[libcxx-commits] [PATCH] D155180: [libc++] Use always_inline for std::stringbuf::str() on Windows to work around #40363

[Hans Wennborg via Phabricator via libcxx-commits]

hans created this revision.
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As reported in https://github.com/llvm/llvm-project/issues/40363, the exclude_from_explicit_instantiation attribute doesn't currently really work with dllimport.

Because of that, the new stringbuf::str() overload added in D153709 <https://reviews.llvm.org/D153709> is dllimport on Windows but not actually defined in the cpp file, causing link errors.

As discussed on that code review, this patch works around the problem with the always_inline attribute until Clang can be fixed.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D155180

Files:
  libcxx/include/sstream


Index: libcxx/include/sstream
===================================================================
--- libcxx/include/sstream
+++ libcxx/include/sstream
@@ -334,7 +334,15 @@
 #if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_BUILDING_LIBRARY)
     string_type str() const;
 #else
-    _LIBCPP_HIDE_FROM_ABI string_type str() const & { return str(__str_.get_allocator()); }
+
+#ifdef _WIN32
+    // TODO(LLVM 19): Remove this once we drop support for Clang versions which
+    // have this bug: https://github.com/llvm/llvm-project/issues/40363
+    _LIBCPP_ALWAYS_INLINE
+#else
+    _LIBCPP_HIDE_FROM_ABI
+#endif
+    string_type str() const & { return str(__str_.get_allocator()); }
 
     template <class _SAlloc>
       requires __is_allocator<_SAlloc>::value


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