Embedded development: tips and techniques -- the best practice of defensive programming with C

　　 Best practices are fundamental to every firmware application 、 Basic practice . Defensive programming has always been an important software skill . Here are some uses that embedded developers should keep in mind C Best practices for defensive programming ：

　　

 

　　l Check the input and output of the function

　　l Check the return value of the function ( They are often ignored !)

　　l Monitor the buffer to prevent overflow

　　l Verify that the pointer is not empty , Especially function pointers

　　l Use assertion macros to detect errors rather than error conditions

　　l 2–3% The code of should be assertions

　　l Assert that the state of the system should not be modified

　　l Only expose data and functions that large programs need to know ( encapsulation )

　　l Perform static analysis during the build

　　l Monitor whether the stack overflows

　　l Use known mode 、ISR Vector or stop Instruction fills unused ROM

　　l The watchdog system should be integrated , Don't spoil the watchdog blindly

　　 Embedded developers follow these simple best practices to help ensure improved firmware quality , This is the first step in developing security firmware .