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https://github.com/varun-r-mallya/Python-BPF.git
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69 lines
2.5 KiB
Python
69 lines
2.5 KiB
Python
import ast
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from llvmlite import ir
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from .type_deducer import ctypes_to_ir
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structs_sym_tab = {}
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def structs_proc(tree, module, chunks):
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for cls_node in chunks:
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# Check if this class is a struct
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is_struct = False
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for decorator in cls_node.decorator_list:
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if isinstance(decorator, ast.Name) and decorator.id == "struct":
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is_struct = True
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break
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if is_struct:
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print(f"Found BPF struct: {cls_node.name}")
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process_bpf_struct(cls_node, module)
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continue
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return structs_sym_tab
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def process_bpf_struct(cls_node, module):
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struct_name = cls_node.name
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field_names = []
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field_types = []
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for item in cls_node.body:
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if isinstance(item, ast.AnnAssign) and isinstance(item.target, ast.Name):
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print(f"Field: {item.target.id}, Type: "
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f"{ast.dump(item.annotation)}")
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field_names.append(item.target.id)
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if isinstance(item.annotation, ast.Call) and isinstance(item.annotation.func, ast.Name) and item.annotation.func.id == "str":
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# This is a char array with fixed length
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# TODO: For now assuming str is always called with constant
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field_types.append(ir.ArrayType(
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ir.IntType(8), item.annotation.args[0].value))
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else:
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field_types.append(ctypes_to_ir(item.annotation.id))
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curr_offset = 0
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for ftype in field_types:
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if isinstance(ftype, ir.IntType):
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fsize = ftype.width // 8
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alignment = fsize
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elif isinstance(ftype, ir.ArrayType):
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fsize = ftype.count * (ftype.element.width // 8)
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alignment = ftype.element.width // 8
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elif isinstance(ftype, ir.PointerType):
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fsize = 8
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alignment = 8
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else:
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print(f"Unsupported field type in struct {struct_name}")
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return
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padding = (alignment - (curr_offset % alignment)) % alignment
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curr_offset += padding
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curr_offset += fsize
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final_padding = (8 - (curr_offset % 8)) % 8
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total_size = curr_offset + final_padding
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struct_type = ir.LiteralStructType(field_types)
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structs_sym_tab[struct_name] = {
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"type": struct_type,
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"fields": {name: idx for idx, name in enumerate(field_names)},
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"size": total_size,
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"field_types": field_types,
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}
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print(f"Created struct {struct_name} with fields {field_names}")
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