Implement RFC#1559: allow all literals in attributes.

src/librustc/hir/check_attr.rs

@@ -11,7 +11,7 @@
 use session::Session;
 
 use syntax::ast;
-use syntax::attr::AttrMetaMethods;
+use syntax::attr::{AttrNestedMetaItemMethods, AttrMetaMethods};
 use syntax::visit;
 use syntax::visit::Visitor;
 
@@ -52,18 +52,22 @@ impl<'a> CheckAttrVisitor<'a> {
                 return;
             }
         };
+
         for word in words {
-            let word: &str = &word.name();
-            let message = match word {
+            let name = match word.name() {
+                Some(word) => word,
+                None => continue,
+            };
+
+            let message = match &*name {
                 "C" => {
                     if target != Target::Struct && target != Target::Enum {
-                            "attribute should be applied to struct or enum"
+                        "attribute should be applied to struct or enum"
                     } else {
                         continue
                     }
                 }
-                "packed" |
-                "simd" => {
+                "packed" | "simd" => {
                     if target != Target::Struct {
                         "attribute should be applied to struct"
                     } else {
@@ -74,13 +78,14 @@ impl<'a> CheckAttrVisitor<'a> {
                 "i32" | "u32" | "i64" | "u64" |
                 "isize" | "usize" => {
                     if target != Target::Enum {
-                            "attribute should be applied to enum"
+                        "attribute should be applied to enum"
                     } else {
                         continue
                     }
                 }
                 _ => continue,
             };
+
             span_err!(self.sess, attr.span, E0517, "{}", message);
         }
     }

src/librustc/hir/fold.rs

@@ -12,8 +12,8 @@
 //! and returns a piece of the same type.
 
 use hir::*;
-use syntax::ast::{Name, NodeId, DUMMY_NODE_ID, Attribute, Attribute_, MetaItem};
-use syntax::ast::MetaItemKind;
+use syntax::ast::{Name, NodeId, DUMMY_NODE_ID, Attribute, Attribute_};
+use syntax::ast::{NestedMetaItem, NestedMetaItemKind, MetaItem, MetaItemKind};
 use hir;
 use syntax_pos::Span;
 use syntax::codemap::{respan, Spanned};
@@ -38,6 +38,10 @@ pub trait Folder : Sized {
         noop_fold_meta_items(meta_items, self)
     }
 
+    fn fold_meta_list_item(&mut self, list_item: NestedMetaItem) -> NestedMetaItem {
+        noop_fold_meta_list_item(list_item, self)
+    }
+
     fn fold_meta_item(&mut self, meta_item: P<MetaItem>) -> P<MetaItem> {
         noop_fold_meta_item(meta_item, self)
     }
@@ -486,13 +490,26 @@ pub fn noop_fold_attribute<T: Folder>(at: Attribute, fld: &mut T) -> Option<Attr
     })
 }
 
+pub fn noop_fold_meta_list_item<T: Folder>(li: NestedMetaItem, fld: &mut T)
+    -> NestedMetaItem {
+    Spanned {
+        node: match li.node {
+            NestedMetaItemKind::MetaItem(mi) =>  {
+                NestedMetaItemKind::MetaItem(fld.fold_meta_item(mi))
+            },
+            NestedMetaItemKind::Literal(lit) => NestedMetaItemKind::Literal(lit)
+        },
+        span: fld.new_span(li.span)
+    }
+}
+
 pub fn noop_fold_meta_item<T: Folder>(mi: P<MetaItem>, fld: &mut T) -> P<MetaItem> {
     mi.map(|Spanned { node, span }| {
         Spanned {
             node: match node {
                 MetaItemKind::Word(id) => MetaItemKind::Word(id),
                 MetaItemKind::List(id, mis) => {
-                    MetaItemKind::List(id, mis.move_map(|e| fld.fold_meta_item(e)))
+                    MetaItemKind::List(id, mis.move_map(|e| fld.fold_meta_list_item(e)))
                 }
                 MetaItemKind::NameValue(id, s) => MetaItemKind::NameValue(id, s),
             },

src/librustc/lint/context.rs

@@ -38,7 +38,7 @@ use util::nodemap::FnvHashMap;
 use std::cmp;
 use std::default::Default as StdDefault;
 use std::mem;
-use syntax::attr::{self, AttrMetaMethods};
+use syntax::attr::{self, AttrMetaMethods, AttrNestedMetaItemMethods};
 use syntax::parse::token::InternedString;
 use syntax::ast;
 use syntax_pos::Span;
@@ -372,12 +372,10 @@ pub fn gather_attr(attr: &ast::Attribute)
         return out;
     };
 
-    for meta in metas {
-        out.push(if meta.is_word() {
-            Ok((meta.name().clone(), level, meta.span))
-        } else {
-            Err(meta.span)
-        });
+    for li in metas {
+        out.push(li.word().map_or(Err(li.span), |word| {
+            Ok((word.name().clone(), level, word.span))
+        }));
     }
 
     out

src/librustc_borrowck/borrowck/mir/mod.rs

@@ -11,7 +11,7 @@
 use borrowck::BorrowckCtxt;
 
 use syntax::ast::{self, MetaItem};
-use syntax::attr::AttrMetaMethods;
+use syntax::attr::{AttrMetaMethods, AttrNestedMetaItemMethods};
 use syntax::ptr::P;
 use syntax_pos::{Span, DUMMY_SP};
 
@@ -43,8 +43,9 @@ fn has_rustc_mir_with(attrs: &[ast::Attribute], name: &str) -> Option<P<MetaItem
         if attr.check_name("rustc_mir") {
             let items = attr.meta_item_list();
             for item in items.iter().flat_map(|l| l.iter()) {
-                if item.check_name(name) {
-                    return Some(item.clone())
+                match item.meta_item() {
+                    Some(mi) if mi.check_name(name) => return Some(mi.clone()),
+                    _ => continue
                 }
             }
         }

src/librustc_driver/lib.rs

@@ -655,17 +655,19 @@ impl RustcDefaultCalls {
                         if !allow_unstable_cfg && GatedCfg::gate(&*cfg).is_some() {
                             continue;
                         }
+
                         if cfg.is_word() {
                             println!("{}", cfg.name());
-                        } else if cfg.is_value_str() {
-                            if let Some(s) = cfg.value_str() {
-                                println!("{}=\"{}\"", cfg.name(), s);
-                            }
+                        } else if let Some(s) = cfg.value_str() {
+                            println!("{}=\"{}\"", cfg.name(), s);
                         } else if cfg.is_meta_item_list() {
                             // Right now there are not and should not be any
                             // MetaItemKind::List items in the configuration returned by
                             // `build_configuration`.
-                            panic!("MetaItemKind::List encountered in default cfg")
+                            panic!("Found an unexpected list in cfg attribute '{}'!", cfg.name())
+                        } else {
+                            // There also shouldn't be literals.
+                            panic!("Found an unexpected literal in cfg attribute '{}'!", cfg.name())
                         }
                     }
                 }

src/librustc_incremental/assert_dep_graph.rs

@@ -56,7 +56,7 @@ use std::env;
 use std::fs::File;
 use std::io::Write;
 use syntax::ast;
-use syntax::attr::AttrMetaMethods;
+use syntax::attr::{AttrNestedMetaItemMethods, AttrMetaMethods};
 use syntax::parse::token::InternedString;
 use syntax_pos::Span;
 
@@ -116,31 +116,40 @@ impl<'a, 'tcx> IfThisChanged<'a, 'tcx> {
         for attr in self.tcx.get_attrs(def_id).iter() {
             if attr.check_name(IF_THIS_CHANGED) {
                 let mut id = None;
-                for meta_item in attr.meta_item_list().unwrap_or_default() {
-                    if meta_item.is_word() && id.is_none() {
-                        id = Some(meta_item.name().clone());
-                    } else {
-                        // FIXME better-encapsulate meta_item (don't directly access `node`)
-                        span_bug!(meta_item.span(), "unexpected meta-item {:?}", meta_item.node)
+                for list_item in attr.meta_item_list().unwrap_or_default() {
+                    match list_item.word() {
+                        Some(word) if id.is_none() => {
+                            id = Some(word.name().clone())
+                        },
+                        _ => {
+                            // FIXME better-encapsulate meta_item (don't directly access `node`)
+                            span_bug!(list_item.span(), "unexpected list-item {:?}", list_item.node)
+                        }
                     }
                 }
+
                 let id = id.unwrap_or(InternedString::new(ID));
                 self.if_this_changed.entry(id)
                                     .or_insert(FnvHashSet())
                                     .insert((attr.span, def_id, DepNode::Hir(def_id)));
             } else if attr.check_name(THEN_THIS_WOULD_NEED) {
                 let mut dep_node_interned = None;
                 let mut id = None;
-                for meta_item in attr.meta_item_list().unwrap_or_default() {
-                    if meta_item.is_word() && dep_node_interned.is_none() {
-                        dep_node_interned = Some(meta_item.name().clone());
-                    } else if meta_item.is_word() && id.is_none() {
-                        id = Some(meta_item.name().clone());
-                    } else {
-                        // FIXME better-encapsulate meta_item (don't directly access `node`)
-                        span_bug!(meta_item.span(), "unexpected meta-item {:?}", meta_item.node)
+                for list_item in attr.meta_item_list().unwrap_or_default() {
+                    match list_item.word() {
+                        Some(word) if dep_node_interned.is_none() => {
+                            dep_node_interned = Some(word.name().clone());
+                        },
+                        Some(word) if id.is_none() => {
+                            id = Some(word.name().clone())
+                        },
+                        _ => {
+                            // FIXME better-encapsulate meta_item (don't directly access `node`)
+                            span_bug!(list_item.span(), "unexpected meta-item {:?}", list_item.node)
+                        }
                     }
                 }
+
                 let dep_node = match dep_node_interned {
                     Some(ref n) => {
                         match DepNode::from_label_string(&n[..], def_id) {

src/librustc_incremental/persist/dirty_clean.rs

@@ -31,8 +31,8 @@ use rustc::hir;
 use rustc::hir::def_id::DefId;
 use rustc::hir::intravisit::Visitor;
 use rustc_data_structures::fnv::FnvHashSet;
-use syntax::ast::{self, Attribute, MetaItem};
-use syntax::attr::AttrMetaMethods;
+use syntax::ast::{self, Attribute, NestedMetaItem};
+use syntax::attr::{AttrNestedMetaItemMethods, AttrMetaMethods};
 use syntax::parse::token::InternedString;
 use rustc::ty::TyCtxt;
 
@@ -71,13 +71,17 @@ pub struct DirtyCleanVisitor<'a, 'tcx:'a> {
 }
 
 impl<'a, 'tcx> DirtyCleanVisitor<'a, 'tcx> {
-    fn expect_associated_value(&self, item: &MetaItem) -> InternedString {
+    fn expect_associated_value(&self, item: &NestedMetaItem) -> InternedString {
         if let Some(value) = item.value_str() {
             value
         } else {
-            self.tcx.sess.span_fatal(
-                item.span,
-                &format!("associated value expected for `{}`", item.name()));
+            let msg = if let Some(name) = item.name() {
+                format!("associated value expected for `{}`", name)
+            } else {
+                "expected an associated value".to_string()
+            };
+
+            self.tcx.sess.span_fatal(item.span, &msg);
         }
     }
 

src/librustc_lint/builtin.rs

@@ -44,8 +44,8 @@ use lint::{LintPass, LateLintPass};
 use std::collections::HashSet;
 
 use syntax::{ast};
-use syntax::attr::{self, AttrMetaMethods, AttributeMethods};
-use syntax_pos::Span;
+use syntax::attr::{self, AttrMetaMethods, AttrNestedMetaItemMethods, AttributeMethods};
+use syntax_pos::{Span};
 
 use rustc::hir::{self, PatKind};
 use rustc::hir::intravisit::FnKind;
@@ -317,7 +317,7 @@ impl LateLintPass for MissingDoc {
         let doc_hidden = self.doc_hidden() || attrs.iter().any(|attr| {
             attr.check_name("doc") && match attr.meta_item_list() {
                 None => false,
-                Some(l) => attr::contains_name(&l[..], "hidden"),
+                Some(l) => attr::list_contains_name(&l[..], "hidden"),
             }
         });
         self.doc_hidden_stack.push(doc_hidden);

src/librustc_lint/unused.rs

@@ -234,10 +234,13 @@ impl LintPass for UnusedAttributes {
 
 impl LateLintPass for UnusedAttributes {
     fn check_attribute(&mut self, cx: &LateContext, attr: &ast::Attribute) {
+        debug!("checking attribute: {:?}", attr);
+
         // Note that check_name() marks the attribute as used if it matches.
         for &(ref name, ty, _) in KNOWN_ATTRIBUTES {
             match ty {
                 AttributeType::Whitelisted if attr.check_name(name) => {
+                    debug!("{:?} is Whitelisted", name);
                     break;
                 },
                 _ => ()
@@ -247,11 +250,13 @@ impl LateLintPass for UnusedAttributes {
         let plugin_attributes = cx.sess().plugin_attributes.borrow_mut();
         for &(ref name, ty) in plugin_attributes.iter() {
             if ty == AttributeType::Whitelisted && attr.check_name(&name) {
+                debug!("{:?} (plugin attr) is whitelisted with ty {:?}", name, ty);
                 break;
             }
         }
 
         if !attr::is_used(attr) {
+            debug!("Emitting warning for: {:?}", attr);
             cx.span_lint(UNUSED_ATTRIBUTES, attr.span, "unused attribute");
             // Is it a builtin attribute that must be used at the crate level?
             let known_crate = KNOWN_ATTRIBUTES.iter().find(|&&(name, ty, _)| {
@@ -275,6 +280,8 @@ impl LateLintPass for UnusedAttributes {
                 };
                 cx.span_lint(UNUSED_ATTRIBUTES, attr.span, msg);
             }
+        } else {
+            debug!("Attr was used: {:?}", attr);
         }
     }
 }

src/librustc_metadata/common.rs

@@ -45,26 +45,13 @@ pub const tag_items_closure_kind: usize = 0x2a;
 pub const tag_items_closure_ty: usize = 0x2b;
 pub const tag_def_key: usize = 0x2c;
 
-// GAP 0x2d 0x2e
+// GAP 0x2d 0x34
 
 pub const tag_index: usize = 0x110; // top-level only
 pub const tag_xref_index: usize = 0x111; // top-level only
 pub const tag_xref_data: usize = 0x112; // top-level only
-
-pub const tag_meta_item_name_value: usize = 0x2f;
-
-pub const tag_meta_item_name: usize = 0x30;
-
-pub const tag_meta_item_value: usize = 0x31;
-
 pub const tag_attributes: usize = 0x101; // top-level only
 
-pub const tag_attribute: usize = 0x32;
-
-pub const tag_meta_item_word: usize = 0x33;
-
-pub const tag_meta_item_list: usize = 0x34;
-
 // The list of crates that this crate depends on
 pub const tag_crate_deps: usize = 0x102; // top-level only
 

src/librustc_metadata/creader.rs

@@ -35,8 +35,7 @@ use syntax::ast;
 use syntax::abi::Abi;
 use syntax::codemap;
 use syntax::parse;
-use syntax::attr;
-use syntax::attr::AttrMetaMethods;
+use syntax::attr::{self, AttrMetaMethods, AttrNestedMetaItemMethods};
 use syntax::parse::token::InternedString;
 use syntax::visit;
 use syntax_pos::{self, Span, mk_sp, Pos};