makefile - define gets ignored by target_compile_definitions

Question

I am looking to build a library and I need to pass two defines to that build, but cmake's target_compile_definitions() scrambles them in a manner that renders them unusable.

The two defines are:

• -D'_LIB_EXCEPTION_ABI=__attribute__((visibility("default")))'
• -D'_LIB_FALLTHROUGH()=((void)0)'

Unfortunately, the first one gets translated to (in the command build line):

• -D'_LIB_EXCEPTION_ABI="\__attribute__((visibility("default")))'"

While the second one is missing altogether from the command line.

Answer 1

CMake has known limitations on what compile definitions could be.

Among these limitations are function-style definitions (_LIB_FALLTHROUGH()) and ones containing double quotes (").

Instead of attempting to overcome these limitations, it is recommended to create a separate header file with these compile definitions:

#define _LIB_EXCEPTION_ABI __attribute__((visibility("default")))
#define _LIB_FALLTHROUGH() ((void)0)

This header file could be included with -include compiler option (gcc) or /FI option (Visual Studio).