Use NODE_CASE2 if case expressions don't exist

When NODE_WHEN is compiled by iseq_compile_each0,
the node passed to compile_when is NODE_WHEN (not NODE_CASE).
So we can not handle the location of NODE_CASE of
case statements which don't have case expressions.

e.g. :

```
case; when 1; foo; when 2; bar; else baz; end
```

This commit adds NODE_CASE2, and compiles it by
iseq_compile_each0.

* compile.c (compile_case): Does not call COMPILE_ when
  NODE_CASE does not have case expressions.
* compile.c (compile_case2): Compile NODE_CASE2 by compile_case2.
* compile.c (compile_when): Delete an obsoleted function.
* compile.c (iseq_compile_each0): Compile NODE_CASE2.

* ext/objspace/objspace.c (count_nodes): Add NODE_CASE2 case.

* node.c (dump_node, rb_gc_mark_node): Add NODE_CASE2 case.

* node.h (node_type): Add NODE_CASE2.
* node.h (NEW_CASE2): Add a macro which generates NODE_CASE2.

* parse.y: Generate NODE_CASE2 if case expressions don't exist.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60585 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 3 insertions, 0 deletions

diff --git a/node.h b/node.h
index 04434cb48c..29eaafd3ec 100644
--- a/node.h
+++ b/node.h
@@ -30,6 +30,8 @@ enum node_type {
 #define NODE_UNLESS      NODE_UNLESS
     NODE_CASE,
 #define NODE_CASE        NODE_CASE
+    NODE_CASE2,
+#define NODE_CASE2       NODE_CASE2
     NODE_WHEN,
 #define NODE_WHEN        NODE_WHEN
     NODE_WHILE,
@@ -355,6 +357,7 @@ typedef struct RNode {
 #define NEW_IF(c,t,e) NEW_NODE(NODE_IF,c,t,e)
 #define NEW_UNLESS(c,t,e) NEW_NODE(NODE_UNLESS,c,t,e)
 #define NEW_CASE(h,b) NEW_NODE(NODE_CASE,h,b,0)
+#define NEW_CASE2(h,b) NEW_NODE(NODE_CASE2,h,b,0)
 #define NEW_WHEN(c,t,e) NEW_NODE(NODE_WHEN,c,t,e)
 #define NEW_WHILE(c,b,n) NEW_NODE(NODE_WHILE,c,b,n)
 #define NEW_UNTIL(c,b,n) NEW_NODE(NODE_UNTIL,c,b,n)