The compiler is able to optimize away most of the instructions that we test,
which results in checking only the compiler support for intrinsics, and not
the assembler capability to translate SSSE3 and AVX2 instructions from assembler
into the actual binary code. This commit forces the compiler to actually emit
instructions in the assembler, which then tests binutils capability to translate
those into binary code.
Boost.Build offers better compatibility with different compilers, some of
which use different flags for changing the default visibility. This also
slightly simplifies Boost.Log Jamfile.
The auto-detection was removed in 1.62, which resulted in UDP socket-based implementation being always used. The new auto-detection verifies the presence of syslog.h and all required components it provides.
Fixes ticket #12600.
Boost.ASIO should not use compiler-based TLS unless it is allowed by the user of Boost.Log, otherwise the Boost.Log config option has no practical effect.
As a result, it becomes more probable that Boost.ASIO will be compiled with different config macros in Boost.Log and user's code. As a partial solution use
hidden visibility when building Boost.Log shared libs and ensure it uses its local copy of Boost.ASIO. Added a config test to detect support for visibility
command line option.
Also adjusted project names of other config tests to avoid possible name clashes with other libraries and Boost.Build infrastructure.
MSVC warning 4003 is now silenced on all compiler versions as apparently not only MSVC 8 is affected.
