[libcpp] patch: add used callback

[Basile STARYNKEVITCH]

Arnaud Charlet wrote:
> 
> BTW, here is an updated patch, using the proper source location for the
> macro reference (use pfile->invocation_location instead of
> pfile->directive_line which gives the line of the last cpp directive,
> not very useful in this context).
I would still like a plugin hook here.

> Maybe I could make it clearer that this callback does not get called
> for define/undef in the cpplib.h comment?
Yes please

> 
> What about this patch?
> 
> --
> Index: macro.c
> ===================================================================
> --- macro.c     (revision 153897)
> +++ macro.c     (working copy)
> @@ -885,6 +885,9 @@ enter_macro_context (cpp_reader *pfile, 
>             pfile->cb.used_define (pfile, pfile->directive_line, node);
>         }
>  
> +      if (pfile->cb.used)
> +       pfile->cb.used (pfile, pfile->invocation_location, node);
> +
>        macro->used = 1;

Perhaps something like
          invoke_plugin_callbacks (PLUGIN_EXPAND_MACRO, node);
would be useful at this place (e.g. for a plugin doing metrics on macro expansions)?
[I am not sure to get it right; I don't understand a lot libcpp]

>  
>        if (macro->paramc == 0)
> Index: include/cpplib.h
> ===================================================================
> --- include/cpplib.h    (revision 153897)
> +++ include/cpplib.h    (working copy)
> @@ -508,6 +508,10 @@ struct cpp_callbacks
>    /* Called before #define and #undef or other macro definition
>       changes are processed.  */
>    void (*before_define) (cpp_reader *);
> +  /* Called whenever a macro is expanded or tested.
> +     Note: this callback is not called when a #define/#undef directive is
> +     processed, consider used_define or used_undef instead.  */
> +  void (*used) (cpp_reader *, unsigned int, cpp_hashnode *);
>  };

If a plugin event gets added for macro expansions, please add a comment refering to it here.

Regards.


-- 
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