module CodeOutput( codeOutput, outputForeignStubs ) where

#include "HsVersions.h"

import AsmCodeGen ( nativeCodeGen )
import LlvmCodeGen ( llvmCodeGen )

import UniqSupply       ( mkSplitUniqSupply )

import Finder           ( mkStubPaths )
import PprC             ( writeCs )
import OldCmmLint       ( cmmLint )
import Packages
import OldCmm           ( RawCmmGroup )
import HscTypes
import DynFlags
import Config
import SysTools
import Stream           (Stream)
import qualified Stream

import ErrUtils
import Outputable
import Module
import SrcLoc

import Control.Exception
import System.Directory
import System.FilePath
import System.IO

codeOutput :: DynFlags
           -> Module
           -> ModLocation
           -> ForeignStubs
           -> [PackageId]
           -> Stream IO RawCmmGroup ()                       -- Compiled C--
           -> IO (Bool{-stub_h_exists-}, Maybe FilePath{-stub_c_exists-})

codeOutput dflags this_mod location foreign_stubs pkg_deps cmm_stream
  = 
    do  {
        -- Lint each CmmGroup as it goes past
        ; let linted_cmm_stream =
                 if dopt Opt_DoCmmLinting dflags
                    then Stream.mapM do_lint cmm_stream
                    else cmm_stream

              do_lint cmm = do
                { showPass dflags "CmmLint"
                ; case cmmLint (targetPlatform dflags) cmm of
                        Just err -> do { log_action dflags dflags SevDump noSrcSpan defaultDumpStyle err
                                       ; ghcExit dflags 1
                                       }
                        Nothing  -> return ()
                ; return cmm
                }

        ; showPass dflags "CodeOutput"
        ; let filenm = hscOutName dflags 
        ; stubs_exist <- outputForeignStubs dflags this_mod location foreign_stubs
        ; case hscTarget dflags of {
             HscInterpreted -> return ();
             HscAsm         -> outputAsm dflags filenm linted_cmm_stream;
             HscC           -> outputC dflags filenm linted_cmm_stream pkg_deps;
             HscLlvm        -> outputLlvm dflags filenm linted_cmm_stream;
             HscNothing     -> panic "codeOutput: HscNothing"
          }
        ; return stubs_exist
        }

doOutput :: String -> (Handle -> IO ()) -> IO ()
doOutput filenm io_action = bracket (openFile filenm WriteMode) hClose io_action

outputC :: DynFlags
        -> FilePath
        -> Stream IO RawCmmGroup ()
        -> [PackageId]
        -> IO ()

outputC dflags filenm cmm_stream packages
  = do 
       -- ToDo: make the C backend consume the C-- incrementally, by
       -- pushing the cmm_stream inside (c.f. nativeCodeGen)
       rawcmms <- Stream.collect cmm_stream

       -- figure out which header files to #include in the generated .hc file:
       --
       --   * extra_includes from packages
       --   * -#include options from the cmdline and OPTIONS pragmas
       --   * the _stub.h file, if there is one.
       --
       let rts = getPackageDetails (pkgState dflags) rtsPackageId
                       
       let cc_injects = unlines (map mk_include (includes rts))
           mk_include h_file = 
            case h_file of 
               '"':_{-"-} -> "#include "++h_file
               '<':_      -> "#include "++h_file
               _          -> "#include \""++h_file++"\""

       pkg_configs <- getPreloadPackagesAnd dflags packages
       let pkg_names = map (display.sourcePackageId) pkg_configs

       doOutput filenm $ \ h -> do
          hPutStr h ("/* GHC_PACKAGES " ++ unwords pkg_names ++ "\n*/\n")
          hPutStr h cc_injects
          writeCs dflags h rawcmms

outputAsm :: DynFlags -> FilePath -> Stream IO RawCmmGroup () -> IO ()
outputAsm dflags filenm cmm_stream
 | cGhcWithNativeCodeGen == "YES"
  = do ncg_uniqs <- mkSplitUniqSupply 'n'

       {-# SCC "OutputAsm" #-} doOutput filenm $
           \f -> {-# SCC "NativeCodeGen" #-}
                 nativeCodeGen dflags f ncg_uniqs cmm_stream

 | otherwise
  = panic "This compiler was built without a native code generator"

outputLlvm :: DynFlags -> FilePath -> Stream IO RawCmmGroup () -> IO ()
outputLlvm dflags filenm cmm_stream
  = do ncg_uniqs <- mkSplitUniqSupply 'n'

       -- ToDo: make the LLVM backend consume the C-- incrementally,
       -- by pushing the cmm_stream inside (c.f. nativeCodeGen)
       rawcmms <- Stream.collect cmm_stream

       {-# SCC "llvm_output" #-} doOutput filenm $
           \f -> {-# SCC "llvm_CodeGen" #-}
                 llvmCodeGen dflags f ncg_uniqs rawcmms

outputForeignStubs :: DynFlags -> Module -> ModLocation -> ForeignStubs
                   -> IO (Bool,         -- Header file created
                          Maybe FilePath) -- C file created
outputForeignStubs dflags mod location stubs
 = do
   let stub_h = mkStubPaths dflags (moduleName mod) location
   stub_c <- newTempName dflags "c"

   case stubs of
     NoStubs -> do
        -- When compiling External Core files, may need to use stub
        -- files from a previous compilation
        stub_h_exists <- doesFileExist stub_h
        return (stub_h_exists, Nothing)

     ForeignStubs h_code c_code -> do
        let
            stub_c_output_d = pprCode CStyle c_code
            stub_c_output_w = showSDoc dflags stub_c_output_d
        
            -- Header file protos for "foreign export"ed functions.
            stub_h_output_d = pprCode CStyle h_code
            stub_h_output_w = showSDoc dflags stub_h_output_d

        createDirectoryIfMissing True (takeDirectory stub_h)

        dumpIfSet_dyn dflags Opt_D_dump_foreign
                      "Foreign export header file" stub_h_output_d

        -- we need the #includes from the rts package for the stub files
        let rts_includes = 
               let rts_pkg = getPackageDetails (pkgState dflags) rtsPackageId in
               concatMap mk_include (includes rts_pkg)
            mk_include i = "#include \"" ++ i ++ "\"\n"

            -- wrapper code mentions the ffi_arg type, which comes from ffi.h
            ffi_includes | cLibFFI   = "#include \"ffi.h\"\n"
                         | otherwise = ""

        stub_h_file_exists
           <- outputForeignStubs_help stub_h stub_h_output_w
                ("#include \"HsFFI.h\"\n" ++ cplusplus_hdr) cplusplus_ftr

        dumpIfSet_dyn dflags Opt_D_dump_foreign
                      "Foreign export stubs" stub_c_output_d

        stub_c_file_exists
           <- outputForeignStubs_help stub_c stub_c_output_w
                ("#define IN_STG_CODE 0\n" ++ 
                 "#include \"Rts.h\"\n" ++
                 rts_includes ++
                 ffi_includes ++
                 cplusplus_hdr)
                 cplusplus_ftr
           -- We're adding the default hc_header to the stub file, but this
           -- isn't really HC code, so we need to define IN_STG_CODE==0 to
           -- avoid the register variables etc. being enabled.

        return (stub_h_file_exists, if stub_c_file_exists
                                       then Just stub_c
                                       else Nothing )
 where
   cplusplus_hdr = "#ifdef __cplusplus\nextern \"C\" {\n#endif\n"
   cplusplus_ftr = "#ifdef __cplusplus\n}\n#endif\n"


-- Don't use doOutput for dumping the f. export stubs
-- since it is more than likely that the stubs file will
-- turn out to be empty, in which case no file should be created.
outputForeignStubs_help :: FilePath -> String -> String -> String -> IO Bool
outputForeignStubs_help _fname ""      _header _footer = return False
outputForeignStubs_help fname doc_str header footer
   = do writeFile fname (header ++ doc_str ++ '\n':footer ++ "\n")
        return True