Reading rlib on macOS

[RazrFalcon]

I'm using ar to read rust libraries (.rlib). Under Linux everything is fine, but I got an error under macOS:

Error { repr: Custom(Custom { kind: InvalidData, error: StringError("Invalid file size field in entry header (\"    644   \")") }) }

Is it possible to read rlib?

[mdsteele]

Hmm, that's odd. I just tried it on a couple .rlib files generated on my OS X machine, and it worked fine. Can you attach an example of an .rlib file that doesn't work?

[RazrFalcon]

I got this error on any rlib from macOS.

libatty.zip

[mdsteele]

Thanks for the file. Strangely, running cargo run --example extract -- libatty-d1be7f28c1fcb94e.rlib still works fine for me, though. Does that command give an error for you?

What version of the ar crate are you using? Also, what version of rustc?

[RazrFalcon]

I'm using 0.5 tag archive and run the rlib trough the symbols example.

The extract example works fine.

[mdsteele]

Ah, thanks! I'm able to reproduce the issue now.

I'll take a look and try to figure out what's going wrong.

[mdsteele]

Okay, the error should be fixed by commit e593551 -- I'm now able to run that .rlib through the symbols example without getting an error, and also now there are some new regression tests for that bug.

Separately, however, there's the issue that the library doesn't yet support reading symbol tables from BSD-variant archives (which is the format variant typically used by Mac, as opposed to the GNU variant typically used by Linux), so although the symbols example shouldn't crash anymore, it'll just give you an empty list of symbols, which isn't very helpful.

I'll see about getting BSD-variant symbol table support added.

[mdsteele]

Just pushed commit d43c201, which adds initial support for reading BSD-variant symbol tables. The symbols example should hopefully now give useful output for .rlib files on Mac.