On Sat, Oct 3, 2015 at 9:44 AM, Sandra Loosemore <san...@codesourcery.com> wrote: > On 10/03/2015 06:47 AM, Jonathan Wakely wrote: >> >> https://gcc.gnu.org/onlinedocs/gcc/Template-Instantiation.html >> currently says that using -frepo "is your best option for application >> code written for the Borland model, as it just works." >> >> That was true at one point, but as can be seen from the mentions of >> binutils 2.8 and Solaris 2, the information there is pretty old. >> >> Since then -frepo has bitrotted occasionally, and it's much simpler to >> rely on implicit instantiations in COMDAT sections, controlling >> specific instantiations with explicit instantiations if needed (using >> 'extern template' which was standardised in C++11). >> >> See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51910#c2 for an >> example of bitrot (now fixed) and people being persuaded by the docs >> that -frepo is the best option. >> >> So this revises the docs, to downplay the usefulness of -frepo, >> and to endorse the "do nothing" model (with selective explicit >> instantations as needed). >> >> It also changes another mention of -frepo to use a different C++-only >> option, to further de-emphasize -frepo. >> >> OK for trunk? > > > Thanks for tackling this. I remember thinking that this section looked > bit-rotted when I was reviewing the manual earlier this year. Your patch > looks like a step in the right direction, but can I get you to fix a couple > other things while you're at it? > > First, I think the reference to ancient ld versions is confusing, and it > would be better to rewrite that to emphasize that this is the default > behavior on most targets. (I'd guess that anybody trying to use a recent > GCC release with an ld version from 1996 is going to run into more critical > blocking issues than this one.) Maybe something like: > > "G++ implements the Borland model on targets where the linker supports it, > including both ELF targets (such as GNU/Linux) and Microsoft Windows. > Otherwise G++ implements neither automatic model."
Add "And Mac OS X" to that too. So people don't use that against us for the reason why Apple went to clang/LLVM. Thanks, Andrew > > Second, if "Do nothing" is now the recommended way to handle this, let's > move that option to the front of the itemized list instead of the end. Also, > I'm confused by the "pretend" here; can we just delete that sentence? > > -Sandra >
