Refactor module dependencies code

* moved deps related code into GHC.Unit.Module.Deps
* refactored Deps module to not export Dependencies constructor to help
  maintaining invariants

4 files changed, 11 insertions, 50 deletions

diff --git a/compiler/GHC/Iface/Load.hs b/compiler/GHC/Iface/Load.hs
index dc993aa261..c271613b3d 100644
--- a/compiler/GHC/Iface/Load.hs
+++ b/compiler/GHC/Iface/Load.hs
@@ -115,8 +115,6 @@ import GHC.Data.FastString
 
 import Control.Monad
 import Data.Map ( toList )
-import qualified Data.Set as Set
-import Data.Set (Set)
 import System.FilePath
 import System.Directory
 import GHC.Driver.Env.KnotVars
@@ -1184,32 +1182,6 @@ pprUsageImport usage usg_mod'
         safe | usg_safe usage = text "safe"
              | otherwise      = text " -/ "
 
--- | Pretty-print unit dependencies
-pprDeps :: UnitState -> Dependencies -> SDoc
-pprDeps unit_state (Deps { dep_direct_mods = dmods
-                         , dep_boot_mods = bmods
-                         , dep_orphs = orphs
-                         , dep_direct_pkgs = pkgs
-                         , dep_trusted_pkgs = tps
-                         , dep_finsts = finsts
-                         })
-  = pprWithUnitState unit_state $
-    vcat [text "direct module dependencies:"  <+> ppr_set ppr_mod dmods,
-          text "boot module dependencies:"    <+> ppr_set ppr bmods,
-          text "direct package dependencies:" <+> ppr_set ppr pkgs,
-          if null tps
-            then empty
-            else text "trusted package dependencies:" <+> ppr_set ppr tps,
-          text "orphans:" <+> fsep (map ppr orphs),
-          text "family instance modules:" <+> fsep (map ppr finsts)
-        ]
-  where
-    ppr_mod (GWIB mod IsBoot)  = ppr mod <+> text "[boot]"
-    ppr_mod (GWIB mod NotBoot) = ppr mod
-
-    ppr_set :: Outputable a => (a -> SDoc) -> Set a -> SDoc
-    ppr_set w = fsep . fmap w . Set.toAscList
-
 pprFixities :: [(OccName, Fixity)] -> SDoc
 pprFixities []    = Outputable.empty
 pprFixities fixes = text "fixities" <+> pprWithCommas pprFix fixes
diff --git a/compiler/GHC/Iface/Make.hs b/compiler/GHC/Iface/Make.hs
index ed113ef7fd..b28e777a88 100644
--- a/compiler/GHC/Iface/Make.hs
+++ b/compiler/GHC/Iface/Make.hs
@@ -82,7 +82,7 @@ import GHC.Data.FastString
 import GHC.Data.Maybe
 
 import GHC.HsToCore.Docs
-import GHC.HsToCore.Usage ( mkUsageInfo, mkUsedNames, mkDependencies )
+import GHC.HsToCore.Usage ( mkUsageInfo, mkUsedNames )
 
 import GHC.Unit
 import GHC.Unit.Module.Warnings
diff --git a/compiler/GHC/Iface/Recomp.hs b/compiler/GHC/Iface/Recomp.hs
index 0abee1a5c0..918460a236 100644
--- a/compiler/GHC/Iface/Recomp.hs
+++ b/compiler/GHC/Iface/Recomp.hs
@@ -973,11 +973,11 @@ addFingerprints hsc_env iface0
    (local_env, decls_w_hashes) <-
        foldM fingerprint_group (emptyOccEnv, []) groups
 
-   -- when calculating fingerprints, we always need to use canonical
-   -- ordering for lists of things.  In particular, the mi_deps has various
-   -- lists of modules and suchlike, so put these all in canonical order:
+   -- when calculating fingerprints, we always need to use canonical ordering
+   -- for lists of things. The mi_deps has various lists of modules and
+   -- suchlike, which are stored in canonical order:
    let sorted_deps :: Dependencies
-       sorted_deps = sortDependencies (mi_deps iface0)
+       sorted_deps = mi_deps iface0
 
    -- The export hash of a module depends on the orphan hashes of the
    -- orphan modules below us in the dependency tree.  This is the way
@@ -1193,16 +1193,6 @@ getOrphanHashes hsc_env mods = do
   mapM get_orph_hash mods
 
 
-sortDependencies :: Dependencies -> Dependencies
-sortDependencies d
- = Deps { dep_direct_mods  = dep_direct_mods d,
-          dep_direct_pkgs  = dep_direct_pkgs d,
-          dep_sig_mods     = sort (dep_sig_mods d),
-          dep_trusted_pkgs = dep_trusted_pkgs d,
-          dep_boot_mods    = dep_boot_mods d,
-          dep_orphs  = sortBy stableModuleCmp (dep_orphs d),
-          dep_finsts = sortBy stableModuleCmp (dep_finsts d) }
-
 {-
 ************************************************************************
 *                                                                      *
diff --git a/compiler/GHC/Iface/Rename.hs b/compiler/GHC/Iface/Rename.hs
index e2a89570d3..fdbe0dd55a 100644
--- a/compiler/GHC/Iface/Rename.hs
+++ b/compiler/GHC/Iface/Rename.hs
@@ -128,19 +128,18 @@ rnModExports hsc_env insts iface
     $ mapM rnAvailInfo (mi_exports iface)
 
 rnDependencies :: Rename Dependencies
-rnDependencies deps = do
-    orphs  <- rnDepModules dep_orphs deps
-    finsts <- rnDepModules dep_finsts deps
-    return deps { dep_orphs = orphs, dep_finsts = finsts }
+rnDependencies deps0 = do
+    deps1  <- dep_orphs_update deps0 (rnDepModules dep_orphs)
+    dep_finsts_update deps1 (rnDepModules dep_finsts)
 
-rnDepModules :: (Dependencies -> [Module]) -> Dependencies -> ShIfM [Module]
-rnDepModules sel deps = do
+rnDepModules :: (Dependencies -> [Module]) -> [Module] -> ShIfM [Module]
+rnDepModules sel mods = do
     hsc_env <- getTopEnv
     hmap <- getHoleSubst
     -- NB: It's not necessary to test if we're doing signature renaming,
     -- because ModIface will never contain module reference for itself
     -- in these dependencies.
-    fmap (nubSort . concat) . T.forM (sel deps) $ \mod -> do
+    fmap (nubSort . concat) . T.forM mods $ \mod -> do
         -- For holes, its necessary to "see through" the instantiation
         -- of the hole to get accurate family instance dependencies.
         -- For example, if B imports <A>, and <A> is instantiated with