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

1 files changed, 13 insertions, 5 deletions

diff --git a/php/src/Google/Protobuf/Internal/GPBUtil.php b/php/src/Google/Protobuf/Internal/GPBUtil.php
index 05d5c393..023b07f4 100644
--- a/php/src/Google/Protobuf/Internal/GPBUtil.php
+++ b/php/src/Google/Protobuf/Internal/GPBUtil.php
@@ -191,7 +191,7 @@ class GPBUtil
         $var = boolval($var);
     }
 
-    public static function checkMessage(&$var, $klass)
+    public static function checkMessage(&$var, $klass, $newClass = null)
     {
         if (!$var instanceof $klass && !is_null($var)) {
             throw new \Exception("Expect $klass.");
@@ -303,8 +303,11 @@ class GPBUtil
         $name,
         $file_proto)
     {
-        $classname = implode('_', explode('.', $name));
-        return static::getClassNamePrefix($classname, $file_proto) . $classname;
+        $parts = explode('.', $name);
+        foreach ($parts as $i => $part) {
+            $parts[$i] = static::getClassNamePrefix($parts[$i], $file_proto) . $parts[$i];
+        }
+        return implode('\\', $parts);
     }
 
     public static function getFullClassName(
@@ -347,9 +350,14 @@ class GPBUtil
         if ($package === "") {
             $classname = $class_name_without_package;
         } else {
+            $parts = array_map('ucwords', explode('.', $package));
+            foreach ($parts as $i => $part) {
+                $parts[$i] = self::getClassNamePrefix($part, $file_proto).$part;
+            }
             $classname =
-                implode('\\', array_map('ucwords', explode('.', $package))).
-                "\\".$class_name_without_package;
+                implode('\\', $parts) .
+                "\\".self::getClassNamePrefix($class_name_without_package,$file_proto).
+                $class_name_without_package;
         }
     }