Only include utf8_range if it hasn't been included already

PiperOrigin-RevId: 518361290

cmake/libprotobuf-lite.cmake

@@ -40,5 +40,4 @@ set_target_properties(libprotobuf-lite PROPERTIES
 )
 add_library(protobuf::libprotobuf-lite ALIAS libprotobuf-lite)
 
-target_include_directories(libprotobuf-lite PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/third_party/utf8_range)
 target_link_libraries(libprotobuf-lite PRIVATE utf8_validity)

cmake/libprotobuf.cmake

@@ -43,5 +43,4 @@ set_target_properties(libprotobuf PROPERTIES
 )
 add_library(protobuf::libprotobuf ALIAS libprotobuf)
 
-target_include_directories(libprotobuf PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/third_party/utf8_range)
 target_link_libraries(libprotobuf PRIVATE utf8_validity)

cmake/utf8_range.cmake

@@ -1,12 +1,15 @@
-set(utf8_range_ENABLE_TESTS OFF CACHE BOOL "Disable utf8_range tests")
+if (NOT TARGET utf8_range)
+  set(utf8_range_ENABLE_TESTS OFF CACHE BOOL "Disable utf8_range tests")
 
-if (NOT EXISTS "${protobuf_SOURCE_DIR}/third_party/utf8_range/CMakeLists.txt")
-  message(FATAL_ERROR
-          "Cannot find third_party/utf8_range directory that's needed for "
-          "the protobuf runtime.\n")
-endif()
+  if (NOT EXISTS "${protobuf_SOURCE_DIR}/third_party/utf8_range/CMakeLists.txt")
+    message(FATAL_ERROR
+            "Cannot find third_party/utf8_range directory that's needed for "
+            "the protobuf runtime.\n")
+  endif()
 
-set(utf8_range_ENABLE_INSTALL ${protobuf_INSTALL} CACHE BOOL "Set install")
-add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/third_party/utf8_range third_party/utf8_range)
+  set(utf8_range_ENABLE_INSTALL ${protobuf_INSTALL} CACHE BOOL "Set install")
+  add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/third_party/utf8_range third_party/utf8_range)
+  include_directories(${CMAKE_CURRENT_SOURCE_DIR}/third_party/utf8_range)
+endif ()
 
 set(_protobuf_FIND_UTF8_RANGE "if(NOT TARGET utf8_range)\n  find_package(utf8_range CONFIG)\nendif()")