On Sun, Feb 23, 2020 at 7:58 AM Pierre Labastie via lfs-dev <[email protected]> wrote: > > Le 23/02/2020 à 07:21, Pierre Labastie via lfs-dev a écrit : > > Le 23/02/2020 à 00:33, Tadeus Prastowo via lfs-dev a écrit : > >> On Sat, Feb 22, 2020 at 11:10 PM Pierre Labastie via lfs-dev > >> <[email protected]> wrote: > >>> > >>> Le 22/02/2020 à 18:33, Tadeus Prastowo via lfs-dev a écrit : > >>>> On Sat, Feb 22, 2020 at 6:17 PM Douglas R. Reno via lfs-dev > >>>> <[email protected]> wrote: > >>>>> If we're going off an 'svn blame', it was done at r10226. That would've > >>>>> been GCC-4.8.0: > >>>>> > >>>>> http://wiki.linuxfromscratch.org/lfs/browser/trunk/BOOK/chapter05/libstdc%2B%2B.xml?annotate=blame > >>>> > >>>> Thank you very much for the pointer. I see that the change was > >>>> committed by Pierre. > >>> > >>> I'm almost sure the option was needed at the time. gcc-4.8.0 was the > >>> first gcc > >>> to be written in C++, hence the need for adding C++ support in pass1. > >> > >> I think the `--disable-libstdcxx-threads' option was not needed even > >> at that time. In other words, I am sure that the option was included > >> in the book without a failing build to support the use of the option > >> (perhaps the option was included just because its name includes the > >> word `threads'). > > > > I'm sure I included that because the build was failing. But I remember I've > > been working with svn versions of gcc before 4.8 was released. So it is > > possible I have not tested that it was still needed for 4.8.
Even with the SVN version, I think the build failed not because of lacking the option. I have checked the GCC changelog for the option, and the sole reason the option was added is to avoid a __potential__ program crash when Solaris executables compiled in a newer Solaris are run in an older Solaris (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52189 for the details). The potential program crash, however, virtually cannot happen when following the LFS book because who would stop after compiling the libstdc++ just to use an older Solaris version to obtain the second pass GCC? In other words, the description of the option given in the LFS book about some C library or libgcc not being compiled with a thread support is just wrong. > > In any case, there is now code in libstdc++ configure script to test whether > > threads are available, and it automatically disables threads if they are not > > available. > > > > I think we could completely remove the option: this libstdc++ is only used > > for > > building gcc-pass2, so possibly changing it has no relevance to other parts > > of > > the book, if gcc-pass2 builds successfully. BUt Since lfs is frozen, I'll > > only > > change the text. > > > > Pierre > > > > Reworded this and also the one about --with-sysroot in binutils-pass2 at rev > 11758. Thanks for the discussion. Thank you, and I strongly encourage you to just remove the `--disable-libstdcxx-threads' option from http://www.linuxfromscratch.org/lfs/view/development/chapter05/gcc-libstdc++.html as soon as possible to keep the book trustworthy. > Pierre -- Best regards, Tadeus -- http://lists.linuxfromscratch.org/listinfo/lfs-dev FAQ: http://www.linuxfromscratch.org/faq/ Unsubscribe: See the above information page
