Add and use a clang_linux asset.

infra/bots/assets/clang_linux/create.py

+#!/usr/bin/env python
+#
+# Copyright 2016 Google Inc.
+#
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+
+"""Create a Clang toolchain for Linux hosts."""
+
+
+import argparse
+import os
+import subprocess
+import tempfile
+
+REPO = "https://llvm.googlesource.com/"
+BRANCH = "release_39"
+
+def create_asset(target_dir):
+  os.chdir(tempfile.mkdtemp())
+  subprocess.check_call(["git", "clone", "-b", BRANCH, REPO + "llvm"])
+  os.chdir("llvm/tools")
+  subprocess.check_call(["git", "clone", "-b", BRANCH, REPO + "clang"])
+  os.chdir("../projects")
+  subprocess.check_call(["git", "clone", "-b", BRANCH, REPO + "compiler-rt"])
+  subprocess.check_call(["git", "clone", "-b", BRANCH, REPO + "libcxx"])
+  subprocess.check_call(["git", "clone", "-b", BRANCH, REPO + "libcxxabi"])
+  os.chdir("..")
+  os.mkdir("out")
+  os.chdir("out")
+  subprocess.check_call(["cmake", "..", "-G", "Ninja",
+                         "-DCMAKE_BUILD_TYPE=MinSizeRel",
+                         "-DCMAKE_INSTALL_PREFIX=" + target_dir,
+                         "-DLLVM_INSTALL_TOOLCHAIN_ONLY=ON",
+                         "-DLLVM_ENABLE_TERMINFO=OFF"])
+  subprocess.check_call(["cmake", "--build", "."])
+  subprocess.check_call(["cmake", "--build", ".", "--target", "install"])
+  subprocess.check_call(["cp", "bin/llvm-symbolizer", target_dir + "/bin"])
+
+  libstdcpp = subprocess.check_output(["c++",
+                                       "-print-file-name=libstdc++.so.6"])
+  subprocess.check_call(["cp", libstdcpp.strip(), target_dir + "/lib"])
+
+
+def main():
+  parser = argparse.ArgumentParser()
+  parser.add_argument('--target_dir', '-t', required=True)
+  args = parser.parse_args()
+  create_asset(args.target_dir)
+
+
+if __name__ == '__main__':
+  main()