__attribute__ ((cleanup(xxx))) -- gcc extension

本文介绍在C中如何通过GCC扩展__attribute__((cleanup()))来实现类似C++智能指针的功能,当变量离开其作用域时自动销毁内存。
在C中如何实现C++中smart pointer的部分功能,即当变量离开它作用域时自动destroy/free?在Linux下,可以使用gcc的扩展__attribute__ ((cleanup(xxx))) 。
举例,
#define local_type  __attribute__ ((cleanup(my_free)))

static void my_free(void* pmem)
{
  void** ppmem = (void**) pmem;
  free(*ppmem);
}

int foo(void)
{
  local_type int* p = (int*) malloc(sizeof(int));
  //
  // use *p
  // when return, the memory block pointed by p is freed automatically
  return 0;
}
-- Performing Test HAVE_GCC_THREAD_LOCAL_STORAGE -- Performing Test HAVE_GCC_THREAD_LOCAL_STORAGE - Success -- Performing Test HAVE_MSC_THREAD_LOCAL_STORAGE -- Performing Test HAVE_MSC_THREAD_LOCAL_STORAGE - Failed -- Performing Test HAVE_CONSTRUCTOR_ATTRIBUTE -- Performing Test HAVE_CONSTRUCTOR_ATTRIBUTE - Failed -- Performing Test HAVE_DESTRUCTOR_ATTRIBUTE -- Performing Test HAVE_DESTRUCTOR_ATTRIBUTE - Failed -- Performing Test HAVE_FALLTHROUGH_ATTRIBUTE -- Performing Test HAVE_FALLTHROUGH_ATTRIBUTE - Failed -- Performing Test HAVE_GCC_VOLATILE_MEMORY_PROTECTION -- Performing Test HAVE_GCC_VOLATILE_MEMORY_PROTECTION - Failed -- Performing Test HAVE_GCC_NARG_MACRO -- Performing Test HAVE_GCC_NARG_MACRO - Failed -- Performing Test HAVE_COMPILER__FUNC__ -- Performing Test HAVE_COMPILER__FUNC__ - Failed -- Performing Test HAVE_COMPILER__FUNCTION__ -- Performing Test HAVE_COMPILER__FUNCTION__ - Failed -- Performing Test HAVE_GCC_BOUNDED_ATTRIBUTE -- Performing Test HAVE_GCC_BOUNDED_ATTRIBUTE - Failed -- Performing Test HAVE_LD_VERSION_SCRIPT -- Performing Test HAVE_LD_VERSION_SCRIPT - Failed -- Check if the system is big endian -- Searching 16 bit integer -- Looking for sys/types.h -- Looking for sys/types.h - not found -- Looking for stddef.h -- Looking for stddef.h - not found -- Check size of unsigned short -- Check size of unsigned short - failed -- Check size of unsigned int -- Check size of unsigned int - failed -- Check size of unsigned long -- Check size of unsigned long - failed CMake Error at /usr/share/cmake-3.5/Modules/TestBigEndian.cmake:51 (message): no suitable type found Call Stack (most recent call first): ConfigureChecks.cmake:417 (test_big_endian) CMakeLists.txt:98 (include) -- Configuring incomplete, errors occurred! See also "/home/bba/work/BBA1_5/MBB_Platform/apps/public/libssh/build/CMakeFiles/CMakeOutput.log". See also "/home/bba/work/BBA1_5/MBB_Platform/apps/public/libssh/build/CMakeFiles/CMakeError.log". make/apps/pubapps/libssh.mk:9: recipe for target 'libssh' failed make: *** [libssh] Error 1
最新发布
10-08
评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值