Only attempt to demangle symbols which have the itanium C++ prefix of `_Z`.
This ensures that we do not treat any symbol name as a managled named. We would
previously treat a C function `f` as a mangled name and decode that to `float`
incorrectly.
While it is easy to add tests for this, Mehdi recommended against introducing
tests for the demangler as libc++abi should cover the testing.
llvm-svn: 286795
This adds a copy of the demangler in libcxxabi.
The code also has no dependencies on anything else in LLVM. To enforce
that I added it as another library. That way a BUILD_SHARED_LIBS will
fail if anyone adds an use of StringRef for example.
The no llvm dependency combined with the fact that this has to build
on linux, OS X and Windows required a few changes to the code. In
particular:
No constexpr.
No alignas
On OS X at least this library has only one global symbol:
__ZN4llvm16itanium_demangleEPKcPcPmPi
My current plan is:
Commit something like this
Change lld to use it
Change lldb to use it as the fallback
Add a few #ifdefs so that exactly the same file can be used in
libcxxabi to export abi::__cxa_demangle.
Once the fast demangler in lldb can handle any names this
implementation can be replaced with it and we will have the one true
demangler.
llvm-svn: 280732
