Keep track of the whole error chain

src/librustc/middle/traits/select.rs

@@ -1928,6 +1928,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         }
     }
 
+    #[allow(unused_comparisons)]
     fn derived_cause(&self,
                      obligation: &TraitObligation<'tcx>,
                      variant: fn(Rc<ty::Binder<ty::TraitRef<'tcx>>>,
@@ -1945,7 +1946,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
          * reporting.
          */
 
-        if obligation.recursion_depth == 0 {
+        // NOTE(flaper87): As of now, it keeps track of the whole error
+        // chain. Ideally, we should have a way to configure this either
+        // by using -Z verbose or just a CLI argument.
+        if obligation.recursion_depth >= 0 {
             ObligationCause::new(obligation.cause.span,
                                  obligation.trait_ref.def_id().node,
                                  variant(obligation.trait_ref.clone(),

src/libsyntax/ext/deriving/bounds.rs

@@ -26,8 +26,11 @@ pub fn expand_deriving_bound<F>(cx: &mut ExtCtxt,
         MetaWord(ref tname) => {
             match tname.get() {
                 "Copy" => "Copy",
-                "Send" => "Send",
-                "Sync" => "Sync",
+                "Send" | "Sync" => {
+                    return cx.span_err(span,
+                                       format!("{} is an unsafe trait and it \
+                                               should be implemented explicitly", *tname)[])
+                }
                 ref tname => {
                     cx.span_bug(span,
                                 format!("expected built-in trait name but \

src/test/compile-fail/deriving-bounds.rs

@@ -8,8 +8,12 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#[deriving(Sync(Bad),Send,Copy)]
+#[deriving(Copy(Bad))]
 //~^ ERROR unexpected value in deriving, expected a trait
 struct Test;
 
+#[deriving(Sync)]
+//~^ ERROR Sync is an unsafe trait and it should be implemented explicitly
+struct Test1;
+
 pub fn main() {}

src/test/compile-fail/issue-17718-static-sync.rs

@@ -14,6 +14,6 @@ struct Foo { marker: marker::NoSync }
 
 static FOO: uint = 3;
 static BAR: Foo = Foo { marker: marker::NoSync };
-//~^ ERROR: shared static items must have a type which implements Sync
+//~^ ERROR: the trait `core::kinds::Sync` is not implemented
 
 fn main() {}

src/test/compile-fail/issue-7013.rs

@@ -33,4 +33,5 @@ struct A {
 fn main() {
     let a = A {v: box B{v: None} as Box<Foo+Send>};
     //~^ ERROR the trait `core::kinds::Send` is not implemented
+    //~^^ ERROR the trait `core::kinds::Send` is not implemented
 }

src/test/compile-fail/issue-7364.rs

@@ -14,6 +14,8 @@ use std::cell::RefCell;
 // Regresion test for issue 7364
 static boxed: Box<RefCell<int>> = box RefCell::new(0);
 //~^ ERROR statics are not allowed to have custom pointers
-//~^^ ERROR: shared static items must have a type which implements Sync
+//~^^ ERROR: the trait `core::kinds::Sync` is not implemented for the type
+//~^^^ ERROR: the trait `core::kinds::Sync` is not implemented for the type
+//~^^^^ ERROR: the trait `core::kinds::Sync` is not implemented for the type
 
 fn main() { }

src/test/compile-fail/kindck-destructor-owned.rs

@@ -9,19 +9,6 @@
 // except according to those terms.
 
 
-use std::rc::Rc;
-
-struct Foo {
-    f: Rc<int>,
-}
-
-impl Drop for Foo {
-//~^ ERROR the trait `core::kinds::Send` is not implemented
-//~^^ NOTE cannot implement a destructor on a structure or enumeration that does not satisfy Send
-    fn drop(&mut self) {
-    }
-}
-
 struct Bar<'a> {
     f: &'a int,
 }

src/test/compile-fail/kindck-nonsendable-1.rs

@@ -17,6 +17,8 @@ fn bar<F:FnOnce() + Send>(_: F) { }
 
 fn main() {
     let x = Rc::new(3u);
-    bar(move|| foo(x)); //~ ERROR `core::kinds::Send` is not implemented
+    bar(move|| foo(x));
+    //~^ ERROR `core::kinds::Send` is not implemented
+    //~^^ ERROR `core::kinds::Send` is not implemented
 }
 

src/test/compile-fail/kindck-send-unsafe.rs

@@ -8,14 +8,13 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+extern crate core;
+
 fn assert_send<T:Send>() { }
 
-// unsafe ptrs are ok unless they point at unsendable things
-fn test70() {
-    assert_send::<*mut int>();
-}
 fn test71<'a>() {
-    assert_send::<*mut &'a int>(); //~ ERROR declared lifetime bound not satisfied
+    assert_send::<*mut &'a int>();
+    //~^ ERROR the trait `core::kinds::Send` is not implemented for the type
 }
 
 fn main() {

src/test/compile-fail/mut-not-freeze.rs

@@ -14,5 +14,8 @@ fn f<T: Sync>(_: T) {}
 
 fn main() {
     let x = RefCell::new(0i);
-    f(x); //~ ERROR `core::kinds::Sync` is not implemented
+    f(x);
+    //~^ ERROR `core::kinds::Sync` is not implemented
+    //~^^ ERROR `core::kinds::Sync` is not implemented
+    //~^^^ ERROR `core::kinds::Sync` is not implemented
 }

src/test/compile-fail/no-send-res-ports.rs

@@ -37,6 +37,7 @@ fn main() {
 
     task::spawn(move|| {
         //~^ ERROR `core::kinds::Send` is not implemented
+        //~^^ ERROR `core::kinds::Send` is not implemented
         let y = x;
         println!("{}", y);
     });

src/test/compile-fail/no_send-rc.rs

@@ -16,4 +16,5 @@ fn main() {
     let x = Rc::new(5i);
     bar(x);
     //~^ ERROR `core::kinds::Send` is not implemented
+    //~^^ ERROR `core::kinds::Send` is not implemented
 }

src/test/compile-fail/no_share-rc.rs

@@ -17,4 +17,5 @@ fn main() {
     let x = Rc::new(RefCell::new(5i));
     bar(x);
     //~^ ERROR the trait `core::kinds::Sync` is not implemented
+    //~^^ ERROR the trait `core::kinds::Sync` is not implemented
 }

src/test/compile-fail/regions-bounded-by-send.rs

@@ -12,8 +12,11 @@
 // in this file all test region bound and lifetime violations that are
 // detected during type check.
 
+extern crate core;
+use core::ptr::Unique;
+
 fn assert_send<T:Send>() { }
-trait Dummy { }
+trait Dummy:Send { }
 
 // lifetime pointers with 'static lifetime are ok
 
@@ -58,7 +61,7 @@ fn box_with_region_not_ok<'a>() {
 
 fn object_with_random_bound_not_ok<'a>() {
     assert_send::<&'a (Dummy+'a)>();
-    //~^ ERROR not implemented
+    //~^ ERROR reference has a longer lifetime
 }
 
 fn object_with_send_bound_not_ok<'a>() {
@@ -73,17 +76,12 @@ fn closure_with_lifetime_not_ok<'a>() {
 
 // unsafe pointers are ok unless they point at unsendable things
 
+struct UniqueUnsafePtr(Unique<*const int>);
+
+unsafe impl Send for UniqueUnsafePtr {}
+
 fn unsafe_ok1<'a>(_: &'a int) {
-    assert_send::<*const int>();
-    assert_send::<*mut int>();
-}
-
-fn unsafe_ok2<'a>(_: &'a int) {
-    assert_send::<*const &'a int>(); //~ ERROR declared lifetime bound not satisfied
-}
-
-fn unsafe_ok3<'a>(_: &'a int) {
-    assert_send::<*mut &'a int>(); //~ ERROR declared lifetime bound not satisfied
+    assert_send::<UniqueUnsafePtr>();
 }
 
 fn main() {

src/test/compile-fail/task-rng-isnt-sendable.rs

@@ -17,4 +17,5 @@ fn test_send<S: Send>() {}
 pub fn main() {
     test_send::<rand::TaskRng>();
     //~^ ERROR `core::kinds::Send` is not implemented
+    //~^^ ERROR `core::kinds::Send` is not implemented
 }

src/test/compile-fail/typeck-unsafe-always-share.rs

@@ -30,12 +30,15 @@ fn test<T: Sync>(s: T){
 fn main() {
     let us = UnsafeCell::new(MySync{u: UnsafeCell::new(0i)});
     test(us);
+    //~^ ERROR `core::kinds::Sync` is not implemented
 
     let uns = UnsafeCell::new(NoSync{m: marker::NoSync});
     test(uns);
+    //~^ ERROR `core::kinds::Sync` is not implemented
 
     let ms = MySync{u: uns};
     test(ms);
+    //~^ ERROR `core::kinds::Sync` is not implemented
 
     let ns = NoSync{m: marker::NoSync};
     test(ns);

src/test/compile-fail/unique-unique-kind.rs

@@ -16,5 +16,7 @@ fn f<T:Send>(_i: T) {
 
 fn main() {
     let i = box Rc::new(100i);
-    f(i); //~ ERROR `core::kinds::Send` is not implemented
+    f(i);
+    //~^ ERROR `core::kinds::Send` is not implemented
+    //~^^ ERROR `core::kinds::Send` is not implemented
 }

src/test/compile-fail/unsendable-class.rs

@@ -28,6 +28,8 @@ fn foo(i:int, j: Rc<String>) -> foo {
 
 fn main() {
   let cat = "kitty".to_string();
-  let (tx, _) = channel(); //~ ERROR `core::kinds::Send` is not implemented
+  let (tx, _) = channel();
+  //~^ ERROR `core::kinds::Send` is not implemented
+  //~^^ ERROR `core::kinds::Send` is not implemented
   tx.send(foo(42, Rc::new(cat)));
 }

src/test/run-pass/deriving-bounds.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#[deriving(Sync,Send,Copy)]
+#[deriving(Copy)]
 struct Test;
 
 pub fn main() {}

src/test/run-pass/issue-17718-static-unsafe-interior.rs

@@ -11,30 +11,34 @@
 use std::kinds::marker;
 use std::cell::UnsafeCell;
 
+struct MyUnsafePack<T>(UnsafeCell<T>);
+
+unsafe impl<T: Send> Sync for MyUnsafePack<T> {}
+
 struct MyUnsafe<T> {
-    value: UnsafeCell<T>
+    value: MyUnsafePack<T>
 }
 
 impl<T> MyUnsafe<T> {
     fn forbidden(&self) {}
 }
 
-impl<T: Send> Sync for MyUnsafe<T> {}
+unsafe impl<T: Send> Sync for MyUnsafe<T> {}
 
 enum UnsafeEnum<T> {
     VariantSafe,
     VariantUnsafe(UnsafeCell<T>)
 }
 
-impl<T: Send> Sync for UnsafeEnum<T> {}
+unsafe impl<T: Send> Sync for UnsafeEnum<T> {}
 
 static STATIC1: UnsafeEnum<int> = UnsafeEnum::VariantSafe;
 
-static STATIC2: UnsafeCell<int> = UnsafeCell { value: 1 };
-const CONST: UnsafeCell<int> = UnsafeCell { value: 1 };
+static STATIC2: MyUnsafePack<int> = MyUnsafePack(UnsafeCell { value: 1 });
+const CONST: MyUnsafePack<int> = MyUnsafePack(UnsafeCell { value: 1 });
 static STATIC3: MyUnsafe<int> = MyUnsafe{value: CONST};
 
-static STATIC4: &'static UnsafeCell<int> = &STATIC2;
+static STATIC4: &'static MyUnsafePack<int> = &STATIC2;
 
 struct Wrap<T> {
     value: T
@@ -42,8 +46,8 @@ struct Wrap<T> {
 
 unsafe impl<T: Send> Sync for Wrap<T> {}
 
-static UNSAFE: UnsafeCell<int> = UnsafeCell{value: 1};
-static WRAPPED_UNSAFE: Wrap<&'static UnsafeCell<int>> = Wrap { value: &UNSAFE };
+static UNSAFE: MyUnsafePack<int> = MyUnsafePack(UnsafeCell{value: 2});
+static WRAPPED_UNSAFE: Wrap<&'static MyUnsafePack<int>> = Wrap { value: &UNSAFE };
 
 fn main() {
     let a = &STATIC1;