# Copyright 2019 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import("$zx/public/gn/build_api_module.gni")
import("$zx/public/gn/config/standard.gni")
import("$zx/public/gn/copied_files_dir.gni")
import("$zx/public/gn/prebuilt.gni")
import("$zx/public/gn/test/zbi_test.gni")
import("$zx/public/gn/toolchain/c_utils.gni")
import("$zx/public/gn/toolchain/environment_redirect.gni")
import("$zx/public/gn/zbi.gni")

declare_args() {
  # Defines the `//:default` target: what `ninja` with no arguments does.
  # TODO(fxbug.dev/3156): This must be set by the controlling Fuchsia GN build.
  default_deps = false
}

assert(default_deps != false,
       "TODO(fxbug.dev/3156): Zircon build must be driven by Fuchsia build")

###
### Build API modules.
###

# This is the top-level build API module that just lists all the others.
# Each element of the list is the simple name of the API module; the
# module's contents are found at "$root_build_dir/$target_name.json".
#
# TODO(fxbug.dev/3156): Note this does not include build_api_module() uses meant
# just for legacy build integration.  We don't consider those to be actual
# build API modules; using build_api_module() is just a convenience for
# creating them.  Importantly, they are not part of the API contract with
# consumers of the overall build.  They're purely implementation details of
# the temporary Frankenbuild arrangement.
#
# Type: list(string)
build_api_module("api") {
  testonly = true
  data_keys = [ "build_api_modules" ]
  deps = [
    ":args",
    ":binaries",
    ":generated_sources",
    ":tests",
    ":zbi_tests",
  ]
}

# See //:args in the fuchsia build for a description.
build_api_module("args") {
  contents = read_file("$root_build_dir/args.gn", "scope")
}

# This describes all the binaries linked by the build.
#
# This enumerates each linked binary (executable, shared library, or
# loadable/"plug-in" module) used by the build, or produced by the build.
#
# This includes host tools, kernels, boot loaders, drivers, as well as
# normal executables. This also includes prebuilt toolchain runtime
# libraries that end up in image files. It does not yet include any
# non-native binary formats.
#
# For non-prebuilts, this is meant to reach the entire dependency graph
# of all binaries that the build would ever produce.  Not every binary
# described is necessary actually produced by any given Ninja run.  Either
# the $debug or the $dist file for any individual binary can be passed to
# Ninja as a specific target argument to ensure it's built and
# up to date before making use of that binary.  Like all build_api_module()
# targets, the top-level "binaries" target serves as a Ninja target to
# request that every binary described be built.
#
# Note that in certain cases, the paths in `debug` and `dist` will
# point out of the build tree, and thus cannot be used as Ninja targets.
# This happens for prebuilts or binaries produced by the Zircon build.
#
# Type: list(scope)
#
#   cpu
#     Required: CPU architecture the binary is for, e.g. "arm64" or "x64".
#     Type: string
#
#   os
#     Required: OS the binary is for, e.g. "fuchsia", "linux", or "mac".
#     Type: string
#
#   environment
#     Required: The ${toolchain.environment} name of what specific
#     execution this was built for, e.g. "user", "host", "guest".  The
#     tuple of ($cpu, $os, $environment) should indicate what hardware and
#     software environment this binary is compatible with.
#     Type: string
#
#   label
#     Required: The GN label of the binary target.
#     Type: label_with_toolchain
#
#   type
#     Required: The type of binary.
#     Type: "executable" or "shared_library" or "loadable_module"
#
#   debug
#     Required: Path to where the unstripped or separate debug file is
#     found, relative to $root_build_dir.  If $dist is omitted, this
#     is also the file that is used at runtime.
#     Type: path relative to $root_build_dir
#
#   dist
#     Optional: Path to where the stripped binary for deployment/execution is
#     found, relative to $root_build_dir.  This binary may be required for
#     some debugging tasks if $debug is a separate debug file rather than
#     an unstripped file.  It should exactly match the binary that will be
#     seen on devices or run directly on hosts.
#     Type: path relative to $root_build_dir
#
#   elf_build_id
#     Optional: Path to a file containing the lowercase ASCII hexadecimal
#     representation of the ELF build ID in this binary.  This is omitted
#     for OS environments that don't use ELF.  For an ELF binary that
#     doesn't have a build ID note, this key will be present but point to
#     an empty file.
#     Type: path relative to $root_build_dir
#
#   breakpad
#     Optional: Path to the breakpad symbol file for the debug binary.  This
#     will only be present if $output_breakpad_syms was set.
#     Type: path relative to $root_build_dir
build_api_module("binaries") {
  testonly = true
  deps = [ ":everything" ]
  data_keys = [ "binaries" ]
}

# This describes all the generated source files in the build.
#
# The intent is that telling Ninja to build all these individual files
# will be the minimal work sufficient for source code analysis of all
# the files described in the compilation database to be viable.
#
# Type: list(path relative to $root_build_dir)
#
build_api_module("generated_sources") {
  testonly = true
  deps = [ ":everything" ]
  data_keys = [ "generated_sources" ]
}

# Tests in the build.
#
#  Below, the "testing root" refers to $root_build_dir on host, and the full
#  filesystem path from the root on device.
#
# Type: list(scope)
#
#   * name
#     - Required: Name of test.
#     - Type: string
#
#   * label
#     - Required: GN label associated with the test
#     - Type: label_with_toolchain
#
#   * path
#     - Required: Path to the test's executable.
#     - Type: path relative to the testing root.
#
#   * cpu, os
#     - Required: $current_cpu and $current_os values, respectively, for
#       which this test is intended.
#     - Type: string
#
#   * disabled
#     - Optional: a free-form string indicating a reason for the test being
#       disabled.
#     - Type: string
#
#   * runtime_deps
#     - Optional: a JSON file containing a list of root_build_dir-relative
#       paths defining ascribed runtime dependencies of the test. These
#       dependencies are aggregated via the metadata graph of the associated
#       test target under a data key of "test_runtime_deps.
#     - Type: path relative to root_build_dir
#
build_api_module("tests") {
  testonly = true
  data_keys = [ "tests" ]
  deps = default_deps
}

# This tells the infra recipes how to run ZBI tests, defined with zbi_test(),
# which is a class of tests that are 'run' by booting an associated ZBI and
# listening on serial for a particular string indicating success.
#
# The schema produced here matches //:images with the addition of the
# `success_string` key.
#
# Type: list(scope)
#
#   * cpu
#     - Required: CPU architecture the image is for, e.g. "arm64" or "x64".
#     - Type: string
#
#   * name
#     - Required: The primary way that this ZBI is known to consumers.
#     Note that the name need not be unique within the images list.
#     The tuple of ($name, $cpu) should be unique.
#     - Type: string
#
#   * label
#     - Required: The GN label of the image target.
#     - Type: label_with_toolchain
#
#   * path
#     - Required: Path to where the file is found, relative to $root_build_dir.
#     This is also the argument to Ninja that ensures this image will be built.
#     - Type: path relative to $root_build_dir
#
#   * bootserver_netboot
#     - Required: bootserver commandline option for booting the ZBI.
#     - Type: string
#
#   * success_string
#     - Required: The string that the ZBI test outputs to indicate success.
#     - Type: string
#
#   * device_types
#     - Required: The list of device types that this test should be run on.
#     //build/testing/platforms.gni lists the allowed values; others will
#     be ignored.
#     - Type: list(string)
#
#   * qemu_kernel_label
#     - Optional: Label appearing in $label of an //:images entry.
#     That image should be used in place of the usual `qemu-kernel` image.
#     - Type: label_with_toolchain
#
#   * timeout
#     - Optional: Timeout for running the test, in seconds.
#     - Type: seconds
#
build_api_module("zbi_tests") {
  testonly = true
  data_keys = [ "zbi_tests" ]
  deps = [ ":everything" ]
}

###
### Top-level targets.
###

# This is used in the top-level build_api_module() deps to reach "everything".
# Note that "all" is a magical target name to Ninja, hence this name instead.
group("everything") {
  testonly = true
  deps = default_deps
}

# This is the default target that Ninja builds when given no target arguments.
group("default") {
  testonly = true
  deps = default_deps
}

###
### TODO(fxbug.dev/3156): Temporary hacks for integrating with the legacy Fuchsia
### GN build.
###

if (current_toolchain == default_toolchain) {
  build_api_module("legacy_dirs") {
    testonly = true
    data_keys = [ "legacy_dirs" ]
    walk_keys = [ "legacy_barrier" ]
    deps = []
    foreach(cpu, standard_fuchsia_cpus) {
      deps += [ ":legacy-$cpu" ]
    }
  }

  foreach(cpu, standard_fuchsia_cpus) {
    group("legacy-$cpu") {
      testonly = true
      deps = [
        ":legacy-aux-$cpu",
        ":legacy-deps-$cpu",
        ":legacy-tests-$cpu",
      ]
    }

    build_api_module("legacy_sysroot-$cpu") {
      testonly = true
      data_keys = [ "legacy_sysroot" ]
      walk_keys = [ "legacy_barrier" ]
      deps = [
        ":all-ulib-$cpu",
        ":asan-ulib-$cpu",
      ]
    }
  }
}

foreach(cpu, standard_fuchsia_cpus) {
  if (current_toolchain == default_toolchain) {
    zbi_input("legacy-tests-$cpu") {
      output_dir = root_build_dir
      testonly = true
      cpu = cpu
      deps = [ ":legacy-tests-deps-$cpu" ]
    }

    # The legacy Fuchsia GN build needs to consume a manifest of libraries
    # built for ASan (and all the libraries themselves).  When the main
    # build is ASan, it needs to find the non-ASan libraries here too.
    manifest_file("legacy-aux-$cpu") {
      testonly = true
      deps = [
        ":all-ulib-$cpu",
        ":instrumented-ulib-$cpu",

        # Include the tests so their libraries are in the aux manifest
        # when individual binaries are drawn from the tests manifest.
        ":legacy-tests-deps-$cpu",
      ]
      metadata = {
        # This prevents build_api_module("legacy-$cpu") from visiting the
        # ASan incarnations of all the libraries.  The legacy build wants
        # only the manifest of ASan shared libraries.  It wants the targets
        # themselves only from the primary build.
        legacy_barrier = []
      }
    }
  }

  environment_redirect("legacy-deps-$cpu") {
    visibility = [ ":*" ]
    testonly = true
    environment_label = "$zx/public/gn/toolchain:user"
    cpu = cpu
    deps = [ "$zx/kernel" ]
    metadata = {
      legacy_barrier = []
    }
  }

  environment_redirect("legacy-tests-deps-$cpu") {
    visibility = [ ":*" ]
    testonly = true
    environment_label = "$zx/public/gn/toolchain:user"
    cpu = cpu
    direct = true
    deps = [ "$zx/system/utest" ]
  }

  environment_redirect("all-ulib-$cpu") {
    testonly = true
    cpu = cpu
    environment_label = "$zx/public/gn/toolchain:user"
    shlib = true
    exclude_variant_tags = [ "instrumented" ]
    deps = [ "$zx/system/ulib" ]
  }

  foreach(tag,
          [
            "instrumented",
            "asan",
          ]) {
    environment_redirect("$tag-ulib-$cpu") {
      testonly = true
      cpu = cpu
      environment_label = "$zx/public/gn/toolchain:user"
      deps = [ ":$tag-ulib-redirect" ]
    }
  }
}

if (toolchain.environment == "user") {
  foreach(tag,
          [
            "instrumented",
            "asan",
          ]) {
    variants = []
    foreach(selector, toolchain.variant_selectors) {
      if (selector.tags + [ tag ] - [ tag ] != selector.tags) {
        variants += [ selector.variant ]
        variants -= [ selector.variant ]
        variants += [ selector.variant ]
      }
    }
    group("$tag-ulib-redirect") {
      testonly = true
      visibility = [ ":*" ]
      deps = []
      foreach(variant, variants) {
        deps += [ ":$tag-ulib-redirect.$variant" ]
      }
    }
    foreach(variant, variants) {
      environment_redirect("$tag-ulib-redirect.$variant") {
        testonly = true
        visibility = [ ":$tag-ulib-redirect" ]
        variant = variant

        # NOTE: Order of deps items is important.
        deps = [ "$zx/system/ulib" ]
        foreach(dep, toolchain.implicit_deps) {
          if (dep == "$dep") {
            deps += [ dep ]
          } else {
            deps += dep.add
          }
        }
      }
    }
  }
}

build_api_module("legacy_images") {
  testonly = true
  data_keys = [ "images" ]
  deps = [ ":zbi_tests" ]
  foreach(cpu, standard_fuchsia_cpus) {
    deps += [ ":legacy-$cpu" ]
  }
}

# This target complements legacy_images in that it lists the various elements
# that end up in images.
foreach(cpu, standard_fuchsia_cpus) {
  build_api_module("legacy_unification-$cpu") {
    testonly = true
    data_keys = [ "zx_manifest" ]
    deps = [ ":legacy-$cpu" ]

    # Add the dependencies of legacy-aux directly, as that target sets a barrier
    # that's not desirable here.
    deps += [
      ":all-ulib-$cpu",
      ":instrumented-ulib-$cpu",
      ":legacy-tests-deps-$cpu",
    ]
  }
}