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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@306874 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 177 insertions, 3 deletions

diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index e070396ac0..b5f959f9c1 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -6571,12 +6571,12 @@ TEST_F(FormatTest, PullInlineOnlyFunctionDefinitionsIntoSingleLine) {
                MergeInlineOnly);
 }
 
-TEST_F(FormatTest, SplitEmptyFunctionBody) {
+TEST_F(FormatTest, SplitEmptyFunction) {
   FormatStyle Style = getLLVMStyle();
   Style.AllowShortFunctionsOnASingleLine = FormatStyle::SFS_None;
   Style.BreakBeforeBraces = FormatStyle::BS_Custom;
   Style.BraceWrapping.AfterFunction = true;
-  Style.BraceWrapping.SplitEmptyFunctionBody = false;
+  Style.BraceWrapping.SplitEmptyFunction = false;
   Style.ColumnLimit = 40;
 
   verifyFormat("int f()\n"
@@ -6639,6 +6639,178 @@ TEST_F(FormatTest, SplitEmptyFunctionBody) {
                Style);
 }
 
+TEST_F(FormatTest, SplitEmptyClass) {
+  FormatStyle Style = getLLVMStyle();
+  Style.BreakBeforeBraces = FormatStyle::BS_Custom;
+  Style.BraceWrapping.AfterClass = true;
+  Style.BraceWrapping.SplitEmptyRecord = false;
+
+  verifyFormat("class Foo\n"
+               "{};",
+               Style);
+  verifyFormat("/* something */ class Foo\n"
+               "{};",
+               Style);
+  verifyFormat("template <typename X> class Foo\n"
+               "{};",
+               Style);
+  verifyFormat("class Foo\n"
+               "{\n"
+               "  Foo();\n"
+               "};",
+               Style);
+  verifyFormat("typedef class Foo\n"
+               "{\n"
+               "} Foo_t;",
+               Style);
+}
+
+TEST_F(FormatTest, SplitEmptyStruct) {
+  FormatStyle Style = getLLVMStyle();
+  Style.BreakBeforeBraces = FormatStyle::BS_Custom;
+  Style.BraceWrapping.AfterStruct = true;
+  Style.BraceWrapping.SplitEmptyRecord = false;
+
+  verifyFormat("struct Foo\n"
+               "{};",
+               Style);
+  verifyFormat("/* something */ struct Foo\n"
+               "{};",
+               Style);
+  verifyFormat("template <typename X> struct Foo\n"
+               "{};",
+               Style);
+  verifyFormat("struct Foo\n"
+               "{\n"
+               "  Foo();\n"
+               "};",
+               Style);
+  verifyFormat("typedef struct Foo\n"
+               "{\n"
+               "} Foo_t;",
+               Style);
+  //typedef struct Bar {} Bar_t;
+}
+
+TEST_F(FormatTest, SplitEmptyUnion) {
+  FormatStyle Style = getLLVMStyle();
+  Style.BreakBeforeBraces = FormatStyle::BS_Custom;
+  Style.BraceWrapping.AfterUnion = true;
+  Style.BraceWrapping.SplitEmptyRecord = false;
+
+  verifyFormat("union Foo\n"
+               "{};",
+               Style);
+  verifyFormat("/* something */ union Foo\n"
+               "{};",
+               Style);
+  verifyFormat("union Foo\n"
+               "{\n"
+               "  A,\n"
+               "};",
+               Style);
+  verifyFormat("typedef union Foo\n"
+               "{\n"
+               "} Foo_t;",
+               Style);
+}
+
+TEST_F(FormatTest, SplitEmptyNamespace) {
+  FormatStyle Style = getLLVMStyle();
+  Style.BreakBeforeBraces = FormatStyle::BS_Custom;
+  Style.BraceWrapping.AfterNamespace = true;
+  Style.BraceWrapping.SplitEmptyNamespace = false;
+
+  verifyFormat("namespace Foo\n"
+               "{};",
+               Style);
+  verifyFormat("/* something */ namespace Foo\n"
+               "{};",
+               Style);
+  verifyFormat("inline namespace Foo\n"
+               "{};",
+               Style);
+  verifyFormat("namespace Foo\n"
+               "{\n"
+               "void Bar();\n"
+               "};",
+               Style);
+}
+
+TEST_F(FormatTest, NeverMergeShortRecords) {
+  FormatStyle Style = getLLVMStyle();
+
+  verifyFormat("class Foo {\n"
+               "  Foo();\n"
+               "};",
+               Style);
+  verifyFormat("typedef class Foo {\n"
+               "  Foo();\n"
+               "} Foo_t;",
+               Style);
+  verifyFormat("struct Foo {\n"
+               "  Foo();\n"
+               "};",
+               Style);
+  verifyFormat("typedef struct Foo {\n"
+               "  Foo();\n"
+               "} Foo_t;",
+               Style);
+  verifyFormat("union Foo {\n"
+               "  A,\n"
+               "};",
+               Style);
+  verifyFormat("typedef union Foo {\n"
+               "  A,\n"
+               "} Foo_t;",
+               Style);
+  verifyFormat("namespace Foo {\n"
+               "void Bar();\n"
+               "};",
+               Style);
+
+  Style.BreakBeforeBraces = FormatStyle::BS_Custom;
+  Style.BraceWrapping.AfterClass = true;
+  Style.BraceWrapping.AfterStruct = true;
+  Style.BraceWrapping.AfterUnion = true;
+  Style.BraceWrapping.AfterNamespace = true;
+  verifyFormat("class Foo\n"
+               "{\n"
+               "  Foo();\n"
+               "};",
+               Style);
+  verifyFormat("typedef class Foo\n"
+               "{\n"
+               "  Foo();\n"
+               "} Foo_t;",
+               Style);
+  verifyFormat("struct Foo\n"
+               "{\n"
+               "  Foo();\n"
+               "};",
+               Style);
+  verifyFormat("typedef struct Foo\n"
+               "{\n"
+               "  Foo();\n"
+               "} Foo_t;",
+               Style);
+  verifyFormat("union Foo\n"
+               "{\n"
+               "  A,\n"
+               "};",
+               Style);
+  verifyFormat("typedef union Foo\n"
+               "{\n"
+               "  A,\n"
+               "} Foo_t;",
+               Style);
+  verifyFormat("namespace Foo\n"
+               "{\n"
+               "void Bar();\n"
+               "};",
+               Style);
+}
+
 TEST_F(FormatTest, UnderstandContextOfRecordTypeKeywords) {
   // Elaborate type variable declarations.
   verifyFormat("struct foo a = {bar};\nint n;");
@@ -9371,7 +9543,9 @@ TEST_F(FormatTest, ParsesConfigurationBools) {
   CHECK_PARSE_NESTED_BOOL(BraceWrapping, BeforeCatch);
   CHECK_PARSE_NESTED_BOOL(BraceWrapping, BeforeElse);
   CHECK_PARSE_NESTED_BOOL(BraceWrapping, IndentBraces);
-  CHECK_PARSE_NESTED_BOOL(BraceWrapping, SplitEmptyFunctionBody);
+  CHECK_PARSE_NESTED_BOOL(BraceWrapping, SplitEmptyFunction);
+  CHECK_PARSE_NESTED_BOOL(BraceWrapping, SplitEmptyRecord);
+  CHECK_PARSE_NESTED_BOOL(BraceWrapping, SplitEmptyNamespace);
 }
 
 #undef CHECK_PARSE_BOOL