Always pass ghc-options (backport #8717)

Cabal/src/Distribution/Simple/GHC.hs

@@ -689,7 +689,7 @@ libAbiHash verbosity _pkg_descr lbi lib clbi = do
           , ghcOptFPic = toFlag True
           , ghcOptHiSuffix = toFlag "dyn_hi"
           , ghcOptObjSuffix = toFlag "dyn_o"
-          , ghcOptExtra = hcSharedOptions GHC libBi
+          , ghcOptExtra = hcOptions GHC libBi ++ hcSharedOptions GHC libBi
           }
     profArgs =
       vanillaArgs
@@ -701,7 +701,7 @@ libAbiHash verbosity _pkg_descr lbi lib clbi = do
                 (withProfLibDetail lbi)
           , ghcOptHiSuffix = toFlag "p_hi"
           , ghcOptObjSuffix = toFlag "p_o"
-          , ghcOptExtra = hcProfOptions GHC libBi
+          , ghcOptExtra = hcOptions GHC libBi ++ hcProfOptions GHC libBi
           }
     ghcArgs
       | withVanillaLib lbi = vanillaArgs

Cabal/src/Distribution/Simple/GHCJS.hs

@@ -569,7 +569,7 @@ buildOrReplLib mReplFlags verbosity numJobs _pkg_descr lbi lib clbi = do
             , ghcOptFPic = toFlag True
             , --  ghcOptHiSuffix    = toFlag "dyn_hi",
               --  ghcOptObjSuffix   = toFlag "dyn_o",
-              ghcOptExtra = hcSharedOptions GHC libBi
+              ghcOptExtra = hcOptions GHC libBi ++ hcSharedOptions GHC libBi
             , ghcOptHPCDir = hpcdir Hpc.Dyn
             }
 
@@ -758,7 +758,7 @@ buildOrReplLib mReplFlags verbosity numJobs _pkg_descr lbi lib clbi = do
               , ghcOptDynLinkMode = toFlag GhcDynamicOnly
               , ghcOptInputFiles = toNubListR dynamicObjectFiles
               , ghcOptOutputFile = toFlag sharedLibFilePath
-              , ghcOptExtra = hcSharedOptions GHC libBi
+              , ghcOptExtra = hcOptions GHC libBi ++ hcSharedOptions GHC libBi
               , -- For dynamic libs, Mac OS/X needs to know the install location
                 -- at build time. This only applies to GHC < 7.8 - see the
                 -- discussion in #1660.
@@ -1309,7 +1309,7 @@ gbuild verbosity numJobs pkg_descr lbi bm clbi = do
               ghcOptFPic = toFlag True
             , ghcOptHiSuffix = toFlag "dyn_hi"
             , ghcOptObjSuffix = toFlag "dyn_o"
-            , ghcOptExtra = hcSharedOptions GHC bnfo
+            , ghcOptExtra = hcOptions GHC bnfo ++ hcSharedOptions GHC bnfo
             , ghcOptHPCDir = hpcdir Hpc.Dyn
             }
       dynTooOpts =
@@ -1743,7 +1743,7 @@ libAbiHash verbosity _pkg_descr lbi lib clbi = do
           , ghcOptFPic = toFlag True
           , ghcOptHiSuffix = toFlag "js_dyn_hi"
           , ghcOptObjSuffix = toFlag "js_dyn_o"
-          , ghcOptExtra = hcSharedOptions GHC libBi
+          , ghcOptExtra = hcOptions GHC libBi ++ hcSharedOptions GHC libBi
           }
     profArgs =
       vanillaArgs

changelog.d/pr-8717

@@ -0,0 +1,25 @@
+synopsis: Always pass `ghc-options` to GHC
+packages: Cabal
+prs: #8717
+issues:
+
+description: {
+
+Previously, options set in the package field `ghc-options` would not be passed
+to GHC during the link phase for shared objects (where multiple `.o` or
+`.dyn_o` files are merged into a single object file). This made it impossible
+to use `ghc-options` to use a different linker by setting (for example)
+`ghc-options: -optl-fuse-ld=mold -optlm-fuse-ld=mold`; the options would be
+dropped in the link phase, falling back to the default linker.
+
+It was possible to work around this by duplicating the `ghc-options` to
+`ghc-shared-options`, which _are_ passed in the shared link phase, but that had
+the (undocumented and unfortunate) side-effect of disabling the GHC
+`-dynamic-too` flag, effectively doubling compilation times when
+`ghc-shared-options` are set.
+
+Now, `ghc-options` are combined with `ghc-shared-options` (to accurately
+reflect the documentation on this feature) and the fact that
+`ghc-shared-options` disables `-dynamic-too` is documented.
+
+}