From 0116f0598ac43a9a6f2cb2d5f42b284955695e9b Mon Sep 17 00:00:00 2001
From: simonpj <unknown>
Date: Thu, 12 Jun 2003 16:50:19 +0000
Subject: [PATCH] [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).
---
 ghc/compiler/ghci/Linker.lhs     |   11 +++++++++--
 ghc/compiler/main/DriverState.hs |    9 +++++++--
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/ghc/compiler/ghci/Linker.lhs b/ghc/compiler/ghci/Linker.lhs
index 5f19e2b..e965d01 100644
--- 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
--- 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 ()
-- 
1.7.10.4