pw_toolchain/host_clang/BUILD.gn

# Copyright 2020 The Pigweed Authors
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may not
# use this file except in compliance with the License. You may obtain a copy of
# the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations under
# the License.

import("//build_overrides/pigweed.gni")
import("//build_overrides/pigweed_environment.gni")

# See https://github.com/google/sanitizers
config("sanitize_address") {
  cflags = [ "-fsanitize=address" ]
  ldflags = cflags
}

config("sanitize_memory") {
  cflags = [
    "-fsanitize=memory",

    # Do not optimizes tail recursive calls to get better call stack.
    "-fno-optimize-sibling-calls",

    # Enable check after destruction detection.
    "-fsanitize-memory-use-after-dtor",
  ]
  ldflags = cflags
}

config("sanitize_undefined") {
  cflags = [
    "-fsanitize=undefined",

    # Store the stack frame pointer in a register to get proper debug
    # information.
    "-fno-omit-frame-pointer",

    # Exit the program on check failure. (The default is to continue execution,
    # which prevents test frameworks from realizing the test has failed.)
    "-fno-sanitize-recover=undefined",
  ]
  ldflags = cflags
}

# UBsan configuration that enables additional checks. These checks are
# heuristic and may not correspond to undefined behavior.
config("sanitize_undefined_heuristic") {
  sanitizers = [
    # Base checks for undefined behaviour.
    "undefined",

    # Checks for undefined or suspicious integer behavior.
    "integer",

    # Checks for floating point division by zero.
    "float-divide-by-zero",

    # Checks for suspicious behavior of implicit conversions.
    "implicit-conversion",

    # Checks for null as function arg, lvalue and return type.
    "nullability",
  ]
  cflags = [
    "-fsanitize=" + string_join(",", sanitizers),

    # Store the stack frame pointer in a register to get proper debug
    # information.
    "-fno-omit-frame-pointer",
  ]
  ldflags = cflags
}

config("sanitize_thread") {
  cflags = [ "-fsanitize=thread" ]
  ldflags = cflags
}

config("sanitize_coverage") {
  cflags = [
    "-fprofile-instr-generate",
    "-fcoverage-mapping",
  ]
  ldflags = cflags
}

# Locate XCode's sysroot for Clang.
config("xcode_sysroot") {
  if (current_os == "mac") {
    _xcode_sysroot = exec_script("$dir_pw_build/py/pw_build/exec.py",
                                 [
                                   "--",
                                   "/usr/bin/xcrun",
                                   "--show-sdk-path",
                                 ],
                                 "trim string")
    cflags = [ "--sysroot=$_xcode_sysroot" ]
    ldflags = cflags
  }
}

config("linux_sysroot") {
  if (current_os == "linux") {
    cflags = [ "--sysroot=" +
               rebase_path(pw_env_setup_CIPD_PIGWEED, root_build_dir) +
               "/clang_sysroot/" ]
    ldflags = cflags
  }
}

# The CIPD provided Clang/LLVM toolchain must link against the matched
# libc++ which is also from CIPD. However, by default, Clang on Mac (but
# not on Linux) will fall back to the system libc++, which is
# incompatible due to an ABI change.
#
# Pull the appropriate paths from our Pigweed env setup.
config("no_system_libcpp") {
  if (current_os == "mac") {
    install_dir = pw_env_setup_CIPD_PIGWEED
    assert(install_dir != "",
           "You forgot to activate the Pigweed environment; " +
               "did you source pw_env_setup/setup.sh?")
    ldflags = [
      # Force dropping the system libc++
      "-nostdlib++",

      # Use the libc++ from CIPD.
      rebase_path(pw_env_setup_CIPD_PIGWEED + "/lib/libc++.a", root_build_dir),
    ]
  }
}