clang-format: add options to merge empty record body

Summary:
This patch introduces a few extra BraceWrapping options, similar to
`SplitEmptyFunction`, to allow merging empty 'record' bodies (e.g.
class, struct, union and namespace):
* SplitEmptyClass
* SplitEmptyStruct
* SplitEmptyUnion
* SplitEmptyNamespace

The `SplitEmptyFunction` option name has also been simplified/
shortened (from `SplitEmptyFunctionBody`).

These options are helpful when the correspond AfterXXX option is
enabled, to allow merging the empty record:

  class Foo
  {};

In addition, this fixes an unexpected merging of short records, when
the AfterXXXX options are used, which caused to be formatted like
this:

  class Foo
  { void Foo(); };

This is now properly formatted as:

  class Foo
  {
     void Foo();
  };

Reviewers: djasper, krasimir

Reviewed By: djasper

Subscribers: cfe-commits, klimek

Differential Revision: https://reviews.llvm.org/D34395

llvm-svn: 306874

1 files changed, 11 insertions, 5 deletions

diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index 94147fcbd2a..e6657eb26a6 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -414,7 +414,9 @@ template <> struct MappingTraits<FormatStyle::BraceWrappingFlags> {
     IO.mapOptional("BeforeCatch", Wrapping.BeforeCatch);
     IO.mapOptional("BeforeElse", Wrapping.BeforeElse);
     IO.mapOptional("IndentBraces", Wrapping.IndentBraces);
-    IO.mapOptional("SplitEmptyFunctionBody", Wrapping.SplitEmptyFunctionBody);
+    IO.mapOptional("SplitEmptyFunction", Wrapping.SplitEmptyFunction);
+    IO.mapOptional("SplitEmptyRecord", Wrapping.SplitEmptyRecord);
+    IO.mapOptional("SplitEmptyNamespace", Wrapping.SplitEmptyNamespace);
   }
 };
 
@@ -490,7 +492,8 @@ static FormatStyle expandPresets(const FormatStyle &Style) {
     return Style;
   FormatStyle Expanded = Style;
   Expanded.BraceWrapping = {false, false, false, false, false, false,
-                            false, false, false, false, false, true};
+                            false, false, false, false, false, true,
+                            true,  true};
   switch (Style.BreakBeforeBraces) {
   case FormatStyle::BS_Linux:
     Expanded.BraceWrapping.AfterClass = true;
@@ -503,7 +506,8 @@ static FormatStyle expandPresets(const FormatStyle &Style) {
     Expanded.BraceWrapping.AfterFunction = true;
     Expanded.BraceWrapping.AfterStruct = true;
     Expanded.BraceWrapping.AfterUnion = true;
-    Expanded.BraceWrapping.SplitEmptyFunctionBody = false;
+    Expanded.BraceWrapping.SplitEmptyFunction = false;
+    Expanded.BraceWrapping.SplitEmptyRecord = false;
     break;
   case FormatStyle::BS_Stroustrup:
     Expanded.BraceWrapping.AfterFunction = true;
@@ -523,7 +527,8 @@ static FormatStyle expandPresets(const FormatStyle &Style) {
     break;
   case FormatStyle::BS_GNU:
     Expanded.BraceWrapping = {true, true, true, true, true, true,
-                              true, true, true, true, true, true};
+                              true, true, true, true, true, true,
+                              true, true};
     break;
   case FormatStyle::BS_WebKit:
     Expanded.BraceWrapping.AfterFunction = true;
@@ -560,7 +565,8 @@ FormatStyle getLLVMStyle() {
   LLVMStyle.BreakBeforeTernaryOperators = true;
   LLVMStyle.BreakBeforeBraces = FormatStyle::BS_Attach;
   LLVMStyle.BraceWrapping = {false, false, false, false, false, false,
-                             false, false, false, false, false, true};
+                             false, false, false, false, false, true,
+                             true,  true};
   LLVMStyle.BreakAfterJavaFieldAnnotations = false;
   LLVMStyle.BreakConstructorInitializers = FormatStyle::BCIS_BeforeColon;
   LLVMStyle.BreakBeforeInheritanceComma = false;