rust-clippy/clippy_lints/src/misc_early/zero_prefixed_literal.rs
Nicholas Nethercote f2d83ed1ac Use token::Lit in ast::ExprKind::Lit.
Instead of `ast::Lit`.

Literal lowering now happens at two different times. Expression literals
are lowered when HIR is crated. Attribute literals are lowered during
parsing.

This commit changes the language very slightly. Some programs that used
to not compile now will compile. This is because some invalid literals
that are removed by `cfg` or attribute macros will no longer trigger
errors. See this comment for more details:
https://github.com/rust-lang/rust/pull/102944#issuecomment-1277476773
2022-11-16 09:41:28 +11:00

33 lines
1.2 KiB
Rust

use clippy_utils::diagnostics::span_lint_and_then;
use rustc_errors::Applicability;
use rustc_lint::EarlyContext;
use rustc_span::Span;
use super::ZERO_PREFIXED_LITERAL;
pub(super) fn check(cx: &EarlyContext<'_>, lit_span: Span, lit_snip: &str) {
let trimmed_lit_snip = lit_snip.trim_start_matches(|c| c == '_' || c == '0');
span_lint_and_then(
cx,
ZERO_PREFIXED_LITERAL,
lit_span,
"this is a decimal constant",
|diag| {
diag.span_suggestion(
lit_span,
"if you mean to use a decimal constant, remove the `0` to avoid confusion",
trimmed_lit_snip.to_string(),
Applicability::MaybeIncorrect,
);
// do not advise to use octal form if the literal cannot be expressed in base 8.
if !lit_snip.contains(|c| c == '8' || c == '9') {
diag.span_suggestion(
lit_span,
"if you mean to use an octal constant, use `0o`",
format!("0o{trimmed_lit_snip}"),
Applicability::MaybeIncorrect,
);
}
},
);
}