Building in Android

Create two genrules: One to generate the CXX header, and one to generate the CXX source file. These are then used as inputs to the cc_library_static.

// Generate a C++ header containing the C++ bindings // to the Rust exported functions in lib.rs. genrule { name: "libcxx_test_bridge_header", tools: ["cxxbridge"], cmd: "$(location cxxbridge) $(in) --header > $(out)", srcs: ["lib.rs"], out: ["lib.rs.h"], } // Generate the C++ code that Rust calls into. genrule { name: "libcxx_test_bridge_code", tools: ["cxxbridge"], cmd: "$(location cxxbridge) $(in) > $(out)", srcs: ["lib.rs"], out: ["lib.rs.cc"], }

Speaker Notes

  • The cxxbridge tool is a standalone tool that generates the C++ side of the bridge module. It is included in Android and available as a Soong tool.
  • By convention, if your Rust source file is lib.rs your header file will be named lib.rs.h and your source file will be named lib.rs.cc. This naming convention isn’t enforced, though.