[clang-format] Add new style option IndentGotoLabels

Summary:
This option determines whether goto labels are indented according to scope. Setting this option to false causes goto labels to be flushed to the left.
This is mostly copied from [[ http://lists.llvm.org/pipermail/cfe-dev/2015-September/045014.html | this patch ]] submitted by Christian Neukirchen that didn't make its way into trunk.

```
     true:                                  false:
     int f() {                      vs.     int f() {
       if (foo()) {                           if (foo()) {
       label1:                              label1:
         bar();                                 bar();
       }                                      }
     label2:                                label2:
       return 1;                              return 1;
     }                                      }
```

Reviewers: klimek, MyDeveloperDay

Reviewed By: MyDeveloperDay

Subscribers: cfe-commits

Tags: #clang, #clang-tools-extra

Patch by: tetsuo-cpp

Differential Revision: https://reviews.llvm.org/D67037

llvm-svn: 371719

1 files changed, 17 insertions, 0 deletions

diff --git a/clang/docs/ClangFormatStyleOptions.rst b/clang/docs/ClangFormatStyleOptions.rst
index 5662ad4a44f..7193e3ede29 100644
--- a/clang/docs/ClangFormatStyleOptions.rst
+++ b/clang/docs/ClangFormatStyleOptions.rst
@@ -1527,6 +1527,23 @@ the configuration (without a prefix: ``Auto``).
        plop();                                  plop();
      }                                      }
 
+**IndentGotoLabels** (``bool``)
+  Indent goto labels.
+
+  When ``false``, goto labels are flushed left.
+
+  .. code-block:: c++
+
+     true:                                  false:
+     int f() {                      vs.     int f() {
+       if (foo()) {                           if (foo()) {
+       label1:                              label1:
+         bar();                                 bar();
+       }                                      }
+     label2:                                label2:
+       return 1;                              return 1;
+     }                                      }
+
 **IndentPPDirectives** (``PPDirectiveIndentStyle``)
   The preprocessor directive indenting style to use.