Clang-format: add finer-grained options for putting all arguments on …

…one line

Summary:
Add two new options,
AllowAllArgumentsOnNextLine and
AllowAllConstructorInitializersOnNextLine.  These mirror the existing
AllowAllParametersOfDeclarationOnNextLine and allow me to support an
internal style guide where I work.  I think this would be generally
useful, some have asked for it on stackoverflow:

https://stackoverflow.com/questions/30057534/clang-format-binpackarguments-not-working-as-expected

https://stackoverflow.com/questions/38635106/clang-format-how-to-prevent-all-function-arguments-on-next-line

Reviewers: djasper, krasimir, MyDeveloperDay

Reviewed By: MyDeveloperDay

Subscribers: jkorous, MyDeveloperDay, aol-nnov, lebedev.ri, uohcsemaj, cfe-commits, klimek

Differential Revision: https://reviews.llvm.org/D40988

Patch By: russellmcc  (Russell McClellan)

llvm-svn: 356834

clang/docs/ClangFormatStyleOptions.rst

@@ -277,6 +277,41 @@ the configuration (without a prefix: ``Auto``).
     int a;     // My comment a      vs.     int a; // My comment a
     int b = 2; // comment  b                int b = 2; // comment about b
 
+**AllowAllArgumentsOnNextLine** (``bool``)
+  If a function call or braced initializer list doesn't fit on a
+  line, allow putting all arguments onto the next line, even if
+  ``BinPackArguments`` is ``false``.
+
+  .. code-block:: c++
+
+    true:
+    callFunction(
+        a, b, c, d);
+
+    false:
+    callFunction(a,
+                 b,
+                 c,
+                 d);
+
+**AllowAllConstructorInitializersOnNextLine** (``bool``)
+  If a constructor definition with a member initializer list doesn't
+  fit on a single line, allow putting all member initializers onto the next
+  line, if ```ConstructorInitializerAllOnOneLineOrOnePerLine``` is true.
+  Note that this parameter has no effect if
+  ```ConstructorInitializerAllOnOneLineOrOnePerLine``` is false.
+
+  .. code-block:: c++
+
+    true:
+    MyClass::MyClass() :
+        member0(0), member1(2) {}
+
+    false:
+    MyClass::MyClass() :
+        member0(0),
+        member1(2) {}
+
 **AllowAllParametersOfDeclarationOnNextLine** (``bool``)
   If the function declaration doesn't fit on a line,
   allow putting all parameters of a function declaration onto

clang/include/clang/Format/Format.h

@@ -154,6 +154,38 @@ struct FormatStyle {
   /// \endcode
   bool AlignTrailingComments;
 
+  /// \brief If a function call or braced initializer list doesn't fit on a
+  /// line, allow putting all arguments onto the next line, even if
+  /// ``BinPackArguments`` is ``false``.
+  /// \code
+  ///   true:
+  ///   callFunction(
+  ///       a, b, c, d);
+  ///
+  ///   false:
+  ///   callFunction(a,
+  ///                b,
+  ///                c,
+  ///                d);
+  /// \endcode
+  bool AllowAllArgumentsOnNextLine;
+
+  /// \brief If a constructor definition with a member initializer list doesn't
+  /// fit on a single line, allow putting all member initializers onto the next
+  /// line, if ```ConstructorInitializerAllOnOneLineOrOnePerLine``` is true.
+  /// Note that this parameter has no effect if
+  /// ```ConstructorInitializerAllOnOneLineOrOnePerLine``` is false.
+  /// \code
+  ///   true:
+  ///   MyClass::MyClass() :
+  ///       member0(0), member1(2) {}
+  ///
+  ///   false:
+  ///   MyClass::MyClass() :
+  ///       member0(0),
+  ///       member1(2) {}
+  bool AllowAllConstructorInitializersOnNextLine;
+
   /// If the function declaration doesn't fit on a line,
   /// allow putting all parameters of a function declaration onto
   /// the next line even if ``BinPackParameters`` is ``false``.
@@ -1761,6 +1793,9 @@ struct FormatStyle {
            AlignEscapedNewlines == R.AlignEscapedNewlines &&
            AlignOperands == R.AlignOperands &&
            AlignTrailingComments == R.AlignTrailingComments &&
+           AllowAllArgumentsOnNextLine == R.AllowAllArgumentsOnNextLine &&
+           AllowAllConstructorInitializersOnNextLine ==
+               R.AllowAllConstructorInitializersOnNextLine &&
            AllowAllParametersOfDeclarationOnNextLine ==
                R.AllowAllParametersOfDeclarationOnNextLine &&
            AllowShortBlocksOnASingleLine == R.AllowShortBlocksOnASingleLine &&

clang/lib/Format/ContinuationIndenter.cpp

@@ -881,14 +881,30 @@ unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
     State.Stack.back().BreakBeforeClosingBrace = true;
 
   if (State.Stack.back().AvoidBinPacking) {
-    // If we are breaking after '(', '{', '<', this is not bin packing
-    // unless AllowAllParametersOfDeclarationOnNextLine is false or this is a
-    // dict/object literal.
-    if (!Previous.isOneOf(tok::l_paren, tok::l_brace, TT_BinaryOperator) ||
+    // If we are breaking after '(', '{', '<', or this is the break after a ':'
+    // to start a member initializater list in a constructor, this should not
+    // be considered bin packing unless the relevant AllowAll option is false or
+    // this is a dict/object literal.
+    bool PreviousIsBreakingCtorInitializerColon =
+        Previous.is(TT_CtorInitializerColon) &&
+        Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon;
+    if (!(Previous.isOneOf(tok::l_paren, tok::l_brace, TT_BinaryOperator) ||
+          PreviousIsBreakingCtorInitializerColon) ||
         (!Style.AllowAllParametersOfDeclarationOnNextLine &&
          State.Line->MustBeDeclaration) ||
+        (!Style.AllowAllArgumentsOnNextLine &&
+         !State.Line->MustBeDeclaration) ||
+        (!Style.AllowAllConstructorInitializersOnNextLine &&
+         PreviousIsBreakingCtorInitializerColon) ||
         Previous.is(TT_DictLiteral))
       State.Stack.back().BreakBeforeParameter = true;
+
+    // If we are breaking after a ':' to start a member initializer list,
+    // and we allow all arguments on the next line, we should not break
+    // before the next parameter.
+    if (PreviousIsBreakingCtorInitializerColon &&
+        Style.AllowAllConstructorInitializersOnNextLine)
+      State.Stack.back().BreakBeforeParameter = false;
   }
 
   return Penalty;
@@ -1102,9 +1118,13 @@ unsigned ContinuationIndenter::moveStateToNextToken(LineState &State,
              ? 0
              : 2);
     State.Stack.back().NestedBlockIndent = State.Stack.back().Indent;
-    if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine)
+    if (Style.ConstructorInitializerAllOnOneLineOrOnePerLine) {
       State.Stack.back().AvoidBinPacking = true;
-    State.Stack.back().BreakBeforeParameter = false;
+      State.Stack.back().BreakBeforeParameter =
+          !Style.AllowAllConstructorInitializersOnNextLine;
+    } else {
+      State.Stack.back().BreakBeforeParameter = false;
+    }
   }
   if (Current.is(TT_CtorInitializerColon) &&
       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon) {

clang/lib/Format/Format.cpp

@@ -335,6 +335,10 @@ template <> struct MappingTraits<FormatStyle> {
     IO.mapOptional("AlignEscapedNewlines", Style.AlignEscapedNewlines);
     IO.mapOptional("AlignOperands", Style.AlignOperands);
     IO.mapOptional("AlignTrailingComments", Style.AlignTrailingComments);
+    IO.mapOptional("AllowAllArgumentsOnNextLine",
+                   Style.AllowAllArgumentsOnNextLine);
+    IO.mapOptional("AllowAllConstructorInitializersOnNextLine",
+                   Style.AllowAllConstructorInitializersOnNextLine);
     IO.mapOptional("AllowAllParametersOfDeclarationOnNextLine",
                    Style.AllowAllParametersOfDeclarationOnNextLine);
     IO.mapOptional("AllowShortBlocksOnASingleLine",
@@ -351,6 +355,7 @@ template <> struct MappingTraits<FormatStyle> {
                    Style.AlwaysBreakAfterDefinitionReturnType);
     IO.mapOptional("AlwaysBreakAfterReturnType",
                    Style.AlwaysBreakAfterReturnType);
+
     // If AlwaysBreakAfterDefinitionReturnType was specified but
     // AlwaysBreakAfterReturnType was not, initialize the latter from the
     // former for backwards compatibility.
@@ -641,6 +646,8 @@ FormatStyle getLLVMStyle(FormatStyle::LanguageKind Language) {
   LLVMStyle.AlignTrailingComments = true;
   LLVMStyle.AlignConsecutiveAssignments = false;
   LLVMStyle.AlignConsecutiveDeclarations = false;
+  LLVMStyle.AllowAllArgumentsOnNextLine = true;
+  LLVMStyle.AllowAllConstructorInitializersOnNextLine = true;
   LLVMStyle.AllowAllParametersOfDeclarationOnNextLine = true;
   LLVMStyle.AllowShortFunctionsOnASingleLine = FormatStyle::SFS_All;
   LLVMStyle.AllowShortBlocksOnASingleLine = false;