When emitting PDBs, the TypeStreamMerger class is used to merge .debug$T records from the input .OBJ files into the output .PDB stream.
Records in .OBJs are not required to be aligned on 4-bytes, and "The Netwide Assembler 2.14" generates non-aligned records.
When compiling with -DLLVM_ENABLE_ASSERTIONS=ON, an assert was triggered in MergingTypeTableBuilder when non-ghash merging was used.
With ghash merging there was no assert.
As a result, LLD could potentially generate a non-aligned TPI stream.
We now align records on 4-bytes when record indices are remapped, in TypeStreamMerger::remapIndices().
Differential Revision: https://reviews.llvm.org/D75081
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
llvm-svn: 369013
When type streams with forward references were merged using GHashes, cycles
were introduced in the debug info. This was caused by
GlobalTypeTableBuilder::insertRecordAs() not inserting the record on the second
pass, thus yielding an empty ArrayRef at that record slot. Later on, upon PDB
emission, TpiStreamBuilder::commit() would skip that empty record, thus
offseting all indices that came after in the stream.
This solution comes in two steps:
1. Fix the hash calculation, by doing a multiple-step resolution, iff there are
forward references in the input stream.
2. Fix merge by resolving with multiple passes, therefore moving records with
forward references at the end of the stream.
This patch also adds support for llvm-readoj --codeview-ghash.
Finally, fix dumpCodeViewMergedTypes() which previously could reference deleted
memory.
Fixes PR40221
Differential Revision: https://reviews.llvm.org/D57790
llvm-svn: 353412
PDBs contain several serialized hash tables. In the microsoft-pdb
repo published to support LLVM implementing PDB support, the
provided initializes the bucket count for the TPI and IPI streams
to the maximum size. This occurs in tpi.cpp L33 and tpi.cpp L398.
In the LLVM code for generating PDBs, these streams are created with
minimum number of buckets. This difference makes LLVM generated
PDBs slower for when used for debugging.
Patch by C.J. Hebert
Differential Revision: https://reviews.llvm.org/D56942
llvm-svn: 352117
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
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
llvm-svn: 304623
Merging PDBs is a feature that will be used heavily by
the linker. The functionality already exists but does not
have deep test coverage because it's not easily exposed through
any tools. This patch aims to address that by adding the
ability to merge PDBs via llvm-pdbdump. It takes arbitrarily
many PDBs and outputs a single PDB.
Using this new functionality, a test is added for merging
type records. Future patches will add the ability to merge
symbol records, module information, etc.
llvm-svn: 303389
This adds a visitor that is capable of accessing type
records randomly and caching intermediate results that it
learns about during partial linear scans. This yields
amortized O(1) access to a type stream even though type
streams cannot normally be indexed.
Differential Revision: https://reviews.llvm.org/D33009
llvm-svn: 302936
Summary:
This lets PDB readers lookup type record data by type index in O(log n)
time. It also enables makes `cvdump -t` work on PDBs produced by LLD.
cvdump will not dump a PDB that doesn't have an index-to-offset table.
The table is sorted by type index, and has an entry every 8KB. Looking
up a type record by index is a binary search of this table, followed by
a scan of at most 8KB.
Reviewers: ruiu, zturner, inglorion
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31636
llvm-svn: 299958
Summary:
The TypeTableBuilder provides stable storage for type records. We don't
need to copy all of the bytes into a flat vector before adding it to the
TpiStreamBuilder.
This makes addTypeRecord take an ArrayRef<uint8_t> and a hash code to go
with it, which seems like a simplification.
Reviewers: ruiu, zturner, inglorion
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31634
llvm-svn: 299406
After several smaller patches to get most of the core improvements
finished up, this patch is a straight move and header fixup of
the source.
Differential Revision: https://reviews.llvm.org/D30266
llvm-svn: 296810
Before the endianness was specified on each call to read
or write of the StreamReader / StreamWriter, but in practice
it's extremely rare for streams to have data encoded in
multiple different endiannesses, so we should optimize for the
99% use case.
This makes the code cleaner and more general, but otherwise
has NFC.
llvm-svn: 296415
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`.
llvm-svn: 296394
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?
llvm-svn: 296258
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.
llvm-svn: 296215
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.
llvm-svn: 296211
Alexandre Ganea