From: simonpj@microsoft.com <unknown>
Date: Wed, 22 Nov 2006 17:34:15 +0000 (+0000)
Subject: Improve recovery in hptRules
X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;h=78bfe2ad25ff34cefa14e7f11093923f5d1e940f;p=ghc-hetmet.git

Improve recovery in hptRules
---

diff --git a/compiler/main/HscTypes.lhs b/compiler/main/HscTypes.lhs
index a0e4857..e6e8e4c 100644
--- a/compiler/main/HscTypes.lhs
+++ b/compiler/main/HscTypes.lhs
@@ -295,12 +295,15 @@ hptRules hsc_env deps
     , mod /= moduleName gHC_PRIM
 
 	-- Look it up in the HPT
-    , let mod_info = case lookupUFM hpt mod of
-		  	Nothing -> pprPanic "hptRules" (ppr mod <+> ppr deps)
-		  	Just x  -> x
+    , let rules = case lookupUFM hpt mod of
+		    Just info -> md_rules (hm_details info)
+		    Nothing -> pprTrace "WARNING in hptRules" msg [] 
+	  msg = vcat [ptext SLIT("missing module") <+> ppr mod,
+		      ptext SLIT("Probable cause: out-of-date interface files")]
+			-- This really shouldn't happen, but see Trac #962
 
 	-- And get its dfuns
-    , rule <- md_rules (hm_details mod_info) ]
+    , rule <- rules ]
 \end{code}
 
 %************************************************************************