Add --enable-library-bytecode option for building bytecode libraries

Cabal-syntax/src/Distribution/Types/InstalledPackageInfo.hs

@@ -73,6 +73,7 @@ data InstalledPackageInfo = InstalledPackageInfo
   , libraryDirs :: [FilePath]
   , libraryDirsStatic :: [FilePath]
   , libraryDynDirs :: [FilePath]
+  , libraryBytecodeDirs :: [FilePath]
   -- ^ overrides 'libraryDirs'
   , dataDir :: FilePath
   , hsLibraries :: [String]
@@ -160,6 +161,7 @@ emptyInstalledPackageInfo =
     , hsLibraries = []
     , extraLibraries = []
     , extraLibrariesStatic = []
+    , libraryBytecodeDirs = []
     , extraGHCiLibraries = []
     , includeDirs = []
     , includes = []

Cabal-syntax/src/Distribution/Types/InstalledPackageInfo/FieldGrammar.hs

@@ -108,6 +108,7 @@ ipiFieldGrammar =
     <@> monoidalFieldAla "library-dirs" (alaList' FSep FilePathNT) L.libraryDirs
     <@> monoidalFieldAla "library-dirs-static" (alaList' FSep FilePathNT) L.libraryDirsStatic
     <@> monoidalFieldAla "dynamic-library-dirs" (alaList' FSep FilePathNT) L.libraryDynDirs
+    <@> monoidalFieldAla "bytecode-library-dirs" (alaList' FSep FilePathNT) L.libraryBytecodeDirs
     <@> optionalFieldDefAla "data-dir" FilePathNT L.dataDir ""
     <@> monoidalFieldAla "hs-libraries" (alaList' FSep Token) L.hsLibraries
     <@> monoidalFieldAla "extra-libraries" (alaList' FSep Token) L.extraLibraries

Cabal-syntax/src/Distribution/Types/InstalledPackageInfo/Lens.hs

@@ -123,6 +123,10 @@ libraryDynDirs :: Lens' InstalledPackageInfo [FilePath]
 libraryDynDirs f s = fmap (\x -> s{T.libraryDynDirs = x}) (f (T.libraryDynDirs s))
 {-# INLINE libraryDynDirs #-}
 
+libraryBytecodeDirs :: Lens' InstalledPackageInfo [FilePath]
+libraryBytecodeDirs f s = fmap (\x -> s{T.libraryBytecodeDirs = x}) (f (T.libraryBytecodeDirs s))
+{-# INLINE libraryBytecodeDirs #-}
+
 dataDir :: Lens' InstalledPackageInfo FilePath
 dataDir f s = fmap (\x -> s{T.dataDir = x}) (f (T.dataDir s))
 {-# INLINE dataDir #-}

Cabal-tests/tests/ParserTests/ipi/Includes2.expr

@@ -54,6 +54,7 @@ InstalledPackageInfo {
   libraryDynDirs =
   [
     "/home/travis/build/haskell/cabal/cabal-testsuite/PackageTests/Backpack/Includes2/cabal-internal.dist/work/./dist/build/x86_64-linux/ghc-8.2.2/Includes2-0.1.0.0/l/mylib/Includes2-0.1.0.0-inplace-mylib+3gY9SyjX86dBypHcOaev1n/build/Includes2-0.1.0.0-inplace-mylib+3gY9SyjX86dBypHcOaev1n"],
+  libraryBytecodeDirs = [],
   dataDir =
   "/home/travis/build/haskell/cabal/cabal-testsuite/PackageTests/Backpack/Includes2",
   hsLibraries = [

Cabal-tests/tests/ParserTests/ipi/internal-preprocessor-test.expr

@@ -47,6 +47,7 @@ InstalledPackageInfo {
     "/home/ogre/Documents/other-haskell/cabal/cabal-testsuite/PackageTests/CustomPreProcess/setup.dist/work/dist/build"],
   libraryDirsStatic = [],
   libraryDynDirs = [],
+  libraryBytecodeDirs = [],
   dataDir =
   "/home/ogre/Documents/other-haskell/cabal/cabal-testsuite/PackageTests/CustomPreProcess",
   hsLibraries = [

Cabal-tests/tests/ParserTests/ipi/issue-2276-ghc-9885.expr

@@ -153,6 +153,7 @@ InstalledPackageInfo {
   libraryDirsStatic = [],
   libraryDynDirs = [
     "/opt/ghc/8.2.2/lib/ghc-8.2.2/transformers-0.5.2.0"],
+  libraryBytecodeDirs = [],
   dataDir =
   "/opt/ghc/8.2.2/share/x86_64-linux-ghc-8.2.2/transformers-0.5.2.0",
   hsLibraries = [

Cabal-tests/tests/ParserTests/ipi/transformers.expr

@@ -153,6 +153,7 @@ InstalledPackageInfo {
   libraryDirsStatic = [],
   libraryDynDirs = [
     "/opt/ghc/8.2.2/lib/ghc-8.2.2/transformers-0.5.2.0"],
+  libraryBytecodeDirs = [],
   dataDir =
   "/opt/ghc/8.2.2/share/x86_64-linux-ghc-8.2.2/transformers-0.5.2.0",
   hsLibraries = [

Cabal-tests/tests/UnitTests/Distribution/Utils/Structured.hs

@@ -33,4 +33,4 @@ md5CheckGenericPackageDescription proxy = md5Check proxy
 
 md5CheckLocalBuildInfo :: Proxy LocalBuildInfo -> Assertion
 md5CheckLocalBuildInfo proxy = md5Check proxy
-    0xc35a236a684a15b35690edb21c305eba
+    0xf46cd0819435850a64242cab0fc7aa4b

Cabal/src/Distribution/Simple/BuildPaths.hs

@@ -42,6 +42,7 @@ module Distribution.Simple.BuildPaths
   , mkSharedLibName
   , mkProfSharedLibName
   , mkStaticLibName
+  , mkBytecodeLibName
   , mkGenericSharedBundledLibName
   , exeExtension
   , objExtension
@@ -409,6 +410,9 @@ mkStaticLibName platform (CompilerId compilerFlavor compilerVersion) lib =
   where
     comp = prettyShow compilerFlavor ++ prettyShow compilerVersion
 
+mkBytecodeLibName :: CompilerId -> UnitId -> String
+mkBytecodeLibName _comp lib = getHSLibraryName lib <.> ".bytecodelib"
+
 -- | Create a library name for a bundled shared library from a given name.
 -- This matches the naming convention for shared libraries as implemented in
 -- GHC's packageHsLibs function in the Packages module.

Cabal/src/Distribution/Simple/BuildWay.hs

@@ -1,14 +1,21 @@
 {-# LANGUAGE LambdaCase #-}
 
-module Distribution.Simple.BuildWay where
+module Distribution.Simple.BuildWay
+  ( BuildWay (..)
+  , buildWayObjectExtension
+  , buildWayInterfaceExtension
+  ) where
 
 data BuildWay = StaticWay | DynWay | ProfWay | ProfDynWay
   deriving (Eq, Ord, Show, Read, Enum)
 
--- | Returns the object/interface extension prefix for the given build way (e.g. "dyn_" for 'DynWay')
-buildWayPrefix :: BuildWay -> String
-buildWayPrefix = \case
-  StaticWay -> ""
-  ProfWay -> "p_"
-  DynWay -> "dyn_"
-  ProfDynWay -> "p_dyn_"
+-- | Returns the object extension for the given build way (e.g. "dyn_o" for 'DynWay' on ELF)
+buildWayObjectExtension :: String -> BuildWay -> String
+buildWayObjectExtension ext = \case
+  StaticWay -> ext
+  ProfWay -> "p_" ++ ext
+  DynWay -> "dyn_" ++ ext
+  ProfDynWay -> "p_dyn_" ++ ext
+
+buildWayInterfaceExtension :: BuildWay -> String
+buildWayInterfaceExtension = buildWayObjectExtension "hi"

Cabal/src/Distribution/Simple/Compiler.hs

@@ -79,6 +79,7 @@ module Distribution.Simple.Compiler
   , profilingVanillaSupported
   , profilingVanillaSupportedOrUnknown
   , dynamicSupported
+  , bytecodeArtifactsSupported
   , backpackSupported
   , arResponseFilesSupported
   , arDashLSupported
@@ -575,6 +576,14 @@ profilingDynamicSupportedOrUnknown comp =
 dynamicSupported :: Compiler -> Maybe Bool
 dynamicSupported comp = waySupported "dyn" comp
 
+-- | Does the compiler support producing bytecode objects and bytecode libraries?
+bytecodeArtifactsSupported :: Compiler -> Bool
+bytecodeArtifactsSupported comp
+  | GHC <- compilerFlavor comp
+  , compilerVersion comp >= mkVersion [9, 15, 0] =
+      True
+  | otherwise = False
+
 -- | Does this compiler support a package database entry with:
 -- "visibility"?
 libraryVisibilitySupported :: Compiler -> Bool

Cabal/src/Distribution/Simple/Configure.hs

@@ -751,6 +751,9 @@ computeLocalBuildConfig cfg comp programDb = do
         -- into a huge .a archive) via GHCs -staticlib flag.
         fromFlagOrDefault False $ configStaticLib cfg
 
+      withBytecodeLib_ =
+        fromFlagOrDefault False $ configBytecodeLib cfg
+
       withDynExe_ = fromFlag $ configDynExe cfg
 
       withFullyStaticExe_ = fromFlag $ configFullyStaticExe cfg
@@ -778,12 +781,22 @@ computeLocalBuildConfig cfg comp programDb = do
   strip_lib <- strip_libexe "library" configStripLibs
   strip_exe <- strip_libexe "executable" configStripExes
 
+  checkedWithBytecodeLib <-
+    if bytecodeArtifactsSupported comp
+      then return withBytecodeLib_
+      else do
+        when withBytecodeLib_ $
+          warn verbosity $
+            "This compiler does not support bytecode libraries; ignoring --enable-library-bytecode"
+        return False
+
   let buildOptions =
         setCoverage . setProfiling $
           LBC.BuildOptions
             { withVanillaLib = fromFlag $ configVanillaLib cfg
             , withSharedLib = withSharedLib_
             , withStaticLib = withStaticLib_
+            , withBytecodeLib = checkedWithBytecodeLib
             , withDynExe = withDynExe_
             , withFullyStaticExe = withFullyStaticExe_
             , withProfLib = False

Cabal/src/Distribution/Simple/Errors.hs

@@ -170,6 +170,7 @@ data CabalException
   | MissingCoveredInstalledLibrary UnitId
   | SetupHooksException SetupHooksException
   | MultiReplDoesNotSupportComplexReexportedModules PackageName ComponentName
+  | StandaloneBytecodeNotSupportedYet
   deriving (Show)
 
 exceptionCode :: CabalException -> Int
@@ -304,6 +305,7 @@ exceptionCode e = case e of
   SetupHooksException err ->
     setupHooksExceptionCode err
   MultiReplDoesNotSupportComplexReexportedModules{} -> 9355
+  StandaloneBytecodeNotSupportedYet -> 9356
 
 versionRequirement :: VersionRange -> String
 versionRequirement range
@@ -804,3 +806,8 @@ exceptionMessage e = case e of
       ++ prettyShow pname
       ++ " a module renaming was found.\n"
       ++ "Multi-repl does not work with complicated reexported-modules until GHC-9.12."
+  StandaloneBytecodeNotSupportedYet ->
+    unlines $
+      [ "The ecosystem doesn't support building packages with just bytecode libraries yet."
+      , "If you have run into this error, please comment on issue #11471"
+      ]

Cabal/src/Distribution/Simple/GHC.hs

@@ -986,6 +986,8 @@ installLib verbosity lbi targetDir dynlibTargetDir _builtDir pkg lib clbi = do
 
   -- copy the built library files over:
   when (has_code && hasLib) $ do
+    whenBytecodeLib $ installOrdinary builtDir targetDir bytecodeLibName
+
     forM_ libWays $ \w -> case w of
       StaticWay -> do
         sequence_
@@ -1095,6 +1097,7 @@ installLib verbosity lbi targetDir dynlibTargetDir _builtDir pkg lib clbi = do
     platform = hostPlatform lbi
     uid = componentUnitId clbi
     profileLibName = mkProfLibName uid
+    bytecodeLibName = mkBytecodeLibName compiler_id uid
     ghciLibName = Internal.mkGHCiLibName uid
     ghciProfLibName = Internal.mkGHCiProfLibName uid
 
@@ -1111,6 +1114,7 @@ installLib verbosity lbi targetDir dynlibTargetDir _builtDir pkg lib clbi = do
       _ -> False
     has_code = not (componentIsIndefinite clbi)
     whenGHCi = when (hasLib && withGHCiLib lbi && has_code)
+    whenBytecodeLib = when (hasLib && withBytecodeLib lbi && has_code)
 
 -- -----------------------------------------------------------------------------
 -- Registering

Cabal/src/Distribution/Simple/GHC/Build/Link.hs

@@ -279,6 +279,9 @@ linkLibrary buildTargetDir cleanedExtraLibDirs pkg_descr verbosity runGhcProg li
     staticLibFilePath =
       buildTargetDir
         </> makeRelativePathEx (mkStaticLibName (hostPlatform lbi) compiler_id uid)
+    bytecodeLibFilePath =
+      buildTargetDir
+        </> makeRelativePathEx (mkBytecodeLibName compiler_id uid)
     ghciLibFilePath = buildTargetDir </> makeRelativePathEx (Internal.mkGHCiLibName uid)
     ghciProfLibFilePath = buildTargetDir </> makeRelativePathEx (Internal.mkGHCiProfLibName uid)
     libInstallPath =
@@ -295,23 +298,29 @@ linkLibrary buildTargetDir cleanedExtraLibDirs pkg_descr verbosity runGhcProg li
       libInstallPath
         </> mkProfSharedLibName (hostPlatform lbi) compiler_id uid
 
-    getObjFiles :: BuildWay -> IO [SymbolicPath Pkg File]
-    getObjFiles way =
+    getObjWayFiles :: BuildWay -> IO [SymbolicPath Pkg File]
+    getObjWayFiles w = getObjFiles (buildWayObjectExtension objExtension w) (buildWayObjectExtension objExtension w)
+
+    getObjBytecodeWayFiles :: BuildWay -> IO [SymbolicPath Pkg File]
+    getObjBytecodeWayFiles companion_way = getObjFiles "gbc" (buildWayObjectExtension objExtension companion_way)
+
+    getObjFiles :: String -> String -> IO [SymbolicPath Pkg File]
+    getObjFiles hs_ext obj_ext =
       mconcat
         [ Internal.getHaskellObjects
             implInfo
             lib
             lbi
             clbi
             buildTargetDir
-            (buildWayPrefix way ++ objExtension)
+            hs_ext
             True
-        , pure $ map (srcObjPath way) extraSources
+        , pure $ map (srcObjPath obj_ext) extraSources
         , catMaybes
             <$> sequenceA
               [ findFileCwdWithExtension
                 mbWorkDir
-                [Suffix $ buildWayPrefix way ++ objExtension]
+                [Suffix $ obj_ext]
                 [buildTargetDir]
                 xPath
               | ghcVersion < mkVersion [7, 2] -- ghc-7.2+ does not make _stub.o files
@@ -323,16 +332,16 @@ linkLibrary buildTargetDir cleanedExtraLibDirs pkg_descr verbosity runGhcProg li
 
     -- Get the @.o@ path from a source path (e.g. @.hs@),
     -- in the library target build directory.
-    srcObjPath :: BuildWay -> SymbolicPath Pkg File -> SymbolicPath Pkg File
-    srcObjPath way srcPath =
+    srcObjPath :: String -> SymbolicPath Pkg File -> SymbolicPath Pkg File
+    srcObjPath obj_ext srcPath =
       case symbolicPathRelative_maybe objPath of
         -- Absolute path: should already be in the target build directory
         -- (e.g. a preprocessed file)
         -- TODO: assert this?
         Nothing -> objPath
         Just objRelPath -> coerceSymbolicPath buildTargetDir </> objRelPath
       where
-        objPath = srcPath `replaceExtensionSymbolicPath` (buildWayPrefix way ++ objExtension)
+        objPath = srcPath `replaceExtensionSymbolicPath` obj_ext
 
     -- I'm fairly certain that, just like the executable, we can keep just the
     -- module input list, and point to the right sources dir (as is already
@@ -343,6 +352,7 @@ linkLibrary buildTargetDir cleanedExtraLibDirs pkg_descr verbosity runGhcProg li
     -- we could more easily merge the two.
     --
     -- Right now, instead, we pass the path to each object file.
+    ghcBaseLinkArgs :: GhcOptions
     ghcBaseLinkArgs =
       mempty
         { -- TODO: This basically duplicates componentGhcOptions.
@@ -435,11 +445,17 @@ linkLibrary buildTargetDir cleanedExtraLibDirs pkg_descr verbosity runGhcProg li
         , -- TODO: Shouldn't this use cleanedExtraLibDirsStatic instead?
           ghcOptLinkLibPath = toNubListR $ cleanedExtraLibDirs
         }
+    ghcBytecodeLinkArgs objectFiles =
+      (ghcSharedLinkArgs objectFiles)
+        { ghcOptBytecodeLib = toFlag True
+        , ghcOptInputFiles = toNubListR $ map coerceSymbolicPath objectFiles
+        , ghcOptOutputFile = toFlag bytecodeLibFilePath
+        }
 
-  staticObjectFiles <- getObjFiles StaticWay
-  profObjectFiles <- getObjFiles ProfWay
-  dynamicObjectFiles <- getObjFiles DynWay
-  profDynamicObjectFiles <- getObjFiles ProfDynWay
+  staticObjectFiles <- getObjWayFiles StaticWay
+  profObjectFiles <- getObjWayFiles ProfWay
+  dynamicObjectFiles <- getObjWayFiles DynWay
+  profDynamicObjectFiles <- getObjWayFiles ProfDynWay
 
   let
     linkWay = \case
@@ -457,6 +473,10 @@ linkLibrary buildTargetDir cleanedExtraLibDirs pkg_descr verbosity runGhcProg li
         runGhcProg $ ghcProfSharedLinkArgs profDynamicObjectFiles
       DynWay -> do
         runGhcProg $ ghcSharedLinkArgs dynamicObjectFiles
+        -- The .gbc files were built with DynWay if both are enabled.
+        when (withBytecodeLib lbi) $ do
+          bytecodeObjectFiles <- getObjBytecodeWayFiles DynWay
+          runGhcProg $ ghcBytecodeLinkArgs bytecodeObjectFiles
       StaticWay -> do
         when (withVanillaLib lbi) $ do
           Ar.createArLibArchive verbosity lbi vanillaLibFilePath staticObjectFiles
@@ -470,6 +490,10 @@ linkLibrary buildTargetDir cleanedExtraLibDirs pkg_descr verbosity runGhcProg li
               staticObjectFiles
         when (withStaticLib lbi) $ do
           runGhcProg $ ghcStaticLinkArgs staticObjectFiles
+        -- The .gbc files were built with DynWay if both are enabled.
+        when (withBytecodeLib lbi && (DynWay `notElem` wantedWays)) $ do
+          bytecodeObjectFiles <- getObjBytecodeWayFiles StaticWay
+          runGhcProg $ ghcBytecodeLinkArgs bytecodeObjectFiles
 
   -- ROMES: Why exactly branch on staticObjectFiles, rather than any other build
   -- kind that we might have wanted instead?