2 use std::ffi::OsString;
3 use std::fs::{self, File};
4 use std::iter::TakeWhile;
5 use std::io::{self, BufRead, BufReader, BufWriter, Read, Write};
7 use std::path::{Path, PathBuf};
8 use std::process::Command;
10 use serde::{Deserialize, Serialize};
12 use rustc_version::VersionMeta;
14 const XARGO_MIN_VERSION: (u32, u32, u32) = (0, 3, 22);
16 const CARGO_MIRI_HELP: &str = r#"Runs binary crates and tests in Miri
19 cargo miri [subcommand] [<cargo options>...] [--] [<program/test suite options>...]
24 setup Only perform automatic setup, but without asking questions (for getting a proper libstd)
26 The cargo options are exactly the same as for `cargo run` and `cargo test`, respectively.
30 cargo miri test -- test-suite-filter
33 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
40 /// The information to run a crate with the given environment.
41 #[derive(Serialize, Deserialize)]
43 /// The command-line arguments.
46 env: Vec<(OsString, OsString)>,
47 /// The current working directory.
48 current_dir: OsString,
49 /// The contents passed via standard input.
54 /// Gather all the information we need.
55 fn collect(args: env::Args, capture_stdin: bool) -> Self {
56 let args = args.collect();
57 let env = env::vars_os().collect();
58 let current_dir = env::current_dir().unwrap().into_os_string();
60 let mut stdin = Vec::new();
62 std::io::stdin().lock().read_to_end(&mut stdin).expect("cannot read stdin");
65 CrateRunEnv { args, env, current_dir, stdin }
69 /// The information Miri needs to run a crate. Stored as JSON when the crate is "compiled".
70 #[derive(Serialize, Deserialize)]
72 /// Run it with the given environment.
74 /// Skip it as Miri does not support interpreting such kind of crates.
79 fn store(&self, filename: &Path) {
80 let file = File::create(filename)
81 .unwrap_or_else(|_| show_error(format!("cannot create `{}`", filename.display())));
82 let file = BufWriter::new(file);
83 serde_json::ser::to_writer(file, self)
84 .unwrap_or_else(|_| show_error(format!("cannot write to `{}`", filename.display())));
89 println!("{}", CARGO_MIRI_HELP);
95 env!("CARGO_PKG_VERSION"),
96 env!("VERGEN_GIT_SHA_SHORT"),
97 env!("VERGEN_GIT_COMMIT_DATE")
101 fn show_error(msg: String) -> ! {
102 eprintln!("fatal error: {}", msg);
103 std::process::exit(1)
106 // Determines whether a `--flag` is present.
107 fn has_arg_flag(name: &str) -> bool {
108 let mut args = std::env::args().take_while(|val| val != "--");
109 args.any(|val| val == name)
112 /// Yields all values of command line flag `name`.
113 struct ArgFlagValueIter<'a> {
114 args: TakeWhile<env::Args, fn(&String) -> bool>,
118 impl<'a> ArgFlagValueIter<'a> {
119 fn new(name: &'a str) -> Self {
121 // Stop searching at `--`.
122 args: env::args().take_while(|val| val != "--"),
128 impl Iterator for ArgFlagValueIter<'_> {
131 fn next(&mut self) -> Option<Self::Item> {
133 let arg = self.args.next()?;
134 if !arg.starts_with(self.name) {
137 // Strip leading `name`.
138 let suffix = &arg[self.name.len()..];
139 if suffix.is_empty() {
140 // This argument is exactly `name`; the next one is the value.
141 return self.args.next();
142 } else if suffix.starts_with('=') {
143 // This argument is `name=value`; get the value.
144 // Strip leading `=`.
145 return Some(suffix[1..].to_owned());
151 /// Gets the value of a `--flag`.
152 fn get_arg_flag_value(name: &str) -> Option<String> {
153 ArgFlagValueIter::new(name).next()
156 fn forward_patched_extern_arg(args: &mut impl Iterator<Item = String>, cmd: &mut Command) {
157 cmd.arg("--extern"); // always forward flag, but adjust filename:
158 let path = args.next().expect("`--extern` should be followed by a filename");
159 if let Some(lib) = path.strip_suffix(".rlib") {
160 // If this is an rlib, make it an rmeta.
161 cmd.arg(format!("{}.rmeta", lib));
163 // Some other extern file (e.g. a `.so`). Forward unchanged.
168 fn forward_miri_sysroot(cmd: &mut Command) {
170 env::var_os("MIRI_SYSROOT").expect("the wrapper should have set MIRI_SYSROOT");
171 cmd.arg("--sysroot");
175 /// Returns the path to the `miri` binary
176 fn find_miri() -> PathBuf {
177 if let Some(path) = env::var_os("MIRI") {
180 let mut path = std::env::current_exe().expect("current executable path invalid");
181 path.set_file_name("miri");
185 fn miri() -> Command {
186 Command::new(find_miri())
189 fn version_info() -> VersionMeta {
190 VersionMeta::for_command(miri()).expect("failed to determine underlying rustc version of Miri")
193 fn cargo() -> Command {
194 Command::new(env::var_os("CARGO").unwrap_or_else(|| OsString::from("cargo")))
197 fn xargo_check() -> Command {
198 Command::new(env::var_os("XARGO_CHECK").unwrap_or_else(|| OsString::from("xargo-check")))
201 /// Execute the command. If it fails, fail this process with the same exit code.
202 /// Otherwise, continue.
203 fn exec(mut cmd: Command) {
204 let exit_status = cmd.status().expect("failed to run command");
205 if exit_status.success().not() {
206 std::process::exit(exit_status.code().unwrap_or(-1))
210 /// Execute the command and pipe `input` into its stdin.
211 /// If it fails, fail this process with the same exit code.
212 /// Otherwise, continue.
213 fn exec_with_pipe(mut cmd: Command, input: &[u8]) {
214 cmd.stdin(std::process::Stdio::piped());
215 let mut child = cmd.spawn().expect("failed to spawn process");
217 let stdin = child.stdin.as_mut().expect("failed to open stdin");
218 stdin.write_all(input).expect("failed to write out test source");
220 let exit_status = child.wait().expect("failed to run command");
221 if exit_status.success().not() {
222 std::process::exit(exit_status.code().unwrap_or(-1))
226 fn xargo_version() -> Option<(u32, u32, u32)> {
227 let out = xargo_check().arg("--version").output().ok()?;
228 if !out.status.success() {
231 // Parse output. The first line looks like "xargo 0.3.12 (b004f1c 2018-12-13)".
236 .expect("malformed `xargo --version` output: not at least one line")
237 .expect("malformed `xargo --version` output: error reading first line");
238 let (name, version) = {
239 let mut split = line.split(' ');
241 split.next().expect("malformed `xargo --version` output: empty"),
242 split.next().expect("malformed `xargo --version` output: not at least two words"),
246 // This is some fork of xargo
249 let mut version_pieces = version.split('.');
250 let major = version_pieces
252 .expect("malformed `xargo --version` output: not a major version piece")
254 .expect("malformed `xargo --version` output: major version is not an integer");
255 let minor = version_pieces
257 .expect("malformed `xargo --version` output: not a minor version piece")
259 .expect("malformed `xargo --version` output: minor version is not an integer");
260 let patch = version_pieces
262 .expect("malformed `xargo --version` output: not a patch version piece")
264 .expect("malformed `xargo --version` output: patch version is not an integer");
265 if !version_pieces.next().is_none() {
266 panic!("malformed `xargo --version` output: more than three pieces in version");
268 Some((major, minor, patch))
271 fn ask_to_run(mut cmd: Command, ask: bool, text: &str) {
272 // Disable interactive prompts in CI (GitHub Actions, Travis, AppVeyor, etc).
273 // Azure doesn't set `CI` though (nothing to see here, just Microsoft being Microsoft),
274 // so we also check their `TF_BUILD`.
275 let is_ci = env::var_os("CI").is_some() || env::var_os("TF_BUILD").is_some();
277 let mut buf = String::new();
278 print!("I will run `{:?}` to {}. Proceed? [Y/n] ", cmd, text);
279 io::stdout().flush().unwrap();
280 io::stdin().read_line(&mut buf).unwrap();
281 match buf.trim().to_lowercase().as_ref() {
283 "" | "y" | "yes" => {}
284 "n" | "no" => show_error(format!("aborting as per your request")),
285 a => show_error(format!("invalid answer `{}`", a)),
288 println!("Running `{:?}` to {}.", cmd, text);
291 if cmd.status().expect(&format!("failed to execute {:?}", cmd)).success().not() {
292 show_error(format!("failed to {}", text));
296 /// Performs the setup required to make `cargo miri` work: Getting a custom-built libstd. Then sets
297 /// `MIRI_SYSROOT`. Skipped if `MIRI_SYSROOT` is already set, in which case we expect the user has
298 /// done all this already.
299 fn setup(subcommand: MiriCommand) {
300 if std::env::var_os("MIRI_SYSROOT").is_some() {
301 if subcommand == MiriCommand::Setup {
302 println!("WARNING: MIRI_SYSROOT already set, not doing anything.")
307 // Subcommands other than `setup` will do a setup if necessary, but
308 // interactively confirm first.
309 let ask_user = subcommand != MiriCommand::Setup;
311 // First, we need xargo.
312 if xargo_version().map_or(true, |v| v < XARGO_MIN_VERSION) {
313 if std::env::var_os("XARGO_CHECK").is_some() {
314 // The user manually gave us a xargo binary; don't do anything automatically.
315 show_error(format!("xargo is too old; please upgrade to the latest version"))
317 let mut cmd = cargo();
318 cmd.args(&["install", "xargo"]);
319 ask_to_run(cmd, ask_user, "install a recent enough xargo");
322 // Determine where the rust sources are located. `XARGO_RUST_SRC` env var trumps everything.
323 let rust_src = match std::env::var_os("XARGO_RUST_SRC") {
325 let path = PathBuf::from(path);
326 // Make path absolute if possible.
327 path.canonicalize().unwrap_or(path)
330 // Check for `rust-src` rustup component.
332 .args(&["--print", "sysroot"])
334 .expect("failed to determine sysroot")
336 let sysroot = std::str::from_utf8(&sysroot).unwrap();
337 let sysroot = Path::new(sysroot.trim_end_matches('\n'));
338 // Check for `$SYSROOT/lib/rustlib/src/rust/library`; test if that contains `std/Cargo.toml`.
340 sysroot.join("lib").join("rustlib").join("src").join("rust").join("library");
341 if !rustup_src.join("std").join("Cargo.toml").exists() {
342 // Ask the user to install the `rust-src` component, and use that.
343 let mut cmd = Command::new("rustup");
344 cmd.args(&["component", "add", "rust-src"]);
348 "install the `rust-src` component for the selected toolchain",
354 if !rust_src.exists() {
355 show_error(format!("given Rust source directory `{}` does not exist.", rust_src.display()));
358 // Next, we need our own libstd. Prepare a xargo project for that purpose.
359 // We will do this work in whatever is a good cache dir for this platform.
360 let dirs = directories::ProjectDirs::from("org", "rust-lang", "miri").unwrap();
361 let dir = dirs.cache_dir();
363 fs::create_dir_all(&dir).unwrap();
365 // The interesting bit: Xargo.toml
366 File::create(dir.join("Xargo.toml"))
371 default_features = false
372 # We support unwinding, so enable that panic runtime.
373 features = ["panic_unwind", "backtrace"]
379 // The boring bits: a dummy project for xargo.
380 // FIXME: With xargo-check, can we avoid doing this?
381 File::create(dir.join("Cargo.toml"))
387 description = "A dummy project for building libstd with xargo."
395 File::create(dir.join("lib.rs")).unwrap();
397 // Determine architectures.
398 // We always need to set a target so rustc bootstrap can tell apart host from target crates.
399 let host = version_info().host;
400 let target = get_arg_flag_value("--target");
401 let target = target.as_ref().unwrap_or(&host);
403 let mut command = xargo_check();
404 command.arg("check").arg("-q");
405 command.arg("--target").arg(target);
406 command.current_dir(&dir);
407 command.env("XARGO_HOME", &dir);
408 command.env("XARGO_RUST_SRC", &rust_src);
409 // Use Miri as rustc to build a libstd compatible with us (and use the right flags).
410 // However, when we are running in bootstrap, we cannot just overwrite `RUSTC`,
411 // because we still need bootstrap to distinguish between host and target crates.
412 // In that case we overwrite `RUSTC_REAL` instead which determines the rustc used
413 // for target crates.
414 // We set ourselves (`cargo-miri`) instead of Miri directly to be able to patch the flags
415 // for `libpanic_abort` (usually this is done by bootstrap but we have to do it ourselves).
416 // The `MIRI_CALLED_FROM_XARGO` will mean we dispatch to `phase_setup_rustc`.
417 let cargo_miri_path = std::env::current_exe().expect("current executable path invalid");
418 if env::var_os("RUSTC_STAGE").is_some() {
419 command.env("RUSTC_REAL", &cargo_miri_path);
421 command.env("RUSTC", &cargo_miri_path);
423 command.env("MIRI_CALLED_FROM_XARGO", "1");
424 // Make sure there are no other wrappers or flags getting in our way
425 // (Cc https://github.com/rust-lang/miri/issues/1421).
426 // This is consistent with normal `cargo build` that does not apply `RUSTFLAGS`
427 // to the sysroot either.
428 command.env_remove("RUSTC_WRAPPER");
429 command.env_remove("RUSTFLAGS");
430 // Disable debug assertions in the standard library -- Miri is already slow enough.
431 // But keep the overflow checks, they are cheap.
432 command.env("RUSTFLAGS", "-Cdebug-assertions=off -Coverflow-checks=on");
434 if command.status().expect("failed to run xargo").success().not() {
435 show_error(format!("failed to run xargo"));
438 // That should be it! But we need to figure out where xargo built stuff.
439 // Unfortunately, it puts things into a different directory when the
440 // architecture matches the host.
441 let sysroot = if target == &host { dir.join("HOST") } else { PathBuf::from(dir) };
442 std::env::set_var("MIRI_SYSROOT", &sysroot); // pass the env var to the processes we spawn, which will turn it into "--sysroot" flags
443 // Figure out what to print.
444 let print_sysroot = subcommand == MiriCommand::Setup && has_arg_flag("--print-sysroot"); // whether we just print the sysroot path
446 // Print just the sysroot and nothing else; this way we do not need any escaping.
447 println!("{}", sysroot.display());
448 } else if subcommand == MiriCommand::Setup {
449 println!("A libstd for Miri is now available in `{}`.", sysroot.display());
453 fn phase_cargo_miri(mut args: env::Args) {
454 // Check for version and help flags even when invoked as `cargo-miri`.
455 if has_arg_flag("--help") || has_arg_flag("-h") {
459 if has_arg_flag("--version") || has_arg_flag("-V") {
464 // Require a subcommand before any flags.
465 // We cannot know which of those flags take arguments and which do not,
466 // so we cannot detect subcommands later.
467 let subcommand = match args.next().as_deref() {
468 Some("test") => MiriCommand::Test,
469 Some("run") => MiriCommand::Run,
470 Some("setup") => MiriCommand::Setup,
472 _ => show_error(format!("`cargo miri` supports the following subcommands: `run`, `test`, and `setup`.")),
474 let verbose = has_arg_flag("-v");
479 // Invoke actual cargo for the job, but with different flags.
480 // We re-use `cargo test` and `cargo run`, which makes target and binary handling very easy but
481 // requires some extra work to make the build check-only (see all the `--emit` hacks below).
482 // <https://github.com/rust-lang/miri/pull/1540#issuecomment-693553191> describes an alternative
483 // approach that uses `cargo check`, making that part easier but target and binary handling
485 let cargo_miri_path = std::env::current_exe().expect("current executable path invalid");
486 let cargo_cmd = match subcommand {
487 MiriCommand::Test => "test",
488 MiriCommand::Run => "run",
489 MiriCommand::Setup => return, // `cargo miri setup` stops here.
491 let mut cmd = cargo();
494 // Make sure we know the build target, and cargo does, too.
495 // This is needed to make the `CARGO_TARGET_*_RUNNER` env var do something,
496 // and it later helps us detect which crates are proc-macro/build-script
497 // (host crates) and which crates are needed for the program itself.
498 let host = version_info().host;
499 let target = get_arg_flag_value("--target");
500 let target = if let Some(ref target) = target {
503 // No target given. Pick default and tell cargo about it.
509 // Forward all further arguments to cargo.
512 // Set `RUSTC_WRAPPER` to ourselves. Cargo will prepend that binary to its usual invocation,
513 // i.e., the first argument is `rustc` -- which is what we use in `main` to distinguish
514 // the two codepaths. (That extra argument is why we prefer this over setting `RUSTC`.)
515 if env::var_os("RUSTC_WRAPPER").is_some() {
516 println!("WARNING: Ignoring `RUSTC_WRAPPER` environment variable, Miri does not support wrapping.");
518 cmd.env("RUSTC_WRAPPER", &cargo_miri_path);
520 let runner_env_name = |triple: &str| {
521 format!("CARGO_TARGET_{}_RUNNER", triple.to_uppercase().replace('-', "_"))
523 let host_runner_env_name = runner_env_name(&host);
524 let target_runner_env_name = runner_env_name(target);
525 // Set the target runner to us, so we can interpret the binaries.
526 cmd.env(&target_runner_env_name, &cargo_miri_path);
527 // Unit tests of `proc-macro` crates are run on the host, so we set the host runner to
528 // us in order to skip them.
529 cmd.env(&host_runner_env_name, &cargo_miri_path);
531 // Set rustdoc to us as well, so we can run doctests.
532 cmd.env("RUSTDOC", &cargo_miri_path);
536 eprintln!("[cargo-miri miri] RUSTC_WRAPPER={:?}", cargo_miri_path);
537 eprintln!("[cargo-miri miri] {}={:?}", target_runner_env_name, cargo_miri_path);
539 eprintln!("[cargo-miri miri] {}={:?}", host_runner_env_name, cargo_miri_path);
541 eprintln!("[cargo-miri miri] RUSTDOC={:?}", cargo_miri_path);
542 eprintln!("[cargo-miri miri] {:?}", cmd);
543 cmd.env("MIRI_VERBOSE", ""); // This makes the other phases verbose.
548 #[derive(Debug, Copy, Clone, PartialEq)]
550 /// `rustc` called via `xargo` for sysroot build.
552 /// `rustc` called by `cargo` for regular build.
554 /// `rustc` called by `rustdoc` for doctest.
558 fn phase_rustc(mut args: env::Args, phase: RustcPhase) {
559 /// Determines if we are being invoked (as rustc) to build a crate for
560 /// the "target" architecture, in contrast to the "host" architecture.
561 /// Host crates are for build scripts and proc macros and still need to
562 /// be built like normal; target crates need to be built for or interpreted
565 /// Currently, we detect this by checking for "--target=", which is
566 /// never set for host crates. This matches what rustc bootstrap does,
567 /// which hopefully makes it "reliable enough". This relies on us always
568 /// invoking cargo itself with `--target`, which `in_cargo_miri` ensures.
569 fn is_target_crate() -> bool {
570 get_arg_flag_value("--target").is_some()
573 /// Returns whether or not Cargo invoked the wrapper (this binary) to compile
574 /// the final, binary crate (either a test for 'cargo test', or a binary for 'cargo run')
575 /// Cargo does not give us this information directly, so we need to check
576 /// various command-line flags.
577 fn is_runnable_crate() -> bool {
578 let is_bin = get_arg_flag_value("--crate-type").as_deref().unwrap_or("bin") == "bin";
579 let is_test = has_arg_flag("--test");
583 fn out_filename(prefix: &str, suffix: &str) -> PathBuf {
584 if let Some(out_dir) = get_arg_flag_value("--out-dir") {
585 let mut path = PathBuf::from(out_dir);
589 get_arg_flag_value("--crate-name").unwrap(),
590 // This is technically a `-C` flag but the prefix seems unique enough...
591 // (and cargo passes this before the filename so it should be unique)
592 get_arg_flag_value("extra-filename").unwrap_or(String::new()),
597 let out_file = get_arg_flag_value("-o").unwrap();
598 PathBuf::from(out_file)
602 let verbose = std::env::var_os("MIRI_VERBOSE").is_some();
603 let target_crate = is_target_crate();
604 let print = get_arg_flag_value("--print").is_some() || has_arg_flag("-vV"); // whether this is cargo/xargo invoking rustc to get some infos
606 let store_json = |info: CrateRunInfo| {
607 // Create a stub .d file to stop Cargo from "rebuilding" the crate:
608 // https://github.com/rust-lang/miri/issues/1724#issuecomment-787115693
609 // As we store a JSON file instead of building the crate here, an empty file is fine.
610 let dep_info_name = out_filename("", ".d");
612 eprintln!("[cargo-miri rustc] writing stub dep-info to `{}`", dep_info_name.display());
614 File::create(dep_info_name).expect("failed to create fake .d file");
616 let filename = out_filename("", "");
618 eprintln!("[cargo-miri rustc] writing run info to `{}`", filename.display());
620 info.store(&filename);
621 // For Windows, do the same thing again with `.exe` appended to the filename.
622 // (Need to do this here as cargo moves that "binary" to a different place before running it.)
623 info.store(&out_filename("", ".exe"));
626 let runnable_crate = !print && is_runnable_crate();
628 if runnable_crate && target_crate {
629 assert!(phase != RustcPhase::Setup, "there should be no interpretation during sysroot build");
630 let inside_rustdoc = phase == RustcPhase::Rustdoc;
631 // This is the binary or test crate that we want to interpret under Miri.
632 // But we cannot run it here, as cargo invoked us as a compiler -- our stdin and stdout are not
633 // like we want them.
634 // Instead of compiling, we write JSON into the output file with all the relevant command-line flags
635 // and environment variables; this is used when cargo calls us again in the CARGO_TARGET_RUNNER phase.
636 let env = CrateRunEnv::collect(args, inside_rustdoc);
638 // Rustdoc expects us to exit with an error code if the test is marked as `compile_fail`,
639 // just creating the JSON file is not enough: we need to detect syntax errors,
640 // so we need to run Miri with `MIRI_BE_RUSTC` for a check-only build.
642 let mut cmd = miri();
644 // Ensure --emit argument for a check-only build is present.
645 // We cannot use the usual helpers since we need to check specifically in `env.args`.
646 if let Some(i) = env.args.iter().position(|arg| arg.starts_with("--emit=")) {
647 // For `no_run` tests, rustdoc passes a `--emit` flag; make sure it has the right shape.
648 assert_eq!(env.args[i], "--emit=metadata");
650 // For all other kinds of tests, we can just add our flag.
651 cmd.arg("--emit=metadata");
655 cmd.env("MIRI_BE_RUSTC", "target");
658 eprintln!("[cargo-miri rustc] captured input:\n{}", std::str::from_utf8(&env.stdin).unwrap());
659 eprintln!("[cargo-miri rustc] {:?}", cmd);
662 exec_with_pipe(cmd, &env.stdin);
665 store_json(CrateRunInfo::RunWith(env));
670 if runnable_crate && ArgFlagValueIter::new("--extern").any(|krate| krate == "proc_macro") {
671 // This is a "runnable" `proc-macro` crate (unit tests). We do not support
672 // interpreting that under Miri now, so we write a JSON file to (display a
673 // helpful message and) skip it in the runner phase.
674 store_json(CrateRunInfo::SkipProcMacroTest);
678 let mut cmd = miri();
679 let mut emit_link_hack = false;
680 // Arguments are treated very differently depending on whether this crate is
681 // for interpretation by Miri, or for use by a build script / proc macro.
682 if !print && target_crate {
683 // Forward arguments, but remove "link" from "--emit" to make this a check-only build.
684 let emit_flag = "--emit";
685 while let Some(arg) = args.next() {
686 if arg.starts_with(emit_flag) {
687 // Patch this argument. First, extract its value.
688 let val = &arg[emit_flag.len()..];
689 assert!(val.starts_with("="), "`cargo` should pass `--emit=X` as one argument");
691 let mut val: Vec<_> = val.split(',').collect();
692 // Now make sure "link" is not in there, but "metadata" is.
693 if let Some(i) = val.iter().position(|&s| s == "link") {
694 emit_link_hack = true;
696 if !val.iter().any(|&s| s == "metadata") {
697 val.push("metadata");
700 cmd.arg(format!("{}={}", emit_flag, val.join(",")));
701 } else if arg == "--extern" {
702 // Patch `--extern` filenames, since Cargo sometimes passes stub `.rlib` files:
703 // https://github.com/rust-lang/miri/issues/1705
704 forward_patched_extern_arg(&mut args, &mut cmd);
710 // Use our custom sysroot (but not if that is what we are currently building).
711 if phase != RustcPhase::Setup {
712 forward_miri_sysroot(&mut cmd);
715 // During setup, patch the panic runtime for `libpanic_abort` (mirroring what bootstrap usually does).
716 if phase == RustcPhase::Setup && get_arg_flag_value("--crate-name").as_deref() == Some("panic_abort") {
717 cmd.arg("-C").arg("panic=abort");
720 // For host crates or when we are printing, just forward everything.
724 // We want to compile, not interpret. We still use Miri to make sure the compiler version etc
725 // are the exact same as what is used for interpretation.
726 // MIRI_DEFAULT_ARGS should not be used to build host crates, hence setting "target" or "host"
727 // as the value here to help Miri differentiate them.
728 cmd.env("MIRI_BE_RUSTC", if target_crate { "target" } else { "host" });
732 eprintln!("[cargo-miri rustc] {:?}", cmd);
736 // Create a stub .rlib file if "link" was requested by cargo.
737 // This is necessary to prevent cargo from doing rebuilds all the time.
739 // Some platforms prepend "lib", some do not... let's just create both files.
740 File::create(out_filename("lib", ".rlib")).expect("failed to create fake .rlib file");
741 File::create(out_filename("", ".rlib")).expect("failed to create fake .rlib file");
742 // Just in case this is a cdylib or staticlib, also create those fake files.
743 File::create(out_filename("lib", ".so")).expect("failed to create fake .so file");
744 File::create(out_filename("lib", ".a")).expect("failed to create fake .a file");
745 File::create(out_filename("lib", ".dylib")).expect("failed to create fake .dylib file");
746 File::create(out_filename("", ".dll")).expect("failed to create fake .dll file");
747 File::create(out_filename("", ".lib")).expect("failed to create fake .lib file");
751 #[derive(Debug, Copy, Clone, PartialEq)]
753 /// `cargo` is running a binary
755 /// `rustdoc` is running a binary
759 fn phase_runner(binary: &Path, binary_args: env::Args, phase: RunnerPhase) {
760 let verbose = std::env::var_os("MIRI_VERBOSE").is_some();
762 let file = File::open(&binary)
763 .unwrap_or_else(|_| show_error(format!("file {:?} not found or `cargo-miri` invoked incorrectly; please only invoke this binary through `cargo miri`", binary)));
764 let file = BufReader::new(file);
766 let info = serde_json::from_reader(file)
767 .unwrap_or_else(|_| show_error(format!("file {:?} contains outdated or invalid JSON; try `cargo clean`", binary)));
768 let info = match info {
769 CrateRunInfo::RunWith(info) => info,
770 CrateRunInfo::SkipProcMacroTest => {
771 eprintln!("Running unit tests of `proc-macro` crates is not currently supported by Miri.");
776 let mut cmd = miri();
778 // Set missing env vars. We prefer build-time env vars over run-time ones; see
779 // <https://github.com/rust-lang/miri/issues/1661> for the kind of issue that fixes.
780 for (name, val) in info.env {
782 if let Some(old_val) = env::var_os(&name) {
784 eprintln!("[cargo-miri runner] Overwriting run-time env var {:?}={:?} with build-time value {:?}", name, old_val, val);
791 // Forward rustc arguments.
792 // We need to patch "--extern" filenames because we forced a check-only
793 // build without cargo knowing about that: replace `.rlib` suffix by
795 // We also need to remove `--error-format` as cargo specifies that to be JSON,
796 // but when we run here, cargo does not interpret the JSON any more. `--json`
797 // then also nees to be dropped.
798 let mut args = info.args.into_iter();
799 let error_format_flag = "--error-format";
800 let json_flag = "--json";
801 while let Some(arg) = args.next() {
802 if arg == "--extern" {
803 forward_patched_extern_arg(&mut args, &mut cmd);
804 } else if arg.starts_with(error_format_flag) {
805 let suffix = &arg[error_format_flag.len()..];
806 assert!(suffix.starts_with('='));
807 // Drop this argument.
808 } else if arg.starts_with(json_flag) {
809 let suffix = &arg[json_flag.len()..];
810 assert!(suffix.starts_with('='));
811 // Drop this argument.
816 // Set sysroot (if we are inside rustdoc, we already did that in `phase_cargo_rustdoc`).
817 if phase != RunnerPhase::Rustdoc {
818 forward_miri_sysroot(&mut cmd);
820 // Respect `MIRIFLAGS`.
821 if let Ok(a) = env::var("MIRIFLAGS") {
822 // This code is taken from `RUSTFLAGS` handling in cargo.
826 .filter(|s| !s.is_empty())
827 .map(str::to_string);
831 // Then pass binary arguments.
833 cmd.args(binary_args);
835 // Make sure we use the build-time working directory for interpreting Miri/rustc arguments.
836 // But then we need to switch to the run-time one, which we instruct Miri do do by setting `MIRI_CWD`.
837 cmd.current_dir(info.current_dir);
838 cmd.env("MIRI_CWD", env::current_dir().unwrap());
842 eprintln!("[cargo-miri runner] {:?}", cmd);
846 RunnerPhase::Rustdoc => {
847 exec_with_pipe(cmd, &info.stdin)
849 RunnerPhase::Cargo => {
855 fn phase_rustdoc(fst_arg: &str, mut args: env::Args) {
856 let verbose = std::env::var_os("MIRI_VERBOSE").is_some();
858 // phase_cargo_miri sets the RUSTDOC env var to ourselves, so we can't use that here;
859 // just default to a straight-forward invocation for now:
860 let mut cmd = Command::new("rustdoc");
862 // Because of the way the main function is structured, we have to take the first argument spearately
863 // from the rest; to simplify the following argument patching loop, we'll just skip that one.
864 // This is fine for now, because cargo will never pass --extern arguments in the first position,
865 // but we should defensively assert that this will work.
866 let extern_flag = "--extern";
867 assert!(fst_arg != extern_flag);
870 let runtool_flag = "--runtool";
871 // `crossmode` records if *any* argument matches `runtool_flag`; here we check the first one.
872 let mut crossmode = fst_arg == runtool_flag;
873 while let Some(arg) = args.next() {
874 if arg == extern_flag {
875 // Patch --extern arguments to use *.rmeta files, since phase_cargo_rustc only creates stub *.rlib files.
876 forward_patched_extern_arg(&mut args, &mut cmd);
877 } else if arg == runtool_flag {
878 // An existing --runtool flag indicates cargo is running in cross-target mode, which we don't support.
879 // Note that this is only passed when cargo is run with the unstable -Zdoctest-xcompile flag;
880 // otherwise, we won't be called as rustdoc at all.
889 show_error(format!("cross-interpreting doc-tests is not currently supported by Miri."));
892 // For each doc-test, rustdoc starts two child processes: first the test is compiled,
893 // then the produced executable is invoked. We want to reroute both of these to cargo-miri,
894 // such that the first time we'll enter phase_cargo_rustc, and phase_cargo_runner second.
896 // rustdoc invokes the test-builder by forwarding most of its own arguments, which makes
897 // it difficult to determine when phase_cargo_rustc should run instead of phase_cargo_rustdoc.
898 // Furthermore, the test code is passed via stdin, rather than a temporary file, so we need
899 // to let phase_cargo_rustc know to expect that. We'll use this environment variable as a flag:
900 cmd.env("MIRI_CALLED_FROM_RUSTDOC", "1");
902 // The `--test-builder` and `--runtool` arguments are unstable rustdoc features,
903 // which are disabled by default. We first need to enable them explicitly:
904 cmd.arg("-Z").arg("unstable-options");
906 // rustdoc needs to know the right sysroot.
907 forward_miri_sysroot(&mut cmd);
909 // Make rustdoc call us back.
910 let cargo_miri_path = std::env::current_exe().expect("current executable path invalid");
911 cmd.arg("--test-builder").arg(&cargo_miri_path); // invoked by forwarding most arguments
912 cmd.arg("--runtool").arg(&cargo_miri_path); // invoked with just a single path argument
915 eprintln!("[cargo-miri rustdoc] {:?}", cmd);
922 // Rustc does not support non-UTF-8 arguments so we make no attempt either.
923 // (We do support non-UTF-8 environment variables though.)
924 let mut args = std::env::args();
926 args.next().unwrap();
928 // Dispatch running as part of sysroot compilation.
929 if env::var_os("MIRI_CALLED_FROM_XARGO").is_some() {
930 phase_rustc(args, RustcPhase::Setup);
934 // The way rustdoc invokes rustc is indistuingishable from the way cargo invokes rustdoc by the
935 // arguments alone. `phase_cargo_rustdoc` sets this environment variable to let us disambiguate.
936 if env::var_os("MIRI_CALLED_FROM_RUSTDOC").is_some() {
937 // ...however, we then also see this variable when rustdoc invokes us as the testrunner!
938 // The runner is invoked as `$runtool ($runtool-arg)* output_file`;
939 // since we don't specify any runtool-args, and rustdoc supplies multiple arguments to
940 // the test-builder unconditionally, we can just check the number of remaining arguments:
942 let arg = args.next().unwrap();
943 let binary = Path::new(&arg);
945 phase_runner(binary, args, RunnerPhase::Rustdoc);
947 show_error(format!("`cargo-miri` called with non-existing path argument `{}` in rustdoc mode; please invoke this binary through `cargo miri`", arg));
950 phase_rustc(args, RustcPhase::Rustdoc);
956 // Dispatch to `cargo-miri` phase. There are three phases:
957 // - When we are called via `cargo miri`, we run as the frontend and invoke the underlying
958 // cargo. We set RUSTC_WRAPPER and CARGO_TARGET_RUNNER to ourselves.
959 // - When we are executed due to RUSTC_WRAPPER, we build crates or store the flags of
960 // binary crates for later interpretation.
961 // - When we are executed due to CARGO_TARGET_RUNNER, we start interpretation based on the
962 // flags that were stored earlier.
963 // On top of that, we are also called as RUSTDOC, but that is just a stub currently.
964 match args.next().as_deref() {
965 Some("miri") => phase_cargo_miri(args),
966 Some("rustc") => phase_rustc(args, RustcPhase::Build),
968 // We have to distinguish the "runner" and "rustdoc" cases.
969 // As runner, the first argument is the binary (a file that should exist, with an absolute path);
970 // as rustdoc, the first argument is a flag (`--something`).
971 let binary = Path::new(arg);
973 assert!(!arg.starts_with("--")); // not a flag
974 phase_runner(binary, args, RunnerPhase::Cargo);
975 } else if arg.starts_with("--") {
976 phase_rustdoc(arg, args);
978 show_error(format!("`cargo-miri` called with unexpected first argument `{}`; please only invoke this binary through `cargo miri`", arg));
981 _ => show_error(format!("`cargo-miri` called without first argument; please only invoke this binary through `cargo miri`")),