22 Commits

Author SHA1 Message Date
a0b0ad370e Merge pull request #23 from pythonbpf/formatter
update formatter and pre-commit
2025-10-05 01:15:01 +05:30
bf78ac21fe Remove 'Static Typing' from short term tasks 2025-10-04 07:30:11 +05:30
b35134625b Merge pull request #19 from pythonbpf/fix-expr
Refactor expr_pass
2025-10-03 17:36:31 +05:30
c3db609a90 Revert to using Warning loglevel as default 2025-10-03 17:35:57 +05:30
cc626c38f7 Move binops1 to tests/passing 2025-10-03 17:13:02 +05:30
a8b3f4f86c Fix recursive binops, move failing binops to passing 2025-10-03 17:08:41 +05:30
d593969408 Refactor ugly if-elif chain in handle_binary_op 2025-10-03 14:04:38 +05:30
6d5895ebc2 More fixes to recursive dereferencer, add get_operand value 2025-10-03 13:46:52 +05:30
c9ee6e4f17 Fix recursive_dereferencer in binops 2025-10-03 13:35:15 +05:30
a622c53e0f Add deref 2025-10-03 02:00:01 +05:30
a4f1363aed Add _handle_attribute_expr 2025-10-03 01:50:59 +05:30
3a819dcaee Add _handle_constant_expr 2025-10-02 22:54:38 +05:30
729270b34b Use _handle_name_expr in eval_expr 2025-10-02 22:50:21 +05:30
44cbcccb6c Create _handle_name_expr 2025-10-02 22:43:54 +05:30
86b9ec56d7 update formatter and pre-commit
Signed-off-by: varun-r-mallya <varunrmallya@gmail.com>
2025-10-02 22:43:05 +05:30
253944afd2 Merge pull request #18 from pythonbpf/fix-maps
Fix map calling convention
2025-10-02 22:12:01 +05:30
54993ce5c2 Merge branch 'master' into fix-maps 2025-10-02 22:11:38 +05:30
05083bd513 janitorial nitpicks 2025-10-02 22:10:28 +05:30
6e4c340780 Allow non-call convention for maps 2025-10-02 22:07:28 +05:30
9dbca410c2 Remove calls from map in sys_sync 2025-10-02 21:24:15 +05:30
62ca3b5ffe format errors 2025-10-02 19:07:49 +05:30
f263c35156 move debug cu generation to debug module 2025-10-02 19:05:58 +05:30
14 changed files with 220 additions and 175 deletions

View File

@ -21,7 +21,7 @@ ci:
repos:
# Standard hooks
- repo: https://github.com/pre-commit/pre-commit-hooks
rev: v4.6.0
rev: v6.0.0
hooks:
- id: check-added-large-files
- id: check-case-conflict
@ -36,7 +36,7 @@ repos:
- id: trailing-whitespace
- repo: https://github.com/astral-sh/ruff-pre-commit
rev: "v0.4.2"
rev: "v0.13.2"
hooks:
- id: ruff
args: ["--fix", "--show-fixes"]
@ -45,7 +45,7 @@ repos:
# Checking static types
- repo: https://github.com/pre-commit/mirrors-mypy
rev: "v1.10.0"
rev: "v1.18.2"
hooks:
- id: mypy
exclude: ^(tests)|^(examples)

View File

@ -1,7 +1,6 @@
## Short term
- Implement enough functionality to port the BCC tutorial examples in PythonBPF
- Static Typing
- Add all maps
- XDP support in pylibbpf
- ringbuf support

View File

@ -12,7 +12,7 @@
"from pythonbpf import bpf, map, section, bpfglobal, BPF\n",
"from pythonbpf.helper import pid\n",
"from pythonbpf.maps import HashMap\n",
"from pylibbpf import *\n",
"from pylibbpf import BpfMap\n",
"from ctypes import c_void_p, c_int64, c_uint64, c_int32\n",
"import matplotlib.pyplot as plt"
]

View File

@ -21,17 +21,17 @@ def last() -> HashMap:
@section("tracepoint/syscalls/sys_enter_sync")
def do_trace(ctx: c_void_p) -> c_int64:
key = 0
tsp = last().lookup(key)
tsp = last.lookup(key)
if tsp:
kt = ktime()
delta = kt - tsp
if delta < 1000000000:
time_ms = delta // 1000000
print(f"sync called within last second, last {time_ms} ms ago")
last().delete(key)
last.delete(key)
else:
kt = ktime()
last().update(key, kt)
last.update(key, kt)
return c_int64(0)

View File

@ -8,68 +8,59 @@ logger: Logger = logging.getLogger(__name__)
def recursive_dereferencer(var, builder):
"""dereference until primitive type comes out"""
if var.type == ir.PointerType(ir.PointerType(ir.IntType(64))):
# TODO: Not worrying about stack overflow for now
if isinstance(var.type, ir.PointerType):
a = builder.load(var)
return recursive_dereferencer(a, builder)
elif var.type == ir.PointerType(ir.IntType(64)):
a = builder.load(var)
return recursive_dereferencer(a, builder)
elif var.type == ir.IntType(64):
elif isinstance(var.type, ir.IntType):
return var
else:
raise TypeError(f"Unsupported type for dereferencing: {var.type}")
def handle_binary_op(rval, module, builder, var_name, local_sym_tab, map_sym_tab, func):
logger.info(f"module {module}")
left = rval.left
right = rval.right
def get_operand_value(operand, module, builder, local_sym_tab):
"""Extract the value from an operand, handling variables and constants."""
if isinstance(operand, ast.Name):
if operand.id in local_sym_tab:
return recursive_dereferencer(local_sym_tab[operand.id].var, builder)
raise ValueError(f"Undefined variable: {operand.id}")
elif isinstance(operand, ast.Constant):
if isinstance(operand.value, int):
return ir.Constant(ir.IntType(64), operand.value)
raise TypeError(f"Unsupported constant type: {type(operand.value)}")
elif isinstance(operand, ast.BinOp):
return handle_binary_op_impl(operand, module, builder, local_sym_tab)
raise TypeError(f"Unsupported operand type: {type(operand)}")
def handle_binary_op_impl(rval, module, builder, local_sym_tab):
op = rval.op
# Handle left operand
if isinstance(left, ast.Name):
if left.id in local_sym_tab:
left = recursive_dereferencer(local_sym_tab[left.id].var, builder)
else:
raise SyntaxError(f"Undefined variable: {left.id}")
elif isinstance(left, ast.Constant):
left = ir.Constant(ir.IntType(64), left.value)
else:
raise SyntaxError("Unsupported left operand type")
if isinstance(right, ast.Name):
if right.id in local_sym_tab:
right = recursive_dereferencer(local_sym_tab[right.id].var, builder)
else:
raise SyntaxError(f"Undefined variable: {right.id}")
elif isinstance(right, ast.Constant):
right = ir.Constant(ir.IntType(64), right.value)
else:
raise SyntaxError("Unsupported right operand type")
left = get_operand_value(rval.left, module, builder, local_sym_tab)
right = get_operand_value(rval.right, module, builder, local_sym_tab)
logger.info(f"left is {left}, right is {right}, op is {op}")
if isinstance(op, ast.Add):
builder.store(builder.add(left, right), local_sym_tab[var_name].var)
elif isinstance(op, ast.Sub):
builder.store(builder.sub(left, right), local_sym_tab[var_name].var)
elif isinstance(op, ast.Mult):
builder.store(builder.mul(left, right), local_sym_tab[var_name].var)
elif isinstance(op, ast.Div):
builder.store(builder.sdiv(left, right), local_sym_tab[var_name].var)
elif isinstance(op, ast.Mod):
builder.store(builder.srem(left, right), local_sym_tab[var_name].var)
elif isinstance(op, ast.LShift):
builder.store(builder.shl(left, right), local_sym_tab[var_name].var)
elif isinstance(op, ast.RShift):
builder.store(builder.lshr(left, right), local_sym_tab[var_name].var)
elif isinstance(op, ast.BitOr):
builder.store(builder.or_(left, right), local_sym_tab[var_name].var)
elif isinstance(op, ast.BitXor):
builder.store(builder.xor(left, right), local_sym_tab[var_name].var)
elif isinstance(op, ast.BitAnd):
builder.store(builder.and_(left, right), local_sym_tab[var_name].var)
elif isinstance(op, ast.FloorDiv):
builder.store(builder.udiv(left, right), local_sym_tab[var_name].var)
# 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(rval, module, builder, var_name, local_sym_tab):
result = handle_binary_op_impl(rval, module, builder, local_sym_tab)
builder.store(result, local_sym_tab[var_name].var)

View File

@ -5,7 +5,7 @@ from .functions_pass import func_proc
from .maps import maps_proc
from .structs import structs_proc
from .globals_pass import globals_processing
from .debuginfo import DW_LANG_C11, DwarfBehaviorEnum
from .debuginfo import DW_LANG_C11, DwarfBehaviorEnum, DebugInfoGenerator
import os
import subprocess
import inspect
@ -60,33 +60,17 @@ def compile_to_ir(filename: str, output: str, loglevel=logging.WARNING):
module.triple = "bpf"
if not hasattr(module, "_debug_compile_unit"):
module._file_metadata = module.add_debug_info(
"DIFile",
{ # type: ignore
"filename": filename,
"directory": os.path.dirname(filename),
},
debug_generator = DebugInfoGenerator(module)
debug_generator.generate_file_metadata(filename, os.path.dirname(filename))
debug_generator.generate_debug_cu(
DW_LANG_C11,
f"PythonBPF {VERSION}",
True, # TODO: This is probably not true
# TODO: add a global field here that keeps track of all the globals. Works without it, but I think it might
# be required for kprobes.
True,
)
module._debug_compile_unit = module.add_debug_info(
"DICompileUnit",
{ # type: ignore
"language": DW_LANG_C11,
"file": module._file_metadata, # type: ignore
"producer": f"PythonBPF {VERSION}",
"isOptimized": True, # TODO: This is probably not true
# TODO: add a global field here that keeps track of all the globals. Works without it, but I think it might
# be required for kprobes.
"runtimeVersion": 0,
"emissionKind": 1,
"splitDebugInlining": False,
"nameTableKind": 0,
},
is_distinct=True,
)
module.add_named_metadata("llvm.dbg.cu", module._debug_compile_unit) # type: ignore
processor(source, filename, module)
wchar_size = module.add_metadata(

View File

@ -12,6 +12,34 @@ class DebugInfoGenerator:
self.module = module
self._type_cache = {} # Cache for common debug types
def generate_file_metadata(self, filename, dirname):
self.module._file_metadata = self.module.add_debug_info(
"DIFile",
{ # type: ignore
"filename": filename,
"directory": dirname,
},
)
def generate_debug_cu(
self, language, producer: str, is_optimized: bool, is_distinct: bool
):
self.module._debug_compile_unit = self.module.add_debug_info(
"DICompileUnit",
{ # type: ignore
"language": language,
"file": self.module._file_metadata, # type: ignore
"producer": producer,
"isOptimized": is_optimized,
"runtimeVersion": 0,
"emissionKind": 1,
"splitDebugInlining": False,
"nameTableKind": 0,
},
is_distinct=is_distinct,
)
self.module.add_named_metadata("llvm.dbg.cu", self.module._debug_compile_unit) # type: ignore
def get_basic_type(self, name: str, size: int, encoding: int) -> Any:
"""Get or create a basic type with caching"""
key = (name, size, encoding)

View File

@ -2,10 +2,92 @@ import ast
from llvmlite import ir
from logging import Logger
import logging
from typing import Dict
logger: Logger = logging.getLogger(__name__)
def _handle_name_expr(expr: ast.Name, local_sym_tab: Dict, builder: ir.IRBuilder):
"""Handle ast.Name expressions."""
if expr.id in local_sym_tab:
var = local_sym_tab[expr.id].var
val = builder.load(var)
return val, local_sym_tab[expr.id].ir_type
else:
logger.info(f"Undefined variable {expr.id}")
return None
def _handle_constant_expr(expr: ast.Constant):
"""Handle ast.Constant expressions."""
if isinstance(expr.value, int):
return ir.Constant(ir.IntType(64), expr.value), ir.IntType(64)
elif isinstance(expr.value, bool):
return ir.Constant(ir.IntType(1), int(expr.value)), ir.IntType(1)
else:
logger.info("Unsupported constant type")
return None
def _handle_attribute_expr(
expr: ast.Attribute,
local_sym_tab: Dict,
structs_sym_tab: Dict,
builder: ir.IRBuilder,
):
"""Handle ast.Attribute expressions for struct field access."""
if isinstance(expr.value, ast.Name):
var_name = expr.value.id
attr_name = expr.attr
if var_name in local_sym_tab:
var_ptr, var_type, var_metadata = local_sym_tab[var_name]
logger.info(f"Loading attribute {attr_name} from variable {var_name}")
logger.info(f"Variable type: {var_type}, Variable ptr: {var_ptr}")
metadata = structs_sym_tab[var_metadata]
if attr_name in metadata.fields:
gep = metadata.gep(builder, var_ptr, attr_name)
val = builder.load(gep)
field_type = metadata.field_type(attr_name)
return val, field_type
return None
def _handle_deref_call(expr: ast.Call, local_sym_tab: Dict, builder: ir.IRBuilder):
"""Handle deref function calls."""
logger.info(f"Handling deref {ast.dump(expr)}")
if len(expr.args) != 1:
logger.info("deref takes exactly one argument")
return None
arg = expr.args[0]
if (
isinstance(arg, ast.Call)
and isinstance(arg.func, ast.Name)
and arg.func.id == "deref"
):
logger.info("Multiple deref not supported")
return None
if isinstance(arg, ast.Name):
if arg.id in local_sym_tab:
arg_ptr = local_sym_tab[arg.id].var
else:
logger.info(f"Undefined variable {arg.id}")
return None
else:
logger.info("Unsupported argument type for deref")
return None
if arg_ptr is None:
logger.info("Failed to evaluate deref argument")
return None
# Load the value from pointer
val = builder.load(arg_ptr)
return val, local_sym_tab[arg.id].ir_type
def eval_expr(
func,
module,
@ -17,64 +99,28 @@ def eval_expr(
):
logger.info(f"Evaluating expression: {ast.dump(expr)}")
if isinstance(expr, ast.Name):
if expr.id in local_sym_tab:
var = local_sym_tab[expr.id].var
val = builder.load(var)
return val, local_sym_tab[expr.id].ir_type # return value and type
else:
logger.info(f"Undefined variable {expr.id}")
return None
return _handle_name_expr(expr, local_sym_tab, builder)
elif isinstance(expr, ast.Constant):
if isinstance(expr.value, int):
return ir.Constant(ir.IntType(64), expr.value), ir.IntType(64)
elif isinstance(expr.value, bool):
return ir.Constant(ir.IntType(1), int(expr.value)), ir.IntType(1)
else:
logger.info("Unsupported constant type")
return None
return _handle_constant_expr(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)
# delayed import to avoid circular dependency
from pythonbpf.helper import HelperHandlerRegistry, handle_helper_call
if isinstance(expr.func, ast.Name):
# check deref
if expr.func.id == "deref":
logger.info(f"Handling deref {ast.dump(expr)}")
if len(expr.args) != 1:
logger.info("deref takes exactly one argument")
return None
arg = expr.args[0]
if (
isinstance(arg, ast.Call)
and isinstance(arg.func, ast.Name)
and arg.func.id == "deref"
):
logger.info("Multiple deref not supported")
return None
if isinstance(arg, ast.Name):
if arg.id in local_sym_tab:
arg = local_sym_tab[arg.id].var
else:
logger.info(f"Undefined variable {arg.id}")
return None
if arg is None:
logger.info("Failed to evaluate deref argument")
return None
# Since we are handling only name case, directly take type from sym tab
val = builder.load(arg)
return val, local_sym_tab[expr.args[0].id].ir_type
# check for helpers
if HelperHandlerRegistry.has_handler(expr.func.id):
return handle_helper_call(
expr,
module,
builder,
func,
local_sym_tab,
map_sym_tab,
structs_sym_tab,
)
if isinstance(expr.func, ast.Name) and HelperHandlerRegistry.has_handler(
expr.func.id
):
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(
@ -106,19 +152,7 @@ def eval_expr(
structs_sym_tab,
)
elif isinstance(expr, ast.Attribute):
if isinstance(expr.value, ast.Name):
var_name = expr.value.id
attr_name = expr.attr
if var_name in local_sym_tab:
var_ptr, var_type, var_metadata = local_sym_tab[var_name]
logger.info(f"Loading attribute {attr_name} from variable {var_name}")
logger.info(f"Variable type: {var_type}, Variable ptr: {var_ptr}")
metadata = structs_sym_tab[var_metadata]
if attr_name in metadata.fields:
gep = metadata.gep(builder, var_ptr, attr_name)
val = builder.load(gep)
field_type = metadata.field_type(attr_name)
return val, field_type
return _handle_attribute_expr(expr, local_sym_tab, structs_sym_tab, builder)
logger.info("Unsupported expression evaluation")
return None

View File

@ -146,8 +146,7 @@ def handle_assign(
local_sym_tab[var_name].var,
)
logger.info(
f"Assigned {call_type} constant "
f"{rval.args[0].value} to {var_name}"
f"Assigned {call_type} constant {rval.args[0].value} to {var_name}"
)
elif HelperHandlerRegistry.has_handler(call_type):
# var = builder.alloca(ir.IntType(64), name=var_name)
@ -192,8 +191,23 @@ def handle_assign(
elif isinstance(rval.func, ast.Attribute):
logger.info(f"Assignment call attribute: {ast.dump(rval.func)}")
if isinstance(rval.func.value, ast.Name):
# TODO: probably a struct access
logger.info(f"TODO STRUCT ACCESS {ast.dump(rval)}")
if rval.func.value.id in map_sym_tab:
map_name = rval.func.value.id
method_name = rval.func.attr
if HelperHandlerRegistry.has_handler(method_name):
val = handle_helper_call(
rval,
module,
builder,
func,
local_sym_tab,
map_sym_tab,
structs_sym_tab,
)
builder.store(val[0], local_sym_tab[var_name].var)
else:
# TODO: probably a struct access
logger.info(f"TODO STRUCT ACCESS {ast.dump(rval)}")
elif isinstance(rval.func.value, ast.Call) and isinstance(
rval.func.value.func, ast.Name
):
@ -218,9 +232,7 @@ def handle_assign(
else:
logger.info("Unsupported assignment call function type")
elif isinstance(rval, ast.BinOp):
handle_binary_op(
rval, module, builder, var_name, local_sym_tab, map_sym_tab, func
)
handle_binary_op(rval, module, builder, var_name, local_sym_tab)
else:
logger.info("Unsupported assignment value type")
@ -470,8 +482,7 @@ def allocate_mem(
var = builder.alloca(ir_type, name=var_name)
has_metadata = True
logger.info(
f"Pre-allocated variable {var_name} "
f"for struct {call_type}"
f"Pre-allocated variable {var_name} for struct {call_type}"
)
elif isinstance(rval.func, ast.Attribute):
ir_type = ir.PointerType(ir.IntType(64))

View File

@ -62,7 +62,7 @@ def bpf_map_lookup_elem_emitter(
"""
if not call.args or len(call.args) != 1:
raise ValueError(
"Map lookup expects exactly one argument (key), got " f"{len(call.args)}"
f"Map lookup expects exactly one argument (key), got {len(call.args)}"
)
key_ptr = get_or_create_ptr_from_arg(call.args[0], builder, local_sym_tab)
map_void_ptr = builder.bitcast(map_ptr, ir.PointerType())
@ -145,8 +145,7 @@ def bpf_map_update_elem_emitter(
"""
if not call.args or len(call.args) < 2 or len(call.args) > 3:
raise ValueError(
"Map update expects 2 or 3 args (key, value, flags), "
f"got {len(call.args)}"
f"Map update expects 2 or 3 args (key, value, flags), got {len(call.args)}"
)
key_arg = call.args[0]
@ -196,7 +195,7 @@ def bpf_map_delete_elem_emitter(
"""
if not call.args or len(call.args) != 1:
raise ValueError(
"Map delete expects exactly one argument (key), got " f"{len(call.args)}"
f"Map delete expects exactly one argument (key), got {len(call.args)}"
)
key_ptr = get_or_create_ptr_from_arg(call.args[0], builder, local_sym_tab)
map_void_ptr = builder.bitcast(map_ptr, ir.PointerType())
@ -255,7 +254,7 @@ def bpf_perf_event_output_handler(
):
if len(call.args) != 1:
raise ValueError(
"Perf event output expects exactly one argument, " f"got {len(call.args)}"
f"Perf event output expects exactly one argument, got {len(call.args)}"
)
data_arg = call.args[0]
ctx_ptr = func.args[0] # First argument to the function is ctx

View File

@ -270,7 +270,7 @@ def _prepare_expr_args(expr, func, module, builder, local_sym_tab, struct_sym_ta
val = builder.sext(val, ir.IntType(64))
else:
logger.warning(
"Only int and ptr supported in bpf_printk args. " "Others default to 0."
"Only int and ptr supported in bpf_printk args. Others default to 0."
)
val = ir.Constant(ir.IntType(64), 0)
return val

View File

@ -278,9 +278,7 @@ def process_bpf_map(func_node, module):
if handler:
return handler(map_name, rval, module)
else:
logger.warning(
f"Unknown map type " f"{rval.func.id}, defaulting to HashMap"
)
logger.warning(f"Unknown map type {rval.func.id}, defaulting to HashMap")
return process_hash_map(map_name, rval, module)
else:
raise ValueError("Function under @map must return a map")

View File

@ -3,9 +3,9 @@ from ctypes import c_void_p, c_int64
@bpf
@section("sometag1")
@section("tracepoint/syscalls/sys_enter_sync")
def sometag(ctx: c_void_p) -> c_int64:
a = 1 + 2 + 1
a = 1 + 2 + 1 + 12 + 13
print(f"{a}")
return c_int64(0)

View File

@ -3,11 +3,12 @@ from ctypes import c_void_p, c_int64
@bpf
@section("sometag1")
@section("tracepoint/syscalls/sys_enter_sync")
def sometag(ctx: c_void_p) -> c_int64:
b = 1 + 2
a = 1 + b
return c_int64(a)
print(f"{a}")
return c_int64(0)
@bpf