[project @ 2003-02-05 11:41:50 by simonpj]

Wibble to TcRules (fixes HEAD breakage)

diff --git a/ghc/compiler/typecheck/TcRules.lhs b/ghc/compiler/typecheck/TcRules.lhs
index 3cc7770..492e9ab 100644 (file)
--- a/ghc/compiler/typecheck/TcRules.lhs
+++ b/ghc/compiler/typecheck/TcRules.lhs
@@ -19,7 +19,7 @@ import TcType         ( tyVarsOfTypes, openTypeKind )
 import TcIfaceSig      ( tcCoreExpr, tcCoreLamBndrs )
 import TcMonoType      ( tcHsSigType, UserTypeCtxt(..), tcAddScopedTyVars )
 import TcExpr          ( tcMonoExpr )
-import TcEnv           ( tcExtendLocalValEnv, tcLookupGlobalId )
+import TcEnv           ( tcExtendLocalValEnv, tcLookupGlobalId, tcLookupId )
 import Inst            ( instToId )
 import Id              ( idType, mkLocalId )
 import Outputable
@@ -39,8 +39,15 @@ tcRule (IfaceRule name act vars fun args rhs src_loc)
     tcCoreExpr rhs                     `thenM` \ rhs' ->
     returnM (IfaceRuleOut fun' (Rule name act vars' args' rhs'))
 
-tcRule (IfaceRuleOut fun rule) -- Built-in rules come this way
-  = tcLookupGlobalId fun               `thenM` \ fun' ->
+tcRule (IfaceRuleOut fun rule) -- Built-in rules, and only built-in rules, 
+                               -- come this way.  Usually IfaceRuleOut is only
+                               -- used for the *output* of the type checker
+  = tcLookupId fun             `thenM` \ fun' ->
+       -- NB: tcLookupId, not tcLookupGlobalId
+       -- Reason: when compiling GHC.Base, where eqString is defined,
+       --         we'll get the builtin rule for eqString, but eqString
+       --         will be in the *local* type environment.
+       -- Seems like a bit of a hack
     returnM (IfaceRuleOut fun' rule)   
 
 tcRule (HsRule name act vars lhs rhs src_loc)