add vmlinux expressions to eval expr

pythonbpf/expr/__init__.py

@@ -2,6 +2,7 @@ from .expr_pass import eval_expr, handle_expr, get_operand_value
 from .type_normalization import convert_to_bool, get_base_type_and_depth
 from .ir_ops import deref_to_depth
 from .call_registry import CallHandlerRegistry
+from .vmlinux_registry import VmlinuxHandlerRegistry
 
 __all__ = [
     "eval_expr",
@@ -11,4 +12,5 @@ __all__ = [
     "deref_to_depth",
     "get_operand_value",
     "CallHandlerRegistry",
+    "VmlinuxHandlerRegistry",
 ]

pythonbpf/expr/expr_pass.py

@@ -12,6 +12,7 @@ from .type_normalization import (
     get_base_type_and_depth,
     deref_to_depth,
 )
+from .vmlinux_registry import VmlinuxHandlerRegistry
 
 logger: Logger = logging.getLogger(__name__)
 
@@ -27,8 +28,12 @@ def _handle_name_expr(expr: ast.Name, local_sym_tab: Dict, builder: ir.IRBuilder
         val = builder.load(var)
         return val, local_sym_tab[expr.id].ir_type
     else:
-        logger.info(f"Undefined variable {expr.id}")
-        return None
+        # Check if it's a vmlinux enum/constant
+        vmlinux_result = VmlinuxHandlerRegistry.handle_name(expr.id)
+        if vmlinux_result is not None:
+            return vmlinux_result
+
+        raise SyntaxError(f"Undefined variable {expr.id}")
 
 
 def _handle_constant_expr(module, builder, expr: ast.Constant):
@@ -74,6 +79,13 @@ def _handle_attribute_expr(
                 val = builder.load(gep)
                 field_type = metadata.field_type(attr_name)
                 return val, field_type
+
+        # Try vmlinux handler as fallback
+        vmlinux_result = VmlinuxHandlerRegistry.handle_attribute(
+            expr, local_sym_tab, None, builder
+        )
+        if vmlinux_result is not None:
+            return vmlinux_result
     return None
 
 

pythonbpf/expr/vmlinux_registry.py

@@ -0,0 +1,45 @@
+import ast
+
+
+class VmlinuxHandlerRegistry:
+    """Registry for vmlinux handler operations"""
+
+    _handler = None
+
+    @classmethod
+    def set_handler(cls, handler):
+        """Set the vmlinux handler"""
+        cls._handler = handler
+
+    @classmethod
+    def get_handler(cls):
+        """Get the vmlinux handler"""
+        return cls._handler
+
+    @classmethod
+    def handle_name(cls, name):
+        """Try to handle a name as vmlinux enum/constant"""
+        if cls._handler is None:
+            return None
+        return cls._handler.handle_vmlinux_enum(name)
+
+    @classmethod
+    def handle_attribute(cls, expr, local_sym_tab, module, builder):
+        """Try to handle an attribute access as vmlinux struct field"""
+        if cls._handler is None:
+            return None
+
+        if isinstance(expr.value, ast.Name):
+            var_name = expr.value.id
+            field_name = expr.attr
+            return cls._handler.handle_vmlinux_struct_field(
+                var_name, field_name, module, builder, local_sym_tab
+            )
+        return None
+
+    @classmethod
+    def is_vmlinux_struct(cls, name):
+        """Check if a name refers to a vmlinux struct"""
+        if cls._handler is None:
+            return False
+        return cls._handler.is_vmlinux_struct(name)