1 files changed, 132 insertions, 0 deletions
diff --git a/src/libsyntax/parse/attr.rs b/src/libsyntax/parse/attr.rs
new file mode 100644
index 00000000000..6615938b9ad
--- /dev/null
+++ b/src/libsyntax/parse/attr.rs
@@ -0,0 +1,132 @@
+import either::{either, left, right};
+import ast_util::spanned;
+import common::{parser_common, seq_sep};
+
+export attr_or_ext;
+export parser_attr;
+
+// A type to distingush between the parsing of item attributes or syntax
+// extensions, which both begin with token.POUND
+type attr_or_ext = option<either<[ast::attribute], @ast::expr>>;
+
+impl parser_attr for parser {
+
+    fn parse_outer_attrs_or_ext(first_item_attrs: [ast::attribute])
+        -> attr_or_ext
+    {
+        let expect_item_next = vec::is_not_empty(first_item_attrs);
+        if self.token == token::POUND {
+            let lo = self.span.lo;
+            if self.look_ahead(1u) == token::LBRACKET {
+                self.bump();
+                let first_attr =
+                    self.parse_attribute_naked(ast::attr_outer, lo);
+                ret some(left([first_attr] + self.parse_outer_attributes()));
+            } else if !(self.look_ahead(1u) == token::LT
+                        || self.look_ahead(1u) == token::LBRACKET
+                        || expect_item_next) {
+                self.bump();
+                ret some(right(self.parse_syntax_ext_naked(lo)));
+            } else { ret none; }
+        } else { ret none; }
+    }
+
+    // Parse attributes that appear before an item
+    fn parse_outer_attributes() -> [ast::attribute] {
+        let mut attrs: [ast::attribute] = [];
+        while self.token == token::POUND
+            && self.look_ahead(1u) == token::LBRACKET {
+            attrs += [self.parse_attribute(ast::attr_outer)];
+        }
+        ret attrs;
+    }
+
+    fn parse_attribute(style: ast::attr_style) -> ast::attribute {
+        let lo = self.span.lo;
+        self.expect(token::POUND);
+        ret self.parse_attribute_naked(style, lo);
+    }
+
+    fn parse_attribute_naked(style: ast::attr_style, lo: uint) ->
+        ast::attribute {
+        self.expect(token::LBRACKET);
+        let meta_item = self.parse_meta_item();
+        self.expect(token::RBRACKET);
+        let mut hi = self.span.hi;
+        ret spanned(lo, hi, {style: style, value: *meta_item});
+    }
+
+    // Parse attributes that appear after the opening of an item, each
+    // terminated by a semicolon. In addition to a vector of inner attributes,
+    // this function also returns a vector that may contain the first outer
+    // attribute of the next item (since we can't know whether the attribute
+    // is an inner attribute of the containing item or an outer attribute of
+    // the first contained item until we see the semi).
+    fn parse_inner_attrs_and_next() ->
+        {inner: [ast::attribute], next: [ast::attribute]} {
+        let mut inner_attrs: [ast::attribute] = [];
+        let mut next_outer_attrs: [ast::attribute] = [];
+        while self.token == token::POUND {
+            if self.look_ahead(1u) != token::LBRACKET {
+                // This is an extension
+                break;
+            }
+            let attr = self.parse_attribute(ast::attr_inner);
+            if self.token == token::SEMI {
+                self.bump();
+                inner_attrs += [attr];
+            } else {
+                // It's not really an inner attribute
+                let outer_attr =
+                    spanned(attr.span.lo, attr.span.hi,
+                            {style: ast::attr_outer, value: attr.node.value});
+                next_outer_attrs += [outer_attr];
+                break;
+            }
+        }
+        ret {inner: inner_attrs, next: next_outer_attrs};
+    }
+
+    fn parse_meta_item() -> @ast::meta_item {
+        let lo = self.span.lo;
+        let ident = self.parse_ident();
+        alt self.token {
+          token::EQ {
+            self.bump();
+            let lit = self.parse_lit();
+            let mut hi = self.span.hi;
+            ret @spanned(lo, hi, ast::meta_name_value(ident, lit));
+          }
+          token::LPAREN {
+            let inner_items = self.parse_meta_seq();
+            let mut hi = self.span.hi;
+            ret @spanned(lo, hi, ast::meta_list(ident, inner_items));
+          }
+          _ {
+            let mut hi = self.span.hi;
+            ret @spanned(lo, hi, ast::meta_word(ident));
+          }
+        }
+    }
+
+    fn parse_meta_seq() -> [@ast::meta_item] {
+        ret self.parse_seq(token::LPAREN, token::RPAREN,
+                           seq_sep(token::COMMA),
+                           {|p| p.parse_meta_item()}).node;
+    }
+
+    fn parse_optional_meta() -> [@ast::meta_item] {
+        alt self.token { token::LPAREN { ret self.parse_meta_seq(); }
+                         _ { ret []; } }
+    }
+}
+
+//
+// Local Variables:
+// mode: rust
+// fill-column: 78;
+// indent-tabs-mode: nil
+// c-basic-offset: 4
+// buffer-file-coding-system: utf-8-unix
+// End:
+//