This reapplies 8740360093b, which was reverted in bbddadd46e4 due to buildbot
errors.
This version checks that a JIT instance can be safely constructed, skipping
tests if it can not be. To enable this it introduces new C API to retrieve and
set the target triple for a JITTargetMachineBuilder.
Adds utilities for creating anonymous pointers and jump stubs to x86_64.h. These
are used by the GOT and Stubs builder, but may also be used by pass writers who
want to create pointer stubs for indirection.
This patch also switches the underlying type for LinkGraph content from
StringRef to ArrayRef<char>. This avoids any confusion when working with buffers
that contain null bytes in the middle like, for example, a newly added null
pointer content array. ;)
Unreachable code should be self-documented as unreachable.
Found by the Rotten Green Tests project.
Differential Revision: https://reviews.llvm.org/D98518
This patch introduces generic x86-64 edge kinds, and refactors the MachO/x86-64
backend to use these edge kinds. This simplifies the implementation of the
MachO/x86-64 backend and makes it possible to write generic x86-64 passes and
utilities.
The new edge kinds are different from the original set used in the MachO/x86-64
backend. Several edge kinds that were not meaningfully distinguished in that
backend (e.g. the PCRelMinusN edges) have been merged into single edge kinds in
the new scheme (these edge kinds can be reintroduced later if we find a use for
them). At the same time, new edge kinds have been introduced to convey extra
information about the state of the graph. E.g. The Request*AndTransformTo**
edges represent GOT/TLVP relocations prior to synthesis of the GOT/TLVP
entries, and the 'Relaxable' suffix distinguishes edges that are candidates for
optimization from edges which should be left as-is (e.g. to enable runtime
redirection).
ELF/x86-64 will be refactored to use these generic edges at some point in the
future, and I anticipate a similar refactor to create a generic arm64 support
header too.
Differential Revision: https://reviews.llvm.org/D98305
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.
Separates link graph creation from linking. This allows raw LinkGraphs to be
created and passed to a link. ObjectLinkingLayer is updated to support emission
of raw LinkGraphs in addition to object buffers.
Raw LinkGraphs can be created by in-memory compilers to bypass object encoding /
decoding (though this prevents caching, as LinkGraphs have do not have an
on-disk representation), and by utility code to add programatically generated
data structures to the JIT target process.
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 moves definition generation out from the session lock, instead
running it under a per-dylib generator lock. It also makes the
DefinitionGenerator::tryToGenerate method optionally asynchronous: Generators
are handed an opaque LookupState object which can be captured to stop/restart
the lookup process.
The new scheme provides the following benefits and guarantees:
(1) Queries that do not need to attempt definition generation (because all
requested symbols matched against existing definitions in the JITDylib)
can proceed without being blocked by any running definition generators.
(2) Definition generators can capture the LookupState to continue their work
asynchronously. This allows generators to run for an arbitrary amount of
time without blocking a thread. Definition generators that do not need to
run asynchronously can return without capturing the LookupState to eliminate
unnecessary recursion and improve lookup performance.
(3) Definition generators still do not need to worry about concurrency or
re-entrance: Since they are still run under a (per-dylib) lock, generators
will never be re-entered concurrently, or given overlapping symbol sets to
generate.
Finally, the new system distinguishes between symbols that are candidates for
generation (generation candidates) and symbols that failed to match for a query
(due to symbol visibility). This fixes a bug where an unresolved symbol could
trigger generation of a duplicate definition for an existing hidden symbol.
MSVC doesn't seem to like capturing references to variables in lambdas passed to
the variable's constructor. This should fix the windows bots that have been
unable to build the new ResourceTracker unit test.
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 removes all legacy layers, legacy utilities, the old Orc C bindings,
OrcMCJITReplacement, and OrcMCJITReplacement regression tests.
ExecutionEngine and MCJIT are not affected by this change.
Making MaterializationResponsibility instances immovable allows their
associated VModuleKeys to be updated by the ExecutionSession while the
responsibility is still in-flight. This will be used in the upcoming
removable code feature to enable safe merging of resource keys even if
there are active compiles using the keys being merged.
DFS and Reverse-DFS linkage orders are used to order execution of
deinitializers and initializers respectively.
This patch replaces uses of special purpose DFS order functions in
MachOPlatform and LLJIT with uses of the new methods.
As discussed in
http://lists.llvm.org/pipermail/llvm-dev/2020-July/143801.html.
Currently no users outside of unit tests.
Replace all instances in tests of -constprop with -instsimplify.
Notable changes in tests:
* vscale.ll - @llvm.sadd.sat.nxv16i8 is evaluated by instsimplify, use a fake intrinsic instead
* InsertElement.ll - insertelement undef is removed by instsimplify in @insertelement_undef
llvm/test/Transforms/ConstProp moved to llvm/test/Transforms/InstSimplify/ConstProp
Reviewed By: lattner, nikic
Differential Revision: https://reviews.llvm.org/D85159
MaterializationResponsibility.
MaterializationResponsibility objects provide a connection between a
materialization process (compiler, jit linker, etc.) and the JIT state held in
the ExecutionSession and JITDylib objects. Switching to shared ownership
extends the lifetime of JITDylibs to ensure they remain accessible until all
materializers targeting them have completed. This will allow (in a follow-up
patch) JITDylibs to be removed from the ExecutionSession and placed in a
pending-destruction state while they are kept alive to communicate errors
to/from any still-runnning materialization processes. The intent is to enable
JITDylibs to be safely removed even if they have running compiles targeting
them.
Summary:
Currently the XCOFF backend does not support writing 64-bit object
files, which the ORC JIT tests will try to exercise if we are on AIX. This patch
selectively disables the tests on AIX for now.
Reviewers: hubert.reinterpretcast, jasonliu, DiggerLin, stevewan, lhames
Reviewed By: hubert.reinterpretcast, lhames
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78813
Ensure that symbols explicitly* assigned a section name are placed into
a section with a compatible entry size.
This is done by creating multiple sections with the same name** if
incompatible symbols are explicitly given the name of an incompatible
section, whilst:
- Avoiding using uniqued sections where possible (for readability and
to maximize compatibly with assemblers).
- Creating as few SHF_MERGE sections as possible (for efficiency).
Given that each symbol is assigned to a section in a single pass, we
must decide which section each symbol is assigned to without seeing the
properties of all symbols. A stable and easy to understand assignment is
desirable. The following rules facilitate this: The "generic" section
for a given section name will be mergeable if the name is a mergeable
"default" section name (such as .debug_str), a mergeable "implicit"
section name (such as .rodata.str2.2), or MC has already created a
mergeable "generic" section for the given section name (e.g. in response
to a section directive in inline assembly). Otherwise, the "generic"
section for a given name is non-mergeable; and, non-mergeable symbols
are assigned to the "generic" section, while mergeable symbols are
assigned to uniqued sections.
Terminology:
"default" sections are those always created by MC initially, e.g. .text
or .debug_str.
"implicit" sections are those created normally by MC in response to the
symbols that it encounters, i.e. in the absence of an explicit section
name assignment on the symbol, e.g. a function foo might be placed into
a .text.foo section.
"generic" sections are those that are referred to when a unique section
ID is not supplied, e.g. if there are multiple unique .bob sections then
".quad .bob" will reference the generic .bob section. Typically, the
generic section is just the first section of a given name to be created.
Default sections are always generic.
* Typically, section names might be explicitly assigned in source code
using a language extension e.g. a section attribute: _attribute_
((section ("section-name"))) -
https://clang.llvm.org/docs/AttributeReference.html
** I refer to such sections as unique/uniqued sections. In assembly the
", unique," assembly syntax is used to express such sections.
Fixes https://bugs.llvm.org/show_bug.cgi?id=43457.
See https://reviews.llvm.org/D68101 for previous discussions leading to
this patch.
Some minor fixes were required to LLVM's tests, for tests had been using
the old behavior - which allowed for explicitly assigning globals with
incompatible entry sizes to a section.
This fix relies on the ",unique ," assembly feature. This feature is not
available until bintuils version 2.35
(https://sourceware.org/bugzilla/show_bug.cgi?id=25380). If the
integrated assembler is not being used then we avoid using this feature
for compatibility and instead try to place mergeable symbols into
non-mergeable sections or issue an error otherwise.
Differential Revision: https://reviews.llvm.org/D72194
This flag can be used to mark a symbol as existing only for the purpose of
enabling materialization. Such a symbol can be looked up to trigger
materialization with the lookup returning only once materialization is
complete. Symbols with this flag will never resolve however (to avoid
permanently polluting the symbol table), and should only be looked up using
the SymbolLookupFlags::WeaklyReferencedSymbol flag. The primary use case for
this flag is initialization symbols.
Initializers and deinitializers are used to implement C++ static constructors
and destructors, runtime registration for some languages (e.g. with the
Objective-C runtime for Objective-C/C++ code) and other tasks that would
typically be performed when a shared-object/dylib is loaded or unloaded by a
statically compiled program.
MCJIT and ORC have historically provided limited support for discovering and
running initializers/deinitializers by scanning the llvm.global_ctors and
llvm.global_dtors variables and recording the functions to be run. This approach
suffers from several drawbacks: (1) It only works for IR inputs, not for object
files (including cached JIT'd objects). (2) It only works for initializers
described by llvm.global_ctors and llvm.global_dtors, however not all
initializers are described in this way (Objective-C, for example, describes
initializers via specially named metadata sections). (3) To make the
initializer/deinitializer functions described by llvm.global_ctors and
llvm.global_dtors searchable they must be promoted to extern linkage, polluting
the JIT symbol table (extra care must be taken to ensure this promotion does
not result in symbol name clashes).
This patch introduces several interdependent changes to ORCv2 to support the
construction of new initialization schemes, and includes an implementation of a
backwards-compatible llvm.global_ctor/llvm.global_dtor scanning scheme, and a
MachO specific scheme that handles Objective-C runtime registration (if the
Objective-C runtime is available) enabling execution of LLVM IR compiled from
Objective-C and Swift.
The major changes included in this patch are:
(1) The MaterializationUnit and MaterializationResponsibility classes are
extended to describe an optional "initializer" symbol for the module (see the
getInitializerSymbol method on each class). The presence or absence of this
symbol indicates whether the module contains any initializers or
deinitializers. The initializer symbol otherwise behaves like any other:
searching for it triggers materialization.
(2) A new Platform interface is introduced in llvm/ExecutionEngine/Orc/Core.h
which provides the following callback interface:
- Error setupJITDylib(JITDylib &JD): Can be used to install standard symbols
in JITDylibs upon creation. E.g. __dso_handle.
- Error notifyAdding(JITDylib &JD, const MaterializationUnit &MU): Generally
used to record initializer symbols.
- Error notifyRemoving(JITDylib &JD, VModuleKey K): Used to notify a platform
that a module is being removed.
Platform implementations can use these callbacks to track outstanding
initializers and implement a platform-specific approach for executing them. For
example, the MachOPlatform installs a plugin in the JIT linker to scan for both
__mod_inits sections (for C++ static constructors) and ObjC metadata sections.
If discovered, these are processed in the usual platform order: Objective-C
registration is carried out first, then static initializers are executed,
ensuring that calls to Objective-C from static initializers will be safe.
This patch updates LLJIT to use the new scheme for initialization. Two
LLJIT::PlatformSupport classes are implemented: A GenericIR platform and a MachO
platform. The GenericIR platform implements a modified version of the previous
llvm.global-ctor scraping scheme to provide support for Windows and
Linux. LLJIT's MachO platform uses the MachOPlatform class to provide MachO
specific initialization as described above.
Reviewers: sgraenitz, dblaikie
Subscribers: mgorny, hiraditya, mgrang, ributzka, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74300
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
This commit adds a ManglingOptions struct to IRMaterializationUnit, and replaces
IRCompileLayer::CompileFunction with a new IRCompileLayer::IRCompiler class. The
ManglingOptions struct defines the emulated-TLS state (via a bool member,
EmulatedTLS, which is true if emulated-TLS is enabled and false otherwise). The
IRCompileLayer::IRCompiler class wraps an IRCompiler (the same way that the
CompileFunction typedef used to), but adds a method to return the
IRCompileLayer::ManglingOptions that the compiler will use.
These changes allow us to correctly determine the symbols that will be produced
when a thread local global variable defined at the IR level is compiled with or
without emulated TLS. This is required for ORCv2, where MaterializationUnits
must declare their interface up-front.
Most ORCv2 clients should not require any changes. Clients writing custom IR
compilers will need to wrap their compiler in an IRCompileLayer::IRCompiler,
rather than an IRCompileLayer::CompileFunction, however this should be a
straightforward change (see modifications to CompileUtils.* in this patch for an
example).
A bug in the existing implementation meant that lazyReexports would not work if
the aliased name differed from the alias's name, i.e. all lazy reexports had to
be of the form (lib1, name) -> (lib2, name). This patch fixes the issue by
capturing the alias's name in the NotifyResolved callback. To simplify this
capture, and the LazyCallThroughManager code in general, the NotifyResolved
callback is updated to use llvm::unique_function rather than a custom class.
No test case yet: This can only be tested at runtime, and the only in-tree
client (lli) always uses aliases with matching names. I will add a new LLJIT
example shortly that will directly test the lazyReexports API and the
non-trivial alias use case.
A warning is sent because `std::distance()` returns a signed type so
`CmpHelperEQ()` gets instantiated into a function that compares
differently signed arguments.
Differential Revision: https://reviews.llvm.org/D72632
libraries.
This patch substantially updates ORCv2's lookup API in order to support weak
references, and to better support static archives. Key changes:
-- Each symbol being looked for is now associated with a SymbolLookupFlags
value. If the associated value is SymbolLookupFlags::RequiredSymbol then
the symbol must be defined in one of the JITDylibs being searched (or be
able to be generated in one of these JITDylibs via an attached definition
generator) or the lookup will fail with an error. If the associated value is
SymbolLookupFlags::WeaklyReferencedSymbol then the symbol is permitted to be
undefined, in which case it will simply not appear in the resulting
SymbolMap if the rest of the lookup succeeds.
Since lookup now requires these flags for each symbol, the lookup method now
takes an instance of a new SymbolLookupSet type rather than a SymbolNameSet.
SymbolLookupSet is a vector-backed set of (name, flags) pairs. Clients are
responsible for ensuring that the set property (i.e. unique elements) holds,
though this is usually simple and SymbolLookupSet provides convenience
methods to support this.
-- Lookups now have an associated LookupKind value, which is either
LookupKind::Static or LookupKind::DLSym. Definition generators can inspect
the lookup kind when determining whether or not to generate new definitions.
The StaticLibraryDefinitionGenerator is updated to only pull in new objects
from the archive if the lookup kind is Static. This allows lookup to be
re-used to emulate dlsym for JIT'd symbols without pulling in new objects
from archives (which would not happen in a normal dlsym call).
-- JITLink is updated to allow externals to be assigned weak linkage, and
weak externals now use the SymbolLookupFlags::WeaklyReferencedSymbol value
for lookups. Unresolved weak references will be assigned the default value of
zero.
Since this patch was modifying the lookup API anyway, it alo replaces all of the
"MatchNonExported" boolean arguments with a "JITDylibLookupFlags" enum for
readability. If a JITDylib's associated value is
JITDylibLookupFlags::MatchExportedSymbolsOnly then the lookup will only
match against exported (non-hidden) symbols in that JITDylib. If a JITDylib's
associated value is JITDylibLookupFlags::MatchAllSymbols then the lookup will
match against any symbol defined in the JITDylib.
