上QQ阅读APP看书，第一时间看更新

Controlling compiler flags

The code for this recipe is available at https://github.com/dev-cafe/cmake-cookbook/tree/v1.0/chapter-01/recipe-08 and has a C++ example. The recipe is valid with CMake version 3.5 (and higher) and has been tested on GNU/Linux, macOS, and Windows.

The previous recipes showed how to probe CMake for information on the compilers and how to tune compiler optimizations for all targets in your project. The latter task is a subset of the general need to control which compiler flags are used in your project. CMake offers a lot of flexibility for adjusting or extending compiler flags and you can choose between two main approaches:

CMake treats compile options as properties of targets. Thus, one can set compile options on a per target basis, without overriding CMake defaults.
You can directly modify the CMAKE_<LANG>_FLAGS_<CONFIG> variables by using the -D CLI switch. These will affect all targets in the project and override or extend CMake defaults.

In this recipe, we will show both approaches.