From e7d2393d0182f9837897723e1541c0404bdcd55b Mon Sep 17 00:00:00 2001 From: Yusuke Tanaka Date: Thu, 11 Feb 2021 01:08:48 +0900 Subject: [PATCH] Move transmute_float_to_int to its own module --- clippy_lints/src/transmute/mod.rs | 49 ++------------ .../src/transmute/transmute_float_to_int.rs | 66 +++++++++++++++++++ 2 files changed, 71 insertions(+), 44 deletions(-) create mode 100644 clippy_lints/src/transmute/transmute_float_to_int.rs diff --git a/clippy_lints/src/transmute/mod.rs b/clippy_lints/src/transmute/mod.rs index 6e1207abd524..3ba0872393d0 100644 --- a/clippy_lints/src/transmute/mod.rs +++ b/clippy_lints/src/transmute/mod.rs @@ -1,4 +1,5 @@ mod crosspointer_transmute; +mod transmute_float_to_int; mod transmute_int_to_bool; mod transmute_int_to_char; mod transmute_int_to_float; @@ -390,52 +391,12 @@ impl<'tcx> LateLintPass<'tcx> for Transmute { if triggered { return; } + let triggered = transmute_float_to_int::check(cx, e, from_ty, to_ty, args, const_context); + if triggered { + return; + } match (&from_ty.kind(), &to_ty.kind()) { - (ty::Float(float_ty), ty::Int(_) | ty::Uint(_)) if !const_context => span_lint_and_then( - cx, - TRANSMUTE_FLOAT_TO_INT, - e.span, - &format!("transmute from a `{}` to a `{}`", from_ty, to_ty), - |diag| { - let mut expr = &args[0]; - let mut arg = sugg::Sugg::hir(cx, expr, ".."); - - if let ExprKind::Unary(UnOp::Neg, inner_expr) = &expr.kind { - expr = &inner_expr; - } - - if_chain! { - // if the expression is a float literal and it is unsuffixed then - // add a suffix so the suggestion is valid and unambiguous - let op = format!("{}{}", arg, float_ty.name_str()).into(); - if let ExprKind::Lit(lit) = &expr.kind; - if let ast::LitKind::Float(_, ast::LitFloatType::Unsuffixed) = lit.node; - then { - match arg { - sugg::Sugg::MaybeParen(_) => arg = sugg::Sugg::MaybeParen(op), - _ => arg = sugg::Sugg::NonParen(op) - } - } - } - - arg = sugg::Sugg::NonParen(format!("{}.to_bits()", arg.maybe_par()).into()); - - // cast the result of `to_bits` if `to_ty` is signed - arg = if let ty::Int(int_ty) = to_ty.kind() { - arg.as_ty(int_ty.name_str().to_string()) - } else { - arg - }; - - diag.span_suggestion( - e.span, - "consider using", - arg.to_string(), - Applicability::Unspecified, - ); - }, - ), (ty::Adt(from_adt, from_substs), ty::Adt(to_adt, to_substs)) => { if from_adt.did != to_adt.did || !COLLECTIONS.iter().any(|path| match_def_path(cx, to_adt.did, path)) { diff --git a/clippy_lints/src/transmute/transmute_float_to_int.rs b/clippy_lints/src/transmute/transmute_float_to_int.rs new file mode 100644 index 000000000000..58cd0e217925 --- /dev/null +++ b/clippy_lints/src/transmute/transmute_float_to_int.rs @@ -0,0 +1,66 @@ +use super::TRANSMUTE_FLOAT_TO_INT; +use crate::utils::{span_lint_and_then, sugg}; +use if_chain::if_chain; +use rustc_ast as ast; +use rustc_errors::Applicability; +use rustc_hir::{Expr, ExprKind, UnOp}; +use rustc_lint::LateContext; +use rustc_middle::ty; +use rustc_middle::ty::Ty; + +/// Checks for `transmute_float_to_int` lint. +/// Returns `true` if it's triggered, otherwise returns `false`. +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + e: &'tcx Expr<'_>, + from_ty: Ty<'tcx>, + to_ty: Ty<'tcx>, + args: &'tcx [Expr<'_>], + const_context: bool, +) -> bool { + match (&from_ty.kind(), &to_ty.kind()) { + (ty::Float(float_ty), ty::Int(_) | ty::Uint(_)) if !const_context => { + span_lint_and_then( + cx, + TRANSMUTE_FLOAT_TO_INT, + e.span, + &format!("transmute from a `{}` to a `{}`", from_ty, to_ty), + |diag| { + let mut expr = &args[0]; + let mut arg = sugg::Sugg::hir(cx, expr, ".."); + + if let ExprKind::Unary(UnOp::Neg, inner_expr) = &expr.kind { + expr = &inner_expr; + } + + if_chain! { + // if the expression is a float literal and it is unsuffixed then + // add a suffix so the suggestion is valid and unambiguous + let op = format!("{}{}", arg, float_ty.name_str()).into(); + if let ExprKind::Lit(lit) = &expr.kind; + if let ast::LitKind::Float(_, ast::LitFloatType::Unsuffixed) = lit.node; + then { + match arg { + sugg::Sugg::MaybeParen(_) => arg = sugg::Sugg::MaybeParen(op), + _ => arg = sugg::Sugg::NonParen(op) + } + } + } + + arg = sugg::Sugg::NonParen(format!("{}.to_bits()", arg.maybe_par()).into()); + + // cast the result of `to_bits` if `to_ty` is signed + arg = if let ty::Int(int_ty) = to_ty.kind() { + arg.as_ty(int_ty.name_str().to_string()) + } else { + arg + }; + + diag.span_suggestion(e.span, "consider using", arg.to_string(), Applicability::Unspecified); + }, + ); + true + }, + _ => false, + } +}