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.

  1. // Generate a C++ header containing the C++ bindings
  2. // to the Rust exported functions in lib.rs.
  3. genrule {
  4.     name: "libcxx_test_bridge_header",
  5.     tools: ["cxxbridge"],
  6.     cmd: "$(location cxxbridge) $(in) --header > $(out)",
  7.     srcs: ["lib.rs"],
  8.     out: ["lib.rs.h"],
  9. }
  11. // Generate the C++ code that Rust calls into.
  12. genrule {
  13.     name: "libcxx_test_bridge_code",
  14.     tools: ["cxxbridge"],
  15.     cmd: "$(location cxxbridge) $(in) > $(out)",
  16.     srcs: ["lib.rs"],
  17.     out: ["lib.rs.cc"],
  18. }
  • 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.