-- The Timber compiler <timber-lang.org>
--
-- Copyright 2008-2009 Johan Nordlander <nordland@csee.ltu.se>
-- All rights reserved.
-- 
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that the following conditions
-- are met:
-- 
-- 1. Redistributions of source code must retain the above copyright
--    notice, this list of conditions and the following disclaimer.
-- 
-- 2. Redistributions in binary form must reproduce the above copyright
--    notice, this list of conditions and the following disclaimer in the
--    documentation and/or other materials provided with the distribution.
-- 
-- 3. Neither the names of the copyright holder and any identified
--    contributors, nor the names of their affiliations, may be used to 
--    endorse or promote products derived from this software without 
--    specific prior written permission.
-- 
-- THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND ANY EXPRESS
-- OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-- WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-- DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR
-- ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-- DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-- OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-- HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
-- STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
-- ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-- POSSIBILITY OF SUCH DAMAGE.

--------------------------------------------------------------------------
--
-- Execution control.
--
-- This module contains an interface to the backend and functions to
-- control the execution of the compiler. 
--
---------------------------------------------------------------------------

module Execution (
                  abortCompiler,
                  stopCompiler,
                  compileC,
                  linkO,
                 ) where
    
import System                 (system, exitWith, ExitCode(..))
import qualified Monad
import qualified Directory
import Common

-- Timber compiler
import Config
import Name


-- | Compile a C-file. 
compileC cfg clo c_file = do
                             let cmd = cCompiler cfg
                                     ++ " -c " ++ compileFlags cfg
                                     ++ " -I " ++ libDir clo ++ " " 
                                     ++ " -I " ++ includeDir clo ++ " " 
                                     ++ " -I " ++ rtsDir clo ++ " " 
                                     ++ " -I . "
                                     ++ c_file
                                 o_file = rmSuffix ".c" (rmDirs c_file) ++ ".o"
                             res <- checkUpToDate c_file o_file
                             if not res then do
                                putStrLn ("[compiling "++c_file++"]")
                                execCmd clo cmd
                              else return ()
  where checkUpToDate c_file o_file
                        = do o_exists <- Directory.doesFileExist o_file
                             if not o_exists then
                                return False
                               else do
                                 c_time  <- Directory.getModificationTime c_file
                                 o_time  <- Directory.getModificationTime o_file
                                 return (c_time <= o_time)

-- | Link together a bunch of object files.
linkO cfg clo r o_files = do let Just rmod  = fromMod r
                                 rootId     = name2str r
                                 initId     = "_init_" ++ map f rmod
                                 f '\''     = '_'
                                 f c        = c
                             let cmd = cCompiler cfg
                                       ++ linkFlags cfg
                                       ++ compileFlags cfg
                                       ++ " -o " ++ outfile clo ++ " "
                                       ++ unwords o_files ++ " "
                                       ++ " -L" ++ rtsDir clo ++ " " 
                                       ++ " -I" ++ includeDir clo ++ " " 
                                       ++ " -I" ++ libDir clo ++ " " 
                                       ++ " -I " ++ rtsDir clo ++ " " 
                                       ++ " -DROOT=" ++ rootId ++ " "
                                       ++ " -DROOTINIT=" ++ initId ++ " "
                                       ++ rtsMain clo 
                                       ++ linkLibs cfg
                             putStrLn "[linking]"
                             execCmd clo cmd


-- | Return with exit code /= 0
abortCompiler         = exitWith (ExitFailure 1)

-- | Return with exit code == 0
stopCompiler          = exitWith (ExitSuccess)

execCmd clo cmd       = do Monad.when (isVerbose clo)
                                    (putStrLn ("exec: " ++ show cmd))
                           exitCode <- system $ cmd     
                           case exitCode of
                             ExitSuccess -> return ()
                             _           -> stopCompiler