From 66a44595c8460d3eae439e8b07cb5d2a843deded Mon Sep 17 00:00:00 2001
From: John Alanbrook <john@pockle.world>
Date: Mon, 9 Feb 2026 18:45:55 -0600
Subject: [PATCH] fix errors with mcode

---
 mcode.ce         |   1 +
 mcode.cm         | 352 ++++++++++++++++++++++++++++++-----------------
 source/cell.c    |  93 +++++++------
 source/runtime.c |   2 +-
 4 files changed, 270 insertions(+), 178 deletions(-)

diff --git a/mcode.ce b/mcode.ce
index ef94d7d8..f6614950 100644
--- a/mcode.ce
+++ b/mcode.ce
@@ -1,4 +1,5 @@
 var fd = use("fd")
+var json = use("json")
 var tokenize = use("tokenize")
 var parse = use("parse")
 var mcode = use("mcode")
diff --git a/mcode.cm b/mcode.cm
index 6b444b85..a4720e73 100644
--- a/mcode.cm
+++ b/mcode.cm
@@ -1142,31 +1142,87 @@ var mcode = function(ast) {
 
   // Statement compilation
   gen_statement = function(stmt) {
+    var kind = null
+    var left = null
+    var right = null
+    var name = null
+    var local_slot = 0
+    var arr_expr = null
+    var arr_slot = 0
+    var val_slot = 0
+    var list = null
+    var _i = 0
+    var stmts = null
+    var cond = null
+    var then_stmts = null
+    var else_stmts = null
+    var else_label = null
+    var end_label = null
+    var cond_slot = 0
+    var start_label = null
+    var old_break = null
+    var old_continue = null
+    var cond_label = null
+    var init = null
+    var test = null
+    var update = null
+    var update_label = null
+    var init_kind = null
+    var test_slot = 0
+    var expr = null
+    var slot = 0
+    var null_slot = 0
+    var call_expr = null
+    var callee = null
+    var args_list = null
+    var arg_slots = null
+    var nargs = 0
+    var callee_kind = null
+    var obj_node = null
+    var prop = null
+    var obj_slot = 0
+    var func_slot = 0
+    var cases = null
+    var switch_val = 0
+    var default_label = null
+    var case_labels = null
+    var case_node = null
+    var case_kind = null
+    var case_label = null
+    var case_expr = null
+    var case_val = 0
+    var cmp_slot = 0
+    var case_stmts = null
+    var _j = 0
+    var func = null
+    var func_id = 0
+    var dest = 0
+
     if (stmt == null) {
       return null
     }
     set_pos(stmt)
-    var kind = stmt.kind
+    kind = stmt.kind
     if (kind == null) {
       return null
     }
 
     if (kind == "var" || kind == "def") {
-      var left = stmt.left
-      var right = stmt.right
-      var name = left.name
-      var local_slot = find_var(name)
+      left = stmt.left
+      right = stmt.right
+      name = left.name
+      local_slot = find_var(name)
       // Pop: var val = arr[]
       if (stmt.pop == true && right != null) {
-        var arr_expr = right.left
-        var arr_slot = gen_expr(arr_expr, -1)
+        arr_expr = right.left
+        arr_slot = gen_expr(arr_expr, -1)
         if (local_slot >= 0) {
           emit_2("pop", local_slot, arr_slot)
         }
         return null
       }
       if (right != null) {
-        var val_slot = gen_expr(right, local_slot)
+        val_slot = gen_expr(right, local_slot)
         if (local_slot >= 0 && val_slot != local_slot) {
           emit_2("move", local_slot, val_slot)
         }
@@ -1177,8 +1233,8 @@ var mcode = function(ast) {
     }
 
     if (kind == "var_list" || kind == "def_list") {
-      var list = stmt.list
-      var _i = 0
+      list = stmt.list
+      _i = 0
       while (_i < length(list)) {
         gen_statement(list[_i])
         _i = _i + 1
@@ -1187,8 +1243,8 @@ var mcode = function(ast) {
     }
 
     if (kind == "block") {
-      var stmts = stmt.statements
-      var _i = 0
+      stmts = stmt.statements
+      _i = 0
       while (_i < length(stmts)) {
         gen_statement(stmts[_i])
         _i = _i + 1
@@ -1197,17 +1253,17 @@ var mcode = function(ast) {
     }
 
     if (kind == "if") {
-      var cond = stmt.expression
-      var then_stmts = stmt.then
-      var else_stmts = stmt["else"]
+      cond = stmt.expression
+      then_stmts = stmt.then
+      else_stmts = stmt["else"]
       if (else_stmts == null) {
         else_stmts = stmt.list
       }
-      var else_label = gen_label("if_else")
-      var end_label = gen_label("if_end")
-      var cond_slot = gen_expr(cond, -1)
+      else_label = gen_label("if_else")
+      end_label = gen_label("if_end")
+      cond_slot = gen_expr(cond, -1)
       emit_jump_cond("jump_false", cond_slot, else_label)
-      var _i = 0
+      _i = 0
       while (_i < length(then_stmts)) {
         gen_statement(then_stmts[_i])
         _i = _i + 1
@@ -1226,18 +1282,18 @@ var mcode = function(ast) {
     }
 
     if (kind == "while") {
-      var cond = stmt.expression
-      var stmts = stmt.statements
-      var start_label = gen_label("while_start")
-      var end_label = gen_label("while_end")
-      var old_break = s_loop_break
-      var old_continue = s_loop_continue
+      cond = stmt.expression
+      stmts = stmt.statements
+      start_label = gen_label("while_start")
+      end_label = gen_label("while_end")
+      old_break = s_loop_break
+      old_continue = s_loop_continue
       s_loop_break = end_label
       s_loop_continue = start_label
       emit_label(start_label)
-      var cond_slot = gen_expr(cond, -1)
+      cond_slot = gen_expr(cond, -1)
       emit_jump_cond("jump_false", cond_slot, end_label)
-      var _i = 0
+      _i = 0
       while (_i < length(stmts)) {
         gen_statement(stmts[_i])
         _i = _i + 1
@@ -1250,23 +1306,23 @@ var mcode = function(ast) {
     }
 
     if (kind == "do") {
-      var cond = stmt.expression
-      var stmts = stmt.statements
-      var start_label = gen_label("do_start")
-      var cond_label = gen_label("do_cond")
-      var end_label = gen_label("do_end")
-      var old_break = s_loop_break
-      var old_continue = s_loop_continue
+      cond = stmt.expression
+      stmts = stmt.statements
+      start_label = gen_label("do_start")
+      cond_label = gen_label("do_cond")
+      end_label = gen_label("do_end")
+      old_break = s_loop_break
+      old_continue = s_loop_continue
       s_loop_break = end_label
       s_loop_continue = cond_label
       emit_label(start_label)
-      var _i = 0
+      _i = 0
       while (_i < length(stmts)) {
         gen_statement(stmts[_i])
         _i = _i + 1
       }
       emit_label(cond_label)
-      var cond_slot = gen_expr(cond, -1)
+      cond_slot = gen_expr(cond, -1)
       emit_jump_cond("jump_true", cond_slot, start_label)
       emit_label(end_label)
       s_loop_break = old_break
@@ -1275,19 +1331,19 @@ var mcode = function(ast) {
     }
 
     if (kind == "for") {
-      var init = stmt.init
-      var test = stmt.test
-      var update = stmt.update
-      var stmts = stmt.statements
-      var start_label = gen_label("for_start")
-      var update_label = gen_label("for_update")
-      var end_label = gen_label("for_end")
-      var old_break = s_loop_break
-      var old_continue = s_loop_continue
+      init = stmt.init
+      test = stmt.test
+      update = stmt.update
+      stmts = stmt.statements
+      start_label = gen_label("for_start")
+      update_label = gen_label("for_update")
+      end_label = gen_label("for_end")
+      old_break = s_loop_break
+      old_continue = s_loop_continue
       s_loop_break = end_label
       s_loop_continue = update_label
       if (init != null) {
-        var init_kind = init.kind
+        init_kind = init.kind
         if (init_kind == "var" || init_kind == "def") {
           gen_statement(init)
         } else {
@@ -1296,10 +1352,10 @@ var mcode = function(ast) {
       }
       emit_label(start_label)
       if (test != null) {
-        var test_slot = gen_expr(test, -1)
+        test_slot = gen_expr(test, -1)
         emit_jump_cond("jump_false", test_slot, end_label)
       }
-      var _i = 0
+      _i = 0
       while (_i < length(stmts)) {
         gen_statement(stmts[_i])
         _i = _i + 1
@@ -1316,12 +1372,12 @@ var mcode = function(ast) {
     }
 
     if (kind == "return") {
-      var expr = stmt.expression
+      expr = stmt.expression
       if (expr != null) {
-        var slot = gen_expr(expr, -1)
+        slot = gen_expr(expr, -1)
         emit_1("return", slot)
       } else {
-        var null_slot = alloc_slot()
+        null_slot = alloc_slot()
         emit_1("null", null_slot)
         emit_1("return", null_slot)
       }
@@ -1329,27 +1385,27 @@ var mcode = function(ast) {
     }
 
     if (kind == "go") {
-      var call_expr = stmt.expression
+      call_expr = stmt.expression
       if (call_expr == null || call_expr.kind != "(") {
         return null
       }
-      var callee = call_expr.expression
-      var args_list = call_expr.list
-      var arg_slots = []
-      var _i = 0
-      var nargs = args_list != null ? length(args_list) : 0
+      callee = call_expr.expression
+      args_list = call_expr.list
+      arg_slots = []
+      _i = 0
+      nargs = args_list != null ? length(args_list) : 0
       while (_i < nargs) {
         push(arg_slots, gen_expr(args_list[_i], -1))
         _i = _i + 1
       }
-      var callee_kind = callee.kind
+      callee_kind = callee.kind
       if (callee_kind == ".") {
-        var obj_node = callee.left
-        var prop = callee.right
-        var obj_slot = gen_expr(obj_node, -1)
+        obj_node = callee.left
+        prop = callee.right
+        obj_slot = gen_expr(obj_node, -1)
         emit_go_call_method(obj_slot, prop, arg_slots)
       } else {
-        var func_slot = gen_expr(callee, -1)
+        func_slot = gen_expr(callee, -1)
         emit_go_call(func_slot, arg_slots)
       }
       return null
@@ -1375,27 +1431,27 @@ var mcode = function(ast) {
     }
 
     if (kind == "switch") {
-      var expr = stmt.expression
-      var cases = stmt.cases
-      var switch_val = gen_expr(expr, -1)
-      var end_label = gen_label("switch_end")
-      var default_label = null
-      var old_break = s_loop_break
+      expr = stmt.expression
+      cases = stmt.cases
+      switch_val = gen_expr(expr, -1)
+      end_label = gen_label("switch_end")
+      default_label = null
+      old_break = s_loop_break
       s_loop_break = end_label
       // Phase 1: emit comparisons, collect labels
-      var case_labels = []
-      var _i = 0
+      case_labels = []
+      _i = 0
       while (_i < length(cases)) {
-        var case_node = cases[_i]
-        var case_kind = case_node.kind
+        case_node = cases[_i]
+        case_kind = case_node.kind
         if (case_kind == "default") {
           default_label = gen_label("switch_default")
           push(case_labels, default_label)
         } else {
-          var case_label = gen_label("switch_case")
-          var case_expr = case_node.expression
-          var case_val = gen_expr(case_expr, -1)
-          var cmp_slot = alloc_slot()
+          case_label = gen_label("switch_case")
+          case_expr = case_node.expression
+          case_val = gen_expr(case_expr, -1)
+          cmp_slot = alloc_slot()
           emit_3("eq", cmp_slot, switch_val, case_val)
           emit_jump_cond("jump_true", cmp_slot, case_label)
           push(case_labels, case_label)
@@ -1411,8 +1467,8 @@ var mcode = function(ast) {
       _i = 0
       while (_i < length(cases)) {
         emit_label(case_labels[_i])
-        var case_stmts = cases[_i].statements
-        var _j = 0
+        case_stmts = cases[_i].statements
+        _j = 0
         while (_j < length(case_stmts)) {
           gen_statement(case_stmts[_j])
           _j = _j + 1
@@ -1425,14 +1481,14 @@ var mcode = function(ast) {
     }
 
     if (kind == "function") {
-      var name = stmt.name
+      name = stmt.name
       if (name != null) {
-        var func = gen_function(stmt)
-        var func_id = s_func_counter
+        func = gen_function(stmt)
+        func_id = s_func_counter
         s_func_counter = s_func_counter + 1
         push(s_functions, func)
-        var local_slot = find_var(name)
-        var dest = alloc_slot()
+        local_slot = find_var(name)
+        dest = alloc_slot()
         emit_2("function", dest, func_id)
         if (local_slot >= 0) {
           emit_2("move", local_slot, dest)
@@ -1453,6 +1509,38 @@ var mcode = function(ast) {
   // Function compilation
   gen_function = function(func_node) {
     var saved = save_state()
+    var is_arrow = func_node.arrow == true
+    var fn_nr_node = func_node.function_nr
+    var params = func_node.list
+    var nr_params = 0
+    var param_slot = 1
+    var _i = 0
+    var param = null
+    var param_name = null
+    var ps = 1
+    var default_expr = null
+    var end_label = null
+    var default_slot = 0
+    var hoisted = null
+    var fn = null
+    var fname = null
+    var compiled = null
+    var func_id = 0
+    var local_slot = 0
+    var dest = 0
+    var stmts = null
+    var body = null
+    var null_slot = 0
+    var disruption_start = 0
+    var disrupt_clause = func_node.disruption
+    var null_slot2 = null
+    var fn_name = func_node.name
+    var fn_scope = null
+    var nr_cs = 0
+    var result = null
+    var saved_label = 0
+    var saved_func = 0
+
     push(parent_states, saved)
 
     s_instructions = []
@@ -1461,28 +1549,25 @@ var mcode = function(ast) {
     s_loop_break = null
     s_loop_continue = null
 
-    var is_arrow = func_node.arrow == true
     s_is_arrow = is_arrow
 
-    var fn_nr_node = func_node.function_nr
     s_function_nr = fn_nr_node != null ? fn_nr_node : 0
 
     // Parameters
-    var params = func_node.list
     if (params == null) {
       params = func_node.parameters
     }
-    var nr_params = params != null ? length(params) : 0
+    nr_params = params != null ? length(params) : 0
     s_nr_args = nr_params
     s_this_slot = 0
     s_nr_close_slots = 0
     s_nr_local_slots = 0
 
-    var param_slot = 1
-    var _i = 0
+    param_slot = 1
+    _i = 0
     while (_i < nr_params) {
-      var param = params[_i]
-      var param_name = param.name
+      param = params[_i]
+      param_name = param.name
       if (param_name == null && is_text(param)) {
         param_name = param
       }
@@ -1505,15 +1590,15 @@ var mcode = function(ast) {
     }
 
     // Default parameter initialization
-    var ps = 1
+    ps = 1
     _i = 0
     while (_i < nr_params) {
-      var param = params[_i]
-      var default_expr = param.expression
+      param = params[_i]
+      default_expr = param.expression
       if (default_expr != null) {
-        var end_label = gen_label("default_end")
+        end_label = gen_label("default_end")
         emit_jump_cond("jump_not_null", ps, end_label)
-        var default_slot = gen_expr(default_expr, -1)
+        default_slot = gen_expr(default_expr, -1)
         emit_2("move", ps, default_slot)
         emit_label(end_label)
       }
@@ -1525,19 +1610,19 @@ var mcode = function(ast) {
     load_intrinsics(func_node.intrinsics)
 
     // Compile hoisted function declarations
-    var hoisted = func_node.functions
+    hoisted = func_node.functions
     if (hoisted != null) {
       _i = 0
       while (_i < length(hoisted)) {
-        var fn = hoisted[_i]
-        var fname = fn.name
+        fn = hoisted[_i]
+        fname = fn.name
         if (fname != null) {
-          var compiled = gen_function(fn)
-          var func_id = s_func_counter
+          compiled = gen_function(fn)
+          func_id = s_func_counter
           s_func_counter = s_func_counter + 1
           push(s_functions, compiled)
-          var local_slot = find_var(fname)
-          var dest = alloc_slot()
+          local_slot = find_var(fname)
+          dest = alloc_slot()
           emit_2("function", dest, func_id)
           if (local_slot >= 0) {
             emit_2("move", local_slot, dest)
@@ -1548,9 +1633,9 @@ var mcode = function(ast) {
     }
 
     // Compile body
-    var stmts = func_node.statements
+    stmts = func_node.statements
     if (stmts == null) {
-      var body = func_node.body
+      body = func_node.body
       if (body != null) {
         stmts = body.statements
         if (stmts == null) {
@@ -1567,14 +1652,11 @@ var mcode = function(ast) {
     }
 
     // Implicit return null
-    var null_slot = alloc_slot()
+    null_slot = alloc_slot()
     emit_1("null", null_slot)
     emit_1("return", null_slot)
 
     // Compile disruption clause
-    var disruption_start = 0
-    var disrupt_clause = func_node.disruption
-    var null_slot2 = null
     if (disrupt_clause != null && is_array(disrupt_clause)) {
       disruption_start = length(s_instructions)
       _i = 0
@@ -1588,18 +1670,16 @@ var mcode = function(ast) {
     }
 
     // Build result
-    var fn_name = func_node.name
     if (fn_name == null) {
       fn_name = "<anonymous>"
     }
 
-    var fn_scope = find_scope_record(s_function_nr)
-    var nr_cs = 0
+    fn_scope = find_scope_record(s_function_nr)
     if (fn_scope != null && fn_scope.nr_close_slots != null) {
       nr_cs = fn_scope.nr_close_slots
     }
 
-    var result = {
+    result = {
       name: fn_name,
       nr_args: nr_params,
       nr_close_slots: nr_cs,
@@ -1613,8 +1693,8 @@ var mcode = function(ast) {
     }
 
     // Propagate counters back
-    var saved_label = s_label_counter
-    var saved_func = s_func_counter
+    saved_label = s_label_counter
+    saved_func = s_func_counter
 
     // Pop parent state
     pop(parent_states)
@@ -1628,6 +1708,21 @@ var mcode = function(ast) {
   // Program compilation (top-level entry)
   var gen_program = function(ast) {
     var filename = ast.filename
+    var hoisted = ast.functions
+    var _i = 0
+    var fn = null
+    var name = null
+    var compiled = null
+    var func_id = 0
+    var local_slot = 0
+    var dest = 0
+    var statements = ast.statements
+    var last_expr_slot = -1
+    var stmt = null
+    var kind = null
+    var null_slot = 0
+    var result = null
+
     s_filename = filename
 
     s_instructions = []
@@ -1657,19 +1752,18 @@ var mcode = function(ast) {
     }
 
     // Compile hoisted function declarations from ast.functions
-    var hoisted = ast.functions
     if (hoisted != null) {
-      var _i = 0
+      _i = 0
       while (_i < length(hoisted)) {
-        var fn = hoisted[_i]
-        var name = fn.name
+        fn = hoisted[_i]
+        name = fn.name
         if (name != null) {
-          var compiled = gen_function(fn)
-          var func_id = s_func_counter
+          compiled = gen_function(fn)
+          func_id = s_func_counter
           s_func_counter = s_func_counter + 1
           push(s_functions, compiled)
-          var local_slot = find_var(name)
-          var dest = alloc_slot()
+          local_slot = find_var(name)
+          dest = alloc_slot()
           emit_2("function", dest, func_id)
           if (local_slot >= 0) {
             emit_2("move", local_slot, dest)
@@ -1680,12 +1774,10 @@ var mcode = function(ast) {
     }
 
     // Generate main code
-    var statements = ast.statements
-    var last_expr_slot = -1
-    var _i = 0
+    _i = 0
     while (_i < length(statements)) {
-      var stmt = statements[_i]
-      var kind = stmt.kind
+      stmt = statements[_i]
+      kind = stmt.kind
       if (kind != null) {
         if (kind == "call") {
           last_expr_slot = gen_expr(stmt.expression, -1)
@@ -1713,12 +1805,12 @@ var mcode = function(ast) {
     if (last_expr_slot >= 0) {
       emit_1("return", last_expr_slot)
     } else {
-      var null_slot = alloc_slot()
+      null_slot = alloc_slot()
       emit_1("null", null_slot)
       emit_1("return", null_slot)
     }
 
-    var result = {}
+    result = {}
     result.name = filename != null ? filename : "<eval>"
     result.data = s_data
     result.functions = s_functions
diff --git a/source/cell.c b/source/cell.c
index 71fabb9d..86f5e69c 100644
--- a/source/cell.c
+++ b/source/cell.c
@@ -296,7 +296,7 @@ static void print_usage(const char *prog)
   printf("  --ast <code|file>          Output AST as JSON\n");
   printf("  --tokenize <code|file>     Output token array as JSON\n");
   printf("  --mcode <script> [args]    Run through mcode compilation pipeline\n");
-  printf("  --run-mcode <code|file>    Compile and run through MCODE interpreter\n");
+  printf("  --mcode-print <code|file>  Compile to MCODE JSON and print it\n");
   printf("  --mach <code|file>         Output MACH bytecode\n");
   printf("  --mach-run <code|file>     Compile and run through MACH VM\n");
   printf("  --test [heap_size]         Run C test suite\n");
@@ -420,70 +420,69 @@ int cell_init(int argc, char **argv)
     }
   }
 
-  /* Check for --run-mcode flag to execute via MCODE interpreter */
-  if (argc >= 3 && strcmp(argv[1], "--run-mcode") == 0) {
-    const char *filename = argv[2];
-    if (!find_cell_shop()) return 1;
+  /* Check for --mcode-print flag to compile a script to MCODE JSON and print it */
+  if (argc >= 3 && strcmp(argv[1], "--mcode-print") == 0) {
+    const char *script_or_file = argv[2];
+    char *script = NULL;
+    char *allocated_script = NULL;
+    const char *filename = "<eval>";
 
-    size_t boot_size;
-    char *boot_data = load_core_file("internal/bootstrap.cm", &boot_size);
-    if (!boot_data) {
-      printf("ERROR: Could not load internal/bootstrap.cm from %s\n", core_path);
+    struct stat st;
+    if (stat(script_or_file, &st) == 0 && S_ISREG(st.st_mode)) {
+      FILE *f = fopen(script_or_file, "r");
+      if (!f) {
+        printf("Failed to open file: %s\n", script_or_file);
+        return 1;
+      }
+      allocated_script = malloc(st.st_size + 1);
+      if (!allocated_script) {
+        fclose(f);
+        printf("Failed to allocate memory for script\n");
+        return 1;
+      }
+      size_t read_size = fread(allocated_script, 1, st.st_size, f);
+      fclose(f);
+      allocated_script[read_size] = '\0';
+      script = allocated_script;
+      filename = script_or_file;
+    } else {
+      script = (char *)script_or_file;
+    }
+
+    cJSON *ast = JS_ASTTree(script, strlen(script), filename);
+    if (!ast) {
+      printf("Failed to parse AST\n");
+      free(allocated_script);
       return 1;
     }
 
-    cJSON *boot_ast = JS_ASTTree(boot_data, boot_size, "internal/bootstrap.cm");
-    free(boot_data);
-    if (!boot_ast) {
-      printf("Failed to parse internal/bootstrap.cm\n");
+    if (print_tree_errors(ast)) {
+      cJSON_Delete(ast);
+      free(allocated_script);
       return 1;
     }
 
-    if (print_tree_errors(boot_ast)) {
-      cJSON_Delete(boot_ast);
-      return 1;
-    }
-
-    cJSON *mcode = JS_McodeTree(boot_ast);
-    cJSON_Delete(boot_ast);
+    cJSON *mcode = JS_McodeTree(ast);
+    cJSON_Delete(ast);
 
     if (!mcode) {
       printf("Failed to generate MCODE\n");
+      free(allocated_script);
       return 1;
     }
 
     if (print_tree_errors(mcode)) {
       cJSON_Delete(mcode);
+      free(allocated_script);
       return 1;
     }
 
-    JSRuntime *rt = JS_NewRuntime();
-    if (!rt) { printf("Failed to create JS runtime\n"); cJSON_Delete(mcode); return 1; }
-    JSContext *ctx = JS_NewContextWithHeapSize(rt, 256 * 1024);
-    if (!ctx) { printf("Failed to create execution context\n"); cJSON_Delete(mcode); JS_FreeRuntime(rt); return 1; }
-
-    JS_FreeValue(ctx, js_blob_use(ctx));
-
-    JSValue hidden_env = JS_NewObject(ctx);
-    JS_SetPropertyStr(ctx, hidden_env, "os", js_os_use(ctx));
-    JS_SetPropertyStr(ctx, hidden_env, "program", JS_NewString(ctx, filename));
-    hidden_env = JS_Stone(ctx, hidden_env);
-
-    JSValue result = JS_CallMcodeTreeEnv(ctx, mcode, hidden_env);
-
-    int exit_code = 0;
-    if (JS_IsException(result)) {
-      /* Error already printed to stderr by JS_Throw* */
-      JS_GetException(ctx);
-      exit_code = 1;
-    } else if (!JS_IsNull(result)) {
-      const char *str = JS_ToCString(ctx, result);
-      if (str) { printf("%s\n", str); JS_FreeCString(ctx, str); }
-    }
-
-    JS_FreeContext(ctx);
-    JS_FreeRuntime(rt);
-    return exit_code;
+    char *pretty = cJSON_Print(mcode);
+    cJSON_Delete(mcode);
+    printf("%s\n", pretty);
+    free(pretty);
+    free(allocated_script);
+    return 0;
   }
 
   /* Check for --mach flag to dump MACH bytecode */
diff --git a/source/runtime.c b/source/runtime.c
index 6ea2e76d..0f6c0f88 100644
--- a/source/runtime.c
+++ b/source/runtime.c
@@ -10505,7 +10505,7 @@ static JSValue js_mcode_run (JSContext *ctx, JSValue this_val, int argc, JSValue
 
   JSValue env = (argc >= 3 && JS_IsObject (argv[2])) ? argv[2] : JS_NULL;
   JSValue result = JS_CallMcodeTreeEnv (ctx, mcode, env);
-  cJSON_Delete (mcode);
+  /* mcode tree ownership transferred to JS_CallMcodeTreeEnv — do not free */
   JS_FreeCString (ctx, name);
   return result;
 }