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John Elliott
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Add rust_cxx_bridge CMake function
Summary: We need a better way to create cxxbridges - something that uses the recommended method of cxxbridge-cmd. This function creates C++ bindings using the [cxx] crate. Original function found here: https://github.com/corrosion-rs/corrosion/blob/master/cmake/Corrosion.cmake#L1390 Differential Revision: D51160627
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‎build/fbcode_builder/CMake/RustStaticLibrary.cmake‎

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@@ -314,3 +314,191 @@ function(install_rust_static_library TARGET)
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DESTINATION ${ARG_INSTALL_DIR}
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)
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endfunction()
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# This function creates C++ bindings using the [cxx] crate.
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#
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# Original function found here: https://github.com/corrosion-rs/corrosion/blob/master/cmake/Corrosion.cmake#L1390
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# Simplified for use as part of RustStaticLibrary module. License below.
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#
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# MIT License
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#
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# Copyright (c) 2018 Andrew Gaspar
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#
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# Permission is hereby granted, free of charge, to any person obtaining a copy
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# of this software and associated documentation files (the "Software"), to deal
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# in the Software without restriction, including without limitation the rights
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# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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# copies of the Software, and to permit persons to whom the Software is
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# furnished to do so, subject to the following conditions:
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#
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# The above copyright notice and this permission notice shall be included in all
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# copies or substantial portions of the Software.
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#
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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# SOFTWARE.
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#
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# The rules approximately do the following:
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# - Check which version of `cxx` the Rust crate depends on.
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# - Check if the exact same version of `cxxbridge-cmd` is installed
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# - If not, create a rule to build the exact same version of `cxxbridge-cmd`.
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# - Create rules to run `cxxbridge` and generate
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# - The `rust/cxx.h` header
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# - A header and source file for the specified CXX_BRIDGE_FILE.
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# - The generated sources (and header include directories) are added to the
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# `${TARGET}` CMake library target.
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#
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# ```cmake
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# rust_cxx_bridge(<TARGET> <CXX_BRIDGE_FILE> [CRATE <CRATE_NAME>])
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# ```
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#
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# Parameters:
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# - TARGET:
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# Name of the target name. The target that the bridge will be included with.
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# - CXX_BRIDGE_FILE:
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# Name of the file that include the cxxbridge (e.g., "src/ffi.rs").
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# - CRATE_NAME:
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# Name of the crate. This parameter is optional. If unspecified, it will
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# fallback to `${TARGET}`.
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#
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function(rust_cxx_bridge TARGET CXX_BRIDGE_FILE)
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fb_cmake_parse_args(ARG "" "CRATE" "" "${ARGN}")
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if(DEFINED ARG_CRATE)
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set(crate_name "${ARG_CRATE}")
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else()
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set(crate_name "${TARGET}")
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endif()
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execute_process(COMMAND
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${CARGO_COMMAND} tree -i cxx --depth=0
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WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
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RESULT_VARIABLE cxx_version_result
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OUTPUT_VARIABLE cxx_version_output
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)
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if(NOT "${cxx_version_result}" EQUAL "0")
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message(FATAL_ERROR "Crate ${crate_name} does not depend on cxx.")
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endif()
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if(cxx_version_output MATCHES "cxx v([0-9]+.[0-9]+.[0-9]+)")
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set(cxx_required_version "${CMAKE_MATCH_1}")
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else()
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message(
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FATAL_ERROR
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"Failed to parse cxx version from cargo tree output: `cxx_version_output`")
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endif()
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# First check if a suitable version of cxxbridge is installed
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find_program(INSTALLED_CXXBRIDGE cxxbridge PATHS "$ENV{HOME}/.cargo/bin/")
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mark_as_advanced(INSTALLED_CXXBRIDGE)
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if(INSTALLED_CXXBRIDGE)
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execute_process(
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COMMAND ${INSTALLED_CXXBRIDGE}
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--version OUTPUT_VARIABLE cxxbridge_version_output)
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if(cxxbridge_version_output MATCHES "cxxbridge ([0-9]+.[0-9]+.[0-9]+)")
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set(cxxbridge_version "${CMAKE_MATCH_1}")
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else()
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set(cxxbridge_version "")
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endif()
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endif()
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set(cxxbridge "")
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if(cxxbridge_version)
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if(cxxbridge_version VERSION_EQUAL cxx_required_version)
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set(cxxbridge "${INSTALLED_CXXBRIDGE}")
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if(NOT TARGET "cxxbridge_v${cxx_required_version}")
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# Add an empty target.
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add_custom_target("cxxbridge_v${cxx_required_version}")
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endif()
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endif()
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endif()
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# No suitable version of cxxbridge was installed,
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# so use custom target to install correct version.
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if(NOT cxxbridge)
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if(NOT TARGET "cxxbridge_v${cxx_required_version}")
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add_custom_command(
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OUTPUT
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"${CMAKE_BINARY_DIR}/cxxbridge_v${cxx_required_version}/bin/cxxbridge"
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COMMAND
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${CMAKE_COMMAND} -E make_directory
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"${CMAKE_BINARY_DIR}/cxxbridge_v${cxx_required_version}"
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COMMAND
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${CARGO_COMMAND} install cxxbridge-cmd
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--version "${cxx_required_version}"
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--root "${CMAKE_BINARY_DIR}/cxxbridge_v${cxx_required_version}"
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--quiet
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# todo: use --target-dir to potentially reuse artifacts
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COMMENT "Installing cxxbridge (version ${cxx_required_version})"
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)
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add_custom_target(
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"cxxbridge_v${cxx_required_version}"
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DEPENDS
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"${CMAKE_BINARY_DIR}/cxxbridge_v${cxx_required_version}/bin/cxxbridge"
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)
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endif()
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set(
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cxxbridge
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"${CMAKE_BINARY_DIR}/cxxbridge_v${cxx_required_version}/bin/cxxbridge")
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endif()
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add_library(${crate_name} STATIC)
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target_include_directories(
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${crate_name}
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PUBLIC
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$<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>
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$<INSTALL_INTERFACE:include>
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)
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file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/rust")
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add_custom_command(
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OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/rust/cxx.h"
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COMMAND
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${cxxbridge}
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--header --output "${CMAKE_CURRENT_BINARY_DIR}/rust/cxx.h"
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DEPENDS "cxxbridge_v${cxx_required_version}"
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COMMENT "Generating rust/cxx.h header"
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)
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get_filename_component(filename_component ${CXX_BRIDGE_FILE} NAME)
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get_filename_component(directory_component ${CXX_BRIDGE_FILE} DIRECTORY)
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set(directory "")
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if(directory_component)
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set(directory "${directory_component}")
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endif()
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set(cxx_header ${directory}/${filename_component}.h)
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set(cxx_source ${directory}/${filename_component}.cc)
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set(rust_source_path "${CMAKE_CURRENT_SOURCE_DIR}/${CXX_BRIDGE_FILE}")
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file(
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MAKE_DIRECTORY
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"${CMAKE_CURRENT_BINARY_DIR}/${directory_component}"
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)
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add_custom_command(
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OUTPUT
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"${CMAKE_CURRENT_BINARY_DIR}/${cxx_header}"
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"${CMAKE_CURRENT_BINARY_DIR}/${cxx_source}"
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COMMAND
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${cxxbridge} ${rust_source_path}
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--header --output "${CMAKE_CURRENT_BINARY_DIR}/${cxx_header}"
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COMMAND
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${cxxbridge} ${rust_source_path}
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--output "${CMAKE_CURRENT_BINARY_DIR}/${cxx_source}"
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--include "${cxx_header}"
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DEPENDS "cxxbridge_v${cxx_required_version}" "${rust_source_path}"
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COMMENT "Generating cxx bindings for crate ${crate_name}"
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)
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target_sources(${crate_name}
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PRIVATE
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"${CMAKE_CURRENT_BINARY_DIR}/${cxx_header}"
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"${CMAKE_CURRENT_BINARY_DIR}/rust/cxx.h"
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"${CMAKE_CURRENT_BINARY_DIR}/${cxx_source}"
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)
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endfunction()

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