JavaScript allows parameter lists to include trailing commas:

    myFunction(param1, param2,);

For symmetry with other parenthesized lists ([...], {...}), clang-format should
wrap parenthesized lists one-per-line if they contain a trailing comma:

    myFunction(
        param1,
        param2,
    );

This is particularly useful in function declarations or calls with many
arguments, e.g. commonly in constructors.

Differential Revision: https://reviews.llvm.org/D33023

llvm-svn: 303049

1 files changed, 12 insertions, 0 deletions

diff --git a/clang/lib/Format/ContinuationIndenter.cpp b/clang/lib/Format/ContinuationIndenter.cpp
index 709eeb1539a..488f9dd582f 100644
--- a/clang/lib/Format/ContinuationIndenter.cpp
+++ b/clang/lib/Format/ContinuationIndenter.cpp
@@ -674,6 +674,8 @@ unsigned ContinuationIndenter::getNewLineColumn(const LineState &State) {
       return State.Stack[State.Stack.size() - 2].LastSpace;
     return State.FirstIndent;
   }
+  if (Current.is(tok::r_paren) && State.Stack.size() > 1)
+    return State.Stack[State.Stack.size() - 2].LastSpace;
   if (NextNonComment->is(TT_TemplateString) && NextNonComment->closesScope())
     return State.Stack[State.Stack.size() - 2].LastSpace;
   if (Current.is(tok::identifier) && Current.Next &&
@@ -1038,13 +1040,20 @@ void ContinuationIndenter::moveStatePastScopeOpener(LineState &State,
       NestedBlockIndent = Column;
     }
 
+    bool EndsInComma =
+        Current.MatchingParen &&
+        Current.MatchingParen->getPreviousNonComment() &&
+        Current.MatchingParen->getPreviousNonComment()->is(tok::comma);
+
     AvoidBinPacking =
+        (Style.Language == FormatStyle::LK_JavaScript && EndsInComma) ||
         (State.Line->MustBeDeclaration && !Style.BinPackParameters) ||
         (!State.Line->MustBeDeclaration && !Style.BinPackArguments) ||
         (Style.ExperimentalAutoDetectBinPacking &&
          (Current.PackingKind == PPK_OnePerLine ||
           (!BinPackInconclusiveFunctions &&
            Current.PackingKind == PPK_Inconclusive)));
+
     if (Current.is(TT_ObjCMethodExpr) && Current.MatchingParen) {
       if (Style.ColumnLimit) {
         // If this '[' opens an ObjC call, determine whether all parameters fit
@@ -1065,6 +1074,9 @@ void ContinuationIndenter::moveStatePastScopeOpener(LineState &State,
         }
       }
     }
+
+    if (Style.Language == FormatStyle::LK_JavaScript && EndsInComma)
+      BreakBeforeParameter = true;
   }
   // Generally inherit NoLineBreak from the current scope to nested scope.
   // However, don't do this for non-empty nested blocks, dict literals and