Remove `#[staged_api]`

src/doc/reference.md

@@ -2325,10 +2325,6 @@ The currently implemented features of the reference compiler are:
 * `simd_ffi` - Allows use of SIMD vectors in signatures for foreign functions.
                The SIMD interface is subject to change.
 
-* `staged_api` - Allows usage of stability markers and `#![staged_api]` in a
-                 crate. Stability markers are also attributes: `#[stable]`,
-                 `#[unstable]`, and `#[rustc_deprecated]` are the three levels.
-
 * `start` - Allows use of the `#[start]` attribute, which changes the entry point
             into a Rust program. This capability, especially the signature for the
             annotated function, is subject to change.

src/librustc/metadata/creader.rs

@@ -350,12 +350,19 @@ fn register_crate(&mut self,
     fn is_staged_api(&self, data: &[u8]) -> bool {
         let attrs = decoder::get_crate_attributes(data);
         for attr in &attrs {
-            if &attr.name()[..] == "staged_api" {
-                match attr.node.value.node { ast::MetaWord(_) => return true, _ => (/*pass*/) }
+            if attr.name() == "feature" {
+                if let Some(metas) = attr.meta_item_list() {
+                    for meta in metas {
+                        if let ast::MetaWord(ref name) = meta.node {
+                            if &name[..] == "staged_api" {
+                                return true
+                            }
+                        }
+                    }
+                }
             }
         }
-
-        return false;
+        false
     }
 
     fn resolve_crate(&mut self,

src/librustc/middle/stability.rs

@@ -279,19 +279,9 @@ pub fn build(&mut self, tcx: &ty::ctxt<'tcx>, krate: &Crate, access_levels: &Acc
                            |v| intravisit::walk_crate(v, krate));
     }
 
-    pub fn new(krate: &Crate) -> Index {
-        let mut is_staged_api = false;
-        for attr in &krate.attrs {
-            if attr.name() == "staged_api" {
-                if let ast::MetaWord(_) = attr.node.value.node {
-                    attr::mark_used(attr);
-                    is_staged_api = true;
-                    break
-                }
-            }
-        }
+    pub fn new(sess: &Session) -> Index<'tcx> {
         let mut staged_api = FnvHashMap();
-        staged_api.insert(LOCAL_CRATE, is_staged_api);
+        staged_api.insert(LOCAL_CRATE, sess.features.borrow().staged_api);
         Index {
             staged_api: staged_api,
             map: DefIdMap(),

src/librustc_driver/driver.rs

@@ -738,7 +738,7 @@ pub fn phase_3_run_analysis_passes<'tcx, F, R>(sess: &'tcx Session,
                                freevars,
                                region_map,
                                lang_items,
-                               stability::Index::new(krate),
+                               stability::Index::new(sess),
                                |tcx| {
                                    // passes are timed inside typeck
                                    typeck::check_crate(tcx, trait_map);

src/librustc_driver/test.rs

@@ -136,7 +136,7 @@ fn test_env<F>(source_string: &str,
                                freevars,
                                region_map,
                                lang_items,
-                               stability::Index::new(krate),
+                               stability::Index::new(&sess),
                                |tcx| {
                                    let infcx = infer::new_infer_ctxt(tcx, &tcx.tables, None, false);
                                    body(Env { infcx: &infcx });

src/libsyntax/feature_gate.rs

@@ -277,8 +277,6 @@ enum Status {
     // Not used any more, but we can't feature gate it
     ("no_stack_check", Normal, Ungated),
 
-    ("staged_api", CrateLevel, Gated("staged_api",
-                                     "staged_api is for use by rustc only")),
     ("plugin", CrateLevel, Gated("plugin",
                                  "compiler plugins are experimental \
                                   and possibly buggy")),
@@ -501,6 +499,7 @@ pub struct Features {
     pub cfg_target_vendor: bool,
     pub augmented_assignments: bool,
     pub braced_empty_structs: bool,
+    pub staged_api: bool,
 }
 
 impl Features {
@@ -532,6 +531,7 @@ pub fn new() -> Features {
             cfg_target_vendor: false,
             augmented_assignments: false,
             braced_empty_structs: false,
+            staged_api: false,
         }
     }
 }
@@ -1104,6 +1104,7 @@ fn check_crate_inner<F>(cm: &CodeMap, span_handler: &SpanHandler,
         cfg_target_vendor: cx.has_feature("cfg_target_vendor"),
         augmented_assignments: cx.has_feature("augmented_assignments"),
         braced_empty_structs: cx.has_feature("braced_empty_structs"),
+        staged_api: cx.has_feature("staged_api"),
     }
 }
 

src/test/compile-fail/staged_api.rs

-// Copyright 2015 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.
-
-#![staged_api] //~ ERROR staged_api is for use by rustc only
-
-fn main() { }