Re: [boost] [1.35] what gets built and installed?

From: Vladimir Prus (ghost_at_[hidden])
Date: 2007-12-19 15:10:34

dherring_at_[hidden] wrote:

> On Wed, 19 Dec 2007, Vladimir Prus wrote:
>> John Maddock wrote:
>>> Rene Rivera wrote:
>>>> John Maddock wrote:
>>>>> If I do a:
>>>>>
>>>>> bjam stage --toolset=msvc-8.0 --with-regex
>>>>>
>>>>> Then with 1.35 I don't get any static libraries built, just the
>>>>> dll's.  Was this a deliberate change somewhere?  It's a problem
>>>>> because the default for auto-linking is to look for static rather
>>>>> than dynamic libraries.
>>>>
>>>> Yes, it was intentional
>>>> <http://article.gmane.org/gmane.comp.lib.boost.devel/168552>. We also
>>>> discussed it at one point
>>>> <http://article.gmane.org/gmane.comp.lib.boost.devel/166847>. I guess
>>>> we
>>>> should switch autolink to default to the dynamic libs?
>>>
> ...
>>> If the aim is to reduce the number of variants built, then I would
>>> suggest:
>>>
>>> Dymanic *and* static lib, as Release, multithreaded, dynamic runtime
>>> single build on Unix variants (2 build variants).
>>
>> I'd be opposed to this. How many popular projects can you name,
>> that build two variants on Linux?
> 
> Qt does something clever on Linux.  Their installed libs look like
> lrwxrwxrwx       17 libQtGui.so -> libQtGui.so.4.3.1
> lrwxrwxrwx       17 libQtGui.so.4 -> libQtGui.so.4.3.1
> lrwxrwxrwx       17 libQtGui.so.4.3 -> libQtGui.so.4.3.1
> -rwxr-xr-x  8227640 libQtGui.so.4.3.1
> -rw-r--r-- 67812225 libQtGui.so.4.3.1.debug
> 
> libQtGui.so.4.3.1 contains a special ELF section, .gnu_debuglink, that
> points the debugger to libQtGui.so.4.3.1.debug.  This way they can install
> a "multithreaded release variant", but it points gdb to a file with all
> the Dwarf information needed for a "debug variant".  Deleting that .debug
> file won't hurt people who don't use the debugger.
> 
> I haven't taken the time to figure out how they build this, but it looks
> like a worthwhile trick.

This, still, is a single variant -- release with debug symbols, where debug
symbols are then moved to a separate file. And release variant is not the
best thing to debug, due to code flow messed up, variable optimized out, and so on.

Generation of .debug file is documented at:
http://sourceware.org/gdb/current/onlinedocs/gdb_16.html#SEC154

- Volodya