rust/compiler/rustc_metadata
bors 22f5bdc42b Auto merge of #124686 - saethlin:rust-file-footer, r=fmease
Add a footer in FileEncoder and check for it in MemDecoder

We have a few reports of ICEs due to decoding failures, where the fault does not lie with the compiler. The goal of this PR is to add some very lightweight and on-by-default validation to the compiler's outputs. If validation fails, we emit a fatal error for rmeta files in general that mentions the path that didn't load, and for incremental compilation artifacts we emit a verbose warning that tries to explain the situation and treat the artifacts as outdated.

The validation currently implemented here is very crude, and yet I think we have 11 ICE reports currently open (you can find them by searching issues for `1002111927320821928687967599834759150`) which this simple validation would have detected. The structure of the code changes here should permit the addition of further validation code, such as a checksum, if it is merited. I would like to have code to detect corruption such as reported in https://github.com/rust-lang/rust/issues/124719, but I'm not yet sure how to do that efficiently, and this PR is already a good size.

The ICE reports I have in mind that this PR would have smoothed over are:
https://github.com/rust-lang/rust/issues/124469
https://github.com/rust-lang/rust/issues/123352
https://github.com/rust-lang/rust/issues/123376 [^1]
https://github.com/rust-lang/rust/issues/99763
https://github.com/rust-lang/rust/issues/93900.

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[^1]: This one might be a compiler bug, but even if it is I think the workflow described is pushing the envelope of what we can support. This issue is one of the reasons this warning still asks people to file an issue.
2024-05-22 15:59:56 +00:00
..
src Auto merge of #124686 - saethlin:rust-file-footer, r=fmease 2024-05-22 15:59:56 +00:00
Cargo.toml deps: deduplicate the version of libloading used 2024-01-10 17:18:10 +02:00
messages.ftl Convert uses of BuiltinLintDiag::Normal to custom variants 2024-05-21 20:16:39 +00:00