clang-format: Add SpaceAfterTemplate

[poiru]

Summary

This is required for compliance with the Mozilla style guide.

[djasper]

Where does it say that?

Specifically, this has been discussed for other coding styles as well as the C++ standard itself and the fundamental conclusion is that it is not worth thinking about or adding an option for.

[poiru]

In D10807#196361, @djasper wrote:

Where does it say that?

New Mozilla code generally uses the unspaced version. It is not in the actual style guide because both versions are used inconsistently at the moment.

Specifically, this has been discussed for other coding styles as well as the C++ standard itself and the fundamental conclusion is that it is not worth thinking about or adding an option for.

We want to start using Clang-Format on all Mozilla/Gecko code, but there are a few issues like this that prevent us from doing so. This issue in particular will probably not be a huge deal, so I'll abandon this based on the comment above.

[opilarium]

It's the huge deal for my company too. It would be nice if you reconsider.

[sylvestre.ledru]

To be clear, this is blocking Mozilla to use much more clang-format

[opilarium]

Can we just accept this merge request? It's backward compatible and helps Mozilla to adapt clang-format.

[djasper]

I still believe it's wrong to care about this in particular, but I also don't want to hold clang-format hostage for my own beliefs. Obviously, enough people care and the costs are limited.

include/clang/Format/Format.h

356

Call this SpaceAfterTemplateKeyword.

[sylvestre.ledru]

Thanks. I am rebasing and updating the patch.
I don't know if poiru is still around.

[opilarium]

Thanks. I am rebasing and updating the patch.

Waiting for you.

[sylvestre.ledru]

Done in https://reviews.llvm.org/D23317

docs/ClangFormatStyleOptions.rst

* ``PAS_Right`` (in configuration: ``Right``)
     Align pointer to the right.
   * ``PAS_Middle`` (in configuration: ``Middle``)
     Align pointer in the middle.
 
 
 **SpaceAfterCStyleCast** (``bool``)
   If ``true``, a space may be inserted after C style casts.
 
+**SpaceAfterTemplate** (``bool``)
+  If ``true``, a space will be inserted after the 'template' keyword.
+
 **SpaceBeforeAssignmentOperators** (``bool``)
   If ``false``, spaces will be removed before assignment operators.
 
 **SpaceBeforeParens** (``SpaceBeforeParensOptions``)
   Defines in which cases to put a space before opening parentheses.
 
   Possible values:
 

include/clang/Format/Format.h

struct FormatStyle {
   };
 
   /// Pointer and reference alignment style.
   PointerAlignmentStyle PointerAlignment;
 
   /// \brief If \c true, a space may be inserted after C style casts.
   bool SpaceAfterCStyleCast;
 
+  /// \brief If \c true, a space will be inserted after the 'template' keyword.
+  bool SpaceAfterTemplate;
+
   /// \brief If \c false, spaces will be removed before assignment operators.
   bool SpaceBeforeAssignmentOperators;
 
   /// \brief Different ways to put a space before opening parentheses.
   enum SpaceBeforeParensOptions {
     /// Never put a space before opening parentheses.
     SBPO_Never,
     /// Put a space before opening parentheses only after control statement
return AccessModifierOffset == R.AccessModifierOffset &&
                R.PenaltyBreakBeforeFirstCallParameter &&
            PenaltyBreakComment == R.PenaltyBreakComment &&
            PenaltyBreakFirstLessLess == R.PenaltyBreakFirstLessLess &&
            PenaltyBreakString == R.PenaltyBreakString &&
            PenaltyExcessCharacter == R.PenaltyExcessCharacter &&
            PenaltyReturnTypeOnItsOwnLine == R.PenaltyReturnTypeOnItsOwnLine &&
            PointerAlignment == R.PointerAlignment &&
            SpaceAfterCStyleCast == R.SpaceAfterCStyleCast &&
+           SpaceAfterTemplate == R.SpaceAfterTemplate &&
            SpaceBeforeAssignmentOperators == R.SpaceBeforeAssignmentOperators &&
            SpaceBeforeParens == R.SpaceBeforeParens &&
            SpaceInEmptyParentheses == R.SpaceInEmptyParentheses &&
            SpacesBeforeTrailingComments == R.SpacesBeforeTrailingComments &&
            SpacesInAngles == R.SpacesInAngles &&
            SpacesInContainerLiterals == R.SpacesInContainerLiterals &&
            SpacesInCStyleCastParentheses == R.SpacesInCStyleCastParentheses &&
            SpacesInParentheses == R.SpacesInParentheses &&

lib/Format/Format.cpp

static void mapping(IO &IO, FormatStyle &Style) {
     IO.mapOptional("PenaltyBreakFirstLessLess",
                    Style.PenaltyBreakFirstLessLess);
     IO.mapOptional("PenaltyBreakString", Style.PenaltyBreakString);
     IO.mapOptional("PenaltyExcessCharacter", Style.PenaltyExcessCharacter);
     IO.mapOptional("PenaltyReturnTypeOnItsOwnLine",
                    Style.PenaltyReturnTypeOnItsOwnLine);
     IO.mapOptional("PointerAlignment", Style.PointerAlignment);
     IO.mapOptional("SpaceAfterCStyleCast", Style.SpaceAfterCStyleCast);
+    IO.mapOptional("SpaceAfterTemplate", Style.SpaceAfterTemplate);
     IO.mapOptional("SpaceBeforeAssignmentOperators",
                    Style.SpaceBeforeAssignmentOperators);
     IO.mapOptional("SpaceBeforeParens", Style.SpaceBeforeParens);
     IO.mapOptional("SpaceInEmptyParentheses", Style.SpaceInEmptyParentheses);
     IO.mapOptional("SpacesBeforeTrailingComments",
                    Style.SpacesBeforeTrailingComments);
     IO.mapOptional("SpacesInAngles", Style.SpacesInAngles);
     IO.mapOptional("SpacesInContainerLiterals",
FormatStyle getLLVMStyle() {
   LLVMStyle.Standard = FormatStyle::LS_Cpp11;
   LLVMStyle.UseTab = FormatStyle::UT_Never;
   LLVMStyle.SpacesInParentheses = false;
   LLVMStyle.SpacesInSquareBrackets = false;
   LLVMStyle.SpaceInEmptyParentheses = false;
   LLVMStyle.SpacesInContainerLiterals = true;
   LLVMStyle.SpacesInCStyleCastParentheses = false;
   LLVMStyle.SpaceAfterCStyleCast = false;
+  LLVMStyle.SpaceAfterTemplate = true;
   LLVMStyle.SpaceBeforeParens = FormatStyle::SBPO_ControlStatements;
   LLVMStyle.SpaceBeforeAssignmentOperators = true;
   LLVMStyle.SpacesInAngles = false;
 
   LLVMStyle.PenaltyBreakComment = 300;
   LLVMStyle.PenaltyBreakFirstLessLess = 120;
   LLVMStyle.PenaltyBreakString = 1000;
   LLVMStyle.PenaltyExcessCharacter = 1000000;
FormatStyle getMozillaStyle() {
   MozillaStyle.ConstructorInitializerIndentWidth = 2;
   MozillaStyle.ContinuationIndentWidth = 2;
   MozillaStyle.Cpp11BracedListStyle = false;
   MozillaStyle.IndentCaseLabels = true;
   MozillaStyle.ObjCSpaceAfterProperty = true;
   MozillaStyle.ObjCSpaceBeforeProtocolList = false;
   MozillaStyle.PenaltyReturnTypeOnItsOwnLine = 200;
   MozillaStyle.PointerAlignment = FormatStyle::PAS_Left;
+  MozillaStyle.SpaceAfterTemplate = false;
   return MozillaStyle;
 }
 
 FormatStyle getWebKitStyle() {
   FormatStyle Style = getLLVMStyle();
   Style.AccessModifierOffset = -4;
   Style.AlignAfterOpenBracket = false;
   Style.AlignOperands = false;

lib/Format/TokenAnnotator.cpp

bool TokenAnnotator::spaceRequiredBetween(const AnnotatedLine &Line,
   if (Left.is(tok::l_paren) || Right.is(tok::r_paren))
     return (Right.is(TT_CastRParen) ||
             (Left.MatchingParen && Left.MatchingParen->is(TT_CastRParen)))
                ? Style.SpacesInCStyleCastParentheses
                : Style.SpacesInParentheses;
   if (Right.isOneOf(tok::semi, tok::comma))
     return false;
   if (Right.is(tok::less) &&
-      (Left.is(tok::kw_template) ||
-       (Line.Type == LT_ObjCDecl && Style.ObjCSpaceBeforeProtocolList)))
+      Line.Type == LT_ObjCDecl && Style.ObjCSpaceBeforeProtocolList)
     return true;
+  if (Right.is(tok::less) && Left.is(tok::kw_template))
+    return Style.SpaceAfterTemplate;
   if (Left.isOneOf(tok::exclaim, tok::tilde))
     return false;
   if (Left.is(tok::at) &&
       Right.isOneOf(tok::identifier, tok::string_literal, tok::char_constant,
                     tok::numeric_constant, tok::l_paren, tok::l_brace,
                     tok::kw_true, tok::kw_false))
     return false;
   if (Left.is(tok::coloncolon))

unittests/Format/FormatTest.cpp

TEST_F(FormatTest, ParsesConfigurationBools) {
   CHECK_PARSE_BOOL(Cpp11BracedListStyle);
   CHECK_PARSE_BOOL(SpacesInParentheses);
   CHECK_PARSE_BOOL(SpacesInSquareBrackets);
   CHECK_PARSE_BOOL(SpacesInAngles);
   CHECK_PARSE_BOOL(SpaceInEmptyParentheses);
   CHECK_PARSE_BOOL(SpacesInContainerLiterals);
   CHECK_PARSE_BOOL(SpacesInCStyleCastParentheses);
   CHECK_PARSE_BOOL(SpaceAfterCStyleCast);
+  CHECK_PARSE_BOOL(SpaceAfterTemplate);
   CHECK_PARSE_BOOL(SpaceBeforeAssignmentOperators);
 }
 
 #undef CHECK_PARSE_BOOL
 
 TEST_F(FormatTest, ParsesConfiguration) {
   FormatStyle Style = {};
   Style.Language = FormatStyle::LK_Cpp;
TEST_F(FormatTest, SpacesInAngles) {
   Spaces.Standard = FormatStyle::LS_Cpp11;
   Spaces.SpacesInAngles = true;
   verifyFormat("A< A< int > >();", Spaces);
 
   Spaces.SpacesInAngles = false;
   verifyFormat("A<A<int>>();", Spaces);
 }
 
+TEST_F(FormatTest, SpaceAfterTemplate) {
+  FormatStyle Style = getLLVMStyle();
+  Style.SpaceAfterTemplate = false;
+  verifyFormat("template<int> void foo();", Style);
+}
+
 TEST_F(FormatTest, TripleAngleBrackets) {
   verifyFormat("f<<<1, 1>>>();");
   verifyFormat("f<<<1, 1, 1, s>>>();");
   verifyFormat("f<<<a, b, c, d>>>();");
   EXPECT_EQ("f<<<1, 1>>>();", format("f <<< 1, 1 >>> ();"));
   verifyFormat("f<param><<<1, 1>>>();");
   verifyFormat("f<1><<<1, 1>>>();");
   EXPECT_EQ("f<param><<<1, 1>>>();", format("f< param > <<< 1, 1 >>> ();"));