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1# Copyright 2016 The Chromium Authors. All rights reserved.
2# Use of this source code is governed by a BSD-style license that can be
3# found in the LICENSE file.
4
5import("//build/config/sanitizers/sanitizers.gni")
6
7declare_args() {
8  # This arg is used when we want to tell the JIT-generating v8 code
9  # that we want to have it generate for an architecture that is different
10  # than the architecture that v8 will actually run on; we then run the
11  # code under an emulator. For example, we might run v8 on x86, but
12  # generate arm code and run that under emulation.
13  #
14  # This arg is defined here rather than in the v8 project because we want
15  # some of the common architecture-specific args (like arm_float_abi or
16  # mips_arch_variant) to be set to their defaults either if the current_cpu
17  # applies *or* if the v8_current_cpu applies.
18  #
19  # As described below, you can also specify the v8_target_cpu to use
20  # indirectly by specifying a `custom_toolchain` that contains v8_$cpu in the
21  # name after the normal toolchain.
22  #
23  # For example, `gn gen --args="custom_toolchain=...:clang_x64_v8_arm64"`
24  # is equivalent to setting --args=`v8_target_cpu="arm64"`. Setting
25  # `custom_toolchain` is more verbose but makes the toolchain that is
26  # (effectively) being used explicit.
27  #
28  # v8_target_cpu can only be used to target one architecture in a build,
29  # so if you wish to build multiple copies of v8 that are targeting
30  # different architectures, you will need to do something more
31  # complicated involving multiple toolchains along the lines of
32  # custom_toolchain, above.
33  v8_target_cpu = ""
34}
35
36if (v8_target_cpu == "") {
37  if (current_toolchain == "//build/toolchain/linux:clang_x64_v8_arm64") {
38    v8_target_cpu = "arm64"
39  } else if (current_toolchain == "//build/toolchain/linux:clang_x86_v8_arm") {
40    v8_target_cpu = "arm"
41  } else if (current_toolchain ==
42             "//build/toolchain/linux:clang_x64_v8_x86_64") {
43    v8_target_cpu = "x86_64"
44  } else if (is_msan) {
45    # If we're running under a sanitizer, if we configure v8 to generate
46    # code that will be run under a simulator, then the generated code
47    # also gets the benefits of the sanitizer.
48    v8_target_cpu = "arm64"
49  } else {
50    v8_target_cpu = target_cpu
51  }
52}
53
54declare_args() {
55  # This argument is declared here so that it can be overridden in toolchains.
56  # It should never be explicitly set by the user.
57  v8_current_cpu = v8_target_cpu
58}
59