{-
(c) The GRASP/AQUA Project, Glasgow University, 1993-1998

\section{Code output phase}
-}

{-# LANGUAGE CPP #-}

module CodeOutput( codeOutput, outputForeignStubs ) where

#include "HsVersions.h"

import AsmCodeGen ( nativeCodeGen )
import LlvmCodeGen ( llvmCodeGen )

import UniqSupply       ( mkSplitUniqSupply )

import Finder           ( mkStubPaths )
import PprC             ( writeCs )
import CmmLint          ( cmmLint )
import Packages
import Cmm              ( 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
import Control.Monad (forM)

{-
************************************************************************
*                                                                      *
\subsection{Steering}
*                                                                      *
************************************************************************
-}

codeOutput :: DynFlags
           -> Module
           -> FilePath
           -> ModLocation
           -> ForeignStubs
           -> [(ForeignSrcLang, String)]
           -- ^ additional files to be compiled with with the C compiler
           -> [InstalledUnitId]
           -> Stream IO RawCmmGroup ()                       -- Compiled C--
           -> IO (FilePath,
                  (Bool{-stub_h_exists-}, Maybe FilePath{-stub_c_exists-}),
                  [(ForeignSrcLang, FilePath)]{-foreign_fps-})

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

              do_lint cmm = withTiming (pure dflags)
                                       (text "CmmLint"<+>brackets (ppr this_mod))
                                       (const ()) $ do
                { case cmmLint dflags cmm of
                        Just err -> do { log_action dflags
                                                   dflags
                                                   NoReason
                                                   SevDump
                                                   noSrcSpan
                                                   (defaultDumpStyle dflags)
                                                   err
                                       ; ghcExit dflags 1
                                       }
                        Nothing  -> return ()
                ; return cmm
                }

        ; stubs_exist <- outputForeignStubs dflags this_mod location foreign_stubs
        ; foreign_fps <- forM foreign_files $ \(lang, file_contents) -> do
            { fp <- outputForeignFile dflags lang file_contents;
            ; return (lang, fp);
            }
        ; case hscTarget dflags of {
             HscAsm         -> outputAsm dflags this_mod location filenm
                                         linted_cmm_stream;
             HscC           -> outputC dflags filenm linted_cmm_stream pkg_deps;
             HscLlvm        -> outputLlvm dflags filenm linted_cmm_stream;
             HscInterpreted -> panic "codeOutput: HscInterpreted";
             HscNothing     -> panic "codeOutput: HscNothing"
          }
        ; return (filenm, stubs_exist, foreign_fps)
        }

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

{-
************************************************************************
*                                                                      *
\subsection{C}
*                                                                      *
************************************************************************
-}

outputC :: DynFlags
        -> FilePath
        -> Stream IO RawCmmGroup ()
        -> [InstalledUnitId]
        -> 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 dflags rtsUnitId

       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++"\""

       let pkg_names = map installedUnitIdString packages

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

{-
************************************************************************
*                                                                      *
\subsection{Assembler}
*                                                                      *
************************************************************************
-}

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

       debugTraceMsg dflags 4 (text "Outputing asm to" <+> text filenm)

       _ <- {-# SCC "OutputAsm" #-} doOutput filenm $
           \h -> {-# SCC "NativeCodeGen" #-}
                 nativeCodeGen dflags this_mod location h ncg_uniqs cmm_stream
       return ()

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

{-
************************************************************************
*                                                                      *
\subsection{LLVM}
*                                                                      *
************************************************************************
-}

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

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

{-
************************************************************************
*                                                                      *
\subsection{Foreign import/export}
*                                                                      *
************************************************************************
-}

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 ->
        return (False, 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 dflags rtsUnitId 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

outputForeignFile :: DynFlags -> ForeignSrcLang -> String -> IO FilePath
outputForeignFile dflags lang file_contents
 = do
   extension <- case lang of
     LangC -> return "c"
     LangCxx -> return "cpp"
     LangObjc -> return "m"
     LangObjcxx -> return "mm"
   fp <- newTempName dflags extension
   writeFile fp file_contents
   return fp
