[clang-format/ObjC] Put ObjC method arguments into one line when they fit

Reapply D47195:
Currently BreakBeforeParameter is set to true everytime message receiver spans multiple lines, e.g.:
```
[[object block:^{
  return 42;
}] aa:42 bb:42];
```
will be formatted:
```
[[object block:^{
  return 42;
}] aa:42
   bb:42];
```
even though arguments could fit into one line. This change fixes this behavior.

llvm-svn: 336521

1 files changed, 24 insertions, 0 deletions

diff --git a/clang/lib/Format/ContinuationIndenter.cpp b/clang/lib/Format/ContinuationIndenter.cpp
index 0862a4e0f95..90d2a999711 100644
--- a/clang/lib/Format/ContinuationIndenter.cpp
+++ b/clang/lib/Format/ContinuationIndenter.cpp
@@ -1398,6 +1398,30 @@ void ContinuationIndenter::moveStatePastScopeCloser(LineState &State) {
        (Current.is(tok::greater) && Current.is(TT_DictLiteral))))
     State.Stack.pop_back();
 
+  // Reevaluate whether ObjC message arguments fit into one line.
+  // If a receiver spans multiple lines, e.g.:
+  //   [[object block:^{
+  //     return 42;
+  //   }] a:42 b:42];
+  // BreakBeforeParameter is calculated based on an incorrect assumption
+  // (it is checked whether the whole expression fits into one line without
+  // considering a line break inside a message receiver).
+  // We check whether arguements fit after receiver scope closer (into the same
+  // line).
+  if (State.Stack.back().BreakBeforeParameter && Current.MatchingParen &&
+      Current.MatchingParen->Previous) {
+    const FormatToken &CurrentScopeOpener = *Current.MatchingParen->Previous;
+    if (CurrentScopeOpener.is(TT_ObjCMethodExpr) &&
+        CurrentScopeOpener.MatchingParen) {
+      int NecessarySpaceInLine =
+          getLengthToMatchingParen(CurrentScopeOpener, State.Stack) +
+          CurrentScopeOpener.TotalLength - Current.TotalLength - 1;
+      if (State.Column + Current.ColumnWidth + NecessarySpaceInLine <=
+          Style.ColumnLimit)
+        State.Stack.back().BreakBeforeParameter = false;
+    }
+  }
+
   if (Current.is(tok::r_square)) {
     // If this ends the array subscript expr, reset the corresponding value.
     const FormatToken *NextNonComment = Current.getNextNonComment();