DriverPipeline.hs 25.5 KB
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-----------------------------------------------------------------------------
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-- $Id: DriverPipeline.hs,v 1.4 2000/10/17 11:50:20 simonmar Exp $
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--
-- GHC Driver
--
-- (c) Simon Marlow 2000
--
-----------------------------------------------------------------------------

module DriverPipeline (
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	-- interfaces for the batch-mode driver
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   GhcMode(..), getGhcMode, v_GhcMode,
   genPipeline, runPipeline,
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	-- interfaces for the compilation manager (interpreted/batch-mode)
   preprocess, compile,

	-- batch-mode linking interface
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   doLink,
  ) where

#include "HsVersions.h"

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import CmSummarise
import CmLink
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import DriverState
import DriverUtil
import DriverMkDepend
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import DriverPhases
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import DriverFlags
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import Finder
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import TmpFiles
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import HscTypes
import UniqFM
import Outputable
import Module
import ErrUtils
import CmdLineOpts
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import Config
import Util
import Panic

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import Directory
import System
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import IOExts
import Posix
import Exception

import IO
import Monad
import Maybe

-----------------------------------------------------------------------------
-- GHC modes of operation

data GhcMode
  = DoMkDependHS			-- ghc -M
  | DoMkDLL				-- ghc -mk-dll
  | StopBefore Phase			-- ghc -E | -C | -S | -c
  | DoMake				-- ghc --make
  | DoInteractive			-- ghc --interactive
  | DoLink				-- [ the default ]
  deriving (Eq)

GLOBAL_VAR(v_GhcMode, error "todo", GhcMode)

modeFlag :: String -> Maybe GhcMode
modeFlag "-M" 		 = Just $ DoMkDependHS
modeFlag "-E" 		 = Just $ StopBefore Hsc
modeFlag "-C" 		 = Just $ StopBefore HCc
modeFlag "-S" 		 = Just $ StopBefore As
modeFlag "-c" 		 = Just $ StopBefore Ln
modeFlag "--make"        = Just $ DoMake
modeFlag "--interactive" = Just $ DoInteractive
modeFlag _               = Nothing

getGhcMode :: [String]
	 -> IO ( [String]   -- rest of command line
	       , GhcMode
	       , String	    -- "GhcMode" flag
	       )
getGhcMode flags 
  = case my_partition modeFlag flags of
	([]   , rest) -> return (rest, DoLink,  "") -- default is to do linking
	([(flag,one)], rest) -> return (rest, one, flag)
	(_    , _   ) -> 
	  throwDyn (OtherError 
		"only one of the flags -M, -E, -C, -S, -c, --make, --interactive is allowed")

-----------------------------------------------------------------------------
-- genPipeline
--
-- Herein is all the magic about which phases to run in which order, whether
-- the intermediate files should be in /tmp or in the current directory,
-- what the suffix of the intermediate files should be, etc.

-- The following compilation pipeline algorithm is fairly hacky.  A
-- better way to do this would be to express the whole comilation as a
-- data flow DAG, where the nodes are the intermediate files and the
-- edges are the compilation phases.  This framework would also work
-- nicely if a haskell dependency generator was included in the
-- driver.

-- It would also deal much more cleanly with compilation phases that
-- generate multiple intermediates, (eg. hsc generates .hc, .hi, and
-- possibly stub files), where some of the output files need to be
-- processed further (eg. the stub files need to be compiled by the C
-- compiler).

-- A cool thing to do would then be to execute the data flow graph
-- concurrently, automatically taking advantage of extra processors on
-- the host machine.  For example, when compiling two Haskell files
-- where one depends on the other, the data flow graph would determine
-- that the C compiler from the first comilation can be overlapped
-- with the hsc comilation for the second file.

data IntermediateFileType
  = Temporary
  | Persistent
  deriving (Eq)

genPipeline
   :: GhcMode		-- when to stop
   -> String		-- "stop after" flag (for error messages)
   -> String		-- original filename
   -> IO [ 		-- list of phases to run for this file
	     (Phase,
	      IntermediateFileType,  -- keep the output from this phase?
	      String)   	     -- output file suffix
         ]	

genPipeline todo stop_flag filename
 = do
   split      <- readIORef split_object_files
   mangle     <- readIORef do_asm_mangling
   lang       <- readIORef hsc_lang
   keep_hc    <- readIORef keep_hc_files
   keep_raw_s <- readIORef keep_raw_s_files
   keep_s     <- readIORef keep_s_files

   let
   ----------- -----  ----   ---   --   --  -  -  -
    (_basename, suffix) = splitFilename filename

    start_phase = startPhase suffix

    haskellish = haskellish_suffix suffix
    cish = cish_suffix suffix

   -- for a .hc file, or if the -C flag is given, we need to force lang to HscC
    real_lang 
	| suffix == "hc"  = HscC
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	| todo == StopBefore HCc && haskellish = HscC
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	| otherwise = lang

   let
   ----------- -----  ----   ---   --   --  -  -  -
    pipeline
      | todo == DoMkDependHS = [ Unlit, Cpp, MkDependHS ]

      | haskellish = 
       case real_lang of
	HscC    | split && mangle -> [ Unlit, Cpp, Hsc, HCc, Mangle, 
					SplitMangle, SplitAs ]
	        | mangle          -> [ Unlit, Cpp, Hsc, HCc, Mangle, As ]
	        | split	       	  -> not_valid
	        | otherwise       -> [ Unlit, Cpp, Hsc, HCc, As ]

	HscAsm  | split           -> [ Unlit, Cpp, Hsc, SplitMangle, SplitAs ]
	        | otherwise       -> [ Unlit, Cpp, Hsc, As ]

	HscJava	| split	          -> not_valid
		| otherwise       -> error "not implemented: compiling via Java"

      | cish      = [ Cc, As ]

      | otherwise = [ ]  -- just pass this file through to the linker

	-- ToDo: this is somewhat cryptic
    not_valid = throwDyn (OtherError ("invalid option combination"))
   ----------- -----  ----   ---   --   --  -  -  -

	-- this shouldn't happen.
   if start_phase /= Ln && start_phase `notElem` pipeline
	then throwDyn (OtherError ("can't find starting phase for "
				    ++ filename))
	else do

	-- if we can't find the phase we're supposed to stop before,
	-- something has gone wrong.
   case todo of
	StopBefore phase -> 
	   when (phase /= Ln 
		 && phase `notElem` pipeline
	   	 && not (phase == As && SplitAs `elem` pipeline)) $
	      throwDyn (OtherError 
		("flag " ++ stop_flag
		 ++ " is incompatible with source file `" ++ filename ++ "'"))
	_ -> return ()

   let
   ----------- -----  ----   ---   --   --  -  -  -
      annotatePipeline
	 :: [Phase]		-- raw pipeline
	 -> Phase		-- phase to stop before
     	 -> [(Phase, IntermediateFileType, String{-file extension-})]
      annotatePipeline []     _    = []
      annotatePipeline (Ln:_) _    = []
      annotatePipeline (phase:next_phase:ps) stop = 
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     	  (phase, keep_this_output, phaseInputExt next_phase)
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	     : annotatePipeline (next_phase:ps) stop
     	  where
     		keep_this_output
     		     | next_phase == stop = Persistent
     		     | otherwise =
     			case next_phase of
     			     Ln -> Persistent
     			     Mangle | keep_raw_s -> Persistent
     			     As     | keep_s     -> Persistent
     			     HCc    | keep_hc    -> Persistent
     			     _other              -> Temporary

	-- add information about output files to the pipeline
	-- the suffix on an output file is determined by the next phase
	-- in the pipeline, so we add linking to the end of the pipeline
	-- to force the output from the final phase to be a .o file.
      stop_phase = case todo of StopBefore phase -> phase
				DoMkDependHS	 -> Ln
				DoLink           -> Ln
      annotated_pipeline = annotatePipeline (pipeline ++ [ Ln ]) stop_phase

      phase_ne p (p1,_,_) = (p1 /= p)
   ----------- -----  ----   ---   --   --  -  -  -

   return $
     dropWhile (phase_ne start_phase) . 
	foldr (\p ps -> if phase_ne stop_phase p then p:ps else [])  []
		$ annotated_pipeline


runPipeline
  :: [ (Phase, IntermediateFileType, String) ] -- phases to run
  -> String			-- input file
  -> Bool			-- doing linking afterward?
  -> Bool			-- take into account -o when generating output?
  -> IO String			-- return final filename

runPipeline pipeline input_fn do_linking use_ofile
  = pipeLoop pipeline input_fn do_linking use_ofile basename suffix
  where (basename, suffix) = splitFilename input_fn

pipeLoop [] input_fn _ _ _ _ = return input_fn
pipeLoop ((phase, keep, o_suffix):phases) 
	input_fn do_linking use_ofile orig_basename orig_suffix
  = do

     output_fn <- outputFileName (null phases) keep o_suffix

     carry_on <- run_phase phase orig_basename orig_suffix input_fn output_fn
	-- sometimes we bail out early, eg. when the compiler's recompilation
	-- checker has determined that recompilation isn't necessary.
     if not carry_on 
	then do let (_,keep,final_suffix) = last phases
	        ofile <- outputFileName True keep final_suffix
		return ofile
	else do -- carry on ...

	-- sadly, ghc -E is supposed to write the file to stdout.  We
	-- generate <file>.cpp, so we also have to cat the file here.
     when (null phases && phase == Cpp) $
	run_something "Dump pre-processed file to stdout"
		      ("cat " ++ output_fn)

     pipeLoop phases output_fn do_linking use_ofile orig_basename orig_suffix

  where
     outputFileName last_phase keep suffix
  	= do o_file <- readIORef output_file
   	     if last_phase && not do_linking && use_ofile && isJust o_file
   	       then case o_file of 
   		       Just s  -> return s
   		       Nothing -> error "outputFileName"
   	       else if keep == Persistent
   			   then do f <- odir_ify (orig_basename ++ '.':suffix)
   				   osuf_ify f
   			   else newTempName suffix

-------------------------------------------------------------------------------
-- Unlit phase 

run_phase Unlit _basename _suff input_fn output_fn
  = do unlit <- readIORef pgm_L
       unlit_flags <- getOpts opt_L
       run_something "Literate pre-processor"
	  ("echo '# 1 \"" ++input_fn++"\"' > "++output_fn++" && "
	   ++ unlit ++ ' ':input_fn ++ " - >> " ++ output_fn)
       return True

-------------------------------------------------------------------------------
-- Cpp phase 

run_phase Cpp _basename _suff input_fn output_fn
  = do src_opts <- getOptionsFromSource input_fn
	-- ToDo: this is *wrong* if we're processing more than one file:
	-- the OPTIONS will persist through the subsequent compilations.
       _ <- processArgs dynamic_flags src_opts []

       do_cpp <- readState cpp_flag
       if do_cpp
          then do
       	    cpp <- readIORef pgm_P
	    hscpp_opts <- getOpts opt_P
       	    hs_src_cpp_opts <- readIORef hs_source_cpp_opts

	    cmdline_include_paths <- readIORef include_paths
	    pkg_include_dirs <- getPackageIncludePath
	    let include_paths = map (\p -> "-I"++p) (cmdline_include_paths
							++ pkg_include_dirs)

	    verb <- is_verbose
	    run_something "C pre-processor" 
		(unwords
       	    	   (["echo '{-# LINE 1 \"" ++ input_fn ++ "\" -}'", ">", output_fn, "&&",
		     cpp, verb] 
		    ++ include_paths
		    ++ hs_src_cpp_opts
		    ++ hscpp_opts
		    ++ [ "-x", "c", input_fn, ">>", output_fn ]
		   ))
	  else do
	    run_something "Ineffective C pre-processor"
	           ("echo '{-# LINE 1 \""  ++ input_fn ++ "\" -}' > " 
		    ++ output_fn ++ " && cat " ++ input_fn
		    ++ " >> " ++ output_fn)
       return True

-----------------------------------------------------------------------------
-- MkDependHS phase

run_phase MkDependHS basename suff input_fn _output_fn = do 
   src <- readFile input_fn
   let imports = getImports src

   deps <- mapM (findDependency basename) imports

   osuf_opt <- readIORef output_suf
   let osuf = case osuf_opt of
			Nothing -> "o"
			Just s  -> s

   extra_suffixes <- readIORef dep_suffixes
   let suffixes = osuf : map (++ ('_':osuf)) extra_suffixes
       ofiles = map (\suf -> basename ++ '.':suf) suffixes
   	   
   objs <- mapM odir_ify ofiles
   
   hdl <- readIORef dep_tmp_hdl

	-- std dependeny of the object(s) on the source file
   hPutStrLn hdl (unwords objs ++ " : " ++ basename ++ '.':suff)

   let genDep (dep, False {- not an hi file -}) = 
	  hPutStrLn hdl (unwords objs ++ " : " ++ dep)
       genDep (dep, True  {- is an hi file -}) = do
	  hisuf <- readIORef hi_suf
	  let dep_base = remove_suffix '.' dep
	      deps = (dep_base ++ hisuf)
		     : map (\suf -> dep_base ++ suf ++ '_':hisuf) extra_suffixes
		  -- length objs should be == length deps
	  sequence_ (zipWith (\o d -> hPutStrLn hdl (o ++ " : " ++ d)) objs deps)

   mapM genDep [ d | Just d <- deps ]

   return True

-- add the lines to dep_makefile:
	   -- always:
		   -- this.o : this.hs

  	   -- if the dependency is on something other than a .hi file:
   		   -- this.o this.p_o ... : dep
   	   -- otherwise
   		   -- if the import is {-# SOURCE #-}
   			   -- this.o this.p_o ... : dep.hi-boot[-$vers]
   			   
   		   -- else
   			   -- this.o ...   : dep.hi
   			   -- this.p_o ... : dep.p_hi
   			   -- ...
   
   	   -- (where .o is $osuf, and the other suffixes come from
   	   -- the cmdline -s options).
   
-----------------------------------------------------------------------------
-- Hsc phase

run_phase Hsc	basename suff input_fn output_fn
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  = do
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  -- we add the current directory (i.e. the directory in which
  -- the .hs files resides) to the import path, since this is
  -- what gcc does, and it's probably what you want.
	let current_dir = getdir basename
	
	paths <- readIORef include_paths
	writeIORef include_paths (current_dir : paths)
	
  -- figure out where to put the .hi file
	ohi    <- readIORef output_hi
	hisuf  <- readIORef hi_suf
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	let hifile = case ohi of
			   Nothing -> current_dir ++ {-ToDo: modname!!-}basename
					++ hisuf
			   Just fn -> fn
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  -- figure out if the source has changed, for recompilation avoidance.
  -- only do this if we're eventually going to generate a .o file.
  -- (ToDo: do when generating .hc files too?)
  --
  -- Setting source_unchanged to "-fsource_unchanged" means that M.o seems
  -- to be up to date wrt M.hs; so no need to recompile unless imports have
  -- changed (which the compiler itself figures out).
  -- Setting source_unchanged to "" tells the compiler that M.o is out of
  -- date wrt M.hs (or M.o doesn't exist) so we must recompile regardless.
	do_recomp <- readIORef recomp
	todo <- readIORef v_GhcMode
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        o_file <- odir_ify (basename ++ '.':phaseInputExt Ln)
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	source_unchanged <- 
          if not (do_recomp && ( todo == DoLink || todo == StopBefore Ln ))
	     then return ""
	     else do t1 <- getModificationTime (basename ++ '.':suff)
		     o_file_exists <- doesFileExist o_file
		     if not o_file_exists
		        then return ""	-- Need to recompile
			else do t2 <- getModificationTime o_file
			        if t2 > t1
				  then return "-fsource-unchanged"
				  else return ""

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   -- build a bogus ModSummary to pass to hscMain.
	let summary = ModSummary {
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			ms_location = error "no loc",
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			ms_ppsource = Just (loc, error "no fingerprint"),
			ms_imports = error "no imports"
		     }

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  -- run the compiler!
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	result <- hscMain dyn_flags mod_summary 
				Nothing{-no iface-}
				output_fn emptyUFM emptyPCS

	case result of {

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	    HscErrs pcs errs warns -> do {
		printErrorsAndWarnings errs warns
		throwDyn (PhaseFailed "hsc" (ExitFailure 1)) };
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	    HscOK details maybe_iface maybe_stub_h maybe_stub_c pcs warns -> do
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	pprBagOfWarnings warns

   -- get the module name
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   -- generate the interface file
	case iface of
	   Nothing -> -- compilation not required
	     do run_something "Touching object file" ("touch " ++ o_file)
		return False

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	   Just iface -> do
		-- discover the filename for the .hi file in a roundabout way
		let mod = md_id details
		locn <- mkHomeModule mod basename input_fn
		let hifile = hi_file locn
		-- write out the interface file here...
		return ()		
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    -- deal with stubs
	maybe_stub_o <- dealWithStubs basename maybe_stub_h maybe_stub_c
	case stub_o of
		Nothing -> return ()
		Just stub_o -> add ld_inputs stub_o
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	return True
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    }
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-----------------------------------------------------------------------------
-- Cc phase

-- we don't support preprocessing .c files (with -E) now.  Doing so introduces
-- way too many hacks, and I can't say I've ever used it anyway.

run_phase cc_phase _basename _suff input_fn output_fn
   | cc_phase == Cc || cc_phase == HCc
   = do	cc <- readIORef pgm_c
       	cc_opts <- (getOpts opt_c)
       	cmdline_include_dirs <- readIORef include_paths

        let hcc = cc_phase == HCc

		-- add package include paths even if we're just compiling
		-- .c files; this is the Value Add(TM) that using
		-- ghc instead of gcc gives you :)
        pkg_include_dirs <- getPackageIncludePath
	let include_paths = map (\p -> "-I"++p) (cmdline_include_dirs 
							++ pkg_include_dirs)

	c_includes <- getPackageCIncludes
	cmdline_includes <- readState cmdline_hc_includes -- -#include options

	let cc_injects | hcc = unlines (map mk_include 
					(c_includes ++ reverse cmdline_includes))
		       | otherwise = ""
	    mk_include h_file = 
		case h_file of 
		   '"':_{-"-} -> "#include "++h_file
		   '<':_      -> "#include "++h_file
		   _          -> "#include \""++h_file++"\""

	cc_help <- newTempName "c"
	h <- openFile cc_help WriteMode
	hPutStr h cc_injects
	hPutStrLn h ("#include \"" ++ input_fn ++ "\"\n")
	hClose h

	ccout <- newTempName "ccout"

	mangle <- readIORef do_asm_mangling
	(md_c_flags, md_regd_c_flags) <- machdepCCOpts

        verb <- is_verbose

	o2 <- readIORef opt_minus_o2_for_C
	let opt_flag | o2        = "-O2"
		     | otherwise = "-O"

	pkg_extra_cc_opts <- getPackageExtraCcOpts

	excessPrecision <- readIORef excess_precision

	run_something "C Compiler"
	 (unwords ([ cc, "-x", "c", cc_help, "-o", output_fn ]
		   ++ md_c_flags
		   ++ (if cc_phase == HCc && mangle
			 then md_regd_c_flags
			 else [])
		   ++ [ verb, "-S", "-Wimplicit", opt_flag ]
		   ++ [ "-D__GLASGOW_HASKELL__="++cProjectVersionInt ]
		   ++ cc_opts
#ifdef mingw32_TARGET_OS
                   ++ [" -mno-cygwin"]
#endif
		   ++ (if excessPrecision then [] else [ "-ffloat-store" ])
		   ++ include_paths
		   ++ pkg_extra_cc_opts
--		   ++ [">", ccout]
		   ))
	return True

	-- ToDo: postprocess the output from gcc

-----------------------------------------------------------------------------
-- Mangle phase

run_phase Mangle _basename _suff input_fn output_fn
  = do mangler <- readIORef pgm_m
       mangler_opts <- getOpts opt_m
       machdep_opts <-
	 if (prefixMatch "i386" cTARGETPLATFORM)
	    then do n_regs <- readState stolen_x86_regs
		    return [ show n_regs ]
	    else return []
       run_something "Assembly Mangler"
	(unwords (mangler : 
		     mangler_opts
		  ++ [ input_fn, output_fn ]
		  ++ machdep_opts
		))
       return True

-----------------------------------------------------------------------------
-- Splitting phase

run_phase SplitMangle _basename _suff input_fn _output_fn
  = do  splitter <- readIORef pgm_s

	-- this is the prefix used for the split .s files
	tmp_pfx <- readIORef v_TmpDir
	x <- getProcessID
	let split_s_prefix = tmp_pfx ++ "/ghc" ++ show x
	writeIORef split_prefix split_s_prefix
	addFilesToClean [split_s_prefix ++ "__*"] -- d:-)

	-- allocate a tmp file to put the no. of split .s files in (sigh)
	n_files <- newTempName "n_files"

	run_something "Split Assembly File"
	 (unwords [ splitter
		  , input_fn
		  , split_s_prefix
		  , n_files ]
	 )

	-- save the number of split files for future references
	s <- readFile n_files
	let n = read s :: Int
	writeIORef n_split_files n
	return True

-----------------------------------------------------------------------------
-- As phase

run_phase As _basename _suff input_fn output_fn
  = do 	as <- readIORef pgm_a
        as_opts <- getOpts opt_a

        cmdline_include_paths <- readIORef include_paths
        let cmdline_include_flags = map (\p -> "-I"++p) cmdline_include_paths
        run_something "Assembler"
	   (unwords (as : as_opts
		       ++ cmdline_include_flags
		       ++ [ "-c", input_fn, "-o",  output_fn ]
		    ))
	return True

run_phase SplitAs basename _suff _input_fn _output_fn
  = do  as <- readIORef pgm_a
        as_opts <- getOpts opt_a

	split_s_prefix <- readIORef split_prefix
	n <- readIORef n_split_files

	odir <- readIORef output_dir
	let real_odir = case odir of
				Nothing -> basename
				Just d  -> d

	let assemble_file n = do
		    let input_s  = split_s_prefix ++ "__" ++ show n ++ ".s"
		    let output_o = newdir real_odir 
					(basename ++ "__" ++ show n ++ ".o")
		    real_o <- osuf_ify output_o
		    run_something "Assembler" 
			    (unwords (as : as_opts
				      ++ [ "-c", "-o", real_o, input_s ]
			    ))
	
	mapM_ assemble_file [1..n]
	return True

-----------------------------------------------------------------------------
-- Linking

doLink :: [String] -> IO ()
doLink o_files = do
    ln <- readIORef pgm_l
    verb <- is_verbose
    o_file <- readIORef output_file
    let output_fn = case o_file of { Just s -> s; Nothing -> "a.out"; }

    pkg_lib_paths <- getPackageLibraryPath
    let pkg_lib_path_opts = map ("-L"++) pkg_lib_paths

    lib_paths <- readIORef library_paths
    let lib_path_opts = map ("-L"++) lib_paths

    pkg_libs <- getPackageLibraries
    let pkg_lib_opts = map (\lib -> "-l"++lib) pkg_libs

    libs <- readIORef cmdline_libraries
    let lib_opts = map ("-l"++) (reverse libs)
	 -- reverse because they're added in reverse order from the cmd line

    pkg_extra_ld_opts <- getPackageExtraLdOpts

	-- probably _stub.o files
    extra_ld_inputs <- readIORef ld_inputs

	-- opts from -optl-<blah>
    extra_ld_opts <- getStaticOpts opt_l

    run_something "Linker"
       (unwords 
	 ([ ln, verb, "-o", output_fn ]
	 ++ o_files
	 ++ extra_ld_inputs
	 ++ lib_path_opts
	 ++ lib_opts
	 ++ pkg_lib_path_opts
	 ++ pkg_lib_opts
	 ++ pkg_extra_ld_opts
	 ++ extra_ld_opts
	)
       )

-----------------------------------------------------------------------------
-- Just preprocess a file, put the result in a temp. file (used by the
-- compilation manager during the summary phase).

preprocess :: FilePath -> IO FilePath
preprocess filename =
  ASSERT(haskellish_file filename) 
  do pipeline <- genPipeline (StopBefore Hsc) ("preprocess") filename
     runPipeline pipeline filename False{-no linking-} False{-no -o flag-}
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-----------------------------------------------------------------------------
-- Compile a single module.
--
-- 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.

compile :: Finder                  -- to find modules
        -> ModSummary              -- summary, including source
        -> Maybe ModIFace          -- old interface, if available
        -> HomeSymbolTable         -- for home module ModDetails          
        -> PersistentCompilerState -- persistent compiler state
        -> IO CompResult

compile finder summary old_iface hst pcs = do 
   verb <- readIORef verbose
   when verb (hPutStrLn stderr ("compile: compiling " ++ 
				name_of_summary summary))

   init_dyn_flags <- readIORef v_InitDynFlags
   writeIORef v_DynFlags init_dyn_flags
   
   let input_fn = case ms_ppsource summary of
			Just (ppsource, fingerprint) -> ppsource
			Nothing -> hs_file (ms_location summary)

   when verb (hPutStrLn stderr ("compile: input file " ++ input_fn))

   opts <- getOptionsFromSource input_fn
   processArgs dynamic_flags opts []
   dyn_flags <- readIORef v_DynFlags

   output_fn <- case hsc_lang of
		    HscAsm         -> newTempName (phaseInputExt As)
		    HscC           -> newTempName (phaseInputExt HCc)
        	    HscJava        -> newTempName "java" -- ToDo
		    HscInterpreter -> return (error "no output file")

   -- run the compiler
   hsc_result <- hscMain dyn_flags summary old_iface output_fn hst pcs

   case hsc_result of {
      HscErrs pcs errs warns -> return (CompErrs pcs errs warns);

      HscOK details maybe_iface 
	maybe_stub_h maybe_stub_c maybe_interpreted_code pcs warns -> do
	   
	   -- if no compilation happened, bail out early
	   case maybe_iface of {
		Nothing -> return (CompOK details Nothing pcs warns);
		Just iface -> do

	   let (basename, _) = splitFilename (hs_file (ms_location summary))
	   maybe_stub_o <- dealWithStubs basename maybe_stub_h maybe_stub_c
	   stub_unlinked <- case maybe_stub_o of
				Nothing -> []
				Just stub_o -> [ DotO stub_o ]

	   hs_unlinked <-
	     case hsc_lang of

		-- in interpreted mode, just return the compiled code
		-- as our "unlinked" object.
		HscInterpreter -> 
		    case maybe_interpreted_code of
			Just code -> return (Trees code)
			Nothing   -> panic "compile: no interpreted code"

		-- we're in batch mode: finish the compilation pipeline.
		_other -> do pipe <- genPipeline (StopBefore Ln) "" output_fn
			     o_file <- runPipeline pipe output_fn False False
			     return [ DotO o_file ]

	   let linkable = LM (moduleName (ms_mod summary)) 
				(hs_unlinked ++ stub_unlinked)

	   return (CompOK details (Just (iface, linkable)) pcs warns)
          }
   }

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

dealWithStubs basename maybe_stub_h maybe_stub_c

 = do	let stub_h = basename ++ "_stub.h"
	let stub_c = basename ++ "_stub.c"

  -- copy the .stub_h file into the current dir if necessary
	case maybe_stub_h of
	   Nothing -> return ()
	   Just tmp_stub_h -> do
	      	run_something "Copy stub .h file"
				("cp " ++ tmp_stub_h ++ ' ':stub_h)
	
			-- #include <..._stub.h> in .hc file
		addCmdlineHCInclude tmp_stub_h	-- hack

  -- copy the .stub_c file into the current dir, and compile it, if necessary
	case maybe_stub_c of
	   Nothing -> return Nothing
	   Just tmp_stub_c -> do  -- copy the _stub.c file into the current dir
		run_something "Copy stub .c file" 
		    (unwords [ 
			"rm -f", stub_c, "&&",
			"echo \'#include \""++stub_h++"\"\' >"++stub_c, " &&",
			"cat", tmp_stub_c, ">> ", stub_c
			])

			-- compile the _stub.c file w/ gcc
		pipeline <- genPipeline (StopBefore Ln) "" stub_c
		stub_o <- runPipeline pipeline stub_c False{-no linking-} 
				False{-no -o option-}

		return (Just stub_o)