ICE(stable): thread 'rustc' panicked at 'called Option::unwrap() on a None value', compiler/rustc_middle/src/ty/instance.rs:434:85
#80706
Labels
A-associated-items
Area: Associated items (types, constants & functions)
A-async-await
Area: Async & Await
AsyncAwait-Triaged
Async-await issues that have been triaged during a working group meeting.
C-bug
Category: This is a bug.
E-needs-test
Call for participation: An issue has been fixed and does not reproduce, but no test has been added.
glacier
ICE tracked in rust-lang/glacier.
I-ICE
Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️
I-monomorphization
Issue: An error at monomorphization time.
P-high
High priority
regression-from-stable-to-stable
Performance or correctness regression from one stable version to another.
T-compiler
Relevant to the compiler team, which will review and decide on the PR/issue.
Comments
fominok
added
C-bug
|
Slightly smaller: use futures::future::BoxFuture;
fn main() {
f();
}
#[tokio::main]
async fn f() {
run("dependency").await;
}
struct InMemoryStorage;
struct User<'dep> {
dep: &'dep str,
}
impl<'a> StorageRequest<InMemoryStorage> for SaveUser<'a> {
fn execute(&self) -> BoxFuture<Result<(), String>> {
todo!()
}
}
trait Storage {
type Error;
}
impl Storage for InMemoryStorage {
type Error = String;
}
trait StorageRequestReturnType {
type Output;
}
trait StorageRequest<S: Storage>: StorageRequestReturnType {
fn execute(
&self,
) -> BoxFuture<Result<<Self as StorageRequestReturnType>::Output, <S as Storage>::Error>>;
}
struct SaveUser<'a> {
name: &'a str,
}
impl<'a> StorageRequestReturnType for SaveUser<'a> {
type Output = ();
}
impl<'dep> User<'dep> {
async fn save<S>(self)
where
S: Storage,
for<'a> SaveUser<'a>: StorageRequest<S>,
{
SaveUser { name: "Joe" }
.execute()
.await;
}
}
async fn run<S>(dep: &str)
where
S: Storage,
for<'a> SaveUser<'a>: StorageRequest<S>,
{
User { dep }.save().await;
}There are a few strange things about this:
Backtrace
|
jyn514
added
the
A-associated-items
|
Relevant code: rust/compiler/rustc_middle/src/ty/instance.rs Line 434 in 9919ad6 rust/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs Lines 221 to 233 in 9919ad6 |
|
Removing Edit: Should it be labeled with some priority as it is an ICE on Stable? |
fominok
changed the title
Option::unwrap() on a None value', compiler/rustc_middle/src/ty/instance.rs:434:85Option::unwrap() on a None value', compiler/rustc_middle/src/ty/instance.rs:434:85
|
@fominok can you remove 'dep and post the new code? I don't have time right now.
Normally issues aren't prioritized unless they're regressions or unsound, but I can make an exception since you asked nicely :) |
jyn514
added
the
I-prioritize
|
@jyn514 it's up to you, but many thanks anyway! I just tried to remove 'dep for a simplified example you posted and it compiles, but it doesn't compile for a snippet I posted first, so here is a version that sill larger than yours, but without lifetime parameter for a User struct: |
|
Turns out this is a regression: the code works on 1.47 and ICEs on 1.48. searched nightlies: from nightly-2020-08-24 to nightly-2020-11-14 bisected with cargo-bisect-rustc v0.6.0Host triple: x86_64-unknown-linux-gnu cargo bisect-rustc --preserve --start=2020-08-24 --end=2020-11-14 -- build @rustbot label regression-from-stable-to-stable also, since no-one's posted a reduction without the use of async/await: @rustbot label A-async-await |
rustbot
added
regression-from-stable-to-stable
|
rustbot did not like that, huh @rustbot label A-async-await |
|
Here's a no-dependency version that gives the alternate ICE from #80706 (comment). type BoxFuture<T> = std::pin::Pin<Box<dyn std::future::Future<Output=T>>>;
fn main() {
f();
}
async fn f() {
run("dependency").await;
}
struct InMemoryStorage;
struct User<'dep> {
dep: &'dep str,
}
impl<'a> StorageRequest<InMemoryStorage> for SaveUser<'a> {
fn execute(&self) -> BoxFuture<Result<(), String>> {
todo!()
}
}
trait Storage {
type Error;
}
impl Storage for InMemoryStorage {
type Error = String;
}
trait StorageRequestReturnType {
type Output;
}
trait StorageRequest<S: Storage>: StorageRequestReturnType {
fn execute(
&self,
) -> BoxFuture<Result<<Self as StorageRequestReturnType>::Output, <S as Storage>::Error>>;
}
struct SaveUser<'a> {
name: &'a str,
}
impl<'a> StorageRequestReturnType for SaveUser<'a> {
type Output = ();
}
impl<'dep> User<'dep> {
async fn save<S>(self)
where
S: Storage,
for<'a> SaveUser<'a>: StorageRequest<S>,
{
SaveUser { name: "Joe" }
.execute()
.await;
}
}
async fn run<S>(dep: &str)
where
S: Storage,
for<'a> SaveUser<'a>: StorageRequest<S>,
{
User { dep }.save().await;
} |
@jyn514 To my understanding, this is expected. A function needs to be used in order to be monomorphized; otherwise what whould it be monomorphized to? So, if the bug happens during monomorphization, it should only happen for functions that are actually used (and thus instantiated). |
|
Assigning |
apiraino
added
P-high
tmandry
added
the
AsyncAwait-Triaged
|
In the minimized version above (#80706 (comment)), codegenning debuginfo fails because it doesn't know the layout of the unnormalized type @lcnr, do you know why #78410 might have caused this type to remain unnormalized? |
|
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It could, but it should already have been done (unless I'm confused). So either |
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Fixed by #85499, but not sure how. Going to mark as needs-test, since this case is different from others. |
jackh726
added
the
E-needs-test
|
This ICE has since regressed. #88640 added a test but marked it as check-pass. This did not reproduce the failure which only occurs when codegen runs.
Backtrace |
JohnTitor
removed
the
E-needs-test
lcnr
added
the
E-needs-test
|
all examples seem to run now, marking as |
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@rustbot claim |
|
visiting for P-high review. from what I can tell from the dialogue here, https:/rust-lang/rust/blob/master/src/test/ui/higher-rank-trait-bounds/normalize-under-binder/issue-80706.rs is the test we want, and is now correctly marked as build-pass thanks to PR #95031 closing as fixed |
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Code
EDIT: MCVE is here.
Meta
Also reproducible on beta and nightly;
rustc --version --verbose:Error output
Backtrace
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