1 use clippy_utils::diagnostics::span_lint_and_sugg;
2 use clippy_utils::is_lint_allowed;
3 use clippy_utils::source::snippet;
4 use rustc_ast::ast::LitKind;
5 use rustc_errors::Applicability;
6 use rustc_hir::{Expr, ExprKind, HirId};
7 use rustc_lint::{LateContext, LateLintPass};
8 use rustc_session::{declare_lint_pass, declare_tool_lint};
9 use rustc_span::source_map::Span;
10 use unicode_normalization::UnicodeNormalization;
12 declare_clippy_lint! {
14 /// Checks for invisible Unicode characters in the code.
16 /// ### Why is this bad?
17 /// Having an invisible character in the code makes for all
18 /// sorts of April fools, but otherwise is very much frowned upon.
21 /// You don't see it, but there may be a zero-width space or soft hyphen
22 /// somewhere in this text.
23 #[clippy::version = "1.49.0"]
24 pub INVISIBLE_CHARACTERS,
26 "using an invisible character in a string literal, which is confusing"
29 declare_clippy_lint! {
31 /// Checks for non-ASCII characters in string and char literals.
33 /// ### Why is this bad?
34 /// Yeah, we know, the 90's called and wanted their charset
35 /// back. Even so, there still are editors and other programs out there that
36 /// don't work well with Unicode. So if the code is meant to be used
37 /// internationally, on multiple operating systems, or has other portability
38 /// requirements, activating this lint could be useful.
42 /// let x = String::from("€");
44 /// Could be written as:
46 /// let x = String::from("\u{20ac}");
48 #[clippy::version = "pre 1.29.0"]
49 pub NON_ASCII_LITERAL,
51 "using any literal non-ASCII chars in a string literal instead of using the `\\u` escape"
54 declare_clippy_lint! {
56 /// Checks for string literals that contain Unicode in a form
57 /// that is not equal to its
58 /// [NFC-recomposition](http://www.unicode.org/reports/tr15/#Norm_Forms).
60 /// ### Why is this bad?
61 /// If such a string is compared to another, the results
62 /// may be surprising.
65 /// You may not see it, but "à"" and "à"" aren't the same string. The
66 /// former when escaped is actually `"a\u{300}"` while the latter is `"\u{e0}"`.
67 #[clippy::version = "pre 1.29.0"]
70 "using a Unicode literal not in NFC normal form (see [Unicode tr15](http://www.unicode.org/reports/tr15/) for further information)"
73 declare_lint_pass!(Unicode => [INVISIBLE_CHARACTERS, NON_ASCII_LITERAL, UNICODE_NOT_NFC]);
75 impl LateLintPass<'_> for Unicode {
76 fn check_expr(&mut self, cx: &LateContext<'_>, expr: &'_ Expr<'_>) {
77 if let ExprKind::Lit(ref lit) = expr.kind {
78 if let LitKind::Str(_, _) | LitKind::Char(_) = lit.node {
79 check_str(cx, lit.span, expr.hir_id);
85 fn escape<T: Iterator<Item = char>>(s: T) -> String {
86 let mut result = String::new();
89 for d in c.escape_unicode() {
99 fn check_str(cx: &LateContext<'_>, span: Span, id: HirId) {
100 let string = snippet(cx, span, "");
101 if string.chars().any(|c| ['\u{200B}', '\u{ad}', '\u{2060}'].contains(&c)) {
104 INVISIBLE_CHARACTERS,
106 "invisible character detected",
107 "consider replacing the string with",
109 .replace('\u{200B}', "\\u{200B}")
110 .replace('\u{ad}', "\\u{AD}")
111 .replace('\u{2060}', "\\u{2060}"),
112 Applicability::MachineApplicable,
115 if string.chars().any(|c| c as u32 > 0x7F) {
120 "literal non-ASCII character detected",
121 "consider replacing the string with",
122 if is_lint_allowed(cx, UNICODE_NOT_NFC, id) {
123 escape(string.chars())
127 Applicability::MachineApplicable,
130 if is_lint_allowed(cx, NON_ASCII_LITERAL, id) && string.chars().zip(string.nfc()).any(|(a, b)| a != b) {
135 "non-NFC Unicode sequence detected",
136 "consider replacing the string with",
137 string.nfc().collect::<String>(),
138 Applicability::MachineApplicable,