Check MSRV before suggesting fix in const context

book/src/lint_configuration.md

@@ -804,6 +804,7 @@ The minimum rust version that the project supports. Defaults to the `rust-versio
 * [`manual_flatten`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_flatten)
 * [`manual_hash_one`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_hash_one)
 * [`manual_is_ascii_check`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_is_ascii_check)
+* [`manual_is_power_of_two`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_is_power_of_two)
 * [`manual_let_else`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_let_else)
 * [`manual_midpoint`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_midpoint)
 * [`manual_non_exhaustive`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_non_exhaustive)

clippy_config/src/conf.rs

@@ -721,6 +721,7 @@ define_Conf! {
  manual_flatten,
  manual_hash_one,
  manual_is_ascii_check,
+ manual_is_power_of_two,
  manual_let_else,
  manual_midpoint,
  manual_non_exhaustive,

clippy_lints/src/lib.rs

@@ -969,7 +969,7 @@ pub fn register_lints(store: &mut rustc_lint::LintStore, conf: &'static Conf) {
  store.register_late_pass(|_| Box::new(zombie_processes::ZombieProcesses));
  store.register_late_pass(|_| Box::new(pointers_in_nomem_asm_block::PointersInNomemAsmBlock));
  store.register_late_pass(move |_| Box::new(manual_div_ceil::ManualDivCeil::new(conf)));
- store.register_late_pass(|_| Box::new(manual_is_power_of_two::ManualIsPowerOfTwo));
+ store.register_late_pass(move |_| Box::new(manual_is_power_of_two::ManualIsPowerOfTwo::new(conf)));
  store.register_late_pass(|_| Box::new(non_zero_suggestions::NonZeroSuggestions));
  store.register_late_pass(|_| Box::new(literal_string_with_formatting_args::LiteralStringWithFormattingArg));
  store.register_late_pass(move |_| Box::new(unused_trait_names::UnusedTraitNames::new(conf)));

clippy_lints/src/manual_is_power_of_two.rs

@@ -1,11 +1,13 @@
+use clippy_config::Conf;
 use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::msrvs::{self, Msrv};
 use clippy_utils::sugg::Sugg;
-use clippy_utils::{SpanlessEq, is_integer_literal};
+use clippy_utils::{SpanlessEq, is_in_const_context, is_integer_literal};
 use rustc_errors::Applicability;
 use rustc_hir::{BinOpKind, Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty;
-use rustc_session::declare_lint_pass;
+use rustc_session::impl_lint_pass;
 
 declare_clippy_lint! {
  /// ### What it does
@@ -31,7 +33,36 @@ declare_clippy_lint! {
  "manually reimplementing `is_power_of_two`"
 }
 
-declare_lint_pass!(ManualIsPowerOfTwo => [MANUAL_IS_POWER_OF_TWO]);
+pub struct ManualIsPowerOfTwo {
+ msrv: Msrv,
+}
+
+impl_lint_pass!(ManualIsPowerOfTwo => [MANUAL_IS_POWER_OF_TWO]);
+
+impl ManualIsPowerOfTwo {
+ pub fn new(conf: &'static Conf) -> Self {
+ Self { msrv: conf.msrv }
+ }
+
+ fn build_sugg(&self, cx: &LateContext<'_>, expr: &Expr<'_>, receiver: &Expr<'_>) {
+ if is_in_const_context(cx) && !self.msrv.meets(cx, msrvs::CONST_IS_POWER_OF_TWO) {
+ return;
+ }
+
+ let mut applicability = Applicability::MachineApplicable;
+ let snippet = Sugg::hir_with_applicability(cx, receiver, "_", &mut applicability);
+
+ span_lint_and_sugg(
+ cx,
+ MANUAL_IS_POWER_OF_TWO,
+ expr.span,
+ "manually reimplementing `is_power_of_two`",
+ "consider using `.is_power_of_two()`",
+ format!("{}.is_power_of_two()", snippet.maybe_paren()),
+ applicability,
+ );
+ }
+}
 
 impl<'tcx> LateLintPass<'tcx> for ManualIsPowerOfTwo {
  fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &Expr<'tcx>) {
@@ -41,39 +72,24 @@ impl<'tcx> LateLintPass<'tcx> for ManualIsPowerOfTwo {
  if let Some(a) = count_ones_receiver(cx, lhs)
  && is_integer_literal(rhs, 1)
  {
- build_sugg(cx, expr, a);
+ self.build_sugg(cx, expr, a);
  } else if let Some(a) = count_ones_receiver(cx, rhs)
  && is_integer_literal(lhs, 1)
  {
- build_sugg(cx, expr, a);
+ self.build_sugg(cx, expr, a);
  } else if is_integer_literal(rhs, 0)
  && let Some(a) = is_and_minus_one(cx, lhs)
  {
- build_sugg(cx, expr, a);
+ self.build_sugg(cx, expr, a);
  } else if is_integer_literal(lhs, 0)
  && let Some(a) = is_and_minus_one(cx, rhs)
  {
- build_sugg(cx, expr, a);
+ self.build_sugg(cx, expr, a);
  }
  }
  }
 }
 
-fn build_sugg(cx: &LateContext<'_>, expr: &Expr<'_>, receiver: &Expr<'_>) {
- let mut applicability = Applicability::MachineApplicable;
- let snippet = Sugg::hir_with_applicability(cx, receiver, "_", &mut applicability);
-
- span_lint_and_sugg(
- cx,
- MANUAL_IS_POWER_OF_TWO,
- expr.span,
- "manually reimplementing `is_power_of_two`",
- "consider using `.is_power_of_two()`",
- format!("{}.is_power_of_two()", snippet.maybe_paren()),
- applicability,
- );
-}
-
 /// Return the unsigned integer receiver of `.count_ones()`
 fn count_ones_receiver<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'tcx>) -> Option<&'tcx Expr<'tcx>> {
  if let ExprKind::MethodCall(method_name, receiver, [], _) = expr.kind

clippy_utils/src/msrvs.rs

@@ -63,6 +63,7 @@ msrv_aliases! {
  1,35,0 { OPTION_COPIED, RANGE_CONTAINS }
  1,34,0 { TRY_FROM }
  1,33,0 { UNDERSCORE_IMPORTS }
+ 1,32,0 { CONST_IS_POWER_OF_TWO }
  1,31,0 { OPTION_REPLACE }
  1,30,0 { ITERATOR_FIND_MAP, TOOL_ATTRIBUTES }
  1,29,0 { ITER_FLATTEN }

tests/ui/manual_is_power_of_two.fixed

@@ -45,3 +45,14 @@ fn main() {
  let _ = binop!(a, and, a - 1) == 0;
  let _ = a & binop!(a, minus, 1) == 0;
 }
+
+#[clippy::msrv = "1.31"]
+const fn low_msrv(a: u32) -> bool {
+ a & (a - 1) == 0
+}
+
+#[clippy::msrv = "1.32"]
+const fn high_msrv(a: u32) -> bool {
+ a.is_power_of_two()
+ //~^ manual_is_power_of_two
+}

tests/ui/manual_is_power_of_two.rs

@@ -45,3 +45,14 @@ fn main() {
  let _ = binop!(a, and, a - 1) == 0;
  let _ = a & binop!(a, minus, 1) == 0;
 }
+
+#[clippy::msrv = "1.31"]
+const fn low_msrv(a: u32) -> bool {
+ a & (a - 1) == 0
+}
+
+#[clippy::msrv = "1.32"]
+const fn high_msrv(a: u32) -> bool {
+ a & (a - 1) == 0
+ //~^ manual_is_power_of_two
+}

tests/ui/manual_is_power_of_two.stderr

@@ -43,5 +43,11 @@ error: manually reimplementing `is_power_of_two`
 LL | let _ = i as u32 & (i as u32 - 1) == 0;
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `.is_power_of_two()`: `(i as u32).is_power_of_two()`
 
-error: aborting due to 7 previous errors
+error: manually reimplementing `is_power_of_two`
+ --> tests/ui/manual_is_power_of_two.rs:56:5
+ |
+LL | a & (a - 1) == 0
+ | ^^^^^^^^^^^^^^^^ help: consider using `.is_power_of_two()`: `a.is_power_of_two()`
+
+error: aborting due to 8 previous errors