Files
python-bpf/pythonbpf/helper/helper_utils.py
2025-10-01 19:56:20 +05:30

118 lines
3.9 KiB
Python

import ast
import logging
from llvmlite import ir
logger = logging.getLogger(__name__)
class HelperHandlerRegistry:
"""Registry for BPF helpers"""
_handlers = {}
@classmethod
def register(cls, helper_name):
"""Decorator to register a handler function for a helper"""
def decorator(func):
cls._handlers[helper_name] = func
return func
return decorator
@classmethod
def get_handler(cls, helper_name):
"""Get the handler function for a helper"""
return cls._handlers.get(helper_name)
def get_var_ptr_from_name(var_name, local_sym_tab):
"""Get a pointer to a variable from the symbol table."""
if local_sym_tab and var_name in local_sym_tab:
return local_sym_tab[var_name][0]
raise ValueError(f"Variable '{var_name}' not found in local symbol table")
def create_int_constant_ptr(value, builder, int_width=64):
"""Create a pointer to an integer constant."""
# Default to 64-bit integer
int_type = ir.IntType(int_width)
ptr = builder.alloca(int_type)
ptr.align = int_type.width // 8
builder.store(ir.Constant(int_type, value), ptr)
return ptr
def get_or_create_ptr_from_arg(arg, builder, local_sym_tab):
"""Extract or create pointer from the call arguments."""
if isinstance(arg, ast.Name):
ptr = get_var_ptr_from_name(arg.id, local_sym_tab)
elif isinstance(arg, ast.Constant) and isinstance(arg.value, int):
ptr = create_int_constant_ptr(arg.value, builder)
else:
raise NotImplementedError(
"Only simple variable names are supported as args in map helpers.")
return ptr
def get_flags_val(arg, builder, local_sym_tab):
"""Extract or create flags value from the call arguments."""
if not arg:
return 0
if isinstance(arg, ast.Name):
if local_sym_tab and arg.id in local_sym_tab:
flags_ptr = local_sym_tab[arg.id][0]
return builder.load(flags_ptr)
else:
raise ValueError(
f"Variable '{arg.id}' not found in local symbol table")
elif isinstance(arg, ast.Constant) and isinstance(arg.value, int):
return arg.value
raise NotImplementedError(
"Only simple variable names or integer constants are supported as flags in map helpers.")
def _handle_fstring_print(joined_str, module, builder, func,
local_sym_tab=None, struct_sym_tab=None,
local_var_metadata=None):
"""Handle f-string formatting for bpf_printk emitter."""
fmt_parts = []
exprs = []
for value in joined_str.values:
logger.debug(f"Processing f-string value: {ast.dump(value)}")
if isinstance(value, ast.Constant):
_process_constant_in_fstring(value, fmt_parts, exprs)
elif isinstance(value, ast.FormattedValue):
_process_formatted_value(value, fmt_parts, exprs,
local_sym_tab, struct_sym_tab,
local_var_metadata)
def _process_constant_in_fstring(cst, fmt_parts, exprs):
"""Process constant values in f-string."""
if isinstance(cst.value, str):
fmt_parts.append(cst.value)
elif isinstance(cst.value, int):
fmt_parts.append("%lld")
exprs.append(ir.Constant(ir.IntType(64), cst.value))
else:
raise NotImplementedError(
f"Unsupported constant type in f-string: {type(cst.value)}")
def _process_formatted_value(fval, fmt_parts, exprs,
local_sym_tab, struct_sym_tab,
local_var_metadata):
"""Process formatted values in f-string."""
logger.debug(f"Processing formatted value: {ast.dump(fval)}")
if isinstance(fval.value, ast.Name):
pass
elif isinstance(fval.value, ast.Attribute):
pass
else:
raise NotImplementedError(
f"Unsupported formatted value type in f-string: {type(fval.value)}")