Introduction

Although CMake is cross-platform and in our projects we strive for the source code to be portable across platforms, operating systems, and compilers, sometimes the source code is not fully portable; for example, when using vendor-dependent extensions, we may find it necessary to configure and/or build code slightly differently depending on the platform. This is particularly relevant for legacy code or when cross-compiling, a topic we will return to in Chapter 13, Alternative Generators and Cross-compilation. It can also be advantageous to know the processor instruction set to optimize performance for a specific target platform. This chapter presents recipes to detect such environments and provides recommendations for how to implement such solutions.