module Kempe.Proc.Nasm ( writeO
                       ) where

import           Data.Functor              (void)
import qualified Data.Text.Lazy.IO         as TLIO
import           Prettyprinter             (Doc, layoutCompact)
import           Prettyprinter.Render.Text (renderLazy)
import           System.IO                 (hFlush)
import           System.IO.Temp            (withSystemTempFile)
import           System.Process            (CreateProcess (..), StdStream (Inherit), proc, readCreateProcess)

-- | Assemble using @nasm@, output in some file.
writeO :: Doc ann
       -> FilePath
       -> Bool -- ^ Debug symbols?
       -> IO ()
writeO p fpO dbg = withSystemTempFile "kmp.S" $ \fp h -> do
    let txt = renderLazy $ layoutCompact p
    TLIO.hPutStr h txt
    hFlush h
    let debugFlag = if dbg then ("-g":) else id
    -- -O1 is signed byte optimization but no multi-passes
    void $ readCreateProcess ((proc "nasm" (debugFlag [fp, "-f", "elf64", "-O1", "-o", fpO])) { std_err = Inherit }) ""