elf: add EF_MIPS_ABI_* e_flags constants

[ayrtonm]

This adds a few constants that are needed to fix some targets that are broken on nightly rustc. Values were taken from the LLVM source.

[philipc]

Please add EF_MIPS_ABI too. Also add support in the readobj example. There's existing support for EF_MIPS_ARCH that you can use as a guide.

[ayrtonm]

I just added the EF_MIPS_ABI mask and updated readobj. I'm not entirely sure whether EF_MIPS_ABI2 should be moved to the new flags section in readobj or not. I kept it where it was since the EF_MIPS_ABI mask doesn't cover EF_MIPS_ABI2, but I could see an argument for either case.

Edit: I still need to update the testfiles

[philipc]

I think EF_MIPS_ABI2 is correct where it is, because, as you say, it is not covered by the EF_MIPS_ABI mask.

[ayrtonm]

The existing MIPS test files show <unknown> (0x0) for the new field since they use the 64-bit ABI. I have a MIPS binary using the O32 ABI that I can check in to the object-testfiles repo to actually test the new flags. Is there anything else I'd need to do to update the tests?

[philipc]

As long as the tests pass for you locally, then this PR would just need to update the submodule too. I don't think there's anything else.

[philipc]

We may want to check that the EF_MIPS_ABI fields is non-zero, rather than printing unknown. For example:

object/crates/examples/src/readobj/pe.rs

Lines 423 to 429 in f18fc4b

	if section.characteristics.get(LE) & IMAGE_SCN_ALIGN_MASK != 0 {
	p.flags(
	section.characteristics.get(LE),
	IMAGE_SCN_ALIGN_MASK,
	FLAGS_IMAGE_SCN_ALIGN,
	);
	}

[ayrtonm]

We may want to check that the EF_MIPS_ABI fields is non-zero, rather than printing unknown.

Done and I updated the testfile references. I think the only thing left is updating the submodule, but I assume that has to be after the test binaries are merged.

[philipc]

Thanks! I'm guessing you want a release with this, so I'll try to do one in the near future.

[overdrivenpotato]

A release would help fix some issues in the rust-psp target too 🙂

[philipc]

Published 0.28.4.