[clang-format] Fix a bug in annotating arrows after init braces

[owenca]

Fixes #59066.

[llvmbot]

@llvm/pr-subscribers-clang-format

Author: Owen Pan (owenca)

Changes

Fixes #59066.

---

Full diff: https://github.com/llvm/llvm-project/pull/119958.diff

3 Files Affected:

• (modified) clang/lib/Format/TokenAnnotator.cpp (+2-1)
• (modified) clang/lib/Format/UnwrappedLineParser.cpp (+3-2)
• (modified) clang/unittests/Format/TokenAnnotatorTest.cpp (+7)

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 05c86db55641f6..667874853152ed 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -2403,7 +2403,8 @@ class AnnotatingParser {
       // not auto operator->() -> xxx;
       Current.setType(TT_TrailingReturnArrow);
     } else if (Current.is(tok::arrow) && Current.Previous &&
-               Current.Previous->is(tok::r_brace)) {
+               Current.Previous->is(tok::r_brace) &&
+               Current.Previous->is(BK_Block)) {
       // Concept implicit conversion constraint needs to be treated like
       // a trailing return type  ... } -> <type>.
       Current.setType(TT_TrailingReturnArrow);
diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
index de7e261b21d303..654148a161bd7f 100644
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -570,8 +570,9 @@ void UnwrappedLineParser::calculateBraceTypes(bool ExpectClassBody) {
                                 NextTok->isOneOf(Keywords.kw_of, Keywords.kw_in,
                                                  Keywords.kw_as));
           ProbablyBracedList =
-              ProbablyBracedList || (IsCpp && (PrevTok->Tok.isLiteral() ||
-                                               NextTok->is(tok::l_paren)));
+              ProbablyBracedList ||
+              (IsCpp && (PrevTok->Tok.isLiteral() ||
+                         NextTok->isOneOf(tok::l_paren, tok::arrow)));
 
           // If there is a comma, semicolon or right paren after the closing
           // brace, we assume this is a braced initializer list.
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index 38658fcb0e9990..b2fb5227993c3f 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -2277,6 +2277,13 @@ TEST_F(TokenAnnotatorTest, UnderstandsTrailingReturnArrow) {
   ASSERT_EQ(Tokens.size(), 21u) << Tokens;
   EXPECT_TOKEN(Tokens[13], tok::arrow, TT_Unknown);
 
+  Tokens = annotate("Class<Type>{foo}->func(arg);");
+  ASSERT_EQ(Tokens.size(), 14u) << Tokens;
+  EXPECT_TOKEN(Tokens[4], tok::l_brace, TT_Unknown); // Not FunctionLBrace
+  EXPECT_BRACE_KIND(Tokens[4], BK_BracedInit);
+  EXPECT_BRACE_KIND(Tokens[6], BK_BracedInit);
+  EXPECT_TOKEN(Tokens[7], tok::arrow, TT_Unknown);
+
   auto Style = getLLVMStyle();
   Style.StatementAttributeLikeMacros.push_back("emit");
   Tokens = annotate("emit foo()->bar;", Style);