cargo-miri does not support target x86_64-wrs-vxworks

[syvb]

cargo-miri gets invoked by itself with a non-existent binary path when emulating the x86_64-wrs-vxworks target, causing an error:

$ cargo new t
     Created binary (application) `t` package
$ cd t
$ cargo miri run --target x86_64-wrs-vxworks
   Compiling t v0.1.0 (/tmp/t)
    Finished dev [unoptimized + debuginfo] target(s) in 0.21s
     Running `/home/smit/.cargo/bin/cargo-miri target/x86_64-wrs-vxworks/debug/t.vxe`
fatal error: `cargo-miri` called with unexpected first argument `target/x86_64-wrs-vxworks/debug/t.vxe`; please only invoke this binary through `cargo miri`

cargo-miri probably doesn't know about the .vxe suffix, so it doesn't create t.vxe:

miri/cargo-miri/bin.rs

Lines 703 to 710 in 3ca53e0

	let filename = out_filename("", "");
	if verbose {
	eprintln!("[cargo-miri rustc] writing run info to `{}`", filename.display());
	}
	info.store(&filename);
	// For Windows, do the same thing again with `.exe` appended to the filename.
	// (Need to do this here as cargo moves that "binary" to a different place before running it.)
	info.store(&out_filename("", ".exe"));

I don't know if just fixing that is sufficient to support x86_64-wrs-vxworks. There are some other places that do not support x86_64-wrs-vxworks, for example:

miri/src/shims/foreign_items.rs

Lines 613 to 616 in 3ca53e0

	_ => match this.tcx.sess.target.os.as_str() {
	"linux" | "macos" => return shims::posix::foreign_items::EvalContextExt::emulate_foreign_item_by_name(this, link_name, abi, args, dest, ret),
	"windows" => return shims::windows::foreign_items::EvalContextExt::emulate_foreign_item_by_name(this, link_name, abi, args, dest, ret),
	target => throw_unsup_format!("the target `{}` is not supported", target),

I tried to reproduce this, but I got some different errors. Perhaps I'm not using the correct version.

$ cargo miri run --target x86_64-wrs-vxworks
   Compiling compiler_builtins v0.1.49
    Checking core v0.0.0 (/home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/core)
   Compiling libc v0.2.98
   Compiling cc v1.0.69
   Compiling std v0.0.0 (/home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std)
   Compiling unwind v0.0.0 (/home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/unwind)
    Checking rustc-std-workspace-core v1.99.0 (/home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/rustc-std-workspace-core)
    Checking alloc v0.0.0 (/home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/alloc)
    Checking cfg-if v0.1.10
    Checking adler v0.2.3
    Checking rustc-demangle v0.1.18
    Checking rustc-std-workspace-alloc v1.99.0 (/home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/rustc-std-workspace-alloc)
    Checking panic_unwind v0.0.0 (/home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/panic_unwind)
    Checking panic_abort v0.0.0 (/home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/panic_abort)
    Checking gimli v0.23.0
    Checking std_detect v0.1.5 (/home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/stdarch/crates/std_detect)
    Checking object v0.22.0
    Checking hashbrown v0.11.0
    Checking miniz_oxide v0.4.0
    Checking addr2line v0.14.0
error[E0432]: unresolved import `libc::sigaddset`
  --> /home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/sys/unix/process/process_common.rs:54:37
   |
54 |         pub use libc::{sigemptyset, sigaddset};
   |                                     ^^^^^^^^^ no `sigaddset` in the root

error[E0531]: cannot find unit struct, unit variant or constant `EHOSTUNREACH` in crate `libc`
   --> /home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/sys/unix/mod.rs:147:15
    |
147 |         libc::EHOSTUNREACH => HostUnreachable,
    |               ^^^^^^^^^^^^ help: a constant with a similar name exists: `ENETUNREACH`
    | 
   ::: /home/hyd-dev/.cargo/registry/src/github.com-1ecc6299db9ec823/libc-0.2.98/src/vxworks/mod.rs:656:1
    |
656 | pub const ENETUNREACH: ::c_int = 51;
    | ------------------------------------ similarly named constant `ENETUNREACH` defined here

error[E0531]: cannot find unit struct, unit variant or constant `ELOOP` in crate `libc`
   --> /home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/sys/unix/mod.rs:151:15
    |
151 |         libc::ELOOP => FilesystemLoop,
    |               ^^^^^ not found in `libc`

error[E0531]: cannot find unit struct, unit variant or constant `EMLINK` in crate `libc`
   --> /home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/sys/unix/mod.rs:156:15
    |
156 |         libc::EMLINK => TooManyLinks,
    |               ^^^^^^ not found in `libc`

error[E0531]: cannot find unit struct, unit variant or constant `ENETDOWN` in crate `libc`
   --> /home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/sys/unix/mod.rs:158:15
    |
158 |         libc::ENETDOWN => NetworkDown,
    |               ^^^^^^^^ not found in `libc`

error[E0531]: cannot find unit struct, unit variant or constant `ESPIPE` in crate `libc`
   --> /home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/sys/unix/mod.rs:165:15
    |
165 |         libc::ESPIPE => NotSeekable,
    |               ^^^^^^ help: a constant with a similar name exists: `EPIPE`
    | 
   ::: /home/hyd-dev/.cargo/registry/src/github.com-1ecc6299db9ec823/libc-0.2.98/src/vxworks/mod.rs:642:1
    |
642 | pub const EPIPE: ::c_int = 32;
    | ------------------------------ similarly named constant `EPIPE` defined here

error[E0531]: cannot find unit struct, unit variant or constant `ETXTBSY` in crate `libc`
   --> /home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/sys/unix/mod.rs:168:15
    |
168 |         libc::ETXTBSY => ExecutableFileBusy,
    |               ^^^^^^^ not found in `libc`

error[E0531]: cannot find unit struct, unit variant or constant `EXDEV` in crate `libc`
   --> /home/hyd-dev/.rustup/toolchains/miri/lib/rustlib/src/rust/library/std/src/sys/unix/mod.rs:169:15
    |
169 |         libc::EXDEV => CrossesDevices,
    |               ^^^^^ not found in `libc`

Some errors have detailed explanations: E0432, E0531.
For more information about an error, try `rustc --explain E0432`.
error: could not compile `std` due to 8 previous errors
error: `"/home/hyd-dev/.rustup/toolchains/miri/bin/cargo" "check" "--release" "--manifest-path" "/tmp/xargo.Itu9HV1h4Zag/Cargo.toml" "--target" "x86_64-wrs-vxworks" "-p" "std"` failed with exit code: Some(101)
note: run with `RUST_BACKTRACE=1` for a backtrace
fatal error: failed to run xargo

[RalfJung]

Yeah cargo-miri needs to know about some platform-specific things around here and here. Probably vxworks needs its own special cases there.

[bjorn3]

cargo-miri could use echo | rustc - --crate-name the_crate_name --print=file-names --crate-type bin to get the filename for an executable in a way that will work for every platform rustc supports. This is roughly what cargo does, except that it uses ____ as placeholder name.