diff --git a/CHANGELOG.md b/CHANGELOG.md index 13067e4e92ae..2c69432f31c3 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -3038,6 +3038,7 @@ Released 2018-09-13 [`unicode_not_nfc`]: https://rust-lang.github.io/rust-clippy/master/index.html#unicode_not_nfc [`unimplemented`]: https://rust-lang.github.io/rust-clippy/master/index.html#unimplemented [`uninit_assumed_init`]: https://rust-lang.github.io/rust-clippy/master/index.html#uninit_assumed_init +[`uninit_vec`]: https://rust-lang.github.io/rust-clippy/master/index.html#uninit_vec [`unit_arg`]: https://rust-lang.github.io/rust-clippy/master/index.html#unit_arg [`unit_cmp`]: https://rust-lang.github.io/rust-clippy/master/index.html#unit_cmp [`unit_return_expecting_ord`]: https://rust-lang.github.io/rust-clippy/master/index.html#unit_return_expecting_ord diff --git a/clippy_lints/src/lib.register_all.rs b/clippy_lints/src/lib.register_all.rs index 3e6e0244754f..f0ef0befea03 100644 --- a/clippy_lints/src/lib.register_all.rs +++ b/clippy_lints/src/lib.register_all.rs @@ -278,6 +278,7 @@ store.register_group(true, "clippy::all", Some("clippy_all"), vec![ LintId::of(types::VEC_BOX), LintId::of(undropped_manually_drops::UNDROPPED_MANUALLY_DROPS), LintId::of(unicode::INVISIBLE_CHARACTERS), + LintId::of(uninit_vec::UNINIT_VEC), LintId::of(unit_return_expecting_ord::UNIT_RETURN_EXPECTING_ORD), LintId::of(unit_types::UNIT_ARG), LintId::of(unit_types::UNIT_CMP), diff --git a/clippy_lints/src/lib.register_correctness.rs b/clippy_lints/src/lib.register_correctness.rs index e0ef7b3b8af9..8eb662195e23 100644 --- a/clippy_lints/src/lib.register_correctness.rs +++ b/clippy_lints/src/lib.register_correctness.rs @@ -63,6 +63,7 @@ store.register_group(true, "clippy::correctness", Some("clippy_correctness"), ve LintId::of(transmuting_null::TRANSMUTING_NULL), LintId::of(undropped_manually_drops::UNDROPPED_MANUALLY_DROPS), LintId::of(unicode::INVISIBLE_CHARACTERS), + LintId::of(uninit_vec::UNINIT_VEC), LintId::of(unit_return_expecting_ord::UNIT_RETURN_EXPECTING_ORD), LintId::of(unit_types::UNIT_CMP), LintId::of(unnamed_address::FN_ADDRESS_COMPARISONS), diff --git a/clippy_lints/src/lib.register_lints.rs b/clippy_lints/src/lib.register_lints.rs index 3c4b720671a6..401c5b78b383 100644 --- a/clippy_lints/src/lib.register_lints.rs +++ b/clippy_lints/src/lib.register_lints.rs @@ -470,6 +470,7 @@ store.register_lints(&[ unicode::INVISIBLE_CHARACTERS, unicode::NON_ASCII_LITERAL, unicode::UNICODE_NOT_NFC, + uninit_vec::UNINIT_VEC, unit_return_expecting_ord::UNIT_RETURN_EXPECTING_ORD, unit_types::LET_UNIT_VALUE, unit_types::UNIT_ARG, diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index 7e1bcbbd0ed0..829d5acdfde3 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -361,6 +361,7 @@ mod types; mod undocumented_unsafe_blocks; mod undropped_manually_drops; mod unicode; +mod uninit_vec; mod unit_return_expecting_ord; mod unit_types; mod unnamed_address; @@ -518,6 +519,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_late_pass(|| Box::new(blocks_in_if_conditions::BlocksInIfConditions)); store.register_late_pass(|| Box::new(collapsible_match::CollapsibleMatch)); store.register_late_pass(|| Box::new(unicode::Unicode)); + store.register_late_pass(|| Box::new(uninit_vec::UninitVec)); store.register_late_pass(|| Box::new(unit_return_expecting_ord::UnitReturnExpectingOrd)); store.register_late_pass(|| Box::new(strings::StringAdd)); store.register_late_pass(|| Box::new(implicit_return::ImplicitReturn)); diff --git a/clippy_lints/src/methods/uninit_assumed_init.rs b/clippy_lints/src/methods/uninit_assumed_init.rs index 1a5894e48d14..ce89189bce97 100644 --- a/clippy_lints/src/methods/uninit_assumed_init.rs +++ b/clippy_lints/src/methods/uninit_assumed_init.rs @@ -1,9 +1,8 @@ use clippy_utils::diagnostics::span_lint; -use clippy_utils::{is_expr_path_def_path, match_def_path, paths}; +use clippy_utils::{is_expr_path_def_path, paths, ty::is_uninit_value_valid_for_ty}; use if_chain::if_chain; use rustc_hir as hir; use rustc_lint::LateContext; -use rustc_middle::ty::{self, Ty}; use super::UNINIT_ASSUMED_INIT; @@ -13,7 +12,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr if let hir::ExprKind::Call(callee, args) = recv.kind; if args.is_empty(); if is_expr_path_def_path(cx, callee, &paths::MEM_MAYBEUNINIT_UNINIT); - if !is_maybe_uninit_ty_valid(cx, cx.typeck_results().expr_ty_adjusted(expr)); + if !is_uninit_value_valid_for_ty(cx, cx.typeck_results().expr_ty_adjusted(expr)); then { span_lint( cx, @@ -24,12 +23,3 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr } } } - -fn is_maybe_uninit_ty_valid(cx: &LateContext<'_>, ty: Ty<'_>) -> bool { - match ty.kind() { - ty::Array(component, _) => is_maybe_uninit_ty_valid(cx, component), - ty::Tuple(types) => types.types().all(|ty| is_maybe_uninit_ty_valid(cx, ty)), - ty::Adt(adt, _) => match_def_path(cx, adt.did, &paths::MEM_MAYBEUNINIT), - _ => false, - } -} diff --git a/clippy_lints/src/uninit_vec.rs b/clippy_lints/src/uninit_vec.rs new file mode 100644 index 000000000000..f3e8b6881058 --- /dev/null +++ b/clippy_lints/src/uninit_vec.rs @@ -0,0 +1,223 @@ +use clippy_utils::diagnostics::{span_lint, span_lint_and_then}; +use clippy_utils::higher::{get_vec_init_kind, VecInitKind}; +use clippy_utils::ty::{is_type_diagnostic_item, is_uninit_value_valid_for_ty}; +use clippy_utils::{is_lint_allowed, path_to_local_id, peel_hir_expr_while, SpanlessEq}; +use rustc_hir::{Block, Expr, ExprKind, HirId, PatKind, PathSegment, Stmt, StmtKind}; +use rustc_lint::{LateContext, LateLintPass}; +use rustc_middle::lint::in_external_macro; +use rustc_middle::ty; +use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_span::{sym, Span}; + +// TODO: add `ReadBuf` (RFC 2930) in "How to fix" once it is available in std +declare_clippy_lint! { + /// ### What it does + /// Checks for `set_len()` call that creates `Vec` with uninitialized elements. + /// This is commonly caused by calling `set_len()` right after allocating or + /// reserving a buffer with `new()`, `default()`, `with_capacity()`, or `reserve()`. + /// + /// ### Why is this bad? + /// It creates a `Vec` with uninitialized data, which leads to + /// undefined behavior with most safe operations. Notably, uninitialized + /// `Vec` must not be used with generic `Read`. + /// + /// Moreover, calling `set_len()` on a `Vec` created with `new()` or `default()` + /// creates out-of-bound values that lead to heap memory corruption when used. + /// + /// ### Known Problems + /// This lint only checks directly adjacent statements. + /// + /// ### Example + /// ```rust,ignore + /// let mut vec: Vec = Vec::with_capacity(1000); + /// unsafe { vec.set_len(1000); } + /// reader.read(&mut vec); // undefined behavior! + /// ``` + /// + /// ### How to fix? + /// 1. Use an initialized buffer: + /// ```rust,ignore + /// let mut vec: Vec = vec![0; 1000]; + /// reader.read(&mut vec); + /// ``` + /// 2. Wrap the content in `MaybeUninit`: + /// ```rust,ignore + /// let mut vec: Vec> = Vec::with_capacity(1000); + /// vec.set_len(1000); // `MaybeUninit` can be uninitialized + /// ``` + /// 3. If you are on nightly, `Vec::spare_capacity_mut()` is available: + /// ```rust,ignore + /// let mut vec: Vec = Vec::with_capacity(1000); + /// let remaining = vec.spare_capacity_mut(); // `&mut [MaybeUninit]` + /// // perform initialization with `remaining` + /// vec.set_len(...); // Safe to call `set_len()` on initialized part + /// ``` + pub UNINIT_VEC, + correctness, + "Vec with uninitialized data" +} + +declare_lint_pass!(UninitVec => [UNINIT_VEC]); + +// FIXME: update to a visitor-based implementation. +// Threads: https://github.com/rust-lang/rust-clippy/pull/7682#discussion_r710998368 +impl<'tcx> LateLintPass<'tcx> for UninitVec { + fn check_block(&mut self, cx: &LateContext<'tcx>, block: &'tcx Block<'_>) { + if !in_external_macro(cx.tcx.sess, block.span) { + for w in block.stmts.windows(2) { + if let StmtKind::Expr(expr) | StmtKind::Semi(expr) = w[1].kind { + handle_uninit_vec_pair(cx, &w[0], expr); + } + } + + if let (Some(stmt), Some(expr)) = (block.stmts.last(), block.expr) { + handle_uninit_vec_pair(cx, stmt, expr); + } + } + } +} + +fn handle_uninit_vec_pair( + cx: &LateContext<'tcx>, + maybe_init_or_reserve: &'tcx Stmt<'tcx>, + maybe_set_len: &'tcx Expr<'tcx>, +) { + if_chain! { + if let Some(vec) = extract_init_or_reserve_target(cx, maybe_init_or_reserve); + if let Some((set_len_self, call_span)) = extract_set_len_self(cx, maybe_set_len); + if vec.location.eq_expr(cx, set_len_self); + if let ty::Ref(_, vec_ty, _) = cx.typeck_results().expr_ty_adjusted(set_len_self).kind(); + if let ty::Adt(_, substs) = vec_ty.kind(); + // `#[allow(...)]` attribute can be set on enclosing unsafe block of `set_len()` + if !is_lint_allowed(cx, UNINIT_VEC, maybe_set_len.hir_id); + then { + if vec.has_capacity() { + // with_capacity / reserve -> set_len + + // Check T of Vec + if !is_uninit_value_valid_for_ty(cx, substs.type_at(0)) { + // FIXME: #7698, false positive of the internal lints + #[allow(clippy::collapsible_span_lint_calls)] + span_lint_and_then( + cx, + UNINIT_VEC, + vec![call_span, maybe_init_or_reserve.span], + "calling `set_len()` immediately after reserving a buffer creates uninitialized values", + |diag| { + diag.help("initialize the buffer or wrap the content in `MaybeUninit`"); + }, + ); + } + } else { + // new / default -> set_len + span_lint( + cx, + UNINIT_VEC, + vec![call_span, maybe_init_or_reserve.span], + "calling `set_len()` on empty `Vec` creates out-of-bound values", + ); + } + } + } +} + +/// The target `Vec` that is initialized or reserved +#[derive(Clone, Copy)] +struct TargetVec<'tcx> { + location: VecLocation<'tcx>, + /// `None` if `reserve()` + init_kind: Option, +} + +impl TargetVec<'_> { + pub fn has_capacity(self) -> bool { + !matches!(self.init_kind, Some(VecInitKind::New | VecInitKind::Default)) + } +} + +#[derive(Clone, Copy)] +enum VecLocation<'tcx> { + Local(HirId), + Expr(&'tcx Expr<'tcx>), +} + +impl<'tcx> VecLocation<'tcx> { + pub fn eq_expr(self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> bool { + match self { + VecLocation::Local(hir_id) => path_to_local_id(expr, hir_id), + VecLocation::Expr(self_expr) => SpanlessEq::new(cx).eq_expr(self_expr, expr), + } + } +} + +/// Finds the target location where the result of `Vec` initialization is stored +/// or `self` expression for `Vec::reserve()`. +fn extract_init_or_reserve_target<'tcx>(cx: &LateContext<'tcx>, stmt: &'tcx Stmt<'tcx>) -> Option> { + match stmt.kind { + StmtKind::Local(local) => { + if_chain! { + if let Some(init_expr) = local.init; + if let PatKind::Binding(_, hir_id, _, None) = local.pat.kind; + if let Some(init_kind) = get_vec_init_kind(cx, init_expr); + then { + return Some(TargetVec { + location: VecLocation::Local(hir_id), + init_kind: Some(init_kind), + }) + } + } + }, + StmtKind::Expr(expr) | StmtKind::Semi(expr) => match expr.kind { + ExprKind::Assign(lhs, rhs, _span) => { + if let Some(init_kind) = get_vec_init_kind(cx, rhs) { + return Some(TargetVec { + location: VecLocation::Expr(lhs), + init_kind: Some(init_kind), + }); + } + }, + ExprKind::MethodCall(path, _, [self_expr, _], _) if is_reserve(cx, path, self_expr) => { + return Some(TargetVec { + location: VecLocation::Expr(self_expr), + init_kind: None, + }); + }, + _ => (), + }, + StmtKind::Item(_) => (), + } + None +} + +fn is_reserve(cx: &LateContext<'_>, path: &PathSegment<'_>, self_expr: &Expr<'_>) -> bool { + is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(self_expr).peel_refs(), sym::Vec) + && path.ident.name.as_str() == "reserve" +} + +/// Returns self if the expression is `Vec::set_len()` +fn extract_set_len_self(cx: &LateContext<'_>, expr: &'tcx Expr<'_>) -> Option<(&'tcx Expr<'tcx>, Span)> { + // peel unsafe blocks in `unsafe { vec.set_len() }` + let expr = peel_hir_expr_while(expr, |e| { + if let ExprKind::Block(block, _) = e.kind { + // Extract the first statement/expression + match (block.stmts.get(0).map(|stmt| &stmt.kind), block.expr) { + (None, Some(expr)) => Some(expr), + (Some(StmtKind::Expr(expr) | StmtKind::Semi(expr)), _) => Some(expr), + _ => None, + } + } else { + None + } + }); + match expr.kind { + ExprKind::MethodCall(path, _, [self_expr, _], _) => { + let self_type = cx.typeck_results().expr_ty(self_expr).peel_refs(); + if is_type_diagnostic_item(cx, self_type, sym::Vec) && path.ident.name.as_str() == "set_len" { + Some((self_expr, expr.span)) + } else { + None + } + }, + _ => None, + } +} diff --git a/clippy_lints/src/vec_init_then_push.rs b/clippy_lints/src/vec_init_then_push.rs index d8e241d72af4..b92b6ca4f438 100644 --- a/clippy_lints/src/vec_init_then_push.rs +++ b/clippy_lints/src/vec_init_then_push.rs @@ -1,16 +1,14 @@ use clippy_utils::diagnostics::span_lint_and_sugg; +use clippy_utils::higher::{get_vec_init_kind, VecInitKind}; use clippy_utils::source::snippet; -use clippy_utils::ty::is_type_diagnostic_item; -use clippy_utils::{match_def_path, path_to_local, path_to_local_id, paths}; +use clippy_utils::{path_to_local, path_to_local_id}; use if_chain::if_chain; -use rustc_ast::ast::LitKind; use rustc_errors::Applicability; -use rustc_hir::{BindingAnnotation, Block, Expr, ExprKind, HirId, Local, PatKind, QPath, Stmt, StmtKind}; +use rustc_hir::{BindingAnnotation, Block, Expr, ExprKind, HirId, Local, PatKind, 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_span::{symbol::sym, Span}; -use std::convert::TryInto; +use rustc_span::Span; declare_clippy_lint! { /// ### What it does @@ -41,11 +39,6 @@ pub struct VecInitThenPush { searcher: Option, } -#[derive(Clone, Copy)] -enum VecInitKind { - New, - WithCapacity(u64), -} struct VecPushSearcher { local_id: HirId, init: VecInitKind, @@ -58,7 +51,8 @@ impl VecPushSearcher { fn display_err(&self, cx: &LateContext<'_>) { match self.init { _ if self.found == 0 => return, - VecInitKind::WithCapacity(x) if x > self.found => return, + VecInitKind::WithLiteralCapacity(x) if x > self.found => return, + VecInitKind::WithExprCapacity(_) => return, _ => (), }; @@ -152,37 +146,3 @@ impl LateLintPass<'_> for VecInitThenPush { } } } - -fn get_vec_init_kind<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Option { - if let ExprKind::Call(func, args) = expr.kind { - match func.kind { - ExprKind::Path(QPath::TypeRelative(ty, name)) - if is_type_diagnostic_item(cx, cx.typeck_results().node_type(ty.hir_id), sym::Vec) => - { - if name.ident.name == sym::new { - return Some(VecInitKind::New); - } else if name.ident.name.as_str() == "with_capacity" { - return args.get(0).and_then(|arg| { - if_chain! { - if let ExprKind::Lit(lit) = &arg.kind; - if let LitKind::Int(num, _) = lit.node; - then { - Some(VecInitKind::WithCapacity(num.try_into().ok()?)) - } else { - None - } - } - }); - } - } - ExprKind::Path(QPath::Resolved(_, path)) - if match_def_path(cx, path.res.opt_def_id()?, &paths::DEFAULT_TRAIT_METHOD) - && is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym::Vec) => - { - return Some(VecInitKind::New); - } - _ => (), - } - } - None -} diff --git a/clippy_utils/src/higher.rs b/clippy_utils/src/higher.rs index ba4d50bf7446..1ff282de9509 100644 --- a/clippy_utils/src/higher.rs +++ b/clippy_utils/src/higher.rs @@ -2,13 +2,16 @@ #![deny(clippy::missing_docs_in_private_items)] +use crate::ty::is_type_diagnostic_item; use crate::{is_expn_of, match_def_path, paths}; use if_chain::if_chain; use rustc_ast::ast::{self, LitKind}; use rustc_hir as hir; -use rustc_hir::{Arm, Block, BorrowKind, Expr, ExprKind, LoopSource, MatchSource, Node, Pat, StmtKind, UnOp}; +use rustc_hir::{ + Arm, Block, BorrowKind, Expr, ExprKind, HirId, LoopSource, MatchSource, Node, Pat, QPath, StmtKind, UnOp, +}; use rustc_lint::LateContext; -use rustc_span::{sym, ExpnKind, Span, Symbol}; +use rustc_span::{sym, symbol, ExpnKind, Span, Symbol}; /// The essential nodes of a desugared for loop as well as the entire span: /// `for pat in arg { body }` becomes `(pat, arg, body)`. Return `(pat, arg, body, span)`. @@ -632,3 +635,51 @@ impl PanicExpn<'tcx> { } } } + +/// A parsed `Vec` initialization expression +#[derive(Clone, Copy)] +pub enum VecInitKind { + /// `Vec::new()` + New, + /// `Vec::default()` or `Default::default()` + Default, + /// `Vec::with_capacity(123)` + WithLiteralCapacity(u64), + /// `Vec::with_capacity(slice.len())` + WithExprCapacity(HirId), +} + +/// Checks if given expression is an initialization of `Vec` and returns its kind. +pub fn get_vec_init_kind<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Option { + if let ExprKind::Call(func, args) = expr.kind { + match func.kind { + ExprKind::Path(QPath::TypeRelative(ty, name)) + if is_type_diagnostic_item(cx, cx.typeck_results().node_type(ty.hir_id), sym::Vec) => + { + if name.ident.name == sym::new { + return Some(VecInitKind::New); + } else if name.ident.name == symbol::kw::Default { + return Some(VecInitKind::Default); + } else if name.ident.name.as_str() == "with_capacity" { + let arg = args.get(0)?; + if_chain! { + if let ExprKind::Lit(lit) = &arg.kind; + if let LitKind::Int(num, _) = lit.node; + then { + return Some(VecInitKind::WithLiteralCapacity(num.try_into().ok()?)) + } + } + return Some(VecInitKind::WithExprCapacity(arg.hir_id)); + } + } + ExprKind::Path(QPath::Resolved(_, path)) + if match_def_path(cx, path.res.opt_def_id()?, &paths::DEFAULT_TRAIT_METHOD) + && is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym::Vec) => + { + return Some(VecInitKind::Default); + } + _ => (), + } + } + None +} diff --git a/clippy_utils/src/ty.rs b/clippy_utils/src/ty.rs index 6ebe1a0028a3..ca64ac7de3ee 100644 --- a/clippy_utils/src/ty.rs +++ b/clippy_utils/src/ty.rs @@ -367,3 +367,13 @@ pub fn same_type_and_consts(a: Ty<'tcx>, b: Ty<'tcx>) -> bool { _ => a == b, } } + +/// Checks if a given type looks safe to be uninitialized. +pub fn is_uninit_value_valid_for_ty(cx: &LateContext<'_>, ty: Ty<'_>) -> bool { + match ty.kind() { + ty::Array(component, _) => is_uninit_value_valid_for_ty(cx, component), + ty::Tuple(types) => types.types().all(|ty| is_uninit_value_valid_for_ty(cx, ty)), + ty::Adt(adt, _) => cx.tcx.lang_items().maybe_uninit() == Some(adt.did), + _ => false, + } +} diff --git a/tests/ui/uninit_vec.rs b/tests/ui/uninit_vec.rs new file mode 100644 index 000000000000..dc150cf28f2c --- /dev/null +++ b/tests/ui/uninit_vec.rs @@ -0,0 +1,94 @@ +#![warn(clippy::uninit_vec)] + +use std::mem::MaybeUninit; + +#[derive(Default)] +struct MyVec { + vec: Vec, +} + +fn main() { + // with_capacity() -> set_len() should be detected + let mut vec: Vec = Vec::with_capacity(1000); + unsafe { + vec.set_len(200); + } + + // reserve() -> set_len() should be detected + vec.reserve(1000); + unsafe { + vec.set_len(200); + } + + // new() -> set_len() should be detected + let mut vec: Vec = Vec::new(); + unsafe { + vec.set_len(200); + } + + // default() -> set_len() should be detected + let mut vec: Vec = Default::default(); + unsafe { + vec.set_len(200); + } + + let mut vec: Vec = Vec::default(); + unsafe { + vec.set_len(200); + } + + // test when both calls are enclosed in the same unsafe block + unsafe { + let mut vec: Vec = Vec::with_capacity(1000); + vec.set_len(200); + + vec.reserve(1000); + vec.set_len(200); + } + + let mut vec: Vec = Vec::with_capacity(1000); + unsafe { + // test the case where there are other statements in the following unsafe block + vec.set_len(200); + assert!(vec.len() == 200); + } + + // handle vec stored in the field of a struct + let mut my_vec = MyVec::default(); + my_vec.vec.reserve(1000); + unsafe { + my_vec.vec.set_len(200); + } + + my_vec.vec = Vec::with_capacity(1000); + unsafe { + my_vec.vec.set_len(200); + } + + // Test `#[allow(...)]` attributes on inner unsafe block (shouldn't trigger) + let mut vec: Vec = Vec::with_capacity(1000); + #[allow(clippy::uninit_vec)] + unsafe { + vec.set_len(200); + } + + // MaybeUninit-wrapped types should not be detected + unsafe { + let mut vec: Vec> = Vec::with_capacity(1000); + vec.set_len(200); + + let mut vec: Vec<(MaybeUninit, MaybeUninit)> = Vec::with_capacity(1000); + vec.set_len(200); + + let mut vec: Vec<(MaybeUninit, [MaybeUninit; 2])> = Vec::with_capacity(1000); + vec.set_len(200); + } + + // known false negative + let mut vec1: Vec = Vec::with_capacity(1000); + let mut vec2: Vec = Vec::with_capacity(1000); + unsafe { + vec1.set_len(200); + vec2.set_len(200); + } +} diff --git a/tests/ui/uninit_vec.stderr b/tests/ui/uninit_vec.stderr new file mode 100644 index 000000000000..520bfb26b62e --- /dev/null +++ b/tests/ui/uninit_vec.stderr @@ -0,0 +1,105 @@ +error: calling `set_len()` immediately after reserving a buffer creates uninitialized values + --> $DIR/uninit_vec.rs:12:5 + | +LL | let mut vec: Vec = Vec::with_capacity(1000); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | unsafe { +LL | vec.set_len(200); + | ^^^^^^^^^^^^^^^^ + | + = note: `-D clippy::uninit-vec` implied by `-D warnings` + = help: initialize the buffer or wrap the content in `MaybeUninit` + +error: calling `set_len()` immediately after reserving a buffer creates uninitialized values + --> $DIR/uninit_vec.rs:18:5 + | +LL | vec.reserve(1000); + | ^^^^^^^^^^^^^^^^^^ +LL | unsafe { +LL | vec.set_len(200); + | ^^^^^^^^^^^^^^^^ + | + = help: initialize the buffer or wrap the content in `MaybeUninit` + +error: calling `set_len()` on empty `Vec` creates out-of-bound values + --> $DIR/uninit_vec.rs:24:5 + | +LL | let mut vec: Vec = Vec::new(); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | unsafe { +LL | vec.set_len(200); + | ^^^^^^^^^^^^^^^^ + +error: calling `set_len()` on empty `Vec` creates out-of-bound values + --> $DIR/uninit_vec.rs:30:5 + | +LL | let mut vec: Vec = Default::default(); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | unsafe { +LL | vec.set_len(200); + | ^^^^^^^^^^^^^^^^ + +error: calling `set_len()` on empty `Vec` creates out-of-bound values + --> $DIR/uninit_vec.rs:35:5 + | +LL | let mut vec: Vec = Vec::default(); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | unsafe { +LL | vec.set_len(200); + | ^^^^^^^^^^^^^^^^ + +error: calling `set_len()` immediately after reserving a buffer creates uninitialized values + --> $DIR/uninit_vec.rs:49:5 + | +LL | let mut vec: Vec = Vec::with_capacity(1000); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +... +LL | vec.set_len(200); + | ^^^^^^^^^^^^^^^^ + | + = help: initialize the buffer or wrap the content in `MaybeUninit` + +error: calling `set_len()` immediately after reserving a buffer creates uninitialized values + --> $DIR/uninit_vec.rs:58:5 + | +LL | my_vec.vec.reserve(1000); + | ^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | unsafe { +LL | my_vec.vec.set_len(200); + | ^^^^^^^^^^^^^^^^^^^^^^^ + | + = help: initialize the buffer or wrap the content in `MaybeUninit` + +error: calling `set_len()` immediately after reserving a buffer creates uninitialized values + --> $DIR/uninit_vec.rs:63:5 + | +LL | my_vec.vec = Vec::with_capacity(1000); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | unsafe { +LL | my_vec.vec.set_len(200); + | ^^^^^^^^^^^^^^^^^^^^^^^ + | + = help: initialize the buffer or wrap the content in `MaybeUninit` + +error: calling `set_len()` immediately after reserving a buffer creates uninitialized values + --> $DIR/uninit_vec.rs:42:9 + | +LL | let mut vec: Vec = Vec::with_capacity(1000); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | vec.set_len(200); + | ^^^^^^^^^^^^^^^^ + | + = help: initialize the buffer or wrap the content in `MaybeUninit` + +error: calling `set_len()` immediately after reserving a buffer creates uninitialized values + --> $DIR/uninit_vec.rs:45:9 + | +LL | vec.reserve(1000); + | ^^^^^^^^^^^^^^^^^^ +LL | vec.set_len(200); + | ^^^^^^^^^^^^^^^^ + | + = help: initialize the buffer or wrap the content in `MaybeUninit` + +error: aborting due to 10 previous errors +