[project @ 2005-05-03 13:41:01 by simonpj]

[ghc-hetmet.git] / ghc / compiler / typecheck / TcInstDcls.lhs

diff --git a/ghc/compiler/typecheck/TcInstDcls.lhs b/ghc/compiler/typecheck/TcInstDcls.lhs
index 6fdc327..dcf8986 100644 (file)
--- a/ghc/compiler/typecheck/TcInstDcls.lhs
+++ b/ghc/compiler/typecheck/TcInstDcls.lhs
@@ -9,7 +9,7 @@ module TcInstDcls ( tcInstDecls1, tcInstDecls2 ) where
 #include "HsVersions.h"
 
 import HsSyn
-import TcBinds         ( tcSpecSigs )
+import TcBinds         ( tcSpecSigs, badBootDeclErr )
 import TcClassDcl      ( tcMethodBind, mkMethodBind, badMethodErr, 
                          tcClassDecl2, getGenericInstances )
 import TcRnMonad       
@@ -208,6 +208,11 @@ tcLocalInstDecl1 decl@(L loc (InstDecl poly_ty binds uprags))
     let dfun  = mkDictFunId dfun_name tyvars theta clas inst_tys
        ispec = mkLocalInstance dfun overlap_flag
     in
+
+    tcIsHsBoot                                         `thenM` \ is_boot ->
+    checkTc (not is_boot || (isEmptyLHsBinds binds && null uprags))
+           badBootDeclErr                              `thenM_`
+
     returnM (Just (InstInfo { iSpec = ispec, iBinds = VanillaInst binds uprags }))
   where
     msg  = parens (ptext SLIT("the instance types do not agree with the functional dependencies of the class"))