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From c
C语言内存管理规范，涵盖malloc/free安全分配模式、内存泄漏检测（Valgrind/AddressSanitizer）、内存对齐、内存池、RAII-like自动释放宏。适用于内存分配、泄漏调试、缓存优化。
npx claudepluginhub lazygophers/ccplugin --plugin cHow this skill is triggered — by the user, by Claude, or both
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/c:memorysonnetThe summary Claude sees in its skill listing — used to decide when to auto-load this skill
- **dev** - 实现内存分配和数据结构
Use when managing memory in C programs with malloc/free, pointers, and avoiding common memory safety pitfalls.
Detects function-local misuse of memory and resource APIs in C, C++, and Rust unsafe — unchecked allocations, double-frees, uninitialized locks, and fd leaks across exec. Use when writing or reviewing low-level code that calls malloc, mmap, pthread_mutex, fopen, or raw FFI pointer APIs.
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| 场景 | Skill | 说明 |
|---|---|---|
| 核心规范 | Skills(c:core) | C11/C17 标准、编码约定 |
| 并发编程 | Skills(c:concurrency) | 线程安全分配、原子操作 |
| 错误处理 | Skills(c:error) | 分配失败的错误处理 |
| AI 理性化 | 实际检查 |
|---|---|
| "不检查 malloc 没事" | 所有分配是否检查了返回值？ |
| "free 后不用置 NULL" | 是否有 use-after-free 风险？ |
| "realloc 直接赋值原指针" | 失败时原指针是否丢失？ |
| "Valgrind 太慢不用跑" | 是否有其他内存检查？ |
| "栈上分配就安全" | VLA 是否可能栈溢出？ |
| "aligned_alloc 不需要" | 是否有 SIMD 或缓存行对齐需求？ |
// malloc：未初始化内存
int* arr = malloc(n * sizeof(*arr)); // 使用 sizeof(*ptr) 而非 sizeof(type)
if (arr == NULL) {
perror("malloc");
goto cleanup;
}
// calloc：零初始化，自动处理溢出检查
int* arr = calloc(n, sizeof(*arr));
if (arr == NULL) {
perror("calloc");
goto cleanup;
}
// realloc：必须用临时指针
int* tmp = realloc(arr, new_count * sizeof(*arr));
if (tmp == NULL) {
perror("realloc");
// arr 仍然有效，需要 free
goto cleanup;
}
arr = tmp;
free(arr);
arr = NULL; // 防止 use-after-free 和 double-free
#define AUTO_FREE __attribute__((cleanup(auto_free_ptr)))
static inline void auto_free_ptr(void* p) {
free(*(void**)p);
}
void example(void) {
AUTO_FREE char* buf = malloc(256);
if (buf == NULL) return;
// buf 在作用域结束时自动 free
}
// C11 aligned_alloc（大小必须是对齐的整数倍）
void* buf = aligned_alloc(64, 1024); // 64 字节对齐
// POSIX posix_memalign
void* buf = NULL;
if (posix_memalign(&buf, 64, 1024) != 0) {
perror("posix_memalign");
}
// 结构体对齐
_Alignas(64) struct CacheLine {
int data[16];
};
// 检查对齐
static_assert(_Alignof(struct CacheLine) == 64, "cache line alignment");
typedef struct MemPool {
uint8_t* base; // 池内存基地址
size_t capacity; // 总容量
size_t used; // 已使用
} MemPool;
MemPool* mempool_create(size_t capacity) {
MemPool* pool = malloc(sizeof(MemPool));
if (pool == NULL) return NULL;
pool->base = malloc(capacity);
if (pool->base == NULL) { free(pool); return NULL; }
pool->capacity = capacity;
pool->used = 0;
return pool;
}
void* mempool_alloc(MemPool* pool, size_t size) {
// 对齐到 8 字节
size = (size + 7) & ~(size_t)7;
if (pool->used + size > pool->capacity) return NULL;
void* ptr = pool->base + pool->used;
pool->used += size;
return ptr;
}
void mempool_destroy(MemPool* pool) {
if (pool) { free(pool->base); free(pool); }
}
# Valgrind 全面检查
valgrind --leak-check=full --show-leak-kinds=all \
--track-origins=yes --error-exitcode=1 ./program
# AddressSanitizer（编译时）
gcc -std=c17 -fsanitize=address -fno-omit-frame-pointer -g program.c -o program
# MemorySanitizer（检测未初始化内存读取，仅 Clang）
clang -std=c17 -fsanitize=memory -fno-omit-frame-pointer -g program.c -o program
sizeof(*ptr) 而非 sizeof(Type)