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matthewjricheymatthewjrichey
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cmake: support building Rust libraries
This commit adds a new cmake function rust_cargo_library() to build a Rust staticlib library with cbindgen-generated header file, which can be linked into a C application. Signed-off-by: Matthew Richey <[email protected]>
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‎CMakeLists.txt

Lines changed: 123 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -89,12 +89,13 @@ function(rust_cargo_application)
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# TODO: Make sure RUSTFLAGS is not set.
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if(CONFIG_DEBUG)
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set(RUST_BUILD_TYPE "debug")
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set(rust_build_type_arg "")
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# choose debug/release build based on Kconfig choice
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if(CONFIG_RUST_CARGO_PROFILE_RELEASE)
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message(STATUS "Cargo build profile: release")
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set(RUST_BUILD_TYPE release)
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else()
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set(RUST_BUILD_TYPE "release")
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set(rust_build_type_arg "--release")
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message(STATUS "Cargo build profile: dev")
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set(RUST_BUILD_TYPE debug)
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endif()
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set(BUILD_LIB_DIR "${CMAKE_CURRENT_SOURCE_DIR}/${RUST_TARGET}/${RUST_BUILD_TYPE}")
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@@ -178,7 +179,7 @@ ${config_paths}
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DT_AUGMENTS="${DT_AUGMENTS}"
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BINARY_DIR_INCLUDE_GENERATED="${BINARY_DIR_INCLUDE_GENERATED}"
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cargo build
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${rust_build_type_arg}
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--profile $<IF:$<BOOL:${CONFIG_RUST_CARGO_PROFILE_RELEASE}>,release,dev>
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# Override the features according to the shield given. For a general case,
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# this will need to come from a variable or argument.
@@ -194,6 +195,7 @@ ${config_paths}
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${CARGO_EXTRA_FLAGS}
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COMMENT "Building Rust application"
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WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
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USES_TERMINAL
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)
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# Be sure we don't try building this until all of the generated headers have been generated.
@@ -261,3 +263,118 @@ ${config_paths}
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# Add an empty file so that this will build. The main will come from the rust library.
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target_sources(app PRIVATE $CACHE{RUST_MODULE_DIR}/main.c ${WRAPPER_FILE})
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endfunction()
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# Function to build a Rust library using cargo, to be integrated into a C-based
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# Zephyr application.
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#
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# In contrast to the rust_cargo_application function, which builds an entire
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# Zephyr application from primarily Rust source files, this function is designed
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# to build a standalone Rust crate into a library that can be integrated into a
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# Zephyr application whose source code base is primarily written in C.
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#
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# A library built with this function will typically provide a C API through a
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# Foreign Function Interface (FFI) whose C header files will be automatically
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# generated from the Rust source code by the cbindgen tool, therefore use of
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# this function requires the cbindgen tool to be installed on the build host.
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#
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# The caller must specify the following arguments:
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#
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# LIBRARY_NAME <library-name> - the name of the library
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# CRATE_PATH <crate-path> - path to the root of the Rust crate to build
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#
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# The caller may optionally specify the following argument:
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#
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# MEMORY_PARTITION <memory-partition-name>
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#
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# which, if specified, will place any static global symbols built from the Rust
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# sources into the specified memory partition, which can allow the symbols to be
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# used from user mode threads.
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#
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# The function will add the specified library name into the build environment as
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# a symbol that can be linked into the target Zephyr application using e.g.
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# target_link_libraries.
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#
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# Usage:
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# rust_cargo_library(LIBRARY_NAME <library-name>
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# CRATE_PATH <crate-path>
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# |MEMORY_PARTITION <memory-partition-name>|
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# )
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#
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function(rust_cargo_library)
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# parse function arguments
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set(flags)
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set(args LIBRARY_NAME CRATE_PATH MEMORY_PARTITION)
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set(listArgs)
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cmake_parse_arguments(arg "${flags}" "${args}" "${listArgs}" ${ARGN})
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# verify required arguments
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if (NOT arg_LIBRARY_NAME)
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message(FATAL_ERROR "[rust_cargo_library]: LIBRARY_NAME is a required argument")
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endif()
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if (NOT arg_CRATE_PATH)
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message(FATAL_ERROR "[rust_cargo_library]: CRATE_PATH is a required argument")
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endif()
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# locate cbindgen executable
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find_program(CBINDGEN_EXE cbindgen REQUIRED)
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_rust_map_target()
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message(STATUS "Building Rust library ${arg_LIBRARY_NAME} for llvm target ${RUST_TARGET}")
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# choose debug/release build based on Kconfig choice
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if(CONFIG_RUST_CARGO_PROFILE_RELEASE)
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message(STATUS "Cargo build profile: release")
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set(RUST_BUILD_TYPE release)
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else()
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message(STATUS "Cargo build profile: dev")
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set(RUST_BUILD_TYPE debug)
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endif()
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set(BUILD_LIB_DIR ${CMAKE_CURRENT_SOURCE_DIR}/${RUST_TARGET}/${RUST_BUILD_TYPE})
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# library filename is based on arg_LIBRARY_NAME
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set(CARGO_TARGET_DIR ${CMAKE_CURRENT_BINARY_DIR}/rust/target)
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set(RUST_LIBRARY ${CARGO_TARGET_DIR}/${RUST_TARGET}/${RUST_BUILD_TYPE}/lib${arg_LIBRARY_NAME}.a)
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# cbindgen header filename is based on arg_LIBRARY_NAME with _ replaced by -
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string(REPLACE "_" "-" CBINDGEN_FILENAME "${arg_LIBRARY_NAME}-cbindgen.h")
340+
set(CBINDGEN_HEADER ${CMAKE_CURRENT_BINARY_DIR}/${CBINDGEN_FILENAME})
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# The library is built by invoking Cargo.
343+
add_custom_target(
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${arg_LIBRARY_NAME}_builder
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BYPRODUCTS ${RUST_LIBRARY} ${CBINDGEN_HEADER}
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# build the library
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COMMAND
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cargo build
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--profile $<IF:$<STREQUAL:${CONFIG_RUST_CARGO_PROFILE_RELEASE},y>,release,dev>
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--target ${RUST_TARGET}
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--target-dir ${CARGO_TARGET_DIR}
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${CARGO_EXTRA_FLAGS}
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# autogenerate the C header file using cbindgen
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COMMAND
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${CMAKE_COMMAND}
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-E env ${CBINDGEN_EXE}
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--config cbindgen.toml
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--output ${CBINDGEN_HEADER}
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--lang c
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WORKING_DIRECTORY ${arg_CRATE_PATH}
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USES_TERMINAL
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)
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# Create a library target and add the location of the generated header file
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# to its include path.
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add_library(${arg_LIBRARY_NAME} STATIC IMPORTED GLOBAL)
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add_dependencies(${arg_LIBRARY_NAME} ${arg_LIBRARY_NAME}_builder)
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set_target_properties(${arg_LIBRARY_NAME} PROPERTIES IMPORTED_LOCATION ${RUST_LIBRARY})
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set_target_properties(${arg_LIBRARY_NAME} PROPERTIES INTERFACE_INCLUDE_DIRECTORIES ${CMAKE_CURRENT_BINARY_DIR})
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# Place any statics from the rust library into the specified memory partition.
375+
if (arg_MEMORY_PARTITION)
376+
zephyr_append_cmake_library(${arg_LIBRARY_NAME})
377+
set(ZEPHYR_CURRENT_LIBRARY ${arg_LIBRARY_NAME})
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zephyr_library_app_memory(${arg_MEMORY_PARTITION})
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endif()
380+
endfunction()

‎Kconfig

Lines changed: 18 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -31,6 +31,24 @@ config RUST_ALLOC
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Zephyr allocator (malloc/free). This this enabled, Rust
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applications can use the `alloc` crate.
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choice RUST_CARGO_PROFILE
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prompt "Cargo profile"
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default RUST_CARGO_PROFILE_DEV
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help
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Select the profile to use when invoking cargo.
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config RUST_CARGO_PROFILE_DEV
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bool "Development profile"
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help
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Cargo profile suitable for development and debugging builds.
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config RUST_CARGO_PROFILE_RELEASE
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bool "Release profile"
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help
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Cargo profile suitable for release builds.
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endchoice # RUST_BUILD_TYPE
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3452
endif # RUST
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endmenu

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