Re: Makefile to Makefile.am

[John Calcote]

 On 8/14/2010 7:09 PM, samson.pierre wrote:
>
> Yes it works :-)
>
> But I see a little warning when I call autoreconf :
> `%'-style pattern rules are a GNU make extension
>
> I think it is because I use this character ‘%’ in my rules. But this ‘%’ is 
> very interesting to define an implicit rules.
>
> Is there an equivalent or anything else which can help me to write this rule 
> avoiding this warning message?

The use of % in rules is indeed a GNU make extension. This is called a
pattern rule. Pattern rules in GNU make should be used in place of older
style suffix rules which use asterisk (*) to define the stem of a
wildcard pattern. The difference is that pattern rule patterns can
define general file matching patterns (e.g., a%de.o) , whereas suffix
rules can only define patterns that match files with a particular
extension (e.g., *.txt).

The warning you're seeing is harmless enough on platforms that support
GNU make. The purpose of the warning is to let you know that your users
will not be able to build your project on systems that support the
Autotools, but do not support GNU make (not many these days).

Regards,
John