diff options
| -rw-r--r-- | clippy_lints/src/casts/mod.rs | 26 | ||||
| -rw-r--r-- | clippy_lints/src/casts/zero_ptr.rs | 39 | ||||
| -rw-r--r-- | clippy_lints/src/declared_lints.rs | 2 | ||||
| -rw-r--r-- | clippy_lints/src/lib.rs | 2 | ||||
| -rw-r--r-- | clippy_lints/src/misc.rs | 84 |
5 files changed, 75 insertions, 78 deletions
diff --git a/clippy_lints/src/casts/mod.rs b/clippy_lints/src/casts/mod.rs index 88ffbb55486..b00130ffd76 100644 --- a/clippy_lints/src/casts/mod.rs +++ b/clippy_lints/src/casts/mod.rs @@ -20,6 +20,7 @@ mod ptr_as_ptr; mod ptr_cast_constness; mod unnecessary_cast; mod utils; +mod zero_ptr; use clippy_utils::is_hir_ty_cfg_dependant; use clippy_utils::msrvs::{self, Msrv}; @@ -665,6 +666,29 @@ declare_clippy_lint! { "casting a known floating-point NaN into an integer" } +declare_clippy_lint! { + /// ### What it does + /// Catch casts from `0` to some pointer type + /// + /// ### Why is this bad? + /// This generally means `null` and is better expressed as + /// {`std`, `core`}`::ptr::`{`null`, `null_mut`}. + /// + /// ### Example + /// ```rust + /// let a = 0 as *const u32; + /// ``` + /// + /// Use instead: + /// ```rust + /// let a = std::ptr::null::<u32>(); + /// ``` + #[clippy::version = "pre 1.29.0"] + pub ZERO_PTR, + style, + "using `0 as *{const, mut} T`" +} + pub struct Casts { msrv: Msrv, } @@ -699,6 +723,7 @@ impl_lint_pass!(Casts => [ CAST_SLICE_FROM_RAW_PARTS, AS_PTR_CAST_MUT, CAST_NAN_TO_INT, + ZERO_PTR, ]); impl<'tcx> LateLintPass<'tcx> for Casts { @@ -729,6 +754,7 @@ impl<'tcx> LateLintPass<'tcx> for Casts { fn_to_numeric_cast_any::check(cx, expr, cast_expr, cast_from, cast_to); fn_to_numeric_cast::check(cx, expr, cast_expr, cast_from, cast_to); fn_to_numeric_cast_with_truncation::check(cx, expr, cast_expr, cast_from, cast_to); + zero_ptr::check(cx, expr, cast_expr, cast_to_hir); if cast_to.is_numeric() && !in_external_macro(cx.sess(), expr.span) { cast_possible_truncation::check(cx, expr, cast_expr, cast_from, cast_to, cast_to_hir.span); diff --git a/clippy_lints/src/casts/zero_ptr.rs b/clippy_lints/src/casts/zero_ptr.rs new file mode 100644 index 00000000000..5071af5ecb9 --- /dev/null +++ b/clippy_lints/src/casts/zero_ptr.rs @@ -0,0 +1,39 @@ +use clippy_utils::diagnostics::span_lint_and_sugg; +use clippy_utils::source::snippet_opt; +use clippy_utils::{in_constant, is_integer_literal, std_or_core}; +use rustc_errors::Applicability; +use rustc_hir::{Expr, Mutability, Ty, TyKind}; +use rustc_lint::LateContext; + +use super::ZERO_PTR; + +pub fn check(cx: &LateContext<'_>, expr: &Expr<'_>, from: &Expr<'_>, to: &Ty<'_>) { + if let TyKind::Ptr(ref mut_ty) = to.kind + && is_integer_literal(from, 0) + && !in_constant(cx, from.hir_id) + && let Some(std_or_core) = std_or_core(cx) + { + let (msg, sugg_fn) = match mut_ty.mutbl { + Mutability::Mut => ("`0 as *mut _` detected", "ptr::null_mut"), + Mutability::Not => ("`0 as *const _` detected", "ptr::null"), + }; + + let sugg = if let TyKind::Infer = mut_ty.ty.kind { + format!("{std_or_core}::{sugg_fn}()") + } else if let Some(mut_ty_snip) = snippet_opt(cx, mut_ty.ty.span) { + format!("{std_or_core}::{sugg_fn}::<{mut_ty_snip}>()") + } else { + return; + }; + + span_lint_and_sugg( + cx, + ZERO_PTR, + expr.span, + msg, + "try", + sugg, + Applicability::MachineApplicable, + ); + } +} diff --git a/clippy_lints/src/declared_lints.rs b/clippy_lints/src/declared_lints.rs index aa2ca0e1149..4d1281ec1e7 100644 --- a/clippy_lints/src/declared_lints.rs +++ b/clippy_lints/src/declared_lints.rs @@ -97,6 +97,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::casts::PTR_AS_PTR_INFO, crate::casts::PTR_CAST_CONSTNESS_INFO, crate::casts::UNNECESSARY_CAST_INFO, + crate::casts::ZERO_PTR_INFO, crate::checked_conversions::CHECKED_CONVERSIONS_INFO, crate::cognitive_complexity::COGNITIVE_COMPLEXITY_INFO, crate::collapsible_if::COLLAPSIBLE_ELSE_IF_INFO, @@ -443,7 +444,6 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::misc::SHORT_CIRCUIT_STATEMENT_INFO, crate::misc::TOPLEVEL_REF_ARG_INFO, crate::misc::USED_UNDERSCORE_BINDING_INFO, - crate::misc::ZERO_PTR_INFO, crate::misc_early::BUILTIN_TYPE_SHADOW_INFO, crate::misc_early::DOUBLE_NEG_INFO, crate::misc_early::DUPLICATE_UNDERSCORE_ARGUMENT_INFO, diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index dcc6ee68e1b..fa009c8b2d6 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -637,7 +637,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_late_pass(|_| Box::new(needless_bool::NeedlessBool)); store.register_late_pass(|_| Box::new(needless_bool::BoolComparison)); store.register_late_pass(|_| Box::new(needless_for_each::NeedlessForEach)); - store.register_late_pass(|_| Box::<misc::LintPass>::default()); + store.register_late_pass(|_| Box::new(misc::LintPass)); store.register_late_pass(|_| Box::new(eta_reduction::EtaReduction)); store.register_late_pass(|_| Box::new(mut_mut::MutMut)); store.register_late_pass(|_| Box::new(mut_reference::UnnecessaryMutPassed)); diff --git a/clippy_lints/src/misc.rs b/clippy_lints/src/misc.rs index f8e76a5833e..9c8b47fb303 100644 --- a/clippy_lints/src/misc.rs +++ b/clippy_lints/src/misc.rs @@ -1,21 +1,20 @@ -use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg, span_lint_and_then, span_lint_hir_and_then}; -use clippy_utils::source::{snippet, snippet_opt, snippet_with_context}; +use clippy_utils::diagnostics::{span_lint, span_lint_and_then, span_lint_hir_and_then}; +use clippy_utils::source::{snippet, snippet_with_context}; use clippy_utils::sugg::Sugg; use clippy_utils::{ - any_parent_is_automatically_derived, fulfill_or_allowed, get_parent_expr, in_constant, is_integer_literal, - is_lint_allowed, is_no_std_crate, iter_input_pats, last_path_segment, SpanlessEq, + any_parent_is_automatically_derived, fulfill_or_allowed, get_parent_expr, is_lint_allowed, iter_input_pats, + last_path_segment, SpanlessEq, }; use if_chain::if_chain; use rustc_errors::Applicability; use rustc_hir::def::Res; use rustc_hir::intravisit::FnKind; use rustc_hir::{ - BinOpKind, BindingAnnotation, Body, ByRef, Expr, ExprKind, FnDecl, Mutability, PatKind, QPath, Stmt, StmtKind, Ty, - TyKind, + BinOpKind, BindingAnnotation, Body, ByRef, Expr, ExprKind, FnDecl, Mutability, PatKind, QPath, Stmt, StmtKind, }; use rustc_lint::{LateContext, LateLintPass, LintContext}; use rustc_middle::lint::in_external_macro; -use rustc_session::{declare_tool_lint, impl_lint_pass}; +use rustc_session::{declare_lint_pass, declare_tool_lint}; use rustc_span::def_id::LocalDefId; use rustc_span::source_map::Span; @@ -55,6 +54,7 @@ declare_clippy_lint! { style, "an entire binding declared as `ref`, in a function argument or a `let` statement" } + declare_clippy_lint! { /// ### What it does /// Checks for the use of bindings with a single leading @@ -102,51 +102,13 @@ declare_clippy_lint! { "using a short circuit boolean condition as a statement" } -declare_clippy_lint! { - /// ### What it does - /// Catch casts from `0` to some pointer type - /// - /// ### Why is this bad? - /// This generally means `null` and is better expressed as - /// {`std`, `core`}`::ptr::`{`null`, `null_mut`}. - /// - /// ### Example - /// ```rust - /// let a = 0 as *const u32; - /// ``` - /// - /// Use instead: - /// ```rust - /// let a = std::ptr::null::<u32>(); - /// ``` - #[clippy::version = "pre 1.29.0"] - pub ZERO_PTR, - style, - "using `0 as *{const, mut} T`" -} - -pub struct LintPass { - std_or_core: &'static str, -} -impl Default for LintPass { - fn default() -> Self { - Self { std_or_core: "std" } - } -} -impl_lint_pass!(LintPass => [ +declare_lint_pass!(LintPass => [ TOPLEVEL_REF_ARG, USED_UNDERSCORE_BINDING, SHORT_CIRCUIT_STATEMENT, - ZERO_PTR, ]); impl<'tcx> LateLintPass<'tcx> for LintPass { - fn check_crate(&mut self, cx: &LateContext<'_>) { - if is_no_std_crate(cx) { - self.std_or_core = "core"; - } - } - fn check_fn( &mut self, cx: &LateContext<'tcx>, @@ -252,10 +214,6 @@ impl<'tcx> LateLintPass<'tcx> for LintPass { } fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { - if let ExprKind::Cast(e, ty) = expr.kind { - self.check_cast(cx, expr.span, e, ty); - return; - } if in_external_macro(cx.sess(), expr.span) || expr.span.desugaring_kind().is_some() || any_parent_is_automatically_derived(cx.tcx, expr.hir_id) @@ -320,29 +278,3 @@ fn is_used(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { _ => is_used(cx, parent), }) } - -impl LintPass { - fn check_cast(&self, cx: &LateContext<'_>, span: Span, e: &Expr<'_>, ty: &Ty<'_>) { - if_chain! { - if let TyKind::Ptr(ref mut_ty) = ty.kind; - if is_integer_literal(e, 0); - if !in_constant(cx, e.hir_id); - then { - let (msg, sugg_fn) = match mut_ty.mutbl { - Mutability::Mut => ("`0 as *mut _` detected", "ptr::null_mut"), - Mutability::Not => ("`0 as *const _` detected", "ptr::null"), - }; - - let (sugg, appl) = if let TyKind::Infer = mut_ty.ty.kind { - (format!("{}::{sugg_fn}()", self.std_or_core), Applicability::MachineApplicable) - } else if let Some(mut_ty_snip) = snippet_opt(cx, mut_ty.ty.span) { - (format!("{}::{sugg_fn}::<{mut_ty_snip}>()", self.std_or_core), Applicability::MachineApplicable) - } else { - // `MaybeIncorrect` as type inference may not work with the suggested code - (format!("{}::{sugg_fn}()", self.std_or_core), Applicability::MaybeIncorrect) - }; - span_lint_and_sugg(cx, ZERO_PTR, span, msg, "try", sugg, appl); - } - } - } -} |