Fix #6083: allow depending on public sublibrary with pkg:lib qualified syntax

cabal-install/Distribution/Client/Dependency.hs

@@ -91,8 +91,6 @@ import qualified Distribution.PackageDescription as PD
 import qualified Distribution.PackageDescription.Configuration as PD
 import Distribution.PackageDescription.Configuration
          ( finalizePD )
-import Distribution.Client.PackageUtils
-         ( externalBuildDepends )
 import Distribution.Compiler
          ( CompilerInfo(..) )
 import Distribution.System
@@ -890,22 +888,27 @@ showPackageProblem (InvalidDep dep pkgid) =
 configuredPackageProblems :: Platform -> CompilerInfo
                           -> SolverPackage UnresolvedPkgLoc -> [PackageProblem]
 configuredPackageProblems platform cinfo
-  (SolverPackage pkg specifiedFlags stanzas specifiedDeps' _specifiedExeDeps') =
+  (SolverPackage pkg specifiedFlags stanzas specifiedDeps0  _specifiedExeDeps') =
      [ DuplicateFlag flag
      | flag <- PD.findDuplicateFlagAssignments specifiedFlags ]
   ++ [ MissingFlag flag | OnlyInLeft  flag <- mergedFlags ]
   ++ [ ExtraFlag   flag | OnlyInRight flag <- mergedFlags ]
   ++ [ DuplicateDeps pkgs
      | pkgs <- CD.nonSetupDeps (fmap (duplicatesBy (comparing packageName))
-                                specifiedDeps) ]
+                                specifiedDeps1) ]
   ++ [ MissingDep dep       | OnlyInLeft  dep       <- mergedDeps ]
   ++ [ ExtraDep       pkgid | OnlyInRight     pkgid <- mergedDeps ]
   ++ [ InvalidDep dep pkgid | InBoth      dep pkgid <- mergedDeps
                             , not (packageSatisfiesDependency pkgid dep) ]
   -- TODO: sanity tests on executable deps
   where
-    specifiedDeps :: ComponentDeps [PackageId]
-    specifiedDeps = fmap (map solverSrcId) specifiedDeps'
+    thisPkgName = packageName (packageDescription pkg)
+
+    specifiedDeps1 :: ComponentDeps [PackageId]
+    specifiedDeps1 = fmap (map solverSrcId) specifiedDeps0
+
+    specifiedDeps :: [PackageId]
+    specifiedDeps = CD.flatDeps specifiedDeps1
 
     mergedFlags = mergeBy compare
       (sort $ map PD.flagName (PD.genPackageFlags (packageDescription pkg)))
@@ -919,7 +922,7 @@ configuredPackageProblems platform cinfo
     dependencyName (Dependency name _ _) = name
 
     mergedDeps :: [MergeResult Dependency PackageId]
-    mergedDeps = mergeDeps requiredDeps (CD.flatDeps specifiedDeps)
+    mergedDeps = mergeDeps requiredDeps specifiedDeps
 
     mergeDeps :: [Dependency] -> [PackageId]
               -> [MergeResult Dependency PackageId]
@@ -947,7 +950,15 @@ configuredPackageProblems platform cinfo
          []
          (packageDescription pkg) of
         Right (resolvedPkg, _) ->
-             externalBuildDepends resolvedPkg compSpec
+            -- we filter self/internal dependencies. They are still there.
+            -- This is INCORRECT.
+            --
+            -- If we had per-component solver, it would make this unnecessary,
+            -- but no finalizePDs picks components we are not building, eg. exes.
+            -- See #3775
+            --
+            filter ((/= thisPkgName) . dependencyName)
+                (PD.enabledBuildDepends resolvedPkg compSpec)
           ++ maybe [] PD.setupDepends (PD.setupBuildInfo resolvedPkg)
         Left  _ ->
           error "configuredPackageInvalidDeps internal error"

cabal-install/Distribution/Solver/Modular/IndexConversion.hs

@@ -17,7 +17,6 @@ import Distribution.Simple.BuildToolDepends          -- from Cabal
 import Distribution.Types.ExeDependency              -- from Cabal
 import Distribution.Types.PkgconfigDependency        -- from Cabal
 import Distribution.Types.ComponentName              -- from Cabal
-import Distribution.Types.UnqualComponentName        -- from Cabal
 import Distribution.Types.CondTree                   -- from Cabal
 import Distribution.Types.MungedPackageId            -- from Cabal
 import Distribution.Types.MungedPackageName          -- from Cabal
@@ -181,19 +180,11 @@ convGPD os arch cinfo constraints strfl solveExes pn
   let
     fds  = flagInfo strfl flags
 
-    -- | We have to be careful to filter out dependencies on
-    -- internal libraries, since they don't refer to real packages
-    -- and thus cannot actually be solved over.  We'll do this
-    -- by creating a set of package names which are "internal"
-    -- and dropping them as we convert.
-
-    ipns = S.fromList $ [ unqualComponentNameToPackageName nm
-                        | (nm, _) <- sub_libs ]
 
     conv :: Monoid a => Component -> (a -> BuildInfo) -> DependencyReason PN ->
             CondTree ConfVar [Dependency] a -> FlaggedDeps PN
     conv comp getInfo dr =
-        convCondTree M.empty dr pkg os arch cinfo pn fds comp getInfo ipns solveExes .
+        convCondTree M.empty dr pkg os arch cinfo pn fds comp getInfo solveExes .
         addBuildableCondition getInfo
 
     initDR = DependencyReason pn M.empty S.empty
@@ -331,41 +322,29 @@ flagInfo (StrongFlags strfl) =
     weak m = WeakOrTrivial $ not (strfl || m)
     flagType m = if m then Manual else Automatic
 
--- | Internal package names, which should not be interpreted as true
--- dependencies.
-type IPNs = S.Set PN
-
--- | Convenience function to delete a 'Dependency' if it's
--- for a 'PN' that isn't actually real.
-filterIPNs :: IPNs -> Dependency -> Maybe Dependency
-filterIPNs ipns d@(Dependency pn _ _)
-    | S.notMember pn ipns = Just d
-    | otherwise           = Nothing
-
 -- | Convert condition trees to flagged dependencies.  Mutually
 -- recursive with 'convBranch'.  See 'convBranch' for an explanation
 -- of all arguments preceding the input 'CondTree'.
 convCondTree :: Map FlagName Bool -> DependencyReason PN -> PackageDescription -> OS -> Arch -> CompilerInfo -> PN -> FlagInfo ->
                 Component ->
                 (a -> BuildInfo) ->
-                IPNs ->
                 SolveExecutables ->
                 CondTree ConfVar [Dependency] a -> FlaggedDeps PN
-convCondTree flags dr pkg os arch cinfo pn fds comp getInfo ipns solveExes@(SolveExecutables solveExes') (CondNode info ds branches) =
+convCondTree flags dr pkg os arch cinfo pn fds comp getInfo solveExes@(SolveExecutables solveExes') (CondNode info ds branches) =
              -- Merge all library and build-tool dependencies at every level in
              -- the tree of flagged dependencies. Otherwise 'extractCommon'
              -- could create duplicate dependencies, and the number of
              -- duplicates could grow exponentially from the leaves to the root
              -- of the tree.
              mergeSimpleDeps $
                  [ D.Simple singleDep comp
-                 | dep <- mapMaybe (filterIPNs ipns) ds
+                 | dep <- ds
                  , singleDep <- convLibDeps dr dep ]  -- unconditional package dependencies
 
               ++ L.map (\e -> D.Simple (LDep dr (Ext  e)) comp) (allExtensions bi) -- unconditional extension dependencies
               ++ L.map (\l -> D.Simple (LDep dr (Lang l)) comp) (allLanguages  bi) -- unconditional language dependencies
               ++ L.map (\(PkgconfigDependency pkn vr) -> D.Simple (LDep dr (Pkg pkn vr)) comp) (pkgconfigDepends bi) -- unconditional pkg-config dependencies
-              ++ concatMap (convBranch flags dr pkg os arch cinfo pn fds comp getInfo ipns solveExes) branches
+              ++ concatMap (convBranch flags dr pkg os arch cinfo pn fds comp getInfo solveExes) branches
               -- build-tools dependencies
               -- NB: Only include these dependencies if SolveExecutables
               -- is True.  It might be false in the legacy solver
@@ -481,14 +460,13 @@ convBranch :: Map FlagName Bool
            -> FlagInfo
            -> Component
            -> (a -> BuildInfo)
-           -> IPNs
            -> SolveExecutables
            -> CondBranch ConfVar [Dependency] a
            -> FlaggedDeps PN
-convBranch flags dr pkg os arch cinfo pn fds comp getInfo ipns solveExes (CondBranch c' t' mf') =
+convBranch flags dr pkg os arch cinfo pn fds comp getInfo solveExes (CondBranch c' t' mf') =
     go c'
-       (\flags' dr' ->           convCondTree flags' dr' pkg os arch cinfo pn fds comp getInfo ipns solveExes  t')
-       (\flags' dr' -> maybe [] (convCondTree flags' dr' pkg os arch cinfo pn fds comp getInfo ipns solveExes) mf')
+       (\flags' dr' ->           convCondTree flags' dr' pkg os arch cinfo pn fds comp getInfo solveExes  t')
+       (\flags' dr' -> maybe [] (convCondTree flags' dr' pkg os arch cinfo pn fds comp getInfo solveExes) mf')
        flags dr
   where
     go :: Condition ConfVar

cabal-install/cabal-install.cabal

@@ -225,7 +225,6 @@ executable cabal
         Distribution.Client.NixStyleOptions
         Distribution.Client.Outdated
         Distribution.Client.PackageHash
-        Distribution.Client.PackageUtils
         Distribution.Client.ParseUtils
         Distribution.Client.ProjectBuilding
         Distribution.Client.ProjectBuilding.Types

cabal-install/cabal-install.cabal.dev

@@ -217,7 +217,6 @@ library cabal-lib-client
         Distribution.Client.NixStyleOptions
         Distribution.Client.Outdated
         Distribution.Client.PackageHash
-        Distribution.Client.PackageUtils
         Distribution.Client.ParseUtils
         Distribution.Client.ProjectBuilding
         Distribution.Client.ProjectBuilding.Types

cabal-install/cabal-install.cabal.prod

@@ -225,7 +225,6 @@ executable cabal
         Distribution.Client.NixStyleOptions
         Distribution.Client.Outdated
         Distribution.Client.PackageHash
-        Distribution.Client.PackageUtils
         Distribution.Client.ParseUtils
         Distribution.Client.ProjectBuilding
         Distribution.Client.ProjectBuilding.Types

cabal-install/cabal-install.cabal.zinza

@@ -161,7 +161,6 @@ Version:            3.3.0.0
         Distribution.Client.NixStyleOptions
         Distribution.Client.Outdated
         Distribution.Client.PackageHash
-        Distribution.Client.PackageUtils
         Distribution.Client.ParseUtils
         Distribution.Client.ProjectBuilding
         Distribution.Client.ProjectBuilding.Types

cabal-testsuite/PackageTests/MultipleLibraries/T6083Post/cabal.out

@@ -0,0 +1,15 @@
+# cabal v2-run
+Resolving dependencies...
+Build profile: -w ghc-<GHCVER> -O1
+In order, the following will be built:
+ - pkg-def-0.1.0.0 (lib) (first run)
+ - pkg-abc-0.1.0.0 (exe:program) (first run)
+Warning: pkg-def.cabal:13:27: visibility is experimental feature (issue #5660)
+Configuring library for pkg-def-0.1.0.0..
+Preprocessing library for pkg-def-0.1.0.0..
+Building library for pkg-def-0.1.0.0..
+Warning: pkg-abc.cabal:19:15: colon specifier is experimental feature (issue #5660)
+Configuring executable 'program' for pkg-abc-0.1.0.0..
+Warning: The package has an extraneous version range for a dependency on an internal library: pkg-def >=0 && ==0.1.0.0. This version range includes the current package but isn't needed as the current package's library will always be used.
+Preprocessing executable 'program' for pkg-abc-0.1.0.0..
+Building executable 'program' for pkg-abc-0.1.0.0..

cabal-testsuite/PackageTests/MultipleLibraries/T6083Post/cabal.project

@@ -0,0 +1,4 @@
+packages:
+  pkg-abc
+  pkg-def
+

cabal-testsuite/PackageTests/MultipleLibraries/T6083Post/cabal.test.hs

@@ -0,0 +1,6 @@
+import Test.Cabal.Prelude
+
+-- https://github.com/haskell/cabal/issues/6083
+-- see pkg-abc.cabal
+main = cabalTest $
+    cabal' "v2-run" ["pkg-abc:program"] >>= assertOutputContains "pkg-def:pkg-def"

cabal-testsuite/PackageTests/MultipleLibraries/T6083Post/pkg-abc/exe/Main.hs

@@ -0,0 +1,5 @@
+module Main (main) where
+import PkgDef (defValue)
+
+main :: IO ()
+main = print defValue

cabal-testsuite/PackageTests/MultipleLibraries/T6083Post/pkg-abc/pkg-abc.cabal

@@ -0,0 +1,19 @@
+cabal-version: 3.4
+name:          pkg-abc
+version:       0.1.0.0
+
+library pkg-def
+  default-language: Haskell2010
+  hs-source-dirs:   pkg-def
+  build-depends:    base
+  exposed-modules:  PkgDef
+
+executable program
+  default-language: Haskell2010
+  hs-source-dirs:   exe
+  main-is:          Main.hs
+
+  -- we want that to resolve to pkg-def main library.
+  build-depends:
+    , base
+    , pkg-def:pkg-def

cabal-testsuite/PackageTests/MultipleLibraries/T6083Post/pkg-abc/pkg-def/PkgDef.hs

@@ -0,0 +1,4 @@
+module PkgDef (defValue) where
+
+defValue :: String
+defValue = "pkg-abc:pkg-def"

cabal-testsuite/PackageTests/MultipleLibraries/T6083Post/pkg-def/pkg-def.cabal

@@ -0,0 +1,17 @@
+cabal-version: 3.0
+name:          pkg-def
+version:       0.1.0.0
+
+library
+  default-language: Haskell2010
+  hs-source-dirs:   src
+  build-depends:    base
+  exposed-modules:  PkgDef
+
+library publib
+  default-language: Haskell2010
+  visibility:       public
+  hs-source-dirs:   publib
+  build-depends:    base
+  exposed-modules:  PkgDef
+

cabal-testsuite/PackageTests/MultipleLibraries/T6083Post/pkg-def/publib/PkgDef.hs

@@ -0,0 +1,4 @@
+module PkgDef (defValue) where
+
+defValue :: String
+defValue = "pkg-def:publib"

cabal-testsuite/PackageTests/MultipleLibraries/T6083Post/pkg-def/src/PkgDef.hs

@@ -0,0 +1,4 @@
+module PkgDef (defValue) where
+
+defValue :: String
+defValue = "pkg-def:pkg-def"