[clang] [clang-format] Fix a bug in annotating lambda l_square (PR #95084)

[Owen Pan via cfe-commits]

https://github.com/owenca updated https://github.com/llvm/llvm-project/pull/95084

>From b89f8a5bcbf525d779565219951359162655929e Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Tue, 11 Jun 2024 01:32:32 -0700
Subject: [PATCH 1/2] [clang-format] Fix a bug in annotating lambda l_square

Fixes #95072.
---
 clang/lib/Format/UnwrappedLineParser.cpp      | 2 ++
 clang/unittests/Format/TokenAnnotatorTest.cpp | 6 ++++++
 2 files changed, 8 insertions(+)

diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
index eb96b54ec4c96..08387d2e08ee0 100644
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -2257,6 +2257,8 @@ bool UnwrappedLineParser::tryToParseLambda() {
       break;
     case tok::kw_auto:
     case tok::kw_class:
+    case tok::kw_struct:
+    case tok::kw_union:
     case tok::kw_template:
     case tok::kw_typename:
     case tok::amp:
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index 3d609a1f041bc..0a1fb8c657ceb 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -1591,6 +1591,12 @@ TEST_F(TokenAnnotatorTest, UnderstandsLambdas) {
   EXPECT_TOKEN(Tokens[15], tok::arrow, TT_TrailingReturnArrow);
   EXPECT_TOKEN(Tokens[17], tok::l_brace, TT_LambdaLBrace);
 
+  Tokens = annotate("auto l = [] -> struct S { return {}; };");
+  ASSERT_EQ(Tokens.size(), 16u) << Tokens;
+  EXPECT_TOKEN(Tokens[3], tok::l_square, TT_LambdaLSquare);
+  EXPECT_TOKEN(Tokens[5], tok::arrow, TT_TrailingReturnArrow);
+  EXPECT_TOKEN(Tokens[8], tok::l_brace, TT_LambdaLBrace);
+
   Tokens = annotate("[] <typename T> () {}");
   ASSERT_EQ(Tokens.size(), 11u) << Tokens;
   EXPECT_TOKEN(Tokens[0], tok::l_square, TT_LambdaLSquare);

>From 14cd4ea57ed78a5f08780882f5ec5d3d237b0316 Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Tue, 11 Jun 2024 19:16:54 -0700
Subject: [PATCH 2/2] Simplify the test case.

---
 clang/unittests/Format/TokenAnnotatorTest.cpp | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index 0a1fb8c657ceb..27b903468de4b 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -1585,18 +1585,18 @@ TEST_F(TokenAnnotatorTest, UnderstandsLambdas) {
   EXPECT_TOKEN(Tokens[2], tok::arrow, TT_TrailingReturnArrow);
   EXPECT_TOKEN(Tokens[4], tok::l_brace, TT_LambdaLBrace);
 
+  Tokens = annotate("[] -> struct S { return {}; }");
+  ASSERT_EQ(Tokens.size(), 12u) << Tokens;
+  EXPECT_TOKEN(Tokens[0], tok::l_square, TT_LambdaLSquare);
+  EXPECT_TOKEN(Tokens[2], tok::arrow, TT_TrailingReturnArrow);
+  EXPECT_TOKEN(Tokens[5], 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("auto l = [] -> struct S { return {}; };");
-  ASSERT_EQ(Tokens.size(), 16u) << Tokens;
-  EXPECT_TOKEN(Tokens[3], tok::l_square, TT_LambdaLSquare);
-  EXPECT_TOKEN(Tokens[5], tok::arrow, TT_TrailingReturnArrow);
-  EXPECT_TOKEN(Tokens[8], tok::l_brace, TT_LambdaLBrace);
-
   Tokens = annotate("[] <typename T> () {}");
   ASSERT_EQ(Tokens.size(), 11u) << Tokens;
   EXPECT_TOKEN(Tokens[0], tok::l_square, TT_LambdaLSquare);