import("//llvm/utils/gn/build/toolchain/compiler.gni")

declare_args() {
  # If is_goma is true, the location of the goma client install.
  # Set this to the output of `goma_ctl goma_dir`.
  if (host_os == "win") {
    goma_dir = "C:/src/goma/goma-win64"
  } else {
    goma_dir = getenv("HOME") + "/goma"
  }
}

assert(!use_goma || goma_dir != "",
       "set goma_dir to the output of `goma_ctl goma_dir` in your args.gn")

template("unix_toolchain") {
  toolchain(target_name) {
    # https://groups.google.com/a/chromium.org/d/msg/gn-dev/F_lv5T-tNDM
    forward_variables_from(invoker.toolchain_args, "*")
    not_needed("*")

    forward_variables_from(invoker, "*")

    cc = "cc"
    cxx = "c++"

    if (clang_base_path != "") {
      cc = "$clang_base_path/bin/clang"
      cxx = "$clang_base_path/bin/clang++"
    }

    ld = cxx  # Don't use goma wrapper for linking.
    if (use_goma) {
      cc = "$goma_dir/gomacc $cc"
      cxx = "$goma_dir/gomacc $cxx"
    }

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

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

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

    tool("alink") {
      if (current_os == "ios" || current_os == "mac") {
        command = "libtool -D -static -no_warning_for_no_symbols {{arflags}} -o {{output}} {{inputs}}"
      } else {
        # Remove the output file first so that ar doesn't try to modify the
        # existing file.
        command =
            "rm -f {{output}} && $ar rcsD {{arflags}} {{output}} {{inputs}}"
      }
      description = "AR {{output}}"
      outputs = [ "{{output_dir}}/{{target_output_name}}.a" ]
      output_prefix = "lib"
      default_output_dir = "{{root_out_dir}}/lib"
    }

    if (current_os == "ios" || current_os == "mac") {
      # gn < 1693 (e214b5d35898) doesn't support |frameworks|, requiring
      # frameworks to be listed in |libs|, but gn >= 1808 (3028c6a426a4) forbids
      # frameworks from appearing in |libs|. This assertion provides a helpful
      # cue to upgrade, and is much more user-friendly than the failure that
      # occurs when an older gn encounters |frameworks|.
      #
      # gn_version doesn’t actually exist in gn < 1709 (52cb644a3fb4), and
      # defined(gn_version) doesn't actually work as expected
      # (https://crbug.com/gn/183), so 1709 is the true minimum enforced by
      # this construct, and if gn_version is not available, this line will still
      # be blamed, making the resolution somewhat discoverable.
      assert(gn_version >= 1693,
             "Your GN is too old! " +
                 "Update it, perhaps by running llvm/utils/gn/get.py")
    }

    tool("solink") {
      outfile = "{{output_dir}}/{{target_output_name}}{{output_extension}}"
      if (current_os == "ios" || current_os == "mac") {
        command = "$ld -shared {{ldflags}} -o $outfile {{inputs}} {{libs}} {{frameworks}}"
        default_output_extension = ".dylib"
      } else {
        command = "$ld -shared {{ldflags}} -Wl,-z,defs -Wl,-soname,{{target_output_name}}{{output_extension}} -o $outfile {{inputs}} {{libs}}"
        default_output_extension = ".so"
      }
      description = "SOLINK $outfile"
      outputs = [ outfile ]
      lib_switch = "-l"
      output_prefix = "lib"
      default_output_dir = "{{root_out_dir}}/lib"
    }

    tool("solink_module") {
      outfile = "{{output_dir}}/{{target_output_name}}{{output_extension}}"
      if (current_os == "ios" || current_os == "mac") {
        command = "$ld -shared {{ldflags}} -Wl,-flat_namespace -Wl,-undefined,suppress -o $outfile {{inputs}} {{libs}} {{frameworks}}"
        default_output_extension = ".dylib"
      } else {
        command = "$ld -shared {{ldflags}} -Wl,-soname,{{target_output_name}}{{output_extension}} -o $outfile {{inputs}} {{libs}}"
        default_output_extension = ".so"
      }
      description = "SOLINK $outfile"
      outputs = [ outfile ]
      lib_switch = "-l"
      default_output_dir = "{{root_out_dir}}/lib"
    }

    tool("link") {
      outfile = "{{output_dir}}/{{target_output_name}}{{output_extension}}"
      if (current_os == "ios" || current_os == "mac") {
        command =
            "$ld {{ldflags}} -o $outfile {{inputs}} {{libs}} {{frameworks}}"
      } else {
        command = "$ld {{ldflags}} -o $outfile -Wl,--start-group {{inputs}} -Wl,--end-group {{libs}}"
      }
      description = "LINK $outfile"
      outputs = [ outfile ]
      lib_switch = "-l"

      # Setting this allows targets to override the default executable output by
      # setting output_dir.
      default_output_dir = "{{root_out_dir}}/bin"
    }

    copy_command = "ln -f {{source}} {{output}} 2>/dev/null || (rm -rf {{output}} && cp -af {{source}} {{output}})"
    tool("copy") {
      command = copy_command
      description = "COPY {{source}} {{output}}"
    }

    if (current_os == "ios" || current_os == "mac") {
      tool("copy_bundle_data") {
        # https://github.com/nico/hack/blob/master/notes/copydir.md
        _copydir = "cd {{source}} && " +
                   "find . | cpio -pdl \"\$OLDPWD\"/{{output}} 2>/dev/null"
        command = "rm -rf {{output}} && if [[ -d {{source}} ]]; then " +
                  _copydir + "; else " + copy_command + "; fi"
        description = "COPY_BUNDLE_DATA {{source}} {{output}}"
      }
      tool("compile_xcassets") {
        command = "false"
        description = "The LLVM build doesn't use any xcasset files"
      }
    }

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

unix_toolchain("unix") {
  if (current_os != "ios" && current_os != "mac") {
    ar = "ar"
  }

  toolchain_args = {
    current_os = host_os
    current_cpu = host_cpu
  }
}

# This template defines a toolchain that uses just-built clang and lld
# as compiler and linker.
template("stage2_unix_toolchain") {
  unix_toolchain(target_name) {
    toolchain_args = {
      forward_variables_from(invoker.toolchain_args, "*")

      clang_base_path = "."
      use_goma = false
    }

    deps = [
      "//:clang($host_toolchain)",
      "//:lld($host_toolchain)",
    ]
    if (current_os != "ios" && current_os != "mac") {
      ar = "bin/llvm-ar"
      deps += [ "//:llvm-ar($host_toolchain)" ]
    }
  }
}

stage2_unix_toolchain("stage2_unix") {
  toolchain_args = {
    current_os = host_os
    current_cpu = host_cpu
  }
}

if (android_ndk_path != "") {
  stage2_unix_toolchain("stage2_android_aarch64") {
    toolchain_args = {
      current_os = "android"
      current_cpu = "arm64"
    }
  }

  stage2_unix_toolchain("stage2_android_arm") {
    toolchain_args = {
      current_os = "android"
      current_cpu = "arm"
    }
  }
}

if (host_os == "mac") {
  stage2_unix_toolchain("stage2_ios_aarch64") {
    toolchain_args = {
      current_os = "ios"
      current_cpu = "arm64"
    }
  }

  stage2_unix_toolchain("stage2_iossim_x64") {
    toolchain_args = {
      current_os = "ios"
      current_cpu = "x64"
    }
  }
}

toolchain("win") {
  cl = "cl"
  link = "link"

  if (clang_base_path != "") {
    cl = "$clang_base_path/bin/clang-cl"
    if (use_lld) {
      link = "$clang_base_path/bin/lld-link"
    }
  }

  if (use_goma) {
    cl = "$goma_dir/gomacc $cl"
  }

  tool("cc") {
    command = "$cl /nologo /showIncludes /Fo{{output}} /c {{source}} {{defines}} {{include_dirs}} {{cflags}} {{cflags_c}}"
    depsformat = "msvc"
    description = "CC {{output}}"
    outputs = [ "{{source_out_dir}}/{{label_name}}.{{source_name_part}}.obj" ]
  }

  tool("cxx") {
    command = "$cl /nologo /showIncludes /Fo{{output}} /c {{source}} {{defines}} {{include_dirs}} {{cflags}} {{cflags_cc}}"
    depsformat = "msvc"
    description = "CXX {{output}}"
    outputs = [ "{{source_out_dir}}/{{label_name}}.{{source_name_part}}.obj" ]
  }

  tool("alink") {
    command = "$link /lib /nologo {{arflags}} /out:{{output}} {{inputs}}"
    description = "LIB {{output}}"
    outputs = [ "{{output_dir}}/{{target_output_name}}.lib" ]
    default_output_dir = "{{root_out_dir}}/lib"
  }

  tool("solink") {
    outprefix = "{{output_dir}}/{{target_output_name}}"
    dllfile = "$outprefix{{output_extension}}"
    libfile = "$outprefix.lib"
    pdbfile = "$outprefix.pdb"
    command = "$link /nologo /dll {{ldflags}} /out:$dllfile /implib:$libfile /pdb:$pdbfile {{inputs}} {{libs}} "
    description = "LINK $dllfile"
    link_output = libfile
    depend_output = libfile
    runtime_outputs = [ dllfile ]
    outputs = [
      dllfile,
      libfile,
    ]
    lib_switch = ""
    default_output_extension = ".dll"
    restat = true

    # Put dlls next to the executables in bin/ on Windows, since Windows
    # doesn't have a configurable rpath. This matches initialization of
    # module_dir to bin/ in AddLLVM.cmake's set_output_directory().
    default_output_dir = "{{root_out_dir}}/bin"
  }

  # Plugins for opt and clang and so on don't work in LLVM's Windows build
  # since the code doesn't have export annotations, but there are a few
  # standalone loadable modules used for unit-testing LLVM's dynamic library
  # loading code.
  tool("solink_module") {
    outprefix = "{{output_dir}}/{{target_output_name}}"
    dllfile = "$outprefix{{output_extension}}"
    pdbfile = "$outprefix.pdb"
    command = "$link /nologo /dll {{ldflags}} /out:$dllfile /pdb:$pdbfile {{inputs}} {{libs}} "
    description = "LINK_MODULE $dllfile"
    outputs = [ dllfile ]
    lib_switch = ""
    runtime_outputs = outputs
    default_output_extension = ".dll"

    # No default_output_dir, all clients set output_dir.
  }

  tool("link") {
    outprefix = "{{output_dir}}/{{target_output_name}}"
    outfile = "$outprefix{{output_extension}}"
    pdbfile = "$outprefix.pdb"
    command = "$link /nologo {{ldflags}} /out:$outfile /pdb:$pdbfile {{inputs}} {{libs}}"
    description = "LINK $outfile"
    outputs = [ outfile ]
    lib_switch = ""
    default_output_extension = ".exe"

    # Setting this allows targets to override the default executable output by
    # setting output_dir.
    default_output_dir = "{{root_out_dir}}/bin"
  }

  tool("copy") {
    # GN hands out slash-using paths, but cmd's copy needs backslashes.
    # Use cmd's %foo:a=b% substitution feature to convert.
    command = "cmd /c set source=\"{{source}}\" & set output=\"{{output}}\" & call copy /Y %source:/=\% %output:\=/% > nul"
    description = "COPY {{source}} {{output}}"
  }

  tool("stamp") {
    command = "cmd /c type nul > {{output}}"
    description = "STAMP {{output}}"
  }

  toolchain_args = {
    current_os = "win"
    current_cpu = host_cpu
  }
}