This refactor was motivated by two bugs identified in out-of-tree
builds:
1. Some implementations of the VisitMembersFunction type (often used to
implement special loading semantics, e.g. -all_load or -ObjC) were assuming
that buffers for archive members were null-terminated, which they are not in
general. This was triggering occasional assertions.
2. Archives may include multiple members with the same file name, e.g.
when constructed by appending files with the same name:
% llvm-ar crs libfoo.a foo.o
% llvm-ar q libfoo.a foo.o
% llvm-ar t libfoo.a foo.o
foo.o
While confusing, these members may be safe to link (provided that they're
individually valid and don't define duplicate symbols). In ORC however, the
archive member name may be used to construct an ORC initializer symbol,
which must also be unique. In that case the duplicate member names lead to a
duplicate definition error even if the members define unrelated symbols.
In addition to these bugs, StaticLibraryDefinitionGenerator had grown a
collection of all member buffers (ObjectFilesMap), a BumpPtrAllocator
that was redundantly storing synthesized archive member names (these are
copied into the MemoryBuffers created for each Object, but were never
freed in the allocator), and a set of COFF-specific import files.
To fix the bugs above and simplify StaticLibraryDefinitionGenerator this
patch makes the following changes:
1. StaticLibraryDefinitionGenerator::VisitMembersFunction is generalized
to take a reference to the containing archive, and the index of the
member within the archive. It now returns an Expected<bool> indicating
whether the member visited should be treated as loadable, not loadable,
or as invalidating the entire archive.
2. A static StaticLibraryDefinitionGenerator::createMemberBuffer method
is added which creates MemoryBuffers with unique names of the form
`<archive-name>[<index>](<member-name>)`. This defers construction of
member names until they're loaded, allowing the BumpPtrAllocator (with
its redundant name storage) to be removed.
3. The ObjectFilesMap (symbol name -> memory-buffer-ref) is replaced
with a SymbolToMemberIndexMap (symbol name -> index) which should be
smaller and faster to construct.
4. The 'loadability' result from VisitMemberFunctions is now taken into
consideration when building the SymbolToMemberIndexMap so that members
that have already been loaded / filtered out can be skipped, and do not
take up any ongoing space.
5. The COFF ImportedDynamicLibraries member is moved out into the
COFFImportFileScanner utility, which can be used as a
VisitMemberFunction.
This fixes the bugs described above; and should lower memory consumption
slightly, especially for archives with many files and / or symbol where
most files are eventually loaded.
We had been abusing the setOverrideObjectFlagsWithResponsibilityFlags method to
do this. Handling it explicitly ensures that flags are only modified on the
intended files, and not accedintally modified elsewhere.
This reapplies 6d72bf47606, which was reverted in 57447d3ddf to investigate
build failures, e.g. https://lab.llvm.org/buildbot/#/builders/3/builds/10114.
The original patch contained an invalid unused friend declaration of
std::make_shared. This has been removed.
Also adds a new IdleTask type and updates DynamicThreadPoolTaskDispatcher to
schedule IdleTasks whenever the total number of threads running is less than
the maximum number of MaterializationThreads.
A SimpleLazyReexportsSpeculator instance maintains a list of speculation
suggestions ((JITDylib, Function) pairs) and registered lazy reexports. When
speculation opportunities are available (having been added via
addSpeculationSuggestions or when lazy reexports were created) it schedules
an IdleTask that triggers the next speculative lookup as soon as resources
are available. Speculation suggestions are processed first, followed by
lookups for lazy reexport bodies. A callback can be registered at object
construction time to record lazy reexport executions as they happen, and these
executions can be fed back into the speculator as suggestions on subsequent
executions.
The llvm-jitlink tool is updated to support speculation when lazy linking is
used via three new arguments:
-speculate=[none|simple] : When the 'simple' value is specified a
SimpleLazyReexportsSpeculator instances is used
for speculation.
-speculate-order <path> : Specifies a path to a CSV containing
(jit dylib name, function name) triples to use
as speculative suggestions in the current run.
-record-lazy-execs <path> : Specifies a path in which to record lazy function
executions as a CSV of (jit dylib name, function
name) pairs, suitable for use with
-speculate-order.
The same path can be passed to -speculate-order and -record-lazy-execs, in
which case the file will be overwritten at the end of the execution.
No testcase yet: Speculative linking is difficult to test (since by definition
execution behavior should be unaffected by speculation) and this is an new
prototype of the concept*. Tests will be added in the future once the interface
and behavior settle down.
* An earlier implementation of the speculation concept can be found in
llvm/include/llvm/ExecutionEngine/Orc/Speculation.h. Both systems have the
same goal (hiding compilation latency) but different mechanisms. This patch
relies entirely on information available in the controller, where the old
system could receive additional information from the JIT'd runtime via
callbacks. I aim to combine the two in the future, but want to gain more
practical experience with speculation first.
ORC dependence tracking is fine-grained (i.e. per-symbol), however when running
-check mode we want to wait for all links triggered by the entry point lookup
to complete, regardless of whether the code / data in them is actually
reachable from the entry point. This simplifies test-cases, since authors don't
need to reason about per-symbol dependencies to know that additional files will
be linked (if referenced transitively in any way from the test-case).
The new Session::waitForFilesLinkedFromEntryPointFile utility does _not_ wait
for lazily linked (-lazy) files.
This will be used to fix buildbot errors caused by edca1d9bad2.
Adds a -threads option to llvm-jitlink. By default llvm-jitlink will now use a
DynamicThreadPoolTaskDispatcher with the number of materialization threads set
to whatever is returned by std::hardware_concurrency(). This brings the default
in-place linking behavior in line with the concurrent linking that is used for
-oop-executor and -oop-executor-connect mode.
In-place linking on the main thread can be forced by passing -threads=0.
This re-applies 570ecdcf8b4, which was reverted in 74e8a37ff32 due to bot
failures. This commit renames sysv_resolve.cpp to resolve.cpp, which was the
cause of the config errors.
This reapplies 570ecdcf8b4, which was reverted in 6073dd923b8 due to bot
failures.
The test failures on Linux were fixed by:
1. Removing an overly restrictive assertion (query dependence on a symbol no
longer implies a MaterializingInfo for that symbol)
2. Adding reentry and resolver files to the ORC runtime CMakeLists.txt for
Linux.
3. Adding the __orc_rt_reentry -> __orc_rt_sysv_reentry alias to ELFNixPlatform.
…d reentry.
These utilities provide new, more generic and easier to use support for
lazy compilation in ORC.
LazyReexportsManager is an alternative to LazyCallThroughManager. It
takes requests for lazy re-entry points in the form of an alias map:
lazy-reexports = {
( <entry point symbol #1>, <implementation symbol #1> ),
( <entry point symbol #2>, <implementation symbol #2> ),
...
( <entry point symbol #n>, <implementation symbol #n> )
}
LazyReexportsManager then:
1. binds the entry points to the implementation names in an internal
table.
2. creates a JIT re-entry trampoline for each entry point.
3. creates a redirectable symbol for each of the entry point name and
binds redirectable symbol to the corresponding reentry trampoline.
When an entry point symbol is first called at runtime (which may be on
any thread of the JIT'd program) it will re-enter the JIT via the
trampoline and trigger a lookup for the implementation symbol stored in
LazyReexportsManager's internal table. When the lookup completes the
entry point symbol will be updated (via the RedirectableSymbolManager)
to point at the implementation symbol, and execution will proceed to the
implementation symbol.
Actual construction of the re-entry trampolines and redirectable symbols
is delegated to an EmitTrampolines functor and the
RedirectableSymbolsManager respectively.
JITLinkReentryTrampolines.h provides a JITLink-based implementation of
the EmitTrampolines functor. (AArch64 only in this patch, but other
architectures will be added in the near future).
Register state save and reentry functionality is added to the ORC
runtime in the __orc_rt_sysv_resolve and __orc_rt_resolve_implementation
functions (the latter is generic, the former will need custom
implementations for each ABI and architecture to be supported, however
this should be much less effort than the existing OrcABISupport
approach, since the ORC runtime allows this code to be written as native
assembly).
The resulting system:
1. Works equally well for in-process and out-of-process JIT'd code.
2. Requires less boilerplate to set up.
Given an ObjectLinkingLayer and PlatformJD (JITDylib containing the ORC
runtime), setup is just:
```c++
auto RSMgr = JITLinkRedirectableSymbolManager::Create(OLL);
if (!RSMgr)
return RSMgr.takeError();
auto LRMgr = createJITLinkLazyReexportsManager(OLL, **RSMgr, PlatformJD);
if (!LRMgr)
return LRMgr.takeError();
```
after which lazy reexports can be introduced with:
```c++
JD.define(lazyReexports(LRMgr, <alias map>));
```
LazyObectLinkingLayer is updated to use this new method, but the LLVM-IR
level CompileOnDemandLayer will continue to use LazyCallThroughManager
and OrcABISupport until the new system supports a wider range of
architectures and ABIs.
The llvm-jitlink utility's -lazy option now uses the new scheme. Since
it depends on the ORC runtime, the lazy-link.ll testcase and associated
helpers are moved to the ORC runtime.
Use SymbolStringPtr for Symbol names in LinkGraph. This reduces string interning
on the boundary between JITLink and ORC, and allows pointer comparisons (rather
than string comparisons) between Symbol names. This should improve the
performance and readability of code that bridges between JITLink and ORC (e.g.
ObjectLinkingLayer and ObjectLinkingLayer::Plugins).
To enable use of SymbolStringPtr a std::shared_ptr<SymbolStringPool> is added to
LinkGraph and threaded through to its construction sites in LLVM and Bolt. All
LinkGraphs that are to have symbol names compared by pointer equality must point
to the same SymbolStringPool instance, which in ORC sessions should be the pool
attached to the ExecutionSession.
---------
Co-authored-by: Lang Hames <lhames@gmail.com>
LazyObjectLinkingLayer can be used to add object files that will not be linked
into the executor unless some function that they define is called at runtime.
(References to data members defined by these objects will still trigger
immediate linking)
To implement lazy linking, LazyObjectLinkingLayer uses the lazyReexports
utility to construct stubs for each function in a given object file, and an
ObjectLinkingLayer::Plugin to rename the function bodies at link-time. (Data
symbols are not renamed)
The llvm-jitlink utility is extended with a -lazy option that can be
passed before input files or archives to add them using the lazy linking
layer rather than the base ObjectLinkingLayer.
We use `jitlink-check` lines in LIT tests as the primary tool for
testing JITLink backends. Parsing and evaluation of the expressions is
implemented in `RuntimeDyldChecker`. The `stub_addr(obj, name)`
expression allows to obtain the linker-generated stub for the external
symbol `name` in object file `obj`.
This patch adds support for a filter parameter to select one out of many
stubs. This is necessary for the AArch32 JITLink backend, which must be
able to emit two different kinds of stubs depending on the instruction
set state (Arm/Thumb) of the relocation site. Since the new parameter is
optional, we don't have to update existing tests.
Filters are regular expressions without brackets that match exactly one
existing stub. Given object file `armv7.o` with two stubs for external
function `ext` of kinds `armv7_abs_le` and `thumbv7_abs_le`, we get the
following filter results e.g.:
```
stub_addr(armv7.o, ext, thumb) thumbv7_abs_le
stub_addr(armv7.o, ext, thumbv7) thumbv7_abs_le
stub_addr(armv7.o, ext, armv7_abs_le) armv7_abs_le
stub_addr(armv7.o, ext, v7_.*_le) Error: "ext" has 2 candidate stubs in file "armv7.o". Please refine stub-kind filter "v7_.*_le" for disambiguation (encountered kinds are "thumbv7_abs_le", "armv7_abs_le").
stub_addr(armv7.o, ext, v8) Error: "ext" has 2 stubs in file "armv7.o", but none of them matches the stub-kind filter "v8" (all encountered kinds are "thumbv7_abs_le", "armv7_abs_le").
```
Add methods `registerGOTEntry()` and `registerStubEntry()` in
`Session::FileInfo` to factor out generic code from the individual
object type implementations.
This reapplies 3d0dd1a7d6, which was reverted in df2485b215a due to bot
failures. This patch addresses the issues seen on the bots by disabling two
Linux atexit tests in the ORC runtime whose behavior could not be maintained
now that the ORC runtime is being loaded into a separate Platform JITDylib.
https://github.com/llvm/llvm-project/issues/74641 has been filed to fix the
issue with atexit.
The Process JITDylib holds reflected process symbols. The Platform JITDylib
holds ORC runtime symbols if the ORC runtime is loaded. The Platform and
Process JITDylibs are appended to the link order of all other JITDylibs,
including the main JITDylib, after any explicitly specified libraries. This
scheme is similar to the one introduced in LLJIT in 371cb1af61d, and makes
it easier to introduce aliases for process and platform symbols in a way that
affects all JITDylibs uniformly.
Since the Process and Platform JITDylibs are created implicitly the -alias
option is generalized to allow source and destination JITDylibs to be explicitly
specified, i.e. the -alias option now supports general re-exports.
Testcases are updated to account for the change.
Moves the llvm-jitlink tool statistics out of the Session struct and into a new
LLVMJITLinkStatistics class.
Also removes the `-show-sizes` option. Each statistic added will now have its
own option. The two previous stats (total size of all blocks before pruning and
after fixups) are now available as -pre-prune-total-block-size and
-post-fixup-total-block-size.
This change should make it easier to add new statistics.
SubtargetFeature.h is currently part of MC while it doesn't depend on
anything in MC. Since some LLVM components might have the need to work
with target features without necessarily needing MC, it might be
worthwhile to move SubtargetFeature.h to a different location. This will
reduce the dependencies of said components.
Note that I choose TargetParser as the destination because that's where
Triple lives and SubtargetFeatures feels related to that.
This issues came up during a JITLink review (D149522). JITLink would
like to avoid a dependency on MC while still needing to store target
features.
Reviewed By: MaskRay, arsenm
Differential Revision: https://reviews.llvm.org/D150549
The reason for this patch is to allow the MCDisassembler used in tests
to disassemble instructions that are only available when a specific
feature is enabled.
For example, on RISC-V it's currently not possible to use
decode_operand() on a compressed instruction. This patch fixes this.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D149523
The original -show-graph option dumped the LinkGraph for all graphs loaded into
the session, but can make it difficult to see small graphs (e.g. reduced test
cases) among the surrounding larger files (especially the ORC runtime).
The new -show-graphs option takes a regex and dumps only those graphs matching
the regex. This allows testcases to specify exactly which graphs to dump.
Initial platform support for COFF/x86_64.
Completed features:
* Statically linked orc runtime.
* Full linking/initialization of static/dynamic vc runtimes and microsoft stl libraries.
* SEH exception handling.
* Full static initializers support
* dlfns
* JIT side symbol lookup/dispatch
Things to note:
* It uses vc runtime libraries found in vc toolchain installations.
* Bootstrapping state is separated because when statically linking orc runtime it needs microsoft stl functions to initialize the orc runtime, but static initializers need to be ran in order to fully initialize stl libraries.
* Process symbols can't be used blidnly on msvc platform; otherwise duplicate definition error gets generated. If process symbols are used, it's destined to get out-of-reach error at some point.
* Atexit currently not handled -- will be handled in the follow-up patches.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D130479
Adds initial COFF support in JITLink. This is able to run a hello world c program in x86 windows successfully.
Implemented
- COFF object loader
- Static local symbols
- Absolute symbols
- External symbols
- Weak external symbols
- Common symbols
- COFF jitlink-check support
- All COMDAT selection type execpt largest
- Implicit symobl size calculation
- Rel32 relocation with PLT stub.
- IMAGE_REL_AMD64_ADDR32NB relocation
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D128968
This adds a GetObjectFileInterface callback member to
StaticLibraryDefinitionGenerator, and adds an optional argument for initializing
that member to StaticLibraryDefinitionGenerator's named constructors. If not
supplied, it will default to getObjectFileInterface from ObjectFileInterface.h.
To enable testing a `-hidden-l<x>` option is added to the llvm-jitlink tool.
This allows archives to be loaded with all contained symbol visibilities demoted
to hidden.
The ObjectLinkingLayer::setOverrideObjectFlagsWithResponsibilityFlags method is
(belatedly) hooked up, and enabled in llvm-jitlink when `-hidden-l<x>` is used
so that the demotion is also applied at symbol resolution time (avoiding any
"mismatched symbol flags" crashes).
Adds -L<search-path> and -l<library> options that are analogous to ld's
versions.
Each instance of -L<search-path> or -l<library> will apply to the most recent
-jd option on the command line (-jd <name> creates a JITDylib with the given
name). Library names will match against JITDylibs first, then llvm-jitlink will
look through the search paths for files named <search-path>/lib<library>.dylib
or <search-path>/lib<library>.a.
The default "main" JITDylib will link against all JITDylibs created by -jd
options, and all JITDylibs will link against the process symbols (unless
-no-process-symbols is specified).
The -dlopen option is renamed -preload, and will load dylibs into the JITDylib
for the ORC runtime only.
The effect of these changes is to make it easier to describe a non-trivial
program layout to llvm-jitlink for testing purposes. E.g. the following
invocation describes a program consisting of three JITDylibs: "main" (created
implicitly) containing main.o, "Foo" containing foo1.o and foo2.o, and linking
against library "bar" (not a JITDylib, so it must be a .dylib or .a on disk)
and "Baz" (which is a JITDylib), and "Baz" containing baz.o.
llvm-jitlink \
main.o \
-jd Foo foo1.o foo2.o -L${HOME}/lib -lbar -lBaz
-jd Baz baz.o
Also moves object interface building functions out of Mangling.h and in to the
new ObjectFileInterfaces.h header, and updates the llvm-jitlink tool to use
custom object interfaces rather than a custom link layer.
ObjectLayer::add overloads are added to match the old signatures (which
do not take a MaterializationUnit::Interface). These overloads use the
standard getObjectFileInterface function to build an interface.
Passing a MaterializationUnit::Interface explicitly makes it easier to alter
the effective interface of the object file being added, e.g. by changing symbol
visibility/linkage, or renaming symbols (in both cases the changes will need to
be mirrored by a JITLink pass at link time to update the LinkGraph to match the
explicit interface). Altering interfaces in this way can be useful when lazily
compiling (e.g. for renaming function bodies) or emulating linker options (e.g.
demoting all symbols to hidden visibility to emulate -load_hidden).
With the removal of OrcRPCExecutorProcessControl and OrcRPCTPCServer in
6aeed7b19c4 the ORC RPC library no longer has any in-tree users.
Clients needing serialization for ORC should move to Simple Packed
Serialization (usually by adopting SimpleRemoteEPC for remote JITing).
This reapplies bb27e4564355243e479cab40885d6e0f7f640572 (SimpleRemoteEPC
support) and 2269a941a450a0d395161cfb792be58870b2875b (#include <mutex>
fix) with further fixes to support building with LLVM_ENABLE_THREADS=Off.
This reverts commit 5629afea9109d3b72064cbe70e1ca91ffb9dc0a2 ("[ORC] Add missing
include."), and bb27e4564355243e479cab40885d6e0f7f640572 ("[ORC] Add
SimpleRemoteEPC: ExecutorProcessControl over SPS + abstract transport.").
The SimpleRemoteEPC patch currently assumes availability of threads, and needs
to be rewritten with LLVM_ENABLE_THREADS guards.
SimpleRemoteEPC is an ExecutorProcessControl implementation (with corresponding
new server class) that uses ORC SimplePackedSerialization (SPS) to serialize and
deserialize EPC-messages to/from byte-buffers. The byte-buffers are sent and
received via a new SimpleRemoteEPCTransport interface that can be implemented to
run SimpleRemoteEPC over whatever underlying transport system (IPC, RPC, network
sockets, etc.) best suits your use case.
The SimpleRemoteEPCServer class provides executor-side support. It uses a
customizable SimpleRemoteEPCServer::Dispatcher object to dispatch wrapper
function calls to prevent the RPC thread from being blocked (a problem in some
earlier remote-JIT server implementations). Almost all functionality (beyond the
bare basics needed to bootstrap) is implemented as wrapper functions to keep the
implementation simple and uniform.
Compared to previous remote JIT utilities (OrcRemoteTarget*,
OrcRPCExecutorProcessControl), more consideration has been given to
disconnection and error handling behavior: Graceful disconnection is now always
initiated by the ORC side of the connection, and failure at either end (or in
the transport) will result in Errors being delivered to both ends to enable
controlled tear-down of the JIT and Executor (in the Executor's case this means
"as controlled as the JIT'd code allows").
The introduction of SimpleRemoteEPC will allow us to remove other remote-JIT
support from ORC (including the legacy OrcRemoteTarget* code used by lli, and
the OrcRPCExecutorProcessControl and OrcRPCEPCServer classes), and then remove
ORC RPC itself.
The llvm-jitlink and llvm-jitlink-executor tools have been updated to use
SimpleRemoteEPC over file descriptors. Future commits will move lli and other
tools and example code to this system, and remove ORC RPC.
Wrapper function call and dispatch handler helpers are moved to
ExecutionSession, and existing EPC-based tools are re-written to take an
ExecutionSession argument instead.
Requiring an ExecutorProcessControl instance simplifies existing EPC based
utilities (which only need to take an ES now), and should encourage more
utilities to use the EPC interface. It also simplifies process termination,
since the session can automatically call ExecutorProcessControl::disconnect
(previously this had to be done manually, and carefully ordered with the
rest of JIT tear-down to work correctly).
Adds support for MachO static initializers/deinitializers and eh-frame
registration via the ORC runtime.
This commit introduces cooperative support code into the ORC runtime and ORC
LLVM libraries (especially the MachOPlatform class) to support macho runtime
features for JIT'd code. This commit introduces support for static
initializers, static destructors (via cxa_atexit interposition), and eh-frame
registration. Near-future commits will add support for MachO native
thread-local variables, and language runtime registration (e.g. for Objective-C
and Swift).
The llvm-jitlink tool is updated to use the ORC runtime where available, and
regression tests for the new MachOPlatform support are added to compiler-rt.
Notable changes on the ORC runtime side:
1. The new macho_platform.h / macho_platform.cpp files contain the bulk of the
runtime-side support. This includes eh-frame registration; jit versions of
dlopen, dlsym, and dlclose; a cxa_atexit interpose to record static destructors,
and an '__orc_rt_macho_run_program' function that defines running a JIT'd MachO
program in terms of the jit- dlopen/dlsym/dlclose functions.
2. Replaces JITTargetAddress (and casting operations) with ExecutorAddress
(copied from LLVM) to improve type-safety of address management.
3. Adds serialization support for ExecutorAddress and unordered_map types to
the runtime-side Simple Packed Serialization code.
4. Adds orc-runtime regression tests to ensure that static initializers and
cxa-atexit interposes work as expected.
Notable changes on the LLVM side:
1. The MachOPlatform class is updated to:
1.1. Load the ORC runtime into the ExecutionSession.
1.2. Set up standard aliases for macho-specific runtime functions. E.g.
___cxa_atexit -> ___orc_rt_macho_cxa_atexit.
1.3. Install the MachOPlatformPlugin to scrape LinkGraphs for information
needed to support MachO features (e.g. eh-frames, mod-inits), and
communicate this information to the runtime.
1.4. Provide entry-points that the runtime can call to request initializers,
perform symbol lookup, and request deinitialiers (the latter is
implemented as an empty placeholder as macho object deinits are rarely
used).
1.5. Create a MachO header object for each JITDylib (defining the __mh_header
and __dso_handle symbols).
2. The llvm-jitlink tool (and llvm-jitlink-executor) are updated to use the
runtime when available.
3. A `lookupInitSymbolsAsync` method is added to the Platform base class. This
can be used to issue an async lookup for initializer symbols. The existing
`lookupInitSymbols` method is retained (the GenericIRPlatform code is still
using it), but is deprecated and will be removed soon.
4. JIT-dispatch support code is added to ExecutorProcessControl.
The JIT-dispatch system allows handlers in the JIT process to be associated with
'tag' symbols in the executor, and allows the executor to make remote procedure
calls back to the JIT process (via __orc_rt_jit_dispatch) using those tags.
The primary use case is ORC runtime code that needs to call bakc to handlers in
orc::Platform subclasses. E.g. __orc_rt_macho_jit_dlopen calling back to
MachOPlatform::rt_getInitializers using __orc_rt_macho_get_initializers_tag.
(The system is generic however, and could be used by non-runtime code).
The new ExecutorProcessControl::JITDispatchInfo struct provides the address
(in the executor) of the jit-dispatch function and a jit-dispatch context
object, and implementations of the dispatch function are added to
SelfExecutorProcessControl and OrcRPCExecutorProcessControl.
5. OrcRPCTPCServer is updated to support JIT-dispatch calls over ORC-RPC.
6. Serialization support for StringMap is added to the LLVM-side Simple Packed
Serialization code.
7. A JITLink::allocateBuffer operation is introduced to allocate writable memory
attached to the graph. This is used by the MachO header synthesis code, and will
be generically useful for other clients who want to create new graph content
from scratch.
This is a first step towards consistently using the term 'executor' for the
process that executes JIT'd code. I've opted for 'executor' as the preferred
term over 'target' as target is already heavily overloaded ("the target
machine for the executor" is much clearer than "the target machine for the
target").
Moves all headers from Orc/RPC to Orc/Shared, and from the llvm::orc::rpc
namespace into llvm::orc::shared. Also renames RPCTypeName to
SerializationTypeName and Function to RPCFunction.
In addition to being a more reasonable home for this code, this will make it
easier for the upcoming Orc runtime to re-use the Serialization system for
creating and parsing wrapper-function binary blobs.
implementation.
This patch aims to improve support for out-of-process JITing using OrcV2. It
introduces two new class templates, OrcRPCTargetProcessControlBase and
OrcRPCTPCServer, which together implement the TargetProcessControl API by
forwarding operations to an execution process via an Orc-RPC Endpoint. These
utilities are used to implement out-of-process JITing from llvm-jitlink to
a new llvm-jitlink-executor tool.
This patch also breaks the OrcJIT library into three parts:
-- OrcTargetProcess: Contains code needed by the JIT execution process.
-- OrcShared: Contains code needed by the JIT execution and compiler
processes
-- OrcJIT: Everything else.
This break-up allows JIT executor processes to link against OrcTargetProcess
and OrcShared only, without having to link in all of OrcJIT. Clients executing
JIT'd code in-process should start linking against OrcTargetProcess as well as
OrcJIT.
In the near future these changes will enable:
-- Removal of the OrcRemoteTargetClient/OrcRemoteTargetServer class templates
which provided similar functionality in OrcV1.
-- Restoration of Chapter 5 of the Building-A-JIT tutorial series, which will
serve as a simple usage example for these APIs.
-- Implementation of lazy, cross-target compilation in lli's -jit-kind=orc-lazy
mode.
This patch introduces new APIs to support resource tracking and removal in Orc.
It is intended as a thread-safe generalization of the removeModule concept from
OrcV1.
Clients can now create ResourceTracker objects (using
JITDylib::createResourceTracker) to track resources for each MaterializationUnit
(code, data, aliases, absolute symbols, etc.) added to the JIT. Every
MaterializationUnit will be associated with a ResourceTracker, and
ResourceTrackers can be re-used for multiple MaterializationUnits. Each JITDylib
has a default ResourceTracker that will be used for MaterializationUnits added
to that JITDylib if no ResourceTracker is explicitly specified.
Two operations can be performed on ResourceTrackers: transferTo and remove. The
transferTo operation transfers tracking of the resources to a different
ResourceTracker object, allowing ResourceTrackers to be merged to reduce
administrative overhead (the source tracker is invalidated in the process). The
remove operation removes all resources associated with a ResourceTracker,
including any symbols defined by MaterializationUnits associated with the
tracker, and also invalidates the tracker. These operations are thread safe, and
should work regardless of the the state of the MaterializationUnits. In the case
of resource transfer any existing resources associated with the source tracker
will be transferred to the destination tracker, and all future resources for
those units will be automatically associated with the destination tracker. In
the case of resource removal all already-allocated resources will be
deallocated, any if any program representations associated with the tracker have
not been compiled yet they will be destroyed. If any program representations are
currently being compiled then they will be prevented from completing: their
MaterializationResponsibility will return errors on any attempt to update the
JIT state.
Clients (usually Layer writers) wishing to track resources can implement the
ResourceManager API to receive notifications when ResourceTrackers are
transferred or removed. The MaterializationResponsibility::withResourceKeyDo
method can be used to create associations between the key for a ResourceTracker
and an allocated resource in a thread-safe way.
RTDyldObjectLinkingLayer and ObjectLinkingLayer are updated to use the
ResourceManager API to enable tracking and removal of memory allocated by the
JIT linker.
The new JITDylib::clear method can be used to trigger removal of every
ResourceTracker associated with the JITDylib (note that this will only
remove resources for the JITDylib, it does not run static destructors).
This patch includes unit tests showing basic usage. A follow-up patch will
update the Kaleidoscope and BuildingAJIT tutorial series to OrcV2 and will
use this API to release code associated with anonymous expressions.
This prevents weak symbols from being immediately dead-stripped when not
directly referenced from the test harneess, enabling use of weak symbols
from the code under test.
