clang-format: Introduce BreakInheritanceList option

Summary:
This option replaces the BreakBeforeInheritanceComma option with an
enum, thus introducing a mode where the colon stays on the same line as
constructor declaration:

  // When it fits on line:
  class A : public B, public C {
    ...
  };

  // When it does not fit:
  class A :
      public B,
      public C {
    ...
  };

This matches the behavior of the `BreakConstructorInitializers` option,
introduced in https://reviews.llvm.org/D32479.

Reviewers: djasper, klimek

Reviewed By: djasper

Subscribers: mzeren-vmw, cfe-commits

Differential Revision: https://reviews.llvm.org/D43015

llvm-svn: 334408

1 files changed, 24 insertions, 3 deletions

diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index d1a5dc8e6c6..7e62d1596c8 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -149,6 +149,16 @@ struct ScalarEnumerationTraits<FormatStyle::BreakConstructorInitializersStyle> {
 };
 
 template <>
+struct ScalarEnumerationTraits<FormatStyle::BreakInheritanceListStyle> {
+  static void
+  enumeration(IO &IO, FormatStyle::BreakInheritanceListStyle &Value) {
+    IO.enumCase(Value, "BeforeColon", FormatStyle::BILS_BeforeColon);
+    IO.enumCase(Value, "BeforeComma", FormatStyle::BILS_BeforeComma);
+    IO.enumCase(Value, "AfterColon", FormatStyle::BILS_AfterColon);
+  }
+};
+
+template <>
 struct ScalarEnumerationTraits<FormatStyle::PPDirectiveIndentStyle> {
   static void enumeration(IO &IO, FormatStyle::PPDirectiveIndentStyle &Value) {
     IO.enumCase(Value, "None", FormatStyle::PPDIS_None);
@@ -350,8 +360,19 @@ template <> struct MappingTraits<FormatStyle> {
     IO.mapOptional("BreakBeforeBinaryOperators",
                    Style.BreakBeforeBinaryOperators);
     IO.mapOptional("BreakBeforeBraces", Style.BreakBeforeBraces);
+
+    bool BreakBeforeInheritanceComma = false;
     IO.mapOptional("BreakBeforeInheritanceComma",
-                   Style.BreakBeforeInheritanceComma);
+                   BreakBeforeInheritanceComma);
+    IO.mapOptional("BreakInheritanceList",
+                   Style.BreakInheritanceList);
+    // If BreakBeforeInheritanceComma was specified but
+    // BreakInheritance was not, initialize the latter from the
+    // former for backwards compatibility.
+    if (BreakBeforeInheritanceComma &&
+        Style.BreakInheritanceList == FormatStyle::BILS_BeforeColon)
+      Style.BreakInheritanceList = FormatStyle::BILS_BeforeComma;
+
     IO.mapOptional("BreakBeforeTernaryOperators",
                    Style.BreakBeforeTernaryOperators);
 
@@ -624,7 +645,7 @@ FormatStyle getLLVMStyle() {
                              false, false, true,  true,  true};
   LLVMStyle.BreakAfterJavaFieldAnnotations = false;
   LLVMStyle.BreakConstructorInitializers = FormatStyle::BCIS_BeforeColon;
-  LLVMStyle.BreakBeforeInheritanceComma = false;
+  LLVMStyle.BreakInheritanceList = FormatStyle::BILS_BeforeColon;
   LLVMStyle.BreakStringLiterals = true;
   LLVMStyle.ColumnLimit = 80;
   LLVMStyle.CommentPragmas = "^ IWYU pragma:";
@@ -840,7 +861,7 @@ FormatStyle getMozillaStyle() {
   MozillaStyle.BinPackArguments = false;
   MozillaStyle.BreakBeforeBraces = FormatStyle::BS_Mozilla;
   MozillaStyle.BreakConstructorInitializers = FormatStyle::BCIS_BeforeComma;
-  MozillaStyle.BreakBeforeInheritanceComma = true;
+  MozillaStyle.BreakInheritanceList = FormatStyle::BILS_BeforeComma;
   MozillaStyle.ConstructorInitializerIndentWidth = 2;
   MozillaStyle.ContinuationIndentWidth = 2;
   MozillaStyle.Cpp11BracedListStyle = false;