Change clang-format's Chromium JavaScript defaults

[danbeam]

Summary

Chromium is starting to use clang-format on more JavaScript.

In doing this, we discovered that our defaults were not doing a good job differentiating between JS and C++.

This change moves some defaults to only apply to C++.

[thakis]

lib/Format/Format.cpp

643

Thanks for the patch! Do we want these as false in Chromium's JS? I would've thought the diff would just be

- } else {
+ } else if (Language != FormatStyle::LK_JavaScript)

so that we just use google style for JS.

If we do want to deviate from google style here for some reason then
a) say why somewhere
b) change the check for cpp to also include || Language == FormatStyle::LK_ObjC

(If you include more diff context as described on http://llvm.org/docs/Phabricator.html, reviewing on phab is a bit easier.)

[danbeam]

make a branch specific to JS and duplicate some format options for explicitness

[danbeam]

lib/Format/Format.cpp

643

so that we just use google style for JS

we want to tweak Google style a little bit. I mentioned this on the chromium-dev@ thread.

I added a specific branch for JS with explicit specializations so it's clearer to the reader how Google and Chromium differ.

(If you include more diff context as described on http://llvm.org/docs/Phabricator.html, reviewing on phab is a bit easier.)

Done.

[thakis]

I'd rather we don't deviate from google style at all, but this brings us closer from where we are to that, so lgtm :-)

[danbeam]

setting up arc

[thakis]

http://llvm.org/viewvc/llvm-project?view=revision&revision=290930

lib/Format/Format.cpp

 
 FormatStyle getChromiumStyle(FormatStyle::LanguageKind Language) {
   FormatStyle ChromiumStyle = getGoogleStyle(Language);
   if (Language == FormatStyle::LK_Java) {
     ChromiumStyle.AllowShortIfStatementsOnASingleLine = true;
     ChromiumStyle.BreakAfterJavaFieldAnnotations = true;
     ChromiumStyle.ContinuationIndentWidth = 8;
     ChromiumStyle.IndentWidth = 4;
+  } else if (Language == FormatStyle::LK_JavaScript) {
+    ChromiumStyle.AllowShortIfStatementsOnASingleLine = false;
+    ChromiumStyle.AllowShortLoopsOnASingleLine = false;
   } else {
     ChromiumStyle.AllowAllParametersOfDeclarationOnNextLine = false;
     ChromiumStyle.AllowShortFunctionsOnASingleLine = FormatStyle::SFS_Inline;
     ChromiumStyle.AllowShortIfStatementsOnASingleLine = false;
     ChromiumStyle.AllowShortLoopsOnASingleLine = false;
     ChromiumStyle.BinPackParameters = false;
     ChromiumStyle.DerivePointerAlignment = false;
   }