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.
LinkGraph::splitBlock will split a block at a given index, returning a new
block covering the range [ 0, index ) and modifying the original block to
cover the range [ index, original-block-size ). Block addresses, content,
edges and symbols will be updated as necessary. This utility will be used
in upcoming improvements to JITLink's eh-frame support.
Summary:
When createing an ORC remote JIT target the current library split forces the target process to link large portions of LLVM (Core, Execution Engine, JITLink, Object, MC, Passes, RuntimeDyld, Support, Target, and TransformUtils). This occurs because the ORC RPC interfaces rely on the static globals the ORC Error types require, which starts a cycle of pulling in more and more.
This patch breaks the ORC RPC Error implementations out into an "OrcError" library which only depends on LLVM Support. It also pulls the ORC RPC headers into their own subdirectory.
With this patch code can include the Orc/RPC/*.h headers and will only incur link dependencies on LLVMOrcError and LLVMSupport.
Reviewers: lhames
Reviewed By: lhames
Subscribers: mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68732
MipsMCAsmInfo was using '$' prefix for Mips32 and '.L' for Mips64
regardless of -target-abi option. By passing MCTargetOptions to MCAsmInfo
we can find out Mips ABI and pick appropriate prefix.
Tags: #llvm, #clang, #lldb
Differential Revision: https://reviews.llvm.org/D66795
In the Atom model the symbols, content and relocations of a relocatable object
file are represented as a graph of atoms, where each Atom represents a
contiguous block of content with a single name (or no name at all if the
content is anonymous), and where edges between Atoms represent relocations.
If more than one symbol is associated with a contiguous block of content then
the content is broken into multiple atoms and layout constraints (represented by
edges) are introduced to ensure that the content remains effectively contiguous.
These layout constraints must be kept in mind when examining the content
associated with a symbol (it may be spread over multiple atoms) or when applying
certain relocation types (e.g. MachO subtractors).
This patch replaces the Atom model in JITLink with a blocks-and-symbols model.
The blocks-and-symbols model represents relocatable object files as bipartite
graphs, with one set of nodes representing contiguous content (Blocks) and
another representing named or anonymous locations (Symbols) within a Block.
Relocations are represented as edges from Blocks to Symbols. This scheme
removes layout constraints (simplifying handling of MachO alt-entry symbols,
and hopefully ELF sections at some point in the future) and simplifies some
relocation logic.
llvm-svn: 373689
ORC-RPC batches calls by default, and the channel's send method must be called
to transfer any buffered calls to the remote. The call to send was missing on
responses and blocking calls in the SingleThreadedRPCEndpoint. This patch adds
the necessary calls and modifies the RPC unit test to check for them.
llvm-svn: 371245
In r369808 the failure scheme for ORC symbols was changed to make
MaterializationResponsibility objects responsible for failing the symbols
they represented. This simplifies error logic in the case where symbols are
still covered by a MaterializationResponsibility, but left a gap in error
handling: Symbols that have been emitted but are not yet ready (due to a
dependence on some unemitted symbol) are not covered by a
MaterializationResponsibility object. Under the scheme introduced in r369808
such symbols would be moved to the error state, but queries on those symbols
were never notified. This led to deadlocks when such symbols were failed.
This commit updates error logic to immediately fail queries on any symbol that
has already been emitted if one of its dependencies fails.
llvm-svn: 369976
Symbols that have not been queried will not have MaterializingInfo entries,
so remove the assert that all failed symbols should have these entries.
Also updates the loop to only remove entries that were found earlier.
llvm-svn: 369975
If the dependencies are not removed then a late failure (one symbol covered by
the query failing after others have already been resolved) can result in an
attempt to detach the query from already finalized symbol, resulting in an
assert/crash. This patch fixes the issue by removing query dependencies in
JITDylib::resolve for symbols that meet the required state.
llvm-svn: 369809
When symbols are failed (via MaterializationResponsibility::failMaterialization)
any symbols depending on them will now be moved to an error state. Attempting
to resolve or emit a symbol in the error state (via the notifyResolved or
notifyEmitted methods on MaterializationResponsibility) will result in an error.
If notifyResolved or notifyEmitted return an error due to failure of a
dependence then the caller should log or discard the error and call
failMaterialization to propagate the failure to any queries waiting on the
symbols being resolved/emitted (plus their dependencies).
llvm-svn: 369808
Summary:
rL367756 (f5c40cb) increases the dependency of LLVMOrcJIT on LLVMPasses.
In particular, symbols defined in LLVMPasses that are referenced by the
destructor of `PassBuilder` are now referenced by LLVMOrcJIT through
`Speculation.cpp.o`.
We believe that referencing symbols defined in LLVMPasses in the
destructor of `PassBuilder` is valid, and that adding to the set of such
symbols is legitimate. To support such cases, this patch adds LLVMPasses
to the set of libraries being linked when linking in LLVMOrcJIT causes
such symbols from LLVMPasses to be referenced.
Reviewers: Whitney, anhtuyen, pree-jackie
Reviewed By: pree-jackie
Subscribers: mgorny, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66441
llvm-svn: 369310
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
llvm-svn: 369013
This patch replaces the JITDylib::DefinitionGenerator typedef with a class of
the same name, and adds support for attaching a sequence of DefinitionGeneration
objects to a JITDylib.
This patch also adds a new definition generator,
StaticLibraryDefinitionGenerator, that can be used to add symbols fom a static
library to a JITDylib. An object from the static library will be added (via
a supplied ObjectLayer reference) whenever a symbol from that object is
referenced.
To enable testing, lli is updated to add support for the --extra-archive option
when running in -jit-kind=orc-lazy mode.
llvm-svn: 368707
ThreadSafeModule/ThreadSafeContext are used to manage lifetimes and locking
for LLVMContexts in ORCv2. Prior to this patch contexts were locked as soon
as an associated Module was emitted (to be compiled and linked), and were not
unlocked until the emit call returned. This could lead to deadlocks if
interdependent modules that shared contexts were compiled on different threads:
when, during emission of the first module, the dependence was discovered the
second module (which would provide the required symbol) could not be emitted as
the thread emitting the first module still held the lock.
This patch eliminates this possibility by moving to a finer-grained locking
scheme. Each client holds the module lock only while they are actively operating
on it. To make this finer grained locking simpler/safer to implement this patch
removes the explicit lock method, 'getContextLock', from ThreadSafeModule and
replaces it with a new method, 'withModuleDo', that implicitly locks the context,
calls a user-supplied function object to operate on the Module, then implicitly
unlocks the context before returning the result.
ThreadSafeModule TSM = getModule(...);
size_t NumFunctions = TSM.withModuleDo(
[](Module &M) { // <- context locked before entry to lambda.
return M.size();
});
Existing ORCv2 layers that operate on ThreadSafeModules are updated to use the
new method.
This method is used to introduce Module locking into each of the existing
layers.
llvm-svn: 367686
Summary:
ORCv1 is deprecated. The current aim is to remove it before the LLVM 10.0
release. This patch adds deprecation attributes to the ORCv1 layers and
utilities to warn clients of the change.
Reviewers: dblaikie, sgraenitz, AlexDenisov
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64609
llvm-svn: 366344
notifyResolved/notifyEmitted.
The 'notify' prefix better describes what these methods do: they update the JIT
symbol states and notify any pending queries that the 'resolved' and 'emitted'
states have been reached (rather than actually performing the resolution or
emission themselves). Since new states are going to be introduced in the near
future (to track symbol registration/initialization) it's worth changing the
convention pre-emptively to avoid further confusion.
llvm-svn: 363322
rather than two callbacks.
The asynchronous lookup API (which the synchronous lookup API wraps for
convenience) used to take two callbacks: OnResolved (called once all requested
symbols had an address assigned) and OnReady to be called once all requested
symbols were safe to access). This patch updates the asynchronous lookup API to
take a single 'OnComplete' callback and a required state (SymbolState) to
determine when the callback should be made. This simplifies the common use case
(where the client is interested in a specific state) and will generalize neatly
as new states are introduced to track runtime initialization of symbols.
Clients who were making use of both callbacks in a single query will now need to
issue two queries (one for SymbolState::Resolved and another for
SymbolState::Ready). Synchronous lookup API clients who were explicitly passing
the WaitOnReady argument will now need neeed to pass a SymbolState instead (for
'WaitOnReady == true' use SymbolState::Ready, for 'WaitOnReady == false' use
SymbolState::Resolved). Synchronous lookup API clients who were using default
arugment values should see no change.
llvm-svn: 362832
Lang Hames