When investigating bugs in PDB generation, the first step is
often to do the same link with link.exe and then compare PDBs.
But comparing PDBs is hard because two completely different byte
sequences can both be correct, so it hampers the investigation when
you also have to spend time figuring out not just which bytes are
different, but also if the difference is meaningful.
This patch fixes a couple of cases related to string table emission,
hash table emission, and the order in which we emit strings that
makes more of our bytes the same as the bytes generated by MS PDBs.
Differential Revision: https://reviews.llvm.org/D44810
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328348 91177308-0d34-0410-b5e6-96231b3b80d8
This is still failing on a different bot this time due to some
issue related to hashing absolute paths. Reverting until I can
figure it out.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328014 91177308-0d34-0410-b5e6-96231b3b80d8
The issue causing this to fail in certain configurations
should be fixed.
It was due to the fact that DIA apparently expects there to be
a null string at ID 1 in the string table. I'm not sure why this
is important but it seems to make a difference, so set it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328002 91177308-0d34-0410-b5e6-96231b3b80d8
This is causing a test failure on a certain bot, so I'm removing
this temporarily until we can figure out the source of the error.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327903 91177308-0d34-0410-b5e6-96231b3b80d8
Natvis is a debug language supported by Visual Studio for
specifying custom visualizers. The /NATVIS option is an
undocumented link.exe flag which will take a .natvis file
and "inject" it into the PDB. This way, you can ship the
debug visualizers for a program along with the PDB, which
is very useful for postmortem debugging.
This is implemented by adding a new "named stream" to the
PDB with a special name of /src/files/<natvis file name>
and simply copying the contents of the xml into this file.
Additionally, we need to emit a single stream named
/src/headerblock which contains a hash table of embedded
files to records describing them.
This patch adds this functionality, including the /NATVIS
option to lld-link.
Differential Revision: https://reviews.llvm.org/D44328
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327895 91177308-0d34-0410-b5e6-96231b3b80d8
This was originally reported as a bug with the symptom being "cvdump
crashes when printing an LLD-linked PDB that has an S_FILESTATIC record
in it". After some additional investigation, I determined that this was
a symptom of a larger problem, and in fact the real problem was in the
way we emitted the global PDB string table. As evidence of this, you can
take any lld-generated PDB, run cvdump -stringtable on it, and it would
return no results.
My hypothesis was that cvdump could not *find* the string table to begin
with. Normally it would do this by looking in the "named stream map",
finding the string /names, and using its value as the stream index. If
this lookup fails, then cvdump would fail to load the string table.
To test this hypothesis, I looked at the name stream map generated by a
link.exe PDB, and I emitted exactly those bytes into an LLD-generated
PDB. Suddenly, cvdump could read our string table!
This code has always been hacky and we knew there was something we
didn't understand. After all, there were some comments to the effect of
"we have to emit strings in a specific order, otherwise things don't
work". The key to fixing this was finally understanding this.
The way it works is that it makes use of a generic serializable hash map
that maps integers to other integers. In this case, the "key" is the
offset into a buffer, and the value is the stream number. If you index
into the buffer at the offset specified by a given key, you find the
name. The underlying cause of all these problems is that we were using
the identity function for the hash. i.e. if a string's offset in the
buffer was 12, the hash value was 12. Instead, we need to hash the
string *at that offset*. There is an additional catch, in that we have
to compute the hash as a uint32 and then truncate it to uint16.
Making this work is a little bit annoying, because we use the same hash
table in other places as well, and normally just using the identity
function for the hash function is actually what's desired. I'm not
totally happy with the template goo I came up with, but it works in any
case.
The reason we never found this bug through our own testing is because we
were building a /parallel/ hash table (in the form of an
llvm::StringMap<>) and doing all of our lookups and "real" hash table
work against that. I deleted all of that code and now everything goes
through the real hash table. Then, to test it, I added a unit test which
adds 7 strings and queries the associated values. I test every possible
insertion order permutation of these 7 strings, to verify that it really
does work as expected.
Differential Revision: https://reviews.llvm.org/D43326
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325386 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
We were treating the GUIDs in TypeServer2Record as strings, and the
non-ASCII bytes in the GUID would not round-trip through YAML.
We already had the PDB_UniqueId type portably represent a Windows GUID,
but we need to hoist that up to the DebugInfo/CodeView library so that
we can use it in the TypeServer2Record as well as in PDB parsing code.
Reviewers: inglorion, amccarth
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D35495
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@308234 91177308-0d34-0410-b5e6-96231b3b80d8
Previously MappedBlockStream owned its own BumpPtrAllocator that
it would allocate from when a read crossed a block boundary. This
way it could still return the user a contiguous buffer of the
requested size. However, It's not uncommon to open a stream, read
some stuff, close it, and then save the information for later.
After all, since the entire file is mapped into memory, the data
should always be available as long as the file is open.
Of course, the exception to this is when the data isn't *in* the
file, but rather in some buffer that we temporarily allocated to
present this contiguous view. And this buffer would get destroyed
as soon as the strema was closed.
The fix here is to force the user to specify the allocator, this
way it can provide an allocator that has whatever lifetime it
chooses.
Differential Revision: https://reviews.llvm.org/D33858
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304623 91177308-0d34-0410-b5e6-96231b3b80d8
This was discovered when running `llvm-pdbdump diff` against
two files, the second of which was generated by running the
first one through pdb2yaml and then yaml2pdb.
The second one was missing some bytes from the PDB Stream, and
tracking this down showed that at the end of the PDB Stream were
some additional bytes that we were ignoring. Looking back
to the reference code, these seem to specify some additional
flags that indicate whether the PDB supports various optional
features.
This patch adds support for reading, writing, and round-tripping
these flags through YAML and the raw dumper, and updates the
tests accordingly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297984 91177308-0d34-0410-b5e6-96231b3b80d8
This was reverted because it was breaking some builds, and
because of incorrect error code usage. Since the CL was
large and contained many different things, I'm resubmitting
it in pieces.
This portion is NFC, and consists of:
1) Renaming classes to follow a consistent naming convention.
2) Fixing the const-ness of the interface methods.
3) Adding detailed doxygen comments.
4) Fixing a few instances of passing `const BinaryStream& X`. These
are now passed as `BinaryStreamRef X`.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296394 91177308-0d34-0410-b5e6-96231b3b80d8
r296215, "[PDB] General improvements to Stream library."
r296217, "Disable BinaryStreamTest.StreamReaderObject temporarily."
r296220, "Re-enable BinaryStreamTest.StreamReaderObject."
r296244, "[PDB] Disable some tests that are breaking bots."
r296249, "Add static_cast to silence -Wc++11-narrowing."
std::errc::no_buffer_space should be used for OS-oriented errors for socket transmission.
(Seek discussions around llvm/xray.)
I could substitute s/no_buffer_space/others/g, but I revert whole them ATM.
Could we define and use LLVM errors there?
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296258 91177308-0d34-0410-b5e6-96231b3b80d8
This adds various new functionality and cleanup surrounding the
use of the Stream library. Major changes include:
* Renaming of all classes for more consistency / meaningfulness
* Addition of some new methods for reading multiple values at once.
* Full suite of unit tests for reader / writer functionality.
* Full set of doxygen comments for all classes.
* Streams now store their own endianness.
* Fixed some bugs in a few of the classes that were discovered
by the unit tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296215 91177308-0d34-0410-b5e6-96231b3b80d8
This is part of a larger effort to get the Stream code moved
up to Support. I don't want to do it in one large patch, in
part because the changes are so big that it will treat everything
as file deletions and add, losing history in the process.
Aside from that though, it's just a good idea in general to
make small changes.
So this change only changes the names of the Stream related
source files, and applies necessary source fix ups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296211 91177308-0d34-0410-b5e6-96231b3b80d8
