Generalize exposed-modules field in installed package database

Summary:
Instead of recording exposed-modules and reexported-modules as seperate
fields in the installed package database, this commit merges them into
a single field (exposed-modules).  The motivation for this change is
in preparation for the inclusion of *signatures* into the installed
package database, which may also be reexported.  Merging the representation
means that we can treat reexports uniformly, no matter if they're a normal
module or a signature.

This commit adds a stub for signatures, but that code isn't wired up to
anything yet.

Contains Cabal submodule update to accommodate these changes.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Test Plan: validate

Reviewers: simonpj, duncan, austin

Subscribers: thomie, carter, simonmar

Differential Revision: https://phabricator.haskell.org/D421

1 files changed, 25 insertions, 2 deletions

diff --git a/compiler/main/PackageConfig.hs b/compiler/main/PackageConfig.hs
index 3f2bf1680b..b94ea65a65 100644
--- a/compiler/main/PackageConfig.hs
+++ b/compiler/main/PackageConfig.hs
@@ -75,6 +75,25 @@ instance Outputable SourcePackageId where
 instance Outputable PackageName where
   ppr (PackageName str) = ftext str
 
+-- | Pretty-print an 'ExposedModule' in the same format used by the textual
+-- installed package database.
+pprExposedModule :: (Outputable a, Outputable b) => ExposedModule a b -> SDoc
+pprExposedModule (ExposedModule exposedName exposedReexport exposedSignature) =
+    sep [ ppr exposedName
+        , case exposedReexport of
+            Just m -> sep [text "from", pprOriginalModule m]
+            Nothing -> empty
+        , case exposedSignature of
+            Just m -> sep [text "is", pprOriginalModule m]
+            Nothing -> empty
+        ]
+
+-- | Pretty-print an 'OriginalModule' in the same format used by the textual
+-- installed package database.
+pprOriginalModule :: (Outputable a, Outputable b) => OriginalModule a b -> SDoc
+pprOriginalModule (OriginalModule originalPackageId originalModuleName) =
+    ppr originalPackageId <> char ':' <> ppr originalModuleName
+
 defaultPackageConfig :: PackageConfig
 defaultPackageConfig = emptyInstalledPackageInfo
 
@@ -101,9 +120,11 @@ pprPackageConfig InstalledPackageInfo {..} =
       field "id"                   (ppr installedPackageId),
       field "key"                  (ppr packageKey),
       field "exposed"              (ppr exposed),
-      field "exposed-modules"      (fsep (map ppr exposedModules)),
+      field "exposed-modules"
+        (if all isExposedModule exposedModules
+           then fsep (map pprExposedModule exposedModules)
+           else pprWithCommas pprExposedModule exposedModules),
       field "hidden-modules"       (fsep (map ppr hiddenModules)),
-      field "reexported-modules"   (fsep (map ppr haddockHTMLs)),
       field "trusted"              (ppr trusted),
       field "import-dirs"          (fsep (map text importDirs)),
       field "library-dirs"         (fsep (map text libraryDirs)),
@@ -122,6 +143,8 @@ pprPackageConfig InstalledPackageInfo {..} =
     ]
   where
     field name body = text name <> colon <+> nest 4 body
+    isExposedModule (ExposedModule _ Nothing Nothing) = True
+    isExposedModule _ = False
 
 
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