diff --git a/clippy_lints/src/operators/manual_is_multiple_of.rs b/clippy_lints/src/operators/manual_is_multiple_of.rs index 821178a43158..55bb78cfce5f 100644 --- a/clippy_lints/src/operators/manual_is_multiple_of.rs +++ b/clippy_lints/src/operators/manual_is_multiple_of.rs @@ -2,11 +2,12 @@ use clippy_utils::consts::is_zero_integer_const; use clippy_utils::diagnostics::span_lint_and_sugg; use clippy_utils::msrvs::{self, Msrv}; use clippy_utils::sugg::Sugg; +use clippy_utils::ty::expr_type_is_certain; use rustc_ast::BinOpKind; use rustc_errors::Applicability; use rustc_hir::{Expr, ExprKind}; use rustc_lint::LateContext; -use rustc_middle::ty; +use rustc_middle::ty::{self, Ty}; use super::MANUAL_IS_MULTIPLE_OF; @@ -22,9 +23,21 @@ pub(super) fn check<'tcx>( && let Some(operand) = uint_compare_to_zero(cx, op, lhs, rhs) && let ExprKind::Binary(operand_op, operand_left, operand_right) = operand.kind && operand_op.node == BinOpKind::Rem + && matches!( + cx.typeck_results().expr_ty_adjusted(operand_left).peel_refs().kind(), + ty::Uint(_) + ) + && matches!( + cx.typeck_results().expr_ty_adjusted(operand_right).peel_refs().kind(), + ty::Uint(_) + ) + && expr_type_is_certain(cx, operand_left) { let mut app = Applicability::MachineApplicable; - let divisor = Sugg::hir_with_applicability(cx, operand_right, "_", &mut app); + let divisor = deref_sugg( + Sugg::hir_with_applicability(cx, operand_right, "_", &mut app), + cx.typeck_results().expr_ty_adjusted(operand_right), + ); span_lint_and_sugg( cx, MANUAL_IS_MULTIPLE_OF, @@ -64,3 +77,11 @@ fn uint_compare_to_zero<'tcx>( matches!(cx.typeck_results().expr_ty_adjusted(operand).kind(), ty::Uint(_)).then_some(operand) } + +fn deref_sugg<'a>(sugg: Sugg<'a>, ty: Ty<'_>) -> Sugg<'a> { + if let ty::Ref(_, target_ty, _) = ty.kind() { + deref_sugg(sugg.deref(), *target_ty) + } else { + sugg + } +} diff --git a/clippy_utils/src/ty/type_certainty/mod.rs b/clippy_utils/src/ty/type_certainty/mod.rs index 84df36c75bf8..d9c7e6eac9f6 100644 --- a/clippy_utils/src/ty/type_certainty/mod.rs +++ b/clippy_utils/src/ty/type_certainty/mod.rs @@ -12,10 +12,11 @@ //! be considered a bug. use crate::paths::{PathNS, lookup_path}; +use rustc_ast::{LitFloatType, LitIntType, LitKind}; use rustc_hir::def::{DefKind, Res}; use rustc_hir::def_id::DefId; use rustc_hir::intravisit::{InferKind, Visitor, VisitorExt, walk_qpath, walk_ty}; -use rustc_hir::{self as hir, AmbigArg, Expr, ExprKind, GenericArgs, HirId, Node, PathSegment, QPath, TyKind}; +use rustc_hir::{self as hir, AmbigArg, Expr, ExprKind, GenericArgs, HirId, Node, Param, PathSegment, QPath, TyKind}; use rustc_lint::LateContext; use rustc_middle::ty::{self, AdtDef, GenericArgKind, Ty}; use rustc_span::Span; @@ -24,22 +25,24 @@ mod certainty; use certainty::{Certainty, Meet, join, meet}; pub fn expr_type_is_certain(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { - expr_type_certainty(cx, expr).is_certain() + expr_type_certainty(cx, expr, false).is_certain() } -fn expr_type_certainty(cx: &LateContext<'_>, expr: &Expr<'_>) -> Certainty { +/// Determine the type certainty of `expr`. `in_arg` indicates that the expression happens within +/// the evaluation of a function or method call argument. +fn expr_type_certainty(cx: &LateContext<'_>, expr: &Expr<'_>, in_arg: bool) -> Certainty { let certainty = match &expr.kind { ExprKind::Unary(_, expr) | ExprKind::Field(expr, _) | ExprKind::Index(expr, _, _) - | ExprKind::AddrOf(_, _, expr) => expr_type_certainty(cx, expr), + | ExprKind::AddrOf(_, _, expr) => expr_type_certainty(cx, expr, in_arg), - ExprKind::Array(exprs) => join(exprs.iter().map(|expr| expr_type_certainty(cx, expr))), + ExprKind::Array(exprs) => join(exprs.iter().map(|expr| expr_type_certainty(cx, expr, in_arg))), ExprKind::Call(callee, args) => { - let lhs = expr_type_certainty(cx, callee); + let lhs = expr_type_certainty(cx, callee, false); let rhs = if type_is_inferable_from_arguments(cx, expr) { - meet(args.iter().map(|arg| expr_type_certainty(cx, arg))) + meet(args.iter().map(|arg| expr_type_certainty(cx, arg, true))) } else { Certainty::Uncertain }; @@ -47,7 +50,7 @@ fn expr_type_certainty(cx: &LateContext<'_>, expr: &Expr<'_>) -> Certainty { }, ExprKind::MethodCall(method, receiver, args, _) => { - let mut receiver_type_certainty = expr_type_certainty(cx, receiver); + let mut receiver_type_certainty = expr_type_certainty(cx, receiver, false); // Even if `receiver_type_certainty` is `Certain(Some(..))`, the `Self` type in the method // identified by `type_dependent_def_id(..)` can differ. This can happen as a result of a `deref`, // for example. So update the `DefId` in `receiver_type_certainty` (if any). @@ -59,7 +62,8 @@ fn expr_type_certainty(cx: &LateContext<'_>, expr: &Expr<'_>) -> Certainty { let lhs = path_segment_certainty(cx, receiver_type_certainty, method, false); let rhs = if type_is_inferable_from_arguments(cx, expr) { meet( - std::iter::once(receiver_type_certainty).chain(args.iter().map(|arg| expr_type_certainty(cx, arg))), + std::iter::once(receiver_type_certainty) + .chain(args.iter().map(|arg| expr_type_certainty(cx, arg, true))), ) } else { Certainty::Uncertain @@ -67,16 +71,39 @@ fn expr_type_certainty(cx: &LateContext<'_>, expr: &Expr<'_>) -> Certainty { lhs.join(rhs) }, - ExprKind::Tup(exprs) => meet(exprs.iter().map(|expr| expr_type_certainty(cx, expr))), + ExprKind::Tup(exprs) => meet(exprs.iter().map(|expr| expr_type_certainty(cx, expr, in_arg))), - ExprKind::Binary(_, lhs, rhs) => expr_type_certainty(cx, lhs).meet(expr_type_certainty(cx, rhs)), + ExprKind::Binary(_, lhs, rhs) => { + // If one of the side of the expression is uncertain, the certainty will come from the other side, + // with no information on the type. + match ( + expr_type_certainty(cx, lhs, in_arg), + expr_type_certainty(cx, rhs, in_arg), + ) { + (Certainty::Uncertain, Certainty::Certain(_)) | (Certainty::Certain(_), Certainty::Uncertain) => { + Certainty::Certain(None) + }, + (l, r) => l.meet(r), + } + }, - ExprKind::Lit(_) => Certainty::Certain(None), + ExprKind::Lit(lit) => { + if !in_arg + && matches!( + lit.node, + LitKind::Int(_, LitIntType::Unsuffixed) | LitKind::Float(_, LitFloatType::Unsuffixed) + ) + { + Certainty::Uncertain + } else { + Certainty::Certain(None) + } + }, ExprKind::Cast(_, ty) => type_certainty(cx, ty), ExprKind::If(_, if_expr, Some(else_expr)) => { - expr_type_certainty(cx, if_expr).join(expr_type_certainty(cx, else_expr)) + expr_type_certainty(cx, if_expr, in_arg).join(expr_type_certainty(cx, else_expr, in_arg)) }, ExprKind::Path(qpath) => qpath_certainty(cx, qpath, false), @@ -188,6 +215,20 @@ fn qpath_certainty(cx: &LateContext<'_>, qpath: &QPath<'_>, resolves_to_type: bo certainty } +/// Tries to tell whether `param` resolves to something certain, e.g., a non-wildcard type if +/// present. The certainty `DefId` is cleared before returning. +fn param_certainty(cx: &LateContext<'_>, param: &Param<'_>) -> Certainty { + let owner_did = cx.tcx.hir_enclosing_body_owner(param.hir_id); + let Some(fn_decl) = cx.tcx.hir_fn_decl_by_hir_id(cx.tcx.local_def_id_to_hir_id(owner_did)) else { + return Certainty::Uncertain; + }; + let inputs = fn_decl.inputs; + let body_params = cx.tcx.hir_body_owned_by(owner_did).params; + std::iter::zip(body_params, inputs) + .find(|(p, _)| p.hir_id == param.hir_id) + .map_or(Certainty::Uncertain, |(_, ty)| type_certainty(cx, ty).clear_def_id()) +} + fn path_segment_certainty( cx: &LateContext<'_>, parent_certainty: Certainty, @@ -240,15 +281,16 @@ fn path_segment_certainty( // `get_parent` because `hir_id` refers to a `Pat`, and we're interested in the node containing the `Pat`. Res::Local(hir_id) => match cx.tcx.parent_hir_node(hir_id) { - // An argument's type is always certain. - Node::Param(..) => Certainty::Certain(None), + // A parameter's type is not always certain, as it may come from an untyped closure definition, + // or from a wildcard in a typed closure definition. + Node::Param(param) => param_certainty(cx, param), // A local's type is certain if its type annotation is certain or it has an initializer whose // type is certain. Node::LetStmt(local) => { let lhs = local.ty.map_or(Certainty::Uncertain, |ty| type_certainty(cx, ty)); let rhs = local .init - .map_or(Certainty::Uncertain, |init| expr_type_certainty(cx, init)); + .map_or(Certainty::Uncertain, |init| expr_type_certainty(cx, init, false)); let certainty = lhs.join(rhs); if resolves_to_type { certainty diff --git a/tests/ui/manual_is_multiple_of.fixed b/tests/ui/manual_is_multiple_of.fixed index 6735b99f298c..03f75e725ed5 100644 --- a/tests/ui/manual_is_multiple_of.fixed +++ b/tests/ui/manual_is_multiple_of.fixed @@ -23,3 +23,81 @@ fn f(a: u64, b: u64) { fn g(a: u64, b: u64) { let _ = a % b == 0; } + +fn needs_deref(a: &u64, b: &u64) { + let _ = a.is_multiple_of(*b); //~ manual_is_multiple_of +} + +fn closures(a: u64, b: u64) { + // Do not lint, types are ambiguous at this point + let cl = |a, b| a % b == 0; + let _ = cl(a, b); + + // Do not lint, types are ambiguous at this point + let cl = |a: _, b: _| a % b == 0; + let _ = cl(a, b); + + // Type of `a` is enough + let cl = |a: u64, b| a.is_multiple_of(b); //~ manual_is_multiple_of + let _ = cl(a, b); + + // Type of `a` is enough + let cl = |a: &u64, b| a.is_multiple_of(b); //~ manual_is_multiple_of + let _ = cl(&a, b); + + // Type of `b` is not enough + let cl = |a, b: u64| a % b == 0; + let _ = cl(&a, b); +} + +fn any_rem>(a: T, b: T) { + // An arbitrary `Rem` implementation should not lint + let _ = a % b == 0; +} + +mod issue15103 { + fn foo() -> Option { + let mut n: u64 = 150_000_000; + + (2..).find(|p| { + while n.is_multiple_of(*p) { + //~^ manual_is_multiple_of + n /= p; + } + n <= 1 + }) + } + + const fn generate_primes() -> [u64; N] { + let mut result = [0; N]; + if N == 0 { + return result; + } + result[0] = 2; + if N == 1 { + return result; + } + let mut idx = 1; + let mut p = 3; + while idx < N { + let mut j = 0; + while j < idx && p % result[j] != 0 { + j += 1; + } + if j == idx { + result[idx] = p; + idx += 1; + } + p += 1; + } + result + } + + fn bar() -> u32 { + let d = |n: u32| -> u32 { (1..=n / 2).filter(|i| n.is_multiple_of(*i)).sum() }; + //~^ manual_is_multiple_of + + let d = |n| (1..=n / 2).filter(|i| n % i == 0).sum(); + (1..1_000).filter(|&i| i == d(d(i)) && i != d(i)).sum() + } +} diff --git a/tests/ui/manual_is_multiple_of.rs b/tests/ui/manual_is_multiple_of.rs index 00b638e4fd9f..7b6fa64c843d 100644 --- a/tests/ui/manual_is_multiple_of.rs +++ b/tests/ui/manual_is_multiple_of.rs @@ -23,3 +23,81 @@ fn f(a: u64, b: u64) { fn g(a: u64, b: u64) { let _ = a % b == 0; } + +fn needs_deref(a: &u64, b: &u64) { + let _ = a % b == 0; //~ manual_is_multiple_of +} + +fn closures(a: u64, b: u64) { + // Do not lint, types are ambiguous at this point + let cl = |a, b| a % b == 0; + let _ = cl(a, b); + + // Do not lint, types are ambiguous at this point + let cl = |a: _, b: _| a % b == 0; + let _ = cl(a, b); + + // Type of `a` is enough + let cl = |a: u64, b| a % b == 0; //~ manual_is_multiple_of + let _ = cl(a, b); + + // Type of `a` is enough + let cl = |a: &u64, b| a % b == 0; //~ manual_is_multiple_of + let _ = cl(&a, b); + + // Type of `b` is not enough + let cl = |a, b: u64| a % b == 0; + let _ = cl(&a, b); +} + +fn any_rem>(a: T, b: T) { + // An arbitrary `Rem` implementation should not lint + let _ = a % b == 0; +} + +mod issue15103 { + fn foo() -> Option { + let mut n: u64 = 150_000_000; + + (2..).find(|p| { + while n % p == 0 { + //~^ manual_is_multiple_of + n /= p; + } + n <= 1 + }) + } + + const fn generate_primes() -> [u64; N] { + let mut result = [0; N]; + if N == 0 { + return result; + } + result[0] = 2; + if N == 1 { + return result; + } + let mut idx = 1; + let mut p = 3; + while idx < N { + let mut j = 0; + while j < idx && p % result[j] != 0 { + j += 1; + } + if j == idx { + result[idx] = p; + idx += 1; + } + p += 1; + } + result + } + + fn bar() -> u32 { + let d = |n: u32| -> u32 { (1..=n / 2).filter(|i| n % i == 0).sum() }; + //~^ manual_is_multiple_of + + let d = |n| (1..=n / 2).filter(|i| n % i == 0).sum(); + (1..1_000).filter(|&i| i == d(d(i)) && i != d(i)).sum() + } +} diff --git a/tests/ui/manual_is_multiple_of.stderr b/tests/ui/manual_is_multiple_of.stderr index 0b1ae70c2a70..8523599ec402 100644 --- a/tests/ui/manual_is_multiple_of.stderr +++ b/tests/ui/manual_is_multiple_of.stderr @@ -37,5 +37,35 @@ error: manual implementation of `.is_multiple_of()` LL | let _ = 0 < a % b; | ^^^^^^^^^ help: replace with: `!a.is_multiple_of(b)` -error: aborting due to 6 previous errors +error: manual implementation of `.is_multiple_of()` + --> tests/ui/manual_is_multiple_of.rs:28:13 + | +LL | let _ = a % b == 0; + | ^^^^^^^^^^ help: replace with: `a.is_multiple_of(*b)` + +error: manual implementation of `.is_multiple_of()` + --> tests/ui/manual_is_multiple_of.rs:41:26 + | +LL | let cl = |a: u64, b| a % b == 0; + | ^^^^^^^^^^ help: replace with: `a.is_multiple_of(b)` + +error: manual implementation of `.is_multiple_of()` + --> tests/ui/manual_is_multiple_of.rs:45:27 + | +LL | let cl = |a: &u64, b| a % b == 0; + | ^^^^^^^^^^ help: replace with: `a.is_multiple_of(b)` + +error: manual implementation of `.is_multiple_of()` + --> tests/ui/manual_is_multiple_of.rs:63:19 + | +LL | while n % p == 0 { + | ^^^^^^^^^^ help: replace with: `n.is_multiple_of(*p)` + +error: manual implementation of `.is_multiple_of()` + --> tests/ui/manual_is_multiple_of.rs:97:58 + | +LL | let d = |n: u32| -> u32 { (1..=n / 2).filter(|i| n % i == 0).sum() }; + | ^^^^^^^^^^ help: replace with: `n.is_multiple_of(*i)` + +error: aborting due to 11 previous errors