fix(codegen): declare loop-local drawing-object handles (line/label/box)

pineforge_codegen/codegen/visit_stmt.py

@@ -100,7 +100,6 @@
 )
 from ..symbols import TypeSpec
 from .tables import (
-    SKIP_VAR_TYPES,
     TA_RETURNS_BOOL,
     TA_TUPLE_FIELDS,
     MATRIX_RETURNING_METHODS,
@@ -356,16 +355,19 @@ def _visit_var_decl(self, node: VarDecl, lines: list[str], pad: str) -> None:
                     lines.append(f"{pad}{cpp_type} {safe};")
                 return
 
-        # Skip visual function assignments — but still emit declaration for
-        # table function results since the var may be used later
+        # Visual/drawing function assignments (line.new, label.new, box.new,
+        # table.new, ...) are no-ops in a backtest, but the assigned variable may
+        # still be referenced later (e.g. pushed into an array<line>, or used as a
+        # handle by sibling set_* calls). Emit a default-valued local declaration
+        # so those references compile; the value is inert. Global members are
+        # already declared at class scope, so only locals need this. (Previously
+        # only `table` results were declared, which dropped loop-local line/label
+        # handles and produced "use of undeclared identifier".)
         if isinstance(node.value, FuncCall) and self._is_skip_expr(node.value):
-            func_name, namespace = self._resolve_callee(node.value.callee)
-            if namespace in SKIP_VAR_TYPES:
-                # Emit var with default value so references don't fail
-                if not is_global_member:
-                    cpp_type = self._type_for_decl(node)
-                    default = "0" if cpp_type in ("int", "double") else ('std::string("")' if cpp_type == "std::string" else "false")
-                    lines.append(f"{pad}{cpp_type} {safe} = {default};")
+            if not is_global_member:
+                cpp_type = self._type_for_decl(node)
+                default = "0" if cpp_type in ("int", "double") else ('std::string("")' if cpp_type == "std::string" else "false")
+                lines.append(f"{pad}{cpp_type} {safe} = {default};")
             return
 
         # TA call

tests/test_codegen_drawing_handles.py

@@ -0,0 +1,33 @@
+"""Regression: loop-local drawing-object handles must be declared.
+
+Drawing calls (line.new / label.new / box.new / table.new ...) are no-ops in a
+backtest, but the variable they're assigned to may still be referenced (e.g.
+pushed into an `array<line>`). When the assignment lives in a for-loop body the
+handle is a local; it must be declared (as an inert default) or the generated
+C++ references an undeclared identifier.
+"""
+
+from pineforge_codegen import transpile
+
+
+def _cpp(body: str) -> str:
+    return transpile('//@version=6\nstrategy("t")\n' + body + "\n")
+
+
+def test_line_handle_in_loop_is_declared():
+    cpp = _cpp(
+        "var a = array.new<line>()\n"
+        "for k = 1 to 3\n"
+        "    ln = line.new(bar_index, close, bar_index + 1, close)\n"
+        "    array.push(a, ln)"
+    )
+    assert "double ln" in cpp or "auto ln" in cpp
+
+
+def test_label_handle_in_loop_is_declared():
+    cpp = _cpp(
+        "for k = 1 to 3\n"
+        "    lb = label.new(bar_index, high, 'x')\n"
+        "    label.delete(lb)"
+    )
+    assert "double lb" in cpp or "auto lb" in cpp