libcxx: update to LLVM 18

release/18.x branch, commit 78b99c73ee4b96fe9ce0e294d4632326afb2db42

This adds the flag `-D_LIBCPP_HARDENING_MODE` which is determined based
on the Zig optimization mode.

This commit also fixes libunwind, libcxx, and libcxxabi to properly
report sub compilation errors.

1 files changed, 186 insertions, 219 deletions

diff --git a/lib/libcxx/src/new.cpp b/lib/libcxx/src/new.cpp
index c435c5ffc8..0869d90661 100644
--- a/lib/libcxx/src/new.cpp
+++ b/lib/libcxx/src/new.cpp
@@ -6,7 +6,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "include/overridable_function.h"
 #include <__memory/aligned_alloc.h>
+#include <cstddef>
 #include <cstdlib>
 #include <new>
 
@@ -15,244 +17,209 @@
 // 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.
 
-_LIBCPP_WEAK
-void *
-operator new(std::size_t size) _THROW_BAD_ALLOC
-{
-    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
-#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
-            throw std::bad_alloc();
-#else
-            break;
-#endif
-    }
-    return p;
-}
-
-_LIBCPP_WEAK
-void*
-operator new(size_t size, const std::nothrow_t&) noexcept
-{
-    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;
-}
-
-_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
-{
-    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;
-}
-
-_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, size_t) noexcept
-{
-    ::operator delete(ptr);
+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;
+}
+
+_LIBCPP_MAKE_OVERRIDABLE_FUNCTION_DETECTABLE _LIBCPP_WEAK 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;
+}
+
+_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). 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
+}
+
+_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). 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
+}
+
+_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, size_t) 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, size_t) noexcept { ::operator delete[](ptr); }
+
+#  if !defined(_LIBCPP_HAS_NO_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;
+}
+
+_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);
+  if (p == nullptr)
+    __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). 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
 }
 
-_LIBCPP_WEAK
-void
-operator delete[] (void* ptr) noexcept
-{
-    ::operator delete(ptr);
+_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 delete[] (void* ptr, const std::nothrow_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)
-
-_LIBCPP_WEAK
-void *
-operator new(std::size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC
-{
-    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.
-    //
-    // 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)
-    {
-        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(size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept
-{
-    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;
-}
+_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). Please make sure you "
+      "override "
+      "`operator new[](size_t, align_val_t, nothrow_t)` as well.");
+#      endif
 
-_LIBCPP_WEAK
-void*
-operator new[](size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC
-{
-    return ::operator new(size, alignment);
+  return operator_new_aligned_impl(size, alignment);
+#    else
+  void* p = nullptr;
+  try {
+    p = ::operator new[](size, alignment);
+  } catch (...) {
+  }
+  return p;
+#    endif
 }
 
-_LIBCPP_WEAK
-void*
-operator new[](size_t size, std::align_val_t alignment, const std::nothrow_t&) noexcept
-{
-    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;
-}
-
-_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
-{
-    ::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) noexcept { std::__libcpp_aligned_free(ptr); }
 
-_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 {
+  ::operator delete(ptr, alignment);
 }
 
-_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);
 }
 
-#endif // !_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
+_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);
+}
+
+#  endif // !_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
 // ------------------ END COPY ------------------
 
 #endif // !__GLIBCXX__ && !_LIBCPP_ABI_VCRUNTIME