Adding workaround for libclang bug on mac

On Mac OS X, libclang will fail to include the standard header search
paths that clang will. So we add the paths ourselves.

Fixes #303

cpp/ycm/.ycm_extra_conf.py

@@ -82,13 +82,6 @@
 '-isystem',
 './tests/gmock/include',
 '-isystem',
-'/usr/include',
-'-isystem',
-'/usr/local/include',
-'-isystem',
-'/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1',
-'-isystem',
-'/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include',
 ]
 
 

ycmd/completers/cpp/flags.py

@@ -21,7 +21,7 @@
 import os
 import inspect
 from ycmd import extra_conf_store
-from ycmd.utils import ToUtf8IfNeeded
+from ycmd.utils import ToUtf8IfNeeded, OnMac
 from ycmd.responses import NoExtraConfDetected
 
 INCLUDE_FLAGS = [ '-isystem', '-I', '-iquote', '--sysroot=', '-isysroot',
@@ -35,6 +35,21 @@
 #   https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Preprocessor-Options.html
 FILE_FLAGS_TO_SKIP = set(['-MD', '-MMD', '-MF', '-MT', '-MQ', '-o'])
 
+# These are the standard header search paths that clang will use on Mac BUT
+# libclang won't, for unknown reasons. We add these paths when the user is on a
+# Mac because if we don't, libclang would fail to find <vector> etc.
+# This should be fixed upstream in libclang, but until it does, we need to help
+# users out.
+# See Valloric/YouCompleteMe#303 for details.
+MAC_INCLUDE_PATHS = [
+ '/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1',
+ '/usr/local/include',
+ '/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include',
+ '/usr/include',
+ '/System/Library/Frameworks',
+ '/Library/Frameworks',
+]
+
 
 class Flags( object ):
   """Keeps track of the flags necessary to compile a file.
@@ -44,13 +59,13 @@ class Flags( object ):
   def __init__( self ):
     # It's caches all the way down...
     self.flags_for_file = {}
-    self.special_clang_flags = _SpecialClangIncludes()
+    self.extra_clang_flags = _ExtraClangFlags()
     self.no_extra_conf_file_warning_posted = False
 
 
   def FlagsForFile( self,
                     filename,
-                    add_special_clang_flags = True,
+                    add_extra_clang_flags = True,
                     client_data = None ):
     try:
       return self.flags_for_file[ filename ]
@@ -73,8 +88,8 @@ def FlagsForFile( self,
       if not flags:
         return None
 
-      if add_special_clang_flags:
-        flags += self.special_clang_flags
+      if add_extra_clang_flags:
+        flags += self.extra_clang_flags
       sanitized_flags = PrepareFlagsForClang( flags, filename )
 
       if results[ 'do_cache' ]:
@@ -207,6 +222,14 @@ def _RemoveUnusedFlags( flags, filename ):
   return new_flags
 
 
+def _ExtraClangFlags():
+  flags = _SpecialClangIncludes()
+  if OnMac():
+    for path in MAC_INCLUDE_PATHS:
+      flags.extend( [ '-isystem', path ] )
+  return flags
+
+
 def _SpecialClangIncludes():
   libclang_dir = os.path.dirname( ycm_core.__file__ )
   path_to_includes = os.path.join( libclang_dir, 'clang_includes' )

ycmd/utils.py

@@ -185,6 +185,10 @@ def OnCygwin():
   return sys.platform == 'cygwin'
 
 
+def OnMac():
+  return sys.platform == 'darwin'
+
+
 # From here: http://stackoverflow.com/a/8536476/1672783
 def TerminateProcess( pid ):
   if OnWindows():