[clang-format] SpacesInSquareBrackets should affect lambdas with parameters too

[mitchell-stellar]

Summary

This patch makes the SpacesInSquareBrackets setting also apply to C++ lambdas with parameters.

Looking through the revision history, it appears support for only array brackets was added, and lambda brackets were ignored. Therefore, I am inclined to think it was simply an omission, rather than a deliberate choice.

See https://bugs.llvm.org/show_bug.cgi?id=17887 and https://reviews.llvm.org/D4944.

[MyDeveloperDay]

Thanks for the patch.

LGTM

[mitchell-stellar]

Thanks, please commit on my behalf.

[MyDeveloperDay]

clang/lib/Format/TokenAnnotator.cpp

2613

super minor git clang-format change on committing.

clang/docs/ClangFormatStyleOptions.rst

**SpacesInParentheses** (``bool``)
 
   .. code-block:: c++
 
      true:                                  false:
      t f( Deleted & ) & = delete;   vs.     t f(Deleted &) & = delete;
 
 **SpacesInSquareBrackets** (``bool``)
   If ``true``, spaces will be inserted after ``[`` and before ``]``.
-  Lambdas or unspecified size array declarations will not be affected.
+  Lambdas without arguments or unspecified size array declarations will not be
+  affected.
 
   .. code-block:: c++
 
      true:                                  false:
      int a[ 5 ];                    vs.     int a[5];
      std::unique_ptr<int[]> foo() {} // Won't be affected
 
 **Standard** (``LanguageStandard``)

clang/lib/Format/TokenAnnotator.cpp

const auto SpaceRequiredForArrayInitializerLSquare =
                 !Style.Cpp11BracedListStyle &&
                 LSquareTok.endsSequence(tok::l_square, tok::colon,
                                         TT_SelectorName));
       };
   if (Left.is(tok::l_square))
     return (Left.is(TT_ArrayInitializerLSquare) && Right.isNot(tok::r_square) &&
             SpaceRequiredForArrayInitializerLSquare(Left, Style)) ||
            (Left.isOneOf(TT_ArraySubscriptLSquare,
-                         TT_StructuredBindingLSquare) &&
+                         TT_StructuredBindingLSquare,
+                         TT_LambdaLSquare) &&
             Style.SpacesInSquareBrackets && Right.isNot(tok::r_square));
   if (Right.is(tok::r_square))
     return Right.MatchingParen &&
            ((Right.MatchingParen->is(TT_ArrayInitializerLSquare) &&
              SpaceRequiredForArrayInitializerLSquare(*Right.MatchingParen,
                                                      Style)) ||
             (Style.SpacesInSquareBrackets &&
              Right.MatchingParen->isOneOf(TT_ArraySubscriptLSquare,
-                                          TT_StructuredBindingLSquare)) ||
+                                          TT_StructuredBindingLSquare,
+                                          TT_LambdaLSquare)) ||
             Right.MatchingParen->is(TT_AttributeParen));
   if (Right.is(tok::l_square) &&
       !Right.isOneOf(TT_ObjCMethodExpr, TT_LambdaLSquare,
                      TT_DesignatedInitializerLSquare,
                      TT_StructuredBindingLSquare, TT_AttributeSquare) &&
       !Left.isOneOf(tok::numeric_constant, TT_DictLiteral))
     return false;
   if (Left.is(tok::l_brace) && Right.is(tok::r_brace))

clang/unittests/Format/FormatTest.cpp

 }
 
 TEST_F(FormatTest, ConfigurableSpacesInSquareBrackets) {
   verifyFormat("int a[5];");
   verifyFormat("a[3] += 42;");
 
   FormatStyle Spaces = getLLVMStyle();
   Spaces.SpacesInSquareBrackets = true;
-  // Lambdas unchanged.
-  verifyFormat("int c = []() -> int { return 2; }();\n", Spaces);
-  verifyFormat("return [i, args...] {};", Spaces);
-
   // Not lambdas.
   verifyFormat("int a[ 5 ];", Spaces);
   verifyFormat("a[ 3 ] += 42;", Spaces);
   verifyFormat("constexpr char hello[]{\"hello\"};", Spaces);
   verifyFormat("double &operator[](int i) { return 0; }\n"
                "int i;",
                Spaces);
   verifyFormat("std::unique_ptr<int[]> foo() {}", Spaces);
   verifyFormat("int i = a[ a ][ a ]->f();", Spaces);
   verifyFormat("int i = (*b)[ a ]->f();", Spaces);
+  // Lambdas.
+  verifyFormat("int c = []() -> int { return 2; }();\n", Spaces);
+  verifyFormat("return [ i, args... ] {};", Spaces);
 }
 
 TEST_F(FormatTest, ConfigurableSpaceBeforeAssignmentOperators) {
   verifyFormat("int a = 5;");
   verifyFormat("a += 42;");
   verifyFormat("a or_eq 8;");
 
   FormatStyle Spaces = getLLVMStyle();