PHP namespaces for nested messages and enums (#4536)

* uses namespaces for nested messages and enums

* fixes namespaces for PHP dist

* fixes namespace for Descriptors, adds Cardinality and Kind

* fixes nested namespaces for reserved words and adds tests

* adds tests and generator fix for php class prefixes

* fixes escaping of protobuf packages, enum comments, misc others

* nice refactor of generated code

* adds class files for backwards compatibility

* simplifies code with templates

* adds compatibility files to makefile

* cleanup of generator and fixes nested namespace bug

* regenerates proto types

* remove internal BC classes

* adds deprecated warning, adds methods back

* simplifies if statement

* fixes dist files

* addresses review comments

* adds back TYPE_URL_PREFIX constant

* adds @deprecated to old nested class files

* skips tests which require a separate process when protobuf.so is enabled

* Adds tests for legacy nested classes that do not require separate processes to test

* uses legacy names for GPBUtil message check

* adds block for IDE @deprecated message

* Namespace for nested message/enum in c extension

* Remove unused code

19 files changed, 297 insertions, 120 deletions

diff --git a/php/tests/array_test.php b/php/tests/array_test.php
index 1a26d72a..36a649ed 100644
--- a/php/tests/array_test.php
+++ b/php/tests/array_test.php
@@ -5,7 +5,7 @@ require_once('test_util.php');
 use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBType;
 use Foo\TestMessage;
-use Foo\TestMessage_Sub;
+use Foo\TestMessage\Sub;
 
 class RepeatedFieldTest extends PHPUnit_Framework_TestCase
 {
@@ -456,10 +456,10 @@ class RepeatedFieldTest extends PHPUnit_Framework_TestCase
 
     public function testMessage()
     {
-        $arr = new RepeatedField(GPBType::MESSAGE, TestMessage_Sub::class);
+        $arr = new RepeatedField(GPBType::MESSAGE, Sub::class);
 
         // Test append.
-        $sub_m = new TestMessage_Sub();
+        $sub_m = new Sub();
         $sub_m->setA(1);
         $arr[] = $sub_m;
         $this->assertSame(1, $arr[0]->getA());
@@ -467,15 +467,15 @@ class RepeatedFieldTest extends PHPUnit_Framework_TestCase
         $this->assertEquals(1, count($arr));
 
         // Test set.
-        $sub_m = new TestMessage_Sub();
+        $sub_m = new Sub();
         $sub_m->setA(2);
         $arr[0] = $sub_m;
         $this->assertSame(2, $arr[0]->getA());
 
         // Test foreach.
-        $arr = new RepeatedField(GPBType::MESSAGE, TestMessage_Sub::class);
+        $arr = new RepeatedField(GPBType::MESSAGE, Sub::class);
         for ($i = 0; $i < 3; $i++) {
-          $arr[] = new TestMessage_Sub();
+          $arr[] = new Sub();
           $arr[$i]->setA($i);
         }
         $i = 0;
diff --git a/php/tests/descriptors_test.php b/php/tests/descriptors_test.php
index 17e8a4f2..93683b82 100644
--- a/php/tests/descriptors_test.php
+++ b/php/tests/descriptors_test.php
@@ -10,7 +10,7 @@ use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\MapField;
 use Descriptors\TestDescriptorsEnum;
 use Descriptors\TestDescriptorsMessage;
-use Descriptors\TestDescriptorsMessage_Sub;
+use Descriptors\TestDescriptorsMessage\Sub;
 
 class DescriptorsTest extends TestBase
 {
diff --git a/php/tests/encode_decode_test.php b/php/tests/encode_decode_test.php
index 74d5526d..d36b883e 100644
--- a/php/tests/encode_decode_test.php
+++ b/php/tests/encode_decode_test.php
@@ -7,7 +7,7 @@ use Google\Protobuf\RepeatedField;
 use Google\Protobuf\GPBType;
 use Foo\TestEnum;
 use Foo\TestMessage;
-use Foo\TestMessage_Sub;
+use Foo\TestMessage\Sub;
 use Foo\TestPackedMessage;
 use Foo\TestRandomFieldOrder;
 use Foo\TestUnpackedMessage;
@@ -82,7 +82,7 @@ class EncodeDecodeTest extends TestBase
         $n->mergeFromString($data);
         $this->assertSame('abc', $n->getOneofString());
 
-        $sub_m = new TestMessage_Sub();
+        $sub_m = new Sub();
         $sub_m->setA(1);
         $m->setOneofMessage($sub_m);
         $data = $m->serializeToString();
@@ -105,7 +105,7 @@ class EncodeDecodeTest extends TestBase
         $this->assertSame("oneof_string", $n->getMyOneof());
         $this->assertSame("", $n->getOneofString());
 
-        $sub_m = new TestMessage_Sub();
+        $sub_m = new Sub();
         $m->setOneofMessage($sub_m);
         $data = $m->serializeToString();
         $n = new TestMessage();
diff --git a/php/tests/gdb_test.sh b/php/tests/gdb_test.sh
index a5f6306e..36fa31bb 100755
--- a/php/tests/gdb_test.sh
+++ b/php/tests/gdb_test.sh
@@ -11,8 +11,8 @@ php -i | grep "Configuration"
 # gdb --args php -dextension=../ext/google/protobuf/modules/protobuf.so `which
 # phpunit` --bootstrap autoload.php tmp_test.php
 #
-# gdb --args php -dextension=../ext/google/protobuf/modules/protobuf.so `which phpunit` --bootstrap autoload.php encode_decode_test.php
+gdb --args php -dextension=../ext/google/protobuf/modules/protobuf.so `which phpunit` --bootstrap autoload.php generated_class_test.php
 #
-gdb --args php -dextension=../ext/google/protobuf/modules/protobuf.so memory_leak_test.php
+# gdb --args php -dextension=../ext/google/protobuf/modules/protobuf.so memory_leak_test.php
 #
 # USE_ZEND_ALLOC=0 valgrind --leak-check=yes php -dextension=../ext/google/protobuf/modules/protobuf.so memory_leak_test.php
diff --git a/php/tests/generated_class_test.php b/php/tests/generated_class_test.php
index fbee29bc..9f20bddc 100644
--- a/php/tests/generated_class_test.php
+++ b/php/tests/generated_class_test.php
@@ -8,14 +8,20 @@ require_once('test_util.php');
 use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\MapField;
 use Google\Protobuf\Internal\GPBType;
+use Bar\TestLegacyMessage;
+use Bar\TestLegacyMessage_NestedEnum;
+use Bar\TestLegacyMessage_NestedMessage;
 use Foo\TestEnum;
 use Foo\TestIncludeNamespaceMessage;
 use Foo\TestIncludePrefixMessage;
 use Foo\TestMessage;
+use Foo\TestMessage\Sub;
 use Foo\TestMessage_Sub;
+use Foo\TestMessage\NestedEnum;
 use Foo\TestReverseFieldOrder;
 use Foo\testLowerCaseMessage;
 use Foo\testLowerCaseEnum;
+use PBEmpty\PBEcho\TestEmptyPackage;
 use Php\Test\TestNamespace;
 
 class GeneratedClassTest extends TestBase
@@ -231,9 +237,26 @@ class GeneratedClassTest extends TestBase
     public function testNestedEnum()
     {
         $m = new TestMessage();
+        $m->setOptionalNestedEnum(NestedEnum::ZERO);
+    }
+
+    public function testLegacyNestedEnum()
+    {
+        $m = new TestMessage();
         $m->setOptionalNestedEnum(\Foo\TestMessage_NestedEnum::ZERO);
     }
 
+    public function testLegacyTypehintWithNestedEnums()
+    {
+        $this->legacyEnum(new TestLegacyMessage\NestedEnum);
+    }
+
+    private function legacyEnum(TestLegacyMessage_NestedEnum $enum)
+    {
+        // If we made it here without a PHP Fatal error, the typehint worked
+        $this->assertTrue(true);
+    }
+
     #########################################################
     # Test float field.
     #########################################################
@@ -370,6 +393,20 @@ class GeneratedClassTest extends TestBase
     {
         $m = new TestMessage();
 
+        $sub_m = new Sub();
+        $sub_m->setA(1);
+        $m->setOptionalMessage($sub_m);
+        $this->assertSame(1, $m->getOptionalMessage()->getA());
+
+        $null = null;
+        $m->setOptionalMessage($null);
+        $this->assertNull($m->getOptionalMessage());
+    }
+
+    public function testLegacyMessageField()
+    {
+        $m = new TestMessage();
+
         $sub_m = new TestMessage_Sub();
         $sub_m->setA(1);
         $m->setOptionalMessage($sub_m);
@@ -380,6 +417,17 @@ class GeneratedClassTest extends TestBase
         $this->assertNull($m->getOptionalMessage());
     }
 
+    public function testLegacyTypehintWithNestedMessages()
+    {
+        $this->legacyMessage(new TestLegacyMessage\NestedMessage);
+    }
+
+    private function legacyMessage(TestLegacyMessage_NestedMessage $sub)
+    {
+        // If we made it here without a PHP Fatal error, the typehint worked
+        $this->assertTrue(true);
+    }
+
     #########################################################
     # Test repeated field.
     #########################################################
@@ -474,7 +522,7 @@ class GeneratedClassTest extends TestBase
         $this->assertSame(NULL, $m->getOneofMessage());
         $this->assertSame("oneof_string", $m->getMyOneof());
 
-        $sub_m = new TestMessage_Sub();
+        $sub_m = new Sub();
         $sub_m->setA(1);
         $m->setOneofMessage($sub_m);
         $this->assertSame(0, $m->getOneofInt32());
@@ -513,7 +561,7 @@ class GeneratedClassTest extends TestBase
 
         // Singular
         $n->setOptionalInt32(100);
-        $sub1 = new TestMessage_Sub();
+        $sub1 = new Sub();
         $sub1->setA(101);
 
         $b = $sub1->getB();
@@ -531,7 +579,7 @@ class GeneratedClassTest extends TestBase
         $repeatedString[] = 'abc';
         $n->setRepeatedString($repeatedString);
 
-        $sub2 = new TestMessage_Sub();
+        $sub2 = new Sub();
         $sub2->setA(201);
         $repeatedMessage = $n->getRepeatedMessage();
         $repeatedMessage[] = $sub2;
@@ -548,9 +596,9 @@ class GeneratedClassTest extends TestBase
         $n->setMapStringString($mapStringString);
 
         $mapInt32Message = $n->getMapInt32Message();
-        $mapInt32Message[1] = new TestMessage_Sub();
+        $mapInt32Message[1] = new Sub();
         $mapInt32Message[1]->setA(302);
-        $mapInt32Message[2] = new TestMessage_Sub();
+        $mapInt32Message[2] = new Sub();
         $mapInt32Message[2]->setA(303);
         $n->setMapInt32Message($mapInt32Message);
 
@@ -607,7 +655,7 @@ class GeneratedClassTest extends TestBase
         $m->mergeFrom($n);
         $this->assertSame(1, $m->getOneofInt32());
 
-        $sub = new TestMessage_Sub();
+        $sub = new Sub();
         $n->setOneofMessage($sub);
         $n->getOneofMessage()->setA(400);
         $m->mergeFrom($n);
@@ -630,14 +678,15 @@ class GeneratedClassTest extends TestBase
     public function testMessageWithoutNamespace()
     {
         $m = new TestMessage();
-        $sub = new NoNameSpaceMessage();
-        $m->setOptionalNoNamespaceMessage($sub);
+        $n = new NoNameSpaceMessage();
+        $m->setOptionalNoNamespaceMessage($n);
         $repeatedNoNamespaceMessage = $m->getRepeatedNoNamespaceMessage();
         $repeatedNoNamespaceMessage[] = new NoNameSpaceMessage();
         $m->setRepeatedNoNamespaceMessage($repeatedNoNamespaceMessage);
 
-        $n = new NoNamespaceMessage();
-        $n->setB(NoNamespaceMessage_NestedEnum::ZERO);
+        // test nested messages
+        $sub = new NoNamespaceMessage\NestedMessage();
+        $n->setNestedMessage($sub);
     }
 
     public function testEnumWithoutNamespace()
@@ -650,35 +699,91 @@ class GeneratedClassTest extends TestBase
     }
 
     #########################################################
-    # Test message with given prefix.
+    # Test message with given namespace.
     #########################################################
 
-    public function testPrefixMessage()
+    public function testNestedMessagesAndEnums()
+    {
+        $m = new TestMessage();
+        $n = new TestMessage\Sub();
+        $m->setOptionalMessage($n);
+        $m->setOptionalNestedEnum(TestMessage\NestedEnum::ZERO);
+        $this->assertSame($n, $m->getOptionalMessage());
+        $this->assertSame(TestMessage\NestedEnum::ZERO, $m->getOptionalNestedEnum());
+    }
+
+    public function testMessagesAndEnumsWithPrefix()
     {
+        // Test message prefix
         $m = new TestIncludePrefixMessage();
         $n = new PrefixTestPrefix();
         $n->setA(1);
         $m->setPrefixMessage($n);
         $this->assertSame(1, $m->getPrefixMessage()->getA());
+
+        // Test nested message prefix
+        $o = new PrefixTestPrefix();
+        $p = new PrefixTestPrefix\PrefixNestedMessage();
+        $o->setNestedMessage($p);
+        $o->setNestedEnum(PrefixTestPrefix\PrefixNestedEnum::ZERO);
+        $this->assertSame($p, $o->getNestedMessage());
+        $this->assertSame(PrefixTestPrefix\PrefixNestedEnum::ZERO, $o->getNestedEnum());
     }
 
-    #########################################################
-    # Test message with given namespace.
-    #########################################################
+    public function testMessagesAndEnumsWithPhpNamespace()
+    {
+        $m = new TestNamespace();
+        $n = new TestNamespace\NestedMessage();
+        $m->setNestedMessage($n);
+        $m->setNestedEnum(TestNamespace\NestedEnum::ZERO);
+        $this->assertSame($n, $m->getNestedMessage());
+        $this->assertSame(TestNamespace\NestedEnum::ZERO, $m->getNestedEnum());
+    }
 
-    public function testNamespaceMessage()
+    public function testMesssagesAndEnumsWithEmptyPhpNamespace()
     {
-        $m = new TestIncludeNamespaceMessage();
+        $m = new TestEmptyNamespace();
+        $n = new TestEmptyNamespace\NestedMessage();
+        $m->setNestedMessage($n);
+        $m->setNestedEnum(TestEmptyNamespace\NestedEnum::ZERO);
+        $this->assertSame($n, $m->getNestedMessage());
+        $this->assertSame(TestEmptyNamespace\NestedEnum::ZERO, $m->getNestedEnum());
+    }
 
-        $n = new TestNamespace();
-        $n->setA(1);
-        $m->setNamespaceMessage($n);
-        $this->assertSame(1, $m->getNamespaceMessage()->getA());
+    public function testMessagesAndEnumsWithNoNamespace()
+    {
+        $m = new NoNamespaceMessage();
+        $n = new NoNamespaceMessage\NestedMessage();
+        $m->setNestedMessage($n);
+        $m->setNestedEnum(NoNamespaceMessage\NestedEnum::ZERO);
+        $this->assertSame($n, $m->getNestedMessage());
+        $this->assertSame(NoNamespaceMessage\NestedEnum::ZERO, $m->getNestedEnum());
+    }
 
-        $n = new TestEmptyNamespace();
-        $n->setA(1);
-        $m->setEmptyNamespaceMessage($n);
-        $this->assertSame(1, $m->getEmptyNamespaceMessage()->getA());
+    public function testReservedWordsInPackageName()
+    {
+        $m = new TestEmptyPackage();
+        $n = new TestEmptyPackage\NestedMessage();
+        $m->setNestedMessage($n);
+        $m->setNestedEnum(TestEmptyPackage\NestedEnum::ZERO);
+        $this->assertSame($n, $m->getNestedMessage());
+        $this->assertSame(TestEmptyPackage\NestedEnum::ZERO, $m->getNestedEnum());
+    }
+
+    public function testReservedWordsInNamespace()
+    {
+        $m = new TestNamespace();
+        $n = new TestNamespace\PBEmpty();
+        $o = new TestNamespace\PBEmpty\NestedMessage();
+        $n->setNestedMessage($o);
+        $n->setNestedEnum(TestNamespace\PBEmpty\NestedEnum::ZERO);
+        $m->setReservedName($n);
+        $this->assertSame($n, $m->getReservedName());
+        $this->assertSame($o, $n->getNestedMessage());
+        $this->assertSame(
+            TestNamespace\PBEmpty\NestedEnum::ZERO,
+            $n->getNestedEnum()
+        );
     }
 
     #########################################################
@@ -687,7 +792,7 @@ class GeneratedClassTest extends TestBase
 
     public function testPrefixForReservedWords()
     {
-        $m = new \Foo\TestMessage_Empty();
+        $m = new \Foo\TestMessage\PBEmpty();
         $m = new \Foo\PBEmpty();
         $m = new \PrefixEmpty();
         $m = new \Foo\PBARRAY();
@@ -1195,7 +1300,7 @@ class GeneratedClassTest extends TestBase
             'optional_string' => 'a',
             'optional_bytes' => 'b',
             'optional_enum' => TestEnum::ONE,
-            'optional_message' => new TestMessage_Sub([
+            'optional_message' => new Sub([
                 'a' => 33
             ]),
             'repeated_int32' => [-42, -52],
@@ -1214,8 +1319,8 @@ class GeneratedClassTest extends TestBase
             'repeated_string' => ['a', 'c'],
             'repeated_bytes' => ['b', 'd'],
             'repeated_enum' => [TestEnum::ZERO, TestEnum::ONE],
-            'repeated_message' => [new TestMessage_Sub(['a' => 34]),
-                                   new TestMessage_Sub(['a' => 35])],
+            'repeated_message' => [new Sub(['a' => 34]),
+                                   new Sub(['a' => 35])],
             'map_int32_int32' => [-62 => -62],
             'map_int64_int64' => [-63 => -63],
             'map_uint32_uint32' => [62 => 62],
@@ -1232,7 +1337,7 @@ class GeneratedClassTest extends TestBase
             'map_string_string' => ['e' => 'e'],
             'map_int32_bytes' => [1 => 'f'],
             'map_int32_enum' => [1 => TestEnum::ONE],
-            'map_int32_message' => [1 => new TestMessage_Sub(['a' => 36])],
+            'map_int32_message' => [1 => new Sub(['a' => 36])],
         ]);
 
         TestUtil::assertTestMessage($m);
diff --git a/php/tests/generated_phpdoc_test.php b/php/tests/generated_phpdoc_test.php
index 505dafea..526927fc 100644
--- a/php/tests/generated_phpdoc_test.php
+++ b/php/tests/generated_phpdoc_test.php
@@ -201,7 +201,7 @@ class GeneratedPhpdocTest extends TestBase
                 [
                     'setRepeatedMessage',
                 ],
-                '@param \Foo\TestMessage_Sub[]|\Google\Protobuf\Internal\RepeatedField $var'
+                '@param \Foo\TestMessage\Sub[]|\Google\Protobuf\Internal\RepeatedField $var'
             ],
             [
                 [
@@ -294,14 +294,14 @@ class GeneratedPhpdocTest extends TestBase
                     'getOptionalMessage',
                     'getOneofMessage'
                 ],
-                '@return \Foo\TestMessage_Sub'
+                '@return \Foo\TestMessage\Sub'
             ],
             [
                 [
                     'setOptionalMessage',
                     'setOneofMessage'
                 ],
-                '@param \Foo\TestMessage_Sub $var'
+                '@param \Foo\TestMessage\Sub $var'
             ],
             [
                 [
diff --git a/php/tests/map_field_test.php b/php/tests/map_field_test.php
index cffa2526..447bdd9b 100644
--- a/php/tests/map_field_test.php
+++ b/php/tests/map_field_test.php
@@ -5,7 +5,7 @@ require_once('test_util.php');
 use Google\Protobuf\Internal\GPBType;
 use Google\Protobuf\Internal\MapField;
 use Foo\TestMessage;
-use Foo\TestMessage_Sub;
+use Foo\TestMessage\Sub;
 
 class MapFieldTest extends PHPUnit_Framework_TestCase {
 
@@ -408,10 +408,10 @@ class MapFieldTest extends PHPUnit_Framework_TestCase {
 
     public function testMessage() {
         $arr = new MapField(GPBType::INT32,
-            GPBType::MESSAGE, TestMessage_Sub::class);
+            GPBType::MESSAGE, Sub::class);
 
         // Test append.
-        $sub_m = new TestMessage_Sub();
+        $sub_m = new Sub();
         $sub_m->setA(1);
         $arr[0] = $sub_m;
         $this->assertSame(1, $arr[0]->getA());
@@ -420,9 +420,9 @@ class MapFieldTest extends PHPUnit_Framework_TestCase {
 
         // Test foreach.
         $arr = new MapField(GPBType::INT32,
-            GPBType::MESSAGE, TestMessage_Sub::class);
+            GPBType::MESSAGE, Sub::class);
         for ($i = 0; $i < 3; $i++) {
-          $arr[$i] = new TestMessage_Sub();;
+          $arr[$i] = new Sub();;
           $arr[$i]->setA($i);
         }
         $i = 0;
diff --git a/php/tests/memory_leak_test.php b/php/tests/memory_leak_test.php
index ad55d578..5456919b 100644
--- a/php/tests/memory_leak_test.php
+++ b/php/tests/memory_leak_test.php
@@ -15,9 +15,9 @@ require_once('generated/Foo/TestEnum.php');
 require_once('generated/Foo/TestIncludeNamespaceMessage.php');
 require_once('generated/Foo/TestIncludePrefixMessage.php');
 require_once('generated/Foo/TestMessage.php');
-require_once('generated/Foo/TestMessage_Empty.php');
-require_once('generated/Foo/TestMessage_NestedEnum.php');
-require_once('generated/Foo/TestMessage_Sub.php');
+require_once('generated/Foo/TestMessage/PBEmpty.php');
+require_once('generated/Foo/TestMessage/NestedEnum.php');
+require_once('generated/Foo/TestMessage/Sub.php');
 require_once('generated/Foo/TestPackedMessage.php');
 require_once('generated/Foo/TestPhpDoc.php');
 require_once('generated/Foo/TestRandomFieldOrder.php');
@@ -37,7 +37,7 @@ require_once('test_util.php');
 use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBType;
 use Foo\TestMessage;
-use Foo\TestMessage_Sub;
+use Foo\TestMessage\Sub;
 
 $from = new TestMessage();
 TestUtil::setTestMessage($from);
@@ -97,7 +97,7 @@ $n = new TestMessage();
 $n->mergeFromString($data);
 assert('abc' === $n->getOneofString());
 
-$sub_m = new TestMessage_Sub();
+$sub_m = new Sub();
 $sub_m->setA(1);
 $m->setOneofMessage($sub_m);
 assert(0 === $m->getOneofInt32());
diff --git a/php/tests/php_implementation_test.php b/php/tests/php_implementation_test.php
index 6481473e..323a36ff 100644
--- a/php/tests/php_implementation_test.php
+++ b/php/tests/php_implementation_test.php
@@ -5,7 +5,7 @@ require_once('test_util.php');
 
 use Foo\TestEnum;
 use Foo\TestMessage;
-use Foo\TestMessage_Sub;
+use Foo\TestMessage\Sub;
 use Foo\TestPackedMessage;
 use Google\Protobuf\Internal\CodedInputStream;
 use Google\Protobuf\Internal\FileDescriptorSet;
@@ -527,7 +527,7 @@ class ImplementationTest extends TestBase
 
     /**
      * @expectedException Exception
-     * @expectedExceptionMessage Expect message.
+     * @expectedExceptionMessage Expect Foo\TestMessage_Sub.
      */
     public function testArraysForMessagesThrowsException()
     {
diff --git a/php/tests/proto/empty/echo.proto b/php/tests/proto/empty/echo.proto
new file mode 100644
index 00000000..1817018d
--- /dev/null
+++ b/php/tests/proto/empty/echo.proto
@@ -0,0 +1,17 @@
+syntax = "proto3";
+
+package empty.echo;
+
+message TestEmptyPackage {
+  int32 a = 1;
+
+  // Test nested messages, enums, and reserved names
+  NestedMessage nested_message = 2;
+  NestedEnum nested_enum = 3;
+  message NestedMessage {
+    int32 a = 1;
+  }
+  enum NestedEnum {
+      ZERO = 0;
+  };
+}
diff --git a/php/tests/proto/test_empty_php_namespace.proto b/php/tests/proto/test_empty_php_namespace.proto
index 1d02f760..c7ed1657 100644
--- a/php/tests/proto/test_empty_php_namespace.proto
+++ b/php/tests/proto/test_empty_php_namespace.proto
@@ -6,4 +6,14 @@ option php_metadata_namespace = "";
 
 message TestEmptyNamespace {
   int32 a = 1;
+
+  // Test nested messages, enums, and reserved names
+  NestedMessage nested_message = 2;
+  NestedEnum nested_enum = 3;
+  message NestedMessage {
+    int32 a = 1;
+  }
+  enum NestedEnum {
+      ZERO = 0;
+  };
 }
diff --git a/php/tests/proto/test_include.proto b/php/tests/proto/test_include.proto
index 9844617f..a9072fe3 100644
--- a/php/tests/proto/test_include.proto
+++ b/php/tests/proto/test_include.proto
@@ -5,3 +5,14 @@ package bar;
 message TestInclude {
   int32 a = 1;
 }
+
+message TestLegacyMessage {
+  NestedMessage message = 1;
+  NestedEnum enum = 2;
+  message NestedMessage {
+    int32 a = 1;
+  }
+  enum NestedEnum {
+    ZERO = 0;
+  }
+}
diff --git a/php/tests/proto/test_no_namespace.proto b/php/tests/proto/test_no_namespace.proto
index 03f89270..cce42ea2 100644
--- a/php/tests/proto/test_no_namespace.proto
+++ b/php/tests/proto/test_no_namespace.proto
@@ -5,11 +5,15 @@ option php_metadata_namespace = "\\";
 message NoNamespaceMessage {
   int32 a = 1;
 
-  enum NestedEnum {
-    ZERO = 0;
+  // Test nested messages, enums, and reserved names
+  NestedMessage nested_message = 2;
+  NestedEnum nested_enum = 3;
+  message NestedMessage {
+    int32 a = 1;
   }
-  NestedEnum b = 2;
-  repeated NestedEnum c = 3;
+  enum NestedEnum {
+      ZERO = 0;
+  };
 }
 
 enum NoNamespaceEnum {
diff --git a/php/tests/proto/test_php_namespace.proto b/php/tests/proto/test_php_namespace.proto
index bb57d617..61085bf7 100644
--- a/php/tests/proto/test_php_namespace.proto
+++ b/php/tests/proto/test_php_namespace.proto
@@ -6,4 +6,26 @@ option php_metadata_namespace = "Metadata\\Php\\Test";
 
 message TestNamespace {
   int32 a = 1;
+
+  // Test nested messages, enums, and reserved names
+  NestedMessage nested_message = 2;
+  NestedEnum nested_enum = 3;
+  Empty reserved_name = 4;
+  message NestedMessage {
+    int32 a = 1;
+  }
+  enum NestedEnum {
+      ZERO = 0;
+  };
+  // Test reserved name
+  message Empty {
+    NestedMessage nested_message = 1;
+    NestedEnum nested_enum = 2;
+    message NestedMessage {
+      int32 a = 1;
+    }
+    enum NestedEnum {
+      ZERO = 0;
+    };
+  }
 }
diff --git a/php/tests/proto/test_prefix.proto b/php/tests/proto/test_prefix.proto
index 9bfbad7f..3fa11381 100644
--- a/php/tests/proto/test_prefix.proto
+++ b/php/tests/proto/test_prefix.proto
@@ -4,6 +4,14 @@ option php_class_prefix = "Prefix";
 
 message TestPrefix {
   int32 a = 1;
+  NestedMessage nested_message = 2;
+  NestedEnum nested_enum = 3;
+  message NestedMessage {
+    int32 a = 1;
+  }
+  enum NestedEnum {
+      ZERO = 0;
+  };
 }
 
 // Test prefix for reserved words.
diff --git a/php/tests/test_base.php b/php/tests/test_base.php
index dc5e73f5..80f603c7 100644
--- a/php/tests/test_base.php
+++ b/php/tests/test_base.php
@@ -2,7 +2,7 @@
 
 use Foo\TestMessage;
 use Foo\TestEnum;
-use Foo\TestMessage_Sub;
+use Foo\TestMessage\Sub;
 
 class TestBase extends PHPUnit_Framework_TestCase
 {
diff --git a/php/tests/test_util.php b/php/tests/test_util.php
index c8afdd3e..a676d097 100644
--- a/php/tests/test_util.php
+++ b/php/tests/test_util.php
@@ -2,7 +2,7 @@
 
 use Foo\TestEnum;
 use Foo\TestMessage;
-use Foo\TestMessage_Sub;
+use Foo\TestMessage\Sub;
 use Foo\TestPackedMessage;
 use Foo\TestUnpackedMessage;
 
@@ -67,7 +67,7 @@ class TestUtil
         $m->setOptionalString('a');
         $m->setOptionalBytes('b');
         $m->setOptionalEnum(TestEnum::ONE);
-        $sub = new TestMessage_Sub();
+        $sub = new Sub();
         $m->setOptionalMessage($sub);
         $m->getOptionalMessage()->SetA(33);
 
@@ -87,7 +87,7 @@ class TestUtil
         self::appendHelper($m, 'RepeatedString',   'a');
         self::appendHelper($m, 'RepeatedBytes',    'b');
         self::appendHelper($m, 'RepeatedEnum',     TestEnum::ZERO);
-        self::appendHelper($m, 'RepeatedMessage',  new TestMessage_Sub());
+        self::appendHelper($m, 'RepeatedMessage',  new Sub());
         $m->getRepeatedMessage()[0]->setA(34);
 
         self::appendHelper($m, 'RepeatedInt32',    -52);
@@ -106,7 +106,7 @@ class TestUtil
         self::appendHelper($m, 'RepeatedString',   'c');
         self::appendHelper($m, 'RepeatedBytes',    'd');
         self::appendHelper($m, 'RepeatedEnum',     TestEnum::ONE);
-        self::appendHelper($m, 'RepeatedMessage',  new TestMessage_Sub());
+        self::appendHelper($m, 'RepeatedMessage',  new Sub());
         $m->getRepeatedMessage()[1]->SetA(35);
 
         self::kvUpdateHelper($m, 'MapInt32Int32', -62, -62);
@@ -125,13 +125,13 @@ class TestUtil
         self::kvUpdateHelper($m, 'MapStringString', 'e', 'e');
         self::kvUpdateHelper($m, 'MapInt32Bytes', 1, 'f');
         self::kvUpdateHelper($m, 'MapInt32Enum', 1, TestEnum::ONE);
-        self::kvUpdateHelper($m, 'MapInt32Message', 1, new TestMessage_Sub());
+        self::kvUpdateHelper($m, 'MapInt32Message', 1, new Sub());
         $m->getMapInt32Message()[1]->SetA(36);
     }
 
     public static function setTestMessage2(TestMessage $m)
     {
-        $sub = new TestMessage_Sub();
+        $sub = new Sub();
 
         $m->setOptionalInt32(-142);
         $m->setOptionalInt64(-143);
@@ -168,7 +168,7 @@ class TestUtil
         self::appendHelper($m, 'RepeatedString',   'aa');
         self::appendHelper($m, 'RepeatedBytes',    'bb');
         self::appendHelper($m, 'RepeatedEnum',     TestEnum::TWO);
-        self::appendHelper($m, 'RepeatedMessage',  new TestMessage_Sub());
+        self::appendHelper($m, 'RepeatedMessage',  new Sub());
         $m->getRepeatedMessage()[0]->setA(134);
 
         self::kvUpdateHelper($m, 'MapInt32Int32', -62, -162);
@@ -187,7 +187,7 @@ class TestUtil
         self::kvUpdateHelper($m, 'MapStringString', 'e', 'ee');
         self::kvUpdateHelper($m, 'MapInt32Bytes', 1, 'ff');
         self::kvUpdateHelper($m, 'MapInt32Enum', 1, TestEnum::TWO);
-        self::kvUpdateHelper($m, 'MapInt32Message', 1, new TestMessage_Sub());
+        self::kvUpdateHelper($m, 'MapInt32Message', 1, new Sub());
         $m->getMapInt32Message()[1]->SetA(136);
 
         self::kvUpdateHelper($m, 'MapInt32Int32', -162, -162);
@@ -206,7 +206,7 @@ class TestUtil
         self::kvUpdateHelper($m, 'MapStringString', 'ee', 'ee');
         self::kvUpdateHelper($m, 'MapInt32Bytes', 2, 'ff');
         self::kvUpdateHelper($m, 'MapInt32Enum', 2, TestEnum::TWO);
-        self::kvUpdateHelper($m, 'MapInt32Message', 2, new TestMessage_Sub());
+        self::kvUpdateHelper($m, 'MapInt32Message', 2, new Sub());
         $m->getMapInt32Message()[2]->SetA(136);
     }
 
diff --git a/php/tests/undefined_test.php b/php/tests/undefined_test.php
index dc6b7086..f8444571 100644
--- a/php/tests/undefined_test.php
+++ b/php/tests/undefined_test.php
@@ -5,7 +5,7 @@ require_once('test_util.php');
 use Google\Protobuf\Internal\RepeatedField;
 use Google\Protobuf\Internal\GPBType;
 use Foo\TestMessage;
-use Foo\TestMessage_Sub;
+use Foo\TestMessage\Sub;
 
 class UndefinedTest extends PHPUnit_Framework_TestCase
 {
@@ -35,7 +35,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testInt32AppendMessageFail()
     {
         $arr = new RepeatedField(GPBType::INT32);
-        $arr[] = new TestMessage_Sub();
+        $arr[] = new Sub();
     }
 
     /**
@@ -45,7 +45,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     {
         $arr = new RepeatedField(GPBType::INT32);
         $arr[] = 0;
-        $arr[0] = new TestMessage_Sub();
+        $arr[0] = new Sub();
     }
 
     /**
@@ -73,7 +73,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testUint32AppendMessageFail()
     {
         $arr = new RepeatedField(GPBType::UINT32);
-        $arr[] = new TestMessage_Sub();
+        $arr[] = new Sub();
     }
 
     /**
@@ -83,7 +83,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     {
         $arr = new RepeatedField(GPBType::UINT32);
         $arr[] = 0;
-        $arr[0] = new TestMessage_Sub();
+        $arr[0] = new Sub();
     }
 
     /**
@@ -111,7 +111,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testInt64AppendMessageFail()
     {
         $arr = new RepeatedField(GPBType::INT64);
-        $arr[] = new TestMessage_Sub();
+        $arr[] = new Sub();
     }
 
     /**
@@ -121,7 +121,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     {
         $arr = new RepeatedField(GPBType::INT64);
         $arr[] = 0;
-        $arr[0] = new TestMessage_Sub();
+        $arr[0] = new Sub();
     }
 
     /**
@@ -149,7 +149,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testUint64AppendMessageFail()
     {
         $arr = new RepeatedField(GPBType::UINT64);
-        $arr[] = new TestMessage_Sub();
+        $arr[] = new Sub();
     }
 
     /**
@@ -159,7 +159,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     {
         $arr = new RepeatedField(GPBType::UINT64);
         $arr[] = 0;
-        $arr[0] = new TestMessage_Sub();
+        $arr[0] = new Sub();
     }
 
     /**
@@ -187,7 +187,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testFloatAppendMessageFail()
     {
         $arr = new RepeatedField(GPBType::FLOAT);
-        $arr[] = new TestMessage_Sub();
+        $arr[] = new Sub();
     }
 
     /**
@@ -197,7 +197,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     {
         $arr = new RepeatedField(GPBType::FLOAT);
         $arr[] = 0.0;
-        $arr[0] = new TestMessage_Sub();
+        $arr[0] = new Sub();
     }
 
     /**
@@ -225,7 +225,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testDoubleAppendMessageFail()
     {
         $arr = new RepeatedField(GPBType::DOUBLE);
-        $arr[] = new TestMessage_Sub();
+        $arr[] = new Sub();
     }
 
     /**
@@ -235,7 +235,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     {
         $arr = new RepeatedField(GPBType::DOUBLE);
         $arr[] = 0.0;
-        $arr[0] = new TestMessage_Sub();
+        $arr[0] = new Sub();
     }
 
     /**
@@ -244,7 +244,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testBoolAppendMessageFail()
     {
         $arr = new RepeatedField(GPBType::BOOL);
-        $arr[] = new TestMessage_Sub();
+        $arr[] = new Sub();
     }
 
     /**
@@ -254,7 +254,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     {
         $arr = new RepeatedField(GPBType::BOOL);
         $arr[] = true;
-        $arr[0] = new TestMessage_Sub();
+        $arr[0] = new Sub();
     }
 
     /**
@@ -263,7 +263,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testStringAppendMessageFail()
     {
         $arr = new RepeatedField(GPBType::STRING);
-        $arr[] = new TestMessage_Sub();
+        $arr[] = new Sub();
     }
 
     /**
@@ -273,7 +273,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     {
         $arr = new RepeatedField(GPBType::STRING);
         $arr[] = 'abc';
-        $arr[0] = new TestMessage_Sub();
+        $arr[0] = new Sub();
     }
 
     /**
@@ -302,7 +302,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
      */
     public function testMessageAppendIntFail()
     {
-        $arr = new RepeatedField(GPBType::MESSAGE, TestMessage_Sub::class);
+        $arr = new RepeatedField(GPBType::MESSAGE, Sub::class);
         $arr[] = 1;
     }
 
@@ -311,8 +311,8 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
      */
     public function testMessageSetIntFail()
     {
-        $arr = new RepeatedField(GPBType::MESSAGE, TestMessage_Sub::class);
-        $arr[] = new TestMessage_Sub;
+        $arr = new RepeatedField(GPBType::MESSAGE, Sub::class);
+        $arr[] = new Sub;
         $arr[0] = 'abc';
     }
 
@@ -321,7 +321,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
      */
     public function testMessageAppendStringFail()
     {
-        $arr = new RepeatedField(GPBType::MESSAGE, TestMessage_Sub::class);
+        $arr = new RepeatedField(GPBType::MESSAGE, Sub::class);
         $arr[] = 'abc';
     }
 
@@ -330,8 +330,8 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
      */
     public function testMessageSetStringFail()
     {
-        $arr = new RepeatedField(GPBType::MESSAGE, TestMessage_Sub::class);
-        $arr[] = new TestMessage_Sub;
+        $arr = new RepeatedField(GPBType::MESSAGE, Sub::class);
+        $arr[] = new Sub;
         $arr[0] = 'abc';
     }
 
@@ -340,7 +340,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
      */
     public function testMessageAppendOtherMessageFail()
     {
-        $arr = new RepeatedField(GPBType::MESSAGE, TestMessage_Sub::class);
+        $arr = new RepeatedField(GPBType::MESSAGE, Sub::class);
         $arr[] = new TestMessage;
     }
 
@@ -349,7 +349,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
      */
     public function testMessageAppendNullFail()
     {
-        $arr = new RepeatedField(GPBType::MESSAGE, TestMessage_Sub::class);
+        $arr = new RepeatedField(GPBType::MESSAGE, Sub::class);
         $null = null;
         $arr[] = $null;
     }
@@ -359,8 +359,8 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
      */
     public function testMessageSetNullFail()
     {
-        $arr = new RepeatedField(GPBType::MESSAGE, TestMessage_Sub::class);
-        $arr[] = new TestMessage_Sub();
+        $arr = new RepeatedField(GPBType::MESSAGE, Sub::class);
+        $arr[] = new Sub();
         $null = null;
         $arr[0] = $null;
     }
@@ -397,7 +397,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     {
         $arr = new RepeatedField(GPBType::INT32);
         $arr[] = 0;
-        $arr[new TestMessage_Sub()] = 0;
+        $arr[new Sub()] = 0;
     }
 
     /**
@@ -656,7 +656,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testMessageMergeFromInvalidTypeFail()
     {
         $m = new TestMessage();
-        $n = new TestMessage_Sub();
+        $n = new Sub();
         $m->mergeFrom($n);
     }
 
@@ -684,7 +684,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testInt32SetMessageKeyFail()
     {
         $arr = new MapField(GPBType::INT32, GPBType::INT32);
-        $arr[new TestMessage_Sub()] = 0;
+        $arr[new Sub()] = 0;
     }
 
     /**
@@ -693,7 +693,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testInt32SetMessageValueFail()
     {
         $arr = new MapField(GPBType::INT32, GPBType::INT32);
-        $arr[0] = new TestMessage_Sub();
+        $arr[0] = new Sub();
     }
 
     /**
@@ -720,7 +720,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testUint32SetMessageKeyFail()
     {
         $arr = new MapField(GPBType::UINT32, GPBType::UINT32);
-        $arr[new TestMessage_Sub()] = 0;
+        $arr[new Sub()] = 0;
     }
 
     /**
@@ -729,7 +729,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testUint32SetMessageValueFail()
     {
         $arr = new MapField(GPBType::UINT32, GPBType::UINT32);
-        $arr[0] = new TestMessage_Sub();
+        $arr[0] = new Sub();
     }
 
     /**
@@ -756,7 +756,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testInt64SetMessageKeyFail()
     {
         $arr = new MapField(GPBType::INT64, GPBType::INT64);
-        $arr[new TestMessage_Sub()] = 0;
+        $arr[new Sub()] = 0;
     }
 
     /**
@@ -765,7 +765,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testInt64SetMessageValueFail()
     {
         $arr = new MapField(GPBType::INT64, GPBType::INT64);
-        $arr[0] = new TestMessage_Sub();
+        $arr[0] = new Sub();
     }
 
     /**
@@ -792,7 +792,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testUint64SetMessageKeyFail()
     {
         $arr = new MapField(GPBType::UINT64, GPBType::UINT64);
-        $arr[new TestMessage_Sub()] = 0;
+        $arr[new Sub()] = 0;
     }
 
     /**
@@ -801,7 +801,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testUint64SetMessageValueFail()
     {
         $arr = new MapField(GPBType::UINT64, GPBType::UINT64);
-        $arr[0] = new TestMessage_Sub();
+        $arr[0] = new Sub();
     }
 
     /**
@@ -819,7 +819,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testDoubleSetMessageValueFail()
     {
         $arr = new MapField(GPBType::INT64, GPBType::DOUBLE);
-        $arr[0] = new TestMessage_Sub();
+        $arr[0] = new Sub();
     }
 
     /**
@@ -828,7 +828,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testBoolSetMessageKeyFail()
     {
         $arr = new MapField(GPBType::BOOL, GPBType::BOOL);
-        $arr[new TestMessage_Sub()] = true;
+        $arr[new Sub()] = true;
     }
 
     /**
@@ -837,7 +837,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testBoolSetMessageValueFail()
     {
         $arr = new MapField(GPBType::BOOL, GPBType::BOOL);
-        $arr[true] = new TestMessage_Sub();
+        $arr[true] = new Sub();
     }
 
     /**
@@ -864,7 +864,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testStringSetMessageKeyFail()
     {
         $arr = new MapField(GPBType::STRING, GPBType::STRING);
-        $arr[new TestMessage_Sub()] = 'abc';
+        $arr[new Sub()] = 'abc';
     }
 
     /**
@@ -873,7 +873,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     public function testStringSetMessageValueFail()
     {
         $arr = new MapField(GPBType::STRING, GPBType::STRING);
-        $arr['abc'] = new TestMessage_Sub();
+        $arr['abc'] = new Sub();
     }
 
     /**
@@ -903,7 +903,7 @@ class UndefinedTest extends PHPUnit_Framework_TestCase
     {
        $arr =
            new MapField(GPBType::INT32, GPBType::MESSAGE, TestMessage::class);
-       $arr[0] = new TestMessage_Sub();
+       $arr[0] = new Sub();
     }
 
     /**
diff --git a/php/tests/well_known_test.php b/php/tests/well_known_test.php
index a7760685..1e8c4f42 100644
--- a/php/tests/well_known_test.php
+++ b/php/tests/well_known_test.php
@@ -14,8 +14,8 @@ use Google\Protobuf\Enum;
 use Google\Protobuf\EnumValue;
 use Google\Protobuf\Field;
 use Google\Protobuf\FieldMask;
-use Google\Protobuf\Field_Cardinality;
-use Google\Protobuf\Field_Kind;
+use Google\Protobuf\Field\Cardinality;
+use Google\Protobuf\Field\Kind;
 use Google\Protobuf\FloatValue;
 use Google\Protobuf\GPBEmpty;
 use Google\Protobuf\Int32Value;
@@ -206,11 +206,11 @@ class WellKnownTest extends TestBase {
     {
         $m = new Field();
 
-        $m->setKind(Field_Kind::TYPE_DOUBLE);
-        $this->assertSame(Field_Kind::TYPE_DOUBLE, $m->getKind());
+        $m->setKind(Kind::TYPE_DOUBLE);
+        $this->assertSame(Kind::TYPE_DOUBLE, $m->getKind());
 
-        $m->setCardinality(Field_Cardinality::CARDINALITY_OPTIONAL);
-        $this->assertSame(Field_Cardinality::CARDINALITY_OPTIONAL, $m->getCardinality());
+        $m->setCardinality(Cardinality::CARDINALITY_OPTIONAL);
+        $this->assertSame(Cardinality::CARDINALITY_OPTIONAL, $m->getCardinality());
 
         $m->setNumber(1);
         $this->assertSame(1, $m->getNumber());