Enable OSS builds for edenfs_ffi

Summary: For backingstore as well as edenfs_ffi, we want to use [CXX](http://cxx.rs). However, we hadn't been able to get it working for our CMake based OSS builds. This diff aims to close that gap.

Differential Revision: D50674596

eden/fs/store/filter/CMakeLists.txt

@@ -24,5 +24,5 @@ target_link_libraries(eden_store_filter PUBLIC
     eden_config
     eden_model
     eden_utils
-    # hg_eden_ffi
+    edenfs_ffi
     ${RE2_LIBRARY})

eden/scm/lib/CMakeLists.txt

@@ -3,4 +3,5 @@
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2.
 
+add_subdirectory(edenfs_ffi)
 add_subdirectory(backingstore)

eden/scm/lib/backingstore/CMakeLists.txt

@@ -55,7 +55,7 @@ else()
   )
 endif()
 
-# Reqwest links against the security framework.
+# Request links against the security framework.
 if (APPLE)
   target_link_libraries(
     backingstore

eden/scm/lib/edenfs_ffi/CMakeLists.txt

@@ -3,80 +3,56 @@
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2.
 
-find_program(CARGO_COMMAND cargo REQUIRED)
-set(crate_name edenfs_ffi)
-if(DEFINED ARG_FEATURES)
-  set(cargo_flags build
-    $<IF:$<CONFIG:Debug>,,--release>
-    -p ${crate_name}
-    --features ${ARG_FEATURES})
-else()
-  set(cargo_flags build $<IF:$<CONFIG:Debug>,,--release> -p ${crate_name})
-endif()
-
-if (CMAKE_BUILD_TYPE STREQUAL "Debug")
-    set(TARGET_DIR "debug")
-else ()
-    set(TARGET_DIR "release")
-endif ()
-
-if(USE_CARGO_VENDOR)
-  set(extra_cargo_env "CARGO_HOME=${RUST_CARGO_HOME}")
-  set(cargo_flags ${cargo_flags})
-endif()
-
-set(CARGO_MANIFEST ${CMAKE_SOURCE_DIR}/eden/scm/lib/edenfs_ffi/Cargo.toml)
-set(CARGO_TARGET_DIR ${CMAKE_SOURCE_DIR}/eden/scm/lib/edenfs_ffi/target)
-
-set(FFI_SOURCE_FILE ${CMAKE_SOURCE_DIR}/eden/scm/lib/edenfs_ffi/src/lib.rs)
-set(FFI_BRIDGE_CPP ${CARGO_TARGET_DIR}/cxxbridge/edenfs_ffi/src/lib.rs.cc)
-set(FFI_LIB ${CARGO_TARGET_DIR}/${TARGET_DIR}/${CMAKE_STATIC_LIBRARY_PREFIX}edenfs_ffi${CMAKE_STATIC_LIBRARY_SUFFIX})
-
-# Add a custom command that builds the rust crate and generates C++ bridge code
-add_custom_command(
-        OUTPUT ${FFI_BRIDGE_CPP} ${FFI_LIB}
-        COMMAND ${extra_cargo_env}
-          ${CARGO_COMMAND}
-          ${cargo_flags}
-          --manifest-path ${CARGO_MANIFEST}
-        DEPENDS ${FFI_SOURCE_FILE}
-        USES_TERMINAL
-        COMMENT "Running cargo..."
+rust_static_library(rust_edenfs_ffi CRATE edenfs_ffi)
+install_rust_static_library(
+  rust_edenfs_ffi
+  INSTALL_DIR lib
 )
 
-file(GLOB STORE_FFI_SRCS ${FFI_BRIDGE_CPP})
-
-add_library(
-  hg_eden_ffi STATIC
-  ${FFI_BRIDGE_CPP}
+file(GLOB edenfs_ffi_srcs "src/ffi.cpp")
+add_library(edenfs_ffi "${edenfs_ffi_srcs}")
+set_target_properties(
+  edenfs_ffi
+  PROPERTIES
+  PUBLIC_HEADER
+  "src/ffi.h"
 )
-
 target_include_directories(
-        hg_eden_ffi
-        PRIVATE
-        include/
-        ${CARGO_TARGET_DIR}/eden/scm/lib/edenfs_ffi/src/
+  edenfs_ffi
+  PUBLIC
+  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+  $<INSTALL_INTERFACE:include>
+  ${CMAKE_CURRENT_BINARY_DIR}/cxxbridge/
 )
-
-target_link_libraries(hg_eden_ffi PUBLIC
-    eden_model
-    eden_utils
-    ${RE2_LIBRARY}
-    ${FFI_LIB})
-
-set_target_properties(
-        hg_eden_ffi
-        PROPERTIES ADDITIONAL_CLEAN_FILES ${CARGO_TARGET_DIR}
+target_link_libraries(
+  edenfs_ffi
+  PRIVATE
+  rust_edenfs_ffi
+  Folly::folly
+  eden_model
+  eden_utils
+  ${RE2_LIBRARY}
 )
 
 # Windows-only configuration
 if(WIN32)
-    target_link_libraries(hg_eden_ffi userenv ws2_32 bcrypt)
-    set_target_properties(
-            hg_eden_ffi
-            PROPERTIES
-            MSVC_RUNTIME_LIBRARY "MultiThreadedDLL"
-            RUNTIME_OUTPUT_DIRECTORY_DEBUG ${CMAKE_BINARY_DIR}
-            RUNTIME_OUTPUT_DIRECTORY_RELEASE ${CMAKE_BINARY_DIR}
-    )
+  target_link_libraries(
+    edenfs_ffi
+    userenv
+    ws2_32
+    bcrypt
+  )
+  set_target_properties(
+    edenfs_ffi
+    PROPERTIES
+    MSVC_RUNTIME_LIBRARY "MultiThreadedDLL"
+    RUNTIME_OUTPUT_DIRECTORY_DEBUG ${CMAKE_BINARY_DIR}
+    RUNTIME_OUTPUT_DIRECTORY_RELEASE ${CMAKE_BINARY_DIR}
+  )
 endif()
+
+install(
+  TARGETS edenfs_ffi
+  LIBRARY DESTINATION ${LIB_INSTALL_DIR}
+  PUBLIC_HEADER DESTINATION "include/eden/scm/lib/edenfs_ffi/src"
+)

eden/scm/lib/edenfs_ffi/src/ffi.h

@@ -8,8 +8,8 @@
 #pragma once
 
 #include <folly/futures/Future.h>
+#include <rust/cxx.h>
 #include <memory>
-#include "rust/cxx.h"
 
 namespace facebook::eden {