Implement ALIAS NODE keyword locations

ast.c

@@ -775,6 +775,10 @@ node_locations(VALUE ast_value, const NODE *node)
 {
     enum node_type type = nd_type(node);
     switch (type) {
+      case NODE_ALIAS:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_ALIAS(node)->keyword_loc));
       case NODE_UNDEF:
         return rb_ary_new_from_args(2,
                                     location_new(nd_code_loc(node)),

node_dump.c

@@ -922,8 +922,9 @@ dump_node(VALUE buf, VALUE indent, int comment, const NODE * node)
         ANN("format: alias [nd_1st] [nd_2nd]");
         ANN("example: alias bar foo");
         F_NODE(nd_1st, RNODE_ALIAS, "new name");
-        LAST_NODE;
         F_NODE(nd_2nd, RNODE_ALIAS, "old name");
+        LAST_NODE;
+        F_LOC(keyword_loc, RNODE_ALIAS);
         return;
 
       case NODE_VALIAS:

parse.y

@@ -1138,7 +1138,7 @@ static rb_node_splat_t *rb_node_splat_new(struct parser_params *p, NODE *nd_head
 static rb_node_block_pass_t *rb_node_block_pass_new(struct parser_params *p, NODE *nd_body, const YYLTYPE *loc);
 static rb_node_defn_t *rb_node_defn_new(struct parser_params *p, ID nd_mid, NODE *nd_defn, const YYLTYPE *loc);
 static rb_node_defs_t *rb_node_defs_new(struct parser_params *p, NODE *nd_recv, ID nd_mid, NODE *nd_defn, const YYLTYPE *loc);
-static rb_node_alias_t *rb_node_alias_new(struct parser_params *p, NODE *nd_1st, NODE *nd_2nd, const YYLTYPE *loc);
+static rb_node_alias_t *rb_node_alias_new(struct parser_params *p, NODE *nd_1st, NODE *nd_2nd, const YYLTYPE *loc, const YYLTYPE *keyword_loc);
 static rb_node_valias_t *rb_node_valias_new(struct parser_params *p, ID nd_alias, ID nd_orig, const YYLTYPE *loc);
 static rb_node_undef_t *rb_node_undef_new(struct parser_params *p, NODE *nd_undef, const YYLTYPE *loc);
 static rb_node_class_t *rb_node_class_new(struct parser_params *p, NODE *nd_cpath, NODE *nd_body, NODE *nd_super, const YYLTYPE *loc);
@@ -1246,7 +1246,7 @@ static rb_node_error_t *rb_node_error_new(struct parser_params *p, const YYLTYPE
 #define NEW_BLOCK_PASS(b,loc) rb_node_block_pass_new(p,b,loc)
 #define NEW_DEFN(i,s,loc) (NODE *)rb_node_defn_new(p,i,s,loc)
 #define NEW_DEFS(r,i,s,loc) (NODE *)rb_node_defs_new(p,r,i,s,loc)
-#define NEW_ALIAS(n,o,loc) (NODE *)rb_node_alias_new(p,n,o,loc)
+#define NEW_ALIAS(n,o,loc,k_loc) (NODE *)rb_node_alias_new(p,n,o,loc,k_loc)
 #define NEW_VALIAS(n,o,loc) (NODE *)rb_node_valias_new(p,n,o,loc)
 #define NEW_UNDEF(i,loc) (NODE *)rb_node_undef_new(p,i,loc)
 #define NEW_CLASS(n,b,s,loc) (NODE *)rb_node_class_new(p,n,b,s,loc)
@@ -3128,7 +3128,7 @@ k_END		: keyword_END lex_ctxt
 
 stmt		: keyword_alias fitem {SET_LEX_STATE(EXPR_FNAME|EXPR_FITEM);} fitem
                     {
-                        $$ = NEW_ALIAS($2, $4, &@$);
+                        $$ = NEW_ALIAS($2, $4, &@$, &@1);
                     /*% ripper: alias!($:2, $:4) %*/
                     }
                 | keyword_alias tGVAR tGVAR
@@ -12297,11 +12297,12 @@ rb_node_block_pass_new(struct parser_params *p, NODE *nd_body, const YYLTYPE *lo
 }
 
 static rb_node_alias_t *
-rb_node_alias_new(struct parser_params *p, NODE *nd_1st, NODE *nd_2nd, const YYLTYPE *loc)
+rb_node_alias_new(struct parser_params *p, NODE *nd_1st, NODE *nd_2nd, const YYLTYPE *loc, const YYLTYPE *keyword_loc)
 {
     rb_node_alias_t *n = NODE_NEWNODE(NODE_ALIAS, rb_node_alias_t, loc);
     n->nd_1st = nd_1st;
     n->nd_2nd = nd_2nd;
+    n->keyword_loc = *keyword_loc;
 
     return n;
 }

rubyparser.h

@@ -820,6 +820,7 @@ typedef struct RNode_ALIAS {
 
     struct RNode *nd_1st;
     struct RNode *nd_2nd;
+    rb_code_location_t keyword_loc;
 } rb_node_alias_t;
 
 typedef struct RNode_VALIAS {

test/ruby/test_ast.rb

@@ -1330,6 +1330,11 @@ dummy
       assert_locations(node.locations, [[1, 0, 1, 5]])
     end
 
+    def test_alias_locations
+      node = RubyVM::AbstractSyntaxTree.parse("alias foo bar")
+      assert_locations(node.children[-1].locations, [[1, 0, 1, 13], [1, 0, 1, 5]])
+    end
+
     def test_unless_locations
       node = RubyVM::AbstractSyntaxTree.parse("unless cond then 1 else 2 end")
       assert_locations(node.children[-1].locations, [[1, 0, 1, 29], [1, 0, 1, 6], [1, 12, 1, 16], [1, 26, 1, 29]])