Make the Cocoa generator dynamic.

- Modify the Cocoa generator constructor to fit the new generic interface.
- Register the Cocoa genrator with the central registry.
- Deprecate the old way of invoking the Cocoa generator.
- main.cc no longer includes t_cocoa_generator.h.


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665603 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/compiler/cpp/src/main.cc b/compiler/cpp/src/main.cc
index dfd5f9e..3499035 100644
--- a/compiler/cpp/src/main.cc
+++ b/compiler/cpp/src/main.cc
@@ -41,7 +41,6 @@
 #include "generate/t_xsd_generator.h"
 #include "generate/t_perl_generator.h"
 #include "generate/t_erl_generator.h"
-#include "generate/t_cocoa_generator.h"
 #include "generate/t_csharp_generator.h"
 
 using namespace std;
@@ -610,7 +609,6 @@
   fprintf(stderr, "  -xsd        Generate XSD output files\n");
   fprintf(stderr, "  -perl       Generate Perl output files\n");
   fprintf(stderr, "  -erl        Generate Erlang output files\n");
-  fprintf(stderr, "  -cocoa      Generate Cocoa/Objective-C output files\n");
   fprintf(stderr, "  -csharp     Generate C# output files\n");
   fprintf(stderr, "  -o dir      Set the output directory for gen-* packages\n");
   fprintf(stderr, "               (default: current directory)\n");
@@ -909,13 +907,6 @@
       delete erl;
     }
 
-    if (gen_cocoa) {
-      pverbose("Generating Cocoa/Objective-C\n");
-      t_cocoa_generator* cocoa = new t_cocoa_generator(program);
-      cocoa->generate_program();
-      delete cocoa;
-    }
-
     if (gen_csharp) {
       pverbose("Generating C#\n");
       t_csharp_generator* csharp = new t_csharp_generator(program);
@@ -1116,6 +1107,10 @@
     pwarning(1, "-javabean is deprecated.  Use --gen java:beans");
     generator_strings.push_back("java:beans");
   }
+  if (gen_cocoa) {
+    pwarning(1, "-cocoa is deprecated.  Use --gen cocoa");
+    generator_strings.push_back("cocoa");
+  }
   if (gen_st) {
     pwarning(1, "-st is deprecated.  Use --gen st");
     generator_strings.push_back("st");
@@ -1130,7 +1125,7 @@
   }
 
   // You gotta generate something!
-  if (!gen_php && !gen_phpi && !gen_py && !gen_rb && !gen_xsd && !gen_perl && !gen_erl && !gen_cocoa && !gen_csharp && generator_strings.empty()) {
+  if (!gen_php && !gen_phpi && !gen_py && !gen_rb && !gen_xsd && !gen_perl && !gen_erl && !gen_csharp && generator_strings.empty()) {
     fprintf(stderr, "!!! No output language(s) specified\n\n");
     usage();
   }