Revert "third_party/protobuf: Update to HEAD (83d681ee2c)"

third_party/protobuf/cmake/CMakeLists.txt

Index: third_party/protobuf/cmake/CMakeLists.txt
diff --git a/third_party/protobuf/cmake/CMakeLists.txt b/third_party/protobuf/cmake/CMakeLists.txt
index df3b20126d4b22e492b75a835c2b72cf2df72bf5..f32a0e4e65e538a91e47cfa09900721e4f3954c4 100644
--- a/third_party/protobuf/cmake/CMakeLists.txt
+++ b/third_party/protobuf/cmake/CMakeLists.txt
@@ -1,28 +1,22 @@
 # Minimum CMake required
-cmake_minimum_required(VERSION 2.8.12)
+cmake_minimum_required(VERSION 2.8)
 
-if(protobuf_VERBOSE)
-  message(STATUS "Protocol Buffers Configuring...")
-endif()
+# Project
+project(protobuf C CXX)
 
 # CMake policies
 cmake_policy(SET CMP0022 NEW)
 
-# Project
-project(protobuf C CXX)
-
 # Options
+option(protobuf_VERBOSE "Enable for verbose output" OFF)
 option(protobuf_BUILD_TESTS "Build tests" ON)
-option(protobuf_BUILD_EXAMPLES "Build examples" OFF)
 if (BUILD_SHARED_LIBS)
   set(protobuf_BUILD_SHARED_LIBS_DEFAULT ON)
 else (BUILD_SHARED_LIBS)
   set(protobuf_BUILD_SHARED_LIBS_DEFAULT OFF)
 endif (BUILD_SHARED_LIBS)
 option(protobuf_BUILD_SHARED_LIBS "Build Shared Libraries" ${protobuf_BUILD_SHARED_LIBS_DEFAULT})
-include(CMakeDependentOption)
-cmake_dependent_option(protobuf_MSVC_STATIC_RUNTIME "Link static runtime libraries" ON
-  "NOT protobuf_BUILD_SHARED_LIBS" OFF)
+option(protobuf_MSVC_STATIC_RUNTIME "Link static runtime libraries" ON)
 if (MSVC)
   set(protobuf_WITH_ZLIB_DEFAULT OFF)
 else (MSVC)
@@ -31,9 +25,6 @@ endif (MSVC)
 option(protobuf_WITH_ZLIB "Build with zlib support" ${protobuf_WITH_ZLIB_DEFAULT})
 set(protobuf_DEBUG_POSTFIX "d"
   CACHE STRING "Default debug postfix")
-mark_as_advanced(protobuf_DEBUG_POSTFIX)
-# User options
-include(protobuf-options.cmake)
 
 # Path to main configure script
 set(protobuf_CONFIGURE_SCRIPT "../configure.ac")
@@ -53,24 +44,17 @@ string(REGEX REPLACE        "${protobuf_AC_INIT_REGEX}" "\\2"
 string(REGEX REPLACE        "${protobuf_AC_INIT_REGEX}" "\\3"
     protobuf_CONTACT        "${protobuf_AC_INIT_LINE}")
 # Parse version tweaks
-set(protobuf_VERSION_REGEX "^([0-9]+)\\.([0-9]+)\\.([0-9]+)-?(.*)$")
+set(protobuf_VERSION_REGEX "^([0-9]+)\\.([0-9]+)\\.([0-9]+).*$")
 string(REGEX REPLACE     "${protobuf_VERSION_REGEX}" "\\1"
   protobuf_VERSION_MAJOR "${protobuf_VERSION_STRING}")
 string(REGEX REPLACE     "${protobuf_VERSION_REGEX}" "\\2"
   protobuf_VERSION_MINOR "${protobuf_VERSION_STRING}")
 string(REGEX REPLACE     "${protobuf_VERSION_REGEX}" "\\3"
   protobuf_VERSION_PATCH "${protobuf_VERSION_STRING}")
-string(REGEX REPLACE     "${protobuf_VERSION_REGEX}" "\\4"
-  protobuf_VERSION_PRERELEASE "${protobuf_VERSION_STRING}")
-
 # Package version
 set(protobuf_VERSION
   "${protobuf_VERSION_MAJOR}.${protobuf_VERSION_MINOR}.${protobuf_VERSION_PATCH}")
 
-if(protobuf_VERSION_PRERELEASE)
-  set(protobuf_VERSION "${protobuf_VERSION}-${protobuf_VERSION_PRERELEASE}")
-endif()
-
 if(protobuf_VERBOSE)
   message(STATUS "Configuration script parsing status [")
   message(STATUS "  Description : ${protobuf_DESCRIPTION}")
@@ -86,7 +70,6 @@ if (CMAKE_USE_PTHREADS_INIT)
   add_definitions(-DHAVE_PTHREAD)
 endif (CMAKE_USE_PTHREADS_INIT)
 
-set(_protobuf_FIND_ZLIB)
 if (protobuf_WITH_ZLIB)
   find_package(ZLIB)
   if (ZLIB_FOUND)
@@ -97,7 +80,6 @@ if (protobuf_WITH_ZLIB)
     # Using imported target if exists
     if (TARGET ZLIB::ZLIB)
       set(ZLIB_LIBRARIES ZLIB::ZLIB)
-      set(_protobuf_FIND_ZLIB "if(NOT ZLIB_FOUND)\n  find_package(ZLIB)\nendif()")
     endif (TARGET ZLIB::ZLIB)
   else (ZLIB_FOUND)
     set(HAVE_ZLIB 0)
@@ -159,10 +141,6 @@ else (MSVC)
   set(LIB_PREFIX)
 endif (MSVC)
 
-if (protobuf_UNICODE)
-  add_definitions(-DUNICODE -D_UNICODE)
-endif (protobuf_UNICODE)
-
 include(libprotobuf-lite.cmake)
 include(libprotobuf.cmake)
 include(libprotoc.cmake)
@@ -173,11 +151,3 @@ if (protobuf_BUILD_TESTS)
 endif (protobuf_BUILD_TESTS)
 
 include(install.cmake)
-
-if (protobuf_BUILD_EXAMPLES)
-  include(examples.cmake)
-endif (protobuf_BUILD_EXAMPLES)
-
-if(protobuf_VERBOSE)
-    message(STATUS "Protocol Buffers Configuring done")
-endif()