[clang] [webkit.UncountedLambdaCapturesChecker] Treat a call to lambda function via a variable as safe. (PR #135688)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-static-analyzer-1

Author: Ryosuke Niwa (rniwa)

<details>
<summary>Changes</summary>

This PR makes the checker ignore a function call to lambda via a local variable.

---
Full diff: https://github.com/llvm/llvm-project/pull/135688.diff


2 Files Affected:

- (modified) clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefLambdaCapturesChecker.cpp (-2) 
- (modified) clang/test/Analysis/Checkers/WebKit/uncounted-lambda-captures.cpp (+8) 


``````````diff
diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefLambdaCapturesChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefLambdaCapturesChecker.cpp
index da403d591a2e2..0a658b59ad8c5 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefLambdaCapturesChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefLambdaCapturesChecker.cpp
@@ -263,8 +263,6 @@ class RawPtrRefLambdaCapturesChecker
           return;
         DeclRefExprsToIgnore.insert(ArgRef);
         LambdasToIgnore.insert(L);
-        Checker->visitLambdaExpr(L, shouldCheckThis() && !hasProtectedThis(L),
-                                 ClsType, /* ignoreParamVarDecl */ true);
       }
 
       bool hasProtectedThis(LambdaExpr *L) {
diff --git a/clang/test/Analysis/Checkers/WebKit/uncounted-lambda-captures.cpp b/clang/test/Analysis/Checkers/WebKit/uncounted-lambda-captures.cpp
index 36135973e78c0..cc3d27bbc1375 100644
--- a/clang/test/Analysis/Checkers/WebKit/uncounted-lambda-captures.cpp
+++ b/clang/test/Analysis/Checkers/WebKit/uncounted-lambda-captures.cpp
@@ -372,6 +372,14 @@ void trivial_lambda() {
   trivial_lambda();
 }
 
+bool call_lambda_var_decl() {
+  RefCountable* ref_countable = make_obj();
+  auto lambda = [&]() -> bool {
+    return ref_countable->next();
+  };
+  return lambda();
+}
+
 void lambda_with_args(RefCountable* obj) {
   auto trivial_lambda = [&](int v) {
     obj->method();

``````````

</details>


https://github.com/llvm/llvm-project/pull/135688