为Major手写导出变异体源码的python脚本

背景

虽然major官方在配置里提供了下面这两个参数

• export.mutants: If set, Major exports each generated mutant as a source code file

• mutants.directory:<DIR>: The export directory for the source-code mutants (default: ./mutants)

但无奈折腾很久都没有办法通过设置参数来导出变异体的源码，于是决定自己从mutants.log中提取有用的信息进行变异体的还原。

基本思想

在mutants.log中，每一条log的基本组成部分如下

Logging of Generated Mutants

Major’s mutator generates a log file?mutants.log, which provides detailed information about the generated mutants and uses a colon (‘:’) as separator. The log file contains one row per generated mutant; each row contains 7 columns with the following information:

1. Mutants’ unique number (id)

2. Name of the applied mutation operator

3. Original operator symbol

4. Replacement operator symbol

5. Fully qualified name of the mutated method

6. Line number in original source file

7. Summary of the applied transformation (<from> |==> <to>)

Here is a log-entry example for an ROR mutation that has the mutant id 11 and was generated on line 18 in a method named?classify?of the class?Triangle:

11:ROR:<=(int,int):<(int,int):Triangle@classify:18:a <= 0 |==> a < 0

如果要还原变异体的源码，至少需要3个信息，即?Line number in original source file,? <from>?和 <to>。鉴于major的变异算子可以归类为替换和删除两大类，因此，我将Name of the applied mutation operator也提取出来，判断变异算子是否是STD，如果是则直接删除 <from>，如果不是，则将 <from>替换为<to>。

代码实现

"""
File:infer_mutants.py
Description:根据变异日志的对变异的描述，推理出变异体
Created Date:24.1.8
Last Updated Date:24.1.9
Usage:图形界面点执行
Input Files:变异前的.java文件以及变异日志mutants.log
Input Parameters:NA  
Output Files:变异后的.java文件
Output Results:推理变异体这一过程成功与否
"""

import re
from pathlib import Path

mutants_log = Path("C:/Software/major/example/standalone/mutants.log")
source_code = Path("C:/Software/major/example/standalone/triangle/Triangle.java")
target_dir = Path("C:/Software/major/example/standalone/mutants")

def extract_mutation_info(mutants_log:Path):
    """
    提取出后面还原要用到的mutation信息：变异算子类型，变异前的组件，变异后的组件
    返回类型是一个List,其中每个元素是一个字典，字典的三个key分别是mutOp,mutate_line,source_comp,target_comp
    example 1:1:ROR:<=(int,int):<(int,int):triangle.Triangle@classify(int,int,int):14:a <= 0 |==> a < 0
    example 2:18:STD:<RETURN>:<NO-OP>:triangle.Triangle@classify(int,int,int):15:return TriangleType.INVALID; |==> <NO-OP>
    """
    mutation_info_list = []
    with open(mutants_log,'r') as f:
        for line in f:
            mutation_info = {}
            mutation_info['mutOp'] = line.split(':')[1]
            mutation_info['mutate_line'] = int(line.split(':')[-2])
            components = line.split(':')[-1]
            # 使用正则表达式匹配模式
            match = re.search(r'(.+?)\s*\|==>\s*(.+)', components)
            if match:
                mutation_info['source_comp'] = match.group(1).strip()
                mutation_info['target_comp'] = match.group(2).strip()
            else:
                raise Exception("Error: mutation log format error!")
            mutation_info_list.append(mutation_info)
    return mutation_info_list
    
def main():
    base_name = str(source_code).split('\\')[-1].split('.')[0] # get the class name
    mutation_info_list = extract_mutation_info(mutants_log)
    # print(f"将产生{len(mutation_info_list)}个变异体")
    source_code_lines = []
    with open(source_code,'r') as f:
        source_code_lines = f.readlines()
    for i,mutation_info in enumerate(mutation_info_list):
        # 从1开始计数
        mutant_id = i+1
        mutate_line = mutation_info['mutate_line']
        mutOp = mutation_info['mutOp']
        source_comp = mutation_info['source_comp']
        target_comp = mutation_info['target_comp']
        if source_code_lines[mutate_line-1].find(source_comp) == -1:
            raise Exception("Error: can't find source component!")
        if mutOp == 'STD' and target_comp != '<NO-OP>':
            raise Exception("Error: mutation log STD type error!")
        file_name = f"{base_name}_{mutant_id}.java"
        target_file = target_dir / file_name
        with open(target_file,'w') as f:
            for line in source_code_lines:
                if source_code_lines.index(line)+1 == mutate_line:
                    if mutOp == 'STD':
                        line = line.replace(source_comp,'')
                    else:
                        line = line.replace(source_comp,target_comp)
                f.write(line)

if __name__ == "__main__":
    main()