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Auto merge of #5132 - JohnTitor:fix-fp-in-unwrap-lint, r=flip1995

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Do not lint `unnecessary_unwrap` in external macros

Fixes #5131

I think we shouldn't lint `{panicking, unnecessary}_unwrap` in macros, not just `assert!`.

changelog: Fix false positive in `unnecessary_unwrap`
This commit is contained in:
bors 2020-02-06 14:17:35 +00:00
parent c1f8be074e 19ce66c1c1
commit a3135ba131
3 changed files with 40 additions and 13 deletions
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5
clippy_lints/src/unwrap.rs
View file

@ -1,6 +1,7 @@
use crate::utils::{higher::if_block, match_type, paths, span_lint_and_then, usage::is_potentially_mutated};
use if_chain::if_chain;
use rustc::hir::map::Map;
use rustc::lint::in_external_macro;
use rustc_hir::intravisit::*;
use rustc_hir::*;
use rustc_lint::{LateContext, LateLintPass};
@ -138,6 +139,10 @@ impl<'a, 'tcx> Visitor<'tcx> for UnwrappableVariablesVisitor<'a, 'tcx> {
type Map = Map<'tcx>;
fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
// Shouldn't lint when `expr` is in macro.
if in_external_macro(self.cx.tcx.sess, expr.span) {
return;
}
if let Some((cond, then, els)) = if_block(&expr) {
walk_expr(self, cond);
self.visit_branch(cond, then, false);

11
tests/ui/checked_unwrap/simple_conditionals.rs
View file

@ -1,6 +1,14 @@
#![deny(clippy::panicking_unwrap, clippy::unnecessary_unwrap)]
#![allow(clippy::if_same_then_else)]
macro_rules! m {
($a:expr) => {
if $a.is_some() {
$a.unwrap(); // unnecessary
}
};
}
fn main() {
let x = Some(());
if x.is_some() {
@ -13,6 +21,7 @@ fn main() {
} else {
x.unwrap(); // unnecessary
}
m!(x);
let mut x: Result<(), ()> = Ok(());
if x.is_ok() {
x.unwrap(); // unnecessary
@ -39,4 +48,6 @@ fn main() {
// it will always panic but the lint is not smart enough to see this (it
// only checks if conditions).
}
assert!(x.is_ok(), "{:?}", x.unwrap_err()); // ok, it's a common test pattern
}

37
tests/ui/checked_unwrap/simple_conditionals.stderr
View file

@ -1,5 +1,5 @@
error: You checked before that `unwrap()` cannot fail. Instead of checking and unwrapping, it's better to use `if let` or `match`.
--> $DIR/simple_conditionals.rs:7:9
--> $DIR/simple_conditionals.rs:15:9
|
LL | if x.is_some() {
| ----------- the check is happening here
@ -13,7 +13,7 @@ LL | #![deny(clippy::panicking_unwrap, clippy::unnecessary_unwrap)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^
error: This call to `unwrap()` will always panic.
--> $DIR/simple_conditionals.rs:9:9
--> $DIR/simple_conditionals.rs:17:9
|
LL | if x.is_some() {
| ----------- because of this check
@ -28,7 +28,7 @@ LL | #![deny(clippy::panicking_unwrap, clippy::unnecessary_unwrap)]
| ^^^^^^^^^^^^^^^^^^^^^^^^
error: This call to `unwrap()` will always panic.
--> $DIR/simple_conditionals.rs:12:9
--> $DIR/simple_conditionals.rs:20:9
|
LL | if x.is_none() {
| ----------- because of this check
@ -36,7 +36,7 @@ LL | x.unwrap(); // will panic
| ^^^^^^^^^^
error: You checked before that `unwrap()` cannot fail. Instead of checking and unwrapping, it's better to use `if let` or `match`.
--> $DIR/simple_conditionals.rs:14:9
--> $DIR/simple_conditionals.rs:22:9
|
LL | if x.is_none() {
| ----------- the check is happening here
@ -45,7 +45,18 @@ LL | x.unwrap(); // unnecessary
| ^^^^^^^^^^
error: You checked before that `unwrap()` cannot fail. Instead of checking and unwrapping, it's better to use `if let` or `match`.
--> $DIR/simple_conditionals.rs:18:9
--> $DIR/simple_conditionals.rs:7:13
|
LL | if $a.is_some() {
| ------------ the check is happening here
LL | $a.unwrap(); // unnecessary
| ^^^^^^^^^^^
...
LL | m!(x);
| ------ in this macro invocation
error: You checked before that `unwrap()` cannot fail. Instead of checking and unwrapping, it's better to use `if let` or `match`.
--> $DIR/simple_conditionals.rs:27:9
|
LL | if x.is_ok() {
| --------- the check is happening here
@ -53,7 +64,7 @@ LL | x.unwrap(); // unnecessary
| ^^^^^^^^^^
error: This call to `unwrap_err()` will always panic.
--> $DIR/simple_conditionals.rs:19:9
--> $DIR/simple_conditionals.rs:28:9
|
LL | if x.is_ok() {
| --------- because of this check
@ -62,7 +73,7 @@ LL | x.unwrap_err(); // will panic
| ^^^^^^^^^^^^^^
error: This call to `unwrap()` will always panic.
--> $DIR/simple_conditionals.rs:21:9
--> $DIR/simple_conditionals.rs:30:9
|
LL | if x.is_ok() {
| --------- because of this check
@ -71,7 +82,7 @@ LL | x.unwrap(); // will panic
| ^^^^^^^^^^
error: You checked before that `unwrap_err()` cannot fail. Instead of checking and unwrapping, it's better to use `if let` or `match`.
--> $DIR/simple_conditionals.rs:22:9
--> $DIR/simple_conditionals.rs:31:9
|
LL | if x.is_ok() {
| --------- the check is happening here
@ -80,7 +91,7 @@ LL | x.unwrap_err(); // unnecessary
| ^^^^^^^^^^^^^^
error: This call to `unwrap()` will always panic.
--> $DIR/simple_conditionals.rs:25:9
--> $DIR/simple_conditionals.rs:34:9
|
LL | if x.is_err() {
| ---------- because of this check
@ -88,7 +99,7 @@ LL | x.unwrap(); // will panic
| ^^^^^^^^^^
error: You checked before that `unwrap_err()` cannot fail. Instead of checking and unwrapping, it's better to use `if let` or `match`.
--> $DIR/simple_conditionals.rs:26:9
--> $DIR/simple_conditionals.rs:35:9
|
LL | if x.is_err() {
| ---------- the check is happening here
@ -97,7 +108,7 @@ LL | x.unwrap_err(); // unnecessary
| ^^^^^^^^^^^^^^
error: You checked before that `unwrap()` cannot fail. Instead of checking and unwrapping, it's better to use `if let` or `match`.
--> $DIR/simple_conditionals.rs:28:9
--> $DIR/simple_conditionals.rs:37:9
|
LL | if x.is_err() {
| ---------- the check is happening here
@ -106,7 +117,7 @@ LL | x.unwrap(); // unnecessary
| ^^^^^^^^^^
error: This call to `unwrap_err()` will always panic.
--> $DIR/simple_conditionals.rs:29:9
--> $DIR/simple_conditionals.rs:38:9
|
LL | if x.is_err() {
| ---------- because of this check
@ -114,5 +125,5 @@ LL | if x.is_err() {
LL | x.unwrap_err(); // will panic
| ^^^^^^^^^^^^^^
error: aborting due to 12 previous errors
error: aborting due to 13 previous errors