My original implementation of this last year was to just export everything from liblldb.so. As lldb-mi recently started including a separate copy of llvm, exporting everything from liblldb.so has the side effect of allowing the Linux dynamic linker to resolve liblldb.so and lldb-mi's two copies of llvm to the same underlying storage. This means any global constructors in LLVM (e.g. the 'debug' command line option that triggered this change when NDEBUG is not defined) have side-effects applied twice to the same underlying data.
This change adjusts the -DLLDB_EXPORT_ALL_SYMBOLS flag's implementation, limiting exports to the normal exports plus the lldb_private namespace symbols. This filters out exporting any of the LLVM symbols for the copy inside liblldb.so, maintaining the firewall between the separate copies of llvm. preventing two sets of global constructors from both occurring on the same underlying data.
This is a fix for:
https://llvm.org/bugs/show_bug.cgi?id=30822