forked from OSchip/llvm-project
e369a989fc
libunwind defines the _Unwind_* ABI used by libc++abi. This ABI is a stable quasi-standard common between multiple implementations such as LLVM and GNU. The _U* symbol name space is also safely within the symbol name space that standard C & C++ reserve for the implementation. Futhermore, libunwind also defines several unw_* symbols, and references these from the _Unwind_* entry points so the standard/reserved part of the ABI is dependent on the unw_* part of the ABI. This is not OK for a C or C++ implementation. The unw_* symbols are reserved for C and extern "C" used by application code. This change renames each unw_* function to __unw* and adds a weak alias unw_* to keep the public <libunwind.h> ABI unchanged for backwards compatibility. Every reference to unw_* in the implementation has been changed to use __unw* so that if other unw_* definitions are in force because nothing uses <libunwind.h> in a particular program, no _Unwind* code path depends on any unw_* symbol. Furthemore, __unw_* symbols are hidden, which saves PLT overhead in the shared library case. In the future, we should cconsider untangling the unw_* API/ABI from the _Unwind_* API/ABI. The internal API backing the _Unwind_* ABI implementation should not rely on any nonstandard symbols not in the implementation-reserved name space. This would then allow separating the _Unwind_* API/ABI from unw_* entirely, but that's a more substantial change that's going to require more significant refactoring. Differential Revision: https://reviews.llvm.org/D59921 llvm-svn: 357640 |
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| .arcconfig | ||
| .clang-format | ||
| CMakeLists.txt | ||
| LICENSE.TXT | ||