Question

我对此事感到难过：

recorders/r5000device.cpp: In function ‘unsigned int r5000_device_tspacket_handler(unsigned char*, int, void*)’:
recorders/r5000device.cpp:34:14: warning: no previous declaration for ‘unsigned int r5000_device_tspacket_handler(unsigned char*, int, void*)’ [-Wmissing-declarations]
 unsigned int r5000_device_tspacket_handler(unsigned char *tspacket, int len, void *callback_data)
          ^
recorders/r5000device.cpp: In function ‘void r5000_msg(char*)’:
recorders/r5000device.cpp:44:6: warning: no previous declaration for ‘void r5000_msg(char*)’ [-Wmissing-declarations]
 void r5000_msg(char * msg)
  ^

Answer 1

您已设置编译标志 -Wmissing-declarations 。编译器希望查看所有函数的声明（原型 - 通常在标题中）。只需添加缺少的标题或在文件顶部声明原型。

Answer 2

C ++中的自由函数需要在头文件中声明，也需要在.cpp文件中定义。 How do you define a global function in C++?

警告：没有以前的声明 - C ++

2 个答案: