Commit Graph

13 Commits

Author SHA1 Message Date
Michael Zolotukhin 5c0ab473f2 Remove redundant includes from unittests.
llvm-svn: 320630
2017-12-13 21:31:05 +00:00
Zachary Turner ca6dbf1440 Split TypeTableBuilder into two classes.
llvm-svn: 319456
2017-11-30 18:39:50 +00:00
Zachary Turner 6900de1dfb [CodeView] Refactor / Rewrite TypeSerializer and TypeTableBuilder.
The motivation behind this patch is that future directions require us to
be able to compute the hash value of records independently of actually
using them for de-duplication.

The current structure of TypeSerializer / TypeTableBuilder being a
single entry point that takes an unserialized type record, and then
hashes and de-duplicates it is not flexible enough to allow this.

At the same time, the existing TypeSerializer is already extremely
complex for this very reason -- it tries to be too many things. In
addition to serializing, hashing, and de-duplicating, ti also supports
splitting up field list records and adding continuations. All of this
functionality crammed into this one class makes it very complicated to
work with and hard to maintain.

To solve all of these problems, I've re-written everything from scratch
and split the functionality into separate pieces that can easily be
reused. The end result is that one class TypeSerializer is turned into 3
new classes SimpleTypeSerializer, ContinuationRecordBuilder, and
TypeTableBuilder, each of which in isolation is simple and
straightforward.

A quick summary of these new classes and their responsibilities are:

- SimpleTypeSerializer : Turns a non-FieldList leaf type into a series of
  bytes. Does not do any hashing. Every time you call it, it will
  re-serialize and return bytes again. The same instance can be re-used
  over and over to avoid re-allocations, and in exchange for this
  optimization the bytes returned by the serializer only live until the
  caller attempts to serialize a new record.

- ContinuationRecordBuilder : Turns a FieldList-like record into a series
  of fragments. Does not do any hashing. Like SimpleTypeSerializer,
  returns references to privately owned bytes, so the storage is
  invalidated as soon as the caller tries to re-use the instance. Works
  equally well for LF_FIELDLIST as it does for LF_METHODLIST, solving a
  long-standing theoretical limitation of the previous implementation.

- TypeTableBuilder : Accepts sequences of bytes that the user has already
  serialized, and inserts them by de-duplicating with a hash table. For
  the sake of convenience and efficiency, this class internally stores a
  SimpleTypeSerializer so that it can accept unserialized records. The
  same is not true of ContinuationRecordBuilder. The user is required to
  create their own instance of ContinuationRecordBuilder.

Differential Revision: https://reviews.llvm.org/D40518

llvm-svn: 319198
2017-11-28 18:33:17 +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
Zachary Turner a56e4ee346 Try to fix uninitialized read in unit test.
llvm-svn: 305753
2017-06-19 21:59:09 +00:00
Zachary Turner ad859bd472 [CodeView] Fix random access of type names.
Suppose we had a type index offsets array with a boundary at type index
N. Then you request the name of the type with index N+1, and that name
requires the name of index N-1 (think a parameter list, for example). We
didn't handle this, and we would print something like (<unknown UDT>,
<unknown UDT>).

The fix for this is not entirely trivial, and speaks to a larger
problem. I think we need to kill TypeDatabase, or at the very least kill
TypeDatabaseVisitor. We need a thing that doesn't do any caching
whatsoever, just given a type index it can compute the type name "the
slow way". The reason for the bug is that we don't have anything like
that. Everything goes through the type database, and if we've visited a
record, then we're "done". It doesn't know how to do the expensive thing
of re-visiting dependent records if they've not yet been visited.

What I've done here is more or less copied the code (albeit greatly
simplified) from TypeDatabaseVisitor, but wrapped it in an interface
that just returns a std::string. The logic of caching the name is now in
LazyRandomTypeCollection. Eventually I'd like to move the record
database here as well and the visited record bitfield here as well, at
which point we can actually just delete TypeDatabase. I don't see any
reason for it if a "sequential" collection is just a special case of a
random access collection with an empty partial offsets array.

Differential Revision: https://reviews.llvm.org/D34297

llvm-svn: 305612
2017-06-16 23:42:44 +00:00
Zachary Turner cb30e705d8 [gtest] Create a shared include directory for gtest utilities.
Many times unit tests for different libraries would like to use
the same helper functions for checking common types of errors.

This patch adds a common library with helpers for testing things
in Support, and introduces helpers in here for integrating the
llvm::Error and llvm::Expected<T> classes with gtest and gmock.

Normally, we would just be able to write:

   EXPECT_THAT(someFunction(), succeeded());

but due to some quirks in llvm::Error's move semantics, gmock
doesn't make this easy, so two macros EXPECT_THAT_ERROR() and
EXPECT_THAT_EXPECTED() are introduced to gloss over the difficulties.
Consider this an exception, and possibly only temporary as we
look for ways to improve this.

Differential Revision: https://reviews.llvm.org/D33059

llvm-svn: 305395
2017-06-14 16:41:50 +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 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 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
Justin Bogner bce6d327be [CodeView] Silence some -Wsign-compare warnings
llvm-svn: 302971
2017-05-13 00:11:39 +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