---

yaml
---
r: 157611
b: refs/heads/snap-stage3
c: 8d8d8d4
h: refs/heads/master
i:
  157609: 1c3a575
  157607: 0df5c2c
v: v3

Author: nrc

[refs]

@@ -1,7 +1,7 @@
 ---
 refs/heads/master: 065caf34f5ff29e04605f95d9c5d511af219439a
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
-refs/heads/snap-stage3: d1fc2dec79689fe6bd37c95f3fe5b7acd476fff6
+refs/heads/snap-stage3: 8d8d8d4e5292c2fa4a622d981a5f85fd3d8f34d0
 refs/heads/try: 0ee4d8b0b112c608646fa75463ab4dc59132efd9
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b

branches/snap-stage3/mk/llvm.mk

@@ -38,7 +38,7 @@ endif
 # the stamp in the source dir.
 $$(LLVM_STAMP_$(1)): $(S)src/rustllvm/llvm-auto-clean-trigger
 	@$$(call E, make: cleaning llvm)
-	$(Q)$(MAKE) clean-llvm$(1)
+	$(Q)$(MAKE) clean-llvm
 	@$$(call E, make: done cleaning llvm)
 	touch $$@
 

branches/snap-stage3/src/librustc/middle/typeck/check/method.rs

@@ -1336,16 +1336,6 @@ impl<'a, 'tcx> LookupContext<'a, 'tcx> {
                self.ty_to_string(rcvr_ty),
                candidate.repr(self.tcx()));
 
-        let mut rcvr_substs = candidate.rcvr_substs.clone();
-
-        if !self.enforce_object_limitations(candidate) {
-            // Here we change `Self` from `Trait` to `err` in the case that
-            // this is an illegal object method. This is necessary to prevent
-            // the user from getting strange, derivative errors when the method
-            // takes an argument/return-type of type `Self` etc.
-            rcvr_substs.types.get_mut_slice(SelfSpace)[0] = ty::mk_err();
-        }
-
         self.enforce_drop_trait_limitations(candidate);
 
         // Determine the values for the generic parameters of the method.
@@ -1554,71 +1544,6 @@ impl<'a, 'tcx> LookupContext<'a, 'tcx> {
         }
     }
 
-    fn enforce_object_limitations(&self, candidate: &Candidate) -> bool {
-        /*!
-         * There are some limitations to calling functions through an
-         * object, because (a) the self type is not known
-         * (that's the whole point of a trait instance, after all, to
-         * obscure the self type) and (b) the call must go through a
-         * vtable and hence cannot be monomorphized.
-         */
-
-        match candidate.origin {
-            MethodStatic(..) |
-            MethodTypeParam(..) |
-            MethodStaticUnboxedClosure(..) => {
-                return true; // not a call to a trait instance
-            }
-            MethodTraitObject(..) => {}
-        }
-
-        match candidate.method_ty.explicit_self {
-            ty::StaticExplicitSelfCategory => { // reason (a) above
-                self.tcx().sess.span_err(
-                    self.span,
-                    "cannot call a method without a receiver \
-                     through an object");
-                return false;
-            }
-
-            ty::ByValueExplicitSelfCategory |
-            ty::ByReferenceExplicitSelfCategory(..) |
-            ty::ByBoxExplicitSelfCategory => {}
-        }
-
-        // reason (a) above
-        let check_for_self_ty = |ty| -> bool {
-            if ty::type_has_self(ty) {
-                span_err!(self.tcx().sess, self.span, E0038,
-                    "cannot call a method whose type contains a \
-                     self-type through an object");
-                false
-            } else {
-                true
-            }
-        };
-        let ref sig = candidate.method_ty.fty.sig;
-        for &input_ty in sig.inputs[1..].iter() {
-            if !check_for_self_ty(input_ty) {
-                return false;
-            }
-        }
-        if let ty::FnConverging(result_type) = sig.output {
-            if !check_for_self_ty(result_type) {
-                return false;
-            }
-        }
-
-        if candidate.method_ty.generics.has_type_params(subst::FnSpace) {
-            // reason (b) above
-            span_err!(self.tcx().sess, self.span, E0039,
-                "cannot call a generic method through an object");
-            return false;
-        }
-
-        true
-    }
-
     fn enforce_drop_trait_limitations(&self, candidate: &Candidate) {
         // No code can call the finalize method explicitly.
         let bad = match candidate.origin {

branches/snap-stage3/src/librustc/middle/typeck/check/mod.rs

@@ -1687,6 +1687,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 self.register_unsize_obligations(span, &**u)
             }
             ty::UnsizeVtable(ref ty_trait, self_ty) => {
+                vtable2::check_object_safety(self.tcx(), ty_trait, span);
                 // If the type is `Foo+'a`, ensures that the type
                 // being cast to `Foo+'a` implements `Foo`:
                 vtable::register_object_cast_obligations(self,

branches/snap-stage3/src/librustc/middle/typeck/check/vtable.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use middle::subst::{SelfSpace};
+use middle::subst::{SelfSpace, FnSpace};
 use middle::traits;
 use middle::traits::{SelectionError, OutputTypeParameterMismatch, Overflow, Unimplemented};
 use middle::traits::{Obligation, obligation_for_builtin_bound};
@@ -46,6 +46,7 @@ pub fn check_object_cast(fcx: &FnCtxt,
 
             // Ensure that if ~T is cast to ~Trait, then T : Trait
             push_cast_obligation(fcx, cast_expr, object_trait, referent_ty);
+            check_object_safety(fcx.tcx(), object_trait, source_expr.span);
         }
 
         (&ty::ty_rptr(referent_region, ty::mt { ty: referent_ty,
@@ -68,6 +69,8 @@ pub fn check_object_cast(fcx: &FnCtxt,
                                infer::RelateObjectBound(source_expr.span),
                                target_region,
                                referent_region);
+
+                check_object_safety(fcx.tcx(), object_trait, source_expr.span);
             }
         }
 
@@ -128,6 +131,70 @@ pub fn check_object_cast(fcx: &FnCtxt,
     }
 }
 
+// TODO comment
+pub fn check_object_safety(tcx: &ty::ctxt, object_trait: &ty::TyTrait, span: Span) {
+    let trait_items = ty::trait_items(tcx, object_trait.def_id);
+    for item in trait_items.iter() {
+        match *item {
+            ty::MethodTraitItem(ref m) => check_object_safety_of_method(tcx, &**m, span),
+            ty::TypeTraitItem(_) => {}
+        }
+    }
+
+    // TODO error messages
+    fn check_object_safety_of_method(tcx: &ty::ctxt, method: &ty::Method, span: Span) {
+        /*!
+         * There are some limitations to calling functions through an
+         * object, because (a) the self type is not known
+         * (that's the whole point of a trait instance, after all, to
+         * obscure the self type) and (b) the call must go through a
+         * vtable and hence cannot be monomorphized.
+         */
+
+        match method.explicit_self {
+            ty::ByValueExplicitSelfCategory => { // reason (a) above
+                tcx.sess.span_err(
+                    span,
+                    "cannot call a method with a by-value receiver \
+                     through a trait object");
+            }
+
+            ty::StaticExplicitSelfCategory |
+            ty::ByReferenceExplicitSelfCategory(..) |
+            ty::ByBoxExplicitSelfCategory => {}
+        }
+
+        // reason (a) above
+        let check_for_self_ty = |ty| {
+            if ty::type_has_self(ty) {
+                span_err!(tcx.sess, span, E0038,
+                    "cannot call a method whose type contains a \
+                     self-type through an object: {}", ::util::ppaux::ty_to_string(tcx, ty));
+                true
+            } else {
+                false
+            }
+        };
+        let ref sig = method.fty.sig;
+        let mut found_self_ty = false;
+        for &input_ty in sig.inputs.tail().iter() {
+            if check_for_self_ty(input_ty) {
+                found_self_ty = true;
+                break;
+            }
+        }
+        if !found_self_ty {
+            check_for_self_ty(sig.output);
+        }
+
+        if method.generics.has_type_params(FnSpace) {
+            // reason (b) above
+            span_err!(tcx.sess, span, E0039,
+                "cannot call a generic method through an object");
+        }
+    }
+}
+
 pub fn register_object_cast_obligations(fcx: &FnCtxt,
                                         span: Span,
                                         object_trait: &ty::TyTrait,