Index: clang/include/clang/Format/Format.h
===================================================================
--- clang/include/clang/Format/Format.h
+++ clang/include/clang/Format/Format.h
@@ -1986,6 +1986,15 @@
   /// \endcode
   bool SpacesInSquareBrackets;
 
+  /// If ``true``, spaces will be before  ``[``.
+  /// Lambdas will not be affected. Only the first ``[`` will get a space added.
+  /// \code
+  ///    true:                                  false:
+  ///    int a [5];                    vs.      int a[5];
+  ///    int a [5][5];                 vs.      int a[5][5];
+  /// \endcode
+  bool SpaceBeforeSquareBrackets;
+
   /// Supported language standards for parsing and formatting C++ constructs.
   /// \code
   ///    Latest:                                vector<set<int>>
@@ -2150,10 +2159,10 @@
            SpacesInCStyleCastParentheses == R.SpacesInCStyleCastParentheses &&
            SpacesInParentheses == R.SpacesInParentheses &&
            SpacesInSquareBrackets == R.SpacesInSquareBrackets &&
+           SpaceBeforeSquareBrackets == R.SpaceBeforeSquareBrackets &&
            Standard == R.Standard && TabWidth == R.TabWidth &&
            StatementMacros == R.StatementMacros && UseTab == R.UseTab &&
-           UseCRLF == R.UseCRLF &&
-           TypenameMacros == R.TypenameMacros;
+           UseCRLF == R.UseCRLF && TypenameMacros == R.TypenameMacros;
   }
 
   llvm::Optional<FormatStyle> GetLanguageStyle(LanguageKind Language) const;
Index: clang/lib/Format/Format.cpp
===================================================================
--- clang/lib/Format/Format.cpp
+++ clang/lib/Format/Format.cpp
@@ -543,6 +543,8 @@
                    Style.SpacesInCStyleCastParentheses);
     IO.mapOptional("SpacesInParentheses", Style.SpacesInParentheses);
     IO.mapOptional("SpacesInSquareBrackets", Style.SpacesInSquareBrackets);
+    IO.mapOptional("SpaceBeforeSquareBrackets",
+                   Style.SpaceBeforeSquareBrackets);
     IO.mapOptional("Standard", Style.Standard);
     IO.mapOptional("StatementMacros", Style.StatementMacros);
     IO.mapOptional("TabWidth", Style.TabWidth);
@@ -813,6 +815,7 @@
   LLVMStyle.SpaceBeforeRangeBasedForLoopColon = true;
   LLVMStyle.SpaceBeforeAssignmentOperators = true;
   LLVMStyle.SpaceBeforeCpp11BracedList = false;
+  LLVMStyle.SpaceBeforeSquareBrackets = false;
   LLVMStyle.SpacesInAngles = false;
 
   LLVMStyle.PenaltyBreakAssignment = prec::Assignment;
Index: clang/lib/Format/TokenAnnotator.cpp
===================================================================
--- clang/lib/Format/TokenAnnotator.cpp
+++ clang/lib/Format/TokenAnnotator.cpp
@@ -2724,7 +2724,9 @@
       !Right.isOneOf(TT_ObjCMethodExpr, TT_LambdaLSquare,
                      TT_DesignatedInitializerLSquare,
                      TT_StructuredBindingLSquare, TT_AttributeSquare) &&
-      !Left.isOneOf(tok::numeric_constant, TT_DictLiteral))
+      !Left.isOneOf(tok::numeric_constant, TT_DictLiteral) &&
+      !(!Left.is(tok::r_square) && Style.SpaceBeforeSquareBrackets &&
+        Right.is(TT_ArraySubscriptLSquare)))
     return false;
   if (Left.is(tok::l_brace) && Right.is(tok::r_brace))
     return !Left.Children.empty(); // No spaces in "{}".
Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -10643,6 +10643,41 @@
   verifyFormat("int foo = [ &bar, = ]() {};", Spaces);
 }
 
+TEST_F(FormatTest, ConfigurableSpaceBeforeBrackets) {
+  FormatStyle NoSpaceStyle = getLLVMStyle();
+  verifyFormat("int a[5];", NoSpaceStyle);
+  verifyFormat("a[3] += 42;", NoSpaceStyle);
+
+  verifyFormat("int a[1];", NoSpaceStyle);
+  verifyFormat("int 1 [a];", NoSpaceStyle);
+  verifyFormat("int a[1][2];", NoSpaceStyle);
+  verifyFormat("a[7] = 5;", NoSpaceStyle);
+  verifyFormat("int a = (f())[23];", NoSpaceStyle);
+  verifyFormat("f([] {})", NoSpaceStyle);
+
+  FormatStyle Space = getLLVMStyle();
+  Space.SpaceBeforeSquareBrackets = true;
+  verifyFormat("int c = []() -> int { return 2; }();\n", Space);
+  verifyFormat("return [i, args...] {};", Space);
+
+  verifyFormat("int a [5];", Space);
+  verifyFormat("a [3] += 42;", Space);
+  verifyFormat("constexpr char hello []{\"hello\"};", Space);
+  verifyFormat("double &operator[](int i) { return 0; }\n"
+               "int i;",
+               Space);
+  verifyFormat("std::unique_ptr<int []> foo() {}", Space);
+  verifyFormat("int i = a [a][a]->f();", Space);
+  verifyFormat("int i = (*b) [a]->f();", Space);
+
+  verifyFormat("int a [1];", Space);
+  verifyFormat("int 1 [a];", Space);
+  verifyFormat("int a [1][2];", Space);
+  verifyFormat("a [7] = 5;", Space);
+  verifyFormat("int a = (f()) [23];", Space);
+  verifyFormat("f([] {})", Space);
+}
+
 TEST_F(FormatTest, ConfigurableSpaceBeforeAssignmentOperators) {
   verifyFormat("int a = 5;");
   verifyFormat("a += 42;");
@@ -12529,6 +12564,7 @@
   CHECK_PARSE_BOOL(SpaceBeforeCtorInitializerColon);
   CHECK_PARSE_BOOL(SpaceBeforeInheritanceColon);
   CHECK_PARSE_BOOL(SpaceBeforeRangeBasedForLoopColon);
+  CHECK_PARSE_BOOL(SpaceBeforeSquareBrackets);
   CHECK_PARSE_BOOL(UseCRLF);
 
   CHECK_PARSE_NESTED_BOOL(BraceWrapping, AfterCaseLabel);