auto merge of #19683 : nikomatsakis/rust/generalized-where-clauses, r=nrc

This patch does not itself enable generalized where clauses, but it lays the groundwork. Rather than storing a list of bounds per type parameter, the trait selection and other logic is now driven by a unified list of predicates. All predicate handling is now driven through a common interface. This also fixes a number of bugs where region predicates were being dropped on the floor. As a drive-by, this patch also fixes some bugs in the opt-out-copy feature flag.

That said, this patch does not change the parser or AST in any way, so we still *generate* the list of predicates by walking a list of bounds (and we still *store* the bounds on the `TypeParameterDef` and so on). Those will get patched in a follow-up.

The commits in this case are standalone; the first few are simple refactorings.

r? @nick29581 
cc @aturon 

14 files changed, 70 insertions, 28 deletions

diff --git a/src/test/compile-fail/builtin-superkinds-self-type.rs b/src/test/compile-fail/builtin-superkinds-self-type.rs
index 86d3d7e9cbc..4c7ff60fbdd 100644
--- a/src/test/compile-fail/builtin-superkinds-self-type.rs
+++ b/src/test/compile-fail/builtin-superkinds-self-type.rs
@@ -17,7 +17,6 @@ trait Foo : Sync+'static {
 
 impl <T: Sync> Foo for T { }
 //~^ ERROR the parameter type `T` may not live long enough
-//~^^ ERROR the parameter type `T` may not live long enough
 
 fn main() {
     let (tx, rx) = channel();
diff --git a/src/test/compile-fail/builtin-superkinds-simple.rs b/src/test/compile-fail/builtin-superkinds-simple.rs
index fda83c03a7d..2c689f6909b 100644
--- a/src/test/compile-fail/builtin-superkinds-simple.rs
+++ b/src/test/compile-fail/builtin-superkinds-simple.rs
@@ -14,6 +14,6 @@
 trait Foo : Send { }
 
 impl <'a> Foo for &'a mut () { }
-//~^ ERROR does not fulfill the required lifetime
+//~^ ERROR declared lifetime bound not satisfied
 
 fn main() { }
diff --git a/src/test/compile-fail/kindck-impl-type-params.rs b/src/test/compile-fail/kindck-impl-type-params.rs
index a430fe72333..57ee4cf7cc3 100644
--- a/src/test/compile-fail/kindck-impl-type-params.rs
+++ b/src/test/compile-fail/kindck-impl-type-params.rs
@@ -34,6 +34,7 @@ fn g<T>(val: T) {
 fn foo<'a>() {
     let t: S<&'a int> = S;
     let a = &t as &Gettable<&'a int>;
+    //~^ ERROR declared lifetime bound not satisfied
 }
 
 fn foo2<'a>() {
diff --git a/src/test/compile-fail/kindck-send-object1.rs b/src/test/compile-fail/kindck-send-object1.rs
index a5519753643..35e928d417c 100644
--- a/src/test/compile-fail/kindck-send-object1.rs
+++ b/src/test/compile-fail/kindck-send-object1.rs
@@ -22,7 +22,7 @@ fn test51<'a>() {
 }
 fn test52<'a>() {
     assert_send::<&'a (Dummy+Send)>();
-    //~^ ERROR does not fulfill the required lifetime
+    //~^ ERROR declared lifetime bound not satisfied
 }
 
 // ...unless they are properly bounded
diff --git a/src/test/compile-fail/kindck-send-owned.rs b/src/test/compile-fail/kindck-send-owned.rs
index 0eed05692b9..11148d2846c 100644
--- a/src/test/compile-fail/kindck-send-owned.rs
+++ b/src/test/compile-fail/kindck-send-owned.rs
@@ -19,7 +19,7 @@ fn test32() { assert_send::<Vec<int> >(); }
 
 // but not if they own a bad thing
 fn test40<'a>(_: &'a int) {
-    assert_send::<Box<&'a int>>(); //~ ERROR does not fulfill the required lifetime
+    assert_send::<Box<&'a int>>(); //~ ERROR declared lifetime bound not satisfied
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/kindck-send-region-pointers.rs b/src/test/compile-fail/kindck-send-region-pointers.rs
index cc46d7f4de9..04172932cfe 100644
--- a/src/test/compile-fail/kindck-send-region-pointers.rs
+++ b/src/test/compile-fail/kindck-send-region-pointers.rs
@@ -22,13 +22,13 @@ fn test10() { assert_send::<&'static mut int>(); }
 
 // otherwise lifetime pointers are not ok
 fn test20<'a>(_: &'a int) {
-    assert_send::<&'a int>(); //~ ERROR does not fulfill the required lifetime
+    assert_send::<&'a int>(); //~ ERROR declared lifetime bound not satisfied
 }
 fn test21<'a>(_: &'a int) {
-    assert_send::<&'a str>(); //~ ERROR does not fulfill the required lifetime
+    assert_send::<&'a str>(); //~ ERROR declared lifetime bound not satisfied
 }
 fn test22<'a>(_: &'a int) {
-    assert_send::<&'a [int]>(); //~ ERROR does not fulfill the required lifetime
+    assert_send::<&'a [int]>(); //~ ERROR declared lifetime bound not satisfied
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/kindck-send-unsafe.rs b/src/test/compile-fail/kindck-send-unsafe.rs
index a9bbfcfa262..33314149d1f 100644
--- a/src/test/compile-fail/kindck-send-unsafe.rs
+++ b/src/test/compile-fail/kindck-send-unsafe.rs
@@ -15,7 +15,7 @@ fn test70() {
     assert_send::<*mut int>();
 }
 fn test71<'a>() {
-    assert_send::<*mut &'a int>(); //~ ERROR does not fulfill the required lifetime
+    assert_send::<*mut &'a int>(); //~ ERROR declared lifetime bound not satisfied
 }
 
 fn main() {
diff --git a/src/test/compile-fail/opt-out-copy-bad.rs b/src/test/compile-fail/opt-out-copy-bad.rs
new file mode 100644
index 00000000000..80f8a154d58
--- /dev/null
+++ b/src/test/compile-fail/opt-out-copy-bad.rs
@@ -0,0 +1,42 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(opt_out_copy)]
+
+// Test that when using the `opt-out-copy` feature we still consider
+// destructors to be non-movable
+
+struct CantCopyThis;
+
+impl Drop for CantCopyThis {
+    fn drop(&mut self) { }
+}
+
+struct IWantToCopyThis {
+    but_i_cant: CantCopyThis,
+}
+
+impl Copy for IWantToCopyThis {}
+//~^ ERROR the trait `Copy` may not be implemented for this type
+
+enum CantCopyThisEither {
+    A,
+    B(::std::kinds::marker::NoCopy),
+}
+
+enum IWantToCopyThisToo {
+    ButICant(CantCopyThisEither),
+}
+
+impl Copy for IWantToCopyThisToo {}
+//~^ ERROR the trait `Copy` may not be implemented for this type
+
+fn main() {}
+
diff --git a/src/test/compile-fail/recursion_limit.rs b/src/test/compile-fail/recursion_limit.rs
index 17afb168a98..1da7f47677a 100644
--- a/src/test/compile-fail/recursion_limit.rs
+++ b/src/test/compile-fail/recursion_limit.rs
@@ -44,8 +44,8 @@ fn main() {
     is_send::<A>();
     //~^ ERROR overflow evaluating
     //~^^ NOTE consider adding a `#![recursion_limit="20"]` attribute to your crate
-    //~^^^ NOTE must be implemented
+    //~^^^ NOTE required by `is_send`
     //~^^^^ ERROR overflow evaluating
     //~^^^^^ NOTE consider adding a `#![recursion_limit="20"]` attribute to your crate
-    //~^^^^^^ NOTE must be implemented
+    //~^^^^^^ NOTE required by `is_send`
 }
diff --git a/src/test/compile-fail/region-object-lifetime-in-coercion.rs b/src/test/compile-fail/region-object-lifetime-in-coercion.rs
index dfeba041092..b2b2d3337c4 100644
--- a/src/test/compile-fail/region-object-lifetime-in-coercion.rs
+++ b/src/test/compile-fail/region-object-lifetime-in-coercion.rs
@@ -15,12 +15,12 @@ trait Foo {}
 impl<'a> Foo for &'a [u8] {}
 
 fn a(v: &[u8]) -> Box<Foo + 'static> {
-    let x: Box<Foo + 'static> = box v; //~ ERROR does not outlive
+    let x: Box<Foo + 'static> = box v; //~ ERROR declared lifetime bound not satisfied
     x
 }
 
 fn b(v: &[u8]) -> Box<Foo + 'static> {
-    box v //~ ERROR does not outlive
+    box v //~ ERROR declared lifetime bound not satisfied
 }
 
 fn c(v: &[u8]) -> Box<Foo> {
@@ -28,7 +28,7 @@ fn c(v: &[u8]) -> Box<Foo> {
 }
 
 fn d<'a,'b>(v: &'a [u8]) -> Box<Foo+'b> {
-    box v //~ ERROR does not outlive
+    box v //~ ERROR declared lifetime bound not satisfied
 }
 
 fn e<'a:'b,'b>(v: &'a [u8]) -> Box<Foo+'b> {
diff --git a/src/test/compile-fail/regions-bounded-by-send.rs b/src/test/compile-fail/regions-bounded-by-send.rs
index 660a9be4f63..ec679a7dda1 100644
--- a/src/test/compile-fail/regions-bounded-by-send.rs
+++ b/src/test/compile-fail/regions-bounded-by-send.rs
@@ -29,15 +29,15 @@ fn static_lifime_ok<'a,T,U:Send>(_: &'a int) {
 // otherwise lifetime pointers are not ok
 
 fn param_not_ok<'a>(x: &'a int) {
-    assert_send::<&'a int>(); //~ ERROR does not fulfill
+    assert_send::<&'a int>(); //~ ERROR declared lifetime bound not satisfied
 }
 
 fn param_not_ok1<'a>(_: &'a int) {
-    assert_send::<&'a str>(); //~ ERROR does not fulfill
+    assert_send::<&'a str>(); //~ ERROR declared lifetime bound not satisfied
 }
 
 fn param_not_ok2<'a>(_: &'a int) {
-    assert_send::<&'a [int]>(); //~ ERROR does not fulfill
+    assert_send::<&'a [int]>(); //~ ERROR declared lifetime bound not satisfied
 }
 
 // boxes are ok
@@ -51,7 +51,7 @@ fn box_ok() {
 // but not if they own a bad thing
 
 fn box_with_region_not_ok<'a>() {
-    assert_send::<Box<&'a int>>(); //~ ERROR does not fulfill
+    assert_send::<Box<&'a int>>(); //~ ERROR declared lifetime bound not satisfied
 }
 
 // objects with insufficient bounds no ok
@@ -63,7 +63,7 @@ fn object_with_random_bound_not_ok<'a>() {
 
 fn object_with_send_bound_not_ok<'a>() {
     assert_send::<&'a (Dummy+Send)>();
-    //~^ ERROR does not fulfill
+    //~^ ERROR declared lifetime bound not satisfied
 }
 
 fn proc_with_lifetime_not_ok<'a>() {
@@ -84,11 +84,11 @@ fn unsafe_ok1<'a>(_: &'a int) {
 }
 
 fn unsafe_ok2<'a>(_: &'a int) {
-    assert_send::<*const &'a int>(); //~ ERROR does not fulfill
+    assert_send::<*const &'a int>(); //~ ERROR declared lifetime bound not satisfied
 }
 
 fn unsafe_ok3<'a>(_: &'a int) {
-    assert_send::<*mut &'a int>(); //~ ERROR does not fulfill
+    assert_send::<*mut &'a int>(); //~ ERROR declared lifetime bound not satisfied
 }
 
 fn main() {
diff --git a/src/test/compile-fail/regions-bounded-by-trait-requiring-static.rs b/src/test/compile-fail/regions-bounded-by-trait-requiring-static.rs
index 04a94b75215..e3939a4e390 100644
--- a/src/test/compile-fail/regions-bounded-by-trait-requiring-static.rs
+++ b/src/test/compile-fail/regions-bounded-by-trait-requiring-static.rs
@@ -29,15 +29,15 @@ fn static_lifime_ok<'a,T,U:Send>(_: &'a int) {
 // otherwise lifetime pointers are not ok
 
 fn param_not_ok<'a>(x: &'a int) {
-    assert_send::<&'a int>(); //~ ERROR does not fulfill
+    assert_send::<&'a int>(); //~ ERROR declared lifetime bound not satisfied
 }
 
 fn param_not_ok1<'a>(_: &'a int) {
-    assert_send::<&'a str>(); //~ ERROR does not fulfill
+    assert_send::<&'a str>(); //~ ERROR declared lifetime bound not satisfied
 }
 
 fn param_not_ok2<'a>(_: &'a int) {
-    assert_send::<&'a [int]>(); //~ ERROR does not fulfill
+    assert_send::<&'a [int]>(); //~ ERROR declared lifetime bound not satisfied
 }
 
 // boxes are ok
@@ -51,7 +51,7 @@ fn box_ok() {
 // but not if they own a bad thing
 
 fn box_with_region_not_ok<'a>() {
-    assert_send::<Box<&'a int>>(); //~ ERROR does not fulfill
+    assert_send::<Box<&'a int>>(); //~ ERROR declared lifetime bound not satisfied
 }
 
 // unsafe pointers are ok unless they point at unsendable things
@@ -62,11 +62,11 @@ fn unsafe_ok1<'a>(_: &'a int) {
 }
 
 fn unsafe_ok2<'a>(_: &'a int) {
-    assert_send::<*const &'a int>(); //~ ERROR does not fulfill
+    assert_send::<*const &'a int>(); //~ ERROR declared lifetime bound not satisfied
 }
 
 fn unsafe_ok3<'a>(_: &'a int) {
-    assert_send::<*mut &'a int>(); //~ ERROR does not fulfill
+    assert_send::<*mut &'a int>(); //~ ERROR declared lifetime bound not satisfied
 }
 
 fn main() {
diff --git a/src/test/compile-fail/regions-bounded-method-type-parameters.rs b/src/test/compile-fail/regions-bounded-method-type-parameters.rs
index 279139d8de9..10484925980 100644
--- a/src/test/compile-fail/regions-bounded-method-type-parameters.rs
+++ b/src/test/compile-fail/regions-bounded-method-type-parameters.rs
@@ -20,7 +20,7 @@ impl Foo {
 
 fn caller<'a>(x: &int) {
     Foo.some_method::<&'a int>();
-    //~^ ERROR does not fulfill the required lifetime
+    //~^ ERROR declared lifetime bound not satisfied
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/regions-proc-bounds.rs b/src/test/compile-fail/regions-proc-bounds.rs
index db71bc4e15c..4c95e1eac6d 100644
--- a/src/test/compile-fail/regions-proc-bounds.rs
+++ b/src/test/compile-fail/regions-proc-bounds.rs
@@ -12,7 +12,7 @@ fn is_static<T: 'static>() {}
 
 fn foo<'a>() {
     is_static::<proc():'a>();
-    //~^ ERROR does not fulfill the required lifetime
+    //~^ ERROR declared lifetime bound not satisfied
 
     is_static::<proc():'static>();
 }