4.6.7.2 dM: Macro Debugging Dump

The -dM option used in conjunction with the -E option dumps a list of all defined macros. Normal compilation does not take place.

The list of macros will include any macro defined in the C source using a #define directive, any defined on the command-line using a -D option, as well as any predefined by the compiler. Each macro will be printed as a #define directive that would define the macro and its value.

If the -E option is not used, the -dM option is ignored.