+python do_write_toolchain_file () {
+ """Writes a BUILD.gn file for Yocto detailing its toolchains."""
+ toolchain_dir = d.expand("${S}/build/toolchain/yocto")
+ bb.utils.mkdirhier(toolchain_dir)
+ toolchain_file = os.path.join(toolchain_dir, "BUILD.gn")
+ write_toolchain_file(d, toolchain_file)
+}
+addtask write_toolchain_file after do_patch before do_configure
+
+# V8's JIT infrastructure requires binaries such as mksnapshot and
+# mkpeephole to be run in the host during the build. However, these
+# binaries must have the same bit-width as the target (e.g. a x86_64
+# host targeting ARMv6 needs to produce a 32-bit binary). Instead of
+# depending on a third Yocto toolchain, we just build those binaries
+# for the target and run them on the host with QEMU.
+python do_create_v8_qemu_wrapper () {
+ """Creates a small wrapper that invokes QEMU to run some target V8 binaries
+ on the host."""
+ qemu_libdirs = [d.expand('${STAGING_DIR_HOST}${libdir}'),
+ d.expand('${STAGING_DIR_HOST}${base_libdir}')]
+ qemu_cmd = qemu_wrapper_cmdline(d, d.getVar('STAGING_DIR_HOST', True),
+ qemu_libdirs)
+ wrapper_path = d.expand('${OUT_PATH}/v8-qemu-wrapper.sh')
+ with open(wrapper_path, 'w') as wrapper_file:
+ wrapper_file.write("""#!/bin/sh
+
+# This file has been generated automatically.
+# It invokes QEMU to run binaries built for the target in the host during the
+# build process.
+
+%s "$@"
+""" % qemu_cmd)
+ os.chmod(wrapper_path, 0o755)
+}
+do_create_v8_qemu_wrapper[dirs] = "${OUT_PATH}"
+addtask create_v8_qemu_wrapper after do_patch before do_configure
+