codeblocks17.12的BUG真的多，刚刚遇到一个开启O3优化不其作用的问题，原因是我看到了图中1处有个O3，我就给开启了。

结果发现根本没有优化。

仔细观察编译log之后发现：

这是1的：

-------------- Build file: "no target" in "no project" (compiler: unknown)---------------

mingw32-g++.exe   -c C:\Users\fz\Desktop\A.cpp -o C:\Users\fz\Desktop\A.o
mingw32-g++.exe  -o C:\Users\fz\Desktop\A.exe C:\Users\fz\Desktop\A.o  -O3  
Process terminated with status 0 (0 minute(s), 0 second(s))
0 error(s), 0 warning(s) (0 minute(s), 0 second(s))

Checking for existence: C:\Users\fz\Desktop\A.exe
Executing: '"C:\Program Files (x86)\CodeBlocks/cb_console_runner.exe" "C:\Users\fz\Desktop\A.exe"' (in 'C:\Users\fz\Desktop')

这是2的：

-------------- Build file: "no target" in "no project" (compiler: unknown)---------------

mingw32-g++.exe -O3  -c C:\Users\fz\Desktop\A.cpp -o C:\Users\fz\Desktop\A.o
mingw32-g++.exe  -o C:\Users\fz\Desktop\A.exe C:\Users\fz\Desktop\A.o   
Process terminated with status 0 (0 minute(s), 0 second(s))
0 error(s), 0 warning(s) (0 minute(s), 0 second(s))

Checking for existence: C:\Users\fz\Desktop\A.exe
Executing: '"C:\Program Files (x86)\CodeBlocks/cb_console_runner.exe" "C:\Users\fz\Desktop\A.exe"' (in 'C:\Users\fz\Desktop')

观察后发现1是对链接过程进行O3，那自然是没有什么作用的了！