1 files changed, 142 insertions, 0 deletions
diff --git a/src/crc32c/.ycm_extra_conf.py b/src/crc32c/.ycm_extra_conf.py
new file mode 100644
index 0000000000..62daa8a4ac
--- /dev/null
+++ b/src/crc32c/.ycm_extra_conf.py
@@ -0,0 +1,142 @@
+# Copyright 2017 The CRC32C Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+"""YouCompleteMe configuration that interprets a .clang_complete file.
+
+This module implementes the YouCompleteMe configuration API documented at:
+https://github.com/ycm-core/ycmd#ycm_extra_confpy-specification
+
+The implementation loads and processes a .clang_complete file, documented at:
+https://github.com/xavierd/clang_complete/blob/master/README.md
+"""
+
+import os
+
+# Flags added to the list in .clang_complete.
+BASE_FLAGS = [
+    '-Werror',  # Unlike clang_complete, YCM can also be used as a linter.
+    '-DUSE_CLANG_COMPLETER',  # YCM needs this.
+    '-xc++',  # YCM needs this to avoid compiling headers as C code.
+]
+
+# Clang flags that take in paths.
+# See https://clang.llvm.org/docs/ClangCommandLineReference.html
+PATH_FLAGS = [
+    '-isystem',
+    '-I',
+    '-iquote',
+    '--sysroot='
+]
+
+
+def DirectoryOfThisScript():
+  """Returns the absolute path to the directory containing this script."""
+  return os.path.dirname(os.path.abspath(__file__))
+
+
+def MakeRelativePathsInFlagsAbsolute(flags, build_root):
+  """Expands relative paths in a list of Clang command-line flags.
+
+  Args:
+    flags: The list of flags passed to Clang.
+    build_root: The current directory when running the Clang compiler. Should be
+        an absolute path.
+
+  Returns:
+    A list of flags with relative paths replaced by absolute paths.
+  """
+  new_flags = []
+  make_next_absolute = False
+  for flag in flags:
+    new_flag = flag
+
+    if make_next_absolute:
+      make_next_absolute = False
+      if not flag.startswith('/'):
+        new_flag = os.path.join(build_root, flag)
+
+    for path_flag in PATH_FLAGS:
+      if flag == path_flag:
+        make_next_absolute = True
+        break
+
+      if flag.startswith(path_flag):
+        path = flag[len(path_flag):]
+        new_flag = path_flag + os.path.join(build_root, path)
+        break
+
+    if new_flag:
+      new_flags.append(new_flag)
+  return new_flags
+
+
+def FindNearest(target, path, build_root):
+  """Looks for a file with a specific name closest to a project path.
+
+  This is similar to the logic used by a version-control system (like git) to
+  find its configuration directory (.git) based on the current directory when a
+  command is invoked.
+
+  Args:
+    target: The file name to search for.
+    path: The directory where the search starts. The search will explore the
+        given directory's ascendants using the parent relationship. Should be an
+        absolute path.
+    build_root: A directory that acts as a fence for the search. If the search
+        reaches this directory, it will not advance to its parent. Should be an
+        absolute path.
+
+  Returns:
+    The path to a file with the desired name. None if the search failed.
+  """
+  candidate = os.path.join(path, target)
+  if os.path.isfile(candidate):
+    return candidate
+
+  if path == build_root:
+    return None
+
+  parent = os.path.dirname(path)
+  if parent == path:
+    return None
+
+  return FindNearest(target, parent, build_root)
+
+
+def FlagsForClangComplete(file_path, build_root):
+  """Reads the .clang_complete flags for a source file.
+
+  Args:
+    file_path: The path to the source file. Should be inside the project. Used
+      to locate the relevant .clang_complete file.
+    build_root: The current directory when running the Clang compiler for this
+        file. Should be an absolute path.
+
+  Returns:
+    A list of strings, where each element is a Clang command-line flag.
+  """
+  clang_complete_path = FindNearest('.clang_complete', file_path, build_root)
+  if clang_complete_path is None:
+    return None
+  clang_complete_flags = open(clang_complete_path, 'r').read().splitlines()
+  return clang_complete_flags
+
+
+def FlagsForFile(filename, **kwargs):
+  """Implements the YouCompleteMe API."""
+
+  # kwargs can be used to pass 'client_data' to the YCM configuration. This
+  # configuration script does not need any extra information, so
+  # pylint: disable=unused-argument
+
+  build_root = DirectoryOfThisScript()
+  file_path = os.path.realpath(filename)
+
+  flags = BASE_FLAGS
+  clang_flags = FlagsForClangComplete(file_path, build_root)
+  if clang_flags:
+    flags += clang_flags
+
+  final_flags = MakeRelativePathsInFlagsAbsolute(flags, build_root)
+
+  return {'flags': final_flags}