Revert "Unify hsig and hs-boot; add preliminary "hs-boot" merging."

Summary:
This reverts commit 06d46b1.

This also has a Haddock submodule update.

Test Plan: validate

Reviewers: simonpj, austin, bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1475

compiler/deSugar/Desugar.hs

@@ -296,7 +296,7 @@ deSugar hsc_env
               hpcInfo    = emptyHpcInfo other_hpc_info
 
         ; (binds_cvr, ds_hpc_info, modBreaks)
-                         <- if not (isHsBoot hsc_src)
+                         <- if not (isHsBootOrSig hsc_src)
                               then addTicksToBinds dflags mod mod_loc export_set
                                           (typeEnvTyCons type_env) binds
                               else return (binds, hpcInfo, emptyModBreaks)

compiler/iface/LoadIface.hs

@@ -897,7 +897,7 @@ pprModIface iface
         ]
   where
     pp_hsc_src HsBootFile = ptext (sLit "[boot]")
-    pp_hsc_src HsBootMerge = ptext (sLit "[merge]")
+    pp_hsc_src HsigFile = ptext (sLit "[hsig]")
     pp_hsc_src HsSrcFile = Outputable.empty
 
 {-

compiler/iface/MkIface.hs

@@ -13,7 +13,6 @@ module MkIface (
                         -- including computing version information
 
         mkIfaceTc,
-        mkIfaceDirect,
 
         writeIfaceFile, -- Write the interface file
 
@@ -154,35 +153,6 @@ mkIface hsc_env maybe_old_fingerprint mod_details
                    warns hpc_info self_trust
                    safe_mode usages mod_details
 
--- | Make an interface from a manually constructed 'ModIface'.  We use
--- this when we are merging 'ModIface's.  We assume that the 'ModIface'
--- has accurate entries but not accurate fingerprint information (so,
--- like @intermediate_iface@ in 'mkIface_'.)
-mkIfaceDirect :: HscEnv
-              -> Maybe Fingerprint
-              -> ModIface
-              -> IO (ModIface, Bool)
-mkIfaceDirect hsc_env maybe_old_fingerprint iface0 = do
-    -- Sort some things to make sure we're deterministic
-    let intermediate_iface = iface0 {
-            mi_exports   = mkIfaceExports (mi_exports iface0),
-            mi_insts     = sortBy cmp_inst     (mi_insts iface0),
-            mi_fam_insts = sortBy cmp_fam_inst (mi_fam_insts iface0),
-            mi_rules     = sortBy cmp_rule     (mi_rules iface0)
-        }
-        dflags = hsc_dflags hsc_env
-    (final_iface, no_change_at_all)
-          <- {-# SCC "versioninfo" #-}
-                   addFingerprints hsc_env maybe_old_fingerprint
-                                   intermediate_iface
-                                   (map snd (mi_decls iface0))
-
-    -- Debug printing
-    dumpIfSet_dyn dflags Opt_D_dump_hi "FINAL INTERFACE"
-                  (pprModIface final_iface)
-
-    return (final_iface, no_change_at_all)
-
 -- | make an interface from the results of typechecking only.  Useful
 -- for non-optimising compilation, or where we aren't generating any
 -- object code at all ('HscNothing').
@@ -320,6 +290,11 @@ mkIface_ hsc_env maybe_old_fingerprint
 
     return (final_iface, no_change_at_all)
   where
+     cmp_rule     = comparing ifRuleName
+     -- Compare these lexicographically by OccName, *not* by unique,
+     -- because the latter is not stable across compilations:
+     cmp_inst     = comparing (nameOccName . ifDFun)
+     cmp_fam_inst = comparing (nameOccName . ifFamInstTcName)
 
      dflags = hsc_dflags hsc_env
 
@@ -337,6 +312,8 @@ mkIface_ hsc_env maybe_old_fingerprint
      deliberatelyOmitted :: String -> a
      deliberatelyOmitted x = panic ("Deliberately omitted: " ++ x)
 
+     ifFamInstTcName = ifFamInstFam
+
      flattenVectInfo (VectInfo { vectInfoVar            = vVar
                                , vectInfoTyCon          = vTyCon
                                , vectInfoParallelVars     = vParallelVars
@@ -350,16 +327,6 @@ mkIface_ hsc_env maybe_old_fingerprint
        , ifaceVectInfoParallelTyCons = nameSetElems vParallelTyCons
        }
 
-cmp_rule :: IfaceRule -> IfaceRule -> Ordering
-cmp_rule     = comparing ifRuleName
--- Compare these lexicographically by OccName, *not* by unique,
--- because the latter is not stable across compilations:
-cmp_inst :: IfaceClsInst -> IfaceClsInst -> Ordering
-cmp_inst     = comparing (nameOccName . ifDFun)
-
-cmp_fam_inst :: IfaceFamInst -> IfaceFamInst -> Ordering
-cmp_fam_inst = comparing (nameOccName . ifFamInstFam)
-
 -----------------------------
 writeIfaceFile :: DynFlags -> FilePath -> ModIface -> IO ()
 writeIfaceFile dflags hi_file_path new_iface

compiler/main/DriverMkDepend.hs

@@ -197,9 +197,9 @@ processDeps dflags _ _ _ _ (CyclicSCC nodes)
     throwGhcExceptionIO (ProgramError (showSDoc dflags $ GHC.cyclicModuleErr nodes))
 
 processDeps dflags hsc_env excl_mods root hdl (AcyclicSCC node)
-  | Just src_file <- msHsFilePath node
   = do  { let extra_suffixes = depSuffixes dflags
               include_pkg_deps = depIncludePkgDeps dflags
+              src_file  = msHsFilePath node
               obj_file  = msObjFilePath node
               obj_files = insertSuffixes obj_file extra_suffixes
 
@@ -233,10 +233,6 @@ processDeps dflags hsc_env excl_mods root hdl (AcyclicSCC node)
         ; do_imps False (ms_imps node)
         }
 
-  | otherwise
-  = ASSERT( ms_hsc_src node == HsBootMerge )
-    panic "HsBootMerge not supported in DriverMkDepend yet"
-
 
 findDependency  :: HscEnv
                 -> SrcSpan

compiler/main/DriverPhases.hs

@@ -10,7 +10,7 @@
 -----------------------------------------------------------------------------
 
 module DriverPhases (
-   HscSource(..), isHsBoot, hscSourceString,
+   HscSource(..), isHsBootOrSig, hscSourceString,
    Phase(..),
    happensBefore, eqPhase, anyHsc, isStopLn,
    startPhase,
@@ -22,10 +22,12 @@ module DriverPhases (
    isCishSuffix,
    isDynLibSuffix,
    isHaskellUserSrcSuffix,
+   isHaskellSigSuffix,
    isSourceSuffix,
 
    isHaskellishFilename,
    isHaskellSrcFilename,
+   isHaskellSigFilename,
    isObjectFilename,
    isCishFilename,
    isDynLibFilename,
@@ -58,51 +60,63 @@ import Binary
 
 -- Note [HscSource types]
 -- ~~~~~~~~~~~~~~~~~~~~~~
--- There are two types of source file for user-written Haskell code:
+-- There are three types of source file for Haskell code:
 --
 --      * HsSrcFile is an ordinary hs file which contains code,
 --
---      * HsBootFile is an hs-boot file.  Within a unit, it can
---        be used to break recursive module imports, in which case there's an
---        HsSrcFile associated with it.  However, externally, it can
---        also be used to specify the *requirements* of a package,
---        in which case there is an HsBootMerge associated with it.
+--      * HsBootFile is an hs-boot file, which is used to break
+--        recursive module imports (there will always be an
+--        HsSrcFile associated with it), and
 --
--- An HsBootMerge is a "fake" source file, which is constructed
--- by collecting up non-recursive HsBootFiles into a single interface.
--- HsBootMerges get an hi and o file, and are treated as "non-boot"
--- sources.
+--      * HsigFile is an hsig file, which contains only type
+--        signatures and is used to specify signatures for
+--        modules.
+--
+-- Syntactically, hs-boot files and hsig files are quite similar: they
+-- only include type signatures and must be associated with an
+-- actual HsSrcFile.  isHsBootOrSig allows us to abstract over code
+-- which is indifferent to which.  However, there are some important
+-- differences, mostly owing to the fact that hsigs are proper
+-- modules (you `import Sig` directly) whereas HsBootFiles are
+-- temporary placeholders (you `import {-# SOURCE #-} Mod).
+-- When we finish compiling the true implementation of an hs-boot,
+-- we replace the HomeModInfo with the real HsSrcFile.  An HsigFile, on the
+-- other hand, is never replaced (in particular, we *cannot* use the
+-- HomeModInfo of the original HsSrcFile backing the signature, since it
+-- will export too many symbols.)
+--
+-- Additionally, while HsSrcFile is the only Haskell file
+-- which has *code*, we do generate .o files for HsigFile, because
+-- this is how the recompilation checker figures out if a file
+-- needs to be recompiled.  These are fake object files which
+-- should NOT be linked against.
 
 data HscSource
-   = HsSrcFile | HsBootFile | HsBootMerge
+   = HsSrcFile | HsBootFile | HsigFile
      deriving( Eq, Ord, Show )
         -- Ord needed for the finite maps we build in CompManager
 
-instance Outputable HscSource where
-    ppr HsSrcFile = text "HsSrcFile"
-    ppr HsBootFile = text "HsBootFile"
-    ppr HsBootMerge = text "HsBootMerge"
-
 instance Binary HscSource where
     put_ bh HsSrcFile = putByte bh 0
     put_ bh HsBootFile = putByte bh 1
-    put_ bh HsBootMerge = putByte bh 2
+    put_ bh HsigFile = putByte bh 2
     get bh = do
         h <- getByte bh
         case h of
             0 -> return HsSrcFile
             1 -> return HsBootFile
-            _ -> return HsBootMerge
+            _ -> return HsigFile
 
 hscSourceString :: HscSource -> String
 hscSourceString HsSrcFile   = ""
 hscSourceString HsBootFile  = "[boot]"
-hscSourceString HsBootMerge = "[merge]"
+hscSourceString HsigFile    = "[sig]"
 
-isHsBoot :: HscSource -> Bool
-isHsBoot HsBootFile  = True
-isHsBoot HsSrcFile   = False
-isHsBoot HsBootMerge = False
+-- See Note [isHsBootOrSig]
+isHsBootOrSig :: HscSource -> Bool
+isHsBootOrSig HsBootFile = True
+isHsBootOrSig HsigFile   = True
+isHsBootOrSig _          = False
 
 data Phase
         = Unlit HscSource
@@ -218,8 +232,10 @@ nextPhase dflags p
 startPhase :: String -> Phase
 startPhase "lhs"      = Unlit HsSrcFile
 startPhase "lhs-boot" = Unlit HsBootFile
+startPhase "lhsig"    = Unlit HsigFile
 startPhase "hs"       = Cpp   HsSrcFile
 startPhase "hs-boot"  = Cpp   HsBootFile
+startPhase "hsig"     = Cpp   HsigFile
 startPhase "hscpp"    = HsPp  HsSrcFile
 startPhase "hspp"     = Hsc   HsSrcFile
 startPhase "hc"       = HCc
@@ -248,9 +264,7 @@ startPhase _          = StopLn     -- all unknown file types
 phaseInputExt :: Phase -> String
 phaseInputExt (Unlit HsSrcFile)   = "lhs"
 phaseInputExt (Unlit HsBootFile)  = "lhs-boot"
-phaseInputExt (Unlit HsBootMerge) = panic "phaseInputExt: Unlit HsBootMerge"
-        -- You can't Unlit an HsBootMerge, because there's no source
-        -- file to Unlit!
+phaseInputExt (Unlit HsigFile)    = "lhsig"
 phaseInputExt (Cpp   _)           = "lpp"       -- intermediate only
 phaseInputExt (HsPp  _)           = "hscpp"     -- intermediate only
 phaseInputExt (Hsc   _)           = "hspp"      -- intermediate only
@@ -275,7 +289,7 @@ phaseInputExt MergeStub           = "o"
 phaseInputExt StopLn              = "o"
 
 haskellish_src_suffixes, haskellish_suffixes, cish_suffixes,
-    haskellish_user_src_suffixes
+    haskellish_user_src_suffixes, haskellish_sig_suffixes
  :: [String]
 -- When a file with an extension in the haskellish_src_suffixes group is
 -- loaded in --make mode, its imports will be loaded too.
@@ -286,7 +300,9 @@ haskellish_suffixes          = haskellish_src_suffixes ++
 cish_suffixes                = [ "c", "cpp", "C", "cc", "cxx", "s", "S", "ll", "bc", "lm_s", "m", "M", "mm" ]
 
 -- Will not be deleted as temp files:
-haskellish_user_src_suffixes = [ "hs", "lhs", "hs-boot", "lhs-boot" ]
+haskellish_user_src_suffixes =
+  haskellish_sig_suffixes ++ [ "hs", "lhs", "hs-boot", "lhs-boot" ]
+haskellish_sig_suffixes      = [ "hsig", "lhsig" ]
 
 objish_suffixes :: Platform -> [String]
 -- Use the appropriate suffix for the system on which
@@ -302,9 +318,10 @@ dynlib_suffixes platform = case platformOS platform of
   _         -> ["so"]
 
 isHaskellishSuffix, isHaskellSrcSuffix, isCishSuffix,
-    isHaskellUserSrcSuffix
+    isHaskellUserSrcSuffix, isHaskellSigSuffix
  :: String -> Bool
 isHaskellishSuffix     s = s `elem` haskellish_suffixes
+isHaskellSigSuffix     s = s `elem` haskellish_sig_suffixes
 isHaskellSrcSuffix     s = s `elem` haskellish_src_suffixes
 isCishSuffix           s = s `elem` cish_suffixes
 isHaskellUserSrcSuffix s = s `elem` haskellish_user_src_suffixes
@@ -317,14 +334,15 @@ isSourceSuffix :: String -> Bool
 isSourceSuffix suff  = isHaskellishSuffix suff || isCishSuffix suff
 
 isHaskellishFilename, isHaskellSrcFilename, isCishFilename,
-    isHaskellUserSrcFilename, isSourceFilename
+    isHaskellUserSrcFilename, isSourceFilename, isHaskellSigFilename
  :: FilePath -> Bool
 -- takeExtension return .foo, so we drop 1 to get rid of the .
 isHaskellishFilename     f = isHaskellishSuffix     (drop 1 $ takeExtension f)
 isHaskellSrcFilename     f = isHaskellSrcSuffix     (drop 1 $ takeExtension f)
 isCishFilename           f = isCishSuffix           (drop 1 $ takeExtension f)
 isHaskellUserSrcFilename f = isHaskellUserSrcSuffix (drop 1 $ takeExtension f)
 isSourceFilename         f = isSourceSuffix         (drop 1 $ takeExtension f)
+isHaskellSigFilename     f = isHaskellSigSuffix     (drop 1 $ takeExtension f)
 
 isObjectFilename, isDynLibFilename :: Platform -> FilePath -> Bool
 isObjectFilename platform f = isObjectSuffix platform (drop 1 $ takeExtension f)