Re: Turn off C compiler warnings in automake

[Alex Vong]

於 二，2015-06-30 於 09:37 +0200，Thomas Jahns 提到：
> On 06/29/15 17:31, Alex Vong wrote:
> > Thanks for telling me there is no portable flag for doing so.
> > I am now using AC_SUBST() to set the value of STREAM and append `
> > $(STREAM)>/dev/null' to every make command. If the user configure with
> > --enable-verbose-compiler, then STREAM will be set to 0, otherwise
> > STREAM will be set to 2. This keeps the flexibility. Does it sound
> > reasonable?
> 
> I'm not sure if an output redirection on stdin is portable. But I think given 
> the way you are going about this you could easily set a Makefile variable to 
> the 
> full redirection (or none), i.e. lose the >/dev/null and instead make STREAM 
> be 
> either '2>/dev/null' or the empty string ''?
> 
> Regards, Thomas
Hi Thomas,
I tried substituting `2>/dev/null' before but without success. However,
I try again just now and find out that if I add a pair of single quotes,
then it will work just fine. In short, the following code will work

AS_IF([test "x$enable_verbose_compiler" != "xyes"],
[AC_SUBST([REDIRECTION], ['2>/dev/null'])]
)

Thanks for the suggestion!

Cheers,
Alex