Use GHC to compile C files

src/Builder.hs

@@ -15,8 +15,8 @@ import Stage
 -- * Extracting source dependencies, e.g. by passing @-M@ command line argument;
 -- * Linking object files & static libraries into an executable.
 -- We have CcMode for C compiler and GhcMode for GHC.
-data CcMode  = CompileC  | FindCDependencies deriving (Eq, Generic, Show)
-data GhcMode = CompileHs | FindHsDependencies | LinkHs
+data CcMode  = CompileC | FindCDependencies deriving (Eq, Generic, Show)
+data GhcMode = CompileCWithGhc | CompileHs | FindHsDependencies | LinkHs
     deriving (Eq, Generic, Show)
 
 -- | GhcPkg can initialise a package database and register packages in it.

src/Rules/Compile.hs

@@ -28,9 +28,9 @@ compilePackage rs context@Context {..} = do
             buildWithResources rs $ Target context (Ghc CompileHs stage) [src] [obj]
 
     priority 2.0 $ do
-        nonHs "c"   %> compile (Cc  CompileC ) (obj2src "c"   isGeneratedCFile  )
-        nonHs "cmm" %> compile (Ghc CompileHs) (obj2src "cmm" isGeneratedCmmFile)
-        nonHs "s"   %> compile (Ghc CompileHs) (obj2src "S"   $ const False     )
+        nonHs "c"   %> compile (Ghc CompileCWithGhc) (obj2src "c"   isGeneratedCFile  )
+        nonHs "cmm" %> compile (Ghc CompileHs)       (obj2src "cmm" isGeneratedCmmFile)
+        nonHs "s"   %> compile (Ghc CompileHs)       (obj2src "S"   $ const False     )
 
     -- TODO: Add dependencies for #include of .h and .hs-incl files (gcc -MM?).
     [ path <//> "*" <.> suf way | suf <- [    osuf,     hisuf] ] &%> compileHs

src/Settings/Builders/Ghc.hs

@@ -1,4 +1,7 @@
-module Settings.Builders.Ghc (ghcBuilderArgs, ghcMBuilderArgs, haddockGhcArgs) where
+module Settings.Builders.Ghc (
+  ghcBuilderArgs, ghcMBuilderArgs, haddockGhcArgs,
+  ghcCbuilderArgs
+) where
 
 import Flavour
 import GHC
@@ -15,6 +18,25 @@ ghcBuilderArgs = (builder (Ghc CompileHs) ||^ builder (Ghc LinkHs)) ? do
             , append =<< getInputs
             , arg "-o", arg =<< getOutput ]
 
+ghcCbuilderArgs :: Args
+ghcCbuilderArgs =
+  builder (Ghc CompileCWithGhc) ? do
+    way <- getWay
+    let ccArgs = [ append =<< getPkgDataList CcArgs
+                 , getSettingList . ConfCcArgs =<< getStage
+                 , cIncludeArgs
+                 , arg "-Werror"
+                 , Dynamic `wayUnit` way ? append [ "-fPIC", "-DDYNAMIC" ] ]
+
+    mconcat [ arg "-Wall"
+            , ghcLinkArgs
+            , commonGhcArgs
+            , mconcat (map (map ("-optc" ++) <$>) ccArgs)
+            , arg "-c"
+            , append =<< getInputs
+            , arg "-o"
+            , arg =<< getOutput ]
+
 ghcLinkArgs :: Args
 ghcLinkArgs = builder (Ghc LinkHs) ? do
     stage   <- getStage

src/Settings/Default.hs

@@ -212,6 +212,7 @@ defaultBuilderArgs = mconcat
     , deriveConstantsBuilderArgs
     , genPrimopCodeBuilderArgs
     , ghcBuilderArgs
+    , ghcCbuilderArgs
     , ghcCabalBuilderArgs
     , ghcCabalHsColourBuilderArgs
     , ghcMBuilderArgs

src/Settings/Packages/Base.hs

@@ -7,4 +7,4 @@ import Settings
 basePackageArgs :: Args
 basePackageArgs = package base ? mconcat
     [ builder GhcCabal ? arg ("--flags=" ++ integerLibraryName)
-    , builder Cc ? arg "-O2" ] -- Fix the 'unknown symbol stat' issue, see #259.
+    , builder (Ghc CompileCWithGhc) ? arg "-optc-O2" ] -- Fix the 'unknown symbol stat' issue, see #259.

src/Settings/Packages/Rts.hs

@@ -48,8 +48,7 @@ rtsPackageArgs = package rts ? do
     ffiIncludeDir  <- getSetting FfiIncludeDir
     ffiLibraryDir  <- getSetting FfiLibDir
     ghclibDir      <- expr installGhcLibDir
-    mconcat
-        [ builder Cc ? mconcat
+    let cArgs =
           [ arg "-Irts"
           , arg $ "-I" ++ path
           , arg $ "-DRtsWay=\"rts_" ++ show way ++ "\""
@@ -96,8 +95,10 @@ rtsPackageArgs = package rts ? do
                 append [ "-Wno-incompatible-pointer-types" ]
             ]
 
+    mconcat
+        [ builder (Cc FindCDependencies) ? mconcat cArgs
+        , builder (Ghc CompileCWithGhc) ? mconcat (map (map ("-optc" ++) <$>) cArgs)
         , builder Ghc ? arg "-Irts"
-
         , builder HsCpp ? append
           [ "-DTOP="             ++ show top
           , "-DFFI_INCLUDE_DIR=" ++ show ffiIncludeDir