Allow breaking after the return type in function declarations.

This has so far been disabled for Google style, but should be done
before breaking at nested name specifiers or in template parameters.

Before (in Google style):
template <typename T>
aaaaaaaa::aaaaa::aaaaaa<T, aaaaaaaaaaaaaaaaaaaaaaaaa> aaaaaaaaaaaaaaaaaaaaaaaa<
    T>::aaaaaaa() {}

After:
template <typename T>
aaaaaaaa::aaaaa::aaaaaa<T, aaaaaaaaaaaaaaaaaaaaaaaaa>
aaaaaaaaaaaaaaaaaaaaaaaa<T>::aaaaaaa() {}

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175074 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 9 insertions, 6 deletions

diff --git a/lib/Format/Format.cpp b/lib/Format/Format.cpp
index d8c02e2e18..8c2128eb01 100644
--- a/lib/Format/Format.cpp
+++ b/lib/Format/Format.cpp
@@ -43,11 +43,11 @@ FormatStyle getLLVMStyle() {
   LLVMStyle.SpacesBeforeTrailingComments = 1;
   LLVMStyle.BinPackParameters = true;
   LLVMStyle.AllowAllParametersOfDeclarationOnNextLine = true;
-  LLVMStyle.AllowReturnTypeOnItsOwnLine = true;
   LLVMStyle.ConstructorInitializerAllOnOneLineOrOnePerLine = false;
   LLVMStyle.AllowShortIfStatementsOnASingleLine = false;
   LLVMStyle.ObjCSpaceBeforeProtocolList = true;
   LLVMStyle.PenaltyExcessCharacter = 1000000;
+  LLVMStyle.PenaltyReturnTypeOnItsOwnLine = 5;
   return LLVMStyle;
 }
 
@@ -63,11 +63,11 @@ FormatStyle getGoogleStyle() {
   GoogleStyle.SpacesBeforeTrailingComments = 2;
   GoogleStyle.BinPackParameters = false;
   GoogleStyle.AllowAllParametersOfDeclarationOnNextLine = true;
-  GoogleStyle.AllowReturnTypeOnItsOwnLine = false;
   GoogleStyle.ConstructorInitializerAllOnOneLineOrOnePerLine = true;
   GoogleStyle.AllowShortIfStatementsOnASingleLine = false;
   GoogleStyle.ObjCSpaceBeforeProtocolList = false;
   GoogleStyle.PenaltyExcessCharacter = 1000000;
+  GoogleStyle.PenaltyReturnTypeOnItsOwnLine = 100;
   return GoogleStyle;
 }
 
@@ -717,9 +717,10 @@ private:
     reconstructPath(State, Current->Previous);
     DEBUG({
       if (Current->NewLine) {
-        llvm::errs() << "Penalty for splitting before "
-                     << Current->State.NextToken->FormatTok.Tok.getName()
-                     << ": " << Current->State.NextToken->SplitPenalty << "\n";
+        llvm::errs()
+            << "Penalty for splitting before "
+            << Current->Previous->State.NextToken->FormatTok.Tok.getName()
+            << ": " << Current->Previous->State.NextToken->SplitPenalty << "\n";
       }
     });
     addTokenToState(Current->NewLine, false, State);
diff --git a/lib/Format/TokenAnnotator.cpp b/lib/Format/TokenAnnotator.cpp
index d2e19af56f..4c36536104 100644
--- a/lib/Format/TokenAnnotator.cpp
+++ b/lib/Format/TokenAnnotator.cpp
@@ -847,6 +847,8 @@ unsigned TokenAnnotator::splitPenalty(const AnnotatedLine &Line,
   const AnnotatedToken &Left = *Tok.Parent;
   const AnnotatedToken &Right = Tok;
 
+  if (Right.Type == TT_StartOfName)
+    return Style.PenaltyReturnTypeOnItsOwnLine;
   if (Left.is(tok::l_brace) && Right.isNot(tok::l_brace))
     return 50;
   if (Left.is(tok::equal) && Right.is(tok::l_brace))
@@ -1026,7 +1028,7 @@ bool TokenAnnotator::spaceRequiredBefore(const AnnotatedLine &Line,
 bool TokenAnnotator::canBreakBefore(const AnnotatedLine &Line,
                                     const AnnotatedToken &Right) {
   const AnnotatedToken &Left = *Right.Parent;
-  if (Right.Type == TT_StartOfName && Style.AllowReturnTypeOnItsOwnLine)
+  if (Right.Type == TT_StartOfName)
     return true;
   if (Right.is(tok::colon) && Right.Type == TT_ObjCMethodExpr)
     return false;