forked from OSchip/llvm-project
18 lines
849 B
ReStructuredText
18 lines
849 B
ReStructuredText
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====================
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Libc++ ABI stability
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====================
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Libc++ aims to preserve stable ABI to avoid subtle bugs when code built to the old ABI
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is linked with the code build to the new ABI. At the same time, libc++ allows ABI-breaking
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improvements and bugfixes for the scenarios when ABI change is not a issue.
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To support both cases, libc++ allows specifying the ABI version at the
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build time. The version is defined with a cmake option
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LIBCXX_ABI_VERSION. Another option LIBCXX_ABI_UNSTABLE can be used to
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include all present ABI breaking features. These options translate
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into C++ macro definitions _LIBCPP_ABI_VERSION, _LIBCPP_ABI_UNSTABLE.
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Any ABI-changing feature is placed under it's own macro, _LIBCPP_ABI_XXX, which is enabled
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based on the value of _LIBCPP_ABI_VERSION. _LIBCPP_ABI_UNSTABLE, if set, enables all features at once.
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