[Vim/YCM] Identify ObjC and ObjC++ headers.

tools/vim/chromium.ycm_extra_conf.py

Index: tools/vim/chromium.ycm_extra_conf.py
diff --git a/tools/vim/chromium.ycm_extra_conf.py b/tools/vim/chromium.ycm_extra_conf.py
index a2f74a2f1089221cbe96a0eea728b510e3655f94..945639423bb810545f9e7721e08f841cf1ca0ac2 100644
--- a/tools/vim/chromium.ycm_extra_conf.py
+++ b/tools/vim/chromium.ycm_extra_conf.py
@@ -63,6 +63,8 @@ _default_flags = [
   'c++',
 ]
 
+_header_alternates = ('.cc', '.cpp', '.c', '.mm', '.m')
+
 _extension_flags = {
   '.m': ['-x', 'objective-c'],
   '.mm': ['-x', 'objective-c++'],
@@ -117,35 +119,6 @@ def GetDefaultSourceFile(chrome_root, filename):
     return os.path.join(chrome_root, 'base', 'logging.cc')
 
 
-def GetBuildableSourceFile(chrome_root, filename):
-  """Returns a buildable source file corresponding to |filename|.
-
-  A buildable source file is one which is likely to be passed into clang as a
-  source file during the build. For .h files, returns the closest matching .cc,
-  .cpp or .c file. If no such file is found, returns the same as
-  GetDefaultSourceFile().
-
-  Args:
-    chrome_root: (String) Absolute path to the root of Chromium checkout.
-    filename: (String) Absolute path to the target source file.
-
-  Returns:
-    (String) Absolute path to source file.
-  """
-  if filename.endswith('.h'):
-    # Header files can't be built. Instead, try to match a header file to its
-    # corresponding source file.
-    alternates = ['.cc', '.cpp', '.c']
-    for alt_extension in alternates:
-      alt_name = filename[:-2] + alt_extension
-      if os.path.exists(alt_name):
-        return alt_name
-
-    return GetDefaultSourceFile(chrome_root, filename)
-
-  return filename
-
-
 def GetNinjaBuildOutputsForSourceFile(out_dir, filename):
   """Returns a list of build outputs for filename.
 
@@ -326,8 +299,22 @@ def GetClangOptionsFromNinjaForFilename(chrome_root, filename):
   from ninja_output import GetNinjaOutputDirectory
   out_dir = GetNinjaOutputDirectory(chrome_root)
 
-  clang_line = GetClangCommandLineFromNinjaForSource(
-      out_dir, GetBuildableSourceFile(chrome_root, filename))
+  basename, extension = os.path.splitext(filename)
+  if extension == '.h':
+    candidates = [basename + ext for ext in _header_alternates]
+  else:
+    candidates = [filename]
+
+  clang_line = None
+  buildable_extension = extension
+  for candidate in candidates:
+    clang_line = GetClangCommandLineFromNinjaForSource(out_dir, candidate)
+    if clang_line:
+      buildable_extension = os.path.splitext(candidate)[1]
+      break
+
+  additional_flags += _extension_flags.get(buildable_extension, [])
+
   if not clang_line:
     # If ninja didn't know about filename or it's companion files, then try a
     # default build target. It is possible that the file is new, or build.ninja
@@ -352,7 +339,6 @@ def FlagsForFile(filename):
       'flags': (List of Strings) Command line flags.
       'do_cache': (Boolean) True if the result should be cached.
   """
-  ext = os.path.splitext(filename)[1]
   abs_filename = os.path.abspath(filename)
   chrome_root = FindChromeSrcFromFilename(abs_filename)
   clang_flags = GetClangOptionsFromNinjaForFilename(chrome_root, abs_filename)
@@ -362,7 +348,7 @@ def FlagsForFile(filename):
   # determine the flags again.
   should_cache_flags_for_file = bool(clang_flags)
 
-  final_flags = _default_flags + _extension_flags.get(ext, []) + clang_flags
+  final_flags = _default_flags + clang_flags
 
   return {
     'flags': final_flags,