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, 3 insertions, 3 deletions

diff --git a/compiler/codeGen/StgCmmProf.hs b/compiler/codeGen/StgCmmProf.hs
index 1aa08a1e58..7249477c9f 100644
--- a/compiler/codeGen/StgCmmProf.hs
+++ b/compiler/codeGen/StgCmmProf.hs
@@ -183,7 +183,7 @@ enterCostCentreFun ccs closure =
   ifProfiling $ do
     if isCurrentCCS ccs
        then do dflags <- getDynFlags
-               emitRtsCall rtsPackageId (fsLit "enterFunCCS")
+               emitRtsCall rtsPackageKey (fsLit "enterFunCCS")
                    [(CmmReg (CmmGlobal BaseReg), AddrHint),
                     (costCentreFrom dflags closure, AddrHint)] False
        else return () -- top-level function, nothing to do
@@ -285,7 +285,7 @@ emitSetCCC cc tick push
 pushCostCentre :: LocalReg -> CmmExpr -> CostCentre -> FCode ()
 pushCostCentre result ccs cc
   = emitRtsCallWithResult result AddrHint
-        rtsPackageId
+        rtsPackageKey
         (fsLit "pushCostCentre") [(ccs,AddrHint),
                                 (CmmLit (mkCCostCentre cc), AddrHint)]
         False
@@ -356,7 +356,7 @@ ldvEnter cl_ptr = do
 
 loadEra :: DynFlags -> CmmExpr
 loadEra dflags = CmmMachOp (MO_UU_Conv (cIntWidth dflags) (wordWidth dflags))
-    [CmmLoad (mkLblExpr (mkCmmDataLabel rtsPackageId (fsLit "era")))
+    [CmmLoad (mkLblExpr (mkCmmDataLabel rtsPackageKey (fsLit "era")))
              (cInt dflags)]
 
 ldvWord :: DynFlags -> CmmExpr -> CmmExpr