Function addWindowsVariables

tools/cli/dev-bundle-bin-helpers.js:124–183

(devBundleDir, env)

var cachedMSVSVersion;

function addWindowsVariables(devBundleDir, env) {
  // On Windows we provide a reliable version of python.exe for use by
  // node-gyp (the tool that rebuilds binary node modules). #WinPy
  env.PYTHON = env.PYTHON || path.join(
    devBundleDir, "python", "python.exe");

  // While the original process.env object allows for case insensitive
  // access on Windows, Object.create interferes with that behavior,
  // so here we ensure env.PATH === env.Path on Windows.
  env.Path = env.PATH;

  if (cachedMSVSVersion) {
    env.GYP_MSVS_VERSION = cachedMSVSVersion;
  }

  if (env.GYP_MSVS_VERSION) {
    return Promise.resolve(env);
  }

  // If $GYP_MSVS_VERSION was not provided, use the gyp Python library to
  // infer it, or default to 2015 if that doesn't work.
  return new Promise(function (resolve) {
    var nodeGypPylibDir = path.join(
      devBundleDir, "lib", "node_modules", "node-gyp", "gyp", "pylib"
    );

    var child = require("child_process").spawn(env.PYTHON, ["-c", [
      "from gyp.MSVSVersion import SelectVisualStudioVersion",
      "try:",
      "  print SelectVisualStudioVersion(allow_fallback=False).short_name",
      "except:",
      "  print 2015"
    ].join("\n")], {
      cwd: nodeGypPylibDir,
      stdio: "pipe"
    });

    var chunks = [];
    child.stdout.on("data", function (chunk) {
      chunks.push(chunk);
    });

    function finish(codeOrError) {
      if (codeOrError) {
        // In the event of any kind of error, default to 2015.
        cachedMSVSVersion = "2015";
      } else {
        cachedMSVSVersion = Buffer.concat(chunks)
          .toString("utf8").replace(/^\s+|\s+$/g, "");
      }

      env.GYP_MSVS_VERSION = cachedMSVSVersion;

      resolve(env);
    }

    child.on("error", finish);
    child.on("exit", finish);