Rollup merge of rust-lang#22803 - huonw:field-stability, r=alexcrichton

 We were recording stability attributes applied to fields in the
compiler, and even annotating it in the libs, but the compiler didn't
actually do the checks to give errors/warnings in user crates.

Details in the commit messages.

Author: Manishearth

src/libcore/str/mod.rs

@@ -939,6 +939,7 @@ impl<'a, P: Pattern<'a>> Iterator for SplitStr<'a, P> {
     type Item = &'a str;
 
     #[inline]
+    #[allow(deprecated)]
     fn next(&mut self) -> Option<&'a str> {
         Iterator::next(&mut self.0)
     }

src/librustc/lint/builtin.rs

@@ -1771,6 +1771,11 @@ impl LintPass for Stability {
         stability::check_path(cx.tcx, path, id,
                               &mut |id, sp, stab| self.lint(cx, id, sp, stab));
     }
+
+    fn check_pat(&mut self, cx: &Context, pat: &ast::Pat) {
+        stability::check_pat(cx.tcx, pat,
+                             &mut |id, sp, stab| self.lint(cx, id, sp, stab))
+    }
 }
 
 declare_lint! {

src/librustc/middle/stability.rs

@@ -58,8 +58,10 @@ impl<'a> Annotator<'a> {
                    attrs: &Vec<Attribute>, item_sp: Span, f: F, required: bool) where
         F: FnOnce(&mut Annotator),
     {
+        debug!("annotate(id = {:?}, attrs = {:?})", id, attrs);
         match attr::find_stability(self.sess.diagnostic(), attrs, item_sp) {
             Some(stab) => {
+                debug!("annotate: found {:?}", stab);
                 self.index.local.insert(id, stab.clone());
 
                 // Don't inherit #[stable(feature = "rust1", since = "1.0.0")]
@@ -72,6 +74,8 @@ impl<'a> Annotator<'a> {
                 }
             }
             None => {
+                debug!("annotate: not found, use_parent = {:?}, parent = {:?}",
+                       use_parent, self.parent);
                 if use_parent {
                     if let Some(stab) = self.parent.clone() {
                         self.index.local.insert(id, stab);
@@ -299,6 +303,12 @@ impl<'a, 'v, 'tcx> Visitor<'v> for Checker<'a, 'tcx> {
                    &mut |id, sp, stab| self.check(id, sp, stab));
         visit::walk_path(self, path)
     }
+
+    fn visit_pat(&mut self, pat: &ast::Pat) {
+        check_pat(self.tcx, pat,
+                  &mut |id, sp, stab| self.check(id, sp, stab));
+        visit::walk_pat(self, pat)
+    }
 }
 
 /// Helper for discovering nodes to check for stability
@@ -385,6 +395,76 @@ pub fn check_expr(tcx: &ty::ctxt, e: &ast::Expr,
                 None => return
             }
         }
+        ast::ExprField(ref base_e, ref field) => {
+            span = field.span;
+            match ty::expr_ty_adjusted(tcx, base_e).sty {
+                ty::ty_struct(did, _) => {
+                    ty::lookup_struct_fields(tcx, did)
+                        .iter()
+                        .find(|f| f.name == field.node.name)
+                        .unwrap_or_else(|| {
+                            tcx.sess.span_bug(field.span,
+                                              "stability::check_expr: unknown named field access")
+                        })
+                        .id
+                }
+                _ => tcx.sess.span_bug(e.span,
+                                       "stability::check_expr: named field access on non-struct")
+            }
+        }
+        ast::ExprTupField(ref base_e, ref field) => {
+            span = field.span;
+            match ty::expr_ty_adjusted(tcx, base_e).sty {
+                ty::ty_struct(did, _) => {
+                    ty::lookup_struct_fields(tcx, did)
+                        .get(field.node)
+                        .unwrap_or_else(|| {
+                            tcx.sess.span_bug(field.span,
+                                              "stability::check_expr: unknown unnamed field access")
+                        })
+                        .id
+                }
+                ty::ty_tup(..) => return,
+                _ => tcx.sess.span_bug(e.span,
+                                       "stability::check_expr: unnamed field access on \
+                                        something other than a tuple or struct")
+            }
+        }
+        ast::ExprStruct(_, ref expr_fields, _) => {
+            let type_ = ty::expr_ty(tcx, e);
+            match type_.sty {
+                ty::ty_struct(did, _) => {
+                    let struct_fields = ty::lookup_struct_fields(tcx, did);
+                    // check the stability of each field that appears
+                    // in the construction expression.
+                    for field in expr_fields {
+                        let did = struct_fields
+                            .iter()
+                            .find(|f| f.name == field.ident.node.name)
+                            .unwrap_or_else(|| {
+                                tcx.sess.span_bug(field.span,
+                                                  "stability::check_expr: unknown named \
+                                                   field access")
+                            })
+                            .id;
+                        maybe_do_stability_check(tcx, did, field.span, cb);
+                    }
+
+                    // we're done.
+                    return
+                }
+                // we don't look at stability attributes on
+                // struct-like enums (yet...), but it's definitely not
+                // a bug to have construct one.
+                ty::ty_enum(..) => return,
+                _ => {
+                    tcx.sess.span_bug(e.span,
+                                      &format!("stability::check_expr: struct construction \
+                                                of non-struct, type {:?}",
+                                               type_.repr(tcx)));
+                }
+            }
+        }
         _ => return
     };
 
@@ -403,6 +483,47 @@ pub fn check_path(tcx: &ty::ctxt, path: &ast::Path, id: ast::NodeId,
 
 }
 
+pub fn check_pat(tcx: &ty::ctxt, pat: &ast::Pat,
+                 cb: &mut FnMut(ast::DefId, Span, &Option<Stability>)) {
+    debug!("check_pat(pat = {:?})", pat);
+    if is_internal(tcx, pat.span) { return; }
+
+    let did = match ty::pat_ty_opt(tcx, pat) {
+        Some(&ty::TyS { sty: ty::ty_struct(did, _), .. }) => did,
+        Some(_) | None => return,
+    };
+    let struct_fields = ty::lookup_struct_fields(tcx, did);
+    match pat.node {
+        // Foo(a, b, c)
+        ast::PatEnum(_, Some(ref pat_fields)) => {
+            for (field, struct_field) in pat_fields.iter().zip(struct_fields.iter()) {
+                // a .. pattern is fine, but anything positional is
+                // not.
+                if let ast::PatWild(ast::PatWildMulti) = field.node {
+                    continue
+                }
+                maybe_do_stability_check(tcx, struct_field.id, field.span, cb)
+            }
+        }
+        // Foo { a, b, c }
+        ast::PatStruct(_, ref pat_fields, _) => {
+            for field in pat_fields {
+                let did = struct_fields
+                    .iter()
+                    .find(|f| f.name == field.node.ident.name)
+                    .unwrap_or_else(|| {
+                        tcx.sess.span_bug(field.span,
+                                          "stability::check_pat: unknown named field access")
+                    })
+                    .id;
+                maybe_do_stability_check(tcx, did, field.span, cb);
+            }
+        }
+        // everything else is fine.
+        _ => {}
+    }
+}
+
 fn maybe_do_stability_check(tcx: &ty::ctxt, id: ast::DefId, span: Span,
                             cb: &mut FnMut(ast::DefId, Span, &Option<Stability>)) {
     if !is_staged_api(tcx, id) { return  }

src/librustc/middle/ty.rs

@@ -4298,6 +4298,9 @@ pub fn free_region_from_def(outlives_extent: region::DestructionScopeData,
 pub fn pat_ty<'tcx>(cx: &ctxt<'tcx>, pat: &ast::Pat) -> Ty<'tcx> {
     return node_id_to_type(cx, pat.id);
 }
+pub fn pat_ty_opt<'tcx>(cx: &ctxt<'tcx>, pat: &ast::Pat) -> Option<Ty<'tcx>> {
+    return node_id_to_type_opt(cx, pat.id);
+}
 
 
 // Returns the type of an expression as a monotype.

src/librustc_privacy/lib.rs

@@ -233,6 +233,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for EmbargoVisitor<'a, 'tcx> {
             ast::ItemEnum(ref def, _) if public_first => {
                 for variant in &def.variants {
                     self.exported_items.insert(variant.node.id);
+                    self.public_items.insert(variant.node.id);
                 }
             }
 
@@ -321,6 +322,15 @@ impl<'a, 'tcx, 'v> Visitor<'v> for EmbargoVisitor<'a, 'tcx> {
                     Some(id) => { self.exported_items.insert(id); }
                     None => {}
                 }
+                // fields can be public or private, so lets check
+                for field in &def.fields {
+                    let vis = match field.node.kind {
+                        ast::NamedField(_, vis) | ast::UnnamedField(vis) => vis
+                    };
+                    if vis == ast::Public {
+                        self.public_items.insert(field.node.id);
+                    }
+                }
             }
 
             ast::ItemTy(ref ty, _) if public_first => {

src/libstd/old_io/mem.rs

@@ -102,6 +102,7 @@ impl MemWriter {
 
 impl Writer for MemWriter {
     #[inline]
+    #[allow(deprecated)]
     fn write_all(&mut self, buf: &[u8]) -> IoResult<()> {
         self.buf.push_all(buf);
         Ok(())

src/libstd/sync/mpsc/mod.rs

@@ -384,7 +384,7 @@ impl<T> !Sync for SyncSender<T> {}
 /// contains the data being sent as a payload so it can be recovered.
 #[stable(feature = "rust1", since = "1.0.0")]
 #[derive(PartialEq, Eq, Clone, Copy)]
-pub struct SendError<T>(pub T);
+pub struct SendError<T>(#[stable(feature = "rust1", since = "1.0.0")] pub T);
 
 /// An error returned from the `recv` function on a `Receiver`.
 ///

src/libstd/thread_local/mod.rs

@@ -105,10 +105,12 @@ pub struct Key<T> {
     // This is trivially devirtualizable by LLVM because we never store anything
     // to this field and rustc can declare the `static` as constant as well.
     #[doc(hidden)]
+    #[unstable(feature = "thread_local_internals")]
     pub inner: fn() -> &'static __impl::KeyInner<UnsafeCell<Option<T>>>,
 
     // initialization routine to invoke to create a value
     #[doc(hidden)]
+    #[unstable(feature = "thread_local_internals")]
     pub init: fn() -> T,
 }
 

src/test/auxiliary/lint_stability.rs

@@ -100,14 +100,22 @@ pub trait UnstableTrait { fn dummy(&self) { } }
 
 #[stable(feature = "test_feature", since = "1.0.0")]
 #[deprecated(since = "1.0.0")]
-pub struct DeprecatedStruct { pub i: int }
+pub struct DeprecatedStruct {
+    #[stable(feature = "test_feature", since = "1.0.0")] pub i: int
+}
 #[unstable(feature = "test_feature")]
 #[deprecated(since = "1.0.0")]
-pub struct DeprecatedUnstableStruct { pub i: int }
+pub struct DeprecatedUnstableStruct {
+    #[stable(feature = "test_feature", since = "1.0.0")] pub i: int
+}
 #[unstable(feature = "test_feature")]
-pub struct UnstableStruct { pub i: int }
+pub struct UnstableStruct {
+    #[stable(feature = "test_feature", since = "1.0.0")] pub i: int
+}
 #[stable(feature = "rust1", since = "1.0.0")]
-pub struct StableStruct { pub i: int }
+pub struct StableStruct {
+    #[stable(feature = "test_feature", since = "1.0.0")] pub i: int
+}
 
 #[stable(feature = "test_feature", since = "1.0.0")]
 #[deprecated(since = "1.0.0")]
@@ -137,14 +145,14 @@ pub enum Enum {
 
 #[stable(feature = "test_feature", since = "1.0.0")]
 #[deprecated(since = "1.0.0")]
-pub struct DeprecatedTupleStruct(pub int);
+pub struct DeprecatedTupleStruct(#[stable(feature = "rust1", since = "1.0.0")] pub int);
 #[unstable(feature = "test_feature")]
 #[deprecated(since = "1.0.0")]
-pub struct DeprecatedUnstableTupleStruct(pub int);
+pub struct DeprecatedUnstableTupleStruct(#[stable(feature = "rust1", since = "1.0.0")] pub int);
 #[unstable(feature = "test_feature")]
-pub struct UnstableTupleStruct(pub int);
+pub struct UnstableTupleStruct(#[stable(feature = "rust1", since = "1.0.0")] pub int);
 #[stable(feature = "rust1", since = "1.0.0")]
-pub struct StableTupleStruct(pub int);
+pub struct StableTupleStruct(#[stable(feature = "rust1", since = "1.0.0")] pub int);
 
 #[macro_export]
 macro_rules! macro_test {

src/test/auxiliary/lint_stability_fields.rs

@@ -0,0 +1,60 @@
+// 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.
+
+#![feature(staged_api)]
+#![staged_api]
+#![stable(feature = "rust1", since = "1.0.0")]
+
+#[stable(feature = "rust1", since = "1.0.0")]
+pub struct Stable {
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub inherit: u8, // it's a lie (stable doesn't inherit)
+    #[unstable(feature = "test_feature")]
+    pub override1: u8,
+    #[deprecated(since = "1.0.0")]
+    #[unstable(feature = "test_feature")]
+    pub override2: u8,
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+pub struct Stable2(#[stable(feature = "rust1", since = "1.0.0")] pub u8,
+                   #[unstable(feature = "test_feature")] pub u8,
+                   #[unstable(feature = "test_feature")] #[deprecated(since = "1.0.0")] pub u8);
+
+#[unstable(feature = "test_feature")]
+pub struct Unstable {
+    pub inherit: u8,
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub override1: u8,
+    #[deprecated(since = "1.0.0")]
+    #[unstable(feature = "test_feature")]
+    pub override2: u8,
+}
+
+#[unstable(feature = "test_feature")]
+pub struct Unstable2(pub u8,
+                     #[stable(feature = "rust1", since = "1.0.0")] pub u8,
+                     #[unstable(feature = "test_feature")] #[deprecated(since = "1.0.0")] pub u8);
+
+#[unstable(feature = "test_feature")]
+#[deprecated(feature = "rust1", since = "1.0.0")]
+pub struct Deprecated {
+    pub inherit: u8,
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub override1: u8,
+    #[unstable(feature = "test_feature")]
+    pub override2: u8,
+}
+
+#[unstable(feature = "test_feature")]
+#[deprecated(feature = "rust1", since = "1.0.0")]
+pub struct Deprecated2(pub u8,
+                       #[stable(feature = "rust1", since = "1.0.0")] pub u8,
+                       #[unstable(feature = "test_feature")] pub u8);