[clang-format] Add an option to control indentation of export { ... }

clang/docs/ClangFormatStyleOptions.rst

@@ -3828,6 +3828,21 @@ the configuration (without a prefix: ``Auto``).
    This is an experimental flag, that might go away or be renamed. Do
    not use this in config files, etc. Use at your own risk.
 
+.. _ExportBlockIndentation:
+
+**ExportBlockIndentation** (``Boolean``) :versionbadge:`clang-format 20` :ref:`¶ <ExportBlockIndentation>`
+  If ``true``, clang-format will indent the body of an ``export { ... }``
+  block. This doesn't affect the formatting of anything else related to
+  exported declarations.
+
+  .. code-block:: c++
+
+     true:                     false:
+     export {          vs.     export {
+       void foo();             void foo();
+       void bar();             void bar();
+     }                         }
+
 .. _FixNamespaceComments:
 
 **FixNamespaceComments** (``Boolean``) :versionbadge:`clang-format 5` :ref:`¶ <FixNamespaceComments>`

clang/docs/ReleaseNotes.rst

@@ -554,6 +554,7 @@ clang-format
 ------------
 
 - Adds ``BreakBinaryOperations`` option.
+- Adds the ``ExportBlockIndentation`` option.
 
 libclang
 --------

clang/include/clang/Format/Format.h

@@ -2655,6 +2655,19 @@ struct FormatStyle {
   /// \version 3.7
   bool ExperimentalAutoDetectBinPacking;
 
+  /// If ``true``, clang-format will indent the body of an ``export { ... }``
+  /// block. This doesn't affect the formatting of anything else related to
+  /// exported declarations.
+  /// \code
+  ///    true:                     false:
+  ///    export {          vs.     export {
+  ///      void foo();             void foo();
+  ///      void bar();             void bar();
+  ///    }                         }
+  /// \endcode
+  /// \version 20
+  bool ExportBlockIndentation;
+
   /// If ``true``, clang-format adds missing namespace end comments for
   /// namespaces and fixes invalid existing ones. This doesn't affect short
   /// namespaces, which are controlled by ``ShortNamespaceLines``.
@@ -5131,6 +5144,7 @@ struct FormatStyle {
            EmptyLineBeforeAccessModifier == R.EmptyLineBeforeAccessModifier &&
            ExperimentalAutoDetectBinPacking ==
                R.ExperimentalAutoDetectBinPacking &&
+           ExportBlockIndentation == R.ExportBlockIndentation &&
            FixNamespaceComments == R.FixNamespaceComments &&
            ForEachMacros == R.ForEachMacros &&
            IncludeStyle.IncludeBlocks == R.IncludeStyle.IncludeBlocks &&

clang/lib/Format/Format.cpp

@@ -1016,6 +1016,7 @@ template <> struct MappingTraits<FormatStyle> {
                    Style.EmptyLineBeforeAccessModifier);
     IO.mapOptional("ExperimentalAutoDetectBinPacking",
                    Style.ExperimentalAutoDetectBinPacking);
+    IO.mapOptional("ExportBlockIndentation", Style.ExportBlockIndentation);
     IO.mapOptional("FixNamespaceComments", Style.FixNamespaceComments);
     IO.mapOptional("ForEachMacros", Style.ForEachMacros);
     IO.mapOptional("IfMacros", Style.IfMacros);
@@ -1522,6 +1523,7 @@ FormatStyle getLLVMStyle(FormatStyle::LanguageKind Language) {
   LLVMStyle.EmptyLineAfterAccessModifier = FormatStyle::ELAAMS_Never;
   LLVMStyle.EmptyLineBeforeAccessModifier = FormatStyle::ELBAMS_LogicalBlock;
   LLVMStyle.ExperimentalAutoDetectBinPacking = false;
+  LLVMStyle.ExportBlockIndentation = false;
   LLVMStyle.FixNamespaceComments = true;
   LLVMStyle.ForEachMacros.push_back("foreach");
   LLVMStyle.ForEachMacros.push_back("Q_FOREACH");

clang/lib/Format/UnwrappedLineParser.cpp

@@ -1616,6 +1616,10 @@ void UnwrappedLineParser::parseStructuralElement(
         parseNamespace();
         return;
       }
+      if (FormatTok->is(tok::l_brace)) {
+        parseCXXExportBlock();
+        return;
+      }
       if (FormatTok->is(Keywords.kw_import) && parseModuleImport())
         return;
     }
@@ -3075,6 +3079,26 @@ void UnwrappedLineParser::parseTryCatch() {
     addUnwrappedLine();
 }
 
+void UnwrappedLineParser::parseNamespaceOrExportBlock(unsigned AddLevels) {
+  bool ManageWhitesmithsBraces =
+      AddLevels == 0u && Style.BreakBeforeBraces == FormatStyle::BS_Whitesmiths;
+
+  // If we're in Whitesmiths mode, indent the brace if we're not indenting
+  // the whole block.
+  if (ManageWhitesmithsBraces)
+    ++Line->Level;
+
+  // Munch the semicolon after a namespace. This is more common than one would
+  // think. Putting the semicolon into its own line is very ugly.
+  parseBlock(/*MustBeDeclaration=*/true, AddLevels, /*MunchSemi=*/true,
+             /*KeepBraces=*/true, /*IfKind=*/nullptr, ManageWhitesmithsBraces);
+
+  addUnwrappedLine(AddLevels > 0 ? LineLevel::Remove : LineLevel::Keep);
+
+  if (ManageWhitesmithsBraces)
+    --Line->Level;
+}
+
 void UnwrappedLineParser::parseNamespace() {
   assert(FormatTok->isOneOf(tok::kw_namespace, TT_NamespaceMacro) &&
          "'namespace' expected");
@@ -3107,29 +3131,15 @@ void UnwrappedLineParser::parseNamespace() {
                  DeclarationScopeStack.size() > 1)
             ? 1u
             : 0u;
-    bool ManageWhitesmithsBraces =
-        AddLevels == 0u &&
-        Style.BreakBeforeBraces == FormatStyle::BS_Whitesmiths;
-
-    // If we're in Whitesmiths mode, indent the brace if we're not indenting
-    // the whole block.
-    if (ManageWhitesmithsBraces)
-      ++Line->Level;
-
-    // Munch the semicolon after a namespace. This is more common than one would
-    // think. Putting the semicolon into its own line is very ugly.
-    parseBlock(/*MustBeDeclaration=*/true, AddLevels, /*MunchSemi=*/true,
-               /*KeepBraces=*/true, /*IfKind=*/nullptr,
-               ManageWhitesmithsBraces);
-
-    addUnwrappedLine(AddLevels > 0 ? LineLevel::Remove : LineLevel::Keep);
-
-    if (ManageWhitesmithsBraces)
-      --Line->Level;
+    parseNamespaceOrExportBlock(AddLevels);
   }
   // FIXME: Add error handling.
 }
 
+void UnwrappedLineParser::parseCXXExportBlock() {
+  parseNamespaceOrExportBlock(Style.ExportBlockIndentation ? 1 : 0);
+}
+
 void UnwrappedLineParser::parseNew() {
   assert(FormatTok->is(tok::kw_new) && "'new' expected");
   nextToken();

clang/lib/Format/UnwrappedLineParser.h

@@ -171,6 +171,8 @@ class UnwrappedLineParser {
   void parseRequiresClause(FormatToken *RequiresToken);
   void parseRequiresExpression(FormatToken *RequiresToken);
   void parseConstraintExpression();
+  void parseCXXExportBlock();
+  void parseNamespaceOrExportBlock(unsigned AddLevels);
   void parseJavaEnumBody();
   // Parses a record (aka class) as a top level element. If ParseAsExpr is true,
   // parses the record as a child block, i.e. if the class declaration is an

clang/unittests/Format/FormatTest.cpp

@@ -9040,6 +9040,31 @@ TEST_F(FormatTest, AdaptiveOnePerLineFormatting) {
                Style);
 }
 
+TEST_F(FormatTest, ExportBlockIndentation) {
+  FormatStyle Style = getLLVMStyleWithColumns(80);
+  Style.ExportBlockIndentation = true;
+  verifyFormat("export {\n"
+               "  int x;\n"
+               "  int y;\n"
+               "}",
+               "export {\n"
+               "int x;\n"
+               "int y;\n"
+               "}",
+               Style);
+
+  Style.ExportBlockIndentation = false;
+  verifyFormat("export {\n"
+               "int x;\n"
+               "int y;\n"
+               "}",
+               "export {\n"
+               "  int x;\n"
+               "  int y;\n"
+               "}",
+               Style);
+}
+
 TEST_F(FormatTest, FormatsBuilderPattern) {
   verifyFormat("return llvm::StringSwitch<Reference::Kind>(name)\n"
                "    .StartsWith(\".eh_frame_hdr\", ORDER_EH_FRAMEHDR)\n"
@@ -26588,10 +26613,7 @@ TEST_F(FormatTest, Cpp20ModulesSupport) {
                "  int foo;\n"
                "};",
                Style);
-  verifyFormat("export {\n"
-               "  int foo;\n"
-               "};",
-               Style);
+  verifyFormat("export { int foo; };", Style);
   verifyFormat("export export char const *hello() { return \"hello\"; }");
 
   verifyFormat("import bar;", Style);