rust-clippy/clippy_dev/src/lib.rs
Andre Bogus cc622608db new lints around #[must_use] fns
`must_use_unit` lints unit-returning functions with a `#[must_use]`
attribute, suggesting to remove it.

`double_must_use` lints functions with a plain `#[must_use]`
attribute, but which return a type which is already `#[must_use]`,
so the attribute has no benefit.

`must_use_candidate` is a pedantic lint that lints functions and
methods that return some non-unit type that is not already
`#[must_use]` and suggests to add the annotation.
2019-10-14 12:09:04 +02:00

494 lines
16 KiB
Rust

use itertools::Itertools;
use lazy_static::lazy_static;
use regex::Regex;
use std::collections::HashMap;
use std::ffi::OsStr;
use std::fs;
use std::io::prelude::*;
use walkdir::WalkDir;
lazy_static! {
static ref DEC_CLIPPY_LINT_RE: Regex = Regex::new(
r#"(?x)
declare_clippy_lint!\s*[\{(]
(?:\s+///.*)*
\s+pub\s+(?P<name>[A-Z_][A-Z_0-9]*)\s*,\s*
(?P<cat>[a-z_]+)\s*,\s*
"(?P<desc>(?:[^"\\]+|\\(?s).(?-s))*)"\s*[})]
"#
)
.unwrap();
static ref DEC_DEPRECATED_LINT_RE: Regex = Regex::new(
r#"(?x)
declare_deprecated_lint!\s*[{(]\s*
(?:\s+///.*)*
\s+pub\s+(?P<name>[A-Z_][A-Z_0-9]*)\s*,\s*
"(?P<desc>(?:[^"\\]+|\\(?s).(?-s))*)"\s*[})]
"#
)
.unwrap();
static ref NL_ESCAPE_RE: Regex = Regex::new(r#"\\\n\s*"#).unwrap();
pub static ref DOCS_LINK: String = "https://rust-lang.github.io/rust-clippy/master/index.html".to_string();
}
/// Lint data parsed from the Clippy source code.
#[derive(Clone, PartialEq, Debug)]
pub struct Lint {
pub name: String,
pub group: String,
pub desc: String,
pub deprecation: Option<String>,
pub module: String,
}
impl Lint {
#[must_use]
pub fn new(name: &str, group: &str, desc: &str, deprecation: Option<&str>, module: &str) -> Self {
Self {
name: name.to_lowercase(),
group: group.to_string(),
desc: NL_ESCAPE_RE.replace(&desc.replace("\\\"", "\""), "").to_string(),
deprecation: deprecation.map(std::string::ToString::to_string),
module: module.to_string(),
}
}
/// Returns all non-deprecated lints and non-internal lints
pub fn usable_lints(lints: impl Iterator<Item = Self>) -> impl Iterator<Item = Self> {
lints.filter(|l| l.deprecation.is_none() && !l.is_internal())
}
/// Returns the lints in a `HashMap`, grouped by the different lint groups
#[must_use]
pub fn by_lint_group(lints: &[Self]) -> HashMap<String, Vec<Self>> {
lints
.iter()
.map(|lint| (lint.group.to_string(), lint.clone()))
.into_group_map()
}
#[must_use]
pub fn is_internal(&self) -> bool {
self.group.starts_with("internal")
}
}
/// Generates the Vec items for `register_lint_group` calls in `clippy_lints/src/lib.rs`.
#[must_use]
pub fn gen_lint_group_list(lints: Vec<Lint>) -> Vec<String> {
lints
.into_iter()
.filter_map(|l| {
if l.is_internal() || l.deprecation.is_some() {
None
} else {
Some(format!(" {}::{},", l.module, l.name.to_uppercase()))
}
})
.sorted()
.collect::<Vec<String>>()
}
/// Generates the `pub mod module_name` list in `clippy_lints/src/lib.rs`.
#[must_use]
pub fn gen_modules_list(lints: Vec<Lint>) -> Vec<String> {
lints
.into_iter()
.filter_map(|l| {
if l.is_internal() || l.deprecation.is_some() {
None
} else {
Some(l.module)
}
})
.unique()
.map(|module| format!("pub mod {};", module))
.sorted()
.collect::<Vec<String>>()
}
/// Generates the list of lint links at the bottom of the README
#[must_use]
pub fn gen_changelog_lint_list(lints: Vec<Lint>) -> Vec<String> {
let mut lint_list_sorted: Vec<Lint> = lints;
lint_list_sorted.sort_by_key(|l| l.name.clone());
lint_list_sorted
.iter()
.filter_map(|l| {
if l.is_internal() {
None
} else {
Some(format!("[`{}`]: {}#{}", l.name, DOCS_LINK.clone(), l.name))
}
})
.collect()
}
/// Generates the `register_removed` code in `./clippy_lints/src/lib.rs`.
#[must_use]
pub fn gen_deprecated(lints: &[Lint]) -> Vec<String> {
lints
.iter()
.filter_map(|l| {
l.clone().deprecation.map(|depr_text| {
vec![
" store.register_removed(".to_string(),
format!(" \"clippy::{}\",", l.name),
format!(" \"{}\",", depr_text),
" );".to_string(),
]
})
})
.flatten()
.collect::<Vec<String>>()
}
/// Gathers all files in `src/clippy_lints` and gathers all lints inside
pub fn gather_all() -> impl Iterator<Item = Lint> {
lint_files().flat_map(|f| gather_from_file(&f))
}
fn gather_from_file(dir_entry: &walkdir::DirEntry) -> impl Iterator<Item = Lint> {
let mut file = fs::File::open(dir_entry.path()).unwrap();
let mut content = String::new();
file.read_to_string(&mut content).unwrap();
let mut filename = dir_entry.path().file_stem().unwrap().to_str().unwrap();
// If the lints are stored in mod.rs, we get the module name from
// the containing directory:
if filename == "mod" {
filename = dir_entry
.path()
.parent()
.unwrap()
.file_stem()
.unwrap()
.to_str()
.unwrap()
}
parse_contents(&content, filename)
}
fn parse_contents(content: &str, filename: &str) -> impl Iterator<Item = Lint> {
let lints = DEC_CLIPPY_LINT_RE
.captures_iter(content)
.map(|m| Lint::new(&m["name"], &m["cat"], &m["desc"], None, filename));
let deprecated = DEC_DEPRECATED_LINT_RE
.captures_iter(content)
.map(|m| Lint::new(&m["name"], "Deprecated", &m["desc"], Some(&m["desc"]), filename));
// Removing the `.collect::<Vec<Lint>>().into_iter()` causes some lifetime issues due to the map
lints.chain(deprecated).collect::<Vec<Lint>>().into_iter()
}
/// Collects all .rs files in the `clippy_lints/src` directory
fn lint_files() -> impl Iterator<Item = walkdir::DirEntry> {
// We use `WalkDir` instead of `fs::read_dir` here in order to recurse into subdirectories.
// Otherwise we would not collect all the lints, for example in `clippy_lints/src/methods/`.
WalkDir::new("../clippy_lints/src")
.into_iter()
.filter_map(std::result::Result::ok)
.filter(|f| f.path().extension() == Some(OsStr::new("rs")))
}
/// Whether a file has had its text changed or not
#[derive(PartialEq, Debug)]
pub struct FileChange {
pub changed: bool,
pub new_lines: String,
}
/// Replaces a region in a file delimited by two lines matching regexes.
///
/// `path` is the relative path to the file on which you want to perform the replacement.
///
/// See `replace_region_in_text` for documentation of the other options.
#[allow(clippy::expect_fun_call)]
pub fn replace_region_in_file<F>(
path: &str,
start: &str,
end: &str,
replace_start: bool,
write_back: bool,
replacements: F,
) -> FileChange
where
F: Fn() -> Vec<String>,
{
let mut f = fs::File::open(path).expect(&format!("File not found: {}", path));
let mut contents = String::new();
f.read_to_string(&mut contents)
.expect("Something went wrong reading the file");
let file_change = replace_region_in_text(&contents, start, end, replace_start, replacements);
if write_back {
let mut f = fs::File::create(path).expect(&format!("File not found: {}", path));
f.write_all(file_change.new_lines.as_bytes())
.expect("Unable to write file");
// Ensure we write the changes with a trailing newline so that
// the file has the proper line endings.
f.write_all(b"\n").expect("Unable to write file");
}
file_change
}
/// Replaces a region in a text delimited by two lines matching regexes.
///
/// * `text` is the input text on which you want to perform the replacement
/// * `start` is a `&str` that describes the delimiter line before the region you want to replace.
/// As the `&str` will be converted to a `Regex`, this can contain regex syntax, too.
/// * `end` is a `&str` that describes the delimiter line until where the replacement should happen.
/// As the `&str` will be converted to a `Regex`, this can contain regex syntax, too.
/// * If `replace_start` is true, the `start` delimiter line is replaced as well. The `end`
/// delimiter line is never replaced.
/// * `replacements` is a closure that has to return a `Vec<String>` which contains the new text.
///
/// If you want to perform the replacement on files instead of already parsed text,
/// use `replace_region_in_file`.
///
/// # Example
///
/// ```
/// let the_text = "replace_start\nsome text\nthat will be replaced\nreplace_end";
/// let result = clippy_dev::replace_region_in_text(the_text, r#"replace_start"#, r#"replace_end"#, false, || {
/// vec!["a different".to_string(), "text".to_string()]
/// })
/// .new_lines;
/// assert_eq!("replace_start\na different\ntext\nreplace_end", result);
/// ```
pub fn replace_region_in_text<F>(text: &str, start: &str, end: &str, replace_start: bool, replacements: F) -> FileChange
where
F: Fn() -> Vec<String>,
{
let lines = text.lines();
let mut in_old_region = false;
let mut found = false;
let mut new_lines = vec![];
let start = Regex::new(start).unwrap();
let end = Regex::new(end).unwrap();
for line in lines.clone() {
if in_old_region {
if end.is_match(&line) {
in_old_region = false;
new_lines.extend(replacements());
new_lines.push(line.to_string());
}
} else if start.is_match(&line) {
if !replace_start {
new_lines.push(line.to_string());
}
in_old_region = true;
found = true;
} else {
new_lines.push(line.to_string());
}
}
if !found {
// This happens if the provided regex in `clippy_dev/src/main.rs` is not found in the
// given text or file. Most likely this is an error on the programmer's side and the Regex
// is incorrect.
eprintln!("error: regex `{:?}` not found. You may have to update it.", start);
}
FileChange {
changed: lines.ne(new_lines.clone()),
new_lines: new_lines.join("\n"),
}
}
#[test]
fn test_parse_contents() {
let result: Vec<Lint> = parse_contents(
r#"
declare_clippy_lint! {
pub PTR_ARG,
style,
"really long \
text"
}
declare_clippy_lint!{
pub DOC_MARKDOWN,
pedantic,
"single line"
}
/// some doc comment
declare_deprecated_lint! {
pub SHOULD_ASSERT_EQ,
"`assert!()` will be more flexible with RFC 2011"
}
"#,
"module_name",
)
.collect();
let expected = vec![
Lint::new("ptr_arg", "style", "really long text", None, "module_name"),
Lint::new("doc_markdown", "pedantic", "single line", None, "module_name"),
Lint::new(
"should_assert_eq",
"Deprecated",
"`assert!()` will be more flexible with RFC 2011",
Some("`assert!()` will be more flexible with RFC 2011"),
"module_name",
),
];
assert_eq!(expected, result);
}
#[test]
fn test_replace_region() {
let text = "\nabc\n123\n789\ndef\nghi";
let expected = FileChange {
changed: true,
new_lines: "\nabc\nhello world\ndef\nghi".to_string(),
};
let result = replace_region_in_text(text, r#"^\s*abc$"#, r#"^\s*def"#, false, || {
vec!["hello world".to_string()]
});
assert_eq!(expected, result);
}
#[test]
fn test_replace_region_with_start() {
let text = "\nabc\n123\n789\ndef\nghi";
let expected = FileChange {
changed: true,
new_lines: "\nhello world\ndef\nghi".to_string(),
};
let result = replace_region_in_text(text, r#"^\s*abc$"#, r#"^\s*def"#, true, || {
vec!["hello world".to_string()]
});
assert_eq!(expected, result);
}
#[test]
fn test_replace_region_no_changes() {
let text = "123\n456\n789";
let expected = FileChange {
changed: false,
new_lines: "123\n456\n789".to_string(),
};
let result = replace_region_in_text(text, r#"^\s*123$"#, r#"^\s*456"#, false, || vec![]);
assert_eq!(expected, result);
}
#[test]
fn test_usable_lints() {
let lints = vec![
Lint::new("should_assert_eq", "Deprecated", "abc", Some("Reason"), "module_name"),
Lint::new("should_assert_eq2", "Not Deprecated", "abc", None, "module_name"),
Lint::new("should_assert_eq2", "internal", "abc", None, "module_name"),
Lint::new("should_assert_eq2", "internal_style", "abc", None, "module_name"),
];
let expected = vec![Lint::new(
"should_assert_eq2",
"Not Deprecated",
"abc",
None,
"module_name",
)];
assert_eq!(expected, Lint::usable_lints(lints.into_iter()).collect::<Vec<Lint>>());
}
#[test]
fn test_by_lint_group() {
let lints = vec![
Lint::new("should_assert_eq", "group1", "abc", None, "module_name"),
Lint::new("should_assert_eq2", "group2", "abc", None, "module_name"),
Lint::new("incorrect_match", "group1", "abc", None, "module_name"),
];
let mut expected: HashMap<String, Vec<Lint>> = HashMap::new();
expected.insert(
"group1".to_string(),
vec![
Lint::new("should_assert_eq", "group1", "abc", None, "module_name"),
Lint::new("incorrect_match", "group1", "abc", None, "module_name"),
],
);
expected.insert(
"group2".to_string(),
vec![Lint::new("should_assert_eq2", "group2", "abc", None, "module_name")],
);
assert_eq!(expected, Lint::by_lint_group(&lints));
}
#[test]
fn test_gen_changelog_lint_list() {
let lints = vec![
Lint::new("should_assert_eq", "group1", "abc", None, "module_name"),
Lint::new("should_assert_eq2", "group2", "abc", None, "module_name"),
Lint::new("incorrect_internal", "internal_style", "abc", None, "module_name"),
];
let expected = vec![
format!("[`should_assert_eq`]: {}#should_assert_eq", DOCS_LINK.to_string()),
format!("[`should_assert_eq2`]: {}#should_assert_eq2", DOCS_LINK.to_string()),
];
assert_eq!(expected, gen_changelog_lint_list(lints));
}
#[test]
fn test_gen_deprecated() {
let lints = vec![
Lint::new(
"should_assert_eq",
"group1",
"abc",
Some("has been superseded by should_assert_eq2"),
"module_name",
),
Lint::new(
"another_deprecated",
"group2",
"abc",
Some("will be removed"),
"module_name",
),
Lint::new("should_assert_eq2", "group2", "abc", None, "module_name"),
];
let expected: Vec<String> = vec![
" store.register_removed(",
" \"clippy::should_assert_eq\",",
" \"has been superseded by should_assert_eq2\",",
" );",
" store.register_removed(",
" \"clippy::another_deprecated\",",
" \"will be removed\",",
" );",
]
.into_iter()
.map(String::from)
.collect();
assert_eq!(expected, gen_deprecated(&lints));
}
#[test]
fn test_gen_modules_list() {
let lints = vec![
Lint::new("should_assert_eq", "group1", "abc", None, "module_name"),
Lint::new("should_assert_eq2", "group2", "abc", Some("abc"), "deprecated"),
Lint::new("incorrect_stuff", "group3", "abc", None, "another_module"),
Lint::new("incorrect_internal", "internal_style", "abc", None, "module_name"),
];
let expected = vec![
"pub mod another_module;".to_string(),
"pub mod module_name;".to_string(),
];
assert_eq!(expected, gen_modules_list(lints));
}
#[test]
fn test_gen_lint_group_list() {
let lints = vec![
Lint::new("abc", "group1", "abc", None, "module_name"),
Lint::new("should_assert_eq", "group1", "abc", None, "module_name"),
Lint::new("should_assert_eq2", "group2", "abc", Some("abc"), "deprecated"),
Lint::new("incorrect_internal", "internal_style", "abc", None, "module_name"),
];
let expected = vec![
" module_name::ABC,".to_string(),
" module_name::SHOULD_ASSERT_EQ,".to_string(),
];
assert_eq!(expected, gen_lint_group_list(lints));
}