-// 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 crate::rustc::hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
-use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass, Lint};
-use crate::rustc::{declare_tool_lint, lint_array};
-use crate::rustc::hir::*;
-use if_chain::if_chain;
-use crate::syntax_pos::symbol::Symbol;
-use crate::syntax::ast::{LitKind, NodeId};
-use crate::utils::{match_qpath, span_lint_and_then, SpanlessEq, get_enclosing_block};
use crate::utils::sugg::Sugg;
-use crate::rustc_errors::{Applicability};
-
-/// **What it does:** Checks slow zero-filled vector initialization
-///
-/// **Why is this bad?** This structures are non-idiomatic and less efficient than simply using
-/// `vec![len; 0]`.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// let mut vec1 = Vec::with_capacity(len);
-/// vec1.resize(len, 0);
-///
-/// let mut vec2 = Vec::with_capacity(len);
-/// vec2.extend(repeat(0).take(len))
-/// ```
+use crate::utils::{get_enclosing_block, match_qpath, span_lint_and_then, SpanlessEq};
+use if_chain::if_chain;
+use rustc::hir::intravisit::{walk_block, walk_expr, walk_stmt, NestedVisitorMap, Visitor};
+use rustc::hir::*;
+use rustc::lint::{LateContext, LateLintPass, Lint, LintArray, LintPass};
+use rustc::{declare_tool_lint, lint_array};
+use rustc_errors::Applicability;
+use syntax::ast::LitKind;
+use syntax_pos::symbol::Symbol;
+
declare_clippy_lint! {
+ /// **What it does:** Checks slow zero-filled vector initialization
+ ///
+ /// **Why is this bad?** These structures are non-idiomatic and less efficient than simply using
+ /// `vec![0; len]`.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let mut vec1 = Vec::with_capacity(len);
+ /// vec1.resize(len, 0);
+ ///
+ /// let mut vec2 = Vec::with_capacity(len);
+ /// vec2.extend(repeat(0).take(len))
+ /// ```
pub SLOW_VECTOR_INITIALIZATION,
perf,
"slow vector initialization"
}
-/// **What it does:** Checks unsafe vector initialization
-///
-/// **Why is this bad?** Changing the length of a vector may expose uninitialized memory, which
-/// can lead to memory safety issues
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// let mut vec1 = Vec::with_capacity(len);
-/// unsafe { vec1.set_len(len); }
-/// ```
-declare_clippy_lint! {
- pub UNSAFE_VECTOR_INITIALIZATION,
- correctness,
- "unsafe vector initialization"
-}
-
#[derive(Copy, Clone, Default)]
pub struct Pass;
impl LintPass for Pass {
fn get_lints(&self) -> LintArray {
- lint_array!(
- SLOW_VECTOR_INITIALIZATION,
- UNSAFE_VECTOR_INITIALIZATION,
- )
+ lint_array!(SLOW_VECTOR_INITIALIZATION,)
+ }
+
+ fn name(&self) -> &'static str {
+ "SlowVectorInit"
}
}
/// Resize is a slow initialization with the form `vec.resize(.., 0)`
Resize(&'tcx Expr),
-
- /// UnsafeSetLen is a slow initialization with the form `vec.set_len(..)`
- UnsafeSetLen(&'tcx Expr),
}
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
len_expr: len_arg,
};
- Self::search_initialization(cx, vi, expr.id);
+ Self::search_initialization(cx, vi, expr.hir_id);
}
}
}
fn check_stmt(&mut self, cx: &LateContext<'a, 'tcx>, stmt: &'tcx Stmt) {
// Matches statements which initializes vectors. For example: `let mut vec = Vec::with_capacity(10)`
if_chain! {
- if let StmtKind::Decl(ref decl, _) = stmt.node;
- if let DeclKind::Local(ref local) = decl.node;
- if let PatKind::Binding(BindingAnnotation::Mutable, _, variable_name, None) = local.pat.node;
+ if let StmtKind::Local(ref local) = stmt.node;
+ if let PatKind::Binding(BindingAnnotation::Mutable, .., variable_name, None) = local.pat.node;
if let Some(ref init) = local.init;
if let Some(ref len_arg) = Self::is_vec_with_capacity(init);
len_expr: len_arg,
};
- Self::search_initialization(cx, vi, stmt.node.id());
+ Self::search_initialization(cx, vi, stmt.hir_id);
}
}
}
}
/// Search initialization for the given vector
- fn search_initialization<'tcx>(
- cx: &LateContext<'_, 'tcx>,
- vec_alloc: VecAllocation<'tcx>,
- parent_node: NodeId
- ) {
+ fn search_initialization<'tcx>(cx: &LateContext<'_, 'tcx>, vec_alloc: VecAllocation<'tcx>, parent_node: HirId) {
let enclosing_body = get_enclosing_block(cx, parent_node);
if enclosing_body.is_none() {
}
}
- fn lint_initialization<'tcx>(cx: &LateContext<'_, 'tcx>, initialization: &InitializationType<'tcx>, vec_alloc: &VecAllocation<'_>) {
+ fn lint_initialization<'tcx>(
+ cx: &LateContext<'_, 'tcx>,
+ initialization: &InitializationType<'tcx>,
+ vec_alloc: &VecAllocation<'_>,
+ ) {
match initialization {
- InitializationType::UnsafeSetLen(e) =>
- Self::emit_lint(
- cx,
- e,
- vec_alloc,
- "unsafe vector initialization",
- UNSAFE_VECTOR_INITIALIZATION
- ),
-
- InitializationType::Extend(e) |
- InitializationType::Resize(e) =>
- Self::emit_lint(
- cx,
- e,
- vec_alloc,
- "slow zero-filling initialization",
- SLOW_VECTOR_INITIALIZATION
- )
+ InitializationType::Extend(e) | InitializationType::Resize(e) => Self::emit_lint(
+ cx,
+ e,
+ vec_alloc,
+ "slow zero-filling initialization",
+ SLOW_VECTOR_INITIALIZATION,
+ ),
};
}
slow_fill: &Expr,
vec_alloc: &VecAllocation<'_>,
msg: &str,
- lint: &'static Lint
+ lint: &'static Lint,
) {
let len_expr = Sugg::hir(cx, vec_alloc.len_expr, "len");
- span_lint_and_then(
- cx,
- lint,
- slow_fill.span,
- msg,
- |db| {
- db.span_suggestion_with_applicability(
- vec_alloc.allocation_expr.span,
- "consider replace allocation with",
- format!("vec![0; {}]", len_expr),
- Applicability::Unspecified
- );
- }
- );
+ span_lint_and_then(cx, lint, slow_fill.span, msg, |db| {
+ db.span_suggestion(
+ vec_alloc.allocation_expr.span,
+ "consider replace allocation with",
+ format!("vec![0; {}]", len_expr),
+ Applicability::Unspecified,
+ );
+ });
}
}
struct VectorInitializationVisitor<'a, 'tcx: 'a> {
cx: &'a LateContext<'a, 'tcx>,
- /// Contains the information
+ /// Contains the information.
vec_alloc: VecAllocation<'tcx>,
- /// Contains, if found, the slow initialization expression
+ /// Contains the slow initialization expression, if one was found.
slow_expression: Option<InitializationType<'tcx>>,
- /// true if the initialization of the vector has been found on the visited block
+ /// `true` if the initialization of the vector has been found on the visited block.
initialization_found: bool,
}
}
}
- /// Checks if the given expression is using `set_len` to initialize the vector
- fn search_unsafe_set_len(&mut self, expr: &'tcx Expr) {
- if_chain! {
- if self.initialization_found;
- if let ExprKind::MethodCall(ref path, _, ref args) = expr.node;
- if let ExprKind::Path(ref qpath_subj) = args[0].node;
- if match_qpath(&qpath_subj, &[&self.vec_alloc.variable_name.to_string()]);
- if path.ident.name == "set_len";
- if let Some(ref len_arg) = args.get(1);
-
- // Check that len expression is equals to `with_capacity` expression
- if SpanlessEq::new(self.cx).eq_expr(len_arg, self.vec_alloc.len_expr);
-
- then {
- self.slow_expression = Some(InitializationType::UnsafeSetLen(expr));
- }
- }
- }
-
/// Returns `true` if give expression is `repeat(0).take(...)`
fn is_repeat_take(&self, expr: &Expr) -> bool {
if_chain! {
}
impl<'a, 'tcx> Visitor<'tcx> for VectorInitializationVisitor<'a, 'tcx> {
- fn visit_expr(&mut self, expr: &'tcx Expr) {
- // Stop the search if we already found a slow zero-filling initialization
- if self.slow_expression.is_some() {
- return
+ 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.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 {
+ if self.vec_alloc.allocation_expr.hir_id == expr.hir_id {
self.initialization_found = true;
}
-
- self.search_slow_extend_filling(expr);
- self.search_slow_resize_filling(expr);
- self.search_unsafe_set_len(expr);
walk_expr(self, expr);
}
projects / rust.git / blobdiff