[libcxx-commits] [libcxx] [libcxxabi] [libc++] Fix the behavior of throwing `operator new` under -fno-exceptions (PR #69498)
Louis Dionne via libcxx-commits
libcxx-commits at lists.llvm.org
Wed Dec 13 13:51:42 PST 2023
https://github.com/ldionne updated https://github.com/llvm/llvm-project/pull/69498
>From c87338c13a9163d1abd5939051aaee564bcdb9be Mon Sep 17 00:00:00 2001
From: Louis Dionne <ldionne.2 at gmail.com>
Date: Wed, 14 Jun 2023 17:49:22 -0700
Subject: [PATCH 1/3] [libc++] Fix the behavior of throwing `operator new`
under -fno-exceptions
In D144319, Clang tried to land a change that would cause some functions
that are not supposed to return nullptr to optimize better. As reported
in https://reviews.llvm.org/D144319#4203982, libc++ started seeing failures
in its CI shortly after this change was landed.
As explained in D146379, the reason for these failures is that libc++'s
throwing `operator new` can in fact return nullptr when compiled with
exceptions disabled. However, this contradicts the Standard, which
clearly says that the throwing version of `operator new(size_t)`
should never return nullptr. This is actually a long standing issue.
I've previously seen a case where LTO would optimize incorrectly based
on the assumption that `operator new` doesn't return nullptr, an
assumption that was violated in that case because libc++.dylib was
compiled with -fno-exceptions.
Unfortunately, fixing this is kind of tricky. The Standard has a few
requirements for the allocation functions, some of which are impossible
to satisfy under -fno-exceptions:
1. `operator new(size_t)` must never return nullptr
2. `operator new(size_t, nothrow_t)` must call the throwing version
and return nullptr on failure to allocate
3. We can't throw exceptions when compiled with -fno-exceptions
In the case where exceptions are enabled, things work nicely. `new(size_t)`
throws and `new(size_t, nothrow_t)` uses a try-catch to return nullptr.
However, when compiling the library with -fno-exceptions, we can't throw
an exception from `new(size_t)`, and we can't catch anything from
`new(size_t, nothrow_t)`. The only thing we can do from `new(size_t)`
is actually abort the program, which does not make it possible for
`new(size_t, nothrow_t)` to catch something and return nullptr.
This patch makes the following changes:
1. When compiled with -fno-exceptions, the throwing version of
`operator new` will now abort on failure instead of returning
nullptr on failure. This resolves the issue that the compiler
could mis-compile based on the assumption that nullptr is never
returned. This constitutes an API and ABI breaking change for
folks compiling the library with -fno-exceptions (which is not
the general public, who merely uses libc++ headers but use a
shared library that has already been compiled). This should mostly
impact vendors and other folks who compile libc++.dylib themselves.
2. When the library is compiled with -fexceptions, the nothrow version
of `operator new` has no change. When the library is compiled with
-fno-exceptions, the nothrow version of `operator new` will now check
whether the throwing version of `operator new` has been overridden.
If it has not been overridden, then it will use an implementation
equivalent to that of the throwing `operator new`, except it will
return nullptr on failure to allocate (instead of terminating).
However, if the throwing `operator new` has been overridden, it is
now an error NOT to also override the nothrow `operator new`. Indeed,
there is no way for us to implement a valid nothrow `operator new`
without knowing the exact implementation of the throwing version.
rdar://103958777
Differential Revision: https://reviews.llvm.org/D150610
---
libcxx/docs/ReleaseNotes/18.rst | 23 +++
libcxx/include/CMakeLists.txt | 1 +
libcxx/include/__overridable_function | 119 +++++++++++++
libcxx/src/new.cpp | 99 ++++++++---
...new_not_overridden_fno_exceptions.pass.cpp | 59 ++++++
.../new_dont_return_nullptr.pass.cpp | 37 ++++
libcxx/test/support/check_assertion.h | 6 +
libcxx/utils/generate_iwyu_mapping.py | 2 +
libcxxabi/src/stdlib_new_delete.cpp | 168 +++++++++++-------
9 files changed, 426 insertions(+), 88 deletions(-)
create mode 100644 libcxx/include/__overridable_function
create mode 100644 libcxx/test/libcxx/language.support/support.dynamic/assert.nothrow_new_not_overridden_fno_exceptions.pass.cpp
create mode 100644 libcxx/test/libcxx/language.support/support.dynamic/new_dont_return_nullptr.pass.cpp
diff --git a/libcxx/docs/ReleaseNotes/18.rst b/libcxx/docs/ReleaseNotes/18.rst
index 9e509db6359c4a..405f1e172893bc 100644
--- a/libcxx/docs/ReleaseNotes/18.rst
+++ b/libcxx/docs/ReleaseNotes/18.rst
@@ -142,6 +142,29 @@ LLVM 20
ABI Affecting Changes
---------------------
+- When the shared/static library is built with ``-fno-exceptions``, the behavior of ``operator new`` was changed
+ to make it standards-conforming. In LLVM 17 and before, the throwing versions of ``operator new`` would return
+ ``nullptr`` upon failure to allocate, when the shared/static library was built with exceptions disabled. This
+ was non-conforming, since the throwing versions of ``operator new`` are never expected to return ``nullptr``, and
+ this non-conformance could actually lead to miscompiles in subtle cases.
+
+ Starting in LLVM 18, the throwing versions of ``operator new`` will abort the program when they fail to allocate
+ if the shared/static library has been built with ``-fno-exceptions``. This is consistent with the behavior of all
+ other potentially-throwing functions in the library, which abort the program instead of throwing when ``-fno-exceptions``
+ is used.
+
+ Furthermore, when the shared/static library is built with ``-fno-exceptions``, users who override the throwing
+ version of ``operator new`` will now need to also override the ``std::nothrow_t`` version of ``operator new`` if
+ they want to use it. Indeed, this is because there is no way to implement a conforming ``operator new(nothrow)``
+ from a conforming potentially-throwing ``operator new`` when compiled with ``-fno-exceptions``. In that case, using
+ ``operator new(nothrow)`` without overriding it explicitly but after overriding the throwing ``operator new`` will
+ result in an error.
+
+ Note that this change only impacts vendors/users that build the shared/static library themselves and pass
+ ``-DLIBCXX_ENABLE_EXCEPTIONS=OFF``, which is not the default configuration. If you are using the default
+ configuration of the library, the libc++ shared/static library will be built with exceptions enabled, and
+ there is no change between LLVM 17 and LLVM 18, even for users who build their own code using ``-fno-exceptions``.
+
- The symbol of a non-visible function part of ``std::system_error`` was removed.
This is not a breaking change as the private function ``__init`` was never referenced internally outside of the dylib.
diff --git a/libcxx/include/CMakeLists.txt b/libcxx/include/CMakeLists.txt
index 533b7ac9103ab0..ce20d6a4c566ea 100644
--- a/libcxx/include/CMakeLists.txt
+++ b/libcxx/include/CMakeLists.txt
@@ -569,6 +569,7 @@ set(files
__numeric/transform_exclusive_scan.h
__numeric/transform_inclusive_scan.h
__numeric/transform_reduce.h
+ __overridable_function
__random/bernoulli_distribution.h
__random/binomial_distribution.h
__random/cauchy_distribution.h
diff --git a/libcxx/include/__overridable_function b/libcxx/include/__overridable_function
new file mode 100644
index 00000000000000..81dd81bdc0ae8a
--- /dev/null
+++ b/libcxx/include/__overridable_function
@@ -0,0 +1,119 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___OVERRIDABLE_FUNCTION
+#define _LIBCPP___OVERRIDABLE_FUNCTION
+
+#include <__config>
+#include <cstdint>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+# pragma GCC system_header
+#endif
+
+//
+// This file provides the std::__is_function_overridden utility, which allows checking
+// whether an overridable function (typically a weak symbol) like `operator new`
+// has been overridden by a user or not.
+//
+// This is a low-level utility which does not work on all platforms, since it needs
+// to make assumptions about the object file format in use. Furthermore, it requires
+// the "base definition" of the function (the one we want to check whether it has been
+// overridden) to be annotated with the _LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE macro.
+//
+// This currently works with Mach-O files (used on Darwin) and with ELF files (used on Linux
+// and others). On platforms where we know how to implement this detection, the macro
+// _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION is defined to 1, and it is defined to 0 on
+// other platforms. The _LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE macro is defined to
+// nothing on unsupported platforms so that it can be used to decorate functions regardless
+// of whether detection is actually supported.
+//
+// How does this work?
+// -------------------
+//
+// Let's say we want to check whether a weak function `f` has been overridden by the user.
+// The general mechanism works by placing `f`'s definition (in the libc++ built library)
+// inside a special section, which we do using the `__section__` attribute via the
+// _LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE macro.
+//
+// Then, when comes the time to check whether the function has been overridden, we take
+// the address of the function and we check whether it falls inside the special function
+// we created. This can be done by finding pointers to the start and the end of the section
+// (which is done differently for ELF and Mach-O), and then checking whether `f` falls
+// within those bounds. If it falls within those bounds, then `f` is still inside the
+// special section and so it is the version we defined in the libc++ built library, i.e.
+// it was not overridden. Otherwise, it was overridden by the user because it falls
+// outside of the section.
+//
+// Important note
+// --------------
+//
+// This mechanism should never be used outside of the libc++ built library. In particular,
+// attempting to use this within the libc++ headers will not work at all because we don't
+// want to be defining special sections inside user's executables which use our headers.
+// This is provided inside libc++'s include tree solely to make it easier to share with
+// libc++abi, which needs the same mechanism.
+//
+
+#if defined(_LIBCPP_OBJECT_FORMAT_MACHO)
+
+# define _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION 1
+# define _LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE \
+ __attribute__((__section__("__TEXT,__lcxx_override,regular,pure_instructions")))
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+template <class _Ret, class... _Args>
+_LIBCPP_HIDE_FROM_ABI bool __is_function_overridden(_Ret (*__fptr)(_Args...)) noexcept {
+ // Declare two dummy bytes and give them these special `__asm` values. These values are
+ // defined by the linker, which means that referring to `&__lcxx_override_start` will
+ // effectively refer to the address where the section starts (and same for the end).
+ extern char __lcxx_override_start __asm("section$start$__TEXT$__lcxx_override");
+ extern char __lcxx_override_end __asm("section$end$__TEXT$__lcxx_override");
+
+ // Now get a uintptr_t out of these locations, and out of the function pointer.
+ uintptr_t __start = reinterpret_cast<uintptr_t>(&__lcxx_override_start);
+ uintptr_t __end = reinterpret_cast<uintptr_t>(&__lcxx_override_end);
+ uintptr_t __ptr = reinterpret_cast<uintptr_t>(__fptr);
+
+ // Finally, the function was overridden if it falls outside of the section's bounds.
+ return __ptr < __start || __ptr > __end;
+}
+_LIBCPP_END_NAMESPACE_STD
+
+#elif defined(_LIBCPP_OBJECT_FORMAT_ELF)
+
+# define _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION 1
+# define _LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE __attribute__((__section__("__lcxx_override")))
+
+// This is very similar to what we do for Mach-O above. The ELF linker will implicitly define
+// variables with those names corresponding to the start and the end of the section.
+//
+// See https://stackoverflow.com/questions/16552710/how-do-you-get-the-start-and-end-addresses-of-a-custom-elf-section
+extern char __start___lcxx_override;
+extern char __stop___lcxx_override;
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+template <class _Ret, class... _Args>
+_LIBCPP_HIDE_FROM_ABI bool __is_function_overridden(_Ret (*__fptr)(_Args...)) noexcept {
+ uintptr_t __start = reinterpret_cast<uintptr_t>(&__start___lcxx_override);
+ uintptr_t __end = reinterpret_cast<uintptr_t>(&__stop___lcxx_override);
+ uintptr_t __ptr = reinterpret_cast<uintptr_t>(__fptr);
+
+ return __ptr < __start || __ptr > __end;
+}
+_LIBCPP_END_NAMESPACE_STD
+
+#else
+
+# define _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION 0
+# define _LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE /* nothing */
+
+#endif
+
+#endif // _LIBCPP___OVERRIDABLE_FUNCTION
diff --git a/libcxx/src/new.cpp b/libcxx/src/new.cpp
index 033bba5c1fc95b..7a3ad413601061 100644
--- a/libcxx/src/new.cpp
+++ b/libcxx/src/new.cpp
@@ -7,6 +7,8 @@
//===----------------------------------------------------------------------===//
#include <__memory/aligned_alloc.h>
+#include <__overridable_function>
+#include <cstddef>
#include <cstdlib>
#include <new>
@@ -15,6 +17,10 @@
// The code below is copied as-is into libc++abi's libcxxabi/src/stdlib_new_delete.cpp
// file. The version in this file is the canonical one.
+inline void __throw_bad_alloc_shim() { std::__throw_bad_alloc(); }
+
+# define _LIBCPP_ASSERT_SHIM(expr, str) _LIBCPP_ASSERT(expr, str)
+
// ------------------ BEGIN COPY ------------------
// Implement all new and delete operators as weak definitions
// in this shared library, so that they can be overridden by programs
@@ -36,41 +42,61 @@ static void* operator_new_impl(std::size_t size) noexcept {
return p;
}
-_LIBCPP_WEAK void* operator new(std::size_t size) _THROW_BAD_ALLOC {
+_LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE _LIBCPP_WEAK void* operator new(std::size_t size) _THROW_BAD_ALLOC {
void* p = operator_new_impl(size);
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
if (p == nullptr)
- throw std::bad_alloc();
-# endif
+ __throw_bad_alloc_shim();
return p;
}
_LIBCPP_WEAK void* operator new(size_t size, const std::nothrow_t&) noexcept {
+# ifdef _LIBCPP_HAS_NO_EXCEPTIONS
+# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
+ _LIBCPP_ASSERT_SHIM(
+ !std::__is_function_overridden(static_cast<void* (*)(std::size_t)>(&operator new)),
+ "libc++ was configured with exceptions disabled and `operator new(size_t)` has been overridden, "
+ "but `operator new(size_t, nothrow_t)` has not been overridden. This is problematic because "
+ "`operator new(size_t, nothrow_t)` must call `operator new(size_t)`, which will terminate in case "
+ "it fails to allocate, making it impossible for `operator new(size_t, nothrow_t)` to fulfill its "
+ "contract (since it should return nullptr upon failure).");
+# endif
+
+ return operator_new_impl(size);
+# else
void* p = nullptr;
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
try {
-# endif // _LIBCPP_HAS_NO_EXCEPTIONS
p = ::operator new(size);
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
} catch (...) {
}
-# endif // _LIBCPP_HAS_NO_EXCEPTIONS
return p;
+# endif
}
-_LIBCPP_WEAK void* operator new[](size_t size) _THROW_BAD_ALLOC { return ::operator new(size); }
+_LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE _LIBCPP_WEAK void* operator new[](size_t size) _THROW_BAD_ALLOC {
+ return ::operator new(size);
+}
_LIBCPP_WEAK void* operator new[](size_t size, const std::nothrow_t&) noexcept {
+# ifdef _LIBCPP_HAS_NO_EXCEPTIONS
+# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
+ _LIBCPP_ASSERT_SHIM(
+ !std::__is_function_overridden(static_cast<void* (*)(std::size_t)>(&operator new[])),
+ "libc++ was configured with exceptions disabled and `operator new[](size_t)` has been overridden, "
+ "but `operator new[](size_t, nothrow_t)` has not been overridden. This is problematic because "
+ "`operator new[](size_t, nothrow_t)` must call `operator new[](size_t)`, which will terminate in case "
+ "it fails to allocate, making it impossible for `operator new[](size_t, nothrow_t)` to fulfill its "
+ "contract (since it should return nullptr upon failure).");
+# endif
+
+ return operator_new_impl(size);
+# else
void* p = nullptr;
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
try {
-# endif // _LIBCPP_HAS_NO_EXCEPTIONS
p = ::operator new[](size);
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
} catch (...) {
}
-# endif // _LIBCPP_HAS_NO_EXCEPTIONS
return p;
+# endif
}
_LIBCPP_WEAK void operator delete(void* ptr) noexcept { std::free(ptr); }
@@ -107,43 +133,64 @@ static void* operator_new_aligned_impl(std::size_t size, std::align_val_t alignm
return p;
}
-_LIBCPP_WEAK void* operator new(std::size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC {
+_LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE _LIBCPP_WEAK void*
+operator new(std::size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC {
void* p = operator_new_aligned_impl(size, alignment);
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
if (p == nullptr)
- throw std::bad_alloc();
-# endif
+ __throw_bad_alloc_shim();
return p;
}
_LIBCPP_WEAK void* operator new(size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept {
+# ifdef _LIBCPP_HAS_NO_EXCEPTIONS
+# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
+ _LIBCPP_ASSERT_SHIM(
+ !std::__is_function_overridden(static_cast<void* (*)(std::size_t, std::align_val_t)>(&operator new)),
+ "libc++ was configured with exceptions disabled and `operator new(size_t, align_val_t)` has been overridden, "
+ "but `operator new(size_t, align_val_t, nothrow_t)` has not been overridden. This is problematic because "
+ "`operator new(size_t, align_val_t, nothrow_t)` must call `operator new(size_t, align_val_t)`, which will "
+ "terminate in case it fails to allocate, making it impossible for `operator new(size_t, align_val_t, nothrow_t)` "
+ "to fulfill its contract (since it should return nullptr upon failure).");
+# endif
+
+ return operator_new_aligned_impl(size, alignment);
+# else
void* p = nullptr;
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
try {
-# endif // _LIBCPP_HAS_NO_EXCEPTIONS
p = ::operator new(size, alignment);
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
} catch (...) {
}
-# endif // _LIBCPP_HAS_NO_EXCEPTIONS
return p;
+# endif
}
-_LIBCPP_WEAK void* operator new[](size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC {
+_LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE _LIBCPP_WEAK void*
+operator new[](size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC {
return ::operator new(size, alignment);
}
_LIBCPP_WEAK void* operator new[](size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept {
+# ifdef _LIBCPP_HAS_NO_EXCEPTIONS
+# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
+ _LIBCPP_ASSERT_SHIM(
+ !std::__is_function_overridden(static_cast<void* (*)(std::size_t, std::align_val_t)>(&operator new[])),
+ "libc++ was configured with exceptions disabled and `operator new[](size_t, align_val_t)` has been overridden, "
+ "but `operator new[](size_t, align_val_t, nothrow_t)` has not been overridden. This is problematic because "
+ "`operator new[](size_t, align_val_t, nothrow_t)` must call `operator new[](size_t, align_val_t)`, which will "
+ "terminate in case it fails to allocate, making it impossible for `operator new[](size_t, align_val_t, "
+ "nothrow_t)` "
+ "to fulfill its contract (since it should return nullptr upon failure).");
+# endif
+
+ return operator_new_aligned_impl(size, alignment);
+# else
void* p = nullptr;
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
try {
-# endif // _LIBCPP_HAS_NO_EXCEPTIONS
p = ::operator new[](size, alignment);
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
} catch (...) {
}
-# endif // _LIBCPP_HAS_NO_EXCEPTIONS
return p;
+# endif
}
_LIBCPP_WEAK void operator delete(void* ptr, std::align_val_t) noexcept { std::__libcpp_aligned_free(ptr); }
diff --git a/libcxx/test/libcxx/language.support/support.dynamic/assert.nothrow_new_not_overridden_fno_exceptions.pass.cpp b/libcxx/test/libcxx/language.support/support.dynamic/assert.nothrow_new_not_overridden_fno_exceptions.pass.cpp
new file mode 100644
index 00000000000000..7aa51b365f74eb
--- /dev/null
+++ b/libcxx/test/libcxx/language.support/support.dynamic/assert.nothrow_new_not_overridden_fno_exceptions.pass.cpp
@@ -0,0 +1,59 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// void* operator new(std::size_t, const std::nothrow_t&);
+// void* operator new(std::size_t, std::align_val_t, const std::nothrow_t&);
+// void* operator new[](std::size_t, const std::nothrow_t&);
+// void* operator new[](std::size_t, std::align_val_t, const std::nothrow_t&);
+
+// This test ensures that we catch the case where `new` has been overridden but `new(nothrow)`
+// has not been overridden, and the library is compiled with -fno-exceptions.
+//
+// In that case, it is impossible for libc++ to provide a Standards conforming implementation
+// of `new(nothrow)`, so the only viable option is to terminate the program.
+
+// REQUIRES: has-unix-headers
+// UNSUPPORTED: c++03
+// XFAIL: availability-verbose_abort-missing
+
+// We only know how to diagnose this on platforms that use the ELF or Mach-O object file formats.
+// XFAIL: target={{.+}}-windows-{{.+}}
+
+// TODO: We currently don't have a way to express that the built library was
+// compiled with -fno-exceptions, so if the library was built with support
+// for exceptions but we run the test suite without exceptions, this will
+// spuriously fail.
+// REQUIRES: no-exceptions
+
+#include <cstddef>
+#include <new>
+
+#include "check_assertion.h"
+
+// Override the throwing versions of operator new, but not the nothrow versions.
+alignas(32) char DummyData[32 * 3];
+void* operator new(std::size_t) { return DummyData; }
+void* operator new(std::size_t, std::align_val_t) { return DummyData; }
+void* operator new[](std::size_t) { return DummyData; }
+void* operator new[](std::size_t, std::align_val_t) { return DummyData; }
+
+void operator delete(void*) noexcept {}
+void operator delete(void*, std::align_val_t) noexcept {}
+void operator delete[](void*) noexcept {}
+void operator delete[](void*, std::align_val_t) noexcept {}
+
+int main(int, char**) {
+ std::size_t size = 3;
+ std::align_val_t align = static_cast<std::align_val_t>(32);
+ EXPECT_DEATH((void)operator new(size, std::nothrow));
+ EXPECT_DEATH((void)operator new(size, align, std::nothrow));
+ EXPECT_DEATH((void)operator new[](size, std::nothrow));
+ EXPECT_DEATH((void)operator new[](size, align, std::nothrow));
+
+ return 0;
+}
diff --git a/libcxx/test/libcxx/language.support/support.dynamic/new_dont_return_nullptr.pass.cpp b/libcxx/test/libcxx/language.support/support.dynamic/new_dont_return_nullptr.pass.cpp
new file mode 100644
index 00000000000000..548046b0ab43d2
--- /dev/null
+++ b/libcxx/test/libcxx/language.support/support.dynamic/new_dont_return_nullptr.pass.cpp
@@ -0,0 +1,37 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// void* operator new(std::size_t);
+// void* operator new(std::size_t, std::align_val_t);
+// void* operator new[](std::size_t);
+// void* operator new[](std::size_t, std::align_val_t);
+
+// This test ensures that we abort the program instead of returning nullptr
+// when we fail to satisfy the allocation request. The throwing versions of
+// `operator new` must never return nullptr on failure to allocate (per the
+// Standard) and the compiler actually relies on that for optimizations.
+// Returning nullptr from the throwing `operator new` can basically result
+// in miscompiles.
+
+// REQUIRES: has-unix-headers
+// REQUIRES: no-exceptions
+// UNSUPPORTED: c++03, c++11, c++14
+
+#include <cstddef>
+#include <limits>
+#include <new>
+
+#include "check_assertion.h"
+
+int main(int, char**) {
+ EXPECT_DEATH((void)operator new(std::numeric_limits<std::size_t>::max()));
+ EXPECT_DEATH((void)operator new(std::numeric_limits<std::size_t>::max(), static_cast<std::align_val_t>(32)));
+ EXPECT_DEATH((void)operator new[](std::numeric_limits<std::size_t>::max()));
+ EXPECT_DEATH((void)operator new[](std::numeric_limits<std::size_t>::max(), static_cast<std::align_val_t>(32)));
+ return 0;
+}
diff --git a/libcxx/test/support/check_assertion.h b/libcxx/test/support/check_assertion.h
index 98dd95b11556e6..34e41e8f0d8eaf 100644
--- a/libcxx/test/support/check_assertion.h
+++ b/libcxx/test/support/check_assertion.h
@@ -10,6 +10,7 @@
#define TEST_SUPPORT_CHECK_ASSERTION_H
#include <cassert>
+#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
@@ -257,9 +258,14 @@ void std::__libcpp_verbose_abort(char const* format, ...) {
std::exit(DeathTest::RK_Terminate);
}
+[[noreturn]] inline void abort_handler(int) {
+ std::exit(DeathTest::RK_Terminate);
+}
+
template <class Func>
inline bool ExpectDeath(const char* stmt, Func&& func, AssertionInfoMatcher Matcher) {
std::set_terminate(terminate_handler);
+ std::signal(SIGABRT, abort_handler);
DeathTest DT(Matcher);
DeathTest::ResultKind RK = DT.Run(func);
auto OnFailure = [&](const char* msg) {
diff --git a/libcxx/utils/generate_iwyu_mapping.py b/libcxx/utils/generate_iwyu_mapping.py
index 343538a6cae481..88840eff8f6e29 100644
--- a/libcxx/utils/generate_iwyu_mapping.py
+++ b/libcxx/utils/generate_iwyu_mapping.py
@@ -65,6 +65,8 @@ def generate_map(include):
continue
elif i == "__node_handle":
public = ["map", "set", "unordered_map", "unordered_set"]
+ elif i == "__overridable_function":
+ continue
elif i == "__pstl_algorithm":
continue
elif i == "__pstl_config_site.in":
diff --git a/libcxxabi/src/stdlib_new_delete.cpp b/libcxxabi/src/stdlib_new_delete.cpp
index 6c9990f063dde6..5bd9b5e58b36c6 100644
--- a/libcxxabi/src/stdlib_new_delete.cpp
+++ b/libcxxabi/src/stdlib_new_delete.cpp
@@ -7,7 +7,10 @@
//===----------------------------------------------------------------------===//
#include "__cxxabi_config.h"
+#include "abort_message.h"
#include <__memory/aligned_alloc.h>
+#include <__overridable_function>
+#include <cstddef>
#include <cstdlib>
#include <new>
@@ -25,6 +28,20 @@
# error libc++ and libc++abi seem to disagree on whether exceptions are enabled
#endif
+inline void __throw_bad_alloc_shim() {
+#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+ throw std::bad_alloc();
+#else
+ abort_message("bad_alloc was thrown in -fno-exceptions mode");
+#endif
+}
+
+#define _LIBCPP_ASSERT_SHIM(expr, str) \
+ do { \
+ if (!expr) \
+ abort_message(str); \
+ } while (false)
+
// ------------------ BEGIN COPY ------------------
// Implement all new and delete operators as weak definitions
// in this shared library, so that they can be overridden by programs
@@ -46,64 +63,74 @@ static void* operator_new_impl(std::size_t size) noexcept {
return p;
}
-_LIBCPP_WEAK
-void* operator new(std::size_t size) _THROW_BAD_ALLOC {
+_LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE _LIBCPP_WEAK void* operator new(std::size_t size) _THROW_BAD_ALLOC {
void* p = operator_new_impl(size);
-#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
if (p == nullptr)
- throw std::bad_alloc();
-#endif
+ __throw_bad_alloc_shim();
return p;
}
-_LIBCPP_WEAK
-void* operator new(size_t size, const std::nothrow_t&) noexcept {
+_LIBCPP_WEAK void* operator new(size_t size, const std::nothrow_t&) noexcept {
+#ifdef _LIBCPP_HAS_NO_EXCEPTIONS
+# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
+ _LIBCPP_ASSERT_SHIM(
+ !std::__is_function_overridden(static_cast<void* (*)(std::size_t)>(&operator new)),
+ "libc++ was configured with exceptions disabled and `operator new(size_t)` has been overridden, "
+ "but `operator new(size_t, nothrow_t)` has not been overridden. This is problematic because "
+ "`operator new(size_t, nothrow_t)` must call `operator new(size_t)`, which will terminate in case "
+ "it fails to allocate, making it impossible for `operator new(size_t, nothrow_t)` to fulfill its "
+ "contract (since it should return nullptr upon failure).");
+# endif
+
+ return operator_new_impl(size);
+#else
void* p = nullptr;
-#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
try {
-#endif // _LIBCPP_HAS_NO_EXCEPTIONS
p = ::operator new(size);
-#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
} catch (...) {
}
-#endif // _LIBCPP_HAS_NO_EXCEPTIONS
return p;
+#endif
}
-_LIBCPP_WEAK
-void* operator new[](size_t size) _THROW_BAD_ALLOC { return ::operator new(size); }
+_LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE _LIBCPP_WEAK void* operator new[](size_t size) _THROW_BAD_ALLOC {
+ return ::operator new(size);
+}
-_LIBCPP_WEAK
-void* operator new[](size_t size, const std::nothrow_t&) noexcept {
+_LIBCPP_WEAK void* operator new[](size_t size, const std::nothrow_t&) noexcept {
+#ifdef _LIBCPP_HAS_NO_EXCEPTIONS
+# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
+ _LIBCPP_ASSERT_SHIM(
+ !std::__is_function_overridden(static_cast<void* (*)(std::size_t)>(&operator new[])),
+ "libc++ was configured with exceptions disabled and `operator new[](size_t)` has been overridden, "
+ "but `operator new[](size_t, nothrow_t)` has not been overridden. This is problematic because "
+ "`operator new[](size_t, nothrow_t)` must call `operator new[](size_t)`, which will terminate in case "
+ "it fails to allocate, making it impossible for `operator new[](size_t, nothrow_t)` to fulfill its "
+ "contract (since it should return nullptr upon failure).");
+# endif
+
+ return operator_new_impl(size);
+#else
void* p = nullptr;
-#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
try {
-#endif // _LIBCPP_HAS_NO_EXCEPTIONS
p = ::operator new[](size);
-#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
} catch (...) {
}
-#endif // _LIBCPP_HAS_NO_EXCEPTIONS
return p;
+#endif
}
-_LIBCPP_WEAK
-void operator delete(void* ptr) noexcept { std::free(ptr); }
+_LIBCPP_WEAK void operator delete(void* ptr) noexcept { std::free(ptr); }
-_LIBCPP_WEAK
-void operator delete(void* ptr, const std::nothrow_t&) noexcept { ::operator delete(ptr); }
+_LIBCPP_WEAK void operator delete(void* ptr, const std::nothrow_t&) noexcept { ::operator delete(ptr); }
-_LIBCPP_WEAK
-void operator delete(void* ptr, size_t) noexcept { ::operator delete(ptr); }
+_LIBCPP_WEAK void operator delete(void* ptr, size_t) noexcept { ::operator delete(ptr); }
-_LIBCPP_WEAK
-void operator delete[](void* ptr) noexcept { ::operator delete(ptr); }
+_LIBCPP_WEAK void operator delete[](void* ptr) noexcept { ::operator delete(ptr); }
-_LIBCPP_WEAK
-void operator delete[](void* ptr, const std::nothrow_t&) noexcept { ::operator delete[](ptr); }
+_LIBCPP_WEAK void operator delete[](void* ptr, const std::nothrow_t&) noexcept { ::operator delete[](ptr); }
-_LIBCPP_WEAK
-void operator delete[](void* ptr, size_t) noexcept { ::operator delete[](ptr); }
+_LIBCPP_WEAK void operator delete[](void* ptr, size_t) noexcept { ::operator delete[](ptr); }
#if !defined(_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION)
@@ -127,70 +154,87 @@ static void* operator_new_aligned_impl(std::size_t size, std::align_val_t alignm
return p;
}
-_LIBCPP_WEAK
-void* operator new(std::size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC {
+_LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE _LIBCPP_WEAK void*
+operator new(std::size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC {
void* p = operator_new_aligned_impl(size, alignment);
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
if (p == nullptr)
- throw std::bad_alloc();
-# endif
+ __throw_bad_alloc_shim();
return p;
}
-_LIBCPP_WEAK
-void* operator new(size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept {
+_LIBCPP_WEAK void* operator new(size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept {
+# ifdef _LIBCPP_HAS_NO_EXCEPTIONS
+# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
+ _LIBCPP_ASSERT_SHIM(
+ !std::__is_function_overridden(static_cast<void* (*)(std::size_t, std::align_val_t)>(&operator new)),
+ "libc++ was configured with exceptions disabled and `operator new(size_t, align_val_t)` has been overridden, "
+ "but `operator new(size_t, align_val_t, nothrow_t)` has not been overridden. This is problematic because "
+ "`operator new(size_t, align_val_t, nothrow_t)` must call `operator new(size_t, align_val_t)`, which will "
+ "terminate in case it fails to allocate, making it impossible for `operator new(size_t, align_val_t, nothrow_t)` "
+ "to fulfill its contract (since it should return nullptr upon failure).");
+# endif
+
+ return operator_new_aligned_impl(size, alignment);
+# else
void* p = nullptr;
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
try {
-# endif // _LIBCPP_HAS_NO_EXCEPTIONS
p = ::operator new(size, alignment);
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
} catch (...) {
}
-# endif // _LIBCPP_HAS_NO_EXCEPTIONS
return p;
+# endif
}
-_LIBCPP_WEAK
-void* operator new[](size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC {
+_LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE _LIBCPP_WEAK void*
+operator new[](size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC {
return ::operator new(size, alignment);
}
-_LIBCPP_WEAK
-void* operator new[](size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept {
+_LIBCPP_WEAK void* operator new[](size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept {
+# ifdef _LIBCPP_HAS_NO_EXCEPTIONS
+# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
+ _LIBCPP_ASSERT_SHIM(
+ !std::__is_function_overridden(static_cast<void* (*)(std::size_t, std::align_val_t)>(&operator new[])),
+ "libc++ was configured with exceptions disabled and `operator new[](size_t, align_val_t)` has been overridden, "
+ "but `operator new[](size_t, align_val_t, nothrow_t)` has not been overridden. This is problematic because "
+ "`operator new[](size_t, align_val_t, nothrow_t)` must call `operator new[](size_t, align_val_t)`, which will "
+ "terminate in case it fails to allocate, making it impossible for `operator new[](size_t, align_val_t, "
+ "nothrow_t)` "
+ "to fulfill its contract (since it should return nullptr upon failure).");
+# endif
+
+ return operator_new_aligned_impl(size, alignment);
+# else
void* p = nullptr;
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
try {
-# endif // _LIBCPP_HAS_NO_EXCEPTIONS
p = ::operator new[](size, alignment);
-# ifndef _LIBCPP_HAS_NO_EXCEPTIONS
} catch (...) {
}
-# endif // _LIBCPP_HAS_NO_EXCEPTIONS
return p;
+# endif
}
-_LIBCPP_WEAK
-void operator delete(void* ptr, std::align_val_t) noexcept { std::__libcpp_aligned_free(ptr); }
+_LIBCPP_WEAK void operator delete(void* ptr, std::align_val_t) noexcept { std::__libcpp_aligned_free(ptr); }
-_LIBCPP_WEAK
-void operator delete(void* ptr, std::align_val_t alignment, const std::nothrow_t&) noexcept {
+_LIBCPP_WEAK void operator delete(void* ptr, std::align_val_t alignment, const std::nothrow_t&) noexcept {
::operator delete(ptr, alignment);
}
-_LIBCPP_WEAK
-void operator delete(void* ptr, size_t, std::align_val_t alignment) noexcept { ::operator delete(ptr, alignment); }
+_LIBCPP_WEAK void operator delete(void* ptr, size_t, std::align_val_t alignment) noexcept {
+ ::operator delete(ptr, alignment);
+}
-_LIBCPP_WEAK
-void operator delete[](void* ptr, std::align_val_t alignment) noexcept { ::operator delete(ptr, alignment); }
+_LIBCPP_WEAK void operator delete[](void* ptr, std::align_val_t alignment) noexcept {
+ ::operator delete(ptr, alignment);
+}
-_LIBCPP_WEAK
-void operator delete[](void* ptr, std::align_val_t alignment, const std::nothrow_t&) noexcept {
+_LIBCPP_WEAK void operator delete[](void* ptr, std::align_val_t alignment, const std::nothrow_t&) noexcept {
::operator delete[](ptr, alignment);
}
-_LIBCPP_WEAK
-void operator delete[](void* ptr, size_t, std::align_val_t alignment) noexcept { ::operator delete[](ptr, alignment); }
+_LIBCPP_WEAK void operator delete[](void* ptr, size_t, std::align_val_t alignment) noexcept {
+ ::operator delete[](ptr, alignment);
+}
#endif // !_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
// ------------------ END COPY ------------------
>From 0061f12a5b1d427d33d1be31cdd66019cdda1da8 Mon Sep 17 00:00:00 2001
From: Louis Dionne <ldionne.2 at gmail.com>
Date: Tue, 14 Nov 2023 22:55:06 -0500
Subject: [PATCH 2/3] Improve diagnostic
---
libcxx/src/new.cpp | 14 +++++++++-----
libcxxabi/src/stdlib_new_delete.cpp | 14 +++++++++-----
2 files changed, 18 insertions(+), 10 deletions(-)
diff --git a/libcxx/src/new.cpp b/libcxx/src/new.cpp
index 7a3ad413601061..5ca9d6b43da443 100644
--- a/libcxx/src/new.cpp
+++ b/libcxx/src/new.cpp
@@ -58,7 +58,8 @@ _LIBCPP_WEAK void* operator new(size_t size, const std::nothrow_t&) noexcept {
"but `operator new(size_t, nothrow_t)` has not been overridden. This is problematic because "
"`operator new(size_t, nothrow_t)` must call `operator new(size_t)`, which will terminate in case "
"it fails to allocate, making it impossible for `operator new(size_t, nothrow_t)` to fulfill its "
- "contract (since it should return nullptr upon failure).");
+ "contract (since it should return nullptr upon failure). Please make sure you override "
+ "`operator new(size_t, nothrow_t)` as well.");
# endif
return operator_new_impl(size);
@@ -85,7 +86,8 @@ _LIBCPP_WEAK void* operator new[](size_t size, const std::nothrow_t&) noexcept {
"but `operator new[](size_t, nothrow_t)` has not been overridden. This is problematic because "
"`operator new[](size_t, nothrow_t)` must call `operator new[](size_t)`, which will terminate in case "
"it fails to allocate, making it impossible for `operator new[](size_t, nothrow_t)` to fulfill its "
- "contract (since it should return nullptr upon failure).");
+ "contract (since it should return nullptr upon failure). Please make sure you override "
+ "`operator new[](size_t, nothrow_t)` as well.");
# endif
return operator_new_impl(size);
@@ -150,7 +152,8 @@ _LIBCPP_WEAK void* operator new(size_t size, std::align_val_t alignment, const s
"but `operator new(size_t, align_val_t, nothrow_t)` has not been overridden. This is problematic because "
"`operator new(size_t, align_val_t, nothrow_t)` must call `operator new(size_t, align_val_t)`, which will "
"terminate in case it fails to allocate, making it impossible for `operator new(size_t, align_val_t, nothrow_t)` "
- "to fulfill its contract (since it should return nullptr upon failure).");
+ "to fulfill its contract (since it should return nullptr upon failure). Please make sure you override "
+ "`operator new(size_t, align_val_t, nothrow_t)` as well.");
# endif
return operator_new_aligned_impl(size, alignment);
@@ -178,8 +181,9 @@ _LIBCPP_WEAK void* operator new[](size_t size, std::align_val_t alignment, const
"but `operator new[](size_t, align_val_t, nothrow_t)` has not been overridden. This is problematic because "
"`operator new[](size_t, align_val_t, nothrow_t)` must call `operator new[](size_t, align_val_t)`, which will "
"terminate in case it fails to allocate, making it impossible for `operator new[](size_t, align_val_t, "
- "nothrow_t)` "
- "to fulfill its contract (since it should return nullptr upon failure).");
+ "nothrow_t)` to fulfill its contract (since it should return nullptr upon failure). Please make sure you "
+ "override "
+ "`operator new[](size_t, align_val_t, nothrow_t)` as well.");
# endif
return operator_new_aligned_impl(size, alignment);
diff --git a/libcxxabi/src/stdlib_new_delete.cpp b/libcxxabi/src/stdlib_new_delete.cpp
index 5bd9b5e58b36c6..cba6c3968775ab 100644
--- a/libcxxabi/src/stdlib_new_delete.cpp
+++ b/libcxxabi/src/stdlib_new_delete.cpp
@@ -79,7 +79,8 @@ _LIBCPP_WEAK void* operator new(size_t size, const std::nothrow_t&) noexcept {
"but `operator new(size_t, nothrow_t)` has not been overridden. This is problematic because "
"`operator new(size_t, nothrow_t)` must call `operator new(size_t)`, which will terminate in case "
"it fails to allocate, making it impossible for `operator new(size_t, nothrow_t)` to fulfill its "
- "contract (since it should return nullptr upon failure).");
+ "contract (since it should return nullptr upon failure). Please make sure you override "
+ "`operator new(size_t, nothrow_t)` as well.");
# endif
return operator_new_impl(size);
@@ -106,7 +107,8 @@ _LIBCPP_WEAK void* operator new[](size_t size, const std::nothrow_t&) noexcept {
"but `operator new[](size_t, nothrow_t)` has not been overridden. This is problematic because "
"`operator new[](size_t, nothrow_t)` must call `operator new[](size_t)`, which will terminate in case "
"it fails to allocate, making it impossible for `operator new[](size_t, nothrow_t)` to fulfill its "
- "contract (since it should return nullptr upon failure).");
+ "contract (since it should return nullptr upon failure). Please make sure you override "
+ "`operator new[](size_t, nothrow_t)` as well.");
# endif
return operator_new_impl(size);
@@ -171,7 +173,8 @@ _LIBCPP_WEAK void* operator new(size_t size, std::align_val_t alignment, const s
"but `operator new(size_t, align_val_t, nothrow_t)` has not been overridden. This is problematic because "
"`operator new(size_t, align_val_t, nothrow_t)` must call `operator new(size_t, align_val_t)`, which will "
"terminate in case it fails to allocate, making it impossible for `operator new(size_t, align_val_t, nothrow_t)` "
- "to fulfill its contract (since it should return nullptr upon failure).");
+ "to fulfill its contract (since it should return nullptr upon failure). Please make sure you override "
+ "`operator new(size_t, align_val_t, nothrow_t)` as well.");
# endif
return operator_new_aligned_impl(size, alignment);
@@ -199,8 +202,9 @@ _LIBCPP_WEAK void* operator new[](size_t size, std::align_val_t alignment, const
"but `operator new[](size_t, align_val_t, nothrow_t)` has not been overridden. This is problematic because "
"`operator new[](size_t, align_val_t, nothrow_t)` must call `operator new[](size_t, align_val_t)`, which will "
"terminate in case it fails to allocate, making it impossible for `operator new[](size_t, align_val_t, "
- "nothrow_t)` "
- "to fulfill its contract (since it should return nullptr upon failure).");
+ "nothrow_t)` to fulfill its contract (since it should return nullptr upon failure). Please make sure you "
+ "override "
+ "`operator new[](size_t, align_val_t, nothrow_t)` as well.");
# endif
return operator_new_aligned_impl(size, alignment);
>From 5102b53f221db651dfe99a574f7dd0cc547a466b Mon Sep 17 00:00:00 2001
From: Louis Dionne <ldionne.2 at gmail.com>
Date: Tue, 14 Nov 2023 23:10:35 -0500
Subject: [PATCH 3/3] Make sure to override operator new(nothrow) count_new
tests
---
libcxx/test/support/count_new.h | 105 +++++++++++++++++++++-----------
1 file changed, 68 insertions(+), 37 deletions(-)
diff --git a/libcxx/test/support/count_new.h b/libcxx/test/support/count_new.h
index b6424850101625..f89cdc0c01487d 100644
--- a/libcxx/test/support/count_new.h
+++ b/libcxx/test/support/count_new.h
@@ -374,78 +374,109 @@ TEST_DIAGNOSTIC_POP
MemCounter &globalMemCounter = *getGlobalMemCounter();
#ifndef DISABLE_NEW_COUNT
-void* operator new(std::size_t s) TEST_THROW_SPEC(std::bad_alloc)
-{
- getGlobalMemCounter()->newCalled(s);
- void* ret = std::malloc(s);
- if (ret == nullptr)
- detail::throw_bad_alloc_helper();
- return ret;
+// operator new(size_t[, nothrow_t]) and operator delete(size_t[, nothrow_t])
+void* operator new(std::size_t s) TEST_THROW_SPEC(std::bad_alloc) {
+ void* ret = operator new(s, std::nothrow);
+ if (ret == nullptr)
+ detail::throw_bad_alloc_helper();
+ return ret;
}
-void operator delete(void* p) TEST_NOEXCEPT
-{
- getGlobalMemCounter()->deleteCalled(p);
- std::free(p);
+void* operator new(std::size_t s, std::nothrow_t const&) TEST_NOEXCEPT {
+ getGlobalMemCounter()->newCalled(s);
+ void* ret = std::malloc(s);
+ return ret;
}
-void* operator new[](std::size_t s) TEST_THROW_SPEC(std::bad_alloc)
-{
- getGlobalMemCounter()->newArrayCalled(s);
- return operator new(s);
+void operator delete(void* p) TEST_NOEXCEPT { operator delete(p, std::nothrow); }
+
+void operator delete(void* p, std::nothrow_t const&) TEST_NOEXCEPT {
+ getGlobalMemCounter()->deleteCalled(p);
+ std::free(p);
}
-void operator delete[](void* p) TEST_NOEXCEPT
-{
- getGlobalMemCounter()->deleteArrayCalled(p);
- operator delete(p);
+// operator new[](size_t[, nothrow_t]) and operator delete[](size_t[, nothrow_t])
+void* operator new[](std::size_t s) TEST_THROW_SPEC(std::bad_alloc) {
+ void* ret = operator new[](s, std::nothrow);
+ if (ret == nullptr)
+ detail::throw_bad_alloc_helper();
+ return ret;
}
-#ifndef TEST_HAS_NO_ALIGNED_ALLOCATION
-#if defined(_LIBCPP_MSVCRT_LIKE) || \
- (!defined(_LIBCPP_VERSION) && defined(_WIN32))
-#define USE_ALIGNED_ALLOC
-#endif
+void* operator new[](std::size_t s, std::nothrow_t const&) TEST_NOEXCEPT {
+ getGlobalMemCounter()->newArrayCalled(s);
+ return operator new(s);
+}
+
+void operator delete[](void* p) TEST_NOEXCEPT { operator delete[](p, std::nothrow); }
+
+void operator delete[](void* p, std::nothrow_t const&) TEST_NOEXCEPT {
+ getGlobalMemCounter()->deleteArrayCalled(p);
+ operator delete(p);
+}
+# ifndef TEST_HAS_NO_ALIGNED_ALLOCATION
+# if defined(_LIBCPP_MSVCRT_LIKE) || (!defined(_LIBCPP_VERSION) && defined(_WIN32))
+# define USE_ALIGNED_ALLOC
+# endif
+
+// operator new(size_t, align_val_t[, nothrow_t]) and operator delete(size_t, align_val_t[, nothrow_t])
void* operator new(std::size_t s, std::align_val_t av) TEST_THROW_SPEC(std::bad_alloc) {
+ void* p = operator new(s, av, std::nothrow);
+ if (p == nullptr)
+ detail::throw_bad_alloc_helper();
+ return p;
+}
+
+void* operator new(std::size_t s, std::align_val_t av, std::nothrow_t const&) TEST_NOEXCEPT {
const std::size_t a = static_cast<std::size_t>(av);
getGlobalMemCounter()->alignedNewCalled(s, a);
- void *ret = nullptr;
-#ifdef USE_ALIGNED_ALLOC
+ void* ret = nullptr;
+# ifdef USE_ALIGNED_ALLOC
ret = _aligned_malloc(s, a);
-#else
+# else
assert(posix_memalign(&ret, std::max(a, sizeof(void*)), s) != EINVAL);
-#endif
- if (ret == nullptr)
- detail::throw_bad_alloc_helper();
+# endif
return ret;
}
-void operator delete(void *p, std::align_val_t av) TEST_NOEXCEPT {
+void operator delete(void* p, std::align_val_t av) TEST_NOEXCEPT { operator delete(p, av, std::nothrow); }
+
+void operator delete(void* p, std::align_val_t av, std::nothrow_t const&) TEST_NOEXCEPT {
const std::size_t a = static_cast<std::size_t>(av);
getGlobalMemCounter()->alignedDeleteCalled(p, a);
if (p) {
-#ifdef USE_ALIGNED_ALLOC
+# ifdef USE_ALIGNED_ALLOC
::_aligned_free(p);
-#else
+# else
::free(p);
-#endif
+# endif
}
}
+// operator new[](size_t, align_val_t[, nothrow_t]) and operator delete[](size_t, align_val_t[, nothrow_t])
void* operator new[](std::size_t s, std::align_val_t av) TEST_THROW_SPEC(std::bad_alloc) {
+ void* ret = operator new[](s, av, std::nothrow);
+ if (ret == nullptr)
+ detail::throw_bad_alloc_helper();
+ return ret;
+}
+
+void* operator new[](std::size_t s, std::align_val_t av, std::nothrow_t const&) TEST_NOEXCEPT {
const std::size_t a = static_cast<std::size_t>(av);
getGlobalMemCounter()->alignedNewArrayCalled(s, a);
- return operator new(s, av);
+ return operator new(s, av, std::nothrow);
}
-void operator delete[](void *p, std::align_val_t av) TEST_NOEXCEPT {
+void operator delete[](void* p, std::align_val_t av) TEST_NOEXCEPT { operator delete[](p, av, std::nothrow); }
+
+void operator delete[](void* p, std::align_val_t av, std::nothrow_t const&) TEST_NOEXCEPT {
const std::size_t a = static_cast<std::size_t>(av);
getGlobalMemCounter()->alignedDeleteArrayCalled(p, a);
return operator delete(p, av);
}
-#endif // TEST_HAS_NO_ALIGNED_ALLOCATION
+# endif // TEST_HAS_NO_ALIGNED_ALLOCATION
#endif // DISABLE_NEW_COUNT
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