Override Cabal's library visibility check on GHC <8.8

GHC <8.8 isn't able to read the "visibility" field from the package database, since it's built against an older Cabal. For this reason, using multiple public libraries with it did not work (all sublibraries appeared as private). This patch makes cabal-install override Cabal's library visibility checks when GHC is older than 8.8, extending the multiple libraries feature compatibiliy to older GHCs.
haskell · May 22, 2020 · fa9e5fc · fa9e5fc
1 parent 03dd11a
commit fa9e5fc
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Showing 5 changed files with 14 additions and 15 deletions.
diff --git a/Cabal/Distribution/Simple/Compiler.hs b/Cabal/Distribution/Simple/Compiler.hs
@@ -63,6 +63,7 @@ module Distribution.Simple.Compiler (
         backpackSupported,
         arResponseFilesSupported,
         libraryDynDirSupported,
+        libraryVisibilitySupported,
 
         -- * Support for profiling detail levels
         ProfDetailLevel(..),
@@ -380,6 +381,15 @@ profilingSupported comp =
     GHCJS -> True
     _     -> False
 
+-- | Does this compiler support a package database entry with:
+-- "visibility"?
+libraryVisibilitySupported :: Compiler -> Bool
+libraryVisibilitySupported comp = case compilerFlavor comp of
+  GHC -> v >= mkVersion [8,8]
+  _   -> False
+ where
+  v = compilerVersion comp
+
 -- | Utility function for GHC only features
 ghcSupported :: String -> Compiler -> Bool
 ghcSupported key comp =

diff --git a/cabal-install/Distribution/Client/ProjectPlanning.hs b/cabal-install/Distribution/Client/ProjectPlanning.hs
@@ -3412,9 +3412,7 @@ setupHsConfigureFlags (ReadyPackage elab@ElaboratedConfiguredPackage{..})
     configUserInstall         = mempty -- don't rely on defaults
     configPrograms_           = mempty -- never use, shouldn't exist
     configUseResponseFiles    = mempty
-    -- TODO set to true when the solver can prevent private-library-deps by itself
-    -- (issue #6039)
-    configAllowDependingOnPrivateLibs = mempty
+    configAllowDependingOnPrivateLibs = Flag $ not $ libraryVisibilitySupported pkgConfigCompiler
 
 setupHsConfigureArgs :: ElaboratedConfiguredPackage
                      -> [String]

diff --git a/cabal-testsuite/PackageTests/MultipleLibraries/Successful/cabal.test.hs b/cabal-testsuite/PackageTests/MultipleLibraries/Successful/cabal.test.hs
@@ -1,7 +1,4 @@
 import Test.Cabal.Prelude
-main = cabalTest $ do
-    -- https://github.com/haskell/cabal/pull/6047 should make this work for older GHCs too?
-    skipIf =<< ghcVersionIs (< mkVersion [8,8])
-
+main = cabalTest $
     cabal' "v2-run" ["pkg-abc:program"] >>= assertOutputContains "pkg-def:publib"
 
diff --git a/cabal-testsuite/PackageTests/MultipleLibraries/T6083Pre/cabal.test.hs b/cabal-testsuite/PackageTests/MultipleLibraries/T6083Pre/cabal.test.hs
@@ -2,8 +2,5 @@ import Test.Cabal.Prelude
 
 -- https://github.com/haskell/cabal/issues/6083
 -- see pkg-abc.cabal
-main = cabalTest $ do
-    -- https://github.com/haskell/cabal/pull/6047 should make this work for older GHCs too?
-    skipIf =<< ghcVersionIs (< mkVersion [8,8])
-
+main = cabalTest $
     cabal' "v2-run" ["pkg-abc:program"] >>= assertOutputContains "pkg-abc:pkg-def"
diff --git a/cabal-testsuite/PackageTests/MultipleLibraries/T6083PreMixin/cabal.test.hs b/cabal-testsuite/PackageTests/MultipleLibraries/T6083PreMixin/cabal.test.hs
@@ -2,8 +2,5 @@ import Test.Cabal.Prelude
 
 -- This is like T6083Pre, but also goes via mixins
 --
-main = cabalTest $ do
-    -- https://github.com/haskell/cabal/pull/6047 should make this work for older GHCs too?
-    skipIf =<< ghcVersionIs (< mkVersion [8,8])
-
+main = cabalTest $
     cabal' "v2-run" ["pkg-abc:program"] >>= assertOutputContains "pkg-abc:pkg-def"