Re: [PATCH iproute2] build: Fix link errors on some systems

[Roi Dayan <roid@nvidia.com>]

On 2021-01-06 3:16 PM, Petr Machata wrote:
> 
> Roi Dayan <roid@nvidia.com> writes:
> 
>> On 2021-01-06 10:42 AM, Roi Dayan wrote:
>>>
>>> On 2021-01-04 6:07 PM, Petr Machata wrote:
>>>>
>>>> I think that just adding an unnecessary -lm is more of a tidiness issue
>>>> than anything else. One way to avoid it is to split the -lm deps out
>>>> from util.c / json_print.c to like util_math.c / json_print_math.c. That
>>>> way they will be in an .o of their own, and won't be linked in unless
>>>> the binary in question needs the code. Then the binaries that do call it
>>>> can keep on linking in -lm like they did so far.
>>>>
>>>> Thoughts?
>>>>
>>> ok fine by me.
>>
>> I looked at this and for get_size()/rate/.. it went smooth.
>> but for print_color_size() there is an issue that it uses
>> _IS_JSON_CONTEXT and statuic *_jw which are defined in json_print.c
>> Is it ok to expose those in json_print.h now so json_print_math.c
>> could use?
> 
> You don't need json_print_math.h IMHO, it can all be backed by the same
> header, just different implementation modules. From the API point of
> view, I don't think the user should really care which of the symbols use
> math (though of course they will have to know whether to link in -lm).

right ok.

> 
> Regarding the publishing, the _jw reference can be changed to a call to
> is_json_context(), which does the same thing. Then _jw can stay private
> in json_print.c.
> 
> Exposing an _IS_JSON_CONTEXT / _IS_FP_CONTEXT might be odd on account of
> the initial underscore, but since it's only used in implementations,
> maybe it's OK?
> 

With is_json_context() I cannot check the type passed by the caller.
i.e. PRINT_JSON, PRINT_FP, PRINT_ANY.

 From what I see now callers use is_json_context() to decide which print
to use. but in print_color_size() I should check the type to decide
which print.