Rename PackageId to PackageKey, distinguishing it from Cabal's PackageId.

Summary:
Previously, both Cabal and GHC defined the type PackageId, and we expected
them to be roughly equivalent (but represented differently).  This refactoring
separates these two notions.

A package ID is a user-visible identifier; it's the thing you write in a
Cabal file, e.g. containers-0.9.  The components of this ID are semantically
meaningful, and decompose into a package name and a package vrsion.

A package key is an opaque identifier used by GHC to generate linking symbols.
Presently, it just consists of a package name and a package version, but
pursuant to #9265 we are planning to extend it to record other information.
Within a single executable, it uniquely identifies a package.  It is *not* an
InstalledPackageId, as the choice of a package key affects the ABI of a package
(whereas an InstalledPackageId is computed after compilation.)  Cabal computes
a package key for the package and passes it to GHC using -package-name (now
*extremely* misnamed).

As an added bonus, we don't have to worry about shadowing anymore.

As a follow on, we should introduce -current-package-key having the same role as
-package-name, and deprecate the old flag.  This commit is just renaming.

The haddock submodule needed to be updated.

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/D79

Conflicts:
	compiler/main/HscTypes.lhs
	compiler/main/Packages.lhs
	utils/haddock

1 files changed, 6 insertions, 6 deletions

diff --git a/ghc/InteractiveUI.hs b/ghc/InteractiveUI.hs
index c66b025739..9ac3be4773 100644
--- a/ghc/InteractiveUI.hs
+++ b/ghc/InteractiveUI.hs
@@ -1604,21 +1604,21 @@ 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 packageIdString good))
+                        (intercalate ", " $ map packageKeyString 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 packageIdString bad))
+                            ++ (intercalate ", " $ map packageKeyString bad))
             liftIO $ putStrLn $ mname ++ " is NOT trusted!"
 
   where
     mname = GHC.moduleNameString $ GHC.moduleName m
 
     packageTrusted dflags md
-        | thisPackage dflags == modulePackageId md = True
-        | otherwise = trusted $ getPackageDetails (pkgState dflags) (modulePackageId md)
+        | thisPackage dflags == modulePackageKey md = True
+        | otherwise = trusted $ getPackageDetails (pkgState dflags) (modulePackageKey md)
 
     tallyPkgs dflags deps | not (packageTrustOn dflags) = ([], [])
                           | otherwise = partition part deps
@@ -3131,7 +3131,7 @@ lookupModuleName :: GHC.GhcMonad m => ModuleName -> m Module
 lookupModuleName mName = GHC.lookupModule mName Nothing
 
 isHomeModule :: Module -> Bool
-isHomeModule m = GHC.modulePackageId m == mainPackageId
+isHomeModule m = GHC.modulePackageKey m == mainPackageKey
 
 -- TODO: won't work if home dir is encoded.
 -- (changeDirectory may not work either in that case.)
@@ -3161,7 +3161,7 @@ wantInterpretedModuleName modname = do
    modl <- lookupModuleName modname
    let str = moduleNameString modname
    dflags <- getDynFlags
-   when (GHC.modulePackageId modl /= thisPackage dflags) $
+   when (GHC.modulePackageKey modl /= thisPackage dflags) $
       throwGhcException (CmdLineError ("module '" ++ str ++ "' is from another package;\nthis command requires an interpreted module"))
    is_interpreted <- GHC.moduleIsInterpreted modl
    when (not is_interpreted) $