Commit Graph

3 Commits

Author SHA1 Message Date
Zachary Turner 15b2bdfd8b [llvm-pdbutil] Add the ability to explain binary files.
Using this, you can use llvm-pdbutil to export the contents of a
stream to a binary file, then run explain on the binary file so
that it treats the offset as an offset into the stream instead
of an offset into a file.  This makes it easy to compare the
contents of the same stream from two different files.

llvm-svn: 329207
2018-04-04 17:29:09 +00:00
Zachary Turner d5cf5cf637 [llvm-pdbutil] Dig deeper into the PDB and DBI streams when explaining.
This will show more detail when using `llvm-pdbutil explain` on an
offset in the DBI or PDB streams.  Specifically, it will dig into
individual header fields and substreams to give a more precise
description of what the byte represents.

llvm-svn: 328878
2018-03-30 17:16:50 +00:00
Zachary Turner ea40f40e1b [PDB] Add an explain subcommand.
When investigating various things, we often have a file offset
and what to know what's in the PDB at that address.  For example
we may be doing a binary comparison of two LLD-generated PDBs
to look for sources of non-determinism, or we may wish to compare
an LLD-generated PDB with a Microsoft generated PDB for sources
of byte-for-byte incompatibility.  In these cases, we can do a
binary diff of the two files, and once we find a mismatched byte
we can use explain to figure out what that byte is, immediately
honining in on the problem.

This patch implements this by trying to narrow the meaning of
a particular file offset down as much as possible.

Differential Revision: https://reviews.llvm.org/D44959

llvm-svn: 328799
2018-03-29 16:28:20 +00:00