On Tue, Jan 13, 2026 at 12:35:07PM +0100, Frank Scheiner wrote: > On 13.01.26 12:27, Jonathan Wakely wrote: > > On Tue, 13 Jan 2026 at 11:26, Jonathan Wakely <[email protected]> wrote: > >> > >> On Tue, 13 Jan 2026 at 11:10, Frank Scheiner wrote: > >>> BTW, I have not yet found out how to derive a revision like the just > >>> mentioned one from a git commit hash. I know that it includes a > >>> shortened commit hash and I assume the major GCC version number at > >>> the start, but how can I in general determine such a revision from a > >>> full git commit hash? > >> > >> Using the gcc-descr and gcc-undescr aliases provided by the > >> https://gcc.gnu.org/gitwrite.html#customization setup. > > > > Or the contrib/git-descr.sh and contrib/git-undescr.sh scripts, which > > are what the aliases use. > > > > $ git help gcc-descr > > 'gcc-descr' is aliased to '!f() { "`git rev-parse > > --show-toplevel`/contrib/git-descr.sh" $@; } ; f' > > $ git help gcc-undescr > > 'gcc-undescr' is aliased to '!f() { "`git rev-parse > > --show-toplevel`/contrib/git-undescr.sh" $@; } ; f' > > Thanks!
Note, the hashes like r10-2142-gec8ac265ff21fb can be used directly by git, git diff r10-2142-gec8ac265ff21fb^ r10-2142-gec8ac265ff21fb etc. works just fine. In the even more shortened version, like r10-2142, you need the git gcc-undescr command to transform it to git hash. Or you can use https://gcc.gnu.org/r10-2142 to see it with gitweb. And the reason why these exist is that normal git hashes give on the first sight no information how old a commit is and which commit is newer than another one. With rNN-NNNN-gHHHHHHHH you know immediately on which upstream branch the commit was committed (for trunk it is always the version of the upcoming release) and the NNNN in there is number of commits since branchpoint, so when we've branched off gcc 15 branch, there was r16-0 commit right after branchpoint and so on, so you can easily know that r16-500 was roughly from May 2025, while r16-6700 is very recent commit. The shorter form is meant especially for gcc bugzilla bug subjects so that it is not too long, while the ones including hash are meant e.g. for bugzilla comments. bugzilla links such strings to the gitweb URLs too. Jakub
