use crate::consts::{constant, Constant};
-use crate::utils::{is_expn_of, match_def_path, match_type, 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;
-use rustc_hir::*;
+use rustc_hir::{BorrowKind, Expr, ExprKind, HirId};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_tool_lint, impl_lint_pass};
use rustc_span::source_map::{BytePos, Span};
use std::convert::TryFrom;
-use syntax::ast::{LitKind, StrStyle};
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.
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"
}
-declare_clippy_lint! {
- /// **What it does:** Checks for usage of `regex!(_)` which (as of now) is
- /// usually slower than `Regex::new(_)` unless called in a loop (which is a bad
- /// idea anyway).
- ///
- /// **Why is this bad?** Performance, at least for now. The macro version is
- /// likely to catch up long-term, but for now the dynamic version is faster.
- ///
- /// **Known problems:** None.
- ///
- /// **Example:**
- /// ```ignore
- /// regex!("foo|bar")
- /// ```
- pub REGEX_MACRO,
- style,
- "use of `regex!(_)` instead of `Regex::new(_)`"
-}
-
#[derive(Clone, Default)]
pub struct Regex {
spans: FxHashSet<Span>,
last: Option<HirId>,
}
-impl_lint_pass!(Regex => [INVALID_REGEX, REGEX_MACRO, TRIVIAL_REGEX]);
-
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Regex {
- fn check_crate(&mut self, _: &LateContext<'a, 'tcx>, _: &'tcx Crate<'_>) {
- self.spans.clear();
- }
-
- fn check_block(&mut self, cx: &LateContext<'a, 'tcx>, block: &'tcx Block<'_>) {
- if_chain! {
- if self.last.is_none();
- if let Some(ref expr) = block.expr;
- if match_type(cx, cx.tables.expr_ty(expr), &paths::REGEX);
- if let Some(span) = is_expn_of(expr.span, "regex");
- then {
- if !self.spans.contains(&span) {
- span_lint(cx,
- REGEX_MACRO,
- span,
- "`regex!(_)` found. \
- Please use `Regex::new(_)`, which is faster for now.");
- self.spans.insert(span);
- }
- self.last = Some(block.hir_id);
- }
- }
- }
-
- fn check_block_post(&mut self, _: &LateContext<'a, 'tcx>, block: &'tcx Block<'_>) {
- if self.last.map_or(false, |id| block.hir_id == id) {
- self.last = None;
- }
- }
+impl_lint_pass!(Regex => [INVALID_REGEX, TRIVIAL_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::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) {
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,
})
}
fn is_trivial_regex(s: ®ex_syntax::hir::Hir) -> Option<&'static str> {
- use regex_syntax::hir::Anchor::*;
- use regex_syntax::hir::HirKind::*;
+ 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"),
}
}
-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::Array(exprs) = expr.kind;
}
}
-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();
match parser.parse(r) {
Ok(r) => {
if let Some(repl) = is_trivial_regex(&r) {
- span_lint_and_help(cx, TRIVIAL_REGEX, expr.span, "trivial regex", repl);
+ span_lint_and_help(cx, TRIVIAL_REGEX, expr.span, "trivial regex", None, repl);
}
},
Err(regex_syntax::Error::Parse(e)) => {
match parser.parse(&r) {
Ok(r) => {
if let Some(repl) = is_trivial_regex(&r) {
- span_lint_and_help(cx, TRIVIAL_REGEX, expr.span, "trivial regex", repl);
+ span_lint_and_help(cx, TRIVIAL_REGEX, expr.span, "trivial regex", None, repl);
}
},
Err(regex_syntax::Error::Parse(e)) => {
projects / rust.git / blobdiff