Re: [boost] Build: Trying to get Boost.Build to see my OpenSSL on Windows

Subject: Re: [boost] Build: Trying to get Boost.Build to see my OpenSSL on Windows
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2016-10-01 14:09:49

AMDG

On 10/01/2016 11:30 AM, Peter Dimov wrote:
> Steven Watanabe wrote:
>> > That's incredibly inconvenient... surely this is not the recommended
>> > approach to finding library dependencies...
>>
>>
>> No it isn't.  This is really a workaround for the user when the author
>> of the Jamfile decided to be lazy.
> ...
>> A better way is to create a module like tools/zlib.jam.
> 
> Is it really fair to blame the author of the Jamfile for the lack of
> tools/ssl.jam?
> 

  No, probably not.  It should at least
allow configuration through environmental
variables, though.

> Besides, a module is probably best when we want to support building the
> library from source, but OpenSSL is pretty hard to build (and, I think,
> CMake based), so I doubt that anyone would volunteer to translate its
> build script (or, for extra fun, the build scripts for each of its
> releases).
> 

Building from source is really only viable for
simple libraries.  There are several other reasons
for writing a module:
- Configuring the library from user-config.jam is
  using ssl : [various options] ;
  which is consistent with everything else.
- The code for finding the library doesn't
  need to be duplicated if it's needed in
  multiple places.

> I don't think that the recommended approach for finding an arbitrary
> preinstalled library should be "write a module".
> 

  If there's any significant logic beyond
just lib xxx, (and possibly getting a path
from an environmental variable) I don't
think that factoring it into a separate
module is a significant extra burden.
I know that there's a fair amount of
code in zlib.jam, but most of it is error
checking, messages for --debug-configuration,
and support for building from source.

> By looking around, I can deduce that ac.check-library was probably
> intended to be the way to do that, but it doesn't appear to be documented.
> 
> BTW libtiff.jam and libjpeg.jam look for ZLIB_SOURCE. I assume this is a
> typo, because libpng.jam looks for LIBONG_SOURCE.
> 

Definitely.

> BTW2, the Asio example Jamfile does not do
> 
>    lib ssl ;
> 
> under Windows. It does
> 
>    lib ssl : : <name>ssleay32 ;
>    lib crypto : : <name>libeay32  ;
> 

In Christ,
Steven Watanabe