1// Copyright 2016 rustc-version-rs developers
2//
3// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
4// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
5// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
6// option. This file may not be copied, modified, or distributed
7// except according to those terms.
8
9#![warn(missing_docs)]
10
11//! Simple library for getting the version information of a `rustc`
12//! compiler.
13//!
14//! This can be used by build scripts or other tools dealing with Rust sources
15//! to make decisions based on the version of the compiler.
16//!
17//! It calls `$RUSTC --version -v` and parses the output, falling
18//! back to `rustc` if `$RUSTC` is not set.
19//!
20//! # Example
21//!
22//! ```rust
23//! // This could be a cargo build script
24//!
25//! use rustc_version::{version, version_meta, Channel, Version};
26//!
27//! // Assert we haven't travelled back in time
28//! assert!(version().unwrap().major >= 1);
29//!
30//! // Set cfg flags depending on release channel
31//! match version_meta().unwrap().channel {
32//! Channel::Stable => {
33//! println!("cargo:rustc-cfg=RUSTC_IS_STABLE");
34//! }
35//! Channel::Beta => {
36//! println!("cargo:rustc-cfg=RUSTC_IS_BETA");
37//! }
38//! Channel::Nightly => {
39//! println!("cargo:rustc-cfg=RUSTC_IS_NIGHTLY");
40//! }
41//! Channel::Dev => {
42//! println!("cargo:rustc-cfg=RUSTC_IS_DEV");
43//! }
44//! }
45//!
46//! // Check for a minimum version
47//! if version().unwrap() >= Version::parse("1.4.0").unwrap() {
48//! println!("cargo:rustc-cfg=compiler_has_important_bugfix");
49//! }
50//! ```
51
52#[cfg(test)]
53#[macro_use]
54extern crate doc_comment;
55
56#[cfg(test)]
57doctest!("../README.md");
58
59use std::collections::HashMap;
60use std::process::Command;
61use std::{env, error, fmt, io, num, str};
62use std::{ffi::OsString, str::FromStr};
63
64// Convenience re-export to allow version comparison without needing to add
65// semver crate.
66pub use semver::Version;
67
68use Error::*;
69
70/// Release channel of the compiler.
71#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Debug)]
72pub enum Channel {
73 /// Development release channel
74 Dev,
75 /// Nightly release channel
76 Nightly,
77 /// Beta release channel
78 Beta,
79 /// Stable release channel
80 Stable,
81}
82
83/// LLVM version
84///
85/// LLVM's version numbering scheme is not semver compatible until version 4.0
86///
87/// rustc [just prints the major and minor versions], so other parts of the version are not included.
88///
89/// [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
90#[derive(Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
91pub struct LlvmVersion {
92 // fields must be ordered major, minor for comparison to be correct
93 /// Major version
94 pub major: u64,
95 /// Minor version
96 pub minor: u64,
97 // TODO: expose micro version here
98}
99
100impl fmt::Display for LlvmVersion {
101 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
102 write!(f, "{}.{}", self.major, self.minor)
103 }
104}
105
106impl FromStr for LlvmVersion {
107 type Err = LlvmVersionParseError;
108
109 fn from_str(s: &str) -> Result<Self, Self::Err> {
110 let mut parts = s
111 .split('.')
112 .map(|part| -> Result<u64, LlvmVersionParseError> {
113 if part == "0" {
114 Ok(0)
115 } else if part.starts_with('0') {
116 Err(LlvmVersionParseError::ComponentMustNotHaveLeadingZeros)
117 } else if part.starts_with('-') || part.starts_with('+') {
118 Err(LlvmVersionParseError::ComponentMustNotHaveSign)
119 } else {
120 Ok(part.parse()?)
121 }
122 });
123
124 let major = parts.next().unwrap()?;
125 let mut minor = 0;
126
127 if let Some(part) = parts.next() {
128 minor = part?;
129 } else if major < 4 {
130 // LLVM versions earlier than 4.0 have significant minor versions, so require the minor version in this case.
131 return Err(LlvmVersionParseError::MinorVersionRequiredBefore4);
132 }
133
134 if let Some(Err(e)) = parts.next() {
135 return Err(e);
136 }
137
138 if parts.next().is_some() {
139 return Err(LlvmVersionParseError::TooManyComponents);
140 }
141
142 Ok(Self { major, minor })
143 }
144}
145
146/// Rustc version plus metadata like git short hash and build date.
147#[derive(Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
148pub struct VersionMeta {
149 /// Version of the compiler
150 pub semver: Version,
151
152 /// Git short hash of the build of the compiler
153 pub commit_hash: Option<String>,
154
155 /// Commit date of the compiler
156 pub commit_date: Option<String>,
157
158 /// Build date of the compiler; this was removed between Rust 1.0.0 and 1.1.0.
159 pub build_date: Option<String>,
160
161 /// Release channel of the compiler
162 pub channel: Channel,
163
164 /// Host target triple of the compiler
165 pub host: String,
166
167 /// Short version string of the compiler
168 pub short_version_string: String,
169
170 /// Version of LLVM used by the compiler
171 pub llvm_version: Option<LlvmVersion>,
172}
173
174impl VersionMeta {
175 /// Returns the version metadata for `cmd`, which should be a `rustc` command.
176 pub fn for_command(mut cmd: Command) -> Result<VersionMeta> {
177 let out: Output = cmd
178 .arg("-vV")
179 .output()
180 .map_err(op:Error::CouldNotExecuteCommand)?;
181
182 if !out.status.success() {
183 return Err(Error::CommandError {
184 stdout: String::from_utf8_lossy(&out.stdout).into(),
185 stderr: String::from_utf8_lossy(&out.stderr).into(),
186 });
187 }
188
189 version_meta_for(verbose_version_string:str::from_utf8(&out.stdout)?)
190 }
191}
192
193/// Returns the `rustc` SemVer version.
194pub fn version() -> Result<Version> {
195 Ok(version_meta()?.semver)
196}
197
198/// Returns the `rustc` SemVer version and additional metadata
199/// like the git short hash and build date.
200pub fn version_meta() -> Result<VersionMeta> {
201 let rustc: OsString = env::var_os(key:"RUSTC").unwrap_or_else(|| OsString::from("rustc"));
202 let cmd: Command = if let Some(wrapper: OsString) = env::var_os(key:"RUSTC_WRAPPER").filter(|w: &OsString| !w.is_empty()) {
203 let mut cmd: Command = Command::new(program:wrapper);
204 cmd.arg(rustc);
205 cmd
206 } else {
207 Command::new(program:rustc)
208 };
209
210 VersionMeta::for_command(cmd)
211}
212
213/// Parses a "rustc -vV" output string and returns
214/// the SemVer version and additional metadata
215/// like the git short hash and build date.
216pub fn version_meta_for(verbose_version_string: &str) -> Result<VersionMeta> {
217 let mut map = HashMap::new();
218 for (i, line) in verbose_version_string.lines().enumerate() {
219 if i == 0 {
220 map.insert("short", line);
221 continue;
222 }
223
224 let mut parts = line.splitn(2, ": ");
225 let key = match parts.next() {
226 Some(key) => key,
227 None => continue,
228 };
229
230 if let Some(value) = parts.next() {
231 map.insert(key, value);
232 }
233 }
234
235 let short_version_string = expect_key("short", &map)?;
236 let host = expect_key("host", &map)?;
237 let release = expect_key("release", &map)?;
238 let semver: Version = release.parse()?;
239
240 let channel = match semver.pre.split('.').next().unwrap() {
241 "" => Channel::Stable,
242 "dev" => Channel::Dev,
243 "beta" => Channel::Beta,
244 "nightly" => Channel::Nightly,
245 x => return Err(Error::UnknownPreReleaseTag(x.to_owned())),
246 };
247
248 let commit_hash = expect_key_or_unknown("commit-hash", &map)?;
249 let commit_date = expect_key_or_unknown("commit-date", &map)?;
250 let build_date = map
251 .get("build-date")
252 .filter(|&v| *v != "unknown")
253 .map(|&v| String::from(v));
254 let llvm_version = match map.get("LLVM version") {
255 Some(&v) => Some(v.parse()?),
256 None => None,
257 };
258
259 Ok(VersionMeta {
260 semver,
261 commit_hash,
262 commit_date,
263 build_date,
264 channel,
265 host,
266 short_version_string,
267 llvm_version,
268 })
269}
270
271fn expect_key_or_unknown(key: &str, map: &HashMap<&str, &str>) -> Result<Option<String>, Error> {
272 match map.get(key) {
273 Some(&"unknown") => Ok(None),
274 Some(&v: &str) => Ok(Some(String::from(v))),
275 None => Err(Error::UnexpectedVersionFormat),
276 }
277}
278
279fn expect_key(key: &str, map: &HashMap<&str, &str>) -> Result<String, Error> {
280 map.get(key)
281 .map(|&v| String::from(v))
282 .ok_or(err:Error::UnexpectedVersionFormat)
283}
284
285/// LLVM Version Parse Error
286#[derive(Debug)]
287pub enum LlvmVersionParseError {
288 /// An error occurred in parsing a version component as an integer
289 ParseIntError(num::ParseIntError),
290 /// A version component must not have leading zeros
291 ComponentMustNotHaveLeadingZeros,
292 /// A version component has a sign
293 ComponentMustNotHaveSign,
294 /// Minor version component must be zero on LLVM versions later than 4.0
295 MinorVersionMustBeZeroAfter4,
296 /// Minor version component is required on LLVM versions earlier than 4.0
297 MinorVersionRequiredBefore4,
298 /// Too many components
299 TooManyComponents,
300}
301
302impl From<num::ParseIntError> for LlvmVersionParseError {
303 fn from(e: num::ParseIntError) -> Self {
304 LlvmVersionParseError::ParseIntError(e)
305 }
306}
307
308impl fmt::Display for LlvmVersionParseError {
309 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
310 match self {
311 LlvmVersionParseError::ParseIntError(e: &ParseIntError) => {
312 write!(f, "error parsing LLVM version component: {}", e)
313 }
314 LlvmVersionParseError::ComponentMustNotHaveLeadingZeros => {
315 write!(f, "a version component must not have leading zeros")
316 }
317 LlvmVersionParseError::ComponentMustNotHaveSign => {
318 write!(f, "a version component must not have a sign")
319 }
320 LlvmVersionParseError::MinorVersionMustBeZeroAfter4 => write!(
321 f,
322 "LLVM's minor version component must be 0 for versions greater than 4.0"
323 ),
324 LlvmVersionParseError::MinorVersionRequiredBefore4 => write!(
325 f,
326 "LLVM's minor version component is required for versions less than 4.0"
327 ),
328 LlvmVersionParseError::TooManyComponents => write!(f, "too many version components"),
329 }
330 }
331}
332
333impl error::Error for LlvmVersionParseError {
334 fn source(&self) -> Option<&(dyn error::Error + 'static)> {
335 match self {
336 LlvmVersionParseError::ParseIntError(e: &ParseIntError) => Some(e),
337 LlvmVersionParseError::ComponentMustNotHaveLeadingZeros
338 | LlvmVersionParseError::ComponentMustNotHaveSign
339 | LlvmVersionParseError::MinorVersionMustBeZeroAfter4
340 | LlvmVersionParseError::MinorVersionRequiredBefore4
341 | LlvmVersionParseError::TooManyComponents => None,
342 }
343 }
344}
345
346/// The error type for this crate.
347#[derive(Debug)]
348pub enum Error {
349 /// An error occurred while trying to find the `rustc` to run.
350 CouldNotExecuteCommand(io::Error),
351 /// Error output from the command that was run.
352 CommandError {
353 /// stdout output from the command
354 stdout: String,
355 /// stderr output from the command
356 stderr: String,
357 },
358 /// The output of `rustc -vV` was not valid utf-8.
359 Utf8Error(str::Utf8Error),
360 /// The output of `rustc -vV` was not in the expected format.
361 UnexpectedVersionFormat,
362 /// An error occurred in parsing the semver.
363 SemVerError(semver::Error),
364 /// The pre-release tag is unknown.
365 UnknownPreReleaseTag(String),
366 /// An error occurred in parsing a `LlvmVersion`.
367 LlvmVersionError(LlvmVersionParseError),
368}
369
370impl fmt::Display for Error {
371 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
372 match *self {
373 CouldNotExecuteCommand(ref e: &Error) => write!(f, "could not execute command: {}", e),
374 CommandError {
375 ref stdout: &String,
376 ref stderr: &String,
377 } => write!(
378 f,
379 "error from command -- stderr:\n\n{}\n\nstderr:\n\n{}",
380 stderr, stdout,
381 ),
382 Utf8Error(_) => write!(f, "invalid UTF-8 output from `rustc -vV`"),
383 UnexpectedVersionFormat => write!(f, "unexpected `rustc -vV` format"),
384 SemVerError(ref e: &Error) => write!(f, "error parsing version: {}", e),
385 UnknownPreReleaseTag(ref i: &String) => write!(f, "unknown pre-release tag: {}", i),
386 LlvmVersionError(ref e: &LlvmVersionParseError) => write!(f, "error parsing LLVM's version: {}", e),
387 }
388 }
389}
390
391impl error::Error for Error {
392 fn source(&self) -> Option<&(dyn error::Error + 'static)> {
393 match *self {
394 CouldNotExecuteCommand(ref e: &Error) => Some(e),
395 CommandError { .. } => None,
396 Utf8Error(ref e: &Utf8Error) => Some(e),
397 UnexpectedVersionFormat => None,
398 SemVerError(ref e: &Error) => Some(e),
399 UnknownPreReleaseTag(_) => None,
400 LlvmVersionError(ref e: &LlvmVersionParseError) => Some(e),
401 }
402 }
403}
404
405macro_rules! impl_from {
406 ($($err_ty:ty => $variant:ident),* $(,)*) => {
407 $(
408 impl From<$err_ty> for Error {
409 fn from(e: $err_ty) -> Error {
410 Error::$variant(e)
411 }
412 }
413 )*
414 }
415}
416
417impl_from! {
418 str::Utf8Error => Utf8Error,
419 semver::Error => SemVerError,
420 LlvmVersionParseError => LlvmVersionError,
421}
422
423/// The result type for this crate.
424pub type Result<T, E = Error> = std::result::Result<T, E>;
425