[project @ 2003-06-12 16:50:19 by simonpj]

----------------------------------
	Fix the no-GHC.Err problem in GHCi
	----------------------------------

Merge this to the stable branch.

Pattern-match failure error-ids are wired-in, which means the
GHC.Err interface isn't loaded, which in turn confused the linker
when tried to find what package GHC.Err is from.

Now we exclude wired-in names from the free variables looked at
by the linker (in Linker.linkExpr), and make sure the base package
is loaded unconditionally (DriverState.initPackageList).

diff --git a/ghc/compiler/ghci/Linker.lhs b/ghc/compiler/ghci/Linker.lhs
index 5f19e2b..e965d01 100644 (file)
--- a/ghc/compiler/ghci/Linker.lhs
+++ b/ghc/compiler/ghci/Linker.lhs
@@ -35,7 +35,7 @@ import DriverState    ( v_Cmdline_frameworks, v_Framework_paths )
 #endif
 import Finder          ( findModule, findLinkable )
 import HscTypes
-import Name            ( Name,  nameModule, isExternalName )
+import Name            ( Name,  nameModule, isExternalName, isWiredInName )
 import NameEnv
 import NameSet         ( nameSetToList )
 import Module
@@ -327,7 +327,14 @@ linkExpr hsc_env pcs root_ul_bco
      free_names = nameSetToList (bcoFreeNames root_ul_bco)
 
      needed_mods :: [Module]
-     needed_mods = [ nameModule n | n <- free_names, isExternalName n ]
+     needed_mods = [ nameModule n | n <- free_names, 
+                                   isExternalName n,           -- Names from other modules
+                                   not (isWiredInName n)       -- Exclude wired-in names
+                  ]                                            -- (see note below)
+       -- Exclude wired-in names because we may not have read
+       -- their interface files, so getLinkDeps will fail
+       -- All wired-in names are in the base package, which we link
+       -- by default, so we can safely ignore them here.
  
 dieWith msg = throwDyn (ProgramError (showSDoc msg))
 

diff --git a/ghc/compiler/main/DriverState.hs b/ghc/compiler/main/DriverState.hs
index 78ee4d3..76c8295 100644 (file)
--- a/ghc/compiler/main/DriverState.hs
+++ b/ghc/compiler/main/DriverState.hs
@@ -1,5 +1,5 @@
 -----------------------------------------------------------------------------
--- $Id: DriverState.hs,v 1.90 2003/02/04 15:09:40 simonpj Exp $
+-- $Id: DriverState.hs,v 1.91 2003/06/12 16:50:19 simonpj Exp $
 --
 -- Settings for the driver
 --
@@ -478,7 +478,12 @@ mungePackagePaths top_dir ps = map munge_pkg ps
 -- earlier packages may depend on later ones, but not vice versa
 GLOBAL_VAR(v_ExplicitPackages, initPackageList, [PackageName])
 
-initPackageList = [rtsPackage]
+initPackageList = [basePackage, rtsPackage]
+       -- basePackage is part of this list entirely because of 
+       -- wired-in names in GHCi.  See the notes on wired-in names in
+       -- Linker.linkExpr.  By putting the base backage in initPackageList
+       -- we make sure that it'll always by linked.
+
 
 -- add a package requested from the command-line
 addPackage :: String -> IO ()