Follows proper autoloading standards (#3123)

* Follows proper autoloading standards
 - Splits PHP classes in descriptor.php into separate files
 - Splits MapFieldIter and RepeatedFieldIter into separate files
 - Moves descriptor.php to Internal/functions.php
 - Moves all namespaced functions into Iternal/functions.php

* fixes Makefile.am for added php files

* [PHP] moves all functions to GPBUtil

* removes description.php from the makefile

12 files changed, 1038 insertions, 232 deletions

diff --git a/php/src/Google/Protobuf/Internal/Descriptor.php b/php/src/Google/Protobuf/Internal/Descriptor.php
new file mode 100644
index 00000000..d0d1e259
--- /dev/null
+++ b/php/src/Google/Protobuf/Internal/Descriptor.php
@@ -0,0 +1,167 @@
+<?php
+
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+namespace Google\Protobuf\Internal;
+
+class Descriptor
+{
+
+    private $full_name;
+    private $field = [];
+    private $nested_type = [];
+    private $enum_type = [];
+    private $klass;
+    private $options;
+    private $oneof_decl = [];
+
+    public function addOneofDecl($oneof)
+    {
+        $this->oneof_decl[] = $oneof;
+    }
+
+    public function getOneofDecl()
+    {
+        return $this->oneof_decl;
+    }
+
+    public function setFullName($full_name)
+    {
+        $this->full_name = $full_name;
+    }
+
+    public function getFullName()
+    {
+        return $this->full_name;
+    }
+
+    public function addField($field)
+    {
+        $this->field[$field->getNumber()] = $field;
+    }
+
+    public function getField()
+    {
+        return $this->field;
+    }
+
+    public function addNestedType($desc)
+    {
+        $this->nested_type[] = $desc;
+    }
+
+    public function getNestedType()
+    {
+        return $this->nested_type;
+    }
+
+    public function addEnumType($desc)
+    {
+        $this->enum_type[] = $desc;
+    }
+
+    public function getEnumType()
+    {
+        return $this->enum_type;
+    }
+
+    public function getFieldByNumber($number)
+    {
+      if (!isset($this->field[$number])) {
+        return NULL;
+      } else {
+        return $this->field[$number];
+      }
+    }
+
+    public function setClass($klass)
+    {
+        $this->klass = $klass;
+    }
+
+    public function getClass()
+    {
+        return $this->klass;
+    }
+
+    public function setOptions($options)
+    {
+        $this->options = $options;
+    }
+
+    public function getOptions()
+    {
+        return $this->options;
+    }
+
+    public static function buildFromProto($proto, $file_proto, $containing)
+    {
+        $desc = new Descriptor();
+
+        $message_name_without_package  = "";
+        $classname = "";
+        $fullname = "";
+        getFullClassName(
+            $proto,
+            $containing,
+            $file_proto,
+            $message_name_without_package,
+            $classname,
+            $fullname);
+        $desc->setFullName($fullname);
+        $desc->setClass($classname);
+        $desc->setOptions($proto->getOptions());
+
+        foreach ($proto->getField() as $field_proto) {
+            $desc->addField(FieldDescriptor::buildFromProto($field_proto));
+        }
+
+        // Handle nested types.
+        foreach ($proto->getNestedType() as $nested_proto) {
+            $desc->addNestedType(Descriptor::buildFromProto(
+              $nested_proto, $file_proto, $message_name_without_package));
+        }
+
+        // Handle nested enum.
+        foreach ($proto->getEnumType() as $enum_proto) {
+            $desc->addEnumType(EnumDescriptor::buildFromProto(
+              $enum_proto, $file_proto, $message_name_without_package));
+        }
+
+        // Handle oneof fields.
+        foreach ($proto->getOneofDecl() as $oneof_proto) {
+            $desc->addOneofDecl(
+                OneofDescriptor::buildFromProto($oneof_proto, $desc));
+        }
+
+        return $desc;
+    }
+}
diff --git a/php/src/Google/Protobuf/Internal/EnumDescriptor.php b/php/src/Google/Protobuf/Internal/EnumDescriptor.php
new file mode 100644
index 00000000..7360a477
--- /dev/null
+++ b/php/src/Google/Protobuf/Internal/EnumDescriptor.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace Google\Protobuf\Internal;
+
+class EnumDescriptor
+{
+
+    private $klass;
+    private $full_name;
+    private $value;
+
+    public function setFullName($full_name)
+    {
+        $this->full_name = $full_name;
+    }
+
+    public function getFullName()
+    {
+        return $this->full_name;
+    }
+
+    public function addValue($number, $value)
+    {
+        $this->value[$number] = $value;
+    }
+
+    public function setClass($klass)
+    {
+        $this->klass = $klass;
+    }
+
+    public function getClass()
+    {
+        return $this->klass;
+    }
+
+    public static function buildFromProto($proto, $file_proto, $containing)
+    {
+        $desc = new EnumDescriptor();
+
+        $enum_name_without_package  = "";
+        $classname = "";
+        $fullname = "";
+        GPBUtil::getFullClassName(
+            $proto,
+            $containing,
+            $file_proto,
+            $enum_name_without_package,
+            $classname,
+            $fullname);
+        $desc->setFullName($fullname);
+        $desc->setClass($classname);
+
+        return $desc;
+    }
+}
diff --git a/php/src/Google/Protobuf/Internal/EnumValueDescriptor.php b/php/src/Google/Protobuf/Internal/EnumValueDescriptor.php
new file mode 100644
index 00000000..e65a4e8d
--- /dev/null
+++ b/php/src/Google/Protobuf/Internal/EnumValueDescriptor.php
@@ -0,0 +1,37 @@
+<?php
+
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+namespace Google\Protobuf\Internal;
+
+class EnumValueDescriptor
+{
+}
diff --git a/php/src/Google/Protobuf/Internal/FieldDescriptor.php b/php/src/Google/Protobuf/Internal/FieldDescriptor.php
new file mode 100644
index 00000000..6c91950f
--- /dev/null
+++ b/php/src/Google/Protobuf/Internal/FieldDescriptor.php
@@ -0,0 +1,236 @@
+<?php
+
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+namespace Google\Protobuf\Internal;
+
+class FieldDescriptor
+{
+
+    private $name;
+    private $setter;
+    private $getter;
+    private $number;
+    private $label;
+    private $type;
+    private $message_type;
+    private $enum_type;
+    private $packed;
+    private $is_map;
+    private $oneof_index = -1;
+
+    public function setOneofIndex($index)
+    {
+        $this->oneof_index = $index;
+    }
+
+    public function getOneofIndex()
+    {
+        return $this->oneof_index;
+    }
+
+    public function setName($name)
+    {
+        $this->name = $name;
+    }
+
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    public function setSetter($setter)
+    {
+        $this->setter = $setter;
+    }
+
+    public function getSetter()
+    {
+        return $this->setter;
+    }
+
+    public function setGetter($getter)
+    {
+        $this->getter = $getter;
+    }
+
+    public function getGetter()
+    {
+        return $this->getter;
+    }
+
+    public function setNumber($number)
+    {
+        $this->number = $number;
+    }
+
+    public function getNumber()
+    {
+        return $this->number;
+    }
+
+    public function setLabel($label)
+    {
+        $this->label = $label;
+    }
+
+    public function getLabel()
+    {
+        return $this->label;
+    }
+
+    public function isRepeated()
+    {
+        return $this->label === GPBLabel::REPEATED;
+    }
+
+    public function setType($type)
+    {
+        $this->type = $type;
+    }
+
+    public function getType()
+    {
+        return $this->type;
+    }
+
+    public function setMessageType($message_type)
+    {
+        $this->message_type = $message_type;
+    }
+
+    public function getMessageType()
+    {
+        return $this->message_type;
+    }
+
+    public function setEnumType($enum_type)
+    {
+        $this->enum_type = $enum_type;
+    }
+
+    public function getEnumType()
+    {
+        return $this->enum_type;
+    }
+
+    public function setPacked($packed)
+    {
+        $this->packed = $packed;
+    }
+
+    public function getPacked()
+    {
+        return $this->packed;
+    }
+
+    public function isPackable()
+    {
+        return $this->isRepeated() && self::isTypePackable($this->type);
+    }
+
+    public function isMap()
+    {
+        return $this->getType() == GPBType::MESSAGE &&
+               !is_null($this->getMessageType()->getOptions()) &&
+               $this->getMessageType()->getOptions()->getMapEntry();
+    }
+
+    private static function isTypePackable($field_type)
+    {
+        return ($field_type !== GPBType::STRING  &&
+            $field_type !== GPBType::GROUP   &&
+            $field_type !== GPBType::MESSAGE &&
+            $field_type !== GPBType::BYTES);
+    }
+
+    public static function getFieldDescriptor(
+        $name,
+        $label,
+        $type,
+        $number,
+        $oneof_index,
+        $packed,
+        $type_name = null)
+    {
+        $field = new FieldDescriptor();
+        $field->setName($name);
+        $camel_name = implode('', array_map('ucwords', explode('_', $name)));
+        $field->setGetter('get' . $camel_name);
+        $field->setSetter('set' . $camel_name);
+        $field->setType($type);
+        $field->setNumber($number);
+        $field->setLabel($label);
+        $field->setPacked($packed);
+        $field->setOneofIndex($oneof_index);
+
+        // At this time, the message/enum type may have not been added to pool.
+        // So we use the type name as place holder and will replace it with the
+        // actual descriptor in cross building.
+        switch ($type) {
+            case GPBType::MESSAGE:
+                $field->setMessageType($type_name);
+                break;
+            case GPBType::ENUM:
+                $field->setEnumType($type_name);
+                break;
+            default:
+                break;
+        }
+
+        return $field;
+    }
+
+    public static function buildFromProto($proto)
+    {
+        $type_name = null;
+        switch ($proto->getType()) {
+            case GPBType::MESSAGE:
+            case GPBType::GROUP:
+            case GPBType::ENUM:
+                $type_name = $proto->getTypeName();
+                break;
+            default:
+                break;
+        }
+
+        $oneof_index = $proto->hasOneofIndex() ? $proto->getOneofIndex() : -1;
+        $packed = false;
+        $options = $proto->getOptions();
+        if ($options !== null) {
+            $packed = $options->getPacked();
+        }
+
+        return FieldDescriptor::getFieldDescriptor(
+            $proto->getName(), $proto->getLabel(), $proto->getType(),
+            $proto->getNumber(), $oneof_index, $packed, $type_name);
+    }
+}
diff --git a/php/src/Google/Protobuf/Internal/FileDescriptor.php b/php/src/Google/Protobuf/Internal/FileDescriptor.php
new file mode 100644
index 00000000..14716390
--- /dev/null
+++ b/php/src/Google/Protobuf/Internal/FileDescriptor.php
@@ -0,0 +1,90 @@
+<?php
+
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+namespace Google\Protobuf\Internal;
+
+class FileDescriptor
+{
+
+    private $package;
+    private $message_type = [];
+    private $enum_type = [];
+
+    public function setPackage($package)
+    {
+        $this->package = $package;
+    }
+
+    public function getPackage()
+    {
+        return $this->package;
+    }
+
+    public function getMessageType()
+    {
+        return $this->message_type;
+    }
+
+    public function addMessageType($desc)
+    {
+        $this->message_type[] = $desc;
+    }
+
+    public function getEnumType()
+    {
+        return $this->enum_type;
+    }
+
+    public function addEnumType($desc)
+    {
+        $this->enum_type[]= $desc;
+    }
+
+    public static function buildFromProto($proto)
+    {
+        $file = new FileDescriptor();
+        $file->setPackage($proto->getPackage());
+        foreach ($proto->getMessageType() as $message_proto) {
+            $file->addMessageType(Descriptor::buildFromProto(
+                $message_proto, $proto, ""));
+        }
+        foreach ($proto->getEnumType() as $enum_proto) {
+            $file->getEnumType()[] =
+                $file->addEnumType(
+                    EnumDescriptor::buildFromProto(
+                        $enum_proto,
+                        $proto,
+                        ""));
+        }
+        return $file;
+    }
+}
diff --git a/php/src/Google/Protobuf/Internal/GPBUtil.php b/php/src/Google/Protobuf/Internal/GPBUtil.php
index 0e66ae6f..1b71f7b7 100644
--- a/php/src/Google/Protobuf/Internal/GPBUtil.php
+++ b/php/src/Google/Protobuf/Internal/GPBUtil.php
@@ -67,7 +67,6 @@ class GPBUtil
         }
     }
 
-
     public static function checkString(&$var, $check_utf8)
     {
         if (is_array($var) || is_object($var)) {
@@ -242,4 +241,103 @@ class GPBUtil
     {
         return new Uint64($value);
     }
+
+    public static function getClassNamePrefix(
+        $classname,
+        $file_proto)
+    {
+        $option = $file_proto->getOptions();
+        $prefix = is_null($option) ? "" : $option->getPhpClassPrefix();
+        if ($prefix !== "") {
+            return $prefix;
+        }
+
+        $reserved_words = array("Empty");
+        foreach ($reserved_words as $reserved_word) {
+            if ($classname === $reserved_word) {
+                if ($file_proto->getPackage() === "google.protobuf") {
+                    return "GPB";
+                } else {
+                    return "PB";
+                }
+            }
+        }
+
+        return "";
+    }
+
+    public static function getClassNameWithoutPackage(
+        $name,
+        $file_proto)
+    {
+        $classname = implode('_', array_map('ucwords', explode('.', $name)));
+        return static::getClassNamePrefix($classname, $file_proto) . $classname;
+    }
+
+    public static function getFullClassName(
+        $proto,
+        $containing,
+        $file_proto,
+        &$message_name_without_package,
+        &$classname,
+        &$fullname)
+    {
+        // Full name needs to start with '.'.
+        $message_name_without_package = $proto->getName();
+        if ($containing !== "") {
+            $message_name_without_package =
+                $containing . "." . $message_name_without_package;
+        }
+
+        $package = $file_proto->getPackage();
+        if ($package === "") {
+            $fullname = "." . $message_name_without_package;
+        } else {
+            $fullname = "." . $package . "." . $message_name_without_package;
+        }
+
+        $class_name_without_package =
+            static::getClassNameWithoutPackage($message_name_without_package, $file_proto);
+
+        $option = $file_proto->getOptions();
+        if (!is_null($option) && $option->hasPhpNamespace()) {
+            $namespace = $option->getPhpNamespace();
+            if ($namespace !== "") {
+                $classname = $namespace . "\\" . $class_name_without_package;
+                return;
+            } else {
+                $classname = $class_name_without_package;
+                return;
+            }
+        }
+
+        if ($package === "") {
+            $classname = $class_name_without_package;
+        } else {
+            $classname =
+                implode('\\', array_map('ucwords', explode('.', $package))).
+                "\\".$class_name_without_package;
+        }
+    }
+
+    public static function combineInt32ToInt64($high, $low)
+    {
+        $isNeg = $high < 0;
+        if ($isNeg) {
+            $high = ~$high;
+            $low = ~$low;
+            $low++;
+            if (!$low) {
+                $high++;
+            }
+        }
+        $result = bcadd(bcmul($high, 4294967296), $low);
+        if ($low < 0) {
+            $result = bcadd($result, 4294967296);
+        }
+        if ($isNeg) {
+          $result = bcsub(0, $result);
+        }
+        return $result;
+    }
 }
diff --git a/php/src/Google/Protobuf/Internal/InputStream.php b/php/src/Google/Protobuf/Internal/InputStream.php
index 8012a225..f84e1aee 100644
--- a/php/src/Google/Protobuf/Internal/InputStream.php
+++ b/php/src/Google/Protobuf/Internal/InputStream.php
@@ -34,27 +34,6 @@ namespace Google\Protobuf\Internal;
 
 use Google\Protobuf\Internal\Uint64;
 
-function combineInt32ToInt64($high, $low)
-{
-    $isNeg = $high < 0;
-    if ($isNeg) {
-        $high = ~$high;
-        $low = ~$low;
-        $low++;
-        if (!$low) {
-            $high++;
-        }
-    }
-    $result = bcadd(bcmul($high, 4294967296), $low);
-    if ($low < 0) {
-        $result = bcadd($result, 4294967296);
-    }
-    if ($isNeg) {
-      $result = bcsub(0, $result);
-    }
-    return $result;
-}
-
 class InputStream
 {
 
@@ -192,7 +171,7 @@ class InputStream
                 $count += 1;
             } while ($b & 0x80);
 
-            $var = combineInt32ToInt64($high, $low);
+            $var = GPBUtil::combineInt32ToInt64($high, $low);
         } else {
             $result = 0;
             $shift = 0;
@@ -265,7 +244,7 @@ class InputStream
         }
         $high = unpack('V', $data)[1];
         if (PHP_INT_SIZE == 4) {
-            $var = combineInt32ToInt64($high, $low);
+            $var = GPBUtil::combineInt32ToInt64($high, $low);
         } else {
             $var = ($high << 32) | $low;
         }
diff --git a/php/src/Google/Protobuf/Internal/MapField.php b/php/src/Google/Protobuf/Internal/MapField.php
index 55cc12ce..12f09d61 100644
--- a/php/src/Google/Protobuf/Internal/MapField.php
+++ b/php/src/Google/Protobuf/Internal/MapField.php
@@ -38,131 +38,6 @@
 namespace Google\Protobuf\Internal;
 
 /**
- * MapFieldIter is used to iterate MapField. It is also need for the foreach
- * syntax.
- */
-class MapFieldIter implements \Iterator
-{
-
-    /**
-     * @ignore
-     */
-    private $container;
-
-    /**
-     * Create iterator instance for MapField.
-     *
-     * @param MapField The MapField instance for which this iterator is
-     * created.
-     * @ignore
-     */
-    public function __construct($container)
-    {
-        $this->container = $container;
-    }
-
-    /**
-     * Reset the status of the iterator
-     *
-     * @return void
-     */
-    public function rewind()
-    {
-        return reset($this->container);
-    }
-
-    /**
-     * Return the element at the current position.
-     *
-     * @return object The element at the current position.
-     */
-    public function current()
-    {
-        return current($this->container);
-    }
-
-    /**
-     * Return the current key.
-     *
-     * @return object The current key.
-     */
-    public function key()
-    {
-        return key($this->container);
-    }
-
-    /**
-     * Move to the next position.
-     *
-     * @return void
-     */
-    public function next()
-    {
-        return next($this->container);
-    }
-
-    /**
-     * Check whether there are more elements to iterate.
-     *
-     * @return bool True if there are more elements to iterate.
-     */
-    public function valid()
-    {
-        return key($this->container) !== null;
-    }
-}
-
-/**
- * @ignore
- */
-function checkKey($key_type, &$key)
-{
-    switch ($key_type) {
-        case GPBType::INT32:
-            GPBUtil::checkInt32($key);
-            break;
-        case GPBType::UINT32:
-            GPBUtil::checkUint32($key);
-            break;
-        case GPBType::INT64:
-            GPBUtil::checkInt64($key);
-            break;
-        case GPBType::UINT64:
-            GPBUtil::checkUint64($key);
-            break;
-        case GPBType::FIXED64:
-            GPBUtil::checkUint64($key);
-            break;
-        case GPBType::FIXED32:
-            GPBUtil::checkUint32($key);
-            break;
-        case GPBType::SFIXED64:
-            GPBUtil::checkInt64($key);
-            break;
-        case GPBType::SFIXED32:
-            GPBUtil::checkInt32($key);
-            break;
-        case GPBType::SINT64:
-            GPBUtil::checkInt64($key);
-            break;
-        case GPBType::SINT32:
-            GPBUtil::checkInt32($key);
-            break;
-        case GPBType::BOOL:
-            GPBUtil::checkBool($key);
-            break;
-        case GPBType::STRING:
-            GPBUtil::checkString($key, true);
-            break;
-        default:
-            trigger_error(
-                "Given type cannot be map key.",
-                E_USER_ERROR);
-            break;
-    }
-}
-
-/**
  * MapField is used by generated protocol message classes to manipulate map
  * fields. It can be used like native PHP array.
  */
@@ -255,7 +130,7 @@ class MapField implements \ArrayAccess, \IteratorAggregate, \Countable
      */
     public function offsetSet($key, $value)
     {
-        checkKey($this->key_type, $key);
+        $this->checkKey($this->key_type, $key);
 
         switch ($this->value_type) {
             case GPBType::INT32:
@@ -306,7 +181,7 @@ class MapField implements \ArrayAccess, \IteratorAggregate, \Countable
      */
     public function offsetUnset($key)
     {
-        checkKey($this->key_type, $key);
+        $this->checkKey($this->key_type, $key);
         unset($this->container[$key]);
     }
 
@@ -321,7 +196,7 @@ class MapField implements \ArrayAccess, \IteratorAggregate, \Countable
      */
     public function offsetExists($key)
     {
-        checkKey($this->key_type, $key);
+        $this->checkKey($this->key_type, $key);
         return isset($this->container[$key]);
     }
 
@@ -344,4 +219,54 @@ class MapField implements \ArrayAccess, \IteratorAggregate, \Countable
     {
         return count($this->container);
     }
+
+    /**
+     * @ignore
+     */
+    private function checkKey($key_type, &$key)
+    {
+        switch ($key_type) {
+            case GPBType::INT32:
+                GPBUtil::checkInt32($key);
+                break;
+            case GPBType::UINT32:
+                GPBUtil::checkUint32($key);
+                break;
+            case GPBType::INT64:
+                GPBUtil::checkInt64($key);
+                break;
+            case GPBType::UINT64:
+                GPBUtil::checkUint64($key);
+                break;
+            case GPBType::FIXED64:
+                GPBUtil::checkUint64($key);
+                break;
+            case GPBType::FIXED32:
+                GPBUtil::checkUint32($key);
+                break;
+            case GPBType::SFIXED64:
+                GPBUtil::checkInt64($key);
+                break;
+            case GPBType::SFIXED32:
+                GPBUtil::checkInt32($key);
+                break;
+            case GPBType::SINT64:
+                GPBUtil::checkInt64($key);
+                break;
+            case GPBType::SINT32:
+                GPBUtil::checkInt32($key);
+                break;
+            case GPBType::BOOL:
+                GPBUtil::checkBool($key);
+                break;
+            case GPBType::STRING:
+                GPBUtil::checkString($key, true);
+                break;
+            default:
+                trigger_error(
+                    "Given type cannot be map key.",
+                    E_USER_ERROR);
+                break;
+        }
+    }
 }
diff --git a/php/src/Google/Protobuf/Internal/MapFieldIter.php b/php/src/Google/Protobuf/Internal/MapFieldIter.php
new file mode 100644
index 00000000..a0388d92
--- /dev/null
+++ b/php/src/Google/Protobuf/Internal/MapFieldIter.php
@@ -0,0 +1,113 @@
+<?php
+
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+/**
+ * MapField and MapFieldIter are used by generated protocol message classes to
+ * manipulate map fields.
+ */
+
+namespace Google\Protobuf\Internal;
+
+/**
+ * MapFieldIter is used to iterate MapField. It is also need for the foreach
+ * syntax.
+ */
+class MapFieldIter implements \Iterator
+{
+
+    /**
+     * @ignore
+     */
+    private $container;
+
+    /**
+     * Create iterator instance for MapField.
+     *
+     * @param MapField The MapField instance for which this iterator is
+     * created.
+     * @ignore
+     */
+    public function __construct($container)
+    {
+        $this->container = $container;
+    }
+
+    /**
+     * Reset the status of the iterator
+     *
+     * @return void
+     */
+    public function rewind()
+    {
+        return reset($this->container);
+    }
+
+    /**
+     * Return the element at the current position.
+     *
+     * @return object The element at the current position.
+     */
+    public function current()
+    {
+        return current($this->container);
+    }
+
+    /**
+     * Return the current key.
+     *
+     * @return object The current key.
+     */
+    public function key()
+    {
+        return key($this->container);
+    }
+
+    /**
+     * Move to the next position.
+     *
+     * @return void
+     */
+    public function next()
+    {
+        return next($this->container);
+    }
+
+    /**
+     * Check whether there are more elements to iterate.
+     *
+     * @return bool True if there are more elements to iterate.
+     */
+    public function valid()
+    {
+        return key($this->container) !== null;
+    }
+}
\ No newline at end of file
diff --git a/php/src/Google/Protobuf/Internal/OneofDescriptor.php b/php/src/Google/Protobuf/Internal/OneofDescriptor.php
new file mode 100644
index 00000000..04988737
--- /dev/null
+++ b/php/src/Google/Protobuf/Internal/OneofDescriptor.php
@@ -0,0 +1,67 @@
+<?php
+
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+namespace Google\Protobuf\Internal;
+
+class OneofDescriptor
+{
+
+    private $name;
+    private $fields;
+
+    public function setName($name)
+    {
+        $this->name = $name;
+    }
+
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    public function addField(&$field)
+    {
+        $this->fields[] = $field;
+    }
+
+    public function getFields()
+    {
+        return $this->fields;
+    }
+
+    public static function buildFromProto($oneof_proto)
+    {
+        $oneof = new OneofDescriptor();
+        $oneof->setName($oneof_proto->getName());
+        return $oneof;
+    }
+}
diff --git a/php/src/Google/Protobuf/Internal/RepeatedField.php b/php/src/Google/Protobuf/Internal/RepeatedField.php
index 2ad4709a..797b3b3a 100644
--- a/php/src/Google/Protobuf/Internal/RepeatedField.php
+++ b/php/src/Google/Protobuf/Internal/RepeatedField.php
@@ -41,86 +41,6 @@ use Google\Protobuf\Internal\GPBType;
 use Google\Protobuf\Internal\GPBUtil;
 
 /**
- * RepeatedFieldIter is used to iterate RepeatedField. It is also need for the
- * foreach syntax.
- */
-class RepeatedFieldIter implements \Iterator
-{
-
-    /**
-     * @ignore
-     */
-    private $position;
-    /**
-     * @ignore
-     */
-    private $container;
-
-    /**
-     * Create iterator instance for RepeatedField.
-     *
-     * @param RepeatedField The RepeatedField instance for which this iterator
-     * is created.
-     * @ignore
-     */
-    public function __construct($container)
-    {
-        $this->position = 0;
-        $this->container = $container;
-    }
-
-    /**
-     * Reset the status of the iterator
-     *
-     * @return void
-     */
-    public function rewind()
-    {
-        $this->position = 0;
-    }
-
-    /**
-     * Return the element at the current position.
-     *
-     * @return object The element at the current position.
-     */
-    public function current()
-    {
-        return $this->container[$this->position];
-    }
-
-    /**
-     * Return the current position.
-     *
-     * @return integer The current position.
-     */
-    public function key()
-    {
-        return $this->position;
-    }
-
-    /**
-     * Move to the next position.
-     *
-     * @return void
-     */
-    public function next()
-    {
-        ++$this->position;
-    }
-
-    /**
-     * Check whether there are more elements to iterate.
-     *
-     * @return bool True if there are more elements to iterate.
-     */
-    public function valid()
-    {
-        return isset($this->container[$this->position]);
-    }
-}
-
-/**
  * RepeatedField is used by generated protocol message classes to manipulate
  * repeated fields. It can be used like native PHP array.
  */
diff --git a/php/src/Google/Protobuf/Internal/RepeatedFieldIter.php b/php/src/Google/Protobuf/Internal/RepeatedFieldIter.php
new file mode 100644
index 00000000..2b6f8230
--- /dev/null
+++ b/php/src/Google/Protobuf/Internal/RepeatedFieldIter.php
@@ -0,0 +1,118 @@
+<?php
+
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+/**
+ * RepeatedField and RepeatedFieldIter are used by generated protocol message
+ * classes to manipulate repeated fields.
+ */
+
+namespace Google\Protobuf\Internal;
+
+/**
+ * RepeatedFieldIter is used to iterate RepeatedField. It is also need for the
+ * foreach syntax.
+ */
+class RepeatedFieldIter implements \Iterator
+{
+
+    /**
+     * @ignore
+     */
+    private $position;
+    /**
+     * @ignore
+     */
+    private $container;
+
+    /**
+     * Create iterator instance for RepeatedField.
+     *
+     * @param RepeatedField The RepeatedField instance for which this iterator
+     * is created.
+     * @ignore
+     */
+    public function __construct($container)
+    {
+        $this->position = 0;
+        $this->container = $container;
+    }
+
+    /**
+     * Reset the status of the iterator
+     *
+     * @return void
+     */
+    public function rewind()
+    {
+        $this->position = 0;
+    }
+
+    /**
+     * Return the element at the current position.
+     *
+     * @return object The element at the current position.
+     */
+    public function current()
+    {
+        return $this->container[$this->position];
+    }
+
+    /**
+     * Return the current position.
+     *
+     * @return integer The current position.
+     */
+    public function key()
+    {
+        return $this->position;
+    }
+
+    /**
+     * Move to the next position.
+     *
+     * @return void
+     */
+    public function next()
+    {
+        ++$this->position;
+    }
+
+    /**
+     * Check whether there are more elements to iterate.
+     *
+     * @return bool True if there are more elements to iterate.
+     */
+    public function valid()
+    {
+        return isset($this->container[$this->position]);
+    }
+}