The hash table is a list of buckets, and the *value* stored in
the bucket cannot be 0 since that is reserved. However, the code
here was incorrectly skipping over the 0'th bucket entirely.
The 0'th bucket is perfectly fine, just none of these buckets
can contain the value 0.
As a result, whenever there was a string where hash(S) % Size
was equal to 0, we would write the value in the next bucket
instead. We never caught this in our tests due to *another*
bug, which is that we would iterate the entire list of buckets
looking for the value, only using the hash value as a starting
point. However, the real algorithm stops when it finds 0 in
a bucket since it takes that to mean "the item is not in the
hash table".
The unit test is updated to carefully construct a set of hash
values that will cause one item to hash to 0 mod bucket count,
and the reader is also updated to return an error indicating that
the item is not found when it encounters a 0 bucket.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328162 91177308-0d34-0410-b5e6-96231b3b80d8
We're getting to the point that some MS tools (e.g. DIA) can recognize
our PDBs but others (e.g. link.exe) cannot. I think the way forward is
to improve our tooling to help us find differences more easily. For
example, if we can compile the same program with clang-cl and cl and
have a tool tell us all the places where the PDBs differ, this could
tell us what we're doing wrong. It's tricky though, because there are a
lot of "benign" differences in a PDB. For example, if the string table
in one PDB consists of "foo" followed by "bar" and in the other PDB it
consists of "bar" followed by "foo", this is not necessarily a critical
difference, as long as the uses of these strings also refer to the
correct location. On the other hand, if the second PDB doesn't even
contain the string "foo" at all, this is a critical difference.
diff mode has been in llvm-pdbutil for quite a while, but because of the
above challenge along with some others, it's been hard to make it
useful. I think this patch addresses that. It looks for all the same
things, but it now prints the output in tabular format (carefully
formatted and aligned into tables and fields), and it highlights
critical differences in red, non-critical differences in yellow, and
identical fields in green. This makes it easy to spot the places we
differ, and the general concept of outputting arbitrary fields in
tabular format can be extended to provide analysis into many of the
different types of information that show up in a PDB.
Differential Revision: https://reviews.llvm.org/D35039
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307421 91177308-0d34-0410-b5e6-96231b3b80d8
This was originally reverted because of some non-deterministic
failures on certain buildbots. Luckily ASAN eventually caught
this as a stack-use-after-scope, so the fix is included in
this patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305393 91177308-0d34-0410-b5e6-96231b3b80d8
Previously we would expect certain subsections to appear
in a certain order because some subsections would reference
other subsections, but in practice we need to support
arbitrary orderings since some object file and PDB file
producers generate them this way. This also paves the
way for supporting Yaml <-> Object File conversion of
CodeView, since Object Files typically have quite a
large number of subsections in their debug info.
Differential Revision: https://reviews.llvm.org/D33807
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304588 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-readobj hand rolls some CodeView parsing code for string
tables, so this patch updates it to re-use some of the newly
introduced parsing code in LLVMDebugInfoCodeView.
Differential Revision: https://reviews.llvm.org/D32772
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302052 91177308-0d34-0410-b5e6-96231b3b80d8
This was reverted due to a "missing" file, but in reality
what happened was that I renamed a file, and then due to
a merge conflict both the old file and the new file got
added to the repository. This led to an unused cpp file
being in the repo and not referenced by any CMakeLists.txt
but #including a .h file that wasn't in the repo. In an
even more unfortunate coincidence, CMake didn't report the
unused cpp file because it was in a subdirectory of the
folder with the CMakeLists.txt, and not in the same directory
as any CMakeLists.txt.
The presence of the unused file was then breaking certain
tools that determine file lists by globbing rather than
by what's specified in CMakeLists.txt
In any case, the fix is to just remove the unused file from
the patch set.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302042 91177308-0d34-0410-b5e6-96231b3b80d8
The patch is failing to add StringTableStreamBuilder.h, but that isn't
even discovered because the corresponding StringTableStreamBuilder.cpp
isn't added to any CMakeLists.txt file and thus never built. I think
this patch is just incomplete.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302002 91177308-0d34-0410-b5e6-96231b3b80d8
Previously we had knowledge of how to serialize and deserialize
a string table inside of DebugInfo/PDB, but the string table
that it serializes contains a piece that is actually considered
CodeView and can appear outside of a PDB. We already have logic
in llvm-readobj and MCCodeView to read and write this format,
so it doesn't make sense to duplicate the logic in DebugInfoPDB
as well.
This patch makes codeview::StringTable (for writing) and
codeview::StringTableRef (for reading), updates DebugInfoPDB
to use these classes for its own writing, and updates llvm-readobj
to additionally use StringTableRef for reading.
It's a bit more difficult to get MCCodeView to use this for
writing, but it's a logical next step.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301986 91177308-0d34-0410-b5e6-96231b3b80d8
With the forthcoming codeview::StringTable which a pdb::StringTable
would hold an instance of as one member, this ambiguity becomes
confusing. Rename to PDBStringTable to avoid this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301948 91177308-0d34-0410-b5e6-96231b3b80d8
