# Copyright 2021 The Cobalt Authors. All Rights Reserved.
#
# 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("//build/toolchain/cc_wrapper.gni")
import("//build/toolchain/toolchain.gni")

tool_wrapper_path = rebase_path("tool_wrapper.py", root_build_dir)

template("msvc_toolchain") {
  # Write the environment variables file in the out directory.
  required_environment_variables = ["SYSTEMROOT", "TEMP", "TMP"]
  optional_environment_variables = [
    "INCLUDE",
    "LIB",
    "PATH",
    "PATHEXT",
    "XEDK", # TODO: What does this do?
    "IS_DOCKER", # needed for ninja to invoke docker-specific logic
    "IS_CI",     # needed for ninja to exclude some logic on GKE

    # The remaining variables should be explicitly enumerated.
    # "cell_.*",
    # "sn_.*",
    # "sce_.*",
  ]

  environment_key_value_pairs = []

  foreach(key, required_environment_variables) {
    value = getenv(key)
    assert(value != "", "Envionment variable $key is required to be set.")
    environment_key_value_pairs += [ "$key=$value" ]
  }
  foreach(key, optional_environment_variables) {
    value = getenv(key)
    if (value != "") {
      environment_key_value_pairs += [ "$key=$value" ]
    }
  }

  nul = "$0x00"
  env_block = string_join(nul, environment_key_value_pairs) + nul
  write_file("$root_build_dir/environment.$target_cpu", env_block)

  toolchain(target_name) {
    # When invoking this toolchain not as the default one, these args will be
    # passed to the build. They are ignored when this is the default toolchain.
    assert(defined(invoker.toolchain_args))
    toolchain_args = {
      if (defined(invoker.toolchain_args)) {
        forward_variables_from(invoker.toolchain_args, "*")
      }
    }

    # Make these apply to all tools below.
    lib_switch = ""
    lib_dir_switch = "/LIBPATH:"

    # Object files go in this directory.
    object_subdir = "{{target_out_dir}}/{{label_name}}"

    env = "environment.$target_cpu"

    cl = invoker.cl
    lib = invoker.lib
    link = invoker.link
    asm = invoker.asm

    env_wrapper = "ninja -t msvc -e $env -- "  # Note trailing space.

    # TODO(https://crbug.com/gn/273): Always use sccache for cc and cxx tools.
    if (cc_wrapper != "") {
      cl_prefix = "${cc_wrapper} "  # Note trailing space.
    } else {
      cl_prefix = env_wrapper
    }

    sys_include_flags = ""

    tool("cc") {
      precompiled_header_type = "msvc"
      pdbname = "{{target_out_dir}}/{{label_name}}_c.pdb"

      # Label names may have spaces in them so the pdbname must be quoted. The
      # source and output don't need to be quoted because GN knows they're a
      # full file name and will quote automatically when necessary.
      depsformat = "msvc"
      description = "CC {{output}}"
      outputs = [ "$object_subdir/{{source_name_part}}.obj" ]

      command = "$cl_prefix\"$cl\" /nologo /showIncludes $sys_include_flags{{defines}} {{include_dirs}} {{cflags}} {{cflags_c}} /c {{source}} /Fo{{output}} /Fd\"$pdbname\""
    }

    tool("cxx") {
      precompiled_header_type = "msvc"

      # The PDB name needs to be different between C and C++ compiled files.
      pdbname = "{{target_out_dir}}/{{label_name}}_cc.pdb"

      # See comment in CC tool about quoting.
      depsformat = "msvc"
      description = "CXX {{output}}"
      outputs = [ "$object_subdir/{{source_name_part}}.obj" ]

      command = "$cl_prefix\"$cl\" /nologo /showIncludes $sys_include_flags{{defines}} {{include_dirs}} {{cflags}} {{cflags_cc}} /c {{source}} /Fo{{output}} /Fd\"$pdbname\""
    }

    tool("asm") {
      description = "ASM {{output}}"
      outputs = [ "$object_subdir/{{source_name_part}}.obj" ]
      command ="$env_wrapper$asm /nologo /Fo{{output}} /c {{defines}} {{include_dirs}} {{asmflags}} {{source}}"
    }

    sys_lib_flags = "${invoker.sys_lib_flags} "  # Note trailing space.

    tool("alink") {
      rspfile = "{{output}}.rsp"
      command = "$env_wrapper$lib /OUT:{{output}} /nologo ${sys_lib_flags}{{arflags}} @$rspfile"
      description = "LIB {{output}}"
      outputs = [
        # Ignore {{output_extension}} and always use .lib, there's no reason to
        # allow targets to override this extension on Windows.
        "{{output_dir}}/{{target_output_name}}.lib",
      ]
      default_output_extension = ".lib"
      default_output_dir = "{{target_out_dir}}"

      # The use of inputs_newline is to work around a fixed per-line buffer
      # size in the linker.
      rspfile_content = "{{inputs_newline}}"
    }

    tool("solink") {
      # E.g. "foo.dll":
      dllname = "{{output_dir}}/{{target_output_name}}{{output_extension}}"
      libname = "${dllname}.lib"  # e.g. foo.dll.lib
      pdbname = "${dllname}.pdb"
      rspfile = "${dllname}.rsp"
      pool = "//build/toolchain:link_pool($default_toolchain)"

      command = "$env_wrapper$link /OUT:$dllname /nologo ${sys_lib_flags}/IMPLIB:$libname /DLL /PDB:$pdbname @$rspfile"

      default_output_extension = ".dll"
      default_output_dir = "{{root_out_dir}}"
      description = "LINK(DLL) {{output}}"
      outputs = [
        dllname,
        libname,
        pdbname,
      ]
      link_output = libname
      depend_output = libname
      runtime_outputs = [
        dllname,
        pdbname,
      ]

      # Since the above commands only updates the .lib file when it changes, ask
      # Ninja to check if the timestamp actually changed to know if downstream
      # dependencies should be recompiled.
      restat = true

      # The use of inputs_newline is to work around a fixed per-line buffer
      # size in the linker.
      rspfile_content = "{{libs}} {{solibs}} {{inputs_newline}} {{ldflags}}"
    }

    tool("solink_module") {
      # E.g. "foo.dll":
      dllname = "{{output_dir}}/{{target_output_name}}{{output_extension}}"
      pdbname = "${dllname}.pdb"
      rspfile = "${dllname}.rsp"
      pool = "//build/toolchain:link_pool($default_toolchain)"

      command = "$env_wrapper$link /OUT:$dllname /nologo ${sys_lib_flags}/DLL /PDB:$pdbname @$rspfile"

      default_output_extension = ".dll"
      default_output_dir = "{{root_out_dir}}"
      description = "LINK_MODULE(DLL) {{output}}"
      outputs = [
        dllname,
        pdbname,
      ]
      runtime_outputs = outputs

      # The use of inputs_newline is to work around a fixed per-line buffer
      # size in the linker.
      rspfile_content = "{{libs}} {{solibs}} {{inputs_newline}} {{ldflags}}"
    }

    tool("link") {
      exename = "{{output_dir}}/{{target_output_name}}{{output_extension}}"
      pdbname = "$exename.pdb"
      rspfile = "$exename.rsp"
      pool = "//build/toolchain:link_pool($default_toolchain)"

      command = "$env_wrapper$link /OUT:$exename /nologo ${sys_lib_flags} /PDB:$pdbname @$rspfile"

      default_output_extension = ".exe"
      default_output_dir = "{{root_out_dir}}"
      description = "LINK {{output}}"
      outputs = [
        exename,
        pdbname,
      ]
      runtime_outputs = outputs

      # The use of inputs_newline is to work around a fixed per-line buffer
      # size in the linker.
      rspfile_content = "{{inputs_newline}} {{libs}} {{solibs}} {{ldflags}}"
    }

    # These two are really entirely generic, but have to be repeated in
    # each toolchain because GN doesn't allow a template to be used here.
    # See //build/toolchain/toolchain.gni for details.
    tool("stamp") {
      command = stamp_command
      description = stamp_description
      pool = "//build/toolchain:action_pool($default_toolchain)"
    }
    tool("copy") {
      command = copy_command
      description = copy_description
      pool = "//build/toolchain:action_pool($default_toolchain)"
    }

    tool("action") {
      pool = "//build/toolchain:action_pool($default_toolchain)"
    }
  }
}