On 09/27/2017 11:01 AM, Joseph Myers wrote: > On Wed, 27 Sep 2017, Florian Weimer wrote: > >> This is part of the ABI GCC implements, so it has to be documented somewhere, >> and not just as part of the GCC source code. >> >> CET is not properly described in the ABI supplement and I don't think this >> will change, so detailed documentation in the GCC manual is very much >> desirable. > > Isn't this a matter to take up further in the thread HJ started on the ABI > mailing lists, or a new such thread (possibly e.g. sending pull requests > that build further on his wording, or propose alternative wording, to > clarify them things left unclear there, with a goal of getting it clearly > defined in the master sources for x86_64 and x86)? Clearly the best > result would be proper documentation in the ABI and the GCC manual > cross-referencing the relevant ABI documents.
The documentation should be AFAICT independent of the compiler in use -- ie, gcc, llvm and icc all should agree on where/when these new instructions should be inserted. Which argues that the documentation belongs in the ABI docs, not the GCC docs. *users* aren't really going to care about these kinds of details. So I think the summary is that I agree with Joseph on this. Let's push it into the ABI docs. HJ can and should play a central role in making that happen. jeff