/
features.rs
433 lines (395 loc) · 16.2 KB
/
features.rs
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// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Tidy check to ensure that unstable features are all in order
//!
//! This check will ensure properties like:
//!
//! * All stability attributes look reasonably well formed
//! * The set of library features is disjoint from the set of language features
//! * Library features have at most one stability level
//! * Library features have at most one `since` value
//! * All unstable lang features have tests to ensure they are actually unstable
use std::collections::HashMap;
use std::fmt;
use std::fs::File;
use std::io::prelude::*;
use std::path::Path;
#[derive(Debug, PartialEq, Clone)]
pub enum Status {
Stable,
Removed,
Unstable,
}
impl fmt::Display for Status {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let as_str = match *self {
Status::Stable => "stable",
Status::Unstable => "unstable",
Status::Removed => "removed",
};
fmt::Display::fmt(as_str, f)
}
}
#[derive(Debug, Clone)]
pub struct Feature {
pub level: Status,
pub since: String,
pub has_gate_test: bool,
pub tracking_issue: Option<u32>,
}
impl Feature {
fn check_match(&self, other: &Feature)-> Result<(), Vec<&'static str>> {
let mut mismatches = Vec::new();
if self.level != other.level {
mismatches.push("stability level");
}
if self.level == Status::Stable || other.level == Status::Stable {
// As long as a feature is unstable, the since field tracks
// when the given part of the feature has been implemented.
// Mismatches are tolerable as features evolve and functionality
// gets added.
// Once a feature is stable, the since field tracks the first version
// it was part of the stable distribution, and mismatches are disallowed.
if self.since != other.since {
mismatches.push("since");
}
}
if self.tracking_issue != other.tracking_issue {
mismatches.push("tracking issue");
}
if mismatches.is_empty() {
Ok(())
} else {
Err(mismatches)
}
}
}
pub type Features = HashMap<String, Feature>;
pub fn check(path: &Path, bad: &mut bool, quiet: bool) {
let mut features = collect_lang_features(path, bad);
assert!(!features.is_empty());
let lib_features = get_and_check_lib_features(path, bad, &features);
assert!(!lib_features.is_empty());
let mut contents = String::new();
super::walk_many(&[&path.join("test/ui-fulldeps"),
&path.join("test/ui"),
&path.join("test/compile-fail"),
&path.join("test/compile-fail-fulldeps"),
&path.join("test/parse-fail"),
&path.join("test/ui"),],
&mut |path| super::filter_dirs(path),
&mut |file| {
let filename = file.file_name().unwrap().to_string_lossy();
if !filename.ends_with(".rs") || filename == "features.rs" ||
filename == "diagnostic_list.rs" {
return;
}
let filen_underscore = filename.replace("-","_").replace(".rs","");
let filename_is_gate_test = test_filen_gate(&filen_underscore, &mut features);
contents.truncate(0);
t!(t!(File::open(&file), &file).read_to_string(&mut contents));
for (i, line) in contents.lines().enumerate() {
let mut err = |msg: &str| {
tidy_error!(bad, "{}:{}: {}", file.display(), i + 1, msg);
};
let gate_test_str = "gate-test-";
if !line.contains(gate_test_str) {
continue;
}
let feature_name = match line.find(gate_test_str) {
Some(i) => {
&line[i+gate_test_str.len()..line[i+1..].find(' ').unwrap_or(line.len())]
},
None => continue,
};
match features.get_mut(feature_name) {
Some(f) => {
if filename_is_gate_test {
err(&format!("The file is already marked as gate test \
through its name, no need for a \
'gate-test-{}' comment",
feature_name));
}
f.has_gate_test = true;
}
None => {
err(&format!("gate-test test found referencing a nonexistent feature '{}'",
feature_name));
}
}
}
});
// Only check the number of lang features.
// Obligatory testing for library features is dumb.
let gate_untested = features.iter()
.filter(|&(_, f)| f.level == Status::Unstable)
.filter(|&(_, f)| !f.has_gate_test)
.collect::<Vec<_>>();
for &(name, _) in gate_untested.iter() {
println!("Expected a gate test for the feature '{}'.", name);
println!("Hint: create a failing test file named 'feature-gate-{}.rs'\
\n in the 'ui' test suite, with its failures due to\
\n missing usage of #![feature({})].", name, name);
println!("Hint: If you already have such a test and don't want to rename it,\
\n you can also add a // gate-test-{} line to the test file.",
name);
}
if gate_untested.len() > 0 {
tidy_error!(bad, "Found {} features without a gate test.", gate_untested.len());
}
if *bad {
return;
}
if quiet {
println!("* {} features", features.len());
return;
}
let mut lines = Vec::new();
for (name, feature) in features.iter() {
lines.push(format!("{:<32} {:<8} {:<12} {:<8}",
name,
"lang",
feature.level,
feature.since));
}
for (name, feature) in lib_features {
lines.push(format!("{:<32} {:<8} {:<12} {:<8}",
name,
"lib",
feature.level,
feature.since));
}
lines.sort();
for line in lines {
println!("* {}", line);
}
}
fn find_attr_val<'a>(line: &'a str, attr: &str) -> Option<&'a str> {
line.find(attr)
.and_then(|i| line[i..].find('"').map(|j| i + j + 1))
.and_then(|i| line[i..].find('"').map(|j| (i, i + j)))
.map(|(i, j)| &line[i..j])
}
fn test_filen_gate(filen_underscore: &str, features: &mut Features) -> bool {
if filen_underscore.starts_with("feature_gate") {
for (n, f) in features.iter_mut() {
if filen_underscore == format!("feature_gate_{}", n) {
f.has_gate_test = true;
return true;
}
}
}
return false;
}
pub fn collect_lang_features(base_src_path: &Path, bad: &mut bool) -> Features {
let mut contents = String::new();
let path = base_src_path.join("libsyntax/feature_gate.rs");
t!(t!(File::open(path)).read_to_string(&mut contents));
// we allow rustc-internal features to omit a tracking issue.
// these features must be marked with `// rustc internal` in its own group.
let mut next_feature_is_rustc_internal = false;
contents.lines().zip(1..)
.filter_map(|(line, line_number)| {
let line = line.trim();
if line.starts_with("// rustc internal") {
next_feature_is_rustc_internal = true;
return None;
} else if line.is_empty() {
next_feature_is_rustc_internal = false;
return None;
}
let mut parts = line.split(',');
let level = match parts.next().map(|l| l.trim().trim_left_matches('(')) {
Some("active") => Status::Unstable,
Some("removed") => Status::Removed,
Some("accepted") => Status::Stable,
_ => return None,
};
let name = parts.next().unwrap().trim();
let since = parts.next().unwrap().trim().trim_matches('"');
let issue_str = parts.next().unwrap().trim();
let tracking_issue = if issue_str.starts_with("None") {
if level == Status::Unstable && !next_feature_is_rustc_internal {
*bad = true;
tidy_error!(
bad,
"libsyntax/feature_gate.rs:{}: no tracking issue for feature {}",
line_number,
name,
);
}
None
} else {
next_feature_is_rustc_internal = false;
let s = issue_str.split("(").nth(1).unwrap().split(")").nth(0).unwrap();
Some(s.parse().unwrap())
};
Some((name.to_owned(),
Feature {
level,
since: since.to_owned(),
has_gate_test: false,
tracking_issue,
}))
})
.collect()
}
pub fn collect_lib_features(base_src_path: &Path) -> Features {
let mut lib_features = Features::new();
// This library feature is defined in the `compiler_builtins` crate, which
// has been moved out-of-tree. Now it can no longer be auto-discovered by
// `tidy`, because we need to filter out its (submodule) directory. Manually
// add it to the set of known library features so we can still generate docs.
lib_features.insert("compiler_builtins_lib".to_owned(), Feature {
level: Status::Unstable,
since: "".to_owned(),
has_gate_test: false,
tracking_issue: None,
});
map_lib_features(base_src_path,
&mut |res, _, _| {
match res {
Ok((name, feature)) => {
if lib_features.get(name).is_some() {
return;
}
lib_features.insert(name.to_owned(), feature);
},
Err(_) => (),
}
});
lib_features
}
fn get_and_check_lib_features(base_src_path: &Path,
bad: &mut bool,
lang_features: &Features) -> Features {
let mut lib_features = Features::new();
map_lib_features(base_src_path,
&mut |res, file, line| {
match res {
Ok((name, f)) => {
let mut check_features = |f: &Feature, list: &Features, display: &str| {
if let Some(ref s) = list.get(name) {
if let Err(m) = (&f).check_match(s) {
tidy_error!(bad,
"{}:{}: mismatches to {} in: {:?}",
file.display(),
line,
display,
&m);
}
}
};
check_features(&f, &lang_features, "corresponding lang feature");
check_features(&f, &lib_features, "previous");
lib_features.insert(name.to_owned(), f);
},
Err(msg) => {
tidy_error!(bad, "{}:{}: {}", file.display(), line, msg);
},
}
});
lib_features
}
fn map_lib_features(base_src_path: &Path,
mf: &mut FnMut(Result<(&str, Feature), &str>, &Path, usize)) {
let mut contents = String::new();
super::walk(base_src_path,
&mut |path| super::filter_dirs(path) || path.ends_with("src/test"),
&mut |file| {
let filename = file.file_name().unwrap().to_string_lossy();
if !filename.ends_with(".rs") || filename == "features.rs" ||
filename == "diagnostic_list.rs" {
return;
}
contents.truncate(0);
t!(t!(File::open(&file), &file).read_to_string(&mut contents));
let mut becoming_feature: Option<(String, Feature)> = None;
for (i, line) in contents.lines().enumerate() {
macro_rules! err {
($msg:expr) => {{
mf(Err($msg), file, i + 1);
continue;
}};
};
if let Some((ref name, ref mut f)) = becoming_feature {
if f.tracking_issue.is_none() {
f.tracking_issue = find_attr_val(line, "issue")
.map(|s| s.parse().unwrap());
}
if line.ends_with("]") {
mf(Ok((name, f.clone())), file, i + 1);
} else if !line.ends_with(",") && !line.ends_with("\\") {
// We need to bail here because we might have missed the
// end of a stability attribute above because the "]"
// might not have been at the end of the line.
// We could then get into the very unfortunate situation that
// we continue parsing the file assuming the current stability
// attribute has not ended, and ignoring possible feature
// attributes in the process.
err!("malformed stability attribute");
} else {
continue;
}
}
becoming_feature = None;
if line.contains("rustc_const_unstable(") {
// const fn features are handled specially
let feature_name = match find_attr_val(line, "feature") {
Some(name) => name,
None => err!("malformed stability attribute"),
};
let feature = Feature {
level: Status::Unstable,
since: "None".to_owned(),
has_gate_test: false,
// Whether there is a common tracking issue
// for these feature gates remains an open question
// https://github.com/rust-lang/rust/issues/24111#issuecomment-340283184
// But we take 24111 otherwise they will be shown as
// "internal to the compiler" which they are not.
tracking_issue: Some(24111),
};
mf(Ok((feature_name, feature)), file, i + 1);
continue;
}
let level = if line.contains("[unstable(") {
Status::Unstable
} else if line.contains("[stable(") {
Status::Stable
} else {
continue;
};
let feature_name = match find_attr_val(line, "feature") {
Some(name) => name,
None => err!("malformed stability attribute"),
};
let since = match find_attr_val(line, "since") {
Some(name) => name,
None if level == Status::Stable => {
err!("malformed stability attribute");
}
None => "None",
};
let tracking_issue = find_attr_val(line, "issue").map(|s| s.parse().unwrap());
let feature = Feature {
level,
since: since.to_owned(),
has_gate_test: false,
tracking_issue,
};
if line.contains("]") {
mf(Ok((feature_name, feature)), file, i + 1);
} else {
becoming_feature = Some((feature_name.to_owned(), feature));
}
}
});
}