[generator] Ignore types without names (#837)

Fixes: #835
Context: https://github.com/firebase/firebase-android-sdk/blob/1fba4a70395c20dcc858b22ee8247acbed7cf8d3/firebase-firestore/src/main/java/com/google/firebase/firestore/model/Document.java
Context: https://maven.google.com/web/index.html?q=firestore#com.google.firebase:firebase-firestore:22.1.2
Somehow Google has compiled `firebase-firestore.aar` to contain a
`Document$.class` with a "non-sensical" *empty* inner class name:
<class
abstract="false"
deprecated="not deprecated"
jni-extends="Ljava/lang/Object;"
extends="java.lang.Object"
extends-generic-aware="java.lang.Object"
final="false"
name="Document."
jni-signature="Lcom/google/firebase/firestore/model/Document$;"
source-file-name="Document.java"
static="false"
visibility="public"
/>
The presence of a `//class[@name='Document.']` element causes an
`IndexOutOfRangeException` for `generator` when it tries to parse
`Document.` into a parent class name and nested class name.
System.IndexOutOfRangeException: Index was outside the bounds of the array.
at MonoDroid.Generation.XmlApiImporter.CreateGenBaseSupport (System.Xml.Linq.XElement pkg, System.Xml.Linq.XElement elem, System.Boolean isInterface)
at MonoDroid.Generation.XmlApiImporter.CreateClass (System.Xml.Linq.XElement pkg, System.Xml.Linq.XElement elem, at MonoDroid.Generation.Parser.ParsePackage (System.Xml.Linq.XElement ns, System.Predicate`1[T] p)
at MonoDroid.Generation.Parser.ParsePackage (System.Xml.Linq.XElement ns)
at MonoDroid.Generation.Parser.Parse (System.Xml.Linq.XDocument doc, System.Collections.Generic.IEnumerable`1[T] fixups, at MonoDroid.Generation.Parser.Parse (System.String filename, System.Collections.Generic.IEnumerable`1[T] fixups, at Xamarin.Android.Binder.CodeGenerator.Run (Xamarin.Android.Binder.CodeGeneratorOptions options, at Xamarin.Android.Binder.CodeGenerator.Run (Xamarin.Android.Binder.CodeGeneratorOptions options)
at Xamarin.Android.Binder.CodeGenerator.Main (System.String[] args)
We cannot reproduce *how* to get a `Document$.class` file, so we're
currently assuming this is some sort of bytecode manipulation.
As such, we are going to have `generator` ignore types with an empty
name and types that end in a period, which would indicate a nested
type with an empty name.

Author: jpobst

tests/generator-Tests/Unit-Tests/XmlApiImporterTests.cs

@@ -266,5 +266,41 @@ public void IgnoreKotlinInternalMembers ()
 Assert.AreEqual(0,klass.Fields.Count);
 Assert.AreEqual(0,klass.Methods.Count);
 }
+
+[Test]
+publicvoidIgnoreTypesWithInvalidNames()
+{
+varxml=XDocument.Parse(@"
+ <api>
+ <package name='com.example.test' jni-name='com/example/test'>
+ <class name='' visibility='public' />
+ <class name='Document.' visibility='public' />
+ <interface name='' visibility='public' />
+ <interface name='Document.' visibility='public' />
+ </package>
+ </api>");
+
+vargens=XmlApiImporter.Parse(xml,opt);
+
+// None of these should be parsed because they have invalid names
+Assert.AreEqual(0,gens.Count);
+}
+
+[Test]
+publicvoidIgnoreUserObfuscatedTypes()
+{
+varxml=XDocument.Parse(@"
+ <api>
+ <package name='com.example.test' jni-name='com/example/test'>
+ <class name='MyClass' visibility='public' obfuscated='true' />
+ <interface name='MyInterface' visibility='public' obfuscated='true' />
+ </package>
+ </api>");
+
+vargens=XmlApiImporter.Parse(xml,opt);
+
+// None of these should be parsed because the user has said they are obfuscated
+Assert.AreEqual(0,gens.Count);
+}
 }
 }

tools/generator/Java.Interop.Tools.Generator.Importers/XmlApiImporter.cs

@@ -61,14 +61,12 @@ public static List<GenBase> ParsePackage (XElement ns, CodeGenerationOptions opt
 
 switch(elem.Name.LocalName){
 case"class":
-if(elem.XGetAttribute("obfuscated")=="true")
-continue;
-gen=CreateClass(ns,elem,options);
+if(ShouldBind(elem))
+gen=CreateClass(ns,elem,options);
 break;
 case"interface":
-if(elem.XGetAttribute("obfuscated")=="true")
-continue;
-gen=CreateInterface(ns,elem,options);
+if(ShouldBind(elem))
+gen=CreateInterface(ns,elem,options);
 break;
 default:
 Report.LogCodedWarning(0,Report.WarningUnexpectedPackageChildNode,elem.Name.ToString());
@@ -522,5 +520,20 @@ static void SetLineInfo (ISourceLineInfo model, XNode node, CodeGenerationOption
 model.LinePosition=info.LinePosition;
 }
 }
+
+staticboolShouldBind(XElementelem)
+{
+// Don't bind things the user has said are "obfuscated"
+if(elem.XGetAttribute("obfuscated")=="true")
+returnfalse;
+
+varjava_name=elem.XGetAttribute("name");
+
+// Ignore types that do not have a name (nested classes would end in a period like "Document.")
+if(!java_name.HasValue()||java_name.EndsWith(".",StringComparison.Ordinal))
+returnfalse;
+
+returntrue;
+}
 }
 }