Remove deadcode and seperate modules for pythonbpf.functions

Use dependency inversion to remove handler delayed import in eval_expr

README.md

@@ -83,14 +83,14 @@ def hist() -> HashMap:
 def hello(ctx: c_void_p) -> c_int64:
     process_id = pid()
     one = 1
-    prev = hist().lookup(process_id)
+    prev = hist.lookup(process_id)
     if prev:
         previous_value = prev + 1
         print(f"count: {previous_value} with {process_id}")
-        hist().update(process_id, previous_value)
+        hist.update(process_id, previous_value)
         return c_int64(0)
     else:
-        hist().update(process_id, one)
+        hist.update(process_id, one)
     return c_int64(0)
 
 

TODO.md

@@ -1,13 +0,0 @@
-## Short term
-
-- Implement enough functionality to port the BCC tutorial examples in PythonBPF
-- Add all maps
-- XDP support in pylibbpf
-- ringbuf support
-- Add oneline IfExpr conditionals (wishlist)
-
-## Long term
-
-- Refactor the codebase to be better than a hackathon project
-- Port to C++ and use actual LLVM?
-- Fix struct_kioctx issue in the vmlinux transpiler

pythonbpf/binary_ops.py

@@ -1,110 +0,0 @@
-import ast
-from llvmlite import ir
-from logging import Logger
-import logging
-
-from pythonbpf.expr import get_base_type_and_depth, deref_to_depth, eval_expr
-
-logger: Logger = logging.getLogger(__name__)
-
-
-def get_operand_value(
-    func, module, operand, builder, local_sym_tab, map_sym_tab, structs_sym_tab=None
-):
-    """Extract the value from an operand, handling variables and constants."""
-    logger.info(f"Getting operand value for: {ast.dump(operand)}")
-    if isinstance(operand, ast.Name):
-        if operand.id in local_sym_tab:
-            var = local_sym_tab[operand.id].var
-            var_type = var.type
-            base_type, depth = get_base_type_and_depth(var_type)
-            logger.info(f"var is {var}, base_type is {base_type}, depth is {depth}")
-            val = deref_to_depth(func, builder, var, depth)
-            return val
-        raise ValueError(f"Undefined variable: {operand.id}")
-    elif isinstance(operand, ast.Constant):
-        if isinstance(operand.value, int):
-            cst = ir.Constant(ir.IntType(64), int(operand.value))
-            return cst
-        raise TypeError(f"Unsupported constant type: {type(operand.value)}")
-    elif isinstance(operand, ast.BinOp):
-        res = handle_binary_op_impl(
-            func, module, operand, builder, local_sym_tab, map_sym_tab, structs_sym_tab
-        )
-        return res
-    else:
-        res = eval_expr(
-            func, module, builder, operand, local_sym_tab, map_sym_tab, structs_sym_tab
-        )
-        if res is None:
-            raise ValueError(f"Failed to evaluate call expression: {operand}")
-        val, _ = res
-        logger.info(f"Evaluated expr to {val} of type {val.type}")
-        base_type, depth = get_base_type_and_depth(val.type)
-        if depth > 0:
-            val = deref_to_depth(func, builder, val, depth)
-        return val
-    raise TypeError(f"Unsupported operand type: {type(operand)}")
-
-
-def handle_binary_op_impl(
-    func, module, rval, builder, local_sym_tab, map_sym_tab, structs_sym_tab=None
-):
-    op = rval.op
-    left = get_operand_value(
-        func, module, rval.left, builder, local_sym_tab, map_sym_tab, structs_sym_tab
-    )
-    right = get_operand_value(
-        func, module, rval.right, builder, local_sym_tab, map_sym_tab, structs_sym_tab
-    )
-    logger.info(f"left is {left}, right is {right}, op is {op}")
-
-    # NOTE: Before doing the operation, if the operands are integers
-    # we always extend them to i64. The assignment to LHS will take
-    # care of truncation if needed.
-    if isinstance(left.type, ir.IntType) and left.type.width < 64:
-        left = builder.sext(left, ir.IntType(64))
-    if isinstance(right.type, ir.IntType) and right.type.width < 64:
-        right = builder.sext(right, ir.IntType(64))
-
-    # Map AST operation nodes to LLVM IR builder methods
-    op_map = {
-        ast.Add: builder.add,
-        ast.Sub: builder.sub,
-        ast.Mult: builder.mul,
-        ast.Div: builder.sdiv,
-        ast.Mod: builder.srem,
-        ast.LShift: builder.shl,
-        ast.RShift: builder.lshr,
-        ast.BitOr: builder.or_,
-        ast.BitXor: builder.xor,
-        ast.BitAnd: builder.and_,
-        ast.FloorDiv: builder.udiv,
-    }
-
-    if type(op) in op_map:
-        result = op_map[type(op)](left, right)
-        return result
-    else:
-        raise SyntaxError("Unsupported binary operation")
-
-
-def handle_binary_op(
-    func,
-    module,
-    rval,
-    builder,
-    var_name,
-    local_sym_tab,
-    map_sym_tab,
-    structs_sym_tab=None,
-):
-    result = handle_binary_op_impl(
-        func, module, rval, builder, local_sym_tab, map_sym_tab, structs_sym_tab
-    )
-    if var_name and var_name in local_sym_tab:
-        logger.info(
-            f"Storing result {result} into variable {local_sym_tab[var_name].var}"
-        )
-        builder.store(result, local_sym_tab[var_name].var)
-    return result, result.type

pythonbpf/expr/__init__.py

@@ -1,5 +1,7 @@
-from .expr_pass import eval_expr, handle_expr
+from .expr_pass import eval_expr, handle_expr, get_operand_value
-from .type_normalization import convert_to_bool, get_base_type_and_depth, deref_to_depth
+from .type_normalization import convert_to_bool, get_base_type_and_depth
+from .ir_ops import deref_to_depth
+from .call_registry import CallHandlerRegistry
 
 __all__ = [
     "eval_expr",
@@ -7,4 +9,6 @@ __all__ = [
     "convert_to_bool",
     "get_base_type_and_depth",
     "deref_to_depth",
+    "get_operand_value",
+    "CallHandlerRegistry",
 ]

pythonbpf/expr/call_registry.py

@@ -0,0 +1,20 @@
+class CallHandlerRegistry:
+    """Registry for handling different types of calls (helpers, etc.)"""
+
+    _handler = None
+
+    @classmethod
+    def set_handler(cls, handler):
+        """Set the handler for unknown calls"""
+        cls._handler = handler
+
+    @classmethod
+    def handle_call(
+        cls, call, module, builder, func, local_sym_tab, map_sym_tab, structs_sym_tab
+    ):
+        """Handle a call using the registered handler"""
+        if cls._handler is None:
+            return None
+        return cls._handler(
+            call, module, builder, func, local_sym_tab, map_sym_tab, structs_sym_tab
+        )

pythonbpf/expr/expr_pass.py

@@ -5,10 +5,20 @@ import logging
 from typing import Dict
 
 from pythonbpf.type_deducer import ctypes_to_ir, is_ctypes
-from .type_normalization import convert_to_bool, handle_comparator
+from .call_registry import CallHandlerRegistry
+from .type_normalization import (
+    convert_to_bool,
+    handle_comparator,
+    get_base_type_and_depth,
+    deref_to_depth,
+)
 
 logger: Logger = logging.getLogger(__name__)
 
+# ============================================================================
+# Leaf Handlers (No Recursive eval_expr calls)
+# ============================================================================
+
 
 def _handle_name_expr(expr: ast.Name, local_sym_tab: Dict, builder: ir.IRBuilder):
     """Handle ast.Name expressions."""
@@ -21,10 +31,24 @@ def _handle_name_expr(expr: ast.Name, local_sym_tab: Dict, builder: ir.IRBuilder
         return None
 
 
-def _handle_constant_expr(expr: ast.Constant):
+def _handle_constant_expr(module, builder, expr: ast.Constant):
     """Handle ast.Constant expressions."""
     if isinstance(expr.value, int) or isinstance(expr.value, bool):
         return ir.Constant(ir.IntType(64), int(expr.value)), ir.IntType(64)
+    elif isinstance(expr.value, str):
+        str_name = f".str.{id(expr)}"
+        str_bytes = expr.value.encode("utf-8") + b"\x00"
+        str_type = ir.ArrayType(ir.IntType(8), len(str_bytes))
+        str_constant = ir.Constant(str_type, bytearray(str_bytes))
+
+        # Create global variable
+        global_str = ir.GlobalVariable(module, str_type, name=str_name)
+        global_str.linkage = "internal"
+        global_str.global_constant = True
+        global_str.initializer = str_constant
+
+        str_ptr = builder.bitcast(global_str, ir.PointerType(ir.IntType(8)))
+        return str_ptr, ir.PointerType(ir.IntType(8))
     else:
         logger.error(f"Unsupported constant type {ast.dump(expr)}")
         return None
@@ -88,6 +112,118 @@ def _handle_deref_call(expr: ast.Call, local_sym_tab: Dict, builder: ir.IRBuilde
     return val, local_sym_tab[arg.id].ir_type
 
 
+# ============================================================================
+# Binary Operations
+# ============================================================================
+
+
+def get_operand_value(
+    func, module, operand, builder, local_sym_tab, map_sym_tab, structs_sym_tab=None
+):
+    """Extract the value from an operand, handling variables and constants."""
+    logger.info(f"Getting operand value for: {ast.dump(operand)}")
+    if isinstance(operand, ast.Name):
+        if operand.id in local_sym_tab:
+            var = local_sym_tab[operand.id].var
+            var_type = var.type
+            base_type, depth = get_base_type_and_depth(var_type)
+            logger.info(f"var is {var}, base_type is {base_type}, depth is {depth}")
+            val = deref_to_depth(func, builder, var, depth)
+            return val
+        raise ValueError(f"Undefined variable: {operand.id}")
+    elif isinstance(operand, ast.Constant):
+        if isinstance(operand.value, int):
+            cst = ir.Constant(ir.IntType(64), int(operand.value))
+            return cst
+        raise TypeError(f"Unsupported constant type: {type(operand.value)}")
+    elif isinstance(operand, ast.BinOp):
+        res = _handle_binary_op_impl(
+            func, module, operand, builder, local_sym_tab, map_sym_tab, structs_sym_tab
+        )
+        return res
+    else:
+        res = eval_expr(
+            func, module, builder, operand, local_sym_tab, map_sym_tab, structs_sym_tab
+        )
+        if res is None:
+            raise ValueError(f"Failed to evaluate call expression: {operand}")
+        val, _ = res
+        logger.info(f"Evaluated expr to {val} of type {val.type}")
+        base_type, depth = get_base_type_and_depth(val.type)
+        if depth > 0:
+            val = deref_to_depth(func, builder, val, depth)
+        return val
+    raise TypeError(f"Unsupported operand type: {type(operand)}")
+
+
+def _handle_binary_op_impl(
+    func, module, rval, builder, local_sym_tab, map_sym_tab, structs_sym_tab=None
+):
+    op = rval.op
+    left = get_operand_value(
+        func, module, rval.left, builder, local_sym_tab, map_sym_tab, structs_sym_tab
+    )
+    right = get_operand_value(
+        func, module, rval.right, builder, local_sym_tab, map_sym_tab, structs_sym_tab
+    )
+    logger.info(f"left is {left}, right is {right}, op is {op}")
+
+    # NOTE: Before doing the operation, if the operands are integers
+    # we always extend them to i64. The assignment to LHS will take
+    # care of truncation if needed.
+    if isinstance(left.type, ir.IntType) and left.type.width < 64:
+        left = builder.sext(left, ir.IntType(64))
+    if isinstance(right.type, ir.IntType) and right.type.width < 64:
+        right = builder.sext(right, ir.IntType(64))
+
+    # Map AST operation nodes to LLVM IR builder methods
+    op_map = {
+        ast.Add: builder.add,
+        ast.Sub: builder.sub,
+        ast.Mult: builder.mul,
+        ast.Div: builder.sdiv,
+        ast.Mod: builder.srem,
+        ast.LShift: builder.shl,
+        ast.RShift: builder.lshr,
+        ast.BitOr: builder.or_,
+        ast.BitXor: builder.xor,
+        ast.BitAnd: builder.and_,
+        ast.FloorDiv: builder.udiv,
+    }
+
+    if type(op) in op_map:
+        result = op_map[type(op)](left, right)
+        return result
+    else:
+        raise SyntaxError("Unsupported binary operation")
+
+
+def _handle_binary_op(
+    func,
+    module,
+    rval,
+    builder,
+    var_name,
+    local_sym_tab,
+    map_sym_tab,
+    structs_sym_tab=None,
+):
+    result = _handle_binary_op_impl(
+        func, module, rval, builder, local_sym_tab, map_sym_tab, structs_sym_tab
+    )
+    if var_name and var_name in local_sym_tab:
+        logger.info(
+            f"Storing result {result} into variable {local_sym_tab[var_name].var}"
+        )
+        builder.store(result, local_sym_tab[var_name].var)
+    return result, result.type
+
+
+# ============================================================================
+# Comparison and Unary Operations
+# ============================================================================
+
+
 def _handle_ctypes_call(
     func,
     module,
@@ -180,8 +316,6 @@ def _handle_unary_op(
         logger.error("Only 'not' and '-' unary operators are supported")
         return None
 
-    from pythonbpf.binary_ops import get_operand_value
-
     operand = get_operand_value(
         func, module, expr.operand, builder, local_sym_tab, map_sym_tab, structs_sym_tab
     )
@@ -200,6 +334,11 @@ def _handle_unary_op(
         return result, ir.IntType(64)
 
 
+# ============================================================================
+# Boolean Operations
+# ============================================================================
+
+
 def _handle_and_op(func, builder, expr, local_sym_tab, map_sym_tab, structs_sym_tab):
     """Handle `and` boolean operations."""
 
@@ -330,6 +469,11 @@ def _handle_boolean_op(
         return None
 
 
+# ============================================================================
+# Expression Dispatcher
+# ============================================================================
+
+
 def eval_expr(
     func,
     module,
@@ -343,7 +487,7 @@ def eval_expr(
     if isinstance(expr, ast.Name):
         return _handle_name_expr(expr, local_sym_tab, builder)
     elif isinstance(expr, ast.Constant):
-        return _handle_constant_expr(expr)
+        return _handle_constant_expr(module, builder, expr)
     elif isinstance(expr, ast.Call):
         if isinstance(expr.func, ast.Name) and expr.func.id == "deref":
             return _handle_deref_call(expr, local_sym_tab, builder)
@@ -359,57 +503,18 @@ def eval_expr(
                 structs_sym_tab,
             )
 
-        # delayed import to avoid circular dependency
+        result = CallHandlerRegistry.handle_call(
-        from pythonbpf.helper import HelperHandlerRegistry, handle_helper_call
+            expr, module, builder, func, local_sym_tab, map_sym_tab, structs_sym_tab
+        )
+        if result is not None:
+            return result
 
-        if isinstance(expr.func, ast.Name) and HelperHandlerRegistry.has_handler(
+        logger.warning(f"Unknown call: {ast.dump(expr)}")
-            expr.func.id
+        return None
-        ):
-            return handle_helper_call(
-                expr,
-                module,
-                builder,
-                func,
-                local_sym_tab,
-                map_sym_tab,
-                structs_sym_tab,
-            )
-        elif isinstance(expr.func, ast.Attribute):
-            logger.info(f"Handling method call: {ast.dump(expr.func)}")
-            if isinstance(expr.func.value, ast.Call) and isinstance(
-                expr.func.value.func, ast.Name
-            ):
-                method_name = expr.func.attr
-                if HelperHandlerRegistry.has_handler(method_name):
-                    return handle_helper_call(
-                        expr,
-                        module,
-                        builder,
-                        func,
-                        local_sym_tab,
-                        map_sym_tab,
-                        structs_sym_tab,
-                    )
-            elif isinstance(expr.func.value, ast.Name):
-                obj_name = expr.func.value.id
-                method_name = expr.func.attr
-                if obj_name in map_sym_tab:
-                    if HelperHandlerRegistry.has_handler(method_name):
-                        return handle_helper_call(
-                            expr,
-                            module,
-                            builder,
-                            func,
-                            local_sym_tab,
-                            map_sym_tab,
-                            structs_sym_tab,
-                        )
     elif isinstance(expr, ast.Attribute):
         return _handle_attribute_expr(expr, local_sym_tab, structs_sym_tab, builder)
     elif isinstance(expr, ast.BinOp):
-        from pythonbpf.binary_ops import handle_binary_op
+        return _handle_binary_op(
-
-        return handle_binary_op(
             func,
             module,
             expr,

pythonbpf/expr/ir_ops.py

@@ -0,0 +1,50 @@
+import logging
+from llvmlite import ir
+
+logger = logging.getLogger(__name__)
+
+
+def deref_to_depth(func, builder, val, target_depth):
+    """Dereference a pointer to a certain depth."""
+
+    cur_val = val
+    cur_type = val.type
+
+    for depth in range(target_depth):
+        if not isinstance(val.type, ir.PointerType):
+            logger.error("Cannot dereference further, non-pointer type")
+            return None
+
+        # dereference with null check
+        pointee_type = cur_type.pointee
+        null_check_block = builder.block
+        not_null_block = func.append_basic_block(name=f"deref_not_null_{depth}")
+        merge_block = func.append_basic_block(name=f"deref_merge_{depth}")
+
+        null_ptr = ir.Constant(cur_type, None)
+        is_not_null = builder.icmp_signed("!=", cur_val, null_ptr)
+        logger.debug(f"Inserted null check for pointer at depth {depth}")
+
+        builder.cbranch(is_not_null, not_null_block, merge_block)
+
+        builder.position_at_end(not_null_block)
+        dereferenced_val = builder.load(cur_val)
+        logger.debug(f"Dereferenced to depth {depth - 1}, type: {pointee_type}")
+        builder.branch(merge_block)
+
+        builder.position_at_end(merge_block)
+        phi = builder.phi(pointee_type, name=f"deref_result_{depth}")
+
+        zero_value = (
+            ir.Constant(pointee_type, 0)
+            if isinstance(pointee_type, ir.IntType)
+            else ir.Constant(pointee_type, None)
+        )
+        phi.add_incoming(zero_value, null_check_block)
+
+        phi.add_incoming(dereferenced_val, not_null_block)
+
+        # Continue with phi result
+        cur_val = phi
+        cur_type = pointee_type
+    return cur_val

pythonbpf/expr/type_normalization.py

@@ -1,6 +1,7 @@
-from llvmlite import ir
 import logging
 import ast
+from llvmlite import ir
+from .ir_ops import deref_to_depth
 
 logger = logging.getLogger(__name__)
 
@@ -26,52 +27,6 @@ def get_base_type_and_depth(ir_type):
     return cur_type, depth
 
 
-def deref_to_depth(func, builder, val, target_depth):
-    """Dereference a pointer to a certain depth."""
-
-    cur_val = val
-    cur_type = val.type
-
-    for depth in range(target_depth):
-        if not isinstance(val.type, ir.PointerType):
-            logger.error("Cannot dereference further, non-pointer type")
-            return None
-
-        # dereference with null check
-        pointee_type = cur_type.pointee
-        null_check_block = builder.block
-        not_null_block = func.append_basic_block(name=f"deref_not_null_{depth}")
-        merge_block = func.append_basic_block(name=f"deref_merge_{depth}")
-
-        null_ptr = ir.Constant(cur_type, None)
-        is_not_null = builder.icmp_signed("!=", cur_val, null_ptr)
-        logger.debug(f"Inserted null check for pointer at depth {depth}")
-
-        builder.cbranch(is_not_null, not_null_block, merge_block)
-
-        builder.position_at_end(not_null_block)
-        dereferenced_val = builder.load(cur_val)
-        logger.debug(f"Dereferenced to depth {depth - 1}, type: {pointee_type}")
-        builder.branch(merge_block)
-
-        builder.position_at_end(merge_block)
-        phi = builder.phi(pointee_type, name=f"deref_result_{depth}")
-
-        zero_value = (
-            ir.Constant(pointee_type, 0)
-            if isinstance(pointee_type, ir.IntType)
-            else ir.Constant(pointee_type, None)
-        )
-        phi.add_incoming(zero_value, null_check_block)
-
-        phi.add_incoming(dereferenced_val, not_null_block)
-
-        # Continue with phi result
-        cur_val = phi
-        cur_type = pointee_type
-    return cur_val
-
-
 def _normalize_types(func, builder, lhs, rhs):
     """Normalize types for comparison."""
 

pythonbpf/functions/func_registry_handlers.py

@@ -1,22 +0,0 @@
-from typing import Dict
-
-
-class StatementHandlerRegistry:
-    """Registry for statement handlers."""
-
-    _handlers: Dict = {}
-
-    @classmethod
-    def register(cls, stmt_type):
-        """Register a handler for a specific statement type."""
-
-        def decorator(handler):
-            cls._handlers[stmt_type] = handler
-            return handler
-
-        return decorator
-
-    @classmethod
-    def __getitem__(cls, stmt_type):
-        """Get the handler for a specific statement type."""
-        return cls._handlers.get(stmt_type, None)

pythonbpf/functions/function_metadata.py

@@ -0,0 +1,88 @@
+import ast
+
+
+def get_probe_string(func_node):
+    """Extract the probe string from the decorator of the function node"""
+    # TODO: right now we have the whole string in the section decorator
+    # But later we can implement typed tuples for tracepoints and kprobes
+    # For helper functions, we return "helper"
+
+    for decorator in func_node.decorator_list:
+        if isinstance(decorator, ast.Name) and decorator.id == "bpfglobal":
+            return None
+        if isinstance(decorator, ast.Call) and isinstance(decorator.func, ast.Name):
+            if decorator.func.id == "section" and len(decorator.args) == 1:
+                arg = decorator.args[0]
+                if isinstance(arg, ast.Constant) and isinstance(arg.value, str):
+                    return arg.value
+    return "helper"
+
+
+def is_global_function(func_node):
+    """Check if the function is a global"""
+    for decorator in func_node.decorator_list:
+        if isinstance(decorator, ast.Name) and decorator.id in (
+            "map",
+            "bpfglobal",
+            "struct",
+        ):
+            return True
+    return False
+
+
+def infer_return_type(func_node: ast.FunctionDef):
+    if not isinstance(func_node, (ast.FunctionDef, ast.AsyncFunctionDef)):
+        raise TypeError("Expected ast.FunctionDef")
+    if func_node.returns is not None:
+        try:
+            return ast.unparse(func_node.returns)
+        except Exception:
+            node = func_node.returns
+            if isinstance(node, ast.Name):
+                return node.id
+            if isinstance(node, ast.Attribute):
+                return getattr(node, "attr", type(node).__name__)
+            try:
+                return str(node)
+            except Exception:
+                return type(node).__name__
+    found_type = None
+
+    def _expr_type(e):
+        if e is None:
+            return "None"
+        if isinstance(e, ast.Constant):
+            return type(e.value).__name__
+        if isinstance(e, ast.Name):
+            return e.id
+        if isinstance(e, ast.Call):
+            f = e.func
+            if isinstance(f, ast.Name):
+                return f.id
+            if isinstance(f, ast.Attribute):
+                try:
+                    return ast.unparse(f)
+                except Exception:
+                    return getattr(f, "attr", type(f).__name__)
+            try:
+                return ast.unparse(f)
+            except Exception:
+                return type(f).__name__
+        if isinstance(e, ast.Attribute):
+            try:
+                return ast.unparse(e)
+            except Exception:
+                return getattr(e, "attr", type(e).__name__)
+        try:
+            return ast.unparse(e)
+        except Exception:
+            return type(e).__name__
+
+    for walked_node in ast.walk(func_node):
+        if isinstance(walked_node, ast.Return):
+            t = _expr_type(walked_node.value)
+            if found_type is None:
+                found_type = t
+            elif found_type != t:
+                raise ValueError(f"Conflicting return types: {found_type} vs {t}")
+    return found_type or "None"

pythonbpf/functions/functions_pass.py

@@ -14,27 +14,125 @@ from pythonbpf.assign_pass import (
 )
 from pythonbpf.allocation_pass import handle_assign_allocation, allocate_temp_pool
 
-from .return_utils import _handle_none_return, _handle_xdp_return, _is_xdp_name
+from .return_utils import handle_none_return, handle_xdp_return, is_xdp_name
+from .function_metadata import get_probe_string, is_global_function, infer_return_type
 
 
 logger = logging.getLogger(__name__)
 
 
-def get_probe_string(func_node):
+# ============================================================================
-    """Extract the probe string from the decorator of the function node."""
+# SECTION 1: Memory Allocation
-    # TODO: right now we have the whole string in the section decorator
+# ============================================================================
-    # But later we can implement typed tuples for tracepoints and kprobes
-    # For helper functions, we return "helper"
 
-    for decorator in func_node.decorator_list:
+
-        if isinstance(decorator, ast.Name) and decorator.id == "bpfglobal":
+def count_temps_in_call(call_node, local_sym_tab):
-            return None
+    """Count the number of temporary variables needed for a function call."""
-        if isinstance(decorator, ast.Call) and isinstance(decorator.func, ast.Name):
+
-            if decorator.func.id == "section" and len(decorator.args) == 1:
+    count = 0
-                arg = decorator.args[0]
+    is_helper = False
-                if isinstance(arg, ast.Constant) and isinstance(arg.value, str):
+
-                    return arg.value
+    # NOTE: We exclude print calls for now
-    return "helper"
+    if isinstance(call_node.func, ast.Name):
+        if (
+            HelperHandlerRegistry.has_handler(call_node.func.id)
+            and call_node.func.id != "print"
+        ):
+            is_helper = True
+    elif isinstance(call_node.func, ast.Attribute):
+        if HelperHandlerRegistry.has_handler(call_node.func.attr):
+            is_helper = True
+
+    if not is_helper:
+        return 0
+
+    for arg in call_node.args:
+        # NOTE: Count all non-name arguments
+        # For struct fields, if it is being passed as an argument,
+        # The struct object should already exist in the local_sym_tab
+        if not isinstance(arg, ast.Name) and not (
+            isinstance(arg, ast.Attribute) and arg.value.id in local_sym_tab
+        ):
+            count += 1
+
+    return count
+
+
+def handle_if_allocation(
+    module, builder, stmt, func, ret_type, map_sym_tab, local_sym_tab, structs_sym_tab
+):
+    """Recursively handle allocations in if/else branches."""
+    if stmt.body:
+        allocate_mem(
+            module,
+            builder,
+            stmt.body,
+            func,
+            ret_type,
+            map_sym_tab,
+            local_sym_tab,
+            structs_sym_tab,
+        )
+    if stmt.orelse:
+        allocate_mem(
+            module,
+            builder,
+            stmt.orelse,
+            func,
+            ret_type,
+            map_sym_tab,
+            local_sym_tab,
+            structs_sym_tab,
+        )
+
+
+def allocate_mem(
+    module, builder, body, func, ret_type, map_sym_tab, local_sym_tab, structs_sym_tab
+):
+    max_temps_needed = 0
+
+    def update_max_temps_for_stmt(stmt):
+        nonlocal max_temps_needed
+        temps_needed = 0
+
+        if isinstance(stmt, ast.If):
+            for s in stmt.body:
+                update_max_temps_for_stmt(s)
+            for s in stmt.orelse:
+                update_max_temps_for_stmt(s)
+            return
+
+        for node in ast.walk(stmt):
+            if isinstance(node, ast.Call):
+                temps_needed += count_temps_in_call(node, local_sym_tab)
+        max_temps_needed = max(max_temps_needed, temps_needed)
+
+    for stmt in body:
+        update_max_temps_for_stmt(stmt)
+
+        # Handle allocations
+        if isinstance(stmt, ast.If):
+            handle_if_allocation(
+                module,
+                builder,
+                stmt,
+                func,
+                ret_type,
+                map_sym_tab,
+                local_sym_tab,
+                structs_sym_tab,
+            )
+        elif isinstance(stmt, ast.Assign):
+            handle_assign_allocation(builder, stmt, local_sym_tab, structs_sym_tab)
+
+    allocate_temp_pool(builder, max_temps_needed, local_sym_tab)
+
+    return local_sym_tab
+
+
+# ============================================================================
+# SECTION 2: Statement Handlers
+# ============================================================================
 
 
 def handle_assign(
@@ -146,9 +244,9 @@ def handle_if(
 def handle_return(builder, stmt, local_sym_tab, ret_type):
     logger.info(f"Handling return statement: {ast.dump(stmt)}")
     if stmt.value is None:
-        return _handle_none_return(builder)
+        return handle_none_return(builder)
-    elif isinstance(stmt.value, ast.Name) and _is_xdp_name(stmt.value.id):
+    elif isinstance(stmt.value, ast.Name) and is_xdp_name(stmt.value.id):
-        return _handle_xdp_return(stmt, builder, ret_type)
+        return handle_xdp_return(stmt, builder, ret_type)
     else:
         val = eval_expr(
             func=None,
@@ -207,108 +305,9 @@ def process_stmt(
     return did_return
 
 
-def handle_if_allocation(
+# ============================================================================
-    module, builder, stmt, func, ret_type, map_sym_tab, local_sym_tab, structs_sym_tab
+# SECTION 3: Function Body Processing
-):
+# ============================================================================
-    """Recursively handle allocations in if/else branches."""
-    if stmt.body:
-        allocate_mem(
-            module,
-            builder,
-            stmt.body,
-            func,
-            ret_type,
-            map_sym_tab,
-            local_sym_tab,
-            structs_sym_tab,
-        )
-    if stmt.orelse:
-        allocate_mem(
-            module,
-            builder,
-            stmt.orelse,
-            func,
-            ret_type,
-            map_sym_tab,
-            local_sym_tab,
-            structs_sym_tab,
-        )
-
-
-def count_temps_in_call(call_node, local_sym_tab):
-    """Count the number of temporary variables needed for a function call."""
-
-    count = 0
-    is_helper = False
-
-    # NOTE: We exclude print calls for now
-    if isinstance(call_node.func, ast.Name):
-        if (
-            HelperHandlerRegistry.has_handler(call_node.func.id)
-            and call_node.func.id != "print"
-        ):
-            is_helper = True
-    elif isinstance(call_node.func, ast.Attribute):
-        if HelperHandlerRegistry.has_handler(call_node.func.attr):
-            is_helper = True
-
-    if not is_helper:
-        return 0
-
-    for arg in call_node.args:
-        # NOTE: Count all non-name arguments
-        # For struct fields, if it is being passed as an argument,
-        # The struct object should already exist in the local_sym_tab
-        if not isinstance(arg, ast.Name) and not (
-            isinstance(arg, ast.Attribute) and arg.value.id in local_sym_tab
-        ):
-            count += 1
-
-    return count
-
-
-def allocate_mem(
-    module, builder, body, func, ret_type, map_sym_tab, local_sym_tab, structs_sym_tab
-):
-    max_temps_needed = 0
-
-    def update_max_temps_for_stmt(stmt):
-        nonlocal max_temps_needed
-        temps_needed = 0
-
-        if isinstance(stmt, ast.If):
-            for s in stmt.body:
-                update_max_temps_for_stmt(s)
-            for s in stmt.orelse:
-                update_max_temps_for_stmt(s)
-            return
-
-        for node in ast.walk(stmt):
-            if isinstance(node, ast.Call):
-                temps_needed += count_temps_in_call(node, local_sym_tab)
-        max_temps_needed = max(max_temps_needed, temps_needed)
-
-    for stmt in body:
-        update_max_temps_for_stmt(stmt)
-
-        # Handle allocations
-        if isinstance(stmt, ast.If):
-            handle_if_allocation(
-                module,
-                builder,
-                stmt,
-                func,
-                ret_type,
-                map_sym_tab,
-                local_sym_tab,
-                structs_sym_tab,
-            )
-        elif isinstance(stmt, ast.Assign):
-            handle_assign_allocation(builder, stmt, local_sym_tab, structs_sym_tab)
-
-    allocate_temp_pool(builder, max_temps_needed, local_sym_tab)
-
-    return local_sym_tab
 
 
 def process_func_body(
@@ -390,18 +389,14 @@ def process_bpf_chunk(func_node, module, return_type, map_sym_tab, structs_sym_t
     return func
 
 
+# ============================================================================
+# SECTION 4: Top-Level Function Processor
+# ============================================================================
+
+
 def func_proc(tree, module, chunks, map_sym_tab, structs_sym_tab):
     for func_node in chunks:
-        is_global = False
+        if is_global_function(func_node):
-        for decorator in func_node.decorator_list:
-            if isinstance(decorator, ast.Name) and decorator.id in (
-                "map",
-                "bpfglobal",
-                "struct",
-            ):
-                is_global = True
-                break
-        if is_global:
             continue
         func_type = get_probe_string(func_node)
         logger.info(f"Found probe_string of {func_node.name}: {func_type}")
@@ -415,67 +410,7 @@ def func_proc(tree, module, chunks, map_sym_tab, structs_sym_tab):
         )
 
 
-def infer_return_type(func_node: ast.FunctionDef):
+# TODO: WIP, for string assignment to fixed-size arrays
-    if not isinstance(func_node, (ast.FunctionDef, ast.AsyncFunctionDef)):
-        raise TypeError("Expected ast.FunctionDef")
-    if func_node.returns is not None:
-        try:
-            return ast.unparse(func_node.returns)
-        except Exception:
-            node = func_node.returns
-            if isinstance(node, ast.Name):
-                return node.id
-            if isinstance(node, ast.Attribute):
-                return getattr(node, "attr", type(node).__name__)
-            try:
-                return str(node)
-            except Exception:
-                return type(node).__name__
-    found_type = None
-
-    def _expr_type(e):
-        if e is None:
-            return "None"
-        if isinstance(e, ast.Constant):
-            return type(e.value).__name__
-        if isinstance(e, ast.Name):
-            return e.id
-        if isinstance(e, ast.Call):
-            f = e.func
-            if isinstance(f, ast.Name):
-                return f.id
-            if isinstance(f, ast.Attribute):
-                try:
-                    return ast.unparse(f)
-                except Exception:
-                    return getattr(f, "attr", type(f).__name__)
-            try:
-                return ast.unparse(f)
-            except Exception:
-                return type(f).__name__
-        if isinstance(e, ast.Attribute):
-            try:
-                return ast.unparse(e)
-            except Exception:
-                return getattr(e, "attr", type(e).__name__)
-        try:
-            return ast.unparse(e)
-        except Exception:
-            return type(e).__name__
-
-    for walked_node in ast.walk(func_node):
-        if isinstance(walked_node, ast.Return):
-            t = _expr_type(walked_node.value)
-            if found_type is None:
-                found_type = t
-            elif found_type != t:
-                raise ValueError(f"Conflicting return types: {found_type} vs {t}")
-    return found_type or "None"
-
-
-# For string assignment to fixed-size arrays
-
-
 def assign_string_to_array(builder, target_array_ptr, source_string_ptr, array_length):
     """
     Copy a string (i8*) to a fixed-size array ([N x i8]*)

pythonbpf/functions/return_utils.py

@@ -14,19 +14,19 @@ XDP_ACTIONS = {
 }
 
 
-def _handle_none_return(builder) -> bool:
+def handle_none_return(builder) -> bool:
     """Handle return or return None -> returns 0."""
     builder.ret(ir.Constant(ir.IntType(64), 0))
     logger.debug("Generated default return: 0")
     return True
 
 
-def _is_xdp_name(name: str) -> bool:
+def is_xdp_name(name: str) -> bool:
     """Check if a name is an XDP action"""
     return name in XDP_ACTIONS
 
 
-def _handle_xdp_return(stmt: ast.Return, builder, ret_type) -> bool:
+def handle_xdp_return(stmt: ast.Return, builder, ret_type) -> bool:
     """Handle XDP returns"""
     if not isinstance(stmt.value, ast.Name):
         return False
@@ -37,7 +37,6 @@ def _handle_xdp_return(stmt: ast.Return, builder, ret_type) -> bool:
         raise ValueError(
             f"Unknown XDP action: {action_name}. Available: {XDP_ACTIONS.keys()}"
         )
-        return False
 
     value = XDP_ACTIONS[action_name]
     builder.ret(ir.Constant(ret_type, value))

pythonbpf/helper/__init__.py

@@ -2,6 +2,58 @@ from .helper_utils import HelperHandlerRegistry, reset_scratch_pool
 from .bpf_helper_handler import handle_helper_call
 from .helpers import ktime, pid, deref, XDP_DROP, XDP_PASS
 
+
+# Register the helper handler with expr module
+def _register_helper_handler():
+    """Register helper call handler with the expression evaluator"""
+    from pythonbpf.expr.expr_pass import CallHandlerRegistry
+
+    def helper_call_handler(
+        call, module, builder, func, local_sym_tab, map_sym_tab, structs_sym_tab
+    ):
+        """Check if call is a helper and handle it"""
+        import ast
+
+        # Check for direct helper calls (e.g., ktime(), print())
+        if isinstance(call.func, ast.Name):
+            if HelperHandlerRegistry.has_handler(call.func.id):
+                return handle_helper_call(
+                    call,
+                    module,
+                    builder,
+                    func,
+                    local_sym_tab,
+                    map_sym_tab,
+                    structs_sym_tab,
+                )
+
+        # Check for method calls (e.g., map.lookup())
+        elif isinstance(call.func, ast.Attribute):
+            method_name = call.func.attr
+
+            # Handle: my_map.lookup(key)
+            if isinstance(call.func.value, ast.Name):
+                obj_name = call.func.value.id
+                if map_sym_tab and obj_name in map_sym_tab:
+                    if HelperHandlerRegistry.has_handler(method_name):
+                        return handle_helper_call(
+                            call,
+                            module,
+                            builder,
+                            func,
+                            local_sym_tab,
+                            map_sym_tab,
+                            structs_sym_tab,
+                        )
+
+        return None
+
+    CallHandlerRegistry.set_handler(helper_call_handler)
+
+
+# Register on module import
+_register_helper_handler()
+
 __all__ = [
     "HelperHandlerRegistry",
     "reset_scratch_pool",

pythonbpf/helper/bpf_helper_handler.py

@@ -135,7 +135,7 @@ def bpf_printk_emitter(
     fn_ptr = builder.inttoptr(fn_addr, fn_ptr_type)
 
     builder.call(fn_ptr, args, tail=True)
-    return None
+    return True
 
 
 @HelperHandlerRegistry.register("update")

pythonbpf/helper/helper_utils.py

@@ -3,8 +3,12 @@ import logging
 from collections.abc import Callable
 
 from llvmlite import ir
-from pythonbpf.expr import eval_expr, get_base_type_and_depth, deref_to_depth
+from pythonbpf.expr import (
-from pythonbpf.binary_ops import get_operand_value
+    eval_expr,
+    get_base_type_and_depth,
+    deref_to_depth,
+    get_operand_value,
+)
 
 logger = logging.getLogger(__name__)
 

tools/vmlinux-gen.py

@@ -243,6 +243,17 @@ class BTFConverter:
             data
         )
 
+        # below to replace those c_bool with bitfield greater than 8
+        def repl(m):
+            name, bits = m.groups()
+            return f"('{name}', ctypes.c_uint32, {bits})" if int(bits) > 8 else m.group(0)
+
+        data = re.sub(
+            r"\('([^']+)',\s*ctypes\.c_bool,\s*(\d+)\)",
+            repl,
+            data
+        )
+
         # Remove ctypes. prefix from invalid entries
         invalid_ctypes = ["bpf_iter_state", "_cache_type", "fs_context_purpose"]
         for name in invalid_ctypes: