root/compiler/main/CodeOutput.lhs

%
% (c) The GRASP/AQUA Project, Glasgow University, 1993-1998
%
\section{Code output phase}

\begin{code}
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 OldCmm           ( RawCmmGroup )
import HscTypes
import DynFlags
import Config
import SysTools

import ErrUtils         ( dumpIfSet_dyn, showPass, ghcExit )
import Outputable
import Module
import Maybes           ( firstJusts )

import Control.Exception
import Control.Monad
import System.Directory
import System.FilePath
import System.IO
\end{code}

%************************************************************************
%*                                                                      *
\subsection{Steering}
%*                                                                      *
%************************************************************************

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

codeOutput dflags this_mod location foreign_stubs pkg_deps flat_abstractC
  = 
    do  { when (dopt Opt_DoCmmLinting dflags) $ do
                { showPass dflags "CmmLint"
                ; let lints = map (cmmLint (targetPlatform dflags)) flat_abstractC
                ; case firstJusts lints of
                        Just err -> do { printDump err
                                       ; ghcExit dflags 1
                                       }
                        Nothing  -> return ()
                }

        ; 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 flat_abstractC;
             HscC           -> outputC dflags filenm flat_abstractC pkg_deps;
             HscLlvm        -> outputLlvm dflags filenm flat_abstractC;
             HscNothing     -> panic "codeOutput: HscNothing"
          }
        ; return stubs_exist
        }

doOutput :: String -> (Handle -> IO ()) -> IO ()
doOutput filenm io_action = bracket (openFile filenm WriteMode) hClose io_action
\end{code}


%************************************************************************
%*                                                                      *
\subsection{C}
%*                                                                      *
%************************************************************************

\begin{code}
outputC :: DynFlags
        -> FilePath
        -> [RawCmmGroup]
        -> [PackageId]
        -> IO ()

outputC dflags filenm flat_absC packages
  = do 
       -- 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 flat_absC
\end{code}


%************************************************************************
%*                                                                      *
\subsection{Assembler}
%*                                                                      *
%************************************************************************

\begin{code}
outputAsm :: DynFlags -> FilePath -> [RawCmmGroup] -> IO ()
outputAsm dflags filenm flat_absC
 | cGhcWithNativeCodeGen == "YES"
  = do ncg_uniqs <- mkSplitUniqSupply 'n'

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

 | otherwise
  = panic "This compiler was built without a native code generator"
\end{code}


%************************************************************************
%*                                                                      *
\subsection{LLVM}
%*                                                                      *
%************************************************************************

\begin{code}
outputLlvm :: DynFlags -> FilePath -> [RawCmmGroup] -> IO ()
outputLlvm dflags filenm flat_absC
  = do ncg_uniqs <- mkSplitUniqSupply 'n'
       {-# SCC "llvm_output" #-} doOutput filenm $
           \f -> {-# SCC "llvm_CodeGen" #-}
                 llvmCodeGen dflags f ncg_uniqs flat_absC
\end{code}


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

\begin{code}
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 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 stub_h_output_d
        -- in

        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
\end{code}