jh7370 wrote: > > Rather than a new option, I'd rather you just add support for > > `--only-section` and `--dump-section`, which can then be specified in > > conjunction with each other to achieve the same result. IIRC, a while back, > > `--split-dwo` was considered a mistake, because the same effect could be > > achieved by specifying `--extract-dwo` and `--strip-dwo` and `--split-dwo` > > doesn't exist in GNU objcopy (which we aim for broad compatibility with). > > I assume you mean `--remove-section` and `--dump-section`. The issue for our > use-case is that `--dump-section` only outputs the section contents, it does > not output a valid object with just one section specified.
No, I mean `--only-section`, which you'd use in one run, and then a separate `--remove-section` invocation removing that same section. > We thought it best not to have a different implementation of `dump-section` > for `DXContainer` that outputs more than just the contents. Yes, agreed with this. > The concern that I have with this is that if we want to take an input file > that has 8 sections, pull 3 out into their own files and leave the remaining > 5, can we do that without invoking `objcopy` 4 times? > > My reading of the current options is that to do what I described above we > would need to invoke objcopy multiple times like: > > ``` > llvm-objcopy <input object> --only-section=RTS0 <path to new signature> > llvm-objcopy <input object> --only-section=STAT <path to new reflection> > llvm-objcopy <input object> --only-section=ILDB <path to new debug info> > llvm-objcopy <input object> --remove-section=RTS0 --remove-section=STAT > --remove-section=ILDB <path to stripped file> > ``` Thanks for the further explanation. Yes, that is what you'd need to do. > It does seem like we should support the `--only-section` and > `--remove-section` options (and maybe that's where we should start), but it > would be really nice if we could reduce the number of process launches and > times reading the input object file. Fair enough. My instinct is that a more "objcopy" way of doing things would be to have an option similar to `--dump-section`, which wraps it in the necessary object metadata, without removing the section from the file, which can be combined with `--remove-section` to also remove it. So the above becomes something like: ``` llvm-objcopy <input object> --split-section=RTS0=rts0.o --split-section=STAT=stat.o --split-section=ILDB=ildb.o --remove-section=RTS0 --remove-section=STAT --remove-section=ILDB ``` I've used `--split-section` as the name here, but I'd probably actually consider `--extract-section` as the name, since it's more akin to `--extract-dwo` than `--split-dwo` at this point, but I'm open to suggestions. @MaskRay, do you have any thoughts on the best way to approach this? https://github.com/llvm/llvm-project/pull/153265 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
