DriverPipeline.hs 63.7 KB
Newer Older
1 2 3
{-# OPTIONS -fno-cse #-}
-- -fno-cse is needed for GLOBAL_VAR's to behave properly

4 5 6 7
-----------------------------------------------------------------------------
--
-- GHC Driver
--
8
-- (c) The University of Glasgow 2005
9 10 11 12
--
-----------------------------------------------------------------------------

module DriverPipeline (
13 14
	-- Run a series of compilation steps in a pipeline, for a
	-- collection of source files.
15
   oneShot, compileFile,
16

17
	-- Interfaces for the batch-mode driver
18
   linkBinary,
19

20 21
	-- Interfaces for the compilation manager (interpreted/batch-mode)
   preprocess, 
22
   compile, compile',
23
   link, 
24

25 26 27 28
  ) where

#include "HsVersions.h"

29
import Packages
30
import HeaderInfo
31
import DriverPhases
32
import SysTools
33
import HscMain
34
import Finder
35 36 37
import HscTypes
import Outputable
import Module
38
import LazyUniqFM		( eltsUFM )
39
import ErrUtils
40
import DynFlags
41
import StaticFlags	( v_Ld_inputs, opt_Static, WayName(..) )
42
import Config
43
import Panic
44
import Util
45
import StringBuffer	( hGetStringBuffer )
46
import BasicTypes	( SuccessFlag(..) )
47
import Maybes		( expectJust )
48
import ParserCoreUtils	( getCoreModuleName )
49
import SrcLoc
50
import FastString
51
import MonadUtils
52

53
import Data.Either
54
import Exception
Simon Marlow's avatar
Simon Marlow committed
55 56 57
import Data.IORef	( readIORef, writeIORef, IORef )
import GHC.Exts		( Int(..) )
import System.Directory
Ian Lynagh's avatar
Ian Lynagh committed
58
import System.FilePath
Simon Marlow's avatar
Simon Marlow committed
59
import System.IO
60
import System.IO.Error as IO
Simon Marlow's avatar
Simon Marlow committed
61
import Control.Monad
62
import Data.List	( isSuffixOf )
Simon Marlow's avatar
Simon Marlow committed
63 64
import Data.Maybe
import System.Environment
65

66 67
-- ---------------------------------------------------------------------------
-- Pre-process
68

69
-- | Just preprocess a file, put the result in a temp. file (used by the
70
-- compilation manager during the summary phase).
71 72 73
--
-- We return the augmented DynFlags, because they contain the result
-- of slurping in the OPTIONS pragmas
74

75 76 77 78
preprocess :: GhcMonad m =>
              HscEnv
           -> (FilePath, Maybe Phase) -- ^ filename and starting phase
           -> m (DynFlags, FilePath)
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
79
preprocess hsc_env (filename, mb_phase) =
80
  ASSERT2(isJust mb_phase || isHaskellSrcFilename filename, text filename) 
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
81
  runPipeline anyHsc hsc_env (filename, mb_phase) 
Simon Marlow's avatar
Simon Marlow committed
82
        Nothing Temporary Nothing{-no ModLocation-}
83

84
-- ---------------------------------------------------------------------------
85

86 87
-- | Compile
--
88 89 90 91 92 93
-- Compile a single module, under the control of the compilation manager.
--
-- This is the interface between the compilation manager and the
-- compiler proper (hsc), where we deal with tedious details like
-- reading the OPTIONS pragma from the source file, and passing the
-- output of hsc through the C compiler.
94
--
95 96
-- NB.  No old interface can also mean that the source has changed.

97 98 99 100 101 102 103 104
compile :: GhcMonad m =>
           HscEnv
        -> ModSummary      -- ^ summary for module being compiled
        -> Int             -- ^ module N ...
        -> Int             -- ^ ... of M
        -> Maybe ModIface  -- ^ old interface, if we have one
        -> Maybe Linkable  -- ^ old linkable, if we have one
        -> m HomeModInfo   -- ^ the complete HomeModInfo, if successful
105

dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
106
compile hsc_env0 summary mod_index nmods mb_old_iface maybe_old_linkable
107 108 109 110
 = do
   let dflags0     = ms_hspp_opts summary
       this_mod    = ms_mod summary
       src_flavour = ms_hsc_src summary
111 112 113
       location	   = ms_location summary
       input_fn    = expectJust "compile:hs" (ml_hs_file location) 
       input_fnpp  = ms_hspp_file summary
114

115
   liftIO $ debugTraceMsg dflags0 2 (text "compile: input file" <+> text input_fnpp)
116

Ian Lynagh's avatar
Ian Lynagh committed
117
   let basename = dropExtension input_fn
118

119 120 121
  -- We add the directory in which the .hs files resides) to the import path.
  -- This is needed when we try to compile the .hc file later, if it
  -- imports a _stub.h file that we created here.
Ian Lynagh's avatar
Ian Lynagh committed
122 123 124
   let current_dir = case takeDirectory basename of
                     "" -> "." -- XXX Hack
                     d -> d
125 126
       old_paths   = includePaths dflags0
       dflags      = dflags0 { includePaths = current_dir : old_paths }
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
127
       hsc_env     = hsc_env0 {hsc_dflags = dflags}
128

129
   -- Figure out what lang we're generating
130
   let hsc_lang = hscMaybeAdjustTarget dflags StopLn src_flavour (hscTarget dflags)
131
   -- ... and what the next phase should be
132
   let next_phase = hscNextPhase dflags src_flavour hsc_lang
133
   -- ... and what file to generate the output into
134
   output_fn <- liftIO $ getOutputFilename next_phase
135
			Temporary basename dflags next_phase (Just location)
136

137
   let dflags' = dflags { hscTarget = hsc_lang,
138
				hscOutName = output_fn,
139
				extCoreName = basename ++ ".hcr" }
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
140
   let hsc_env' = hsc_env { hsc_dflags = dflags' }
141

142
   -- -fforce-recomp should also work with --make
143 144
   let force_recomp = dopt Opt_ForceRecomp dflags
       source_unchanged = isJust maybe_old_linkable && not force_recomp
145
       object_filename = ml_obj_file location
146

147 148
   let getStubLinkable False = return []
       getStubLinkable True
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
149
           = do stub_o <- compileStub hsc_env' this_mod location
150 151
                return [ DotO stub_o ]

152
       handleBatch HscNoRecomp
153
           = ASSERT (isJust maybe_old_linkable)
154 155
             return maybe_old_linkable

Thomas Schilling's avatar
Thomas Schilling committed
156
       handleBatch (HscRecomp hasStub _)
157
           | isHsBoot src_flavour
158
               = do when (isObjectTarget hsc_lang) $ -- interpreted reaches here too
159
                       liftIO $ SysTools.touch dflags' "Touching object file"
160
                                   object_filename
161 162
                    return maybe_old_linkable

163 164 165 166 167
           | otherwise
               = do stub_unlinked <- getStubLinkable hasStub
                    (hs_unlinked, unlinked_time) <-
                        case hsc_lang of
                          HscNothing
168
                            -> return ([], ms_hs_date summary)
169 170
                          -- We're in --make mode: finish the compilation pipeline.
                          _other
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
171
                            -> do runPipeline StopLn hsc_env' (output_fn,Nothing)
Simon Marlow's avatar
Simon Marlow committed
172 173
                                              (Just basename)
                                              Persistent
174 175
                                              (Just location)
                                  -- The object filename comes from the ModLocation
176
                                  o_time <- liftIO $ getModificationTime object_filename
177 178 179
                                  return ([DotO object_filename], o_time)
                    let linkable = LM unlinked_time this_mod
			           (hs_unlinked ++ stub_unlinked)
180
                    return (Just linkable)
181

Thomas Schilling's avatar
Thomas Schilling committed
182
       handleInterpreted HscNoRecomp
183
           = ASSERT (isJust maybe_old_linkable)
184
             return maybe_old_linkable
185 186 187 188
       handleInterpreted (HscRecomp _hasStub Nothing)
           = ASSERT (isHsBoot src_flavour)
             return maybe_old_linkable
       handleInterpreted (HscRecomp hasStub (Just (comp_bc, modBreaks)))
189
           = do stub_unlinked <- getStubLinkable hasStub
190
                let hs_unlinked = [BCOs comp_bc modBreaks]
191
                    unlinked_time = ms_hs_date summary
192 193 194 195 196 197 198 199
                  -- Why do we use the timestamp of the source file here,
                  -- rather than the current time?  This works better in
                  -- the case where the local clock is out of sync
                  -- with the filesystem's clock.  It's just as accurate:
                  -- if the source is modified, then the linkable will
                  -- be out of date.
                let linkable = LM unlinked_time this_mod
                               (hs_unlinked ++ stub_unlinked)
200
                return (Just linkable)
201

202
   let -- runCompiler :: Compiler result -> (result -> Maybe Linkable)
203
       --            -> m HomeModInfo
204
       runCompiler compiler handle
205 206 207 208 209 210 211
           = do (result, iface, details)
                    <- compiler hsc_env' summary source_unchanged mb_old_iface
                                (Just (mod_index, nmods))
                linkable <- handle result
                return (HomeModInfo{ hm_details  = details,
                                     hm_iface    = iface,
                                     hm_linkable = linkable })
212
   -- run the compiler
213
   case hsc_lang of
214 215 216 217 218 219 220 221 222
      HscInterpreted
        | isHsBoot src_flavour -> 
                runCompiler hscCompileNothing handleBatch
        | otherwise -> 
                runCompiler hscCompileInteractive handleInterpreted
      HscNothing -> 
                runCompiler hscCompileNothing handleBatch
      _other -> 
                runCompiler hscCompileBatch handleBatch
223

224
-----------------------------------------------------------------------------
225 226
-- stub .h and .c files (for foreign export support)

227 228 229
-- The _stub.c file is derived from the haskell source file, possibly taking
-- into account the -stubdir option.
--
230 231 232 233 234 235 236 237 238 239 240 241 242
-- Consequently, we derive the _stub.o filename from the haskell object
-- filename.  
--
-- This isn't necessarily the same as the object filename we
-- would get if we just compiled the _stub.c file using the pipeline.
-- For example:
--
--    ghc src/A.hs -odir obj
-- 
-- results in obj/A.o, and src/A_stub.c.  If we compile src/A_stub.c with
-- -odir obj, we would get obj/src/A_stub.o, which is wrong; we want
-- obj/A_stub.o.

243 244
compileStub :: GhcMonad m => HscEnv -> Module -> ModLocation
            -> m FilePath
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
245
compileStub hsc_env mod location = do
Ian Lynagh's avatar
Ian Lynagh committed
246 247
	let (o_base, o_ext) = splitExtension (ml_obj_file location)
	    stub_o = (o_base ++ "_stub") <.> o_ext
248

249
	-- compile the _stub.c file w/ gcc
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
250 251
	let (stub_c,_,_) = mkStubPaths (hsc_dflags hsc_env) (moduleName mod) location
	runPipeline StopLn hsc_env (stub_c,Nothing)  Nothing
252 253 254
		(SpecificFile stub_o) Nothing{-no ModLocation-}

	return stub_o
255 256


257 258
-- ---------------------------------------------------------------------------
-- Link
259

Ian Lynagh's avatar
Ian Lynagh committed
260 261 262 263
link :: GhcLink                 -- interactive or batch
     -> DynFlags                -- dynamic flags
     -> Bool                    -- attempt linking in batch mode?
     -> HomePackageTable        -- what to link
264 265 266 267 268 269 270 271 272 273
     -> IO SuccessFlag

-- For the moment, in the batch linker, we don't bother to tell doLink
-- which packages to link -- it just tries all that are available.
-- batch_attempt_linking should only be *looked at* in batch mode.  It
-- should only be True if the upsweep was successful and someone
-- exports main, i.e., we have good reason to believe that linking
-- will succeed.

#ifdef GHCI
274
link LinkInMemory _ _ _
275
    = do -- Not Linking...(demand linker will do the job)
Ian Lynagh's avatar
Ian Lynagh committed
276
         return Succeeded
277 278
#endif

279
link NoLink _ _ _
280 281
   = return Succeeded

282
link LinkBinary dflags batch_attempt_linking hpt
283
   | batch_attempt_linking
Ian Lynagh's avatar
Ian Lynagh committed
284 285 286
   = do
        let
            home_mod_infos = eltsUFM hpt
287

Ian Lynagh's avatar
Ian Lynagh committed
288 289
            -- the packages we depend on
            pkg_deps  = concatMap (dep_pkgs . mi_deps . hm_iface) home_mod_infos
290

Ian Lynagh's avatar
Ian Lynagh committed
291 292
            -- the linkables to link
            linkables = map (expectJust "link".hm_linkable) home_mod_infos
293

294
        debugTraceMsg dflags 3 (text "link: linkables are ..." $$ vcat (map ppr linkables))
295

Ian Lynagh's avatar
Ian Lynagh committed
296 297 298 299 300
        -- check for the -no-link flag
        if isNoLink (ghcLink dflags)
          then do debugTraceMsg dflags 3 (text "link(batch): linking omitted (-c flag given).")
                  return Succeeded
          else do
301

Ian Lynagh's avatar
Ian Lynagh committed
302 303
        let getOfiles (LM _ _ us) = map nameOfObject (filter isObject us)
            obj_files = concatMap getOfiles linkables
304

Ian Lynagh's avatar
Ian Lynagh committed
305
            exe_file = exeFileName dflags
306

307
        linking_needed <- linkingNeeded dflags linkables pkg_deps
308

Ian Lynagh's avatar
Ian Lynagh committed
309
        if not (dopt Opt_ForceRecomp dflags) && not linking_needed
310
           then do debugTraceMsg dflags 2 (text exe_file <+> ptext (sLit "is up to date, linking not required."))
Ian Lynagh's avatar
Ian Lynagh committed
311 312
                   return Succeeded
           else do
313

314
        debugTraceMsg dflags 1 (ptext (sLit "Linking") <+> text exe_file
Ian Lynagh's avatar
Ian Lynagh committed
315
                                 <+> text "...")
316

Ian Lynagh's avatar
Ian Lynagh committed
317 318 319 320
        -- Don't showPass in Batch mode; doLink will do that for us.
        let link = case ghcLink dflags of
                LinkBinary  -> linkBinary
                LinkDynLib  -> linkDynLib
321
                other       -> panicBadLink other
Ian Lynagh's avatar
Ian Lynagh committed
322
        link dflags obj_files pkg_deps
323

324
        debugTraceMsg dflags 3 (text "link: done")
325

Ian Lynagh's avatar
Ian Lynagh committed
326
        -- linkBinary only returns if it succeeds
327 328 329
        return Succeeded

   | otherwise
330 331
   = do debugTraceMsg dflags 3 (text "link(batch): upsweep (partially) failed OR" $$
                                text "   Main.main not exported; not linking.")
332
        return Succeeded
Ian Lynagh's avatar
Ian Lynagh committed
333

334 335 336 337 338 339
-- warning suppression
link other _ _ _ = panicBadLink other

panicBadLink :: GhcLink -> a
panicBadLink other = panic ("link: GHC not built to link this way: " ++
                            show other)
340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384


linkingNeeded :: DynFlags -> [Linkable] -> [PackageId] -> IO Bool
linkingNeeded dflags linkables pkg_deps = do
        -- if the modification time on the executable is later than the
        -- modification times on all of the objects and libraries, then omit
        -- linking (unless the -fforce-recomp flag was given).
  let exe_file = exeFileName dflags
  e_exe_time <- IO.try $ getModificationTime exe_file
  case e_exe_time of
    Left _  -> return True
    Right t -> do
        -- first check object files and extra_ld_inputs
        extra_ld_inputs <- readIORef v_Ld_inputs
        e_extra_times <- mapM (IO.try . getModificationTime) extra_ld_inputs
        let (errs,extra_times) = splitEithers e_extra_times
        let obj_times =  map linkableTime linkables ++ extra_times
        if not (null errs) || any (t <) obj_times
            then return True 
            else do

        -- next, check libraries. XXX this only checks Haskell libraries,
        -- not extra_libraries or -l things from the command line.
        let pkg_map = pkgIdMap (pkgState dflags)
            pkg_hslibs  = [ (libraryDirs c, lib)
                          | Just c <- map (lookupPackage pkg_map) pkg_deps,
                            lib <- packageHsLibs dflags c ]

        pkg_libfiles <- mapM (uncurry findHSLib) pkg_hslibs
        if any isNothing pkg_libfiles then return True else do
        e_lib_times <- mapM (IO.try . getModificationTime)
                          (catMaybes pkg_libfiles)
        let (lib_errs,lib_times) = splitEithers e_lib_times
        if not (null lib_errs) || any (t <) lib_times
           then return True
           else return False

findHSLib :: [String] -> String -> IO (Maybe FilePath)
findHSLib dirs lib = do
  let batch_lib_file = "lib" ++ lib <.> "a"
  found <- filterM doesFileExist (map (</> batch_lib_file) dirs)
  case found of
    [] -> return Nothing
    (x:_) -> return (Just x)

385 386 387
-- -----------------------------------------------------------------------------
-- Compile files in one-shot mode.

388 389
oneShot :: GhcMonad m =>
           HscEnv -> Phase -> [(String, Maybe Phase)] -> m ()
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
390 391
oneShot hsc_env stop_phase srcs = do
  o_files <- mapM (compileFile hsc_env stop_phase) srcs
392
  liftIO $ doLink (hsc_dflags hsc_env) stop_phase o_files
393

394 395
compileFile :: GhcMonad m =>
               HscEnv -> Phase -> (FilePath, Maybe Phase) -> m FilePath
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
396
compileFile hsc_env stop_phase (src, mb_phase) = do
397
   exists <- liftIO $ doesFileExist src
398
   when (not exists) $ 
399
   	ghcError (CmdLineError ("does not exist: " ++ src))
400 401
   
   let
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
402
        dflags = hsc_dflags hsc_env
403 404 405 406 407 408 409 410 411 412 413 414 415 416 417
	split     = dopt Opt_SplitObjs dflags
	mb_o_file = outputFile dflags
	ghc_link  = ghcLink dflags	-- Set by -c or -no-link

	-- When linking, the -o argument refers to the linker's output.	
	-- otherwise, we use it as the name for the pipeline's output.
        output
	 | StopLn <- stop_phase, not (isNoLink ghc_link) = Persistent
		-- -o foo applies to linker
	 | Just o_file <- mb_o_file = SpecificFile o_file
		-- -o foo applies to the file we are compiling now
	 | otherwise = Persistent

        stop_phase' = case stop_phase of 
			As | split -> SplitAs
418
                        _          -> stop_phase
419

420 421 422
   ( _, out_file) <- runPipeline stop_phase' hsc_env
                            (src, mb_phase) Nothing output
                            Nothing{-no ModLocation-}
423 424 425 426 427 428 429 430 431 432 433
   return out_file


doLink :: DynFlags -> Phase -> [FilePath] -> IO ()
doLink dflags stop_phase o_files
  | not (isStopLn stop_phase)
  = return ()		-- We stopped before the linking phase

  | otherwise
  = case ghcLink dflags of
	NoLink     -> return ()
434 435
	LinkBinary -> linkBinary dflags o_files link_pkgs
	LinkDynLib -> linkDynLib dflags o_files []
436
        other      -> panicBadLink other
437 438 439
  where
   -- Always link in the haskell98 package for static linking.  Other
   -- packages have to be specified via the -package flag.
440
    link_pkgs
441 442
     | dopt Opt_AutoLinkPackages dflags = [haskell98PackageId]
     | otherwise                        = []
443 444


445
-- ---------------------------------------------------------------------------
446 447 448

data PipelineOutput 
  = Temporary
449 450
	-- ^ Output should be to a temporary file: we're going to
	-- run more compilation steps on this output later.
451
  | Persistent
452
	-- ^ We want a persistent file, i.e. a file in the current directory
453 454 455
	-- derived from the input filename, but with the appropriate extension.
	-- eg. in "ghc -c Foo.hs" the output goes into ./Foo.o.
  | SpecificFile FilePath
456
	-- ^ The output must go into the specified file.
457

458 459 460 461 462 463 464 465 466
-- | Run a compilation pipeline, consisting of multiple phases.
--
-- This is the interface to the compilation pipeline, which runs
-- a series of compilation steps on a single source file, specifying
-- at which stage to stop.
--
-- The DynFlags can be modified by phases in the pipeline (eg. by
-- GHC_OPTIONS pragmas), and the changes affect later phases in the
-- pipeline.
467
runPipeline
468 469 470 471 472 473 474 475
  :: GhcMonad m =>
     Phase		        -- ^ When to stop
  -> HscEnv                     -- ^ Compilation environment
  -> (FilePath,Maybe Phase)     -- ^ Input filename (and maybe -x suffix)
  -> Maybe FilePath             -- ^ original basename (if different from ^^^)
  -> PipelineOutput	        -- ^ Output filename
  -> Maybe ModLocation          -- ^ A ModLocation, if this is a Haskell module
  -> m (DynFlags, FilePath)	-- ^ (final flags, output filename)
476

dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
477
runPipeline stop_phase hsc_env0 (input_fn, mb_phase) mb_basename output maybe_loc
478
  = do
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
479
  let dflags0 = hsc_dflags hsc_env0
Ian Lynagh's avatar
Ian Lynagh committed
480 481
      (input_basename, suffix) = splitExtension input_fn
      suffix' = drop 1 suffix -- strip off the .
Simon Marlow's avatar
Simon Marlow committed
482 483
      basename | Just b <- mb_basename = b
               | otherwise             = input_basename
484

485 486
      -- Decide where dump files should go based on the pipeline output
      dflags = dflags0 { dumpPrefix = Just (basename ++ ".") }
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
487
      hsc_env = hsc_env0 {hsc_dflags = dflags}
488

489
	-- If we were given a -x flag, then use that phase to start from
Ian Lynagh's avatar
Ian Lynagh committed
490
      start_phase = fromMaybe (startPhase suffix') mb_phase
491

492 493 494 495 496 497
  -- We want to catch cases of "you can't get there from here" before
  -- we start the pipeline, because otherwise it will just run off the
  -- end.
  --
  -- There is a partial ordering on phases, where A < B iff A occurs
  -- before B in a normal compilation pipeline.
498

499
  when (not (start_phase `happensBefore` stop_phase)) $
500
	ghcError (UsageError 
501 502
		    ("cannot compile this file to desired target: "
		       ++ input_fn))
503

504 505
  -- this is a function which will be used to calculate output file names
  -- as we go along (we partially apply it to some of its inputs here)
506
  let get_output_fn = getOutputFilename stop_phase output basename
507

508
  -- Execute the pipeline...
509
  (dflags', output_fn, maybe_loc) <- 
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
510
	pipeLoop hsc_env start_phase stop_phase input_fn 
Ian Lynagh's avatar
Ian Lynagh committed
511
	  	 basename suffix' get_output_fn maybe_loc
512

513
  -- Sometimes, a compilation phase doesn't actually generate any output
514 515
  -- (eg. the CPP phase when -fcpp is not turned on).  If we end on this
  -- stage, but we wanted to keep the output, then we have to explicitly
516 517
  -- copy the file, remembering to prepend a {-# LINE #-} pragma so that
  -- further compilation stages can tell what the original filename was.
518 519 520
  case output of
    Temporary -> 
	return (dflags', output_fn)
521
    _other -> liftIO $
522
	do final_fn <- get_output_fn dflags' stop_phase maybe_loc
523 524 525 526
	   when (final_fn /= output_fn) $ do
              let msg = ("Copying `" ++ output_fn ++"' to `" ++ final_fn ++ "'")
                  line_prag = Just ("{-# LINE 1 \"" ++ input_fn ++ "\" #-}\n")
	      copyWithHeader dflags msg line_prag output_fn final_fn
527
	   return (dflags', final_fn)
528

529 530


531 532
pipeLoop :: GhcMonad m =>
            HscEnv -> Phase -> Phase
533
	 -> FilePath  -> String -> Suffix
534
	 -> (DynFlags -> Phase -> Maybe ModLocation -> IO FilePath)
535
	 -> Maybe ModLocation
536
	 -> m (DynFlags, FilePath, Maybe ModLocation)
537

dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
538
pipeLoop hsc_env phase stop_phase 
539 540
	 input_fn orig_basename orig_suff 
	 orig_get_output_fn maybe_loc
541

542
  | phase `eqPhase` stop_phase		  -- All done
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
543
  = return (hsc_dflags hsc_env, input_fn, maybe_loc)
544

545
  | not (phase `happensBefore` stop_phase)
546 547 548 549
	-- Something has gone wrong.  We'll try to cover all the cases when
	-- this could happen, so if we reach here it is a panic.
	-- eg. it might happen if the -C flag is used on a source file that
	-- has {-# OPTIONS -fasm #-}.
550 551 552 553
  = panic ("pipeLoop: at phase " ++ show phase ++ 
	   " but I wanted to stop at phase " ++ show stop_phase)

  | otherwise 
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
554 555 556 557 558 559
  = do (next_phase, dflags', maybe_loc, output_fn)
          <- runPhase phase stop_phase hsc_env orig_basename 
                      orig_suff input_fn orig_get_output_fn maybe_loc
       let hsc_env' = hsc_env {hsc_dflags = dflags'}
       pipeLoop hsc_env' next_phase stop_phase output_fn
                orig_basename orig_suff orig_get_output_fn maybe_loc
560

561
getOutputFilename
562 563 564
  :: Phase -> PipelineOutput -> String
  -> DynFlags -> Phase{-next phase-} -> Maybe ModLocation -> IO FilePath
getOutputFilename stop_phase output basename
565 566
 = func
 where
567
	func dflags next_phase maybe_location
568 569 570 571
	   | is_last_phase, Persistent <- output     = persistent_fn
	   | is_last_phase, SpecificFile f <- output = return f
	   | keep_this_output	   		     = persistent_fn
     	   | otherwise        	   		     = newTempName dflags suffix
572
	   where
573 574 575 576 577 578 579 580 581 582 583
		hcsuf      = hcSuf dflags
		odir       = objectDir dflags
		osuf       = objectSuf dflags
		keep_hc    = dopt Opt_KeepHcFiles dflags
		keep_raw_s = dopt Opt_KeepRawSFiles dflags
		keep_s     = dopt Opt_KeepSFiles dflags

		myPhaseInputExt HCc    = hcsuf
		myPhaseInputExt StopLn = osuf
		myPhaseInputExt other  = phaseInputExt other

584
		is_last_phase = next_phase `eqPhase` stop_phase
585 586 587 588

		-- sometimes, we keep output from intermediate stages
		keep_this_output = 
     		     case next_phase of
589
     			     StopLn              -> True
590 591 592 593 594
     			     Mangle | keep_raw_s -> True
     			     As     | keep_s     -> True
     			     HCc    | keep_hc    -> True
     			     _other              -> False

595
		suffix = myPhaseInputExt next_phase
596 597 598

		-- persistent object files get put in odir
	        persistent_fn 
599 600
		   | StopLn <- next_phase = return odir_persistent
		   | otherwise            = return persistent
601

Ian Lynagh's avatar
Ian Lynagh committed
602
		persistent = basename <.> suffix
603

604
		odir_persistent
605
		   | Just loc <- maybe_location = ml_obj_file loc
Ian Lynagh's avatar
Ian Lynagh committed
606
		   | Just d <- odir = d </> persistent
607 608
		   | otherwise      = persistent

609

610
-- -----------------------------------------------------------------------------
611
-- | Each phase in the pipeline returns the next phase to execute, and the
612 613 614 615 616 617 618
-- name of the file in which the output was placed.
--
-- We must do things dynamically this way, because we often don't know
-- what the rest of the phases will be until part-way through the
-- compilation: for example, an {-# OPTIONS -fasm #-} at the beginning
-- of a source file can change the latter stages of the pipeline from
-- taking the via-C route to using the native code generator.
619 620 621 622
--
runPhase :: GhcMonad m =>
            Phase	-- ^ Do this phase first
	 -> Phase	-- ^ Stop just before this phase
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
623
	 -> HscEnv
624 625 626
	 -> String	-- ^ basename of original input source
	 -> String	-- ^ its extension
	 -> FilePath	-- ^ name of file which contains the input to this phase.
627
	 -> (DynFlags -> Phase -> Maybe ModLocation -> IO FilePath)
628 629 630 631 632 633
			-- ^ how to calculate the output filename
	 -> Maybe ModLocation		-- ^ the ModLocation, if we have one
	 -> m (Phase,	  		-- next phase
               DynFlags,		-- new dynamic flags
	       Maybe ModLocation,	-- the ModLocation, if we have one
	       FilePath)		-- output filename
634

635 636 637 638
	-- Invariant: the output filename always contains the output
	-- Interesting case: Hsc when there is no recompilation to do
	--		     Then the output filename is still a .o file 

639 640 641
-------------------------------------------------------------------------------
-- Unlit phase 

dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
642
runPhase (Unlit sf) _stop hsc_env _basename _suff input_fn get_output_fn maybe_loc
643
  = do
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
644
       let dflags = hsc_dflags hsc_env
645
       output_fn <- liftIO $ get_output_fn dflags (Cpp sf) maybe_loc
646

647 648 649 650 651 652 653 654 655 656 657 658
       let unlit_flags = getOpts dflags opt_L
           flags = map SysTools.Option unlit_flags ++
                   [ -- The -h option passes the file name for unlit to
                     -- put in a #line directive
                     SysTools.Option     "-h"
                     -- cpp interprets \b etc as escape sequences,
                     -- so we use / for filenames in pragmas
                   , SysTools.Option $ reslash Forwards $ normalise input_fn
                   , SysTools.FileOption "" input_fn
                   , SysTools.FileOption "" output_fn
                   ]

659
       liftIO $ SysTools.runUnlit dflags flags
660

661
       return (Cpp sf, dflags, maybe_loc, output_fn)
662 663

-------------------------------------------------------------------------------
664 665
-- Cpp phase : (a) gets OPTIONS out of file
--	       (b) runs cpp if necessary
666

667
runPhase (Cpp sf) _stop hsc_env _basename _suff input_fn get_output_fn maybe_loc
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
668
  = do let dflags0 = hsc_dflags hsc_env
669 670
       src_opts <- liftIO $ getOptionsFromFile dflags0 input_fn
       (dflags, unhandled_flags, warns)
671
           <- liftIO $ parseDynamicNoPackageFlags dflags0 src_opts
672
       handleFlagWarnings dflags warns
673
       checkProcessArgsResult unhandled_flags
674

675
       if not (dopt Opt_Cpp dflags) then
sof's avatar
sof committed
676 677
           -- no need to preprocess CPP, just pass input file along
	   -- to the next phase of the pipeline.
678
          return (HsPp sf, dflags, maybe_loc, input_fn)
sof's avatar
sof committed
679
	else do
680 681
	    output_fn <- liftIO $ get_output_fn dflags (HsPp sf) maybe_loc
	    liftIO $ doCpp dflags True{-raw-} False{-no CC opts-} input_fn output_fn
682
	    return (HsPp sf, dflags, maybe_loc, output_fn)
683

sof's avatar
sof committed
684 685 686
-------------------------------------------------------------------------------
-- HsPp phase 

dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
687 688 689
runPhase (HsPp sf) _stop hsc_env basename suff input_fn get_output_fn maybe_loc
  = do let dflags = hsc_dflags hsc_env
       if not (dopt Opt_Pp dflags) then
sof's avatar
sof committed
690 691
           -- no need to preprocess, just pass input file along
	   -- to the next phase of the pipeline.
692
          return (Hsc sf, dflags, maybe_loc, input_fn)
sof's avatar
sof committed
693
	else do
694
	    let hspp_opts = getOpts dflags opt_F
Ian Lynagh's avatar
Ian Lynagh committed
695
	    let orig_fn = basename <.> suff
696 697
	    output_fn <- liftIO $ get_output_fn dflags (Hsc sf) maybe_loc
	    liftIO $ SysTools.runPp dflags
698
			   ( [ SysTools.Option     orig_fn
sof's avatar
sof committed
699 700 701 702 703
			     , SysTools.Option     input_fn
			     , SysTools.FileOption "" output_fn
			     ] ++
			     map SysTools.Option hspp_opts
			   )
704
	    return (Hsc sf, dflags, maybe_loc, output_fn)
705

706 707 708
-----------------------------------------------------------------------------
-- Hsc phase

709 710
-- Compilation of a single module, in "legacy" mode (_not_ under
-- the direction of the compilation manager).
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
711
runPhase (Hsc src_flavour) stop hsc_env basename suff input_fn get_output_fn _maybe_loc 
712
 = do	-- normal Hsc mode, not mkdependHS
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
713
        let dflags0 = hsc_dflags hsc_env
714

715
  -- we add the current directory (i.e. the directory in which
716
  -- the .hs files resides) to the include path, since this is
717
  -- what gcc does, and it's probably what you want.
Ian Lynagh's avatar
Ian Lynagh committed
718 719 720
	let current_dir = case takeDirectory basename of
                      "" -> "." -- XXX Hack
                      d -> d
721
	
722 723
	    paths = includePaths dflags0
	    dflags = dflags0 { includePaths = current_dir : paths }
724
	
725
  -- gather the imports and module name
726
        (hspp_buf,mod_name,imps,src_imps) <- 
727
            case src_flavour of
728 729 730
                ExtCoreFile -> do  -- no explicit imports in ExtCore input.
                    m <- liftIO $ getCoreModuleName input_fn
                    return (Nothing, mkModuleName m, [], [])
731

732 733
                _           -> do
                    buf <- liftIO $ hGetStringBuffer input_fn
734 735
                    (src_imps,imps,L _ mod_name) <- getImports dflags buf input_fn (basename <.> suff)
                    return (Just buf, mod_name, imps, src_imps)
736 737 738 739 740 741 742

  -- Build a ModLocation to pass to hscMain.
  -- The source filename is rather irrelevant by now, but it's used
  -- by hscMain for messages.  hscMain also needs 
  -- the .hi and .o filenames, and this is as good a way
  -- as any to generate them, and better than most. (e.g. takes 
  -- into accout the -osuf flags)
743
	location1 <- liftIO $ mkHomeModLocation2 dflags mod_name basename suff
744 745 746 747 748 749 750 751 752

  -- Boot-ify it if necessary
	let location2 | isHsBoot src_flavour = addBootSuffixLocn location1
		      | otherwise	     = location1 
					

  -- Take -ohi into account if present
  -- This can't be done in mkHomeModuleLocation because
  -- it only applies to the module being compiles
753 754
	let ohi = outputHi dflags
	    location3 | Just fn <- ohi = location2{ ml_hi_file = fn }
755 756 757 758 759 760 761
		      | otherwise      = location2

  -- Take -o into account if present
  -- Very like -ohi, but we must *only* do this if we aren't linking
  -- (If we're linking then the -o applies to the linked thing, not to
  -- the object file for one module.)
  -- Note the nasty duplication with the same computation in compileFile above
762 763 764
	let expl_o_file = outputFile dflags
	    location4 | Just ofile <- expl_o_file
		      , isNoLink (ghcLink dflags)
765 766 767 768 769 770 771
		      = location3 { ml_obj_file = ofile }
		      | otherwise = location3

	    o_file = ml_obj_file location4 	-- The real object file


  -- Figure out if the source has changed, for recompilation avoidance.
772
  --
773
  -- Setting source_unchanged to True means that M.o seems
774 775
  -- to be up to date wrt M.hs; so no need to recompile unless imports have
  -- changed (which the compiler itself figures out).
776
  -- Setting source_unchanged to False tells the compiler that M.o is out of
777
  -- date wrt M.hs (or M.o doesn't exist) so we must recompile regardless.
778
	src_timestamp <- liftIO $ getModificationTime (basename <.> suff)
Simon Marlow's avatar
Simon Marlow committed
779

780
	let force_recomp = dopt Opt_ForceRecomp dflags
781
	source_unchanged <-
782
          if force_recomp || not (isStopLn stop)
783 784
		-- Set source_unchanged to False unconditionally if
		--	(a) recompilation checker is off, or
785
		-- 	(b) we aren't going all the way to .o file (e.g. ghc -S)
786 787
	     then return False	
		-- Otherwise look at file modification dates
788
	     else do o_file_exists <- liftIO $ doesFileExist o_file
789
		     if not o_file_exists
790
		        then return False	-- Need to recompile
791
			else do t2 <- liftIO $ getModificationTime o_file
792
			        if t2 > src_timestamp
793 794
				  then return True
				  else return False
795

796
  -- get the DynFlags
797
	let hsc_lang = hscMaybeAdjustTarget dflags stop src_flavour (hscTarget dflags)
798
	let next_phase = hscNextPhase dflags src_flavour hsc_lang
799
	output_fn  <- liftIO $ get_output_fn dflags next_phase (Just location4)
800

801
        let dflags' = dflags { hscTarget = hsc_lang,
802 803
			       hscOutName = output_fn,
			       extCoreName = basename ++ ".hcr" }
804

dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
805
        let hsc_env' = hsc_env {hsc_dflags = dflags'}
806

807
  -- Tell the finder cache about this module
808
	mod <- liftIO $ addHomeModuleToFinder hsc_env' mod_name location4
Simon Marlow's avatar
Simon Marlow committed
809 810 811 812 813 814 815 816 817 818 819

  -- Make the ModSummary to hand to hscMain
	let
	    mod_summary = ModSummary {	ms_mod 	     = mod, 
					ms_hsc_src   = src_flavour,
				 	ms_hspp_file = input_fn,
                                        ms_hspp_opts = dflags,
					ms_hspp_buf  = hspp_buf,
					ms_location  = location4,
					ms_hs_date   = src_timestamp,
					ms_obj_date  = Nothing,
820 821
					ms_imps	     = imps,
					ms_srcimps   = src_imps }
822

823
  -- run the compiler!
824
	result <- hscCompileOneShot hsc_env'
825 826
			  mod_summary source_unchanged 
			  Nothing	-- No iface
827
                          Nothing       -- No "module i of n" progress info
828

829 830 831
	case result of
          HscNoRecomp
              -> do liftIO $ SysTools.touch dflags' "Touching object file" o_file
832 833 834 835
                    -- The .o file must have a later modification date
                    -- than the source file (else we wouldn't be in HscNoRecomp)
                    -- but we touch it anyway, to keep 'make' happy (we think).
                    return (StopLn, dflags', Just location4, o_file)
Thomas Schilling's avatar
Thomas Schilling committed
836
          (HscRecomp hasStub _)
837
              -> do when hasStub $
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
838
                         do stub_o <- compileStub hsc_env' mod location4
839
                            liftIO $ consIORef v_Ld_inputs stub_o
840 841 842
                    -- In the case of hs-boot files, generate a dummy .o-boot 
                    -- stamp file for the benefit of Make
                    when (isHsBoot src_flavour) $
843
                      liftIO $ SysTools.touch dflags' "Touching object file" o_file
844
                    return (next_phase, dflags', Just location4, output_fn)
845

846 847 848
-----------------------------------------------------------------------------
-- Cmm phase

dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
849
runPhase CmmCpp _stop hsc_env _basename _suff input_fn get_output_fn maybe_loc
850
  = do
dias@eecs.harvard.edu's avatar
dias@eecs.harvard.edu committed
851
       let dflags = hsc_dflags hsc_env
852 853
       output_fn <- liftIO $ get_output_fn dflags Cmm maybe_loc
       liftIO $ doCpp dflags False{-not raw-} True{-include CC opts-} input_fn output_fn
854
       return (Cmm, dflags, maybe_loc, output_fn)
855