libstdc++: Introduce GLIBCXX_3.4.37 version for symbols not backported to GCC-16.
New ABI version GLIBCXX_3.4.37 added to libstdc++ for symbols not backported to GCC 16.
This change introduces the GLIBCXX_3.4.37 ABI version to libstdc++. It adds specific symbols, related to chrono and format_arg, that were not backported to GCC 16. Additionally, it moves basic_string’s _S_allocate_at_least and _M_create_plus symbols to this new version. The libtool version has been bumped to 3.4.36, and related baseline symbol files and testsuite configurations are updated.
In Details
libstdc++ ABI management: This commit updates the ABI versioning for libstdc++ by introducing GLIBCXX_3.4.37. It backports symbols from GCC 17, specifically chrono::__detail::__recent_leap_second_info, basic_format_arg specializations, and basic_string internal allocation/creation helpers, ensuring compatibility for users on older GCCToolchain releases. The libtool_VERSION is incremented and baseline symbol files are regenerated to reflect these changes.
- libstdc++
- The standard C++ library implementation used by GCC. It provides fundamental C++ features like containers, algorithms, and I/O streams.
- ABI
- Application Binary Interface. Defines how compiled code can interact at the binary level, including function calling conventions, data layout, and symbol naming. Changes to ABI can break compatibility between different toolchain versions.
- GLIBCXX_3.4.37
- A specific symbol version marker used by libstdc++ to denote compatibility for symbols introduced or changed in that version. This allows older binaries to link against newer libraries if the ABI is compatible.
- backport
- The process of taking code fixes or features from a newer version of a software project and applying them to an older, usually stable, release.
- baseline_symbols.txt
- A file used by libstdc++ to track symbols and their ABI versions for different target platforms. It's used for ABI compatibility checks and regeneration.