use rustc_ast::token::LitKind;
use rustc_ast::{Expr, ExprKind, MethodCall, UnOp};
use rustc_session::{declare_lint, declare_lint_pass};
use crate::lints::{
AmbiguousNegativeLiteralsCurrentBehaviorSuggestion, AmbiguousNegativeLiteralsDiag,
AmbiguousNegativeLiteralsNegativeLiteralSuggestion,
};
use crate::{EarlyContext, EarlyLintPass, LintContext};
declare_lint! {
pub AMBIGUOUS_NEGATIVE_LITERALS,
Allow,
"ambiguous negative literals operations",
report_in_external_macro
}
declare_lint_pass!(Precedence => [AMBIGUOUS_NEGATIVE_LITERALS]);
impl EarlyLintPass for Precedence {
fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
let ExprKind::Unary(UnOp::Neg, operand) = &expr.kind else {
return;
};
let mut arg = operand;
let mut at_least_one = false;
while let ExprKind::MethodCall(box MethodCall { receiver, .. }) = &arg.kind {
at_least_one = true;
arg = receiver;
}
if at_least_one
&& let ExprKind::Lit(lit) = &arg.kind
&& let LitKind::Integer | LitKind::Float = &lit.kind
{
cx.emit_span_lint(
AMBIGUOUS_NEGATIVE_LITERALS,
expr.span,
AmbiguousNegativeLiteralsDiag {
negative_literal: AmbiguousNegativeLiteralsNegativeLiteralSuggestion {
start_span: expr.span.shrink_to_lo(),
end_span: arg.span.shrink_to_hi(),
},
current_behavior: AmbiguousNegativeLiteralsCurrentBehaviorSuggestion {
start_span: operand.span.shrink_to_lo(),
end_span: operand.span.shrink_to_hi(),
},
},
);
}
}
}