The result of the function cannot be correctly interpreted without
knowing the precise form type (a type signature needs to be looked up
very differently from a supplementary debug info reference). The
function sort of worked because the two reference types (unit-relative
and section-relative) that can be handled uniformly are also the most
common types of references, but this setup made it easy to write code
which does not support other kinds of reference (and if one tried to
support them, the result didn't look pretty --
https://github.com/llvm/llvm-project/pull/97423/files#r1676217081).
The split is based on the reference type classification from DWARFv5
(Section 7.5.5 Classes and Forms), and it should enable uniform (if
slightly more verbose) hadling. Note that this only affects users which
want more control of how (or if) the references are resolved. Users
which just want to access the referenced DIE can use the higher level
API (DWARFDie::GetAttributeValueAsReferencedDie) which returns (or will
return after #97423 is merged) the correct die for all reference types
(except for supplementary references, which we don't support right now).
The function was meant to find the Developer/ dir, but it found a
Developer directory nested deep inside the top-level Developer dir.
The new implementation rejects everything in Xcode.app/Developer in
broad strokes.
rdar://128571037
This patch is extracted from #74725.
The DwarfStreamer interface looks overcomplicated and has unnecessary
dependencies. This patch avoids creation of DwarfStreamer by DWARFLinker and
simplifies interface.
This patch creates DWARFLinkerBase library, places DWARFLinker code into
DWARFLinker\Classic, places DWARFLinkerParallel into DWARFLinker\Parallel.
updates BOLT to use new library. This patch is NFC.
