[project @ 2005-11-02 09:57:45 by simonpj]

Correct the TH fix of Oct 26, involving thFAKE
		MERGE TO STABLE

Original message
  1) A bug in the renaming of [d| brackets |]. The problem was
  that when we renamed the bracket we messed up the name cache, because
  the module was still that of the parent module. Now we set a fake
  module before renaming it.

But we have to tell the *typechecker* too, not just the renamer.
See comments with TcSplice.tc_bracket (DecBr case).

Should fix TH failures in the STABLE branch

diff --git a/ghc/compiler/typecheck/TcRnMonad.lhs b/ghc/compiler/typecheck/TcRnMonad.lhs
index a4032cd..845bdd4 100644 (file)
--- a/ghc/compiler/typecheck/TcRnMonad.lhs
+++ b/ghc/compiler/typecheck/TcRnMonad.lhs
@@ -373,6 +373,9 @@ dumpOptTcRn flag doc = ifOptM flag (dumpTcRn doc)
 getModule :: TcRn Module
 getModule = do { env <- getGblEnv; return (tcg_mod env) }
 
+setModule :: Module -> TcRn a -> TcRn a
+setModule mod thing_inside = updGblEnv (\env -> env { tcg_mod = mod }) thing_inside
+
 tcIsHsBoot :: TcRn Bool
 tcIsHsBoot = do { env <- getGblEnv; return (isHsBoot (tcg_src env)) }
 

diff --git a/ghc/compiler/typecheck/TcSplice.lhs b/ghc/compiler/typecheck/TcSplice.lhs
index 1262674..37adac1 100644 (file)
--- a/ghc/compiler/typecheck/TcSplice.lhs
+++ b/ghc/compiler/typecheck/TcSplice.lhs
@@ -34,6 +34,7 @@ import TcMType                ( newTyFlexiVarTy, newKindVar, UserTypeCtxt(ExprSigCtxt), zonkTc
 import TcHsType                ( tcHsSigType, kcHsType )
 import TcIface         ( tcImportDecl )
 import TypeRep         ( Type(..), PredType(..), TyThing(..) ) -- For reification
+import PrelNames       ( thFAKE )
 import Name            ( Name, NamedThing(..), nameOccName, nameModule, isExternalName, 
                          nameIsLocalOrFrom )
 import NameEnv         ( lookupNameEnv )
@@ -139,9 +140,13 @@ tc_bracket (TypBr typ)
        -- Result type is Type (= Q Typ)
 
 tc_bracket (DecBr decls)
-  = do { tcTopSrcDecls emptyModDetails decls
+  = do { setModule thFAKE $ tcTopSrcDecls emptyModDetails decls
        -- Typecheck the declarations, dicarding the result
        -- We'll get all that stuff later, when we splice it in
+       -- See comments with RnExpr.rnBracket for the thFAKE stuff;
+       --      the type checker uses the module name to decide which
+       --      names are local (and hence can be found in the local
+       --      type envt), so we do need to set the module here too.
 
        ; decl_ty <- tcMetaTy decTyConName
        ; q_ty    <- tcMetaTy qTyConName