Fixes bug 20587 - Add K&R break before braces style

Summary:
http://llvm.org/bugs/show_bug.cgi?id=20587

Added K&R style. It could be enabled by the following option:

```
BreakBeforeBraces: KernighanRitchie
```

This style is like `Attach`, but break *only* before function
declarations.

As I can see, no additional logic required to support this style, any
style different from other styles automagically satisfies K&R.

Reviewers: djasper

Reviewed By: djasper

Subscribers: cfe-commits, klimek

Differential Revision: http://reviews.llvm.org/D4837

llvm-svn: 215354

1 files changed, 18 insertions, 6 deletions

diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
index 9f355c930ea..7e55e04c7f7 100644
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -434,6 +434,19 @@ static bool IsGoogScope(const UnwrappedLine &Line) {
   return I->Tok->is(tok::l_paren);
 }
 
+static bool ShouldBreakBeforeBrace(const FormatStyle &Style,
+                                   const FormatToken &InitialToken) {
+  switch (Style.BreakBeforeBraces) {
+  case FormatStyle::BS_Linux:
+    return InitialToken.isOneOf(tok::kw_namespace, tok::kw_class);
+  case FormatStyle::BS_Allman:
+  case FormatStyle::BS_GNU:
+    return true;
+  default:
+    return false;
+  }
+}
+
 void UnwrappedLineParser::parseChildBlock() {
   FormatTok->BlockKind = BK_Block;
   nextToken();
@@ -1167,13 +1180,13 @@ void UnwrappedLineParser::parseTryCatch() {
 
 void UnwrappedLineParser::parseNamespace() {
   assert(FormatTok->Tok.is(tok::kw_namespace) && "'namespace' expected");
+
+  const FormatToken &InitialToken = *FormatTok;
   nextToken();
   if (FormatTok->Tok.is(tok::identifier))
     nextToken();
   if (FormatTok->Tok.is(tok::l_brace)) {
-    if (Style.BreakBeforeBraces == FormatStyle::BS_Linux ||
-        Style.BreakBeforeBraces == FormatStyle::BS_Allman ||
-        Style.BreakBeforeBraces == FormatStyle::BS_GNU)
+    if (ShouldBreakBeforeBrace(Style, InitialToken))
       addUnwrappedLine();
 
     bool AddLevel = Style.NamespaceIndentation == FormatStyle::NI_All ||
@@ -1327,6 +1340,7 @@ void UnwrappedLineParser::parseEnum() {
 }
 
 void UnwrappedLineParser::parseRecord() {
+  const FormatToken &InitialToken = *FormatTok;
   nextToken();
   if (FormatTok->isOneOf(tok::identifier, tok::coloncolon, tok::kw___attribute,
                          tok::kw___declspec, tok::kw_alignas)) {
@@ -1361,9 +1375,7 @@ void UnwrappedLineParser::parseRecord() {
     }
   }
   if (FormatTok->Tok.is(tok::l_brace)) {
-    if (Style.BreakBeforeBraces == FormatStyle::BS_Linux ||
-        Style.BreakBeforeBraces == FormatStyle::BS_Allman ||
-        Style.BreakBeforeBraces == FormatStyle::BS_GNU)
+    if (ShouldBreakBeforeBrace(Style, InitialToken))
       addUnwrappedLine();
 
     parseBlock(/*MustBeDeclaration=*/true, /*AddLevel=*/true,