The Value type holds pointers but currently has alignment of 1. Since LSAN by default only looks for pointers in aligned addresses, it can report false-positive leaks of memory pointed to by a misaligned Value. This will be fixed by giving Value at least pointer alignment.

Original title: Use use_unaligned for LSAN

Original Description:

Pointers to the RCString class may be stored in memory not aligned to 8 bytes, and therefore LSAN does not mark the RCString as reachable. This results in false positive leak reports.

To fix, pass "use_unaligned=1" in the LSAN_OPTIONS environment variable.

See
https://github.com/llvm-mirror/compiler-rt/blob/b3c632084941e7b9669416f91c7f90b7fcd49645/lib/lsan/lsan_common.cc#L160-L165
https://github.com/llvm-mirror/compiler-rt/blob/b3c632084941e7b9669416f91c7f90b7fcd49645/lib/lsan/lsan_common.h#L71-L73