From 75d5f107ddbac9e0872f1551e70dfbf5d441f3e0 Mon Sep 17 00:00:00 2001
From: Morten Lohne <lohnemorten@gmail.com>
Date: Thu, 10 Aug 2023 01:14:19 +0200
Subject: [PATCH] Bugfix: 'can_have_side_effects()' would return 'false' for
struct/enum/array/tuple literals unless *all* sub-expressions had side
effects. This would easily allow side effects to slip through, and also
wrongly label empty literals as having side effects. Add some tests for the
last point
---
compiler/rustc_hir/src/hir.rs | 4 +--
.../in-trait/return-type-suggestion.rs | 1 -
.../in-trait/return-type-suggestion.stderr | 4 +--
tests/ui/return/return-struct.rs | 24 +++++++++++++
tests/ui/return/return-struct.stderr | 35 +++++++++++++++++++
5 files changed, 62 insertions(+), 6 deletions(-)
create mode 100644 tests/ui/return/return-struct.rs
create mode 100644 tests/ui/return/return-struct.stderr
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index 92a91766d91..6340f1dcca1 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -1843,7 +1843,7 @@ impl Expr<'_> {
.iter()
.map(|field| field.expr)
.chain(init.into_iter())
- .all(|e| e.can_have_side_effects()),
+ .any(|e| e.can_have_side_effects()),
ExprKind::Array(args)
| ExprKind::Tup(args)
@@ -1857,7 +1857,7 @@ impl Expr<'_> {
..
},
args,
- ) => args.iter().all(|arg| arg.can_have_side_effects()),
+ ) => args.iter().any(|arg| arg.can_have_side_effects()),
ExprKind::If(..)
| ExprKind::Match(..)
| ExprKind::MethodCall(..)
diff --git a/tests/ui/async-await/in-trait/return-type-suggestion.rs b/tests/ui/async-await/in-trait/return-type-suggestion.rs
index 92a9e035e89..cdab4ea0f37 100644
--- a/tests/ui/async-await/in-trait/return-type-suggestion.rs
+++ b/tests/ui/async-await/in-trait/return-type-suggestion.rs
@@ -6,7 +6,6 @@ trait A {
async fn e() {
Ok(())
//~^ ERROR mismatched types
- //~| HELP consider using a semicolon here
}
}
diff --git a/tests/ui/async-await/in-trait/return-type-suggestion.stderr b/tests/ui/async-await/in-trait/return-type-suggestion.stderr
index d9309459812..179c9ed93db 100644
--- a/tests/ui/async-await/in-trait/return-type-suggestion.stderr
+++ b/tests/ui/async-await/in-trait/return-type-suggestion.stderr
@@ -2,9 +2,7 @@ error[E0308]: mismatched types
--> $DIR/return-type-suggestion.rs:7:9
|
LL | Ok(())
- | ^^^^^^- help: consider using a semicolon here: `;`
- | |
- | expected `()`, found `Result<(), _>`
+ | ^^^^^^ expected `()`, found `Result<(), _>`
|
= note: expected unit type `()`
found enum `Result<(), _>`
diff --git a/tests/ui/return/return-struct.rs b/tests/ui/return/return-struct.rs
new file mode 100644
index 00000000000..446445c17ba
--- /dev/null
+++ b/tests/ui/return/return-struct.rs
@@ -0,0 +1,24 @@
+struct S;
+
+enum Age {
+ Years(i64, i64)
+}
+
+fn foo() {
+ let mut age = 29;
+ Age::Years({age += 1; age}, 55)
+ //~^ ERROR mismatched types
+}
+
+fn bar() {
+ let mut age = 29;
+ Age::Years(age, 55)
+ //~^ ERROR mismatched types
+}
+
+fn baz() {
+ S
+ //~^ ERROR mismatched types
+}
+
+fn main() {}
diff --git a/tests/ui/return/return-struct.stderr b/tests/ui/return/return-struct.stderr
new file mode 100644
index 00000000000..e6c0363e363
--- /dev/null
+++ b/tests/ui/return/return-struct.stderr
@@ -0,0 +1,35 @@
+error[E0308]: mismatched types
+ --> $DIR/return-struct.rs:9:5
+ |
+LL | Age::Years({age += 1; age}, 55)
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `()`, found `Age`
+ |
+help: consider using a semicolon here
+ |
+LL | Age::Years({age += 1; age}, 55);
+ | +
+help: try adding a return type
+ |
+LL | fn foo() -> Age {
+ | ++++++
+
+error[E0308]: mismatched types
+ --> $DIR/return-struct.rs:15:5
+ |
+LL | fn bar() {
+ | - help: try adding a return type: `-> Age`
+LL | let mut age = 29;
+LL | Age::Years(age, 55)
+ | ^^^^^^^^^^^^^^^^^^^ expected `()`, found `Age`
+
+error[E0308]: mismatched types
+ --> $DIR/return-struct.rs:20:5
+ |
+LL | fn baz() {
+ | - help: try adding a return type: `-> S`
+LL | S
+ | ^ expected `()`, found `S`
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0308`.