| 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 \"{substring}\" {} in the feature name \"{feature}\" is {}", |
| if is_prefix { "prefix" } else { "suffix" }, |
| 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); |
| } |