[libc++] Move unused basic_string function definition to the dylib sources (#126219)
`__init(const value_type*, size_type, size_type)` is part of our ABI,
but we don't actually use the function anymore in the dylib. THis moves
the definition to the `src/` directory to make it clear that the code is
unused. This also allows us to remove it entirely in the unstable ABI.
diff --git a/libcxx/src/string.cpp b/libcxx/src/string.cpp
index dc16ce7..e335639 100644
--- a/libcxx/src/string.cpp
+++ b/libcxx/src/string.cpp
@@ -37,6 +37,44 @@
#endif // _LIBCPP_ABI_DO_NOT_EXPORT_BASIC_STRING_COMMON
+// Define legacy ABI functions
+// ---------------------------
+
+#ifndef _LIBCPP_ABI_STRING_OPTIMIZED_EXTERNAL_INSTANTIATION
+
+template <class _CharT, class _Traits, class _Allocator>
+void basic_string<_CharT, _Traits, _Allocator>::__init(const value_type* __s, size_type __sz, size_type __reserve) {
+ if (__libcpp_is_constant_evaluated())
+ __rep_ = __rep();
+ if (__reserve > max_size())
+ __throw_length_error();
+ pointer __p;
+ if (__fits_in_sso(__reserve)) {
+ __set_short_size(__sz);
+ __p = __get_short_pointer();
+ } else {
+ auto __allocation = std::__allocate_at_least(__alloc_, __recommend(__reserve) + 1);
+ __p = __allocation.ptr;
+ __begin_lifetime(__p, __allocation.count);
+ __set_long_pointer(__p);
+ __set_long_cap(__allocation.count);
+ __set_long_size(__sz);
+ }
+ traits_type::copy(std::__to_address(__p), __s, __sz);
+ traits_type::assign(__p[__sz], value_type());
+ __annotate_new(__sz);
+}
+
+# define STRING_LEGACY_API(CharT) \
+ template _LIBCPP_EXPORTED_FROM_ABI void basic_string<CharT>::__init(const value_type*, size_type, size_type)
+
+STRING_LEGACY_API(char);
+# if _LIBCPP_HAS_WIDE_CHARACTERS
+STRING_LEGACY_API(wchar_t);
+# endif
+
+#endif // _LIBCPP_ABI_STRING_OPTIMIZED_EXTERNAL_INSTANTIATION
+
#define _LIBCPP_EXTERN_TEMPLATE_DEFINE(...) template __VA_ARGS__;
#ifdef _LIBCPP_ABI_STRING_OPTIMIZED_EXTERNAL_INSTANTIATION
_LIBCPP_STRING_UNSTABLE_EXTERN_TEMPLATE_LIST(_LIBCPP_EXTERN_TEMPLATE_DEFINE, char)
