mruby-compiler: convert node_heredoc to variable-sized nodes and cleanup

This completes the conversion of NODE_HEREDOC from traditional cons-list
nodes to variable-sized nodes by:

1. Modified new_heredoc to always use variable-sized nodes with embedded
   parser_heredoc_info struct and updated function signature to return
   info pointer via output parameter
2. Fixed parsing_heredoc_info to handle NODE_VARIABLE wrapper detection
   and return address of embedded struct
3. Updated gen_heredoc_var to use embedded info structure for codegen
4. Removed obsolete NODE_HEREDOC case and codegen_heredoc function from
   traditional codegen path
5. Replaced codegen_heredoc_str wrapper with direct codegen_cons_list_string
   calls for cleaner semantic naming

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

mrbgems/mruby-compiler/core/codegen.c

@@ -4307,18 +4307,6 @@ codegen_xstr(codegen_scope *s, node *tree, int val)
   if (val) push();
 }
 
-
-
-/* codegen_cons_list_string forward declaration moved to top of file */
-
-static void
-codegen_heredoc_str(codegen_scope *s, node *tree, int val)
-{
-  /* Use common cons list string codegen since tree is now in cons list format */
-  codegen_cons_list_string(s, tree, val);
-}
-
-
 /* Common function to generate bytecode for cons list string representation
  * Handles list of elements where each element is either:
  * - (len . str) for string literals
@@ -4843,12 +4831,6 @@ codegen_block_arg(codegen_scope *s, node *tree, int val)
   }
 }
 
-static void
-codegen_heredoc(codegen_scope *s, node *tree, int val)
-{
-  tree = ((struct mrb_parser_heredoc_info*)tree)->doc;
-  codegen_heredoc_str(s, tree, val);
-}
 
 static void
 codegen_super(codegen_scope *s, node *tree, int val)
@@ -5780,15 +5762,9 @@ gen_dregx_var(codegen_scope *s, node *varnode, int val)
 static void
 gen_heredoc_var(codegen_scope *s, node *varnode, int val)
 {
-  struct mrb_ast_heredoc_node *n = (struct mrb_ast_heredoc_node*)varnode;
-  // For heredocs, we need to handle them similar to strings
-  if (val) {
-    mrb_int len;
-    const char *str = mrb_sym2name_len(s->mrb, n->name, &len);
-    int off = new_lit_str(s, str, (int)len);
-    genop_2(s, OP_STRING, cursp(), off);
-    push();
-  }
+  struct mrb_ast_heredoc_node *n = heredoc_node(varnode);
+  // Process heredoc doc field as cons list string
+  codegen_cons_list_string(s, n->info.doc, val);
 }
 
 static void
@@ -6648,12 +6624,9 @@ codegen(codegen_scope *s, node *tree, int val)
     codegen_negate(s, tree, val);
     break;
 
-  case NODE_HEREDOC:
-    codegen_heredoc(s, tree, val);
-    break;
 
   case NODE_STR:
-    codegen_heredoc_str(s, tree, val);
+    codegen_cons_list_string(s, tree, val);
     break;
 
 

mrbgems/mruby-compiler/core/node.h

@@ -700,7 +700,7 @@ struct mrb_ast_dregx_node {
 
 struct mrb_ast_heredoc_node {
   struct mrb_ast_var_header hdr;
-  mrb_sym name;
+  struct mrb_parser_heredoc_info info;
 };
 
 struct mrb_ast_dsym_node {

mrbgems/mruby-compiler/core/parse.y

@@ -12,6 +12,7 @@
 #define YYSTACK_USE_ALLOCA 1
 
 #include <ctype.h>
+#include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
 #include <mruby.h>
@@ -2245,18 +2246,27 @@ new_nth_ref(parser_state *p, int n)
 
 /* (:heredoc . a) */
 static node*
-new_heredoc(parser_state *p)
+new_heredoc(parser_state *p, struct mrb_parser_heredoc_info **infop)
 {
-  if (!p->var_nodes_enabled) {
-    parser_heredoc_info *inf = (parser_heredoc_info*)parser_palloc(p, sizeof(parser_heredoc_info));
-    return cons_head((node*)NODE_HEREDOC, (node*)inf);
-  }
-
   size_t total_size = sizeof(struct mrb_ast_heredoc_node);
   enum mrb_ast_size_class class = size_to_class(total_size);
   struct mrb_ast_heredoc_node *n = (struct mrb_ast_heredoc_node*)parser_alloc_var(p, total_size, class);
   init_var_header(&n->hdr, p, NODE_HEREDOC, class);
-  n->name = 0; // Will be set by heredoc processing
+
+  /* Initialize embedded heredoc info struct */
+  n->info.allow_indent = FALSE;
+  n->info.remove_indent = FALSE;
+  n->info.line_head = FALSE;
+  n->info.indent = 0;
+  n->info.indented = NULL;
+  n->info.type = str_not_parsing;  // Will be set by heredoc processing
+  n->info.term = NULL;  // Will be set by heredoc processing
+  n->info.term_len = 0;
+  n->info.doc = NULL;
+
+  /* Return pointer to embedded info if requested */
+  *infop = &n->info;
+
   return cons_head((node*)NODE_VARIABLE, (node*)n);
 }
 
@@ -2514,6 +2524,11 @@ parsing_heredoc_info(parser_state *p)
   node *nd = p->parsing_heredoc;
   if (nd == NULL) return NULL;
   /* mrb_assert(nd->car->car == NODE_HEREDOC); */
+  if (nd->car->car == (node*)NODE_VARIABLE) {
+    /* Variable-sized heredoc node - return address of embedded info struct */
+    struct mrb_ast_heredoc_node *heredoc = heredoc_node(NODE_VAR_NODE_PTR(nd->car));
+    return &heredoc->info;
+  }
   return (parser_heredoc_info*)nd->car->cdr;
 }
 
@@ -6339,8 +6354,7 @@ heredoc_identifier(parser_state *p)
     pushback(p, c);
   }
   tokfix(p);
-  newnode = new_heredoc(p);
-  info = (parser_heredoc_info*)newnode->cdr;
+  newnode = new_heredoc(p, &info);
   info->term = strndup(tok(p), toklen(p));
   info->term_len = toklen(p);
   if (! quote)