Move imports to a concrete class

This CL moves Map<String(alias), String(qname)> imports to a concrete
ImportBag class. It is mostly a cleanup so that in a follow-up CL,
we can start caching findClass calls based on available imports.
Right now it is not possible since imports are all bloated with
java.lang.

This CL also stops adding all java.lang.* as static identifiers to
every single model. Instead, it lazily registers it if an identifier
expression cannot be found and name matches a java.lang class.

Bug: 117808327
Test: ImportBagTest, existing tests pass
Change-Id: Ideb41ab8cfc68aa4c7b55e84ffa218ba65558eb3

13 files changed, 233 insertions, 136 deletions

diff --git a/compiler/src/main/java/android/databinding/tool/Binding.java b/compiler/src/main/java/android/databinding/tool/Binding.java
index 19884201..9e7dccb3 100644
--- a/compiler/src/main/java/android/databinding/tool/Binding.java
+++ b/compiler/src/main/java/android/databinding/tool/Binding.java
@@ -22,6 +22,7 @@ import android.databinding.tool.expr.LambdaExpr;
 import android.databinding.tool.processing.ErrorMessages;
 import android.databinding.tool.processing.Scope;
 import android.databinding.tool.processing.scopes.LocationScopeProvider;
+import android.databinding.tool.reflection.ImportBag;
 import android.databinding.tool.reflection.ModelAnalyzer;
 import android.databinding.tool.reflection.ModelClass;
 import android.databinding.tool.reflection.ModelMethod;
@@ -34,7 +35,6 @@ import android.databinding.tool.util.Preconditions;
 import android.databinding.tool.writer.LayoutBinderWriterKt;
 
 import java.util.List;
-import java.util.Map;
 
 public class Binding implements LocationScopeProvider {
 
@@ -314,7 +314,7 @@ public class Binding implements LocationScopeProvider {
         private final SetterCall mWrappedCall;
 
         public ViewStubDirectCall(String name, ModelClass viewType, ModelClass resolvedType,
-                Map<String, String> imports) {
+                                  ImportBag imports) {
             mWrappedCall = SetterStore.get().getSetterCall(name,
                     viewType, resolvedType, imports);
             if (mWrappedCall == null) {
diff --git a/compiler/src/main/java/android/databinding/tool/CompilerChef.java b/compiler/src/main/java/android/databinding/tool/CompilerChef.java
index a2b609d5..46cd6724 100644
--- a/compiler/src/main/java/android/databinding/tool/CompilerChef.java
+++ b/compiler/src/main/java/android/databinding/tool/CompilerChef.java
@@ -15,8 +15,10 @@ package android.databinding.tool;
 
 import android.databinding.tool.processing.Scope;
 import android.databinding.tool.processing.ScopedException;
+import android.databinding.tool.reflection.ImportBag;
 import android.databinding.tool.reflection.InjectedClass;
 import android.databinding.tool.reflection.ModelAnalyzer;
+import android.databinding.tool.reflection.MutableImportBag;
 import android.databinding.tool.store.FeatureInfoList;
 import android.databinding.tool.store.GenClassInfoLog;
 import android.databinding.tool.store.ResourceBundle;
@@ -143,7 +145,7 @@ public class CompilerChef {
             analyzer.injectClass(bindingClass);
 
             for (ResourceBundle.LayoutFileBundle layoutFileBundle : bundles) {
-                final HashMap<String, String> imports = new HashMap<String, String>();
+                final MutableImportBag imports = new MutableImportBag();
                 for (ResourceBundle.NameTypeLocation imp : layoutFileBundle.getImports()) {
                     imports.put(imp.name, imp.type);
                 }
diff --git a/compiler/src/main/java/android/databinding/tool/LayoutBinder.java b/compiler/src/main/java/android/databinding/tool/LayoutBinder.java
index b8024c3b..9befb9cf 100644
--- a/compiler/src/main/java/android/databinding/tool/LayoutBinder.java
+++ b/compiler/src/main/java/android/databinding/tool/LayoutBinder.java
@@ -65,106 +65,6 @@ public class LayoutBinder implements FileScopeProvider {
 
     private LayoutBinderWriter mWriter;
     private ResourceBundle.LayoutFileBundle mBundle;
-    private static final String[] sJavaLangClasses = {
-            "Deprecated",
-            "Override",
-            "SafeVarargs",
-            "SuppressWarnings",
-            "Appendable",
-            "AutoCloseable",
-            "CharSequence",
-            "Cloneable",
-            "Comparable",
-            "Iterable",
-            "Readable",
-            "Runnable",
-            "Thread.UncaughtExceptionHandler",
-            "Boolean",
-            "Byte",
-            "Character",
-            "Character.Subset",
-            "Character.UnicodeBlock",
-            "Class",
-            "ClassLoader",
-            "Compiler",
-            "Double",
-            "Enum",
-            "Float",
-            "InheritableThreadLocal",
-            "Integer",
-            "Long",
-            "Math",
-            "Number",
-            "Object",
-            "Package",
-            "Process",
-            "ProcessBuilder",
-            "Runtime",
-            "RuntimePermission",
-            "SecurityManager",
-            "Short",
-            "StackTraceElement",
-            "StrictMath",
-            "String",
-            "StringBuffer",
-            "StringBuilder",
-            "System",
-            "Thread",
-            "ThreadGroup",
-            "ThreadLocal",
-            "Throwable",
-            "Void",
-            "Thread.State",
-            "ArithmeticException",
-            "ArrayIndexOutOfBoundsException",
-            "ArrayStoreException",
-            "ClassCastException",
-            "ClassNotFoundException",
-            "CloneNotSupportedException",
-            "EnumConstantNotPresentException",
-            "Exception",
-            "IllegalAccessException",
-            "IllegalArgumentException",
-            "IllegalMonitorStateException",
-            "IllegalStateException",
-            "IllegalThreadStateException",
-            "IndexOutOfBoundsException",
-            "InstantiationException",
-            "InterruptedException",
-            "NegativeArraySizeException",
-            "NoSuchFieldException",
-            "NoSuchMethodException",
-            "NullPointerException",
-            "NumberFormatException",
-            "ReflectiveOperationException",
-            "RuntimeException",
-            "SecurityException",
-            "StringIndexOutOfBoundsException",
-            "TypeNotPresentException",
-            "UnsupportedOperationException",
-            "AbstractMethodError",
-            "AssertionError",
-            "ClassCircularityError",
-            "ClassFormatError",
-            "Error",
-            "ExceptionInInitializerError",
-            "IllegalAccessError",
-            "IncompatibleClassChangeError",
-            "InstantiationError",
-            "InternalError",
-            "LinkageError",
-            "NoClassDefFoundError",
-            "NoSuchFieldError",
-            "NoSuchMethodError",
-            "OutOfMemoryError",
-            "StackOverflowError",
-            "ThreadDeath",
-            "UnknownError",
-            "UnsatisfiedLinkError",
-            "UnsupportedClassVersionError",
-            "VerifyError",
-            "VirtualMachineError",
-    };
 
     public final ResourceBundle.LayoutFileBundle mLayoutBundle;
 
@@ -197,9 +97,6 @@ public class LayoutBinder implements FileScopeProvider {
                         "getRoot().getContext()");
                 names.add("context");
             }
-            for (String javaLangClass : sJavaLangClasses) {
-                mExprModel.addImport(javaLangClass, "java.lang." + javaLangClass, null);
-            }
             // First resolve all the View fields
             // Ensure there are no conflicts with variable names
             for (BindingTargetBundle targetBundle : mBundle.getBindingTargetBundles()) {
diff --git a/compiler/src/main/java/android/databinding/tool/expr/CallbackExprModel.java b/compiler/src/main/java/android/databinding/tool/expr/CallbackExprModel.java
index af49ee1d..9c3495a6 100644
--- a/compiler/src/main/java/android/databinding/tool/expr/CallbackExprModel.java
+++ b/compiler/src/main/java/android/databinding/tool/expr/CallbackExprModel.java
@@ -18,6 +18,7 @@ package android.databinding.tool.expr;
 
 import android.databinding.tool.processing.ErrorMessages;
 import android.databinding.tool.processing.Scope;
+import android.databinding.tool.reflection.ImportBag;
 import android.databinding.tool.store.Location;
 import android.databinding.tool.util.L;
 import android.databinding.tool.util.Preconditions;
@@ -42,7 +43,7 @@ public class CallbackExprModel extends ExprModel {
     }
 
     @Override
-    public Map<String, String> getImports() {
+    public ImportBag getImports() {
         return mOriginal.getImports();
     }
 
diff --git a/compiler/src/main/java/android/databinding/tool/expr/ExprModel.java b/compiler/src/main/java/android/databinding/tool/expr/ExprModel.java
index 1aa57b08..6a946c69 100644
--- a/compiler/src/main/java/android/databinding/tool/expr/ExprModel.java
+++ b/compiler/src/main/java/android/databinding/tool/expr/ExprModel.java
@@ -20,9 +20,11 @@ import android.databinding.tool.BindingTarget;
 import android.databinding.tool.CallbackWrapper;
 import android.databinding.tool.InverseBinding;
 import android.databinding.tool.processing.ErrorMessages;
+import android.databinding.tool.reflection.ImportBag;
 import android.databinding.tool.reflection.ModelAnalyzer;
 import android.databinding.tool.reflection.ModelClass;
 import android.databinding.tool.reflection.ModelMethod;
+import android.databinding.tool.reflection.MutableImportBag;
 import android.databinding.tool.store.Location;
 import android.databinding.tool.util.L;
 import android.databinding.tool.util.Preconditions;
@@ -45,7 +47,7 @@ import java.util.stream.Collectors;
 public class ExprModel {
     public static final String SAFE_UNBOX_METHOD_NAME = "safeUnbox";
 
-    Map<String, Expr> mExprMap = new HashMap<String, Expr>();
+    Map<String, Expr> mExprMap = new HashMap<>();
 
     List<Expr> mBindingExpressions = new ArrayList<Expr>();
 
@@ -81,7 +83,7 @@ public class ExprModel {
 
     private boolean mSealed = false;
 
-    private Map<String, String> mImports = new HashMap<String, String>();
+    private MutableImportBag mImports = new MutableImportBag();
 
     private ParserRuleContext mCurrentParserContext;
     private Location mCurrentLocationInFile;
@@ -116,6 +118,15 @@ public class ExprModel {
         }
         //noinspection unchecked
         T existing = (T) mExprMap.get(expr.getUniqueKey());
+        if (existing == null) {
+            // if it is identifier, look for java.lang
+            // extra check to exclude StaticIdentifier since
+            // while registering it, we'll hit this case
+            if (expr instanceof IdentifierExpr && !(expr instanceof StaticIdentifierExpr)) {
+                IdentifierExpr id = (IdentifierExpr) expr;
+                existing = (T) lazyImportFromJavaLang(id.getName());
+            }
+        }
         if (existing != null) {
             Preconditions.check(expr.getParents().isEmpty(),
                     "If an expression already exists, it should've never been added to a parent,"
@@ -269,7 +280,7 @@ public class ExprModel {
         }
         while (true) {
             String candidate = cnt == 0 ? baseName : baseName + cnt;
-            if (!mImports.containsKey(candidate)) {
+            if (!mImports.contains(candidate)) {
                 return addImport(candidate, type, null);
             }
             cnt ++;
@@ -339,7 +350,7 @@ public class ExprModel {
     }
 
     public StaticIdentifierExpr addImport(String alias, String type, Location location) {
-        String existing = mImports.get(alias);
+        String existing = mImports.find(alias);
         if (existing != null) {
             if (existing.equals(type)) {
                 final StaticIdentifierExpr id = findStaticIdentifierExpr(type);
@@ -362,7 +373,7 @@ public class ExprModel {
         return id;
     }
 
-    public Map<String, String> getImports() {
+    public ImportBag getImports() {
         return mImports;
     }
 
@@ -784,6 +795,18 @@ public class ExprModel {
                 return (IdentifierExpr) expr;
             }
         }
+        return lazyImportFromJavaLang(name);
+    }
+
+    @Nullable
+    private StaticIdentifierExpr lazyImportFromJavaLang(String name) {
+        // check for java lang imports and add from there if it exists
+        if (ImportBag.JAVA_LANG_IMPORTS.contains(name)) {
+            final StaticIdentifierExpr id = staticIdentifier(name);
+            L.d("adding java lang import %s", name);
+            id.setUserDefinedType("java.lang." + name);
+            return id;
+        }
         return null;
     }
 }
diff --git a/compiler/src/main/java/android/databinding/tool/expr/ResourceExpr.java b/compiler/src/main/java/android/databinding/tool/expr/ResourceExpr.java
index 56418e3e..ce32889c 100644
--- a/compiler/src/main/java/android/databinding/tool/expr/ResourceExpr.java
+++ b/compiler/src/main/java/android/databinding/tool/expr/ResourceExpr.java
@@ -16,6 +16,7 @@
 package android.databinding.tool.expr;
 
 import android.databinding.tool.BindingTarget;
+import android.databinding.tool.reflection.ImportBag;
 import android.databinding.tool.reflection.ModelAnalyzer;
 import android.databinding.tool.reflection.ModelClass;
 import android.databinding.tool.writer.KCode;
@@ -66,7 +67,7 @@ public class ResourceExpr extends Expr {
 
     private Map<String, ModelClass> getResourceToTypeMapping(ModelAnalyzer modelAnalyzer) {
         if (mResourceToTypeMapping == null) {
-            final Map<String, String> imports = getModel().getImports();
+            final ImportBag imports = getModel().getImports();
             mResourceToTypeMapping = new HashMap<String, ModelClass>();
             mResourceToTypeMapping.put("anim", modelAnalyzer.findClass("android.view.animation.Animation",
                             imports));
diff --git a/compiler/src/main/java/android/databinding/tool/expr/TwoWayListenerExpr.java b/compiler/src/main/java/android/databinding/tool/expr/TwoWayListenerExpr.java
index 9444c3cc..4e1cc0d3 100644
--- a/compiler/src/main/java/android/databinding/tool/expr/TwoWayListenerExpr.java
+++ b/compiler/src/main/java/android/databinding/tool/expr/TwoWayListenerExpr.java
@@ -16,6 +16,7 @@
 package android.databinding.tool.expr;
 
 import android.databinding.tool.InverseBinding;
+import android.databinding.tool.reflection.ImportBag;
 import android.databinding.tool.reflection.ModelAnalyzer;
 import android.databinding.tool.reflection.ModelClass;
 import android.databinding.tool.writer.KCode;
@@ -37,7 +38,7 @@ public class TwoWayListenerExpr extends Expr {
     @Override
     protected ModelClass resolveType(ModelAnalyzer modelAnalyzer) {
         return modelAnalyzer.findClass(modelAnalyzer.libTypes.getInverseBindingListener(),
-                Collections.emptyMap());
+                ImportBag.EMPTY);
     }
 
     @Override
diff --git a/compiler/src/main/java/android/databinding/tool/reflection/ImportBag.kt b/compiler/src/main/java/android/databinding/tool/reflection/ImportBag.kt
new file mode 100644
index 00000000..8b6fae1a
--- /dev/null
+++ b/compiler/src/main/java/android/databinding/tool/reflection/ImportBag.kt
@@ -0,0 +1,171 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package android.databinding.tool.reflection
+
+class MutableImportBag : ImportBag() {
+    open fun put(alias : String, qName : String) {
+        imports.putIfAbsent(alias, qName)
+    }
+}
+
+private class ImmutableImportBag : ImportBag() {
+
+}
+
+/**
+ * A class that can keep a list of imports and also run an equals check against itself.
+ *
+ * We do import everything in java.lang which is a waste of memory and killer for equals
+ * check. Instead, this class optimizes that part automatically.
+ *
+ * Equals on ImportBag is important because we resolve classes based on imports.
+ */
+sealed class ImportBag {
+    // alias to Import mapping
+    protected val imports = mutableMapOf<String, String>()
+
+    fun find(alias: String) : String? {
+        return imports[alias] ?: importJavaLang(alias)
+    }
+
+    fun contains(alias: String) = find(alias) != null
+
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (other !is ImportBag) return false
+
+        if (imports != other.imports) return false
+
+        return true
+    }
+
+    override fun hashCode(): Int {
+        return imports.hashCode()
+    }
+
+    companion object {
+        @JvmField
+        val EMPTY : ImportBag = ImmutableImportBag()
+        @JvmField
+        val JAVA_LANG_IMPORTS = setOf(
+                "Deprecated",
+                "Override",
+                "SafeVarargs",
+                "SuppressWarnings",
+                "Appendable",
+                "AutoCloseable",
+                "CharSequence",
+                "Cloneable",
+                "Comparable",
+                "Iterable",
+                "Readable",
+                "Runnable",
+                "Thread.UncaughtExceptionHandler",
+                "Boolean",
+                "Byte",
+                "Character",
+                "Character.Subset",
+                "Character.UnicodeBlock",
+                "Class",
+                "ClassLoader",
+                "Compiler",
+                "Double",
+                "Enum",
+                "Float",
+                "InheritableThreadLocal",
+                "Integer",
+                "Long",
+                "Math",
+                "Number",
+                "Object",
+                "Package",
+                "Process",
+                "ProcessBuilder",
+                "Runtime",
+                "RuntimePermission",
+                "SecurityManager",
+                "Short",
+                "StackTraceElement",
+                "StrictMath",
+                "String",
+                "StringBuffer",
+                "StringBuilder",
+                "System",
+                "Thread",
+                "ThreadGroup",
+                "ThreadLocal",
+                "Throwable",
+                "Void",
+                "Thread.State",
+                "ArithmeticException",
+                "ArrayIndexOutOfBoundsException",
+                "ArrayStoreException",
+                "ClassCastException",
+                "ClassNotFoundException",
+                "CloneNotSupportedException",
+                "EnumConstantNotPresentException",
+                "Exception",
+                "IllegalAccessException",
+                "IllegalArgumentException",
+                "IllegalMonitorStateException",
+                "IllegalStateException",
+                "IllegalThreadStateException",
+                "IndexOutOfBoundsException",
+                "InstantiationException",
+                "InterruptedException",
+                "NegativeArraySizeException",
+                "NoSuchFieldException",
+                "NoSuchMethodException",
+                "NullPointerException",
+                "NumberFormatException",
+                "ReflectiveOperationException",
+                "RuntimeException",
+                "SecurityException",
+                "StringIndexOutOfBoundsException",
+                "TypeNotPresentException",
+                "UnsupportedOperationException",
+                "AbstractMethodError",
+                "AssertionError",
+                "ClassCircularityError",
+                "ClassFormatError",
+                "Error",
+                "ExceptionInInitializerError",
+                "IllegalAccessError",
+                "IncompatibleClassChangeError",
+                "InstantiationError",
+                "InternalError",
+                "LinkageError",
+                "NoClassDefFoundError",
+                "NoSuchFieldError",
+                "NoSuchMethodError",
+                "OutOfMemoryError",
+                "StackOverflowError",
+                "ThreadDeath",
+                "UnknownError",
+                "UnsatisfiedLinkError",
+                "UnsupportedClassVersionError",
+                "VerifyError",
+                "VirtualMachineError"
+        )
+        private fun importJavaLang(alias : String) : String? {
+            return if (JAVA_LANG_IMPORTS.contains(alias)) {
+                "java.lang.$alias"
+            } else {
+                null
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/compiler/src/main/java/android/databinding/tool/reflection/InjectedClass.java b/compiler/src/main/java/android/databinding/tool/reflection/InjectedClass.java
index 45bedcb0..1ae22afa 100644
--- a/compiler/src/main/java/android/databinding/tool/reflection/InjectedClass.java
+++ b/compiler/src/main/java/android/databinding/tool/reflection/InjectedClass.java
@@ -46,7 +46,7 @@ public class InjectedClass extends ModelClass {
         mSuperClass = superClass;
     }
 
-    public void addVariable(String name, String type, Map<String, String> imports) {
+    public void addVariable(String name, String type, ImportBag imports) {
         String capName = StringUtils.capitalize(name);
         String setName = "set" + capName;
         String getName = "get" + capName;
diff --git a/compiler/src/main/java/android/databinding/tool/reflection/InjectedMethod.java b/compiler/src/main/java/android/databinding/tool/reflection/InjectedMethod.java
index be1f8d79..0a9f3ce5 100644
--- a/compiler/src/main/java/android/databinding/tool/reflection/InjectedMethod.java
+++ b/compiler/src/main/java/android/databinding/tool/reflection/InjectedMethod.java
@@ -31,13 +31,13 @@ public class InjectedMethod extends ModelMethod {
     private final String mName;
     private final String mReturnTypeName;
     private final String[] mParameterTypeNames;
-    private final Map<String, String> mImports;
+    private final ImportBag mImports;
     private ModelClass[] mParameterTypes;
     private ModelClass mReturnType;
     private boolean mIsStatic;
 
     public InjectedMethod(InjectedClass containingClass, boolean isStatic, String name,
-            Map<String, String> imports, String returnType, String... parameters) {
+            ImportBag imports, String returnType, String... parameters) {
         mContainingClass = containingClass;
         mName = name;
         mIsStatic = isStatic;
diff --git a/compiler/src/main/java/android/databinding/tool/reflection/ModelAnalyzer.java b/compiler/src/main/java/android/databinding/tool/reflection/ModelAnalyzer.java
index f650b9c5..0671165d 100644
--- a/compiler/src/main/java/android/databinding/tool/reflection/ModelAnalyzer.java
+++ b/compiler/src/main/java/android/databinding/tool/reflection/ModelAnalyzer.java
@@ -19,7 +19,6 @@ import android.databinding.tool.Context;
 import android.databinding.tool.LibTypes;
 import android.databinding.tool.util.L;
 import android.databinding.tool.util.Preconditions;
-import com.android.annotations.Nullable;
 
 import java.util.HashMap;
 import java.util.List;
@@ -251,14 +250,14 @@ public abstract class ModelAnalyzer {
         return "null";
     }
 
-    public final ModelClass findClass(String className, Map<String, String> imports) {
+    public final ModelClass findClass(String className, ImportBag imports) {
         if (mInjectedClasses.containsKey(className)) {
             return mInjectedClasses.get(className);
         }
         return findClassInternal(className, imports);
     }
 
-    public abstract ModelClass findClassInternal(String className, Map<String, String> imports);
+    public abstract ModelClass findClassInternal(String className, ImportBag importBag);
 
     public abstract ModelClass findClass(Class classType);
 
diff --git a/compiler/src/main/java/android/databinding/tool/reflection/annotation/AnnotationAnalyzer.java b/compiler/src/main/java/android/databinding/tool/reflection/annotation/AnnotationAnalyzer.java
index 7ef7585c..ec7b872e 100644
--- a/compiler/src/main/java/android/databinding/tool/reflection/annotation/AnnotationAnalyzer.java
+++ b/compiler/src/main/java/android/databinding/tool/reflection/annotation/AnnotationAnalyzer.java
@@ -16,6 +16,7 @@
 package android.databinding.tool.reflection.annotation;
 
 import android.databinding.tool.LibTypes;
+import android.databinding.tool.reflection.ImportBag;
 import android.databinding.tool.reflection.ModelAnalyzer;
 import android.databinding.tool.reflection.ModelClass;
 import android.databinding.tool.reflection.TypeUtil;
@@ -71,7 +72,7 @@ public class AnnotationAnalyzer extends ModelAnalyzer {
     }
 
     @Override
-    public ModelClass findClassInternal(String className, Map<String, String> imports) {
+    public ModelClass findClassInternal(String className, ImportBag imports) {
         className = className.trim();
         int numDimensions = 0;
         while (className.endsWith("[]")) {
@@ -130,12 +131,12 @@ public class AnnotationAnalyzer extends ModelAnalyzer {
         return new AnnotationClass(type);
     }
 
-    private TypeElement getTypeElement(String className, Map<String, String> imports) {
+    private TypeElement getTypeElement(String className, ImportBag imports) {
         Elements elementUtils = getElementUtils();
         final boolean hasDot = className.indexOf('.') >= 0;
         if (!hasDot && imports != null) {
             // try the imports
-            String importedClass = imports.get(className);
+            String importedClass = imports.find(className);
             if (importedClass != null) {
                 className = importedClass;
             }
@@ -177,7 +178,7 @@ public class AnnotationAnalyzer extends ModelAnalyzer {
     }
 
     private ArrayList<String> splitTemplateParameters(String templateParameters) {
-        ArrayList<String> list = new ArrayList<String>();
+        ArrayList<String> list = new ArrayList<>();
         int index = 0;
         int openCount = 0;
         StringBuilder arg = new StringBuilder();
diff --git a/compiler/src/main/java/android/databinding/tool/store/SetterStore.java b/compiler/src/main/java/android/databinding/tool/store/SetterStore.java
index b8c07ec9..4fce56ef 100644
--- a/compiler/src/main/java/android/databinding/tool/store/SetterStore.java
+++ b/compiler/src/main/java/android/databinding/tool/store/SetterStore.java
@@ -16,6 +16,7 @@
 package android.databinding.tool.store;
 
 import android.databinding.tool.Context;
+import android.databinding.tool.reflection.ImportBag;
 import android.databinding.tool.reflection.ModelAnalyzer;
 import android.databinding.tool.reflection.ModelClass;
 import android.databinding.tool.reflection.ModelMethod;
@@ -553,7 +554,7 @@ public class SetterStore {
     }
 
     public SetterCall getSetterCall(String attribute, ModelClass viewType,
-            ModelClass valueType, Map<String, String> imports) {
+                                    ModelClass valueType, ImportBag imports) {
         if (viewType == null) {
             return null;
         }
@@ -628,7 +629,7 @@ public class SetterStore {
     }
 
     public BindingGetterCall getGetterCall(String attribute, ModelClass viewType,
-            ModelClass valueType, Map<String, String> imports) {
+            ModelClass valueType, ImportBag imports) {
         if (viewType == null) {
             return null;
         } else if (viewType.isViewDataBinding()) {
@@ -660,7 +661,7 @@ public class SetterStore {
                             ModelAnalyzer modelAnalyzer = ModelAnalyzer.getInstance();
                             ModelClass listenerType = modelAnalyzer.findClass(
                                     modelAnalyzer.libTypes.getInverseBindingListener(),
-                                    Collections.emptyMap());
+                                    ImportBag.EMPTY);
                             BindingSetterCall eventCall = getSetterCall(
                                     inverseDescription.event, finalViewType, listenerType, imports);
                             if (eventCall == null) {
@@ -704,7 +705,7 @@ public class SetterStore {
     }
 
     private ModelMethod getBestSetter(ModelClass viewType, ModelClass argumentType,
-            String attribute, Map<String, String> imports) {
+            String attribute, ImportBag imports) {
         if (viewType.isGeneric()) {
             argumentType = eraseType(argumentType, viewType.getTypeArguments());
             viewType = viewType.erasure();
@@ -747,7 +748,7 @@ public class SetterStore {
     }
 
     private InverseMethod getBestGetter(ModelClass viewType, ModelClass valueType,
-            String attribute, Map<String, String> imports) {
+            String attribute, ImportBag imports) {
         @SuppressWarnings("WeakerAccess")
         class BestSetter {
             @Nullable
@@ -797,7 +798,7 @@ public class SetterStore {
         if (bestSetter.description != null) {
             ModelAnalyzer modelAnalyzer = ModelAnalyzer.getInstance();
             final ModelClass listenerType = modelAnalyzer.findClass(
-                    modelAnalyzer.libTypes.getInverseBindingListener(), Collections.emptyMap());
+                    modelAnalyzer.libTypes.getInverseBindingListener(), ImportBag.EMPTY);
             SetterCall eventSetter = getSetterCall(bestSetter.description.event, viewType,
                     listenerType, imports);
             if (eventSetter == null) {
@@ -856,7 +857,7 @@ public class SetterStore {
      * another for an argument. It is assumed that both view types match the targeted view.
      * <p>
      * Note that this has different priorities than
-     * {@link #isBetterReturn(ModelClass, ModelClass, ModelClass, ModelClass, ModelClass, Map)}
+     * {@link #isBetterReturn(ModelClass, ModelClass, ModelClass, ModelClass, ModelClass, ImportBag)}
      *
      * @param argument The argument type being passed to the setter.
      * @param newViewType The type of the view in the BindingAdapter or setter method.
@@ -873,7 +874,7 @@ public class SetterStore {
     private boolean isBetterParameter(@NonNull ModelClass argument,
             @NonNull ModelClass newViewType, @NonNull ModelClass newParameter,
             @Nullable ModelClass oldViewType, @Nullable ModelClass oldParameter,
-            @Nullable Map<String, String> imports) {
+            @Nullable ImportBag imports) {
         if (oldParameter == null) {
             // just validate that it can be converted
             return calculateConversionPriority(argument, newParameter, imports) >= 0;
@@ -913,7 +914,7 @@ public class SetterStore {
      * than another for a method call. It is assumed that both view types match the targeted view.
      * <p>
      * Note that this has different priorities than
-     * {@link #isBetterParameter(ModelClass, ModelClass, ModelClass, ModelClass, ModelClass, Map)}
+     * {@link #isBetterParameter(ModelClass, ModelClass, ModelClass, ModelClass, ModelClass, ImportBag)}
      *
      * @param expected The type that is expected from the getter.
      * @param newViewType The type of the view in the InverseBindingAdapter or getter method.
@@ -931,7 +932,7 @@ public class SetterStore {
     private boolean isBetterReturn(@NonNull ModelClass expected,
             @NonNull ModelClass newViewType, @NonNull ModelClass newReturnType,
             @Nullable ModelClass oldViewType, @Nullable ModelClass oldReturnType,
-            @Nullable Map<String, String> imports) {
+            @Nullable ImportBag imports) {
         if (oldReturnType == null) {
             // just validate that it can be converted
             return calculateConversionPriority(newReturnType, expected, imports) >= 0;
@@ -980,7 +981,7 @@ public class SetterStore {
      * where {@code 0} is an exact match and greater numbers are progressively worse matches.
      */
     private int calculateConversionPriority(@NonNull ModelClass from, @NonNull ModelClass to,
-            @Nullable Map<String, String> imports) {
+            @Nullable ImportBag imports) {
         if (to.equals(from)) {
             return 0; // exact match
         }
@@ -1004,7 +1005,7 @@ public class SetterStore {
     }
 
     private MethodDescription getConversionMethod(ModelClass from, ModelClass to,
-            Map<String, String> imports) {
+            ImportBag imports) {
         if (from != null && to != null) {
             if (to.isObject()) {
                 return null;