To be used around code where some compiler, in some circumstances,
generates bogus warnings about unreachable code, that it would be much
uglier to work around otherwise.
Specifically, I will at first now use this to get rid of MSVC warnings
about unreachable code when calling a function defined in another
source file (but going into the same library) that always throws. The
compiler notices this when one uses link-time code generation and it
thus can do global inlining of code from all compilation units that go
into a library (or executable).
For MSVC, the __pragma that the SAL_WNOUNREACHABLE_CODE_PUSH macro
expands to needs to be in force at the start curly brace of a
function, so place the PUSH macro before the function definition. For
clarity, I guess it is best that the corresponding POP macro comes
after the end of the function.
Change-Id: Icef5259c5360b9facdc136fec1f207665ce79d90
The warn_unused attribute has been upstream to GCC and Clang, so use it if present.
Still warn about STL types if those do not use it yet (which is the status as of now).
Change-Id: I3c003e44c08d1d141e23bba38cf92e663a5ac353
