-use crate::rustc::hir::*;
-use crate::rustc::hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
-use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use crate::rustc::{declare_tool_lint, lint_array};
-use if_chain::if_chain;
-use crate::syntax::source_map::Span;
use crate::utils::SpanlessEq;
-use crate::utils::{get_item_name, match_type, paths, snippet, span_lint_and_then, walk_ptrs_ty};
-use crate::rustc_errors::Applicability;
+use crate::utils::{get_item_name, higher, match_type, paths, snippet, snippet_opt};
+use crate::utils::{snippet_with_applicability, span_lint_and_then, walk_ptrs_ty};
+use if_chain::if_chain;
+use rustc::declare_lint_pass;
+use rustc::hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
+use rustc::hir::*;
+use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use rustc_errors::Applicability;
+use rustc_session::declare_tool_lint;
+use syntax::source_map::Span;
-/// **What it does:** Checks for uses of `contains_key` + `insert` on `HashMap`
-/// or `BTreeMap`.
-///
-/// **Why is this bad?** Using `entry` is more efficient.
-///
-/// **Known problems:** Some false negatives, eg.:
-/// ```rust
-/// let k = &key;
-/// if !m.contains_key(k) { m.insert(k.clone(), v); }
-/// ```
-///
-/// **Example:**
-/// ```rust
-/// if !m.contains_key(&k) { m.insert(k, v) }
-/// ```
-/// can be rewritten as:
-/// ```rust
-/// m.entry(k).or_insert(v);
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for uses of `contains_key` + `insert` on `HashMap`
+ /// or `BTreeMap`.
+ ///
+ /// **Why is this bad?** Using `entry` is more efficient.
+ ///
+ /// **Known problems:** Some false negatives, eg.:
+ /// ```rust
+ /// # use std::collections::HashMap;
+ /// # let mut map = HashMap::new();
+ /// # let v = 1;
+ /// # let k = 1;
+ /// if !map.contains_key(&k) {
+ /// map.insert(k.clone(), v);
+ /// }
+ /// ```
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # use std::collections::HashMap;
+ /// # let mut map = HashMap::new();
+ /// # let k = 1;
+ /// # let v = 1;
+ /// if !map.contains_key(&k) {
+ /// map.insert(k, v);
+ /// }
+ /// ```
+ /// can both be rewritten as:
+ /// ```rust
+ /// # use std::collections::HashMap;
+ /// # let mut map = HashMap::new();
+ /// # let k = 1;
+ /// # let v = 1;
+ /// map.entry(k).or_insert(v);
+ /// ```
pub MAP_ENTRY,
perf,
"use of `contains_key` followed by `insert` on a `HashMap` or `BTreeMap`"
}
-#[derive(Copy, Clone)]
-pub struct HashMapLint;
-
-impl LintPass for HashMapLint {
- fn get_lints(&self) -> LintArray {
- lint_array!(MAP_ENTRY)
- }
-}
+declare_lint_pass!(HashMapPass => [MAP_ENTRY]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for HashMapLint {
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for HashMapPass {
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
- if let ExprKind::If(ref check, ref then_block, ref else_block) = expr.node {
- if let ExprKind::Unary(UnOp::UnNot, ref check) = check.node {
+ if let Some((ref check, ref then_block, ref else_block)) = higher::if_block(&expr) {
+ if let ExprKind::Unary(UnOp::UnNot, ref check) = check.kind {
if let Some((ty, map, key)) = check_cond(cx, check) {
// in case of `if !m.contains_key(&k) { m.insert(k, v); }`
// we can give a better error message
let sole_expr = {
- else_block.is_none() && if let ExprKind::Block(ref then_block, _) = then_block.node {
- (then_block.expr.is_some() as usize) + then_block.stmts.len() == 1
- } else {
- true
- }
+ else_block.is_none()
+ && if let ExprKind::Block(ref then_block, _) = then_block.kind {
+ (then_block.expr.is_some() as usize) + then_block.stmts.len() == 1
+ } else {
+ true
+ }
+ // XXXManishearth we can also check for if/else blocks containing `None`.
};
let mut visitor = InsertVisitor {
check: &'b Expr,
) -> Option<(&'static str, &'b Expr, &'b Expr)> {
if_chain! {
- if let ExprKind::MethodCall(ref path, _, ref params) = check.node;
+ if let ExprKind::MethodCall(ref path, _, ref params) = check.kind;
if params.len() >= 2;
- if path.ident.name == "contains_key";
- if let ExprKind::AddrOf(_, ref key) = params[1].node;
+ if path.ident.name == sym!(contains_key);
+ if let ExprKind::AddrOf(BorrowKind::Ref, _, ref key) = params[1].kind;
then {
let map = ¶ms[0];
let obj_ty = walk_ptrs_ty(cx.tables.expr_ty(map));
None
}
-struct InsertVisitor<'a, 'tcx: 'a, 'b> {
+struct InsertVisitor<'a, 'tcx, 'b> {
cx: &'a LateContext<'a, 'tcx>,
span: Span,
ty: &'static str,
impl<'a, 'tcx, 'b> Visitor<'tcx> for InsertVisitor<'a, 'tcx, 'b> {
fn visit_expr(&mut self, expr: &'tcx Expr) {
if_chain! {
- if let ExprKind::MethodCall(ref path, _, ref params) = expr.node;
+ if let ExprKind::MethodCall(ref path, _, ref params) = expr.kind;
if params.len() == 3;
- if path.ident.name == "insert";
+ if path.ident.name == sym!(insert);
if get_item_name(self.cx, self.map) == get_item_name(self.cx, ¶ms[0]);
if SpanlessEq::new(self.cx).eq_expr(self.key, ¶ms[1]);
+ if snippet_opt(self.cx, self.map.span) == snippet_opt(self.cx, params[0].span);
then {
span_lint_and_then(self.cx, MAP_ENTRY, self.span,
&format!("usage of `contains_key` followed by `insert` on a `{}`", self.ty), |db| {
if self.sole_expr {
- let help = format!("{}.entry({}).or_insert({})",
- snippet(self.cx, self.map.span, "map"),
- snippet(self.cx, params[1].span, ".."),
- snippet(self.cx, params[2].span, ".."));
+ let mut app = Applicability::MachineApplicable;
+ let help = format!("{}.entry({}).or_insert({});",
+ snippet_with_applicability(self.cx, self.map.span, "map", &mut app),
+ snippet_with_applicability(self.cx, params[1].span, "..", &mut app),
+ snippet_with_applicability(self.cx, params[2].span, "..", &mut app));
- db.span_suggestion_with_applicability(
+ db.span_suggestion(
self.span,
"consider using",
help,
- Applicability::Unspecified,
+ Applicability::MachineApplicable, // snippet
);
}
else {
- let help = format!("{}.entry({})",
+ let help = format!("consider using `{}.entry({})`",
snippet(self.cx, self.map.span, "map"),
snippet(self.cx, params[1].span, ".."));
- db.span_suggestion_with_applicability(
+ db.span_label(
self.span,
- "consider using",
- help,
- Applicability::Unspecified,
+ &help,
);
}
});
projects / rust.git / blobdiff