1 #![allow(clippy::useless_format, clippy::derive_partial_eq_without_eq)]
6 use std::ffi::{OsStr, OsString};
7 use std::fmt::Write as _;
8 use std::fs::{self, File};
9 use std::io::{self, BufRead, BufReader, BufWriter, Read, Write};
10 use std::iter::TakeWhile;
12 use std::path::{Path, PathBuf};
13 use std::process::{self, Command};
15 use rustc_version::VersionMeta;
16 use serde::{Deserialize, Serialize};
20 const CARGO_MIRI_HELP: &str = r#"Runs binary crates and tests in Miri
23 cargo miri [subcommand] [<cargo options>...] [--] [<program/test suite options>...]
28 setup Only perform automatic setup, but without asking questions (for getting a proper libstd)
30 The cargo options are exactly the same as for `cargo run` and `cargo test`, respectively.
34 cargo miri test -- test-suite-filter
37 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
44 /// The information to run a crate with the given environment.
45 #[derive(Serialize, Deserialize)]
47 /// The command-line arguments.
50 env: Vec<(OsString, OsString)>,
51 /// The current working directory.
52 current_dir: OsString,
53 /// The contents passed via standard input.
58 /// Gather all the information we need.
59 fn collect(args: env::Args, capture_stdin: bool) -> Self {
60 let args = args.collect();
61 let env = env::vars_os().collect();
62 let current_dir = env::current_dir().unwrap().into_os_string();
64 let mut stdin = Vec::new();
66 std::io::stdin().lock().read_to_end(&mut stdin).expect("cannot read stdin");
69 CrateRunEnv { args, env, current_dir, stdin }
73 /// The information Miri needs to run a crate. Stored as JSON when the crate is "compiled".
74 #[derive(Serialize, Deserialize)]
76 /// Run it with the given environment.
78 /// Skip it as Miri does not support interpreting such kind of crates.
83 fn store(&self, filename: &Path) {
84 let file = File::create(filename)
85 .unwrap_or_else(|_| show_error(format!("cannot create `{}`", filename.display())));
86 let file = BufWriter::new(file);
87 serde_json::ser::to_writer(file, self)
88 .unwrap_or_else(|_| show_error(format!("cannot write to `{}`", filename.display())));
93 println!("{}", CARGO_MIRI_HELP);
97 let mut version = format!("miri {}", env!("CARGO_PKG_VERSION"));
98 // Only use `option_env` on vergen variables to ensure the build succeeds
99 // when vergen failed to find the git info.
100 if let Some(sha) = option_env!("VERGEN_GIT_SHA_SHORT") {
101 // This `unwrap` can never fail because if VERGEN_GIT_SHA_SHORT exists, then so does
102 // VERGEN_GIT_COMMIT_DATE.
103 #[allow(clippy::option_env_unwrap)]
104 write!(&mut version, " ({} {})", sha, option_env!("VERGEN_GIT_COMMIT_DATE").unwrap())
107 println!("{}", version);
110 fn show_error(msg: String) -> ! {
111 eprintln!("fatal error: {}", msg);
112 std::process::exit(1)
115 // Determines whether a `--flag` is present.
116 fn has_arg_flag(name: &str) -> bool {
117 let mut args = std::env::args().take_while(|val| val != "--");
118 args.any(|val| val == name)
121 /// Yields all values of command line flag `name` as `Ok(arg)`, and all other arguments except
122 /// the flag as `Err(arg)`. (The flag `name` itself is not yielded at all, only its values are.)
123 struct ArgSplitFlagValue<'a, I> {
124 args: TakeWhile<I, fn(&String) -> bool>,
128 impl<'a, I: Iterator<Item = String>> ArgSplitFlagValue<'a, I> {
129 fn new(args: I, name: &'a str) -> Self {
131 // Stop searching at `--`.
132 args: args.take_while(|val| val != "--"),
138 impl<I: Iterator<Item = String>> Iterator for ArgSplitFlagValue<'_, I> {
139 type Item = Result<String, String>;
141 fn next(&mut self) -> Option<Self::Item> {
142 let arg = self.args.next()?;
143 if let Some(suffix) = arg.strip_prefix(self.name) {
144 // Strip leading `name`.
145 if suffix.is_empty() {
146 // This argument is exactly `name`; the next one is the value.
147 return self.args.next().map(Ok);
148 } else if let Some(suffix) = suffix.strip_prefix('=') {
149 // This argument is `name=value`; get the value.
150 return Some(Ok(suffix.to_owned()));
157 /// Yields all values of command line flag `name`.
158 struct ArgFlagValueIter<'a>(ArgSplitFlagValue<'a, env::Args>);
160 impl<'a> ArgFlagValueIter<'a> {
161 fn new(name: &'a str) -> Self {
162 Self(ArgSplitFlagValue::new(env::args(), name))
166 impl Iterator for ArgFlagValueIter<'_> {
169 fn next(&mut self) -> Option<Self::Item> {
171 if let Ok(value) = self.0.next()? {
178 /// Gets the value of a `--flag`.
179 fn get_arg_flag_value(name: &str) -> Option<String> {
180 ArgFlagValueIter::new(name).next()
183 fn forward_patched_extern_arg(args: &mut impl Iterator<Item = String>, cmd: &mut Command) {
184 cmd.arg("--extern"); // always forward flag, but adjust filename:
185 let path = args.next().expect("`--extern` should be followed by a filename");
186 if let Some(lib) = path.strip_suffix(".rlib") {
187 // If this is an rlib, make it an rmeta.
188 cmd.arg(format!("{}.rmeta", lib));
190 // Some other extern file (e.g. a `.so`). Forward unchanged.
195 fn forward_miri_sysroot(cmd: &mut Command) {
196 let sysroot = env::var_os("MIRI_SYSROOT").expect("the wrapper should have set MIRI_SYSROOT");
197 cmd.arg("--sysroot");
201 /// Returns the path to the `miri` binary
202 fn find_miri() -> PathBuf {
203 if let Some(path) = env::var_os("MIRI") {
206 let mut path = std::env::current_exe().expect("current executable path invalid");
207 path.set_file_name("miri");
211 fn miri() -> Command {
212 Command::new(find_miri())
215 fn version_info() -> VersionMeta {
216 VersionMeta::for_command(miri()).expect("failed to determine underlying rustc version of Miri")
219 fn cargo() -> Command {
220 Command::new(env::var_os("CARGO").unwrap_or_else(|| OsString::from("cargo")))
223 fn xargo_check() -> Command {
224 Command::new(env::var_os("XARGO_CHECK").unwrap_or_else(|| OsString::from("xargo-check")))
227 /// Execute the command. If it fails, fail this process with the same exit code.
228 /// Otherwise, continue.
229 fn exec(mut cmd: Command) {
230 let exit_status = cmd.status().expect("failed to run command");
231 if exit_status.success().not() {
232 std::process::exit(exit_status.code().unwrap_or(-1))
236 /// Execute the command and pipe `input` into its stdin.
237 /// If it fails, fail this process with the same exit code.
238 /// Otherwise, continue.
239 fn exec_with_pipe(mut cmd: Command, input: &[u8]) {
240 cmd.stdin(process::Stdio::piped());
241 let mut child = cmd.spawn().expect("failed to spawn process");
243 let stdin = child.stdin.as_mut().expect("failed to open stdin");
244 stdin.write_all(input).expect("failed to write out test source");
246 let exit_status = child.wait().expect("failed to run command");
247 if exit_status.success().not() {
248 std::process::exit(exit_status.code().unwrap_or(-1))
252 fn xargo_version() -> Option<(u32, u32, u32)> {
253 let out = xargo_check().arg("--version").output().ok()?;
254 if !out.status.success() {
257 // Parse output. The first line looks like "xargo 0.3.12 (b004f1c 2018-12-13)".
262 .expect("malformed `xargo --version` output: not at least one line")
263 .expect("malformed `xargo --version` output: error reading first line");
264 let (name, version) = {
265 let mut split = line.split(' ');
267 split.next().expect("malformed `xargo --version` output: empty"),
268 split.next().expect("malformed `xargo --version` output: not at least two words"),
272 // This is some fork of xargo
275 let mut version_pieces = version.split('.');
276 let major = version_pieces
278 .expect("malformed `xargo --version` output: not a major version piece")
280 .expect("malformed `xargo --version` output: major version is not an integer");
281 let minor = version_pieces
283 .expect("malformed `xargo --version` output: not a minor version piece")
285 .expect("malformed `xargo --version` output: minor version is not an integer");
286 let patch = version_pieces
288 .expect("malformed `xargo --version` output: not a patch version piece")
290 .expect("malformed `xargo --version` output: patch version is not an integer");
291 if version_pieces.next().is_some() {
292 panic!("malformed `xargo --version` output: more than three pieces in version");
294 Some((major, minor, patch))
297 fn ask_to_run(mut cmd: Command, ask: bool, text: &str) {
298 // Disable interactive prompts in CI (GitHub Actions, Travis, AppVeyor, etc).
299 // Azure doesn't set `CI` though (nothing to see here, just Microsoft being Microsoft),
300 // so we also check their `TF_BUILD`.
301 let is_ci = env::var_os("CI").is_some() || env::var_os("TF_BUILD").is_some();
303 let mut buf = String::new();
304 print!("I will run `{:?}` to {}. Proceed? [Y/n] ", cmd, text);
305 io::stdout().flush().unwrap();
306 io::stdin().read_line(&mut buf).unwrap();
307 match buf.trim().to_lowercase().as_ref() {
309 "" | "y" | "yes" => {}
310 "n" | "no" => show_error(format!("aborting as per your request")),
311 a => show_error(format!("invalid answer `{}`", a)),
314 println!("Running `{:?}` to {}.", cmd, text);
317 if cmd.status().unwrap_or_else(|_| panic!("failed to execute {:?}", cmd)).success().not() {
318 show_error(format!("failed to {}", text));
322 /// Performs the setup required to make `cargo miri` work: Getting a custom-built libstd. Then sets
323 /// `MIRI_SYSROOT`. Skipped if `MIRI_SYSROOT` is already set, in which case we expect the user has
324 /// done all this already.
325 fn setup(subcommand: MiriCommand) {
326 if std::env::var_os("MIRI_SYSROOT").is_some() {
327 if subcommand == MiriCommand::Setup {
328 println!("WARNING: MIRI_SYSROOT already set, not doing anything.")
333 // Subcommands other than `setup` will do a setup if necessary, but
334 // interactively confirm first.
335 let ask_user = subcommand != MiriCommand::Setup;
337 // First, we need xargo.
338 if xargo_version().map_or(true, |v| v < XARGO_MIN_VERSION) {
339 if std::env::var_os("XARGO_CHECK").is_some() {
340 // The user manually gave us a xargo binary; don't do anything automatically.
341 show_error(format!("xargo is too old; please upgrade to the latest version"))
343 let mut cmd = cargo();
344 cmd.args(&["install", "xargo"]);
345 ask_to_run(cmd, ask_user, "install a recent enough xargo");
348 // Determine where the rust sources are located. The env vars manually setting the source
349 // (`MIRI_LIB_SRC`, `XARGO_RUST_SRC`) trump auto-detection.
350 let rust_src_env_var =
351 std::env::var_os("MIRI_LIB_SRC").or_else(|| std::env::var_os("XARGO_RUST_SRC"));
352 let rust_src = match rust_src_env_var {
354 let path = PathBuf::from(path);
355 // Make path absolute if possible.
356 path.canonicalize().unwrap_or(path)
359 // Check for `rust-src` rustup component.
361 .args(&["--print", "sysroot"])
363 .expect("failed to determine sysroot")
365 let sysroot = std::str::from_utf8(&sysroot).unwrap();
366 let sysroot = Path::new(sysroot.trim_end_matches('\n'));
367 // Check for `$SYSROOT/lib/rustlib/src/rust/library`; test if that contains `std/Cargo.toml`.
369 sysroot.join("lib").join("rustlib").join("src").join("rust").join("library");
370 if !rustup_src.join("std").join("Cargo.toml").exists() {
371 // Ask the user to install the `rust-src` component, and use that.
372 let mut cmd = Command::new("rustup");
373 cmd.args(&["component", "add", "rust-src"]);
377 "install the `rust-src` component for the selected toolchain",
383 if !rust_src.exists() {
384 show_error(format!("given Rust source directory `{}` does not exist.", rust_src.display()));
386 if rust_src.file_name().and_then(OsStr::to_str) != Some("library") {
388 "given Rust source directory `{}` does not seem to be the `library` subdirectory of \
389 a Rust source checkout.",
394 // Next, we need our own libstd. Prepare a xargo project for that purpose.
395 // We will do this work in whatever is a good cache dir for this platform.
396 let dirs = directories::ProjectDirs::from("org", "rust-lang", "miri").unwrap();
397 let dir = dirs.cache_dir();
399 fs::create_dir_all(&dir).unwrap();
401 let mut xargo_toml = File::create(dir.join("Xargo.toml")).unwrap();
402 if std::env::var_os("MIRI_NO_STD").is_none() {
403 // The interesting bit: Xargo.toml (only needs content if we actually need std)
408 default_features = false
409 # We support unwinding, so enable that panic runtime.
410 features = ["panic_unwind", "backtrace"]
417 // The boring bits: a dummy project for xargo.
418 // FIXME: With xargo-check, can we avoid doing this?
419 File::create(dir.join("Cargo.toml"))
425 description = "A dummy project for building libstd with xargo."
433 File::create(dir.join("lib.rs")).unwrap().write_all(b"#![no_std]").unwrap();
435 // Determine architectures.
436 // We always need to set a target so rustc bootstrap can tell apart host from target crates.
437 let host = version_info().host;
438 let target = get_arg_flag_value("--target");
439 let target = target.as_ref().unwrap_or(&host);
441 let mut command = xargo_check();
442 command.arg("check").arg("-q");
443 command.arg("--target").arg(target);
444 command.current_dir(&dir);
445 command.env("XARGO_HOME", &dir);
446 command.env("XARGO_RUST_SRC", &rust_src);
447 // Use Miri as rustc to build a libstd compatible with us (and use the right flags).
448 // However, when we are running in bootstrap, we cannot just overwrite `RUSTC`,
449 // because we still need bootstrap to distinguish between host and target crates.
450 // In that case we overwrite `RUSTC_REAL` instead which determines the rustc used
451 // for target crates.
452 // We set ourselves (`cargo-miri`) instead of Miri directly to be able to patch the flags
453 // for `libpanic_abort` (usually this is done by bootstrap but we have to do it ourselves).
454 // The `MIRI_CALLED_FROM_XARGO` will mean we dispatch to `phase_setup_rustc`.
455 let cargo_miri_path = std::env::current_exe().expect("current executable path invalid");
456 if env::var_os("RUSTC_STAGE").is_some() {
457 command.env("RUSTC_REAL", &cargo_miri_path);
459 command.env("RUSTC", &cargo_miri_path);
461 command.env("MIRI_CALLED_FROM_XARGO", "1");
462 // Make sure there are no other wrappers or flags getting in our way
463 // (Cc https://github.com/rust-lang/miri/issues/1421).
464 // This is consistent with normal `cargo build` that does not apply `RUSTFLAGS`
465 // to the sysroot either.
466 command.env_remove("RUSTC_WRAPPER");
467 command.env_remove("RUSTFLAGS");
468 // Disable debug assertions in the standard library -- Miri is already slow enough.
469 // But keep the overflow checks, they are cheap.
470 command.env("RUSTFLAGS", "-Cdebug-assertions=off -Coverflow-checks=on");
472 if command.status().expect("failed to run xargo").success().not() {
473 show_error(format!("failed to run xargo"));
476 // That should be it! But we need to figure out where xargo built stuff.
477 // Unfortunately, it puts things into a different directory when the
478 // architecture matches the host.
479 let sysroot = if target == &host { dir.join("HOST") } else { PathBuf::from(dir) };
480 std::env::set_var("MIRI_SYSROOT", &sysroot); // pass the env var to the processes we spawn, which will turn it into "--sysroot" flags
481 // Figure out what to print.
482 let print_sysroot = subcommand == MiriCommand::Setup && has_arg_flag("--print-sysroot"); // whether we just print the sysroot path
484 // Print just the sysroot and nothing else; this way we do not need any escaping.
485 println!("{}", sysroot.display());
486 } else if subcommand == MiriCommand::Setup {
487 println!("A libstd for Miri is now available in `{}`.", sysroot.display());
491 #[derive(Deserialize)]
493 target_directory: PathBuf,
494 workspace_members: Vec<String>,
497 fn get_cargo_metadata() -> Metadata {
498 let mut cmd = cargo();
499 // `-Zunstable-options` is required by `--config`.
500 cmd.args(["metadata", "--no-deps", "--format-version=1", "-Zunstable-options"]);
501 // The `build.target-dir` config can be passed by `--config` flags, so forward them to
503 let config_flag = "--config";
504 for arg in ArgSplitFlagValue::new(
505 env::args().skip(3), // skip the program name, "miri" and "run" / "test"
511 cmd.arg(config_flag).arg(arg);
514 .stdin(process::Stdio::null())
515 .stdout(process::Stdio::piped())
517 .expect("failed ro run `cargo metadata`");
518 // Check this `Result` after `status.success()` is checked, so we don't print the error
519 // to stderr if `cargo metadata` is also printing to stderr.
520 let metadata: Result<Metadata, _> = serde_json::from_reader(child.stdout.take().unwrap());
521 let status = child.wait().expect("failed to wait for `cargo metadata` to exit");
522 if !status.success() {
523 std::process::exit(status.code().unwrap_or(-1));
525 metadata.unwrap_or_else(|e| show_error(format!("invalid `cargo metadata` output: {}", e)))
528 /// Pulls all the crates in this workspace from the cargo metadata.
529 /// Workspace members are emitted like "miri 0.1.0 (path+file:///path/to/miri)"
530 /// Additionally, somewhere between cargo metadata and TyCtxt, '-' gets replaced with '_' so we
531 /// make that same transformation here.
532 fn local_crates(metadata: &Metadata) -> String {
533 assert!(!metadata.workspace_members.is_empty());
534 let mut local_crates = String::new();
535 for member in &metadata.workspace_members {
536 let name = member.split(' ').next().unwrap();
537 let name = name.replace('-', "_");
538 local_crates.push_str(&name);
539 local_crates.push(',');
541 local_crates.pop(); // Remove the trailing ','
546 fn phase_cargo_miri(mut args: env::Args) {
547 // Check for version and help flags even when invoked as `cargo-miri`.
548 if has_arg_flag("--help") || has_arg_flag("-h") {
552 if has_arg_flag("--version") || has_arg_flag("-V") {
557 // Require a subcommand before any flags.
558 // We cannot know which of those flags take arguments and which do not,
559 // so we cannot detect subcommands later.
560 let subcommand = match args.next().as_deref() {
561 Some("test" | "t") => MiriCommand::Test,
562 Some("run" | "r") => MiriCommand::Run,
563 Some("setup") => MiriCommand::Setup,
567 "`cargo miri` supports the following subcommands: `run`, `test`, and `setup`."
570 let verbose = has_arg_flag("-v");
575 // Invoke actual cargo for the job, but with different flags.
576 // We re-use `cargo test` and `cargo run`, which makes target and binary handling very easy but
577 // requires some extra work to make the build check-only (see all the `--emit` hacks below).
578 // <https://github.com/rust-lang/miri/pull/1540#issuecomment-693553191> describes an alternative
579 // approach that uses `cargo check`, making that part easier but target and binary handling
581 let cargo_miri_path = std::env::current_exe().expect("current executable path invalid");
582 let cargo_cmd = match subcommand {
583 MiriCommand::Test => "test",
584 MiriCommand::Run => "run",
585 MiriCommand::Setup => return, // `cargo miri setup` stops here.
587 let mut cmd = cargo();
590 // Make sure we know the build target, and cargo does, too.
591 // This is needed to make the `CARGO_TARGET_*_RUNNER` env var do something,
592 // and it later helps us detect which crates are proc-macro/build-script
593 // (host crates) and which crates are needed for the program itself.
594 let host = version_info().host;
595 let target = get_arg_flag_value("--target");
596 let target = if let Some(ref target) = target {
599 // No target given. Pick default and tell cargo about it.
605 let mut target_dir = None;
607 // Forward all arguments before `--` other than `--target-dir` and its value to Cargo.
608 for arg in ArgSplitFlagValue::new(&mut args, "--target-dir") {
611 if target_dir.is_some() {
612 show_error(format!("`--target-dir` is provided more than once"));
614 target_dir = Some(value.into());
622 let metadata = get_cargo_metadata();
624 // Detect the target directory if it's not specified via `--target-dir`.
625 let target_dir = target_dir.get_or_insert_with(|| metadata.target_directory.clone());
627 // Set `--target-dir` to `miri` inside the original target directory.
628 target_dir.push("miri");
629 cmd.arg("--target-dir").arg(target_dir);
631 // Forward all further arguments after `--` to cargo.
632 cmd.arg("--").args(args);
634 // Set `RUSTC_WRAPPER` to ourselves. Cargo will prepend that binary to its usual invocation,
635 // i.e., the first argument is `rustc` -- which is what we use in `main` to distinguish
636 // the two codepaths. (That extra argument is why we prefer this over setting `RUSTC`.)
637 if env::var_os("RUSTC_WRAPPER").is_some() {
639 "WARNING: Ignoring `RUSTC_WRAPPER` environment variable, Miri does not support wrapping."
642 cmd.env("RUSTC_WRAPPER", &cargo_miri_path);
643 // Having both `RUSTC_WRAPPER` and `RUSTC` set does some odd things, so let's avoid that.
644 // See <https://github.com/rust-lang/miri/issues/2238>.
645 if env::var_os("RUSTC").is_some() && env::var_os("MIRI").is_none() {
647 "WARNING: Ignoring `RUSTC` environment variable; set `MIRI` if you want to control the binary used as the driver."
650 cmd.env_remove("RUSTC");
652 let runner_env_name =
653 |triple: &str| format!("CARGO_TARGET_{}_RUNNER", triple.to_uppercase().replace('-', "_"));
654 let host_runner_env_name = runner_env_name(&host);
655 let target_runner_env_name = runner_env_name(target);
656 // Set the target runner to us, so we can interpret the binaries.
657 cmd.env(&target_runner_env_name, &cargo_miri_path);
658 // Unit tests of `proc-macro` crates are run on the host, so we set the host runner to
659 // us in order to skip them.
660 cmd.env(&host_runner_env_name, &cargo_miri_path);
662 // Set rustdoc to us as well, so we can run doctests.
663 cmd.env("RUSTDOC", &cargo_miri_path);
665 cmd.env("MIRI_LOCAL_CRATES", local_crates(&metadata));
669 eprintln!("[cargo-miri miri] RUSTC_WRAPPER={:?}", cargo_miri_path);
670 eprintln!("[cargo-miri miri] {}={:?}", target_runner_env_name, cargo_miri_path);
672 eprintln!("[cargo-miri miri] {}={:?}", host_runner_env_name, cargo_miri_path);
674 eprintln!("[cargo-miri miri] RUSTDOC={:?}", cargo_miri_path);
675 eprintln!("[cargo-miri miri] {:?}", cmd);
676 cmd.env("MIRI_VERBOSE", ""); // This makes the other phases verbose.
681 #[derive(Debug, Copy, Clone, PartialEq)]
683 /// `rustc` called via `xargo` for sysroot build.
685 /// `rustc` called by `cargo` for regular build.
687 /// `rustc` called by `rustdoc` for doctest.
691 fn phase_rustc(mut args: env::Args, phase: RustcPhase) {
692 /// Determines if we are being invoked (as rustc) to build a crate for
693 /// the "target" architecture, in contrast to the "host" architecture.
694 /// Host crates are for build scripts and proc macros and still need to
695 /// be built like normal; target crates need to be built for or interpreted
698 /// Currently, we detect this by checking for "--target=", which is
699 /// never set for host crates. This matches what rustc bootstrap does,
700 /// which hopefully makes it "reliable enough". This relies on us always
701 /// invoking cargo itself with `--target`, which `in_cargo_miri` ensures.
702 fn is_target_crate() -> bool {
703 get_arg_flag_value("--target").is_some()
706 /// Returns whether or not Cargo invoked the wrapper (this binary) to compile
707 /// the final, binary crate (either a test for 'cargo test', or a binary for 'cargo run')
708 /// Cargo does not give us this information directly, so we need to check
709 /// various command-line flags.
710 fn is_runnable_crate() -> bool {
711 let is_bin = get_arg_flag_value("--crate-type").as_deref().unwrap_or("bin") == "bin";
712 let is_test = has_arg_flag("--test");
716 fn out_filename(prefix: &str, suffix: &str) -> PathBuf {
717 if let Some(out_dir) = get_arg_flag_value("--out-dir") {
718 let mut path = PathBuf::from(out_dir);
722 get_arg_flag_value("--crate-name").unwrap(),
723 // This is technically a `-C` flag but the prefix seems unique enough...
724 // (and cargo passes this before the filename so it should be unique)
725 get_arg_flag_value("extra-filename").unwrap_or_default(),
730 let out_file = get_arg_flag_value("-o").unwrap();
731 PathBuf::from(out_file)
735 let verbose = std::env::var_os("MIRI_VERBOSE").is_some();
736 let target_crate = is_target_crate();
737 let print = get_arg_flag_value("--print").is_some() || has_arg_flag("-vV"); // whether this is cargo/xargo invoking rustc to get some infos
739 let store_json = |info: CrateRunInfo| {
740 // Create a stub .d file to stop Cargo from "rebuilding" the crate:
741 // https://github.com/rust-lang/miri/issues/1724#issuecomment-787115693
742 // As we store a JSON file instead of building the crate here, an empty file is fine.
743 let dep_info_name = out_filename("", ".d");
745 eprintln!("[cargo-miri rustc] writing stub dep-info to `{}`", dep_info_name.display());
747 File::create(dep_info_name).expect("failed to create fake .d file");
749 let filename = out_filename("", "");
751 eprintln!("[cargo-miri rustc] writing run info to `{}`", filename.display());
753 info.store(&filename);
754 // For Windows, do the same thing again with `.exe` appended to the filename.
755 // (Need to do this here as cargo moves that "binary" to a different place before running it.)
756 info.store(&out_filename("", ".exe"));
759 let runnable_crate = !print && is_runnable_crate();
761 if runnable_crate && target_crate {
763 phase != RustcPhase::Setup,
764 "there should be no interpretation during sysroot build"
766 let inside_rustdoc = phase == RustcPhase::Rustdoc;
767 // This is the binary or test crate that we want to interpret under Miri.
768 // But we cannot run it here, as cargo invoked us as a compiler -- our stdin and stdout are not
769 // like we want them.
770 // Instead of compiling, we write JSON into the output file with all the relevant command-line flags
771 // and environment variables; this is used when cargo calls us again in the CARGO_TARGET_RUNNER phase.
772 let env = CrateRunEnv::collect(args, inside_rustdoc);
774 // Rustdoc expects us to exit with an error code if the test is marked as `compile_fail`,
775 // just creating the JSON file is not enough: we need to detect syntax errors,
776 // so we need to run Miri with `MIRI_BE_RUSTC` for a check-only build.
778 let mut cmd = miri();
780 // Ensure --emit argument for a check-only build is present.
781 // We cannot use the usual helpers since we need to check specifically in `env.args`.
782 if let Some(i) = env.args.iter().position(|arg| arg.starts_with("--emit=")) {
783 // For `no_run` tests, rustdoc passes a `--emit` flag; make sure it has the right shape.
784 assert_eq!(env.args[i], "--emit=metadata");
786 // For all other kinds of tests, we can just add our flag.
787 cmd.arg("--emit=metadata");
791 cmd.env("MIRI_BE_RUSTC", "target");
795 "[cargo-miri rustc] captured input:\n{}",
796 std::str::from_utf8(&env.stdin).unwrap()
798 eprintln!("[cargo-miri rustc] {:?}", cmd);
801 exec_with_pipe(cmd, &env.stdin);
804 store_json(CrateRunInfo::RunWith(env));
809 if runnable_crate && ArgFlagValueIter::new("--extern").any(|krate| krate == "proc_macro") {
810 // This is a "runnable" `proc-macro` crate (unit tests). We do not support
811 // interpreting that under Miri now, so we write a JSON file to (display a
812 // helpful message and) skip it in the runner phase.
813 store_json(CrateRunInfo::SkipProcMacroTest);
817 let mut cmd = miri();
818 let mut emit_link_hack = false;
819 // Arguments are treated very differently depending on whether this crate is
820 // for interpretation by Miri, or for use by a build script / proc macro.
821 if !print && target_crate {
822 // Forward arguments, but remove "link" from "--emit" to make this a check-only build.
823 let emit_flag = "--emit";
824 while let Some(arg) = args.next() {
825 if let Some(val) = arg.strip_prefix(emit_flag) {
826 // Patch this argument. First, extract its value.
828 val.strip_prefix('=').expect("`cargo` should pass `--emit=X` as one argument");
829 let mut val: Vec<_> = val.split(',').collect();
830 // Now make sure "link" is not in there, but "metadata" is.
831 if let Some(i) = val.iter().position(|&s| s == "link") {
832 emit_link_hack = true;
834 if !val.iter().any(|&s| s == "metadata") {
835 val.push("metadata");
838 cmd.arg(format!("{}={}", emit_flag, val.join(",")));
839 } else if arg == "--extern" {
840 // Patch `--extern` filenames, since Cargo sometimes passes stub `.rlib` files:
841 // https://github.com/rust-lang/miri/issues/1705
842 forward_patched_extern_arg(&mut args, &mut cmd);
848 // Use our custom sysroot (but not if that is what we are currently building).
849 if phase != RustcPhase::Setup {
850 forward_miri_sysroot(&mut cmd);
853 // During setup, patch the panic runtime for `libpanic_abort` (mirroring what bootstrap usually does).
854 if phase == RustcPhase::Setup
855 && get_arg_flag_value("--crate-name").as_deref() == Some("panic_abort")
857 cmd.arg("-C").arg("panic=abort");
860 // For host crates or when we are printing, just forward everything.
864 // We want to compile, not interpret. We still use Miri to make sure the compiler version etc
865 // are the exact same as what is used for interpretation.
866 // MIRI_DEFAULT_ARGS should not be used to build host crates, hence setting "target" or "host"
867 // as the value here to help Miri differentiate them.
868 cmd.env("MIRI_BE_RUSTC", if target_crate { "target" } else { "host" });
872 eprintln!("[cargo-miri rustc] {:?}", cmd);
876 // Create a stub .rlib file if "link" was requested by cargo.
877 // This is necessary to prevent cargo from doing rebuilds all the time.
879 // Some platforms prepend "lib", some do not... let's just create both files.
880 File::create(out_filename("lib", ".rlib")).expect("failed to create fake .rlib file");
881 File::create(out_filename("", ".rlib")).expect("failed to create fake .rlib file");
882 // Just in case this is a cdylib or staticlib, also create those fake files.
883 File::create(out_filename("lib", ".so")).expect("failed to create fake .so file");
884 File::create(out_filename("lib", ".a")).expect("failed to create fake .a file");
885 File::create(out_filename("lib", ".dylib")).expect("failed to create fake .dylib file");
886 File::create(out_filename("", ".dll")).expect("failed to create fake .dll file");
887 File::create(out_filename("", ".lib")).expect("failed to create fake .lib file");
891 #[derive(Debug, Copy, Clone, PartialEq)]
893 /// `cargo` is running a binary
895 /// `rustdoc` is running a binary
899 fn phase_runner(binary: &Path, binary_args: env::Args, phase: RunnerPhase) {
900 let verbose = std::env::var_os("MIRI_VERBOSE").is_some();
902 let file = File::open(&binary)
903 .unwrap_or_else(|_| show_error(format!("file {:?} not found or `cargo-miri` invoked incorrectly; please only invoke this binary through `cargo miri`", binary)));
904 let file = BufReader::new(file);
906 let info = serde_json::from_reader(file).unwrap_or_else(|_| {
908 "file {:?} contains outdated or invalid JSON; try `cargo clean`",
912 let info = match info {
913 CrateRunInfo::RunWith(info) => info,
914 CrateRunInfo::SkipProcMacroTest => {
916 "Running unit tests of `proc-macro` crates is not currently supported by Miri."
922 let mut cmd = miri();
924 // Set missing env vars. We prefer build-time env vars over run-time ones; see
925 // <https://github.com/rust-lang/miri/issues/1661> for the kind of issue that fixes.
926 for (name, val) in info.env {
928 if let Some(old_val) = env::var_os(&name) {
931 "[cargo-miri runner] Overwriting run-time env var {:?}={:?} with build-time value {:?}",
940 // Forward rustc arguments.
941 // We need to patch "--extern" filenames because we forced a check-only
942 // build without cargo knowing about that: replace `.rlib` suffix by
944 // We also need to remove `--error-format` as cargo specifies that to be JSON,
945 // but when we run here, cargo does not interpret the JSON any more. `--json`
946 // then also nees to be dropped.
947 let mut args = info.args.into_iter();
948 let error_format_flag = "--error-format";
949 let json_flag = "--json";
950 while let Some(arg) = args.next() {
951 if arg == "--extern" {
952 forward_patched_extern_arg(&mut args, &mut cmd);
953 } else if let Some(suffix) = arg.strip_prefix(error_format_flag) {
954 assert!(suffix.starts_with('='));
955 // Drop this argument.
956 } else if let Some(suffix) = arg.strip_prefix(json_flag) {
957 assert!(suffix.starts_with('='));
958 // Drop this argument.
963 // Set sysroot (if we are inside rustdoc, we already did that in `phase_cargo_rustdoc`).
964 if phase != RunnerPhase::Rustdoc {
965 forward_miri_sysroot(&mut cmd);
967 // Respect `MIRIFLAGS`.
968 if let Ok(a) = env::var("MIRIFLAGS") {
969 // This code is taken from `RUSTFLAGS` handling in cargo.
970 let args = a.split(' ').map(str::trim).filter(|s| !s.is_empty()).map(str::to_string);
974 // Then pass binary arguments.
976 cmd.args(binary_args);
978 // Make sure we use the build-time working directory for interpreting Miri/rustc arguments.
979 // But then we need to switch to the run-time one, which we instruct Miri do do by setting `MIRI_CWD`.
980 cmd.current_dir(info.current_dir);
981 cmd.env("MIRI_CWD", env::current_dir().unwrap());
985 eprintln!("[cargo-miri runner] {:?}", cmd);
989 RunnerPhase::Rustdoc => exec_with_pipe(cmd, &info.stdin),
990 RunnerPhase::Cargo => exec(cmd),
994 fn phase_rustdoc(fst_arg: &str, mut args: env::Args) {
995 let verbose = std::env::var_os("MIRI_VERBOSE").is_some();
997 // phase_cargo_miri sets the RUSTDOC env var to ourselves, so we can't use that here;
998 // just default to a straight-forward invocation for now:
999 let mut cmd = Command::new("rustdoc");
1001 // Because of the way the main function is structured, we have to take the first argument spearately
1002 // from the rest; to simplify the following argument patching loop, we'll just skip that one.
1003 // This is fine for now, because cargo will never pass --extern arguments in the first position,
1004 // but we should defensively assert that this will work.
1005 let extern_flag = "--extern";
1006 assert!(fst_arg != extern_flag);
1009 let runtool_flag = "--runtool";
1010 // `crossmode` records if *any* argument matches `runtool_flag`; here we check the first one.
1011 let mut crossmode = fst_arg == runtool_flag;
1012 while let Some(arg) = args.next() {
1013 if arg == extern_flag {
1014 // Patch --extern arguments to use *.rmeta files, since phase_cargo_rustc only creates stub *.rlib files.
1015 forward_patched_extern_arg(&mut args, &mut cmd);
1016 } else if arg == runtool_flag {
1017 // An existing --runtool flag indicates cargo is running in cross-target mode, which we don't support.
1018 // Note that this is only passed when cargo is run with the unstable -Zdoctest-xcompile flag;
1019 // otherwise, we won't be called as rustdoc at all.
1028 show_error(format!("cross-interpreting doctests is not currently supported by Miri."));
1031 // Doctests of `proc-macro` crates (and their dependencies) are always built for the host,
1032 // so we are not able to run them in Miri.
1033 if ArgFlagValueIter::new("--crate-type").any(|crate_type| crate_type == "proc-macro") {
1034 eprintln!("Running doctests of `proc-macro` crates is not currently supported by Miri.");
1038 // For each doctest, rustdoc starts two child processes: first the test is compiled,
1039 // then the produced executable is invoked. We want to reroute both of these to cargo-miri,
1040 // such that the first time we'll enter phase_cargo_rustc, and phase_cargo_runner second.
1042 // rustdoc invokes the test-builder by forwarding most of its own arguments, which makes
1043 // it difficult to determine when phase_cargo_rustc should run instead of phase_cargo_rustdoc.
1044 // Furthermore, the test code is passed via stdin, rather than a temporary file, so we need
1045 // to let phase_cargo_rustc know to expect that. We'll use this environment variable as a flag:
1046 cmd.env("MIRI_CALLED_FROM_RUSTDOC", "1");
1048 // The `--test-builder` and `--runtool` arguments are unstable rustdoc features,
1049 // which are disabled by default. We first need to enable them explicitly:
1050 cmd.arg("-Z").arg("unstable-options");
1052 // rustdoc needs to know the right sysroot.
1053 forward_miri_sysroot(&mut cmd);
1054 // make sure the 'miri' flag is set for rustdoc
1055 cmd.arg("--cfg").arg("miri");
1057 // Make rustdoc call us back.
1058 let cargo_miri_path = std::env::current_exe().expect("current executable path invalid");
1059 cmd.arg("--test-builder").arg(&cargo_miri_path); // invoked by forwarding most arguments
1060 cmd.arg("--runtool").arg(&cargo_miri_path); // invoked with just a single path argument
1063 eprintln!("[cargo-miri rustdoc] {:?}", cmd);
1070 // Rustc does not support non-UTF-8 arguments so we make no attempt either.
1071 // (We do support non-UTF-8 environment variables though.)
1072 let mut args = std::env::args();
1073 // Skip binary name.
1074 args.next().unwrap();
1076 // Dispatch to `cargo-miri` phase. There are four phases:
1077 // - When we are called via `cargo miri`, we run as the frontend and invoke the underlying
1078 // cargo. We set RUSTDOC, RUSTC_WRAPPER and CARGO_TARGET_RUNNER to ourselves.
1079 // - When we are executed due to RUSTDOC, we run rustdoc and set both `--test-builder` and
1080 // `--runtool` to ourselves.
1081 // - When we are executed due to RUSTC_WRAPPER (or as the rustdoc test builder), we build crates
1082 // or store the flags of binary crates for later interpretation.
1083 // - When we are executed due to CARGO_TARGET_RUNNER (or as the rustdoc runtool), we start
1084 // interpretation based on the flags that were stored earlier.
1086 // Additionally, we also set ourselves as RUSTC when calling xargo to build the sysroot, which
1087 // has to be treated slightly differently than when we build regular crates.
1089 // Dispatch running as part of sysroot compilation.
1090 if env::var_os("MIRI_CALLED_FROM_XARGO").is_some() {
1091 phase_rustc(args, RustcPhase::Setup);
1095 // The way rustdoc invokes rustc is indistuingishable from the way cargo invokes rustdoc by the
1096 // arguments alone. `phase_cargo_rustdoc` sets this environment variable to let us disambiguate.
1097 if env::var_os("MIRI_CALLED_FROM_RUSTDOC").is_some() {
1098 // ...however, we then also see this variable when rustdoc invokes us as the testrunner!
1099 // The runner is invoked as `$runtool ($runtool-arg)* output_file`;
1100 // since we don't specify any runtool-args, and rustdoc supplies multiple arguments to
1101 // the test-builder unconditionally, we can just check the number of remaining arguments:
1102 if args.len() == 1 {
1103 let arg = args.next().unwrap();
1104 let binary = Path::new(&arg);
1105 if binary.exists() {
1106 phase_runner(binary, args, RunnerPhase::Rustdoc);
1109 "`cargo-miri` called with non-existing path argument `{}` in rustdoc mode; please invoke this binary through `cargo miri`",
1114 phase_rustc(args, RustcPhase::Rustdoc);
1120 match args.next().as_deref() {
1121 Some("miri") => phase_cargo_miri(args),
1122 Some("rustc") => phase_rustc(args, RustcPhase::Build),
1124 // We have to distinguish the "runner" and "rustdoc" cases.
1125 // As runner, the first argument is the binary (a file that should exist, with an absolute path);
1126 // as rustdoc, the first argument is a flag (`--something`).
1127 let binary = Path::new(arg);
1128 if binary.exists() {
1129 assert!(!arg.starts_with("--")); // not a flag
1130 phase_runner(binary, args, RunnerPhase::Cargo);
1131 } else if arg.starts_with("--") {
1132 phase_rustdoc(arg, args);
1135 "`cargo-miri` called with unexpected first argument `{}`; please only invoke this binary through `cargo miri`",
1142 "`cargo-miri` called without first argument; please only invoke this binary through `cargo miri`"