[project @ 2000-03-06 11:58:27 by simonmar]

Turn the panic in Lex.popContext into a parse error.

2 files changed, 16 insertions, 15 deletions

diff --git a/ghc/compiler/parser/Lex.lhs b/ghc/compiler/parser/Lex.lhs
index b2f04b04ff..6d56a6de73 100644
--- a/ghc/compiler/parser/Lex.lhs
+++ b/ghc/compiler/parser/Lex.lhs
@@ -20,7 +20,7 @@ An example that provokes the error is
 
 module Lex (
 
-	ifaceParseErr,
+	ifaceParseErr, srcParseErr,
 
 	-- Monad for parser
 	Token(..), lexer, ParseResult(..), PState(..),
@@ -1250,10 +1250,10 @@ layoutOff buf s@(PState{ context = ctx }) =
     POk s{ context = NoLayout:ctx } ()
 
 popContext :: P ()
-popContext = \ buf s@(PState{ context = ctx }) ->
+popContext = \ buf s@(PState{ context = ctx, loc = loc }) ->
   case ctx of
 	(_:tl) -> POk s{ context = tl } ()
-	[]    -> panic "Lex.popContext: empty context"
+	[]     -> PFailed (srcParseErr buf loc)
 
 {- 
  Note that if the name of the file we're processing ends
@@ -1295,4 +1295,17 @@ ifaceVersionErr hi_vers l toks
         Nothing -> ptext SLIT("pre ghc-3.02 version")
 	Just v  -> ptext SLIT("version") <+> integer v
 
+-----------------------------------------------------------------------------
+
+srcParseErr :: StringBuffer -> SrcLoc -> Message
+srcParseErr s l
+  = hcat [ppr l, 
+	  if null token 
+	     then ptext SLIT(": parse error (possibly incorrect indentation)")
+	     else hcat [ptext SLIT(": parse error on input "),
+          	  	char '`', text token, char '\'']
+    ]
+  where 
+	token = lexemeToString s
+
 \end{code}
diff --git a/ghc/compiler/parser/ParseUtil.lhs b/ghc/compiler/parser/ParseUtil.lhs
index c396e3f936..e26415e4d9 100644
--- a/ghc/compiler/parser/ParseUtil.lhs
+++ b/ghc/compiler/parser/ParseUtil.lhs
@@ -6,7 +6,6 @@
 \begin{code}
 module ParseUtil (
 	  parseError		-- String -> Pa
-	, srcParseErr		-- StringBuffer -> SrcLoc -> Message
 	, cbot			-- a
 	, splitForConApp        -- RdrNameHsType -> [RdrNameBangType]
 				--     -> P (RdrName, [RdrNameBangType])
@@ -71,17 +70,6 @@ parseError s =
   getSrcLocP `thenP` \ loc ->
   failMsgP (hcat [ppr loc, text ": ", text s])
 
-srcParseErr :: StringBuffer -> SrcLoc -> Message
-srcParseErr s l
-  = hcat [ppr l, 
-	  if null token 
-	     then ptext SLIT(": parse error (possibly incorrect indentation)")
-	     else hcat [ptext SLIT(": parse error on input "),
-          	  	char '`', text token, char '\'']
-    ]
-  where 
-	token = lexemeToString s
-
 cbot = panic "CCall:result_ty"
 
 -----------------------------------------------------------------------------