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Merged
asLody merged 1 commit into from
Aug 16, 2026
Merged

Tolerate incomplete FunctionN instantiations #23

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41 changes: 17 additions & 24 deletions dexdec/src/analysis/method_override.rs
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -134,16 +134,13 @@ pub(crate) fn collect_instantiated_super_types<H: ClassHierarchy>(
if !seen.insert(details.descriptor.clone()) {
continue;
}
let instantiated = bind_class(hierarchy, &details, &instantiated_parent)?;
let Ok(instantiated) = bind_class(hierarchy, &details, &instantiated_parent) else {
continue;
};
for (idx, parent_ty) in instantiated.parents.iter().enumerate() {
let generic = instantiated
.generic_parents
.get(idx)
.cloned()
.ok_or_else(|| OverrideAnalysisError::MissingErasedParent {
class: instantiated.descriptor.clone(),
index: idx,
})?;
let Some(generic) = instantiated.generic_parents.get(idx).cloned() else {
continue;
};
queue.push_back((parent_ty.clone(), generic));
}
out.push(instantiated);
Expand Down Expand Up @@ -177,9 +174,13 @@ where
T: OverrideAnalysisTarget,
{
for class in classes {
let ancestors = self.collect_super_types(class)?;
let Ok(ancestors) = self.collect_super_types(class) else {
continue;
};
for method in &class.methods {
let semantics = self.analyze_method(class, method, &ancestors)?;
let Ok(semantics) = self.analyze_method(class, method, &ancestors) else {
continue;
};
target.set_method_override(
&method.reference.declaring_class,
&method.reference.short_id,
Expand Down Expand Up @@ -528,23 +529,15 @@ fn collect_scope_type_parameters(
substitutions: &mut TypeSubstitution,
) -> OverrideResult<()> {
let Some(signature) = declared.generic_signature.as_ref() else {
if type_arguments.is_empty() {
return Ok(());
}
return Err(OverrideAnalysisError::GenericArity {
class: declared.descriptor.clone(),
expected: 0,
actual: type_arguments.len(),
});
return Ok(());
};
let expected = signature.type_parameters.len();
let actual = type_arguments.len();
// Kotlin FunctionN and some SAM/lambda signatures omit a type
// argument (commonly the return type). Keep analysis going as a
// raw instantiation instead of failing the whole archive.
if actual != 0 && actual != expected {
return Err(OverrideAnalysisError::GenericArity {
class: declared.descriptor.clone(),
expected,
actual,
});
return Ok(());
}
collect_instantiated_class_type_parameters(signature, type_arguments, substitutions)
}
Expand Down
150 changes: 150 additions & 0 deletions dexdec/src/analysis/method_override/tests.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -463,6 +463,156 @@ fn binds_outer_and_inner_generic_scopes() {
);
}

#[test]
fn incomplete_functionn_instantiation_does_not_fail_scope_binding() {
let function3 = class_with_signature(
"Lkotlin/jvm/functions/Function3;",
["Ljava/lang/Object;"],
[],
Some(
GenericSignatures::class(
"<P1:Ljava/lang/Object;P2:Ljava/lang/Object;P3:Ljava/lang/Object;R:Ljava/lang/Object;>Ljava/lang/Object;",
)
.expect("Function3 class signature"),
),
"kotlin.jvm.functions",
);
let args = ["java/lang/String", "java/lang/Integer", "java/lang/Long"]
.into_iter()
.map(|name| {
TypeArgument::Exact(JvmTypeSignature::ClassType(parse_class_type_signature(
name,
)))
})
.collect::<Vec<_>>();
let mut substitutions = TypeSubstitution::new();

collect_scope_type_parameters(&function3, &args, &mut substitutions)
.expect("Function3 instantiated with three arguments must not fail");
}

#[test]
fn incomplete_functionn_parent_does_not_abort_override_analysis() {
let function3 = class_with_signature(
"Lkotlin/jvm/functions/Function3;",
["Ljava/lang/Object;"],
[method(
"Lkotlin/jvm/functions/Function3;",
"invoke(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;",
vec![
ArgType::object("java/lang/Object"),
ArgType::object("java/lang/Object"),
ArgType::object("java/lang/Object"),
],
ArgType::object("java/lang/Object"),
0x0401,
)],
Some(
GenericSignatures::class(
"<P1:Ljava/lang/Object;P2:Ljava/lang/Object;P3:Ljava/lang/Object;R:Ljava/lang/Object;>Ljava/lang/Object;",
)
.expect("Function3 class signature"),
),
"kotlin.jvm.functions",
);
let child = class_with_signature(
"Lcom/example/Callback;",
["Lkotlin/jvm/functions/Function3;"],
[method(
"Lcom/example/Callback;",
"invoke(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;",
vec![
ArgType::object("java/lang/Object"),
ArgType::object("java/lang/Object"),
ArgType::object("java/lang/Object"),
],
ArgType::object("java/lang/Object"),
0x0001,
)],
Some(
GenericSignatures::class(
"Ljava/lang/Object;Lkotlin/jvm/functions/Function3<Ljava/lang/String;Ljava/lang/Integer;Ljava/lang/Long;>;",
)
.expect("three-argument Function3 instantiation"),
),
"com.example",
);
let hierarchy = LocalHierarchy::new([function3, child.clone()]);
let analyzer = MethodOverrideAnalyzer::new(&hierarchy);
let ancestors = analyzer
.collect_super_types(&child)
.expect("ancestor walk must survive a Function3 arity mismatch");
assert!(ancestors
.iter()
.any(|class| class.descriptor == "Lkotlin/jvm/functions/Function3;"));

let mut sink = OverrideSink::default();
analyzer
.analyze(&mut sink, std::slice::from_ref(&child))
.expect("archive override analysis must not fail");
assert!(sink.0.iter().any(|(class, method)| {
class == "Lcom/example/Callback;"
&& method
== "invoke(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;"
}));
}

#[test]
fn override_analysis_skips_a_broken_class_and_continues() {
let healthy = class(
"Lcom/example/Ok;",
["Ljava/lang/Object;"],
[method(
"Lcom/example/Ok;",
"size()I",
Vec::new(),
ArgType::INT,
0x0001,
)],
"com.example",
);
let broken = ClassDetails {
descriptor: "Lcom/example/Broken;".to_string(),
package: "com.example".to_string(),
access_flags: AccessInfo::for_class(0x0001),
parents: vec![ArgType::object("java/lang/Object")],
generic_parents: Vec::new(),
generic_signature: None,
instantiated_self: None,
methods: vec![method(
"Lcom/example/Broken;",
"size()I",
Vec::new(),
ArgType::INT,
0x0001,
)],
};
let hierarchy = LocalHierarchy::new([healthy.clone(), broken.clone()]);
let mut sink = OverrideSink::default();
MethodOverrideAnalyzer::new(&hierarchy)
.analyze(&mut sink, &[broken, healthy])
.expect("one broken class must not abort the archive");
assert!(
sink.0.iter().any(|(class, _)| class == "Lcom/example/Ok;"),
"healthy class should still be analyzed"
);
}

#[derive(Default)]
struct OverrideSink(Vec<(String, String)>);

impl OverrideAnalysisTarget for OverrideSink {
fn set_method_override(
&mut self,
declaring_class: &str,
method_short_id: &str,
_semantics: Option<MethodOverrideSemantics>,
) {
self.0
.push((declaring_class.to_string(), method_short_id.to_string()));
}
}

struct TestHierarchy {
app: ClassDetails,
platform: PlatformClassSet,
Expand Down