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

Summary:
This reverts commit 06d46b1e.

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
@@ -317,7 +334,7 @@ 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)
@@ -325,6 +342,7 @@ 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)

compiler/main/DriverPipeline.hs

@@ -13,7 +13,7 @@
 module DriverPipeline (
         -- Run a series of compilation steps in a pipeline, for a
         -- collection of source files.
-   oneShot, compileFile, mergeRequirement,
+   oneShot, compileFile,
 
         -- Interfaces for the batch-mode driver
    linkBinary,
@@ -23,9 +23,6 @@ module DriverPipeline (
    compileOne, compileOne',
    link,
 
-        -- Misc utility
-   makeMergeRequirementSummary,
-
         -- Exports for hooks to override runPhase and link
    PhasePlus(..), CompPipeline(..), PipeEnv(..), PipeState(..),
    phaseOutputFilename, getPipeState, getPipeEnv,
@@ -73,7 +70,6 @@ import System.IO
 import Control.Monad
 import Data.List        ( isSuffixOf )
 import Data.Maybe
-import Data.Time
 import Data.Version
 
 -- ---------------------------------------------------------------------------
@@ -133,6 +129,22 @@ compileOne' m_tc_result mHscMessage
             hsc_env0 summary mod_index nmods mb_old_iface maybe_old_linkable
             source_modified0
  = do
+   let dflags0     = ms_hspp_opts summary
+       this_mod    = ms_mod summary
+       src_flavour = ms_hsc_src summary
+       location    = ms_location summary
+       input_fnpp  = ms_hspp_file summary
+       mod_graph   = hsc_mod_graph hsc_env0
+       needsTH     = any (xopt Opt_TemplateHaskell . ms_hspp_opts) mod_graph
+       needsQQ     = any (xopt Opt_QuasiQuotes     . ms_hspp_opts) mod_graph
+       needsLinker = needsTH || needsQQ
+       isDynWay    = any (== WayDyn) (ways dflags0)
+       isProfWay   = any (== WayProf) (ways dflags0)
+   -- #8180 - when using TemplateHaskell, switch on -dynamic-too so
+   -- the linker can correctly load the object files.
+   let dflags1 = if needsLinker && dynamicGhc && not isDynWay && not isProfWay
+                  then gopt_set dflags0 Opt_BuildDynamicToo
+                  else dflags0
 
    debugTraceMsg dflags1 2 (text "compile: input file" <+> text input_fnpp)
 
@@ -146,7 +158,7 @@ compileOne' m_tc_result mHscMessage
             ASSERT( isJust maybe_old_linkable || isNoLink (ghcLink dflags) )
             return hmi0 { hm_linkable = maybe_old_linkable }
         (HscNotGeneratingCode, HscNothing) ->
-            let mb_linkable = if isHsBoot src_flavour
+            let mb_linkable = if isHsBootOrSig src_flavour
                                 then Nothing
                                 -- TODO: Questionable.
                                 else Just (LM (ms_hs_date summary) this_mod [])
@@ -158,10 +170,10 @@ compileOne' m_tc_result mHscMessage
         (HscUpdateBoot, _) -> do
             touchObjectFile dflags object_filename
             return hmi0
-        (HscUpdateBootMerge, HscInterpreted) ->
+        (HscUpdateSig, HscInterpreted) ->
             let linkable = LM (ms_hs_date summary) this_mod []
             in return hmi0 { hm_linkable = Just linkable }
-        (HscUpdateBootMerge, _) -> do
+        (HscUpdateSig, _) -> do
             output_fn <- getOutputFilename next_phase
                             Temporary basename dflags next_phase (Just location)
 
@@ -171,7 +183,7 @@ compileOne' m_tc_result mHscMessage
             _ <- runPipeline StopLn hsc_env
                               (output_fn,
                                Just (HscOut src_flavour
-                                            mod_name HscUpdateBootMerge))
+                                            mod_name HscUpdateSig))
                               (Just basename)
                               Persistent
                               (Just location)
@@ -218,7 +230,6 @@ compileOne' m_tc_result mHscMessage
  where dflags0     = ms_hspp_opts summary
        location    = ms_location summary
        input_fn    = expectJust "compile:hs" (ml_hs_file location)
-       input_fnpp  = ms_hspp_file summary
        mod_graph   = hsc_mod_graph hsc_env0
        needsTH     = any (xopt Opt_TemplateHaskell . ms_hspp_opts) mod_graph
        needsQQ     = any (xopt Opt_QuasiQuotes     . ms_hspp_opts) mod_graph
@@ -228,7 +239,6 @@ compileOne' m_tc_result mHscMessage
 
 
        src_flavour = ms_hsc_src summary
-       this_mod = ms_mod summary
        mod_name = ms_mod_name summary
        next_phase = hscPostBackendPhase dflags src_flavour hsc_lang
        object_filename = ml_obj_file location
@@ -489,50 +499,6 @@ oneShot hsc_env stop_phase srcs = do
   o_files <- mapM (compileFile hsc_env stop_phase) srcs
   doLink (hsc_dflags hsc_env) stop_phase o_files
 
--- | Constructs a 'ModSummary' for a "signature merge" node.
--- This is a simplified construction function which only checks
--- for a local hs-boot file.
-makeMergeRequirementSummary :: HscEnv -> Bool -> ModuleName -> IO ModSummary
-makeMergeRequirementSummary hsc_env obj_allowed mod_name = do
-    let dflags = hsc_dflags hsc_env
-    location <- liftIO $ mkHomeModLocation2 dflags mod_name
-                         (moduleNameSlashes mod_name) (hiSuf dflags)
-    obj_timestamp <-
-         if isObjectTarget (hscTarget dflags) || obj_allowed -- bug #1205
-             then liftIO $ modificationTimeIfExists (ml_obj_file location)
-             else return Nothing
-    r <- findHomeModule hsc_env mod_name
-    let has_local_boot = case r of
-                            Found _ _ -> True
-                            _ -> False
-    src_timestamp <- case obj_timestamp of
-                        Just date -> return date
-                        Nothing -> getCurrentTime -- something fake
-    return ModSummary {
-            ms_mod = mkModule (thisPackage dflags) mod_name,
-            ms_hsc_src = HsBootMerge,
-            ms_location = location,
-            ms_hs_date = src_timestamp,
-            ms_obj_date = obj_timestamp,
-            ms_iface_date = Nothing,
-            -- TODO: fill this in with all the imports eventually
-            ms_srcimps = [],
-            ms_textual_imps = [],
-            ms_merge_imps = (has_local_boot, []),
-            ms_hspp_file = "FAKE",
-            ms_hspp_opts = dflags,
-            ms_hspp_buf = Nothing
-            }
-
--- | Top-level entry point for @ghc -merge-requirement ModName@.
-mergeRequirement :: HscEnv -> ModuleName -> IO ()
-mergeRequirement hsc_env mod_name = do
-    mod_summary <- makeMergeRequirementSummary hsc_env True mod_name
-    -- Based off of GhcMake handling
-    _ <- liftIO $ compileOne' Nothing Nothing hsc_env mod_summary 1 1 Nothing
-                              Nothing SourceUnmodified
-    return ()
-
 compileFile :: HscEnv -> Phase -> (FilePath, Maybe Phase) -> IO FilePath
 compileFile hsc_env stop_phase (src, mb_phase) = do
    exists <- doesFileExist src
@@ -1014,8 +980,7 @@ runPhase (RealPhase (Hsc src_flavour)) input_fn dflags0
                                         ms_obj_date  = Nothing,
                                         ms_iface_date   = Nothing,
                                         ms_textual_imps = imps,
-                                        ms_srcimps      = src_imps,
-                                        ms_merge_imps = (False, []) }
+                                        ms_srcimps      = src_imps }
 
   -- run the compiler!
         let msg hsc_env _ what _ = oneShotMsg hsc_env what
@@ -1048,7 +1013,7 @@ runPhase (HscOut src_flavour mod_name result) _ dflags = do
                    -- stamp file for the benefit of Make
                    liftIO $ touchObjectFile dflags o_file
                    return (RealPhase StopLn, o_file)
-            HscUpdateBootMerge ->
+            HscUpdateSig ->
                 do -- We need to create a REAL but empty .o file
                    -- because we are going to attempt to put it in a library
                    PipeState{hsc_env=hsc_env'} <- getPipeState
@@ -2211,7 +2176,7 @@ writeInterfaceOnlyMode dflags =
 -- | What phase to run after one of the backend code generators has run
 hscPostBackendPhase :: DynFlags -> HscSource -> HscTarget -> Phase
 hscPostBackendPhase _ HsBootFile _    =  StopLn
-hscPostBackendPhase _ HsBootMerge _    =  StopLn
+hscPostBackendPhase _ HsigFile _      =  StopLn
 hscPostBackendPhase dflags _ hsc_lang =
   case hsc_lang of
         HscC -> HCc

compiler/main/Finder.hs

@@ -228,11 +228,8 @@ findHomeModule hsc_env mod_name =
      source_exts =
       [ ("hs",   mkHomeModLocationSearched dflags mod_name "hs")
       , ("lhs",  mkHomeModLocationSearched dflags mod_name "lhs")
-      -- TODO: This is a giant hack!  If we find an hs-boot file,
-      -- pretend that there's an hs file here too, even if there isn't.
-      -- GhcMake will know what to do next.
-      , ("hs-boot",   mkHomeModLocationSearched dflags mod_name "hs")
-      , ("lhs-boot",  mkHomeModLocationSearched dflags mod_name "lhs")
+      , ("hsig",  mkHomeModLocationSearched dflags mod_name "hsig")
+      , ("lhsig",  mkHomeModLocationSearched dflags mod_name "lhsig")
       ]
 
      hi_exts = [ (hisuf,                mkHiOnlyModLocation dflags hisuf)
@@ -253,6 +250,7 @@ findHomeModule hsc_env mod_name =
         then return (Found (error "GHC.Prim ModLocation") mod)
         else searchPathExts home_path mod exts
 
+
 -- | Search for a module in external packages only.
 findPackageModule :: HscEnv -> Module -> IO FindResult
 findPackageModule hsc_env mod = do

compiler/main/GHC.hs

@@ -988,7 +988,7 @@ compileCore simplify fn = do
    _ <- load LoadAllTargets
    -- Then find dependencies
    modGraph <- depanal [] True
-   case find ((== Just fn) . msHsFilePath) modGraph of
+   case find ((== fn) . msHsFilePath) modGraph of
      Just modSummary -> do
        -- Now we have the module name;
        -- parse, typecheck and desugar the module

compiler/main/GhcMake.hs

@@ -1424,7 +1424,7 @@ reachableBackwards mod summaries
   = [ ms | (ms,_,_) <- reachableG (transposeG graph) root ]
   where -- the rest just sets up the graph:
         (graph, lookup_node) = moduleGraphNodes False summaries
-        root  = expectJust "reachableBackwards" (lookup_node IsBoot mod)
+        root  = expectJust "reachableBackwards" (lookup_node HsBootFile mod)
 
 -- ---------------------------------------------------------------------------
 --
@@ -1463,8 +1463,7 @@ topSortModuleGraph drop_hs_boot_nodes summaries mb_root_mod
             -- the specified module.  We do this by building a graph with
             -- the full set of nodes, and determining the reachable set from
             -- the specified node.
-            let root | Just node <- lookup_node NotBoot root_mod
-                     , graph `hasVertexG` node = node
+            let root | Just node <- lookup_node HsSrcFile root_mod, graph `hasVertexG` node = node
                      | otherwise = throwGhcException (ProgramError "module does not exist")
             in graphFromEdgedVertices (seq root (reachableG graph root))
 
@@ -1477,48 +1476,36 @@ summaryNodeSummary :: SummaryNode -> ModSummary
 summaryNodeSummary (s, _, _) = s
 
 moduleGraphNodes :: Bool -> [ModSummary]
-  -> (Graph SummaryNode, IsBoot -> ModuleName -> Maybe SummaryNode)
+  -> (Graph SummaryNode, HscSource -> ModuleName -> Maybe SummaryNode)
 moduleGraphNodes drop_hs_boot_nodes summaries = (graphFromEdgedVertices nodes, lookup_node)
   where
     numbered_summaries = zip summaries [1..]
 
-    lookup_node :: IsBoot -> ModuleName -> Maybe SummaryNode
-    lookup_node is_boot mod = Map.lookup (mod, is_boot) node_map
+    lookup_node :: HscSource -> ModuleName -> Maybe SummaryNode
+    lookup_node hs_src mod = Map.lookup (mod, hscSourceToIsBoot hs_src) node_map
 
-    lookup_key :: IsBoot -> ModuleName -> Maybe Int
-    lookup_key is_boot mod = fmap summaryNodeKey (lookup_node is_boot mod)
+    lookup_key :: HscSource -> ModuleName -> Maybe Int
+    lookup_key hs_src mod = fmap summaryNodeKey (lookup_node hs_src mod)
 
     node_map :: NodeMap SummaryNode
     node_map = Map.fromList [ ((moduleName (ms_mod s),
                                 hscSourceToIsBoot (ms_hsc_src s)), node)
                             | node@(s, _, _) <- nodes ]
 
-    hasImplSet :: Set.Set ModuleName
-    hasImplSet = Set.fromList [ ms_mod_name s
-                              | s <- summaries, ms_hsc_src s == HsSrcFile ]
-
-    hasImpl :: ModuleName -> Bool
-    hasImpl modname = modname `Set.member` hasImplSet
-
     -- We use integers as the keys for the SCC algorithm
     nodes :: [SummaryNode]
     nodes = [ (s, key, out_keys)
             | (s, key) <- numbered_summaries
              -- Drop the hi-boot ones if told to do so
-            , not (isBootSummary s && hasImpl (ms_mod_name s)
-                                   && drop_hs_boot_nodes)
-            , let out_keys
-                    = out_edge_keys IsBoot  (map unLoc (ms_home_srcimps s)) ++
-                      out_edge_keys NotBoot (map unLoc (ms_home_imps s)) ++
-                      (if fst (ms_merge_imps s)
-                        then out_edge_keys IsBoot [moduleName (ms_mod s)]
-                        else []) ++
-                      (-- see [boot-edges] below
-                       if drop_hs_boot_nodes || ms_hsc_src s /= HsSrcFile
-                       then []
-                       else case lookup_key IsBoot (ms_mod_name s) of
-                             Nothing -> []
-                             Just k  -> [k]) ]
+            , not (isBootSummary s && drop_hs_boot_nodes)
+            , let out_keys = out_edge_keys hs_boot_key (map unLoc (ms_home_srcimps s)) ++
+                             out_edge_keys HsSrcFile   (map unLoc (ms_home_imps s)) ++
+                             (-- see [boot-edges] below
+                              if drop_hs_boot_nodes || ms_hsc_src s == HsBootFile
+                              then []
+                              else case lookup_key HsBootFile (ms_mod_name s) of
+                                    Nothing -> []
+                                    Just k  -> [k]) ]
 
     -- [boot-edges] if this is a .hs and there is an equivalent
     -- .hs-boot, add a link from the former to the latter.  This
@@ -1528,13 +1515,12 @@ moduleGraphNodes drop_hs_boot_nodes summaries = (graphFromEdgedVertices nodes, l
     -- the .hs, and so the HomePackageTable will always have the
     -- most up to date information.
 
-    out_edge_keys :: IsBoot -> [ModuleName] -> [Int]
-    out_edge_keys hi_boot ms = mapMaybe (lookup_out_edge_key hi_boot) ms
+    -- Drop hs-boot nodes by using HsSrcFile as the key
+    hs_boot_key | drop_hs_boot_nodes = HsSrcFile
+                | otherwise          = HsBootFile
 
-    lookup_out_edge_key :: IsBoot ->