zircon/system/ulib/zircon/BUILD.gn

# 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("$zx/kernel/syscalls/abigen.gni")
import("$zx/public/gn/toolchain/environment_redirect.gni")

# The vDSO can't be built with instrumentation.
exclude_tags = [ "instrumented" ]

if (toolchain.tags + exclude_tags - exclude_tags != toolchain.tags ||
    toolchain.environment != "user") {
  # References from other toolchains just redirect.  This prevents extra
  # abigen runs in other toolchains just to get identical generated headers.
  foreach(target,
          [
            "zircon",
            "headers",
          ]) {
    environment_redirect(target) {
      environment_label = "$zx/public/gn/toolchain:user"
      deps = [
        ":$target",
      ]
    }
  }
} else {
  # TODO(mcgrathr): Rename the source files and the abigen switch.
  if (zircon_cpu == "x86") {
    zircon_cpu = "x86-64"
    abigen_cpu = "x86"
  } else if (zircon_cpu == "arm64") {
    abigen_cpu = "arm"
  }

  library("zircon") {
    # TODO(BLD-353): Legacy export for this is handled in $zx/system/ulib/c.
    shared = true
    static = false

    # The vDSO is never installed as a file, only baked into the kernel.
    install_path = false

    sources = [
      "data.S",
      "syscall-wrappers.cpp",
      "zx_cache_flush.cpp",
      "zx_channel_call.cpp",
      "zx_cprng_draw.cpp",
      "zx_deadline_after.cpp",
      "zx_status_get_string.cpp",
      "zx_system_get_dcache_line_size.cpp",
      "zx_system_get_features.cpp",
      "zx_system_get_num_cpus.cpp",
      "zx_system_get_physmem.cpp",
      "zx_system_get_version.cpp",
      "zx_ticks_get.cpp",
      "zx_ticks_per_second.cpp",
    ]

    configs += [ ":config" ]
    deps = [
      ":generate",
      ":syscall-asm",
      "$zx/kernel/lib/vdso:headers",
    ]
    public_deps = [
      ":generated-public-headers",
    ]

    # Instruct the linker to preserve the hidden alternate entry points.
    # Note, "./" makes GN realize this is a file rather than a -l switch.
    libs = [ "./alternates.ld" ]

    # This doesn't get normal default deps on libc.
    no_implicit_deps = true
  }

  # Everything with ":config" in configs needs ":generate" in deps.
  config("config") {
    visibility = [ ":*" ]

    # This library should not depend on libc.
    cflags = [ "-ffreestanding" ]
    configs = [
      "$zx/public/gn/config:no_sanitizers",
      "$zx/public/gn/config:rodso",
    ]

    include_dirs = [ target_gen_dir ]
  }

  source_set("syscall-asm") {
    sources = [
      "syscalls-$zircon_cpu.S",
      "zx_futex_wake_handle_close_thread_exit-$zircon_cpu.S",
      "zx_vmar_unmap_handle_close_thread_exit-$zircon_cpu.S",
    ]
    configs += [ ":config" ]
    deps = [
      ":generate",
      "$zx/kernel/syscalls:syscall-abi",
    ]
    if (toolchain.environment == "user") {
      configs -= [ "$zx/public/gn/config:user" ]
    }
  }

  group("generated-public-headers") {
    public_configs = [ ":generated-public-headers.config" ]
    deps = [
      ":generate",
    ]
  }

  config("generated-public-headers.config") {
    visibility = [ ":generated-public-headers" ]
    include_dirs = [ root_gen_dir ]
  }

  abigen("generate") {
    visibility = [ ":*" ]
    gen = [
      # These are the public headers.
      {
        args = [ "-user-header" ]
        outputs = [
          "$root_gen_dir/zircon/syscalls/definitions.h",
        ]
      },
      {
        args = [ "-rust" ]
        outputs = [
          "$root_gen_dir/zircon/syscalls/definitions.rs",
        ]
      },

      # TODO(mcgrathr): Drop the zircon/ prefix from the remaining files.
      # These are private.
      {
        args = [ "-vdso-header" ]
        outputs = [
          "$target_gen_dir/zircon/syscall-vdso-definitions.h",
        ]
      },
      {
        args = [ "-vdso-wrappers" ]
        outputs = [
          "$target_gen_dir/zircon/syscall-vdso-wrappers.inc",
        ]
      },
      {
        args = [ "-${abigen_cpu}-asm" ]
        outputs = [
          "$target_gen_dir/zircon/syscalls-$zircon_cpu.S",
        ]
      },
    ]
  }
}