Remove `NODE_DASGN_CURR` [Feature #18406]

This `NODE` type was used in pre-YARV implementation, to improve
the performance of assignment to dynamic local variable defined at
the innermost scope.  It has no longer any actual difference with
`NODE_DASGN`, except for the node dump.

ast.c

@@ -417,7 +417,6 @@ node_children(rb_ast_t *ast, const NODE *node)
         }
       case NODE_LASGN:
       case NODE_DASGN:
-      case NODE_DASGN_CURR:
       case NODE_IASGN:
       case NODE_CVASGN:
       case NODE_GASGN:

compile.c

@@ -4928,7 +4928,6 @@ compile_massign_opt(rb_iseq_t *iseq, LINK_ANCHOR *const ret,
 	    MEMORY(ln->nd_vid);
 	    break;
 	  case NODE_DASGN:
-	  case NODE_DASGN_CURR:
 	  case NODE_IASGN:
 	  case NODE_CVASGN:
 	    MEMORY(ln->nd_vid);
@@ -5322,7 +5321,6 @@ defined_expr0(rb_iseq_t *iseq, LINK_ANCHOR *const ret,
       case NODE_MASGN:
       case NODE_LASGN:
       case NODE_DASGN:
-      case NODE_DASGN_CURR:
       case NODE_GASGN:
       case NODE_IASGN:
       case NODE_CDECL:
@@ -6592,8 +6590,7 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
         ADD_INSNL(ret, line_node, jump, matched);
         break;
       }
-      case NODE_DASGN:
-      case NODE_DASGN_CURR: {
+      case NODE_DASGN: {
         int idx, lv, ls;
         ID id = node->nd_vid;
 
@@ -6609,7 +6606,7 @@ iseq_compile_pattern_each(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *c
         }
 
         if (idx < 0) {
-            COMPILE_ERROR(ERROR_ARGS "NODE_DASGN(_CURR): unknown id (%"PRIsVALUE")",
+            COMPILE_ERROR(ERROR_ARGS "NODE_DASGN: unknown id (%"PRIsVALUE")",
                           rb_id2str(id));
             return COMPILE_NG;
         }
@@ -9199,8 +9196,7 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
 	ADD_SETLOCAL(ret, node, idx, get_lvar_level(iseq));
 	break;
       }
-      case NODE_DASGN:
-      case NODE_DASGN_CURR:{
+      case NODE_DASGN: {
 	int idx, lv, ls;
 	ID id = node->nd_vid;
 	CHECK(COMPILE(ret, "dvalue", node->nd_value));
@@ -9213,7 +9209,7 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const no
 	idx = get_dyna_var_idx(iseq, id, &lv, &ls);
 
 	if (idx < 0) {
-	    COMPILE_ERROR(ERROR_ARGS "NODE_DASGN(_CURR): unknown id (%"PRIsVALUE")",
+	    COMPILE_ERROR(ERROR_ARGS "NODE_DASGN: unknown id (%"PRIsVALUE")",
 			  rb_id2str(id));
 	    goto ng;
 	}

ext/objspace/objspace.c

@@ -423,7 +423,6 @@ count_nodes(int argc, VALUE *argv, VALUE os)
 		COUNT_NODE(NODE_MASGN);
 		COUNT_NODE(NODE_LASGN);
 		COUNT_NODE(NODE_DASGN);
-		COUNT_NODE(NODE_DASGN_CURR);
 		COUNT_NODE(NODE_GASGN);
 		COUNT_NODE(NODE_IASGN);
 		COUNT_NODE(NODE_CDECL);

node.c

@@ -407,16 +407,9 @@ dump_node(VALUE buf, VALUE indent, int comment, const NODE * node)
 	}
 	return;
       case NODE_DASGN:
-	ANN("dynamic variable assignment (out of current scope)");
+	ANN("dynamic variable assignment");
 	ANN("format: [nd_vid](dvar) = [nd_value]");
 	ANN("example: x = nil; 1.times { x = foo }");
-	F_ID(nd_vid, "local variable");
-	LAST_NODE;
-	F_NODE(nd_value, "rvalue");
-	return;
-      case NODE_DASGN_CURR:
-	ANN("dynamic variable assignment (in current scope)");
-	ANN("format: [nd_vid](current dvar) = [nd_value]");
 	ANN("example: 1.times { x = foo }");
 	F_ID(nd_vid, "local variable");
 	if (NODE_REQUIRED_KEYWORD_P(node)) {

node.h

@@ -48,7 +48,6 @@ enum node_type {
     NODE_MASGN,
     NODE_LASGN,
     NODE_DASGN,
-    NODE_DASGN_CURR,
     NODE_GASGN,
     NODE_IASGN,
     NODE_CDECL,
@@ -327,7 +326,6 @@ typedef struct RNode {
 #define NEW_GASGN(v,val,loc) NEW_NODE(NODE_GASGN,v,val,v,loc)
 #define NEW_LASGN(v,val,loc) NEW_NODE(NODE_LASGN,v,val,0,loc)
 #define NEW_DASGN(v,val,loc) NEW_NODE(NODE_DASGN,v,val,0,loc)
-#define NEW_DASGN_CURR(v,val,loc) NEW_NODE(NODE_DASGN_CURR,v,val,0,loc)
 #define NEW_IASGN(v,val,loc) NEW_NODE(NODE_IASGN,v,val,0,loc)
 #define NEW_CDECL(v,val,path,loc) NEW_NODE(NODE_CDECL,v,val,path,loc)
 #define NEW_CVASGN(v,val,loc) NEW_NODE(NODE_CVASGN,v,val,0,loc)

parse.y

@@ -3177,8 +3177,7 @@ primary		: literal
 
 			switch (nd_type($2)) {
 			  case NODE_LASGN:
-			  case NODE_DASGN:
-			  case NODE_DASGN_CURR: /* e.each {|internal_var| a = internal_var; ... } */
+			  case NODE_DASGN: /* e.each {|internal_var| a = internal_var; ... } */
 			    $2->nd_value = internal_var;
 			    id = 0;
 			    m->nd_plen = 1;
@@ -10879,11 +10878,11 @@ assignable0(struct parser_params *p, ID id, const char **err)
 			      NUMPARAM_ID_TO_IDX(id));
 		return -1;
 	    }
-	    if (dvar_curr(p, id)) return NODE_DASGN_CURR;
+	    if (dvar_curr(p, id)) return NODE_DASGN;
 	    if (dvar_defined(p, id)) return NODE_DASGN;
 	    if (local_id(p, id)) return NODE_LASGN;
 	    dyna_var(p, id);
-	    return NODE_DASGN_CURR;
+	    return NODE_DASGN;
 	}
 	else {
 	    if (!local_id(p, id)) local_var(p, id);
@@ -10910,7 +10909,6 @@ assignable(struct parser_params *p, ID id, NODE *val, const YYLTYPE *loc)
     const char *err = 0;
     int node_type = assignable0(p, id, &err);
     switch (node_type) {
-      case NODE_DASGN_CURR: return NEW_DASGN_CURR(id, val, loc);
       case NODE_DASGN: return NEW_DASGN(id, val, loc);
       case NODE_LASGN: return NEW_LASGN(id, val, loc);
       case NODE_GASGN: return NEW_GASGN(id, val, loc);
@@ -11122,7 +11120,6 @@ mark_lvar_used(struct parser_params *p, NODE *rhs)
 	}
 	break;
       case NODE_DASGN:
-      case NODE_DASGN_CURR:
 	if (dvar_defined_ref(p, rhs->nd_vid, &vidp)) {
 	    if (vidp) *vidp |= LVAR_USED;
 	}
@@ -11397,7 +11394,6 @@ node_assign(struct parser_params *p, NODE *lhs, NODE *rhs, struct lex_context ct
       case NODE_IASGN:
       case NODE_LASGN:
       case NODE_DASGN:
-      case NODE_DASGN_CURR:
       case NODE_MASGN:
       case NODE_CVASGN:
 	lhs->nd_value = rhs;
@@ -11477,7 +11473,6 @@ value_expr_check(struct parser_params *p, NODE *node)
 
 	  case NODE_LASGN:
 	  case NODE_DASGN:
-	  case NODE_DASGN_CURR:
 	  case NODE_MASGN:
 	    mark_lvar_used(p, node);
 	    return NULL;
@@ -11713,7 +11708,6 @@ assign_in_cond(struct parser_params *p, NODE *node)
       case NODE_MASGN:
       case NODE_LASGN:
       case NODE_DASGN:
-      case NODE_DASGN_CURR:
       case NODE_GASGN:
       case NODE_IASGN:
 	break;