The document discusses techniques for defensive programming including: 1. Using static analysis tools and assertions at compile time to catch errors early. 2. Treating warnings as errors and using tools like Pclint to detect issues like uninitialized variables. 3. Employing assertions to check for data integrity and function pre/postconditions, especially in alpha and debug versions. 4. Leveraging runtime analysis tools like Valgrind to detect issues not caught during compilation such as out-of-bounds memory accesses.

1. Defensive Programming

2. Summary Defensive at compile time Use Static Analysis Tools Assertion Use Runtime Analysis Tools Alpha Version

3. Failing fast Don ‘ t Work around problems Fail immediately and vis i bly Prefer compile err to runtime err Dead Programs Tell No Lies

4. W arning as error Turn on all warnings (-Wall) Turn on variable argument s check (-Wformat) Treat warning as error (-Werror) Use -isystem to ignore warnings

5. Refine define Static cast #define FLY(pBird) static_cast<CBird*>(pBird)->Eat() So FLY(pDuck); will fail Do while(0) : limit the scope of variables in define

6. Pclint Variable have not been initialized new [] / delete mismatch Access out-of-bounds

7. Pclint walker Enhanced Error description (Chinese) Only Essential Errors, without errors that compiler can check. Automatically and recursively check all project files Easily Integrated to tools (e.g. Jenkins)

8. Keys of Assertion D ata invariants that ensure data integrity Pre- and postconditions that ensure function correctness No Side effect Enable In Alpha and D ebug Version R edirect o utput on Linux, or log to file

9. Examples of Assertion MFC assert_valid Default of switch Null pointer Index of array u32 defer u8 memory in our Sybase SDK

10. Valgrind Runtime Analysis Tool More Precise new [] / delete Mismatch Access out-of-bounds Uninitialized Memory

11. Alpha Version Enable Core and Symbol -fstack-protector-all(>gcc4.1) Enable Assert, and Crash ASAP Enable Optimize Same As Release Version Enable Runtime Analysis Tool(eg. TCMalloc heapcheck)

12. Reference Code complete C hapter 8 defensive programming Code craft Chapter 1 on the defensive