Merge pull request #3365 from gnieto/lint/slow-initialization
Add slow vector initializations lint
This commit is contained in:
Oliver S̶c̶h̶n̶e̶i̶d̶e̶r Scherer
GitHub
commit
1e2291c90c
7 changed files with 561 additions and 1 deletions
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@ -842,6 +842,7 @@ All notable changes to this project will be documented in this file.
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[`single_char_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_char_pattern
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[`single_match`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_match
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[`single_match_else`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_match_else
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[`slow_vector_initialization`]: https://rust-lang.github.io/rust-clippy/master/index.html#slow_vector_initialization
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[`str_to_string`]: https://rust-lang.github.io/rust-clippy/master/index.html#str_to_string
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[`string_add`]: https://rust-lang.github.io/rust-clippy/master/index.html#string_add
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[`string_add_assign`]: https://rust-lang.github.io/rust-clippy/master/index.html#string_add_assign
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@ -880,6 +881,7 @@ All notable changes to this project will be documented in this file.
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[`unneeded_field_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#unneeded_field_pattern
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[`unreadable_literal`]: https://rust-lang.github.io/rust-clippy/master/index.html#unreadable_literal
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[`unsafe_removed_from_name`]: https://rust-lang.github.io/rust-clippy/master/index.html#unsafe_removed_from_name
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[`unsafe_vector_initialization`]: https://rust-lang.github.io/rust-clippy/master/index.html#unsafe_vector_initialization
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[`unseparated_literal_suffix`]: https://rust-lang.github.io/rust-clippy/master/index.html#unseparated_literal_suffix
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[`unstable_as_mut_slice`]: https://rust-lang.github.io/rust-clippy/master/index.html#unstable_as_mut_slice
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[`unstable_as_slice`]: https://rust-lang.github.io/rust-clippy/master/index.html#unstable_as_slice
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@ -9,7 +9,7 @@ We are currently in the process of discussing Clippy 1.0 via the RFC process in
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A collection of lints to catch common mistakes and improve your [Rust](https://github.com/rust-lang/rust) code.
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[There are 288 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html)
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[There are 290 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html)
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We have a bunch of lint categories to allow you to choose how much Clippy is supposed to ~~annoy~~ help you:
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@ -190,6 +190,7 @@ pub mod replace_consts;
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pub mod returns;
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pub mod serde_api;
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pub mod shadow;
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pub mod slow_vector_initialization;
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pub mod strings;
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pub mod suspicious_trait_impl;
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pub mod swap;
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@ -459,6 +460,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry<'_>, conf: &Conf) {
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reg.register_late_lint_pass(box non_copy_const::NonCopyConst);
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reg.register_late_lint_pass(box ptr_offset_with_cast::Pass);
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reg.register_late_lint_pass(box redundant_clone::RedundantClone);
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reg.register_late_lint_pass(box slow_vector_initialization::Pass);
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reg.register_lint_group("clippy::restriction", Some("clippy_restriction"), vec![
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arithmetic::FLOAT_ARITHMETIC,
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@ -709,6 +711,8 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry<'_>, conf: &Conf) {
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returns::NEEDLESS_RETURN,
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returns::UNUSED_UNIT,
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serde_api::SERDE_API_MISUSE,
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slow_vector_initialization::SLOW_VECTOR_INITIALIZATION,
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slow_vector_initialization::UNSAFE_VECTOR_INITIALIZATION,
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strings::STRING_LIT_AS_BYTES,
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suspicious_trait_impl::SUSPICIOUS_ARITHMETIC_IMPL,
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suspicious_trait_impl::SUSPICIOUS_OP_ASSIGN_IMPL,
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@ -955,6 +959,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry<'_>, conf: &Conf) {
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ranges::ITERATOR_STEP_BY_ZERO,
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regex::INVALID_REGEX,
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serde_api::SERDE_API_MISUSE,
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slow_vector_initialization::UNSAFE_VECTOR_INITIALIZATION,
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suspicious_trait_impl::SUSPICIOUS_ARITHMETIC_IMPL,
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suspicious_trait_impl::SUSPICIOUS_OP_ASSIGN_IMPL,
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swap::ALMOST_SWAPPED,
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@ -980,6 +985,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry<'_>, conf: &Conf) {
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methods::SINGLE_CHAR_PATTERN,
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misc::CMP_OWNED,
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mutex_atomic::MUTEX_ATOMIC,
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slow_vector_initialization::SLOW_VECTOR_INITIALIZATION,
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trivially_copy_pass_by_ref::TRIVIALLY_COPY_PASS_BY_REF,
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types::BOX_VEC,
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vec::USELESS_VEC,
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398
clippy_lints/src/slow_vector_initialization.rs
Normal file
398
clippy_lints/src/slow_vector_initialization.rs
Normal file
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@ -0,0 +1,398 @@
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// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use crate::rustc::hir::intravisit::{walk_expr, walk_stmt, walk_block, NestedVisitorMap, Visitor};
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use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass, Lint};
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use crate::rustc::{declare_tool_lint, lint_array};
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use crate::rustc::hir::*;
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use if_chain::if_chain;
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use crate::syntax_pos::symbol::Symbol;
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use crate::syntax::ast::{LitKind, NodeId};
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use crate::utils::{match_qpath, span_lint_and_then, SpanlessEq, get_enclosing_block};
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use crate::utils::sugg::Sugg;
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use crate::rustc_errors::{Applicability};
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/// **What it does:** Checks slow zero-filled vector initialization
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///
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/// **Why is this bad?** This structures are non-idiomatic and less efficient than simply using
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/// `vec![len; 0]`.
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///
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/// **Known problems:** None.
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///
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/// **Example:**
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/// ```rust
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/// let mut vec1 = Vec::with_capacity(len);
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/// vec1.resize(len, 0);
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///
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/// let mut vec2 = Vec::with_capacity(len);
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/// vec2.extend(repeat(0).take(len))
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/// ```
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declare_clippy_lint! {
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pub SLOW_VECTOR_INITIALIZATION,
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perf,
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"slow vector initialization"
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}
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/// **What it does:** Checks unsafe vector initialization
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///
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/// **Why is this bad?** Changing the length of a vector may expose uninitialized memory, which
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/// can lead to memory safety issues
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///
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/// **Known problems:** None.
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///
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/// **Example:**
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/// ```rust
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/// let mut vec1 = Vec::with_capacity(len);
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/// unsafe { vec1.set_len(len); }
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/// ```
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declare_clippy_lint! {
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pub UNSAFE_VECTOR_INITIALIZATION,
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correctness,
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"unsafe vector initialization"
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}
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#[derive(Copy, Clone, Default)]
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pub struct Pass;
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impl LintPass for Pass {
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fn get_lints(&self) -> LintArray {
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lint_array!(
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SLOW_VECTOR_INITIALIZATION,
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UNSAFE_VECTOR_INITIALIZATION,
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)
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}
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}
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/// `VecAllocation` contains data regarding a vector allocated with `with_capacity` and then
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/// assigned to a variable. For example, `let mut vec = Vec::with_capacity(0)` or
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/// `vec = Vec::with_capacity(0)`
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struct VecAllocation<'tcx> {
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/// Symbol of the local variable name
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variable_name: Symbol,
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/// Reference to the expression which allocates the vector
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allocation_expr: &'tcx Expr,
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/// Reference to the expression used as argument on `with_capacity` call. This is used
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/// to only match slow zero-filling idioms of the same length than vector initialization.
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len_expr: &'tcx Expr,
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}
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/// Type of slow initialization
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enum InitializationType<'tcx> {
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/// Extend is a slow initialization with the form `vec.extend(repeat(0).take(..))`
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Extend(&'tcx Expr),
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/// Resize is a slow initialization with the form `vec.resize(.., 0)`
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Resize(&'tcx Expr),
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/// UnsafeSetLen is a slow initialization with the form `vec.set_len(..)`
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UnsafeSetLen(&'tcx Expr),
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}
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impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
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fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
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// Matches initialization on reassignements. For example: `vec = Vec::with_capacity(100)`
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if_chain! {
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if let ExprKind::Assign(ref left, ref right) = expr.node;
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// Extract variable name
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if let ExprKind::Path(QPath::Resolved(_, ref path)) = left.node;
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if let Some(variable_name) = path.segments.get(0);
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// Extract len argument
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if let Some(ref len_arg) = Self::is_vec_with_capacity(right);
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then {
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let vi = VecAllocation {
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variable_name: variable_name.ident.name,
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allocation_expr: right,
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len_expr: len_arg,
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};
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Self::search_initialization(cx, vi, expr.id);
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}
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}
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}
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fn check_stmt(&mut self, cx: &LateContext<'a, 'tcx>, stmt: &'tcx Stmt) {
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// Matches statements which initializes vectors. For example: `let mut vec = Vec::with_capacity(10)`
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if_chain! {
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if let StmtKind::Decl(ref decl, _) = stmt.node;
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if let DeclKind::Local(ref local) = decl.node;
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if let PatKind::Binding(BindingAnnotation::Mutable, _, variable_name, None) = local.pat.node;
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if let Some(ref init) = local.init;
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if let Some(ref len_arg) = Self::is_vec_with_capacity(init);
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then {
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let vi = VecAllocation {
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variable_name: variable_name.name,
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allocation_expr: init,
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len_expr: len_arg,
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};
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Self::search_initialization(cx, vi, stmt.node.id());
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}
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}
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}
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}
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impl Pass {
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/// Checks if the given expression is `Vec::with_capacity(..)`. It will return the expression
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/// of the first argument of `with_capacity` call if it matches or `None` if it does not.
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fn is_vec_with_capacity(expr: &Expr) -> Option<&Expr> {
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if_chain! {
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if let ExprKind::Call(ref func, ref args) = expr.node;
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if let ExprKind::Path(ref path) = func.node;
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if match_qpath(path, &["Vec", "with_capacity"]);
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if args.len() == 1;
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then {
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return Some(&args[0]);
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}
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}
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None
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}
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/// Search initialization for the given vector
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fn search_initialization<'tcx>(
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cx: &LateContext<'_, 'tcx>,
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vec_alloc: VecAllocation<'tcx>,
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parent_node: NodeId
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) {
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let enclosing_body = get_enclosing_block(cx, parent_node);
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if enclosing_body.is_none() {
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return;
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}
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let mut v = VectorInitializationVisitor {
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cx,
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vec_alloc,
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slow_expression: None,
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initialization_found: false,
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};
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v.visit_block(enclosing_body.unwrap());
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if let Some(ref allocation_expr) = v.slow_expression {
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Self::lint_initialization(cx, allocation_expr, &v.vec_alloc);
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}
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}
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fn lint_initialization<'tcx>(cx: &LateContext<'_, 'tcx>, initialization: &InitializationType<'tcx>, vec_alloc: &VecAllocation<'_>) {
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match initialization {
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InitializationType::UnsafeSetLen(e) =>
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Self::emit_lint(
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cx,
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e,
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vec_alloc,
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"unsafe vector initialization",
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UNSAFE_VECTOR_INITIALIZATION
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),
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InitializationType::Extend(e) |
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InitializationType::Resize(e) =>
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Self::emit_lint(
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cx,
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e,
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vec_alloc,
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"slow zero-filling initialization",
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SLOW_VECTOR_INITIALIZATION
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)
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};
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}
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fn emit_lint<'tcx>(
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cx: &LateContext<'_, 'tcx>,
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slow_fill: &Expr,
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vec_alloc: &VecAllocation<'_>,
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msg: &str,
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lint: &'static Lint
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) {
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let len_expr = Sugg::hir(cx, vec_alloc.len_expr, "len");
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span_lint_and_then(
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cx,
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lint,
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slow_fill.span,
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msg,
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|db| {
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db.span_suggestion_with_applicability(
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vec_alloc.allocation_expr.span,
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"consider replace allocation with",
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format!("vec![0; {}]", len_expr),
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Applicability::Unspecified
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);
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}
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);
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}
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}
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/// `VectorInitializationVisitor` searches for unsafe or slow vector initializations for the given
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/// vector.
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struct VectorInitializationVisitor<'a, 'tcx: 'a> {
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cx: &'a LateContext<'a, 'tcx>,
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/// Contains the information
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vec_alloc: VecAllocation<'tcx>,
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/// Contains, if found, the slow initialization expression
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slow_expression: Option<InitializationType<'tcx>>,
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/// true if the initialization of the vector has been found on the visited block
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initialization_found: bool,
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}
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impl<'a, 'tcx> VectorInitializationVisitor<'a, 'tcx> {
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/// Checks if the given expression is extending a vector with `repeat(0).take(..)`
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fn search_slow_extend_filling(&mut self, expr: &'tcx Expr) {
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if_chain! {
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if self.initialization_found;
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if let ExprKind::MethodCall(ref path, _, ref args) = expr.node;
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if let ExprKind::Path(ref qpath_subj) = args[0].node;
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if match_qpath(&qpath_subj, &[&self.vec_alloc.variable_name.to_string()]);
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if path.ident.name == "extend";
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if let Some(ref extend_arg) = args.get(1);
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if self.is_repeat_take(extend_arg);
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then {
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self.slow_expression = Some(InitializationType::Extend(expr));
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}
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}
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}
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/// Checks if the given expression is resizing a vector with 0
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fn search_slow_resize_filling(&mut self, expr: &'tcx Expr) {
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if_chain! {
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if self.initialization_found;
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if let ExprKind::MethodCall(ref path, _, ref args) = expr.node;
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if let ExprKind::Path(ref qpath_subj) = args[0].node;
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if match_qpath(&qpath_subj, &[&self.vec_alloc.variable_name.to_string()]);
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if path.ident.name == "resize";
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if let (Some(ref len_arg), Some(fill_arg)) = (args.get(1), args.get(2));
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// Check that is filled with 0
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if let ExprKind::Lit(ref lit) = fill_arg.node;
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if let LitKind::Int(0, _) = lit.node;
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// Check that len expression is equals to `with_capacity` expression
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if SpanlessEq::new(self.cx).eq_expr(len_arg, self.vec_alloc.len_expr);
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then {
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self.slow_expression = Some(InitializationType::Resize(expr));
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}
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}
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}
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/// Checks if the given expression is using `set_len` to initialize the vector
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fn search_unsafe_set_len(&mut self, expr: &'tcx Expr) {
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if_chain! {
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if self.initialization_found;
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if let ExprKind::MethodCall(ref path, _, ref args) = expr.node;
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if let ExprKind::Path(ref qpath_subj) = args[0].node;
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if match_qpath(&qpath_subj, &[&self.vec_alloc.variable_name.to_string()]);
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if path.ident.name == "set_len";
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if let Some(ref len_arg) = args.get(1);
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// Check that len expression is equals to `with_capacity` expression
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if SpanlessEq::new(self.cx).eq_expr(len_arg, self.vec_alloc.len_expr);
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then {
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self.slow_expression = Some(InitializationType::UnsafeSetLen(expr));
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}
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}
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}
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/// Returns `true` if give expression is `repeat(0).take(...)`
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fn is_repeat_take(&self, expr: &Expr) -> bool {
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if_chain! {
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if let ExprKind::MethodCall(ref take_path, _, ref take_args) = expr.node;
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if take_path.ident.name == "take";
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// Check that take is applied to `repeat(0)`
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if let Some(ref repeat_expr) = take_args.get(0);
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if self.is_repeat_zero(repeat_expr);
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// Check that len expression is equals to `with_capacity` expression
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if let Some(ref len_arg) = take_args.get(1);
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if SpanlessEq::new(self.cx).eq_expr(len_arg, self.vec_alloc.len_expr);
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then {
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return true;
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}
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}
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false
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}
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/// Returns `true` if given expression is `repeat(0)`
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fn is_repeat_zero(&self, expr: &Expr) -> bool {
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if_chain! {
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if let ExprKind::Call(ref fn_expr, ref repeat_args) = expr.node;
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if let ExprKind::Path(ref qpath_repeat) = fn_expr.node;
|
||||
if match_qpath(&qpath_repeat, &["repeat"]);
|
||||
if let Some(ref repeat_arg) = repeat_args.get(0);
|
||||
if let ExprKind::Lit(ref lit) = repeat_arg.node;
|
||||
if let LitKind::Int(0, _) = lit.node;
|
||||
|
||||
then {
|
||||
return true
|
||||
}
|
||||
}
|
||||
|
||||
false
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, 'tcx> Visitor<'tcx> for VectorInitializationVisitor<'a, 'tcx> {
|
||||
fn visit_stmt(&mut self, stmt: &'tcx Stmt) {
|
||||
if self.initialization_found {
|
||||
match stmt.node {
|
||||
StmtKind::Expr(ref expr, _) |
|
||||
StmtKind::Semi(ref expr, _) => {
|
||||
self.search_slow_extend_filling(expr);
|
||||
self.search_slow_resize_filling(expr);
|
||||
self.search_unsafe_set_len(expr);
|
||||
},
|
||||
_ => (),
|
||||
}
|
||||
|
||||
self.initialization_found = false;
|
||||
} else {
|
||||
walk_stmt(self, stmt);
|
||||
}
|
||||
}
|
||||
|
||||
fn visit_block(&mut self, block: &'tcx Block) {
|
||||
if self.initialization_found {
|
||||
if let Some(ref s) = block.stmts.get(0) {
|
||||
self.visit_stmt( s)
|
||||
}
|
||||
|
||||
self.initialization_found = false;
|
||||
} else {
|
||||
walk_block(self, block);
|
||||
}
|
||||
}
|
||||
|
||||
fn visit_expr(&mut self, expr: &'tcx Expr) {
|
||||
// Skip all the expressions previous to the vector initialization
|
||||
if self.vec_alloc.allocation_expr.id == expr.id {
|
||||
self.initialization_found = true;
|
||||
}
|
||||
|
||||
walk_expr(self, expr);
|
||||
}
|
||||
|
||||
fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
|
||||
NestedVisitorMap::None
|
||||
}
|
||||
}
|
||||
83
tests/ui/slow_vector_initialization.rs
Normal file
83
tests/ui/slow_vector_initialization.rs
Normal file
|
|
@ -0,0 +1,83 @@
|
|||
// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
|
||||
// file at the top-level directory of this distribution.
|
||||
//
|
||||
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
||||
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
||||
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
||||
// option. This file may not be copied, modified, or distributed
|
||||
// except according to those terms.
|
||||
|
||||
use std::iter::repeat;
|
||||
|
||||
fn main() {
|
||||
resize_vector();
|
||||
extend_vector();
|
||||
mixed_extend_resize_vector();
|
||||
unsafe_vector();
|
||||
}
|
||||
|
||||
fn extend_vector() {
|
||||
// Extend with constant expression
|
||||
let len = 300;
|
||||
let mut vec1 = Vec::with_capacity(len);
|
||||
vec1.extend(repeat(0).take(len));
|
||||
|
||||
// Extend with len expression
|
||||
let mut vec2 = Vec::with_capacity(len - 10);
|
||||
vec2.extend(repeat(0).take(len - 10));
|
||||
|
||||
// Extend with mismatching expression should not be warned
|
||||
let mut vec3 = Vec::with_capacity(24322);
|
||||
vec3.extend(repeat(0).take(2));
|
||||
}
|
||||
|
||||
fn mixed_extend_resize_vector() {
|
||||
// Mismatching len
|
||||
let mut mismatching_len = Vec::with_capacity(30);
|
||||
mismatching_len.extend(repeat(0).take(40));
|
||||
|
||||
// Slow initialization
|
||||
let mut resized_vec = Vec::with_capacity(30);
|
||||
resized_vec.resize(30, 0);
|
||||
|
||||
let mut extend_vec = Vec::with_capacity(30);
|
||||
extend_vec.extend(repeat(0).take(30));
|
||||
}
|
||||
|
||||
fn resize_vector() {
|
||||
// Resize with constant expression
|
||||
let len = 300;
|
||||
let mut vec1 = Vec::with_capacity(len);
|
||||
vec1.resize(len, 0);
|
||||
|
||||
// Resize mismatch len
|
||||
let mut vec2 = Vec::with_capacity(200);
|
||||
vec2.resize(10, 0);
|
||||
|
||||
// Resize with len expression
|
||||
let mut vec3 = Vec::with_capacity(len - 10);
|
||||
vec3.resize(len - 10, 0);
|
||||
|
||||
// Reinitialization should be warned
|
||||
vec1 = Vec::with_capacity(10);
|
||||
vec1.resize(10, 0);
|
||||
}
|
||||
|
||||
fn unsafe_vector() {
|
||||
let mut unsafe_vec: Vec<u8> = Vec::with_capacity(200);
|
||||
|
||||
unsafe {
|
||||
unsafe_vec.set_len(200);
|
||||
}
|
||||
}
|
||||
|
||||
fn do_stuff(vec: &mut Vec<u8>) {
|
||||
|
||||
}
|
||||
|
||||
fn extend_vector_with_manipulations_between() {
|
||||
let len = 300;
|
||||
let mut vec1:Vec<u8> = Vec::with_capacity(len);
|
||||
do_stuff(&mut vec1);
|
||||
vec1.extend(repeat(0).take(len));
|
||||
}
|
||||
71
tests/ui/slow_vector_initialization.stderr
Normal file
71
tests/ui/slow_vector_initialization.stderr
Normal file
|
|
@ -0,0 +1,71 @@
|
|||
error: slow zero-filling initialization
|
||||
--> $DIR/slow_vector_initialization.rs:23:5
|
||||
|
|
||||
22 | let mut vec1 = Vec::with_capacity(len);
|
||||
| ----------------------- help: consider replace allocation with: `vec![0; len]`
|
||||
23 | vec1.extend(repeat(0).take(len));
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
||||
|
|
||||
= note: `-D clippy::slow-vector-initialization` implied by `-D warnings`
|
||||
|
||||
error: slow zero-filling initialization
|
||||
--> $DIR/slow_vector_initialization.rs:27:5
|
||||
|
|
||||
26 | let mut vec2 = Vec::with_capacity(len - 10);
|
||||
| ---------------------------- help: consider replace allocation with: `vec![0; len - 10]`
|
||||
27 | vec2.extend(repeat(0).take(len - 10));
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
||||
|
||||
error: slow zero-filling initialization
|
||||
--> $DIR/slow_vector_initialization.rs:41:5
|
||||
|
|
||||
40 | let mut resized_vec = Vec::with_capacity(30);
|
||||
| ---------------------- help: consider replace allocation with: `vec![0; 30]`
|
||||
41 | resized_vec.resize(30, 0);
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^
|
||||
|
||||
error: slow zero-filling initialization
|
||||
--> $DIR/slow_vector_initialization.rs:44:5
|
||||
|
|
||||
43 | let mut extend_vec = Vec::with_capacity(30);
|
||||
| ---------------------- help: consider replace allocation with: `vec![0; 30]`
|
||||
44 | extend_vec.extend(repeat(0).take(30));
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
||||
|
||||
error: slow zero-filling initialization
|
||||
--> $DIR/slow_vector_initialization.rs:51:5
|
||||
|
|
||||
50 | let mut vec1 = Vec::with_capacity(len);
|
||||
| ----------------------- help: consider replace allocation with: `vec![0; len]`
|
||||
51 | vec1.resize(len, 0);
|
||||
| ^^^^^^^^^^^^^^^^^^^
|
||||
|
||||
error: slow zero-filling initialization
|
||||
--> $DIR/slow_vector_initialization.rs:59:5
|
||||
|
|
||||
58 | let mut vec3 = Vec::with_capacity(len - 10);
|
||||
| ---------------------------- help: consider replace allocation with: `vec![0; len - 10]`
|
||||
59 | vec3.resize(len - 10, 0);
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^
|
||||
|
||||
error: slow zero-filling initialization
|
||||
--> $DIR/slow_vector_initialization.rs:63:5
|
||||
|
|
||||
62 | vec1 = Vec::with_capacity(10);
|
||||
| ---------------------- help: consider replace allocation with: `vec![0; 10]`
|
||||
63 | vec1.resize(10, 0);
|
||||
| ^^^^^^^^^^^^^^^^^^
|
||||
|
||||
error: unsafe vector initialization
|
||||
--> $DIR/slow_vector_initialization.rs:70:9
|
||||
|
|
||||
67 | let mut unsafe_vec: Vec<u8> = Vec::with_capacity(200);
|
||||
| ----------------------- help: consider replace allocation with: `vec![0; 200]`
|
||||
...
|
||||
70 | unsafe_vec.set_len(200);
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^
|
||||
|
|
||||
= note: #[deny(clippy::unsafe_vector_initialization)] on by default
|
||||
|
||||
error: aborting due to 8 previous errors
|
||||
|
||||
0
tests/ui/slow_vector_initialization.stdout
Normal file
0
tests/ui/slow_vector_initialization.stdout
Normal file
Loading…
Reference in a new issue