[clang-format] Correctly annotate list init braces of class types (#89706)

Fixes #71939.

Author: owenca

clang/lib/Format/UnwrappedLineParser.cpp

@@ -819,8 +819,11 @@ FormatToken *UnwrappedLineParser::parseBlock(bool MustBeDeclaration,
     return IfLBrace;
   }
 
-  if (FormatTok->is(tok::r_brace) && Tok->is(TT_NamespaceLBrace))
-    FormatTok->setFinalizedType(TT_NamespaceRBrace);
+  if (FormatTok->is(tok::r_brace)) {
+    FormatTok->setBlockKind(BK_Block);
+    if (Tok->is(TT_NamespaceLBrace))
+      FormatTok->setFinalizedType(TT_NamespaceRBrace);
+  }
 
   const bool IsFunctionRBrace =
       FormatTok->is(tok::r_brace) && Tok->is(TT_FunctionLBrace);
@@ -3910,6 +3913,8 @@ void UnwrappedLineParser::parseRecord(bool ParseAsExpr) {
   const FormatToken &InitialToken = *FormatTok;
   nextToken();
 
+  const FormatToken *ClassName = nullptr;
+  bool IsDerived = false;
   auto IsNonMacroIdentifier = [](const FormatToken *Tok) {
     return Tok->is(tok::identifier) && Tok->TokenText != Tok->TokenText.upper();
   };
@@ -3934,15 +3939,35 @@ void UnwrappedLineParser::parseRecord(bool ParseAsExpr) {
     }
     if (FormatTok->is(tok::l_square) && handleCppAttributes())
       continue;
+    const auto *Previous = FormatTok;
     nextToken();
-    // We can have macros in between 'class' and the class name.
-    if (!IsNonMacroIdentifier(FormatTok->Previous) &&
-        FormatTok->is(tok::l_paren)) {
-      parseParens();
+    switch (FormatTok->Tok.getKind()) {
+    case tok::l_paren:
+      // We can have macros in between 'class' and the class name.
+      if (!IsNonMacroIdentifier(Previous))
+        parseParens();
+      break;
+    case tok::coloncolon:
+      break;
+    default:
+      if (!ClassName && Previous->is(tok::identifier))
+        ClassName = Previous;
     }
   }
 
+  auto IsListInitialization = [&] {
+    if (!ClassName || IsDerived)
+      return false;
+    assert(FormatTok->is(tok::l_brace));
+    const auto *Prev = FormatTok->getPreviousNonComment();
+    assert(Prev);
+    return Prev != ClassName && Prev->is(tok::identifier) &&
+           Prev->isNot(Keywords.kw_final) && tryToParseBracedList();
+  };
+
   if (FormatTok->isOneOf(tok::colon, tok::less)) {
+    if (FormatTok->is(tok::colon))
+      IsDerived = true;
     int AngleNestingLevel = 0;
     do {
       if (FormatTok->is(tok::less))
@@ -3955,6 +3980,8 @@ void UnwrappedLineParser::parseRecord(bool ParseAsExpr) {
         break;
       }
       if (FormatTok->is(tok::l_brace)) {
+        if (AngleNestingLevel == 0 && IsListInitialization())
+          return;
         calculateBraceTypes(/*ExpectClassBody=*/true);
         if (!tryToParseBracedList())
           break;
@@ -3999,6 +4026,8 @@ void UnwrappedLineParser::parseRecord(bool ParseAsExpr) {
     }
   };
   if (FormatTok->is(tok::l_brace)) {
+    if (IsListInitialization())
+      return;
     auto [OpenBraceType, ClosingBraceType] = GetBraceTypes(InitialToken);
     FormatTok->setFinalizedType(OpenBraceType);
     if (ParseAsExpr) {

clang/unittests/Format/TokenAnnotatorTest.cpp

@@ -2855,6 +2855,66 @@ TEST_F(TokenAnnotatorTest, BraceKind) {
   ASSERT_EQ(Tokens.size(), 18u) << Tokens;
   EXPECT_BRACE_KIND(Tokens[8], BK_BracedInit);
   EXPECT_BRACE_KIND(Tokens[16], BK_BracedInit);
+
+  Tokens = annotate("struct {};");
+  ASSERT_EQ(Tokens.size(), 5u) << Tokens;
+  EXPECT_BRACE_KIND(Tokens[1], BK_Block);
+  EXPECT_BRACE_KIND(Tokens[2], BK_Block);
+
+  Tokens = annotate("struct : Base {};");
+  ASSERT_EQ(Tokens.size(), 7u) << Tokens;
+  EXPECT_BRACE_KIND(Tokens[3], BK_Block);
+  EXPECT_BRACE_KIND(Tokens[4], BK_Block);
+
+  Tokens = annotate("struct Foo {};");
+  ASSERT_EQ(Tokens.size(), 6u) << Tokens;
+  EXPECT_BRACE_KIND(Tokens[2], BK_Block);
+  EXPECT_BRACE_KIND(Tokens[3], BK_Block);
+
+  Tokens = annotate("struct ::Foo {};");
+  ASSERT_EQ(Tokens.size(), 7u) << Tokens;
+  EXPECT_BRACE_KIND(Tokens[3], BK_Block);
+  EXPECT_BRACE_KIND(Tokens[4], BK_Block);
+
+  Tokens = annotate("struct NS::Foo {};");
+  ASSERT_EQ(Tokens.size(), 8u) << Tokens;
+  EXPECT_BRACE_KIND(Tokens[4], BK_Block);
+  EXPECT_BRACE_KIND(Tokens[5], BK_Block);
+
+  Tokens = annotate("struct Foo<int> {};");
+  ASSERT_EQ(Tokens.size(), 9u) << Tokens;
+  EXPECT_BRACE_KIND(Tokens[5], BK_Block);
+  EXPECT_BRACE_KIND(Tokens[6], BK_Block);
+
+  Tokens = annotate("struct Foo final {};");
+  ASSERT_EQ(Tokens.size(), 7u) << Tokens;
+  EXPECT_BRACE_KIND(Tokens[3], BK_Block);
+  EXPECT_BRACE_KIND(Tokens[4], BK_Block);
+
+  Tokens = annotate("struct [[foo]] [[bar]] Foo final : Base1, Base2 {};");
+  ASSERT_EQ(Tokens.size(), 21u) << Tokens;
+  EXPECT_BRACE_KIND(Tokens[17], BK_Block);
+  EXPECT_BRACE_KIND(Tokens[18], BK_Block);
+
+  Tokens = annotate("struct Foo x{};");
+  ASSERT_EQ(Tokens.size(), 7u) << Tokens;
+  EXPECT_BRACE_KIND(Tokens[3], BK_BracedInit);
+  EXPECT_BRACE_KIND(Tokens[4], BK_BracedInit);
+
+  Tokens = annotate("struct ::Foo x{};");
+  ASSERT_EQ(Tokens.size(), 8u) << Tokens;
+  EXPECT_BRACE_KIND(Tokens[4], BK_BracedInit);
+  EXPECT_BRACE_KIND(Tokens[5], BK_BracedInit);
+
+  Tokens = annotate("struct NS::Foo x{};");
+  ASSERT_EQ(Tokens.size(), 9u) << Tokens;
+  EXPECT_BRACE_KIND(Tokens[5], BK_BracedInit);
+  EXPECT_BRACE_KIND(Tokens[6], BK_BracedInit);
+
+  Tokens = annotate("struct Foo<int> x{};");
+  ASSERT_EQ(Tokens.size(), 10u) << Tokens;
+  EXPECT_BRACE_KIND(Tokens[6], BK_BracedInit);
+  EXPECT_BRACE_KIND(Tokens[7], BK_BracedInit);
 }
 
 TEST_F(TokenAnnotatorTest, UnderstandsElaboratedTypeSpecifier) {