NR UE & gNB imscope.

A new phy scope based on ImGui and ImPlot. This scope uses a different concurrency model than previous
scopes.

The PHY thread writing the data first checks if the data is ready to be written. If its not, nothing is copied.
The GUI thread reads data if available and marks it ready to write. This makes sure that the PHY threads are not
busy copying data that would never be displayed.

Some of the scopes also have a freeze functionality that further limit the amount of data that needs to be copied
from PHY threads. If a scope is "frozen" it still allows the user to explore the data using plots zoom/pan functions
but doesn't cause PHY threads to perform extra writes on the displayed data.

A compile option was added to enable/disable the scope. Use cmake -DENABLE_IMSCOPE=ON to enable the scope.

Update CXX standard to 17; it is required by some libraries (e.g., dear imgui). The oldest gcc version in
use by a distribution supported is Ubuntu 20, which has gcc 9.4 with c++17 support.

CMakeLists.txt

@@ -23,6 +23,7 @@
 
 cmake_minimum_required (VERSION 3.16)
 project (OpenAirInterface LANGUAGES C CXX)
+set(CMAKE_CXX_STANDARD 17)
 
 #########################################################
 # Base directories, compatible with legacy OAI building #
@@ -30,6 +31,10 @@ project (OpenAirInterface LANGUAGES C CXX)
 set (OPENAIR_DIR     ${CMAKE_SOURCE_DIR})
 
 include("cmake_targets/macros.cmake")
+if(NOT DEFINED ENV{CPM_SOURCE_CACHE})
+ set(CPM_SOURCE_CACHE ~/.cache/cpm/)
+endif()
+include("cmake_targets/CPM.cmake")
 
 ##############################
 ### CCache: reduce compilation time
@@ -288,6 +293,8 @@ set_property(CACHE KPM_VERSION PROPERTY STRINGS "KPM_V2_03" "KPM_V3_00")
 message(STATUS "Selected KPM Version: ${KPM_VERSION}")
 
 
+add_boolean_option(ENABLE_IMSCOPE OFF "Enable phy scope based on imgui" ON)
+
 ##################################################
 # ASN.1 grammar C code generation & dependencies #
 ##################################################
@@ -2340,30 +2347,24 @@ if(ENABLE_TESTS)
   find_package(GTest)
   if (NOT GTest_FOUND)
     message(STATUS "GTest package not found, will download googletest automatically. To prevent that install google test on your system (libgtest-dev)")
-    include(FetchContent)
-    FetchContent_Declare(
-      googletest
-      GIT_REPOSITORY https://github.com/google/googletest.git
-      GIT_TAG        58d77fa8070e8cec2dc1ed015d66b454c8d78850 # 1.12.1
+    CPMAddPackage(
+      NAME googletest
+      GITHUB_REPOSITORY google/googletest
+      GIT_TAG release-1.12.1
+      VERSION 1.12.1
+      OPTIONS "INSTALL_GTEST OFF" "gtest_force_shared_crt" "BUILD_GMOCK OFF"
     )
-    set(BUILD_GMOCK OFF)
-    set(INSTALL_GTEST OFF)
-    FetchContent_MakeAvailable(googletest)
-    add_library(GTest::gtest ALIAS gtest)
-    add_library(GTest::gtest_main ALIAS gtest_main)
   endif()
 
   find_package(benchmark)
   if (NOT benchmark_FOUND)
     message(STATUS "benchmark package not found, will download benchmark automatically. To prevent that install google benchmark on your system (libbenchmark-dev)")
-    include(FetchContent)
-    set(BENCHMARK_ENABLE_TESTING OFF)
-    FetchContent_Declare(
-      benchmark
-      GIT_REPOSITORY https://github.com/google/benchmark.git
-      GIT_TAG v1.9.0
+    CPMAddPackage(
+      NAME benchmark
+      GITHUB_REPOSITORY google/benchmark
+      VERSION 1.9.0
+      OPTIONS "BENCHMARK_ENABLE_TESTING OFF"
     )
-    FetchContent_MakeAvailable(benchmark)
   endif()
 endif()