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// Copyright 2016 rustc-version-rs developers
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![warn(missing_docs)]
//! Simple library for getting the version information of a `rustc`
//! compiler.
//!
//! This can be used by build scripts or other tools dealing with Rust sources
//! to make decisions based on the version of the compiler.
//!
//! It calls `$RUSTC --version -v` and parses the output, falling
//! back to `rustc` if `$RUSTC` is not set.
//!
//! # Example
//!
//! ```rust
//! // This could be a cargo build script
//!
//! use rustc_version::{version, version_meta, Channel, Version};
//!
//! // Assert we haven't travelled back in time
//! assert!(version().unwrap().major >= 1);
//!
//! // Set cfg flags depending on release channel
//! match version_meta().unwrap().channel {
//! Channel::Stable => {
//! println!("cargo:rustc-cfg=RUSTC_IS_STABLE");
//! }
//! Channel::Beta => {
//! println!("cargo:rustc-cfg=RUSTC_IS_BETA");
//! }
//! Channel::Nightly => {
//! println!("cargo:rustc-cfg=RUSTC_IS_NIGHTLY");
//! }
//! Channel::Dev => {
//! println!("cargo:rustc-cfg=RUSTC_IS_DEV");
//! }
//! }
//!
//! // Check for a minimum version
//! if version().unwrap() >= Version::parse("1.4.0").unwrap() {
//! println!("cargo:rustc-cfg=compiler_has_important_bugfix");
//! }
//! ```
#[cfg(test)]
#[macro_use]
extern crate doc_comment;
#[cfg(test)]
doctest!("../README.md");
use std::collections::HashMap;
use std::process::Command;
use std::{env, error, fmt, io, num, str};
use std::{ffi::OsString, str::FromStr};
// Convenience re-export to allow version comparison without needing to add
// semver crate.
pub use semver::Version;
use Error::*;
/// Release channel of the compiler.
#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Debug)]
pub enum Channel {
/// Development release channel
Dev,
/// Nightly release channel
Nightly,
/// Beta release channel
Beta,
/// Stable release channel
Stable,
}
/// LLVM version
///
/// LLVM's version numbering scheme is not semver compatible until version 4.0
///
/// rustc [just prints the major and minor versions], so other parts of the version are not included.
///
/// [just prints the major and minor versions]: https://github.com/rust-lang/rust/blob/b5c9e2448c9ace53ad5c11585803894651b18b0a/compiler/rustc_codegen_llvm/src/llvm_util.rs#L173-L178
#[derive(Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub struct LlvmVersion {
// fields must be ordered major, minor for comparison to be correct
/// Major version
pub major: u64,
/// Minor version
pub minor: u64,
// TODO: expose micro version here
}
impl fmt::Display for LlvmVersion {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}.{}", self.major, self.minor)
}
}
impl FromStr for LlvmVersion {
type Err = LlvmVersionParseError;
fn from_str(s: &str) -> Result<Self, Self::Err> {
let mut parts = s
.split('.')
.map(|part| -> Result<u64, LlvmVersionParseError> {
if part == "0" {
Ok(0)
} else if part.starts_with('0') {
Err(LlvmVersionParseError::ComponentMustNotHaveLeadingZeros)
} else if part.starts_with('-') || part.starts_with('+') {
Err(LlvmVersionParseError::ComponentMustNotHaveSign)
} else {
Ok(part.parse()?)
}
});
let major = parts.next().unwrap()?;
let mut minor = 0;
if let Some(part) = parts.next() {
minor = part?;
} else if major < 4 {
// LLVM versions earlier than 4.0 have significant minor versions, so require the minor version in this case.
return Err(LlvmVersionParseError::MinorVersionRequiredBefore4);
}
if let Some(Err(e)) = parts.next() {
return Err(e);
}
if parts.next().is_some() {
return Err(LlvmVersionParseError::TooManyComponents);
}
Ok(Self { major, minor })
}
}
/// Rustc version plus metadata like git short hash and build date.
#[derive(Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub struct VersionMeta {
/// Version of the compiler
pub semver: Version,
/// Git short hash of the build of the compiler
pub commit_hash: Option<String>,
/// Commit date of the compiler
pub commit_date: Option<String>,
/// Build date of the compiler; this was removed between Rust 1.0.0 and 1.1.0.
pub build_date: Option<String>,
/// Release channel of the compiler
pub channel: Channel,
/// Host target triple of the compiler
pub host: String,
/// Short version string of the compiler
pub short_version_string: String,
/// Version of LLVM used by the compiler
pub llvm_version: Option<LlvmVersion>,
}
impl VersionMeta {
/// Returns the version metadata for `cmd`, which should be a `rustc` command.
pub fn for_command(mut cmd: Command) -> Result<VersionMeta> {
let out = cmd
.arg("-vV")
.output()
.map_err(Error::CouldNotExecuteCommand)?;
if !out.status.success() {
return Err(Error::CommandError {
stdout: String::from_utf8_lossy(&out.stdout).into(),
stderr: String::from_utf8_lossy(&out.stderr).into(),
});
}
version_meta_for(str::from_utf8(&out.stdout)?)
}
}
/// Returns the `rustc` SemVer version.
pub fn version() -> Result<Version> {
Ok(version_meta()?.semver)
}
/// Returns the `rustc` SemVer version and additional metadata
/// like the git short hash and build date.
pub fn version_meta() -> Result<VersionMeta> {
let cmd = env::var_os("RUSTC").unwrap_or_else(|| OsString::from("rustc"));
VersionMeta::for_command(Command::new(cmd))
}
/// Parses a "rustc -vV" output string and returns
/// the SemVer version and additional metadata
/// like the git short hash and build date.
pub fn version_meta_for(verbose_version_string: &str) -> Result<VersionMeta> {
let mut map = HashMap::new();
for (i, line) in verbose_version_string.lines().enumerate() {
if i == 0 {
map.insert("short", line);
continue;
}
let mut parts = line.splitn(2, ": ");
let key = match parts.next() {
Some(key) => key,
None => continue,
};
if let Some(value) = parts.next() {
map.insert(key, value);
}
}
let short_version_string = expect_key("short", &map)?;
let host = expect_key("host", &map)?;
let release = expect_key("release", &map)?;
let semver: Version = release.parse()?;
let channel = match semver.pre.split('.').next().unwrap() {
"" => Channel::Stable,
"dev" => Channel::Dev,
"beta" => Channel::Beta,
"nightly" => Channel::Nightly,
x => return Err(Error::UnknownPreReleaseTag(x.to_owned())),
};
let commit_hash = expect_key_or_unknown("commit-hash", &map)?;
let commit_date = expect_key_or_unknown("commit-date", &map)?;
let build_date = map
.get("build-date")
.filter(|&v| *v != "unknown")
.map(|&v| String::from(v));
let llvm_version = match map.get("LLVM version") {
Some(&v) => Some(v.parse()?),
None => None,
};
Ok(VersionMeta {
semver,
commit_hash,
commit_date,
build_date,
channel,
host,
short_version_string,
llvm_version,
})
}
fn expect_key_or_unknown(key: &str, map: &HashMap<&str, &str>) -> Result<Option<String>, Error> {
match map.get(key) {
Some(&v) if v == "unknown" => Ok(None),
Some(&v) => Ok(Some(String::from(v))),
None => Err(Error::UnexpectedVersionFormat),
}
}
fn expect_key(key: &str, map: &HashMap<&str, &str>) -> Result<String, Error> {
map.get(key)
.map(|&v| String::from(v))
.ok_or(Error::UnexpectedVersionFormat)
}
/// LLVM Version Parse Error
#[derive(Debug)]
pub enum LlvmVersionParseError {
/// An error occurred in parsing a version component as an integer
ParseIntError(num::ParseIntError),
/// A version component must not have leading zeros
ComponentMustNotHaveLeadingZeros,
/// A version component has a sign
ComponentMustNotHaveSign,
/// Minor version component must be zero on LLVM versions later than 4.0
MinorVersionMustBeZeroAfter4,
/// Minor version component is required on LLVM versions earlier than 4.0
MinorVersionRequiredBefore4,
/// Too many components
TooManyComponents,
}
impl From<num::ParseIntError> for LlvmVersionParseError {
fn from(e: num::ParseIntError) -> Self {
LlvmVersionParseError::ParseIntError(e)
}
}
impl fmt::Display for LlvmVersionParseError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
LlvmVersionParseError::ParseIntError(e) => {
write!(f, "error parsing LLVM version component: {}", e)
}
LlvmVersionParseError::ComponentMustNotHaveLeadingZeros => {
write!(f, "a version component must not have leading zeros")
}
LlvmVersionParseError::ComponentMustNotHaveSign => {
write!(f, "a version component must not have a sign")
}
LlvmVersionParseError::MinorVersionMustBeZeroAfter4 => write!(
f,
"LLVM's minor version component must be 0 for versions greater than 4.0"
),
LlvmVersionParseError::MinorVersionRequiredBefore4 => write!(
f,
"LLVM's minor version component is required for versions less than 4.0"
),
LlvmVersionParseError::TooManyComponents => write!(f, "too many version components"),
}
}
}
impl error::Error for LlvmVersionParseError {
fn source(&self) -> Option<&(dyn error::Error + 'static)> {
match self {
LlvmVersionParseError::ParseIntError(e) => Some(e),
LlvmVersionParseError::ComponentMustNotHaveLeadingZeros
| LlvmVersionParseError::ComponentMustNotHaveSign
| LlvmVersionParseError::MinorVersionMustBeZeroAfter4
| LlvmVersionParseError::MinorVersionRequiredBefore4
| LlvmVersionParseError::TooManyComponents => None,
}
}
}
/// The error type for this crate.
#[derive(Debug)]
pub enum Error {
/// An error occurred while trying to find the `rustc` to run.
CouldNotExecuteCommand(io::Error),
/// Error output from the command that was run.
CommandError {
/// stdout output from the command
stdout: String,
/// stderr output from the command
stderr: String,
},
/// The output of `rustc -vV` was not valid utf-8.
Utf8Error(str::Utf8Error),
/// The output of `rustc -vV` was not in the expected format.
UnexpectedVersionFormat,
/// An error occurred in parsing the semver.
SemVerError(semver::Error),
/// The pre-release tag is unknown.
UnknownPreReleaseTag(String),
/// An error occurred in parsing a `LlvmVersion`.
LlvmVersionError(LlvmVersionParseError),
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match *self {
CouldNotExecuteCommand(ref e) => write!(f, "could not execute command: {}", e),
CommandError {
ref stdout,
ref stderr,
} => write!(
f,
"error from command -- stderr:\n\n{}\n\nstderr:\n\n{}",
stderr, stdout,
),
Utf8Error(_) => write!(f, "invalid UTF-8 output from `rustc -vV`"),
UnexpectedVersionFormat => write!(f, "unexpected `rustc -vV` format"),
SemVerError(ref e) => write!(f, "error parsing version: {}", e),
UnknownPreReleaseTag(ref i) => write!(f, "unknown pre-release tag: {}", i),
LlvmVersionError(ref e) => write!(f, "error parsing LLVM's version: {}", e),
}
}
}
impl error::Error for Error {
fn source(&self) -> Option<&(dyn error::Error + 'static)> {
match *self {
CouldNotExecuteCommand(ref e) => Some(e),
CommandError { .. } => None,
Utf8Error(ref e) => Some(e),
UnexpectedVersionFormat => None,
SemVerError(ref e) => Some(e),
UnknownPreReleaseTag(_) => None,
LlvmVersionError(ref e) => Some(e),
}
}
}
macro_rules! impl_from {
($($err_ty:ty => $variant:ident),* $(,)*) => {
$(
impl From<$err_ty> for Error {
fn from(e: $err_ty) -> Error {
Error::$variant(e)
}
}
)*
}
}
impl_from! {
str::Utf8Error => Utf8Error,
semver::Error => SemVerError,
LlvmVersionParseError => LlvmVersionError,
}
/// The result type for this crate.
pub type Result<T, E = Error> = std::result::Result<T, E>;