llvm-efi
========

llvm-efi is a Bazel cc toolchain that uses the machine's host LLVM/clang with flags targeting freestanding EFI.
EFI headers are not shipped as part of the toolchain, but are available as a cc_library from `@gnuefi//:gnuefi`.

At some point, this toolchain should be replaced by a fully hermetic toolchain that doesn't depend on the host environment.

Usage
-----

To use this toolchain explicitly while building a `cc_binary`, do:

    bazel build --crosstool_top=//build/toolchain/llvm-efi:efi_cc_suite //foo/bar

During an actual build however, the right toolchain should be selected using aspects or other Bazel configurability features, instead of a hardcoded `--crosstool_top`.

fltused
-------

This is a special symbol emitted by MSVC-compatible compilers. In an EFI environment it can be ignored, but it needs to
be defined. See fltused.c for more information on the symbol. Since we cannot build an object file with Bazel and
building things for toolchains isn't a thing anyways, this file is prebuilt. If this ever needs to be rebuilt (which
will probably never happen since there is only one static symbol in there) this can be done with the following clang
invocation:

    clang -target x86_64-unknown-windows -fno-ms-compatibility -fno-ms-extensions -ffreestanding -o fltused.o .o -c fltused.c