Hi,
Yes. I understand your point. But I would like to clear one more doubt. Is
it possible to prevent macro expansion if the key is quoted?
For example,
- getApproximateValue(MY_CUSTOM_KEY) should be converted to
getApproximateValue(50)
- getApproximateValue("MY_CUSTOM_KEY") should remain as
getApproximateValue("MY_CUSTOM_KEY")
Thanks,
Nidhin
On Fri, Apr 29, 2016 at 8:36 PM, Eric Blake <[email protected]> wrote:
> On 04/29/2016 08:56 AM, Nidhin Joseph wrote:
> > Hi,
> > I'm stuck with a doubt regarding M4 usage. I want M4 to identify quoted
> > strings and replace the quotes along with the key.
> >
> > For example,
> > I have a definition inside .m4 file as
> > define_m4(MY_CUSTOM_KEY, 50 );
> >
> > And now in my source file, I have two funtion calls
> > getApproximateValue(MY_CUSTOM_KEY);
> > getApproximateValue("MY_CUSTOM_KEY");
> >
> > After running M4, what I'm expecting is
> > getApproximateValue(50);
> > getApproximateValue(50); //replace the quotes also
>
> The only way to also replace the quotes is if the quotes are part of the
> macro name (perhaps possible with the unreleased 2.0 branch of m4
> playing games with syntax definitions of what makes a macro, but you'd
> still have to define two macros, one named MY_CUSTOM_KEY and one named
> "MY_CUSTOM_KEY", and it still won't help you if there is any whitespace
> in the string alongside MY_CUSTOM_KEY).
>
> It would also be possible to write an m4 macro named
> getApproximateValue() that can do conditional things to its body (if the
> body appears unquoted, keep it unquoted; if the body appears quoted,
> then strip those quotes), but that's a new macro getApproximateValue()
> and not something you can do with your existing MY_CUSTOM_KEY macro.
>
>
> > But what I'm getting is simple macro expansion as shown below.
> > getApproximateValue(50);
> > getApproximateValue("50")
>
> Indeed, that's all the more M4 is really capable of - expanding a macro
> CANNOT affect the text that was contextually outside the bounds of the
> macro name or () argument list.
>
> >
> > I understand, M4 is working as expected. Could you please help me to know
> > whether my requirement is achievable without modifying the .M4 definition
> > file?
>
> I'm coming up blank; looks like you'll have to modify your .M4
> definition file.
>
>
> --
> Eric Blake eblake redhat com +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
>
>
--
*-Nidhin Joseph*
