Also, make SerializationTraits for pairs forward the actual pair
template type arguments to the underlying serializer. This allows, for example,
std::pair<StringRef, bool> to be passed as an argument to an RPC call expecting
a std::pair<std::string, bool>, since there is an underlying serializer from
StringRef to std::string that can be used.
llvm-svn: 338305
deprecating SymbolResolver and AsynchronousSymbolQuery.
Both lookup overloads take a VSO search order to perform the lookup. The first
overload is non-blocking and takes OnResolved and OnReady callbacks. The second
is blocking, takes a boolean flag to indicate whether to wait until all symbols
are ready, and returns a SymbolMap. Both overloads take a RegisterDependencies
function to register symbol dependencies (if any) on the query.
llvm-svn: 337595
This discards the unresolved symbols set and returns the flags map directly
(rather than mutating it via the first argument).
The unresolved symbols result made it easy to chain lookupFlags calls, but such
chaining should be rare to non-existant (especially now that symbol resolvers
are being deprecated) so the simpler method signature is preferable.
llvm-svn: 337594
A search order is a list of VSOs to be searched linearly to find symbols. Each
VSO now has a search order that will be used when fixing up definitions in that
VSO. Each VSO's search order defaults to just that VSO itself.
This is a first step towards removing symbol resolvers from ORC altogether. In
practice symbol resolvers tended to be used to implement a search order anyway,
sometimes with additional programatic generation of symbols. Now that VSOs
support programmatic generation of definitions via fallback generators, search
orders provide a cleaner way to achieve the desired effect (while removing a lot
of boilerplate).
llvm-svn: 337593
delegate method (and unit test).
The name 'replace' better captures what the old delegate method did: it
returned materialization responsibility for a set of symbols to the VSO.
The new delegate method delegates responsibility for a set of symbols to a new
MaterializationResponsibility instance. This can be used to split responsibility
between multiple threads, or multiple materialization methods.
llvm-svn: 336603
Once a symbol has been selected for materialization it can no longer be
overridden. Stripping the weak flag guarantees this (override attempts will
then be treated as duplicate definitions and result in a DuplicateDefinition
error).
llvm-svn: 334771
If a VSO has a fallback definition generator attached it will be called during
lookup (and lookupFlags) for any unresolved symbols. The definition generator
can add new definitions to the VSO for any unresolved symbol. This allows VSOs
to generate new definitions on demand.
The immediate use case for this code is supporting VSOs that can import
definitions found via dlsym on demand.
llvm-svn: 334538
Existing implementations of these methods do not require lazy materialization,
and switching to JITEvaluatedSymbol allows us to remove error checking on the
client side.
llvm-svn: 333835
This method returns the set of symbols in the target VSO that have queries
waiting on them. This can be used to make decisions about which symbols to
delegate to another MaterializationUnit (typically this will involve
delegating all symbols that have *not* been requested to another
MaterializationUnit so that materialization of those symbols can be
deferred until they are requested).
llvm-svn: 333684
Previously JITCompileCallbackManager only supported single threaded code. This
patch embeds a VSO (see include/llvm/ExecutionEngine/Orc/Core.h) in the callback
manager. The VSO ensures that the compile callback is only executed once and that
the resulting address cached for use by subsequent re-entries.
llvm-svn: 333490
Re-appply r333147, reverted in r333152 due to a pre-existing bug. As
D47308 has been merged in r333206, the OSX issue should now be
resolved.
In many cases JIT users will know in which module a symbol
resides. Avoiding to search other modules can be more efficient. It
also allows to handle duplicate symbol names between modules.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D44889
llvm-svn: 333215
This reverts r333147 until https://reviews.llvm.org/D47308 is ready to
be reviewed. r333147 exposed a behavioural difference between
OrcCBindingsStack::findSymbolIn() and OrcCBindingsStack::findSymbol(),
where only the latter does name mangling. After r333147 that causes a
test failure on OSX, because the new test looks for main using
findSymbolIn() but the mangled name is _main.
llvm-svn: 333152
In many cases JIT users will know in which module a symbol
resides. Avoiding to search other modules can be more efficient. It
also allows to handle duplicate symbol names between modules.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D44889
llvm-svn: 333147
The lookup function provides blocking symbol resolution for JIT clients (not
layers themselves) so it does not need to track symbol dependencies via a
MaterializationResponsibility.
llvm-svn: 332897
notifyFailed method rather than passing in an error generator.
VSO::notifyFailed is responsible for notifying queries that they will not
succeed due to error. In practice the queries don't care about the details
of the failure, just the fact that a failure occurred for some symbols.
Having VSO::notifyFailed take care of this simplifies the interface.
llvm-svn: 332666
VSOs now track dependencies for materializing symbols. Each symbol must have its
dependencies registered with the VSO prior to finalization. Usually this will
involve registering the dependencies returned in
AsynchronousSymbolQuery::ResolutionResults for queries made while linking the
symbols being materialized.
Queries against symbols are notified that a symbol is ready once it and all of
its transitive dependencies are finalized, allowing compilation work to be
broken up and moved between threads without queries returning until their
symbols fully safe to access / execute.
Related utilities (VSO, MaterializationUnit, MaterializationResponsibility) are
updated to support dependence tracking and more explicitly track responsibility
for symbols from the point of definition until they are finalized.
llvm-svn: 332541
See r331124 for how I made a list of files missing the include.
I then ran this Python script:
for f in open('filelist.txt'):
f = f.strip()
fl = open(f).readlines()
found = False
for i in xrange(len(fl)):
p = '#include "llvm/'
if not fl[i].startswith(p):
continue
if fl[i][len(p):] > 'Config':
fl.insert(i, '#include "llvm/Config/llvm-config.h"\n')
found = True
break
if not found:
print 'not found', f
else:
open(f, 'w').write(''.join(fl))
and then looked through everything with `svn diff | diffstat -l | xargs -n 1000 gvim -p`
and tried to fix include ordering and whatnot.
No intended behavior change.
llvm-svn: 331184
LLVM_ON_WIN32 is set exactly with MSVC and MinGW (but not Cygwin) in
HandleLLVMOptions.cmake, which is where _WIN32 defined too. Just use the
default macro instead of a reinvented one.
See thread "Replacing LLVM_ON_WIN32 with just _WIN32" on llvm-dev and cfe-dev.
No intended behavior change.
This moves over all uses of the macro, but doesn't remove the definition
of it in (llvm-)config.h yet.
llvm-svn: 331127
/usr/local/bin/ld.lld: error: undefined symbol: llvm::createAggressiveInstCombinerPass()
>>> referenced by cc1_main.cpp
>>> tools/clang/tools/driver/CMakeFiles/clang.dir/cc1_main.cpp.o:(_GLOBAL__sub_I_cc1_main.cpp)
And so on
The bot coverage is clearly missing.
llvm-svn: 330693
materializing function definitions.
MaterializationUnit instances are responsible for resolving and finalizing
symbol definitions when their materialize method is called. By contract, the
MaterializationUnit must materialize all definitions it is responsible for and
no others. If it can not materialize all definitions (because of some error)
then it must notify the associated VSO about each definition that could not be
materialized. The MaterializationResponsibility class tracks this
responsibility, asserting that all required symbols are resolved and finalized,
and that no extraneous symbols are resolved or finalized. In the event of an
error it provides a convenience method for notifying the VSO about each
definition that could not be materialized.
llvm-svn: 330142
notifyMaterializationFailed.
The notifyMaterializationFailed method can determine which error to raise by
looking at which queue the pending queries are in (resolution or finalization).
llvm-svn: 330141
Previously this crashed because a nullptr (returned by
createLocalIndirectStubsManagerBuilder() on platforms without
indirection support) functor was unconditionally invoked.
Patch by Andres Freund. Thanks Andres!
llvm-svn: 328687
There's are race between this thread and the destructor of the test ORC
components on the main threads. I saw flaky failures there in about 4%
of the runs of this unit test.
llvm-svn: 328300
operation all-or-nothing, rather than allowing materialization on a per-symbol
basis.
This addresses a shortcoming of per-symbol materialization: If a
MaterializationUnit (/SymbolSource) wants to materialize more symbols than
requested (which is likely: most materializers will want to materialize whole
modules) then it needs a way to notify the symbol table about the extra symbols
being materialized. This process (checking what has been requested against what
is being provided and notifying the symbol table about the difference) has to
be repeated at every level of the JIT stack. Making materialization
all-or-nothing eliminates this issue, simplifying both materializer
implementations and the symbol table (VSO class) API. The cost is that
per-symbol materialization (e.g. for individual symbols in a module) now
requires multiple MaterializationUnits.
llvm-svn: 327946
This reverts commit r327566, it breaks
test/ExecutionEngine/OrcMCJIT/test-global-ctors.ll.
The test doesn't crash with a stack trace, unfortunately. It merely
returns 1 as the exit code.
ASan didn't produce a report, and I reproduced this on my Linux machine
and Windows box.
llvm-svn: 327576
Layer implementations typically mutate module state, and this is better
reflected by having layers own the Module they are operating on.
llvm-svn: 327566
The lookup function takes a list of VSOs, a set of symbol names (or just one
symbol name) and a materialization function object. It returns an
Expected<SymbolMap> (if given a set of names) or an Expected<JITEvaluatedSymbol>
(if given just one name). The lookup method constructs an
AsynchronousSymbolQuery for the given names, applies that query to each VSO in
the list in turn, and then blocks waiting for the query to complete. If
threading is enabled then the materialization function object can be used to
execute the materialization on different threads. If threading is disabled the
MaterializeOnCurrentThread utility must be used.
llvm-svn: 327474
than a shared ObjectFile/MemoryBuffer pair.
There's no need to pre-parse the buffer into an ObjectFile before passing it
down to the linking layer, and moving the parsing into the linking layer allows
us remove the parsing code at each call site.
llvm-svn: 325725
Handles were returned by addModule and used as keys for removeModule,
findSymbolIn, and emitAndFinalize. Their job is now subsumed by VModuleKeys,
which simplify resource management by providing a consistent handle across all
layers.
llvm-svn: 324700
In particular this patch switches RTDyldObjectLinkingLayer to use
orc::SymbolResolver and threads the requried changse (ExecutionSession
references and VModuleKeys) through the existing layer APIs.
The purpose of the new resolver interface is to improve query performance and
better support parallelism, both in JIT'd code and within the compiler itself.
The most visibile change is switch of the <Layer>::addModule signatures from:
Expected<Handle> addModule(std::shared_ptr<ModuleType> Mod,
std::shared_ptr<JITSymbolResolver> Resolver)
to:
Expected<Handle> addModule(VModuleKey K, std::shared_ptr<ModuleType> Mod);
Typical usage of addModule will now look like:
auto K = ES.allocateVModuleKey();
Resolvers[K] = createSymbolResolver(...);
Layer.addModule(K, std::move(Mod));
See the BuildingAJIT tutorial code for example usage.
llvm-svn: 324405
This resolver conforms to the LegacyJITSymbolResolver interface, and will be
replaced with a null-returning resolver conforming to the newer
orc::SymbolResolver interface in the near future. This patch renames the class
to avoid a clash.
llvm-svn: 324175
first argument.
This makes lookupFlags more consistent with lookup (which takes the query as the
first argument) and composes better in practice, since lookups are usually
linearly chained: Each lookupFlags can populate the result map based on the
symbols not found in the previous lookup. (If the maps were returned rather than
passed by reference there would have to be a merge step at the end).
llvm-svn: 323398
functions/methods that return JITSymbols.
lookupFlagsWithLegacyFn takes a SymbolNameSet and a legacy lookup function and
returns a LookupFlagsResult. It uses the legacy lookup function to search for
each symbol. If found, getFlags is called on the symbol and the flags added to
the SymbolFlags map. If not found, the symbol is added to the SymbolsNotFound
set.
lookupWithLegacyFn takes an AsynchronousSymbolQuery, a SymbolNameSet and a
legacy lookup function. Each symbol in the SymbolNameSet is searched for via the
legacy lookup function. If it is found, its getAddress function is called
(triggering materialization if it has not happened already) and the resulting
mapping stored in the query. If it is not found the symbol is added to the
unresolved symbols set which is returned at the end of the function. If an
error occurs during legacy lookup or materialization it is passed to the
query via setFailed and the function returns immediately.
llvm-svn: 323388
This patch adds a LambdaSymbolResolver convenience utility that can create an
orc::SymbolResolver from a pair of function objects that supply the behavior for
the lookupFlags and lookup methods.
This class plays the same role for orc::SymbolResolver as the legacy
LambdaResolver class plays for LegacyJITSymbolResolver, and will replace the
latter class once all ORC APIs are migrated to orc::SymbolResolver.
This patch also adds some documentation for the orc::SymbolResolver class as
this was left out of the original commit.
llvm-svn: 323375
orc::SymbolResolver to JITSymbolResolver adapter.
The new orc::SymbolResolver interface uses asynchronous queries for better
performance. (Asynchronous queries with bulk lookup minimize RPC/IPC overhead,
support parallel incoming queries, and expose more available work for
distribution). Existing ORC layers will soon be updated to use the
orc::SymbolResolver API rather than the legacy llvm::JITSymbolResolver API.
Because RuntimeDyld still uses JITSymbolResolver, this patch also includes an
adapter that wraps an orc::SymbolResolver with a JITSymbolResolver API.
llvm-svn: 323073
lookupFlags returns a SymbolFlagsMap for the requested symbols, along with a
set containing the SymbolStringPtr for any symbol not found in the VSO.
The JITSymbolFlags for each symbol will have been stripped of its transient
JIT-state flags (i.e. NotMaterialized, Materializing).
Calling lookupFlags does not trigger symbol materialization.
llvm-svn: 323060
version being used on some of the green dragon builders (plus a clang-format).
Workaround: AsynchronousSymbolQuery and VSO want to work with
JITEvaluatedSymbols anyway, so just use them (instead of JITSymbol, which
happens to tickle the bug).
The libcxx bug being worked around was fixed in r276003, and there are plans to
update the offending builders.
llvm-svn: 322140
The original commit broke the builders due to a think-o in an assertion:
AsynchronousSymbolQuery's constructor needs to check the callback member
variables, not the constructor arguments.
llvm-svn: 321853
SymbolSource.
These new APIs are a first stab at tackling some current shortcomings of ORC,
especially in performance and threading support.
VSO (Virtual Shared Object) is a symbol table representing the symbol
definitions of a set of modules that behave as if they had been statically
linked together into a shared object or dylib. Symbol definitions, either
pre-defined addresses or lazy definitions, can be added and queries for symbol
addresses made. The table applies the same linkage strength rules that static
linkers do when constructing a dylib or shared object: duplicate definitions
result in errors, strong definitions override weak or common ones. This class
should improve symbol lookup speed by providing centralized symbol tables (as
compared to the findSymbol implementation in the in-tree ORC layers, which
maintain one symbol table per object file / module added).
AsynchronousSymbolQuery is a query for the addresses of a set of symbols.
Query results are returned via a callback once they become available. Querying
for a set of symbols, rather than one symbol at a time (as the current lookup
scheme does) the JIT has the opportunity to make better use of available
resources (e.g. by spawning multiple jobs to materialize the requested symbols
if possible). Returning results via a callback makes queries asynchronous, so
queries from multiple threads of JIT'd code can proceed simultaneously.
SymbolSource represents a source of symbol definitions. It is used when
adding lazy symbol definitions to a VSO. Symbol definitions can be materialized
when needed or discarded if a stronger definition is found. Materializing on
demand via SymbolSources should (eventually) allow us to remove the lazy
materializers from JITSymbol, which will in turn allow the removal of many
current error checks and reduce the number of RPC round-trips involved in
materializing remote symbols. Adding a discard function allows sources to
discard symbol definitions (or mark them as available_externally), reducing the
amount of redundant code generated by the JIT for ODR symbols.
llvm-svn: 321838
rL319838 introduced SymbolStringPool which uses 8 byte atomics for
reference counters. On systems which do not support such atomics
natively such as MIPS32, explicitly add libatomic as one of the
libraries for SymbolStringPool's unittest.
Reviewers: lhames, beanz
Differential Revision: https://reviews.llvm.org/D41010
llvm-svn: 321225
We currently use target_link_libraries without an explicit scope
specifier (INTERFACE, PRIVATE or PUBLIC) when linking executables.
Dependencies added in this way apply to both the target and its
dependencies, i.e. they become part of the executable's link interface
and are transitive.
Transitive dependencies generally don't make sense for executables,
since you wouldn't normally be linking against an executable. This also
causes issues for generating install export files when using
LLVM_DISTRIBUTION_COMPONENTS. For example, clang has a lot of LLVM
library dependencies, which are currently added as interface
dependencies. If clang is in the distribution components but the LLVM
libraries it depends on aren't (which is a perfectly legitimate use case
if the LLVM libraries are being built static and there are therefore no
run-time dependencies on them), CMake will complain about the LLVM
libraries not being in export set when attempting to generate the
install export file for clang. This is reasonable behavior on CMake's
part, and the right thing is for LLVM's build system to explicitly use
PRIVATE dependencies for executables.
Unfortunately, CMake doesn't allow you to mix and match the keyword and
non-keyword target_link_libraries signatures for a single target; i.e.,
if a single call to target_link_libraries for a particular target uses
one of the INTERFACE, PRIVATE, or PUBLIC keywords, all other calls must
also be updated to use those keywords. This means we must do this change
in a single shot. I also fully expect to have missed some instances; I
tested by enabling all the projects in the monorepo (except dragonegg),
and configuring both with and without shared libraries, on both Darwin
and Linux, but I'm planning to rely on the buildbots for other
configurations (since it should be pretty easy to fix those).
Even after this change, we still have a lot of target_link_libraries
calls that don't specify a scope keyword, mostly for shared libraries.
I'm thinking about addressing those in a follow-up, but that's a
separate change IMO.
Differential Revision: https://reviews.llvm.org/D40823
llvm-svn: 319840
comparison of symbol names.
SymbolStringPool is a thread-safe string pool that will be used in upcoming Orc
APIs to facilitate efficient storage and fast comparison of symbol name strings.
llvm-svn: 319839
/code/llvm-project/llvm/unittests/ExecutionEngine/Orc/RTDyldObjectLinkingLayerTest.cpp:260:38: error: lambda capture 'this' is not used [-Werror,-Wunused-lambda-capture]
[this](decltype(ObjLayer)::ObjHandleT,
llvm-svn: 314454
concept.
Add a unit-test to make sure we don't backslide, and tweak the MockBaseLayer
utility to make it easier to test this kind of thing in the future.
llvm-svn: 314374
This will allow async handlers to be added that return void or Error::success().
Such handlers are expected to be common, since one of the primary uses of
addAsyncHandler is to run the body of the handler in a detached thread, in which
case the main handler returns immediately and does not need to provide an Error
value.
llvm-svn: 312746
The existing code created a JITSymbol with an invalid materializer instead,
guaranteeing a 'missing symbol' error when someone tried to materialize the
symbol.
llvm-svn: 312584
This patch introduces RemoteObjectClientLayer and RemoteObjectServerLayer,
which can be used to forward ORC object-layer operations from a JIT stack in
the client to a JIT stack (consisting only of object-layers) in the server.
This is a new way to support remote-JITing in LLVM. The previous approach
(supported by OrcRemoteTargetClient and OrcRemoteTargetServer) used a
remote-mapping memory manager that sat "beneath" the JIT stack and sent
fully-relocated binary blobs to the server. The main advantage of the new
approach is that relocatable objects can be cached on the server and re-used
(if the code that they represent hasn't changed), whereas fully-relocated blobs
can not (since the addresses they have been permanently bound to will change
from run to run).
llvm-svn: 312511
Calling grow may result in an error if, for example, this is a callback
manager for a remote target. We need to be able to return this error to the
callee.
llvm-svn: 312429
IMHO it is an antipattern to have a enum value that is Default.
At any given piece of code it is not clear if we have to handle
Default or if has already been mapped to a concrete value. In this
case in particular, only the target can do the mapping and it is nice
to make sure it is always done.
This deletes the two default enum values of CodeModel and uses an
explicit Optional<CodeModel> when it is possible that it is
unspecified.
llvm-svn: 309911
This patch updates the ORC layers and utilities to return and propagate
llvm::Errors where appropriate. This is necessary to allow ORC to safely handle
error cases in cross-process and remote JITing.
llvm-svn: 307350
symbol resolver argument.
De-templatizing the symbol resolver is part of the ongoing simplification of
ORC layer API.
Removing the memory management argument (and delegating construction of memory
managers for RTDyldObjectLinkingLayer to a functor passed in to the constructor)
allows us to build JITs whose base object layers need not be compatible with
RTDyldObjectLinkingLayer's memory mangement scheme. For example, a 'remote
object layer' that sends fully relocatable objects directly to the remote does
not need a memory management scheme at all (that will be handled by the remote).
llvm-svn: 307058
Revert "[ORC] Remove redundant semicolons from DEFINE_SIMPLE_CONVERSION_FUNCTIONS uses."
Revert "[ORC] Move ORC IR layer interface from addModuleSet to addModule and fix the module type as std::shared_ptr<Module>."
They broke ExecutionEngine/OrcMCJIT/test-global-ctors.ll on linux.
llvm-svn: 306176
move the ObjectCache from the IRCompileLayer to SimpleCompiler.
This is the first in a series of patches aimed at cleaning up and improving the
robustness and performance of the ORC APIs.
llvm-svn: 306058
clang-format (https://reviews.llvm.org/D33932) to keep primary headers
at the top and handle new utility headers like 'gmock' consistently with
other utility headers.
No other change was made. I did no manual edits, all of this is
clang-format.
This should allow other changes to have more clear and focused diffs,
and is especially motivated by moving some headers into more focused
libraries.
llvm-svn: 304786
frames.
RuntimeDyld was previously responsible for tracking allocated EH frames, but it
makes more sense to have the RuntimeDyld::MemoryManager track them (since the
frames are allocated through the memory manager, and written to memory owned by
the memory manager). This patch moves the frame tracking into
RTDyldMemoryManager, and changes the deregisterFrames method on
RuntimeDyld::MemoryManager from:
void deregisterEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size);
to:
void deregisterEHFrames();
Separating this responsibility will allow ORC to continue to throw the
RuntimeDyld instances away post-link (saving a few dozen bytes per lazy
function) while properly deregistering frames when modules are unloaded.
This patch also updates ORC to call deregisterEHFrames when modules are
unloaded. This fixes a bug where an exception that tears down the JIT can then
unwind through dangling EH frames that have been deallocated but not
deregistered, resulting in UB.
For people using SectionMemoryManager this should be pretty much a no-op. For
people with custom allocators that override registerEHFrames/deregisterEHFrames,
you will now be responsible for tracking allocated EH frames.
Reviewed in https://reviews.llvm.org/D32829
llvm-svn: 302589
Use variadic templates instead of relying on <cstdarg> + sentinel.
This enforces better type checking and makes code more readable.
Differential Revision: https://reviews.llvm.org/D32541
llvm-svn: 302571
Summary:
Do three things to help with that:
- Add AttributeList::FirstArgIndex, which is an enumerator currently set
to 1. It allows us to change the indexing scheme with fewer changes.
- Add addParamAttr/removeParamAttr. This just shortens addAttribute call
sites that would otherwise need to spell out FirstArgIndex.
- Remove some attribute-specific getters and setters from Function that
take attribute list indices. Most of these were only used from
BuildLibCalls, and doesNotAlias was only used to test or set if the
return value is malloc-like.
I'm happy to split the patch, but I think they are probably easier to
review when taken together.
This patch should be NFC, but it sets the stage to change the indexing
scheme to this, which is more convenient when indexing into an array:
0: func attrs
1: retattrs
2...: arg attrs
Reviewers: chandlerc, pete, javed.absar
Subscribers: david2050, llvm-commits
Differential Revision: https://reviews.llvm.org/D32811
llvm-svn: 302060
This avoids the confusing 'CS.paramHasAttr(ArgNo + 1, Foo)' pattern.
Previously we were testing return value attributes with index 0, so I
introduced hasReturnAttr() for that use case.
llvm-svn: 300367
The tests were failing due to an occasional deadlock in SerializationTraits
for Error: Both serializers and deserializers were protected by a single
mutex and in the unit test (where both ends of the RPC are in the same
process) one side might obtain the mutex, then block waiting for input,
leaving the other side of the connection unable to obtain the mutex to
write the data the first side was waiting for. Splitting the mutex into
two (one for serialization, one for deserialization) appears to have fixed the
issue.
llvm-svn: 300286
This patch allows Error and Expected types to be passed to and returned from
RPC functions.
Serializers and deserializers for custom error types (types deriving from the
ErrorInfo class template) can be registered with the SerializationTraits for
a given channel type (see registerStringError in RPCSerialization.h for an
example), allowing a given custom type to be sent/received. Unregistered types
will be serialized/deserialized as StringErrors using the custom type's log
message as the error string.
llvm-svn: 300167