rust/src/bin/cargo-miri.rs

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#![feature(inner_deref)]
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use std::env;
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use std::fs::{self, File};
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use std::io::{self, BufRead, Write};
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use std::ops::Not;
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use std::path::{Path, PathBuf};
use std::process::Command;
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const XARGO_MIN_VERSION: (u32, u32, u32) = (0, 3, 20);
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const CARGO_MIRI_HELP: &str = r#"Interprets bin crates and tests in Miri
Usage:
cargo miri [subcommand] [options] [--] [<miri opts>...] [--] [<program opts>...]
Subcommands:
run Run binaries (default)
test Run tests
setup Only perform automatic setup, but without asking questions (for getting a proper libstd)
Common options:
-h, --help Print this message
--features Features to compile for the package
-V, --version Print version info and exit
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Other [options] are the same as `cargo check`. Everything after the first "--" is
passed verbatim to Miri, which will pass everything after the second "--" verbatim
to the interpreted program.
"#;
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
enum MiriCommand {
Run,
Test,
Setup,
}
fn show_help() {
println!("{}", CARGO_MIRI_HELP);
}
fn show_version() {
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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)
}
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// 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)
}
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/// Gets the value of a `--flag`.
fn get_arg_flag_value(name: &str) -> Option<String> {
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// 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;
}
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// Strip leading `name`.
let suffix = &arg[name.len()..];
if suffix.is_empty() {
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// This argument is exactly `name`; the next one is the value.
return args.next();
} else if suffix.starts_with('=') {
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// This argument is `name=value`; get the value.
// Strip leading `=`.
return Some(suffix[1..].to_owned());
}
}
}
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/// Returns the path to the `miri` binary
fn find_miri() -> PathBuf {
let mut path = std::env::current_exe().expect("current executable path invalid");
path.set_file_name("miri");
path
}
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fn cargo() -> Command {
if let Ok(val) = std::env::var("CARGO") {
// Bootstrap tells us where to find cargo
Command::new(val)
} else {
Command::new("cargo")
}
}
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fn xargo_check() -> Command {
if let Ok(val) = std::env::var("XARGO_CHECK") {
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// Bootstrap tells us where to find xargo
Command::new(val)
} else {
Command::new("xargo-check")
}
}
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fn list_targets() -> impl Iterator<Item = cargo_metadata::Target> {
// We need to get the manifest, and then the metadata, to enumerate targets.
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let manifest_path =
get_arg_flag_value("--manifest-path").map(|m| Path::new(&m).canonicalize().unwrap());
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let mut cmd = cargo_metadata::MetadataCommand::new();
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if let Some(manifest_path) = &manifest_path {
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cmd.manifest_path(manifest_path);
}
let mut metadata = if let Ok(metadata) = cmd.exec() {
metadata
} else {
show_error(format!("Could not obtain Cargo metadata; likely an ill-formed manifest"));
};
let current_dir = std::env::current_dir();
let package_index = metadata
.packages
.iter()
.position(|package| {
let package_manifest_path = Path::new(&package.manifest_path);
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if let Some(manifest_path) = &manifest_path {
package_manifest_path == manifest_path
} else {
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let current_dir = current_dir.as_ref().expect("could not read current directory");
let package_manifest_directory = package_manifest_path
.parent()
.expect("could not find parent directory of package manifest");
package_manifest_directory == current_dir
}
})
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.unwrap_or_else(|| {
show_error(format!(
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"this seems to be a workspace, which is not supported by `cargo miri`.\n\
Try to `cd` into the crate you want to test, and re-run `cargo miri` there."
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))
});
let package = metadata.packages.remove(package_index);
// Finally we got the list of targets to build
package.targets.into_iter()
}
/// Make sure that the `miri` and `rustc` binary are from the same sysroot.
/// This can be violated e.g. when miri is locally built and installed with a different
/// toolchain than what is used when `cargo miri` is run.
fn test_sysroot_consistency() {
fn get_sysroot(mut cmd: Command) -> PathBuf {
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let out = cmd
.arg("--print")
.arg("sysroot")
.output()
.expect("Failed to run rustc to get sysroot info");
let stdout = String::from_utf8(out.stdout).expect("stdout is not valid UTF-8");
let stderr = String::from_utf8(out.stderr).expect("stderr is not valid UTF-8");
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assert!(
out.status.success(),
"Bad status code {} when getting sysroot info via {:?}.\nstdout:\n{}\nstderr:\n{}",
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out.status,
cmd,
stdout,
stderr,
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);
let stdout = stdout.trim();
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PathBuf::from(stdout)
.canonicalize()
.unwrap_or_else(|_| panic!("Failed to canonicalize sysroot: {}", stdout))
}
// Do not check sysroots if we got built as part of a Rust distribution.
// During `bootstrap`, the sysroot does not match anyway, and then some distros
// play symlink tricks so the sysroots may be different even for the final stage
// (see <https://github.com/mozilla/nixpkgs-mozilla/issues/198>).
if option_env!("RUSTC_STAGE").is_some() {
return;
}
let rustc_sysroot = get_sysroot(Command::new("rustc"));
let miri_sysroot = get_sysroot(Command::new(find_miri()));
if rustc_sysroot != miri_sysroot {
show_error(format!(
"miri was built for a different sysroot than the rustc in your current toolchain.\n\
Make sure you use the same toolchain to run miri that you used to build it!\n\
rustc sysroot: `{}`\n\
miri sysroot: `{}`",
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rustc_sysroot.display(),
miri_sysroot.display()
));
}
}
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fn xargo_version() -> Option<(u32, u32, u32)> {
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let out = xargo_check().arg("--version").output().ok()?;
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if !out.status.success() {
return None;
}
// Parse output. The first line looks like "xargo 0.3.12 (b004f1c 2018-12-13)".
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let line = out
.stderr
.lines()
.nth(0)
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.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(' ');
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(
split.next().expect("malformed `xargo --version` output: empty"),
split.next().expect("malformed `xargo --version` output: not at least two words"),
)
};
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if name != "xargo" {
// This is some fork of xargo
return None;
}
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let mut version_pieces = version.split('.');
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let major = version_pieces
.next()
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.expect("malformed `xargo --version` output: not a major version piece")
.parse()
.expect("malformed `xargo --version` output: major version is not an integer");
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let minor = version_pieces
.next()
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.expect("malformed `xargo --version` output: not a minor version piece")
.parse()
.expect("malformed `xargo --version` output: minor version is not an integer");
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let patch = version_pieces
.next()
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.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).
if ask && env::var_os("CI").is_none() {
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.
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"" | "y" | "yes" => {}
"n" | "no" => show_error(format!("Aborting as per your request")),
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a => show_error(format!("I do not understand `{}`", a)),
};
} else {
println!("Running `{:?}` to {}.", cmd, text);
}
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if cmd.status().expect(&format!("failed to execute {:?}", cmd)).success().not() {
show_error(format!("Failed to {}", text));
}
}
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/// 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("MIRI_SYSROOT").is_ok() {
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;
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// First, we need xargo.
if xargo_version().map_or(true, |v| v < XARGO_MIN_VERSION) {
if std::env::var("XARGO_CHECK").is_ok() {
// The user manually gave us a xargo binary; don't do anything automatically.
show_error(format!("Your 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("XARGO_RUST_SRC") {
Ok(val) => PathBuf::from(val),
Err(_) => {
// Check for `rust-src` rustup component.
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let sysroot = Command::new("rustc")
.args(&["--print", "sysroot"])
.output()
.expect("failed to get rustc 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/src`; test if that contains `libstd/lib.rs`.
let rustup_src = sysroot.join("lib").join("rustlib").join("src").join("rust").join("src");
if !rustup_src.join("libstd").join("lib.rs").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 rustc-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()));
}
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// Next, we need our own libstd. We will do this work in whatever is a good cache dir for this platform.
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let dirs = directories::ProjectDirs::from("org", "rust-lang", "miri").unwrap();
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let dir = dirs.cache_dir();
if !dir.exists() {
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fs::create_dir_all(&dir).unwrap();
}
// The interesting bit: Xargo.toml
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File::create(dir.join("Xargo.toml"))
.unwrap()
.write_all(
br#"
[dependencies.std]
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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.
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features = ["panic_unwind"]
[dependencies.test]
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"#,
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)
.unwrap();
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// The boring bits: a dummy project for xargo.
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// FIXME: With xargo-check, can we avoid doing this?
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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"
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"#,
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)
.unwrap();
File::create(dir.join("lib.rs")).unwrap();
// Prepare xargo invocation.
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let target = get_arg_flag_value("--target");
let print_sysroot = subcommand == MiriCommand::Setup
&& has_arg_flag("--print-sysroot"); // whether we just print the sysroot path
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let mut command = xargo_check();
command.arg("build").arg("-q");
command.current_dir(&dir);
command.env("RUSTFLAGS", miri::miri_default_args().join(" "));
command.env("XARGO_HOME", &dir);
command.env("XARGO_RUST_SRC", &rust_src);
// Handle target flag.
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if let Some(target) = &target {
command.arg("--target").arg(target);
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}
// Finally run it!
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if command.status().expect("failed to run xargo").success().not() {
show_error(format!("Failed to run xargo"));
}
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// That should be it! But we need to figure out where xargo built stuff.
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// Unfortunately, it puts things into a different directory when the
// architecture matches the host.
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let is_host = match &target {
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None => true,
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Some(target) => target == &rustc_version::version_meta().unwrap().host,
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};
let sysroot = if is_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
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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 in_cargo_miri() {
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let (subcommand, skip) = match std::env::args().nth(2).as_deref() {
Some("test") => (MiriCommand::Test, 3),
Some("run") => (MiriCommand::Run, 3),
Some("setup") => (MiriCommand::Setup, 3),
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// Default command, if there is an option or nothing.
Some(s) if s.starts_with("-") => (MiriCommand::Run, 2),
None => (MiriCommand::Run, 2),
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// Invalid command.
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Some(s) => show_error(format!("Unknown command `{}`", s)),
};
let verbose = has_arg_flag("-v");
// Some basic sanity checks
test_sysroot_consistency();
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// We always setup.
setup(subcommand);
if subcommand == MiriCommand::Setup {
// Stop here.
return;
}
// Now run the command.
for target in list_targets() {
let mut args = std::env::args().skip(skip);
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let kind = target
.kind
.get(0)
.expect("badly formatted cargo metadata: target::kind is an empty array");
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// Now we run `cargo check $FLAGS $ARGS`, giving the user the
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// change to add additional arguments. `FLAGS` is set to identify
// this target. The user gets to control what gets actually passed to Miri.
let mut cmd = cargo();
cmd.arg("check");
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match (subcommand, kind.as_str()) {
(MiriCommand::Run, "bin") => {
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// FIXME: we just run all the binaries here.
// We should instead support `cargo miri --bin foo`.
cmd.arg("--bin").arg(target.name);
}
(MiriCommand::Test, "test") => {
cmd.arg("--test").arg(target.name);
}
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(MiriCommand::Test, "lib") => {
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// There can be only one lib.
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cmd.arg("--lib").arg("--profile").arg("test");
}
(MiriCommand::Test, "bin") => {
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cmd.arg("--bin").arg(target.name).arg("--profile").arg("test");
}
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// The remaining targets we do not even want to build.
_ => continue,
}
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// Forward user-defined `cargo` args until first `--`.
while let Some(arg) = args.next() {
if arg == "--" {
break;
}
cmd.arg(arg);
}
// We want to always run `cargo` with `--target`. This later helps us detect
// which crates are proc-macro/build-script (host crates) and which crates are
// needed for the program itself.
if get_arg_flag_value("--target").is_none() {
// When no `--target` is given, default to the host.
cmd.arg("--target");
cmd.arg(rustc_version::version_meta().unwrap().host);
}
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// Serialize the remaining args into a special environemt variable.
// This will be read by `inside_cargo_rustc` when we go to invoke
// our actual target crate (the binary or the test we are running).
// Since we're using "cargo check", we have no other way of passing
// these arguments.
let args_vec: Vec<String> = args.collect();
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cmd.env("MIRI_ARGS", serde_json::to_string(&args_vec).expect("failed to serialize args"));
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// 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.
let path = std::env::current_exe().expect("current executable path invalid");
cmd.env("RUSTC_WRAPPER", path);
if verbose {
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cmd.env("MIRI_VERBOSE", ""); // this makes `inside_cargo_rustc` verbose.
eprintln!("+ {:?}", cmd);
}
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let exit_status =
cmd.spawn().expect("could not run cargo").wait().expect("failed to wait for cargo?");
if !exit_status.success() {
std::process::exit(exit_status.code().unwrap_or(-1))
}
}
}
fn inside_cargo_rustc() {
/// 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.
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///
/// Currently, we detect this by checking for "--target=", which flag is
/// never set for host crates. This matches what rustc bootstrap does,
/// which hopefully makes it "reliable enough".
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fn is_target_crate() -> bool {
get_arg_flag_value("--target").is_some()
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}
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/// 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')
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/// 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() == Some("bin");
let is_test = has_arg_flag("--test");
// The final runnable (under Miri) crate will either be a binary crate
// or a test crate. We make sure to exclude build scripts here, since
// they are also build with "--crate-type bin"
is_bin || is_test
}
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let verbose = std::env::var("MIRI_VERBOSE").is_ok();
let target_crate = is_target_crate();
// Figure out which arguments we need to pass.
let mut args: Vec<String> = std::env::args().skip(2).collect(); // skip `cargo-miri rustc`
// We make sure to only specify our custom Xargo sysroot and
// other args for target crates - that is, crates which are ultimately
// going to get interpreted by Miri.
if target_crate {
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let sysroot =
std::env::var("MIRI_SYSROOT").expect("The wrapper should have set MIRI_SYSROOT");
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args.push("--sysroot".to_owned());
args.push(sysroot);
args.splice(0..0, miri::miri_default_args().iter().map(ToString::to_string));
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}
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// Figure out the binary we need to call. If this is a runnable target crate, we want to call
// Miri to start interpretation; otherwise we want to call rustc to build the crate as usual.
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let mut command = if target_crate && is_runnable_crate() {
// This is the 'target crate' - the binary or test crate that
// we want to interpret under Miri. We deserialize the user-provided arguments
// from the special environment variable "MIRI_ARGS", and feed them
// to the 'miri' binary.
let magic = std::env::var("MIRI_ARGS").expect("missing MIRI_ARGS");
let mut user_args: Vec<String> =
serde_json::from_str(&magic).expect("failed to deserialize MIRI_ARGS");
args.append(&mut user_args);
// Run this in Miri.
Command::new(find_miri())
} else {
Command::new("rustc")
};
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// Run it.
command.args(&args);
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if verbose {
eprintln!("+ {:?}", command);
}
match command.status() {
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Ok(exit) =>
if !exit.success() {
std::process::exit(exit.code().unwrap_or(42));
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},
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Err(e) => panic!("error running {:?}:\n{:?}", command, e),
}
}
fn main() {
// 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;
}
if let Some("miri") = std::env::args().nth(1).as_deref() {
// This arm is for when `cargo miri` is called. We call `cargo check` for each applicable target,
// but with the `RUSTC` env var set to the `cargo-miri` binary so that we come back in the other branch,
// and dispatch the invocations to `rustc` and `miri`, respectively.
in_cargo_miri();
} else if let Some("rustc") = std::env::args().nth(1).as_deref() {
// This arm is executed when `cargo-miri` runs `cargo check` with the `RUSTC_WRAPPER` env var set to itself:
// dependencies get dispatched to `rustc`, the final test/binary to `miri`.
inside_cargo_rustc();
} else {
show_error(format!("must be called with either `miri` or `rustc` as first argument."))
}
}