# This sets up the GN configs that are used by default in GN targets in
# BUILDCONFIG.gn.
#
# This is based on LLVM `utils/gn/build/BUILD.gn`. Only the LLVM and Clang
# related options are retained

import("//build_overrides/clspv.gni")

declare_args() {
  # Whether to build everything with test coverage information.
  # After building with this, run tests and then run
  #    llvm/utils/prepare-code-coverage-artifact.py \
  #        --compilation-dir=out/gn \
  #        .../llvm-profdata .../llvm-cov out/gn/profiles/ report/ \
  #        out/gn/bin/llvm-undname ...
  # to generate a HTML report for the binaries passed in the last line.
  llvm_build_instrumented_coverage = false

  # Whether to build everything with instrumentation for PGO
  # After building with this:
  # 1. Remove old profile data with `rm *.profraw`
  # 2. Run the built instrumented binaries.
  #    This will produce *.profraw files in the current working directory.
  # 3. Run `llvm-profdata merge *.profraw -o llvm.profdata` to merge them.
  # 4. Then build again, with this set to false, and with
  #    `llvm_pgo_use = "//llvm.profdata"` set to use the created profile.
  llvm_pgo_instrument = false

  # If non-empty, path to merged profiling data used for optimization
  # See documentation for llvm_pgo_instrument for how to create profile data.
  llvm_pgo_use = ""

  # If set, puts relative paths in debug info.
  # Makes the build output independent of the build directory, but makes
  # most debuggers harder to use. See "Getting to local determinism" and
  # "Getting debuggers to work well with locally deterministic builds" in
  # http://blog.llvm.org/2019/11/deterministic-builds-with-clang-and-lld.html
  # for more information.
  use_relative_paths_in_debug_info = false

  # The version of host gcc. Ignored if is_clang is true.
  gcc_version = 9
}

assert(!llvm_build_instrumented_coverage || is_clang,
       "llvm_build_instrumented_coverage requires clang as host compiler")
assert(!llvm_pgo_instrument || is_clang,
       "llvm_pgo_instrument requires clang as host compiler")
assert(llvm_pgo_use == "" || is_clang,
       "llvm_pgo_use requires clang as host compiler")
assert(!llvm_pgo_instrument || llvm_pgo_use == "",
       "set at most one of llvm_pgo_instrument and llvm_pgo_use")

config("llvm_code") {
  include_dirs = [
    "//$clspv_llvm_dir/llvm/include",
    "$root_gen_dir/$clspv_llvm_dir//llvm/include",
  ]
  if (current_os != "win") {
    cflags = [ "-fPIC" ]
    if (is_clang) {
      cflags += [
        "-Wno-deprecated-declarations",
        "-Wno-deprecated-this-capture",
        "-Wno-deprecated-enum-enum-conversion",
        "-Wno-deprecated-anon-enum-enum-conversion",
      ]
    }
  }
}

config("clang_code") {
  if (current_os != "win") {
    cflags = [
      "-fno-strict-aliasing",
      "-Wno-deprecated-declarations",
    ]
  }
  include_dirs = [
    "//$clspv_llvm_dir/clang/include",
    "$root_gen_dir/$clspv_llvm_dir//clang/include",
  ]
}

config("warn_covered_switch_default") {
  if (is_clang) {
    cflags = [ "-Wcovered-switch-default" ]
  }
}