From 19ccb1227f5dc338d4b2d9dbbaeaa973c293f8d0 Mon Sep 17 00:00:00 2001
From: Daniel Jasper <djasper@google.com>
Date: Tue, 8 Oct 2013 05:11:18 +0000
Subject: [PATCH] clang-format: Improve constructor initializer linewrapping.

Specifically make ConstructorInitializerAllOnOneLineOrOnePerLine work
nicely with BreakConstructorInitializersBeforeComma.

This fixes llvm.org/PR17395.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192168 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Format/ContinuationIndenter.cpp | 27 ++++++++++++++++-----------
 lib/Format/TokenAnnotator.cpp       |  6 +++++-
 unittests/Format/FormatTest.cpp     | 14 ++++++++++++++
 3 files changed, 35 insertions(+), 12 deletions(-)

diff --git a/lib/Format/ContinuationIndenter.cpp b/lib/Format/ContinuationIndenter.cpp
index 6a5f8763d9..ff1f1aa853 100644
--- a/lib/Format/ContinuationIndenter.cpp
+++ b/lib/Format/ContinuationIndenter.cpp
@@ -44,6 +44,18 @@ static bool startsSegmentOfBuilderTypeCall(const FormatToken &Tok) {
   return Tok.isMemberAccess() && Tok.Previous && Tok.Previous->closesScope();
 }
 
+// Returns \c true if \c Current starts a new parameter.
+static bool startsNextParameter(const FormatToken &Current,
+                                const FormatStyle &Style) {
+  const FormatToken &Previous = *Current.Previous;
+  if (Current.Type == TT_CtorInitializerComma &&
+      Style.BreakConstructorInitializersBeforeComma)
+    return true;
+  return Previous.is(tok::comma) && !Current.isTrailingComment() &&
+         (Previous.Type != TT_CtorInitializerComma ||
+          !Style.BreakConstructorInitializersBeforeComma);
+}
+
 ContinuationIndenter::ContinuationIndenter(const FormatStyle &Style,
                                            SourceManager &SourceMgr,
                                            WhitespaceManager &Whitespaces,
@@ -113,15 +125,9 @@ bool ContinuationIndenter::mustBreak(const LineState &State) {
     return true;
   if (Previous.is(tok::semi) && State.LineContainsContinuedForLoopSection)
     return true;
-  if (Style.BreakConstructorInitializersBeforeComma) {
-    if (Previous.Type == TT_CtorInitializerComma)
-      return false;
-    if (Current.Type == TT_CtorInitializerComma)
-      return true;
-  }
-  if ((Previous.isOneOf(tok::comma, tok::semi) || Current.is(tok::question) ||
-       (Current.Type == TT_ConditionalExpr &&
-        !(Current.is(tok::colon) && Previous.is(tok::question)))) &&
+  if ((startsNextParameter(Current, Style) || Previous.is(tok::semi) ||
+       Current.is(tok::question) ||
+       (Current.Type == TT_ConditionalExpr && Previous.isNot(tok::question))) &&
       State.Stack.back().BreakBeforeParameter && !Current.isTrailingComment() &&
       !Current.isOneOf(tok::r_paren, tok::r_brace))
     return true;
@@ -250,8 +256,7 @@ void ContinuationIndenter::addTokenOnCurrentLine(LineState &State, bool DryRun,
   if (Previous.opensScope() && Previous.Type != TT_ObjCMethodExpr &&
       Current.Type != TT_LineComment)
     State.Stack.back().Indent = State.Column + Spaces;
-  if (Previous.is(tok::comma) && !Current.isTrailingComment() &&
-      State.Stack.back().AvoidBinPacking)
+  if (State.Stack.back().AvoidBinPacking && startsNextParameter(Current, Style))
     State.Stack.back().NoLineBreak = true;
   if (startsSegmentOfBuilderTypeCall(Current))
     State.Stack.back().ContainsUnwrappedBuilder = true;
diff --git a/lib/Format/TokenAnnotator.cpp b/lib/Format/TokenAnnotator.cpp
index 220da707b1..0e06d3b651 100644
--- a/lib/Format/TokenAnnotator.cpp
+++ b/lib/Format/TokenAnnotator.cpp
@@ -1366,7 +1366,8 @@ bool TokenAnnotator::mustBreakBefore(const AnnotatedLine &Line,
     // FIXME: Fix horrible hack of using BindingStrength to find top-level <>.
     return true;
   } else if (Right.Type == TT_CtorInitializerComma &&
-             Style.BreakConstructorInitializersBeforeComma) {
+             Style.BreakConstructorInitializersBeforeComma &&
+             !Style.ConstructorInitializerAllOnOneLineOrOnePerLine) {
     return true;
   } else if (Right.Previous->BlockKind == BK_Block &&
              Right.Previous->isNot(tok::r_brace) &&
@@ -1450,6 +1451,9 @@ bool TokenAnnotator::canBreakBefore(const AnnotatedLine &Line,
   if (Left.Type == TT_CtorInitializerComma &&
       Style.BreakConstructorInitializersBeforeComma)
     return false;
+  if (Right.Type == TT_CtorInitializerComma &&
+      Style.BreakConstructorInitializersBeforeComma)
+    return true;
   if (Right.isBinaryOperator() && Style.BreakBeforeBinaryOperators)
     return true;
   if (Left.is(tok::greater) && Right.is(tok::greater) &&
diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index 6bb38e92f8..1916076ca0 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -6587,6 +6587,20 @@ TEST_F(FormatTest, ConstructorInitializerIndentWidth) {
                ", b(b)\n"
                ", c(c) {}",
                Style);
+
+  Style.ConstructorInitializerAllOnOneLineOrOnePerLine = true;
+  Style.ConstructorInitializerIndentWidth = 4;
+  verifyFormat(
+      "SomeClass::Constructor()\n"
+      "    : aaaaaaaa(aaaaaaaa), aaaaaaaa(aaaaaaaa), aaaaaaaa(aaaaaaaa) {}",
+      Style);
+  Style.ConstructorInitializerIndentWidth = 4;
+  Style.ColumnLimit = 60;
+  verifyFormat("SomeClass::Constructor()\n"
+               "    : aaaaaaaa(aaaaaaaa)\n"
+               "    , aaaaaaaa(aaaaaaaa)\n"
+               "    , aaaaaaaa(aaaaaaaa) {}",
+               Style);
 }
 
 TEST_F(FormatTest, FormatsWithWebKitStyle) {
-- 
2.40.0