# Copyright 2018 Google LLC
#
# 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.

# Host toolchain specific build arguments.
declare_args() {
  # Build with a specific compiler version e.g. when building with clang, set
  # to "3.9" to build with `clang-3.9`.
  host_cc_version = ""
}

# Template for host toolchains.
template("cc_toolchain") {
  toolchain(target_name) {
    assert(defined(invoker.ar), "cc_toolchain() must specify a \"ar\" value")
    assert(defined(invoker.cc), "cc_toolchain() must specify a \"cc\" value")
    assert(defined(invoker.cxx), "cc_toolchain() must specify a \"cxx\" value")

    cc = "${invoker.cc}"
    cxx = "${invoker.cxx}"
    if (host_cc_version != "") {
      cc += "-${host_cc_version}"
      cxx += "-${host_cc_version}"
    }
    if (defined(invoker.cflags)) {
      cc += " ${invoker.cflags}"
      cxx += " ${invoker.cflags}"
    }

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

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

    tool("alink") {
      rspfile = "{{output}}.rsp"
      command = "rm -f {{output}} && ${invoker.ar} rcs {{output}} @$rspfile"
      description = "AR {{target_output_name}}{{output_extension}}"
      rspfile_content = "{{inputs}}"
      outputs = [
        "{{target_out_dir}}/{{target_output_name}}{{output_extension}}",
      ]
      default_output_extension = ".a"
      output_prefix = "lib"
    }

    tool("solink") {
      soname = "{{target_output_name}}{{output_extension}}"  # e.g. "libfoo.so".
      sofile = "{{output_dir}}/$soname"
      rspfile = soname + ".rsp"

      command =
          "${cxx} -shared {{ldflags}} -o $sofile -Wl,-soname=$soname @$rspfile"
      rspfile_content = "-Wl,--whole-archive {{inputs}} {{solibs}} -Wl,--no-whole-archive {{libs}}"

      description = "SOLINK $soname"

      # Use this for {{output_extension}} expansions unless a target manually
      # overrides it (in which case {{output_extension}} will be what the target
      # specifies).
      default_output_extension = ".so"

      # Use this for {{output_dir}} expansions unless a target manually overrides
      # it (in which case {{output_dir}} will be what the target specifies).
      default_output_dir = "{{root_out_dir}}"

      outputs = [
        sofile,
      ]
      link_output = sofile
      depend_output = sofile
      output_prefix = "lib"
    }

    tool("link") {
      outfile = "{{output_dir}}/{{target_output_name}}{{output_extension}}"
      rspfile = "$outfile.rsp"
      command = "${cxx} {{ldflags}} -o $outfile -Wl,--start-group @$rspfile {{solibs}} -Wl,--end-group {{libs}}"
      description = "LINK $outfile"
      default_output_dir = "{{root_out_dir}}"
      rspfile_content = "{{inputs}}"
      outputs = [
        outfile,
      ]
    }

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

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

    if (defined(invoker.toolchain_args)) {
      toolchain_args = {
        forward_variables_from(invoker.toolchain_args, "*")
      }
    }
  }
}

# Specialize for clang or gcc
cc_toolchain("clang") {
  ar = "llvm-ar"
  cc = "clang"
  cxx = "clang++"
  cflags = "-fcolor-diagnostics"
}

cc_toolchain("clang_fake_arch") {
  ar = "llvm-ar"
  cc = "clang"
  cxx = "clang++"
  cflags = "-fcolor-diagnostics"

  toolchain_args = {
    # When building for the host, use the fake architecture to make things
    # testable.
    arch = "fake"
  }
}

cc_toolchain("gcc") {
  ar = "ar"
  cc = "gcc"
  cxx = "g++"
  cflags = "-fdiagnostics-color=always"
}

cc_toolchain("gcc_fake_arch") {
  ar = "ar"
  cc = "gcc"
  cxx = "g++"
  cflags = "-fdiagnostics-color=always"

  toolchain_args = {
    # When building for the host, use the fake architecture to make things
    # testable.
    arch = "fake"
  }
}