---

yaml
---
r: 209718
b: refs/heads/try
c: a4541b0
h: refs/heads/master
v: v3

Author: erickt

[refs]

@@ -2,7 +2,7 @@
 refs/heads/master: 3e561f05c00cd180ec02db4ccab2840a4aba93d2
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: ba0e1cd8147d452c356aacb29fb87568ca26f111
-refs/heads/try: 957cb422a98585568558ad88ec5a0841c43961ae
+refs/heads/try: a4541b02a33e7c4fdcc8f50459bad6ab99463919
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/dist-snap: ba4081a5a8573875fed17545846f6f6902c8ba8d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596

branches/try/src/librustc/metadata/loader.rs

@@ -692,16 +692,11 @@ pub fn note_crate_name(diag: &SpanHandler, name: &str) {
 
 impl ArchiveMetadata {
     fn new(ar: ArchiveRO) -> Option<ArchiveMetadata> {
-        let data = {
-            let section = ar.iter().find(|sect| {
-                sect.name() == Some(METADATA_FILENAME)
-            });
-            match section {
-                Some(s) => s.data() as *const [u8],
-                None => {
-                    debug!("didn't find '{}' in the archive", METADATA_FILENAME);
-                    return None;
-                }
+        let data = match ar.read(METADATA_FILENAME) {
+            Some(data) => data as *const [u8],
+            None => {
+                debug!("didn't find '{}' in the archive", METADATA_FILENAME);
+                return None;
             }
         };
 

branches/try/src/librustc/middle/resolve_lifetime.rs

@@ -24,7 +24,6 @@ use middle::region;
 use middle::subst;
 use middle::ty;
 use std::fmt;
-use std::mem::replace;
 use syntax::ast;
 use syntax::codemap::Span;
 use syntax::parse::token::special_idents;
@@ -71,9 +70,6 @@ struct LifetimeContext<'a> {
 
     // I'm sorry.
     trait_ref_hack: bool,
-
-    // List of labels in the function/method currently under analysis.
-    labels_in_fn: Vec<(ast::Ident, Span)>,
 }
 
 enum ScopeChain<'a> {
@@ -101,18 +97,13 @@ pub fn krate(sess: &Session, krate: &ast::Crate, def_map: &DefMap) -> NamedRegio
         scope: &ROOT_SCOPE,
         def_map: def_map,
         trait_ref_hack: false,
-        labels_in_fn: vec![],
     }, krate);
     sess.abort_if_errors();
     named_region_map
 }
 
 impl<'a, 'v> Visitor<'v> for LifetimeContext<'a> {
     fn visit_item(&mut self, item: &ast::Item) {
-        // Items save/restore the set of labels. This way innner items
-        // can freely reuse names, be they loop labels or lifetimes.
-        let saved = replace(&mut self.labels_in_fn, vec![]);
-
         // Items always introduce a new root scope
         self.with(RootScope, |_, this| {
             match item.node {
@@ -146,26 +137,23 @@ impl<'a, 'v> Visitor<'v> for LifetimeContext<'a> {
                 }
             }
         });
-
-        // Done traversing the item; restore saved set of labels.
-        replace(&mut self.labels_in_fn, saved);
     }
 
     fn visit_fn(&mut self, fk: visit::FnKind<'v>, fd: &'v ast::FnDecl,
                 b: &'v ast::Block, s: Span, _: ast::NodeId) {
         match fk {
             visit::FkItemFn(_, generics, _, _, _) => {
                 self.visit_early_late(subst::FnSpace, generics, |this| {
-                    this.walk_fn(fk, fd, b, s)
+                    visit::walk_fn(this, fk, fd, b, s)
                 })
             }
             visit::FkMethod(_, sig, _) => {
                 self.visit_early_late(subst::FnSpace, &sig.generics, |this| {
-                    this.walk_fn(fk, fd, b, s)
+                    visit::walk_fn(this, fk, fd, b, s)
                 })
             }
             visit::FkFnBlock(..) => {
-                self.walk_fn(fk, fd, b, s)
+                visit::walk_fn(self, fk, fd, b, s)
             }
         }
     }
@@ -202,19 +190,13 @@ impl<'a, 'v> Visitor<'v> for LifetimeContext<'a> {
     }
 
     fn visit_trait_item(&mut self, trait_item: &ast::TraitItem) {
-        // We reset the labels on every trait item, so that different
-        // methods in an impl can reuse label names.
-        let saved = replace(&mut self.labels_in_fn, vec![]);
-
         if let ast::MethodTraitItem(ref sig, None) = trait_item.node {
             self.visit_early_late(
                 subst::FnSpace, &sig.generics,
                 |this| visit::walk_trait_item(this, trait_item))
         } else {
             visit::walk_trait_item(self, trait_item);
         }
-
-        replace(&mut self.labels_in_fn, saved);
     }
 
     fn visit_block(&mut self, b: &ast::Block) {
@@ -304,170 +286,7 @@ impl<'a, 'v> Visitor<'v> for LifetimeContext<'a> {
     }
 }
 
-#[derive(Copy, Clone, PartialEq)]
-enum ShadowKind { Label, Lifetime }
-struct Original { kind: ShadowKind, span: Span }
-struct Shadower { kind: ShadowKind, span: Span }
-
-fn original_label(span: Span) -> Original {
-    Original { kind: ShadowKind::Label, span: span }
-}
-fn shadower_label(span: Span) -> Shadower {
-    Shadower { kind: ShadowKind::Label, span: span }
-}
-fn original_lifetime(l: &ast::Lifetime) -> Original {
-    Original { kind: ShadowKind::Lifetime, span: l.span }
-}
-fn shadower_lifetime(l: &ast::Lifetime) -> Shadower {
-    Shadower { kind: ShadowKind::Lifetime, span: l.span }
-}
-
-impl ShadowKind {
-    fn desc(&self) -> &'static str {
-        match *self {
-            ShadowKind::Label => "label",
-            ShadowKind::Lifetime => "lifetime",
-        }
-    }
-}
-
-fn signal_shadowing_problem(
-    sess: &Session, name: ast::Name, orig: Original, shadower: Shadower) {
-    if let (ShadowKind::Lifetime, ShadowKind::Lifetime) = (orig.kind, shadower.kind) {
-        // lifetime/lifetime shadowing is an error
-        sess.span_err(shadower.span,
-                      &format!("{} name `{}` shadows a \
-                                {} name that is already in scope",
-                               shadower.kind.desc(), name, orig.kind.desc()));
-    } else {
-        // shadowing involving a label is only a warning, due to issues with
-        // labels and lifetimes not being macro-hygienic.
-        sess.span_warn(shadower.span,
-                      &format!("{} name `{}` shadows a \
-                                {} name that is already in scope",
-                               shadower.kind.desc(), name, orig.kind.desc()));
-    }
-    sess.span_note(orig.span,
-                   &format!("shadowed {} `{}` declared here",
-                            orig.kind.desc(), name));
-}
-
-// Adds all labels in `b` to `ctxt.labels_in_fn`, signalling a warning
-// if one of the label shadows a lifetime or another label.
-fn extract_labels<'v, 'a>(ctxt: &mut LifetimeContext<'a>, b: &'v ast::Block) {
-
-    struct GatherLabels<'a> {
-        sess: &'a Session,
-        scope: Scope<'a>,
-        labels_in_fn: &'a mut Vec<(ast::Ident, Span)>,
-    }
-
-    let mut gather = GatherLabels {
-        sess: ctxt.sess,
-        scope: ctxt.scope,
-        labels_in_fn: &mut ctxt.labels_in_fn,
-    };
-    gather.visit_block(b);
-    return;
-
-    impl<'v, 'a> Visitor<'v> for GatherLabels<'a> {
-        fn visit_expr(&mut self, ex: &'v ast::Expr) {
-            if let Some(label) = expression_label(ex) {
-                for &(prior, prior_span) in &self.labels_in_fn[..] {
-                    // FIXME (#24278): non-hygienic comparision
-                    if label.name == prior.name {
-                        signal_shadowing_problem(self.sess,
-                                                 label.name,
-                                                 original_label(prior_span),
-                                                 shadower_label(ex.span));
-                    }
-                }
-
-                check_if_label_shadows_lifetime(self.sess,
-                                                self.scope,
-                                                label,
-                                                ex.span);
-
-                self.labels_in_fn.push((label, ex.span));
-            }
-            visit::walk_expr(self, ex)
-        }
-
-        fn visit_item(&mut self, _: &ast::Item) {
-            // do not recurse into items defined in the block
-        }
-    }
-
-    fn expression_label(ex: &ast::Expr) -> Option<ast::Ident> {
-        match ex.node {
-            ast::ExprWhile(_, _, Some(label))       |
-            ast::ExprWhileLet(_, _, _, Some(label)) |
-            ast::ExprForLoop(_, _, _, Some(label))  |
-            ast::ExprLoop(_, Some(label))          => Some(label),
-            _ => None,
-        }
-    }
-
-    fn check_if_label_shadows_lifetime<'a>(sess: &'a Session,
-                                           mut scope: Scope<'a>,
-                                           label: ast::Ident,
-                                           label_span: Span) {
-        loop {
-            match *scope {
-                BlockScope(_, s) => { scope = s; }
-                RootScope => { return; }
-
-                EarlyScope(_, lifetimes, s) |
-                LateScope(lifetimes, s) => {
-                    for lifetime_def in lifetimes {
-                        // FIXME (#24278): non-hygienic comparision
-                        if label.name == lifetime_def.lifetime.name {
-                            signal_shadowing_problem(
-                                sess,
-                                label.name,
-                                original_lifetime(&lifetime_def.lifetime),
-                                shadower_label(label_span));
-                            return;
-                        }
-                    }
-                    scope = s;
-                }
-            }
-        }
-    }
-}
-
 impl<'a> LifetimeContext<'a> {
-    // This is just like visit::walk_fn, except that it extracts the
-    // labels of the function body and swaps them in before visiting
-    // the function body itself.
-    fn walk_fn<'b>(&mut self,
-                   fk: visit::FnKind,
-                   fd: &ast::FnDecl,
-                   fb: &'b ast::Block,
-                   _span: Span) {
-        match fk {
-            visit::FkItemFn(_, generics, _, _, _) => {
-                visit::walk_fn_decl(self, fd);
-                self.visit_generics(generics);
-            }
-            visit::FkMethod(_, sig, _) => {
-                visit::walk_fn_decl(self, fd);
-                self.visit_generics(&sig.generics);
-                self.visit_explicit_self(&sig.explicit_self);
-            }
-            visit::FkFnBlock(..) => {
-                visit::walk_fn_decl(self, fd);
-            }
-        }
-
-        // After inpsecting the decl, add all labels from the body to
-        // `self.labels_in_fn`.
-        extract_labels(self, fb);
-
-        self.visit_block(fb);
-    }
-
     fn with<F>(&mut self, wrap_scope: ScopeChain, f: F) where
         F: FnOnce(Scope, &mut LifetimeContext),
     {
@@ -478,7 +297,6 @@ impl<'a> LifetimeContext<'a> {
             scope: &wrap_scope,
             def_map: self.def_map,
             trait_ref_hack: self.trait_ref_hack,
-            labels_in_fn: self.labels_in_fn.clone(),
         };
         debug!("entering scope {:?}", this.scope);
         f(self.scope, &mut this);
@@ -676,17 +494,6 @@ impl<'a> LifetimeContext<'a> {
                                         mut old_scope: Scope,
                                         lifetime: &ast::Lifetime)
     {
-        for &(label, label_span) in &self.labels_in_fn {
-            // FIXME (#24278): non-hygienic comparision
-            if lifetime.name == label.name {
-                signal_shadowing_problem(self.sess,
-                                         lifetime.name,
-                                         original_label(label_span),
-                                         shadower_lifetime(&lifetime));
-                return;
-            }
-        }
-
         loop {
             match *old_scope {
                 BlockScope(_, s) => {
@@ -700,11 +507,15 @@ impl<'a> LifetimeContext<'a> {
                 EarlyScope(_, lifetimes, s) |
                 LateScope(lifetimes, s) => {
                     if let Some((_, lifetime_def)) = search_lifetimes(lifetimes, lifetime) {
-                        signal_shadowing_problem(
-                            self.sess,
-                            lifetime.name,
-                            original_lifetime(&lifetime_def),
-                            shadower_lifetime(&lifetime));
+                        self.sess.span_err(
+                            lifetime.span,
+                            &format!("lifetime name `{}` shadows another \
+                                     lifetime name that is already in scope",
+                                     token::get_name(lifetime.name)));
+                        self.sess.span_note(
+                            lifetime_def.span,
+                            &format!("shadowed lifetime `{}` declared here",
+                                     token::get_name(lifetime.name)));
                         return;
                     }