[clang-format] Handle attributes before lambda return arrow (#94119)

Fixes #92657.

Author: owenca

clang/lib/Format/UnwrappedLineParser.cpp

@@ -2236,7 +2236,7 @@ bool UnwrappedLineParser::tryToParseLambda() {
   bool InTemplateParameterList = false;
 
   while (FormatTok->isNot(tok::l_brace)) {
-    if (FormatTok->isTypeName(LangOpts)) {
+    if (FormatTok->isTypeName(LangOpts) || FormatTok->isAttribute()) {
       nextToken();
       continue;
     }

clang/unittests/Format/FormatTest.cpp

@@ -22664,6 +22664,7 @@ TEST_F(FormatTest, FormatsLambdas) {
   verifyFormat("SomeFunction({[]() -> int *[] { return {}; }});");
   verifyFormat("SomeFunction({[]() -> int (*)[] { return {}; }});");
   verifyFormat("SomeFunction({[]() -> ns::type<int (*)[]> { return {}; }});");
+  verifyFormat("foo([&](u32 bar) __attribute__((always_inline)) -> void {});");
   verifyFormat("return int{[x = x]() { return x; }()};");
 
   // Lambdas with explicit template argument lists.

clang/unittests/Format/TokenAnnotatorTest.cpp

@@ -1577,6 +1577,12 @@ TEST_F(TokenAnnotatorTest, UnderstandsLambdas) {
   EXPECT_TOKEN(Tokens[2], tok::arrow, TT_TrailingReturnArrow);
   EXPECT_TOKEN(Tokens[4], tok::l_brace, TT_LambdaLBrace);
 
+  Tokens = annotate("foo([&](u32 bar) __attribute__((attr)) -> void {});");
+  ASSERT_EQ(Tokens.size(), 22u) << Tokens;
+  EXPECT_TOKEN(Tokens[2], tok::l_square, TT_LambdaLSquare);
+  EXPECT_TOKEN(Tokens[15], tok::arrow, TT_TrailingReturnArrow);
+  EXPECT_TOKEN(Tokens[17], tok::l_brace, TT_LambdaLBrace);
+
   Tokens = annotate("[] <typename T> () {}");
   ASSERT_EQ(Tokens.size(), 11u) << Tokens;
   EXPECT_TOKEN(Tokens[0], tok::l_square, TT_LambdaLSquare);