[Mono.Android] Fix generated code build warnings by simonrozsival · Pull Request #12835 · dotnet/android

simonrozsival · 2026-09-20T00:26:49Z

Stacked on #12809 (simonrozsival-fix-mono-android-warnings), which fixed every handwritten C# warning in src/Mono.Android/Mono.Android.csproj. This PR goes after the generated code.

Approach

Warnings in generated bindings are fixed in the generator, not suppressed. Where a warning is a genuine consequence of faithfully projecting a Java API into C#, the generator determines which member provokes which diagnostic and emits a #pragma warning disable scoped to that one member, with a comment saying why. An unexpected occurrence of the same diagnostic anywhere else still breaks the build.

Warnings attributable to Mono.Android.csproj at API 37 go from 684 to 88.

Generator bugs fixed

These were producing warnings, not merely hiding them:

BoundAbstractProperty never emitted [Obsolete]. An abstract declaration of a deprecated Java property silently lost its deprecation, while the invoker/implementor overrides generated for it kept theirs. That mismatch produced every CS0809.
BoundPropertyStringVariant had the same omission. The string convenience property generated alongside a deprecated ICharSequence property lost its deprecation, then reported CS0618 for calling it.
MethodAsyncWrapper/MethodExtensionAsyncWrapper did not carry the deprecation of the synchronous method they invoke.
GenBase.RequiresNew (Property, ...) applied the System.Object member check to interfaces, which do not inherit System.Object (CS0109).
GenBase.HidesInheritedMember ignored generic arity, so methods differing only in type-parameter count compared equal.
BoundMethodAbstractDeclaration computed IsShadow from Name rather than AdjustedName — a name the generator does not emit — and computed it before IsOverride was known.

Plus, from the earlier commit on this branch: ~1600 CS0108/CS0114 fixed by correcting new-modifier detection across GenBase and 14 source writers; CS0169 on unused weak-implementor fields; RS0041 fixed by making build-tools/jnienv-gen nullable-aware and regenerating JNIEnv.g.cs; and the javac -source/-target warning replaced with --release.

New infrastructure

Xamarin.SourceWriter gains ISuppressWarnings, implemented by the method, property, field and type writers, which brackets a member with #pragma warning disable/restore and an explanatory comment.
Method.OverriddenBaseMethod and GenBase.FindOverriddenMethod record the base member an override resolves to, so the generator can compare deprecation and nullability against it. Java allows covariant returns, so the match is on the parameter portion of the JNI signature.
SourceWriterExtensions.EmitsObsoleteAttribute factors out the [Obsolete]-versus-[ObsoletedOSPlatform] decision, so the suppression logic and the attribute logic cannot drift apart.

Suppressions actually emitted

Only where the generator has positively determined the diagnostic applies to that member:

Code	Emitted when
CS0465	The bound member is `Finalize ()`, which Java permits and C# reserves
CS0618	The member's signature, base type or body references a deprecated binding and the member is not itself deprecated
CS0672	A non-deprecated member overrides a deprecated one
CS0809	A deprecated member overrides a non-deprecated one
CS8764 / CS8766	The return type's nullness annotation differs from the overridden / implemented member
CS8765 / CS8767	A parameter's nullness annotation differs from the overridden / implemented member

Java's @Nullable/@NonNull are documentation rather than part of the type system, so these disagreements can only be resolved by the Java author.

Also in this PR

PublicAPI.Unshipped.txt for API-37.1 and API-37.2 was stale since the API-37.1 binding work, and two duplicate entries (VP9Profile2HDR, VP9Profile3HDR) in PublicAPI.Shipped.txt were triggering RS0025, which makes the analyzer bail out and masks every RS0016/RS0017 it would otherwise report. Deduplicating revealed 418 real errors at 37.1 and 2029 at 37.2; all are now recorded.

Validation

Configuration	Result
API 37, Debug, `_AndroidTreatWarningsAsErrors=true`	0 errors, 88 unique warnings
API 37.1, Debug, `_AndroidTreatWarningsAsErrors=true`	0 errors, same 88
API 37.2, Debug, `_AndroidTreatWarningsAsErrors=true`	0 errors, same 88
API 37, Release	0 warnings attributable to `Mono.Android.csproj`
`generator-Tests`	497 passed, 0 failed

Not yet fixed

88 warnings remain and need further generator work, so the _AllowProjectWarnings entry for Mono.Android.csproj stays for now — the warnings remain visible in build output rather than silenced by <NoWarn>. The main <NoWarn> list is gone; only the Javadoc-only documentation filter remains.

CS0618 (35) — event/listener scaffolding referencing deprecated types.
CS0108/CS0114 (28) — two groups. Synthesized string/ICharSequence convenience overloads are invisible to the hiding scan (StringBuffer.Append(string?), ArrayAdapter.GetAutofillOptions(), MockPackageManager.*); and genuinely hand-bound base members the generator cannot see (CellInfo*.CellIdentity/CellSignalStrength, ICompletionStage.Handle). The latter group wants a managedOverride="new" metadata value so src/Mono.Android/metadata can declare them precisely.
CS8603/CS8604/CS8625 (11) — body-level nullability in generated marshalling.
CS8764/CS8766/CS8767/CS8768 (14) — override/implement pairs the base-member resolution still misses.

The bottom of this stack fixed every handwritten warning in `Mono.Android.csproj` and trimmed `$(NoWarn)` down to the set that only generated code still needed. This change fixes those at the source, in the binding generator and `jnienv-gen`, and removes `$(NoWarn)` entirely along with the `Mono.Android.csproj` entry in `$(_AllowProjectWarnings)`. Roughly 1600 of the ~1690 warnings were the generator not emitting `new` on a member that hides an inherited one (CS0108/CS0114), so `GenBase` now models C# hiding rules: * A class hides members of its base classes, an interface hides members of its base interfaces. Base interfaces that are const sugar or non-public are excluded, matching `BoundInterface.AddImplements()`. * Methods hide only on a matching signature (an unnecessary `new` is CS0109), while fields, properties and nested types hide by name alone. * `new` is invalid on an `override` (CS0113) or an explicit interface implementation (CS0106), so `IsShadow` is computed after the managed override fixups. * Only a class inherits `Java.Lang.Object`, so `ToString()`/`Equals()`/ `Clone()` on an interface must not be marked `new`. * The generated callback infrastructure (`_members`, `cb_`, `n_`, `__n_`, `Get*Handler`) hides the enclosing type's members when a type is nested inside one of its own base types. `Xamarin.SourceWriter.FieldWriter` also had to move `new` ahead of `static`/`readonly`/`const`, since `public const new int` does not parse. The remaining diagnostics are inherent to projecting the Java API surface - deprecated Java types used by non-deprecated members, `finalize()`, disagreeing nullness annotations, and base members that are hand-bound rather than generated - so generated files now carry a documented, narrow `#pragma warning disable` block instead. CS0109 is deliberately left enabled so an over-applied `new` still fails the build. Also in this change: * `jnienv-gen` emits `#nullable enable` and a nullable `NewArray` parameter, which fixes RS0041 in `JNIEnv.g.cs`. The resulting nullability annotations are reflected in `PublicAPI.Shipped.txt`. * The listener event helpers no longer emit unused weak implementor fields (CS0169). * `JavaCallableWrappers.targets` uses `--release` instead of `-source`/`-target`, and lists itself in `Inputs` so the target is invalidated when it changes. * `PublicAPI.Unshipped.txt` for API-37.1 and API-37.2 was stale. The duplicate entries in their `PublicAPI.Shipped.txt` were masking every RS0016/RS0017 the analyzer would otherwise have reported. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot

Copilot review overview

🟡 Changes recommended

Critical issues remain in Java release-version handling, interface property shadowing, and override modifier computation.

Get a fresh assessment by requesting another Copilot review.

Review effort: Lite
Findings: 3 · 1

Open (4)

Normalize Javac release version from 1.8 to 8 · New
Avoid Object-name hiding checks for interface properties · New
Compute IsShadow after applying override fixups · New
Include generic method arity in signature hiding checks · New

What changed in this PR

Fixes generated Mono.Android build warnings by correcting member-hiding code generation, narrowing suppressions, updating JNI nullability, and improving Java callable-wrapper compilation.

Changes:

Corrects generated new modifiers and modifier ordering.
Adds targeted generated-code warning suppressions.
Updates JNI nullability and javac --release handling.
Refreshes generator fixtures and API baselines.
Removes obsolete project-level warning allowances.

File	Summary
`src/Mono.Android/Mono.Android.csproj`	Removes obsolete warning suppressions.
`external/Java.Interop/tools/generator/SourceWriters/PeerMembersField.cs`	Updates generated member handling.
`external/Java.Interop/tools/generator/SourceWriters/InterfaceMemberAlternativeClass.cs`	Updates interface member generation.
`external/Java.Interop/tools/generator/SourceWriters/InterfaceInvokerMethod.cs`	Updates generated invoker methods.
`external/Java.Interop/tools/generator/SourceWriters/InterfaceConstsClass.cs`	Updates interface constant generation.
`external/Java.Interop/tools/generator/SourceWriters/BoundProperty.cs`	Updates property hiding logic.
`external/Java.Interop/tools/generator/SourceWriters/BoundMethodAbstractDeclaration.cs`	Updates abstract method modifiers.
`external/Java.Interop/tools/generator/SourceWriters/BoundMethod.cs`	Updates method hiding logic.
`external/Java.Interop/tools/generator/SourceWriters/BoundInterfacePropertyDeclaration.cs`	Updates interface property modifiers.
`external/Java.Interop/tools/generator/SourceWriters/BoundInterfaceMethodDeclaration.cs`	Updates interface method modifiers.
`external/Java.Interop/tools/generator/SourceWriters/BoundInterface.cs`	Updates interface generation.
`external/Java.Interop/tools/generator/SourceWriters/BoundFieldAsProperty.cs`	Updates field-backed property generation.
`external/Java.Interop/tools/generator/SourceWriters/BoundField.cs`	Updates field generation.
`external/Java.Interop/tools/generator/SourceWriters/BoundClass.cs`	Updates class generation.
`external/Java.Interop/tools/generator/SourceWriters/BoundAbstractProperty.cs`	Updates abstract property modifiers.
`external/Java.Interop/tools/generator/Java.Interop.Tools.Generator.ObjectModel/InterfaceGen.cs`	Updates interface warning output.
`external/Java.Interop/tools/generator/Java.Interop.Tools.Generator.ObjectModel/ClassGen.cs`	Updates class warning output.
`external/Java.Interop/tests/generator-Tests/Unit-Tests/CodeGeneratorExpectedResults/XAJavaInterop1/WriteInterfaceRedeclaredDefaultMethod.txt`	Refreshes expected output.
`external/Java.Interop/tests/generator-Tests/Unit-Tests/CodeGeneratorExpectedResults/JavaInterop1/WriteInterfaceRedeclaredDefaultMethod.txt`	Refreshes expected output.
`external/Java.Interop/tests/generator-Tests/Unit-Tests/CodeGeneratorExpectedResults/Common/WriteInterfaceRedeclaredDefaultMethod.txt`	Refreshes expected output.
`external/Java.Interop/tests/generator-Tests/expected.xaji/TestInterface/Test.ME.TestInterfaceImplementation.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/TestInterface/Test.ME.ITestInterface.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/TestInterface/Test.ME.IGenericPropertyInterface.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/TestInterface/Test.ME.IGenericInterface.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/TestInterface/Test.ME.GenericStringPropertyImplementation.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/TestInterface/Test.ME.GenericStringImplementation.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/TestInterface/Test.ME.GenericObjectPropertyImplementation.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/TestInterface/Test.ME.GenericImplementation.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/TestInterface/Java.Util.ICollection.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/TestInterface/Java.Lang.String.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/TestInterface/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/TestInterface/IInterfaceWithoutNamespace.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/TestInterface/ClassWithoutNamespace.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Streams/Java.Lang.Throwable.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Streams/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Streams/Java.IO.OutputStream.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Streams/Java.IO.IOException.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Streams/Java.IO.InputStream.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Streams/Java.IO.FilterOutputStream.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/StaticProperties/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/StaticProperties/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/StaticMethods/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/StaticMethods/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/StaticFields/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/StaticFields/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/ParameterXPath/Xamarin.Test.A.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/ParameterXPath/Java.Util.IList.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/ParameterXPath/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/ParameterXPath/Java.Lang.Integer.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/NormalProperties/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/NormalProperties/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/NormalMethods/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/NormalMethods/Xamarin.Test.C.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/NormalMethods/Xamarin.Test.A.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/NormalMethods/Java.Lang.Throwable.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/NormalMethods/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/NormalMethods/Java.Lang.Integer.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/NormalMethods/Java.Lang.Class.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/NonStaticFields/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/NonStaticFields/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/NestedTypes/Xamarin.Test.NotificationCompatBase.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/NestedTypes/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/java.util.List/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/java.util.List/Java.Util.IList.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/java.util.List/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/java.lang.Object/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/java.lang.Enum/Java.Lang.State.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/java.lang.Enum/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/java.lang.Enum/Java.Lang.IComparable.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/java.lang.Enum/Java.Lang.Enum.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/InterfaceMethodsConflict/Xamarin.Test.SomeObject2.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/InterfaceMethodsConflict/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/InterfaceMethodsConflict/Xamarin.Test.II2.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/InterfaceMethodsConflict/Xamarin.Test.II1.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/InterfaceMethodsConflict/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/GenericArguments/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/CSharpKeywords/Xamarin.Test.CSharpKeywords.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/CSharpKeywords/Java.Lang.Throwable.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/CSharpKeywords/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Core_Jar2Xml/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Core_Jar2Xml/Android.Views.View.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Core_Jar2Xml/Android.Text.SpannableStringInternal.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Core_Jar2Xml/Android.Text.SpannableString.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Core_Jar2Xml/Android.Text.ISpanned.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Core_Jar2Xml/Android.Text.ISpannable.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Core_ClassParse/Xamarin.Test.Invalidnames.InvalidNameMembers.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Core_ClassParse/Xamarin.Test.Invalidnames.In.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Core_ClassParse/Xamarin.Google.Composable.MyClass.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Core_ClassParse/Java.Lang.String.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Core_ClassParse/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Constructors/Xamarin.Test.SomeObject2.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Constructors/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Constructors/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Arrays/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Arrays/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Android.Graphics.Color/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Android.Graphics.Color/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Adapters/Xamarin.Test.ISpinnerAdapter.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Adapters/Xamarin.Test.IAdapter.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Adapters/Xamarin.Test.GenericReturnObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Adapters/Xamarin.Test.AdapterView.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Adapters/Xamarin.Test.AbsSpinner.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/Adapters/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/AccessModifiers/Xamarin.Test.TestClass.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/AccessModifiers/Xamarin.Test.PublicFinalClass.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/AccessModifiers/Xamarin.Test.PublicClass.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/AccessModifiers/Xamarin.Test.IExtendedInterface.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/AccessModifiers/Xamarin.Test.ExtendPublicClass.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/AccessModifiers/Xamarin.Test.BasePublicClass.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.xaji/AccessModifiers/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/TestInterface/Test.ME.TestInterfaceImplementation.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/TestInterface/Test.ME.ITestInterface.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/TestInterface/Test.ME.IGenericPropertyInterface.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/TestInterface/Test.ME.IGenericInterface.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/TestInterface/Test.ME.GenericStringPropertyImplementation.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/TestInterface/Test.ME.GenericStringImplementation.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/TestInterface/Test.ME.GenericObjectPropertyImplementation.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/TestInterface/Test.ME.GenericImplementation.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/TestInterface/Java.Util.ICollection.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/TestInterface/Java.Lang.String.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/TestInterface/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/TestInterface/IInterfaceWithoutNamespace.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/TestInterface/ClassWithoutNamespace.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Streams/Java.Lang.Throwable.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Streams/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Streams/Java.IO.OutputStream.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Streams/Java.IO.IOException.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Streams/Java.IO.InputStream.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Streams/Java.IO.FilterOutputStream.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/StaticProperties/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/StaticProperties/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/StaticMethods/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/StaticMethods/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/StaticFields/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/StaticFields/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/ParameterXPath/Xamarin.Test.A.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/ParameterXPath/Java.Util.IList.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/ParameterXPath/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/ParameterXPath/Java.Lang.Integer.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/NormalProperties/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/NormalProperties/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/NormalMethods/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/NormalMethods/Xamarin.Test.C.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/NormalMethods/Xamarin.Test.A.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/NormalMethods/Java.Lang.Throwable.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/NormalMethods/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/NormalMethods/Java.Lang.Integer.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/NormalMethods/Java.Lang.Class.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/NonStaticFields/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/NonStaticFields/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/NestedTypes/Xamarin.Test.NotificationCompatBase.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/NestedTypes/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/java.util.List/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/java.util.List/Java.Util.IList.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/java.util.List/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/java.lang.Object/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/java.lang.Enum/Java.Lang.State.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/java.lang.Enum/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/java.lang.Enum/Java.Lang.IComparable.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/java.lang.Enum/Java.Lang.Enum.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/InterfaceMethodsConflict/Xamarin.Test.SomeObject2.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/InterfaceMethodsConflict/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/InterfaceMethodsConflict/Xamarin.Test.II2.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/InterfaceMethodsConflict/Xamarin.Test.II1.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/InterfaceMethodsConflict/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/GenericArguments/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/CSharpKeywords/Xamarin.Test.CSharpKeywords.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/CSharpKeywords/Java.Lang.Throwable.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/CSharpKeywords/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Core_Jar2Xml/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Core_Jar2Xml/Android.Views.View.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Core_Jar2Xml/Android.Text.SpannableStringInternal.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Core_Jar2Xml/Android.Text.SpannableString.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Core_Jar2Xml/Android.Text.ISpanned.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Core_Jar2Xml/Android.Text.ISpannable.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Core_ClassParse/Xamarin.Test.Invalidnames.InvalidNameMembers.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Core_ClassParse/Xamarin.Test.Invalidnames.In.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Core_ClassParse/Xamarin.Google.Composable.MyClass.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Core_ClassParse/Java.Lang.String.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Core_ClassParse/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Constructors/Xamarin.Test.SomeObject2.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Constructors/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Constructors/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Arrays/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Arrays/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Android.Graphics.Color/Xamarin.Test.SomeObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Android.Graphics.Color/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Adapters/Xamarin.Test.ISpinnerAdapter.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Adapters/Xamarin.Test.IAdapter.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Adapters/Xamarin.Test.GenericReturnObject.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Adapters/Xamarin.Test.AdapterView.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Adapters/Xamarin.Test.AbsSpinner.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Adapters/SupportFiles/AdapterView.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/Adapters/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/AccessModifiers/Xamarin.Test.TestClass.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/AccessModifiers/Xamarin.Test.PublicFinalClass.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/AccessModifiers/Xamarin.Test.PublicClass.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/AccessModifiers/Xamarin.Test.IExtendedInterface.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/AccessModifiers/Xamarin.Test.ExtendPublicClass.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/AccessModifiers/Xamarin.Test.BasePublicClass.cs`	Refreshes generated fixture.
`external/Java.Interop/tests/generator-Tests/expected.ji/AccessModifiers/Java.Lang.Object.cs`	Refreshes generated fixture.
`external/Java.Interop/src/Xamarin.SourceWriter/Models/FieldWriter.cs`	Corrects modifier ordering.
`Directory.Build.props`	Removes the Mono.Android warning allowance.
`build-tools/scripts/JavaCallableWrappers.targets`	Updates release handling and incremental inputs.
`build-tools/jnienv-gen/Generator.cs`	Emits nullable JNI signatures.

The previous commit disabled 14 diagnostics at the top of every generated file. That is the same blanket suppression `<NoWarn>` provided, just moved somewhere less visible, and it leaked into every third-party binding built with this generator. This removes it. In its place the generator now works out which member provokes which diagnostic and, where the warning is genuinely unavoidable, emits a `#pragma warning disable` scoped to that one member for that one code. An unexpected occurrence of the same diagnostic anywhere else still breaks the build. Generator bugs fixed (these were causing warnings, not just hiding them): * `BoundAbstractProperty` never emitted `[Obsolete]`, so an abstract declaration of a deprecated Java property silently lost its deprecation while the invoker/implementor overrides generated for it kept theirs. That mismatch is what produced every CS0809. * `BoundPropertyStringVariant` had the same omission, so the `string` convenience property generated alongside a deprecated `ICharSequence` property lost its deprecation and then reported CS0618 for calling it. * `MethodAsyncWrapper`/`MethodExtensionAsyncWrapper` did not carry the deprecation of the synchronous method they invoke. * `GenBase.RequiresNew (Property, ...)` applied the `System.Object` member check to interfaces, which do not inherit `System.Object` (CS0109). * `GenBase.HidesInheritedMember` ignored generic arity, so methods that differ only in type-parameter count compared equal. * `BoundMethodAbstractDeclaration` computed `IsShadow` from `Name` rather than `AdjustedName`, so the hiding check used a name the generator does not emit, and computed it before `IsOverride` was known. New infrastructure: * `Xamarin.SourceWriter` gains `ISuppressWarnings`, implemented by the method, property, field and type writers, which brackets a member with `#pragma warning disable`/`restore` plus a comment explaining why. * `Method.OverriddenBaseMethod` and `GenBase.FindOverriddenMethod` record the base member an override resolves to, so the generator can compare deprecation and nullability against it. * `SourceWriterExtensions.EmitsObsoleteAttribute` factors out the `[Obsolete]`-versus-`[ObsoletedOSPlatform]` decision so the suppression logic and the attribute logic cannot drift apart. Remaining suppressions are emitted only where the generator has positively determined the diagnostic applies: * CS0465 on a bound `Finalize ()`, which Java permits and C# reserves. * CS0618/CS0672/CS0809 where a member's signature, base type or overridden member is deprecated and the member itself is not, or vice versa. * CS8764-CS8767 where the nullness annotation on a return type or parameter differs from the member being overridden or implemented. Java's nullness annotations are advisory, so only the Java author can reconcile these. Warnings from `Mono.Android.csproj` at API 37 drop from 684 to 88. The remainder are CS0108/CS0114 hiding cases and body-level nullability, which need further generator work, so the `_AllowProjectWarnings` entry stays until they are resolved, keeping the warnings visible rather than silenced. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot AI lite review requested due to automatic review settings September 20, 2026 00:26

simonrozsival requested a review from jonathanpeppers as a code owner September 20, 2026 00:26

Copilot started reviewing on behalf of simonrozsival September 20, 2026 00:27 View session

Copilot AI reviewed Sep 20, 2026

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[Mono.Android] Fix generated code build warnings - #12835

[Mono.Android] Fix generated code build warnings#12835
simonrozsival wants to merge 2 commits into
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simonrozsival-mono-android-codegen-warnings

simonrozsival commented Sep 20, 2026 •

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simonrozsival commented Sep 20, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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🟡 Changes recommended

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simonrozsival commented Sep 20, 2026 •

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