Re: problem with ifelse

[Vincent Torri]

> > Here is an example of use:
> >
> > want_ecore_win32="no"
> > ECORE_CHECK_MODULE([Win32], [${want_ecore_win32}], [yes],
> >   [ecore_win32_libs="-lole32 -lgdi32"])
>
> Bingo.  You are attempting to mix a shell variable ${want_ecore_win32}
> (expanded at ./configure time) with an m4 argument $2 (expanded at
> autoconf time).  That won't work.  You have to make a decision - either
> the code is statically determined at autoconf time (in other words, you
> pass a literal "yes" or "no" as the second argument), or you have to emit
> both option choices and emit a shell conditional (AS_IF or even
> if...then...fi) to choose the right code path at configure time.  The
> reason your code is always selecting the false path is becase
> "${want_ecore_win32}" is not identical to "no" during m4 expansion at
> autoconf time, and m4 has no way to predict what value that shell variable
> will later have at configure time.

haaa, i understand ! And indeed, i used if / then / else and it worked, 
but i wanted to understand why ifelse (or m4_if) does not work. Now i see 
the problem and it's actually obvious when we know it :p

As the value of want_ecore_win32 changes acoording to the host, i think 
I'll have to use AS_IF or if / then /else. Which one is better ?

Vincent Torri