diff --git a/clippy_lints/src/consts.rs b/clippy_lints/src/consts.rs index c700af1e6e39..36417cd08777 100644 --- a/clippy_lints/src/consts.rs +++ b/clippy_lints/src/consts.rs @@ -122,21 +122,32 @@ impl Hash for Constant { } } -impl PartialOrd for Constant { - fn partial_cmp(&self, other: &Self) -> Option { - match (self, other) { +impl Constant { + pub fn partial_cmp(tcx: TyCtxt, cmp_type: &ty::TypeVariants, left: &Self, right: &Self) -> Option { + match (left, right) { (&Constant::Str(ref ls), &Constant::Str(ref rs)) => Some(ls.cmp(rs)), (&Constant::Char(ref l), &Constant::Char(ref r)) => Some(l.cmp(r)), - (&Constant::Int(l), &Constant::Int(r)) => Some(l.cmp(&r)), + (&Constant::Int(l), &Constant::Int(r)) => { + if let ty::TyInt(int_ty) = *cmp_type { + Some(sext(tcx, l, int_ty).cmp(&sext(tcx, r, int_ty))) + } else { + Some(l.cmp(&r)) + } + }, (&Constant::F64(l), &Constant::F64(r)) => l.partial_cmp(&r), (&Constant::F32(l), &Constant::F32(r)) => l.partial_cmp(&r), (&Constant::Bool(ref l), &Constant::Bool(ref r)) => Some(l.cmp(r)), - (&Constant::Tuple(ref l), &Constant::Tuple(ref r)) | (&Constant::Vec(ref l), &Constant::Vec(ref r)) => { - l.partial_cmp(r) - }, - (&Constant::Repeat(ref lv, ref ls), &Constant::Repeat(ref rv, ref rs)) => match lv.partial_cmp(rv) { - Some(Equal) => Some(ls.cmp(rs)), - x => x, + (&Constant::Tuple(ref l), &Constant::Tuple(ref r)) | (&Constant::Vec(ref l), &Constant::Vec(ref r)) => l + .iter() + .zip(r.iter()) + .map(|(li, ri)| Constant::partial_cmp(tcx, cmp_type, li, ri)) + .find(|r| r.map_or(true, |o| o != Ordering::Equal)) + .unwrap_or_else(|| Some(l.len().cmp(&r.len()))), + (&Constant::Repeat(ref lv, ref ls), &Constant::Repeat(ref rv, ref rs)) => { + match Constant::partial_cmp(tcx, cmp_type, lv, rv) { + Some(Equal) => Some(ls.cmp(rs)), + x => x, + } }, _ => None, // TODO: Are there any useful inter-type orderings? } diff --git a/clippy_lints/src/minmax.rs b/clippy_lints/src/minmax.rs index 8c511d8f0ad9..4be2b9f52271 100644 --- a/clippy_lints/src/minmax.rs +++ b/clippy_lints/src/minmax.rs @@ -1,8 +1,8 @@ use crate::consts::{constant_simple, Constant}; -use rustc::lint::*; -use rustc::hir::*; -use std::cmp::{Ordering, PartialOrd}; use crate::utils::{match_def_path, opt_def_id, paths, span_lint}; +use rustc::hir::*; +use rustc::lint::*; +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. @@ -36,14 +36,22 @@ impl LintPass for MinMaxPass { 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).sty, &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", + ); }, } } diff --git a/tests/ui/min_max.rs b/tests/ui/min_max.rs index 1199206e42c3..9b29f73b2ac2 100644 --- a/tests/ui/min_max.rs +++ b/tests/ui/min_max.rs @@ -23,6 +23,9 @@ fn main() { min(1, max(LARGE, x)); // no error, we don't lookup consts here + let y = 2isize; + min(max(y, -1), 3); + let s; s = "Hello"; diff --git a/tests/ui/min_max.stderr b/tests/ui/min_max.stderr index de4c4e16fa03..b8ea183fcc94 100644 --- a/tests/ui/min_max.stderr +++ b/tests/ui/min_max.stderr @@ -31,15 +31,15 @@ error: this min/max combination leads to constant result | ^^^^^^^^^^^^^^^^^^^^^^^ error: this min/max combination leads to constant result - --> $DIR/min_max.rs:29:5 + --> $DIR/min_max.rs:32:5 | -29 | min("Apple", max("Zoo", s)); +32 | min("Apple", max("Zoo", s)); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: this min/max combination leads to constant result - --> $DIR/min_max.rs:30:5 + --> $DIR/min_max.rs:33:5 | -30 | max(min(s, "Apple"), "Zoo"); +33 | max(min(s, "Apple"), "Zoo"); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to 7 previous errors