On 10/10/20 8:00 AM, Marc Nieper-Wißkirchen wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97364 Looking at that bug report and related material (particularly Richard Biener's 2012 comment ) the GCC folks seem to have decided long ago that const and pure attributes were intended more as directives for common subexpression elimination than as independent notions in their own right, it's just that they haven't gotten around to (or are embarrassed to :-) document that decision. In the meantime, to try to help out Gnulib hackers I installed the attached commentary changes. It was cleaner to document 'const' first so I rearranged the #defines.