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

clang/docs/ReleaseNotes.rst

@@ -310,7 +310,7 @@ C++23 Feature Support
 
 - Extend lifetime of temporaries in mem-default-init for P2718R0. Clang now fully
   supports `P2718R0 Lifetime extension in range-based for loops <https://wg21.link/P2718R0>`_.
-  
+
 - ``__cpp_explicit_this_parameter`` is now defined. (#GH82780)
 
 C++20 Feature Support
@@ -715,7 +715,7 @@ Improvements to Clang's diagnostics
 
 - Clang now diagnoses dangling references for C++20's parenthesized aggregate initialization (#101957).
 
-- Fixed a bug where Clang would not emit ``-Wunused-private-field`` warnings when an unrelated class 
+- Fixed a bug where Clang would not emit ``-Wunused-private-field`` warnings when an unrelated class
   defined a defaulted comparison operator (#GH116270).
 
   .. code-block:: c++
@@ -935,7 +935,7 @@ Bug Fixes to C++ Support
 - Fixed an assertion failure caused by invalid default argument substitutions in non-defining
   friend declarations. (#GH113324)
 - Fix a crash caused by incorrect argument position in merging deduced template arguments. (#GH113659)
-- Fixed a parser crash when using pack indexing as a nested name specifier. (#GH119072) 
+- Fixed a parser crash when using pack indexing as a nested name specifier. (#GH119072)
 - Fixed a null pointer dereference issue when heuristically computing ``sizeof...(pack)`` expressions. (#GH81436)
 - Fixed an assertion failure caused by mangled names with invalid identifiers. (#GH112205)
 - Fixed an incorrect lambda scope of generic lambdas that caused Clang to crash when computing potential lambda
@@ -1211,6 +1211,17 @@ clang-format
 ------------
 
 - Adds ``BreakBinaryOperations`` option.
+- Adds ``TemplateNames`` option.
+- Adds ``AlignFunctionDeclarations`` option to ``AlignConsecutiveDeclarations``.
+- Adds ``IndentOnly`` suboption to ``ReflowComments`` to fix the indentation of
+  multi-line comments without touching their contents, renames ``false`` to
+  ``Never``, and ``true`` to ``Always``.
+- Adds ``RemoveEmptyLinesInUnwrappedLines`` option.
+- Adds ``KeepFormFeed`` option and set it to ``true`` for ``GNU`` style.
+- Adds ``AllowShortNamespacesOnASingleLine`` option.
+- Adds ``VariableTemplates`` option.
+- Adds support for bash globstar in ``.clang-format-ignore``.
+- Adds ``WrapNamespaceBodyWithEmptyLines`` option.
 - Adds the ``ExportBlockIndentation`` option.
 
 libclang

clang/lib/Format/Format.cpp

@@ -1551,7 +1551,7 @@ FormatStyle getLLVMStyle(FormatStyle::LanguageKind Language) {
   LLVMStyle.EmptyLineAfterAccessModifier = FormatStyle::ELAAMS_Never;
   LLVMStyle.EmptyLineBeforeAccessModifier = FormatStyle::ELBAMS_LogicalBlock;
   LLVMStyle.ExperimentalAutoDetectBinPacking = false;
-  LLVMStyle.ExportBlockIndentation = false;
+  LLVMStyle.ExportBlockIndentation = true;
   LLVMStyle.FixNamespaceComments = true;
   LLVMStyle.ForEachMacros.push_back("foreach");
   LLVMStyle.ForEachMacros.push_back("Q_FOREACH");

clang/lib/Format/TokenAnnotator.h

@@ -154,6 +154,11 @@ class AnnotatedLine {
            startsWith(tok::kw_export, tok::kw_namespace);
   }
 
+  /// \c true if this line starts a C++ export block.
+  bool startsWithExportBlock() const {
+    return startsWith(tok::kw_export, tok::l_brace);
+  }
+
   FormatToken *getFirstNonComment() const {
     assert(First);
     return First->is(tok::comment) ? First->getNextNonComment() : First;

clang/lib/Format/UnwrappedLineFormatter.cpp

@@ -432,8 +432,9 @@ class LineJoiner {
 
     // Try to merge a control statement block with left brace unwrapped.
     if (TheLine->Last->is(tok::l_brace) && FirstNonComment != TheLine->Last &&
-        FirstNonComment->isOneOf(tok::kw_if, tok::kw_while, tok::kw_for,
-                                 TT_ForEachMacro)) {
+        (FirstNonComment->isOneOf(tok::kw_if, tok::kw_while, tok::kw_for,
+                                  TT_ForEachMacro) ||
+         TheLine->startsWithExportBlock())) {
       return Style.AllowShortBlocksOnASingleLine != FormatStyle::SBS_Never
                  ? tryMergeSimpleBlock(I, E, Limit)
                  : 0;
@@ -832,7 +833,8 @@ class LineJoiner {
     if (IsCtrlStmt(Line) ||
         Line.First->isOneOf(tok::kw_try, tok::kw___try, tok::kw_catch,
                             tok::kw___finally, tok::r_brace,
-                            Keywords.kw___except)) {
+                            Keywords.kw___except) ||
+        Line.startsWithExportBlock()) {
       if (IsSplitBlock)
         return 0;
       // Don't merge when we can't except the case when

clang/lib/Format/UnwrappedLineParser.cpp

@@ -3118,7 +3118,7 @@ void UnwrappedLineParser::parseNamespaceOrExportBlock(unsigned AddLevels) {
   if (ManageWhitesmithsBraces)
     ++Line->Level;
 
-  // Munch the semicolon after a namespace. This is more common than one would
+  // Munch the semicolon after the block. 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);
@@ -3167,7 +3167,8 @@ void UnwrappedLineParser::parseNamespace() {
 }
 
 void UnwrappedLineParser::parseCXXExportBlock() {
-  parseNamespaceOrExportBlock(Style.ExportBlockIndentation ? 1 : 0);
+  parseNamespaceOrExportBlock(/*AddLevels=*/Style.ExportBlockIndentation ? 1
+                                                                         : 0);
 }
 
 void UnwrappedLineParser::parseNew() {

clang/unittests/Format/FormatTest.cpp

@@ -9095,6 +9095,96 @@ TEST_F(FormatTest, ExportBlockIndentation) {
                Style);
 }
 
+TEST_F(FormatTest, ShortExportBlocks) {
+  FormatStyle Style = getLLVMStyleWithColumns(80);
+  Style.ExportBlockIndentation = false;
+
+  Style.AllowShortBlocksOnASingleLine = FormatStyle::SBS_Never;
+  verifyFormat("export {\n"
+               "}",
+               Style);
+
+  verifyFormat("export {\n"
+               "int x;\n"
+               "}",
+               Style);
+
+  verifyFormat("export {\n"
+               "int x;\n"
+               "}",
+               "export\n"
+               "{\n"
+               "int x;\n"
+               "}",
+               Style);
+
+  verifyFormat("export {\n"
+               "}",
+               "export {}", Style);
+
+  verifyFormat("export {\n"
+               "int x;\n"
+               "}",
+               "export { int x; }", Style);
+
+  Style.AllowShortBlocksOnASingleLine = FormatStyle::SBS_Always;
+  verifyFormat("export {}",
+               "export {\n"
+               "}",
+               Style);
+
+  verifyFormat("export { int x; }",
+               "export {\n"
+               "int x;\n"
+               "}",
+               Style);
+
+  verifyFormat("export { int x; }",
+               "export\n"
+               "{\n"
+               "int x;\n"
+               "}",
+               Style);
+
+  verifyFormat("export {}",
+               "export {\n"
+               "}",
+               Style);
+
+  verifyFormat("export { int x; }",
+               "export {\n"
+               "int x;\n"
+               "}",
+               Style);
+
+  Style.AllowShortBlocksOnASingleLine = FormatStyle::SBS_Empty;
+  verifyFormat("export {}",
+               "export {\n"
+               "}",
+               Style);
+
+  verifyFormat("export {\n"
+               "int x;\n"
+               "}",
+               Style);
+
+  verifyFormat("export {\n"
+               "int x;\n"
+               "}",
+               "export\n"
+               "{\n"
+               "int x;\n"
+               "}",
+               Style);
+
+  verifyFormat("export {}", Style);
+
+  verifyFormat("export {\n"
+               "int x;\n"
+               "}",
+               "export { int x; }", Style);
+}
+
 TEST_F(FormatTest, FormatsBuilderPattern) {
   verifyFormat("return llvm::StringSwitch<Reference::Kind>(name)\n"
                "    .StartsWith(\".eh_frame_hdr\", ORDER_EH_FRAMEHDR)\n"
@@ -26675,7 +26765,10 @@ TEST_F(FormatTest, Cpp20ModulesSupport) {
                "  int foo;\n"
                "};",
                Style);
-  verifyFormat("export { int foo; };", Style);
+  verifyFormat("export {\n"
+               "  int foo;\n"
+               "};",
+               Style);
   verifyFormat("export export char const *hello() { return \"hello\"; }");
 
   verifyFormat("import bar;", Style);