# Copyright (C) 2017 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.

import("//gn/perfetto.gni")
import("//gn/standalone/android.gni")
import("//gn/standalone/wasm.gni")
import("llvm.gni")

# This file is evaluated once, within the context of the default toolchain,
# which is the target toolchain.
# Note: This means that is_android=true even on a mac when cross-compiling for
# Android.
assert(current_os == target_os && current_cpu == target_cpu,
       "Assumptions on current_xxx in this file have been violated")

declare_args() {
  cc_wrapper = ""
}

# First of all determine the host toolchain. The user can override this by:
# 1. setting ar/cc/cxx vars in args.gn.
# 2. setting is_system_compiler=true in args.gn and the env vars AR/CC/CXX.
#    This is used by OSSFuzz.
declare_args() {
  sysroot = ""
  ar = "ar"
  if (is_linux_host) {
    linker = "gold"
  } else {
    linker = ""
  }

  if (is_system_compiler) {
    ar = "\$AR"
    cc = "\$CC"
    cxx = "\$CXX"
  } else if (is_clang) {
    if (is_linux_host) {
      cc = linux_clang_bin
      cxx = linux_clangxx_bin
      linker = linux_clang_linker
    } else {
      cc = "clang"
      cxx = "clang++"
      linker = ""
    }
  } else {  # GCC
    cc = "gcc"
    cxx = "g++"
  }
}

# Then determine the target toolchain.

declare_args() {
  target_sysroot = sysroot
  if (!is_cross_compiling) {
    target_triplet = ""
  } else if (target_os == "mac" && target_cpu == "x64") {
    target_triplet = "x86_64-apple-darwin"
  } else if (target_os == "mac" && target_cpu == "x86") {
    target_triplet = "i686-apple-darwin"
  } else if (target_os == "linux" && target_cpu == "arm64") {
    target_triplet = "aarch64-linux-gnu"
  } else if (target_os == "linux" && target_cpu == "x64") {
    target_triplet = "x86_64-linux-gnu"
  } else if (target_os == "linux" && target_cpu == "x86") {
    target_triplet = "i686-linux-gnu"
  } else if (target_os == "android" && target_cpu == "arm64") {
    target_triplet = "aarch64-linux-android"
  } else if (target_os == "android" && target_cpu == "arm") {
    target_triplet = "arm-linux-androideabi"
  } else if (target_os == "android" && target_cpu == "x86") {
    target_triplet = "i686-linux-android"
  } else if (target_os == "android" && target_cpu == "x64") {
    target_triplet = "x86_64-linux-android"
  } else {
    assert(false,
           "Unsupported cross-compilation for ${target_os}-${target_cpu}")
  }
}

declare_args() {
  if (!is_cross_compiling || is_perfetto_build_generator) {
    target_ar = ar
    target_cc = cc
    target_cxx = cxx
    target_linker = linker
  } else {
    target_ar = "ar"
    if (is_linux || is_android) {
      target_linker = "gold"
    } else {
      target_linker = ""
    }
    if (is_android) {
      target_ar = "$android_toolchain_root/bin/$android_abi_target-ar"
      target_cc = "$android_llvm_dir/bin/clang"
      target_cxx = "$android_llvm_dir/bin/clang++"
    } else {
      assert(target_triplet != "",
             "target_triplet must be non-empty when cross-compiling")
      if (is_clang) {
        target_cc = "${linux_clang_bin} --target=${target_triplet}"
        target_cxx = "${linux_clangxx_bin} --target=${target_triplet}"
        target_linker = "${linux_clang_linker} --target=${target_triplet}"
      } else {  # GCC
        target_ar = "${target_triplet}-ar"
        target_cc = "${target_triplet}-gcc"
        target_cxx = "${target_triplet}-g++"
      }
    }
  }
}

template("gcc_like_toolchain") {
  toolchain(target_name) {
    ar = invoker.ar
    cc = invoker.cc
    cxx = invoker.cxx
    lib_switch = "-l"
    lib_dir_switch = "-L"
    ld_arg = ""
    if (defined(invoker.linker) && invoker.linker != "") {
      _invoker_linker = invoker.linker
      ld_arg = "-fuse-ld=$_invoker_linker"
    }
    if (defined(invoker.sysroot) && invoker.sysroot != "") {
      _invoker_sysroot = invoker.sysroot
      cc = "$cc --sysroot=$_invoker_sysroot"
      cxx = "$cxx --sysroot=$_invoker_sysroot"
    }

    tool("cc") {
      depfile = "{{output}}.d"
      command = "$cc_wrapper $cc -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_c}} ${extra_cflags} -c {{source}} -o {{output}}"
      depsformat = "gcc"
      outputs = [
        "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.o",
      ]
      description = "compile {{source}}"
    }

    tool("cxx") {
      depfile = "{{output}}.d"
      command = "$cc_wrapper $cxx -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_cc}}  ${extra_cflags} ${extra_cxxflags} -c {{source}} -o {{output}}"
      depsformat = "gcc"
      outputs = [
        "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.o",
      ]
      description = "compile {{source}}"
    }

    tool("asm") {
      depfile = "{{output}}.d"
      command = "$cc_wrapper $cc -MMD -MF $depfile {{defines}} {{include_dirs}} {{asmflags}} -c {{source}} -o {{output}}"
      depsformat = "gcc"
      outputs = [
        "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.o",
      ]
      description = "assemble {{source}}"
    }

    tool("alink") {
      rspfile = "{{output}}.rsp"
      if (is_mac && ar != "suppress_unused_ar_variable_warning") {
        rspfile_content = "{{inputs_newline}}"
        command = "rm -f {{output}} && libtool -static {{arflags}} -o {{output}} -filelist $rspfile"
      } else {
        rspfile_content = "{{inputs}}"
        command = "rm -f {{output}} && $ar rcsD {{output}} @$rspfile"
      }
      outputs = [
        "{{root_out_dir}}/{{target_output_name}}{{output_extension}}",
      ]
      default_output_extension = ".a"
      output_prefix = "lib"
      description = "link {{output}}"
    }

    tool("solink") {
      soname = "{{target_output_name}}{{output_extension}}"

      rpath = "-Wl,-soname,$soname"
      if (is_mac) {
        rpath = "-Wl,-install_name,@rpath/$soname"
      }

      command = "$cc_wrapper $cxx $ld_arg -shared {{ldflags}} ${extra_ldflags} {{inputs}} {{solibs}} {{libs}} $rpath -o {{output}}"
      outputs = [
        "{{root_out_dir}}/$soname",
      ]
      output_prefix = "lib"
      default_output_extension = ".so"
      description = "link {{output}}"
    }

    tool("link") {
      command = "$cc_wrapper $cxx $ld_arg {{ldflags}} ${extra_ldflags} {{inputs}} {{solibs}} {{libs}} -o {{output}}"
      outputs = [
        "{{root_out_dir}}/{{target_output_name}}{{output_extension}}",
      ]
      description = "link {{output}}"
    }

    tool("stamp") {
      command = "touch {{output}}"
      description = "stamp {{output}}"
    }

    tool("copy") {
      command = "cp -af {{source}} {{output}}"
      description = "COPY {{source}} {{output}}"
    }

    toolchain_args = {
      current_cpu = invoker.cpu
      current_os = invoker.os
    }
  }
}

gcc_like_toolchain("gcc_like") {
  cpu = current_cpu
  os = current_os
  ar = target_ar
  cc = target_cc
  cxx = target_cxx
  linker = target_linker
  sysroot = target_sysroot
}

gcc_like_toolchain("gcc_like_host") {
  cpu = host_cpu
  os = host_os
  ar = ar
  cc = cc
  cxx = cxx
  linker = linker
  sysroot = sysroot
}

gcc_like_toolchain("wasm") {
  # emsdk_dir and em_config are defined in wasm.gni.
  cpu = host_cpu
  os = host_os
  ar = "$emsdk_dir/emscripten/emar --em-config $em_config"
  cc = "$emsdk_dir/emscripten/emcc --em-config $em_config"
  cxx = "$emsdk_dir/emscripten/em++ --em-config $em_config"
}