Rust integration (experimental) (#99)

* First support for Rust.
* Bump version to 0.7.0

---------

Signed-off-by: Holger Rapp <HolgerRapp@gmx.net>
Signed-off-by: Kai-Uwe Hermann <kai-uwe.hermann@pionix.de>
Co-authored-by: Kai-Uwe Hermann <kai-uwe.hermann@pionix.de>

.gitignore

@@ -1,3 +1,5 @@
 *build
 *build-cross
+target
+watcher.lua
 workspace.yaml

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.14)
 
 project(everest-framework
-    VERSION 0.6.2
+    VERSION 0.7.0
     DESCRIPTION "The open operating system for e-mobility charging stations"
 	LANGUAGES CXX C
 )
@@ -16,6 +16,7 @@ option(FRAMEWORK_INSTALL "Install the library (shared data might be installed an
 option(CMAKE_RUN_CLANG_TIDY "Run clang-tidy" OFF)
 option(EVEREST_ENABLE_JS_SUPPORT "Enable everestjs for JavaScript modules" ON)
 option(EVEREST_ENABLE_PY_SUPPORT "Enable everestpy for Python modules" ON)
+option(EVEREST_ENABLE_RS_SUPPORT "Enable everestrs for Rust modules" OFF)
 
 # make own cmake modules available
 list(INSERT CMAKE_MODULE_PATH 0 "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
@@ -93,6 +94,10 @@ if (EVEREST_ENABLE_PY_SUPPORT)
     add_subdirectory(everestpy)
 endif()
 
+if (EVEREST_ENABLE_RS_SUPPORT)
+  add_subdirectory(everestrs)
+endif()
+
 # FIXME (aw): should this be installed or not?  Right now it is needed for the
 #             current packaging approach
 install(TARGETS framework

cmake/cxxrs.cmake

@@ -0,0 +1,19 @@
+function(emit_cxxrs_header)
+  set(output_dir "${CMAKE_CURRENT_BINARY_DIR}/cxxbridge/rust/")
+  file(MAKE_DIRECTORY ${output_dir})
+  execute_process(COMMAND ${CXXBRIDGE} --header -o ${output_dir}cxx.h)
+endfunction()
+
+function(emit_cxxrs_for_module module_name)
+  set(output_dir "${CMAKE_CURRENT_BINARY_DIR}/cxxbridge/${module_name}/")
+  file(MAKE_DIRECTORY ${output_dir})
+
+  add_custom_command(
+      OUTPUT ${output_dir}lib.rs.h ${output_dir}lib.rs.cc
+      COMMAND ${CXXBRIDGE} ${CMAKE_CURRENT_SOURCE_DIR}/${module_name}/src/lib.rs --header -o ${output_dir}lib.rs.h
+      COMMAND ${CXXBRIDGE} ${CMAKE_CURRENT_SOURCE_DIR}/${module_name}/src/lib.rs -o ${output_dir}lib.rs.cc
+      DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/${module_name}/src/lib.rs
+      COMMENT "Generating cxx for ${module_name}"
+      VERBATIM
+    )
+endfunction()

everestrs/CMakeLists.txt

@@ -0,0 +1,35 @@
+include(cxxrs)
+
+find_program(CXXBRIDGE cxxbridge PATHS "$ENV{HOME}/.cargo/bin/")
+if (CXXBRIDGE STREQUAL "CXXBRIDGE-NOTFOUND")
+  message("Could not find cxxbridge, trying to install with `cargo install cxxbridge-cmd'")
+  find_program(CARGO cargo PATHS "$ENV{HOME}/.cargo/bin/")
+  if (CARGO STREQUAL "CARGO-NOTFOUND")
+    message(FATAL_ERROR "Requires cargo available in path, install via rustup https://rustup.rs/")
+  endif()
+  execute_process(COMMAND ${CARGO} install cxxbridge-cmd --version 1.0.107)
+  find_program(CXXBRIDGE cxxbridge PATHS "$ENV{HOME}/.cargo/bin/")
+endif()
+
+emit_cxxrs_header()
+emit_cxxrs_for_module(everestrs)
+
+add_library(everestrs_sys STATIC
+  ${CMAKE_CURRENT_BINARY_DIR}/cxxbridge/everestrs/lib.rs.cc
+  everestrs_sys/everestrs_sys.cpp
+)
+
+target_include_directories(everestrs_sys PRIVATE
+  ${CMAKE_CURRENT_SOURCE_DIR}
+  ${CMAKE_CURRENT_BINARY_DIR}/cxxbridge
+)
+
+# This is a requirement that linking works on systems enforcing PIE.
+set_property(TARGET everestrs_sys PROPERTY POSITION_INDEPENDENT_CODE ON)
+target_link_libraries(everestrs_sys
+    PRIVATE
+    everest::framework
+    everest::log
+)
+
+install(TARGETS everestrs_sys LIBRARY)

everestrs/Cargo.toml

@@ -0,0 +1,5 @@
+[workspace]
+resolver = "2"
+members = [
+   "everestrs",
+]

everestrs/everestrs/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "everestrs"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+argh = "0.1.10"
+cxx = { version = "1.0.107", features = ["c++17"] }
+serde = { version = "1.0.175", features = ["derive"] }
+serde_json = "1"
+thiserror = "1.0.48"

everestrs/everestrs/README.md

@@ -0,0 +1,29 @@
+# Rust support for everest
+
+This is Rust support using cxx.rs to wrap the framework C++ library.
+
+## Trying it out
+
+    - Install rust as outlined on <https://rustup.rs/>, which should just be this
+      one line: `curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh`
+    - Built your workspace as outlined in `everest-core` README, make sure to tell
+      cMake to enable `EVEREST_ENABLE_RS_SUPPORT`. Note, that the Rust code relies
+      on being built in a workspace where `make install` was run once.
+    - You can now try building the code, but it will not do anything: `cd everestrs
+      && cargo build --all`
+    - If you want to play with a node, check out `https://github.com/EVerest/everest-core/pull/344` in your workspace and run make install.
+    - Go to `everest-core/modules/RsSomkeTest` and run `cargo build` there.
+    - There is no support for building or installing Rust modules with cMake
+      currently, so let's fake the installation:
+    - Go to `everest-core/build/dist/libexec/everest/modules` and create the stuff needed for a module:
+        ~~~bash
+        mkdir RsSmokeTest
+        ln -s ../../../../../../modules/RsSmokeTest/target/debug/smoke_test RsSmokeTest
+        ln -s ../../../../../../modules/RsSmokeTest/manifest.yaml . 
+        ~~~
+    - You should now be able to configure the `RsSmokeTest` module in your config
+      YAML.
+
+## Status
+
+This code is currently only supporting providing an interface to be implemented, i.e. no variables publish or receiving and no calling of other interfaces. Those features are straightforward, quick and easy to implement, but for now this is probably enough to iron out the integration questions.