# Copyright 2014 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.

# Instantiate grit. This will produce a script target to run grit, and a
# static library that compiles the .cc files.
#
# Parameters
#
#   source (required)
#       Path to .grd file.
#
#   source_is_generated (optional, defaults to false)
#       Declares that the input (or one of its dependencies) is generated so
#       that grit_info is not run on the file when
#       compute_grit_inputs_for_analyze is set (because the file will not
#       exist at analyze time). For "analyze" to be correct in this case, the
#       inputs to the grit file must either be listed in the inputs variable
#       or are listed as inputs to dependencies of this target.
#
#   inputs  (optional)
#       List of additional files, required for grit to process source file.
#
#   outputs (required)
#       List of outputs from grit, relative to the target_gen_dir. Grit will
#       verify at build time that this list is correct and will fail if there
#       is a mismatch between the outputs specified by the .grd file and the
#       outputs list here.
#
#       To get this list, you can look in the .grd file for
#       <output filename="..." and put those filename here. The base directory
#       of the list in Grit and the output list specified in the GN grit target
#       are the same (the target_gen_dir) so you can generally copy the names
#       exactly.
#
#       To get the list of outputs programatically, run:
#           python tools/grit/grit_info.py --outputs . path/to/your.grd
#       And strip the leading "./" from the output files.
#
#   defines (optional)
#       Extra defines to pass to grit (on top of the global grit_defines list).
#
#   grit_flags (optional)
#       List of strings containing extra command-line flags to pass to Grit.
#
#   resource_ids (optional)
#       Path to a grit "firstidsfile". Default is
#       //tools/gritsettings/resource_ids. Set to "" to use the value specified
#       in the <grit> nodes of the processed files.
#
#   output_dir (optional)
#       Directory for generated files. If you specify this, you will often
#       want to specify output_name if the target name is not particularly
#       unique, since this can cause files from multiple grit targets to
#       overwrite each other.
#
#   output_name (optional)
#       Provide an alternate base name for the generated files, like the .d
#       files. Normally these are based on the target name and go in the
#       output_dir, but if multiple targets with the same name end up in
#       the same output_dir, they can collide.
#
#   depfile_dir (optional)
#       If set, used to store the depfile and corresponding stamp file.
#       Defaults to output_dir
#
#   configs (optional)
#       List of additional configs to be applied to the generated target.
#   deps  (optional)
#   visibility  (optional)
#       Normal meaning.
#
# Example
#
#   grit("my_resources") {
#     # Source and outputs are required.
#     source = "myfile.grd"
#     outputs = [
#       "foo_strings.h",
#       "foo_strings.pak",
#     ]
#
#     grit_flags = [ "-E", "foo=bar" ]  # Optional extra flags.
#     # You can also put deps here if the grit source depends on generated
#     # files.
#   }
import("//build/config/android/config.gni")
import("//build/config/chrome_build.gni")
import("//build/config/crypto.gni")
import("//build/config/features.gni")
import("//build/config/ui.gni")
import("//third_party/closure_compiler/closure_args.gni")

assert(!enable_resource_whitelist_generation || is_android,
       "resource whitelist generation only works on android")

declare_args() {
  # When set, this will fork out to grit at GN-time to get all inputs
  # referenced by the .grd file.
  #
  # Normal builds don't need this since proper incremental builds are handled
  # by grit writing out the inputs in .d files at build-time. But for analyze
  # to work on the bots, it needs to know about all input files at GN-time so
  # it knows which tests to trigger when something changes. This option will
  # slow down the GN run.
  compute_grit_inputs_for_analyze = false
}

grit_defines = []

# Mac and iOS want Title Case strings.
use_titlecase_in_grd_files = is_mac || is_ios
if (use_titlecase_in_grd_files) {
  grit_defines += [
    "-D",
    "use_titlecase",
  ]
}

if (is_chrome_branded) {
  grit_defines += [
    "-D",
    "_google_chrome",
    "-E",
    "CHROMIUM_BUILD=google_chrome",
  ]
} else {
  grit_defines += [
    "-D",
    "_chromium",
    "-E",
    "CHROMIUM_BUILD=chromium",
  ]
}

if (is_chromeos) {
  grit_defines += [
    "-D",
    "chromeos",
    "-D",
    "scale_factors=2x",
  ]
}

if (is_desktop_linux) {
  grit_defines += [
    "-D",
    "desktop_linux",
  ]
}

if (toolkit_views) {
  grit_defines += [
    "-D",
    "toolkit_views",
  ]
}

if (use_aura) {
  grit_defines += [
    "-D",
    "use_aura",
  ]
}

if (use_ash) {
  grit_defines += [
    "-D",
    "use_ash",
  ]
}

if (use_nss_certs) {
  grit_defines += [
    "-D",
    "use_nss_certs",
  ]
}

if (use_ozone) {
  grit_defines += [
    "-D",
    "use_ozone",
  ]
}

if (is_android) {
  grit_defines += [
    "-E",
    "ANDROID_JAVA_TAGGED_ONLY=true",
  ]
}

if (is_mac || is_ios) {
  grit_defines += [
    "-D",
    "scale_factors=2x",
  ]
}

# When cross-compiling, explicitly pass the target system to grit.
if (current_toolchain != host_toolchain) {
  if (is_android) {
    grit_defines += [
      "-t",
      "android",
    ]
  }
  if (is_ios) {
    grit_defines += [
      "-t",
      "ios",
    ]
  }
  if (is_linux) {
    grit_defines += [
      "-t",
      "linux2",
    ]
  }
  if (is_mac) {
    grit_defines += [
      "-t",
      "darwin",
    ]
  }
  if (is_win) {
    grit_defines += [
      "-t",
      "win32",
    ]
  }
}

# TODO(aberent): Enable for other platforms once the build machines have
#                Java on them (and hence can run the closure compiler).
_strip_resource_files = is_android
_js_minifier = "//third_party/closure_compiler/js_minify.py"

grit_resource_id_file = "//tools/gritsettings/resource_ids"
grit_info_script = "//tools/grit/grit_info.py"

# TODO(asvitkine): Add predetermined ids files for other platforms.
grit_predetermined_resource_ids_file = ""
if (is_mac) {
  grit_predetermined_resource_ids_file =
      "//tools/gritsettings/startup_resources_mac.txt"
}
if (is_win) {
  grit_predetermined_resource_ids_file =
      "//tools/gritsettings/startup_resources_win.txt"
}

template("grit") {
  assert(defined(invoker.source),
         "\"source\" must be defined for the grit template $target_name")

  if (defined(invoker.resource_ids)) {
    resource_ids = invoker.resource_ids
  } else {
    resource_ids = grit_resource_id_file
  }

  if (defined(invoker.output_dir)) {
    output_dir = invoker.output_dir
  } else {
    output_dir = target_gen_dir
  }

  if (defined(invoker.output_name)) {
    grit_output_name = invoker.output_name
  } else {
    grit_output_name = target_name
  }

  if (defined(invoker.depfile_dir)) {
    depfile_dir = invoker.depfile_dir
  } else {
    depfile_dir = output_dir
  }

  # These are all passed as arguments to the script so have to be relative to
  # the build directory.
  rebased_output_dir = rebase_path(output_dir, root_build_dir)
  source_path = rebase_path(invoker.source, root_build_dir)

  # Compute flags.
  grit_flags = []
  if (enable_resource_whitelist_generation) {
    grit_flags += [ "-h" ]
    if (is_win) {
      grit_flags += [ "#define {textual_id} __pragma(message(\"whitelisted_resource_{numeric_id}\")) {numeric_id}" ]
    } else {
      grit_flags += [ "#define {textual_id} _Pragma(\"whitelisted_resource_{numeric_id}\") {numeric_id}" ]
    }
  }
  if (defined(invoker.grit_flags)) {
    grit_flags += invoker.grit_flags
  }
  if (resource_ids != "") {
    grit_flags += [
      "-f",
      rebase_path(resource_ids, root_build_dir),
    ]
  }
  if (grit_predetermined_resource_ids_file != "") {
    grit_flags += [
      "-p",
      rebase_path(grit_predetermined_resource_ids_file, root_build_dir),
    ]
  }

  if (defined(invoker.source_is_generated)) {
    source_is_generated = invoker.source_is_generated
  } else {
    source_is_generated = false
  }

  assert_files_flags = []

  # We want to make sure the declared outputs actually match what Grit is
  # writing. We write the list to a file (some of the output lists are long
  # enough to not fit on a Windows command line) and ask Grit to verify those
  # are the actual outputs at runtime.
  asserted_list_file =
      "$target_out_dir/${grit_output_name}_expected_outputs.txt"
  write_file(asserted_list_file,
             rebase_path(invoker.outputs, root_build_dir, output_dir))
  assert_files_flags += [ "--assert-file-list=" +
                          rebase_path(asserted_list_file, root_build_dir) ]
  grit_outputs =
      get_path_info(rebase_path(invoker.outputs, ".", output_dir), "abspath")

  # The config and the action below get this visibility son only the generated
  # source set can depend on them. The variable "target_name" will get
  # overwritten inside the inner classes so we need to compute it here.
  target_visibility = [ ":$target_name" ]

  # This config sets up flags needed for enable_resource_whitelist_generation.
  grit_config = target_name + "_grit_config"
  config(grit_config) {
    if ((is_linux || is_android) && enable_resource_whitelist_generation) {
      cflags = [
        "-Wunknown-pragmas",
        "-Wno-error=unknown-pragmas",
      ]
    }
    visibility = target_visibility
  }

  grit_custom_target = target_name + "_grit"
  action(grit_custom_target) {
    script = "//tools/grit/grit.py"

    inputs = [
      invoker.source,
    ]
    if (resource_ids != "") {
      # The script depends on the ID file. Only add this dependency if the ID
      # file is specified.
      inputs += [ resource_ids ]
    }

    depfile = "$depfile_dir/${grit_output_name}_stamp.d"
    outputs = [ "${depfile}.stamp" ] + grit_outputs

    args = [
             "-i",
             source_path,
             "build",
             "-o",
             rebased_output_dir,
             "--depdir",
             ".",
             "--depfile",
             rebase_path(depfile, root_build_dir),
             "--write-only-new=1",
             "--depend-on-stamp",
           ] + grit_defines

    # Add extra defines with -D flags.
    define_args = []
    if (defined(invoker.defines)) {
      foreach(i, invoker.defines) {
        define_args += [
          "-D",
          i,
        ]
      }
    }

    args += define_args + grit_flags + assert_files_flags

    if (_strip_resource_files) {
      js_minifier_command = rebase_path(_js_minifier)
      js_minifier_command = "$js_minifier_command --closure_args"
      foreach(closure_arg,
              common_closure_args + minifying_closure_args +
                  default_disabled_closure_args) {
        js_minifier_command = "$js_minifier_command $closure_arg"
      }
      args += [
        "--js-minifier",
        js_minifier_command,
      ]
      inputs += [
        _js_minifier,
        "//third_party/closure_compiler/compiler/compiler.jar",
      ]
    }

    # Must be after the args are computed since they are re-used.
    # See the comments for the two variables used in this condition for
    # why this works this way.
    if (compute_grit_inputs_for_analyze && !source_is_generated) {
      grit_info_script = "//tools/grit/grit_info.py"
      grit_info_args = [
                         "--inputs",
                         source_path,
                       ] + grit_flags + grit_defines

      # Only call exec_script when the user has explicitly opted into greater
      # precision at the expense of performance.
      rel_inputs = exec_script(grit_info_script,
                               grit_info_args,
                               "list lines",
                               [ grit_info_script ])
      inputs += rebase_path(rel_inputs, ".", root_build_dir)
    } else {
      assert(source_is_generated || !source_is_generated)  # Prevent error.
    }

    if (defined(invoker.visibility)) {
      # This needs to include both what the invoker specified (since they
      # probably include generated headers from this target), as well as the
      # generated source set (since there's no guarantee that the visibility
      # specified by the invoker includes our target).
      #
      # Only define visibility at all if the invoker specified it. Otherwise,
      # we want to keep the public "no visibility specified" default.
      visibility = target_visibility + invoker.visibility
    }

    deps = [
      "//tools/grit:grit_sources",
    ]
    if (defined(invoker.deps)) {
      deps += invoker.deps
    }
    if (defined(invoker.inputs)) {
      inputs += invoker.inputs
    }
  }

  # This is the thing that people actually link with, it must be named the
  # same as the argument the template was invoked with.
  source_set(target_name) {
    # Since we generate a file, we need to be run before the targets that
    # depend on us.
    sources = grit_outputs

    # Deps set on the template invocation will go on the action that runs
    # grit above rather than this library. This target needs to depend on the
    # action publicly so other scripts can take the outputs from the grit
    # script as inputs.
    public_deps = [
      ":$grit_custom_target",
    ]
    public_configs = [ ":$grit_config" ]

    if (defined(invoker.public_configs)) {
      public_configs += invoker.public_configs
    }

    if (defined(invoker.configs)) {
      configs += invoker.configs
    }

    if (defined(invoker.visibility)) {
      visibility = invoker.visibility
    }
    output_name = grit_output_name
  }
}