mirror of
https://github.com/varun-r-mallya/Python-BPF.git
synced 2025-12-31 21:06:25 +00:00
142 lines
5.1 KiB
Python
142 lines
5.1 KiB
Python
import ast
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from llvmlite import ir
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from .license_pass import license_processing
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from .functions_pass import func_proc
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from pythonbpf.maps import maps_proc
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from .structs.structs_pass import structs_proc
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from .globals_pass import globals_processing
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from .debuginfo import DW_LANG_C11, DwarfBehaviorEnum
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import os
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import subprocess
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import inspect
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from pathlib import Path
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from pylibbpf import BpfProgram
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import tempfile
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VERSION = "v0.1.3"
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def find_bpf_chunks(tree):
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"""Find all functions decorated with @bpf in the AST."""
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bpf_functions = []
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for node in ast.walk(tree):
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if isinstance(node, ast.FunctionDef) or isinstance(node, ast.ClassDef):
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for decorator in node.decorator_list:
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if isinstance(decorator, ast.Name) and decorator.id == "bpf":
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bpf_functions.append(node)
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break
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return bpf_functions
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def processor(source_code, filename, module):
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tree = ast.parse(source_code, filename)
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print(ast.dump(tree, indent=4))
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bpf_chunks = find_bpf_chunks(tree)
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for func_node in bpf_chunks:
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print(f"Found BPF function/struct: {func_node.name}")
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structs_sym_tab = structs_proc(tree, module, bpf_chunks)
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map_sym_tab = maps_proc(tree, module, bpf_chunks)
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func_proc(tree, module, bpf_chunks, map_sym_tab, structs_sym_tab)
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license_processing(tree, module)
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globals_processing(tree, module)
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def compile_to_ir(filename: str, output: str):
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with open(filename) as f:
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source = f.read()
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module = ir.Module(name=filename)
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module.data_layout = "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128"
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module.triple = "bpf"
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if not hasattr(module, '_debug_compile_unit'):
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module._file_metadata = module.add_debug_info("DIFile", { # type: ignore
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"filename": filename,
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"directory": os.path.dirname(filename)
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})
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module._debug_compile_unit = module.add_debug_info("DICompileUnit", { # type: ignore
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"language": 29, # DW_LANG_C11
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"file": module._file_metadata, # type: ignore
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"producer": f"PythonBPF {VERSION}",
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"isOptimized": True,
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"runtimeVersion": 0,
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"emissionKind": 1,
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"splitDebugInlining": False,
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"nameTableKind": 0
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}, is_distinct=True)
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module.add_named_metadata(
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"llvm.dbg.cu", module._debug_compile_unit) # type: ignore
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processor(source, filename, module)
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wchar_size = module.add_metadata([ir.Constant(ir.IntType(32), 1),
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"wchar_size",
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ir.Constant(ir.IntType(32), 4)])
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frame_pointer = module.add_metadata([ir.Constant(ir.IntType(32), 7),
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"frame-pointer",
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ir.Constant(ir.IntType(32), 2)])
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# Add Debug Info Version (3 = DWARF v3, which LLVM expects)
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debug_info_version = module.add_metadata([ir.Constant(ir.IntType(32), 2),
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"Debug Info Version",
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ir.Constant(ir.IntType(32), 3)])
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# Add explicit DWARF version (4 is common, works with LLVM BPF backend)
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dwarf_version = module.add_metadata([ir.Constant(ir.IntType(32), 2),
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"Dwarf Version",
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ir.Constant(ir.IntType(32), 4)])
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module.add_named_metadata("llvm.module.flags", wchar_size)
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module.add_named_metadata("llvm.module.flags", frame_pointer)
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module.add_named_metadata("llvm.module.flags", debug_info_version)
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module.add_named_metadata("llvm.module.flags", dwarf_version)
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module.add_named_metadata("llvm.ident", [f"PythonBPF {VERSION}"])
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print(f"IR written to {output}")
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with open(output, "w") as f:
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f.write(f"source_filename = \"{filename}\"\n")
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f.write(str(module))
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f.write("\n")
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return output
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def compile():
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# Look one level up the stack to the caller of this function
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caller_frame = inspect.stack()[1]
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caller_file = Path(caller_frame.filename).resolve()
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ll_file = Path("/tmp") / caller_file.with_suffix(".ll").name
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o_file = caller_file.with_suffix(".o")
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compile_to_ir(str(caller_file), str(ll_file))
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subprocess.run([
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"llc", "-march=bpf", "-filetype=obj", "-O2",
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str(ll_file), "-o", str(o_file)
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], check=True)
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print(f"Object written to {o_file}, {ll_file} can be removed")
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def BPF() -> BpfProgram:
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caller_frame = inspect.stack()[1]
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src = inspect.getsource(caller_frame.frame)
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with tempfile.NamedTemporaryFile(mode="w+", delete=True, suffix=".py") as f, \
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tempfile.NamedTemporaryFile(mode="w+", delete=True, suffix=".ll") as inter, \
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tempfile.NamedTemporaryFile(mode="w+", delete=False, suffix=".o") as obj_file:
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f.write(src)
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f.flush()
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source = f.name
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compile_to_ir(source, str(inter.name))
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subprocess.run([
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"llc", "-march=bpf", "-filetype=obj", "-O2",
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str(inter.name), "-o", str(obj_file.name)
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], check=True)
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return BpfProgram(str(obj_file.name))
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