Bun 的 Rust 重写审计：13000 个 unsafe 块，七成其实不必存在

# 安装 cargo-geiger
cargo install cargo-geiger

# 在项目根目录运行扫描
cargo geiger --all-features

# 统计自己代码（不含依赖）中的 unsafe 块数量
find src -name '*.rs' -exec grep -n 'unsafe' {} + | wc -l

# 列出每个文件中的 unsafe 行及行号
find src -name '*.rs' -exec grep -Hn 'unsafe' {} +

"""
unsafe_audit.py — 初筛 Rust 源码中的 unsafe 块，标记可能可移除的项

用法：
    python unsafe_audit.py /path/to/rust/project/src

输出每个 unsafe 块的位置和内部操作分类，标记"无真正 unsafe 操作"的块。
"""

import os, re, sys

TRUE_UNSAFE_PATTERNS = [
    r'\*\w+',           # 裸指针解引用，如 *ptr
    r'as\s+\*\w+',      # 转裸指针，如 as *const u8
    r'extern\s*\{',     # FFI 声明
    r'static\s+mut',    # 可变静态变量
    r'union\s+\w+',     # Union 定义
    r'unsafe\s+trait',  # unsafe trait
    r'unsafe\s+fn',     # unsafe 函数定义
]

def find_unsafe_blocks(content):
    """粗略提取 unsafe { ... } 块的内容"""
    pattern = r'unsafe\s*\{([^}]*)\}'
    return re.findall(pattern, content, re.DOTALL)

def classify_block(block_body):
    """判断块内是否包含真正的 unsafe 操作"""
    has_true_unsafe = False
    for p in TRUE_UNSAFE_PATTERNS:
        if re.search(p, block_body):
            has_true_unsafe = True
            break
    return has_true_unsafe

def audit_dir(src_dir):
    results = []
    for root, _, files in os.walk(src_dir):
        for f in files:
            if not f.endswith('.rs'):
                continue
            path = os.path.join(root, f)
            with open(path) as fh:
                content = fh.read()
            blocks = find_unsafe_blocks(content)
            for i, body in enumerate(blocks):
                is_necessary = classify_block(body)
                results.append({
                    'file': path,
                    'block_index': i,
                    'body_preview': body.strip()[:80],
                    'necessary': is_necessary,
                })
    return results

if __name__ == '__main__':
    src = sys.argv[1] if len(sys.argv) > 1 else 'src'
    results = audit_dir(src)
    removable = [r for r in results if not r['necessary']]
    necessary = [r for r in results if r['necessary']]
    print(f"总 unsafe 块: {len(results)}")
    print(f"可能可移除: {len(removable)} ({len(removable)/max(len(results),1)*100:.1f}%)")
    print(f"可能需保留: {len(necessary)} ({len(necessary)/max(len(results),1)*100:.1f}%)")
    print("\n--- 可能可移除的块 ---")
    for r in removable[:20]:
        print(f"  {r['file']} #{r['block_index']}: {r['body_preview']}")

python unsafe_audit.py ./src

// 之前：整块标 unsafe，范围过大
unsafe fn process_buffer(buf: *const u8, len: usize) -> Vec<u8> {
    let slice = unsafe { std::slice::from_raw_parts(buf, len) }; // 这行才需要 unsafe
    let mut result = Vec::with_capacity(len);                    // 这行不需要
    result.extend_from_slice(slice);                              // 这行不需要
    result
}

// 之后：unsafe 只包裹真正需要的操作
fn process_buffer(buf: *const u8, len: usize) -> Vec<u8> {
    let slice = unsafe { std::slice::from_raw_parts(buf, len) };
    let mut result = Vec::with_capacity(len);
    result.extend_from_slice(slice);
    result
}