mruby-compiler: remove codegen_stmts and inline logic into gen_stmts_var

Complete NODE_STMTS migration by removing unused codegen_stmts function
and inlining statement traversal logic directly into gen_stmts_var.

Co-authored-by: Claude <noreply@anthropic.com>

mrbgems/mruby-compiler/core/codegen.c

@@ -3578,18 +3578,6 @@ codegen_masgn(codegen_scope *s, node *tree, int val)
   }
 }
 
-static void
-codegen_stmts(codegen_scope *s, node *tree, int val)
-{
-  if (val && !tree) {
-    gen_load_nil(s, 1);
-  }
-  while (tree) {
-    codegen(s, tree->car, tree->cdr ? NOVAL : val);
-    tree = tree->cdr;
-  }
-}
-
 static void
 codegen_lambda(codegen_scope *s, node *tree, int val)
 {
@@ -4881,6 +4869,9 @@ gen_def_var(codegen_scope *s, node *varnode, int val)
 }
 
 /* Helper function for generating class/module/singleton class body */
+/* Forward declaration */
+static mrb_bool is_empty_stmts(node *stmt_node);
+
 static void
 gen_class_body(codegen_scope *s, node *body, int val)
 {
@@ -4892,7 +4883,7 @@ gen_class_body(codegen_scope *s, node *body, int val)
     node *body_stmts = body->cdr;
 
     /* Check for empty body case */
-    if (node_to_int(body_stmts->car) == NODE_STMTS && body_stmts->cdr == NULL) {
+    if (is_empty_stmts(body_stmts)) {
       genop_1(s, OP_LOADNIL, cursp());
     }
     else {
@@ -5876,9 +5867,7 @@ gen_ensure_var(codegen_scope *s, node *varnode, int val)
   node *body = ensure->body;
   node *ensure_clause = ensure->ensure_clause;
 
-  if (!ensure_clause ||
-      (node_to_int(ensure_clause->car) == NODE_STMTS &&
-       ensure_clause->cdr)) {
+  if (!ensure_clause || !is_empty_stmts(ensure_clause)) {
     int catch_entry, begin, end, target;
     int idx;
 
@@ -5901,6 +5890,41 @@ gen_ensure_var(codegen_scope *s, node *varnode, int val)
   }
 }
 
+static void
+gen_stmts_var(codegen_scope *s, node *varnode, int val)
+{
+  struct mrb_ast_stmts_node *stmts = stmts_node(varnode);
+  node *tree = STMTS_NODE_STMTS(stmts);
+
+  if (val && !tree) {
+    gen_load_nil(s, 1);
+  }
+  while (tree) {
+    codegen(s, tree->car, tree->cdr ? NOVAL : val);
+    tree = tree->cdr;
+  }
+}
+
+static mrb_bool
+is_empty_stmts(node *stmt_node)
+{
+  if (!stmt_node) return TRUE;
+
+  if (node_to_int(stmt_node->car) == NODE_VARIABLE) {
+    /* Variable-sized NODE_STMTS with internal cons-list */
+    if (NODE_TYPE(stmt_node) == NODE_STMTS) {
+      struct mrb_ast_stmts_node *stmts = stmts_node(NODE_VAR_NODE_PTR(stmt_node));
+      return STMTS_NODE_STMTS(stmts) == NULL;
+    }
+  }
+  else if (node_to_int(stmt_node->car) == NODE_STMTS) {
+    /* Traditional cons-list NODE_STMTS */
+    return stmt_node->cdr == NULL;
+  }
+
+  return FALSE;
+}
+
 // Group 16: Declarations and Definitions
 
 static void
@@ -6275,6 +6299,10 @@ codegen_variable_node(codegen_scope *s, node *varnode, int val)
     gen_ensure_var(s, varnode, val);
     return TRUE;
 
+  case NODE_STMTS:
+    gen_stmts_var(s, varnode, val);
+    return TRUE;
+
   case NODE_ALIAS:
     gen_alias_var(s, varnode, val);
     return TRUE;
@@ -6334,10 +6362,6 @@ codegen(codegen_scope *s, node *tree, int val)
   s->lineno = head->lineno;
   tree = tree->cdr;
   switch (nt) {
-  case NODE_STMTS:
-    codegen_stmts(s, tree, val);
-    break;
-
   case NODE_LAMBDA:
     codegen_lambda(s, tree, val);
     break;

mrbgems/mruby-compiler/core/node.h

@@ -870,6 +870,11 @@ struct mrb_ast_ensure_node {
   struct mrb_ast_node *ensure_clause;
 };
 
+struct mrb_ast_stmts_node {
+  struct mrb_ast_var_header hdr;
+  struct mrb_ast_node *stmts;        /* Cons-list of statements */
+};
+
 struct mrb_ast_iter_node {
   struct mrb_ast_var_header hdr;
   struct mrb_ast_node *vars;
@@ -924,6 +929,7 @@ struct mrb_ast_sdef_node {
 #define scope_node(n) ((struct mrb_ast_scope_node*)(n))
 #define begin_node(n) ((struct mrb_ast_begin_node*)(n))
 #define ensure_node(n) ((struct mrb_ast_ensure_node*)(n))
+#define stmts_node(n) ((struct mrb_ast_stmts_node*)(n))
 #define iter_node(n) ((struct mrb_ast_iter_node*)(n))
 #define when_node(n) ((struct mrb_ast_when_node*)(n))
 #define alias_node(n) ((struct mrb_ast_alias_node*)(n))

mrbgems/mruby-compiler/core/parse.y

@@ -492,16 +492,18 @@ new_scope(parser_state *p, node *body)
 static node*
 new_stmts(parser_state *p, node *body)
 {
-  if (body) {
-    /* If body is already a NODE_STMTS, just return it directly */
-    if (node_to_type(body->car) == NODE_STMTS) {
-      return body;
-    }
-    return list2((node*)NODE_STMTS, body);
-  }
-  return cons_head((node*)NODE_STMTS, 0);
+  size_t total_size = sizeof(struct mrb_ast_stmts_node);
+  enum mrb_ast_size_class class = size_to_class(total_size);
+
+  struct mrb_ast_stmts_node *n = (struct mrb_ast_stmts_node*)parser_alloc_var(p, total_size, class);
+
+  init_var_header(&n->hdr, p, NODE_STMTS, class);
+  n->stmts = body ? list1(body) : 0;  /* Wrap single statement in cons-list */
+
+  return cons_head((node*)NODE_VARIABLE, (node*)n);
 }
 
+
 /* (:begin body) - Always use variable-sized nodes */
 static node*
 new_begin(parser_state *p, node *body)
@@ -2668,7 +2670,9 @@ stmts           : none
                     }
                 | stmts terms stmt
                     {
-                      $$ = push($1, newline_node($3));
+                      /* Update the cons-list inside the existing variable-sized node */
+                      STMTS_NODE_STMTS($1->cdr) = push(STMTS_NODE_STMTS($1->cdr), newline_node($3));
+                      $$ = $1;
                     }
                 | error stmt
                     {
@@ -7652,7 +7656,7 @@ mrb_parser_new(mrb_state *mrb)
     p->var_alloc_counts[i] = 0;
   }
   p->var_total_allocated = 0;
-  p->var_nodes_enabled = TRUE;   /* Enable variable-sized nodes by default */
+  p->var_nodes_enabled = TRUE;
 
   return p;
 }