Stefan Gränitz via llvm-dev
2021-Jan-18 13:49 UTC
[llvm-dev] LLVM Orc Weekly #28 -- ORC Runtime Prototype update
Wow, thanks for the update. One more ORC milestone in a short period of
time!
On macOS I built the C++ example like this:
% cmake -GNinja -DLLVM_TARGETS_TO_BUILD=host
-DLLVM_ENABLE_PROJECTS="clang;compiler-rt" ../llvm
% ninja llvm-jitlink llvm-jitlink-executor
lib/clang/12.0.0/lib/darwin/libclang_rt.orc_osx.a
% clang++ -c -o inits.o inits.cpp
The in-process version works perfectly, but with the out-of-process flag
the examples fails:
% ./bin/llvm-jitlink inits.o
Foo::Foo()
Foo::foo()
Foo::~Foo()
% ./bin/llvm-jitlink -oop-executor inits.o
JIT session error: Symbols not found: [
__ZTIN4llvm6detail14format_adapterE ]
Any idea what could go wrong here? Otherwise I can try to debug it later
this week. (Full error below.)
Best
Stefan
--
JIT session error: Symbols not found: [
__ZTIN4llvm6detail14format_adapterE ]
/Users/staefsn/Develop/LLVM/monorepo/llvm-orc-runtime/build/bin/llvm-jitlink:
Failed to materialize symbols: { (Main, {
___orc_rt_macho_symbol_lookup_remote,
__ZN4llvm3orc6shared21WrapperFunctionResult22destroyWithArrayDeleteE39LLVMOrcSharedCWrapperFunctionResultDatay,
__ZNSt3__113__vector_baseIN4llvm3orc6shared25MachOJITDylibInitializersENS_9allocatorIS4_EEED2Ev,
__ZNK4llvm8ExpectedINS_3orc6shared21WrapperFunctionResultEE22fatalUncheckedExpectedEv,
__ZN4llvm3orc6shared21toWrapperFunctionBlobIJNSt3__112basic_stringIcNS3_11char_traitsIcEENS3_9allocatorIcEEEEEEENS1_21WrapperFunctionResultEDpRKT_,
__ZN4llvm3orc6shared20VectorRawByteChannelD1Ev,
__ZN4llvm3orc6shared21SequenceSerializationINS1_20VectorRawByteChannelEJNSt3__16vectorINS1_25MachOJITDylibInitializers13SectionExtentENS4_9allocatorIS7_EEEESA_SA_EE11deserializeISA_JSA_SA_EEENS_5ErrorERS3_RT_DpRT0_,
__ZNSt3__16vectorIN4llvm3orc6shared25MachOJITDylibInitializers13SectionExtentENS_9allocatorIS5_EEE8__appendEm,
__ZN4llvm3orc6shared21toWrapperFunctionBlobIJyNSt3__112basic_stringIcNS3_11char_traitsIcEENS3_9allocatorIcEEEEEEENS1_21WrapperFunctionResultEDpRKT_,
__ZN4llvm29VerifyEnableABIBreakingChecksE,
__ZN4llvm15format_providerImvE6formatERKmRNS_11raw_ostreamENS_9StringRefE,
__ZNSt3__114__split_bufferIN4llvm3orc6shared25MachOJITDylibInitializersERNS_9allocatorIS4_EEED2Ev,
__ZTVN4llvm6detail23provider_format_adapterIRmEE,
__ZN4llvm3orc6shared21SequenceSerializationINS1_20VectorRawByteChannelEJyNSt3__112basic_stringIcNS4_11char_traitsIcEENS4_9allocatorIcEEEEEE9serializeIRKyJRKSA_EEENS_5ErrorERS3_OT_DpOT0_,
__ZTVN4llvm6detail23provider_format_adapterImEE,
__ZN4llvm6detail23provider_format_adapterImE6formatERNS_11raw_ostreamENS_9StringRefE,
__ZN4llvm6detail23provider_format_adapterIRmED1Ev,
___orc_rt_macho_get_deinitializers_tag,
__ZN4llvm6detail23provider_format_adapterIRmED0Ev,
__ZTVN4llvm3orc6shared14RawByteChannelE,
__ZN6orc_rt12jit_dispatchEPKvN4llvm8ArrayRefIhEE,
__ZN4llvm3orc6shared20VectorRawByteChannelD0Ev,
__ZTVN4llvm3orc6shared20VectorRawByteChannelE,
__ZN4llvm8cantFailENS_5ErrorEPKc,
__ZN4llvm6detail23provider_format_adapterImED1Ev,
__ZTVN4llvm6detail23provider_format_adapterIRjEE,
__ZN4llvm6detail23provider_format_adapterImED0Ev,
__ZN4llvm15format_providerIjvE6formatERKjRNS_11raw_ostreamENS_9StringRefE,
__ZTSN4llvm3orc6shared14RawByteChannelE,
__ZN4llvm6detail23provider_format_adapterIRjE6formatERNS_11raw_ostreamENS_9StringRefE,
__ZN4llvm6detail23provider_format_adapterIRjED0Ev,
__ZN4llvm3orc6shared19SerializationTraitsINS1_20VectorRawByteChannelENSt3__16vectorINS1_25MachOJITDylibInitializersENS4_9allocatorIS6_EEEES9_vE11deserializeERS3_RS9_,
__ZTIN4llvm6detail23provider_format_adapterImEE,
__ZN4llvm6detail15HelperFunctions15consumeHexStyleERNS_9StringRefERNS_13HexPrintStyleE,
__ZTIN4llvm6detail23provider_format_adapterIRmEE,
___orc_rt_macho_get_initializers_tag,
__ZTSN4llvm6detail23provider_format_adapterImEE,
__ZN4llvm3orc6shared20VectorRawByteChannel4sendEv,
__ZN4llvm6detail23provider_format_adapterIRmE6formatERNS_11raw_ostreamENS_9StringRefE,
___orc_rt_macho_symbol_lookup_tag,
__ZTSN4llvm6detail23provider_format_adapterIRmEE,
__ZN4llvm3orc6shared20VectorRawByteChannel11appendBytesEPKcj,
__ZTSN4llvm6detail23provider_format_adapterIRjEE,
__ZN4llvm3orc6shared20VectorRawByteChannel9readBytesEPcj,
__ZTSN4llvm3orc6shared20VectorRawByteChannelE,
__ZN4llvm6detail23provider_format_adapterIRjED1Ev,
__ZN4llvm3orc6shared14RawByteChannelD1Ev,
__ZN4llvm3orc6shared23fromWrapperFunctionBlobIJNSt3__16vectorINS1_25MachOJITDylibInitializersENS3_9allocatorIS5_EEEEEEENS_5ErrorENS_8ArrayRefIhEEDpRT_,
__ZN4llvm3orc6shared14RawByteChannelD0Ev,
__ZN4llvm3orc6shared21SequenceSerializationINS1_20VectorRawByteChannelEJyyNSt3__16vectorINS1_25MachOJITDylibInitializers13SectionExtentENS4_9allocatorIS7_EEEESA_SA_EE11deserializeIyJySA_SA_SA_EEENS_5ErrorERS3_RT_DpRT0_,
__ZNSt3__16vectorIN4llvm3orc6shared25MachOJITDylibInitializersENS_9allocatorIS4_EEE8__appendEm,
__ZN4llvm3orc6shared21SequenceSerializationINS1_20VectorRawByteChannelEJyyEE11deserializeIyJyEEENS_5ErrorERS3_RT_DpRT0_,
__ZNSt3__16vectorIN4llvm3orc6shared25MachOJITDylibInitializersENS_9allocatorIS4_EEE6resizeEm,
__ZN4llvm3orc6shared19SerializationTraitsINS1_20VectorRawByteChannelENSt3__112basic_stringIcNS4_11char_traitsIcEENS4_9allocatorIcEEEESA_vE11deserializeERNS1_14RawByteChannelERSA_,
__ZN4llvm3orc6shared23fromWrapperFunctionBlobIJyEEENS_5ErrorENS_8ArrayRefIhEEDpRT_,
__ZTIN4llvm6detail23provider_format_adapterIRjEE,
__ZN4llvm3orc6shared21WrapperFunctionResult20getAnyOutOfBandErrorEv,
__ZTIN4llvm3orc6shared20VectorRawByteChannelE,
___orc_rt_macho_get_initializers_remote,
__ZTIN4llvm3orc6shared14RawByteChannelE,
__ZNSt3__16vectorIhNS_9allocatorIhEEE26__swap_out_circular_bufferERNS_14__split_bufferIhRS2_EE,
__ZN4llvm3orc6shared19SerializationTraitsINS1_20VectorRawByteChannelENSt3__16vectorINS1_25MachOJITDylibInitializers13SectionExtentENS4_9allocatorIS7_EEEESA_vE11deserializeERS3_RSA_
}) }
/Users/staefsn/Develop/LLVM/monorepo/llvm-orc-runtime/build/bin/llvm-jitlink-executor:Response
has unknown sequence number 527162
On 18/01/2021 08:55, Lang Hames wrote:> Hi All,
>
> Happy 2021!
>
> I've just posted a new Orc Runtime Preview patch:
>
https://github.com/lhames/llvm-project/commit/8833a7f24693f1c7a3616438718e7927c6624894
>
<https://github.com/lhames/llvm-project/commit/8833a7f24693f1c7a3616438718e7927c6624894>
>
> Quick background:
>
> To date, neither ORC nor MCJIT have had their own runtime libraries.
> This has limited and complicated the implementation of many features
> (e.g. jit re-entry functions, exception handling, JID'd initializers
> and de-initializers), and more-or-less prevented the implementation of
> others (e.g. native thread local storage).
>
> Late last year I started work on a prototype ORC runtime library to
> address this, and with the above commit I've finally got something
> worth sharing.
>
> The prototype above is simultaneously limited and complex. Limited, in
> that it only tackles a small subset of the desired functionality.
> Complex in that it's one of the most involved pieces of functionality
> that I anticipate supporting, as it requires two-way communication
> between the executor and JIT processes. My aim in choosing to tackle
> the hard part first was to get a sense of our ultimate requirements
> for the project, particularly in regards to /where it should live
> within the LLVM Project/. It's not a perfect fit for LLVM proper:
> there will be lots of target specific code, including assembly, and it
> should be easily buildable for multiple targets (that sounds more like
> compiler-rt). On the other hand it's not a perfect fit for
> compiler-rt: it shares data structures with LLVM, and it would be very
> useful to be able to re-use llvm::Error / llvm::Expected (that sounds
> like LLVM). At the moment I think the best way to square things would
> be to keep it in compiler-rt, allow inclusion of header-only code from
> LLVM in compiler-rt, and then make Error / Expected header-only (or
> copy / adapt them for this library). This will be a discussion for
> llvm-dev at some point in the near future.
>
> On to the actual functionality though: The prototype makes significant
> changes to the MachOPlatform class and introduces an ORC runtime
> library in compiler-rt/lib/orc. Together, these changes allow us to
> emulate the dlopen / dlsym / dlclose in the JIT executor process. We
> can use this to define what it means to run a /JIT program/, rather
> than just running a JIT function (the way
> TargetProcessControl::runAsMain does):
>
> ORC_RT_INTERFACE int64_t __orc_rt_macho_run_program(int argc, char *argv[])
> {
> using MainTy = int (*)(int, char *[]);
>
> void *H = __orc_rt_macho_jit_dlopen("Main", ORC_RT_RTLD_LAZY);
> if (!H) {
> __orc_rt_log_error(__orc_rt_macho_jit_dlerror());
> return -1;
> }
>
>
auto *Main = reinterpret_cast<MainTy>(__orc_rt_macho_jit_dlsym(H, "main"));
> if (!Main) {
> __orc_rt_log_error(__orc_rt_macho_jit_dlerror());
> return -1;
> }
>
> int Result = Main(argc, argv);
>
> if (__orc_rt_macho_jit_dlclose(H) == -1)
> __orc_rt_log_error(__orc_rt_macho_jit_dlerror());
>
> return Result;
> }
>
> The functions __orc_rt_macho_jit_dlopen, __orc_rt_macho_jit_dlsym,
> and __orc_rt_macho_jit_dlclose behave the same as their dlfcn.h
> counterparts (dlopen, dlsym, dlclose), but operate on JITDylibs rather
> than regular dylibs. This includes running static initializers and
> registering with language runtimes (e.g. ObjC).
>
> While we could run static initializers before (e.g. via
> LLJIT::runConstructors), we had to initiate this from the JIT process
> side, which has two significant drawbacks: (1) Extra RPC round trips,
> and (2) in the out-of-process case: initializers not running on the
> executor thread that requested them, since that thread will be blocked
> waiting for its call to return. Issue (1) only affects performance,
> but (2) can affect correctness if the initializers modify thread local
> values, or interact with locks or threads. Interacting with threads
> from initializers is generally best avoided, but nonetheless is done
> by real-world code, so we want to support it. By using the runtime we
> can improve both performance and correctness (or at least consistency
> with current behavior).
>
> The effect of this is that we can now load C++, Objective-C and Swift
> programs in the JIT and expect them to run correctly, at least for
> simple cases. This works regardless of whether the JIT'd code runs
> in-process or out-of-process. To test all this I have integrated
> support for the prototype runtime into llvm-jitlink. You can demo
> output from this tool below for two simple input programs: One swift,
> one C++. All of this is MachO specific at the moment, but provides a
> template that could be easily re-used to support this on ELF
> platforms, and likely on COFF platforms too.
>
> While the discussion on where the runtime should live plays out I will
> continue adding / moving functionality to the prototype runtime. Next
> up will be eh-frame registration and resolver functions (both
> currently in OrcTargetProcess). After that I'll try to tackle support
> for native MachO thread local storage.
>
> As always: Questions and comments are very welcome.
>
> -- Lang.
>
> lhames at Langs-MacBook-Pro scratch % cat foo.swift
> class MyClass {
> func foo() {
> print("foo")
> }
> }
>
> let m = MyClass()
> m.foo();
>
> lhames at Langs-MacBook-Pro scratch % xcrun swiftc -emit-object -o foo.o
> foo.swift
> lhames at Langs-MacBook-Pro scratch % llvm-jitlink -dlopen
> /usr/lib/swift/libswiftCore.dylib foo.o
> foo
> lhames at Langs-MacBook-Pro scratch % llvm-jitlink -oop-executor -dlopen
> /usr/lib/swift/libswiftCore.dylib foo.o
> foo
> lhames at Langs-MacBook-Pro scratch % cat inits.cpp
> #include <iostream>
>
> class Foo {
> public:
> Foo() { std::cout << "Foo::Foo()\n"; }
> ~Foo() { std::cout << "Foo::~Foo()\n"; }
> void foo() { std::cout << "Foo::foo()\n"; }
> };
>
> Foo F;
>
> int main(int argc, char *argv[]) {
> F.foo();
> return 0;
> }
> lhames at Langs-MacBook-Pro scratch % xcrun clang++ -c -o inits.o inits.cpp
> lhames at Langs-MacBook-Pro scratch % llvm-jitlink inits.o
>
> Foo::Foo()
> Foo::foo()
> Foo::~Foo()
> lhames at Langs-MacBook-Pro scratch % llvm-jitlink -oop-executor inits.o
> Foo::Foo()
> Foo::foo()
> Foo::~Foo()
--
https://flowcrypt.com/pub/stefan.graenitz at gmail.com
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Lang Hames via llvm-dev
2021-Jan-18 21:45 UTC
[llvm-dev] LLVM Orc Weekly #28 -- ORC Runtime Prototype update
Hi Stefan, % ./bin/llvm-jitlink -oop-executor inits.o> JIT session error: Symbols not found: [ > __ZTIN4llvm6detail14format_adapterE ]I've been testing with a debug build: % xcrun cmake -GNinja -DCMAKE_BUILD_TYPE=Debug -DLLVM_ENABLE_PROJECTS="llvm;clang;compiler-rt" ../llvm Matching this build might fix the issue, though building with my config (if it works) is only a short-term fix. The error that you're seeing implies that the runtime is dependending on a symbol from libSupport that is not being linked in to the target (llvm-jitlink-executor). I'll aim to break these dependencies on libSupport in the future. Mostly that means either removing the dependence on llvm::Error / llvm::Expected (e.g. by creating stripped down versions for the orc runtime), or making those types header-only. -- Lang. On Tue, Jan 19, 2021 at 12:50 AM Stefan Gränitz <stefan.graenitz at gmail.com> wrote:> Wow, thanks for the update. One more ORC milestone in a short period of > time! > > On macOS I built the C++ example like this: > > % cmake -GNinja -DLLVM_TARGETS_TO_BUILD=host > -DLLVM_ENABLE_PROJECTS="clang;compiler-rt" ../llvm > % ninja llvm-jitlink llvm-jitlink-executor > lib/clang/12.0.0/lib/darwin/libclang_rt.orc_osx.a > % clang++ -c -o inits.o inits.cpp > > The in-process version works perfectly, but with the out-of-process flag > the examples fails: > > % ./bin/llvm-jitlink inits.o > Foo::Foo() > Foo::foo() > Foo::~Foo() > % ./bin/llvm-jitlink -oop-executor inits.o > JIT session error: Symbols not found: [ > __ZTIN4llvm6detail14format_adapterE ] > > Any idea what could go wrong here? Otherwise I can try to debug it later > this week. (Full error below.) > > Best > Stefan > > -- > > JIT session error: Symbols not found: [ > __ZTIN4llvm6detail14format_adapterE ] > /Users/staefsn/Develop/LLVM/monorepo/llvm-orc-runtime/build/bin/llvm-jitlink: > Failed to materialize symbols: { (Main, { > ___orc_rt_macho_symbol_lookup_remote, > __ZN4llvm3orc6shared21WrapperFunctionResult22destroyWithArrayDeleteE39LLVMOrcSharedCWrapperFunctionResultDatay, > __ZNSt3__113__vector_baseIN4llvm3orc6shared25MachOJITDylibInitializersENS_9allocatorIS4_EEED2Ev, > __ZNK4llvm8ExpectedINS_3orc6shared21WrapperFunctionResultEE22fatalUncheckedExpectedEv, > __ZN4llvm3orc6shared21toWrapperFunctionBlobIJNSt3__112basic_stringIcNS3_11char_traitsIcEENS3_9allocatorIcEEEEEEENS1_21WrapperFunctionResultEDpRKT_, > __ZN4llvm3orc6shared20VectorRawByteChannelD1Ev, > __ZN4llvm3orc6shared21SequenceSerializationINS1_20VectorRawByteChannelEJNSt3__16vectorINS1_25MachOJITDylibInitializers13SectionExtentENS4_9allocatorIS7_EEEESA_SA_EE11deserializeISA_JSA_SA_EEENS_5ErrorERS3_RT_DpRT0_, > __ZNSt3__16vectorIN4llvm3orc6shared25MachOJITDylibInitializers13SectionExtentENS_9allocatorIS5_EEE8__appendEm, > __ZN4llvm3orc6shared21toWrapperFunctionBlobIJyNSt3__112basic_stringIcNS3_11char_traitsIcEENS3_9allocatorIcEEEEEEENS1_21WrapperFunctionResultEDpRKT_, > __ZN4llvm29VerifyEnableABIBreakingChecksE, > __ZN4llvm15format_providerImvE6formatERKmRNS_11raw_ostreamENS_9StringRefE, > __ZNSt3__114__split_bufferIN4llvm3orc6shared25MachOJITDylibInitializersERNS_9allocatorIS4_EEED2Ev, > __ZTVN4llvm6detail23provider_format_adapterIRmEE, > __ZN4llvm3orc6shared21SequenceSerializationINS1_20VectorRawByteChannelEJyNSt3__112basic_stringIcNS4_11char_traitsIcEENS4_9allocatorIcEEEEEE9serializeIRKyJRKSA_EEENS_5ErrorERS3_OT_DpOT0_, > __ZTVN4llvm6detail23provider_format_adapterImEE, > __ZN4llvm6detail23provider_format_adapterImE6formatERNS_11raw_ostreamENS_9StringRefE, > __ZN4llvm6detail23provider_format_adapterIRmED1Ev, > ___orc_rt_macho_get_deinitializers_tag, > __ZN4llvm6detail23provider_format_adapterIRmED0Ev, > __ZTVN4llvm3orc6shared14RawByteChannelE, > __ZN6orc_rt12jit_dispatchEPKvN4llvm8ArrayRefIhEE, > __ZN4llvm3orc6shared20VectorRawByteChannelD0Ev, > __ZTVN4llvm3orc6shared20VectorRawByteChannelE, > __ZN4llvm8cantFailENS_5ErrorEPKc, > __ZN4llvm6detail23provider_format_adapterImED1Ev, > __ZTVN4llvm6detail23provider_format_adapterIRjEE, > __ZN4llvm6detail23provider_format_adapterImED0Ev, > __ZN4llvm15format_providerIjvE6formatERKjRNS_11raw_ostreamENS_9StringRefE, > __ZTSN4llvm3orc6shared14RawByteChannelE, > __ZN4llvm6detail23provider_format_adapterIRjE6formatERNS_11raw_ostreamENS_9StringRefE, > __ZN4llvm6detail23provider_format_adapterIRjED0Ev, > __ZN4llvm3orc6shared19SerializationTraitsINS1_20VectorRawByteChannelENSt3__16vectorINS1_25MachOJITDylibInitializersENS4_9allocatorIS6_EEEES9_vE11deserializeERS3_RS9_, > __ZTIN4llvm6detail23provider_format_adapterImEE, > __ZN4llvm6detail15HelperFunctions15consumeHexStyleERNS_9StringRefERNS_13HexPrintStyleE, > __ZTIN4llvm6detail23provider_format_adapterIRmEE, > ___orc_rt_macho_get_initializers_tag, > __ZTSN4llvm6detail23provider_format_adapterImEE, > __ZN4llvm3orc6shared20VectorRawByteChannel4sendEv, > __ZN4llvm6detail23provider_format_adapterIRmE6formatERNS_11raw_ostreamENS_9StringRefE, > ___orc_rt_macho_symbol_lookup_tag, > __ZTSN4llvm6detail23provider_format_adapterIRmEE, > __ZN4llvm3orc6shared20VectorRawByteChannel11appendBytesEPKcj, > __ZTSN4llvm6detail23provider_format_adapterIRjEE, > __ZN4llvm3orc6shared20VectorRawByteChannel9readBytesEPcj, > __ZTSN4llvm3orc6shared20VectorRawByteChannelE, > __ZN4llvm6detail23provider_format_adapterIRjED1Ev, > __ZN4llvm3orc6shared14RawByteChannelD1Ev, > __ZN4llvm3orc6shared23fromWrapperFunctionBlobIJNSt3__16vectorINS1_25MachOJITDylibInitializersENS3_9allocatorIS5_EEEEEEENS_5ErrorENS_8ArrayRefIhEEDpRT_, > __ZN4llvm3orc6shared14RawByteChannelD0Ev, > __ZN4llvm3orc6shared21SequenceSerializationINS1_20VectorRawByteChannelEJyyNSt3__16vectorINS1_25MachOJITDylibInitializers13SectionExtentENS4_9allocatorIS7_EEEESA_SA_EE11deserializeIyJySA_SA_SA_EEENS_5ErrorERS3_RT_DpRT0_, > __ZNSt3__16vectorIN4llvm3orc6shared25MachOJITDylibInitializersENS_9allocatorIS4_EEE8__appendEm, > __ZN4llvm3orc6shared21SequenceSerializationINS1_20VectorRawByteChannelEJyyEE11deserializeIyJyEEENS_5ErrorERS3_RT_DpRT0_, > __ZNSt3__16vectorIN4llvm3orc6shared25MachOJITDylibInitializersENS_9allocatorIS4_EEE6resizeEm, > __ZN4llvm3orc6shared19SerializationTraitsINS1_20VectorRawByteChannelENSt3__112basic_stringIcNS4_11char_traitsIcEENS4_9allocatorIcEEEESA_vE11deserializeERNS1_14RawByteChannelERSA_, > __ZN4llvm3orc6shared23fromWrapperFunctionBlobIJyEEENS_5ErrorENS_8ArrayRefIhEEDpRT_, > __ZTIN4llvm6detail23provider_format_adapterIRjEE, > __ZN4llvm3orc6shared21WrapperFunctionResult20getAnyOutOfBandErrorEv, > __ZTIN4llvm3orc6shared20VectorRawByteChannelE, > ___orc_rt_macho_get_initializers_remote, > __ZTIN4llvm3orc6shared14RawByteChannelE, > __ZNSt3__16vectorIhNS_9allocatorIhEEE26__swap_out_circular_bufferERNS_14__split_bufferIhRS2_EE, > __ZN4llvm3orc6shared19SerializationTraitsINS1_20VectorRawByteChannelENSt3__16vectorINS1_25MachOJITDylibInitializers13SectionExtentENS4_9allocatorIS7_EEEESA_vE11deserializeERS3_RSA_ > }) } > /Users/staefsn/Develop/LLVM/monorepo/llvm-orc-runtime/build/bin/llvm-jitlink-executor:Response > has unknown sequence number 527162 > > On 18/01/2021 08:55, Lang Hames wrote: > > Hi All, > > Happy 2021! > > I've just posted a new Orc Runtime Preview patch: > https://github.com/lhames/llvm-project/commit/8833a7f24693f1c7a3616438718e7927c6624894 > > Quick background: > > To date, neither ORC nor MCJIT have had their own runtime libraries. This > has limited and complicated the implementation of many features (e.g. jit > re-entry functions, exception handling, JID'd initializers and > de-initializers), and more-or-less prevented the implementation of others > (e.g. native thread local storage). > > Late last year I started work on a prototype ORC runtime library to > address this, and with the above commit I've finally got something worth > sharing. > > The prototype above is simultaneously limited and complex. Limited, in > that it only tackles a small subset of the desired functionality. Complex > in that it's one of the most involved pieces of functionality that I > anticipate supporting, as it requires two-way communication between the > executor and JIT processes. My aim in choosing to tackle the hard part > first was to get a sense of our ultimate requirements for the project, > particularly in regards to *where it should live within the LLVM Project*. > It's not a perfect fit for LLVM proper: there will be lots of target > specific code, including assembly, and it should be easily buildable for > multiple targets (that sounds more like compiler-rt). On the other hand > it's not a perfect fit for compiler-rt: it shares data structures with > LLVM, and it would be very useful to be able to re-use llvm::Error / > llvm::Expected (that sounds like LLVM). At the moment I think the best way > to square things would be to keep it in compiler-rt, allow inclusion of > header-only code from LLVM in compiler-rt, and then make Error / Expected > header-only (or copy / adapt them for this library). This will be a > discussion for llvm-dev at some point in the near future. > > On to the actual functionality though: The prototype makes significant > changes to the MachOPlatform class and introduces an ORC runtime library in > compiler-rt/lib/orc. Together, these changes allow us to emulate the dlopen > / dlsym / dlclose in the JIT executor process. We can use this to define > what it means to run a *JIT program*, rather than just running a JIT > function (the way TargetProcessControl::runAsMain does): > > ORC_RT_INTERFACE int64_t __orc_rt_macho_run_program(int argc, char *argv[]) > { > using MainTy = int (*)(int, char *[]); > > void *H = __orc_rt_macho_jit_dlopen("Main", ORC_RT_RTLD_LAZY); > if (!H) { > __orc_rt_log_error(__orc_rt_macho_jit_dlerror()); > return -1; > } > > auto *Main = reinterpret_cast<MainTy>(__orc_rt_macho_jit_dlsym(H, "main" > )); > if (!Main) { > __orc_rt_log_error(__orc_rt_macho_jit_dlerror()); > return -1; > } > > int Result = Main(argc, argv); > > if (__orc_rt_macho_jit_dlclose(H) == -1) > __orc_rt_log_error(__orc_rt_macho_jit_dlerror()); > > return Result; > } > > The functions __orc_rt_macho_jit_dlopen, __orc_rt_macho_jit_dlsym, > and __orc_rt_macho_jit_dlclose behave the same as their dlfcn.h > counterparts (dlopen, dlsym, dlclose), but operate on JITDylibs rather than > regular dylibs. This includes running static initializers and registering > with language runtimes (e.g. ObjC). > > While we could run static initializers before (e.g. via > LLJIT::runConstructors), we had to initiate this from the JIT process side, > which has two significant drawbacks: (1) Extra RPC round trips, and (2) in > the out-of-process case: initializers not running on the executor thread > that requested them, since that thread will be blocked waiting for its call > to return. Issue (1) only affects performance, but (2) can affect > correctness if the initializers modify thread local values, or interact > with locks or threads. Interacting with threads from initializers is > generally best avoided, but nonetheless is done by real-world code, so we > want to support it. By using the runtime we can improve both performance > and correctness (or at least consistency with current behavior). > > The effect of this is that we can now load C++, Objective-C and Swift > programs in the JIT and expect them to run correctly, at least for simple > cases. This works regardless of whether the JIT'd code runs in-process or > out-of-process. To test all this I have integrated support for the > prototype runtime into llvm-jitlink. You can demo output from this tool > below for two simple input programs: One swift, one C++. All of this is > MachO specific at the moment, but provides a template that could be easily > re-used to support this on ELF platforms, and likely on COFF platforms too. > > While the discussion on where the runtime should live plays out I will > continue adding / moving functionality to the prototype runtime. Next up > will be eh-frame registration and resolver functions (both currently in > OrcTargetProcess). After that I'll try to tackle support for native MachO > thread local storage. > > As always: Questions and comments are very welcome. > > -- Lang. > > lhames at Langs-MacBook-Pro scratch % cat foo.swift > class MyClass { > func foo() { > print("foo") > } > } > > let m = MyClass() > m.foo(); > > lhames at Langs-MacBook-Pro scratch % xcrun swiftc -emit-object -o foo.o > foo.swift > lhames at Langs-MacBook-Pro scratch % llvm-jitlink -dlopen > /usr/lib/swift/libswiftCore.dylib foo.o > foo > lhames at Langs-MacBook-Pro scratch % llvm-jitlink -oop-executor -dlopen > /usr/lib/swift/libswiftCore.dylib foo.o > foo > lhames at Langs-MacBook-Pro scratch % cat inits.cpp > #include <iostream> > > class Foo { > public: > Foo() { std::cout << "Foo::Foo()\n"; } > ~Foo() { std::cout << "Foo::~Foo()\n"; } > void foo() { std::cout << "Foo::foo()\n"; } > }; > > Foo F; > > int main(int argc, char *argv[]) { > F.foo(); > return 0; > } > lhames at Langs-MacBook-Pro scratch % xcrun clang++ -c -o inits.o inits.cpp > lhames at Langs-MacBook-Pro scratch % llvm-jitlink inits.o > > Foo::Foo() > Foo::foo() > Foo::~Foo() > lhames at Langs-MacBook-Pro scratch % llvm-jitlink -oop-executor inits.o > Foo::Foo() > Foo::foo() > Foo::~Foo() > > -- https://flowcrypt.com/pub/stefan.graenitz at gmail.com > >-------------- next part -------------- An HTML attachment was scrubbed... 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