mirror of
https://github.com/rust-lang/rust-clippy
synced 2024-11-23 21:23:56 +00:00
Merge pull request #689 from mcarton/entries
Improve the `MAP_ENTRY` lint
This commit is contained in:
llogiq
commit
b3ffc1868f
2 changed files with 103 additions and 59 deletions
128
src/entry.rs
128
src/entry.rs
|
|
@ -1,5 +1,6 @@
|
|||
use rustc::lint::*;
|
||||
use rustc_front::hir::*;
|
||||
use rustc_front::intravisit::{Visitor, walk_expr, walk_block};
|
||||
use syntax::codemap::Span;
|
||||
use utils::SpanlessEq;
|
||||
use utils::{BTREEMAP_PATH, HASHMAP_PATH};
|
||||
|
|
@ -41,73 +42,108 @@ impl LintPass for HashMapLint {
|
|||
|
||||
impl LateLintPass for HashMapLint {
|
||||
fn check_expr(&mut self, cx: &LateContext, expr: &Expr) {
|
||||
if_let_chain! {
|
||||
[
|
||||
let ExprIf(ref check, ref then, _) = expr.node,
|
||||
let ExprUnary(UnOp::UnNot, ref check) = check.node,
|
||||
let ExprMethodCall(ref name, _, ref params) = check.node,
|
||||
params.len() >= 2,
|
||||
name.node.as_str() == "contains_key"
|
||||
], {
|
||||
let key = match params[1].node {
|
||||
ExprAddrOf(_, ref key) => key,
|
||||
_ => return
|
||||
if let ExprIf(ref check, ref then_block, ref else_block) = expr.node {
|
||||
if let ExprUnary(UnOp::UnNot, ref check) = check.node {
|
||||
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 then_block.expr.is_some() { 1 } else { 0 } + then_block.stmts.len() == 1;
|
||||
|
||||
let mut visitor = InsertVisitor {
|
||||
cx: cx,
|
||||
span: expr.span,
|
||||
ty: ty,
|
||||
map: map,
|
||||
key: key,
|
||||
sole_expr: sole_expr,
|
||||
};
|
||||
|
||||
walk_block(&mut visitor, then_block);
|
||||
}
|
||||
} else if let Some(ref else_block) = *else_block {
|
||||
if let Some((ty, map, key)) = check_cond(cx, check) {
|
||||
let mut visitor = InsertVisitor {
|
||||
cx: cx,
|
||||
span: expr.span,
|
||||
ty: ty,
|
||||
map: map,
|
||||
key: key,
|
||||
sole_expr: false,
|
||||
};
|
||||
|
||||
walk_expr(&mut visitor, else_block);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn check_cond<'a, 'tcx, 'b>(cx: &'a LateContext<'a, 'tcx>, check: &'b Expr) -> Option<(&'static str, &'b Expr, &'b Expr)> {
|
||||
if_let_chain! {[
|
||||
let ExprMethodCall(ref name, _, ref params) = check.node,
|
||||
params.len() >= 2,
|
||||
name.node.as_str() == "contains_key",
|
||||
let ExprAddrOf(_, ref key) = params[1].node
|
||||
], {
|
||||
let map = ¶ms[0];
|
||||
let obj_ty = walk_ptrs_ty(cx.tcx.expr_ty(map));
|
||||
|
||||
let kind = if match_type(cx, obj_ty, &BTREEMAP_PATH) {
|
||||
"BTreeMap"
|
||||
return if match_type(cx, obj_ty, &BTREEMAP_PATH) {
|
||||
Some(("BTreeMap", map, key))
|
||||
}
|
||||
else if match_type(cx, obj_ty, &HASHMAP_PATH) {
|
||||
"HashMap"
|
||||
Some(("HashMap", map, key))
|
||||
}
|
||||
else {
|
||||
return
|
||||
None
|
||||
};
|
||||
}}
|
||||
|
||||
let sole_expr = if then.expr.is_some() { 1 } else { 0 } + then.stmts.len() == 1;
|
||||
|
||||
if let Some(ref then) = then.expr {
|
||||
check_for_insert(cx, expr.span, map, key, then, sole_expr, kind);
|
||||
}
|
||||
|
||||
for stmt in &then.stmts {
|
||||
if let StmtSemi(ref stmt, _) = stmt.node {
|
||||
check_for_insert(cx, expr.span, map, key, stmt, sole_expr, kind);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
None
|
||||
}
|
||||
|
||||
fn check_for_insert(cx: &LateContext, span: Span, map: &Expr, key: &Expr, expr: &Expr, sole_expr: bool, kind: &str) {
|
||||
if_let_chain! {
|
||||
[
|
||||
struct InsertVisitor<'a, 'tcx: 'a, 'b> {
|
||||
cx: &'a LateContext<'a, 'tcx>,
|
||||
span: Span,
|
||||
ty: &'static str,
|
||||
map: &'b Expr,
|
||||
key: &'b Expr,
|
||||
sole_expr: bool,
|
||||
}
|
||||
|
||||
impl<'a, 'tcx, 'v, 'b> Visitor<'v> for InsertVisitor<'a, 'tcx, 'b> {
|
||||
fn visit_expr(&mut self, expr: &'v Expr) {
|
||||
if_let_chain! {[
|
||||
let ExprMethodCall(ref name, _, ref params) = expr.node,
|
||||
params.len() == 3,
|
||||
name.node.as_str() == "insert",
|
||||
get_item_name(cx, map) == get_item_name(cx, &*params[0]),
|
||||
SpanlessEq::new(cx).eq_expr(key, ¶ms[1])
|
||||
get_item_name(self.cx, self.map) == get_item_name(self.cx, &*params[0]),
|
||||
SpanlessEq::new(self.cx).eq_expr(self.key, ¶ms[1])
|
||||
], {
|
||||
let help = if sole_expr {
|
||||
format!("{}.entry({}).or_insert({})",
|
||||
snippet(cx, map.span, "map"),
|
||||
snippet(cx, params[1].span, ".."),
|
||||
snippet(cx, params[2].span, ".."))
|
||||
|
||||
span_lint_and_then(self.cx, MAP_ENTRY, self.span,
|
||||
&format!("usage of `contains_key` followed by `insert` on `{}`", 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, ".."));
|
||||
|
||||
db.span_suggestion(self.span, "Consider using", help);
|
||||
}
|
||||
else {
|
||||
format!("{}.entry({})",
|
||||
snippet(cx, map.span, "map"),
|
||||
snippet(cx, params[1].span, ".."))
|
||||
};
|
||||
let help = format!("Consider using `{}.entry({})`",
|
||||
snippet(self.cx, self.map.span, "map"),
|
||||
snippet(self.cx, params[1].span, ".."));
|
||||
|
||||
span_lint_and_then(cx, MAP_ENTRY, span,
|
||||
&format!("usage of `contains_key` followed by `insert` on `{}`", kind), |db| {
|
||||
db.span_suggestion(span, "Consider using", help);
|
||||
db.span_note(self.span, &help);
|
||||
}
|
||||
});
|
||||
}}
|
||||
|
||||
if !self.sole_expr {
|
||||
walk_expr(self, expr);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
|
|||
|
|
@ -19,29 +19,37 @@ fn insert_if_absent0<K: Eq + Hash, V>(m: &mut HashMap<K, V>, k: K, v: V) {
|
|||
fn insert_if_absent1<K: Eq + Hash, V>(m: &mut HashMap<K, V>, k: K, v: V) {
|
||||
if !m.contains_key(&k) { foo(); m.insert(k, v); }
|
||||
//~^ ERROR usage of `contains_key` followed by `insert` on `HashMap`
|
||||
//~| HELP Consider
|
||||
//~| SUGGESTION m.entry(k)
|
||||
//~| NOTE Consider using `m.entry(k)`
|
||||
}
|
||||
|
||||
fn insert_if_absent2<K: Eq + Hash, V>(m: &mut HashMap<K, V>, k: K, v: V) {
|
||||
if !m.contains_key(&k) { m.insert(k, v) } else { None };
|
||||
//~^ ERROR usage of `contains_key` followed by `insert` on `HashMap`
|
||||
//~| HELP Consider
|
||||
//~| SUGGESTION m.entry(k).or_insert(v)
|
||||
//~| NOTE Consider using `m.entry(k)`
|
||||
}
|
||||
|
||||
fn insert_if_present2<K: Eq + Hash, V>(m: &mut HashMap<K, V>, k: K, v: V) {
|
||||
if m.contains_key(&k) { None } else { m.insert(k, v) };
|
||||
//~^ ERROR usage of `contains_key` followed by `insert` on `HashMap`
|
||||
//~| NOTE Consider using `m.entry(k)`
|
||||
}
|
||||
|
||||
fn insert_if_absent3<K: Eq + Hash, V>(m: &mut HashMap<K, V>, k: K, v: V) {
|
||||
if !m.contains_key(&k) { foo(); m.insert(k, v) } else { None };
|
||||
//~^ ERROR usage of `contains_key` followed by `insert` on `HashMap`
|
||||
//~| HELP Consider
|
||||
//~| SUGGESTION m.entry(k)
|
||||
//~| NOTE Consider using `m.entry(k)`
|
||||
}
|
||||
|
||||
fn insert_if_present3<K: Eq + Hash, V>(m: &mut HashMap<K, V>, k: K, v: V) {
|
||||
if m.contains_key(&k) { None } else { foo(); m.insert(k, v) };
|
||||
//~^ ERROR usage of `contains_key` followed by `insert` on `HashMap`
|
||||
//~| NOTE Consider using `m.entry(k)`
|
||||
}
|
||||
|
||||
fn insert_in_btreemap<K: Ord, V>(m: &mut BTreeMap<K, V>, k: K, v: V) {
|
||||
if !m.contains_key(&k) { foo(); m.insert(k, v) } else { None };
|
||||
//~^ ERROR usage of `contains_key` followed by `insert` on `BTreeMap`
|
||||
//~| HELP Consider
|
||||
//~| SUGGESTION m.entry(k)
|
||||
//~| NOTE Consider using `m.entry(k)`
|
||||
}
|
||||
|
||||
fn insert_other_if_absent<K: Eq + Hash, V>(m: &mut HashMap<K, V>, k: K, o: K, v: V) {
|
||||
|
|
|
|||
Loading…
Reference in a new issue