tools/gn/function_set_default_toolchain.cc

   1 // Copyright (c) 2013 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
   5 #include "tools/gn/build_settings.h"
   6 #include "tools/gn/functions.h"
   7 #include "tools/gn/loader.h"
   8 #include "tools/gn/parse_tree.h"
   9 #include "tools/gn/scope.h"
  10 #include "tools/gn/settings.h"
  11
  12 namespace functions {
  13
  14 const char kSetDefaultToolchain[] = "set_default_toolchain";
  15 const char kSetDefaultToolchain_HelpShort[] =
  16     "set_default_toolchain: Sets the default toolchain name.";
  17 const char kSetDefaultToolchain_Help[] =
  18     "set_default_toolchain: Sets the default toolchain name.\n"
  19     "\n"
  20     "  set_default_toolchain(toolchain_label)\n"
  21     "\n"
  22     "  The given label should identify a toolchain definition (see\n"
  23     "  \"help toolchain\"). This toolchain will be used for all targets\n"
  24     "  unless otherwise specified.\n"
  25     "\n"
  26     "  This function is only valid to call during the processing of the build\n"
  27     "  configuration file. Since the build configuration file is processed\n"
  28     "  separately for each toolchain, this function will be a no-op when\n"
  29     "  called under any non-default toolchains.\n"
  30     "\n"
  31     "  For example, the default toolchain should be appropriate for the\n"
  32     "  current environment. If the current environment is 32-bit and \n"
  33     "  somebody references a target with a 64-bit toolchain, we wouldn't\n"
  34     "  want processing of the build config file for the 64-bit toolchain to\n"
  35     "  reset the default toolchain to 64-bit, we want to keep it 32-bits.\n"
  36     "\n"
  37     "Argument:\n"
  38     "\n"
  39     "  toolchain_label\n"
  40     "      Toolchain name.\n"
  41     "\n"
  42     "Example:\n"
  43     "\n"
  44     "  set_default_toolchain(\"//build/config/win:vs32\")";
  45
  46 Value RunSetDefaultToolchain(Scope* scope,
  47                              const FunctionCallNode* function,
  48                              const std::vector<Value>& args,
  49                              Err* err) {
  50   if (!scope->IsProcessingBuildConfig()) {
  51     *err = Err(function->function(), "Must be called from build config.",
  52         "set_default_toolchain can only be called from the build configuration "
  53         "file.");
  54     return Value();
  55   }
  56
  57   // When the loader is expecting the default toolchain to be set, it will set
  58   // this key on the scope to point to the destination.
  59   Label* default_toolchain_dest = static_cast<Label*>(
  60       scope->GetProperty(Loader::kDefaultToolchainKey, nullptr));
  61   if (!default_toolchain_dest)
  62     return Value();
  63
  64   const SourceDir& current_dir = scope->GetSourceDir();
  65   const Label& default_toolchain = ToolchainLabelForScope(scope);
  66
  67   if (!EnsureSingleStringArg(function, args, err))
  68     return Value();
  69   Label toolchain_label(
  70       Label::Resolve(current_dir, default_toolchain, args[0], err));
  71   if (toolchain_label.is_null())
  72     return Value();
  73
  74   *default_toolchain_dest = toolchain_label;
  75   return Value();
  76 }
  77
  78 }  // namespace functions