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

3 files changed, 16 insertions, 16 deletions

diff --git a/compiler/ghci/ByteCodeLink.lhs b/compiler/ghci/ByteCodeLink.lhs
index d508a1c5aa..cbedb717fe 100644
--- a/compiler/ghci/ByteCodeLink.lhs
+++ b/compiler/ghci/ByteCodeLink.lhs
@@ -260,13 +260,13 @@ linkFail who what
 -- HACKS!!!  ToDo: cleaner
 nameToCLabel :: Name -> String{-suffix-} -> String
 nameToCLabel n suffix
-   = if pkgid /= mainPackageId
+   = if pkgid /= mainPackageKey
         then package_part ++ '_': qual_name
         else qual_name
   where
-        pkgid = modulePackageId mod
+        pkgid = modulePackageKey mod
         mod = ASSERT( isExternalName n ) nameModule n
-        package_part = zString (zEncodeFS (packageIdFS (modulePackageId mod)))
+        package_part = zString (zEncodeFS (packageKeyFS (modulePackageKey mod)))
         module_part  = zString (zEncodeFS (moduleNameFS (moduleName mod)))
         occ_part     = zString (zEncodeFS (occNameFS (nameOccName n)))
         qual_name = module_part ++ '_':occ_part ++ '_':suffix
diff --git a/compiler/ghci/DebuggerUtils.hs b/compiler/ghci/DebuggerUtils.hs
index 67767e41b9..9ccb113314 100644
--- a/compiler/ghci/DebuggerUtils.hs
+++ b/compiler/ghci/DebuggerUtils.hs
@@ -46,7 +46,7 @@ dataConInfoPtrToName x = do
        modFS = mkFastStringByteList mod
        occFS = mkFastStringByteList occ
        occName = mkOccNameFS OccName.dataName occFS
-       modName = mkModule (fsToPackageId pkgFS) (mkModuleNameFS modFS) 
+       modName = mkModule (fsToPackageKey pkgFS) (mkModuleNameFS modFS)
    return (Left $ showSDoc dflags $ ppr modName <> dot <> ppr occName)
     `recoverM` (Right `fmap` lookupOrig modName occName)
 
diff --git a/compiler/ghci/Linker.lhs b/compiler/ghci/Linker.lhs
index 0dbab24de7..74dec19d14 100644
--- a/compiler/ghci/Linker.lhs
+++ b/compiler/ghci/Linker.lhs
@@ -70,7 +70,7 @@ import System.Directory hiding (findFile)
 import System.Directory
 #endif
 
-import Distribution.Package hiding (depends, PackageId)
+import Distribution.Package hiding (depends)
 
 import Exception
 \end{code}
@@ -124,7 +124,7 @@ data PersistentLinkerState
         -- The currently-loaded packages; always object code
         -- Held, as usual, in dependency order; though I am not sure if
         -- that is really important
-        pkgs_loaded :: ![PackageId]
+        pkgs_loaded :: ![PackageKey]
      }
 
 emptyPLS :: DynFlags -> PersistentLinkerState
@@ -140,10 +140,10 @@ emptyPLS _ = PersistentLinkerState {
   --
   -- The linker's symbol table is populated with RTS symbols using an
   -- explicit list.  See rts/Linker.c for details.
-  where init_pkgs = [rtsPackageId]
+  where init_pkgs = [rtsPackageKey]
 
 
-extendLoadedPkgs :: [PackageId] -> IO ()
+extendLoadedPkgs :: [PackageKey] -> IO ()
 extendLoadedPkgs pkgs =
   modifyPLS_ $ \s ->
       return s{ pkgs_loaded = pkgs ++ pkgs_loaded s }
@@ -527,7 +527,7 @@ getLinkDeps :: HscEnv -> HomePackageTable
             -> Maybe FilePath                   -- replace object suffices?
             -> SrcSpan                          -- for error messages
             -> [Module]                         -- If you need these
-            -> IO ([Linkable], [PackageId])     -- ... then link these first
+            -> IO ([Linkable], [PackageKey])     -- ... then link these first
 -- Fails with an IO exception if it can't find enough files
 
 getLinkDeps hsc_env hpt pls replace_osuf span mods
@@ -565,8 +565,8 @@ getLinkDeps hsc_env hpt pls replace_osuf span mods
         -- tree recursively.  See bug #936, testcase ghci/prog007.
     follow_deps :: [Module]             -- modules to follow
                 -> UniqSet ModuleName         -- accum. module dependencies
-                -> UniqSet PackageId          -- accum. package dependencies
-                -> IO ([ModuleName], [PackageId]) -- result
+                -> UniqSet PackageKey          -- accum. package dependencies
+                -> IO ([ModuleName], [PackageKey]) -- result
     follow_deps []     acc_mods acc_pkgs
         = return (uniqSetToList acc_mods, uniqSetToList acc_pkgs)
     follow_deps (mod:mods) acc_mods acc_pkgs
@@ -580,7 +580,7 @@ getLinkDeps hsc_env hpt pls replace_osuf span mods
           when (mi_boot iface) $ link_boot_mod_error mod
 
           let
-            pkg = modulePackageId mod
+            pkg = modulePackageKey mod
             deps  = mi_deps iface
 
             pkg_deps = dep_pkgs deps
@@ -1045,7 +1045,7 @@ showLS (Framework nm) = "(framework) " ++ nm
 -- automatically, and it doesn't matter what order you specify the input
 -- packages.
 --
-linkPackages :: DynFlags -> [PackageId] -> IO ()
+linkPackages :: DynFlags -> [PackageKey] -> IO ()
 -- NOTE: in fact, since each module tracks all the packages it depends on,
 --       we don't really need to use the package-config dependencies.
 --
@@ -1061,7 +1061,7 @@ linkPackages dflags new_pkgs = do
   modifyPLS_ $ \pls -> do
     linkPackages' dflags new_pkgs pls
 
-linkPackages' :: DynFlags -> [PackageId] -> PersistentLinkerState
+linkPackages' :: DynFlags -> [PackageKey] -> PersistentLinkerState
              -> IO PersistentLinkerState
 linkPackages' dflags new_pks pls = do
     pkgs' <- link (pkgs_loaded pls) new_pks
@@ -1070,7 +1070,7 @@ linkPackages' dflags new_pks pls = do
      pkg_map = pkgIdMap (pkgState dflags)
      ipid_map = installedPackageIdMap (pkgState dflags)
 
-     link :: [PackageId] -> [PackageId] -> IO [PackageId]
+     link :: [PackageKey] -> [PackageKey] -> IO [PackageKey]
      link pkgs new_pkgs =
          foldM link_one pkgs new_pkgs
 
@@ -1088,7 +1088,7 @@ linkPackages' dflags new_pks pls = do
              ; return (new_pkg : pkgs') }
 
         | otherwise
-        = throwGhcExceptionIO (CmdLineError ("unknown package: " ++ packageIdString new_pkg))
+        = throwGhcExceptionIO (CmdLineError ("unknown package: " ++ packageKeyString new_pkg))
 
 
 linkPackage :: DynFlags -> PackageConfig -> IO ()