Re: Conditional problem

[Ralf Corsepius]

On Fri, 2004-02-06 at 09:24, Jose Roman Bilbao wrote:
> Hi,
> 
> What is wrong with this piece of code? It always says that there is no
> OpenGL although it has been found:
> 
> #checking for OpenGL
> MDL_HAVE_OPENGL
> 
> if test -z "$GL_LIBS"
> then
>       AC_MSG_RESULT([GL libs not found, OpenGL disabled.])
> else
>       if test -z "$GL_CFLAGS"
>       then
>               AC_MSG_RESULT([GL headers not found, OpenGL disabled.])
>       else
>               AC_MSG_RESULT([OpenGL flags: $GL_CFLAGS])
>               AC_MSG_RESULT([OpenGL libs: $GL_LIBS])
>       fi
> fi
> AM_CONDITIONAL( WITH_OPENGL, test -n "$GL_FLAGS")
> AM_CONDITIONAL( WITH_OPENGL, test -n "$GL_LIBS")
The WITH_OPENGL's in these AM_CONDITIONALS are strings autoconf
internally uses to set up its magic. 

> if test x"$WITH_OPENGL" = xtrue; then
Here, you expect WITH_OPENGL to be a shell variable.

>       AC_MSG_RESULT( OpenGL)
> else
>       AC_MSG_RESULT( NO OpenGL )
> fi
> 
> I suppose it is my inexperience, I have read autoconf and automake
> manuals and still no solution. 
Have a look into your configure and search for WITH_OPENGL.

AFAIS, you are expecting WITH_OPENGL to be a shell-variable while
autoconf uses it as a string.

> Another minor question. Why do we add "x" in:
> if test x"$WITH_OPENGL" = xtrue; then

Cf. The "Limitations of Builtins" chapter in info autoconf

Ralf