# Copyright 2017 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import("//build/toolchain/variant.gni")

config("frame_pointers") {
  cflags = [ "-fno-omit-frame-pointer" ]
  ldflags = cflags
}

declare_args() {
  # Default [AddressSanitizer](https://llvm.org/docs/AddressSanitizer.html)
  # options (before the `ASAN_OPTIONS` environment variable is read at
  # runtime).  This can be set as a build argument to affect most "asan"
  # variants in `known_variants` (which see), or overridden in
  # toolchain_args in one of those variants.  Note that setting this
  # nonempty may conflict with programs that define their own
  # `__asan_default_options` C function.
  asan_default_options = ""
}

variant("asan") {
  common_flags = [ "-fsanitize=address" ]

  # ASan wants frame pointers because it captures stack traces
  # on allocations and such, not just on errors.
  configs = [ ":frame_pointers" ]

  if (asan_default_options != "") {
    deps = [
      ":asan_default_options",
    ]
  }
}

if (asan_default_options != "") {
  source_set("asan_default_options") {
    visibility = [ ":*" ]
    sources = [
      "asan_default_options.c",
    ]
    defines = [ "ASAN_DEFAULT_OPTIONS=\"${asan_default_options}\"" ]

    # On Fuchsia, the ASan runtime is dynamically linked and needs to have
    # the __asan_default_options symbol exported.  On systems where the
    # ASan runtime is statically linked, it doesn't matter either way.
    configs -= [ "//build/config:symbol_visibility_hidden" ]
  }
}

variant("ubsan") {
  common_flags = [ "-fsanitize=undefined" ]
}

variant("fuzzer") {
  common_flags = [ "-fsanitize=fuzzer" ]

  # TODO (TC-251): This shouldn't be necessary, but libzircon isn't currently
  # linked into libFuzzer on Fuchsia.
  if (is_fuchsia) {
    libs = [ "zircon" ]
  }
}

variant("sancov") {
  common_flags = [ "-fsanitize-coverage=trace-pc-guard" ]
}