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.
53 /// The information Miri needs to run a crate. Stored as JSON when the crate is "compiled".
54 #[derive(Serialize, Deserialize)]
56 /// Run it with the given environment.
58 /// Skip it as Miri does not support interpreting such kind of crates.
63 /// Gather all the information we need.
64 fn collect(args: env::Args) -> Self {
65 let args = args.collect();
66 let env = env::vars_os().collect();
67 let current_dir = env::current_dir().unwrap().into_os_string();
69 let mut stdin = Vec::new();
70 if env::var_os("MIRI_CALLED_FROM_RUSTDOC").is_some() {
71 std::io::stdin().lock().read_to_end(&mut stdin).expect("cannot read stdin");
74 Self::RunWith(CrateRunEnv { args, env, current_dir, stdin })
77 fn store(&self, filename: &Path) {
78 let file = File::create(filename)
79 .unwrap_or_else(|_| show_error(format!("cannot create `{}`", filename.display())));
80 let file = BufWriter::new(file);
81 serde_json::ser::to_writer(file, self)
82 .unwrap_or_else(|_| show_error(format!("cannot write to `{}`", filename.display())));
87 println!("{}", CARGO_MIRI_HELP);
93 env!("CARGO_PKG_VERSION"),
94 env!("VERGEN_GIT_SHA_SHORT"),
95 env!("VERGEN_GIT_COMMIT_DATE")
99 fn show_error(msg: String) -> ! {
100 eprintln!("fatal error: {}", msg);
101 std::process::exit(1)
104 // Determines whether a `--flag` is present.
105 fn has_arg_flag(name: &str) -> bool {
106 let mut args = std::env::args().take_while(|val| val != "--");
107 args.any(|val| val == name)
110 /// Yields all values of command line flag `name`.
111 struct ArgFlagValueIter<'a> {
112 args: TakeWhile<env::Args, fn(&String) -> bool>,
116 impl<'a> ArgFlagValueIter<'a> {
117 fn new(name: &'a str) -> Self {
119 // Stop searching at `--`.
120 args: env::args().take_while(|val| val != "--"),
126 impl Iterator for ArgFlagValueIter<'_> {
129 fn next(&mut self) -> Option<Self::Item> {
131 let arg = self.args.next()?;
132 if !arg.starts_with(self.name) {
135 // Strip leading `name`.
136 let suffix = &arg[self.name.len()..];
137 if suffix.is_empty() {
138 // This argument is exactly `name`; the next one is the value.
139 return self.args.next();
140 } else if suffix.starts_with('=') {
141 // This argument is `name=value`; get the value.
142 // Strip leading `=`.
143 return Some(suffix[1..].to_owned());
149 /// Gets the value of a `--flag`.
150 fn get_arg_flag_value(name: &str) -> Option<String> {
151 ArgFlagValueIter::new(name).next()
154 fn forward_patched_extern_arg(args: &mut impl Iterator<Item = String>, cmd: &mut Command) {
155 cmd.arg("--extern"); // always forward flag, but adjust filename:
156 let path = args.next().expect("`--extern` should be followed by a filename");
157 if let Some(lib) = path.strip_suffix(".rlib") {
158 // If this is an rlib, make it an rmeta.
159 cmd.arg(format!("{}.rmeta", lib));
161 // Some other extern file (e.g. a `.so`). Forward unchanged.
166 /// Returns the path to the `miri` binary
167 fn find_miri() -> PathBuf {
168 if let Some(path) = env::var_os("MIRI") {
171 let mut path = std::env::current_exe().expect("current executable path invalid");
172 path.set_file_name("miri");
176 fn miri() -> Command {
177 Command::new(find_miri())
180 fn version_info() -> VersionMeta {
181 VersionMeta::for_command(miri()).expect("failed to determine underlying rustc version of Miri")
184 fn cargo() -> Command {
185 Command::new(env::var_os("CARGO").unwrap_or_else(|| OsString::from("cargo")))
188 fn xargo_check() -> Command {
189 Command::new(env::var_os("XARGO_CHECK").unwrap_or_else(|| OsString::from("xargo-check")))
192 /// Execute the command. If it fails, fail this process with the same exit code.
193 /// Otherwise, continue.
194 fn exec(mut cmd: Command) {
195 let exit_status = cmd.status().expect("failed to run command");
196 if exit_status.success().not() {
197 std::process::exit(exit_status.code().unwrap_or(-1))
201 /// Execute the command and pipe `input` into its stdin.
202 /// If it fails, fail this process with the same exit code.
203 /// Otherwise, continue.
204 fn exec_with_pipe(mut cmd: Command, input: &[u8]) {
205 cmd.stdin(std::process::Stdio::piped());
206 let mut child = cmd.spawn().expect("failed to spawn process");
208 let stdin = child.stdin.as_mut().expect("failed to open stdin");
209 stdin.write_all(input).expect("failed to write out test source");
211 let exit_status = child.wait().expect("failed to run command");
212 if exit_status.success().not() {
213 std::process::exit(exit_status.code().unwrap_or(-1))
217 fn xargo_version() -> Option<(u32, u32, u32)> {
218 let out = xargo_check().arg("--version").output().ok()?;
219 if !out.status.success() {
222 // Parse output. The first line looks like "xargo 0.3.12 (b004f1c 2018-12-13)".
227 .expect("malformed `xargo --version` output: not at least one line")
228 .expect("malformed `xargo --version` output: error reading first line");
229 let (name, version) = {
230 let mut split = line.split(' ');
232 split.next().expect("malformed `xargo --version` output: empty"),
233 split.next().expect("malformed `xargo --version` output: not at least two words"),
237 // This is some fork of xargo
240 let mut version_pieces = version.split('.');
241 let major = version_pieces
243 .expect("malformed `xargo --version` output: not a major version piece")
245 .expect("malformed `xargo --version` output: major version is not an integer");
246 let minor = version_pieces
248 .expect("malformed `xargo --version` output: not a minor version piece")
250 .expect("malformed `xargo --version` output: minor version is not an integer");
251 let patch = version_pieces
253 .expect("malformed `xargo --version` output: not a patch version piece")
255 .expect("malformed `xargo --version` output: patch version is not an integer");
256 if !version_pieces.next().is_none() {
257 panic!("malformed `xargo --version` output: more than three pieces in version");
259 Some((major, minor, patch))
262 fn ask_to_run(mut cmd: Command, ask: bool, text: &str) {
263 // Disable interactive prompts in CI (GitHub Actions, Travis, AppVeyor, etc).
264 // Azure doesn't set `CI` though (nothing to see here, just Microsoft being Microsoft),
265 // so we also check their `TF_BUILD`.
266 let is_ci = env::var_os("CI").is_some() || env::var_os("TF_BUILD").is_some();
268 let mut buf = String::new();
269 print!("I will run `{:?}` to {}. Proceed? [Y/n] ", cmd, text);
270 io::stdout().flush().unwrap();
271 io::stdin().read_line(&mut buf).unwrap();
272 match buf.trim().to_lowercase().as_ref() {
274 "" | "y" | "yes" => {}
275 "n" | "no" => show_error(format!("aborting as per your request")),
276 a => show_error(format!("invalid answer `{}`", a)),
279 println!("Running `{:?}` to {}.", cmd, text);
282 if cmd.status().expect(&format!("failed to execute {:?}", cmd)).success().not() {
283 show_error(format!("failed to {}", text));
287 /// Performs the setup required to make `cargo miri` work: Getting a custom-built libstd. Then sets
288 /// `MIRI_SYSROOT`. Skipped if `MIRI_SYSROOT` is already set, in which case we expect the user has
289 /// done all this already.
290 fn setup(subcommand: MiriCommand) {
291 if std::env::var_os("MIRI_SYSROOT").is_some() {
292 if subcommand == MiriCommand::Setup {
293 println!("WARNING: MIRI_SYSROOT already set, not doing anything.")
298 // Subcommands other than `setup` will do a setup if necessary, but
299 // interactively confirm first.
300 let ask_user = subcommand != MiriCommand::Setup;
302 // First, we need xargo.
303 if xargo_version().map_or(true, |v| v < XARGO_MIN_VERSION) {
304 if std::env::var_os("XARGO_CHECK").is_some() {
305 // The user manually gave us a xargo binary; don't do anything automatically.
306 show_error(format!("xargo is too old; please upgrade to the latest version"))
308 let mut cmd = cargo();
309 cmd.args(&["install", "xargo"]);
310 ask_to_run(cmd, ask_user, "install a recent enough xargo");
313 // Determine where the rust sources are located. `XARGO_RUST_SRC` env var trumps everything.
314 let rust_src = match std::env::var_os("XARGO_RUST_SRC") {
316 let path = PathBuf::from(path);
317 // Make path absolute if possible.
318 path.canonicalize().unwrap_or(path)
321 // Check for `rust-src` rustup component.
323 .args(&["--print", "sysroot"])
325 .expect("failed to determine sysroot")
327 let sysroot = std::str::from_utf8(&sysroot).unwrap();
328 let sysroot = Path::new(sysroot.trim_end_matches('\n'));
329 // Check for `$SYSROOT/lib/rustlib/src/rust/library`; test if that contains `std/Cargo.toml`.
331 sysroot.join("lib").join("rustlib").join("src").join("rust").join("library");
332 if !rustup_src.join("std").join("Cargo.toml").exists() {
333 // Ask the user to install the `rust-src` component, and use that.
334 let mut cmd = Command::new("rustup");
335 cmd.args(&["component", "add", "rust-src"]);
339 "install the `rust-src` component for the selected toolchain",
345 if !rust_src.exists() {
346 show_error(format!("given Rust source directory `{}` does not exist.", rust_src.display()));
349 // Next, we need our own libstd. Prepare a xargo project for that purpose.
350 // We will do this work in whatever is a good cache dir for this platform.
351 let dirs = directories::ProjectDirs::from("org", "rust-lang", "miri").unwrap();
352 let dir = dirs.cache_dir();
354 fs::create_dir_all(&dir).unwrap();
356 // The interesting bit: Xargo.toml
357 File::create(dir.join("Xargo.toml"))
362 default_features = false
363 # We support unwinding, so enable that panic runtime.
364 features = ["panic_unwind", "backtrace"]
370 // The boring bits: a dummy project for xargo.
371 // FIXME: With xargo-check, can we avoid doing this?
372 File::create(dir.join("Cargo.toml"))
378 description = "A dummy project for building libstd with xargo."
386 File::create(dir.join("lib.rs")).unwrap();
388 // Determine architectures.
389 // We always need to set a target so rustc bootstrap can tell apart host from target crates.
390 let host = version_info().host;
391 let target = get_arg_flag_value("--target");
392 let target = target.as_ref().unwrap_or(&host);
394 let mut command = xargo_check();
395 command.arg("check").arg("-q");
396 command.arg("--target").arg(target);
397 command.current_dir(&dir);
398 command.env("XARGO_HOME", &dir);
399 command.env("XARGO_RUST_SRC", &rust_src);
400 // Use Miri as rustc to build a libstd compatible with us (and use the right flags).
401 // However, when we are running in bootstrap, we cannot just overwrite `RUSTC`,
402 // because we still need bootstrap to distinguish between host and target crates.
403 // In that case we overwrite `RUSTC_REAL` instead which determines the rustc used
404 // for target crates.
405 // We set ourselves (`cargo-miri`) instead of Miri directly to be able to patch the flags
406 // for `libpanic_abort` (usually this is done by bootstrap but we have to do it ourselves).
407 // The `MIRI_BE_RUSTC` will mean we dispatch to `phase_setup_rustc`.
408 let cargo_miri_path = std::env::current_exe().expect("current executable path invalid");
409 if env::var_os("RUSTC_STAGE").is_some() {
410 command.env("RUSTC_REAL", &cargo_miri_path);
412 command.env("RUSTC", &cargo_miri_path);
414 command.env("MIRI_BE_RUSTC", "1");
415 // Make sure there are no other wrappers or flags getting in our way
416 // (Cc https://github.com/rust-lang/miri/issues/1421).
417 // This is consistent with normal `cargo build` that does not apply `RUSTFLAGS`
418 // to the sysroot either.
419 command.env_remove("RUSTC_WRAPPER");
420 command.env_remove("RUSTFLAGS");
421 // Disable debug assertions in the standard library -- Miri is already slow enough.
422 // But keep the overflow checks, they are cheap.
423 command.env("RUSTFLAGS", "-Cdebug-assertions=off -Coverflow-checks=on");
425 if command.status().expect("failed to run xargo").success().not() {
426 show_error(format!("failed to run xargo"));
429 // That should be it! But we need to figure out where xargo built stuff.
430 // Unfortunately, it puts things into a different directory when the
431 // architecture matches the host.
432 let sysroot = if target == &host { dir.join("HOST") } else { PathBuf::from(dir) };
433 std::env::set_var("MIRI_SYSROOT", &sysroot); // pass the env var to the processes we spawn, which will turn it into "--sysroot" flags
434 // Figure out what to print.
435 let print_sysroot = subcommand == MiriCommand::Setup && has_arg_flag("--print-sysroot"); // whether we just print the sysroot path
437 // Print just the sysroot and nothing else; this way we do not need any escaping.
438 println!("{}", sysroot.display());
439 } else if subcommand == MiriCommand::Setup {
440 println!("A libstd for Miri is now available in `{}`.", sysroot.display());
444 fn phase_setup_rustc(args: env::Args) {
445 // Mostly we just forward everything.
446 // `MIRI_BE_RUST` is already set.
447 let mut cmd = miri();
450 // Patch the panic runtime for `libpanic_abort` (mirroring what bootstrap usually does).
451 if get_arg_flag_value("--crate-name").as_deref() == Some("panic_abort") {
452 cmd.arg("-C").arg("panic=abort");
459 fn phase_cargo_miri(mut args: env::Args) {
460 // Check for version and help flags even when invoked as `cargo-miri`.
461 if has_arg_flag("--help") || has_arg_flag("-h") {
465 if has_arg_flag("--version") || has_arg_flag("-V") {
470 // Require a subcommand before any flags.
471 // We cannot know which of those flags take arguments and which do not,
472 // so we cannot detect subcommands later.
473 let subcommand = match args.next().as_deref() {
474 Some("test") => MiriCommand::Test,
475 Some("run") => MiriCommand::Run,
476 Some("setup") => MiriCommand::Setup,
478 _ => show_error(format!("`cargo miri` supports the following subcommands: `run`, `test`, and `setup`.")),
480 let verbose = has_arg_flag("-v");
485 // Invoke actual cargo for the job, but with different flags.
486 // We re-use `cargo test` and `cargo run`, which makes target and binary handling very easy but
487 // requires some extra work to make the build check-only (see all the `--emit` hacks below).
488 // <https://github.com/rust-lang/miri/pull/1540#issuecomment-693553191> describes an alternative
489 // approach that uses `cargo check`, making that part easier but target and binary handling
491 let cargo_miri_path = std::env::current_exe().expect("current executable path invalid");
492 let cargo_cmd = match subcommand {
493 MiriCommand::Test => "test",
494 MiriCommand::Run => "run",
495 MiriCommand::Setup => return, // `cargo miri setup` stops here.
497 let mut cmd = cargo();
500 // Make sure we know the build target, and cargo does, too.
501 // This is needed to make the `CARGO_TARGET_*_RUNNER` env var do something,
502 // and it later helps us detect which crates are proc-macro/build-script
503 // (host crates) and which crates are needed for the program itself.
504 let host = version_info().host;
505 let target = get_arg_flag_value("--target");
506 let target = if let Some(ref target) = target {
509 // No target given. Pick default and tell cargo about it.
515 // Forward all further arguments. We do some processing here because we want to
516 // detect people still using the old way of passing flags to Miri
517 // (`cargo miri -- -Zmiri-foo`).
518 while let Some(arg) = args.next() {
521 // Check if the next argument starts with `-Zmiri`. If yes, we assume
522 // this is an old-style invocation.
523 if let Some(next_arg) = args.next() {
524 if next_arg.starts_with("-Zmiri") || next_arg == "--" {
526 "WARNING: it seems like you are setting Miri's flags in `cargo miri` the old way,\n\
527 i.e., by passing them after the first `--`. This style is deprecated; please set\n\
528 the MIRIFLAGS environment variable instead. `cargo miri run/test` now interprets\n\
529 arguments the exact same way as `cargo run/test`."
531 // Old-style invocation. Turn these into MIRIFLAGS, if there are any.
532 if next_arg != "--" {
533 let mut miriflags = env::var("MIRIFLAGS").unwrap_or_default();
535 miriflags.push_str(&next_arg);
536 while let Some(further_arg) = args.next() {
537 if further_arg == "--" {
538 // End of the Miri flags!
542 miriflags.push_str(&further_arg);
544 env::set_var("MIRIFLAGS", miriflags);
546 // Pass the remaining flags to cargo.
550 // Not a Miri argument after all, make sure we pass it to cargo.
556 // Set `RUSTC_WRAPPER` to ourselves. Cargo will prepend that binary to its usual invocation,
557 // i.e., the first argument is `rustc` -- which is what we use in `main` to distinguish
558 // the two codepaths. (That extra argument is why we prefer this over setting `RUSTC`.)
559 if env::var_os("RUSTC_WRAPPER").is_some() {
560 println!("WARNING: Ignoring `RUSTC_WRAPPER` environment variable, Miri does not support wrapping.");
562 cmd.env("RUSTC_WRAPPER", &cargo_miri_path);
564 let runner_env_name = |triple: &str| {
565 format!("CARGO_TARGET_{}_RUNNER", triple.to_uppercase().replace('-', "_"))
567 let host_runner_env_name = runner_env_name(&host);
568 let target_runner_env_name = runner_env_name(target);
569 // Set the target runner to us, so we can interpret the binaries.
570 cmd.env(&target_runner_env_name, &cargo_miri_path);
571 // Unit tests of `proc-macro` crates are run on the host, so we set the host runner to
572 // us in order to skip them.
573 cmd.env(&host_runner_env_name, &cargo_miri_path);
575 // Set rustdoc to us as well, so we can run doctests.
576 cmd.env("RUSTDOC", &cargo_miri_path);
580 eprintln!("[cargo-miri miri] RUSTC_WRAPPER={:?}", cargo_miri_path);
581 eprintln!("[cargo-miri miri] {}={:?}", target_runner_env_name, cargo_miri_path);
583 eprintln!("[cargo-miri miri] {}={:?}", host_runner_env_name, cargo_miri_path);
585 eprintln!("[cargo-miri miri] RUSTDOC={:?}", cargo_miri_path);
586 eprintln!("[cargo-miri miri] {:?}", cmd);
587 cmd.env("MIRI_VERBOSE", ""); // This makes the other phases verbose.
592 fn phase_cargo_rustc(mut args: env::Args) {
593 /// Determines if we are being invoked (as rustc) to build a crate for
594 /// the "target" architecture, in contrast to the "host" architecture.
595 /// Host crates are for build scripts and proc macros and still need to
596 /// be built like normal; target crates need to be built for or interpreted
599 /// Currently, we detect this by checking for "--target=", which is
600 /// never set for host crates. This matches what rustc bootstrap does,
601 /// which hopefully makes it "reliable enough". This relies on us always
602 /// invoking cargo itself with `--target`, which `in_cargo_miri` ensures.
603 fn is_target_crate() -> bool {
604 get_arg_flag_value("--target").is_some()
607 /// Returns whether or not Cargo invoked the wrapper (this binary) to compile
608 /// the final, binary crate (either a test for 'cargo test', or a binary for 'cargo run')
609 /// Cargo does not give us this information directly, so we need to check
610 /// various command-line flags.
611 fn is_runnable_crate() -> bool {
612 let is_bin = get_arg_flag_value("--crate-type").as_deref().unwrap_or("bin") == "bin";
613 let is_test = has_arg_flag("--test");
617 fn out_filename(prefix: &str, suffix: &str) -> PathBuf {
618 if let Some(out_dir) = get_arg_flag_value("--out-dir") {
619 let mut path = PathBuf::from(out_dir);
623 get_arg_flag_value("--crate-name").unwrap(),
624 // This is technically a `-C` flag but the prefix seems unique enough...
625 // (and cargo passes this before the filename so it should be unique)
626 get_arg_flag_value("extra-filename").unwrap_or(String::new()),
631 let out_file = get_arg_flag_value("-o").unwrap();
632 PathBuf::from(out_file)
636 let verbose = std::env::var_os("MIRI_VERBOSE").is_some();
637 let target_crate = is_target_crate();
638 let print = get_arg_flag_value("--print").is_some(); // whether this is cargo passing `--print` to get some infos
640 let store_json = |info: &CrateRunInfo| {
641 // Create a stub .d file to stop Cargo from "rebuilding" the crate:
642 // https://github.com/rust-lang/miri/issues/1724#issuecomment-787115693
643 // As we store a JSON file instead of building the crate here, an empty file is fine.
644 let dep_info_name = out_filename("", ".d");
646 eprintln!("[cargo-miri rustc] writing stub dep-info to `{}`", dep_info_name.display());
648 File::create(dep_info_name).expect("failed to create fake .d file");
650 let filename = out_filename("", "");
652 eprintln!("[cargo-miri rustc] writing run info to `{}`", filename.display());
654 info.store(&filename);
655 // For Windows, do the same thing again with `.exe` appended to the filename.
656 // (Need to do this here as cargo moves that "binary" to a different place before running it.)
657 info.store(&out_filename("", ".exe"));
660 let runnable_crate = !print && is_runnable_crate();
662 if runnable_crate && target_crate {
663 // This is the binary or test crate that we want to interpret under Miri.
664 // But we cannot run it here, as cargo invoked us as a compiler -- our stdin and stdout are not
665 // like we want them.
666 // Instead of compiling, we write JSON into the output file with all the relevant command-line flags
667 // and environment variables; this is used when cargo calls us again in the CARGO_TARGET_RUNNER phase.
668 let info = CrateRunInfo::collect(args);
671 // Rustdoc expects us to exit with an error code if the test is marked as `compile_fail`,
672 // just creating the JSON file is not enough: we need to detect syntax errors,
673 // so we need to run Miri with `MIRI_BE_RUSTC` for a check-only build.
674 if std::env::var_os("MIRI_CALLED_FROM_RUSTDOC").is_some() {
675 let mut cmd = miri();
676 let env = if let CrateRunInfo::RunWith(env) = info {
682 // use our own sysroot
683 if !has_arg_flag("--sysroot") {
684 let sysroot = env::var_os("MIRI_SYSROOT")
685 .expect("the wrapper should have set MIRI_SYSROOT");
686 cmd.arg("--sysroot").arg(sysroot);
689 // ensure --emit argument for a check-only build is present
690 if let Some(i) = env.args.iter().position(|arg| arg.starts_with("--emit=")) {
691 // We need to make sure we're not producing a binary that overwrites the JSON file.
692 // rustdoc should only ever pass an --emit=metadata argument for tests marked as `no_run`:
693 assert_eq!(env.args[i], "--emit=metadata");
695 cmd.arg("--emit=dep-info,metadata");
699 cmd.env("MIRI_BE_RUSTC", "1");
702 eprintln!("[cargo-miri rustc] captured input:\n{}", std::str::from_utf8(&env.stdin).unwrap());
703 eprintln!("[cargo-miri rustc] {:?}", cmd);
706 exec_with_pipe(cmd, &env.stdin);
712 if runnable_crate && ArgFlagValueIter::new("--extern").any(|krate| krate == "proc_macro") {
713 // This is a "runnable" `proc-macro` crate (unit tests). We do not support
714 // interpreting that under Miri now, so we write a JSON file to (display a
715 // helpful message and) skip it in the runner phase.
716 store_json(&CrateRunInfo::SkipProcMacroTest);
720 let mut cmd = miri();
721 let mut emit_link_hack = false;
722 // Arguments are treated very differently depending on whether this crate is
723 // for interpretation by Miri, or for use by a build script / proc macro.
724 if !print && target_crate {
725 // Forward arguments, but remove "link" from "--emit" to make this a check-only build.
726 let emit_flag = "--emit";
727 while let Some(arg) = args.next() {
728 if arg.starts_with(emit_flag) {
729 // Patch this argument. First, extract its value.
730 let val = &arg[emit_flag.len()..];
731 assert!(val.starts_with("="), "`cargo` should pass `--emit=X` as one argument");
733 let mut val: Vec<_> = val.split(',').collect();
734 // Now make sure "link" is not in there, but "metadata" is.
735 if let Some(i) = val.iter().position(|&s| s == "link") {
736 emit_link_hack = true;
738 if !val.iter().any(|&s| s == "metadata") {
739 val.push("metadata");
742 cmd.arg(format!("{}={}", emit_flag, val.join(",")));
743 } else if arg == "--extern" {
744 // Patch `--extern` filenames, since Cargo sometimes passes stub `.rlib` files:
745 // https://github.com/rust-lang/miri/issues/1705
746 forward_patched_extern_arg(&mut args, &mut cmd);
752 // Use our custom sysroot.
754 env::var_os("MIRI_SYSROOT").expect("the wrapper should have set MIRI_SYSROOT");
755 cmd.arg("--sysroot");
758 // For host crates or when we are printing, just forward everything.
762 // We want to compile, not interpret. We still use Miri to make sure the compiler version etc
763 // are the exact same as what is used for interpretation.
764 cmd.env("MIRI_BE_RUSTC", "1");
768 eprintln!("[cargo-miri rustc] {:?}", cmd);
772 // Create a stub .rlib file if "link" was requested by cargo.
773 // This is necessary to prevent cargo from doing rebuilds all the time.
775 // Some platforms prepend "lib", some do not... let's just create both files.
776 File::create(out_filename("lib", ".rlib")).expect("failed to create fake .rlib file");
777 File::create(out_filename("", ".rlib")).expect("failed to create fake .rlib file");
778 // Just in case this is a cdylib or staticlib, also create those fake files.
779 File::create(out_filename("lib", ".so")).expect("failed to create fake .so file");
780 File::create(out_filename("lib", ".a")).expect("failed to create fake .a file");
781 File::create(out_filename("lib", ".dylib")).expect("failed to create fake .dylib file");
782 File::create(out_filename("", ".dll")).expect("failed to create fake .dll file");
783 File::create(out_filename("", ".lib")).expect("failed to create fake .lib file");
787 fn phase_cargo_runner(binary: &Path, binary_args: env::Args) {
788 let verbose = std::env::var_os("MIRI_VERBOSE").is_some();
790 let file = File::open(&binary)
791 .unwrap_or_else(|_| show_error(format!("file {:?} not found or `cargo-miri` invoked incorrectly; please only invoke this binary through `cargo miri`", binary)));
792 let file = BufReader::new(file);
794 let info = serde_json::from_reader(file)
795 .unwrap_or_else(|_| show_error(format!("file {:?} contains outdated or invalid JSON; try `cargo clean`", binary)));
796 let info = match info {
797 CrateRunInfo::RunWith(info) => info,
798 CrateRunInfo::SkipProcMacroTest => {
799 eprintln!("Running unit tests of `proc-macro` crates is not currently supported by Miri.");
804 let mut cmd = miri();
806 // Set missing env vars. We prefer build-time env vars over run-time ones; see
807 // <https://github.com/rust-lang/miri/issues/1661> for the kind of issue that fixes.
808 for (name, val) in info.env {
810 if let Some(old_val) = env::var_os(&name) {
812 eprintln!("[cargo-miri runner] Overwriting run-time env var {:?}={:?} with build-time value {:?}", name, old_val, val);
819 // Forward rustc arguments.
820 // We need to patch "--extern" filenames because we forced a check-only
821 // build without cargo knowing about that: replace `.rlib` suffix by
823 // We also need to remove `--error-format` as cargo specifies that to be JSON,
824 // but when we run here, cargo does not interpret the JSON any more. `--json`
825 // then also nees to be dropped.
826 let mut args = info.args.into_iter();
827 let error_format_flag = "--error-format";
828 let json_flag = "--json";
829 while let Some(arg) = args.next() {
830 if arg == "--extern" {
831 forward_patched_extern_arg(&mut args, &mut cmd);
832 } else if arg.starts_with(error_format_flag) {
833 let suffix = &arg[error_format_flag.len()..];
834 assert!(suffix.starts_with('='));
835 // Drop this argument.
836 } else if arg.starts_with(json_flag) {
837 let suffix = &arg[json_flag.len()..];
838 assert!(suffix.starts_with('='));
839 // Drop this argument.
846 env::var_os("MIRI_SYSROOT").expect("the wrapper should have set MIRI_SYSROOT");
847 cmd.arg("--sysroot");
849 // Respect `MIRIFLAGS`.
850 if let Ok(a) = env::var("MIRIFLAGS") {
851 // This code is taken from `RUSTFLAGS` handling in cargo.
855 .filter(|s| !s.is_empty())
856 .map(str::to_string);
860 // Then pass binary arguments.
862 cmd.args(binary_args);
864 // Make sure we use the build-time working directory for interpreting Miri/rustc arguments.
865 // But then we need to switch to the run-time one, which we instruct Miri do do by setting `MIRI_CWD`.
866 cmd.current_dir(info.current_dir);
867 cmd.env("MIRI_CWD", env::current_dir().unwrap());
871 eprintln!("[cargo-miri runner] {:?}", cmd);
874 if std::env::var_os("MIRI_CALLED_FROM_RUSTDOC").is_some() {
875 exec_with_pipe(cmd, &info.stdin)
881 fn phase_cargo_rustdoc(fst_arg: &str, mut args: env::Args) {
882 let verbose = std::env::var_os("MIRI_VERBOSE").is_some();
884 // phase_cargo_miri sets the RUSTDOC env var to ourselves, so we can't use that here;
885 // just default to a straight-forward invocation for now:
886 let mut cmd = Command::new(OsString::from("rustdoc"));
888 // Because of the way the main function is structured, we have to take the first argument spearately
889 // from the rest; to simplify the following argument patching loop, we'll just skip that one.
890 // This is fine for now, because cargo will never pass --extern arguments in the first position,
891 // but we should defensively assert that this will work.
892 let extern_flag = "--extern";
893 assert!(fst_arg != extern_flag);
896 let runtool_flag = "--runtool";
897 let mut crossmode = fst_arg == runtool_flag;
898 while let Some(arg) = args.next() {
899 if arg == extern_flag {
900 // Patch --extern arguments to use *.rmeta files, since phase_cargo_rustc only creates stub *.rlib files.
901 forward_patched_extern_arg(&mut args, &mut cmd);
902 } else if arg == runtool_flag {
903 // An existing --runtool flag indicates cargo is running in cross-target mode, which we don't support.
904 // Note that this is only passed when cargo is run with the unstable -Zdoctest-xcompile flag;
905 // otherwise, we won't be called as rustdoc at all.
914 show_error(format!("cross-interpreting doc-tests is not currently supported by Miri."));
917 // For each doc-test, rustdoc starts two child processes: first the test is compiled,
918 // then the produced executable is invoked. We want to reroute both of these to cargo-miri,
919 // such that the first time we'll enter phase_cargo_rustc, and phase_cargo_runner second.
921 // rustdoc invokes the test-builder by forwarding most of its own arguments, which makes
922 // it difficult to determine when phase_cargo_rustc should run instead of phase_cargo_rustdoc.
923 // Furthermore, the test code is passed via stdin, rather than a temporary file, so we need
924 // to let phase_cargo_rustc know to expect that. We'll use this environment variable as a flag:
925 cmd.env("MIRI_CALLED_FROM_RUSTDOC", "1");
927 // The `--test-builder` and `--runtool` arguments are unstable rustdoc features,
928 // which are disabled by default. We first need to enable them explicitly:
929 cmd.arg("-Z").arg("unstable-options");
931 let cargo_miri_path = std::env::current_exe().expect("current executable path invalid");
932 cmd.arg("--test-builder").arg(&cargo_miri_path); // invoked by forwarding most arguments
933 cmd.arg("--runtool").arg(&cargo_miri_path); // invoked with just a single path argument
936 eprintln!("[cargo-miri rustdoc] {:?}", cmd);
943 // Rustc does not support non-UTF-8 arguments so we make no attempt either.
944 // (We do support non-UTF-8 environment variables though.)
945 let mut args = std::env::args();
947 args.next().unwrap();
949 // Dispatch running as part of sysroot compilation.
950 if env::var_os("MIRI_BE_RUSTC").is_some() {
951 phase_setup_rustc(args);
955 // The way rustdoc invokes rustc is indistuingishable from the way cargo invokes rustdoc
956 // by the arguments alone, and we can't take from the args iterator in this case.
957 // phase_cargo_rustdoc sets this environment variable to let us disambiguate here
958 let invoked_by_rustdoc = env::var_os("MIRI_CALLED_FROM_RUSTDOC").is_some();
959 if invoked_by_rustdoc {
960 // ...however, we then also see this variable when rustdoc invokes us as the testrunner!
961 // The runner is invoked as `$runtool ($runtool-arg)* output_file`;
962 // since we don't specify any runtool-args, and rustdoc supplies multiple arguments to
963 // the test-builder unconditionally, we can just check the number of remaining arguments:
965 let arg = args.next().unwrap();
966 let binary = Path::new(&arg);
968 phase_cargo_runner(binary, args);
970 show_error(format!("`cargo-miri` called with non-existing path argument `{}` in rustdoc mode; please invoke this binary through `cargo miri`", arg));
973 phase_cargo_rustc(args);
979 // Dispatch to `cargo-miri` phase. There are three phases:
980 // - When we are called via `cargo miri`, we run as the frontend and invoke the underlying
981 // cargo. We set RUSTC_WRAPPER and CARGO_TARGET_RUNNER to ourselves.
982 // - When we are executed due to RUSTC_WRAPPER, we build crates or store the flags of
983 // binary crates for later interpretation.
984 // - When we are executed due to CARGO_TARGET_RUNNER, we start interpretation based on the
985 // flags that were stored earlier.
986 // On top of that, we are also called as RUSTDOC, but that is just a stub currently.
987 match args.next().as_deref() {
988 Some("miri") => phase_cargo_miri(args),
989 Some("rustc") => phase_cargo_rustc(args),
991 // We have to distinguish the "runner" and "rustdoc" cases.
992 // As runner, the first argument is the binary (a file that should exist, with an absolute path);
993 // as rustdoc, the first argument is a flag (`--something`).
994 let binary = Path::new(arg);
996 assert!(!arg.starts_with("--")); // not a flag
997 phase_cargo_runner(binary, args);
998 } else if arg.starts_with("--") {
999 phase_cargo_rustdoc(arg, args);
1001 show_error(format!("`cargo-miri` called with unexpected first argument `{}`; please only invoke this binary through `cargo miri`", arg));
1004 _ => show_error(format!("`cargo-miri` called without first argument; please only invoke this binary through `cargo miri`")),