[clang] [clang-tools-extra] [clang-tidy] fix false positive in bugprone-unchecked-optional-access for nested loops (PR #177858)

[via cfe-commits]

https://github.com/zeyi2 updated https://github.com/llvm/llvm-project/pull/177858

>From d2ec6c53b7c534258dd08fdbe9fd183c09cf0de4 Mon Sep 17 00:00:00 2001
From: mtx <mitchell.xu2 at gmail.com>
Date: Sun, 25 Jan 2026 22:09:53 +0800
Subject: [PATCH] [clang-tidy] fix false positive in
 bugprone-unchecked-optional-access for nested loops

---
 clang-tools-extra/docs/ReleaseNotes.rst       |  5 +++
 .../bugprone/unchecked-optional-access.cpp    | 35 +++++++++++++++++++
 .../Models/UncheckedOptionalAccessModel.cpp   |  8 +++--
 3 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 5af634c77f54d..0b2bde80edff2 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -109,6 +109,11 @@ New check aliases
 Changes in existing checks
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+- Improved :doc:`bugprone-unchecked-optional-access
+  <clang-tidy/checks/bugprone/unchecked-optional-access>` check to avoid false
+  positives in nested loops by excluding generic const accessors from
+  unnecessary dataflow analysis.
+
 - Improved :doc:`bugprone-unsafe-functions
   <clang-tidy/checks/bugprone/unsafe-functions>` check by adding the function
   ``std::get_temporary_buffer`` to the default list of unsafe functions. (This
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/unchecked-optional-access.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/unchecked-optional-access.cpp
index 984156c028c00..14672f5ab5546 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/bugprone/unchecked-optional-access.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/unchecked-optional-access.cpp
@@ -370,3 +370,38 @@ void foo() {
   if (!vec.empty())
     vec[0].x = 0;
 }
+
+namespace std {
+template <typename T>
+struct vector_iterator {
+  T& operator*();
+  vector_iterator& operator++();
+  bool operator!=(const vector_iterator&);
+};
+
+template <typename T>
+struct vector_with_iter {
+  vector_iterator<T> begin();
+  vector_iterator<T> end();
+};
+
+} // namespace std
+
+void nested_loops() {
+  std::vector_with_iter<absl::optional<int>> optionals;
+  for (const auto &opt : optionals) {
+    if (opt.has_value()) {
+      for (int i = 0; i < 10; ++i) {
+        opt.value(); // no-warning
+      }
+    }
+  }
+
+  for (const auto &opt : optionals) {
+    if (opt.has_value()) {
+      for (;;) {
+        opt.value(); // no-warning
+      }
+    }
+  }
+}
diff --git a/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp b/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp
index 04a2a557debb2..dcc88f8a7f838 100644
--- a/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp
+++ b/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp
@@ -338,13 +338,15 @@ auto isValueOrNotEqX() {
 }
 
 auto isZeroParamConstMemberCall() {
-  return cxxMemberCallExpr(
-      callee(cxxMethodDecl(parameterCountIs(0), isConst())));
+  return cxxMemberCallExpr(callee(cxxMethodDecl(
+      parameterCountIs(0), isConst(),
+      unless(hasAnyName("value", "has_value", "hasValue", "operator bool")))));
 }
 
 auto isZeroParamConstMemberOperatorCall() {
   return cxxOperatorCallExpr(
-      callee(cxxMethodDecl(parameterCountIs(0), isConst())));
+      callee(cxxMethodDecl(parameterCountIs(0), isConst(),
+                           unless(hasAnyName("operator*", "operator->")))));
 }
 
 auto isNonConstMemberCall() {