map_entry: the insert suggestion doesn't take into account #[cfg]-d-out code and comments #15781
Description
Summary
Normally, if a block that contains insert contains anything else, or_insert_with is suggested, and if it's the only thing in the block, then or_insert is suggested instead. But if the only other things that the block contains are statements that are #[cfg]-d out, or comments, then they get ignored by the lint, and an or_insert is suggested that doesn't contain them.
Reproducer
I tried this code:
#![allow(unused)]
#![warn(clippy::map_entry)]
fn very_important_fn() {}
fn foo(m: &mut std::collections::HashMap<i32, i32>, k: i32, v: i32) {
if !m.contains_key(&k) {
// very important comment
#[cfg(test)]
very_important_fn();
m.insert(k, v);
}
}I expected to see this happen:
warning: usage of `contains_key` followed by `insert` on a `HashMap`
--> src/main.rs:7:5
|
7 | / if !m.contains_key(&k) {
8 | | // very important comment
9 | | #[cfg(test)]
10 | | very_important_fn();
11 | | m.insert(k, v);
12 | | }
| |_____^
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_entry
note: the lint level is defined here
--> src/main.rs:2:9
|
2 | #![warn(clippy::map_entry)]
| ^^^^^^^^^^^^^^^^^
help: try
|
7 ~ m.entry(k).or_insert_with(|| {
8 + // very important comment
9 + #[cfg(test)]
10 + very_important_fn();
11 + v
12 + });
|
Instead, this happened:
warning: usage of `contains_key` followed by `insert` on a `HashMap`
--> src/main.rs:7:5
|
7 | / if !m.contains_key(&k) {
8 | | // very important comment
9 | | #[cfg(test)]
10 | | very_important_fn();
11 | | m.insert(k, v);
12 | | }
| |_____^ help: try: `m.entry(k).or_insert(v);`
|
And if I make change the cfg condition to something that's true:
fn foo(m: &mut std::collections::HashMap<i32, i32>, k: i32, v: i32) {
if !m.contains_key(&k) {
// very important comment
#[cfg(not(test))]
very_important_fn();
m.insert(k, v);
}
}I get the correct suggestion again:
help: try
|
7 ~ m.entry(k).or_insert_with(|| {
8 + // very important comment
9 + #[cfg(not(test))]
10 + very_important_fn();
11 + v
12 + });
|
Version
rustc 1.90.0 (1159e78c4 2025-09-14)
binary: rustc
commit-hash: 1159e78c4747b02ef996e55082b704c09b970588
commit-date: 2025-09-14
host: x86_64-unknown-linux-gnu
release: 1.90.0
LLVM version: 20.1.8
rustc 1.92.0-nightly (c8905eaa6 2025-09-28)
binary: rustc
commit-hash: c8905eaa66e0c35a33626e974b9ce6955c739b5b
commit-date: 2025-09-28
host: x86_64-unknown-linux-gnu
release: 1.92.0-nightly
LLVM version: 21.1.2
Additional Labels
@rustbot label I-suggestion-causes-bug