Android: adds Get(Static)MethodIDOrNULL.

When generating JNI bindings for system classes, we try to get the ids
for methods based in the .class file in the SDK.
However, this may trigger run-time errors when trying to run on an older
SDK.
For these system classes, the JNI generator will bind using the "OrNULL"
variation.

BUG=152987
TEST=

Review URL: https://chromiumcodereview.appspot.com/10996063

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@159769 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 53 insertions, 17 deletions

diff --git a/base/android/jni_android.cc b/base/android/jni_android.cc
index d3b4e79..a34bc18 100644
--- a/base/android/jni_android.cc
+++ b/base/android/jni_android.cc
@@ -96,6 +96,36 @@ std::string GetJavaExceptionInfo(JNIEnv* env, jthrowable java_throwable) {
 
   return ConvertJavaStringToUTF8(exception_string);
 }
+
+enum MethodType {
+  METHODTYPE_STATIC,
+  METHODTYPE_NORMAL,
+};
+
+enum ExceptionCheck {
+  EXCEPTIONCHECK_YES,
+  EXCEPTIONCHECK_NO,
+};
+
+template<MethodType method_type, ExceptionCheck exception_check>
+jmethodID GetMethodIDInternal(JNIEnv* env,
+                              jclass clazz,
+                              const char* method_name,
+                              const char* jni_signature) {
+  jmethodID method_id = method_type == METHODTYPE_STATIC ?
+      env->GetStaticMethodID(clazz, method_name, jni_signature) :
+      env->GetMethodID(clazz, method_name, jni_signature);
+  if (exception_check == EXCEPTIONCHECK_YES) {
+    CHECK(!base::android::ClearException(env) && method_id) <<
+      "Failed to find " <<
+      (method_type == METHODTYPE_STATIC ? "static " : "") <<
+      "method " << method_name << " " << jni_signature;
+  } else if (base::android::HasException(env)) {
+    env->ExceptionClear();
+  }
+  return method_id;
+}
+
 }  // namespace
 
 namespace base {
@@ -138,7 +168,7 @@ ScopedJavaLocalRef<jclass> GetClass(JNIEnv* env, const char* class_name) {
 
 jclass GetUnscopedClass(JNIEnv* env, const char* class_name) {
   jclass clazz = env->FindClass(class_name);
-  CHECK(clazz && !ClearException(env)) << "Failed to find class " << class_name;
+  CHECK(!ClearException(env) && clazz) << "Failed to find class " << class_name;
   return clazz;
 }
 
@@ -165,11 +195,16 @@ jmethodID GetMethodID(JNIEnv* env,
                       jclass clazz,
                       const char* method_name,
                       const char* jni_signature) {
-  jmethodID method_id =
-      env->GetMethodID(clazz, method_name, jni_signature);
-  CHECK(method_id && !ClearException(env)) << "Failed to find method " <<
-      method_name << " " << jni_signature;
-  return method_id;
+  return GetMethodIDInternal<METHODTYPE_NORMAL, EXCEPTIONCHECK_YES>(
+      env, clazz, method_name, jni_signature);
+}
+
+jmethodID GetMethodIDOrNull(JNIEnv* env,
+                            jclass clazz,
+                            const char* method_name,
+                            const char* jni_signature) {
+  return GetMethodIDInternal<METHODTYPE_NORMAL, EXCEPTIONCHECK_NO>(
+      env, clazz, method_name, jni_signature);
 }
 
 jmethodID GetStaticMethodID(JNIEnv* env,
@@ -184,11 +219,16 @@ jmethodID GetStaticMethodID(JNIEnv* env,
                             jclass clazz,
                             const char* method_name,
                             const char* jni_signature) {
-  jmethodID method_id =
-      env->GetStaticMethodID(clazz, method_name, jni_signature);
-  CHECK(method_id && !ClearException(env)) << "Failed to find static method " <<
-      method_name << " " << jni_signature;
-  return method_id;
+  return GetMethodIDInternal<METHODTYPE_STATIC, EXCEPTIONCHECK_YES>(
+      env, clazz, method_name, jni_signature);
+}
+
+jmethodID GetStaticMethodIDOrNull(JNIEnv* env,
+                                  jclass clazz,
+                                  const char* method_name,
+                                  const char* jni_signature) {
+  return GetMethodIDInternal<METHODTYPE_STATIC, EXCEPTIONCHECK_NO>(
+      env, clazz, method_name, jni_signature);
 }
 
 bool HasMethod(JNIEnv* env,
@@ -211,10 +251,8 @@ jfieldID GetFieldID(JNIEnv* env,
                     const char* field_name,
                     const char* jni_signature) {
   jfieldID field_id = env->GetFieldID(clazz.obj(), field_name, jni_signature);
-  CHECK(field_id && !ClearException(env)) << "Failed to find field " <<
+  CHECK(!ClearException(env) && field_id) << "Failed to find field " <<
       field_name << " " << jni_signature;
-  bool error = ClearException(env);
-  DCHECK(!error);
   return field_id;
 }
 
@@ -238,10 +276,8 @@ jfieldID GetStaticFieldID(JNIEnv* env,
                           const char* jni_signature) {
   jfieldID field_id =
       env->GetStaticFieldID(clazz.obj(), field_name, jni_signature);
-  CHECK(field_id && !ClearException(env)) << "Failed to find static field " <<
+  CHECK(!ClearException(env) && field_id) << "Failed to find static field " <<
       field_name << " " << jni_signature;
-  bool error = ClearException(env);
-  DCHECK(!error);
   return field_id;
 }