergeStub
+      Ccpp       -> As False
+      Cc         -> As False
+      Cobjc      -> As False
+      Cobjcpp    -> As False
       CmmCpp     -> Cmm
       Cmm        -> maybeHCc
-      HCc        -> As
+      HCc        -> As False
       MergeStub  -> StopLn
       StopLn     -> panic "nextPhase: nothing after StopLn"
     where maybeHCc = if platformUnregisterised (targetPlatform dflags)
                      then HCc
-                     else As
+                     else As False
 
 -- the first compilation phase for a given file is determined
 -- by its suffix.
@@ -186,8 +186,8 @@ startPhase "mm"       = Cobjcpp
 startPhase "cc"       = Ccpp
 startPhase "cxx"      = Ccpp
 startPhase "split_s"  = Splitter
-startPhase "s"        = As
-startPhase "S"        = As
+startPhase "s"        = As False
+startPhase "S"        = As True
 startPhase "ll"       = LlvmOpt
 startPhase "bc"       = LlvmLlc
 startPhase "lm_s"     = LlvmMangle
@@ -215,7 +215,8 @@ phaseInputExt Cobjc               = "m"
 phaseInputExt Cobjcpp             = "mm"
 phaseInputExt Cc                  = "c"
 phaseInputExt Splitter            = "split_s"
-phaseInputExt As                  = "s"
+phaseInputExt (As True)           = "S"
+phaseInputExt (As False)          = "s"
 phaseInputExt LlvmOpt             = "ll"
 phaseInputExt LlvmLlc             = "bc"
 phaseInputExt LlvmMangle          = "lm_s"
diff --git a/compiler/main/DriverPipeline.hs b/compiler/main/DriverPipeline.hs
index 564edd27f7..2c719670c5 100644
--- a/compiler/main/DriverPipeline.hs
+++ b/compiler/main/DriverPipeline.hs
@@ -498,8 +498,8 @@ compileFile hsc_env stop_phase (src, mb_phase) = do
          | otherwise = Persistent
 
         stop_phase' = case stop_phase of
-                        As | split -> SplitAs
-                        _          -> stop_phase
+                        As _ | split -> SplitAs
+                        _            -> stop_phase
 
    ( _, out_file) <- runPipeline stop_phase' hsc_env
                             (src, fmap RealPhase mb_phase) Nothing output
@@ -730,7 +730,7 @@ getOutputFilename stop_phase output basename dflags next_phase maybe_location
           -- sometimes, we keep output from intermediate stages
           keep_this_output =
                case next_phase of
-                       As      | keep_s     -> True
+                       As _    | keep_s     -> True
                        LlvmOpt | keep_bc    -> True
                        HCc     | keep_hc    -> True
                        _other               -> False
@@ -1078,7 +1078,7 @@ runPhase (RealPhase cc_phase) input_fn dflags
                    | otherwise            = []
 
         -- Decide next phase
-        let next_phase = As
+        let next_phase = As False
         output_fn <- phaseOutputFilename next_phase
 
         let
@@ -1190,7 +1190,7 @@ runPhase (RealPhase Splitter) input_fn dflags
 -- As, SpitAs phase : Assembler
 
 -- This is for calling the assembler on a regular assembly file (not split).
-runPhase (RealPhase As) input_fn dflags
+runPhase (RealPhase (As with_cpp)) input_fn dflags
   = do
         -- LLVM from version 3.0 onwards doesn't support the OS X system
         -- assembler, so we use clang as the assembler instead. (#5636)
@@ -1231,7 +1231,10 @@ runPhase (RealPhase As) input_fn dflags
                            then [SysTools.Option "-mcpu=v9"]
                            else [])
 
-                       ++ [ SysTools.Option "-x", SysTools.Option "assembler-with-cpp"
+                       ++ [ SysTools.Option "-x"
+                          , if with_cpp
+                              then SysTools.Option "assembler-with-cpp"
+                              else SysTools.Option "assembler"
                           , SysTools.Option "-c"
                           , SysTools.FileOption "" inputFilename
                           , SysTools.Option "-o"
@@ -1385,7 +1388,7 @@ runPhase (RealPhase LlvmLlc) input_fn dflags
     let next_phase = case gopt Opt_NoLlvmMangler dflags of
                          False                            -> LlvmMangle
                          True | gopt Opt_SplitObjs dflags -> Splitter
-                         True                             -> As
+                         True                             -> As False
                         
     output_fn <- phaseOutputFilename next_phase
 
@@ -1454,7 +1457,7 @@ runPhase (RealPhase LlvmLlc) input_fn dflags
 
 runPhase (RealPhase LlvmMangle) input_fn dflags
   = do
-      let next_phase = if gopt Opt_SplitObjs dflags then Splitter else As
+      let next_phase = if gopt Opt_SplitObjs dflags then Splitter else As False
       output_fn <- phaseOutputFilename next_phase
       liftIO $ llvmFixupAsm dflags input_fn output_fn
       return (RealPhase next_phase, output_fn)
@@ -2186,7 +2189,7 @@ hscPostBackendPhase dflags _ hsc_lang =
   case hsc_lang of
         HscC -> HCc
         HscAsm | gopt Opt_SplitObjs dflags -> Splitter
-               | otherwise                 -> As
+               | otherwise                 -> As False
         HscLlvm        -> LlvmOpt
         HscNothing     -> StopLn
         HscInterpreted -> StopLn
diff --git a/ghc/Main.hs b/ghc/Main.hs
index 46b0970de6..d056bf97c4 100644
--- a/ghc/Main.hs
+++ b/ghc/Main.hs
@@ -562,7 +562,7 @@ mode_flags =
   , Flag "M"            (PassFlag (setMode doMkDependHSMode))
   , Flag "E"            (PassFlag (setMode (stopBeforeMode anyHsc)))
   , Flag "C"            (PassFlag (setMode (stopBeforeMode HCc)))
-  , Flag "S"            (PassFlag (setMode (stopBeforeMode As)))
+  , Flag "S"            (PassFlag (setMode (stopBeforeMode (As False))))
   , Flag "-make"        (PassFlag (setMode doMakeMode))
   , Flag "-interactive" (PassFlag (setMode doInteractiveMode))
   , Flag "-abi-hash"    (PassFlag (setMode doAbiHashMode))
@@ -629,7 +629,8 @@ doMake srcs  = do
         haskellish (f,Nothing) =
           looksLikeModuleName f || isHaskellUserSrcFilename f || '.' `notElem` f
         haskellish (_,Just phase) =
-          phase `notElem` [As, Cc, Cobjc, Cobjcpp, CmmCpp, Cmm, StopLn]
+          phase `notElem` [ As True, As False, Cc, Cobjc, Cobjcpp, CmmCpp, Cmm
+                          , StopLn]
 
     hsc_env <- GHC.getSession