[clang] [clang] Fix false positive regression for lifetime analysis warning. (PR #127460)

[Haojian Wu via cfe-commits]

https://github.com/hokein updated 
https://github.com/llvm/llvm-project/pull/127460

>From 26cf4cd668f9a2d533014a85e8da4a91ce6c8994 Mon Sep 17 00:00:00 2001
From: Haojian Wu <hokein...@gmail.com>
Date: Mon, 17 Feb 2025 10:08:14 +0100
Subject: [PATCH] [clang] Fix false positive regression for lifetime analysis
 warning.

---
 clang/lib/Sema/CheckExprLifetime.cpp          |  5 ++--
 clang/test/Sema/Inputs/lifetime-analysis.h    |  2 ++
 .../Sema/warn-lifetime-analysis-nocfg.cpp     | 24 +++++++++++++++++++
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Sema/CheckExprLifetime.cpp 
b/clang/lib/Sema/CheckExprLifetime.cpp
index 8963cad86dbca..3e0867343ccee 100644
--- a/clang/lib/Sema/CheckExprLifetime.cpp
+++ b/clang/lib/Sema/CheckExprLifetime.cpp
@@ -1239,11 +1239,12 @@ static AnalysisResult analyzePathForGSLPointer(const 
IndirectLocalPath &Path,
     }
     // Check the return type, e.g.
     //   const GSLOwner& func(const Foo& foo [[clang::lifetimebound]])
+    //   GSLOwner* func(cosnt Foo& foo [[clang::lifetimebound]])
     //   GSLPointer func(const Foo& foo [[clang::lifetimebound]])
     if (FD &&
-        ((FD->getReturnType()->isReferenceType() &&
+        ((FD->getReturnType()->isPointerOrReferenceType() &&
           isRecordWithAttr<OwnerAttr>(FD->getReturnType()->getPointeeType())) 
||
-         isPointerLikeType(FD->getReturnType())))
+          isGLSPointerType(FD->getReturnType())))
       return Report;
 
     return Abandon;
diff --git a/clang/test/Sema/Inputs/lifetime-analysis.h 
b/clang/test/Sema/Inputs/lifetime-analysis.h
index d318033ff0cc4..2072e4603cead 100644
--- a/clang/test/Sema/Inputs/lifetime-analysis.h
+++ b/clang/test/Sema/Inputs/lifetime-analysis.h
@@ -61,6 +61,7 @@ struct basic_string_view {
   basic_string_view();
   basic_string_view(const T *);
   const T *begin() const;
+  const T *data() const;
 };
 using string_view = basic_string_view<char>;
 
@@ -80,6 +81,7 @@ struct basic_string {
   const T *c_str() const;
   operator basic_string_view<T> () const;
   using const_iterator = iter<T>;
+  const T *data() const;
 };
 using string = basic_string<char>;
 
diff --git a/clang/test/Sema/warn-lifetime-analysis-nocfg.cpp 
b/clang/test/Sema/warn-lifetime-analysis-nocfg.cpp
index 04bb1330ded4c..a65bb936ca8cb 100644
--- a/clang/test/Sema/warn-lifetime-analysis-nocfg.cpp
+++ b/clang/test/Sema/warn-lifetime-analysis-nocfg.cpp
@@ -852,3 +852,27 @@ struct Test {
 };
 
 } // namespace GH120543
+
+namespace GH127195 {
+template <typename T>
+struct StatusOr {
+  T* operator->() [[clang::lifetimebound]];
+  T* value() [[clang::lifetimebound]];
+};
+
+const char* foo() {
+  StatusOr<std::string> s;
+  return s->data(); // expected-warning {{address of stack memory associated 
with local variable}}
+  
+  StatusOr<std::string_view> s2;
+  return s2->data();
+
+  StatusOr<StatusOr<std::string_view>> s3;
+  return s3.value()->value()->data();
+
+  // would be nice to support the nested cases.
+  StatusOr<StatusOr<std::string>> s4;
+  return s4.value()->value()->data();
+}
+
+} // namespace GH127195

_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits