1 use super::TRANSMUTE_FLOAT_TO_INT;
2 use crate::utils::{span_lint_and_then, sugg};
3 use if_chain::if_chain;
5 use rustc_errors::Applicability;
6 use rustc_hir::{Expr, ExprKind, UnOp};
7 use rustc_lint::LateContext;
8 use rustc_middle::ty::{self, Ty};
10 /// Checks for `transmute_float_to_int` lint.
11 /// Returns `true` if it's triggered, otherwise returns `false`.
12 pub(super) fn check<'tcx>(
13 cx: &LateContext<'tcx>,
17 args: &'tcx [Expr<'_>],
20 match (&from_ty.kind(), &to_ty.kind()) {
21 (ty::Float(float_ty), ty::Int(_) | ty::Uint(_)) if !const_context => {
24 TRANSMUTE_FLOAT_TO_INT,
26 &format!("transmute from a `{}` to a `{}`", from_ty, to_ty),
28 let mut expr = &args[0];
29 let mut arg = sugg::Sugg::hir(cx, expr, "..");
31 if let ExprKind::Unary(UnOp::Neg, inner_expr) = &expr.kind {
36 // if the expression is a float literal and it is unsuffixed then
37 // add a suffix so the suggestion is valid and unambiguous
38 let op = format!("{}{}", arg, float_ty.name_str()).into();
39 if let ExprKind::Lit(lit) = &expr.kind;
40 if let ast::LitKind::Float(_, ast::LitFloatType::Unsuffixed) = lit.node;
43 sugg::Sugg::MaybeParen(_) => arg = sugg::Sugg::MaybeParen(op),
44 _ => arg = sugg::Sugg::NonParen(op)
49 arg = sugg::Sugg::NonParen(format!("{}.to_bits()", arg.maybe_par()).into());
51 // cast the result of `to_bits` if `to_ty` is signed
52 arg = if let ty::Int(int_ty) = to_ty.kind() {
53 arg.as_ty(int_ty.name_str().to_string())
58 diag.span_suggestion(e.span, "consider using", arg.to_string(), Applicability::Unspecified);