rust/clippy_lints/src/cargo/feature_name.rs
2022-02-13 17:36:33 -05:00

93 lines
2.9 KiB
Rust

use cargo_metadata::Metadata;
use clippy_utils::diagnostics::span_lint_and_help;
use rustc_lint::LateContext;
use rustc_span::source_map::DUMMY_SP;
use super::{NEGATIVE_FEATURE_NAMES, REDUNDANT_FEATURE_NAMES};
static PREFIXES: [&str; 8] = ["no-", "no_", "not-", "not_", "use-", "use_", "with-", "with_"];
static SUFFIXES: [&str; 2] = ["-support", "_support"];
pub(super) fn check(cx: &LateContext<'_>, metadata: &Metadata) {
for package in &metadata.packages {
let mut features: Vec<&String> = package.features.keys().collect();
features.sort();
for feature in features {
let prefix_opt = {
let i = PREFIXES.partition_point(|prefix| prefix < &feature.as_str());
if i > 0 && feature.starts_with(PREFIXES[i - 1]) {
Some(PREFIXES[i - 1])
} else {
None
}
};
if let Some(prefix) = prefix_opt {
lint(cx, feature, prefix, true);
}
let suffix_opt: Option<&str> = {
let i = SUFFIXES.partition_point(|suffix| {
suffix.bytes().rev().cmp(feature.bytes().rev()) == std::cmp::Ordering::Less
});
if i > 0 && feature.ends_with(SUFFIXES[i - 1]) {
Some(SUFFIXES[i - 1])
} else {
None
}
};
if let Some(suffix) = suffix_opt {
lint(cx, feature, suffix, false);
}
}
}
}
fn is_negative_prefix(s: &str) -> bool {
s.starts_with("no")
}
fn lint(cx: &LateContext<'_>, feature: &str, substring: &str, is_prefix: bool) {
let is_negative = is_prefix && is_negative_prefix(substring);
span_lint_and_help(
cx,
if is_negative {
NEGATIVE_FEATURE_NAMES
} else {
REDUNDANT_FEATURE_NAMES
},
DUMMY_SP,
&format!(
"the \"{}\" {} in the feature name \"{}\" is {}",
substring,
if is_prefix { "prefix" } else { "suffix" },
feature,
if is_negative { "negative" } else { "redundant" }
),
None,
&format!(
"consider renaming the feature to \"{}\"{}",
if is_prefix {
feature.strip_prefix(substring)
} else {
feature.strip_suffix(substring)
}
.unwrap(),
if is_negative {
", but make sure the feature adds functionality"
} else {
""
}
),
);
}
#[test]
fn test_prefixes_sorted() {
let mut sorted_prefixes = PREFIXES;
sorted_prefixes.sort_unstable();
assert_eq!(PREFIXES, sorted_prefixes);
let mut sorted_suffixes = SUFFIXES;
sorted_suffixes.sort_by(|a, b| a.bytes().rev().cmp(b.bytes().rev()));
assert_eq!(SUFFIXES, sorted_suffixes);
}