# Copyright (c) 2013 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

# TODO(brettw) Use "gcc_toolchain.gni" like the Linux toolchains. This requires
# some enhancements since the commands on Mac are slightly different than on
# Linux.

import("../goma.gni")
import("//build/config/clang/clang.gni")
if (is_ios) {
  import("//build/config/ios/ios_sdk.gni")
}
import("//build/config/mac/mac_sdk.gni")
import("//build/config/mac/symbols.gni")

assert(host_os == "mac")

import("//build/toolchain/cc_wrapper.gni")
import("//build/toolchain/goma.gni")
import("//build/toolchain/toolchain.gni")
import("//build/toolchain/concurrent_links.gni")

declare_args() {
  # Reduce the number of tasks using the copy_bundle_data and compile_xcassets
  # tools as they can cause lots of I/O contention when invoking ninja with a
  # large number of parallel jobs (e.g. when using distributed build like goma).
  bundle_pool_depth = -1
}

if (current_toolchain == default_toolchain) {
  pool("bundle_pool") {
    if (bundle_pool_depth == -1) {
      depth = concurrent_links
    } else {
      depth = bundle_pool_depth
    }
  }
}

# When implementing tools using Python scripts, a TOOL_VERSION=N env
# variable is placed in front of the command. The N should be incremented
# whenever the script is changed, so that the build system rebuilds all
# edges that utilize the script. Ideally this should be changed to use
# proper input-dirty checking, but that could be expensive. Instead, use a
# script to get the tool scripts' modification time to use as the version.
# This won't cause a re-generation of GN files when the tool script changes
# but it will cause edges to be marked as dirty if the ninja files are
# regenerated. See https://crbug.com/619083 for details. A proper fix
# would be to have inputs to tools (https://crbug.com/621119).
tool_versions =
    exec_script("get_tool_mtime.py",
                rebase_path([
                              "//build/toolchain/mac/compile_xcassets.py",
                              "//build/toolchain/mac/filter_libtool.py",
                              "//build/toolchain/mac/linker_driver.py",
                            ],
                            root_build_dir),
                "trim scope")

# Shared toolchain definition. Invocations should set current_os to set the
# build args in this definition.
template("mac_toolchain") {
  toolchain(target_name) {
    if (use_system_xcode) {
      env_wrapper = ""
    } else {
      env_wrapper = "export DEVELOPER_DIR=$hermetic_xcode_path; "
    }

    # 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),
           "Toolchains must declare toolchain_args")
    toolchain_args = {
      # Populate toolchain args from the invoker.
      forward_variables_from(invoker.toolchain_args, "*")

      # The host toolchain value computed by the default toolchain's setup
      # needs to be passed through unchanged to all secondary toolchains to
      # ensure that it's always the same, regardless of the values that may be
      # set on those toolchains.
      host_toolchain = host_toolchain
    }

    # When the invoker has explicitly overridden use_goma or cc_wrapper in the
    # toolchain args, use those values, otherwise default to the global one.
    # This works because the only reasonable override that toolchains might
    # supply for these values are to force-disable them.
    if (defined(toolchain_args.use_goma)) {
      toolchain_uses_goma = toolchain_args.use_goma
    } else {
      toolchain_uses_goma = use_goma
    }
    if (defined(toolchain_args.cc_wrapper)) {
      toolchain_cc_wrapper = toolchain_args.cc_wrapper
    } else {
      toolchain_cc_wrapper = cc_wrapper
    }

    # Compute the compiler prefix.
    if (toolchain_uses_goma) {
      assert(toolchain_cc_wrapper == "",
             "Goma and cc_wrapper can't be used together.")
      compiler_prefix = "$goma_dir/gomacc "
    } else if (toolchain_cc_wrapper != "") {
      compiler_prefix = toolchain_cc_wrapper + " "
    } else {
      compiler_prefix = ""
    }

    if (toolchain_args.current_os != "ios" || !use_xcode_clang) {
      compiler_prefix += rebase_path("$clang_base_path/bin/", root_build_dir)
    }

    cc = "${compiler_prefix}clang"
    cxx = "${compiler_prefix}clang++"
    ld = cxx

    linker_driver =
        "TOOL_VERSION=${tool_versions.linker_driver} " +
        rebase_path("//build/toolchain/mac/linker_driver.py", root_build_dir)

    # On iOS, the final applications are assembled using lipo (to support fat
    # builds). The correct flags are passed to the linker_driver.py script
    # directly during the lipo call.
    if (toolchain_args.current_os != "ios") {
      _enable_dsyms = enable_dsyms
      _save_unstripped_output = save_unstripped_output
    } else {
      _enable_dsyms = false
      _save_unstripped_output = false
    }

    # Make these apply to all tools below.
    lib_switch = "-l"
    lib_dir_switch = "-L"

    # Object files go in this directory. Use label_name instead of
    # target_output_name since labels will generally have no spaces and will be
    # unique in the directory.
    object_subdir = "{{target_out_dir}}/{{label_name}}"

    # If dSYMs are enabled, this flag will be added to the link tools.
    if (_enable_dsyms) {
      dsym_switch = " -Wcrl,dsym,{{root_out_dir}} "
      dsym_output_dir =
          "{{root_out_dir}}/{{target_output_name}}{{output_extension}}.dSYM"
      dsym_output = [
        "$dsym_output_dir/",
        "$dsym_output_dir/Contents/Info.plist",
        "$dsym_output_dir/Contents/Resources/DWARF/" +
            "{{target_output_name}}{{output_extension}}",
      ]
    } else {
      dsym_switch = ""
    }

    if (_save_unstripped_output) {
      _unstripped_output = "{{root_out_dir}}/{{target_output_name}}{{output_extension}}.unstripped"
    }

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

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

    tool("asm") {
      # For GCC we can just use the C compiler to compile assembly.
      depfile = "{{output}}.d"
      command = "$cc -MMD -MF $depfile {{defines}} {{include_dirs}} {{asmflags}} -c {{source}} -o {{output}}"
      depsformat = "gcc"
      description = "ASM {{output}}"
      outputs = [
        "$object_subdir/{{source_name_part}}.o",
      ]
    }

    tool("objc") {
      depfile = "{{output}}.d"
      precompiled_header_type = "gcc"
      command = "$cc -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_objc}} -c {{source}} -o {{output}}"
      depsformat = "gcc"
      description = "OBJC {{output}}"
      outputs = [
        "$object_subdir/{{source_name_part}}.o",
      ]
    }

    tool("objcxx") {
      depfile = "{{output}}.d"
      precompiled_header_type = "gcc"
      command = "$cxx -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_objcc}} -c {{source}} -o {{output}}"
      depsformat = "gcc"
      description = "OBJCXX {{output}}"
      outputs = [
        "$object_subdir/{{source_name_part}}.o",
      ]
    }

    tool("alink") {
      script =
          rebase_path("//build/toolchain/mac/filter_libtool.py", root_build_dir)
      command = "$env_wrapper rm -f {{output}} && TOOL_VERSION=${tool_versions.filter_libtool} python $script libtool -static {{arflags}} -o {{output}} {{inputs}}"
      description = "LIBTOOL-STATIC {{output}}"
      outputs = [
        "{{output_dir}}/{{target_output_name}}{{output_extension}}",
      ]
      default_output_dir = "{{target_out_dir}}"
      default_output_extension = ".a"
      output_prefix = "lib"
    }

    tool("solink") {
      dylib = "{{output_dir}}/{{target_output_name}}{{output_extension}}"  # eg "./libfoo.dylib"
      rspfile = dylib + ".rsp"
      pool = "//build/toolchain:link_pool($default_toolchain)"

      # These variables are not built into GN but are helpers that implement
      # (1) linking to produce a .dylib, (2) extracting the symbols from that
      # file to a temporary file, (3) if the temporary file has differences from
      # the existing .TOC file, overwrite it, otherwise, don't change it.
      #
      # As a special case, if the library reexports symbols from other dynamic
      # libraries, we always update the .TOC and skip the temporary file and
      # diffing steps, since that library always needs to be re-linked.
      tocname = dylib + ".TOC"
      temporary_tocname = dylib + ".tmp"

      does_reexport_command = "[ ! -e \"$dylib\" -o ! -e \"$tocname\" ] || otool -l \"$dylib\" | grep -q LC_REEXPORT_DYLIB"

      link_command = "$linker_driver $ld -shared "
      if (is_component_build) {
        link_command += " -Wl,-install_name,@rpath/\"{{target_output_name}}{{output_extension}}\" "
      }
      link_command += dsym_switch
      link_command += "{{ldflags}} -o \"$dylib\" -Wl,-filelist,\"$rspfile\" {{libs}} {{solibs}}"

      replace_command = "if ! cmp -s \"$temporary_tocname\" \"$tocname\"; then mv \"$temporary_tocname\" \"$tocname\""
      extract_toc_command = "{ otool -l \"$dylib\" | grep LC_ID_DYLIB -A 5; nm -gP \"$dylib\" | cut -f1-2 -d' ' | grep -v U\$\$; true; }"

      command = "$env_wrapper if $does_reexport_command ; then $link_command && $extract_toc_command > \"$tocname\"; else $link_command && $extract_toc_command > \"$temporary_tocname\" && $replace_command ; fi; fi"

      rspfile_content = "{{inputs_newline}}"

      description = "SOLINK {{output}}"

      # 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_dir = "{{root_out_dir}}"
      default_output_extension = ".dylib"

      output_prefix = "lib"

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

      # Tell GN about the output files. It will link to the dylib but use the
      # tocname for dependency management.
      outputs = [
        dylib,
        tocname,
      ]
      link_output = dylib
      depend_output = tocname

      if (_enable_dsyms) {
        outputs += dsym_output
      }
      if (_save_unstripped_output) {
        outputs += [ _unstripped_output ]
      }
    }

    tool("solink_module") {
      sofile = "{{output_dir}}/{{target_output_name}}{{output_extension}}"  # eg "./libfoo.so"
      rspfile = sofile + ".rsp"
      pool = "//build/toolchain:link_pool($default_toolchain)"

      link_command = "$env_wrapper $linker_driver $ld -bundle {{ldflags}} -o \"$sofile\" -Wl,-filelist,\"$rspfile\""
      if (is_component_build) {
        link_command += " -Wl,-install_name,@rpath/{{target_output_name}}{{output_extension}}"
      }
      link_command += dsym_switch
      link_command += " {{solibs}} {{libs}}"
      command = link_command

      rspfile_content = "{{inputs_newline}}"

      description = "SOLINK_MODULE {{output}}"

      # 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_dir = "{{root_out_dir}}"
      default_output_extension = ".so"

      outputs = [
        sofile,
      ]

      if (_enable_dsyms) {
        outputs += dsym_output
      }
      if (_save_unstripped_output) {
        outputs += [ _unstripped_output ]
      }
    }

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

      # Note about --filelist: Apple's linker reads the file list file and
      # interprets each newline-separated chunk of text as a file name. It
      # doesn't do the things one would expect from the shell like unescaping
      # or handling quotes. In contrast, when Ninja finds a file name with
      # spaces, it single-quotes them in $inputs_newline as it would normally
      # do for command-line arguments. Thus any source names with spaces, or
      # label names with spaces (which GN bases the output paths on) will be
      # corrupted by this process. Don't use spaces for source files or labels.
      command = "$env_wrapper $linker_driver $ld $dsym_switch {{ldflags}} -o \"$outfile\" -Wl,-filelist,\"$rspfile\" {{solibs}} {{libs}}"
      description = "LINK $outfile"
      rspfile_content = "{{inputs_newline}}"
      outputs = [
        outfile,
      ]

      if (_enable_dsyms) {
        outputs += dsym_output
      }
      if (_save_unstripped_output) {
        outputs += [ _unstripped_output ]
      }

      default_output_dir = "{{root_out_dir}}"
    }

    # 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
    }
    tool("copy") {
      command = copy_command
      description = copy_description
    }

    tool("copy_bundle_data") {
      # copy_command use hardlink if possible but this does not work with
      # directories. If source is a directory, instead use "pax" to create
      # the same tree structure using hardlinks to individual files (this
      # preserve symbolic links too) as recommended in the replies to the
      # question at http://serverfault.com/q/209888/43689 ("cp -al" isn't
      # available on macOS).
      #
      # According to the man page for pax, the commands to use to clone
      # olddir to newdir using pax are the following:
      #
      #   $ mkdir newdir
      #   $ cd olddir
      #   $ pax -rwl . ../newdir
      #
      # The _copydir command does exactly that but use an absolute path
      # constructed using shell variable $OLDPWD (automatically set when
      # cd is used) as computing the relative path is a bit complex and
      # using pwd would requires a sub-shell to be created.
      _copydir = "mkdir -p {{output}} && cd {{source}} && " +
                 "pax -rwl . \"\$OLDPWD\"/{{output}}"
      command = "rm -rf {{output}} && if [[ -d {{source}} ]]; then " +
                _copydir + "; else " + copy_command + "; fi"

      description = "COPY_BUNDLE_DATA {{source}} {{output}}"
      pool = ":bundle_pool($default_toolchain)"
    }
    tool("compile_xcassets") {
      _tool = rebase_path("//build/toolchain/mac/compile_xcassets.py",
                          root_build_dir)
      if (is_ios) {
        _sdk_name = ios_sdk_name
        _min_deployment_target = ios_deployment_target
      } else {
        _sdk_name = mac_sdk_name
        _min_deployment_target = mac_deployment_target
      }
      command = "$env_wrapper rm -f {{output}} && " +
                "TOOL_VERSION=${tool_versions.compile_xcassets} " +
                "python $_tool -p $_sdk_name -t $_min_deployment_target " +
                "-T {{bundle_product_type}} -o {{output}} {{inputs}}"

      description = "COMPILE_XCASSETS {{output}}"
      pool = ":bundle_pool($default_toolchain)"
    }
  }
}

mac_toolchain("clang_arm") {
  toolchain_args = {
    current_cpu = "arm"
    current_os = "mac"
  }
}

mac_toolchain("clang_x64") {
  toolchain_args = {
    current_cpu = "x64"
    current_os = "mac"
  }
}

if (is_ios) {
  mac_toolchain("ios_clang_arm") {
    toolchain_args = {
      current_cpu = "arm"
      current_os = "ios"
    }
  }

  mac_toolchain("ios_clang_arm64") {
    toolchain_args = {
      current_cpu = "arm64"
      current_os = "ios"
    }
  }

  mac_toolchain("ios_clang_x86") {
    toolchain_args = {
      current_cpu = "x86"
      current_os = "ios"
    }
  }

  mac_toolchain("ios_clang_x64") {
    toolchain_args = {
      current_cpu = "x64"
      current_os = "ios"
    }
  }
}