Mach-O corefiles have LC_NOTE metadata, one LC_NOTE that lldb recognizes
is `main bin spec` which can specify that this is a kernel corefile,
userland corefile, or firmware/standalone corefile. With a userland
corefile, the LC_NOTE would specify the virtual address of the dyld
binary's Mach-O header. lldb would create a Module from that in-memory
binary, find the `dyld_all_image_infos` object in dyld's DATA segment,
and use that object to find all of the binaries present in the corefile.
ProcessMachCore takes the metadata from this LC_NOTE and passes the
address to the DynamicLoader plugin via its `GetImageInfoAddress()`
method, so the DynamicLoader can find all of the binaries and load them
in the Target at their correct virtual addresses.
We have a corefile creator who would prefer to specify the address of
`dyld_all_image_infos` directly, instead of specifying the address of
dyld and parsing that to find the object. DynamicLoaderMacOSX, the
DynamicLoader plugin being used here, will accept either a dyld virtual
address or a `dyld_all_image_infos` virtual address from
ProcessMachCore, and do the correct thing with either value.
lldb's process save-core mach-o corefile reader will continue to specify
the virtual address of the dyld binary.
rdar://144322688
1f5edb17b2