src/tools/clippy/clippy_lints/src/misc_early/mixed_case_hex_literals.rs

   1 use clippy_utils::diagnostics::span_lint;
   2 use rustc_lint::EarlyContext;
   3 use rustc_span::Span;
   4
   5 use super::MIXED_CASE_HEX_LITERALS;
   6
   7 pub(super) fn check(cx: &EarlyContext<'_>, lit_span: Span, suffix: &str, lit_snip: &str) {
   8     let Some(maybe_last_sep_idx) = lit_snip.len().checked_sub(suffix.len() + 1) else {
   9         return; // It's useless so shouldn't lint.
  10     };
  11     if maybe_last_sep_idx <= 2 {
  12         // It's meaningless or causes range error.
  13         return;
  14     }
  15     let mut seen = (false, false);
  16     for ch in lit_snip.as_bytes()[2..=maybe_last_sep_idx].iter() {
  17         match ch {
  18             b'a'..=b'f' => seen.0 = true,
  19             b'A'..=b'F' => seen.1 = true,
  20             _ => {},
  21         }
  22         if seen.0 && seen.1 {
  23             span_lint(
  24                 cx,
  25                 MIXED_CASE_HEX_LITERALS,
  26                 lit_span,
  27                 "inconsistent casing in hexadecimal literal",
  28             );
  29             break;
  30         }
  31     }
  32 }