diff --git a/clippy_lints/src/implicit_saturating_sub.rs b/clippy_lints/src/implicit_saturating_sub.rs index 7b6f8729cb75..516f9e3aa60c 100644 --- a/clippy_lints/src/implicit_saturating_sub.rs +++ b/clippy_lints/src/implicit_saturating_sub.rs @@ -1,9 +1,13 @@ +use std::borrow::Cow; + use clippy_config::Conf; use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then}; use clippy_utils::msrvs::{self, Msrv}; +use clippy_utils::source::snippet_with_applicability; use clippy_utils::sugg::{Sugg, make_binop}; use clippy_utils::{ - SpanlessEq, eq_expr_value, higher, is_in_const_context, is_integer_literal, peel_blocks, peel_blocks_with_stmt, sym, + SpanlessEq, eq_expr_value, higher, is_in_const_context, is_integer_literal, is_integer_literal_untyped, + peel_blocks, peel_blocks_with_stmt, sym, }; use rustc_ast::ast::LitKind; use rustc_data_structures::packed::Pu128; @@ -238,10 +242,21 @@ fn check_subtraction( if eq_expr_value(cx, left, big_expr) && eq_expr_value(cx, right, little_expr) { // This part of the condition is voluntarily split from the one before to ensure that // if `snippet_opt` fails, it won't try the next conditions. - if (!is_in_const_context(cx) || msrv.meets(cx, msrvs::SATURATING_SUB_CONST)) - && let Some(big_expr_sugg) = Sugg::hir_opt(cx, big_expr).map(Sugg::maybe_paren) - && let Some(little_expr_sugg) = Sugg::hir_opt(cx, little_expr) - { + if !is_in_const_context(cx) || msrv.meets(cx, msrvs::SATURATING_SUB_CONST) { + let mut applicability = Applicability::MachineApplicable; + let big_expr_sugg = (if is_integer_literal_untyped(big_expr) { + let get_snippet = |span: Span| { + let snippet = snippet_with_applicability(cx, span, "..", &mut applicability); + let big_expr_ty = cx.typeck_results().expr_ty(big_expr); + Cow::Owned(format!("{snippet}_{big_expr_ty}")) + }; + Sugg::hir_from_snippet(cx, big_expr, get_snippet) + } else { + Sugg::hir_with_applicability(cx, big_expr, "..", &mut applicability) + }) + .maybe_paren(); + let little_expr_sugg = Sugg::hir_with_applicability(cx, little_expr, "..", &mut applicability); + let sugg = format!( "{}{big_expr_sugg}.saturating_sub({little_expr_sugg}){}", if is_composited { "{ " } else { "" }, @@ -254,7 +269,7 @@ fn check_subtraction( "manual arithmetic check found", "replace it with", sugg, - Applicability::MachineApplicable, + applicability, ); } } else if eq_expr_value(cx, left, little_expr) diff --git a/clippy_utils/src/lib.rs b/clippy_utils/src/lib.rs index 954c32687af6..2d079deb0ce4 100644 --- a/clippy_utils/src/lib.rs +++ b/clippy_utils/src/lib.rs @@ -90,7 +90,7 @@ use std::sync::{Mutex, MutexGuard, OnceLock}; use itertools::Itertools; use rustc_abi::Integer; use rustc_ast::ast::{self, LitKind, RangeLimits}; -use rustc_ast::join_path_syms; +use rustc_ast::{LitIntType, join_path_syms}; use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::indexmap; use rustc_data_structures::packed::Pu128; @@ -1385,6 +1385,17 @@ pub fn is_integer_literal(expr: &Expr<'_>, value: u128) -> bool { false } +/// Checks whether the given expression is an untyped integer literal. +pub fn is_integer_literal_untyped(expr: &Expr<'_>) -> bool { + if let ExprKind::Lit(spanned) = expr.kind + && let LitKind::Int(_, suffix) = spanned.node + { + return suffix == LitIntType::Unsuffixed; + } + + false +} + /// Checks whether the given expression is a constant literal of the given value. pub fn is_float_literal(expr: &Expr<'_>, value: f64) -> bool { if let ExprKind::Lit(spanned) = expr.kind diff --git a/clippy_utils/src/sugg.rs b/clippy_utils/src/sugg.rs index 2ef2afb45071..3ade38bea8ed 100644 --- a/clippy_utils/src/sugg.rs +++ b/clippy_utils/src/sugg.rs @@ -127,7 +127,7 @@ impl<'a> Sugg<'a> { /// Generate a suggestion for an expression with the given snippet. This is used by the `hir_*` /// function variants of `Sugg`, since these use different snippet functions. - fn hir_from_snippet( + pub fn hir_from_snippet( cx: &LateContext<'_>, expr: &hir::Expr<'_>, mut get_snippet: impl FnMut(Span) -> Cow<'a, str>, diff --git a/tests/ui/implicit_saturating_sub.fixed b/tests/ui/implicit_saturating_sub.fixed index 1aab6c54407e..22e59bbd2705 100644 --- a/tests/ui/implicit_saturating_sub.fixed +++ b/tests/ui/implicit_saturating_sub.fixed @@ -252,3 +252,11 @@ fn arbitrary_expression() { 0 }; } + +fn issue16307() { + let x: u8 = 100; + let y = 100_u8.saturating_sub(x); + //~^ implicit_saturating_sub + + println!("{y}"); +} diff --git a/tests/ui/implicit_saturating_sub.rs b/tests/ui/implicit_saturating_sub.rs index 7ca57a2902db..7fa19f0c8ad2 100644 --- a/tests/ui/implicit_saturating_sub.rs +++ b/tests/ui/implicit_saturating_sub.rs @@ -326,3 +326,11 @@ fn arbitrary_expression() { 0 }; } + +fn issue16307() { + let x: u8 = 100; + let y = if x >= 100 { 0 } else { 100 - x }; + //~^ implicit_saturating_sub + + println!("{y}"); +} diff --git a/tests/ui/implicit_saturating_sub.stderr b/tests/ui/implicit_saturating_sub.stderr index 0c225856fd07..2f3d2ba787e8 100644 --- a/tests/ui/implicit_saturating_sub.stderr +++ b/tests/ui/implicit_saturating_sub.stderr @@ -238,5 +238,11 @@ error: manual arithmetic check found LL | let _ = if a < b * 2 { 0 } else { a - b * 2 }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `a.saturating_sub(b * 2)` -error: aborting due to 27 previous errors +error: manual arithmetic check found + --> tests/ui/implicit_saturating_sub.rs:332:13 + | +LL | let y = if x >= 100 { 0 } else { 100 - x }; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `100_u8.saturating_sub(x)` + +error: aborting due to 28 previous errors