This is a counterpart to ffe2dda29f, and does for scope what that commit did
for linkage.
Making the scope of external definitions visible to JITLink plugins will
allow us to distinguish hidden weak defs (which do not need to be tracked by
default) from default-scoped weak defs (which need to be updated to point at
a single chosen definition at runtime).
Previously we stripped Weak flags from JITDylib symbol table entries once they
were resolved (there was no particularly good reason for this). Now we want to
retain them and query them when setting the Linkage on external symbols in
LinkGraphs during symbol resolution (this was the motivation for 75404e9ef8).
Making weak linkage of external definitions discoverable in the LinkGraph will
in turn allow future plugins to implement correct handling for them (by
recording locations that depend on exported weak definitions and pointing all
of these at one chosen definition at runtime).
Introduces two new methods on Symbol: isWeaklyReferenced and
setWeaklyReferenced. These are now used to track/set whether an external symbol
is weakly referenced, rather than having the Symbol's linkage set to weak.
This change is a first step towards proper handling of weak defs used across
JITDylib boundaries: It frees up the Linkage field on external symbols so that
it can be used to represent the linkage of the definition that the symbol resolves
to. It is expected that Platform plugins will use this information to track
locations that need to be updated if the selected weak definition changes (e.g.
because JITDylibs were dlclosed and then dlopened again in a different order).
If we want to be able to close and then re-open a library then we need to reset
the data section states when the library is closed. This commit updates
MachOPlatform and the ORC runtime to track __data and __common sections, and
reset the state in MachOPlatformRuntimeState::dlcloseDeinitialize.
This is only a first step to full support -- there are other data sections that
we're not capturing, and we'll probably want a more efficient representation
for the sections (rather than passing their string name over IPC), but this is
a reasonable first step.
This commit also contains a fix to MapperJITLinkMemoryManager that prevents it
from calling OnDeallocated twice in the case of an error.
I'm planning to deprecate and eventually remove llvm::empty.
I thought about replacing llvm::empty(x) with std::empty(x), but it
turns out that all uses can be converted to x.empty(). That is, no
use requires the ability of std::empty to accept C arrays and
std::initializer_list.
Differential Revision: https://reviews.llvm.org/D133677
Removes public bootstrap method that is not really necessary and not consistent with other platform API.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D132780
Supports dynamic VC runtime. It implements atexits handling which is required to load msvcrt.lib successfully. (the object file containing atexit symbol somehow resolves to static vc runtim symbols) It also default to dynamic vc runtime which tends to be more robust.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D132525
This updates the ExecutorSharedMemoryMapperService::deinitialize and
InProcessMemoryMapper::deinitialize methods to deinitialize in reverse order,
bringing them into alignment with the behavior of
InProcessMemoryManager::deallocate and SimpleExecutorMemoryManager::deallocate.
Reverse deinitialization is required because later allocations can depend on
earlier ones.
This fixes failures in the ORC runtime test suite.
SharedMemoryMapper assumed each reservation will have its corresponding
allocations starting from the beginning. However with the introduction
of the slab allocator, there can be a possible offset from the start
from where the initialization is being performed.
This commit also simplifies the logic for finding the parent reservation
and makes the assert messages consistent.
When deinitializing, the allocation needs to be removed from the
allocation list of its associated reservation so that remaining
allocations can be deinitialized when releasing the reservation.
Differential Revision: https://reviews.llvm.org/D132313
When slab allocator is used, the MappingBase is not necessarily
the same as the original reservation base as the allocation could
be a part of the whole reservation.
In this case the original reservation address needs to be passed to
ExecutorSharedMemoryMapperService to associate the new allocation
with the original reservation.
Differential Revision: https://reviews.llvm.org/D132313
By the time SharedMemoryMapper destructor is called, the RPC
connection is no longer available causing the release() call to
always fail. Instead at this point only shared memory regions
can be unmapped safely.
Deinitializers are called and mapped memory is released at the
executor side by ExecutorSharedMemoryMapperService::shutdown()
instead. Memory can also be released earlier by calling release()
earlier before RPC connection is closed.
Differential Revision: https://reviews.llvm.org/D132313
The callback function was captured by reference but it lived on the
stack and was in danger of being overwritten and could cause a crash.
Differential Revision: https://reviews.llvm.org/D132313
Commit 9189a26664 caused llvm-jitlink to create bare JITDylibs to wrap real
dylibs loaded via -preload. This exposed a bug in MachOPlatform where we
assumed that all JITDylibs had been registered with the platform through
MachOPlatform::setupJITDylib (bare JITDylibs are _not_ run through this
function), and errored out where this was not the case.
This bug in MachOPlatform was causing test failures in compilert-rt:
Failed Tests (2):
ORC-x86_64-darwin :: TestCases/Darwin/x86-64/trivial-objc-methods.S
ORC-x86_64-darwin :: TestCases/Darwin/x86-64/trivial-swift-types-section.S
This commit fixes the issue by skipping JITDylibs that haven't been registered
with the platform via MachOPlatform::setupJITDylib.
This patch updates MachOLinkGraphBuilder to honor the MH_SUBSECTIONS_VIA_SYMBOLS
flag. Prior to this patch we assumed MH_SUBSECTIONS_VIA_SYMBOLS, but never
checked the flag.
If MH_SUBSECTIONS_VIA_SYMBOLS is set (the default for MachO output on modern
compilers) then MachOLinkGraphBuilder will break MachO section content into
jitlink::Blocks on symbol boundaries. (This is how JITLink has always handled
MachO sections previously).
If MH_SUBSECTIONS_VIA_SYMBOLS is not set then MachOLinkGraphBuilder will create
a single jitlink::Block for each MachO section.
Existing hand-written testcases that were _not_ using the
.subsections_via_symbols directive are updated to use it. A new testcase for
non-subsections-via-symbols behavior is included.
I (lhames) accidentally pushed 5f300397c6 on
Kshitij Jain's behalf without updating the patch author first (my apologies
Kshitij!).
Re-applying with correct authorship.
https://reviews.llvm.org/D131347
This class will be used to properly solve the `__imp_` symbol and jump-thunk generation issues. It is assumed to be the last definition generator to be called, and as it's the last generator the only symbols remaining in the lookup set are the symbols that are supposed to be queried outside this jitdylib. Instead of just letting them through, we issue another lookup invocation and fetch the allocated addresses, and then create jitlink graph containing `__imp_` GOT symbols and jump-thunks targetting the fetched addresses.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D131833
Add a fix to check that FDE pc-begin targets are defined before calling
getBlock (which will crash if the target is not defined). FDE pc-begins
pointing at undefined symbols are expected to arise only in obscure
circumstances (malformed objects, or removal of targets by JITLink
passes), but we want to handle them gracefully. With this patch the
FDE will be retained, but without any keepalive edge to it. Unless
some pass takes action to mark it as live it will be dead-stripped.
To make it easier for passes to connect FDEs to their targets a new
EHFrameCFIBlockInspector utility is added. This allows clients to
quickly determine whether a CFI record is a CIE or an FDE (assuming
that it's valid), and retrieve any personality, pc-begin, cie, or
LSDA edges associated with it.
MapperJITLinkMemoryManager uses a free list to keep track of available
memory regions. Using an IntervalMap instead of vector allow automatic
coalescing of memory regions as they are freed.
Differential Revision: https://reviews.llvm.org/D131831
When memory is deallocated from MapperJITLinkMemoryManager deinitialize
actions are run through mapper and in case of InProcessMapper, memory
protections of the region are reset to read/write as they were previously
changed and can be reused in future.
Differential Revision: https://reviews.llvm.org/D131768
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
When memory is deallocated from MapperJITLinkMemoryManager deinitialize
actions are run through mapper and in case of InProcessMapper, memory
protections of the region are reset to read/write as they were previously
changed and can be reused in future.
Differential Revision: https://reviews.llvm.org/D131768
Introduces COFFVCRuntimeBootstrapper that loads/initialize vc runtime libraries. In COFF, we *must* jit-link vc runtime libraries as COFF relocation types have no proper way to deal with out-of-reach data symbols ragardless of linking mode. (even dynamic version msvcrt.lib have tons of static data symbols that must be jit-linked) This class tries to load vc runtime library files from msvc installations with an option to override the path.
There are some complications when dealing with static version of vc runtimes. First, they need static initializers to be ran that requires COFFPlatform support but orc runtime will not be usable before vc runtimes are fully initialized. (as orc runtime will use msvc stl libraries) COFFPlatform that will be introduced in a following up patch will collect static initializers and run them manually in host before boostrapping itself. So, the user will have to do the following.
1. Create COFFPlatform that addes static initializer collecting passes.
2. LoadVCRuntime
3. InitializeVCRuntime
4. COFFPlatform.bootstrap()
Second, the internal crt initialization function had to be reimplemented in orc side. There are other ways of doing this, but this is the simplest implementation that makes platform fully responsible for static initializer. The complication comes from the fact that crt initialization functions (such as acrt_initialize or dllmain_crt_process_attach) actually run all static initializers by traversing from `__xi_a` symbol to `__xi_z`. This requires symbols to be contiguously allocated in sections alphabetically sorted in memory, which is not possible right now and not practical in jit setting. We might ignore emission of `__xi_a` and `__xi_z` symbol and allocate them ourselves, but we have to take extra care after orc runtime boostrap has been done -- as that point orc runtime should be the one running the static initializers.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D130456
Stubs SECREL relocation to external symbol. In order to correctly deal with this, we want to requrest memory manager to keep track of address of first block of sepecific section and keep address to be only increased from that point. We also should give jitlink to get information about global section. The relocation is only used for debug and tls info which we don't support yet anyways, so just stubbing it for now.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D130451
Implements SECTION/SECREL relocation. These are used by debug info (pdb) data.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D130275
Calling reserve() used to require an RPC call. This commit allows large
ranges of executor address space to be reserved. Subsequent calls to
reserve() will return subranges of already reserved address space while
there is still space available.
Differential Revision: https://reviews.llvm.org/D130392
This reverts commit 6ea5bf436a.
6ea5bf436a made use of new c++17 rules regarding
order of evaluation (specifically: in function calls the expression naming the
function should be sequenced before the evalution of any operands) to simplify
some continuation-passing calls. Unfortunately this appears to break at least
one MSVC bot: https://lab.llvm.org/buildbot/#/builders/123/builds/12149 .
Includes an update to the comments to note that the workaround is now based on
MSVC limitations, not on LLVM adopting c++17.
Lang Hames