add assignment dict handling to class_handler.py

Add debug info handling to vmlinux
* Does not add support for recursive ctypes pointer based resolution
* Still does not support unions and function pointers.
* Has the mechanism to build for function pointers added.

pyproject.toml

@@ -10,6 +10,20 @@ authors = [
   { name = "r41k0u", email="pragyanshchaturvedi18@gmail.com" },
   { name = "varun-r-mallya", email="varunrmallya@gmail.com" }
 ]
+classifiers = [
+    "Development Status :: 3 - Alpha",
+    "Intended Audience :: Developers",
+    "Operating System :: POSIX :: Linux",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python",
+    "Topic :: Software Development :: Libraries :: Python Modules",
+    "Topic :: System :: Operating System Kernels :: Linux",
+]
 readme = "README.md"
 license = {text = "Apache-2.0"}
 requires-python = ">=3.8"

pythonbpf/codegen.py

@@ -55,11 +55,11 @@ def processor(source_code, filename, module):
     for func_node in bpf_chunks:
         logger.info(f"Found BPF function/struct: {func_node.name}")
 
-    vmlinux_proc(tree, module)
+    vmlinux_symtab = vmlinux_proc(tree, module)
     populate_global_symbol_table(tree, module)
     license_processing(tree, module)
     globals_processing(tree, module)
-
+    print("DEBUG:", vmlinux_symtab)
     structs_sym_tab = structs_proc(tree, module, bpf_chunks)
     map_sym_tab = maps_proc(tree, module, bpf_chunks)
     func_proc(tree, module, bpf_chunks, map_sym_tab, structs_sym_tab)

pythonbpf/debuginfo/debug_info_generator.py

@@ -81,6 +81,20 @@ class DebugInfoGenerator:
             },
         )
 
+    def create_array_type_vmlinux(self, type_info: Any, count: int) -> Any:
+        """Create an array type of the given base type with specified count"""
+        base_type, type_sizing = type_info
+        subrange = self.module.add_debug_info("DISubrange", {"count": count})
+        return self.module.add_debug_info(
+            "DICompositeType",
+            {
+                "tag": dc.DW_TAG_array_type,
+                "baseType": base_type,
+                "size": type_sizing,
+                "elements": [subrange],
+            },
+        )
+
     @staticmethod
     def _compute_array_size(base_type: Any, count: int) -> int:
         # Extract size from base_type if possible
@@ -101,6 +115,23 @@ class DebugInfoGenerator:
             },
         )
 
+    def create_struct_member_vmlinux(
+        self, name: str, base_type_with_size: Any, offset: int
+    ) -> Any:
+        """Create a struct member with the given name, type, and offset"""
+        base_type, type_size = base_type_with_size
+        return self.module.add_debug_info(
+            "DIDerivedType",
+            {
+                "tag": dc.DW_TAG_member,
+                "name": name,
+                "file": self.module._file_metadata,
+                "baseType": base_type,
+                "size": type_size,
+                "offset": offset,
+            },
+        )
+
     def create_struct_type(
         self, members: List[Any], size: int, is_distinct: bool
     ) -> Any:
@@ -116,6 +147,22 @@ class DebugInfoGenerator:
             is_distinct=is_distinct,
         )
 
+    def create_struct_type_with_name(
+        self, name: str, members: List[Any], size: int, is_distinct: bool
+    ) -> Any:
+        """Create a struct type with the given members and size"""
+        return self.module.add_debug_info(
+            "DICompositeType",
+            {
+                "name": name,
+                "tag": dc.DW_TAG_structure_type,
+                "file": self.module._file_metadata,
+                "size": size,
+                "elements": members,
+            },
+            is_distinct=is_distinct,
+        )
+
     def create_global_var_debug_info(
         self, name: str, var_type: Any, is_local: bool = False
     ) -> Any:

pythonbpf/vmlinux_parser/assignment_info.py

@@ -0,0 +1,35 @@
+from enum import Enum, auto
+from typing import Any, Dict, List, Optional, TypedDict
+from dataclasses import dataclass
+
+from pythonbpf.vmlinux_parser.dependency_node import Field
+
+
+@dataclass
+class AssignmentType(Enum):
+    CONSTANT = auto()
+    STRUCT = auto()
+    ARRAY = auto()  # probably won't be used
+    FUNCTION_POINTER = auto()
+    POINTER = auto()  # again, probably won't be used
+
+
+@dataclass
+class FunctionSignature(TypedDict):
+    return_type: str
+    param_types: List[str]
+    varargs: bool
+
+
+# Thew name of the assignment will be in the dict that uses this class
+@dataclass
+class AssignmentInfo(TypedDict):
+    value_type: AssignmentType
+    python_type: type
+    value: Optional[Any]
+    pointer_level: Optional[int]
+    signature: Optional[FunctionSignature]  # For function pointers
+    # The key of the dict is the name of the field.
+    #   Value is a tuple that contains the global variable representing that field
+    #   along with all the information about that field as a Field type.
+    members: Optional[Dict[str, tuple[str, Field]]]  # For structs.

pythonbpf/vmlinux_parser/class_handler.py

@@ -1,8 +1,10 @@
 import logging
 from functools import lru_cache
 import importlib
+
+from .assignment_info import AssignmentInfo, AssignmentType
 from .dependency_handler import DependencyHandler
-from .dependency_node import DependencyNode
+from .dependency_node import DependencyNode, Field
 import ctypes
 from typing import Optional, Any, Dict
 
@@ -15,17 +17,26 @@ def get_module_symbols(module_name: str):
     return [name for name in dir(imported_module)], imported_module
 
 
-def process_vmlinux_class(node, llvm_module, handler: DependencyHandler):
+def process_vmlinux_class(
+    node,
+    llvm_module,
+    handler: DependencyHandler,
+    assignments: dict[str, AssignmentInfo],
+):
     symbols_in_module, imported_module = get_module_symbols("vmlinux")
     if node.name in symbols_in_module:
         vmlinux_type = getattr(imported_module, node.name)
-        process_vmlinux_post_ast(vmlinux_type, llvm_module, handler)
+        process_vmlinux_post_ast(vmlinux_type, llvm_module, handler, assignments)
     else:
         raise ImportError(f"{node.name} not in vmlinux")
 
 
 def process_vmlinux_post_ast(
-    elem_type_class, llvm_handler, handler: DependencyHandler, processing_stack=None
+    elem_type_class,
+    llvm_handler,
+    handler: DependencyHandler,
+    assignments: dict[str, AssignmentInfo],
+    processing_stack=None,
 ):
     # Initialize processing stack on first call
     if processing_stack is None:
@@ -46,7 +57,7 @@ def process_vmlinux_post_ast(
         logger.debug(f"Node {current_symbol_name} already processed and ready")
         return True
 
-    # XXX:Check it's use. It's probably not being used.
+    # XXX:Check its use. It's probably not being used.
     if current_symbol_name in processing_stack:
         logger.debug(
             f"Dependency already in processing stack for {current_symbol_name}, skipping"
@@ -92,18 +103,61 @@ def process_vmlinux_post_ast(
             else:
                 raise TypeError("Could not get required class and definition")
 
+            # Create a members dictionary for AssignmentInfo
+            members_dict: Dict[str, tuple[str, Field]] = {}
+
             logger.debug(f"Extracted fields for {current_symbol_name}: {field_table}")
             for elem in field_table.items():
                 elem_name, elem_temp_list = elem
                 [elem_type, elem_bitfield_size] = elem_temp_list
                 local_module_name = getattr(elem_type, "__module__", None)
                 new_dep_node.add_field(elem_name, elem_type, ready=False)
+
+                # Store field reference for struct assignment info
+                field_ref = new_dep_node.get_field(elem_name)
+                if field_ref:
+                    members_dict[elem_name] = (elem_name, field_ref)
+
                 if local_module_name == ctypes.__name__:
+                    # TODO: need to process pointer to ctype and also CFUNCTYPES here recursively. Current processing is a single dereference
                     new_dep_node.set_field_bitfield_size(elem_name, elem_bitfield_size)
-                    new_dep_node.set_field_ready(elem_name, is_ready=True)
+
-                    logger.debug(
+                    # Process pointer to ctype
-                        f"Field {elem_name} is direct ctypes type: {elem_type}"
+                    if isinstance(elem_type, type) and issubclass(
-                    )
+                        elem_type, ctypes._Pointer
+                    ):
+                        # Get the pointed-to type
+                        pointed_type = elem_type._type_
+                        logger.debug(f"Found pointer to type: {pointed_type}")
+                        new_dep_node.set_field_containing_type(elem_name, pointed_type)
+                        new_dep_node.set_field_ctype_complex_type(
+                            elem_name, ctypes._Pointer
+                        )
+                        new_dep_node.set_field_ready(elem_name, is_ready=True)
+
+                    # Process function pointers (CFUNCTYPE)
+                    elif hasattr(elem_type, "_restype_") and hasattr(
+                        elem_type, "_argtypes_"
+                    ):
+                        # This is a CFUNCTYPE or similar
+                        logger.info(
+                            f"Function pointer detected for {elem_name} with return type {elem_type._restype_} and arguments {elem_type._argtypes_}"
+                        )
+                        # Set the field as ready but mark it with special handling
+                        new_dep_node.set_field_ctype_complex_type(
+                            elem_name, ctypes.CFUNCTYPE
+                        )
+                        new_dep_node.set_field_ready(elem_name, is_ready=True)
+                        logger.warning(
+                            "Blindly processing CFUNCTYPE ctypes to ensure compilation. Unsupported"
+                        )
+
+                    else:
+                        # Regular ctype
+                        new_dep_node.set_field_ready(elem_name, is_ready=True)
+                        logger.debug(
+                            f"Field {elem_name} is direct ctypes type: {elem_type}"
+                        )
                 elif local_module_name == "vmlinux":
                     new_dep_node.set_field_bitfield_size(elem_name, elem_bitfield_size)
                     logger.debug(
@@ -127,6 +181,10 @@ def process_vmlinux_post_ast(
                                     ctype_complex_type = ctypes.Array
                                 elif issubclass(elem_type, ctypes._Pointer):
                                     ctype_complex_type = ctypes._Pointer
+                                else:
+                                    raise ImportError(
+                                        "Non Array and Pointer type ctype imports not supported in current version"
+                                    )
                             else:
                                 raise TypeError("Unsupported ctypes subclass")
                         else:
@@ -171,6 +229,7 @@ def process_vmlinux_post_ast(
                                     containing_type,
                                     llvm_handler,
                                     handler,
+                                    assignments,  # Pass assignments to recursive call
                                     processing_stack,
                                 )
                                 new_dep_node.set_field_ready(elem_name, True)
@@ -188,7 +247,11 @@ def process_vmlinux_post_ast(
                             else str(elem_type)
                         )
                         process_vmlinux_post_ast(
-                            elem_type, llvm_handler, handler, processing_stack
+                            elem_type,
+                            llvm_handler,
+                            handler,
+                            assignments,
+                            processing_stack,
                         )
                         new_dep_node.set_field_ready(elem_name, True)
                 else:
@@ -196,10 +259,21 @@ def process_vmlinux_post_ast(
                         f"{elem_name} with type {elem_type} from module {module_name} not supported in recursive resolver"
                     )
 
+            # Add struct to assignments dictionary
+            assignments[current_symbol_name] = AssignmentInfo(
+                value_type=AssignmentType.STRUCT,
+                python_type=elem_type_class,
+                value=None,
+                pointer_level=None,
+                signature=None,
+                members=members_dict,
+            )
+            logger.info(f"Added struct assignment info for {current_symbol_name}")
+
     else:
         raise ImportError("UNSUPPORTED Module")
 
-    logging.info(
+    logger.info(
         f"{current_symbol_name} processed and handler readiness {handler.is_ready}"
     )
     return True

pythonbpf/vmlinux_parser/import_detector.py

@@ -1,9 +1,9 @@
 import ast
 import logging
-from typing import List, Tuple, Any
 import importlib
 import inspect
 
+from .assignment_info import AssignmentInfo, AssignmentType
 from .dependency_handler import DependencyHandler
 from .ir_gen import IRGenerator
 from .class_handler import process_vmlinux_class
@@ -11,7 +11,7 @@ from .class_handler import process_vmlinux_class
 logger = logging.getLogger(__name__)
 
 
-def detect_import_statement(tree: ast.AST) -> List[Tuple[str, ast.ImportFrom]]:
+def detect_import_statement(tree: ast.AST) -> list[tuple[str, ast.ImportFrom]]:
     """
     Parse AST and detect import statements from vmlinux.
 
@@ -82,7 +82,7 @@ def vmlinux_proc(tree: ast.AST, module):
     # initialise dependency handler
     handler = DependencyHandler()
     # initialise assignment dictionary of name to type
-    assignments: dict[str, tuple[type, Any]] = {}
+    assignments: dict[str, AssignmentInfo] = {}
 
     if not import_statements:
         logger.info("No vmlinux imports found")
@@ -112,7 +112,7 @@ def vmlinux_proc(tree: ast.AST, module):
                     isinstance(mod_node, ast.ClassDef)
                     and mod_node.name == imported_name
                 ):
-                    process_vmlinux_class(mod_node, module, handler)
+                    process_vmlinux_class(mod_node, module, handler, assignments)
                     found = True
                     break
                 if isinstance(mod_node, ast.Assign):
@@ -132,16 +132,31 @@ def vmlinux_proc(tree: ast.AST, module):
     return assignments
 
 
-def process_vmlinux_assign(node, module, assignments: dict[str, tuple[type, Any]]):
+def process_vmlinux_assign(node, module, assignments: dict[str, AssignmentInfo]):
-    # Check if this is a simple assignment with a constant value
+    """Process assignments from vmlinux module."""
+    # Only handle single-target assignments
     if len(node.targets) == 1 and isinstance(node.targets[0], ast.Name):
         target_name = node.targets[0].id
+
+        # Handle constant value assignments
         if isinstance(node.value, ast.Constant):
-            assignments[target_name] = (type(node.value.value), node.value.value)
+            # Fixed: using proper TypedDict creation syntax with named arguments
+            assignments[target_name] = AssignmentInfo(
+                value_type=AssignmentType.CONSTANT,
+                python_type=type(node.value.value),
+                value=node.value.value,
+                pointer_level=None,
+                signature=None,
+                members=None,
+            )
             logger.info(
                 f"Added assignment: {target_name} = {node.value.value!r} of type {type(node.value.value)}"
             )
+
+        # Handle other assignment types that we may need to support
         else:
-            raise ValueError(f"Unsupported assignment type for {target_name}")
+            logger.warning(
+                f"Unsupported assignment type for {target_name}: {ast.dump(node.value)}"
+            )
     else:
         raise ValueError("Not a simple assignment")

pythonbpf/vmlinux_parser/ir_gen/debug_info_gen.py

@@ -1,15 +1,161 @@
-from pythonbpf.debuginfo import DebugInfoGenerator
+from pythonbpf.debuginfo import DebugInfoGenerator, dwarf_constants as dc
+from ..dependency_node import DependencyNode
+import ctypes
+import logging
+from typing import List, Any, Tuple
+
+logger = logging.getLogger(__name__)
 
 
-def debug_info_generation(struct, llvm_module):
+def debug_info_generation(
+    struct: DependencyNode,
+    llvm_module,
+    generated_debug_info: List[Tuple[DependencyNode, Any]],
+) -> Any:
+    """
+    Generate DWARF debug information for a struct defined in a DependencyNode.
+
+    Args:
+        struct: The dependency node containing struct information
+        llvm_module: The LLVM module to add debug info to
+        generated_debug_info: List of tuples (struct, debug_info) to track generated debug info
+
+    Returns:
+        The generated global variable debug info
+    """
+    # Set up debug info generator
     generator = DebugInfoGenerator(llvm_module)
-    # this is sample debug info generation
-    # i64type = generator.get_uint64_type()
 
-    struct_type = generator.create_struct_type([], 64 * 4, is_distinct=True)
+    # Check if debug info for this struct has already been generated
+    for existing_struct, debug_info in generated_debug_info:
+        if existing_struct.name == struct.name:
+            return debug_info
 
-    global_var = generator.create_global_var_debug_info(
+    # Process all fields and create members for the struct
-        struct.name, struct_type, is_local=False
+    members = []
+    for field_name, field in struct.fields.items():
+        # Get appropriate debug type for this field
+        field_type = _get_field_debug_type(
+            field_name, field, generator, struct, generated_debug_info
+        )
+        # Create struct member with proper offset
+        member = generator.create_struct_member_vmlinux(
+            field_name, field_type, field.offset * 8
+        )
+        members.append(member)
+
+    if struct.name.startswith("struct_"):
+        struct_name = struct.name.removeprefix("struct_")
+    else:
+        raise ValueError("Unions are not supported in the current version")
+    # Create struct type with all members
+    struct_type = generator.create_struct_type_with_name(
+        struct_name, members, struct.__sizeof__() * 8, is_distinct=True
     )
 
-    return global_var
+    return struct_type
+
+
+def _get_field_debug_type(
+    field_name: str,
+    field,
+    generator: DebugInfoGenerator,
+    parent_struct: DependencyNode,
+    generated_debug_info: List[Tuple[DependencyNode, Any]],
+) -> tuple[Any, int]:
+    """
+    Determine the appropriate debug type for a field based on its Python/ctypes type.
+
+    Args:
+        field_name: Name of the field
+        field: Field object containing type information
+        generator: DebugInfoGenerator instance
+        parent_struct: The parent struct containing this field
+        generated_debug_info: List of already generated debug info
+
+    Returns:
+        The debug info type for this field
+    """
+    # Handle complex types (arrays, pointers)
+    if field.ctype_complex_type is not None:
+        if issubclass(field.ctype_complex_type, ctypes.Array):
+            # Handle array types
+            element_type, base_type_size = _get_basic_debug_type(
+                field.containing_type, generator
+            )
+            return generator.create_array_type_vmlinux(
+                (element_type, base_type_size * field.type_size), field.type_size
+            ), field.type_size * base_type_size
+        elif issubclass(field.ctype_complex_type, ctypes._Pointer):
+            # Handle pointer types
+            pointee_type, _ = _get_basic_debug_type(field.containing_type, generator)
+            return generator.create_pointer_type(pointee_type), 64
+
+    # Handle other vmlinux types (nested structs)
+    if field.type.__module__ == "vmlinux":
+        # If it's a struct from vmlinux, check if we've already generated debug info for it
+        struct_name = field.type.__name__
+
+        # Look for existing debug info in the list
+        for existing_struct, debug_info in generated_debug_info:
+            if existing_struct.name == struct_name:
+                # Use existing debug info
+                return debug_info, existing_struct.__sizeof__()
+
+        # If not found, create a forward declaration
+        # This will be completed when the actual struct is processed
+        logger.warning("Forward declaration in struct created")
+        forward_type = generator.create_struct_type([], 0, is_distinct=True)
+        return forward_type, 0
+
+    # Handle basic C types
+    return _get_basic_debug_type(field.type, generator)
+
+
+def _get_basic_debug_type(ctype, generator: DebugInfoGenerator) -> Any:
+    """
+    Map a ctypes type to a DWARF debug type.
+
+    Args:
+        ctype: A ctypes type or Python type
+        generator: DebugInfoGenerator instance
+
+    Returns:
+        The corresponding debug type
+    """
+    # Map ctypes to debug info types
+    if ctype == ctypes.c_char or ctype == ctypes.c_byte:
+        return generator.get_basic_type("char", 8, dc.DW_ATE_signed_char), 8
+    elif ctype == ctypes.c_ubyte or ctype == ctypes.c_uint8:
+        return generator.get_basic_type("unsigned char", 8, dc.DW_ATE_unsigned_char), 8
+    elif ctype == ctypes.c_short or ctype == ctypes.c_int16:
+        return generator.get_basic_type("short", 16, dc.DW_ATE_signed), 16
+    elif ctype == ctypes.c_ushort or ctype == ctypes.c_uint16:
+        return generator.get_basic_type("unsigned short", 16, dc.DW_ATE_unsigned), 16
+    elif ctype == ctypes.c_int or ctype == ctypes.c_int32:
+        return generator.get_basic_type("int", 32, dc.DW_ATE_signed), 32
+    elif ctype == ctypes.c_uint or ctype == ctypes.c_uint32:
+        return generator.get_basic_type("unsigned int", 32, dc.DW_ATE_unsigned), 32
+    elif ctype == ctypes.c_long:
+        return generator.get_basic_type("long", 64, dc.DW_ATE_signed), 64
+    elif ctype == ctypes.c_ulong:
+        return generator.get_basic_type("unsigned long", 64, dc.DW_ATE_unsigned), 64
+    elif ctype == ctypes.c_longlong or ctype == ctypes.c_int64:
+        return generator.get_basic_type("long long", 64, dc.DW_ATE_signed), 64
+    elif ctype == ctypes.c_ulonglong or ctype == ctypes.c_uint64:
+        return generator.get_basic_type(
+            "unsigned long long", 64, dc.DW_ATE_unsigned
+        ), 64
+    elif ctype == ctypes.c_float:
+        return generator.get_basic_type("float", 32, dc.DW_ATE_float), 32
+    elif ctype == ctypes.c_double:
+        return generator.get_basic_type("double", 64, dc.DW_ATE_float), 64
+    elif ctype == ctypes.c_bool:
+        return generator.get_basic_type("bool", 8, dc.DW_ATE_boolean), 8
+    elif ctype == ctypes.c_char_p:
+        char_type = generator.get_basic_type("char", 8, dc.DW_ATE_signed_char), 8
+        return generator.create_pointer_type(char_type)
+    elif ctype == ctypes.c_void_p:
+        return generator.create_pointer_type(None), 64
+    else:
+        return generator.get_uint64_type(), 64

pythonbpf/vmlinux_parser/ir_gen/ir_generation.py

@@ -14,6 +14,7 @@ class IRGenerator:
         self.llvm_module = llvm_module
         self.handler: DependencyHandler = handler
         self.generated: list[str] = []
+        self.generated_debug_info: list = []
         if not handler.is_ready:
             raise ImportError(
                 "Semantic analysis of vmlinux imports failed. Cannot generate IR"
@@ -67,18 +68,22 @@ class IRGenerator:
                             )
 
             # Actual processor logic here after dependencies are resolved
-            self.gen_ir(struct)
+            self.generated_debug_info.append(
+                (struct, self.gen_ir(struct, self.generated_debug_info))
+            )
             self.generated.append(struct.name)
 
         finally:
             # Remove from processing stack after we're done
             processing_stack.discard(struct.name)
 
-    def gen_ir(self, struct):
+    def gen_ir(self, struct, generated_debug_info):
         # TODO: we add the btf_ama attribute by monkey patching in the end of compilation, but once llvmlite
         #  accepts our issue, we will resort to normal accessed attribute based attribute addition
         # currently we generate all possible field accesses for CO-RE and put into the assignment table
-        debug_info = debug_info_generation(struct, self.llvm_module)
+        debug_info = debug_info_generation(
+            struct, self.llvm_module, generated_debug_info
+        )
         field_index = 0
         for field_name, field in struct.fields.items():
             # does not take arrays and similar types into consideration yet.
@@ -126,6 +131,7 @@ class IRGenerator:
                 )
                 globvar.linkage = "external"
                 globvar.set_metadata("llvm.preserve.access.index", debug_info)
+        return debug_info
 
     def _struct_name_generator(
         self,
@@ -136,6 +142,7 @@ class IRGenerator:
         index: int = 0,
         containing_type_size: int = 0,
     ) -> str:
+        # TODO: Does not support Unions as well as recursive pointer and array type naming
         if is_indexed:
             name = (
                 "llvm."

tests/c-form/ex7.bpf.c

@@ -19,7 +19,7 @@ struct {
 SEC("tp/syscalls/sys_enter_setuid")
 int handle_setuid_entry(struct trace_event_raw_sys_enter *ctx) {
   struct event data = {};
-
+  struct blk_integrity_iter it = {};
   // Extract UID from the syscall arguments
   data.uid = (unsigned int)ctx->args[0];
   data.ts = bpf_ktime_get_ns();

tests/passing_tests/vmlinux/simple_struct_test.py

@@ -0,0 +1,29 @@
+from pythonbpf import bpf, section, bpfglobal, compile_to_ir
+from vmlinux import TASK_COMM_LEN  # noqa: F401
+from vmlinux import struct_trace_event_raw_sys_enter  # noqa: F401
+
+# from vmlinux import struct_uinput_device
+# from vmlinux import struct_blk_integrity_iter
+from ctypes import c_int64
+
+
+# Instructions to how to run this program
+# 1. Install PythonBPF: pip install pythonbpf
+# 2. Run the program: python examples/simple_struct_test.py
+# 3. Run the program with sudo: sudo tools/check.sh run examples/simple_struct_test.o
+# 4. Attach object file to any network device with something like ./check.sh run examples/simple_struct_test.o tailscale0
+# 5. send traffic through the device and observe effects
+@bpf
+@section("tracepoint/syscalls/sys_enter_execve")
+def hello_world(ctx: struct_trace_event_raw_sys_enter) -> c_int64:
+    print("Hello, World!")
+    return c_int64(0)
+
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+compile_to_ir("simple_struct_test.py", "simple_struct_test.ll")