I'm trying to compile my test program with various GCC optimizations options and I'd like to see all of them in the program output. Something like that (the __cpp_optimizations constant is invented for this question):
std::cout << __cpp_optimizations << std::endl;
Is it any way to do that?
Get the compiler options from a compiled executable? . Compile with -frecord-gcc-switches than read the command line options from the executable, in pseudocode:
buf = popen(std::string() + "readelf -p .GCC.command.line /proc/self/exe").read()
// or read elf yourself instead of popen
// tokenize buf, get all compiler options
// filter out only optimization options
Alternatively, you could instruct your build system to pass that information as a macro. For example, in CMake:
add_compile_options(-O3)
add_compile_definitions("CPP_OPTIMIZATIONS=\"-O3\"")