Extract meta_item sorting from back::link to middle::attr

Author: brson

src/comp/back/link.rs

@@ -306,32 +306,15 @@ fn crate_link_metas(&ast::crate c) -> link_metas {
 
 // This calculates CMH as defined above
 fn crate_meta_extras_hash(sha1 sha, &ast::crate crate) -> str {
-    // FIXME (#487) Move this sorting stuff into middle::attr
-    fn lteq(&@ast::meta_item ma, &@ast::meta_item mb) -> bool {
-        fn key(&@ast::meta_item m) -> ast::ident {
-            alt (m.node) {
-                case (ast::meta_word(?name)) {
-                    name
-                }
-                case (ast::meta_name_value(?name, _)) {
-                    name
-                }
-                case (ast::meta_list(?name, _)) {
-                    name
-                }
-            }
-        }
-        ret key(ma) <= key(mb);
-    }
     fn len_and_str(&str s) -> str { ret #fmt("%u_%s", str::byte_len(s), s); }
+    
+    auto cmh_items = {
+        auto cmh_items = crate_link_metas(crate).cmh_items;
+        attr::sort_meta_items(cmh_items)
+    };
 
-    let vec[mutable @ast::meta_item] v = [mutable ];
-    for (@ast::meta_item mi in crate_link_metas(crate).cmh_items) {
-        v += [mutable mi];
-    }
-    sort::quick_sort(lteq, v);
     sha.reset();
-    for (@ast::meta_item m_ in v) {
+    for (@ast::meta_item m_ in cmh_items) {
         auto m = m_;
         alt (m.node) {
             case (ast::meta_name_value(?key, ?value)) {

src/comp/middle/attr.rs

@@ -8,6 +8,7 @@ export attr_metas;
 export find_linkage_metas;
 export find_attrs_by_name;
 export contains;
+export sort_meta_items;
 
 // From a list of crate attributes get only the meta_items that impact crate
 // linkage
@@ -103,6 +104,39 @@ fn contains(&vec[@ast::meta_item] haystack, @ast::meta_item needle) -> bool {
     ret false;
 }
 
+fn sort_meta_items(&vec[@ast::meta_item] items) -> vec[@ast::meta_item] {
+    fn lteq(&@ast::meta_item ma, &@ast::meta_item mb) -> bool {
+        fn key(&@ast::meta_item m) -> ast::ident {
+            alt (m.node) {
+                case (ast::meta_word(?name)) {
+                    name
+                }
+                case (ast::meta_name_value(?name, _)) {
+                    name
+                }
+                case (ast::meta_list(?name, _)) {
+                    name
+                }
+            }
+        }
+        ret key(ma) <= key(mb);
+    }
+
+    // This is sort of stupid here, converting to a vec of mutables and back
+    let vec[mutable @ast::meta_item] v = [mutable ];
+    for (@ast::meta_item mi in items) {
+        v += [mutable mi];
+    }
+
+    std::sort::quick_sort(lteq, v);
+
+    let vec[@ast::meta_item] v2 = [];
+    for (@ast::meta_item mi in v) {
+        v2 += [mi]
+    }
+    ret v2;
+}
+
 //
 // Local Variables:
 // mode: rust