pw_toolchain/arm_gcc/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")

import("$dir_pw_build/target_types.gni")
import("$dir_pw_toolchain/generate_toolchain.gni")

# Disable obnoxious ABI warning.
#
# GCC 7.1 adds an over-zealous ABI warning with little useful information
# on how to resolve the issue. The warning you get is:
#
#   note: parameter passing for argument of type '...' changed in GCC 7.1
#
# There is no other information, and searching for the error is needed to
# understand what is happening. For upstream Pigweed, we compile from
# source so this is irrelevant; so disable it.
#
# See: https://gcc.gnu.org/gcc-7/changes.html (search for "psabi").
#      https://gcc.gnu.org/ml/gcc/2017-05/msg00073.html
config("disable_psabi_warning") {
  cflags = [ "-Wno-psabi" ]
}

# binutils 2.39 introduced new warnings that trigger on embedded ARM GCC builds:
#
#   warning: *.elf has a LOAD segment with RWX permissions
#
# Disable these warnings --no-warn-rwx-segment. For details see:
# https://www.redhat.com/en/blog/linkers-warnings-about-executable-stacks-and-segments
config("disable_rwx_segment_warning") {
  ldflags = [ "-Wl,--no-warn-rwx-segment" ]
}

config("cortex_common") {
  asmflags = [
    "-mabi=aapcs",
    "-mthumb",
  ]
  cflags = asmflags + [
             "--sysroot=" + rebase_path(pw_env_setup_CIPD_ARM, root_build_dir),
             "-specs=nano.specs",
             "-specs=nosys.specs",
           ]
  ldflags = cflags + [
              "-lnosys",
              "-lc",
            ]
}

config("enable_float_printf") {
  cflags = [ "-u_printf_float" ]
  ldflags = cflags
}

config("cortex_m0plus") {
  cflags = [ "-mcpu=cortex-m0plus" ]
  asmflags = cflags
  ldflags = cflags
}

config("cortex_m3") {
  cflags = [ "-mcpu=cortex-m3" ]
  asmflags = cflags
  ldflags = cflags
}

config("cortex_m4") {
  cflags = [ "-mcpu=cortex-m4" ]
  asmflags = cflags
  ldflags = cflags
}

config("cortex_m7") {
  cflags = [ "-mcpu=cortex-m7" ]
  asmflags = cflags
  ldflags = cflags
}

config("cortex_m33") {
  cflags = [ "-mcpu=cortex-m33" ]
  asmflags = cflags
  ldflags = cflags
}

config("cortex_a32") {
  cflags = [ "-mcpu=cortex-a32" ]
  asmflags = cflags
  ldflags = cflags
}

config("cortex_software_fpu") {
  cflags = [ "-mfloat-abi=soft" ]
  asmflags = cflags
  ldflags = cflags
}

config("cortex_hardware_fpu") {
  cflags = [
    "-mfloat-abi=hard",
    "-mfpu=fpv4-sp-d16",
  ]
  asmflags = cflags
  defines = [ "PW_ARMV7M_ENABLE_FPU=1" ]
  ldflags = cflags
}

config("cortex_hardware_fpu_v5") {
  cflags = [
    "-mfloat-abi=hard",
    "-mfpu=fpv5-d16",
  ]
  asmflags = cflags
  defines = [ "PW_ARMV7M_ENABLE_FPU=1" ]
  ldflags = cflags
}

config("cortex_hardware_fpu_v5_sp") {
  cflags = [
    "-mfloat-abi=hard",
    "-mfpu=fpv5-sp-d16",
  ]
  asmflags = cflags
  defines = [ "PW_ARMV7M_ENABLE_FPU=1" ]
  ldflags = cflags
}

config("wrap_newlib_stdio_functions") {
  ldflags = [
    "-Wl,--wrap=__sread",
    "-Wl,--wrap=__swrite",
    "-Wl,--wrap=__sseek",
    "-Wl,--wrap=__sclose",
  ]
  visibility = [ ":*" ]
}

pw_source_set("newlib_os_interface_stubs") {
  all_dependent_configs = [ ":wrap_newlib_stdio_functions" ]
  sources = [ "newlib_os_interface_stubs.cc" ]
  deps = [ dir_pw_assert ]
}

# Basic libraries any arm-none-eabi-gcc target should use. This library should
# be included in pw_build_LINK_DEPS.
group("arm_none_eabi_gcc_support") {
  deps = [ "$dir_pw_toolchain:wrap_abort" ]

  # TODO: b/301079199 - Stubs are not yet usable on clang.
  # AttempedToInvokeUnsupportedNewlibOsInterfaceFunction (write_) is triggering,
  # but not sure why yet.
  # TODO: b/301262374 - Provide a better way to detect the compiler type.
  if (get_path_info(pw_toolchain_SCOPE.cc, "file") != "clang") {
    deps += [ ":newlib_os_interface_stubs" ]
  }
}