Make VCRuntime ABI configuration a first-class option.

[EricWF]

Summary

On Windows we currently provide two separate ABI configurations. One which defers to vcruntime to provide the C++ runtime and another which doesn't.
Using vcruntime allows interoperability which programs compiled against the MSVC STL, and should be preferred whenever possible.

When deferring to vcruntime much of the ABI we provide changes. Including the layout of <stdexcept> types, their vtables, and how the linkage of their members.

This patch introduces the _LIBCPP_ABI_VCRUNTIME macro to denote this configuration. It also cleans up the existing configuration for using vcruntime.

This cleanup lays the groundwork for fixing a number of ABI and interoperability bugs in <stdexcept>.

[smeenai]

LGTM; this is a nice cleanup.

include/__config

 #else
 #  if defined(_WIN32) && defined(_MSC_VER)
 #    define _LIBCPP_ABI_MICROSOFT
 #  else
 #    define _LIBCPP_ABI_ITANIUM
 #  endif
 #endif
 
+#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
+# define _LIBCPP_ABI_VCRUNTIME
+#endif
+
 // Need to detect which libc we're using if we're on Linux.
 #if defined(__linux__)
 #  include <features.h>
 #  if defined(__GLIBC_PREREQ)
 #    define _LIBCPP_GLIBC_PREREQ(a, b) __GLIBC_PREREQ(a, b)
 #  else
 #    define _LIBCPP_GLIBC_PREREQ(a, b) 0
 #  endif // defined(__GLIBC_PREREQ)

 #    define _LIBCPP_HAS_CATOPEN 1
 #  endif
 #endif
 
 #ifdef __FreeBSD__
 #define _DECLARE_C99_LDBL_MATH 1
 #endif
 
-#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
-#  define _LIBCPP_DEFER_NEW_TO_VCRUNTIME
-#endif
-
 // If we are getting operator new from the MSVC CRT, then allocation overloads
 // for align_val_t were added in 19.12, aka VS 2017 version 15.3.
 #if defined(_LIBCPP_MSVCRT) && defined(_MSC_VER) && _MSC_VER < 1912
 #  define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
-#elif defined(_LIBCPP_DEFER_NEW_TO_VCRUNTIME) && !defined(__cpp_aligned_new)
+#elif defined(_LIBCPP_ABI_VCRUNTIME) && !defined(__cpp_aligned_new)
    // We're defering to Microsoft's STL to provide aligned new et al. We don't
    // have it unless the language feature test macro is defined.
 #  define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
 #endif
 
 #if defined(__APPLE__)
 #  if !defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && \
       defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__)

include/exception

 */
 
 #include <__config>
 #include <cstddef>
 #include <cstdlib>
 #include <type_traits>
 #include <version>
 
-#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
+#if defined(_LIBCPP_ABI_VCRUNTIME)
 #include <vcruntime_exception.h>
 #endif
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
 namespace std  // purposefully not using versioning namespace
 {
 
-#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
+#if !defined(_LIBCPP_ABI_VCRUNTIME)
 class _LIBCPP_EXCEPTION_ABI exception
 {
 public:
     _LIBCPP_INLINE_VISIBILITY exception() _NOEXCEPT {}
     virtual ~exception() _NOEXCEPT;
     virtual const char* what() const _NOEXCEPT;
 };
 
 class _LIBCPP_EXCEPTION_ABI bad_exception
     : public exception
 {
 public:
     _LIBCPP_INLINE_VISIBILITY bad_exception() _NOEXCEPT {}
     virtual ~bad_exception() _NOEXCEPT;
     virtual const char* what() const _NOEXCEPT;
 };
-#endif // !_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME
+#endif // !_LIBCPP_ABI_VCRUNTIME
 
 #if _LIBCPP_STD_VER <= 14 \
     || defined(_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS) \
     || defined(_LIBCPP_BUILDING_LIBRARY)
 typedef void (*unexpected_handler)();
 _LIBCPP_FUNC_VIS unexpected_handler set_unexpected(unexpected_handler) _NOEXCEPT;
 _LIBCPP_FUNC_VIS unexpected_handler get_unexpected() _NOEXCEPT;
 _LIBCPP_NORETURN _LIBCPP_FUNC_VIS void unexpected();

include/new

 #include <exception>
 #include <type_traits>
 #include <cstddef>
 #include <version>
 #ifdef _LIBCPP_NO_EXCEPTIONS
 #include <cstdlib>
 #endif
 
-#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
+#if defined(_LIBCPP_ABI_VCRUNTIME)
 #include <new.h>
 #endif
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
 #if !defined(__cpp_sized_deallocation) || __cpp_sized_deallocation  < 201309L

 #if !__has_builtin(__builtin_operator_new) || \
    __has_builtin(__builtin_operator_new) < 201802L
 #define _LIBCPP_HAS_NO_BUILTIN_OVERLOADED_OPERATOR_NEW_DELETE
 #endif
 
 namespace std  // purposefully not using versioning namespace
 {
 
-#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
+#if !defined(_LIBCPP_ABI_VCRUNTIME)
 struct _LIBCPP_TYPE_VIS nothrow_t {};
 extern _LIBCPP_FUNC_VIS const nothrow_t nothrow;
 
 class _LIBCPP_EXCEPTION_ABI bad_alloc
     : public exception
 {
 public:
     bad_alloc() _NOEXCEPT;
public:
     virtual ~bad_array_new_length() _NOEXCEPT;
     virtual const char* what() const _NOEXCEPT;
 };
 
 typedef void (*new_handler)();
 _LIBCPP_FUNC_VIS new_handler set_new_handler(new_handler) _NOEXCEPT;
 _LIBCPP_FUNC_VIS new_handler get_new_handler() _NOEXCEPT;
 
-#endif // !_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME
+#endif // !_LIBCPP_ABI_VCRUNTIME
 
 _LIBCPP_NORETURN _LIBCPP_FUNC_VIS void __throw_bad_alloc();  // not in C++ spec
 
 #if !defined(_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION) && \
-    !defined(_LIBCPP_DEFER_NEW_TO_VCRUNTIME)
+    !defined(_LIBCPP_ABI_VCRUNTIME)
 #ifndef _LIBCPP_CXX03_LANG
 enum class _LIBCPP_ENUM_VIS align_val_t : size_t { };
 #else
 enum align_val_t { __zero = 0, __max = (size_t)-1 };
 #endif
 #endif
 
 }  // std
 
 #if defined(_LIBCPP_CXX03_LANG)
 #define _THROW_BAD_ALLOC throw(std::bad_alloc)
 #else
 #define _THROW_BAD_ALLOC
 #endif
 
-#if !defined(_LIBCPP_DEFER_NEW_TO_VCRUNTIME)
+#if !defined(_LIBCPP_ABI_VCRUNTIME)
 
 _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz) _THROW_BAD_ALLOC;
 _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _LIBCPP_NOALIAS;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete(void* __p) _NOEXCEPT;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete(void* __p, const std::nothrow_t&) _NOEXCEPT;
 #ifndef _LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION
 _LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE void  operator delete(void* __p, std::size_t __sz) _NOEXCEPT;
 #endif

 #endif
 #endif
 
 _LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new  (std::size_t, void* __p) _NOEXCEPT {return __p;}
 _LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new[](std::size_t, void* __p) _NOEXCEPT {return __p;}
 inline _LIBCPP_INLINE_VISIBILITY void  operator delete  (void*, void*) _NOEXCEPT {}
 inline _LIBCPP_INLINE_VISIBILITY void  operator delete[](void*, void*) _NOEXCEPT {}
 
-#endif // !_LIBCPP_DEFER_NEW_TO_VCRUNTIME
+#endif // !_LIBCPP_ABI_VCRUNTIME
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 _LIBCPP_CONSTEXPR inline _LIBCPP_INLINE_VISIBILITY bool __is_overaligned_for_new(size_t __align) _NOEXCEPT {
 #ifdef __STDCPP_DEFAULT_NEW_ALIGNMENT__
   return __align > __STDCPP_DEFAULT_NEW_ALIGNMENT__;
 #else
   return __align > alignment_of<max_align_t>::value;

include/typeinfo

 #ifdef _LIBCPP_NO_EXCEPTIONS
 #include <cstdlib>
 #endif
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
-#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
+#if defined(_LIBCPP_ABI_VCRUNTIME)
 #include <vcruntime_typeinfo.h>
 #else
 
 #if defined(_LIBCPP_NONUNIQUE_RTTI_BIT) && !defined(_LIBCPP_ABI_MICROSOFT)
 #   define _LIBCPP_HAS_NONUNIQUE_TYPEINFO
 #endif
 
 namespace std  // purposefully not using versioning namespace

 public:
     bad_typeid() _NOEXCEPT;
     virtual ~bad_typeid() _NOEXCEPT;
     virtual const char* what() const _NOEXCEPT;
 };
 
 }  // std
 
-#endif // defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
+#endif // defined(_LIBCPP_ABI_VCRUNTIME)
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 _LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
 void __throw_bad_cast()
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS
     throw bad_cast();
 #else
     _VSTD::abort();
 #endif
 }
 _LIBCPP_END_NAMESPACE_STD
 
 #endif  // __LIBCPP_TYPEINFO

src/new.cpp

 //===--------------------------- new.cpp ----------------------------------===//
 //
 // 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 <stdlib.h>
 
 #include "new"
 #include "include/atomic_support.h"
 
 #if defined(_LIBCPP_ABI_MICROSOFT)
-#if defined(_LIBCPP_NO_VCRUNTIME)
+#if !defined(_LIBCPP_ABI_VCRUNTIME)
 #include "support/runtime/new_handler_fallback.ipp"
 #endif
 #elif defined(LIBCXX_BUILDING_LIBCXXABI)
 #include <cxxabi.h>
 #elif defined(LIBCXXRT)
 #include <cxxabi.h>
 #include "support/runtime/new_handler_fallback.ipp"
 #elif defined(__GLIBCXX__)

 #endif
 }
 
 #endif // !LIBSTDCXX
 
 }  // std
 
 #if !defined(__GLIBCXX__) &&                                                   \
-    !defined(_LIBCPP_DEFER_NEW_TO_VCRUNTIME) &&      \
+    !defined(_LIBCPP_ABI_VCRUNTIME) &&      \
     !defined(_LIBCPP_DISABLE_NEW_DELETE_DEFINITIONS)
 
 // 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 *

 _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
-#endif // !__GLIBCXX__ && (!_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME) && !_LIBCPP_DISABLE_NEW_DELETE_DEFINITIONS
+#endif // !__GLIBCXX__ && !_LIBCPP_ABI_VCRUNTIME && !_LIBCPP_DISABLE_NEW_DELETE_DEFINITIONS

src/stdexcept.cpp

 }
 
 const char*
 runtime_error::what() const _NOEXCEPT
 {
     return __imp_.c_str();
 }
 
-#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
+#if !defined(_LIBCPP_ABI_VCRUNTIME)
 
 logic_error::~logic_error() _NOEXCEPT {}
 domain_error::~domain_error() _NOEXCEPT {}
 invalid_argument::~invalid_argument() _NOEXCEPT {}
 length_error::~length_error() _NOEXCEPT {}
 out_of_range::~out_of_range() _NOEXCEPT {}
 
 runtime_error::~runtime_error() _NOEXCEPT {}
 range_error::~range_error() _NOEXCEPT {}
 overflow_error::~overflow_error() _NOEXCEPT {}
 underflow_error::~underflow_error() _NOEXCEPT {}
 
 #endif
 #endif
 
 }  // std

src/support/runtime/exception_msvc.ipp

 }
 
 bool uncaught_exception() _NOEXCEPT { return uncaught_exceptions() > 0; }
 
 int uncaught_exceptions() _NOEXCEPT {
     return __uncaught_exceptions();
 }
 
-#if defined(_LIBCPP_NO_VCRUNTIME)
+#if !defined(_LIBCPP_ABI_VCRUNTIME)
 bad_cast::bad_cast() _NOEXCEPT
 {
 }
 
 bad_cast::~bad_cast() _NOEXCEPT
 {
 }
 

 {
 }
 
 const char*
 bad_array_new_length::what() const _NOEXCEPT
 {
     return "bad_array_new_length";
 }
-#endif // _LIBCPP_NO_VCRUNTIME
+#endif // !_LIBCPP_ABI_VCRUNTIME
 
 } // namespace std

src/typeinfo.cpp

 //===------------------------- typeinfo.cpp -------------------------------===//
 //
 // 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 "typeinfo"
 
-#if defined(_LIBCPP_ABI_MICROSOFT) && defined(_LIBCPP_NO_VCRUNTIME)
+#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_ABI_VCRUNTIME)
 #include <string.h>
 
 int std::type_info::__compare(const type_info &__rhs) const _NOEXCEPT {
   if (&__data == &__rhs.__data)
     return 0;
   return strcmp(&__data.__decorated_name[1], &__rhs.__data.__decorated_name[1]);
 }
 
#endif
   return value;
 }
 #endif // _LIBCPP_ABI_MICROSOFT
 
 // FIXME: Remove __APPLE__ default here once buildit is gone.
 // FIXME: Remove the _LIBCPP_BUILDING_HAS_NO_ABI_LIBRARY configuration.
 #if (!defined(LIBCXX_BUILDING_LIBCXXABI) && !defined(LIBCXXRT) &&              \
      !defined(__GLIBCXX__) && !defined(__APPLE__) &&                           \
-     !(defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME))) ||   \
+     !defined(_LIBCPP_ABI_VCRUNTIME)) ||   \
     defined(_LIBCPP_BUILDING_HAS_NO_ABI_LIBRARY)
 std::type_info::~type_info()
 {
 }
 #endif