https://github.com/hanickadot created
https://github.com/llvm/llvm-project/pull/99773
As in title, code which check eligibility of exceptions with pointer types to
be handled by exception handler of type `void *` disallowed this case. It was
check:
```c++
if (isStandardPointerConvertible(ExceptionCanTy, HandlerCanTy) &&
isUnambiguousPublicBaseClass(
ExceptionCanTy->getTypePtr()->getPointeeType().getTypePtr(),
HandlerCanTy->getTypePtr()->getPointeeType().getTypePtr())) {
```
but in `isUnambiguousPublicBaseClass` there was code which looked for
definitions:
```c++
bool isUnambiguousPublicBaseClass(const Type *DerivedType,
const Type *BaseType) {
const auto *DerivedClass =
DerivedType->getCanonicalTypeUnqualified()->getAsCXXRecordDecl();
const auto *BaseClass =
BaseType->getCanonicalTypeUnqualified()->getAsCXXRecordDecl();
if (!DerivedClass || !BaseClass)
return false;
```
This code disallowed usage of `void *` type which was correctly detected in
`isStandardPointerConvertible`.
AFAIK this seems like misinterpretation of specification:
> 14.4 Handling an exception
> a standard [pointer conversion](https://eel.is/c++draft/conv.ptr) not
> involving conversions to pointers to private or protected or ambiguous classes
(https://eel.is/c++draft/except.handle#3.3.1)
and
> 7.3.12 Pointer conversions
> ... If B is an inaccessible
> ([[class.access]](https://eel.is/c++draft/class.access)) or ambiguous
> ([[class.member.lookup]](https://eel.is/c++draft/class.member.lookup)) base
> class of D, a program that necessitates this conversion is
> ill-formed[.](https://eel.is/c++draft/conv.ptr#3.sentence-2) ...
(https://eel.is/c++draft/conv.ptr#3)
14.4 is carving out private, protected, and ambiguous base classes, but they
are already carved out in 7.3.12 and implemented in
`isStandardPointerConvertible`
From 3ea4f5d28e3183243f9aa9da1c264e5d70b16563 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hana=20Dusi=CC=81kova=CC=81?= <hani...@hanicka.net>
Date: Sat, 20 Jul 2024 20:12:45 +0200
Subject: [PATCH] [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..8e8c0cd0cc3d8 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -518,6 +518,10 @@ Changes in existing checks
usages of ``std::string_view::compare``. Added a `StringLikeClasses` option
to detect usages of ``compare`` method in custom string-like classes.
+- 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.
+
Removed checks
^^^^^^^^^^^^^^
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 *) {
+ }
+}
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
