Add gnu_get_libc_[release|version] shims.
#2494
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Note that even on linux these functions may not exist, as alternative libcs like musl don't implement them. Do we have a way for shims to deal with this case? |
| @@ -54,9 +54,9 @@ checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa" | |||
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| [[package]] | |||
| name = "backtrace" | |||
| version = "0.3.65" | |||
| version = "0.3.66" | |||
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Could you please not updated unrelated packages?
Why does libc need updating, anyway?
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Ok, this was just cargo update. rust-lang/libc#2862 was only included recently and I thought we'd need it for a passthrough.
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No that won't work. libc calls the external fn, so if Miri implements the external fn by calling libc, at best we'll get an infinite loop.
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Also this lock file is only relevant for things Miri needs to call on the host, and we certainly don't want to call the host libc for these functions.
| // Miscellaneous | ||
| "gnu_get_libc_release" => { | ||
| let [] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?; | ||
| let v = this.eval_libc("gnu_get_libc_release")?; |
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Uh, how does this make any sense? This will return a function pointer...
| // [The GNU manual notes](https://www.gnu.org/software/gnulib/manual/html_node/Glibc-gnu_002flibc_002dversion_002eh.html): | ||
| // > This function is missing on some platforms: macOS 11.1, FreeBSD 13.0, NetBSD 9.0, | ||
| // > OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, IRIX 6.5, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0. | ||
| #[cfg(target_os = "linux")] |
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This is strictly redundant, since you already have only-target-linux.
Then why should Miri even implement them? |
| use std::ffi::CStr; | ||
| // Release name. | ||
| let x = unsafe { libc::gnu_get_libc_release() }; | ||
| assert!(!x.is_null()); |
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If you actually try to print this as a c string, I think you'll notice that the return value is nonsense.
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Going to think about this some more |
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(I was on vacation when you posted this and just remembered to comment now) FYI, |
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