[clang-format] Do not insert space before closing brace in ObjC dict literal

[benhamilton]

Summary

Previously, clang-format would sometimes insert a space
before the closing brace in an Objective-C dictionary literal.

Unlike array literals (which obey Style.SpacesInContainerLiterals
to add a space after [ and before ]), Objective-C dictionary
literals currently are not meant to insert a space after { and before
}, regardless of Style.SpacesInContainerLiterals.

However, some constructs like @{foo : @(bar)} caused clang-format
to insert a space between ) and }.

This fixes the issue and adds tests. (I understand the behavior is
not consistent between array literals and dictionary literals, but
that's existing behavior that's a much larger change.)

Test Plan: New tests added. Ran tests with:

% make -j12 FormatTests && ./tools/clang/unittests/Format/FormatTests

[djasper]

Generally looks good, one minor simplification.

lib/Format/TokenAnnotator.cpp

2484

Could you use Right.MatchingParen->endsSequence(TT_DictLiteral, tok::at) here?

[benhamilton]

• Use Right.MatchingParen->endsSequence(TT_DictLiteral, tok::at)

lib/Format/TokenAnnotator.cpp

2484

Yes, done. I keep forgetting about the reverse order of that method (it makes sense, I just can't keep that info in my brain for some reason.)

[djasper]

Yeah, it's one of these things where neither way would be totally intuitive to everyone.

[benhamilton]

I filed https://bugs.llvm.org/show_bug.cgi?id=36919 to follow up and make ObjC dictionary literal spacing consistent with ObjC array literals.

lib/Format/TokenAnnotator.cpp

if (Right.is(tok::hash) && Left.is(tok::identifier) && Left.TokenText == "L")
     return false;
   if (Left.is(TT_TemplateCloser) && Left.MatchingParen &&
       Left.MatchingParen->Previous &&
       Left.MatchingParen->Previous->is(tok::period))
     // A.<B<C<...>>>DoSomething();
     return false;
   if (Left.is(TT_TemplateCloser) && Right.is(tok::l_square))
     return false;
+  if (Right.is(tok::r_brace) && Right.MatchingParen &&
+      Right.MatchingParen->endsSequence(TT_DictLiteral, tok::at))
+    // Objective-C dictionary literal -> no space before closing brace.
+    return false;
   return true;
 }
 
 bool TokenAnnotator::spaceRequiredBefore(const AnnotatedLine &Line,
                                          const FormatToken &Right) {
   const FormatToken &Left = *Right.Previous;
   if (Right.Tok.getIdentifierInfo() && Left.Tok.getIdentifierInfo())
     return true; // Never ever merge two identifiers.

unittests/Format/FormatTestObjC.cpp

verifyFormat("NSMutableDictionary *dictionary =\n"
                "    }];");
 
   // Ensure that casts before the key are kept on the same line as the key.
   verifyFormat(
       "NSDictionary *d = @{\n"
       "  (aaaaaaaa id)aaaaaaaaa : (aaaaaaaa id)aaaaaaaaaaaaaaaaaaaaaaaa,\n"
       "  (aaaaaaaa id)aaaaaaaaaaaaaa : (aaaaaaaa id)aaaaaaaaaaaaaa,\n"
       "};");
+  Style.ColumnLimit = 40;
+  verifyFormat("int Foo() {\n"
+               "  a12345 = @{a12345 : a12345};\n"
+               "}");
+  verifyFormat("int Foo() {\n"
+               "  a12345 = @{(Foo *)a12345 : @(a12345)};\n"
+               "}");
+  Style.SpacesInContainerLiterals = false;
+  verifyFormat("int Foo() {\n"
+               "  b12345 = @{b12345: b12345};\n"
+               "}");
+  verifyFormat("int Foo() {\n"
+               "  b12345 = @{(Foo *)b12345: @(b12345)};\n"
+               "}");
+  Style.SpacesInContainerLiterals = true;
 
   Style = getGoogleStyle(FormatStyle::LK_ObjC);
   verifyFormat(
       "@{\n"
       "  NSFontAttributeNameeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee : "
       "regularFont,\n"
       "};");
 }
TEST_F(FormatTestObjC, ObjCArrayLiterals) {
   verifyFormat(
       "- (NSAttributedString *)attributedStringForSegment:(NSUInteger)segment\n"
       "                                             index:(NSUInteger)index\n"
       "                                nonDigitAttributes:\n"
       "                                    (NSDictionary *)noDigitAttributes;");
   verifyFormat("[someFunction someLooooooooooooongParameter:@[\n"
                "  NSBundle.mainBundle.infoDictionary[@\"a\"]\n"
                "]];");
+  Style.ColumnLimit = 40;
+  verifyFormat("int Foo() {\n"
+               "  a12345 = @[ a12345, a12345 ];\n"
+               "}");
+  verifyFormat("int Foo() {\n"
+               "  a123 = @[ (Foo *)a12345, @(a12345) ];\n"
+               "}");
+  Style.SpacesInContainerLiterals = false;
+  verifyFormat("int Foo() {\n"
+               "  b12345 = @[b12345, b12345];\n"
+               "}");
+  verifyFormat("int Foo() {\n"
+               "  b12345 = @[(Foo *)b12345, @(b12345)];\n"
+               "}");
+  Style.SpacesInContainerLiterals = true;
   Style.ColumnLimit = 20;
   // We can't break string literals inside NSArray literals
   // (that raises -Wobjc-string-concatenation).
   verifyFormat("NSArray *foo = @[\n"
                "  @\"aaaaaaaaaaaaaaaaaaaaaaaaaa\"\n"
                "];\n");
 }
 } // end namespace
 } // end namespace format
 } // end namespace clang