[libcxx-commits] [libcxx] [libcxxabi] [libc++][libc++abi] Merge the operator new implementations into a shared file (PR #213427)
via libcxx-commits
libcxx-commits at lists.llvm.org
Tue Aug 4 02:03:26 PDT 2026
llvmorg-github-actions[bot] wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-libcxxabi
Author: Nikolas Klauser (philnik777)
<details>
<summary>Changes</summary>
Instead of copying the code around we can simply share a file that actually implements operator new/delete and include that file in the two places that need the definitions.
---
Patch is 25.19 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/213427.diff
3 Files Affected:
- (modified) libcxx/src/new.cpp (+1-202)
- (added) libcxx/src/support/new.ipp (+210)
- (modified) libcxxabi/src/stdlib_new_delete.cpp (+1-199)
``````````diff
diff --git a/libcxx/src/new.cpp b/libcxx/src/new.cpp
index 25bdaea32f57a..0d4e9fce2f40f 100644
--- a/libcxx/src/new.cpp
+++ b/libcxx/src/new.cpp
@@ -6,216 +6,15 @@
//
//===----------------------------------------------------------------------===//
-#include "include/aligned_alloc.h"
-#include "include/overridable_function.h"
#include <__assert>
-#include <cstddef>
-#include <cstdlib>
#include <new>
#if !defined(__GLIBCXX__) && !defined(_LIBCPP_ABI_VCRUNTIME)
-// 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
-// that define non-weak copies of the functions.
-
-static void* operator_new_impl(std::size_t size) {
- if (size == 0)
- size = 1;
- void* p;
- while ((p = std::malloc(size)) == nullptr) {
- // If malloc fails and there is a new_handler,
- // call it to try free up memory.
- std::new_handler nh = std::get_new_handler();
- if (nh)
- nh();
- else
- break;
- }
- return p;
-}
-
-OVERRIDABLE_FUNCTION void* operator new(std::size_t size) _THROW_BAD_ALLOC {
- void* p = operator_new_impl(size);
- if (p == nullptr)
- __throw_bad_alloc_shim();
- return p;
-}
-
-[[gnu::weak]] void* operator new(size_t size, const std::nothrow_t&) noexcept {
-# if !_LIBCPP_HAS_EXCEPTIONS
-# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
- _LIBCPP_ASSERT_SHIM(
- (!std::__is_function_overridden < 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). Please make sure you override "
- "`operator new(size_t, nothrow_t)` as well.");
-# endif
-
- return operator_new_impl(size);
-# else
- void* p = nullptr;
- try {
- p = ::operator new(size);
- } catch (...) {
- }
- return p;
-# endif
-}
-
-OVERRIDABLE_FUNCTION void* operator new[](size_t size) _THROW_BAD_ALLOC { return ::operator new(size); }
-
-[[gnu::weak]] void* operator new[](size_t size, const std::nothrow_t&) noexcept {
-# if !_LIBCPP_HAS_EXCEPTIONS
-# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
- _LIBCPP_ASSERT_SHIM(
- (!std::__is_function_overridden < 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). Please make sure you override "
- "`operator new[](size_t, nothrow_t)` as well.");
-# endif
-
- return operator_new_impl(size);
-# else
- void* p = nullptr;
- try {
- p = ::operator new[](size);
- } catch (...) {
- }
- return p;
-# endif
-}
-
-[[gnu::weak]] void operator delete(void* ptr) noexcept { std::free(ptr); }
-
-[[gnu::weak]] void operator delete(void* ptr, const std::nothrow_t&) noexcept { ::operator delete(ptr); }
-
-[[gnu::weak]] void operator delete(void* ptr, size_t) noexcept { ::operator delete(ptr); }
-
-[[gnu::weak]] void operator delete[](void* ptr) noexcept { ::operator delete(ptr); }
-
-[[gnu::weak]] void operator delete[](void* ptr, const std::nothrow_t&) noexcept { ::operator delete[](ptr); }
-
-[[gnu::weak]] void operator delete[](void* ptr, size_t) noexcept { ::operator delete[](ptr); }
-
-# if _LIBCPP_HAS_LIBRARY_ALIGNED_ALLOCATION
-
-static void* operator_new_aligned_impl(std::size_t size, std::align_val_t alignment) {
- if (size == 0)
- size = 1;
- if (static_cast<size_t>(alignment) < sizeof(void*))
- alignment = std::align_val_t(sizeof(void*));
-
- // Try allocating memory. If allocation fails and there is a new_handler,
- // call it to try free up memory, and try again until it succeeds, or until
- // the new_handler decides to terminate.
- void* p;
- while ((p = std::__libcpp_aligned_alloc(static_cast<std::size_t>(alignment), size)) == nullptr) {
- std::new_handler nh = std::get_new_handler();
- if (nh)
- nh();
- else
- break;
- }
- return p;
-}
-
-OVERRIDABLE_FUNCTION void* operator new(std::size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC {
- void* p = operator_new_aligned_impl(size, alignment);
- if (p == nullptr)
- __throw_bad_alloc_shim();
- return p;
-}
-
-[[gnu::weak]] void* operator new(size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept {
-# if !_LIBCPP_HAS_EXCEPTIONS
-# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
- _LIBCPP_ASSERT_SHIM(
- (!std::__is_function_overridden < 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). Please make sure you override "
- "`operator new(size_t, align_val_t, nothrow_t)` as well.");
-# endif
-
- return operator_new_aligned_impl(size, alignment);
-# else
- void* p = nullptr;
- try {
- p = ::operator new(size, alignment);
- } catch (...) {
- }
- return p;
-# endif
-}
-
-OVERRIDABLE_FUNCTION void* operator new[](size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC {
- return ::operator new(size, alignment);
-}
-
-[[gnu::weak]] void* operator new[](size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept {
-# if !_LIBCPP_HAS_EXCEPTIONS
-# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
- _LIBCPP_ASSERT_SHIM(
- (!std::__is_function_overridden < 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). Please make sure you "
- "override `operator new[](size_t, align_val_t, nothrow_t)` as well.");
-# endif
-
- return operator_new_aligned_impl(size, alignment);
-# else
- void* p = nullptr;
- try {
- p = ::operator new[](size, alignment);
- } catch (...) {
- }
- return p;
-# endif
-}
-
-[[gnu::weak]] void operator delete(void* ptr, std::align_val_t) noexcept { std::__libcpp_aligned_free(ptr); }
-
-[[gnu::weak]] void operator delete(void* ptr, std::align_val_t alignment, const std::nothrow_t&) noexcept {
- ::operator delete(ptr, alignment);
-}
-
-[[gnu::weak]] void operator delete(void* ptr, size_t, std::align_val_t alignment) noexcept {
- ::operator delete(ptr, alignment);
-}
-
-[[gnu::weak]] void operator delete[](void* ptr, std::align_val_t alignment) noexcept {
- ::operator delete(ptr, alignment);
-}
-
-[[gnu::weak]] void operator delete[](void* ptr, std::align_val_t alignment, const std::nothrow_t&) noexcept {
- ::operator delete[](ptr, alignment);
-}
-
-[[gnu::weak]] void operator delete[](void* ptr, size_t, std::align_val_t alignment) noexcept {
- ::operator delete[](ptr, alignment);
-}
-
-# endif // _LIBCPP_HAS_LIBRARY_ALIGNED_ALLOCATION
-// ------------------ END COPY ------------------
+#include "support/new.ipp"
#endif // !__GLIBCXX__ && !_LIBCPP_ABI_VCRUNTIME
diff --git a/libcxx/src/support/new.ipp b/libcxx/src/support/new.ipp
new file mode 100644
index 0000000000000..abf34f2910a31
--- /dev/null
+++ b/libcxx/src/support/new.ipp
@@ -0,0 +1,210 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include <cstddef>
+#include <cstdlib>
+#include <new>
+
+#include "include/aligned_alloc.h"
+#include "include/overridable_function.h"
+
+void __throw_bad_alloc_shim();
+
+#ifndef _LIBCPP_ASSERT_SHIM
+# error _LIBCPP_ASSERT_SHIM should be defined
+# define _LIBCPP_ASSERT_SHIM
+#endif
+
+static void* operator_new_impl(std::size_t size) {
+ if (size == 0)
+ size = 1;
+ void* p;
+ while ((p = std::malloc(size)) == nullptr) {
+ // If malloc fails and there is a new_handler,
+ // call it to try free up memory.
+ std::new_handler nh = std::get_new_handler();
+ if (nh)
+ nh();
+ else
+ break;
+ }
+ return p;
+}
+
+OVERRIDABLE_FUNCTION void* operator new(std::size_t size) _THROW_BAD_ALLOC {
+ void* p = operator_new_impl(size);
+ if (p == nullptr)
+ __throw_bad_alloc_shim();
+ return p;
+}
+
+[[gnu::weak]] void* operator new(size_t size, const std::nothrow_t&) noexcept {
+# if !_LIBCPP_HAS_EXCEPTIONS
+# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
+ _LIBCPP_ASSERT_SHIM(
+ (!std::__is_function_overridden < 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). Please make sure you override "
+ "`operator new(size_t, nothrow_t)` as well.");
+# endif
+
+ return operator_new_impl(size);
+# else
+ void* p = nullptr;
+ try {
+ p = ::operator new(size);
+ } catch (...) {
+ }
+ return p;
+# endif
+}
+
+OVERRIDABLE_FUNCTION void* operator new[](size_t size) _THROW_BAD_ALLOC { return ::operator new(size); }
+
+[[gnu::weak]] void* operator new[](size_t size, const std::nothrow_t&) noexcept {
+# if !_LIBCPP_HAS_EXCEPTIONS
+# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
+ _LIBCPP_ASSERT_SHIM(
+ (!std::__is_function_overridden < 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). Please make sure you override "
+ "`operator new[](size_t, nothrow_t)` as well.");
+# endif
+
+ return operator_new_impl(size);
+# else
+ void* p = nullptr;
+ try {
+ p = ::operator new[](size);
+ } catch (...) {
+ }
+ return p;
+# endif
+}
+
+[[gnu::weak]] void operator delete(void* ptr) noexcept { std::free(ptr); }
+
+[[gnu::weak]] void operator delete(void* ptr, const std::nothrow_t&) noexcept { ::operator delete(ptr); }
+
+[[gnu::weak]] void operator delete(void* ptr, size_t) noexcept { ::operator delete(ptr); }
+
+[[gnu::weak]] void operator delete[](void* ptr) noexcept { ::operator delete(ptr); }
+
+[[gnu::weak]] void operator delete[](void* ptr, const std::nothrow_t&) noexcept { ::operator delete[](ptr); }
+
+[[gnu::weak]] void operator delete[](void* ptr, size_t) noexcept { ::operator delete[](ptr); }
+
+# if _LIBCPP_HAS_LIBRARY_ALIGNED_ALLOCATION
+
+static void* operator_new_aligned_impl(std::size_t size, std::align_val_t alignment) {
+ if (size == 0)
+ size = 1;
+ if (static_cast<size_t>(alignment) < sizeof(void*))
+ alignment = std::align_val_t(sizeof(void*));
+
+ // Try allocating memory. If allocation fails and there is a new_handler,
+ // call it to try free up memory, and try again until it succeeds, or until
+ // the new_handler decides to terminate.
+ void* p;
+ while ((p = std::__libcpp_aligned_alloc(static_cast<std::size_t>(alignment), size)) == nullptr) {
+ std::new_handler nh = std::get_new_handler();
+ if (nh)
+ nh();
+ else
+ break;
+ }
+ return p;
+}
+
+OVERRIDABLE_FUNCTION void* operator new(std::size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC {
+ void* p = operator_new_aligned_impl(size, alignment);
+ if (p == nullptr)
+ __throw_bad_alloc_shim();
+ return p;
+}
+
+[[gnu::weak]] void* operator new(size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept {
+# if !_LIBCPP_HAS_EXCEPTIONS
+# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
+ _LIBCPP_ASSERT_SHIM(
+ (!std::__is_function_overridden < 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). Please make sure you override "
+ "`operator new(size_t, align_val_t, nothrow_t)` as well.");
+# endif
+
+ return operator_new_aligned_impl(size, alignment);
+# else
+ void* p = nullptr;
+ try {
+ p = ::operator new(size, alignment);
+ } catch (...) {
+ }
+ return p;
+# endif
+}
+
+OVERRIDABLE_FUNCTION void* operator new[](size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC {
+ return ::operator new(size, alignment);
+}
+
+[[gnu::weak]] void* operator new[](size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept {
+# if !_LIBCPP_HAS_EXCEPTIONS
+# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
+ _LIBCPP_ASSERT_SHIM(
+ (!std::__is_function_overridden < 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). Please make sure you "
+ "override `operator new[](size_t, align_val_t, nothrow_t)` as well.");
+# endif
+
+ return operator_new_aligned_impl(size, alignment);
+# else
+ void* p = nullptr;
+ try {
+ p = ::operator new[](size, alignment);
+ } catch (...) {
+ }
+ return p;
+# endif
+}
+
+[[gnu::weak]] void operator delete(void* ptr, std::align_val_t) noexcept { std::__libcpp_aligned_free(ptr); }
+
+[[gnu::weak]] void operator delete(void* ptr, std::align_val_t alignment, const std::nothrow_t&) noexcept {
+ ::operator delete(ptr, alignment);
+}
+
+[[gnu::weak]] void operator delete(void* ptr, size_t, std::align_val_t alignment) noexcept {
+ ::operator delete(ptr, alignment);
+}
+
+[[gnu::weak]] void operator delete[](void* ptr, std::align_val_t alignment) noexcept {
+ ::operator delete(ptr, alignment);
+}
+
+[[gnu::weak]] void operator delete[](void* ptr, std::align_val_t alignment, const std::nothrow_t&) noexcept {
+ ::operator delete[](ptr, alignment);
+}
+
+[[gnu::weak]] void operator delete[](void* ptr, size_t, std::align_val_t alignment) noexcept {
+ ::operator delete[](ptr, alignment);
+}
+# endif // _LIBCPP_HAS_LIBRARY_ALIGNED_ALLOCATION
diff --git a/libcxxabi/src/stdlib_new_delete.cpp b/libcxxabi/src/stdlib_new_delete.cpp
index 164a26335eb38..3517a8f37b185 100644
--- a/libcxxabi/src/stdlib_new_delete.cpp
+++ b/libcxxabi/src/stdlib_new_delete.cpp
@@ -8,10 +8,6 @@
#include "__cxxabi_config.h"
#include "abort_message.h"
-#include "include/aligned_alloc.h" // from libc++
-#include "include/overridable_function.h" // from libc++
-#include <cstddef>
-#include <cstdlib>
#include <new>
// Perform a few sanity checks on libc++ and libc++abi macros to ensure that
@@ -38,198 +34,4 @@ inline void __throw_bad_alloc_shim() {
__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
-// that define non-weak copies of the functions.
-
-static void* operator_new_impl(std::size_t size) {
- if (size == 0)
- size = 1;
- void* p;
- while ((p = std::malloc(size)) == nullptr) {
- // If malloc fails and there is a new_handler,
- // call it to try free up memory.
- std::new_handler nh = std::get_new_handler();
- if (nh)
- nh();
- else
- break;
- }
- return p;
-}
-
-OVERRIDABLE_FUNCTION void* operator new(std::size_t size) _THROW_BAD_ALLOC {
- void* p = operator_new_impl(size);
- if (p == nullptr)
- __throw_bad_alloc_shim();
- return p;
-}
-
-[[gnu::weak]] void* operator new(size_t size, const std::nothrow_t&) noexcept {
-#if !_LIBCPP_HAS_EXCEPTIONS
-# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
- _LIBCPP_ASSERT_SHIM(
- (!std::__is_function_overridden < 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). Please make sure you override "
- "`operator new(size_t, nothrow_t)` as well.");
-# endif
-
- return operator_new_impl(size);
-#else
- void* p = nullptr;
- try {
- p = ::operator new(size);
- } catch (...) {
- }
- return p;
-#endif
-}
-
-OVERRIDABLE_FUNCTION void* operator new[](size_t size) _THROW_BAD_ALLOC { return ::operator new(size); }
-
-[[gnu::weak]] void* operator new[](size_t size, const std::nothrow_t&) noexcept {
-#if !_LIBCPP_HAS_EXCEPTIONS
-# if _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION
- _LIBCPP_ASSERT_SHIM(
- (!std::__is_function_overridden < 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, no...
[truncated]
``````````
</details>
https://github.com/llvm/llvm-project/pull/213427
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