[project @ 2005-04-07 11:35:48 by simonmar]

Add the -hide-all-packages flag.

ghc/compiler/main/DynFlags.hs

@@ -60,7 +60,9 @@ import Util		( notNull, splitLongestPrefix, split, normalisePath )
 import DATA_IOREF	( readIORef )
 import EXCEPTION	( throwDyn )
 import Monad		( when )
+#ifdef mingw32_TARGET_OS
 import Data.List	( isPrefixOf )
+#endif
 import Maybe		( fromJust )
 import Char		( isDigit, isUpper )
 
@@ -168,6 +170,7 @@ data DynFlag
    | Opt_NoHsMain
    | Opt_SplitObjs
    | Opt_StgStats
+   | Opt_HideAllPackages
 
    -- keeping stuff
    | Opt_KeepHiDiffs
@@ -819,6 +822,7 @@ dynamic_flags = [
   ,  ( "package-name"   , HasArg ignorePackage ) -- for compatibility
   ,  ( "package"        , HasArg exposePackage )
   ,  ( "hide-package"   , HasArg hidePackage )
+  ,  ( "hide-all-packages", NoArg (setDynFlag Opt_HideAllPackages) )
   ,  ( "ignore-package" , HasArg ignorePackage )
   ,  ( "syslib"         , HasArg exposePackage )  -- for compatibility
 

ghc/compiler/main/Packages.lhs

@@ -228,9 +228,16 @@ readPackageConfig dflags pkg_map conf_file = do
   debugTraceMsg dflags 2 ("Using package config file: " ++ conf_file)
   proto_pkg_configs <- loadPackageConfig conf_file
   top_dir 	    <- getTopDir
-  let pkg_configs = mungePackagePaths top_dir proto_pkg_configs
-  return (extendPackageConfigMap pkg_map pkg_configs)
-
+  let pkg_configs1 = mungePackagePaths top_dir proto_pkg_configs
+      pkg_configs2 = maybeHidePackages dflags pkg_configs1
+  return (extendPackageConfigMap pkg_map pkg_configs2)
+
+maybeHidePackages :: DynFlags -> [PackageConfig] -> [PackageConfig]
+maybeHidePackages dflags pkgs
+  | dopt Opt_HideAllPackages dflags = map hide pkgs
+  | otherwise 			    = pkgs
+  where
+    hide pkg = pkg{ exposed = False }
 
 mungePackagePaths :: String -> [PackageConfig] -> [PackageConfig]
 -- Replace the string "$topdir" at the beginning of a path
@@ -257,7 +264,7 @@ mkPackageState :: DynFlags -> PackageConfigMap -> IO PackageState
 mkPackageState dflags pkg_db = do
   --
   -- Modify the package database according to the command-line flags
-  -- (-package, -hide-package, -ignore-package).
+  -- (-package, -hide-package, -ignore-package, -hide-all-packages).
   --
   -- Also, here we build up a set of the packages mentioned in -package
   -- flags on the command line; these are called the "explicit" packages.

ghc/docs/users_guide/flags.xml

@@ -480,6 +480,12 @@
 	      <entry>static</entry>
 	      <entry>-</entry>
 	    </row>
+	    <row>
+	      <entry><option>-hide-all-packages</option></entry>
+	      <entry>Hide all packages by default</entry>
+	      <entry>static</entry>
+	      <entry>-</entry>
+	    </row>
 	    <row>
 	      <entry><option>-hide-package</option> <replaceable>name</replaceable></entry>
 	      <entry>Hide package <replaceable>P</replaceable></entry>

ghc/docs/users_guide/packages.xml

@@ -130,6 +130,23 @@ exposed-modules: Network.BSD,
 	</listitem>
       </varlistentry>
       
+      <varlistentry>
+	<term><option>-hide-all-packages</option>
+	<indexterm><primary><option>-hide-package</option></primary>
+	  </indexterm></term>
+	<listitem>
+	  <para>Ignore the exposed flag on installed packages, and hide them
+	    all by default.  If you use
+	    this flag, then any packages you require (including
+	    <literal>base</literal>) need to be explicitly exposed using
+	    <option>-package</option> options.</para>
+
+	  <para>This is a good way to insulate your program from differences
+	    in the globally exposed packages, and being explicit about package
+	    dependencies is a Good Thing.</para>
+	</listitem>
+      </varlistentry>
+
       <varlistentry>
 	<term><option>-hide-package</option> <replaceable>P</replaceable>
 	<indexterm><primary><option>-hide-package</option></primary>