[ hmf. This one got lost to an smtp error when I sent it yesterday. It appears there's more or less agreement that at the moment you're supposed to manually annotate all external entry points if you want to use -fwhole-program on a library. On windows, where we often do that anyway, it looks like it would make a great deal of sense to infer externally_visible from dllexport. ]
On 17/05/2010 19:26, Dave Korn wrote: > On 17/05/2010 18:57, Toon Moene wrote: >> On 05/17/2010 08:08 PM, Dave Korn wrote: >>> Hi! >>> >>> PR42904 is a bug where, when compiling a windows DLL using >>> -fwhole-program, >>> the compiler optimises away the entire library body, because there's no >>> dependency chain related to 'main' to anchor it. >> Aren't "shared library" and "whole program" mutually exclusive concepts ? >> >> The mere fact that you are building a library means that it cannot be >> the whole program, and because a shared library cannot be determined to >> have being used by any fixed program, by definition cannot be "the whole >> program". >> >> Or so I'd think. > > Well, indeed that is strictly the case, but a shared library is also a > self-contained bundle of dependencies, and if all the externally visible > functions were treated as roots like 'main', I would have thought > -fwhole-program could usefully do its thing. So I wondered if anyone had > thought about making it work. (I guess the PR should be treated as an > enhancement request.) > > cheers, > DaveK
