Fix Cmake build environment and harden Warnings

-Remove unused sweetcomb CmakeList.txt Warnings
-Add more Warnings to plugins, scvpp and gNMI Cmake projects
-Remove unused/useless Cmake options in CmakeList files & add comments
-Improve gNMI CMakeList.txt and make it independant of a gRPC cmake build for
later package integration.
-Add FindGRPC.cmake
-Remove the use of CXX17 variant and use a dedicated Cmake module for
gRPC

Change-Id: Iafa3c031d12802e8d8c914cbce6b119c2a5c4800
Signed-off-by: Yohan Pipereau <ypiperea@cisco.com>

1 files changed, 76 insertions, 0 deletions

diff --git a/src/cmake/FindGRPC.cmake b/src/cmake/FindGRPC.cmake
new file mode 100644
index 0000000..e45f969
--- /dev/null
+++ b/src/cmake/FindGRPC.cmake
@@ -0,0 +1,76 @@
+# From https://github.com/wastl/cmarmotta/blob/master/cmake/FindGRPC.cmake
+#
+# - Try to find gRPC
+# Once done this will define
+#
+#  GRPC_CPP_PLUGIN - Absolute path to grpc c++ plugin
+#  GRPCPP_LIBRARY -
+#  GPR_LIBRARY -
+#
+#  VPP_FOUND - system has VPP
+#  VPP_INCLUDE_DIRS - the VPP include directory
+#  VPP_LIBRARIES - Link these to use LibSSH
+
+#Absolute path to grpc_cpp_plugin
+find_program(GRPC_CPP_PLUGIN grpc_cpp_plugin)
+
+find_library(GRPC_LIBRARY NAMES grpc)
+find_library(GRPCPP_LIBRARY NAMES grpc++)
+find_library(GPR_LIBRARY NAMES gpr)
+set(GRPC_LIBRARIES ${GRPCPP_LIBRARY} ${GRPC_LIBRARY} ${GPR_LIBRARY})
+
+function(PROTOBUF_GENERATE_GRPC_CPP SRCS HDRS)
+  if(NOT ARGN)
+    message(SEND_ERROR "Error: PROTOBUF_GENERATE_GRPC_CPP() called without any proto files")
+    return()
+  endif()
+
+  if(PROTOBUF_GENERATE_CPP_APPEND_PATH) # This variable is common for all types of output.
+    # Create an include path for each file specified
+    foreach(FIL ${ARGN})
+      get_filename_component(ABS_FIL ${FIL} ABSOLUTE)
+      get_filename_component(ABS_PATH ${ABS_FIL} PATH)
+      list(FIND _protobuf_include_path ${ABS_PATH} _contains_already)
+      if(${_contains_already} EQUAL -1)
+          list(APPEND _protobuf_include_path -I ${ABS_PATH})
+      endif()
+    endforeach()
+  else()
+    set(_protobuf_include_path -I ${CMAKE_CURRENT_SOURCE_DIR})
+  endif()
+
+  if(DEFINED PROTOBUF_IMPORT_DIRS)
+    foreach(DIR ${PROTOBUF_IMPORT_DIRS})
+      get_filename_component(ABS_PATH ${DIR} ABSOLUTE)
+      list(FIND _protobuf_include_path ${ABS_PATH} _contains_already)
+      if(${_contains_already} EQUAL -1)
+          list(APPEND _protobuf_include_path -I ${ABS_PATH})
+      endif()
+    endforeach()
+  endif()
+
+  set(${SRCS})
+  set(${HDRS})
+  foreach(FIL ${ARGN})
+    get_filename_component(ABS_FIL ${FIL} ABSOLUTE)
+    get_filename_component(FIL_WE ${FIL} NAME_WE)
+
+    list(APPEND ${SRCS} "${CMAKE_CURRENT_BINARY_DIR}/${FIL_WE}.grpc.pb.cc")
+    list(APPEND ${HDRS} "${CMAKE_CURRENT_BINARY_DIR}/${FIL_WE}.grpc.pb.h")
+
+    add_custom_command(
+      OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/${FIL_WE}.grpc.pb.cc"
+             "${CMAKE_CURRENT_BINARY_DIR}/${FIL_WE}.grpc.pb.h"
+      COMMAND  ${PROTOBUF_PROTOC_EXECUTABLE}
+      ARGS --grpc_out=${CMAKE_CURRENT_BINARY_DIR}
+           --plugin=protoc-gen-grpc=${GRPC_CPP_PLUGIN}
+           ${_protobuf_include_path} ${ABS_FIL}
+      DEPENDS ${ABS_FIL} ${PROTOBUF_PROTOC_EXECUTABLE}
+      COMMENT "Running gRPC C++ protocol buffer compiler on ${FIL}"
+      VERBATIM)
+  endforeach()
+
+  set_source_files_properties(${${SRCS}} ${${HDRS}} PROPERTIES GENERATED TRUE)
+  set(${SRCS} ${${SRCS}} PARENT_SCOPE)
+  set(${HDRS} ${${HDRS}} PARENT_SCOPE)
+endfunction()