build: export vapi generation in vpp-dev

Adds the higher-level vapi generation to cmake/api.cmake and exposes
the necessary python scripts in vpp-dev, so that out-of-tree/downstream
plugins can also leverage the more convenient API.

Type: feature

Signed-off-by: Oliver Giles <oliver_g@radwin.com>
Change-Id: I8c40a14d27ba3cb972c6907632e03c0e7b0ce982

4 files changed, 84 insertions, 10 deletions

diff --git a/src/cmake/VPPConfig.cmake b/src/cmake/VPPConfig.cmake
index c6fd9fa3ded..870c2a5b182 100644
--- a/src/cmake/VPPConfig.cmake
+++ b/src/cmake/VPPConfig.cmake
@@ -15,6 +15,8 @@ get_filename_component(CMAKE_CURRENT_LIST_DIR ${CMAKE_CURRENT_LIST_FILE} PATH)
 
 find_path(VPP_INCLUDE_DIR PATH_SUFFIXES NAMES vppinfra/clib.h)
 find_program(VPP_APIGEN vppapigen)
+find_program(VPP_VAPI_C_GEN vapi_c_gen.py)
+find_program(VPP_VAPI_CPP_GEN vapi_cpp_gen.py)
 
 if(VPP_INCLUDE_DIR AND VPP_APIGEN)
   include_directories (${VPP_INCLUDE_DIR})
diff --git a/src/cmake/api.cmake b/src/cmake/api.cmake
index 922c83a8b4d..c936f731632 100644
--- a/src/cmake/api.cmake
+++ b/src/cmake/api.cmake
@@ -56,24 +56,95 @@ function(vpp_generate_api_json_header file dir component)
 endfunction()
 
 ##############################################################################
+# VPP-API
+##############################################################################
+function(vpp_generate_vapi_c_header f)
+  get_filename_component(output ${f}.vapi.h NAME)
+  set (output_name ${CMAKE_BINARY_DIR}/vpp-api/vapi/${output})
+  if(NOT VPP_VAPI_C_GEN)
+    set(VPP_VAPI_C_GEN ${CMAKE_SOURCE_DIR}/vpp-api/vapi/vapi_c_gen.py)
+    set(VPP_VAPI_C_GEN_DEPENDS
+        ${CMAKE_SOURCE_DIR}/vpp-api/vapi/vapi_c_gen.py
+        ${CMAKE_SOURCE_DIR}/vpp-api/vapi/vapi_json_parser.py
+    )
+  endif()
+
+  # C VAPI Headers
+  set(input ${CMAKE_CURRENT_BINARY_DIR}/${f}.json)
+  add_custom_command(
+    OUTPUT ${output_name}
+    WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/vpp-api/vapi
+    COMMAND ${VPP_VAPI_C_GEN}
+    ARGS --remove-path ${input}
+    DEPENDS ${input} ${VPP_VAPI_C_GEN_DEPENDS}
+    COMMENT "Generating VAPI C header ${output_name}"
+  )
+  install(
+    FILES ${output_name}
+    DESTINATION include/vapi
+    COMPONENT vpp-dev
+  )
+endfunction ()
+
+function (vpp_generate_vapi_cpp_header f)
+  get_filename_component(output ${f}.vapi.hpp NAME)
+  set (output_name ${CMAKE_BINARY_DIR}/vpp-api/vapi/${output})
+  if(NOT VPP_VAPI_CPP_GEN)
+    set(VPP_VAPI_CPP_GEN ${CMAKE_SOURCE_DIR}/vpp-api/vapi/vapi_cpp_gen.py)
+    set(VPP_VAPI_CPP_GEN_DEPENDS
+        ${CMAKE_SOURCE_DIR}/vpp-api/vapi/vapi_cpp_gen.py
+        ${CMAKE_SOURCE_DIR}/vpp-api/vapi/vapi_json_parser.py
+    )
+  endif()
+  # C++ VAPI Headers
+  set(input ${CMAKE_CURRENT_BINARY_DIR}/${f}.json)
+  add_custom_command(
+    OUTPUT ${output_name}
+    WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/vpp-api/vapi
+    COMMAND ${VPP_VAPI_CPP_GEN}
+    ARGS --gen-h-prefix=vapi --remove-path ${input}
+    DEPENDS ${input} ${VPP_VAPI_CPP_GEN_DEPENDS}
+    COMMENT "Generating VAPI C++ header ${output_name}"
+  )
+  install(
+    FILES ${output_name}
+    DESTINATION include/vapi
+    COMPONENT vpp-dev
+  )
+endfunction ()
+
+
+##############################################################################
 # generate the .h and .json files for a .api file
 #  @param file - the name of the .api
 #  @param dir  - the install directory under ROOT/share/vpp/api to place the
 #                generated .json file
 ##############################################################################
 function(vpp_generate_api_header file dir component)
-    vpp_generate_api_c_header (${file})
-    vpp_generate_api_json_header (${file} ${dir} ${component})
+  vpp_generate_api_c_header (${file})
+  vpp_generate_api_json_header (${file} ${dir} ${component})
+  vpp_generate_vapi_c_header (${file})
+  vpp_generate_vapi_cpp_header (${file})
 endfunction()
 
-function(vpp_add_api_files name)
+function(vpp_add_api_files name dir component)
   unset(header_files)
   set(target ${name}_api_headers)
   file(RELATIVE_PATH rpath ${CMAKE_SOURCE_DIR} ${CMAKE_CURRENT_SOURCE_DIR})
   foreach(file ${ARGN})
-    vpp_generate_api_header (${file} core vpp)
-    list(APPEND header_files ${file}.h ${file}.json)
-    set_property(GLOBAL APPEND PROPERTY VPP_API_FILES ${rpath}/${file})
+    vpp_generate_api_header (${file} ${dir} ${component})
+    # Basic api headers get installed in a subdirectory according to
+    # their component name, but vapi is expected to be found directly under
+    # "vapi". Both by in-source components (e.g. vpp-api/vapi/vapi.c), and
+    # out-of-tree plugins use #include <vapi/component.api.vapi.h>.
+    # ${file} contains the subdirectory, so strip it here.
+    get_filename_component(name ${file} NAME)
+    list(APPEND header_files
+      ${file}.h
+      ${file}.json
+      ${CMAKE_BINARY_DIR}/vpp-api/vapi/${name}.vapi.h
+      ${CMAKE_BINARY_DIR}/vpp-api/vapi/${name}.vapi.hpp
+    )
   endforeach()
   add_custom_target(${target} DEPENDS ${header_files})
 endfunction()
diff --git a/src/cmake/library.cmake b/src/cmake/library.cmake
index fd6c077ea21..dc14ae59e46 100644
--- a/src/cmake/library.cmake
+++ b/src/cmake/library.cmake
@@ -43,7 +43,7 @@ macro(add_vpp_library lib)
   endif()
 
   if(ARG_API_FILES)
-    vpp_add_api_files(${lib} ${ARG_API_FILES})
+    vpp_add_api_files(${lib} core vpp ${ARG_API_FILES})
     foreach(file ${ARG_API_FILES})
       get_filename_component(dir ${file} DIRECTORY)
       install(
diff --git a/src/cmake/plugin.cmake b/src/cmake/plugin.cmake
index a0c3de78f3c..2e2749a440e 100644
--- a/src/cmake/plugin.cmake
+++ b/src/cmake/plugin.cmake
@@ -31,12 +31,10 @@ macro(add_vpp_plugin name)
     endif()
   endif()
 
-  file(RELATIVE_PATH rpath ${CMAKE_SOURCE_DIR} ${CMAKE_CURRENT_SOURCE_DIR})
+  vpp_add_api_files(${plugin_name} plugins ${PLUGIN_COMPONENT} ${PLUGIN_API_FILES})
   foreach(f ${PLUGIN_API_FILES})
     get_filename_component(dir ${f} DIRECTORY)
-    vpp_generate_api_header(${f} plugins ${PLUGIN_COMPONENT})
     list(APPEND api_includes ${f}.h ${f}.json)
-    set_property(GLOBAL APPEND PROPERTY VPP_API_FILES ${rpath}/${f})
     install(
       FILES ${CMAKE_CURRENT_BINARY_DIR}/${f}.h
       ${CMAKE_CURRENT_BINARY_DIR}/${f}_enum.h
@@ -47,6 +45,9 @@ macro(add_vpp_plugin name)
   endforeach()
   add_library(${plugin_name} SHARED ${PLUGIN_SOURCES} ${api_includes})
   set_target_properties(${plugin_name} PROPERTIES NO_SONAME 1)
+  if(PLUGIN_API_FILES)
+    add_dependencies(${plugin_name} ${plugin_name}_api_headers)
+  endif()
   if(NOT VPP_EXTERNAL_PROJECT)
     add_dependencies(${plugin_name} vpp_version_h api_headers)
   endif()