[clang-tools-extra] [clang-tidy] `bugprone-exception-escape` didn't detech catching of an exception with pointer type by `void *` exception handler (PR #99773)

[Hana Dusíková via cfe-commits]

https://github.com/hanickadot updated https://github.com/llvm/llvm-project/pull/99773

>From ebf1c6996f18cbd706ec3d76a1887c58c9ce3230 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hana=20Dusi=CC=81kova=CC=81?= <hanicka at hanicka.net>
Date: Sat, 20 Jul 2024 20:12:45 +0200
Subject: [PATCH 1/2] [clang-tidy] `bugprone-exception-escape` didn't detech
 catching of an exception with pointer type by `void *` exception handler

---
 .../clang-tidy/utils/ExceptionAnalyzer.cpp     | 10 +++++-----
 clang-tools-extra/docs/ReleaseNotes.rst        |  4 ++++
 .../checkers/bugprone/exception-escape.cpp     | 18 ++++++++++++++++++
 3 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/utils/ExceptionAnalyzer.cpp b/clang-tools-extra/clang-tidy/utils/ExceptionAnalyzer.cpp
index 6ae46e2b1262a..9bfb7e2677533 100644
--- a/clang-tools-extra/clang-tidy/utils/ExceptionAnalyzer.cpp
+++ b/clang-tools-extra/clang-tidy/utils/ExceptionAnalyzer.cpp
@@ -141,7 +141,10 @@ bool isStandardPointerConvertible(QualType From, QualType To) {
     if (RD->isCompleteDefinition() &&
         isBaseOf(From->getPointeeType().getTypePtr(),
                  To->getPointeeType().getTypePtr())) {
-      return true;
+      // If B is an inaccessible or ambiguous base class of D, a program
+      // that necessitates this conversion is ill-formed
+      return isUnambiguousPublicBaseClass(From->getPointeeType().getTypePtr(),
+                                          To->getPointeeType().getTypePtr());
     }
   }
 
@@ -375,10 +378,7 @@ bool ExceptionAnalyzer::ExceptionInfo::filterByCatch(
         isPointerOrPointerToMember(ExceptionCanTy->getTypePtr())) {
       // A standard pointer conversion not involving conversions to pointers to
       // private or protected or ambiguous classes ...
-      if (isStandardPointerConvertible(ExceptionCanTy, HandlerCanTy) &&
-          isUnambiguousPublicBaseClass(
-              ExceptionCanTy->getTypePtr()->getPointeeType().getTypePtr(),
-              HandlerCanTy->getTypePtr()->getPointeeType().getTypePtr())) {
+      if (isStandardPointerConvertible(ExceptionCanTy, HandlerCanTy)) {
         TypesToDelete.push_back(ExceptionTy);
       }
       // A function pointer conversion ...
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index a23483e6df6d2..30228828686da 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -245,6 +245,10 @@ Changes in existing checks
   where source is already a ``void``` pointer, making middle ``void`` pointer
   casts bug-free.
 
+- Improved :doc:`exception-escape <clang-tidy/checks/bugprone/exception-escape>`
+  check to correctly detect exception handler of type ``CV void *`` as catching all 
+  ``CV`` compatible pointer types.
+
 - Improved :doc:`bugprone-forwarding-reference-overload
   <clang-tidy/checks/bugprone/forwarding-reference-overload>`
   check to ignore deleted constructors which won't hide other overloads.
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/exception-escape.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/exception-escape.cpp
index f5e74df1621ce..26c443b139629 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/bugprone/exception-escape.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/exception-escape.cpp
@@ -756,3 +756,21 @@ struct test_implicit_throw {
 };
 
 }}
+
+void pointer_exception_can_not_escape_with_const_void_handler() noexcept {
+  // CHECK-MESSAGES-NOT: :[[@LINE-1]]:6: warning: an exception may be thrown in function 'pointer_exception_can_not_escape_with_const_void_handler' which should not throw exceptions
+  const int value = 42;
+  try {
+    throw &value;
+  } catch (const void *) {
+  }
+}
+
+void pointer_exception_can_not_escape_with_void_handler() noexcept {
+  // CHECK-MESSAGES-NOT: :[[@LINE-1]]:6: warning: an exception may be thrown in function 'pointer_exception_can_not_escape_with_void_handler' which should not throw exceptions
+  int value = 42;
+  try {
+    throw &value;
+  } catch (void *) {
+  }
+}

>From 1363d619a264f3e4633870d950e26bd3ba59692f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hana=20Dus=C3=ADkov=C3=A1?= <hanicka at hanicka.net>
Date: Mon, 22 Jul 2024 20:45:42 +0200
Subject: [PATCH 2/2] Update clang-tools-extra/docs/ReleaseNotes.rst

Co-authored-by: Piotr Zegar <me at piotrzegar.pl>
---
 clang-tools-extra/docs/ReleaseNotes.rst | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 30228828686da..233fb0e01be86 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -245,9 +245,9 @@ Changes in existing checks
   where source is already a ``void``` pointer, making middle ``void`` pointer
   casts bug-free.
 
-- Improved :doc:`exception-escape <clang-tidy/checks/bugprone/exception-escape>`
-  check to correctly detect exception handler of type ``CV void *`` as catching all 
-  ``CV`` compatible pointer types.
+- Improved :doc:`bugprone-exception-escape
+  <clang-tidy/checks/bugprone/exception-escape>`  check to correctly detect exception 
+  handler of type ``CV void *`` as catching all  ``CV`` compatible pointer types.
 
 - Improved :doc:`bugprone-forwarding-reference-overload
   <clang-tidy/checks/bugprone/forwarding-reference-overload>`