build/cmake/flags.cmake

# Copyright (C) 2020 The Android Open Source Project
#
# 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
#
#      http://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.

# This file will be included directly by cmake. It is used to provide
# additional cflags / ldflags.

cmake_minimum_required(VERSION 3.6.0)

set(_ANDROID_NDK_INIT_CFLAGS)
set(_ANDROID_NDK_INIT_CFLAGS_DEBUG)
set(_ANDROID_NDK_INIT_CFLAGS_RELEASE)
set(_ANDROID_NDK_INIT_LDFLAGS)
set(_ANDROID_NDK_INIT_LDFLAGS_EXE)

# Generic flags.
string(APPEND _ANDROID_NDK_INIT_CFLAGS
  " -DANDROID"
  " -fdata-sections"
  " -ffunction-sections"
  " -funwind-tables"
  " -fstack-protector-strong"
  " -no-canonical-prefixes")

if(DEFINED ANDROID_SUPPORT_FLEXIBLE_PAGE_SIZES)
  if (ANDROID_SUPPORT_FLEXIBLE_PAGE_SIZES)
    if(ANDROID_ABI STREQUAL arm64-v8a OR ANDROID_ABI STREQUAL x86_64)
      string(APPEND _ANDROID_NDK_INIT_LDFLAGS " -Wl,-z,max-page-size=16384")
    endif()
  else()
    string(APPEND _ANDROID_NDK_INIT_CFLAGS " -D__BIONIC_DEPRECATED_PAGE_SIZE_MACRO")
  endif()
endif()

if(ANDROID_WEAK_API_DEFS)
  string(APPEND _ANDROID_NDK_INIT_CFLAGS
    " -D__ANDROID_UNAVAILABLE_SYMBOLS_ARE_WEAK__"
    " -Werror=unguarded-availability")
endif()

if("hwaddress" IN_LIST ANDROID_SANITIZE)
  string(APPEND _ANDROID_NDK_INIT_CFLAGS " -fsanitize=hwaddress -fno-omit-frame-pointer")
  string(APPEND _ANDROID_NDK_INIT_LDFLAGS " -fsanitize=hwaddress")
endif()

if("memtag" IN_LIST ANDROID_SANITIZE)
  string(APPEND _ANDROID_NDK_INIT_CFLAGS " -fsanitize=memtag-stack -fno-omit-frame-pointer")
  string(APPEND _ANDROID_NDK_INIT_LDFLAGS " -fsanitize=memtag-stack,memtag-heap -fsanitize-memtag-mode=sync")
  if(CMAKE_ANDROID_ARCH_ABI STREQUAL "arm64-v8a")
    string(APPEND _ANDROID_NDK_INIT_CFLAGS " -march=armv8-a+memtag")
    string(APPEND _ANDROID_NDK_INIT_LDFLAGS " -march=armv8-a+memtag")
  endif()
endif()

string(APPEND _ANDROID_NDK_INIT_CFLAGS_DEBUG " -fno-limit-debug-info")

# If we're using LLD we need to use a slower build-id algorithm to work around
# the old version of LLDB in Android Studio, which doesn't understand LLD's
# default hash ("fast").
#
# https://github.com/android/ndk/issues/885
string(APPEND _ANDROID_NDK_INIT_LDFLAGS " -Wl,--build-id=sha1")

if(CMAKE_SYSTEM_VERSION LESS 30)
  # https://github.com/android/ndk/issues/1196
  # https://github.com/android/ndk/issues/1589
  string(APPEND _ANDROID_NDK_INIT_LDFLAGS " -Wl,--no-rosegment")
endif()

if (NOT ANDROID_ALLOW_UNDEFINED_VERSION_SCRIPT_SYMBOLS)
  string(APPEND _ANDROID_NDK_INIT_LDFLAGS " -Wl,--no-undefined-version")
endif()

string(APPEND _ANDROID_NDK_INIT_LDFLAGS " -Wl,--fatal-warnings")
# This should only be set for release modes, but CMake doesn't provide a way for
# us to be that specific in the new toolchain file.
# https://github.com/android/ndk/issues/1813
string(APPEND _ANDROID_NDK_INIT_LDFLAGS " -Wl,--gc-sections")
string(APPEND _ANDROID_NDK_INIT_LDFLAGS_EXE " -Wl,--gc-sections")

# Toolchain and ABI specific flags.
if(CMAKE_ANDROID_ARCH_ABI STREQUAL x86 AND CMAKE_SYSTEM_VERSION LESS 24)
  # http://b.android.com/222239
  # http://b.android.com/220159 (internal http://b/31809417)
  # x86 devices have stack alignment issues.
  string(APPEND _ANDROID_NDK_INIT_CFLAGS " -mstackrealign")
endif()

string(APPEND _ANDROID_NDK_INIT_CFLAGS " -D_FORTIFY_SOURCE=2")

if(CMAKE_ANDROID_ARCH_ABI MATCHES "armeabi")
  # Clang does not set this up properly when using -fno-integrated-as.
  # https://github.com/android-ndk/ndk/issues/906
  string(APPEND _ANDROID_NDK_INIT_CFLAGS " -march=armv7-a")
  if(NOT CMAKE_ANDROID_ARM_MODE)
    string(APPEND _ANDROID_NDK_INIT_CFLAGS " -mthumb")
  endif()
endif()

# CMake automatically forwards all compiler flags to the linker, and clang
# doesn't like having -Wa flags being used for linking. To prevent CMake from
# doing this would require meddling with the CMAKE_<LANG>_COMPILE_OBJECT rules,
# which would get quite messy.
string(APPEND _ANDROID_NDK_INIT_LDFLAGS " -Qunused-arguments")

if(ANDROID_DISABLE_FORMAT_STRING_CHECKS)
  string(APPEND _ANDROID_NDK_INIT_CFLAGS " -Wno-error=format-security")
else()
  string(APPEND _ANDROID_NDK_INIT_CFLAGS " -Wformat -Werror=format-security")
endif()

if(NOT ANDROID_ALLOW_UNDEFINED_SYMBOLS)
  string(APPEND _ANDROID_NDK_INIT_LDFLAGS " -Wl,--no-undefined")
endif()