{-# LANGUAGE TupleSections #-}
-----------------------------------------------------------------------------
-- |
-- Module : NgxExport.Distribution
-- Copyright : (c) Alexey Radkov 2021
-- License : BSD-style
--
-- Maintainer : alexey.radkov@gmail.com
-- Stability : experimental
-- Portability : portable
--
-- Quick and dirty build of simple shared libraries and collecting
-- dependencies. This was designed to build custom Haskell handlers for
-- <http://github.com/lyokha/nginx-haskell-module nginx-haskell-module>.
--
-----------------------------------------------------------------------------
module NgxExport.Distribution (
-- * Usage and examples
-- $usage
defaultMain
) where
import Distribution.Simple hiding (defaultMain)
import Distribution.Simple.LocalBuildInfo
import Distribution.Simple.Program.Builtin
import Distribution.Simple.Program.Run
import Distribution.Simple.Program.Db
import Distribution.Simple.Program
import Distribution.Simple.Setup
import Distribution.Types.PackageDescription
import Distribution.Types.BuildInfo
import Distribution.Types.Library
import Distribution.Verbosity
import Distribution.Pretty
import System.FilePath
import Control.Exception
import Control.Arrow
import Control.Monad
import Data.Maybe
-- $usage
--
-- This module allows for building simple shared libraries with Cabal.
--
-- Below is a simple example.
--
-- ==== File /ngx_distribution_test.hs/
-- @
-- {-\# LANGUAGE TemplateHaskell \#-}
--
-- module NgxDistributionTest where
--
-- import NgxExport
--
-- import Data.ByteString (ByteString)
-- import qualified Data.ByteString.Lazy.Char8 as C8L
-- import Data.Aeson
-- import Data.Maybe
--
-- incCnt :: ByteString -> C8L.ByteString
-- incCnt = C8L.pack . show . succ . fromMaybe (0 :: Int) . decodeStrict
-- ngxExportYY \'incCnt
-- @
--
-- ==== File /ngx-distribution-test.cabal/
-- @
-- name: ngx-distribution-test
-- version: 0.1.0.0
-- build-type: __/Custom/__
-- cabal-version: 1.20
--
-- library
-- default-language: Haskell2010
-- build-depends: base >= 4.8 && < 5
-- , ngx-export
-- , ngx-export-distribution
-- , bytestring
-- , aeson
--
-- ghc-options: -Wall -O2 -no-keep-hi-files -no-keep-o-files
-- @
--
-- ==== File /ngx-distribution-test.cabal/
-- @
-- import __/NgxExport.Distribution/__
-- main = 'defaultMain'
-- @
--
-- The configuration step requires that utilities /patchelf/ and
-- <https://github.com/lyokha/nginx-haskell-module/blob/master/utils/hslibdeps hslibdeps>
-- were found in /$PATH/.
--
-- Building is a bit cumbersome: it expects explicit option /--prefix/ at the
-- configuration step (which will be interpreted as the first part of the
-- /rpath/ by utility /hslibdeps/), and requires explicit ghc option /-o/ at
-- the build step which is as well used by /hslibdeps/ as the name of the
-- target library. The build also requires the explicit option for linkage
-- against the Haskell RTS library.
--
-- Let's build the example with commands /cabal v1-configure/ and
-- /cabal v1-build/ (the /v2-/commands should probably work as well).
--
-- > $ cabal v1-configure --prefix=/var/lib/nginx
-- > Resolving dependencies...
-- > [1 of 1] Compiling Main ( dist/setup/setup.hs, dist/setup/Main.o )
-- > Linking ./dist/setup/setup ...
-- > Configuring ngx-distribution-test-0.1.0.0...
--
-- > $ cabal v1-build --ghc-options="ngx_distribution_test.hs -o ngx_distribution_test.so -lHSrts_thr-ghc$(ghc --numeric-version)"
-- > [1 of 1] Compiling NgxDistributionTest ( ngx_distribution_test.hs, ngx_distribution_test.o )
-- > Linking ngx_distribution_test.so ...
-- > ---> Collecting libraries
-- > '/usr/lib64/libHSrts_thr-ghc8.10.5.so' -> 'x86_64-linux-ghc-8.10.5/libHSrts_thr-ghc8.10.5.so'
-- > '/home/lyokha/.cabal/lib/x86_64-linux-ghc-8.10.5/libHSngx-export-1.7.5-JzTEmHewqdC9gGi6rzcAtt-ghc8.10.5.so' -> 'x86_64-linux-ghc-8.10.5/libHSngx-export-1.7.5-JzTEmHewqdC9gGi6rzcAtt-ghc8.10.5.so'
-- > '/home/lyokha/.cabal/lib/x86_64-linux-ghc-8.10.5/libHSmonad-loops-0.4.3-8Lx5Hn3pTtO62yOPdPW77x-ghc8.10.5.so' -> 'x86_64-linux-ghc-8.10.5/libHSmonad-loops-0.4.3-8Lx5Hn3pTtO62yOPdPW77x-ghc8.10.5.so'
-- > '/home/lyokha/.cabal/lib/x86_64-linux-ghc-8.10.5/libHSasync-2.2.4-ENjuIeC23kaKyMVDRYThP3-ghc8.10.5.so' -> 'x86_64-linux-ghc-8.10.5/libHSasync-2.2.4-ENjuIeC23kaKyMVDRYThP3-ghc8.10.5.so'
-- > '/usr/lib64/libHSstm-2.5.0.1-ghc8.10.5.so' -> 'x86_64-linux-ghc-8.10.5/libHSstm-2.5.0.1-ghc8.10.5.so'
-- > '/home/lyokha/.cabal/lib/x86_64-linux-ghc-8.10.5/libHSaeson-1.5.6.0-6XeGmWHoO3vJYEUW5PXPgC-ghc8.10.5.so' -> 'x86_64-linux-ghc-8.10.5/libHSaeson-1.5.6.0-6XeGmWHoO3vJYEUW5PXPgC-ghc8.10.5.so'
-- >
-- > ...
-- >
-- > '/usr/lib64/libHSbase-4.14.2.0-ghc8.10.5.so' -> 'x86_64-linux-ghc-8.10.5/libHSbase-4.14.2.0-ghc8.10.5.so'
-- > '/usr/lib64/libHSinteger-gmp-1.0.3.0-ghc8.10.5.so' -> 'x86_64-linux-ghc-8.10.5/libHSinteger-gmp-1.0.3.0-ghc8.10.5.so'
-- > '/usr/lib64/libHSghc-prim-0.6.1-ghc8.10.5.so' -> 'x86_64-linux-ghc-8.10.5/libHSghc-prim-0.6.1-ghc8.10.5.so'
-- >
-- > ---> Patching ngx_distribution_test.so
-- > /var/lib/nginx/x86_64-linux-ghc-8.10.5:/home/lyokha/.cabal/lib/x86_64-linux-ghc-8.10.5:/usr/lib64:/usr/lib64/ghc-8.10.5/rts
--
-- Now the current working directory contains new files
-- /ngx_distribution_test.so/ and /ngx_distribution_test-0.1.0.0.tar.gz/ and a
-- new directory /x86_64-linux-ghc-8.10.5/. The tar-file contains the patched
-- shared library and the directory with dependent libraries: it is ready for
-- installation in directory /\/var\/lib\/nginx/ at the target system.
--
-- With this building approach, the following list of drawbacks must be taken
-- into account.
--
-- 1. Utility /hslibdeps/ collects only libraries prefixed with /libHS/.
-- 2. Command /cabal v1-clean/ only deletes directory /dist/, it does not
-- delete build artifacts in the current working directory.
-- 3. Behavior of Cabal commands other than /configure/, /build/ and /clean/ is
-- not well defined.
data LibNameNotSpecified = LibNameNotSpecified
instance Exception LibNameNotSpecified
instance Show LibNameNotSpecified where
show = const "Error: the library name was not specified, \
\the name must be passed in ghc with option -o"
hslibdeps :: Program
hslibdeps = simpleProgram "hslibdeps"
patchelf :: Program
patchelf = simpleProgram "patchelf"
buildAndHslibdeps :: Verbosity -> PackageDescription -> LocalBuildInfo ->
BuildFlags -> IO ()
buildAndHslibdeps verbosity desc lbi flags = do
let configGhcOptions =
map (("ghc", ) . pure) . concatMap snd
. filter (\(c, o) -> c == GHC && not (null o)) $
perCompilerFlavorToList $
options $ libBuildInfo $ fromJust $ library desc
lib = fst $
foldl (\a@(r, ready) (prog, v) ->
if prog /= "ghc" || null v || isJust r
then a
else let v' = head v
in if v' == "-o"
then (Nothing, True)
else if ready
then (Just v', False)
else (Nothing, False)
) (Nothing, False) $
buildProgramArgs flags ++ configGhcOptions
env = map (second fromPathTemplate) $
compilerTemplateEnv (compilerInfo $ compiler lbi) ++
platformTemplateEnv (hostPlatform lbi)
dir = maybeUnknown (lookup ArchVar env) ++
'-' : maybeUnknown (lookup OSVar env) ++
'-' : maybeUnknown (lookup CompilerVar env)
dirArg = "-d" : [dir]
maybeUnknown = fromMaybe "unknown"
rpathArg = maybe [] (("-t" :) . pure . (</> dir) . fromPathTemplate) $
flagToMaybe $ prefix $ configInstallDirs $ configFlags lbi
when (isNothing lib) $ throwIO LibNameNotSpecified
let lib' = fromJust lib
plbi = withPrograms lbi
ghcP <- fst <$> requireProgram verbosity ghcProgram plbi
let ghcR = programInvocation ghcP $ ["-dynamic", "-shared", "-fPIC"] ++
map (head . snd) configGhcOptions
runProgramInvocation verbosity ghcR
hslibdepsP <- fst <$> requireProgram verbosity hslibdeps plbi
let hslibdepsR = programInvocation hslibdepsP $ lib' : rpathArg ++ dirArg
runProgramInvocation verbosity hslibdepsR
tarP <- fst <$> requireProgram verbosity tarProgram plbi
let ver = pkgVersion $ package desc
tar = addExtension (takeBaseName lib' ++ '-' : prettyShow ver) "tar.gz"
tarR = programInvocation tarP ["czf", tar, lib', dir]
runProgramInvocation verbosity tarR
ngxExportHooks :: UserHooks
ngxExportHooks =
let hooks = simpleUserHooks
in hooks { hookedPrograms = [hslibdeps]
, confHook = \desc flags -> do
let pdb = configPrograms flags
_ <- requireProgram normal hslibdeps pdb >>=
requireProgram normal patchelf . snd
confHook simpleUserHooks desc flags
, buildHook = \desc lbi _ flags ->
buildAndHslibdeps normal desc lbi flags
}
-- | A simple implementation of /main/ for a Cabal setup script.
defaultMain :: IO ()
defaultMain = defaultMainWithHooks ngxExportHooks