Merge PR #1310 'Improve YCM contrib.'

contrib/YouCompleteMe/README.md

@@ -1,4 +1,8 @@
-# YouCompleteMe
+# YouCompleteMe Integration
+
+## What is this?
+
+This provides the necessary to configure vim's YCM plugin to provide C semantic support (completion, go-to-definition, etc) for the neovim project.
 
 ## Installation
 
@@ -9,7 +13,10 @@ Install [YouCompleteMe](https://github.com/Valloric/YouCompleteMe).
 ### Step 2
 
 ```bash
-cp ycm_extra_conf.py ../../src/nvim/.ycm_extra_conf.py
-echo src/nvim/.ycm_extra_conf.py >> ../../.git/info/exclude
-make -C ../.. cmake
+cp contrib/YouCompleteMe/ycm_extra_conf.py src/.ycm_extra_conf.py
+echo .ycm_extra_conf.py >> .git/info/exclude
+make
+
+(somewhere in you .vimrc files)
+autocmd FileType c nnoremap <buffer> <silent> <C-]> :YcmCompleter GoTo<cr>
 ```

contrib/YouCompleteMe/ycm_extra_conf.py

@@ -8,7 +8,7 @@ def DirectoryOfThisScript():
 
 
 def GetDatabase():
-    compilation_database_folder = DirectoryOfThisScript() + '/../../build'
+    compilation_database_folder = DirectoryOfThisScript() + '/../build'
     if os.path.exists(compilation_database_folder):
         return ycm_core.CompilationDatabase(compilation_database_folder)
     return None
@@ -26,6 +26,9 @@ def GetCompilationInfoForFile(filename):
     if IsHeaderFile(filename):
         basename = os.path.splitext(filename)[0]
         c_file = basename + '.c'
+        # for pure headers (no c file), default to main.c
+        if not os.path.exists(c_file):
+            c_file = os.path.join(DirectoryOfThisScript(), 'main.c')
         if os.path.exists(c_file):
             compilation_info = database.GetCompilationInfoForFile(c_file)
             if compilation_info.compiler_flags_:
@@ -38,7 +41,14 @@ def FlagsForFile(filename):
     compilation_info = GetCompilationInfoForFile(filename)
     if not compilation_info:
         return None
+    # Add flags not needed for clang-the-binary,
+    # but needed for libclang-the-library (YCM uses this last one).
+    flags = (list(compilation_info.compiler_flags_)
+             if compilation_info.compiler_flags_
+             else [])
+    extra_flags = ['-Wno-newline-eof']
+    final_flags = flags + extra_flags
     return {
-        'flags': compilation_info.compiler_flags_,
+        'flags': final_flags,
         'do_cache': True
     }