Re: [release] Boost 1.85.0 Release Candidate 1 is available.

From: Rainer Deyke (rdeyke_at_[hidden])
Date: 2024-03-12 12:17:15

On 12.03.24 11:11, Peter Dimov via Boost wrote:
> Rainer Deyke wrote:
>> I am trying to produce portable binaries while using modern C++, so my policy
>> is this:
>>     - Compile on a Docker image with an older OS installed (currently Ubuntu
>> 16.04 LTS) so that I can link to an older libc.
>>     - Build my own compiler (currently gcc 13.2.0) instead of relying on the OS
>> package manager.  This means libraries are installed in
>> /usr/local/lib64 instead of /usr/lib.
>>     - Statically link everything except libc, including libstdc++ (by setting
>> CXXFLAGS=-static-libstdc++).
>>     - Deliberately don't point LD_LIBRARY_PATH to /usr/local/lib64, because
>> these libraries won't exist on the target system and should only be statically
>> linked.
>>
>> The problem is that while tools/build/src/engine/build.sh respects CXXFLAGS,
>> bootstrap.sh deliberately clobbers CXXFLAGS from the environment, so b2 is
>> built dynamically linked to a version of libstdc++ that it can't find at runtime.
> 
> You should use the --cxxflags option.

That would work for tools/build/src/engine/build.sh, but bootstrap.sh 
neither understands that argument nor passes it along to build.sh.

Anyway, now that I understand the problem, it's not hard to work around 
it by setting LD_LIBRARY_PATH just for while I'm building Boost.  I 
managed to successfully build the subset of Boost that I am interested 
in, although I did get a warning about undefined behavior:

In file included from libs/container/src/dlmalloc_ext_2_8_6.c:52,
                  from libs/container/src/alloc_lib.c:24:
In function ‘internal_multialloc_arrays’,
     inlined from ‘boost_cont_multialloc_arrays’ at 
libs/container/src/dlmalloc_ext_2_8_6.c:1112:13:
libs/container/src/dlmalloc_ext_2_8_6.c:1085:41: warning: iteration 
2305843009213693951 invokes undefined behavior 
[-Waggressive-loop-optimizations]
  1085 |                size = request2size(sizes[i]*element_size);
       |                                         ^
libs/container/src/dlmalloc_2_8_6.c:2231:6: note: in definition of macro 
‘request2size’
  2231 |   (((req) < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(req))
       |      ^~~
libs/container/src/dlmalloc_ext_2_8_6.c:1083:24: note: within this loop
  1083 |             for(++i; i != next_i; ++i) {
       |                      ~~^~~~~~~~~

-- 
Rainer Deyke (rainerd_at_[hidden])