[clang] [clang-tools-extra] [clang-tidy] `bugprone-unchecked-optional-access`: handle `NullableValue::makeValue` to prevent false-positives (PR #144313)

[Valentyn Yukhymenko via cfe-commits]

https://github.com/BaLiKfromUA created https://github.com/llvm/llvm-project/pull/144313

https://github.com/llvm/llvm-project/pull/101450 added support for `BloombergLP::bdlb::NullableValue`.

However, `NullableValue::makeValue` and `NullableValue::makeValueInplace` have been missed which impacts code like this:
```cpp
  if (opt.isNull()) {
    opt.makeValue(42);
  }

  opt.value(); // triggers false positive warning from `bugprone-unchecked-optional-access`
```

My patch addresses this issue.

>From b2e5ee18bf7f03bbf5f99ef124ef707dc3116886 Mon Sep 17 00:00:00 2001
From: Valentyn Yukhymenko <valentin.yukhymenko at gmail.com>
Date: Mon, 16 Jun 2025 08:55:06 +0100
Subject: [PATCH] first iteration of fix

---
 .../bde/types/bdlb_nullablevalue.h                 |  8 ++++++++
 .../bugprone/unchecked-optional-access.cpp         | 14 ++++++++++++++
 .../Models/UncheckedOptionalAccessModel.cpp        | 13 +++++++++++++
 3 files changed, 35 insertions(+)

diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/Inputs/unchecked-optional-access/bde/types/bdlb_nullablevalue.h b/clang-tools-extra/test/clang-tidy/checkers/bugprone/Inputs/unchecked-optional-access/bde/types/bdlb_nullablevalue.h
index 4411bcfd60a74..0812677111995 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/bugprone/Inputs/unchecked-optional-access/bde/types/bdlb_nullablevalue.h
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/Inputs/unchecked-optional-access/bde/types/bdlb_nullablevalue.h
@@ -20,6 +20,14 @@ class NullableValue : public bsl::optional<T> {
   const T &value() const &;
   T &value() &;
 
+  constexpr T &makeValue();
+
+  template <typename U>
+  constexpr T &makeValue(U&& v);
+
+  template <typename... ARGS>
+  constexpr T &makeValueInplace(ARGS &&... args);
+
   // 'operator bool' is inherited from bsl::optional
 
   constexpr bool isNull() const noexcept;
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 3167b85f0e024..b910db20b3c2e 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
@@ -141,6 +141,20 @@ void nullable_value_after_swap(BloombergLP::bdlb::NullableValue<int> &opt1, Bloo
   }
 }
 
+void nullable_value_make_value(BloombergLP::bdlb::NullableValue<int> &opt1, BloombergLP::bdlb::NullableValue<int> &opt2) {
+  if (opt1.isNull()) {
+    opt1.makeValue(42);
+  }
+
+  opt1.value();
+
+  if (opt2.isNull()) {
+    opt2.makeValueInplace(42);
+  }
+
+  opt2.value();
+}
+
 template <typename T>
 void function_template_without_user(const absl::optional<T> &opt) {
   opt.value(); // no-warning
diff --git a/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp b/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp
index 164d2574132dd..decb32daa9410 100644
--- a/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp
+++ b/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp
@@ -985,6 +985,19 @@ auto buildTransferMatchSwitch() {
           isOptionalMemberCallWithNameMatcher(hasName("isNull")),
           transferOptionalIsNullCall)
 
+      // NullableValue::makeValue, NullableValue::makeValueInplace
+      // Only NullableValue has these methods, but this
+      // will also pass for other types  
+      .CaseOfCFGStmt<CXXMemberCallExpr>(
+          isOptionalMemberCallWithNameMatcher(hasAnyName("makeValue", "makeValueInplace")),
+          [](const CXXMemberCallExpr *E, const MatchFinder::MatchResult &,
+             LatticeTransferState &State) {
+            if (RecordStorageLocation *Loc =
+                    getImplicitObjectLocation(*E, State.Env)) {
+              setHasValue(*Loc, State.Env.getBoolLiteralValue(true), State.Env);
+            }
+          })
+
       // optional::emplace
       .CaseOfCFGStmt<CXXMemberCallExpr>(
           isOptionalMemberCallWithNameMatcher(hasName("emplace")),