Add an SPI for @Provides methods (using the extensions SPI) so that users can

do more analysis (with the enclosing instance, method, etc..).

Notably, this can let users write analysis that looks for @Provides methods
declared with @Nullable, and compare against injection points w/o @Nullable,
failing if so.
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=62834918

3 files changed, 66 insertions, 2 deletions

diff --git a/core/src/com/google/inject/internal/ProviderMethod.java b/core/src/com/google/inject/internal/ProviderMethod.java
index 62214992..d8bc18b1 100644
--- a/core/src/com/google/inject/internal/ProviderMethod.java
+++ b/core/src/com/google/inject/internal/ProviderMethod.java
@@ -24,8 +24,13 @@ import com.google.inject.Key;
 import com.google.inject.PrivateBinder;
 import com.google.inject.Provider;
 import com.google.inject.internal.util.StackTraceElements;
+import com.google.inject.spi.BindingTargetVisitor;
 import com.google.inject.spi.Dependency;
-import com.google.inject.spi.ProviderWithDependencies;
+import com.google.inject.spi.HasDependencies;
+import com.google.inject.spi.ProviderInstanceBinding;
+import com.google.inject.spi.ProviderWithExtensionVisitor;
+import com.google.inject.spi.ProvidesMethodBinding;
+import com.google.inject.spi.ProvidesMethodTargetVisitor;
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.InvocationTargetException;
@@ -38,7 +43,8 @@ import java.util.Set;
  *
  * @author jessewilson@google.com (Jesse Wilson)
  */
-public class ProviderMethod<T> implements ProviderWithDependencies<T> {
+public class ProviderMethod<T> implements ProviderWithExtensionVisitor<T>, HasDependencies,
+    ProvidesMethodBinding<T> {
   private final Key<T> key;
   private final Class<? extends Annotation> scopeAnnotation;
   private final Object instance;
@@ -76,6 +82,10 @@ public class ProviderMethod<T> implements ProviderWithDependencies<T> {
   public Object getInstance() {
     return instance;
   }
+  
+  public Object getEnclosingInstance() {
+    return instance;
+  }
 
   public void configure(Binder binder) {
     binder = binder.withSource(method);
@@ -114,6 +124,15 @@ public class ProviderMethod<T> implements ProviderWithDependencies<T> {
   public Set<Dependency<?>> getDependencies() {
     return dependencies;
   }
+  
+  @SuppressWarnings("unchecked")
+  public <B, V> V acceptExtensionVisitor(BindingTargetVisitor<B, V> visitor,
+      ProviderInstanceBinding<? extends B> binding) {
+    if (visitor instanceof ProvidesMethodTargetVisitor) {
+      return ((ProvidesMethodTargetVisitor<T, V>)visitor).visit(this);
+    }
+    return visitor.visit(binding);
+  }
 
   @Override public String toString() {
     return "@Provides " + StackTraceElements.forMember(method).toString();
diff --git a/core/src/com/google/inject/spi/ProvidesMethodBinding.java b/core/src/com/google/inject/spi/ProvidesMethodBinding.java
new file mode 100644
index 00000000..f35d9a44
--- /dev/null
+++ b/core/src/com/google/inject/spi/ProvidesMethodBinding.java
@@ -0,0 +1,24 @@
+package com.google.inject.spi;
+
+import com.google.inject.Key;
+import com.google.inject.Provides;
+
+import java.lang.reflect.Method;
+
+/**
+ * An {@literal @}{@link Provides} binding.
+ * 
+ * @since 4.0
+ * @author sameb@google.com (Sam Berlin)
+ */
+public interface ProvidesMethodBinding<T> extends HasDependencies {
+  
+  /** Returns the method this binding uses. */
+  Method getMethod(); 
+  
+  /** Returns the instance of the object the method is defined in. */
+  Object getEnclosingInstance();
+  
+  /** Returns the key of the binding. */
+  Key<T> getKey();
+}
diff --git a/core/src/com/google/inject/spi/ProvidesMethodTargetVisitor.java b/core/src/com/google/inject/spi/ProvidesMethodTargetVisitor.java
new file mode 100644
index 00000000..d6c49734
--- /dev/null
+++ b/core/src/com/google/inject/spi/ProvidesMethodTargetVisitor.java
@@ -0,0 +1,21 @@
+package com.google.inject.spi;
+
+import com.google.inject.Provides;
+import com.google.inject.spi.BindingTargetVisitor;
+
+/**
+ * A visitor for the {@literal @}{@link Provides} bindings.
+ * <p>
+ * If your {@link BindingTargetVisitor} implements this interface, bindings created by using
+ * {@code @Provides} will be visited through this interface.
+ *
+ * @since 4.0
+ * @author sameb@google.com (Sam Berlin)
+ */
+public interface ProvidesMethodTargetVisitor<T, V> extends BindingTargetVisitor<T, V> {
+  
+  /**
+   * Visits an {@link ProvidesMethodBinding} created with an {@literal @}{@link Provides} method.
+   */
+  V visit(ProvidesMethodBinding<? extends T> providesMethodBinding);
+}