hadrian: Disable ghci libraries when object merging is not available

3 files changed, 19 insertions, 5 deletions

diff --git a/hadrian/src/Oracles/Flag.hs b/hadrian/src/Oracles/Flag.hs
index 40ae3e8f9b..7c05be5a68 100644
--- a/hadrian/src/Oracles/Flag.hs
+++ b/hadrian/src/Oracles/Flag.hs
@@ -1,8 +1,11 @@
 {-# LANGUAGE MultiWayIf #-}
 
 module Oracles.Flag (
-    Flag (..), flag, getFlag, platformSupportsSharedLibs,
-    targetSupportsSMP, useLibffiForAdjustors
+    Flag (..), flag, getFlag,
+    platformSupportsSharedLibs,
+    platformSupportsGhciObjects,
+    targetSupportsSMP,
+    useLibffiForAdjustors
     ) where
 
 import Hadrian.Oracles.TextFile
@@ -60,6 +63,12 @@ flag f = do
 getFlag :: Flag -> Expr c b Bool
 getFlag = expr . flag
 
+-- | Does the platform support object merging (and therefore we can build GHCi objects
+-- when appropriate).
+platformSupportsGhciObjects :: Action Bool
+platformSupportsGhciObjects =
+    not . null <$> settingsFileSetting SettingsFileSetting_MergeObjectsCommand
+
 platformSupportsSharedLibs :: Action Bool
 platformSupportsSharedLibs = do
     windows       <- isWinTarget
diff --git a/hadrian/src/Rules/Register.hs b/hadrian/src/Rules/Register.hs
index cefdf04cb7..c510e96c02 100644
--- a/hadrian/src/Rules/Register.hs
+++ b/hadrian/src/Rules/Register.hs
@@ -9,6 +9,7 @@ import Expression ( getContextData )
 import Hadrian.BuildPath
 import Hadrian.Expression
 import Hadrian.Haskell.Cabal
+import Oracles.Flag (platformSupportsGhciObjects)
 import Packages
 import Rules.Rts
 import {-# SOURCE #-} Rules.Library (needLibrary)
@@ -206,12 +207,14 @@ extraTargets context
 -- | Given a library 'Package' this action computes all of its targets. Needing
 -- all the targets should build the library such that it is ready to be
 -- registered into the package database.
--- See 'packageTargets' for the explanation of the @includeGhciLib@ parameter.
+-- See 'Rules.packageTargets' for the explanation of the @includeGhciLib@
+-- parameter.
 libraryTargets :: Bool -> Context -> Action [FilePath]
 libraryTargets includeGhciLib context@Context {..} = do
     libFile  <- pkgLibraryFile     context
     ghciLib  <- pkgGhciLibraryFile context
-    ghci     <- if includeGhciLib && not (wayUnit Dynamic way)
+    ghciObjsSupported <- platformSupportsGhciObjects
+    ghci     <- if ghciObjsSupported && includeGhciLib && not (wayUnit Dynamic way)
                 then interpretInContext context $ getContextData buildGhciLib
                 else return False
     extra    <- extraTargets context
diff --git a/hadrian/src/Settings/Builders/Cabal.hs b/hadrian/src/Settings/Builders/Cabal.hs
index 1ef20147ae..c6a83ce12b 100644
--- a/hadrian/src/Settings/Builders/Cabal.hs
+++ b/hadrian/src/Settings/Builders/Cabal.hs
@@ -139,6 +139,7 @@ libraryArgs = do
     package     <- getPackage
     withGhci    <- expr ghcWithInterpreter
     dynPrograms <- expr (flavour >>= dynamicGhcPrograms)
+    ghciObjsSupported <- expr platformSupportsGhciObjects
     let ways = flavourWays ++ [contextWay]
         hasVanilla = vanilla `elem` ways
         hasProfiling = any (wayUnit Profiling) ways
@@ -149,7 +150,8 @@ libraryArgs = do
          , if hasProfiling
            then  "--enable-library-profiling"
            else "--disable-library-profiling"
-         , if (hasVanilla || hasProfiling) &&
+         , if ghciObjsSupported &&
+              (hasVanilla || hasProfiling) &&
               package /= rts && withGhci && not dynPrograms
            then  "--enable-library-for-ghci"
            else "--disable-library-for-ghci"