[libc++] P2867R1: Remove Deprecated strstreams From C++26 (llvm#87107)

H-G-Hristov · Zingam · web-flow · commit fb635be0b8a3 · 2024-04-04T06:03:00.000+03:00
Implements: https://wg21.link/P2867R2 --------- Co-authored-by: Hristo Hristov <zingam@outlook.com>
diff --git a/libcxx/docs/ReleaseNotes/19.rst b/libcxx/docs/ReleaseNotes/19.rst
@@ -42,6 +42,7 @@ Implemented Papers
 - P2652R2 - Disallow User Specialization of ``allocator_traits``
 - P2819R2 - Add ``tuple`` protocol to ``complex``
 - P2495R3 - Interfacing ``stringstream``\s with ``string_view``
+- P2867R2 - Remove Deprecated ``strstream``\s From C++26
 - P2302R4 - ``std::ranges::contains``
 - P1659R3 - ``std::ranges::starts_with`` and ``std::ranges::ends_with``
 
@@ -54,6 +55,8 @@ Improvements and New Features
 - The ``std::mismatch`` algorithm has been optimized for integral types, which can lead up to 40x performance
   improvements.
 
+- The ``_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM`` macro has been added to make the declarations in ``<strstream>`` available.
+
 Deprecations and Removals
 -------------------------
 
diff --git a/libcxx/docs/Status/Cxx2cPapers.csv b/libcxx/docs/Status/Cxx2cPapers.csv
@@ -47,7 +47,7 @@
 "`P1673R13 <https://wg21.link/P1673R13>`__","LWG","A free function linear algebra interface based on the BLAS","Kona November 2023","","",""
 "","","","","","",""
 "`P2875R4 <https://wg21.link/P2875R4>`__","LWG","Undeprecate ``polymorphic_allocator::destroy`` for C++26","Tokyo March 2024","|Complete|","15.0",""
-"`P2867R2 <https://wg21.link/P2867R2>`__","LWG","Remove Deprecated ``strstreams`` From C++26","Tokyo March 2024","","",""
+"`P2867R2 <https://wg21.link/P2867R2>`__","LWG","Remove Deprecated ``strstreams`` From C++26","Tokyo March 2024","|Complete|","19.0",""
 "`P2869R4 <https://wg21.link/P2869R4>`__","LWG","Remove Deprecated ``shared_ptr`` Atomic Access APIs from C++26","Tokyo March 2024","","",""
 "`P2872R3 <https://wg21.link/P2872R3>`__","LWG","Remove ``wstring_convert`` From C++26","Tokyo March 2024","","",""
 "`P3107R5 <https://wg21.link/P3107R5>`__","LWG","Permit an efficient implementation of ``std::print``","Tokyo March 2024","","","|format| |DR|"
diff --git a/libcxx/docs/UsingLibcxx.rst b/libcxx/docs/UsingLibcxx.rst
@@ -272,7 +272,10 @@ C++26 Specific Configuration Macros
   ``std::basic_string<...>::reserve()``.
 
 **_LIBCPP_ENABLE_CXX26_REMOVED_ALLOCATOR_MEMBERS**:
-  This macro is used to re-enable redundant member of ``allocator<T>::is_always_equal``
+  This macro is used to re-enable redundant member of ``allocator<T>::is_always_equal``.
+
+**_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM**:
+  This macro is used to re-enable all named declarations in ``<strstream>``.
 
 Libc++ Extensions
 =================
diff --git a/libcxx/include/strstream b/libcxx/include/strstream
@@ -13,7 +13,7 @@
 /*
     strstream synopsis
 
-class strstreambuf
+class strstreambuf                                    // Removed in C++26
     : public basic_streambuf<char>
 {
 public:
@@ -63,7 +63,7 @@ private:
     void (*pfree)(void*);               // exposition only
 };
 
-class istrstream
+class istrstream                                      // Removed in C++26
     : public basic_istream<char>
 {
 public:
@@ -81,7 +81,7 @@ private:
     strstreambuf sb; // exposition only
 };
 
-class ostrstream
+class ostrstream                                      // Removed in C++26
     : public basic_ostream<char>
 {
 public:
@@ -99,7 +99,7 @@ private:
     strstreambuf sb; // exposition only
 };
 
-class strstream
+class strstream                                       // Removed in C++26
     : public basic_iostream<char>
 {
 public:
@@ -138,6 +138,8 @@ private:
 #  pragma GCC system_header
 #endif
 
+#if _LIBCPP_STD_VER < 26 || defined(_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM) || defined(_LIBCPP_BUILDING_LIBRARY)
+
 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
 
@@ -344,4 +346,6 @@ _LIBCPP_END_NAMESPACE_STD
 
 _LIBCPP_POP_MACROS
 
+#endif // _LIBCPP_STD_VER < 26 || defined(_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM) || defined(_LIBCPP_BUILDING_LIBRARY)
+
 #endif // _LIBCPP_STRSTREAM
diff --git a/libcxx/modules/std/strstream.inc b/libcxx/modules/std/strstream.inc
@@ -9,9 +9,11 @@
 
 export namespace std {
 #ifndef _LIBCPP_HAS_NO_LOCALIZATION
+#  if _LIBCPP_STD_VER < 26 || defined(_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM)
   using std::istrstream;
   using std::ostrstream;
   using std::strstream;
   using std::strstreambuf;
+#  endif // _LIBCPP_STD_VER < 26 || defined(_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM)
 #endif // _LIBCPP_HAS_NO_LOCALIZATION
 } // namespace std
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/depr.istrstream.cons/ccp.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/depr.istrstream.cons/ccp.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/depr.istrstream.cons/ccp_size.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/depr.istrstream.cons/ccp_size.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/depr.istrstream.cons/cp.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/depr.istrstream.cons/cp.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/depr.istrstream.cons/cp_size.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/depr.istrstream.cons/cp_size.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/depr.istrstream.members/rdbuf.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/depr.istrstream.members/rdbuf.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/depr.istrstream.members/str.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/depr.istrstream.members/str.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/depr.verify.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/depr.verify.cpp
@@ -6,6 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
+
 // <strstream>
 
 // check that istrstream is marked deprecated
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/types.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.istrstream/types.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/depr.ostrstream.cons/cp_size_mode.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/depr.ostrstream.cons/cp_size_mode.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/depr.ostrstream.cons/default.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/depr.ostrstream.cons/default.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/depr.ostrstream.members/freeze.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/depr.ostrstream.members/freeze.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/depr.ostrstream.members/pcount.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/depr.ostrstream.members/pcount.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/depr.ostrstream.members/rdbuf.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/depr.ostrstream.members/rdbuf.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/depr.ostrstream.members/str.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/depr.ostrstream.members/str.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/depr.verify.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/depr.verify.cpp
@@ -6,6 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
+
 // <strstream>
 
 // check that ostrstream is marked deprecated
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/types.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.ostrstream/types.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/depr.strstream.cons/cp_size_mode.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/depr.strstream.cons/cp_size_mode.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/depr.strstream.cons/default.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/depr.strstream.cons/default.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/depr.strstream.dest/rdbuf.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/depr.strstream.dest/rdbuf.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/depr.strstream.oper/freeze.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/depr.strstream.oper/freeze.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/depr.strstream.oper/pcount.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/depr.strstream.oper/pcount.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/depr.strstream.oper/str.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/depr.strstream.oper/str.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/depr.verify.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/depr.verify.cpp
@@ -6,6 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
+
 // <strstream>
 
 // check that strstream is marked deprecated
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/types.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstream/types.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/ccp_size.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/ccp_size.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/cp_size_cp.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/cp_size_cp.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/cscp_size.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/cscp_size.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/cucp_size.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/cucp_size.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/custom_alloc.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/custom_alloc.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/default.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/default.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/scp_size_scp.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/scp_size_scp.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/ucp_size_ucp.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.cons/ucp_size_ucp.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.members/freeze.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.members/freeze.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_STRSTREAM
 
 // <strstream>
 
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.members/overflow.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.members/overflow.pass.cpp
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.members/pcount.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.members/pcount.pass.cpp
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.members/str.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.members/str.pass.cpp
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.virtuals/overflow.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.virtuals/overflow.pass.cpp
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.virtuals/pbackfail.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.virtuals/pbackfail.pass.cpp
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.virtuals/seekoff.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.virtuals/seekoff.pass.cpp
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.virtuals/seekpos.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.virtuals/seekpos.pass.cpp
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.virtuals/setbuf.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.virtuals/setbuf.pass.cpp
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.virtuals/underflow.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.strstreambuf.virtuals/underflow.pass.cpp
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.verify.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/depr.verify.cpp
diff --git a/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/types.pass.cpp b/libcxx/test/std/depr/depr.str.strstreams/depr.strstreambuf/types.pass.cpp
