use std::env; use std::ffi::OsString; use std::fs::{self, File}; use std::io::{self, BufRead, BufReader, BufWriter, Write}; use std::ops::Not; use std::path::{Path, PathBuf}; use std::process::Command; use serde::{Deserialize, Serialize}; use rustc_version::VersionMeta; const XARGO_MIN_VERSION: (u32, u32, u32) = (0, 3, 22); const CARGO_MIRI_HELP: &str = r#"Runs binary crates and tests in Miri Usage: cargo miri [subcommand] [...] [--] [...] Subcommands: run Run binaries test Run tests 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(Copy, Clone, Debug, PartialEq, Eq)] enum MiriCommand { Run, Test, Setup, } /// The inforamtion Miri needs to run a crate. Stored as JSON when the crate is "compiled". #[derive(Serialize, Deserialize)] struct CrateRunInfo { /// The command-line arguments. args: Vec, /// The environment. env: Vec<(OsString, OsString)>, /// The current working directory. current_dir: OsString, } impl CrateRunInfo { /// Gather all the information we need. fn collect(args: env::Args) -> Self { let args = args.collect(); let env = env::vars_os().collect(); let current_dir = env::current_dir().unwrap().into_os_string(); CrateRunInfo { args, env, current_dir } } 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() { println!( "miri {} ({} {})", env!("CARGO_PKG_VERSION"), env!("VERGEN_SHA_SHORT"), env!("VERGEN_COMMIT_DATE") ); } 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 { let mut args = std::env::args().take_while(|val| val != "--"); args.any(|val| val == name) } /// Gets the value of a `--flag`. fn get_arg_flag_value(name: &str) -> Option { // Stop searching at `--`. let mut args = std::env::args().take_while(|val| val != "--"); loop { let arg = match args.next() { Some(arg) => arg, None => return None, }; if !arg.starts_with(name) { continue; } // Strip leading `name`. let suffix = &arg[name.len()..]; if suffix.is_empty() { // This argument is exactly `name`; the next one is the value. return args.next(); } else if suffix.starts_with('=') { // This argument is `name=value`; get the value. // Strip leading `=`. return Some(suffix[1..].to_owned()); } } } /// 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)) } } 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() .nth(0) .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_none() { 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().expect(&format!("failed to execute {:?}", cmd)).success().not() { show_error(format!("failed to {}", text)); } } /// 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) { if std::env::var_os("MIRI_SYSROOT").is_some() { if subcommand == MiriCommand::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 = subcommand != MiriCommand::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", "-f"]); ask_to_run(cmd, ask_user, "install a recent enough xargo"); } // Determine where the rust sources are located. `XARGO_RUST_SRC` env var trumps everything. let rust_src = match std::env::var_os("XARGO_RUST_SRC") { 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 sysroot = miri() .args(&["--print", "sysroot"]) .output() .expect("failed to determine sysroot") .stdout; let sysroot = std::str::from_utf8(&sysroot).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())); } // 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 File::create(dir.join("Xargo.toml")) .unwrap() .write_all( br#" [dependencies.std] default_features = false # We need the `panic_unwind` feature because we use the `unwind` panic strategy. # Using `abort` works for libstd, but then libtest will not compile. features = ["panic_unwind"] [dependencies.test] "#, ) .unwrap(); // The boring bits: a dummy project for xargo. // FIXME: With xargo-check, can we avoid doing this? File::create(dir.join("Cargo.toml")) .unwrap() .write_all( br#" [package] name = "miri-xargo" description = "A dummy project for building libstd with xargo." version = "0.0.0" [lib] path = "lib.rs" "#, ) .unwrap(); File::create(dir.join("lib.rs")).unwrap(); // 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. if env::var_os("RUSTC_STAGE").is_some() { command.env("RUSTC_REAL", find_miri()); } else { command.env("RUSTC", find_miri()); } command.env("MIRI_BE_RUSTC", "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"); // 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 = subcommand == MiriCommand::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 subcommand == MiriCommand::Setup { println!("A libstd for Miri is now available in `{}`.", sysroot.display()); } } 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 subcommand = match args.next().as_deref() { Some("test") => MiriCommand::Test, Some("run") => MiriCommand::Run, Some("setup") => MiriCommand::Setup, // Invalid command. _ => show_error(format!("`cargo miri` supports the following subcommands: `run`, `test`, and `setup`.")), }; let verbose = has_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 miri_path = std::env::current_exe().expect("current executable path invalid"); let cargo_cmd = match subcommand { MiriCommand::Test => "test", MiriCommand::Run => "run", MiriCommand::Setup => return, // `cargo miri setup` stops here. }; let mut cmd = cargo(); cmd.arg(cargo_cmd); // 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 target = if let Some(target) = get_arg_flag_value("--target") { target } else { // No target given. Pick default and tell cargo about it. let host = version_info().host; cmd.arg("--target"); cmd.arg(&host); host }; // Forward all further arguments. We do some processing here because we want to // detect people still using the old way of passing flags to Miri // (`cargo miri -- -Zmiri-foo`). while let Some(arg) = args.next() { cmd.arg(&arg); if arg == "--" { // Check if the next argument starts with `-Zmiri`. If yes, we assume // this is an old-style invocation. if let Some(next_arg) = args.next() { if next_arg.starts_with("-Zmiri") { eprintln!( "WARNING: it seems like you are setting Miri's flags in `cargo miri` the old way,\n\ i.e., by passing them after the first `--`. This style is deprecated; please set\n\ the MIRIFLAGS environment variable instead. `cargo miri run/test` now interprets\n\ arguments the exact same way as `cargo run/test`." ); // Old-style invocation. Turn these into MIRIFLAGS. let mut miriflags = env::var("MIRIFLAGS").unwrap_or_default(); miriflags.push(' '); miriflags.push_str(&next_arg); while let Some(further_arg) = args.next() { if further_arg == "--" { // End of the Miri flags! break; } miriflags.push(' '); miriflags.push_str(&further_arg); } env::set_var("MIRIFLAGS", miriflags); // Pass the remaining flags to cargo. cmd.args(args); break; } // Not a Miri argument after all, make sure we pass it to cargo. cmd.arg(next_arg); } } } // 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", &miri_path); if verbose { eprintln!("+ RUSTC_WRAPPER={:?}", miri_path); } // Set the runner for the current target to us as well, so we can interpret the binaries. let runner_env_name = format!("CARGO_TARGET_{}_RUNNER", target.to_uppercase().replace('-', "_")); cmd.env(runner_env_name, &miri_path); // Set rustdoc to us as well, so we can make it do nothing (see issue #584). cmd.env("RUSTDOC", &miri_path); // Run cargo. if verbose { cmd.env("MIRI_VERBOSE", ""); // This makes the other phases verbose. eprintln!("[cargo-miri miri] {:?}", cmd); } exec(cmd) } fn phase_cargo_rustc(args: env::Args) { /// 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"); let print = get_arg_flag_value("--print").is_some(); (is_bin || is_test) && !print } fn out_filename(prefix: &str, suffix: &str) -> PathBuf { let mut path = PathBuf::from(get_arg_flag_value("--out-dir").unwrap()); 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(String::new()), suffix, )); path } let verbose = std::env::var_os("MIRI_VERBOSE").is_some(); let target_crate = is_target_crate(); if target_crate && is_runnable_crate() { // 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 info = CrateRunInfo::collect(args); let filename = out_filename("", ""); if verbose { 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")); 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 target_crate { // Forward arguments, but remove "link" from "--emit" to make this a check-only build. let emit_flag = "--emit"; for arg in args { if arg.starts_with(emit_flag) { // Patch this argument. First, extract its value. let val = &arg[emit_flag.len()..]; assert!(val.starts_with("="), "`cargo` should pass `--emit=X` as one argument"); let val = &val[1..]; 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 { cmd.arg(arg); } } // Use our custom sysroot. let sysroot = env::var_os("MIRI_SYSROOT").expect("the wrapper should have set MIRI_SYSROOT"); cmd.arg("--sysroot"); cmd.arg(sysroot); } else { // For host crates, 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. cmd.env("MIRI_BE_RUSTC", "1"); // Run it. if verbose { eprintln!("[cargo-miri rustc] {:?}", cmd); } exec(cmd); // Create a stub .rlib file if "link" was requested by cargo. if emit_link_hack { // Some platforms prepend "lib", some do not... let's just create both files. let filename = out_filename("lib", ".rlib"); File::create(filename).expect("failed to create rlib file"); let filename = out_filename("", ".rlib"); File::create(filename).expect("failed to create rlib file"); } } fn phase_cargo_runner(binary: &Path, binary_args: env::Args) { 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: CrateRunInfo = serde_json::from_reader(file) .unwrap_or_else(|_| show_error(format!("file {:?} contains outdated or invalid JSON; try `cargo clean`", binary))); // Set missing env vars. Looks like `build.rs` vars are still set at run-time, but // `CARGO_BIN_EXE_*` are not. This means we can give the run-time environment precedence, // to rather do too little than too much. for (name, val) in info.env { if env::var_os(&name).is_none() { env::set_var(name, val); } } let mut cmd = miri(); // 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 extern_flag = "--extern"; let error_format_flag = "--error-format"; let json_flag = "--json"; while let Some(arg) = args.next() { if arg == extern_flag { // `--extern` is always passed as a separate argument by cargo. let next_arg = args.next().expect("`--extern` should be followed by a filename"); let next_arg = next_arg.strip_suffix(".rlib").expect("all extern filenames should end in `.rlib`"); cmd.arg(extern_flag); cmd.arg(format!("{}.rmeta", next_arg)); } else if arg.starts_with(error_format_flag) { let suffix = &arg[error_format_flag.len()..]; assert!(suffix.starts_with('=')); // Drop this argument. } else if arg.starts_with(json_flag) { let suffix = &arg[json_flag.len()..]; assert!(suffix.starts_with('=')); // Drop this argument. } else { cmd.arg(arg); } } // Set sysroot. let sysroot = env::var_os("MIRI_SYSROOT").expect("the wrapper should have set MIRI_SYSROOT"); cmd.arg("--sysroot"); cmd.arg(sysroot); // 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); } 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 three phases: // - When we are called via `cargo miri`, we run as the frontend and invoke the underlying // cargo. We set RUSTC_WRAPPER and CARGO_TARGET_RUNNER to ourselves. // - When we are executed due to RUSTC_WRAPPER, we build crates or store the flags of // binary crates for later interpretation. // - When we are executed due to CARGO_TARGET_RUNNER, we start interpretation based on the // flags that were stored earlier. // On top of that, we are also called as RUSTDOC, but that is just a stub currently. match args.next().as_deref() { Some("miri") => phase_cargo_miri(args), Some("rustc") => phase_cargo_rustc(args), Some(arg) => { // We have to distinguish the "runner" and "rustfmt" cases. // As runner, the first argument is the binary (a file that should exist, with an absolute path); // as rustfmt, the first argument is a flag (`--something`). let binary = Path::new(arg); if binary.exists() { assert!(!arg.starts_with("--")); // not a flag phase_cargo_runner(binary, args); } else if arg.starts_with("--") { // We are rustdoc. eprintln!("Running doctests is not currently supported by Miri.") } 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`")), } }