[PATCH] D44275: Add the ability to stamp a PDB / EXE with a given GUID / Age, and use it to test LLD reproducibility

[Zachary Turner via Phabricator via llvm-commits]

zturner created this revision.
zturner added reviewers: ruiu, rnk.
Herald added a subscriber: hiraditya.

The idea here is that we want to test

a) That we write a valid timestamp (i.e. hash) into the PE file
and
b) That this doesn't affect determinism,

but it's difficult because the generated PDB GUID is currently not deterministic, so this non-deterministic value gets written into the PE.  There's ideas to fix this, but for now we would still like to be able to test that this is the *only* source of non determinism.  To deal with this, this patch introduces a subcommand to `llvm-pdbutil` which will stamp either an EXE or PDB with a specified GUID and age, then recompute the hash of the executable and update the various timestamp fields.

Two tests are introduced, one which verifies that two identical links without /DEBUG generate the same binary, and another which verifies that two identical links with /DEBUG generate the same binary provided they are stamped with the same GUID and Age.


https://reviews.llvm.org/D44275

Files:
  lld/test/COFF/repro-debug-clean.test
  lld/test/COFF/repro-nodebug.test
  llvm/include/llvm/ADT/StringExtras.h
  llvm/include/llvm/DebugInfo/PDB/PDB.h
  llvm/include/llvm/Object/COFF.h
  llvm/lib/Object/COFFObjectFile.cpp
  llvm/tools/llvm-pdbutil/llvm-pdbutil.cpp

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D44275.137656.patch
Type: text/x-patch
Size: 14574 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20180308/ad4054c7/attachment.bin>