[clang-format][NFC] Fix a bug in setting type FunctionLBrace

[owenpan]

Summary

The l_brace token in a macro definition should not be set to TT_FunctionLBrace.

This patch could have fixed https://github.com/llvm/llvm-project/issues/42087.

[curdeius]

Well, I thought about this approach but actually a macro line should never be merged together with a preceding line, so I went for a generic approach.
That's because one never knows what's in a macro, it can well be a function brace after all depending on what goes before...
Apart from that, could you add an annotator test please?

[owenpan]

Added a test case.

[owenpan]

In D118969#3295909, @curdeius wrote:

Well, I thought about this approach but actually a macro line should never be merged together with a preceding line, so I went for a generic approach.

That's why I didn't say yours would be obsolete. :)

That's because one never knows what's in a macro, it can well be a function brace after all depending on what goes before...

This is exactly why we should not set the type to FunctionLBrace.

Apart from that, could you add an annotator test please?

Done.

[curdeius]

LGTM!

[HazardyKnusperkeks]

LGTM, since when can't I post an empty comment?

[HazardyKnusperkeks]

Ah because of a race condition, I couldn't accept anymore. :)

[owenpan]

In D118969#3297699, @HazardyKnusperkeks wrote:

Ah because of a race condition, I couldn't accept anymore. :)

Sorry! I should have waited a little longer. :D

clang/lib/Format/UnwrappedLineParser.cpp

case tok::l_brace:
           // If necessary, we could set the type to something different than
           // TT_FunctionLBrace.
           if (Style.BraceWrapping.AfterControlStatement ==
               FormatStyle::BWACS_Always)
             addUnwrappedLine();
         } else if (Style.BraceWrapping.AfterFunction) {
           addUnwrappedLine();
         }
+        if (!Line->InPPDirective)
           FormatTok->setType(TT_FunctionLBrace);
         parseBlock();
         addUnwrappedLine();
         return;
       }
       // Otherwise this was a braced init list, and the structural
       // element continues.
       break;
     case tok::kw_try:

clang/unittests/Format/TokenAnnotatorTest.cpp

 }
 
 TEST_F(TokenAnnotatorTest, UnderstandsEnums) {
   auto Tokens = annotate("enum E {};");
   EXPECT_EQ(Tokens.size(), 6u) << Tokens;
   EXPECT_TOKEN(Tokens[2], tok::l_brace, TT_RecordLBrace);
 }
 
+TEST_F(TokenAnnotatorTest, UnderstandsLBracesInMacroDefinition) {
+  auto Tokens = annotate("#define BEGIN NS {");
+  EXPECT_EQ(Tokens.size(), 6u) << Tokens;
+  EXPECT_TOKEN(Tokens[4], tok::l_brace, TT_Unknown);
+}
+
 } // namespace
 } // namespace format
 } // namespace clang