Commit Graph

3 Commits

Author SHA1 Message Date
Jonas Devlieghere f1d5cbbdee [dsymutil] Add preliminary support for DWARF 5.
Currently dsymutil will silently fail when processing binaries with
Dwarf 5 debug info. This patch adds rudimentary support for Dwarf 5 in
dsymutil.

 - Recognize relocations in the debug_addr section.
 - Recognize (a subset of) Dwarf 5 form values.
 - Emits valid Dwarf 5 compile unit header chains.

To simplify things (and avoid having to emit indexed sections) I decided
to emit the relocated addresses directly in the debug info section.

 - DW_FORM_strx gets relocated and rewritten to DW_FORM_strp
 - DW_FORM_addrx gets relocated and rewritten to DW_FORM_addr

Obviously there's a lot of work left, but this should be a step in the
right direction.

rdar://62345491

Differential revision: https://reviews.llvm.org/D94323
2021-01-12 21:55:41 -08:00
Alexey Lapshin 0ed2170dc4 [DWARFLinker][dsymutil] followup for 88c2137b6d
That patch is a followup for "Move DwarfStreamer into DWARFLinker".
It fixes build with LLVM_LINK_LLVM_DYLIB.
2020-04-08 16:46:52 +03:00
Alexey Lapshin 88c2137b6d [DWARFLinker][dsymutil][NFC] Move DwarfStreamer into DWARFLinker.
For implementing "remove obsolete debug info in lld", it is neccesary
to have DWARF generation code implementation. dsymutil uses DwarfStreamer
for that purpose. DwarfStreamer uses AsmPrinter. It is considered OK
to use AsmPrinter based code in lld(D74169). This patch moves
DwarfStreamer implementation into DWARFLinker, so that it could be reused
from lld.

Generally, a better place for such a common DWARF generation code would be
not DWARFLinker but an additional separate library. Such a library could
contain a single version of DWARF generation routines and could also
be independent of AsmPrinter. At the current moment, DwarfStreamer
does not pretend to be such a general implementation of DWARF generation.
So I decided to put it into DWARFLinker since it is the only user
of DwarfStreamer.

Testing: it passes "check-all" lit testing. MD5 checksum for clang .dSYM
bundle matches for the dsymutil with/without that patch.

Reviewed By: JDevlieghere

Differential revision: https://reviews.llvm.org/D77169
2020-04-07 21:21:54 +03:00