diff --git a/clang/docs/ClangFormatStyleOptions.rst b/clang/docs/ClangFormatStyleOptions.rst
--- a/clang/docs/ClangFormatStyleOptions.rst
+++ b/clang/docs/ClangFormatStyleOptions.rst
@@ -5527,6 +5527,13 @@
       InConditionalStatements: true
       Other: true
 
+  * ``bool InAttributeSpecifiers`` Put a space in parentheses of attribute specifiers.
+
+    .. code-block:: c++
+
+       true:                                  false:
+       __attribute__( ( noreturn ) )    vs.     __attribute__((noreturn))
+
   * ``bool InConditionalStatements`` Put a space in parentheses only inside conditional statements
     (``for/if/while/switch...``).
 
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -850,6 +850,8 @@
 - Add ``AllowBreakBeforeNoexceptSpecifier`` option.
 - Add ``AllowShortCompoundRequirementOnASingleLine`` option.
 - Change ``BreakAfterAttributes`` from ``Never`` to ``Leave`` in LLVM style.
+- Add ``InAttributeSpecifiers`` style option to ``SpacesInParensOptions``
+  to control addition of spaces after the ``__attribute__`` keyword.
 
 libclang
 --------
diff --git a/clang/include/clang/Format/Format.h b/clang/include/clang/Format/Format.h
--- a/clang/include/clang/Format/Format.h
+++ b/clang/include/clang/Format/Format.h
@@ -4420,6 +4420,12 @@
   ///     Other: true
   /// \endcode
   struct SpacesInParensCustom {
+    /// Put a space in parentheses of attribute specifiers.
+    /// \code
+    ///    true:                                  false:
+    ///    __attribute__( ( noreturn ) )    vs.     __attribute__((noreturn))
+    /// \endcode
+    bool InAttributeSpecifiers;
     /// Put a space in parentheses only inside conditional statements
     /// (``for/if/while/switch...``).
     /// \code
@@ -4453,17 +4459,20 @@
     bool Other;
 
     SpacesInParensCustom()
-        : InConditionalStatements(false), InCStyleCasts(false),
-          InEmptyParentheses(false), Other(false) {}
+        : InAttributeSpecifiers(false), InConditionalStatements(false),
+          InCStyleCasts(false), InEmptyParentheses(false), Other(false) {}
 
-    SpacesInParensCustom(bool InConditionalStatements, bool InCStyleCasts,
+    SpacesInParensCustom(bool InAttributeSpecifiers,
+                         bool InConditionalStatements, bool InCStyleCasts,
                          bool InEmptyParentheses, bool Other)
-        : InConditionalStatements(InConditionalStatements),
+        : InAttributeSpecifiers(InAttributeSpecifiers),
+          InConditionalStatements(InConditionalStatements),
           InCStyleCasts(InCStyleCasts), InEmptyParentheses(InEmptyParentheses),
           Other(Other) {}
 
     bool operator==(const SpacesInParensCustom &R) const {
-      return InConditionalStatements == R.InConditionalStatements &&
+      return InAttributeSpecifiers == R.InAttributeSpecifiers &&
+             InConditionalStatements == R.InConditionalStatements &&
              InCStyleCasts == R.InCStyleCasts &&
              InEmptyParentheses == R.InEmptyParentheses && Other == R.Other;
     }
diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -752,6 +752,7 @@
 
 template <> struct MappingTraits<FormatStyle::SpacesInParensCustom> {
   static void mapping(IO &IO, FormatStyle::SpacesInParensCustom &Spaces) {
+    IO.mapOptional("InAttributeSpecifiers", Spaces.InAttributeSpecifiers);
     IO.mapOptional("InCStyleCasts", Spaces.InCStyleCasts);
     IO.mapOptional("InConditionalStatements", Spaces.InConditionalStatements);
     IO.mapOptional("InEmptyParentheses", Spaces.InEmptyParentheses);
@@ -1186,6 +1187,7 @@
       if (SpacesInParentheses) {
         // set all options except InCStyleCasts and InEmptyParentheses
         // to true for backward compatibility.
+        Style.SpacesInParensOptions.InAttributeSpecifiers = true;
         Style.SpacesInParensOptions.InConditionalStatements = true;
         Style.SpacesInParensOptions.InCStyleCasts =
             SpacesInCStyleCastParentheses;
diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -3967,10 +3967,19 @@
   }
 
   if (Left.is(tok::l_paren) || Right.is(tok::r_paren)) {
-    return (Right.is(TT_CastRParen) ||
-            (Left.MatchingParen && Left.MatchingParen->is(TT_CastRParen)))
-               ? Style.SpacesInParensOptions.InCStyleCasts
-               : Style.SpacesInParensOptions.Other;
+    if (Right.is(TT_CastRParen) ||
+        (Left.MatchingParen && Left.MatchingParen->is(TT_CastRParen))) {
+      return Style.SpacesInParensOptions.InCStyleCasts;
+    }
+    if (Left.isOneOf(TT_AttributeLParen, TT_AttributeRParen) ||
+        Right.isOneOf(TT_AttributeLParen, TT_AttributeRParen) ||
+        (Left.Previous && Left.Previous->isOneOf(TT_AttributeLParen,
+                                                 TT_AttributeRParen)) ||
+        (Right.Next && Right.Next->isOneOf(TT_AttributeLParen,
+                                           TT_AttributeRParen))) {
+      return Style.SpacesInParensOptions.InAttributeSpecifiers;
+    }
+    return Style.SpacesInParensOptions.Other;
   }
   if (Right.isOneOf(tok::semi, tok::comma))
     return false;
diff --git a/clang/unittests/Format/ConfigParseTest.cpp b/clang/unittests/Format/ConfigParseTest.cpp
--- a/clang/unittests/Format/ConfigParseTest.cpp
+++ b/clang/unittests/Format/ConfigParseTest.cpp
@@ -230,6 +230,7 @@
   CHECK_PARSE_NESTED_BOOL(SpaceBeforeParensOptions, AfterIfMacros);
   CHECK_PARSE_NESTED_BOOL(SpaceBeforeParensOptions, AfterOverloadedOperator);
   CHECK_PARSE_NESTED_BOOL(SpaceBeforeParensOptions, BeforeNonEmptyParentheses);
+  CHECK_PARSE_NESTED_BOOL(SpacesInParensOptions, InAttributeSpecifiers);
   CHECK_PARSE_NESTED_BOOL(SpacesInParensOptions, InCStyleCasts);
   CHECK_PARSE_NESTED_BOOL(SpacesInParensOptions, InConditionalStatements);
   CHECK_PARSE_NESTED_BOOL(SpacesInParensOptions, InEmptyParentheses);
@@ -625,19 +626,23 @@
   Style.SpacesInParens = FormatStyle::SIPO_Never;
   Style.SpacesInParensOptions = {};
   CHECK_PARSE("SpacesInParentheses: true", SpacesInParensOptions,
-              FormatStyle::SpacesInParensCustom(true, false, false, true));
+              FormatStyle::SpacesInParensCustom(true, true, false, false,
+                  true));
   Style.SpacesInParens = FormatStyle::SIPO_Never;
   Style.SpacesInParensOptions = {};
   CHECK_PARSE("SpacesInConditionalStatement: true", SpacesInParensOptions,
-              FormatStyle::SpacesInParensCustom(true, false, false, false));
+              FormatStyle::SpacesInParensCustom(false, true, false, false,
+                  false));
   Style.SpacesInParens = FormatStyle::SIPO_Never;
   Style.SpacesInParensOptions = {};
   CHECK_PARSE("SpacesInCStyleCastParentheses: true", SpacesInParensOptions,
-              FormatStyle::SpacesInParensCustom(false, true, false, false));
+              FormatStyle::SpacesInParensCustom(false, false, true, false,
+                  false));
   Style.SpacesInParens = FormatStyle::SIPO_Never;
   Style.SpacesInParensOptions = {};
   CHECK_PARSE("SpaceInEmptyParentheses: true", SpacesInParensOptions,
-              FormatStyle::SpacesInParensCustom(false, false, true, false));
+              FormatStyle::SpacesInParensCustom(false, false, false, true,
+                  false));
   Style.SpacesInParens = FormatStyle::SIPO_Never;
   Style.SpacesInParensOptions = {};
 
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -16680,6 +16680,7 @@
   Spaces.SpacesInParensOptions = {};
   Spaces.SpacesInParensOptions.Other = true;
   Spaces.SpacesInParensOptions.InConditionalStatements = true;
+  Spaces.SpacesInParensOptions.InAttributeSpecifiers = true;
   verifyFormat("do_something( ::globalVar );", Spaces);
   verifyFormat("call( x, y, z );", Spaces);
   verifyFormat("call();", Spaces);
@@ -16754,6 +16755,12 @@
   verifyFormat("void __attribute__((naked)) foo(int bar)", Spaces);
   verifyFormat("void f( ) __attribute__((asdf));", Spaces);
 
+  Spaces.SpacesInParensOptions.InAttributeSpecifiers = true;
+  verifyFormat("SomeType *__attribute__( ( attr ) ) *a = NULL;", Spaces);
+  verifyFormat("void __attribute__( ( naked ) ) foo(int bar)", Spaces);
+  verifyFormat("void f( ) __attribute__( ( asdf ) );", Spaces);
+  Spaces.SpacesInParensOptions.InAttributeSpecifiers = false;
+
   // Run the first set of tests again with:
   Spaces.SpaceAfterCStyleCast = true;
   verifyFormat("call(x, y, z);", Spaces);