Revert "ghc-pkg: recompute `abi-depends` for updated packages"

This reverts commit 1cdc14f9c014f1a520638f7c0a01799ac6d104e6.

This is causing non-deterministic testsuite output.

1 files changed, 1 insertions, 51 deletions

diff --git a/utils/ghc-pkg/Main.hs b/utils/ghc-pkg/Main.hs
index b2efbb87c4..a32252139f 100644
--- a/utils/ghc-pkg/Main.hs
+++ b/utils/ghc-pkg/Main.hs
@@ -1211,18 +1211,7 @@ updateDBCache verbosity db = do
       pkgsCabalFormat = packages db
 
       pkgsGhcCacheFormat :: [PackageCacheFormat]
-      pkgsGhcCacheFormat
-        = map (recomputeValidAbiDeps pkgsCabalFormat) -- Note [Recompute abi-depends]
-        $ map convertPackageInfoToCacheFormat
-          pkgsCabalFormat
-
-      hasAnyAbiDepends :: InstalledPackageInfo -> Bool
-      hasAnyAbiDepends x = length (abiDepends x) > 0
-
-  -- warn when we find any (possibly-)bogus abi-depends fields;
-  -- Note [Recompute abi-depends]
-  when (any hasAnyAbiDepends pkgsCabalFormat) $
-      infoLn "ignoring (possibly broken) abi-depends field for packages"
+      pkgsGhcCacheFormat = map convertPackageInfoToCacheFormat pkgsCabalFormat
 
   when (verbosity > Normal) $
       infoLn ("writing cache " ++ filename)
@@ -1245,45 +1234,6 @@ type PackageCacheFormat = GhcPkg.InstalledPackageInfo
                             ModuleName
                             OpenModule
 
-{- Note [Recompute abi-depends]
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-Like most fields, `ghc-pkg` relies on who-ever is performing package
-registration to fill in fields; this includes the `abi-depends` field present
-for the package.
-
-However, this was likely a mistake, and is not very robust; in certain cases,
-versions of Cabal may use bogus abi-depends fields for a package when doing
-builds. Why? Because package database information is aggressively cached; it is
-possible to work Cabal into a situation where it uses a cached version of
-`abi-depends`, rather than the one in the actual database after it has been
-recomputed.
-
-However, there is an easy fix: ghc-pkg /already/ knows the `abi-depends` of a
-package, because they are the ABIs of the packages pointed at by the `depends`
-field. So it can simply look up the abi from the dependencies in the original
-database, and ignore whatever the system registering gave it.
-
-So, instead, we do two things here:
-
-  - We throw away the information for a registered package's `abi-depends` field.
-
-  - We recompute it: we simply look up the unit ID of the package in the original
-    database, and use *its* abi-depends.
-
-See Trac #14381, and Cabal issue #4728.
-
--}
-
-recomputeValidAbiDeps :: [InstalledPackageInfo] -> PackageCacheFormat -> PackageCacheFormat
-recomputeValidAbiDeps db pkg = pkg { GhcPkg.abiDepends = catMaybes (newAbiDeps) }
-  where
-    newAbiDeps = flip map (GhcPkg.abiDepends pkg) $ \(k, _) ->
-      case filter (\d -> installedUnitId d == k) db of
-        []  -> Nothing
-        [x] -> Just (k, unAbiHash (abiHash x))
-        _   -> Nothing -- ???
-
 convertPackageInfoToCacheFormat :: InstalledPackageInfo -> PackageCacheFormat
 convertPackageInfoToCacheFormat pkg =
     GhcPkg.InstalledPackageInfo {