Improve `implicit_return`

[rust.git] / clippy_lints / src / regex.rs

diff --git a/clippy_lints/src/regex.rs b/clippy_lints/src/regex.rs
index 7405edbcd1966ac736be2a0f7ed01ff5e11ea438..4b5306de58ecdc4e911a4f3c7a9b78929e730d15 100644 (file)
--- a/clippy_lints/src/regex.rs
+++ b/clippy_lints/src/regex.rs
@@ -1,5 +1,6 @@
 use crate::consts::{constant, Constant};
-use crate::utils::{match_def_path, paths, span_lint, span_lint_and_help};
+use clippy_utils::diagnostics::{span_lint, span_lint_and_help};
+use clippy_utils::{match_def_path, paths};
 use if_chain::if_chain;
 use rustc_ast::ast::{LitKind, StrStyle};
 use rustc_data_structures::fx::FxHashSet;
@@ -11,7 +12,7 @@
 
 declare_clippy_lint! {
     /// **What it does:** Checks [regex](https://crates.io/crates/regex) creation
-    /// (with `Regex::new`,`RegexBuilder::new` or `RegexSet::new`) for correct
+    /// (with `Regex::new`, `RegexBuilder::new`, or `RegexSet::new`) for correct
     /// regex syntax.
     ///
     /// **Why is this bad?** This will lead to a runtime panic.
@@ -29,20 +30,22 @@
 
 declare_clippy_lint! {
     /// **What it does:** Checks for trivial [regex](https://crates.io/crates/regex)
-    /// creation (with `Regex::new`, `RegexBuilder::new` or `RegexSet::new`).
+    /// creation (with `Regex::new`, `RegexBuilder::new`, or `RegexSet::new`).
     ///
     /// **Why is this bad?** Matching the regex can likely be replaced by `==` or
     /// `str::starts_with`, `str::ends_with` or `std::contains` or other `str`
     /// methods.
     ///
-    /// **Known problems:** None.
+    /// **Known problems:** If the same regex is going to be applied to multiple
+    /// inputs, the precomputations done by `Regex` construction can give
+    /// significantly better performance than any of the `str`-based methods.
     ///
     /// **Example:**
     /// ```ignore
     /// Regex::new("^foobar")
     /// ```
     pub TRIVIAL_REGEX,
-    style,
+    nursery,
     "trivial regular expressions"
 }
 
@@ -54,13 +57,13 @@ pub struct Regex {
 
 impl_lint_pass!(Regex => [INVALID_REGEX, TRIVIAL_REGEX]);
 
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Regex {
-    fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+impl<'tcx> LateLintPass<'tcx> for Regex {
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
         if_chain! {
-            if let ExprKind::Call(ref fun, ref args) = expr.kind;
+            if let ExprKind::Call(fun, args) = expr.kind;
             if let ExprKind::Path(ref qpath) = fun.kind;
             if args.len() == 1;
-            if let Some(def_id) = cx.tables().qpath_res(qpath, fun.hir_id).opt_def_id();
+            if let Some(def_id) = cx.qpath_res(qpath, fun.hir_id).opt_def_id();
             then {
                 if match_def_path(cx, def_id, &paths::REGEX_NEW) ||
                    match_def_path(cx, def_id, &paths::REGEX_BUILDER_NEW) {
@@ -88,8 +91,8 @@ fn str_span(base: Span, c: regex_syntax::ast::Span, offset: u16) -> Span {
     Span::new(start, end, base.ctxt())
 }
 
-fn const_str<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, e: &'tcx Expr<'_>) -> Option<String> {
-    constant(cx, cx.tables(), e).and_then(|(c, _)| match c {
+fn const_str<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> Option<String> {
+    constant(cx, cx.typeck_results(), e).and_then(|(c, _)| match c {
         Constant::Str(s) => Some(s),
         _ => None,
     })
@@ -99,12 +102,7 @@ fn is_trivial_regex(s: &regex_syntax::hir::Hir) -> Option<&'static str> {
     use regex_syntax::hir::Anchor::{EndText, StartText};
     use regex_syntax::hir::HirKind::{Alternation, Anchor, Concat, Empty, Literal};
 
-    let is_literal = |e: &[regex_syntax::hir::Hir]| {
-        e.iter().all(|e| match *e.kind() {
-            Literal(_) => true,
-            _ => false,
-        })
-    };
+    let is_literal = |e: &[regex_syntax::hir::Hir]| e.iter().all(|e| matches!(*e.kind(), Literal(_)));
 
     match *s.kind() {
         Empty | Anchor(_) => Some("the regex is unlikely to be useful as it is"),
@@ -134,9 +132,9 @@ fn is_trivial_regex(s: &regex_syntax::hir::Hir) -> Option<&'static str> {
     }
 }
 
-fn check_set<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>, utf8: bool) {
+fn check_set<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, utf8: bool) {
     if_chain! {
-        if let ExprKind::AddrOf(BorrowKind::Ref, _, ref expr) = expr.kind;
+        if let ExprKind::AddrOf(BorrowKind::Ref, _, expr) = expr.kind;
         if let ExprKind::Array(exprs) = expr.kind;
         then {
             for expr in exprs {
@@ -146,9 +144,9 @@ fn check_set<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>, utf8: b
     }
 }
 
-fn check_regex<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>, utf8: bool) {
+fn check_regex<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, utf8: bool) {
     let mut parser = regex_syntax::ParserBuilder::new()
-        .unicode(utf8)
+        .unicode(true)
         .allow_invalid_utf8(!utf8)
         .build();