Re: [Doxygen-users] Documenting macro which are not defined in the code

[Edward D. <eld...@tr...>]

On 4/26/2016 8:04 AM, Richard Damon wrote:
> On 4/26/16 3:37 AM, Edward Diener wrote:
>> In my library there are is a macro which, if defined at all by the
>> end-user, changes the way the code works. I want to include this macro
>> in the doxygen documentation to my library. So I add the doxygen comments:
>>
>> /** @file some_header.hpp
>>       @brief Some brief file description.
>>
>>       Some longer file description.
>> */
>>
>> /** @def MYLIB_SOME_MACRO
>>       @brief When this macro is defined at all, changes the way that xxx
>> works.
>>
>>       When this macro is defined at all xxx works in such and such way
>>       whereas when this macro is not defined xxx works in so and so way.
>> */
>>
>> Unfortunately because the macro itself is never actually defined in any
>> header, when I run doxygen I get output such as:
>>
>> Somepath/some_header.hpp:7: warning: documentation for unknown define
>> MYLIB_SOME_MACRO found.
>>
>> In other words even though I want to include the documentation for the
>> MYLIB_SOME_MACRO macro in my doxygen documentation it is rejected
>> because the macro is never actually defined in any of the source files
>> which doxygen parses.
>>
>> is there any way to tell doxygen to include the doxygen comments for the
>> macro in its documentation even though the macro is not actually defined
>> anywhere ?
>>
>>
> You can include a definition of the macro surrounded by an ifdef guard
> that won't be defined in normal compilation, but will be defined in your
> doxygen config file. Then Doxygen will see that definition and document
> it. I sometimes use the macro DOXYGEN for this. Something like:
>
> #ifdef DOXYGEN
> #define MYLIB_SOME_MACRO
> #endif

Thanks ! That works well.