From c0639316b108ea4ba98d7c74187de4078858c660 Mon Sep 17 00:00:00 2001
From: Zac Sweers <zac.sweers@gmail.com>
Date: Tue, 24 Sep 2019 16:05:12 -0400
Subject: [PATCH] Don't try to access unsafe APIs on android 29+ (#913)

* Don't try to access unsafe APIs on android 29+

Resolves #872. Not sure if we want to try caching some of these lookups

* Checkstyle

* Use correct inner class naming

Co-Authored-By: Jake Wharton <jakew@google.com>

* Name variable ignored

* Cache android check
---
 .../java/com/squareup/moshi/ClassFactory.java | 63 ++++++++++++-------
 1 file changed, 41 insertions(+), 22 deletions(-)

diff --git a/moshi/src/main/java/com/squareup/moshi/ClassFactory.java b/moshi/src/main/java/com/squareup/moshi/ClassFactory.java
index b332039..87d21ae 100644
--- a/moshi/src/main/java/com/squareup/moshi/ClassFactory.java
+++ b/moshi/src/main/java/com/squareup/moshi/ClassFactory.java
@@ -34,6 +34,9 @@ abstract class ClassFactory<T> {
   abstract T newInstance() throws
       InvocationTargetException, IllegalAccessException, InstantiationException;
 
+  private static volatile boolean androidChecked = false;
+  private static volatile boolean tryUnsafe = true;
+
   public static <T> ClassFactory<T> get(final Class<?> rawType) {
     // Try to find a no-args constructor. May be any visibility including private.
     try {
@@ -54,29 +57,45 @@ abstract class ClassFactory<T> {
       // No no-args constructor. Fall back to something more magical...
     }
 
-    // Try the JVM's Unsafe mechanism.
-    // public class Unsafe {
-    //   public Object allocateInstance(Class<?> type);
-    // }
-    try {
-      Class<?> unsafeClass = Class.forName("sun.misc.Unsafe");
-      Field f = unsafeClass.getDeclaredField("theUnsafe");
-      f.setAccessible(true);
-      final Object unsafe = f.get(null);
-      final Method allocateInstance = unsafeClass.getMethod("allocateInstance", Class.class);
-      return new ClassFactory<T>() {
-        @SuppressWarnings("unchecked")
-        @Override public T newInstance() throws InvocationTargetException, IllegalAccessException {
-          return (T) allocateInstance.invoke(unsafe, rawType);
+    if (!androidChecked) {
+      try {
+        Class<?> androidBuildClass = Class.forName("android.os.Build$VERSION");
+        Field sdkIntField = androidBuildClass.getDeclaredField("SDK_INT");
+        int sdk = (int) sdkIntField.get(null);
+        if (sdk >= 29) {
+          tryUnsafe = false;
         }
-        @Override public String toString() {
-          return rawType.getName();
-        }
-      };
-    } catch (IllegalAccessException e) {
-      throw new AssertionError();
-    } catch (ClassNotFoundException | NoSuchMethodException | NoSuchFieldException ignored) {
-      // Not the expected version of the Oracle Java library!
+      } catch (Exception ignored) {
+      } finally {
+        androidChecked = true;
+      }
+    }
+    if (tryUnsafe) {
+      // Try the JVM's Unsafe mechanism.
+      // public class Unsafe {
+      //   public Object allocateInstance(Class<?> type);
+      // }
+      try {
+        Class<?> unsafeClass = Class.forName("sun.misc.Unsafe");
+        Field f = unsafeClass.getDeclaredField("theUnsafe");
+        f.setAccessible(true);
+        final Object unsafe = f.get(null);
+        final Method allocateInstance = unsafeClass.getMethod("allocateInstance", Class.class);
+        return new ClassFactory<T>() {
+          @SuppressWarnings("unchecked")
+          @Override
+          public T newInstance() throws InvocationTargetException, IllegalAccessException {
+            return (T) allocateInstance.invoke(unsafe, rawType);
+          }
+          @Override public String toString() {
+            return rawType.getName();
+          }
+        };
+      } catch (IllegalAccessException e) {
+        throw new AssertionError();
+      } catch (ClassNotFoundException | NoSuchMethodException | NoSuchFieldException ignored) {
+        // Not the expected version of the Oracle Java library!
+      }
     }
 
     // Try (post-Gingerbread) Dalvik/libcore's ObjectStreamClass mechanism.