Commit Graph

519 Commits

Author SHA1 Message Date
Zachary Turner 679aeadda1 [PDB] Support dumping injected sources via the DIA reader.
Injected sources are basically a way to add actual source file content
to your PDB. Presumably you could use this for shipping your source code
with your debug information, but in practice I can only find this being
used for embedding natvis files inside of PDBs.

In order to effectively test LLVM's natvis file injection, we need a way
to dump the injected sources of a PDB in a way that is authoritative
(i.e. based on Microsoft's understanding of the PDB format, and not
LLVM's). To this end, I've added support for dumping injected sources
via DIA. I made a PDB file that used the /natvis option to generate a
test case.

Differential Revision: https://reviews.llvm.org/D44405

llvm-svn: 327428
2018-03-13 17:46:06 +00:00
Aaron Smith 25409ddf2a [DebugInfoPDB] Add DIA implementation for getSrcLineOnTypeDefn
Summary: This helps to determine the line number for a PDB type with definition

Reviewers: zturner, llvm-commits, rnk

Reviewed By: zturner

Subscribers: rengolin, JDevlieghere

Differential Revision: https://reviews.llvm.org/D44119

llvm-svn: 326857
2018-03-07 00:33:09 +00:00
Zachary Turner c6a75a69f1 [PDB] Defer writing the build id until the rest of the PDB is written.
For now this is NFC, but this small refactor opens the door to
letting us embed a hash of the PDB in the build id field of the
PDB.

Differential Revision: https://reviews.llvm.org/D43913

llvm-svn: 326453
2018-03-01 18:00:29 +00:00
Aaron Smith 89a19ac38d [PDB] Check the result of setLoadAddress()
Summary: Change setLoadAddress() to return true or false on failure.

Reviewers: zturner, llvm-commits

Reviewed By: zturner

Differential Revision: https://reviews.llvm.org/D43638

llvm-svn: 325843
2018-02-23 00:02:27 +00:00
Aaron Smith 9161a6cb25 [PDB] Fix buildbot failure from missing include for DIAEnumLineNumbers
llvm-svn: 325826
2018-02-22 20:00:07 +00:00
Aaron Smith fbe65404fd [PDB] Implement more find methods for PDB symbols
Summary:
Add additional find methods on PDB raw symbols.

findChildrenByAddr()
findChildrenByVA()
findInlineFramesByAddr()
findInlineFramesByVA()
findInlineLines()
findInlineLinesByAddr()
findInlineLinesByRVA()
findInlineLinesByVA()




Reviewers: zturner, llvm-commits

Reviewed By: zturner

Differential Revision: https://reviews.llvm.org/D43637

llvm-svn: 325824
2018-02-22 19:47:43 +00:00
Zachary Turner cafd476836 Fix emission of PDB string table.
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

llvm-svn: 325386
2018-02-16 20:46:04 +00:00
Aaron Smith 53a1a1616c Fix pretty printing the unspecified param of a variadic function
Summary:
 - Fix a bug in PrettyBuiltinDumper that returns "void" as the name for
  an unspecified builtin type. Since the unspecified param of a variadic
  function is considered a builtin of unspecified type in PDBs, we set
  "..." for its name.

  - Provide a method to determine if a PDBSymbolFunc is variadic in
  PrettyFunctionDumper since PDBSymbolFunc::getArgument() doesn't return the
  last unspecified-type param.

  - Add a pretty-func-dumper.test to test pretty dumping of variadic
  functions.

Reviewers: zturner, llvm-commits

Reviewed By: zturner

Differential Revision: https://reviews.llvm.org/D41801

llvm-svn: 322608
2018-01-17 01:22:03 +00:00
Michael Zolotukhin 0c169bf7f7 Remove redundant includes from lib/DebugInfo.
llvm-svn: 320620
2017-12-13 21:30:49 +00:00
Zachary Turner bd159d32c4 Don't #include MemoryBuffer.h from Host.h.
It turns out this #include isn't used from Host.h anyway,
but by having it it causes circular include dependencies.
This issues only surfaced while I was working on a separate
patch, so I'm submitting this first so that it's independent
of the other, unrelated patch.

llvm-svn: 318489
2017-11-17 01:00:35 +00:00
Reid Kleckner b5d17d8d30 Fix my typo of PDB_TableType
llvm-svn: 318447
2017-11-16 19:41:12 +00:00
Reid Kleckner 4ca69bdac6 Fix -Wreturn-type falling off the end of a function in new DIA code
llvm-svn: 318444
2017-11-16 19:32:53 +00:00
Aaron Smith 89bca9e566 [DebugInfo/PDB] Adding getUndecoratedNameEx and IPDB interfaces for IDiaEnumTables and IDiaTable.
Initial changes to support debugging PE/COFF files with LLDB on Windows through DIA SDK.
There is another set of changes required on the LLDB side before this does anything.

Differential Revision: https://reviews.llvm.org/D39517

llvm-svn: 318403
2017-11-16 14:33:09 +00:00
Aaron Smith c6ef575909 Test commit. Add a missing dash to the standard llvm file header; NFC.
llvm-svn: 318400
2017-11-16 13:42:28 +00:00
Rafael Espindola e0df357dbd Convert FileOutputBuffer to Expected. NFC.
llvm-svn: 317649
2017-11-08 01:05:44 +00:00
Reid Kleckner 145090f124 [PDB] Handle an empty globals hash table with no buckets
llvm-svn: 316722
2017-10-27 00:45:51 +00:00
Peter Collingbourne 75257bc2ec COFF: Add type server pdb files to linkrepro tar file.
Differential Revision: https://reviews.llvm.org/D38977

llvm-svn: 316233
2017-10-20 19:48:26 +00:00
Hans Wennborg dc8d6f2527 Fix -Wcovered-switch-default warnings from r314821
llvm-svn: 314826
2017-10-03 18:44:12 +00:00
Hans Wennborg 660531085a CodeView: Provide a .def file with the register ids
The list of register ids was previously written out in a couple of dirrent
places. This puts it in a .def file and also adds a few more registers (e.g.
the x87 regs) which should lead to more readable dumps, but I didn't include
the whole list since that seems unnecessary.

X86_MC::initLLVMToSEHAndCVRegMapping is pretty ugly, but at least it's not
relying on magic constants anymore. The TODO of using tablegen still stands.

Differential revision: https://reviews.llvm.org/D38480

llvm-svn: 314821
2017-10-03 18:27:22 +00:00
Peter Collingbourne 9e26e97955 COFF: PDB: Allow multiple modules with the same name.
It is possible for two modules to have the same name if they are
archive members with the same name, or if we are doing LTO (in which
case all modules will have the name "lto.tmp").

Differential Revision: https://reviews.llvm.org/D37589

llvm-svn: 312744
2017-09-07 20:39:46 +00:00
Peter Collingbourne 8ad3aab4e5 Remove dead code. NFCI.
llvm-svn: 312740
2017-09-07 19:17:30 +00:00
Zachary Turner abb17cc084 [llvm-pdbutil] Support dumping CodeView from object files.
We have llvm-readobj for dumping CodeView from object files, and
llvm-pdbutil has always been more focused on PDB.  However,
llvm-pdbutil has a lot of useful options for summarizing debug
information in aggregate and presenting high level statistical
views.  Furthermore, it's arguably better as a testing tool since
we don't have to write tests to conform to a state-machine like
structure where you match multiple lines in succession, each
depending on a previous match.  llvm-pdbutil dumps much more
concisely, so it's possible to use single-line matches in many
cases where as with readobj tests you have to use multi-line
matches with an implicit state machine.

Because of this, I'm adding object file support to llvm-pdbutil.
In fact, this mirrors the cvdump tool from Microsoft, which also
supports both object files and pdb files.  In the future we could
perhaps rename this tool llvm-cvutil.

In the meantime, this allows us to deep dive into object files
the same way we already can with PDB files.

llvm-svn: 312358
2017-09-01 20:06:56 +00:00
Zachary Turner 99c6982bcd [llvm-pdbutil] Print detailed S_UDT stats.
This adds a new command line option, -udt-stats, which breaks
down the stats of S_UDT records.  These are one of the biggest
contributors to the size of /DEBUG:FASTLINK PDBs, so they need
some additional tools to be able to analyze their usage.  This
option will dig into each S_UDT record and determine what kind
of record it points to, and then break down the statistics by
the target type.  The goal here is to identify how our object
files differ from MSVC object files in S_UDT records, so that
we can output fewer of them and reach size parity.

llvm-svn: 312276
2017-08-31 20:43:22 +00:00
Zachary Turner d76dc2d31e [lld/pdb] Speed up construction of publics & globals addr map.
computeAddrMap function calls std::stable_sort with a comparison
function that computes deserialized symbols every time its called.
In the result deserializeAs<PublicSym32> is called 20-30 times per
symbol. It's much faster to calculate it beforehand and pass a
pointer to it to the comparison function.

Patch by Alex Telishev
Differential Revision: https://reviews.llvm.org/D36941

llvm-svn: 311373
2017-08-21 20:08:40 +00:00
Zachary Turner d1de2f4f5e [llvm-pdbutil] Add support for dumping detailed module stats.
This adds support for dumping a summary of module symbols
and CodeView debug chunks.  This option prints a table for
each module of all of the symbols that occurred in the module
and the number of times it occurred and total byte size.  Then
at the end it prints the totals for the entire file.

Additionally, this patch adds the -jmc (just my code) option,
which suppresses modules which are from external libraries or
linker imports, so that you can focus only on the object files
and libraries that originate from your own source code.

llvm-svn: 311338
2017-08-21 14:53:25 +00:00
Benjamin Kramer 49a49fe816 Move helper classes into anonymous namespaces.
No functionality change intended.

llvm-svn: 311288
2017-08-20 13:03:48 +00:00
Zachary Turner ee9906d884 [LLD/PDB] Write actual records to the globals stream.
Previously we were writing an empty globals stream.  Windows
tools interpret this as "private symbols are not present in
this PDB", even when they are, so we need to fix this.  Regardless,
without it we don't have information about global variables, so
we need to fix it anyway.  This patch does that.

With this patch, the "lm" command in WinDbg correctly reports
that we have private symbols available, but the "dv" command
still refuses to display local variables.

Differential Revision: https://reviews.llvm.org/D36535

llvm-svn: 310743
2017-08-11 19:00:03 +00:00
Zachary Turner 5448dabbdd [PDB] Fix an issue writing the publics stream.
In the refactor to merge the publics and globals stream, a bug
was introduced that wrote the wrong value for one of the fields
of the PublicsStreamHeader.  This caused debugging in WinDbg
to break.

We had no way of dumping any of these fields, so in addition to
fixing the bug I've added dumping support for them along with a
test that verifies the correct value is written.

llvm-svn: 310439
2017-08-09 04:23:59 +00:00
Zachary Turner 946204c83e [PDB] Merge Global and Publics Builders.
The publics stream and globals stream are very similar. They both
contain a list of hash buckets that refer into a single shared stream,
the symbol record stream. Because of the need for each builder to manage
both an independent hash stream as well as a single shared record
stream, making the two builders be independent entities is not the right
design. This patch merges them into a single class, of which only a
single instance is needed to create all 3 streams.  PublicsStreamBuilder
and GlobalsStreamBuilder are now merged into the single GSIStreamBuilder
class, which writes all 3 streams at once.

Note that this patch does not contain any functionality change. So we're
still not yet writing any records to the globals stream. All we're doing
is making it so that when we do start writing records to the globals,
this refactor won't have to be part of that patch.

Differential Revision: https://reviews.llvm.org/D36489

llvm-svn: 310438
2017-08-09 04:23:25 +00:00
Adrian McCarthy b41f03e768 Enable llvm-pdbutil to list enumerations using native PDB reader
This extends the native reader to enable llvm-pdbutil to list the enums in a
PDB and it includes a simple test. It does not yet list the values in the
enumerations, which requires an actual implementation of
NativeEnumSymbol::FindChildren.

To exercise this code, use a command like:

    llvm-pdbutil pretty -native -enums foo.pdb

Differential Revision: https://reviews.llvm.org/D35738

llvm-svn: 310144
2017-08-04 22:37:58 +00:00
Reid Kleckner 175af4bcc7 [PDB] Fix section contributions
Summary:
PDB section contributions are supposed to use output section indices and
offsets, not input section indices and offsets.

This allows the debugger to look up the index of the module that it
should look up in the modules stream for symbol information. With this
change, windbg can now find line tables, but it still cannot print local
variables.

Fixes PR34048

Reviewers: zturner

Subscribers: hiraditya, ruiu, llvm-commits

Differential Revision: https://reviews.llvm.org/D36285

llvm-svn: 309987
2017-08-03 21:15:09 +00:00
Zachary Turner 9fb9d71d3e [pdb/lld] Write a valid FPM.
The PDB reserves certain blocks for the FPM that describe which
blocks in the file are allocated and which are free.  We weren't
filling that out at all, and in some cases we were even stomping
it with incorrect data.  This patch writes a correct FPM.

Differential Revision: https://reviews.llvm.org/D36235

llvm-svn: 309896
2017-08-02 22:31:39 +00:00
Zachary Turner c3d8eec9e9 [pdbutil] Add a command to dump the FPM.
Recently problems have been discovered in the way we write the FPM
(free page map).  In order to fix this, we first need to establish
a baseline about what a correct FPM looks like using an MSVC
generated PDB, so that we can then make our own generated PDBs
match.  And in order to do this, the dumper needs a mode where it
can dump an FPM so that we can write tests for it.

This patch adds a command to dump the FPM, as well as a test against
a known-good PDB.

llvm-svn: 309894
2017-08-02 22:25:52 +00:00
Zachary Turner 8d927b6bf9 [lld/pdb] Add an empty globals stream.
We don't write any actual symbols to this stream yet, but for
now we just create the stream and hook it up to the appropriate
places and give it a valid header.

Differential Revision: https://reviews.llvm.org/D35290

llvm-svn: 309608
2017-07-31 19:36:08 +00:00
Reid Kleckner ef443296a4 [PDB] Initialize the std::array<ulittle32_t> used for the gsi bitmap
With ASan, we would write about 512 bytes of malloc fill value to the
PDB, with some random bits ORed in here and there. Dumping the PDB would
always fail reliably.

llvm-svn: 309331
2017-07-27 23:13:05 +00:00
Reid Kleckner eacdf04fdd [PDB] Write public symbol records and the publics hash table
Summary:
MSVC link.exe records all external symbol names in the publics stream.
It provides similar functionality to an ELF .symtab.

Reviewers: zturner, ruiu

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D35871

llvm-svn: 309303
2017-07-27 18:25:59 +00:00
Reid Kleckner 037bcd9345 [PDB] Remove stale GSI.h header that I intended to remove in the previous commit
llvm-svn: 309069
2017-07-26 00:58:49 +00:00
Reid Kleckner 14d90fd05c [PDB] Improve GSI hash table dumping for publics and globals
The PDB "symbol stream" actually contains symbol records for the publics
and the globals stream. The globals and publics streams are essentially
hash tables that point into a single stream of records. In order to
match cvdump's behavior, we need to only dump symbol records referenced
from the hash table. This patch implements that, and then implements
global stream dumping, since it's just a subset of public stream
dumping.

Now we shouldn't see S_PROCREF or S_GDATA32 records when dumping
publics, and instead we should see those record in the globals stream.

llvm-svn: 309066
2017-07-26 00:40:36 +00:00
Tim Northover fe6be421a7 Revert "Debug: handle dumping the D language."
Reid beat me to it.

llvm-svn: 308902
2017-07-24 17:47:46 +00:00
Tim Northover c7bd8255b9 Debug: handle dumping the D language.
Mostly just to silence a warning about an unhandled case. There don't seem to
be any tests for this operator (at least that I could find).

llvm-svn: 308901
2017-07-24 17:39:44 +00:00
Reid Kleckner e2ba971302 Add missing case to switch
llvm-svn: 308894
2017-07-24 16:30:44 +00:00
Reid Kleckner c85041fe00 Fix DebugInfo/PDB build by adding missing changes
llvm-svn: 308765
2017-07-21 18:32:00 +00:00
Reid Kleckner 686f121a5d [PDB] Dump extra info about the publics stream
This includes the hash table, the address map, and the thunk table and
section offset table. The last two are only used for incremental
linking, which LLD doesn't support, so they are less interesting. The
hash table is particularly important to get right, since this is the one
of the streams that debuggers use to translate addresses to symbols.

llvm-svn: 308764
2017-07-21 18:28:55 +00:00
Reid Kleckner c50349d4c6 [PDB] Finish and simplify TPI hashing
Summary:
This removes the CVTypeVisitor updater and verifier classes. They were
made dead by the minimal type dumping refactoring. Replace them with a
single function that takes a type record and produces a hash. Call this
from the minimal type dumper and compare the hash.

I also noticed that the microsoft-pdb reference repository uses a basic
CRC32 for records that aren't special. We already have an implementation
of that CRC ready to use, because it's used in COFF for ICF.

I'll make LLD call this hashing utility in a follow-up change. We might
also consider using this same hash in type stream merging, so that we
don't have to hash our records twice.

Reviewers: inglorion, ruiu

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D35515

llvm-svn: 308240
2017-07-18 00:33:45 +00:00
Reid Kleckner 67653ee086 [codeview] Fix YAML for LF_TYPESERVER2 by hoisting PDB_UniqueId
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

llvm-svn: 308234
2017-07-17 23:59:44 +00:00
Reid Kleckner a842cd75e2 [codeview] Remove TypeServerHandler and PDBTypeServerHandler
Summary:
Instead of wiring these through the CVTypeVisitor interface, clients
should inspect the CVTypeArray before visiting it and potentially load
up the type server's TPI stream if they need it.

No tests relied on this functionality because LLD was the only client.

Reviewers: ruiu

Subscribers: mgorny, hiraditya, zturner, llvm-commits

Differential Revision: https://reviews.llvm.org/D35394

llvm-svn: 308212
2017-07-17 20:28:06 +00:00
Reid Kleckner 6597c28d76 [PDB] Fix type server handling for archives
Summary:
This fixes type indices for SDK or CRT static archives. Previously we'd
try to look next to the archive object file path, which would not exist
on the local machine.

Also error out if we can't resolve a type server record. Hypothetically
we can recover from this error by discarding debug info for this object,
but that is not yet implemented.

Reviewers: ruiu, amccarth

Subscribers: aprantl, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D35369

llvm-svn: 307946
2017-07-13 20:12:23 +00:00
Reid Kleckner 0962cb2e3a Fix non-Windows build after PDB native builtin type change
Some C++14 features slipped in along with an extra member qualification.

llvm-svn: 307835
2017-07-12 19:46:35 +00:00
Adrian McCarthy 8d090fc531 [PDB] Enable NativeSession to create symbols for built-in types on demand
Summary:
There is a reserved range of type indexes for built-in types (like integers).
This will create a symbol for a built-in type if the caller askes for one by
type index.  This is also plumbing for being able to recall symbols by type
index in general, but user-defined types will come in subsequent patches.

Reviewers: rnk, zturner

Subscribers: mgorny, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D35163

llvm-svn: 307834
2017-07-12 19:38:11 +00:00
Zachary Turner 7eaf1d96ad [lld/pdb] Create an empty public symbol record stream.
This is part of the continuing effort to increase parity between
LLD and MSVC PDBs.  link still doesn't like our PDBs, so the most
obvious thing to check was whether adding an empty publics stream
would get it to do something else.  It still fails in the same way
but at least this removes one more variable from the equation.
The next logical step would be to try creating an empty globals
stream.

Differential Revision: https://reviews.llvm.org/D35224

llvm-svn: 307598
2017-07-10 22:40:20 +00:00
Zachary Turner 3a11fdf8ce [PDB] More changes to bring lld PDBs to parity with MSVC.
1) Don't write a /src/headerblock stream.  This appears to be
   written conditionally by MSVC, but it's not clear what the
   condition is.  For now, just remove it since we dont' know
   what it is anyway and the particular pdb we've checked in
   for the test doesn't have one.
2) Write a valid timestamp for the PDB file signature.  This
   leads to non-reproducible builds, but it matches the default
   behavior of link, so it should be out default as well.  If
   we need reproducibility, we should add a separate command
   line option for it that is off by default.
3) Write an empty FPO stream.  MSVC seems to always write an
   FPO stream.  This change makes the stream directory match
   up, although we still need to make the contents of the FPO
   stream match.

llvm-svn: 307436
2017-07-07 20:25:39 +00:00
Zachary Turner c1e93e5fa4 Fix some differences between lld and MSVC generated PDBs.
A couple of things were different about our generated PDBs.

1) We were outputting the wrong Version on the PDB Stream.
   The version we were setting was newer than what MSVC is setting.
   It's not clear what the implications are, but we change LLD
   to use PdbImplVC70, as MSVC does.
2) For the optional debug stream indices in the DBI Stream, we
   were outputting 0 to mean "the stream is not present".  MSVC
   outputs uint16_t(-1), which is the "correct" way to specify
   that a stream is not present.  So we fix that as well.
3) We were setting the PDB Stream signature to 0.  This is supposed
   to be the result of calling time(nullptr).  Although this leads
   to non-deterministic builds, a better way to solve that is by
   having a command line option explicitly for generating a
   reproducible build, and have the default behavior of lld-link
   match the default behavior of link.

To test this, I'm making use of the new and improved `pdb diff`
sub command.  To make it suitable for writing tests against, I had
to modify the diff subcommand slightly to print less verbose output.
Previously it would always print | <column> | <value1> | <value2> |
which is quite verbose, and the values are fragile.  All we really
want to know is "did we produce the same value as link?"  So I added
command line options to print a single character representing the
result status (different, identical, equivalent), and another to
hide the value display.  Note that just inspecting the diff output
used to write the test, you can see some things that are obviously
wrong.  That is just reflective of the fact that this is the state
of affairs today, not that we're asserting that this is "correct".
We can use this as a starting point to discover differences, fix
them, and update the test.

Differential Revision: https://reviews.llvm.org/D35086

llvm-svn: 307422
2017-07-07 18:45:56 +00:00
Zachary Turner f3b4b2d89d [llvm-pdbutil] Improve diff mode.
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

llvm-svn: 307421
2017-07-07 18:45:37 +00:00
Zachary Turner 6c4bfba8f3 [PDB] Teach libpdb to write DBI Stream ECNames.
Based strictly on the name, this seems to have something to do
width edit & continue.  The goal of this patch has nothing to do
with supporting edit and continue though.  msvc link.exe writes
very basic information into this area even when *not* compiling
with support for E&C, and so the goal here is to bring lld-link
to parity.  Since we cannot know what assumptions standard tools
make about the content of PDB files, we need to be as close as
possible.

This ECNames data structure is a standard PDB string hash table.
link.exe puts a single string into this hash table, which is the
full path to the PDB file on disk.  It then references this string
from the module descriptor for the compiler generated `* Linker *`
module.

With this patch, lld-link will generate the exact same sequence of
bytes as MSVC link for this subsection for a given object file
input (as reported by `llvm-pdbutil bytes -ec`).

llvm-svn: 307356
2017-07-07 05:04:36 +00:00
Eugene Zelenko 4fcfc19976 [CodeView, PDB] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 306911
2017-06-30 23:06:03 +00:00
Adrian McCarthy bf0afc3246 Introduce symbol cache to PDB NativeSession
Instead of creating symbols directly in the findChildren methods of the native
symbol implementations, they will rely on the NativeSession to act as a factory
for these types.  This lets NativeSession cache the NativeRawSymbols in its
new symbol cache and makes that cache the source of unique IDs for the symbols.

Right now, this affects only NativeCompilandSymbols.  There's no external
change yet, so I think the existing tests are still sufficient.  Coming soon
are patches to extend this to built-in types and enums.

llvm-svn: 306610
2017-06-28 22:47:40 +00:00
Zachary Turner 1affd805fc [pdb] Fix reading of llvm-generated PDBs by cvdump.
If you dump a pdb to yaml, and then round-trip it back to a pdb,
and run cvdump -l <file> on the new pdb, cvdump will generate
output such as this.

*** LINES

** Module: "d:\src\llvm\test\DebugInfo\PDB\Inputs\empty.obj"

Error: Line number corrupted: invalid file id 0
  <Unknown> (MD5), 0001:00000010-0000001A, line/addr pairs = 3

        5 00000010      6 00000013      7 00000018

Note the error message about the corrupted line number.

It turns out that the problem is that cvdump cannot find the
/names stream (e.g. the global string table), and the reason it
can't find the /names stream is because it doesn't understand
the NameMap that we serialize which tells pdb consumers which
stream has the string table.

Some experimentation shows that if we add items to the hash
table in a specific order before serializing it, cvdump can read
it. This suggests that either we're using the wrong hash function,
or we're serializing something incorrectly, but it will take some
deeper investigation to figure out how / why.  For now, this at
least allows cvdump to read our line information (and incidentally,
produces an identical byte sequence to what Microsoft tools
produce when writing the named stream map).

Differential Revision: https://reviews.llvm.org/D34491

llvm-svn: 306233
2017-06-25 03:51:42 +00:00
Zachary Turner fa33282774 [llvm-pdbutil] Dump raw bytes of module symbols and debug chunks.
llvm-svn: 306179
2017-06-23 23:08:57 +00:00
Zachary Turner c2f5b4bfd9 [llvm-pdbutil] Dump raw bytes of type and id records.
llvm-svn: 306167
2017-06-23 21:50:54 +00:00
Zachary Turner dd73968256 [llvm-pdbutil] Dump raw bytes of various DBI stream subsections.
llvm-svn: 306160
2017-06-23 21:11:54 +00:00
Zachary Turner 6c3e41bbd3 [llvm-pdbutil] Dump raw bytes of pdb name map.
This patch dumps the raw bytes of the pdb name map which contains
the mapping of stream name to stream index for the string table
and other reserved streams.

llvm-svn: 306148
2017-06-23 20:18:38 +00:00
Zachary Turner 0b36c3ebd0 [llvm-pdbutil] Add a function for formatting MSF data.
The goal here is to make it possible to display absolute
file offsets when dumping byets from an MSF.  The problem is
that when dumping bytes from an MSF, often the bytes will
cross a block boundary and encounter a discontinuity.  We
can't use the normal formatBinary() function for this because
this would just treat the sequence as entirely ascending, and
not account out-of-order blocks.

This patch adds a formatMsfData() function to our printer, and
then uses this function to improve the output of the -stream-data
command line option for dumping bytes from a particular stream.

Test coverage is also expanded to make sure to include all possible
scenarios of offsets, sizes, and crossing block boundaries.

llvm-svn: 306141
2017-06-23 18:52:13 +00:00
Adrian McCarthy 4aedc81b8c Fix build break by using llvm::make_unique instead of std::make_unique.
llvm-svn: 306043
2017-06-22 18:57:51 +00:00
Adrian McCarthy 31bcb6f680 Add IDs and clone methods to NativeRawSymbol
All NativeRawSymbols will have a unique symbol ID (retrievable via
getSymIndexId).  For now, these are initialized to 0, but soon the
NativeSession will be responsible for creating the raw symbols, and it will
assign unique IDs.

The symbol cache in the NativeSession will also require the ability to clone
raw symbols, so I've provided implementations for that as well.

llvm-svn: 306042
2017-06-22 18:43:18 +00:00
Adrian McCarthy 6a4b080a5f Make IPDBSession::getGlobalScope a non-const method
There doesn't seem to be a compelling reason why this method should be const
other than it was possible with the DIA implementation.  The native session
is going to act as a symbol factory and cache.  This could be acheived with
mutable (and the existing const_cast), but it seems cleaner to accept that
this method affects the state of the session.

This change eliminates an existing const_cast.

llvm-svn: 306041
2017-06-22 18:42:23 +00:00
Zachary Turner 297b6eb20d [PDB] Don't write uninitialized bytes to a PDB file.
There were certain fields that we didn't know how to write, as
well as various padding bytes that we would ignore.  This leads
to garbage data in the PDB.  While not strictly necessary, we
should initialize these bytes to something meaningful, as it
makes for easier binary comparison between PDBs.

llvm-svn: 305819
2017-06-20 18:50:55 +00:00
Reid Kleckner 44cdb10964 [PDB] Start emitting source file and line information
Summary:
This is a first step towards getting line info to show up in VS and
windbg. So far, only llvm-pdbutil can parse the PDBs that we produce.
cvdump doesn't like something about our file checksum tables. I'll have
to dig into that next.

This patch adds a new DebugSubsectionRecordBuilder which takes bytes
directly from some other producer, such as a linker, and sticks it into
the PDB. Line tables only need to be relocated. No data needs to be
rewritten.

File checksums and string tables, on the other hand, need to be re-done.

Reviewers: zturner, ruiu

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D34257

llvm-svn: 305713
2017-06-19 17:21:45 +00:00
Zachary Turner 4e950647fb [llvm-pdbutil] Add support for dumping lines and inlinee lines.
llvm-svn: 305529
2017-06-15 23:56:19 +00:00
Zachary Turner 0e327d0360 [llvm-pdbutil] Add back support for dumping file checksums.
When dumping module source files, also dump checksums.

llvm-svn: 305526
2017-06-15 23:12:41 +00:00
Zachary Turner f8a2e04812 [llvm-pdbutil] Add back the ability to dump hashes and index offsets.
This was regressed in a previous patch that re-wrote the dumper,
and I'm incrementally adding back the pieces that are missing.

llvm-svn: 305524
2017-06-15 23:04:42 +00:00
Zachary Turner 6305545527 Resubmit "[llvm-pdbutil] rewrite the "raw" output style."
This resubmits commit c0c249e9f2ef83e1d1e5f166b50673d92f3579d7.

It was broken due to some weird template issues, which have
since been fixed.

llvm-svn: 305517
2017-06-15 22:24:24 +00:00
Zachary Turner da504b794c Revert "[llvm-pdbutil] rewrite the "raw" output style."
This reverts commit 83ea17ebf2106859a51fbc2a86031b44d33696ad.

This is failing due to some strange template problems, so reverting
until it can be straightened out.

llvm-svn: 305505
2017-06-15 20:55:51 +00:00
Zachary Turner b560fdf3b8 [llvm-pdbutil] rewrite the "raw" output style.
After some internal discussions, we agreed that the raw output style had
outlived its usefulness. It was originally created before we had even
thought of dumping to YAML, and it was intended to give us some insight
into the internals of a PDB file. Now we have YAML mode which does
almost exactly this but is more powerful in that it can round-trip back
to a PDB, which the raw mode could not do. So the raw mode had become
purely a maintenance burden.

One option was to just delete it. However, its original goal was to be
as readable as possible while staying close to the "metal" - i.e.
presenting the output in a way that maps directly to the underlying file
format. We don't actually need that last requirement anymore since it's
covered by the yaml mode, so we could repurpose "raw" mode to actually
just be as readable as possible.

This patch implements about 80% of the functionality previously in raw
mode, but in a completely different style that is more akin to what
cvdump outputs. Records are very compressed, often times appearing on
just one line. One nice thing about this is that it makes full record
matching easier, because you can grep for indices, names, and leaf types
on a single line often.

See the tests for some examples of what the new output looks like.

Note that this patch actually regresses the functionality of raw mode in
a few areas, but only because the patch was already unreasonably large
and going 100% would have been even worse. Specifically, this patch is
missing:

The ability to dump module debug subsections (checksums, lines, etc)
The ability to dump section headers
Aside from that everything is here. While goign through the tests fixing
them all up, I found many duplicate tests. They've been deleted. In
subsequent patches I will go through and re-add the missing
functionality.

Differential Revision: https://reviews.llvm.org/D34191

llvm-svn: 305495
2017-06-15 19:34:41 +00:00
Zachary Turner a8cfc29c9a Resubmit "[codeview] Make obj2yaml/yaml2obj support .debug$S..."
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.

llvm-svn: 305393
2017-06-14 15:59:27 +00:00
Zachary Turner 0085dce221 Revert "[codeview] Make obj2yaml/yaml2obj support .debug$S..."
This is causing failures on linux bots with an invalid stream
read.  It doesn't repro in any configuration on Windows, so
reverting until I have a chance to investigate on Linux.

llvm-svn: 305371
2017-06-14 06:24:24 +00:00
Zachary Turner a3da4467fa [codeview] Make obj2yaml/yaml2obj support .debug$S/T sections.
This allows us to use yaml2obj and obj2yaml to round-trip CodeView
symbol and type information without having to manually specify the bytes
of the section. This makes for much easier to maintain tests. See the
tests under lld/COFF in this patch for example. Before they just said
SectionData: <blob> whereas now we can use meaningful record
descriptions. Note that it still supports the SectionData yaml field,
which could be useful for initializing a section to invalid bytes for
testing, for example.

Differential Revision: https://reviews.llvm.org/D34127

llvm-svn: 305366
2017-06-14 05:31:00 +00:00
Reid Kleckner 8cbdd0c0f2 [PDB] Add a module descriptor for every object file
Summary:
Expose the module descriptor index and fill it in for section
contributions.

Reviewers: zturner

Subscribers: llvm-commits, ruiu, hiraditya

Differential Revision: https://reviews.llvm.org/D34126

llvm-svn: 305296
2017-06-13 15:49:13 +00:00
Zachary Turner 68ea80d0a7 Slightly better fix for dealing with no-id-stream PDBs.
The last fix required the user to manually add the required
feature.  This caused an LLD test to fail because I failed to
update LLD.  In practice we can hide this logic so it can just
be transparently added when we write the PDB.

llvm-svn: 305236
2017-06-12 21:46:51 +00:00
Zachary Turner 990d0c8158 [llvm-pdbdump] Don't fail on PDBs with no ID stream.
Older PDBs don't have this.  Its presence is detected by using
the various "feature" flags that come at the end of the PDB
Stream.  Detect this, and don't try to dump the ID stream if the
features tells us it's not present.

llvm-svn: 305235
2017-06-12 21:34:53 +00:00
Zachary Turner d334cebac4 Fix a null pointer dereference in llvm-pdbutil pretty.
Static data members were causing a problem because I mistakenly
assumed all members would affect a class's layout and so the
Layout member would be non-null.

llvm-svn: 305229
2017-06-12 20:46:35 +00:00
Zachary Turner 15eb237fd3 [PDB] Don't crash on /debug:fastlink PDBs.
Apparently support for /debug:fastlink PDBs isn't part of the
DIA SDK (!), and it was causing llvm-pdbdump to crash because
we weren't checking for a null pointer return value.  This
manifests when calling findChildren on the IDiaSymbol, and
it returns E_NOTIMPL.

llvm-svn: 304982
2017-06-08 16:00:40 +00:00
Zachary Turner 264b5d9e88 Move Object format code to lib/BinaryFormat.
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.

Differential Revision: https://reviews.llvm.org/D33843

llvm-svn: 304864
2017-06-07 03:48:56 +00:00
Zachary Turner 1bfb9f47af Fix uninitialized read.
llvm-svn: 304846
2017-06-06 23:54:23 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Zachary Turner 349c18f837 [CodeView] Handle Cross Module Imports and Exports.
While it's not entirely clear why a compiler or linker might
put this information into an object or PDB file, one has been
spotted in the wild which was causing llvm-pdbdump to crash.

This patch adds support for reading-writing these sections.
Since I don't know how to get one of the native tools to
generate this kind of debug info, the only test here is one
in which we feed YAML into the tool to produce a PDB and
then spit out YAML from the resulting PDB and make sure that
it matches.

llvm-svn: 304738
2017-06-05 21:40:33 +00:00
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 92dcdda623 [CodeView] Support CodeView subsections in any order.
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

llvm-svn: 304588
2017-06-02 19:49:14 +00:00
Zachary Turner ebd3ae8371 [CodeView] Properly align symbol records on read/write.
Object files have symbol records not aligned to any particular
boundary (e.g. 1-byte aligned), while PDB files have symbol
records padded to 4-byte aligned boundaries.  Since they share
the same reading / writing code, we have to provide an option to
specify the alignment and propagate it up to the producer or
consumer who knows what the alignment is supposed to be for the
given container type.

Added a test for this by modifying the existing PDB -> YAML -> PDB
round-tripping code to round trip symbol records as well as types.

Differential Revision: https://reviews.llvm.org/D33785

llvm-svn: 304484
2017-06-01 21:52:41 +00:00
Adrian Prantl f4bc1f77b7 [DWARF] Introduce Dump Options
This commit introduces a structure that holds all the flags that
control the pretty printing of dwarf output.

Patch by Spyridoula Gravani!

Differential Revision: https://reviews.llvm.org/D33749

llvm-svn: 304446
2017-06-01 18:18:23 +00:00
Galina Kistanova 8c1e2f9108 Added missing break.
llvm-svn: 304230
2017-05-30 19:02:49 +00:00
Zachary Turner 8c099fe06e [CodeView] Rename ModuleDebugFragment -> DebugSubsection.
This is more concise, and matches the terminology used in other
parts of the codebase more closely.

llvm-svn: 304218
2017-05-30 16:36:15 +00:00
Zachary Turner 2897e0306e [lld] Fix a bug where we continually re-follow type servers.
Originally this was intended to be set up so that when linking
a PDB which refers to a type server, it would only visit the
PDB once, and on subsequent visitations it would just skip it
since all the records had already been added.

Due to some C++ scoping issues, this was not occurring and it
was revisiting the type server every time, which caused every
record to end up being thrown away on all subsequent visitations.

This doesn't affect the performance of linking clang-cl generated
object files because we don't use type servers, but when linking
object files and libraries generated with /Zi via MSVC, this means
only 1 object file has to be linked instead of N object files, so
the speedup is quite large.

llvm-svn: 303920
2017-05-25 21:16:03 +00:00
Bob Haarman 55256ada25 [pdb] pad source file name buffer at the end instead of the beginning
Summary:
DbiStreamBuilder calculated the offset of the source file names inside
the file info substream as the size of the file info substream minus
the size of the file names. Since the file info substream is padded to
a multiple of 4 bytes, this caused the first file name to be aligned
on a 4-byte boundary. By contrast, DbiModuleList would read the file
names immediately after the file name offset table, without skipping
to the next 4-byte boundary. This change makes it so that the file
names are written to the location where DbiModuleList expects them,
and puts any necessary padding for the file info substream after the
file names instead of before it.

Reviewers: amccarth, rnk, zturner

Reviewed By: amccarth, zturner

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D33475

llvm-svn: 303917
2017-05-25 21:12:15 +00:00
Zachary Turner dda25b128c [CodeView Type Merging] Avoid record deserialization when possible.
A profile shows the majority of time doing type merging is spent
deserializing records from sequences of bytes into friendly C++ structures
that we can easily access members of in order to find the type indices to
re-write.

Records are prefixed with their length, however, and most records have
type indices that appear at fixed offsets in the record. For these
records, we can save some cycles by just looking at the right place in the
byte sequence and re-writing the value, then skipping the record in the
type stream. This saves us from the costly deserialization of examining
every field, including potentially null terminated strings which are the
slowest, even though it was unnecessary to begin with.

In addition, we apply another optimization. Previously, after
deserializing a record and re-writing its type indices, we would
unconditionally re-serialize it in order to compute the hash of the
re-written record. This would result in an alloc and memcpy for every
record. If no type indices were re-written, however, this was an
unnecessary allocation. In this patch re-writing is made two phase. The
first phase discovers the indices that need to be rewritten and their new
values. This information is passed through to the de-duplication code,
which only copies and re-writes type indices in the serialized byte
sequence if at least one type index is different.

Some records have type indices which only appear after variable length
strings, or which have lists of type indices, or various other situations
that can make it tricky to make this optimization. While I'm not giving up
on optimizing these cases as well, for now we can get the easy cases out
of the way and lay the groundwork for more complicated cases later.

This patch yields another 50% speedup on top of the already large speedups
submitted over the past 2 days. In two tests I have run, I went from 9
seconds to 3 seconds, and from 16 seconds to 8 seconds.

Differential Revision: https://reviews.llvm.org/D33480

llvm-svn: 303914
2017-05-25 21:06:28 +00:00
Zachary Turner d4136e945e Implement various flavors of type merging.
Previous algotirhm assumed that types and ids are in a single
unified stream.  For inputs that come from object files, this
is the case.  But if the input is already a PDB, or is the result
of a previous merge, then the types and ids will already have
been split up, in which case we need an algorithm that can
accept operate on independent streams of types and ids that
refer across stream boundaries to each other.

Differential Revision: https://reviews.llvm.org/D33417

llvm-svn: 303577
2017-05-22 21:07:43 +00:00
Zachary Turner 526f4f2aa8 Resubmit "[CodeView] Provide a common interface for type collections."
This was originally reverted because it was a breaking a bunch
of bots and the breakage was not surfacing on Windows.  After much
head-scratching this was ultimately traced back to a bug in the
lit test runner related to its pipe handling.  Now that the bug
in lit is fixed, Windows correctly reports these test failures,
and as such I have finally (hopefully) fixed all of them in this
patch.

llvm-svn: 303446
2017-05-19 19:26:58 +00:00
Zachary Turner 1dfcf8d92c Revert "[CodeView] Provide a common interface for type collections."
This is a squash of ~5 reverts of, well, pretty much everything
I did today.  Something is seriously broken with lit on Windows
right now, and as a result assertions that fire in tests are
triggering failures.  I've been breaking non-Windows bots all
day which has seriously confused me because all my tests have
been passing, and after running lit with -a to view the output
even on successful runs, I find out that the tool is crashing
and yet lit is still reporting it as a success!

At this point I don't even know where to start, so rather than
leave the tree broken for who knows how long, I will get this
back to green, and then once lit is fixed on Windows, hopefully
hopefully fix the remaining set of problems for real.

llvm-svn: 303409
2017-05-19 05:57:45 +00:00
Zachary Turner 8fb441ab9c [llvm-pdbdump] Add the ability to merge PDBs.
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
2017-05-18 23:03:41 +00:00
Zachary Turner 0c60f269fc [CodeView] Provide a common interface for type collections.
Right now we have multiple notions of things that represent collections of
types. Most commonly used are TypeDatabase, which is supposed to keep
mappings from TypeIndex to type name when reading a type stream, which
happens when reading PDBs. And also TypeTableBuilder, which is used to
build up a collection of types dynamically which we will later serialize
(i.e. when writing PDBs).

But often you just want to do some operation on a collection of types, and
you may want to do the same operation on any kind of collection. For
example, you might want to merge two TypeTableBuilders or you might want
to merge two type streams that you loaded from various files.

This dichotomy between reading and writing is responsible for a lot of the
existing code duplication and overlapping responsibilities in the existing
CodeView library classes. For example, after building up a
TypeTableBuilder with a bunch of type records, if we want to dump it we
have to re-invent a bunch of extra glue because our dumper takes a
TypeDatabase or a CVTypeArray, which are both incompatible with
TypeTableBuilder.

This patch introduces an abstract base class called TypeCollection which
is shared between the various type collection like things. Wherever we
previously stored a TypeDatabase& in some common class, we now store a
TypeCollection&.

The advantage of this is that all the details of how the collection are
implemented, such as lazy deserialization of partial type streams, is
completely transparent and you can just treat any collection of types the
same regardless of where it came from.

Differential Revision: https://reviews.llvm.org/D33293

llvm-svn: 303388
2017-05-18 23:03:06 +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
Bob Haarman de33a63784 [llvm-pdbdump] in yaml2pdb, generate default output filename if none given
Summary:
llvm-pdbdump yaml2pdb used to fail with a misleading error
message ("An I/O error occurred on the file system") if no output file
was specified. This change adds an assert to PDBFileBuilder to check
that an output file name is specified, and makes llvm-pdbdump generate
an output file name based on the input file name if no output file
name is explicitly specified.

Reviewers: amccarth, zturner

Reviewed By: zturner

Subscribers: fhahn, llvm-commits

Differential Revision: https://reviews.llvm.org/D33296

llvm-svn: 303299
2017-05-17 20:46:48 +00:00
Zachary Turner 1d795c451e [CodeView] Simplify the use of visiting type records & streams.
There is often a lot of boilerplate code required to visit a type
record or type stream.  The #1 use case is that you have a sequence
of bytes that represent one or more records, and you want to
deserialize each one, switch on it, and call a callback with the
deserialized record that the user can examine.  Currently this
requires at least 6 lines of code:

  codeview::TypeVisitorCallbackPipeline Pipeline;
  Pipeline.addCallbackToPipeline(Deserializer);
  Pipeline.addCallbackToPipeline(MyCallbacks);

  codeview::CVTypeVisitor Visitor(Pipeline);
  consumeError(Visitor.visitTypeRecord(Record));

With this patch, it becomes one line of code:

  consumeError(codeview::visitTypeRecord(Record, MyCallbacks));

This is done by having the deserialization happen internally inside
of the visitTypeRecord function.  Since this is occasionally not
desirable, the function provides a 3rd parameter that can be used
to change this behavior.

Hopefully this can significantly reduce the barrier to entry
to using the visitation infrastructure.

Differential Revision: https://reviews.llvm.org/D33245

llvm-svn: 303271
2017-05-17 16:39:06 +00:00
Zachary Turner dd3a739d52 [CodeView] Add a random access type visitor.
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
2017-05-12 19:18:12 +00:00
Zachary Turner bedc85fb4b [pdb] Don't verify TPI hash values up front.
Verifying the hash values as we are currently doing
results in iterating every type record before the user
even tries to access the first one, and the API user
has no control over, or ability to hook into this
process.

As a result, when the user wants to iterate over types
to print them or index them, this results in a second
iteration over the same list of types.  When there's
upwards of 1,000,000 type records, this is obviously
quite undesirable.

This patch raises the verification outside of TpiStream
, and llvm-pdbdump hooks a hash verification visitor
into the normal dumping process.  So we still verify
the hash records, but we can do it while not requiring
a second iteration over the type stream.

Differential Revision: https://reviews.llvm.org/D32873

llvm-svn: 302206
2017-05-04 23:53:54 +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 2d5c2cd3ce [llvm-readobj] Update readobj to re-use parsing code.
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

llvm-svn: 302052
2017-05-03 17:11:11 +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 59e83892e0 Fix use after free in BinaryStream library.
This was reported by the ASAN bot, and it turned out to be
a fairly fundamental problem with the design of VarStreamArray
and the way it passes context information to the extractor.

The fix was cumbersome, and I'm not entirely pleased with it,
so I plan to revisit this design in the future when I'm not
pressed to get the bots green again.  For now, this fixes
the issue by storing the context information by value instead
of by reference, and introduces some impossibly-confusing
template magic to make things "work".

llvm-svn: 301999
2017-05-03 05:34:00 +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 e204a6c9a3 Rename pdb::StringTable -> pdb::PDBStringTable.
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.

llvm-svn: 301948
2017-05-02 18:00:13 +00:00
Zachary Turner edef14510e [PDB/CodeView] Read/write codeview inlinee line information.
Previously we wrote line information and file checksum
information, but we did not write information about inlinee
lines and functions.  This patch adds support for that.

llvm-svn: 301936
2017-05-02 16:56:09 +00:00
Zachary Turner 8a2ebfb1cd [CodeView] Write CodeView line information.
Differential Revision: https://reviews.llvm.org/D32716

llvm-svn: 301882
2017-05-01 23:27:42 +00:00
Zachary Turner 7cc13e557c [PDB/CodeView] Rename some classes.
In preparation for introducing writing capabilities for each of
these classes, I would like to adopt a Foo / FooRef naming
convention, where Foo indicates that the class can manipulate and
serialize Foos, and FooRef indicates that it is an immutable view of
an existing Foo.  In other words, Foo is a writer and FooRef is a
reader.  This patch names some existing readers to conform to the
FooRef convention, while offering no functional change.

llvm-svn: 301810
2017-05-01 16:46:39 +00:00
Zachary Turner 5b6e4e0aed [llvm-pdbdump] Abstract some of the YAML/Raw printing code.
There is a lot of duplicate code for printing line info between
YAML and the raw output printer.  This introduces a base class
that can be shared between the two, and makes some minor
cleanups in the process.

llvm-svn: 301728
2017-04-29 01:13:21 +00:00
Zachary Turner 05bd9f3713 [llvm-readobj] Use LLVMDebugInfoCodeView to parse line tables.
The llvm-readobj parsing code currently exists in our CodeView
library, so we use that to parse instead of re-writing the logic
in the tool.

llvm-svn: 301718
2017-04-28 23:41:36 +00:00
Zachary Turner c37cb0c6a5 [CodeView] Isolate Debug Info Fragments into standalone classes.
Previously parsing of these were all grouped together into a
single master class that could parse any type of debug info
fragment.

With writing forthcoming, the complexity of each individual
fragment is enough to warrant them having their own classes so
that reading and writing of each fragment type can be grouped
together, but isolated from the code for reading and writing
other fragment types.

In doing so, I found a place where parsing code was duplicated
for the FileChecksums fragment, across llvm-readobj and the
CodeView library, and one of the implementations had a bug.
Now that the codepaths are merged, the bug is resolved.

Differential Revision: https://reviews.llvm.org/D32547

llvm-svn: 301557
2017-04-27 16:12:16 +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 da307b64dd [llvm-pdbdump] Allow sorting / filtering by immediate padding
llvm-svn: 301358
2017-04-25 20:22:29 +00:00
Zachary Turner ee3b9c2558 [llvm-pdbdump] Dump File / Line Info to YAML.
We were already parsing and dumping this to the human readable
format, but not to the YAML format.  This does so, in preparation
for reading it in and reconstructing the line information from
YAML.

llvm-svn: 301357
2017-04-25 20:22:02 +00:00
Zachary Turner 1690164cac [llvm-pdbdump] Re-write the record layout code to be more resilient.
This reworks the way virtual bases are handled, and also the way
padding is detected across multiple levels of aggregates, producing
a much more accurate result.

llvm-svn: 301203
2017-04-24 17:47:24 +00:00
Zachary Turner 4dc4f01a86 [llvm-pdbdump] Recursively dump class layout.
llvm-svn: 300258
2017-04-13 21:11:00 +00:00
Zachary Turner 75999dff93 Fix initialization order of class members.
llvm-svn: 300137
2017-04-12 23:27:43 +00:00
Zachary Turner 9e7dda3c6d [llvm-pdbdump] Minor prepatory refactor of Class Def Dumper.
In a followup patch I intend to introduce an additional dumping
mode which dumps a graphical representation of a class's layout.
In preparation for this, the text-based layout printer needs to
be split out from the graphical layout printer, and both need
to be able to use the same code for printing the intro and outro
of a class's definition (e.g. base class list, etc).

This patch does so, and in the process introduces a skeleton
definition for the graphical printer, while currently making
the graphical printer just print nothing.

NFC

llvm-svn: 300134
2017-04-12 23:18:51 +00:00
Zachary Turner c883a8c6dc [llvm-pdbdump] More advanced class definition dumping.
Previously the dumping of class definitions was very primitive,
and it made it hard to do more than the most trivial of output
formats when dumping.  As such, we would only dump one line for
each field, and then dump non-layout items like nested types
and enums.

With this patch, we do a complete analysis of the object
hierarchy including aggregate types, bases, virtual bases,
vftable analysis, etc.  The only immediately visible effects
of this are that a) we can now dump a line for the vfptr where
before we would treat that as padding, and b) we now don't
treat virtual bases that come at the end of a class as padding
since we have a more detailed analysis of the class's storage
usage.

In subsequent patches, we should be able to use this analysis
to display a complete graphical view of a class's layout including
recursing arbitrarily deep into an object's base class / aggregate
member hierarchy.

llvm-svn: 300133
2017-04-12 23:18:21 +00:00
Reid Kleckner 6e545ffc4e [PDB] Emit index/offset pairs for TPI and IPI streams
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
2017-04-11 16:26:15 +00:00
Adrian McCarthy 08eb343cce Improves pretty printing of variable types in llvm-pdbdump
* Adds support for pointers to arrays, which was missing
* Adds some tests
* Improves consistency of const and volatile qualifiers
* Eliminates non-composable special case code for arrays and function by using
  a more general recursive approach
* Has a hack for getting the calling convention into the right spot for
  pointer-to-functions

Given the rapid changes happenning in llvm-pdbdump, this may be difficult to
merge.

Differential Revision: https://reviews.llvm.org/D31832

llvm-svn: 299848
2017-04-10 16:43:09 +00:00
Zachary Turner 1b1a70f172 General usability improvements to generic PDB library.
1. Added some asserts to make sure concrete symbol types don't
   get constructed with RawSymbols that have an incompatible
   SymTag enum value.
2. Added new forwarding macros that auto-define an Id/Sym method
   pair whenever there is a method that returns a SymIndexId.
   Previously we would just provide one method that returned only
   the SymIndexId and it was up to the caller to use the Session
   object to get a pointer to the symbol.  Now we automatically
   get both the method that returns the Id, as well as a method
   that returns the pointer directly with just one macro.
3. Added some methods for dumping straight to stdout that can
   be used from inside the debugger for diagnostics during a
   debug session.
4. Added a clone() method and a cast<T>() method to PDBSymbol
   that can shorten some usage patterns.

llvm-svn: 299831
2017-04-10 06:14:09 +00:00
Reid Kleckner 13fc411e39 [PDB] Save one type record copy
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
2017-04-04 00:56:34 +00:00
Adrian McCarthy 4d93d66ddd Re-land: "Make NativeExeSymbol a concrete subclass of NativeRawSymbol [PDB]"
This should work on all platforms now that r299006 has landed.  Tested locally
on Windows and Linux.

This moves exe symbol-specific method implementations out of NativeRawSymbol
into a concrete subclass. Also adds implementations for hasCTypes and
hasPrivateSymbols and a simple test to ensure the native reader can access the
summary information for the executable from the PDB.

Original Differential Revision: https://reviews.llvm.org/D31059

llvm-svn: 299019
2017-03-29 19:27:08 +00:00
Adrian McCarthy 3c0328e011 Somehow this still breaks because of ANSI color codes in test output on Linux.
Reverting until I can figure out the root cause.

Revert "Re-land:  Make NativeExeSymbol a concrete subclass of NativeRawSymbol [PDB]"

This reverts commit f461a70cc376f0f91c8b4917be79479cc86330a5.

llvm-svn: 298626
2017-03-23 17:18:50 +00:00
Adrian McCarthy 997a15c3c3 Re-land: Make NativeExeSymbol a concrete subclass of NativeRawSymbol [PDB]
The new test should pass on all platforms now that llvm-pdbdump has the
`-color-output` option.

This moves exe symbol-specific method implementations out of NativeRawSymbol
into a concrete subclass. Also adds implementations for hasCTypes and
hasPrivateSymbols and a simple test to ensure the native reader can access
the summary information for the executable from the PDB.

Original Differential Revision: https://reviews.llvm.org/D31059

llvm-svn: 298623
2017-03-23 16:45:20 +00:00
Zachary Turner 2d9c082033 Revert "Make NativeExeSymbol a concrete subclass of NativeRawSymbol [PDB]"
For some reason this is causing ANSI color codes to be printed
even when run through FileCheck.

llvm-svn: 298026
2017-03-17 00:46:42 +00:00
Adrian McCarthy 21b54cf632 Make NativeExeSymbol a concrete subclass of NativeRawSymbol [PDB]
This moves exe symbol-specific method implementations out of NativeRawSymbol
into a concrete subclass. Also adds implementations for hasCTypes and
hasPrivateSymbols and a simple test to ensure the native reader can access
the summary information for the executable from the PDB.

Differential Revision: https://reviews.llvm.org/D31059

llvm-svn: 298005
2017-03-16 22:28:39 +00:00
Zachary Turner c9500616d8 Silence -Wcovered-switch-default warning.
llvm-svn: 297990
2017-03-16 20:45:11 +00:00
Zachary Turner 05d5e6136f [PDB] Add support for parsing Flags from PDB Stream.
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.

llvm-svn: 297984
2017-03-16 20:19:11 +00:00
Zachary Turner 02278ce09f [llvm-pdbdump] Add support for diffing the PDB Stream.
In doing so I discovered that we completely ignore some bytes
of the PDB Stream after we "finish" loading it.  These bytes
seem to specify some additional information about what kind
of data is present in the PDB.  A subsequent patch will add
code to read in those fields and store their values.

llvm-svn: 297983
2017-03-16 20:18:41 +00:00
Zachary Turner f1220084f6 [llvm-pdbdump] Add support for diffing the String Table.
llvm-svn: 297901
2017-03-15 22:19:30 +00:00
Zachary Turner ea4e60754e [pdb] Write the module info and symbol record streams.
Previously we did not have support for writing detailed
module information for each module, as well as the symbol
records.  This patch adds support for this, and in doing
so enables the ability to construct minimal PDBs from
just a few lines of YAML.  A test is added to illustrate
this functionality.

llvm-svn: 297900
2017-03-15 22:18:53 +00:00
Adrian McCarthy ad6d60a46b NFC: Corrects comments that were supposed to go in with earlier commit.
llvm-svn: 297887
2017-03-15 20:29:06 +00:00
Adrian McCarthy 65d2688842 Introduce NativeEnumModules and NativeCompilandSymbol
Together, these allow lldb-pdbdump to list all the modules from a PDB using a
native reader (rather than DIA).

Note that I'll probably be specializing NativeRawSymbol in a subsequent patch.

Differential Revision: https://reviews.llvm.org/D30956

llvm-svn: 297883
2017-03-15 20:17:58 +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 d0b44fa788 [PDB] Add BinaryStreamError.
This migrates the stream code away from MSFError to using its
own custom Error class.

llvm-svn: 296494
2017-02-28 17:49:34 +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
Adrian McCarthy 649b8e0c45 Implement some methods for NativeRawSymbol
This allows the ability to call IPDBSession::getGlobalScope with a NativeSession and
to then query it for some basic fields from the PDB's InfoStream.
Note that the symbols now have non-const references back to the Session so that
NativeRawSymbol can access the PDBFile through the Session.

Differential Revision: https://reviews.llvm.org/D30314

llvm-svn: 296049
2017-02-24 00:10:47 +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