Commit Graph

15 Commits

Author SHA1 Message Date
Zachary Turner 5b74ff33e7 [PDB] Fix use after free.
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
2017-06-03 00:33:35 +00:00
Zachary Turner 5a83fb153f Fix some minor issues in PDB parsing library.
1) Until now I'd never seen a valid PDB where the DBI stream and
   the PDB Stream disagreed on the "Age" field.  Because of that,
   we had code to assert that they matched.  Recently though I was
   given a PDB where they disagreed, so this assumption has proven
   to be incorrect.  Remove this check.

2) We were walking the entire list of hash values for types up front
   and then throwing away the values.  For large PDBs this was a
   significant slow down.  Remove this.

With this patch, I can dump the list of all compilands from a
1.5GB PDB file in just a few seconds.

llvm-svn: 303351
2017-05-18 15:14:44 +00:00
Zachary Turner 1eb9a0297c [PDB] Don't build the entire source file list up front.
I tried to run llvm-pdbdump on a very large (~1.5GB) PDB to
try and identify show-stopping performance problems.  This
patch addresses the first such problem.

When loading the DBI stream, before anyone has even tried to
access a single record, we build an in memory map of every
source file for every module.  In the particular PDB I was
using, this was over 85 million files.  Specifically, the
complexity is O(m*n) where m is the number of modules and
n is the average number of source files (including headers)
per module.

The whole reason for doing this was so that we could have
constant time access to any module and any of its source
file lists.  However, we can still get O(1) access to the
source file list for a given module with a simple O(m)
precomputation, and access to the list of modules is
already O(1) anyway.

So this patches reduces the O(m*n) up-front precomputation
to an O(m) one, where n is ~6,500 and n*m is about 85 million
in my pathological test case.

Differential Revision: https://reviews.llvm.org/D32870

llvm-svn: 302205
2017-05-04 23:53:29 +00:00
Zachary Turner c504ae3cef Resubmit r301986 and r301987 "Add codeview::StringTable"
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.

llvm-svn: 302042
2017-05-03 15:58:37 +00:00
Daniel Jasper dff096f217 Revert r301986 (and subsequent r301987).
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.

llvm-svn: 302002
2017-05-03 07:29:25 +00:00
Zachary Turner 7dba20bd2b Make codeview::StringTable.
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.

llvm-svn: 301986
2017-05-02 23:36:17 +00:00
Zachary Turner 67c5601404 Rename some PDB classes.
We have a lot of very similarly named classes related to
dealing with module debug info.  This patch has NFC, it just
renames some classes to be more descriptive (albeit slightly
more to type).  The mapping from old to new class names is as
follows:

   Old          |        New
ModInfo         | DbiModuleDescriptor
ModuleSubstream | ModuleDebugFragment
ModStream       | ModuleDebugStream

With the corresponding Builder classes renamed accordingly.

Differential Revision: https://reviews.llvm.org/D32506

llvm-svn: 301555
2017-04-27 16:11:19 +00:00
Zachary Turner d9dc2829ea [Support] Move Stream library from MSF -> Support.
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
2017-03-02 20:52:51 +00:00
Zachary Turner 695ed56ba5 [PDB] Make streams carry their own endianness.
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
2017-02-28 00:04:07 +00:00
Zachary Turner 120faca41b [PDB] Partial resubmit of r296215, which improved PDB Stream Library.
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
2017-02-27 22:11:43 +00:00
NAKAMURA Takumi 05a75e40da Revert r296215, "[PDB] General improvements to Stream library." and followings.
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
2017-02-25 17:04:23 +00:00
Zachary Turner af299ea5d4 [PDB] General improvements to Stream library.
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
2017-02-25 00:44:30 +00:00
Zachary Turner d2684b7969 [PDB] Rename Stream related source files.
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
2017-02-25 00:33:34 +00:00
Zachary Turner 181fe17b6f Don't assume little endian in StreamReader / StreamWriter.
In an effort to generalize this so it can be used by more than
just PDB code, we shouldn't assume little endian.

llvm-svn: 295525
2017-02-18 01:35:33 +00:00
Adrian McCarthy 6b6b8c4fb9 NFC: Rename (PDB) RawSession to NativeSession
This eliminates one overload on the term Raw.

Differential Revision: https://reviews.llvm.org/D29098

llvm-svn: 293104
2017-01-25 22:38:55 +00:00