[clang-format] Convert AlignEscapedNewlinesLeft to an enum, adding

DontAlign

This converts the clang-format option AlignEscapedNewlinesLeft from a
boolean to an enum, named AlignEscapedNewlines, with options Left (prev.
true), Right (prev. false), and a new option DontAlign.

When set to DontAlign, the backslashes are placed just after the last token in each line:
  #define EXAMPLE \
    do { \
        int x = aaaaa; \
        int b; \
        int dddddddddd; \
    } while (0)

Patch by jtbandes. Thank you!

llvm-svn: 302428

6 files changed, 130 insertions, 49 deletions

diff --git a/clang/docs/ClangFormatStyleOptions.rst b/clang/docs/ClangFormatStyleOptions.rst
index ed628e37008..f54acd9b81d 100644
--- a/clang/docs/ClangFormatStyleOptions.rst
+++ b/clang/docs/ClangFormatStyleOptions.rst
@@ -209,23 +209,45 @@ the configuration (without a prefix: ``Auto``).
     float       b = 23;
     std::string ccc = 23;
 
-**AlignEscapedNewlinesLeft** (``bool``)
-  If ``true``, aligns escaped newlines as far left as possible.
-  Otherwise puts them into the right-most column.
+**AlignEscapedNewlines** (``EscapedNewlineAlignmentStyle``)
+  Options for aligning backslashes in escaped newlines.
 
-  .. code-block:: c++
+  Possible values:
+
+  * ``ENAS_DontAlign`` (in configuration: ``DontAlign``)
+    Don't align escaped newlines.
+
+    .. code-block:: c++
+
+      #define A \
+        int aaaa; \
+        int b; \
+        int dddddddddd;
+
+  * ``ENAS_Left`` (in configuration: ``Left``)
+    Align escaped newlines as far left as possible.
+
+    .. code-block:: c++
+
+      true:
+      #define A   \
+        int aaaa; \
+        int b;    \
+        int dddddddddd;
+
+      false:
+
+  * ``ENAS_Right`` (in configuration: ``Right``)
+    Align escaped newlines in the right-most column.
+
+    .. code-block:: c++
+
+      #define A                                                                      \
+        int aaaa;                                                                    \
+        int b;                                                                       \
+        int dddddddddd;
 
-    true:
-    #define A   \
-      int aaaa; \
-      int b;    \
-      int dddddddddd;
 
-    false:
-    #define A                                                                      \
-      int aaaa;                                                                    \
-      int b;                                                                       \
-      int dddddddddd;
 
 **AlignOperands** (``bool``)
   If ``true``, horizontally align operands of binary and ternary
@@ -1525,7 +1547,7 @@ the configuration (without a prefix: ``Auto``).
     Use C++03-compatible syntax.
 
   * ``LS_Cpp11`` (in configuration: ``Cpp11``)
-    Use features of C++11, C++14 and C++1z (e.g. ``A<A<int>>`` instead of 
+    Use features of C++11, C++14 and C++1z (e.g. ``A<A<int>>`` instead of
     ``A<A<int> >``).
 
   * ``LS_Auto`` (in configuration: ``Auto``)
diff --git a/clang/include/clang/Format/Format.h b/clang/include/clang/Format/Format.h
index 9bed253baca..a963c6369aa 100644
--- a/clang/include/clang/Format/Format.h
+++ b/clang/include/clang/Format/Format.h
@@ -98,22 +98,39 @@ struct FormatStyle {
   /// \endcode
   bool AlignConsecutiveDeclarations;
 
-  /// \brief If ``true``, aligns escaped newlines as far left as possible.
-  /// Otherwise puts them into the right-most column.
-  /// \code
-  ///   true:
-  ///   #define A   \
-  ///     int aaaa; \
-  ///     int b;    \
-  ///     int dddddddddd;
-  ///
-  ///   false:
-  ///   #define A                                                                      \
-  ///     int aaaa;                                                                    \
-  ///     int b;                                                                       \
-  ///     int dddddddddd;
-  /// \endcode
-  bool AlignEscapedNewlinesLeft;
+  /// \brief Different styles for aligning escaped newlines.
+  enum EscapedNewlineAlignmentStyle {
+    /// \brief Don't align escaped newlines.
+    /// \code
+    ///   #define A \
+    ///     int aaaa; \
+    ///     int b; \
+    ///     int dddddddddd;
+    /// \endcode
+    ENAS_DontAlign,
+    /// \brief Align escaped newlines as far left as possible.
+    /// \code
+    ///   true:
+    ///   #define A   \
+    ///     int aaaa; \
+    ///     int b;    \
+    ///     int dddddddddd;
+    ///
+    ///   false:
+    /// \endcode
+    ENAS_Left,
+    /// \brief Align escaped newlines in the right-most column.
+    /// \code
+    ///   #define A                                                                      \
+    ///     int aaaa;                                                                    \
+    ///     int b;                                                                       \
+    ///     int dddddddddd;
+    /// \endcode
+    ENAS_Right,
+  };
+
+  /// \brief Options for aligning backslashes in escaped newlines.
+  EscapedNewlineAlignmentStyle AlignEscapedNewlines;
 
   /// \brief If ``true``, horizontally align operands of binary and ternary
   /// expressions.
@@ -1347,7 +1364,7 @@ struct FormatStyle {
            AlignAfterOpenBracket == R.AlignAfterOpenBracket &&
            AlignConsecutiveAssignments == R.AlignConsecutiveAssignments &&
            AlignConsecutiveDeclarations == R.AlignConsecutiveDeclarations &&
-           AlignEscapedNewlinesLeft == R.AlignEscapedNewlinesLeft &&
+           AlignEscapedNewlines == R.AlignEscapedNewlines &&
            AlignOperands == R.AlignOperands &&
            AlignTrailingComments == R.AlignTrailingComments &&
            AllowAllParametersOfDeclarationOnNextLine ==
diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index f55a623a8d1..e961e5536ef 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -171,6 +171,18 @@ template <> struct ScalarEnumerationTraits<FormatStyle::BracketAlignmentStyle> {
   }
 };
 
+template <> struct ScalarEnumerationTraits<FormatStyle::EscapedNewlineAlignmentStyle> {
+  static void enumeration(IO &IO, FormatStyle::EscapedNewlineAlignmentStyle &Value) {
+    IO.enumCase(Value, "DontAlign", FormatStyle::ENAS_DontAlign);
+    IO.enumCase(Value, "Left", FormatStyle::ENAS_Left);
+    IO.enumCase(Value, "Right", FormatStyle::ENAS_Right);
+
+    // For backward compatibility.
+    IO.enumCase(Value, "true", FormatStyle::ENAS_Left);
+    IO.enumCase(Value, "false", FormatStyle::ENAS_Right);
+  }
+};
+
 template <> struct ScalarEnumerationTraits<FormatStyle::PointerAlignmentStyle> {
   static void enumeration(IO &IO, FormatStyle::PointerAlignmentStyle &Value) {
     IO.enumCase(Value, "Middle", FormatStyle::PAS_Middle);
@@ -233,6 +245,7 @@ template <> struct MappingTraits<FormatStyle> {
 
     // For backward compatibility.
     if (!IO.outputting()) {
+      IO.mapOptional("AlignEscapedNewlinesLeft", Style.AlignEscapedNewlines);
       IO.mapOptional("DerivePointerBinding", Style.DerivePointerAlignment);
       IO.mapOptional("IndentFunctionDeclarationAfterType",
                      Style.IndentWrappedFunctionNames);
@@ -247,7 +260,7 @@ template <> struct MappingTraits<FormatStyle> {
                    Style.AlignConsecutiveAssignments);
     IO.mapOptional("AlignConsecutiveDeclarations",
                    Style.AlignConsecutiveDeclarations);
-    IO.mapOptional("AlignEscapedNewlinesLeft", Style.AlignEscapedNewlinesLeft);
+    IO.mapOptional("AlignEscapedNewlines", Style.AlignEscapedNewlines);
     IO.mapOptional("AlignOperands", Style.AlignOperands);
     IO.mapOptional("AlignTrailingComments", Style.AlignTrailingComments);
     IO.mapOptional("AllowAllParametersOfDeclarationOnNextLine",
@@ -498,7 +511,7 @@ FormatStyle getLLVMStyle() {
   FormatStyle LLVMStyle;
   LLVMStyle.Language = FormatStyle::LK_Cpp;
   LLVMStyle.AccessModifierOffset = -2;
-  LLVMStyle.AlignEscapedNewlinesLeft = false;
+  LLVMStyle.AlignEscapedNewlines = FormatStyle::ENAS_Right;
   LLVMStyle.AlignAfterOpenBracket = FormatStyle::BAS_Align;
   LLVMStyle.AlignOperands = true;
   LLVMStyle.AlignTrailingComments = true;
@@ -587,7 +600,7 @@ FormatStyle getGoogleStyle(FormatStyle::LanguageKind Language) {
   GoogleStyle.Language = Language;
 
   GoogleStyle.AccessModifierOffset = -1;
-  GoogleStyle.AlignEscapedNewlinesLeft = true;
+  GoogleStyle.AlignEscapedNewlines = FormatStyle::ENAS_Left;
   GoogleStyle.AllowShortIfStatementsOnASingleLine = true;
   GoogleStyle.AllowShortLoopsOnASingleLine = true;
   GoogleStyle.AlwaysBreakBeforeMultilineStrings = true;
diff --git a/clang/lib/Format/WhitespaceManager.cpp b/clang/lib/Format/WhitespaceManager.cpp
index 2c1f5932497..3b6311d1548 100644
--- a/clang/lib/Format/WhitespaceManager.cpp
+++ b/clang/lib/Format/WhitespaceManager.cpp
@@ -517,8 +517,11 @@ void WhitespaceManager::alignTrailingComments(unsigned Start, unsigned End,
 }
 
 void WhitespaceManager::alignEscapedNewlines() {
-  unsigned MaxEndOfLine =
-      Style.AlignEscapedNewlinesLeft ? 0 : Style.ColumnLimit;
+  if (Style.AlignEscapedNewlines == FormatStyle::ENAS_DontAlign)
+    return;
+
+  bool AlignLeft = Style.AlignEscapedNewlines == FormatStyle::ENAS_Left;
+  unsigned MaxEndOfLine = AlignLeft ? 0 : Style.ColumnLimit;
   unsigned StartOfMacro = 0;
   for (unsigned i = 1, e = Changes.size(); i < e; ++i) {
     Change &C = Changes[i];
@@ -527,7 +530,7 @@ void WhitespaceManager::alignEscapedNewlines() {
         MaxEndOfLine = std::max(C.PreviousEndOfTokenColumn + 2, MaxEndOfLine);
       } else {
         alignEscapedNewlines(StartOfMacro + 1, i, MaxEndOfLine);
-        MaxEndOfLine = Style.AlignEscapedNewlinesLeft ? 0 : Style.ColumnLimit;
+        MaxEndOfLine = AlignLeft ? 0 : Style.ColumnLimit;
         StartOfMacro = i;
       }
     }
@@ -602,7 +605,7 @@ void WhitespaceManager::appendNewlineText(std::string &Text, unsigned Newlines,
                                           unsigned EscapedNewlineColumn) {
   if (Newlines > 0) {
     unsigned Offset =
-        std::min<int>(EscapedNewlineColumn - 1, PreviousEndOfTokenColumn);
+        std::min<int>(EscapedNewlineColumn - 2, PreviousEndOfTokenColumn);
     for (unsigned i = 0; i < Newlines; ++i) {
       Text.append(EscapedNewlineColumn - Offset - 1, ' ');
       Text.append(UseCRLF ? "\\\r\n" : "\\\n");
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 34faa17b1cb..cec25440a55 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -342,7 +342,7 @@ TEST_F(FormatTest, FormatIfWithoutCompoundStatement) {
   verifyFormat("if (a)\n  if (b) {\n    f();\n  }\ng();");
 
   FormatStyle AllowsMergedIf = getLLVMStyle();
-  AllowsMergedIf.AlignEscapedNewlinesLeft = true;
+  AllowsMergedIf.AlignEscapedNewlines = FormatStyle::ENAS_Left;
   AllowsMergedIf.AllowShortIfStatementsOnASingleLine = true;
   verifyFormat("if (a)\n"
                "  // comment\n"
@@ -6477,7 +6477,7 @@ TEST_F(FormatTest, BreaksStringLiterals) {
   EXPECT_EQ("\"some text other\";", format("\"some text other\";", Style));
 
   FormatStyle AlignLeft = getLLVMStyleWithColumns(12);
-  AlignLeft.AlignEscapedNewlinesLeft = true;
+  AlignLeft.AlignEscapedNewlines = FormatStyle::ENAS_Left;
   EXPECT_EQ("#define A \\\n"
             "  \"some \" \\\n"
             "  \"text \" \\\n"
@@ -6878,7 +6878,7 @@ TEST_F(FormatTest, ConfigurableUseOfTab) {
   FormatStyle Tab = getLLVMStyleWithColumns(42);
   Tab.IndentWidth = 8;
   Tab.UseTab = FormatStyle::UT_Always;
-  Tab.AlignEscapedNewlinesLeft = true;
+  Tab.AlignEscapedNewlines = FormatStyle::ENAS_Left;
 
   EXPECT_EQ("if (aaaaaaaa && // q\n"
             "    bb)\t\t// w\n"
@@ -7659,14 +7659,21 @@ TEST_F(FormatTest, AlignConsecutiveAssignments) {
                    "int oneTwoThree = 123;\n"
                    "int oneTwo = 12;",
                    Alignment));
-  Alignment.AlignEscapedNewlinesLeft = true;
+  Alignment.AlignEscapedNewlines = FormatStyle::ENAS_DontAlign;
+  verifyFormat("#define A \\\n"
+               "  int aaaa       = 12; \\\n"
+               "  int b          = 23; \\\n"
+               "  int ccc        = 234; \\\n"
+               "  int dddddddddd = 2345;",
+               Alignment);
+  Alignment.AlignEscapedNewlines = FormatStyle::ENAS_Left;
   verifyFormat("#define A               \\\n"
                "  int aaaa       = 12;  \\\n"
                "  int b          = 23;  \\\n"
                "  int ccc        = 234; \\\n"
                "  int dddddddddd = 2345;",
                Alignment);
-  Alignment.AlignEscapedNewlinesLeft = false;
+  Alignment.AlignEscapedNewlines = FormatStyle::ENAS_Right;
   verifyFormat("#define A                                                      "
                "                \\\n"
                "  int aaaa       = 12;                                         "
@@ -7933,14 +7940,21 @@ TEST_F(FormatTest, AlignConsecutiveDeclarations) {
                    "}",
                    Alignment));
   Alignment.AlignConsecutiveAssignments = false;
-  Alignment.AlignEscapedNewlinesLeft = true;
+  Alignment.AlignEscapedNewlines = FormatStyle::ENAS_DontAlign;
+  verifyFormat("#define A \\\n"
+               "  int       aaaa = 12; \\\n"
+               "  float     b = 23; \\\n"
+               "  const int ccc = 234; \\\n"
+               "  unsigned  dddddddddd = 2345;",
+               Alignment);
+  Alignment.AlignEscapedNewlines = FormatStyle::ENAS_Left;
   verifyFormat("#define A              \\\n"
                "  int       aaaa = 12; \\\n"
                "  float     b = 23;    \\\n"
                "  const int ccc = 234; \\\n"
                "  unsigned  dddddddddd = 2345;",
                Alignment);
-  Alignment.AlignEscapedNewlinesLeft = false;
+  Alignment.AlignEscapedNewlines = FormatStyle::ENAS_Right;
   Alignment.ColumnLimit = 30;
   verifyFormat("#define A                    \\\n"
                "  int       aaaa = 12;       \\\n"
@@ -8725,7 +8739,6 @@ TEST_F(FormatTest, GetsCorrectBasedOnStyle) {
 TEST_F(FormatTest, ParsesConfigurationBools) {
   FormatStyle Style = {};
   Style.Language = FormatStyle::LK_Cpp;
-  CHECK_PARSE_BOOL(AlignEscapedNewlinesLeft);
   CHECK_PARSE_BOOL(AlignOperands);
   CHECK_PARSE_BOOL(AlignTrailingComments);
   CHECK_PARSE_BOOL(AlignConsecutiveAssignments);
@@ -8848,6 +8861,19 @@ TEST_F(FormatTest, ParsesConfiguration) {
   CHECK_PARSE("AlignAfterOpenBracket: true", AlignAfterOpenBracket,
               FormatStyle::BAS_Align);
 
+  Style.AlignEscapedNewlines = FormatStyle::ENAS_Left;
+  CHECK_PARSE("AlignEscapedNewlines: DontAlign", AlignEscapedNewlines,
+              FormatStyle::ENAS_DontAlign);
+  CHECK_PARSE("AlignEscapedNewlines: Left", AlignEscapedNewlines,
+              FormatStyle::ENAS_Left);
+  CHECK_PARSE("AlignEscapedNewlines: Right", AlignEscapedNewlines,
+              FormatStyle::ENAS_Right);
+  // For backward compatibility:
+  CHECK_PARSE("AlignEscapedNewlinesLeft: true", AlignEscapedNewlines,
+              FormatStyle::ENAS_Left);
+  CHECK_PARSE("AlignEscapedNewlinesLeft: false", AlignEscapedNewlines,
+              FormatStyle::ENAS_Right);
+
   Style.UseTab = FormatStyle::UT_ForIndentation;
   CHECK_PARSE("UseTab: Never", UseTab, FormatStyle::UT_Never);
   CHECK_PARSE("UseTab: ForIndentation", UseTab, FormatStyle::UT_ForIndentation);
diff --git a/clang/unittests/Format/FormatTestSelective.cpp b/clang/unittests/Format/FormatTestSelective.cpp
index 8046d7fab2d..9ee87b34c21 100644
--- a/clang/unittests/Format/FormatTestSelective.cpp
+++ b/clang/unittests/Format/FormatTestSelective.cpp
@@ -325,7 +325,7 @@ TEST_F(FormatTestSelective, WrongIndent) {
 }
 
 TEST_F(FormatTestSelective, AlwaysFormatsEntireMacroDefinitions) {
-  Style.AlignEscapedNewlinesLeft = true;
+  Style.AlignEscapedNewlines = FormatStyle::ENAS_Left;
   EXPECT_EQ("int  i;\n"
             "#define A \\\n"
             "  int i;  \\\n"
@@ -467,7 +467,7 @@ TEST_F(FormatTestSelective, ReformatRegionAdjustsIndent) {
 TEST_F(FormatTestSelective, UnderstandsTabs) {
   Style.IndentWidth = 8;
   Style.UseTab = FormatStyle::UT_Always;
-  Style.AlignEscapedNewlinesLeft = true;
+  Style.AlignEscapedNewlines = FormatStyle::ENAS_Left;
   EXPECT_EQ("void f() {\n"
             "\tf();\n"
             "\tg();\n"