auto merge of #7902 : huonw/rust/attr++, r=cmr,pcwalton

This does a number of things, but especially dramatically reduce the
number of allocations performed for operations involving attributes/
meta items:

- Converts ast::meta_item & ast::attribute and other associated enums
  to CamelCase.
- Converts several standalone functions in syntax::attr into methods,
  defined on two traits AttrMetaMethods & AttributeMethods. The former
  is common to both MetaItem and Attribute since the latter is a thin
  wrapper around the former.
- Deletes functions that are unnecessary due to iterators.
- Converts other standalone functions to use iterators and the generic
  AttrMetaMethods rather than allocating a lot of new vectors (e.g. the
  old code would have to allocate a new vector to use functions that
  operated on &[meta_item] on &[attribute].)
- Moves the core algorithm of the #[cfg] matching to syntax::attr,
  similar to find_inline_attr and find_linkage_metas.

This doesn't have much of an effect on the speed of #[cfg] stripping,
despite hugely reducing the number of allocations performed; presumably
most of the time is spent in the ast folder rather than doing attribute
checks.

Also fixes the Eq instance of MetaItem_ to correctly ignore spans, so
that `rustc --cfg 'foo(bar)'` now works.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index 410849b4482..c7a65c80de1 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -115,7 +115,7 @@ pub fn parse_item_from_source_str(
     name: @str,
     source: @str,
     cfg: ast::crate_cfg,
-    attrs: ~[ast::attribute],
+    attrs: ~[ast::Attribute],
     sess: @mut ParseSess
 ) -> Option<@ast::item> {
     let p = new_parser_from_source_str(
@@ -132,7 +132,7 @@ pub fn parse_meta_from_source_str(
     source: @str,
     cfg: ast::crate_cfg,
     sess: @mut ParseSess
-) -> @ast::meta_item {
+) -> @ast::MetaItem {
     let p = new_parser_from_source_str(
         sess,
         cfg,
@@ -146,7 +146,7 @@ pub fn parse_stmt_from_source_str(
     name: @str,
     source: @str,
     cfg: ast::crate_cfg,
-    attrs: ~[ast::attribute],
+    attrs: ~[ast::Attribute],
     sess: @mut ParseSess
 ) -> @ast::stmt {
     let p = new_parser_from_source_str(