[clang] [clang-format] Don't allow casts in front of ampamp (PR #77704)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-format

Author: Emilia Kond (rymiel)

<details>
<summary>Changes</summary>

clang-format performs a heuristic to see if a right parenthesis is the parenthesis of a cast expression. This check never looked ahead to see if the next token is an ampamp && token. This resulted in the paren being set as an CastRParen, and the following ampamp got annotated as an UnaryOperator!

Since && can never be a unary operator is standard C++, this patch forbids the right paren from ever becoming a cast.

Fixes https://github.com/llvm/llvm-project/issues/77680

---
Full diff: https://github.com/llvm/llvm-project/pull/77704.diff


2 Files Affected:

- (modified) clang/lib/Format/TokenAnnotator.cpp (+1-1) 
- (modified) clang/unittests/Format/TokenAnnotatorTest.cpp (+5) 


``````````diff
diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 8b43438c72dfe1..854e85db5be4d9 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -2369,7 +2369,7 @@ class AnnotatingParser {
       }
     }
 
-    if (Tok.Next->is(tok::question))
+    if (Tok.Next->isOneOf(tok::question, tok::ampamp))
       return false;
 
     // `foreach((A a, B b) in someList)` should not be seen as a cast.
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
index decc0785c5cde7..4f4c54b344e109 100644
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -1066,6 +1066,11 @@ TEST_F(TokenAnnotatorTest, UnderstandsRequiresClausesAndConcepts) {
   EXPECT_EQ(Tokens.size(), 17u) << Tokens;
   EXPECT_TOKEN(Tokens[4], tok::amp, TT_PointerOrReference);
   EXPECT_TOKEN(Tokens[5], tok::kw_requires, TT_RequiresClause);
+
+  Tokens = annotate("template <typename T>\n"
+                    "concept C = (!Foo<T>) && Bar;");
+  ASSERT_EQ(Tokens.size(), 19u) << Tokens;
+  EXPECT_TOKEN(Tokens[15], tok::ampamp, TT_BinaryOperator);
 }
 
 TEST_F(TokenAnnotatorTest, UnderstandsRequiresExpressions) {

``````````

</details>


https://github.com/llvm/llvm-project/pull/77704