[libcxx-commits] [libcxxabi] [libc++][NFC] Refactor the core logic of operator new into helper functions (PR #69407)
via libcxx-commits
libcxx-commits at lists.llvm.org
Tue Oct 17 19:16:55 PDT 2023
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-libcxxabi
Author: Louis Dionne (ldionne)
<details>
<summary>Changes</summary>
This will make it easier to implement new(nothrow) without calling the throwing version of new when exceptions are disabled. See https://llvm.org/D150610 for the full discussion.
---
Full diff: https://github.com/llvm/llvm-project/pull/69407.diff
2 Files Affected:
- (modified) libcxx/src/new.cpp (+29-25)
- (modified) libcxxabi/src/stdlib_new_delete.cpp (+29-25)
``````````diff
diff --git a/libcxx/src/new.cpp b/libcxx/src/new.cpp
index c435c5ffc809c61..d045b0d4570d096 100644
--- a/libcxx/src/new.cpp
+++ b/libcxx/src/new.cpp
@@ -20,30 +20,34 @@
// in this shared library, so that they can be overridden by programs
// that define non-weak copies of the functions.
-_LIBCPP_WEAK
-void *
-operator new(std::size_t size) _THROW_BAD_ALLOC
-{
+static void* operator_new_impl(std::size_t size) noexcept {
if (size == 0)
size = 1;
void* p;
- while ((p = std::malloc(size)) == nullptr)
- {
+ 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
-#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
- throw std::bad_alloc();
-#else
break;
-#endif
}
return p;
}
+_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
+ return p;
+}
+
_LIBCPP_WEAK
void*
operator new(size_t size, const std::nothrow_t&) noexcept
@@ -133,10 +137,7 @@ operator delete[] (void* ptr, size_t) noexcept
#if !defined(_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION)
-_LIBCPP_WEAK
-void *
-operator new(std::size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC
-{
+static void* operator_new_aligned_impl(std::size_t size, std::align_val_t alignment) noexcept {
if (size == 0)
size = 1;
if (static_cast<size_t>(alignment) < sizeof(void*))
@@ -145,26 +146,29 @@ operator new(std::size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC
// 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.
- //
- // If allocation fails and there is no new_handler, we throw bad_alloc
- // (or return nullptr if exceptions are disabled).
void* p;
- while ((p = std::__libcpp_aligned_alloc(static_cast<std::size_t>(alignment), size)) == nullptr)
- {
+ 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 {
-#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
- throw std::bad_alloc();
-#else
+ else
break;
-#endif
- }
}
return p;
}
+_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
+ return p;
+}
+
_LIBCPP_WEAK
void*
operator new(size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept
diff --git a/libcxxabi/src/stdlib_new_delete.cpp b/libcxxabi/src/stdlib_new_delete.cpp
index 080f932ccc60ecf..7946d07a59b72a7 100644
--- a/libcxxabi/src/stdlib_new_delete.cpp
+++ b/libcxxabi/src/stdlib_new_delete.cpp
@@ -30,30 +30,34 @@
// in this shared library, so that they can be overridden by programs
// that define non-weak copies of the functions.
-_LIBCPP_WEAK
-void *
-operator new(std::size_t size) _THROW_BAD_ALLOC
-{
+static void* operator_new_impl(std::size_t size) noexcept {
if (size == 0)
size = 1;
void* p;
- while ((p = std::malloc(size)) == nullptr)
- {
+ 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
-#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
- throw std::bad_alloc();
-#else
break;
-#endif
}
return p;
}
+_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
+ return p;
+}
+
_LIBCPP_WEAK
void*
operator new(size_t size, const std::nothrow_t&) noexcept
@@ -143,10 +147,7 @@ operator delete[] (void* ptr, size_t) noexcept
#if !defined(_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION)
-_LIBCPP_WEAK
-void *
-operator new(std::size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC
-{
+static void* operator_new_aligned_impl(std::size_t size, std::align_val_t alignment) noexcept {
if (size == 0)
size = 1;
if (static_cast<size_t>(alignment) < sizeof(void*))
@@ -155,26 +156,29 @@ operator new(std::size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC
// 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.
- //
- // If allocation fails and there is no new_handler, we throw bad_alloc
- // (or return nullptr if exceptions are disabled).
void* p;
- while ((p = std::__libcpp_aligned_alloc(static_cast<std::size_t>(alignment), size)) == nullptr)
- {
+ 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 {
-#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
- throw std::bad_alloc();
-#else
+ else
break;
-#endif
- }
}
return p;
}
+_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
+ return p;
+}
+
_LIBCPP_WEAK
void*
operator new(size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept
``````````
</details>
https://github.com/llvm/llvm-project/pull/69407
More information about the libcxx-commits
mailing list