[clang-format] Option to insert spaces before the closing */

clang/docs/ClangFormatStyleOptions.rst

@@ -6612,6 +6612,38 @@ the configuration (without a prefix: ``Auto``).
      int a [5];                    vs.      int a[5];
      int a [5][5];                 vs.      int a[5][5];
 
+.. _SpaceInComments:
+
+**SpaceInComments** (``Struct``) :versionbadge:`clang-format 21` :ref:`¶ <SpaceInComments>`
+  Controls whitespace around block comment delimiters and parameter-style
+  inline comments. Each field accepts a ``CommentSpaceMode``: ``Leave``
+  (preserve existing spacing, the default), ``Always`` (insert a single space),
+  or ``Never`` (remove all spaces).
+
+  The available controls are:
+
+  ``AfterOpeningComment``
+    Governs the space immediately after ``/*`` in regular block comments.
+  ``BeforeClosingComment``
+    Governs the space before ``*/`` in regular block comments.
+  ``AfterOpeningParamComment``
+    Governs the space after ``/*`` in parameter comments such as ``/*param=*/``.
+  ``BeforeClosingParamComment``
+    Governs the space before ``*/`` in parameter comments.
+
+  .. code-block:: yaml
+
+     SpaceInComments:
+       BeforeClosingComment: Always
+       BeforeClosingParamComment: Never
+
+  .. code-block:: c++
+
+     // BeforeClosingComment: Always
+     auto Value = foo(/* comment */);
+     // BeforeClosingParamComment: Never
+     auto Number = foo(/*param=*/42);
+
 .. _SpaceInEmptyBlock:
 
 **SpaceInEmptyBlock** (``Boolean``) :versionbadge:`clang-format 10` :ref:`¶ <SpaceInEmptyBlock>`

clang/include/clang/Format/Format.h

@@ -4684,6 +4684,36 @@ struct FormatStyle {
   /// \version 17
   bool SpaceBeforeJsonColon;
 
+  /// Defines how clang-format should treat spaces around block comment
+  /// delimiters and specialized inline comments (such as parameter name
+  /// annotations). The default `Leave` mode preserves existing whitespace.
+  enum class CommentSpaceMode : int8_t {
+    /// Preserve existing whitespace, making no formatting changes.
+    Leave,
+    /// Ensure exactly one space is present.
+    Always,
+    /// Ensure no space is present.
+    Never,
+  };
+
+  /// Specifies spacing behavior for different block comment forms.
+  struct SpaceInCommentsOptions {
+    CommentSpaceMode AfterOpeningComment = CommentSpaceMode::Leave;
+    CommentSpaceMode BeforeClosingComment = CommentSpaceMode::Leave;
+    CommentSpaceMode AfterOpeningParamComment = CommentSpaceMode::Leave;
+    CommentSpaceMode BeforeClosingParamComment = CommentSpaceMode::Leave;
+
+    constexpr bool operator==(const SpaceInCommentsOptions &R) const {
+      return AfterOpeningComment == R.AfterOpeningComment &&
+             BeforeClosingComment == R.BeforeClosingComment &&
+             AfterOpeningParamComment == R.AfterOpeningParamComment &&
+             BeforeClosingParamComment == R.BeforeClosingParamComment;
+    }
+  };
+
+  /// Controls spacing inside block comments.
+  SpaceInCommentsOptions SpaceInComments;
+
   /// Different ways to put a space before opening parentheses.
   enum SpaceBeforeParensStyle : int8_t {
     /// This is **deprecated** and replaced by ``Custom`` below, with all
@@ -5612,6 +5642,7 @@ struct FormatStyle {
            SpaceBeforeRangeBasedForLoopColon ==
                R.SpaceBeforeRangeBasedForLoopColon &&
            SpaceBeforeSquareBrackets == R.SpaceBeforeSquareBrackets &&
+           SpaceInComments == R.SpaceInComments &&
            SpaceInEmptyBraces == R.SpaceInEmptyBraces &&
            SpacesBeforeTrailingComments == R.SpacesBeforeTrailingComments &&
            SpacesInAngles == R.SpacesInAngles &&