X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=clippy_lints%2Fsrc%2Fminmax.rs;h=087aa94a7ecfad42ba9ed5d8548fa8ab747613f6;hb=4d60841205d10293d6759df1948acda4c607c7eb;hp=b5b844e199e9df979abf744c49ae1a1a6a05ed56;hpb=7a06d312fd4d900946f8dba8bae5baaf877e5103;p=rust.git diff --git a/clippy_lints/src/minmax.rs b/clippy_lints/src/minmax.rs index b5b844e199e..087aa94a7ec 100644 --- a/clippy_lints/src/minmax.rs +++ b/clippy_lints/src/minmax.rs @@ -1,8 +1,18 @@ -use consts::{constant_simple, Constant}; -use rustc::lint::*; +// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +use crate::consts::{constant_simple, Constant}; +use crate::utils::{match_def_path, opt_def_id, paths, span_lint}; use rustc::hir::*; -use std::cmp::{Ordering, PartialOrd}; -use utils::{match_def_path, opt_def_id, paths, span_lint}; +use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass}; +use rustc::{declare_tool_lint, lint_array}; +use std::cmp::Ordering; /// **What it does:** Checks for expressions where `std::cmp::min` and `max` are /// used to clamp values, but switched so that the result is constant. @@ -18,13 +28,12 @@ /// ``` /// It will always be equal to `0`. Probably the author meant to clamp the value /// between 0 and 100, but has erroneously swapped `min` and `max`. -declare_lint! { +declare_clippy_lint! { pub MIN_MAX, - Warn, + correctness, "`min(_, max(_, _))` (or vice versa) with bounds clamping the result to a constant" } -#[allow(missing_copy_implementations)] pub struct MinMaxPass; impl LintPass for MinMaxPass { @@ -36,14 +45,22 @@ fn get_lints(&self) -> LintArray { impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MinMaxPass { fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) { if let Some((outer_max, outer_c, oe)) = min_max(cx, expr) { - if let Some((inner_max, inner_c, _)) = min_max(cx, oe) { + if let Some((inner_max, inner_c, ie)) = min_max(cx, oe) { if outer_max == inner_max { return; } - match (outer_max, outer_c.partial_cmp(&inner_c)) { + match ( + outer_max, + Constant::partial_cmp(cx.tcx, cx.tables.expr_ty(ie), &outer_c, &inner_c), + ) { (_, None) | (MinMax::Max, Some(Ordering::Less)) | (MinMax::Min, Some(Ordering::Greater)) => (), _ => { - span_lint(cx, MIN_MAX, expr.span, "this min/max combination leads to constant result"); + span_lint( + cx, + MIN_MAX, + expr.span, + "this min/max combination leads to constant result", + ); }, } } @@ -57,9 +74,9 @@ enum MinMax { Max, } -fn min_max<'a>(cx: &LateContext, expr: &'a Expr) -> Option<(MinMax, Constant, &'a Expr)> { - if let ExprCall(ref path, ref args) = expr.node { - if let ExprPath(ref qpath) = path.node { +fn min_max<'a>(cx: &LateContext<'_, '_>, expr: &'a Expr) -> Option<(MinMax, Constant, &'a Expr)> { + if let ExprKind::Call(ref path, ref args) = expr.node { + if let ExprKind::Path(ref qpath) = path.node { opt_def_id(cx.tables.qpath_def(qpath, path.hir_id)).and_then(|def_id| { if match_def_path(cx.tcx, def_id, &paths::CMP_MIN) { fetch_const(cx, args, MinMax::Min) @@ -77,18 +94,18 @@ fn min_max<'a>(cx: &LateContext, expr: &'a Expr) -> Option<(MinMax, Constant, &' } } -fn fetch_const<'a>(cx: &LateContext, args: &'a [Expr], m: MinMax) -> Option<(MinMax, Constant, &'a Expr)> { +fn fetch_const<'a>(cx: &LateContext<'_, '_>, args: &'a [Expr], m: MinMax) -> Option<(MinMax, Constant, &'a Expr)> { if args.len() != 2 { return None; } - if let Some(c) = constant_simple(cx, &args[0]) { - if constant_simple(cx, &args[1]).is_none() { + if let Some(c) = constant_simple(cx, cx.tables, &args[0]) { + if constant_simple(cx, cx.tables, &args[1]).is_none() { // otherwise ignore Some((m, c, &args[1])) } else { None } - } else if let Some(c) = constant_simple(cx, &args[1]) { + } else if let Some(c) = constant_simple(cx, cx.tables, &args[1]) { Some((m, c, &args[0])) } else { None