2 #![allow(clippy::useless_format, clippy::derive_partial_eq_without_eq)]
7 use std::ffi::{OsStr, OsString};
8 use std::fmt::Write as _;
9 use std::fs::{self, File};
10 use std::io::{self, BufRead, BufReader, BufWriter, Read, Write};
11 use std::iter::TakeWhile;
13 use std::path::{Path, PathBuf};
14 use std::process::{self, Command};
16 use rustc_version::VersionMeta;
17 use serde::{Deserialize, Serialize};
21 const CARGO_MIRI_HELP: &str = r#"Runs binary crates and tests in Miri
24 cargo miri [subcommand] [<cargo options>...] [--] [<program/test suite options>...]
29 setup Only perform automatic setup, but without asking questions (for getting a proper libstd)
31 The cargo options are exactly the same as for `cargo run` and `cargo test`, respectively.
35 cargo miri test -- test-suite-filter
38 #[derive(Clone, Debug)]
40 /// Our own special 'setup' command.
42 /// A command to be forwarded to cargo.
46 /// The information to run a crate with the given environment.
47 #[derive(Serialize, Deserialize)]
49 /// The command-line arguments.
52 env: Vec<(OsString, OsString)>,
53 /// The current working directory.
54 current_dir: OsString,
55 /// The contents passed via standard input.
60 /// Gather all the information we need.
61 fn collect(args: env::Args, capture_stdin: bool) -> Self {
62 let args = args.collect();
63 let env = env::vars_os().collect();
64 let current_dir = env::current_dir().unwrap().into_os_string();
66 let mut stdin = Vec::new();
68 std::io::stdin().lock().read_to_end(&mut stdin).expect("cannot read stdin");
71 CrateRunEnv { args, env, current_dir, stdin }
75 /// The information Miri needs to run a crate. Stored as JSON when the crate is "compiled".
76 #[derive(Serialize, Deserialize)]
78 /// Run it with the given environment.
80 /// Skip it as Miri does not support interpreting such kind of crates.
85 fn store(&self, filename: &Path) {
86 let file = File::create(filename)
87 .unwrap_or_else(|_| show_error(format!("cannot create `{}`", filename.display())));
88 let file = BufWriter::new(file);
89 serde_json::ser::to_writer(file, self)
90 .unwrap_or_else(|_| show_error(format!("cannot write to `{}`", filename.display())));
95 println!("{}", CARGO_MIRI_HELP);
99 let mut version = format!("miri {}", env!("CARGO_PKG_VERSION"));
100 // Only use `option_env` on vergen variables to ensure the build succeeds
101 // when vergen failed to find the git info.
102 if let Some(sha) = option_env!("VERGEN_GIT_SHA_SHORT") {
103 // This `unwrap` can never fail because if VERGEN_GIT_SHA_SHORT exists, then so does
104 // VERGEN_GIT_COMMIT_DATE.
105 #[allow(clippy::option_env_unwrap)]
106 write!(&mut version, " ({} {})", sha, option_env!("VERGEN_GIT_COMMIT_DATE").unwrap())
109 println!("{}", version);
112 fn show_error(msg: String) -> ! {
113 eprintln!("fatal error: {}", msg);
114 std::process::exit(1)
117 // Determines whether a `--flag` is present.
118 fn has_arg_flag(name: &str) -> bool {
119 let mut args = std::env::args().take_while(|val| val != "--");
120 args.any(|val| val == name)
123 /// Yields all values of command line flag `name` as `Ok(arg)`, and all other arguments except
124 /// the flag as `Err(arg)`. (The flag `name` itself is not yielded at all, only its values are.)
125 struct ArgSplitFlagValue<'a, I> {
126 args: TakeWhile<I, fn(&String) -> bool>,
130 impl<'a, I: Iterator<Item = String>> ArgSplitFlagValue<'a, I> {
131 fn new(args: I, name: &'a str) -> Self {
133 // Stop searching at `--`.
134 args: args.take_while(|val| val != "--"),
140 impl<I: Iterator<Item = String>> Iterator for ArgSplitFlagValue<'_, I> {
141 type Item = Result<String, String>;
143 fn next(&mut self) -> Option<Self::Item> {
144 let arg = self.args.next()?;
145 if let Some(suffix) = arg.strip_prefix(self.name) {
146 // Strip leading `name`.
147 if suffix.is_empty() {
148 // This argument is exactly `name`; the next one is the value.
149 return self.args.next().map(Ok);
150 } else if let Some(suffix) = suffix.strip_prefix('=') {
151 // This argument is `name=value`; get the value.
152 return Some(Ok(suffix.to_owned()));
159 /// Yields all values of command line flag `name`.
160 struct ArgFlagValueIter<'a>(ArgSplitFlagValue<'a, env::Args>);
162 impl<'a> ArgFlagValueIter<'a> {
163 fn new(name: &'a str) -> Self {
164 Self(ArgSplitFlagValue::new(env::args(), name))
168 impl Iterator for ArgFlagValueIter<'_> {
171 fn next(&mut self) -> Option<Self::Item> {
173 if let Ok(value) = self.0.next()? {
180 /// Gets the value of a `--flag`.
181 fn get_arg_flag_value(name: &str) -> Option<String> {
182 ArgFlagValueIter::new(name).next()
185 fn forward_patched_extern_arg(args: &mut impl Iterator<Item = String>, cmd: &mut Command) {
186 cmd.arg("--extern"); // always forward flag, but adjust filename:
187 let path = args.next().expect("`--extern` should be followed by a filename");
188 if let Some(lib) = path.strip_suffix(".rlib") {
189 // If this is an rlib, make it an rmeta.
190 cmd.arg(format!("{}.rmeta", lib));
192 // Some other extern file (e.g. a `.so`). Forward unchanged.
197 fn forward_miri_sysroot(cmd: &mut Command) {
198 let sysroot = env::var_os("MIRI_SYSROOT").expect("the wrapper should have set MIRI_SYSROOT");
199 cmd.arg("--sysroot");
203 /// Returns the path to the `miri` binary
204 fn find_miri() -> PathBuf {
205 if let Some(path) = env::var_os("MIRI") {
208 let mut path = std::env::current_exe().expect("current executable path invalid");
209 path.set_file_name("miri");
213 fn miri() -> Command {
214 Command::new(find_miri())
217 fn version_info() -> VersionMeta {
218 VersionMeta::for_command(miri()).expect("failed to determine underlying rustc version of Miri")
221 fn cargo() -> Command {
222 Command::new(env::var_os("CARGO").unwrap_or_else(|| OsString::from("cargo")))
225 fn xargo_check() -> Command {
226 Command::new(env::var_os("XARGO_CHECK").unwrap_or_else(|| OsString::from("xargo-check")))
229 /// Execute the command. If it fails, fail this process with the same exit code.
230 /// Otherwise, continue.
231 fn exec(mut cmd: Command) {
232 let exit_status = cmd.status().expect("failed to run command");
233 if exit_status.success().not() {
234 std::process::exit(exit_status.code().unwrap_or(-1))
238 /// Execute the command and pipe `input` into its stdin.
239 /// If it fails, fail this process with the same exit code.
240 /// Otherwise, continue.
241 fn exec_with_pipe(mut cmd: Command, input: &[u8]) {
242 cmd.stdin(process::Stdio::piped());
243 let mut child = cmd.spawn().expect("failed to spawn process");
245 let stdin = child.stdin.as_mut().expect("failed to open stdin");
246 stdin.write_all(input).expect("failed to write out test source");
248 let exit_status = child.wait().expect("failed to run command");
249 if exit_status.success().not() {
250 std::process::exit(exit_status.code().unwrap_or(-1))
254 fn xargo_version() -> Option<(u32, u32, u32)> {
255 let out = xargo_check().arg("--version").output().ok()?;
256 if !out.status.success() {
259 // Parse output. The first line looks like "xargo 0.3.12 (b004f1c 2018-12-13)".
264 .expect("malformed `xargo --version` output: not at least one line")
265 .expect("malformed `xargo --version` output: error reading first line");
266 let (name, version) = {
267 let mut split = line.split(' ');
269 split.next().expect("malformed `xargo --version` output: empty"),
270 split.next().expect("malformed `xargo --version` output: not at least two words"),
274 // This is some fork of xargo
277 let mut version_pieces = version.split('.');
278 let major = version_pieces
280 .expect("malformed `xargo --version` output: not a major version piece")
282 .expect("malformed `xargo --version` output: major version is not an integer");
283 let minor = version_pieces
285 .expect("malformed `xargo --version` output: not a minor version piece")
287 .expect("malformed `xargo --version` output: minor version is not an integer");
288 let patch = version_pieces
290 .expect("malformed `xargo --version` output: not a patch version piece")
292 .expect("malformed `xargo --version` output: patch version is not an integer");
293 if version_pieces.next().is_some() {
294 panic!("malformed `xargo --version` output: more than three pieces in version");
296 Some((major, minor, patch))
299 fn ask_to_run(mut cmd: Command, ask: bool, text: &str) {
300 // Disable interactive prompts in CI (GitHub Actions, Travis, AppVeyor, etc).
301 // Azure doesn't set `CI` though (nothing to see here, just Microsoft being Microsoft),
302 // so we also check their `TF_BUILD`.
303 let is_ci = env::var_os("CI").is_some() || env::var_os("TF_BUILD").is_some();
305 let mut buf = String::new();
306 print!("I will run `{:?}` to {}. Proceed? [Y/n] ", cmd, text);
307 io::stdout().flush().unwrap();
308 io::stdin().read_line(&mut buf).unwrap();
309 match buf.trim().to_lowercase().as_ref() {
311 "" | "y" | "yes" => {}
312 "n" | "no" => show_error(format!("aborting as per your request")),
313 a => show_error(format!("invalid answer `{}`", a)),
316 println!("Running `{:?}` to {}.", cmd, text);
319 if cmd.status().unwrap_or_else(|_| panic!("failed to execute {:?}", cmd)).success().not() {
320 show_error(format!("failed to {}", text));
324 /// Writes the given content to the given file *cross-process atomically*, in the sense that another
325 /// process concurrently reading that file will see either the old content or the new content, but
326 /// not some intermediate (e.g., empty) state.
328 /// We assume no other parts of this same process are trying to read or write that file.
329 fn write_to_file(filename: &Path, content: &str) {
330 // Create a temporary file with the desired contents.
331 let mut temp_filename = filename.as_os_str().to_os_string();
332 temp_filename.push(&format!(".{}", std::process::id()));
333 let mut temp_file = File::create(&temp_filename).unwrap();
334 temp_file.write_all(content.as_bytes()).unwrap();
337 // Move file to the desired location.
338 fs::rename(temp_filename, filename).unwrap();
341 /// Performs the setup required to make `cargo miri` work: Getting a custom-built libstd. Then sets
342 /// `MIRI_SYSROOT`. Skipped if `MIRI_SYSROOT` is already set, in which case we expect the user has
343 /// done all this already.
344 fn setup(subcommand: &MiriCommand) {
345 let only_setup = matches!(subcommand, MiriCommand::Setup);
346 if std::env::var_os("MIRI_SYSROOT").is_some() {
348 println!("WARNING: MIRI_SYSROOT already set, not doing anything.")
353 // Subcommands other than `setup` will do a setup if necessary, but
354 // interactively confirm first.
355 let ask_user = !only_setup;
357 // First, we need xargo.
358 if xargo_version().map_or(true, |v| v < XARGO_MIN_VERSION) {
359 if std::env::var_os("XARGO_CHECK").is_some() {
360 // The user manually gave us a xargo binary; don't do anything automatically.
361 show_error(format!("xargo is too old; please upgrade to the latest version"))
363 let mut cmd = cargo();
364 cmd.args(&["install", "xargo"]);
365 ask_to_run(cmd, ask_user, "install a recent enough xargo");
368 // Determine where the rust sources are located. The env vars manually setting the source
369 // (`MIRI_LIB_SRC`, `XARGO_RUST_SRC`) trump auto-detection.
370 let rust_src_env_var =
371 std::env::var_os("MIRI_LIB_SRC").or_else(|| std::env::var_os("XARGO_RUST_SRC"));
372 let rust_src = match rust_src_env_var {
374 let path = PathBuf::from(path);
375 // Make path absolute if possible.
376 path.canonicalize().unwrap_or(path)
379 // Check for `rust-src` rustup component.
381 miri().args(&["--print", "sysroot"]).output().expect("failed to determine sysroot");
382 if !output.status.success() {
384 "Failed to determine sysroot; Miri said:\n{}",
385 String::from_utf8_lossy(&output.stderr).trim_end()
388 let sysroot = std::str::from_utf8(&output.stdout).unwrap();
389 let sysroot = Path::new(sysroot.trim_end_matches('\n'));
390 // Check for `$SYSROOT/lib/rustlib/src/rust/library`; test if that contains `std/Cargo.toml`.
392 sysroot.join("lib").join("rustlib").join("src").join("rust").join("library");
393 if !rustup_src.join("std").join("Cargo.toml").exists() {
394 // Ask the user to install the `rust-src` component, and use that.
395 let mut cmd = Command::new("rustup");
396 cmd.args(&["component", "add", "rust-src"]);
400 "install the `rust-src` component for the selected toolchain",
406 if !rust_src.exists() {
407 show_error(format!("given Rust source directory `{}` does not exist.", rust_src.display()));
409 if rust_src.file_name().and_then(OsStr::to_str) != Some("library") {
411 "given Rust source directory `{}` does not seem to be the `library` subdirectory of \
412 a Rust source checkout.",
417 // Next, we need our own libstd. Prepare a xargo project for that purpose.
418 // We will do this work in whatever is a good cache dir for this platform.
419 let dirs = directories::ProjectDirs::from("org", "rust-lang", "miri").unwrap();
420 let dir = dirs.cache_dir();
422 fs::create_dir_all(&dir).unwrap();
424 // The interesting bit: Xargo.toml (only needs content if we actually need std)
425 let xargo_toml = if std::env::var_os("MIRI_NO_STD").is_some() {
430 default_features = false
431 # We support unwinding, so enable that panic runtime.
432 features = ["panic_unwind", "backtrace"]
437 write_to_file(&dir.join("Xargo.toml"), xargo_toml);
438 // The boring bits: a dummy project for xargo.
439 // FIXME: With xargo-check, can we avoid doing this?
441 &dir.join("Cargo.toml"),
445 description = "A dummy project for building libstd with xargo."
452 write_to_file(&dir.join("lib.rs"), "#![no_std]");
454 // Determine architectures.
455 // We always need to set a target so rustc bootstrap can tell apart host from target crates.
456 let host = version_info().host;
457 let target = get_arg_flag_value("--target");
458 let target = target.as_ref().unwrap_or(&host);
460 let mut command = xargo_check();
461 command.arg("check").arg("-q");
462 command.arg("--target").arg(target);
463 command.current_dir(&dir);
464 command.env("XARGO_HOME", &dir);
465 command.env("XARGO_RUST_SRC", &rust_src);
466 // Use Miri as rustc to build a libstd compatible with us (and use the right flags).
467 // However, when we are running in bootstrap, we cannot just overwrite `RUSTC`,
468 // because we still need bootstrap to distinguish between host and target crates.
469 // In that case we overwrite `RUSTC_REAL` instead which determines the rustc used
470 // for target crates.
471 // We set ourselves (`cargo-miri`) instead of Miri directly to be able to patch the flags
472 // for `libpanic_abort` (usually this is done by bootstrap but we have to do it ourselves).
473 // The `MIRI_CALLED_FROM_XARGO` will mean we dispatch to `phase_setup_rustc`.
474 let cargo_miri_path = std::env::current_exe().expect("current executable path invalid");
475 if env::var_os("RUSTC_STAGE").is_some() {
476 command.env("RUSTC_REAL", &cargo_miri_path);
478 command.env("RUSTC", &cargo_miri_path);
480 command.env("MIRI_CALLED_FROM_XARGO", "1");
481 // Make sure there are no other wrappers or flags getting in our way
482 // (Cc https://github.com/rust-lang/miri/issues/1421).
483 // This is consistent with normal `cargo build` that does not apply `RUSTFLAGS`
484 // to the sysroot either.
485 command.env_remove("RUSTC_WRAPPER");
486 command.env_remove("RUSTFLAGS");
487 // Disable debug assertions in the standard library -- Miri is already slow enough.
488 // But keep the overflow checks, they are cheap.
489 command.env("RUSTFLAGS", "-Cdebug-assertions=off -Coverflow-checks=on");
491 if command.status().expect("failed to run xargo").success().not() {
492 show_error(format!("failed to run xargo"));
495 // That should be it! But we need to figure out where xargo built stuff.
496 // Unfortunately, it puts things into a different directory when the
497 // architecture matches the host.
498 let sysroot = if target == &host { dir.join("HOST") } else { PathBuf::from(dir) };
499 std::env::set_var("MIRI_SYSROOT", &sysroot); // pass the env var to the processes we spawn, which will turn it into "--sysroot" flags
500 // Figure out what to print.
501 let print_sysroot = only_setup && has_arg_flag("--print-sysroot"); // whether we just print the sysroot path
503 // Print just the sysroot and nothing else; this way we do not need any escaping.
504 println!("{}", sysroot.display());
505 } else if only_setup {
506 println!("A libstd for Miri is now available in `{}`.", sysroot.display());
510 #[derive(Deserialize)]
512 target_directory: PathBuf,
513 workspace_members: Vec<String>,
516 fn get_cargo_metadata() -> Metadata {
517 let mut cmd = cargo();
518 // `-Zunstable-options` is required by `--config`.
519 cmd.args(["metadata", "--no-deps", "--format-version=1", "-Zunstable-options"]);
520 // The `build.target-dir` config can be passed by `--config` flags, so forward them to
522 let config_flag = "--config";
523 for arg in ArgSplitFlagValue::new(
524 env::args().skip(3), // skip the program name, "miri" and "run" / "test"
530 cmd.arg(config_flag).arg(arg);
533 .stdin(process::Stdio::null())
534 .stdout(process::Stdio::piped())
536 .expect("failed ro run `cargo metadata`");
537 // Check this `Result` after `status.success()` is checked, so we don't print the error
538 // to stderr if `cargo metadata` is also printing to stderr.
539 let metadata: Result<Metadata, _> = serde_json::from_reader(child.stdout.take().unwrap());
540 let status = child.wait().expect("failed to wait for `cargo metadata` to exit");
541 if !status.success() {
542 std::process::exit(status.code().unwrap_or(-1));
544 metadata.unwrap_or_else(|e| show_error(format!("invalid `cargo metadata` output: {}", e)))
547 /// Pulls all the crates in this workspace from the cargo metadata.
548 /// Workspace members are emitted like "miri 0.1.0 (path+file:///path/to/miri)"
549 /// Additionally, somewhere between cargo metadata and TyCtxt, '-' gets replaced with '_' so we
550 /// make that same transformation here.
551 fn local_crates(metadata: &Metadata) -> String {
552 assert!(!metadata.workspace_members.is_empty());
553 let mut local_crates = String::new();
554 for member in &metadata.workspace_members {
555 let name = member.split(' ').next().unwrap();
556 let name = name.replace('-', "_");
557 local_crates.push_str(&name);
558 local_crates.push(',');
560 local_crates.pop(); // Remove the trailing ','
565 fn phase_cargo_miri(mut args: env::Args) {
566 // Check for version and help flags even when invoked as `cargo-miri`.
567 if has_arg_flag("--help") || has_arg_flag("-h") {
571 if has_arg_flag("--version") || has_arg_flag("-V") {
576 // Require a subcommand before any flags.
577 // We cannot know which of those flags take arguments and which do not,
578 // so we cannot detect subcommands later.
579 let Some(subcommand) = args.next() else {
580 show_error(format!("`cargo miri` needs to be called with a subcommand (`run`, `test`)"));
582 let subcommand = match &*subcommand {
583 "setup" => MiriCommand::Setup,
584 "test" | "t" | "run" | "r" => MiriCommand::Forward(subcommand),
588 "`cargo miri` supports the following subcommands: `run`, `test`, and `setup`."
591 let verbose = has_arg_flag("-v");
596 // Invoke actual cargo for the job, but with different flags.
597 // We re-use `cargo test` and `cargo run`, which makes target and binary handling very easy but
598 // requires some extra work to make the build check-only (see all the `--emit` hacks below).
599 // <https://github.com/rust-lang/miri/pull/1540#issuecomment-693553191> describes an alternative
600 // approach that uses `cargo check`, making that part easier but target and binary handling
602 let cargo_miri_path = std::env::current_exe().expect("current executable path invalid");
603 let cargo_cmd = match subcommand {
604 MiriCommand::Forward(s) => s,
605 MiriCommand::Setup => return, // `cargo miri setup` stops here.
607 let mut cmd = cargo();
610 // Make sure we know the build target, and cargo does, too.
611 // This is needed to make the `CARGO_TARGET_*_RUNNER` env var do something,
612 // and it later helps us detect which crates are proc-macro/build-script
613 // (host crates) and which crates are needed for the program itself.
614 let host = version_info().host;
615 let target = get_arg_flag_value("--target");
616 let target = if let Some(ref target) = target {
619 // No target given. Pick default and tell cargo about it.
625 let mut target_dir = None;
627 // Forward all arguments before `--` other than `--target-dir` and its value to Cargo.
628 for arg in ArgSplitFlagValue::new(&mut args, "--target-dir") {
631 if target_dir.is_some() {
632 show_error(format!("`--target-dir` is provided more than once"));
634 target_dir = Some(value.into());
642 let metadata = get_cargo_metadata();
644 // Detect the target directory if it's not specified via `--target-dir`.
645 let target_dir = target_dir.get_or_insert_with(|| metadata.target_directory.clone());
647 // Set `--target-dir` to `miri` inside the original target directory.
648 target_dir.push("miri");
649 cmd.arg("--target-dir").arg(target_dir);
651 // Forward all further arguments after `--` to cargo.
652 cmd.arg("--").args(args);
654 // Set `RUSTC_WRAPPER` to ourselves. Cargo will prepend that binary to its usual invocation,
655 // i.e., the first argument is `rustc` -- which is what we use in `main` to distinguish
656 // the two codepaths. (That extra argument is why we prefer this over setting `RUSTC`.)
657 if env::var_os("RUSTC_WRAPPER").is_some() {
659 "WARNING: Ignoring `RUSTC_WRAPPER` environment variable, Miri does not support wrapping."
662 cmd.env("RUSTC_WRAPPER", &cargo_miri_path);
663 // Having both `RUSTC_WRAPPER` and `RUSTC` set does some odd things, so let's avoid that.
664 // See <https://github.com/rust-lang/miri/issues/2238>.
665 if env::var_os("RUSTC").is_some() && env::var_os("MIRI").is_none() {
667 "WARNING: Ignoring `RUSTC` environment variable; set `MIRI` if you want to control the binary used as the driver."
670 cmd.env_remove("RUSTC");
672 let runner_env_name =
673 |triple: &str| format!("CARGO_TARGET_{}_RUNNER", triple.to_uppercase().replace('-', "_"));
674 let host_runner_env_name = runner_env_name(&host);
675 let target_runner_env_name = runner_env_name(target);
676 // Set the target runner to us, so we can interpret the binaries.
677 cmd.env(&target_runner_env_name, &cargo_miri_path);
678 // Unit tests of `proc-macro` crates are run on the host, so we set the host runner to
679 // us in order to skip them.
680 cmd.env(&host_runner_env_name, &cargo_miri_path);
682 // Set rustdoc to us as well, so we can run doctests.
683 cmd.env("RUSTDOC", &cargo_miri_path);
685 cmd.env("MIRI_LOCAL_CRATES", local_crates(&metadata));
689 eprintln!("[cargo-miri miri] RUSTC_WRAPPER={:?}", cargo_miri_path);
690 eprintln!("[cargo-miri miri] {}={:?}", target_runner_env_name, cargo_miri_path);
692 eprintln!("[cargo-miri miri] {}={:?}", host_runner_env_name, cargo_miri_path);
694 eprintln!("[cargo-miri miri] RUSTDOC={:?}", cargo_miri_path);
695 eprintln!("[cargo-miri miri] {:?}", cmd);
696 cmd.env("MIRI_VERBOSE", ""); // This makes the other phases verbose.
701 #[derive(Debug, Copy, Clone, PartialEq)]
703 /// `rustc` called via `xargo` for sysroot build.
705 /// `rustc` called by `cargo` for regular build.
707 /// `rustc` called by `rustdoc` for doctest.
711 fn phase_rustc(mut args: env::Args, phase: RustcPhase) {
712 /// Determines if we are being invoked (as rustc) to build a crate for
713 /// the "target" architecture, in contrast to the "host" architecture.
714 /// Host crates are for build scripts and proc macros and still need to
715 /// be built like normal; target crates need to be built for or interpreted
718 /// Currently, we detect this by checking for "--target=", which is
719 /// never set for host crates. This matches what rustc bootstrap does,
720 /// which hopefully makes it "reliable enough". This relies on us always
721 /// invoking cargo itself with `--target`, which `in_cargo_miri` ensures.
722 fn is_target_crate() -> bool {
723 get_arg_flag_value("--target").is_some()
726 /// Returns whether or not Cargo invoked the wrapper (this binary) to compile
727 /// the final, binary crate (either a test for 'cargo test', or a binary for 'cargo run')
728 /// Cargo does not give us this information directly, so we need to check
729 /// various command-line flags.
730 fn is_runnable_crate() -> bool {
731 let is_bin = get_arg_flag_value("--crate-type").as_deref().unwrap_or("bin") == "bin";
732 let is_test = has_arg_flag("--test");
736 fn out_filename(prefix: &str, suffix: &str) -> PathBuf {
737 if let Some(out_dir) = get_arg_flag_value("--out-dir") {
738 let mut path = PathBuf::from(out_dir);
742 get_arg_flag_value("--crate-name").unwrap(),
743 // This is technically a `-C` flag but the prefix seems unique enough...
744 // (and cargo passes this before the filename so it should be unique)
745 get_arg_flag_value("extra-filename").unwrap_or_default(),
750 let out_file = get_arg_flag_value("-o").unwrap();
751 PathBuf::from(out_file)
755 let verbose = std::env::var_os("MIRI_VERBOSE").is_some();
756 let target_crate = is_target_crate();
757 let print = get_arg_flag_value("--print").is_some() || has_arg_flag("-vV"); // whether this is cargo/xargo invoking rustc to get some infos
759 let store_json = |info: CrateRunInfo| {
760 // Create a stub .d file to stop Cargo from "rebuilding" the crate:
761 // https://github.com/rust-lang/miri/issues/1724#issuecomment-787115693
762 // As we store a JSON file instead of building the crate here, an empty file is fine.
763 let dep_info_name = out_filename("", ".d");
765 eprintln!("[cargo-miri rustc] writing stub dep-info to `{}`", dep_info_name.display());
767 File::create(dep_info_name).expect("failed to create fake .d file");
769 let filename = out_filename("", "");
771 eprintln!("[cargo-miri rustc] writing run info to `{}`", filename.display());
773 info.store(&filename);
774 // For Windows, do the same thing again with `.exe` appended to the filename.
775 // (Need to do this here as cargo moves that "binary" to a different place before running it.)
776 info.store(&out_filename("", ".exe"));
779 let runnable_crate = !print && is_runnable_crate();
781 if runnable_crate && target_crate {
783 phase != RustcPhase::Setup,
784 "there should be no interpretation during sysroot build"
786 let inside_rustdoc = phase == RustcPhase::Rustdoc;
787 // This is the binary or test crate that we want to interpret under Miri.
788 // But we cannot run it here, as cargo invoked us as a compiler -- our stdin and stdout are not
789 // like we want them.
790 // Instead of compiling, we write JSON into the output file with all the relevant command-line flags
791 // and environment variables; this is used when cargo calls us again in the CARGO_TARGET_RUNNER phase.
792 let env = CrateRunEnv::collect(args, inside_rustdoc);
794 // Rustdoc expects us to exit with an error code if the test is marked as `compile_fail`,
795 // just creating the JSON file is not enough: we need to detect syntax errors,
796 // so we need to run Miri with `MIRI_BE_RUSTC` for a check-only build.
798 let mut cmd = miri();
800 // Ensure --emit argument for a check-only build is present.
801 // We cannot use the usual helpers since we need to check specifically in `env.args`.
802 if let Some(i) = env.args.iter().position(|arg| arg.starts_with("--emit=")) {
803 // For `no_run` tests, rustdoc passes a `--emit` flag; make sure it has the right shape.
804 assert_eq!(env.args[i], "--emit=metadata");
806 // For all other kinds of tests, we can just add our flag.
807 cmd.arg("--emit=metadata");
811 cmd.env("MIRI_BE_RUSTC", "target");
815 "[cargo-miri rustc] captured input:\n{}",
816 std::str::from_utf8(&env.stdin).unwrap()
818 eprintln!("[cargo-miri rustc] {:?}", cmd);
821 exec_with_pipe(cmd, &env.stdin);
824 store_json(CrateRunInfo::RunWith(env));
829 if runnable_crate && ArgFlagValueIter::new("--extern").any(|krate| krate == "proc_macro") {
830 // This is a "runnable" `proc-macro` crate (unit tests). We do not support
831 // interpreting that under Miri now, so we write a JSON file to (display a
832 // helpful message and) skip it in the runner phase.
833 store_json(CrateRunInfo::SkipProcMacroTest);
837 let mut cmd = miri();
838 let mut emit_link_hack = false;
839 // Arguments are treated very differently depending on whether this crate is
840 // for interpretation by Miri, or for use by a build script / proc macro.
841 if !print && target_crate {
842 // Forward arguments, but remove "link" from "--emit" to make this a check-only build.
843 let emit_flag = "--emit";
844 while let Some(arg) = args.next() {
845 if let Some(val) = arg.strip_prefix(emit_flag) {
846 // Patch this argument. First, extract its value.
848 val.strip_prefix('=').expect("`cargo` should pass `--emit=X` as one argument");
849 let mut val: Vec<_> = val.split(',').collect();
850 // Now make sure "link" is not in there, but "metadata" is.
851 if let Some(i) = val.iter().position(|&s| s == "link") {
852 emit_link_hack = true;
854 if !val.iter().any(|&s| s == "metadata") {
855 val.push("metadata");
858 cmd.arg(format!("{}={}", emit_flag, val.join(",")));
859 } else if arg == "--extern" {
860 // Patch `--extern` filenames, since Cargo sometimes passes stub `.rlib` files:
861 // https://github.com/rust-lang/miri/issues/1705
862 forward_patched_extern_arg(&mut args, &mut cmd);
868 // Use our custom sysroot (but not if that is what we are currently building).
869 if phase != RustcPhase::Setup {
870 forward_miri_sysroot(&mut cmd);
873 // During setup, patch the panic runtime for `libpanic_abort` (mirroring what bootstrap usually does).
874 if phase == RustcPhase::Setup
875 && get_arg_flag_value("--crate-name").as_deref() == Some("panic_abort")
877 cmd.arg("-C").arg("panic=abort");
880 // For host crates or when we are printing, just forward everything.
884 // We want to compile, not interpret. We still use Miri to make sure the compiler version etc
885 // are the exact same as what is used for interpretation.
886 // MIRI_DEFAULT_ARGS should not be used to build host crates, hence setting "target" or "host"
887 // as the value here to help Miri differentiate them.
888 cmd.env("MIRI_BE_RUSTC", if target_crate { "target" } else { "host" });
892 eprintln!("[cargo-miri rustc] {:?}", cmd);
896 // Create a stub .rlib file if "link" was requested by cargo.
897 // This is necessary to prevent cargo from doing rebuilds all the time.
899 // Some platforms prepend "lib", some do not... let's just create both files.
900 File::create(out_filename("lib", ".rlib")).expect("failed to create fake .rlib file");
901 File::create(out_filename("", ".rlib")).expect("failed to create fake .rlib file");
902 // Just in case this is a cdylib or staticlib, also create those fake files.
903 File::create(out_filename("lib", ".so")).expect("failed to create fake .so file");
904 File::create(out_filename("lib", ".a")).expect("failed to create fake .a file");
905 File::create(out_filename("lib", ".dylib")).expect("failed to create fake .dylib file");
906 File::create(out_filename("", ".dll")).expect("failed to create fake .dll file");
907 File::create(out_filename("", ".lib")).expect("failed to create fake .lib file");
911 #[derive(Debug, Copy, Clone, PartialEq)]
913 /// `cargo` is running a binary
915 /// `rustdoc` is running a binary
919 fn phase_runner(binary: &Path, binary_args: env::Args, phase: RunnerPhase) {
920 let verbose = std::env::var_os("MIRI_VERBOSE").is_some();
922 let file = File::open(&binary)
923 .unwrap_or_else(|_| show_error(format!("file {:?} not found or `cargo-miri` invoked incorrectly; please only invoke this binary through `cargo miri`", binary)));
924 let file = BufReader::new(file);
926 let info = serde_json::from_reader(file).unwrap_or_else(|_| {
928 "file {:?} contains outdated or invalid JSON; try `cargo clean`",
932 let info = match info {
933 CrateRunInfo::RunWith(info) => info,
934 CrateRunInfo::SkipProcMacroTest => {
936 "Running unit tests of `proc-macro` crates is not currently supported by Miri."
942 let mut cmd = miri();
944 // Set missing env vars. We prefer build-time env vars over run-time ones; see
945 // <https://github.com/rust-lang/miri/issues/1661> for the kind of issue that fixes.
946 for (name, val) in info.env {
948 if let Some(old_val) = env::var_os(&name) {
951 "[cargo-miri runner] Overwriting run-time env var {:?}={:?} with build-time value {:?}",
960 // Forward rustc arguments.
961 // We need to patch "--extern" filenames because we forced a check-only
962 // build without cargo knowing about that: replace `.rlib` suffix by
964 // We also need to remove `--error-format` as cargo specifies that to be JSON,
965 // but when we run here, cargo does not interpret the JSON any more. `--json`
966 // then also nees to be dropped.
967 let mut args = info.args.into_iter();
968 let error_format_flag = "--error-format";
969 let json_flag = "--json";
970 while let Some(arg) = args.next() {
971 if arg == "--extern" {
972 forward_patched_extern_arg(&mut args, &mut cmd);
973 } else if let Some(suffix) = arg.strip_prefix(error_format_flag) {
974 assert!(suffix.starts_with('='));
975 // Drop this argument.
976 } else if let Some(suffix) = arg.strip_prefix(json_flag) {
977 assert!(suffix.starts_with('='));
978 // Drop this argument.
983 // Set sysroot (if we are inside rustdoc, we already did that in `phase_cargo_rustdoc`).
984 if phase != RunnerPhase::Rustdoc {
985 forward_miri_sysroot(&mut cmd);
987 // Respect `MIRIFLAGS`.
988 if let Ok(a) = env::var("MIRIFLAGS") {
989 // This code is taken from `RUSTFLAGS` handling in cargo.
990 let args = a.split(' ').map(str::trim).filter(|s| !s.is_empty()).map(str::to_string);
994 // Then pass binary arguments.
996 cmd.args(binary_args);
998 // Make sure we use the build-time working directory for interpreting Miri/rustc arguments.
999 // But then we need to switch to the run-time one, which we instruct Miri do do by setting `MIRI_CWD`.
1000 cmd.current_dir(info.current_dir);
1001 cmd.env("MIRI_CWD", env::current_dir().unwrap());
1005 eprintln!("[cargo-miri runner] {:?}", cmd);
1009 RunnerPhase::Rustdoc => exec_with_pipe(cmd, &info.stdin),
1010 RunnerPhase::Cargo => exec(cmd),
1014 fn phase_rustdoc(fst_arg: &str, mut args: env::Args) {
1015 let verbose = std::env::var_os("MIRI_VERBOSE").is_some();
1017 // phase_cargo_miri sets the RUSTDOC env var to ourselves, so we can't use that here;
1018 // just default to a straight-forward invocation for now:
1019 let mut cmd = Command::new("rustdoc");
1021 // Because of the way the main function is structured, we have to take the first argument spearately
1022 // from the rest; to simplify the following argument patching loop, we'll just skip that one.
1023 // This is fine for now, because cargo will never pass --extern arguments in the first position,
1024 // but we should defensively assert that this will work.
1025 let extern_flag = "--extern";
1026 assert!(fst_arg != extern_flag);
1029 let runtool_flag = "--runtool";
1030 // `crossmode` records if *any* argument matches `runtool_flag`; here we check the first one.
1031 let mut crossmode = fst_arg == runtool_flag;
1032 while let Some(arg) = args.next() {
1033 if arg == extern_flag {
1034 // Patch --extern arguments to use *.rmeta files, since phase_cargo_rustc only creates stub *.rlib files.
1035 forward_patched_extern_arg(&mut args, &mut cmd);
1036 } else if arg == runtool_flag {
1037 // An existing --runtool flag indicates cargo is running in cross-target mode, which we don't support.
1038 // Note that this is only passed when cargo is run with the unstable -Zdoctest-xcompile flag;
1039 // otherwise, we won't be called as rustdoc at all.
1048 show_error(format!("cross-interpreting doctests is not currently supported by Miri."));
1051 // Doctests of `proc-macro` crates (and their dependencies) are always built for the host,
1052 // so we are not able to run them in Miri.
1053 if ArgFlagValueIter::new("--crate-type").any(|crate_type| crate_type == "proc-macro") {
1054 eprintln!("Running doctests of `proc-macro` crates is not currently supported by Miri.");
1058 // For each doctest, rustdoc starts two child processes: first the test is compiled,
1059 // then the produced executable is invoked. We want to reroute both of these to cargo-miri,
1060 // such that the first time we'll enter phase_cargo_rustc, and phase_cargo_runner second.
1062 // rustdoc invokes the test-builder by forwarding most of its own arguments, which makes
1063 // it difficult to determine when phase_cargo_rustc should run instead of phase_cargo_rustdoc.
1064 // Furthermore, the test code is passed via stdin, rather than a temporary file, so we need
1065 // to let phase_cargo_rustc know to expect that. We'll use this environment variable as a flag:
1066 cmd.env("MIRI_CALLED_FROM_RUSTDOC", "1");
1068 // The `--test-builder` and `--runtool` arguments are unstable rustdoc features,
1069 // which are disabled by default. We first need to enable them explicitly:
1070 cmd.arg("-Z").arg("unstable-options");
1072 // rustdoc needs to know the right sysroot.
1073 forward_miri_sysroot(&mut cmd);
1074 // make sure the 'miri' flag is set for rustdoc
1075 cmd.arg("--cfg").arg("miri");
1077 // Make rustdoc call us back.
1078 let cargo_miri_path = std::env::current_exe().expect("current executable path invalid");
1079 cmd.arg("--test-builder").arg(&cargo_miri_path); // invoked by forwarding most arguments
1080 cmd.arg("--runtool").arg(&cargo_miri_path); // invoked with just a single path argument
1083 eprintln!("[cargo-miri rustdoc] {:?}", cmd);
1090 // Rustc does not support non-UTF-8 arguments so we make no attempt either.
1091 // (We do support non-UTF-8 environment variables though.)
1092 let mut args = std::env::args();
1093 // Skip binary name.
1094 args.next().unwrap();
1096 // Dispatch to `cargo-miri` phase. There are four phases:
1097 // - When we are called via `cargo miri`, we run as the frontend and invoke the underlying
1098 // cargo. We set RUSTDOC, RUSTC_WRAPPER and CARGO_TARGET_RUNNER to ourselves.
1099 // - When we are executed due to RUSTDOC, we run rustdoc and set both `--test-builder` and
1100 // `--runtool` to ourselves.
1101 // - When we are executed due to RUSTC_WRAPPER (or as the rustdoc test builder), we build crates
1102 // or store the flags of binary crates for later interpretation.
1103 // - When we are executed due to CARGO_TARGET_RUNNER (or as the rustdoc runtool), we start
1104 // interpretation based on the flags that were stored earlier.
1106 // Additionally, we also set ourselves as RUSTC when calling xargo to build the sysroot, which
1107 // has to be treated slightly differently than when we build regular crates.
1109 // Dispatch running as part of sysroot compilation.
1110 if env::var_os("MIRI_CALLED_FROM_XARGO").is_some() {
1111 phase_rustc(args, RustcPhase::Setup);
1115 // The way rustdoc invokes rustc is indistuingishable from the way cargo invokes rustdoc by the
1116 // arguments alone. `phase_cargo_rustdoc` sets this environment variable to let us disambiguate.
1117 if env::var_os("MIRI_CALLED_FROM_RUSTDOC").is_some() {
1118 // ...however, we then also see this variable when rustdoc invokes us as the testrunner!
1119 // The runner is invoked as `$runtool ($runtool-arg)* output_file`;
1120 // since we don't specify any runtool-args, and rustdoc supplies multiple arguments to
1121 // the test-builder unconditionally, we can just check the number of remaining arguments:
1122 if args.len() == 1 {
1123 let arg = args.next().unwrap();
1124 let binary = Path::new(&arg);
1125 if binary.exists() {
1126 phase_runner(binary, args, RunnerPhase::Rustdoc);
1129 "`cargo-miri` called with non-existing path argument `{}` in rustdoc mode; please invoke this binary through `cargo miri`",
1134 phase_rustc(args, RustcPhase::Rustdoc);
1140 match args.next().as_deref() {
1141 Some("miri") => phase_cargo_miri(args),
1142 Some("rustc") => phase_rustc(args, RustcPhase::Build),
1144 // We have to distinguish the "runner" and "rustdoc" cases.
1145 // As runner, the first argument is the binary (a file that should exist, with an absolute path);
1146 // as rustdoc, the first argument is a flag (`--something`).
1147 let binary = Path::new(arg);
1148 if binary.exists() {
1149 assert!(!arg.starts_with("--")); // not a flag
1150 phase_runner(binary, args, RunnerPhase::Cargo);
1151 } else if arg.starts_with("--") {
1152 phase_rustdoc(arg, args);
1155 "`cargo-miri` called with unexpected first argument `{}`; please only invoke this binary through `cargo miri`",
1162 "`cargo-miri` called without first argument; please only invoke this binary through `cargo miri`"