[clang] [clang-format] Fix an assertion failure on invalid C++ lambda (PR #185349)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-format

Author: owenca (owenca)

<details>
<summary>Changes</summary>

Fixes #<!-- -->185268

---
Full diff: https://github.com/llvm/llvm-project/pull/185349.diff


2 Files Affected:

- (modified) clang/lib/Format/TokenAnnotator.cpp (+1-1) 
- (modified) clang/unittests/Format/FormatTest.cpp (+4) 


``````````diff
diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 1b588435d6302..965c9195aa7f4 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -4147,7 +4147,7 @@ void TokenAnnotator::calculateFormattingInformation(AnnotatedLine &Line) const {
         if (Tok->is(TT_CtorInitializerColon))
           break;
         if (Tok->is(tok::arrow)) {
-          Tok->setType(TT_TrailingReturnArrow);
+          Tok->overwriteFixedType(TT_TrailingReturnArrow);
           break;
         }
         if (Tok->isNot(TT_TrailingAnnotation))
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 33af71de398be..f2503a0a27bb5 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -29245,6 +29245,10 @@ TEST_F(FormatTest, UnbalancedAngleBrackets) {
                 getLLVMStyleWithColumns(50));
 }
 
+TEST_F(FormatTest, LambdaArrowAsTrailingReturnArrow) {
+  verifyNoCrash("void foo()([] consteval -> int {}())");
+}
+
 } // namespace
 } // namespace test
 } // namespace format

``````````

</details>


https://github.com/llvm/llvm-project/pull/185349