From c52fe8bc2a86adc89754776634ffc146efada745 Mon Sep 17 00:00:00 2001 From: David Tolnay Date: Thu, 28 Nov 2024 12:47:18 -0800 Subject: [PATCH] Eliminate magic numbers from expression precedence --- clippy_lints/src/dereference.rs | 28 +++++++++---------- clippy_lints/src/loops/single_element_loop.rs | 4 +-- clippy_lints/src/matches/manual_utils.rs | 4 +-- clippy_lints/src/neg_multiply.rs | 4 +-- clippy_lints/src/redundant_slicing.rs | 4 +-- .../transmutes_expressible_as_ptr_casts.rs | 5 ++-- 6 files changed, 24 insertions(+), 25 deletions(-) diff --git a/clippy_lints/src/dereference.rs b/clippy_lints/src/dereference.rs index b1d192adff9a..c449a1a875b9 100644 --- a/clippy_lints/src/dereference.rs +++ b/clippy_lints/src/dereference.rs @@ -7,7 +7,7 @@ use clippy_utils::{ peel_middle_ty_refs, }; use core::mem; -use rustc_ast::util::parser::{PREC_PREFIX, PREC_UNAMBIGUOUS}; +use rustc_ast::util::parser::ExprPrecedence; use rustc_data_structures::fx::FxIndexMap; use rustc_errors::Applicability; use rustc_hir::def_id::DefId; @@ -963,7 +963,7 @@ fn report<'tcx>( // expr_str (the suggestion) is never shown if is_final_ufcs is true, since it's // `expr.kind == ExprKind::Call`. Therefore, this is, afaik, always unnecessary. /* - expr_str = if !expr_is_macro_call && is_final_ufcs && expr.precedence() < PREC_PREFIX { + expr_str = if !expr_is_macro_call && is_final_ufcs && expr.precedence() < ExprPrecedence::Prefix { Cow::Owned(format!("({expr_str})")) } else { expr_str @@ -999,13 +999,13 @@ fn report<'tcx>( data.first_expr.span, state.msg, |diag| { - let (precedence, calls_field) = match cx.tcx.parent_hir_node(data.first_expr.hir_id) { + let needs_paren = match cx.tcx.parent_hir_node(data.first_expr.hir_id) { Node::Expr(e) => match e.kind { - ExprKind::Call(callee, _) if callee.hir_id != data.first_expr.hir_id => (0, false), - ExprKind::Call(..) => (PREC_UNAMBIGUOUS, matches!(expr.kind, ExprKind::Field(..))), - _ => (e.precedence(), false), + ExprKind::Call(callee, _) if callee.hir_id != data.first_expr.hir_id => false, + ExprKind::Call(..) => expr.precedence() < ExprPrecedence::Unambiguous || matches!(expr.kind, ExprKind::Field(..)), + _ => expr.precedence() < e.precedence(), }, - _ => (0, false), + _ => false, }; let is_in_tuple = matches!( get_parent_expr(cx, data.first_expr), @@ -1016,7 +1016,7 @@ fn report<'tcx>( ); let sugg = if !snip_is_macro - && (calls_field || expr.precedence() < precedence) + && needs_paren && !has_enclosing_paren(&snip) && !is_in_tuple { @@ -1049,16 +1049,16 @@ fn report<'tcx>( } } - let (prefix, precedence) = match mutability { + let (prefix, needs_paren) = match mutability { Some(mutability) if !ty.is_ref() => { let prefix = match mutability { Mutability::Not => "&", Mutability::Mut => "&mut ", }; - (prefix, PREC_PREFIX) + (prefix, expr.precedence() < ExprPrecedence::Prefix) }, - None if !ty.is_ref() && data.adjusted_ty.is_ref() => ("&", 0), - _ => ("", 0), + None if !ty.is_ref() && data.adjusted_ty.is_ref() => ("&", false), + _ => ("", false), }; span_lint_hir_and_then( cx, @@ -1070,7 +1070,7 @@ fn report<'tcx>( let mut app = Applicability::MachineApplicable; let (snip, snip_is_macro) = snippet_with_context(cx, expr.span, data.first_expr.span.ctxt(), "..", &mut app); - let sugg = if !snip_is_macro && expr.precedence() < precedence && !has_enclosing_paren(&snip) { + let sugg = if !snip_is_macro && needs_paren && !has_enclosing_paren(&snip) { format!("{prefix}({snip})") } else { format!("{prefix}{snip}") @@ -1157,7 +1157,7 @@ impl<'tcx> Dereferencing<'tcx> { }, Some(parent) if !parent.span.from_expansion() => { // Double reference might be needed at this point. - if parent.precedence() == PREC_UNAMBIGUOUS { + if parent.precedence() == ExprPrecedence::Unambiguous { // Parentheses would be needed here, don't lint. *outer_pat = None; } else { diff --git a/clippy_lints/src/loops/single_element_loop.rs b/clippy_lints/src/loops/single_element_loop.rs index 35dc8e9aa4e2..12719c4f94bf 100644 --- a/clippy_lints/src/loops/single_element_loop.rs +++ b/clippy_lints/src/loops/single_element_loop.rs @@ -3,7 +3,7 @@ use clippy_utils::diagnostics::span_lint_and_sugg; use clippy_utils::source::{indent_of, snippet, snippet_with_applicability}; use clippy_utils::visitors::contains_break_or_continue; use rustc_ast::Mutability; -use rustc_ast::util::parser::PREC_PREFIX; +use rustc_ast::util::parser::ExprPrecedence; use rustc_errors::Applicability; use rustc_hir::{BorrowKind, Expr, ExprKind, Pat, PatKind, is_range_literal}; use rustc_lint::LateContext; @@ -84,7 +84,7 @@ pub(super) fn check<'tcx>( if !prefix.is_empty() && ( // Precedence of internal expression is less than or equal to precedence of `&expr`. - arg_expression.precedence() <= PREC_PREFIX || is_range_literal(arg_expression) + arg_expression.precedence() <= ExprPrecedence::Prefix || is_range_literal(arg_expression) ) { arg_snip = format!("({arg_snip})").into(); diff --git a/clippy_lints/src/matches/manual_utils.rs b/clippy_lints/src/matches/manual_utils.rs index 9c6df4d8ac0d..bac5cf88cfbf 100644 --- a/clippy_lints/src/matches/manual_utils.rs +++ b/clippy_lints/src/matches/manual_utils.rs @@ -7,7 +7,7 @@ use clippy_utils::{ CaptureKind, can_move_expr_to_closure, is_else_clause, is_lint_allowed, is_res_lang_ctor, path_res, path_to_local_id, peel_blocks, peel_hir_expr_refs, peel_hir_expr_while, }; -use rustc_ast::util::parser::PREC_UNAMBIGUOUS; +use rustc_ast::util::parser::ExprPrecedence; use rustc_errors::Applicability; use rustc_hir::LangItem::{OptionNone, OptionSome}; use rustc_hir::def::Res; @@ -117,7 +117,7 @@ where // it's being passed by value. let scrutinee = peel_hir_expr_refs(scrutinee).0; let (scrutinee_str, _) = snippet_with_context(cx, scrutinee.span, expr_ctxt, "..", &mut app); - let scrutinee_str = if scrutinee.span.eq_ctxt(expr.span) && scrutinee.precedence() < PREC_UNAMBIGUOUS { + let scrutinee_str = if scrutinee.span.eq_ctxt(expr.span) && scrutinee.precedence() < ExprPrecedence::Unambiguous { format!("({scrutinee_str})") } else { scrutinee_str.into() diff --git a/clippy_lints/src/neg_multiply.rs b/clippy_lints/src/neg_multiply.rs index a0ba2aaf5523..429afff9b664 100644 --- a/clippy_lints/src/neg_multiply.rs +++ b/clippy_lints/src/neg_multiply.rs @@ -2,7 +2,7 @@ use clippy_utils::consts::{self, Constant}; use clippy_utils::diagnostics::span_lint_and_sugg; use clippy_utils::source::snippet_with_context; use clippy_utils::sugg::has_enclosing_paren; -use rustc_ast::util::parser::PREC_PREFIX; +use rustc_ast::util::parser::ExprPrecedence; use rustc_errors::Applicability; use rustc_hir::{BinOpKind, Expr, ExprKind, UnOp}; use rustc_lint::{LateContext, LateLintPass}; @@ -58,7 +58,7 @@ fn check_mul(cx: &LateContext<'_>, span: Span, lit: &Expr<'_>, exp: &Expr<'_>) { { let mut applicability = Applicability::MachineApplicable; let (snip, from_macro) = snippet_with_context(cx, exp.span, span.ctxt(), "..", &mut applicability); - let suggestion = if !from_macro && exp.precedence() < PREC_PREFIX && !has_enclosing_paren(&snip) { + let suggestion = if !from_macro && exp.precedence() < ExprPrecedence::Prefix && !has_enclosing_paren(&snip) { format!("-({snip})") } else { format!("-{snip}") diff --git a/clippy_lints/src/redundant_slicing.rs b/clippy_lints/src/redundant_slicing.rs index 79baa914b031..8e3472b1b5a1 100644 --- a/clippy_lints/src/redundant_slicing.rs +++ b/clippy_lints/src/redundant_slicing.rs @@ -2,7 +2,7 @@ use clippy_utils::diagnostics::span_lint_and_then; use clippy_utils::source::snippet_with_context; use clippy_utils::ty::is_type_lang_item; use clippy_utils::{get_parent_expr, peel_middle_ty_refs}; -use rustc_ast::util::parser::PREC_PREFIX; +use rustc_ast::util::parser::ExprPrecedence; use rustc_errors::Applicability; use rustc_hir::{BorrowKind, Expr, ExprKind, LangItem, Mutability}; use rustc_lint::{LateContext, LateLintPass, Lint}; @@ -85,7 +85,7 @@ impl<'tcx> LateLintPass<'tcx> for RedundantSlicing { let (expr_ty, expr_ref_count) = peel_middle_ty_refs(cx.typeck_results().expr_ty(expr)); let (indexed_ty, indexed_ref_count) = peel_middle_ty_refs(cx.typeck_results().expr_ty(indexed)); let parent_expr = get_parent_expr(cx, expr); - let needs_parens_for_prefix = parent_expr.is_some_and(|parent| parent.precedence() > PREC_PREFIX); + let needs_parens_for_prefix = parent_expr.is_some_and(|parent| parent.precedence() > ExprPrecedence::Prefix); if expr_ty == indexed_ty { if expr_ref_count > indexed_ref_count { diff --git a/clippy_lints/src/transmute/transmutes_expressible_as_ptr_casts.rs b/clippy_lints/src/transmute/transmutes_expressible_as_ptr_casts.rs index 8d71036084d3..0d5cf45a5e65 100644 --- a/clippy_lints/src/transmute/transmutes_expressible_as_ptr_casts.rs +++ b/clippy_lints/src/transmute/transmutes_expressible_as_ptr_casts.rs @@ -1,7 +1,7 @@ use super::TRANSMUTES_EXPRESSIBLE_AS_PTR_CASTS; use clippy_utils::diagnostics::span_lint_and_sugg; use clippy_utils::sugg::Sugg; -use rustc_ast::util::parser::AssocOp; +use rustc_ast::util::parser::ExprPrecedence; use rustc_errors::Applicability; use rustc_hir::{Expr, Node}; use rustc_hir_typeck::cast::check_cast; @@ -44,8 +44,7 @@ pub(super) fn check<'tcx>( }; if let Node::Expr(parent) = cx.tcx.parent_hir_node(e.hir_id) - && parent.precedence() - > i8::try_from(AssocOp::As.precedence()).expect("AssocOp always returns a precedence < 128") + && parent.precedence() > ExprPrecedence::Cast { sugg = format!("({sugg})"); }