Re: AX_BOOST_BASE

[Peter Johansson]

Hi Marcin,

On 11/05/2013 01:36 AM, Marcin Zalewski wrote:
> Peter,

I should start saying I'm neither the writer of AX_BBOST_BASE nor the 
maintainer, but your emailed just made me curious.

> I get a syntax error from expr.

It's always preferable if you copy & paste the error the error message 
you experience.

> The problem is that currently the
> script tries to figure out the version of boost in BOOST_ROOT from the
> directory name in BOOST_ROOT. This works only if boost root is in a
> standard directory name (e.g., boost_1_53_0). I have a client who
> wants to use his unstaged boost that he has in a non-standard
> directory.

Makes sense and I agree looking for version info in 'version.hpp' is 
better like you patch does.

> The reason I am ending up in this region of code is that there is no
> system-wide boost that meets the version requirement. I have
> recommended to my client that he use BOOST_ROOT for his unstaged boost
> (for some reason my client does not want to install the unstaged
> version of his boost library in his home directory).

I asked because you mentioned that you use '--with-boost' and I assumed 
you used it with some argument such as '--with-boost=/my/path/to/boost'. 
IIUC, using '--with-boost' like that will set $as_boost_path and

test "$ac_boost_path" != ""

on line 162 will be true and you will never get into the else clause 
that involves your patch. I realize now that you probably use 
'--with-boost' with no argument in which case $ac_boost_path is not set 
and you could end up in the the patched code

 FWIW, using --with-boost has no effect, i.e., './configure 
--with-boost' should be synonymous to './configure'.

> So, it seems that the version checking for BOOST_ROOT case makes a lot
> of assumptions. An even more problematic issue is the difficulty of
> using unstaged boost, but that would be a bigger patch.

I agree. Most of the boost macros would probably benefit from being 
revised, to reduce number of assumptions and make the shell code more 
portable.

Cheers,
Peter