[AIX] change system dynamic library format

[mustartt]

Historically on AIX, almost all dynamic libraries are distributed in .a Big Archive Format which can consists of both static and shared objects in the same archive (e.g. libc++abi.a(libc++abi.so.1)). During the initial porting process, the dynamic libraries are kept as .a to simplify the migration, but semantically having an XCOFF object under the archive extension is wrong. For crate type cdylib we want to be able to distribute the libraries as archives as well.

We are migrating to archives with the following format:

$ ar -t lib<name>.a
lib<name>.so

where each archive contains a single member that is a shared XCOFF object that can be loaded.

[rustbot]

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[jieyouxu]

Hi @mustartt, is this PR blocked on something?

[daltenty]

@rustbot author

[mustartt]

Keeping this as draft for now. Need to investigate if dylibs should be archived into .a and how to properly detect between static archives and archives that contains shared objects.

[mustartt]

@rustbot review

[gilamn5tr]

Looks good in terms of the AIX implementation.

[jieyouxu]

Thanks, this LGTM overall, left a few nits/questions.

[jieyouxu]

Suggestion: can you convert this to a FIXME and open a C-cleanup issue then link to it FIXME(#nnnnnn): ...?

[jieyouxu]

@rustbot author

[rustbot]

These commits modify the Cargo.lock file. Unintentional changes to Cargo.lock can be introduced when switching branches and rebasing PRs.

If this was unintentional then you should revert the changes before this PR is merged.
Otherwise, you can ignore this comment.

[mustartt]

libc 0.2.163 contains the new RTLD_MEMBER

[mustartt]

Thanks for the comments. Rebase on newer master to avoid llvm assertion for f128. Bumped up libc to 0.2.164 that contains the new aix RTLD_MEMBER.

@rustbot review

[jieyouxu]

Thanks. My only reservation is having to load the whole shared archive in bootstrap for dylib detection, but since that only happens for .a I suppose it's not too bad, and has an associated cleanup issue #133268, so I think that's acceptable.

[jieyouxu]

@bors r+ rollup=never (this PR contains a libc bump)

[bors]

📌 Commit 0db9059 has been approved by jieyouxu

It is now in the queue for this repository.

[mustartt]

Thanks. My only reservation is having to load the whole shared archive in bootstrap for dylib detection, but since that only happens for .a I suppose it's not too bad, and has an associated cleanup issue #133268, so I think that's acceptable.

It have a pretty small impact on the bootstrap time maybe an additional minute at most. But I'm wondering is the bootstrap process okay with including other dependencies such as memmap2? I was a bit hesitant to include it in the initial patch?

[jieyouxu]

But I'm wondering is the bootstrap process okay with including other dependencies such as memmap2? I was a bit hesitant to include it in the initial patch?

Ideally bootstrap needs to build fast with minimal deps, so I'm inclined to say no, not for just this one purpose.

[bors]

⌛ Testing commit 0db9059 with merge f39baca...

[rust-log-analyzer]

A job failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

[bors]

💔 Test failed - checks-actions

[jieyouxu]

@bors retry (not even trying)

[bors]

⌛ Testing commit 0db9059 with merge 5d3c6ee...

[bors]

☀️ Test successful - checks-actions
Approved by: jieyouxu
Pushing 5d3c6ee to master...

[rust-timer]

Finished benchmarking commit (5d3c6ee): comparison URL.

Overall result: ❌ regressions - no action needed

@rustbot label: -perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	1.5%	[1.5%, 1.5%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 1.6%, secondary -3.1%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	1.6%	[1.6%, 1.6%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.1%	[-3.4%, -2.7%]	2
All ❌✅ (primary)	1.6%	[1.6%, 1.6%]	1

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 797.142s -> 796.222s (-0.12%)
Artifact size: 336.05 MiB -> 336.06 MiB (0.00%)