On Fri, 12 Jan 2018, Torvald Riegel wrote: > Another option might be to require a minimum glibc version on Linux, and > build libstdc++ for that. That would yield a minimum kernel version as > well, and we may can make use of other things in return such as syscall > wrappers.
A minimum glibc version of course only applies when libstdc++ is being built with glibc - it can also be built with other C libraries using the Linux kernel (and some - at least uClibc - define __GLIBC__ to pretend to be some old glibc version). One thing to note regarding minimum glibc (or kernel) versions is it can be useful to use new GCC to build binaries to run on older systems - which means building new GCC as a cross compiler with a sysroot with an old glibc version in it. So the relevant question for establishing a minimum glibc or kernel version is not what systems people are using to develop GCC, but what systems they might want to deploy binaries built with current GCC onto. -- Joseph S. Myers jos...@codesourcery.com