rust/cargo-miri/bin.rs
2020-08-26 18:41:01 -05:00

645 lines
24 KiB
Rust

use std::env;
use std::ffi::OsString;
use std::fs::{self, File};
use std::io::{self, BufRead, Write};
use std::ops::Not;
use std::path::{Path, PathBuf};
use std::process::Command;
use rustc_version::VersionMeta;
const XARGO_MIN_VERSION: (u32, u32, u32) = (0, 3, 22);
const CARGO_MIRI_HELP: &str = r#"Interprets bin crates and tests in Miri
Usage:
cargo miri [subcommand] [<cargo options>...] [--] [<miri options>...] [--] [<program/test suite options>...]
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
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.
Examples:
cargo miri run -- -Zmiri-disable-stacked-borrows
cargo miri test -- -- test-suite-filter
"#;
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
enum MiriCommand {
Run,
Test,
Setup,
}
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<String> {
// 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")))
}
fn list_targets() -> impl Iterator<Item = cargo_metadata::Target> {
// We need to get the manifest, and then the metadata, to enumerate targets.
let manifest_path =
get_arg_flag_value("--manifest-path").map(|m| Path::new(&m).canonicalize().unwrap());
let mut cmd = cargo_metadata::MetadataCommand::new();
if let Some(manifest_path) = &manifest_path {
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);
if let Some(manifest_path) = &manifest_path {
package_manifest_path == manifest_path
} else {
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
}
})
.unwrap_or_else(|| {
show_error(format!(
"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."
))
});
let package = metadata.packages.remove(package_index);
// Finally we got the list of targets to build
package.targets.into_iter()
}
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).
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.
"" | "y" | "yes" => {}
"n" | "no" => show_error(format!("Aborting as per your request")),
a => show_error(format!("I do not understand `{}`", 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!("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_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());
}
}
enum CargoTargets {
All,
Filtered { lib: bool, bin: Vec<String>, test: Vec<String> },
}
impl CargoTargets {
fn matches(&self, kind: &str, name: &str) -> bool {
match self {
CargoTargets::All => true,
CargoTargets::Filtered { lib, bin, test } => match kind {
"lib" => *lib,
"bin" => bin.iter().any(|n| n == name),
"test" => test.iter().any(|n| n == name),
_ => false,
},
}
}
}
fn parse_cargo_miri_args(
mut args: impl Iterator<Item = String>,
) -> (CargoTargets, Vec<String>, Vec<String>) {
let mut lib_present = false;
let mut bin_targets = Vec::new();
let mut test_targets = Vec::new();
let mut additional_args = Vec::new();
while let Some(arg) = args.next() {
match arg {
arg if arg == "--" => {
// Miri arguments begin after the first "--".
break;
}
arg if arg == "--lib" => lib_present = true,
arg if arg == "--bin" => {
if let Some(binary) = args.next() {
if binary == "--" {
show_error(format!("\"--bin\" takes one argument."));
} else {
bin_targets.push(binary)
}
} else {
show_error(format!("\"--bin\" takes one argument."));
}
}
arg if arg.starts_with("--bin=") => bin_targets.push((&arg[6..]).to_string()),
arg if arg == "--test" => {
if let Some(test) = args.next() {
if test == "--" {
show_error(format!("\"--test\" takes one argument."));
} else {
test_targets.push(test)
}
} else {
show_error(format!("\"--test\" takes one argument."));
}
}
arg if arg.starts_with("--test=") => test_targets.push((&arg[7..]).to_string()),
other => additional_args.push(other),
}
}
let targets = if !lib_present && bin_targets.len() == 0 && test_targets.len() == 0 {
CargoTargets::All
} else {
CargoTargets::Filtered { lib: lib_present, bin: bin_targets, test: test_targets }
};
(targets, additional_args, args.collect())
}
fn in_cargo_miri() {
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),
// Default command, if there is an option or nothing.
Some(s) if s.starts_with("-") => (MiriCommand::Run, 2),
None => (MiriCommand::Run, 2),
// Invalid command.
Some(s) => show_error(format!("Unknown command `{}`", s)),
};
let verbose = has_arg_flag("-v");
// We always setup.
setup(subcommand);
if subcommand == MiriCommand::Setup {
// Stop here.
return;
}
let (target_filters, cargo_args, miri_args) =
parse_cargo_miri_args(std::env::args().skip(skip));
// Now run the command.
for target in list_targets() {
let kind = target
.kind
.get(0)
.expect("badly formatted cargo metadata: target::kind is an empty array");
if !target_filters.matches(kind, &target.name) {
continue;
}
// Now we run `cargo check $FLAGS $ARGS`, giving the user the
// 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");
match (subcommand, kind.as_str()) {
(MiriCommand::Run, "bin") => {
// FIXME: we default to running all binaries here.
cmd.arg("--bin").arg(target.name);
}
(MiriCommand::Test, "test") => {
cmd.arg("--test").arg(target.name);
}
(MiriCommand::Test, "lib") => {
// There can be only one lib.
cmd.arg("--lib").arg("--profile").arg("test");
}
(MiriCommand::Test, "bin") => {
cmd.arg("--bin").arg(target.name).arg("--profile").arg("test");
}
// The remaining targets we do not even want to build.
_ => continue,
}
// Forward further `cargo` args.
for arg in cargo_args.iter() {
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(version_info().host);
}
// 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.
cmd.env("MIRI_ARGS", serde_json::to_string(&miri_args).expect("failed to serialize 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 existing `RUSTC_WRAPPER` environment variable, Miri does not support wrapping.");
}
let path = std::env::current_exe().expect("current executable path invalid");
cmd.env("RUSTC_WRAPPER", path);
if verbose {
cmd.env("MIRI_VERBOSE", ""); // this makes `inside_cargo_rustc` verbose.
eprintln!("+ {:?}", cmd);
}
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.
///
/// 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() == Some("bin");
let is_test = has_arg_flag("--test");
is_bin || is_test
}
let verbose = std::env::var_os("MIRI_VERBOSE").is_some();
let target_crate = is_target_crate();
let mut cmd = miri();
// Forward arguments.
cmd.args(std::env::args().skip(2)); // skip `cargo-miri rustc`
// We make sure to only specify our custom Xargo sysroot for target crates - that is,
// crates which are needed for interpretation by Miri. proc-macros and build scripts
// should use the default sysroot.
if target_crate {
let sysroot =
env::var_os("MIRI_SYSROOT").expect("The wrapper should have set MIRI_SYSROOT");
cmd.arg("--sysroot");
cmd.arg(sysroot);
}
// If this is a runnable target crate, we want Miri to start interpretation;
// otherwise we want Miri to behave like rustc and build the crate as usual.
if target_crate && is_runnable_crate() {
// This is the binary or test crate that we want to interpret under Miri.
// (Testing `target_crate` is needed to exclude build scripts.)
// We deserialize the arguments that are meant for Miri from the special environment
// variable "MIRI_ARGS", and feed them to the 'miri' binary.
//
// `env::var` is okay here, well-formed JSON is always UTF-8.
let magic = std::env::var("MIRI_ARGS").expect("missing MIRI_ARGS");
let miri_args: Vec<String> =
serde_json::from_str(&magic).expect("failed to deserialize MIRI_ARGS");
cmd.args(miri_args);
} else {
// We want to compile, not interpret.
cmd.env("MIRI_BE_RUSTC", "1");
};
// Run it.
if verbose {
eprintln!("+ {:?}", cmd);
}
match cmd.status() {
Ok(exit) =>
if !exit.success() {
std::process::exit(exit.code().unwrap_or(42));
},
Err(e) => panic!("error running {:?}:\n{:?}", cmd, 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!(
"`cargo-miri` must be called with either `miri` or `rustc` as first argument."
))
}
}