Update protobuf to v25.1 (#183)

# Changes

Since we are upgrading the protobuf version, the location for the root
CMakeLists.txt has changed, hence the update.

We also updated the swift targets (ex: `swift_add_library` or
`swift_add_executable`) so that we can now set a global default C++
version with `SWIFT_CXX_STANDARD`.

Lastly tried to unify the interface between `swift_add_test` and the
rest of the other swift targets since `swift_add_test` was developed
separately to the rest, hence the difference in interface.

These changes will allow us to set the C++ for our Swift targets
independently from the third party libraries.

Author: RReichert

FindGrpc.cmake

@@ -1,6 +1,6 @@
 include("GenericFindDependency")
 
-option(ABSL_PROPAGATE_CXX_STD "Use CMake C++ standard meta features (e.g. cxx_std_11) that propagate to targets that link to Abseil" true)
+option(ABSL_PROPAGATE_CXX_STD "Use CMake C++ standard meta features (e.g. cxx_std_14) that propagate to targets that link to Abseil" true)
 option(protobuf_INSTALL "Install protobuf binaries and files" OFF)
 option(utf8_range_ENABLE_INSTALL "Configure installation" OFF)
 

FindProtobuf.cmake

@@ -10,13 +10,14 @@
 # WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
 #
 
+option(ABSL_PROPAGATE_CXX_STD "Use CMake C++ standard meta features (e.g. cxx_std_14) that propagate to targets that link to Abseil" true)
 option(protobuf_INSTALL "Install protobuf binaries and files" OFF)
 option(utf8_range_ENABLE_INSTALL "Configure installation" OFF)
 
 include("GenericFindDependency")
 option(protocol_BUILD_TESTS "" OFF)
 GenericFindDependency(
   TARGET "libprotobuf"
-  SOURCE_DIR "protobuf/cmake"
+  SOURCE_DIR "protobuf"
   SYSTEM_INCLUDES
 )

SwiftTargets.cmake

@@ -250,8 +250,11 @@ function(swift_add_target target type)
   if (x_C_STANDARD)
     list(APPEND language_standards_args C ${x_C_STANDARD})
   endif()
+
   if (x_CXX_STANDARD)
     list(APPEND language_standards_args CXX ${x_CXX_STANDARD})
+  elseif (SWIFT_CXX_STANDARD)
+    list(APPEND language_standards_args CXX ${SWIFT_CXX_STANDARD})
   endif()
 
   if (x_INTERFACE AND x_OBJECT)

TestTargets.cmake

@@ -261,7 +261,7 @@ endfunction()
 
 function(swift_add_test target)
   set(argOption "INTEGRATION_TEST" "PARALLEL" "POST_BUILD" "UNIT_TEST" "VALGRIND_MEMCHECK")
-  set(argSingle "COMMENT" "WORKING_DIRECTORY")
+  set(argSingle "C_STANDARD" "CXX_STANDARD" "COMMENT" "WORKING_DIRECTORY")
   set(argMulti "SRCS" "LINK" "INCLUDE")
 
   cmake_parse_arguments(x "${argOption}" "${argSingle}" "${argMulti}" ${ARGN})
@@ -290,9 +290,19 @@ function(swift_add_test target)
     message(FATAL_ERROR "VALGRIND_MEMCHECK can only be specified with UNIT_TEST")
   endif()
 
+  set(language_standards_args)
+  if (x_C_STANDARD)
+    list(APPEND language_standards_args C ${x_C_STANDARD})
+  endif()
+  if (x_CXX_STANDARD)
+    list(APPEND language_standards_args CXX ${x_CXX_STANDARD})
+  elseif (SWIFT_CXX_STANDARD)
+    list(APPEND language_standards_args CXX ${SWIFT_CXX_STANDARD})
+  endif()
+
   add_executable(${target} EXCLUDE_FROM_ALL ${x_SRCS})
   set_target_properties(${target} PROPERTIES SWIFT_TYPE "test")
-  swift_set_language_standards(${target} C_EXTENSIONS_ON)
+  swift_set_language_standards(${target} ${language_standards_args} C_EXTENSIONS_ON)
   target_code_coverage(${target} AUTO ALL)
   if(x_INCLUDE)
     target_include_directories(${target} PRIVATE ${x_INCLUDE})