auto merge of #11738 : dmanescu/rust/11721, r=alexcrichton

Fixes #11721

Author: bors

src/librustc/front/feature_gate.rs

@@ -47,6 +47,7 @@ static KNOWN_FEATURES: &'static [(&'static str, Status)] = &[
     ("macro_registrar", Active),
     ("log_syntax", Active),
     ("trace_macros", Active),
+    ("simd", Active),
 
     // These are used to test this portion of the compiler, they don't actually
     // mean anything
@@ -171,6 +172,13 @@ impl Visitor<()> for Context {
                 }
             }
 
+            ast::ItemStruct(..) => {
+                if attr::contains_name(i.attrs, "simd") {
+                    self.gate_feature("simd", i.span,
+                                      "SIMD types are experimental and possibly buggy");
+                }
+            }
+
             _ => {}
         }
 

src/libstd/lib.rs

@@ -52,13 +52,14 @@
       html_favicon_url = "http://www.rust-lang.org/favicon.ico",
       html_root_url = "http://static.rust-lang.org/doc/master")];
 
-#[feature(macro_rules, globs, asm, managed_boxes, thread_local, link_args)];
+#[feature(macro_rules, globs, asm, managed_boxes, thread_local, link_args, simd)];
 
 // Don't link to std. We are std.
 #[no_std];
 
 #[deny(non_camel_case_types)];
 #[deny(missing_doc)];
+#[allow(unknown_features)];
 
 // When testing libstd, bring in libuv as the I/O backend so tests can print
 // things and all of the std::io tests have an I/O interface to run on top

src/libstd/unstable/simd.rs

@@ -12,32 +12,42 @@
 
 #[allow(non_camel_case_types)];
 
+#[experimental]
 #[simd]
 pub struct i8x16(i8, i8, i8, i8, i8, i8, i8, i8, i8, i8, i8, i8, i8, i8, i8, i8);
 
+#[experimental]
 #[simd]
 pub struct i16x8(i16, i16, i16, i16, i16, i16, i16, i16);
 
+#[experimental]
 #[simd]
 pub struct i32x4(i32, i32, i32, i32);
 
+#[experimental]
 #[simd]
 pub struct i64x2(i64, i64);
 
+#[experimental]
 #[simd]
 pub struct u8x16(u8, u8, u8, u8, u8, u8, u8, u8, u8, u8, u8, u8, u8, u8, u8, u8);
 
+#[experimental]
 #[simd]
 pub struct u16x8(u16, u16, u16, u16, u16, u16, u16, u16);
 
+#[experimental]
 #[simd]
 pub struct u32x4(u32, u32, u32, u32);
 
+#[experimental]
 #[simd]
 pub struct u64x2(u64, u64);
 
+#[experimental]
 #[simd]
 pub struct f32x4(f32, f32, f32, f32);
 
+#[experimental]
 #[simd]
 pub struct f64x2(f64, f64);

src/test/compile-fail/gated-simd.rs

@@ -0,0 +1,14 @@
+// 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.
+
+#[simd]
+pub struct i64x2(i64, i64); //~ ERROR: SIMD types are experimental
+
+fn main() {}

src/test/compile-fail/simd-experimental.rs

@@ -0,0 +1,19 @@
+// 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.
+
+// xfail-test FIXME #11741 tuple structs ignore stability attributes
+
+#[deny(experimental)];
+
+use std::unstable::simd;
+
+fn main() {
+    let _ = simd::i64x2(0, 0); //~ ERROR: experimental
+}

src/test/compile-fail/simd-type.rs

@@ -1,3 +1,5 @@
+#[feature(simd)];
+
 #[simd]
 struct vec4<T>(T, T, T, T); //~ ERROR SIMD vector cannot be generic
 

src/test/run-pass/simd-binop.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[allow(experimental)];
+
 use std::unstable::simd::{i32x4, f32x4};
 
 fn test_int(e: i32) -> i32 {

src/test/run-pass/simd-type.rs

@@ -1,3 +1,7 @@
+// xfail-fast feature doesn't work
+
+#[feature(simd)];
+
 #[simd]
 struct RGBA {
     r: f32,