From: simonpj@microsoft.com <unknown>
Date: Fri, 14 Apr 2006 12:04:11 +0000 (+0000)
Subject: Fix TH erorr recovery (test is TH_recover)
X-Git-Tag: Before_FC_branch_merge~546
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=f7f06be1f47dcb3a48c4bc7ef0a2c59e49e28115

Fix TH erorr recovery (test is TH_recover)
---

diff --git a/compiler/typecheck/TcSplice.lhs b/compiler/typecheck/TcSplice.lhs
index 2215c9b..7c3aa86 100644
--- a/compiler/typecheck/TcSplice.lhs
+++ b/compiler/typecheck/TcSplice.lhs
@@ -421,7 +421,16 @@ instance TH.Quasi (IOEnv (Env TcGblEnv TcLclEnv)) where
 
   qCurrentModule = do { m <- getModule; return (moduleString m) }
   qReify v = reify v
-  qRecover = recoverM
+
+	-- For qRecover, discard error messages if 
+	-- the recovery action is chosen.  Otherwise
+	-- we'll only fail higher up.  c.f. tryTcLIE_
+  qRecover recover main = do { (msgs, mb_res) <- tryTcErrs main
+			     ; case mb_res of
+		  	         Just val -> do { addMessages msgs	-- There might be warnings
+				   	        ; return val }
+		  	         Nothing  -> recover			-- Discard all msgs
+			  }
 
   qRunIO io = ioToTcRn io
 \end{code}