Package keys (for linking/type equality) separated from package IDs.

This patch set makes us no longer assume that a package key is a human
readable string, leaving Cabal free to "do whatever it wants" to allocate
keys; we'll look up the PackageId in the database to display to the user.
This also means we have a new level of qualifier decisions to make at the
package level, and rewriting some Safe Haskell error reporting code to DTRT.

Additionally, we adjust the build system to use a new ghc-cabal output
Make variable PACKAGE_KEY to determine library names and other things,
rather than concatenating PACKAGE/VERSION as before.

Adds a new `-this-package-key` flag to subsume the old, erroneously named
`-package-name` flag, and `-package-key` to select packages by package key.

RFC: The md5 hashes are pretty tough on the eye, as far as the file
system is concerned :(

ToDo: safePkg01 test had its output updated, but the fix is not really right:
the rest of the dependencies are truncated due to the fact the we're only
grepping a single line, but ghc-pkg is wrapping its output.

ToDo: In a later commit, update all submodules to stop using -package-name
and use -this-package-key.  For now, we don't do it to avoid submodule
explosion.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Test Plan: validate

Reviewers: simonpj, simonmar, hvr, austin

Subscribers: simonmar, relrod, carter

Differential Revision: https://phabricator.haskell.org/D80

1 files changed, 3 insertions, 2 deletions

diff --git a/ghc/InteractiveUI.hs b/ghc/InteractiveUI.hs
index ab4ea8721b..96b78809d2 100644
--- a/ghc/InteractiveUI.hs
+++ b/ghc/InteractiveUI.hs
@@ -1605,13 +1605,13 @@ isSafeModule m = do
     liftIO $ putStrLn $ "Package Trust: " ++ (if packageTrustOn dflags then "On" else "Off")
     when (not $ null good)
          (liftIO $ putStrLn $ "Trusted package dependencies (trusted): " ++
-                        (intercalate ", " $ map packageKeyString good))
+                        (intercalate ", " $ map (showPpr dflags) good))
     case msafe && null bad of
         True -> liftIO $ putStrLn $ mname ++ " is trusted!"
         False -> do
             when (not $ null bad)
                  (liftIO $ putStrLn $ "Trusted package dependencies (untrusted): "
-                            ++ (intercalate ", " $ map packageKeyString bad))
+                            ++ (intercalate ", " $ map (showPpr dflags) bad))
             liftIO $ putStrLn $ mname ++ " is NOT trusted!"
 
   where
@@ -2341,6 +2341,7 @@ showPackages = do
         showFlag (HidePackage     p) = text $ "  -hide-package " ++ p
         showFlag (IgnorePackage   p) = text $ "  -ignore-package " ++ p
         showFlag (ExposePackageId p) = text $ "  -package-id " ++ p
+        showFlag (ExposePackageKey p) = text $ "  -package-key " ++ p
         showFlag (TrustPackage    p) = text $ "  -trust " ++ p
         showFlag (DistrustPackage p) = text $ "  -distrust " ++ p