add graceful shim for the custom O_TMPFILE file opening flag plus test case
#2718
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Thank you for the speedy review @RalfJung! I just pushed all the requested changes :) |
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LGTM if CI passes, but please squash the commits. |
Pointerbender
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Thanks! The CI passed just now and the commits are squashed, too 👍 |
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@bors r+ |
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☀️ Test successful - checks-actions |
| @@ -605,6 +605,15 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> { | |||
| // (Technically we do not support *not* setting this flag, but we ignore that.) | |||
| mirror |= o_cloexec; | |||
| } | |||
| if this.tcx.sess.target.os == "linux" { | |||
| let o_tmpfile = this.eval_libc_i32("O_TMPFILE")?; | |||
| if flag & o_tmpfile != 0 { | |||
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As you noted, O_TMPFILE = 0x410000, which is more than one bit. This is for historical reasons, since the open() syscall ignores unrecognized flags: https://lwn.net/Articles/588444/
So the right check should be flag & o_tmpfile == o_tmpfile.
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Nice catch! Since this PR is already merged, I will address your feedback within my other related PR #2720
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Since it looks like #2720 might be a bit more tricky, it'd be good to have a separate PR for this.
update Miri Noteworthy PRs: - rust-lang/miri#2357 - rust-lang/miri#2646 - rust-lang/miri#2718 - rust-lang/miri#2721 - rust-lang/miri#2725
update Miri Noteworthy PRs: - rust-lang#2357 - rust-lang#2646 - rust-lang#2718 - rust-lang#2721 - rust-lang#2725
update Miri Noteworthy PRs: - rust-lang/miri#2357 - rust-lang/miri#2646 - rust-lang/miri#2718 - rust-lang/miri#2721 - rust-lang/miri#2725
I'm trying if I can get the
tempfilecrate to work nicely with miri. Right now miri errors out due to an unsupported flagO_TMPFILE(=0x410000) passed toOpenOptions::custom_flags. Interestingly,tempfilehas a fallback in case the underlying file system does not support theO_TMPFILEflag, in which caseopen/open64is expected to return the error codeEOPNOTSUPP(=95). This PR adds support for this scenario and also includes a test case (relevant zulip discussion).