+-- This has to compare the TyThing from the .hi-boot file to the TyThing
+-- in the current source file. We must be careful to allow alpha-renaming
+-- where appropriate, and also the boot declaration is allowed to omit
+-- constructors and class methods.
+--
+-- See rnfail055 for a good test of this stuff.
+
+checkBootDecl :: TyThing -> TyThing -> Bool
+
+checkBootDecl (AnId id1) (AnId id2)
+ = ASSERT(id1 == id2)
+ (idType id1 `tcEqType` idType id2)
+
+checkBootDecl (ATyCon tc1) (ATyCon tc2)
+ = checkBootTyCon tc1 tc2
+
+checkBootDecl (AClass c1) (AClass c2)
+ = let
+ (clas_tyvars1, clas_fds1, sc_theta1, _, ats1, op_stuff1)
+ = classExtraBigSig c1
+ (clas_tyvars2, clas_fds2, sc_theta2, _, ats2, op_stuff2)
+ = classExtraBigSig c2
+
+ env0 = mkRnEnv2 emptyInScopeSet
+ env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2
+
+ eqSig (id1, def_meth1) (id2, def_meth2)
+ = idName id1 == idName id2 &&
+ tcEqTypeX env op_ty1 op_ty2 &&
+ def_meth1 == def_meth2
+ where
+ (_, rho_ty1) = splitForAllTys (idType id1)
+ op_ty1 = funResultTy rho_ty1
+ (_, rho_ty2) = splitForAllTys (idType id2)
+ op_ty2 = funResultTy rho_ty2
+
+ eqFD (as1,bs1) (as2,bs2) =
+ eqListBy (tcEqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) &&
+ eqListBy (tcEqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2)
+
+ same_kind tv1 tv2 = eqKind (tyVarKind tv1) (tyVarKind tv2)
+ in
+ eqListBy same_kind clas_tyvars1 clas_tyvars2 &&
+ -- Checks kind of class
+ eqListBy eqFD clas_fds1 clas_fds2 &&
+ (null sc_theta1 && null op_stuff1 && null ats1
+ || -- Above tests for an "abstract" class
+ eqListBy (tcEqPredX env) sc_theta1 sc_theta2 &&
+ eqListBy eqSig op_stuff1 op_stuff2 &&
+ eqListBy checkBootTyCon ats1 ats2)
+
+checkBootDecl (ADataCon dc1) (ADataCon _)
+ = pprPanic "checkBootDecl" (ppr dc1)
+
+checkBootDecl _ _ = False -- probably shouldn't happen
+