Calls to `cedar_policy::Entity::new` fails in android bindings generated using `uniffi` if the entity's attributes are not empty.

[rmarinn]

Before opening, please confirm:

• I have searched for duplicate or closed issues.
• I have read the guide for submitting bug reports.
• I have done my best to include a minimal, self-contained set of instructions for consistently reproducing the issue.

Bug Category

Other

Describe the bug

Calls to cedar_policy::Entity::new fails in android bindings generated using uniffi if the entity's attributes are not empty.

It works fine if the entity does not have attributes.

Expected behavior

I expected the entity to be created successfully when it gets called in the Kotlin code.

Reproduction steps

1. Write rust code that creates an entity using cedar_policy::Entity::new.
2. Create android bindings using uniffi.
3. Run the code in an android device or emulator.

Code Snippet

let test_entity = "Test::\"abc\"".parse().expect("parse resource uid");
let test_entity_attrs = HashMap::from([
    (
        "item1".to_string(),
        RestrictedExpression::new_string("abc".to_string()),
    ),
    ("attr2".to_string(), RestrictedExpression::new_long(123)),
]);

// This call to Entity::new is what fails in the android binding
let test_entity = Entity::new(test_entity, test_entity_attrs, HashSet::new()).expect("build entity");

Log output

FATAL EXCEPTION: main
Process: com.example.exampleapp, PID: 15076
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:590)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:886)
Caused by: java.lang.reflect.InvocationTargetException
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:580)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:886) 
Caused by: uniffi.android_bindings.InternalException: build entity: EntityAttrEvaluationError { uid: EntityUid(EntityUID { ty: EntityType(Name(InternalName { id: Id("Test"), path: [], loc: Some(Loc { span: SourceSpan { offset: SourceOffset(0), length: 4 }, src: "Test::\"abc\"" }) })), eid: Eid("abc"), loc: Some(Loc { span: SourceSpan { offset: SourceOffset(0), length: 11 }, src: "Test::\"abc\"" }) }), attr_or_tag: "item1", was_attr: true, err: RecursionLimit(RecursionLimitError { source_loc: None }) }

Additional configuration

No response

Operating System

Android

Additional information and screenshots

I think the issue is caused by cedar_policy trying to use stacker::remaining_stack in cedar-policy-core/src/evaludator.rs around line 945 inside the stack_size_check function. The stacker::remaining_stackfunction will always returnNone` when called in an adroid device or emulator.

I also made this repository for convenience when trying to reproduce the issue: https://github.com/rmarinn/cedar-android-bindings-bug.

We also tried it in Swift (also used uniffi to create the bindings) and the same issue arises.

[adpaco-aws]

Hey @rmarinn , thanks for opening this bug report!

We have discussed the issue and agreed that we should change the stack_size_check behavior to return Ok(()) in cases where remaining_stack is None. This should allow the calls to proceed in the android bindings at the risk of running into a stack overflow error.

[rmarinn]

okay, thanks!

[olehbozhok]

@adpaco-aws Thanks for the update!
If I understand correctly, the update will be available in the next release. Do you know when that is expected?

[adpaco-aws]

Thanks for your interest, @olehbozhok !

Yes, the fix should be available in the next release. Unfortunately, we don't know when it's expected yet.

[laraelangdon]

@olehbozhok are you blocked on the release of this?

[olehbozhok]

@olehbozhok are you blocked on the release of this?

Actually yes, we can't merge to main branch changes that use uniffi bindings. Because it needs this fix. For develop we use git link in Cargo file. But is waiting for new version on crates.io