#![feature(let_else)] #![allow(clippy::useless_format, clippy::derive_partial_eq_without_eq)] mod version; use std::collections::HashMap; use std::env; use std::ffi::{OsStr, OsString}; use std::fmt::Write as _; use std::fs::{self, File}; use std::io::{self, BufRead, BufReader, BufWriter, Read, Write}; use std::iter::TakeWhile; use std::ops::Not; use std::path::{Path, PathBuf}; use std::process::{self, Command}; use rustc_version::VersionMeta; use serde::{Deserialize, Serialize}; use version::*; const CARGO_MIRI_HELP: &str = r#"Runs binary crates and tests in Miri Usage: cargo miri [subcommand] [...] [--] [...] Subcommands: run, r Run binaries test, t Run tests nextest Run tests with nextest (requires cargo-nextest installed) setup Only perform automatic setup, but without asking questions (for getting a proper libstd) The cargo options are exactly the same as for `cargo run` and `cargo test`, respectively. Examples: cargo miri run cargo miri test -- test-suite-filter "#; #[derive(Clone, Debug)] enum MiriCommand { /// Our own special 'setup' command. Setup, /// A command to be forwarded to cargo. Forward(String), } /// The information to run a crate with the given environment. #[derive(Serialize, Deserialize)] struct CrateRunEnv { /// The command-line arguments. args: Vec, /// The environment. env: Vec<(OsString, OsString)>, /// The current working directory. current_dir: OsString, /// The contents passed via standard input. stdin: Vec, } impl CrateRunEnv { /// Gather all the information we need. fn collect(args: env::Args, capture_stdin: bool) -> Self { let args = args.collect(); let env = env::vars_os().collect(); let current_dir = env::current_dir().unwrap().into_os_string(); let mut stdin = Vec::new(); if capture_stdin { std::io::stdin().lock().read_to_end(&mut stdin).expect("cannot read stdin"); } CrateRunEnv { args, env, current_dir, stdin } } } /// The information Miri needs to run a crate. Stored as JSON when the crate is "compiled". #[derive(Serialize, Deserialize)] enum CrateRunInfo { /// Run it with the given environment. RunWith(CrateRunEnv), /// Skip it as Miri does not support interpreting such kind of crates. SkipProcMacroTest, } impl CrateRunInfo { fn store(&self, filename: &Path) { let file = File::create(filename) .unwrap_or_else(|_| show_error(format!("cannot create `{}`", filename.display()))); let file = BufWriter::new(file); serde_json::ser::to_writer(file, self) .unwrap_or_else(|_| show_error(format!("cannot write to `{}`", filename.display()))); } } fn show_help() { println!("{}", CARGO_MIRI_HELP); } fn show_version() { let mut version = format!("miri {}", env!("CARGO_PKG_VERSION")); // Only use `option_env` on vergen variables to ensure the build succeeds // when vergen failed to find the git info. if let Some(sha) = option_env!("VERGEN_GIT_SHA_SHORT") { // This `unwrap` can never fail because if VERGEN_GIT_SHA_SHORT exists, then so does // VERGEN_GIT_COMMIT_DATE. #[allow(clippy::option_env_unwrap)] write!(&mut version, " ({} {})", sha, option_env!("VERGEN_GIT_COMMIT_DATE").unwrap()) .unwrap(); } println!("{}", version); } fn show_error(msg: String) -> ! { eprintln!("fatal error: {}", msg); std::process::exit(1) } /// Determines whether a `--flag` is present. fn has_arg_flag(name: &str) -> bool { num_arg_flag(name) > 0 } /// Determines how many times a `--flag` is present. fn num_arg_flag(name: &str) -> usize { std::env::args().take_while(|val| val != "--").filter(|val| val == name).count() } /// Yields all values of command line flag `name` as `Ok(arg)`, and all other arguments except /// the flag as `Err(arg)`. (The flag `name` itself is not yielded at all, only its values are.) struct ArgSplitFlagValue<'a, I> { args: TakeWhile bool>, name: &'a str, } impl<'a, I: Iterator> ArgSplitFlagValue<'a, I> { fn new(args: I, name: &'a str) -> Self { Self { // Stop searching at `--`. args: args.take_while(|val| val != "--"), name, } } } impl> Iterator for ArgSplitFlagValue<'_, I> { type Item = Result; fn next(&mut self) -> Option { let arg = self.args.next()?; if let Some(suffix) = arg.strip_prefix(self.name) { // Strip leading `name`. if suffix.is_empty() { // This argument is exactly `name`; the next one is the value. return self.args.next().map(Ok); } else if let Some(suffix) = suffix.strip_prefix('=') { // This argument is `name=value`; get the value. return Some(Ok(suffix.to_owned())); } } Some(Err(arg)) } } /// Yields all values of command line flag `name`. struct ArgFlagValueIter<'a>(ArgSplitFlagValue<'a, env::Args>); impl<'a> ArgFlagValueIter<'a> { fn new(name: &'a str) -> Self { Self(ArgSplitFlagValue::new(env::args(), name)) } } impl Iterator for ArgFlagValueIter<'_> { type Item = String; fn next(&mut self) -> Option { loop { if let Ok(value) = self.0.next()? { return Some(value); } } } } /// Gets the value of a `--flag`. fn get_arg_flag_value(name: &str) -> Option { ArgFlagValueIter::new(name).next() } fn forward_patched_extern_arg(args: &mut impl Iterator, cmd: &mut Command) { cmd.arg("--extern"); // always forward flag, but adjust filename: let path = args.next().expect("`--extern` should be followed by a filename"); if let Some(lib) = path.strip_suffix(".rlib") { // If this is an rlib, make it an rmeta. cmd.arg(format!("{}.rmeta", lib)); } else { // Some other extern file (e.g. a `.so`). Forward unchanged. cmd.arg(path); } } fn forward_miri_sysroot(cmd: &mut Command) { let sysroot = env::var_os("MIRI_SYSROOT").expect("the wrapper should have set MIRI_SYSROOT"); cmd.arg("--sysroot"); cmd.arg(sysroot); } /// Returns the path to the `miri` binary fn find_miri() -> PathBuf { if let Some(path) = env::var_os("MIRI") { return path.into(); } let mut path = std::env::current_exe().expect("current executable path invalid"); path.set_file_name("miri"); path } fn miri() -> Command { Command::new(find_miri()) } fn version_info() -> VersionMeta { VersionMeta::for_command(miri()).expect("failed to determine underlying rustc version of Miri") } fn cargo() -> Command { Command::new(env::var_os("CARGO").unwrap_or_else(|| OsString::from("cargo"))) } fn xargo_check() -> Command { Command::new(env::var_os("XARGO_CHECK").unwrap_or_else(|| OsString::from("xargo-check"))) } /// Execute the command. If it fails, fail this process with the same exit code. /// Otherwise, continue. fn exec(mut cmd: Command) { let exit_status = cmd.status().expect("failed to run command"); if exit_status.success().not() { std::process::exit(exit_status.code().unwrap_or(-1)) } } /// Execute the command and pipe `input` into its stdin. /// If it fails, fail this process with the same exit code. /// Otherwise, continue. fn exec_with_pipe(mut cmd: Command, input: &[u8]) { cmd.stdin(process::Stdio::piped()); let mut child = cmd.spawn().expect("failed to spawn process"); { let stdin = child.stdin.as_mut().expect("failed to open stdin"); stdin.write_all(input).expect("failed to write out test source"); } let exit_status = child.wait().expect("failed to run command"); if exit_status.success().not() { std::process::exit(exit_status.code().unwrap_or(-1)) } } fn xargo_version() -> Option<(u32, u32, u32)> { let out = xargo_check().arg("--version").output().ok()?; if !out.status.success() { return None; } // Parse output. The first line looks like "xargo 0.3.12 (b004f1c 2018-12-13)". let line = out .stderr .lines() .next() .expect("malformed `xargo --version` output: not at least one line") .expect("malformed `xargo --version` output: error reading first line"); let (name, version) = { let mut split = line.split(' '); ( split.next().expect("malformed `xargo --version` output: empty"), split.next().expect("malformed `xargo --version` output: not at least two words"), ) }; if name != "xargo" { // This is some fork of xargo return None; } let mut version_pieces = version.split('.'); let major = version_pieces .next() .expect("malformed `xargo --version` output: not a major version piece") .parse() .expect("malformed `xargo --version` output: major version is not an integer"); let minor = version_pieces .next() .expect("malformed `xargo --version` output: not a minor version piece") .parse() .expect("malformed `xargo --version` output: minor version is not an integer"); let patch = version_pieces .next() .expect("malformed `xargo --version` output: not a patch version piece") .parse() .expect("malformed `xargo --version` output: patch version is not an integer"); if version_pieces.next().is_some() { panic!("malformed `xargo --version` output: more than three pieces in version"); } Some((major, minor, patch)) } fn ask_to_run(mut cmd: Command, ask: bool, text: &str) { // Disable interactive prompts in CI (GitHub Actions, Travis, AppVeyor, etc). // Azure doesn't set `CI` though (nothing to see here, just Microsoft being Microsoft), // so we also check their `TF_BUILD`. let is_ci = env::var_os("CI").is_some() || env::var_os("TF_BUILD").is_some(); if ask && !is_ci { let mut buf = String::new(); print!("I will run `{:?}` to {}. Proceed? [Y/n] ", cmd, text); io::stdout().flush().unwrap(); io::stdin().read_line(&mut buf).unwrap(); match buf.trim().to_lowercase().as_ref() { // Proceed. "" | "y" | "yes" => {} "n" | "no" => show_error(format!("aborting as per your request")), a => show_error(format!("invalid answer `{}`", a)), }; } else { println!("Running `{:?}` to {}.", cmd, text); } if cmd.status().unwrap_or_else(|_| panic!("failed to execute {:?}", cmd)).success().not() { show_error(format!("failed to {}", text)); } } /// Writes the given content to the given file *cross-process atomically*, in the sense that another /// process concurrently reading that file will see either the old content or the new content, but /// not some intermediate (e.g., empty) state. /// /// We assume no other parts of this same process are trying to read or write that file. fn write_to_file(filename: &Path, content: &str) { // Create a temporary file with the desired contents. let mut temp_filename = filename.as_os_str().to_os_string(); temp_filename.push(&format!(".{}", std::process::id())); let mut temp_file = File::create(&temp_filename).unwrap(); temp_file.write_all(content.as_bytes()).unwrap(); drop(temp_file); // Move file to the desired location. fs::rename(temp_filename, filename).unwrap(); } /// Performs the setup required to make `cargo miri` work: Getting a custom-built libstd. Then sets /// `MIRI_SYSROOT`. Skipped if `MIRI_SYSROOT` is already set, in which case we expect the user has /// done all this already. fn setup(subcommand: &MiriCommand) { let only_setup = matches!(subcommand, MiriCommand::Setup); if std::env::var_os("MIRI_SYSROOT").is_some() { if only_setup { println!("WARNING: MIRI_SYSROOT already set, not doing anything.") } return; } // Subcommands other than `setup` will do a setup if necessary, but // interactively confirm first. let ask_user = !only_setup; // First, we need xargo. if xargo_version().map_or(true, |v| v < XARGO_MIN_VERSION) { if std::env::var_os("XARGO_CHECK").is_some() { // The user manually gave us a xargo binary; don't do anything automatically. show_error(format!("xargo is too old; please upgrade to the latest version")) } let mut cmd = cargo(); cmd.args(&["install", "xargo"]); ask_to_run(cmd, ask_user, "install a recent enough xargo"); } // Determine where the rust sources are located. The env vars manually setting the source // (`MIRI_LIB_SRC`, `XARGO_RUST_SRC`) trump auto-detection. let rust_src_env_var = std::env::var_os("MIRI_LIB_SRC").or_else(|| std::env::var_os("XARGO_RUST_SRC")); let rust_src = match rust_src_env_var { Some(path) => { let path = PathBuf::from(path); // Make path absolute if possible. path.canonicalize().unwrap_or(path) } None => { // Check for `rust-src` rustup component. let output = miri().args(&["--print", "sysroot"]).output().expect("failed to determine sysroot"); if !output.status.success() { show_error(format!( "Failed to determine sysroot; Miri said:\n{}", String::from_utf8_lossy(&output.stderr).trim_end() )); } let sysroot = std::str::from_utf8(&output.stdout).unwrap(); let sysroot = Path::new(sysroot.trim_end_matches('\n')); // Check for `$SYSROOT/lib/rustlib/src/rust/library`; test if that contains `std/Cargo.toml`. let rustup_src = sysroot.join("lib").join("rustlib").join("src").join("rust").join("library"); if !rustup_src.join("std").join("Cargo.toml").exists() { // Ask the user to install the `rust-src` component, and use that. let mut cmd = Command::new("rustup"); cmd.args(&["component", "add", "rust-src"]); ask_to_run( cmd, ask_user, "install the `rust-src` component for the selected toolchain", ); } rustup_src } }; if !rust_src.exists() { show_error(format!("given Rust source directory `{}` does not exist.", rust_src.display())); } if rust_src.file_name().and_then(OsStr::to_str) != Some("library") { show_error(format!( "given Rust source directory `{}` does not seem to be the `library` subdirectory of \ a Rust source checkout.", rust_src.display() )); } // Next, we need our own libstd. Prepare a xargo project for that purpose. // We will do this work in whatever is a good cache dir for this platform. let dirs = directories::ProjectDirs::from("org", "rust-lang", "miri").unwrap(); let dir = dirs.cache_dir(); if !dir.exists() { fs::create_dir_all(&dir).unwrap(); } // The interesting bit: Xargo.toml (only needs content if we actually need std) let xargo_toml = if std::env::var_os("MIRI_NO_STD").is_some() { "" } else { r#" [dependencies.std] default_features = false # We support unwinding, so enable that panic runtime. features = ["panic_unwind", "backtrace"] [dependencies.test] "# }; write_to_file(&dir.join("Xargo.toml"), xargo_toml); // The boring bits: a dummy project for xargo. // FIXME: With xargo-check, can we avoid doing this? write_to_file( &dir.join("Cargo.toml"), r#" [package] name = "miri-xargo" description = "A dummy project for building libstd with xargo." version = "0.0.0" [lib] path = "lib.rs" "#, ); write_to_file(&dir.join("lib.rs"), "#![no_std]"); // Determine architectures. // We always need to set a target so rustc bootstrap can tell apart host from target crates. let host = version_info().host; let target = get_arg_flag_value("--target"); let target = target.as_ref().unwrap_or(&host); // Now invoke xargo. let mut command = xargo_check(); command.arg("check").arg("-q"); command.arg("--target").arg(target); command.current_dir(&dir); command.env("XARGO_HOME", &dir); command.env("XARGO_RUST_SRC", &rust_src); // Use Miri as rustc to build a libstd compatible with us (and use the right flags). // However, when we are running in bootstrap, we cannot just overwrite `RUSTC`, // because we still need bootstrap to distinguish between host and target crates. // In that case we overwrite `RUSTC_REAL` instead which determines the rustc used // for target crates. // We set ourselves (`cargo-miri`) instead of Miri directly to be able to patch the flags // for `libpanic_abort` (usually this is done by bootstrap but we have to do it ourselves). // The `MIRI_CALLED_FROM_XARGO` will mean we dispatch to `phase_setup_rustc`. let cargo_miri_path = std::env::current_exe().expect("current executable path invalid"); if env::var_os("RUSTC_STAGE").is_some() { command.env("RUSTC_REAL", &cargo_miri_path); } else { command.env("RUSTC", &cargo_miri_path); } command.env("MIRI_CALLED_FROM_XARGO", "1"); // Make sure there are no other wrappers or flags getting in our way // (Cc https://github.com/rust-lang/miri/issues/1421). // This is consistent with normal `cargo build` that does not apply `RUSTFLAGS` // to the sysroot either. command.env_remove("RUSTC_WRAPPER"); command.env_remove("RUSTFLAGS"); // Disable debug assertions in the standard library -- Miri is already slow enough. // But keep the overflow checks, they are cheap. command.env("RUSTFLAGS", "-Cdebug-assertions=off -Coverflow-checks=on"); // Finally run it! if command.status().expect("failed to run xargo").success().not() { show_error(format!("failed to run xargo")); } // That should be it! But we need to figure out where xargo built stuff. // Unfortunately, it puts things into a different directory when the // architecture matches the host. let sysroot = if target == &host { dir.join("HOST") } else { PathBuf::from(dir) }; std::env::set_var("MIRI_SYSROOT", &sysroot); // pass the env var to the processes we spawn, which will turn it into "--sysroot" flags // Figure out what to print. let print_sysroot = only_setup && has_arg_flag("--print-sysroot"); // whether we just print the sysroot path if print_sysroot { // Print just the sysroot and nothing else; this way we do not need any escaping. println!("{}", sysroot.display()); } else if only_setup { println!("A libstd for Miri is now available in `{}`.", sysroot.display()); } } #[derive(Deserialize)] struct Metadata { target_directory: PathBuf, workspace_members: Vec, } fn get_cargo_metadata() -> Metadata { let mut cmd = cargo(); // `-Zunstable-options` is required by `--config`. cmd.args(["metadata", "--no-deps", "--format-version=1", "-Zunstable-options"]); // The `build.target-dir` config can be passed by `--config` flags, so forward them to // `cargo metadata`. let config_flag = "--config"; for arg in ArgSplitFlagValue::new( env::args().skip(3), // skip the program name, "miri" and "run" / "test" config_flag, ) // Only look at `Ok` .flatten() { cmd.arg(config_flag).arg(arg); } let mut child = cmd .stdin(process::Stdio::null()) .stdout(process::Stdio::piped()) .spawn() .expect("failed ro run `cargo metadata`"); // Check this `Result` after `status.success()` is checked, so we don't print the error // to stderr if `cargo metadata` is also printing to stderr. let metadata: Result = serde_json::from_reader(child.stdout.take().unwrap()); let status = child.wait().expect("failed to wait for `cargo metadata` to exit"); if !status.success() { std::process::exit(status.code().unwrap_or(-1)); } metadata.unwrap_or_else(|e| show_error(format!("invalid `cargo metadata` output: {}", e))) } /// Pulls all the crates in this workspace from the cargo metadata. /// Workspace members are emitted like "miri 0.1.0 (path+file:///path/to/miri)" /// Additionally, somewhere between cargo metadata and TyCtxt, '-' gets replaced with '_' so we /// make that same transformation here. fn local_crates(metadata: &Metadata) -> String { assert!(!metadata.workspace_members.is_empty()); let mut local_crates = String::new(); for member in &metadata.workspace_members { let name = member.split(' ').next().unwrap(); let name = name.replace('-', "_"); local_crates.push_str(&name); local_crates.push(','); } local_crates.pop(); // Remove the trailing ',' local_crates } fn phase_cargo_miri(mut args: env::Args) { // Check for version and help flags even when invoked as `cargo-miri`. if has_arg_flag("--help") || has_arg_flag("-h") { show_help(); return; } if has_arg_flag("--version") || has_arg_flag("-V") { show_version(); return; } // Require a subcommand before any flags. // We cannot know which of those flags take arguments and which do not, // so we cannot detect subcommands later. let Some(subcommand) = args.next() else { show_error(format!("`cargo miri` needs to be called with a subcommand (`run`, `test`)")); }; let subcommand = match &*subcommand { "setup" => MiriCommand::Setup, "test" | "t" | "run" | "r" | "nextest" => MiriCommand::Forward(subcommand), _ => show_error(format!( "`cargo miri` supports the following subcommands: `run`, `test`, `nextest`, and `setup`." )), }; let verbose = num_arg_flag("-v"); // We always setup. setup(&subcommand); // Invoke actual cargo for the job, but with different flags. // We re-use `cargo test` and `cargo run`, which makes target and binary handling very easy but // requires some extra work to make the build check-only (see all the `--emit` hacks below). // describes an alternative // approach that uses `cargo check`, making that part easier but target and binary handling // harder. let cargo_miri_path = std::env::current_exe().expect("current executable path invalid"); let cargo_cmd = match subcommand { MiriCommand::Forward(s) => s, MiriCommand::Setup => return, // `cargo miri setup` stops here. }; let metadata = get_cargo_metadata(); let mut cmd = cargo(); cmd.arg(cargo_cmd); // Forward all arguments before `--` other than `--target-dir` and its value to Cargo. let mut target_dir = None; for arg in ArgSplitFlagValue::new(&mut args, "--target-dir") { match arg { Ok(value) => { if target_dir.is_some() { show_error(format!("`--target-dir` is provided more than once")); } target_dir = Some(value.into()); } Err(arg) => { cmd.arg(arg); } } } // Detect the target directory if it's not specified via `--target-dir`. let target_dir = target_dir.get_or_insert_with(|| metadata.target_directory.clone()); // Set `--target-dir` to `miri` inside the original target directory. target_dir.push("miri"); cmd.arg("--target-dir").arg(target_dir); // Make sure we know the build target, and cargo does, too. // This is needed to make the `CARGO_TARGET_*_RUNNER` env var do something, // and it later helps us detect which crates are proc-macro/build-script // (host crates) and which crates are needed for the program itself. let host = version_info().host; let target = get_arg_flag_value("--target"); let target = if let Some(ref target) = target { target } else { // No target given. Pick default and tell cargo about it. cmd.arg("--target"); cmd.arg(&host); &host }; // Forward all further arguments after `--` to cargo. cmd.arg("--").args(args); // Set `RUSTC_WRAPPER` to ourselves. Cargo will prepend that binary to its usual invocation, // i.e., the first argument is `rustc` -- which is what we use in `main` to distinguish // the two codepaths. (That extra argument is why we prefer this over setting `RUSTC`.) if env::var_os("RUSTC_WRAPPER").is_some() { println!( "WARNING: Ignoring `RUSTC_WRAPPER` environment variable, Miri does not support wrapping." ); } cmd.env("RUSTC_WRAPPER", &cargo_miri_path); // We are going to invoke `MIRI` for everything, not `RUSTC`. if env::var_os("RUSTC").is_some() && env::var_os("MIRI").is_none() { println!( "WARNING: Ignoring `RUSTC` environment variable; set `MIRI` if you want to control the binary used as the driver." ); } // We'd prefer to just clear this env var, but cargo does not always honor `RUSTC_WRAPPER` // (https://github.com/rust-lang/cargo/issues/10885). There is no good way to single out these invocations; // some build scripts use the RUSTC env var as well. So we set it directly to the `miri` driver and // hope that all they do is ask for the version number -- things could quickly go downhill from here. // In `main`, we need the value of `RUSTC` to distinguish RUSTC_WRAPPER invocations from rustdoc // or TARGET_RUNNER invocations, so we canonicalize it here to make it exceedingly unlikely that // there would be a collision. cmd.env("RUSTC", &fs::canonicalize(find_miri()).unwrap()); let runner_env_name = |triple: &str| format!("CARGO_TARGET_{}_RUNNER", triple.to_uppercase().replace('-', "_")); let host_runner_env_name = runner_env_name(&host); let target_runner_env_name = runner_env_name(target); // Set the target runner to us, so we can interpret the binaries. cmd.env(&target_runner_env_name, &cargo_miri_path); // Unit tests of `proc-macro` crates are run on the host, so we set the host runner to // us in order to skip them. cmd.env(&host_runner_env_name, &cargo_miri_path); // Set rustdoc to us as well, so we can run doctests. cmd.env("RUSTDOC", &cargo_miri_path); cmd.env("MIRI_LOCAL_CRATES", local_crates(&metadata)); // Run cargo. if verbose > 0 { eprintln!("[cargo-miri miri] RUSTC_WRAPPER={:?}", cargo_miri_path); eprintln!("[cargo-miri miri] {}={:?}", target_runner_env_name, cargo_miri_path); if *target != host { eprintln!("[cargo-miri miri] {}={:?}", host_runner_env_name, cargo_miri_path); } eprintln!("[cargo-miri miri] RUSTDOC={:?}", cargo_miri_path); eprintln!("[cargo-miri miri] {:?}", cmd); cmd.env("MIRI_VERBOSE", verbose.to_string()); // This makes the other phases verbose. } exec(cmd) } #[derive(Debug, Copy, Clone, PartialEq)] enum RustcPhase { /// `rustc` called via `xargo` for sysroot build. Setup, /// `rustc` called by `cargo` for regular build. Build, /// `rustc` called by `rustdoc` for doctest. Rustdoc, } fn phase_rustc(mut args: env::Args, phase: RustcPhase) { /// Determines if we are being invoked (as rustc) to build a crate for /// the "target" architecture, in contrast to the "host" architecture. /// Host crates are for build scripts and proc macros and still need to /// be built like normal; target crates need to be built for or interpreted /// by Miri. /// /// Currently, we detect this by checking for "--target=", which is /// never set for host crates. This matches what rustc bootstrap does, /// which hopefully makes it "reliable enough". This relies on us always /// invoking cargo itself with `--target`, which `in_cargo_miri` ensures. fn is_target_crate() -> bool { get_arg_flag_value("--target").is_some() } /// Returns whether or not Cargo invoked the wrapper (this binary) to compile /// the final, binary crate (either a test for 'cargo test', or a binary for 'cargo run') /// Cargo does not give us this information directly, so we need to check /// various command-line flags. fn is_runnable_crate() -> bool { let is_bin = get_arg_flag_value("--crate-type").as_deref().unwrap_or("bin") == "bin"; let is_test = has_arg_flag("--test"); is_bin || is_test } fn out_filename(prefix: &str, suffix: &str) -> PathBuf { if let Some(out_dir) = get_arg_flag_value("--out-dir") { let mut path = PathBuf::from(out_dir); path.push(format!( "{}{}{}{}", prefix, get_arg_flag_value("--crate-name").unwrap(), // This is technically a `-C` flag but the prefix seems unique enough... // (and cargo passes this before the filename so it should be unique) get_arg_flag_value("extra-filename").unwrap_or_default(), suffix, )); path } else { let out_file = get_arg_flag_value("-o").unwrap(); PathBuf::from(out_file) } } let verbose = std::env::var("MIRI_VERBOSE") .map_or(0, |verbose| verbose.parse().expect("verbosity flag must be an integer")); let target_crate = is_target_crate(); let print = get_arg_flag_value("--print").is_some() || has_arg_flag("-vV"); // whether this is cargo/xargo invoking rustc to get some infos let store_json = |info: CrateRunInfo| { // Create a stub .d file to stop Cargo from "rebuilding" the crate: // https://github.com/rust-lang/miri/issues/1724#issuecomment-787115693 // As we store a JSON file instead of building the crate here, an empty file is fine. let dep_info_name = out_filename("", ".d"); if verbose > 0 { eprintln!("[cargo-miri rustc] writing stub dep-info to `{}`", dep_info_name.display()); } File::create(dep_info_name).expect("failed to create fake .d file"); let filename = out_filename("", ""); if verbose > 0 { eprintln!("[cargo-miri rustc] writing run info to `{}`", filename.display()); } info.store(&filename); // For Windows, do the same thing again with `.exe` appended to the filename. // (Need to do this here as cargo moves that "binary" to a different place before running it.) info.store(&out_filename("", ".exe")); }; let runnable_crate = !print && is_runnable_crate(); if runnable_crate && target_crate { assert!( phase != RustcPhase::Setup, "there should be no interpretation during sysroot build" ); let inside_rustdoc = phase == RustcPhase::Rustdoc; // This is the binary or test crate that we want to interpret under Miri. // But we cannot run it here, as cargo invoked us as a compiler -- our stdin and stdout are not // like we want them. // Instead of compiling, we write JSON into the output file with all the relevant command-line flags // and environment variables; this is used when cargo calls us again in the CARGO_TARGET_RUNNER phase. let env = CrateRunEnv::collect(args, inside_rustdoc); // Rustdoc expects us to exit with an error code if the test is marked as `compile_fail`, // just creating the JSON file is not enough: we need to detect syntax errors, // so we need to run Miri with `MIRI_BE_RUSTC` for a check-only build. if inside_rustdoc { let mut cmd = miri(); // Ensure --emit argument for a check-only build is present. // We cannot use the usual helpers since we need to check specifically in `env.args`. if let Some(i) = env.args.iter().position(|arg| arg.starts_with("--emit=")) { // For `no_run` tests, rustdoc passes a `--emit` flag; make sure it has the right shape. assert_eq!(env.args[i], "--emit=metadata"); } else { // For all other kinds of tests, we can just add our flag. cmd.arg("--emit=metadata"); } cmd.args(&env.args); cmd.env("MIRI_BE_RUSTC", "target"); if verbose > 0 { eprintln!( "[cargo-miri rustc] captured input:\n{}", std::str::from_utf8(&env.stdin).unwrap() ); eprintln!("[cargo-miri rustc] {:?}", cmd); } exec_with_pipe(cmd, &env.stdin); } store_json(CrateRunInfo::RunWith(env)); return; } if runnable_crate && ArgFlagValueIter::new("--extern").any(|krate| krate == "proc_macro") { // This is a "runnable" `proc-macro` crate (unit tests). We do not support // interpreting that under Miri now, so we write a JSON file to (display a // helpful message and) skip it in the runner phase. store_json(CrateRunInfo::SkipProcMacroTest); return; } let mut cmd = miri(); let mut emit_link_hack = false; // Arguments are treated very differently depending on whether this crate is // for interpretation by Miri, or for use by a build script / proc macro. if !print && target_crate { // Forward arguments, but remove "link" from "--emit" to make this a check-only build. let emit_flag = "--emit"; while let Some(arg) = args.next() { if let Some(val) = arg.strip_prefix(emit_flag) { // Patch this argument. First, extract its value. let val = val.strip_prefix('=').expect("`cargo` should pass `--emit=X` as one argument"); let mut val: Vec<_> = val.split(',').collect(); // Now make sure "link" is not in there, but "metadata" is. if let Some(i) = val.iter().position(|&s| s == "link") { emit_link_hack = true; val.remove(i); if !val.iter().any(|&s| s == "metadata") { val.push("metadata"); } } cmd.arg(format!("{}={}", emit_flag, val.join(","))); } else if arg == "--extern" { // Patch `--extern` filenames, since Cargo sometimes passes stub `.rlib` files: // https://github.com/rust-lang/miri/issues/1705 forward_patched_extern_arg(&mut args, &mut cmd); } else { cmd.arg(arg); } } // Use our custom sysroot (but not if that is what we are currently building). if phase != RustcPhase::Setup { forward_miri_sysroot(&mut cmd); } // During setup, patch the panic runtime for `libpanic_abort` (mirroring what bootstrap usually does). if phase == RustcPhase::Setup && get_arg_flag_value("--crate-name").as_deref() == Some("panic_abort") { cmd.arg("-C").arg("panic=abort"); } } else { // For host crates (but not when we are printing), we might still have to set the sysroot. if !print { // When we're running `cargo-miri` from `x.py` we need to pass the sysroot explicitly as rustc // can't figure out the sysroot on its own unless it's from rustup. if let Some(sysroot) = std::env::var_os("SYSROOT") { cmd.arg("--sysroot").arg(sysroot); } } // For host crates or when we are printing, just forward everything. cmd.args(args); } // We want to compile, not interpret. We still use Miri to make sure the compiler version etc // are the exact same as what is used for interpretation. // MIRI_DEFAULT_ARGS should not be used to build host crates, hence setting "target" or "host" // as the value here to help Miri differentiate them. cmd.env("MIRI_BE_RUSTC", if target_crate { "target" } else { "host" }); // Run it. if verbose > 0 { eprint!("[cargo-miri rustc] "); if verbose > 1 { for (key, value) in env_vars_from_cmd(&cmd) { eprintln!("{key}={value:?} \\"); } } eprintln!("{:?}", cmd); } exec(cmd); // Create a stub .rlib file if "link" was requested by cargo. // This is necessary to prevent cargo from doing rebuilds all the time. if emit_link_hack { // Some platforms prepend "lib", some do not... let's just create both files. File::create(out_filename("lib", ".rlib")).expect("failed to create fake .rlib file"); File::create(out_filename("", ".rlib")).expect("failed to create fake .rlib file"); // Just in case this is a cdylib or staticlib, also create those fake files. File::create(out_filename("lib", ".so")).expect("failed to create fake .so file"); File::create(out_filename("lib", ".a")).expect("failed to create fake .a file"); File::create(out_filename("lib", ".dylib")).expect("failed to create fake .dylib file"); File::create(out_filename("", ".dll")).expect("failed to create fake .dll file"); File::create(out_filename("", ".lib")).expect("failed to create fake .lib file"); } } fn env_vars_from_cmd(cmd: &Command) -> Vec<(String, String)> { let mut envs = HashMap::new(); for (key, value) in std::env::vars() { envs.insert(key, value); } for (key, value) in cmd.get_envs() { if let Some(value) = value { envs.insert(key.to_str().unwrap().into(), value.to_str().unwrap().to_owned()); } else { envs.remove(key.to_str().unwrap()); } } let mut envs: Vec<_> = envs.into_iter().collect(); envs.sort(); envs } #[derive(Debug, Copy, Clone, PartialEq)] enum RunnerPhase { /// `cargo` is running a binary Cargo, /// `rustdoc` is running a binary Rustdoc, } fn phase_runner(binary: &Path, binary_args: env::Args, phase: RunnerPhase) { let verbose = std::env::var_os("MIRI_VERBOSE").is_some(); let file = File::open(&binary) .unwrap_or_else(|_| show_error(format!("file {:?} not found or `cargo-miri` invoked incorrectly; please only invoke this binary through `cargo miri`", binary))); let file = BufReader::new(file); let info = serde_json::from_reader(file).unwrap_or_else(|_| { show_error(format!( "file {:?} contains outdated or invalid JSON; try `cargo clean`", binary )) }); let info = match info { CrateRunInfo::RunWith(info) => info, CrateRunInfo::SkipProcMacroTest => { eprintln!( "Running unit tests of `proc-macro` crates is not currently supported by Miri." ); return; } }; let mut cmd = miri(); // Set missing env vars. We prefer build-time env vars over run-time ones; see // for the kind of issue that fixes. for (name, val) in info.env { if verbose { if let Some(old_val) = env::var_os(&name) { if old_val != val { eprintln!( "[cargo-miri runner] Overwriting run-time env var {:?}={:?} with build-time value {:?}", name, old_val, val ); } } } cmd.env(name, val); } // Forward rustc arguments. // We need to patch "--extern" filenames because we forced a check-only // build without cargo knowing about that: replace `.rlib` suffix by // `.rmeta`. // We also need to remove `--error-format` as cargo specifies that to be JSON, // but when we run here, cargo does not interpret the JSON any more. `--json` // then also nees to be dropped. let mut args = info.args.into_iter(); let error_format_flag = "--error-format"; let json_flag = "--json"; while let Some(arg) = args.next() { if arg == "--extern" { forward_patched_extern_arg(&mut args, &mut cmd); } else if let Some(suffix) = arg.strip_prefix(error_format_flag) { assert!(suffix.starts_with('=')); // Drop this argument. } else if let Some(suffix) = arg.strip_prefix(json_flag) { assert!(suffix.starts_with('=')); // Drop this argument. } else { cmd.arg(arg); } } // Set sysroot (if we are inside rustdoc, we already did that in `phase_cargo_rustdoc`). if phase != RunnerPhase::Rustdoc { forward_miri_sysroot(&mut cmd); } // Respect `MIRIFLAGS`. if let Ok(a) = env::var("MIRIFLAGS") { // This code is taken from `RUSTFLAGS` handling in cargo. let args = a.split(' ').map(str::trim).filter(|s| !s.is_empty()).map(str::to_string); cmd.args(args); } // Then pass binary arguments. cmd.arg("--"); cmd.args(binary_args); // Make sure we use the build-time working directory for interpreting Miri/rustc arguments. // But then we need to switch to the run-time one, which we instruct Miri do do by setting `MIRI_CWD`. cmd.current_dir(info.current_dir); cmd.env("MIRI_CWD", env::current_dir().unwrap()); // Run it. if verbose { eprintln!("[cargo-miri runner] {:?}", cmd); } match phase { RunnerPhase::Rustdoc => exec_with_pipe(cmd, &info.stdin), RunnerPhase::Cargo => exec(cmd), } } fn phase_rustdoc(fst_arg: &str, mut args: env::Args) { let verbose = std::env::var_os("MIRI_VERBOSE").is_some(); // phase_cargo_miri sets the RUSTDOC env var to ourselves, so we can't use that here; // just default to a straight-forward invocation for now: let mut cmd = Command::new("rustdoc"); // Because of the way the main function is structured, we have to take the first argument spearately // from the rest; to simplify the following argument patching loop, we'll just skip that one. // This is fine for now, because cargo will never pass --extern arguments in the first position, // but we should defensively assert that this will work. let extern_flag = "--extern"; assert!(fst_arg != extern_flag); cmd.arg(fst_arg); let runtool_flag = "--runtool"; // `crossmode` records if *any* argument matches `runtool_flag`; here we check the first one. let mut crossmode = fst_arg == runtool_flag; while let Some(arg) = args.next() { if arg == extern_flag { // Patch --extern arguments to use *.rmeta files, since phase_cargo_rustc only creates stub *.rlib files. forward_patched_extern_arg(&mut args, &mut cmd); } else if arg == runtool_flag { // An existing --runtool flag indicates cargo is running in cross-target mode, which we don't support. // Note that this is only passed when cargo is run with the unstable -Zdoctest-xcompile flag; // otherwise, we won't be called as rustdoc at all. crossmode = true; break; } else { cmd.arg(arg); } } if crossmode { show_error(format!("cross-interpreting doctests is not currently supported by Miri.")); } // Doctests of `proc-macro` crates (and their dependencies) are always built for the host, // so we are not able to run them in Miri. if ArgFlagValueIter::new("--crate-type").any(|crate_type| crate_type == "proc-macro") { eprintln!("Running doctests of `proc-macro` crates is not currently supported by Miri."); return; } // For each doctest, rustdoc starts two child processes: first the test is compiled, // then the produced executable is invoked. We want to reroute both of these to cargo-miri, // such that the first time we'll enter phase_cargo_rustc, and phase_cargo_runner second. // // rustdoc invokes the test-builder by forwarding most of its own arguments, which makes // it difficult to determine when phase_cargo_rustc should run instead of phase_cargo_rustdoc. // Furthermore, the test code is passed via stdin, rather than a temporary file, so we need // to let phase_cargo_rustc know to expect that. We'll use this environment variable as a flag: cmd.env("MIRI_CALLED_FROM_RUSTDOC", "1"); // The `--test-builder` and `--runtool` arguments are unstable rustdoc features, // which are disabled by default. We first need to enable them explicitly: cmd.arg("-Z").arg("unstable-options"); // rustdoc needs to know the right sysroot. forward_miri_sysroot(&mut cmd); // make sure the 'miri' flag is set for rustdoc cmd.arg("--cfg").arg("miri"); // Make rustdoc call us back. let cargo_miri_path = std::env::current_exe().expect("current executable path invalid"); cmd.arg("--test-builder").arg(&cargo_miri_path); // invoked by forwarding most arguments cmd.arg("--runtool").arg(&cargo_miri_path); // invoked with just a single path argument if verbose { eprintln!("[cargo-miri rustdoc] {:?}", cmd); } exec(cmd) } fn main() { // Rustc does not support non-UTF-8 arguments so we make no attempt either. // (We do support non-UTF-8 environment variables though.) let mut args = std::env::args(); // Skip binary name. args.next().unwrap(); // Dispatch to `cargo-miri` phase. There are four phases: // - When we are called via `cargo miri`, we run as the frontend and invoke the underlying // cargo. We set RUSTDOC, RUSTC_WRAPPER and CARGO_TARGET_RUNNER to ourselves. // - When we are executed due to RUSTDOC, we run rustdoc and set both `--test-builder` and // `--runtool` to ourselves. // - When we are executed due to RUSTC_WRAPPER (or as the rustdoc test builder), we build crates // or store the flags of binary crates for later interpretation. // - When we are executed due to CARGO_TARGET_RUNNER (or as the rustdoc runtool), we start // interpretation based on the flags that were stored earlier. // // Additionally, we also set ourselves as RUSTC when calling xargo to build the sysroot, which // has to be treated slightly differently than when we build regular crates. // Dispatch running as part of sysroot compilation. if env::var_os("MIRI_CALLED_FROM_XARGO").is_some() { phase_rustc(args, RustcPhase::Setup); return; } // The way rustdoc invokes rustc is indistuingishable from the way cargo invokes rustdoc by the // arguments alone. `phase_cargo_rustdoc` sets this environment variable to let us disambiguate. if env::var_os("MIRI_CALLED_FROM_RUSTDOC").is_some() { // ...however, we then also see this variable when rustdoc invokes us as the testrunner! // The runner is invoked as `$runtool ($runtool-arg)* output_file`; // since we don't specify any runtool-args, and rustdoc supplies multiple arguments to // the test-builder unconditionally, we can just check the number of remaining arguments: if args.len() == 1 { let arg = args.next().unwrap(); let binary = Path::new(&arg); if binary.exists() { phase_runner(binary, args, RunnerPhase::Rustdoc); } else { show_error(format!( "`cargo-miri` called with non-existing path argument `{}` in rustdoc mode; please invoke this binary through `cargo miri`", arg )); } } else { phase_rustc(args, RustcPhase::Rustdoc); } return; } match args.next().as_deref() { Some("miri") => phase_cargo_miri(args), Some(arg) => { // If the first arg is equal to the RUSTC variable (which should be set at this point), // then we need to behave as rustc. This is the somewhat counter-intuitive behavior of // having both RUSTC and RUSTC_WRAPPER set (see // https://github.com/rust-lang/cargo/issues/10886). if arg == env::var_os("RUSTC").unwrap() { return phase_rustc(args, RustcPhase::Build); } // We have to distinguish the "runner" and "rustdoc" cases. // As runner, the first argument is the binary (a file that should exist, with an absolute path); // as rustdoc, the first argument is a flag (`--something`). let binary = Path::new(arg); if binary.exists() { assert!(!arg.starts_with("--")); // not a flag phase_runner(binary, args, RunnerPhase::Cargo); } else if arg.starts_with("--") { phase_rustdoc(arg, args); } else { show_error(format!( "`cargo-miri` called with unexpected first argument `{}`; please only invoke this binary through `cargo miri`", arg )); } } _ => show_error(format!( "`cargo-miri` called without first argument; please only invoke this binary through `cargo miri`" )), } }