<div dir="ltr"><div dir="ltr">Hi Bjoern,<div><br></div><div>If you had the removable code feature could you merge your LLJIT instances and just have one instance with multiple JITDylibs? That will make your life *much* easier. Interdependencies between modules in different ExecutionSessions are dangerous: Dependencies are not tracked, and it will be easy for everything to look as if it's working, but fail with thread scheduling bugs. E.g. Thread 1 assigns an address to Symbol 1 but yields before setting the memory permissions. Thread 2 is scheduled and sees that Symbol 1 has been resolved, so proceeds to link Symbol 2 against it, set Symbol 2's memory permissions, then jump to it. The program will crash when execution of JIT'd code reaches symbol 1. </div><div><br></div><div>To be clear: Cross JIT references are ok as long as the dependencies form a DAG. If there are any cycles then you're in trouble.</div><div><br></div><div>I'd strongly recommend switching to one LLJIT instance and using removable JITDylibs to solve this.</div><div><br></div><div>If you want to continue with multiple LLJIT instances my comments/recommendations would be:</div><div> (1) Don't use error handling to track the unresolved symbols -- there are places in ORC where we only report the first missing symbol rather than all of them.</div><div> (2) You shouldn't issue a call to ExecutionSession::lookup from inside tryToGenerate: The tryToGenerate method is called under the session lock, but ExecutionSession::lookup should only be called outside the lock. Instead of issuing the lookup in place you should write a custom MaterializationUnit and issue the lookup from its materialize method.</div><div><br></div><div>-- Lang.</div><div><br></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Sep 23, 2020 at 1:02 AM Gaier, Bjoern <<a href="mailto:Bjoern.Gaier@horiba.com">Bjoern.Gaier@horiba.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">
<div lang="DE">
<div class="gmail-m_-6628531847645158004WordSection1">
<p class="MsoNormal"><span lang="EN-GB">Hi Lang,<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Thank you for your answer! This helped me again a lot!! Also that ResourceTracker is a really neat feature! Looking forward to it! :3<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">I changed the title cause… there is another issue I have (sorry about that…)<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">I’m finally allowed to investigate the ORC JIT for integration into our system, which meant I got a few days to actually play around with it. However, another problem arise which breaks
my concept. It is the never ending story of “cross references”. I have again two Modules, which are added to two different LLJIT instances, but they are referencing each other. In the past you suggested me to use the LookUp function of the ExecutionSession
to get the addresses – so I wrote this:<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">bool</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">ModuleLoader</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> :: resolve()<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">{<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">auto</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> &ES =
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">this</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">->jit</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:teal">-></span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">getExecutionSession();<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">SymbolLookupSet</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> lookupSet;<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">this</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">->undefinedReferences.clear();<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">for</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">(</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">const</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">auto</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> &element :
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">this</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">->symbolsOfInterrest)<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> {<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> lookupSet.add(<a href="http://element.second.name" target="_blank">element.second.name</a>,llvm::orc::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">SymbolLookupFlags</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:darkslategray">WeaklyReferencedSymbol</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">);<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> }
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue"><u></u><u></u></span></p>
<p class="MsoNormal" style="text-indent:35.4pt"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">auto</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
result = ES.lookup({{&jit</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:teal">-></span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">getMainJITDylib(),
llvm::orc::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">JITDylibLookupFlags</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:darkslategray">MatchAllSymbols</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">}},
lookupSet, llvm::orc::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">LookupKind</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:darkslategray">Static</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">,
llvm::orc::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">SymbolState</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:darkslategray">Resolved</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">);<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">if</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">(result)<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> {<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">for</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">(</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">const</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">auto</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> &element :
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:teal">*</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">result)<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> {<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">const</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> llvm::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">StringRef</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
&name = (</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:teal">*</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">element.first);<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">const</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">size_t</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> hash = calculateHash(name);<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> printf(</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(163,21,21)">">>>%s
@ 0x%p\n"</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">, name.data(), element.second.getAddress());<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">this</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">->symbolsOfInterrest</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:teal">[</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">hash</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:teal">]</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">.adr
= element.second.getAddress();<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> }<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> }<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">else</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> {<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> ES.reportError(result.takeError());<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> }<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">this</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">->mtx.unlock();<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">return</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> (</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">this</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">->undefinedReferences.size()
== 0ull);<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">}</span><span lang="EN-GB"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">I also attached a reporter to the ES which will handle “</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">llvm::orc::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">SymbolsNotFound</span><span lang="EN-GB">”
by copying SymbolVector to the “undefinedReferences”. If I call this function and have every symbol resolved, then I can use the addresses to actually execute them. That is great! However, when I have an undefined Reference, things get strange… The first call
will trigger my “tryToGenerate” function but it will not be able to resolve a certain symbol. The reporter will be triggered and the “undefinedReferences” SymbolVector will have size 1.<br>
When I call the function a second time however, the “tryToGenerate” function will not be called anymore, so my vector will be empty, the undefined reference is still not resolved, but I return with a true and crash my program. So even if I would have an address
for that one symbol in the second run, I would have no chance to tell “anyone” cause the “tryToGenerate” function was never called… Said function looks like that though:<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">llvm::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">Error</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">ReferenceManager</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">UndefinedReferenceResolver</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
:: tryToGenerate(llvm::orc::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">LookupKind</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:gray">K</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">, llvm::orc::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">JITDylib</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
&</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:gray">JD</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">, llvm::orc::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">JITDylibLookupFlags</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:gray">JDLookupFlags</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">,
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">const</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> llvm::orc::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">SymbolLookupSet</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
&</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:gray">LookupSet</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">)<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">{<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> llvm::orc::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">SymbolNameVector</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
notFound;<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> llvm::orc::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">SymbolMap</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
NewSymbols;<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">for</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">(</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">const</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">auto</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> &name :
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:gray">LookupSet</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">)<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> {<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> printf(</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(163,21,21)">"Generate!\n"</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">);<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">const</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">uintptr_t</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> adr =
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">UndefinedReferenceResolver</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">::lookup((</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:teal">*</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">name.first).data());<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">if</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">(adr)
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> {<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> NewSymbols</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:teal">[</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">name.first</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:teal">]</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:teal">=</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> llvm::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">JITEvaluatedSymbol</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">(adr,
llvm::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">JITSymbolFlags</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:darkslategray">Absolute</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">);<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> }<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">else</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> {<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> notFound.push_back(name.first);<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> }<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> }<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:gray">JD</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">.define(absoluteSymbols(std::move(NewSymbols)));
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">
</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:blue">return</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black"> (notFound.size() == 0) ? llvm::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">Error</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">::success()
: llvm::make_error<llvm::orc::</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:rgb(43,145,175)">SymbolsNotFound</span><span lang="EN-GB" style="font-size:9.5pt;font-family:Consolas;color:black">>(std::move(notFound));<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:9.5pt;font-family:Consolas;color:black">}</span><span lang="EN-GB"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">When I use “llvm::orc::JITDylibLookupFlags::MatchExportedSymbolsOnly” then I will get 1 undefined Reference in the first run, but a total of 9 in the second run, because every symbol
I wanted to lookup was now an undefined reference. <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Thank you for the help in advance!<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Kind greetings<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Björn<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
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<p class="MsoNormal"><b><span lang="EN-US">From:</span></b><span lang="EN-US"> Lang Hames <<a href="mailto:lhames@gmail.com" target="_blank">lhames@gmail.com</a>>
<br>
<b>Sent:</b> 23 September 2020 07:54<br>
<b>To:</b> Gaier, Bjoern <<a href="mailto:Bjoern.Gaier@horiba.com" target="_blank">Bjoern.Gaier@horiba.com</a>><br>
<b>Cc:</b> LLVM Developers Mailing List <<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a>><br>
<b>Subject:</b> Re: ORC JIT - Can modules independently managed with one LLJIT instance?<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-GB">Hi Bjoern,<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
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<div>
<p class="MsoNormal"><span lang="EN-GB">Sounds like you want the removable code feature that's under development in the orcv1-removal branch of
</span><a href="https://hes32-ctp.trendmicro.com:443/wis/clicktime/v1/query?url=https%3a%2f%2fgithub.com%2flhames%2fllvm%2dproject.git&umid=7d73edbc-e566-4ffc-bd01-827f3d6c8c2e&auth=b6f66d00f8195cc5198eee21f0dbabe6af0a3180-918a46b7d72afae12d8ff60470e902dac471e605" target="_blank"><span lang="EN-GB">https://github.com/lhames/llvm-project.git</span></a><span lang="EN-GB">.
I will be aiming to merge this work back into the mainline some time in the next couple of weeks.<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-GB">I have not added a "removeJITDylib" method to ExecutionSession with this feature yet, but will try to design and publish that tomorrow. Then you should be able to do exactly what you want.<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
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<div>
<p class="MsoNormal"><span lang="EN-GB">In the new system you can also perform fine grained removal: It is possible to track and remove individual modules from within a JITDylib. For an example of this see: </span><a href="https://hes32-ctp.trendmicro.com:443/wis/clicktime/v1/query?url=https%3a%2f%2fgithub.com%2flhames%2fllvm%2dproject%2fblob%2f7ec9f8930f68760953a483157e010d0ff88285cd%2fllvm%2fexamples%2fKaleidoscope%2fBuildingAJIT%2fChapter1%2ftoy.cpp%23L1148&umid=7d73edbc-e566-4ffc-bd01-827f3d6c8c2e&auth=b6f66d00f8195cc5198eee21f0dbabe6af0a3180-c0d11d7f66acc6ff5b094b7166067e93a53cc1ff" target="_blank"><span lang="EN-GB">https://github.com/lhames/llvm-project/blob/7ec9f8930f68760953a483157e010d0ff88285cd/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter1/toy.cpp#L1148</span></a><span lang="EN-GB">,
from lines 1148 to line 1161.<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-GB">Also a related but different question:<br>
When using llvm::parseIRFile I need to pass it a LLVMContext - should this be a unique one for every module I pass or can I use a global one?<u></u><u></u></span></p>
</blockquote>
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<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
</div>
<div>
<p class="MsoNormal"><span lang="EN-GB">It depends on whether you want to be able to compile concurrently in the JIT process. If you do want to compile concurrently then each module should get its own context. If you are happy to stick to single threaded compilation
you can load all modules on the same context, potentially saving some memory.<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-GB">-- Lang.<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-GB">On Thu, Sep 17, 2020 at 11:59 PM Gaier, Bjoern <</span><a href="mailto:Bjoern.Gaier@horiba.com" target="_blank"><span lang="EN-GB">Bjoern.Gaier@horiba.com</span></a><span lang="EN-GB">> wrote:<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-GB">Hello everyone and Lang,<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">I have another design or "how-to" question about the ORC JIT. Sorry for having so many about them, to me this is a really complicated yet fascinating subject...<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">How would I design an ORC JIT with the following requirements?
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">At any time it should be possible to load a LLVM Module, every Module is independent and is not allowed to be linked with the other modules, every module can
be removed at any time.<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">My first idea was to have an ORC JIT for every module I load, but then I wondered if I could use a single ORC JIT for it.<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">So, I would create an ORC JIT:<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">- using llvm::orc::LLJITBuilder<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">- configurating it<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">- adding a custom memory manager that requests the entire memory size<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Then I would call "getMainJITDylib" and fill it with symbols that are valid for every module:<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">- adding printf, strlen, usw.
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Now when I get a request to load a module:<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">- load module
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">- get symbols I want to look up<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">- create new DyLib and add module to that<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Now I would do a lookup on that module, plus the main module to get symbol addresses and stuff<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">If a new module is added, it goes to a new DyLib as well and so on.<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">-----<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">However, now I want to delete a module again. Killing the memory is fairly easy with my custom memory manager, but I still have my DyLib of the now dead code...
Can I get rid of it without dumping the others or the entire ORC JIT?<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Or is there a different approach to do this? My goal with this is to speed up the setup phase for a module and also to reduce dynamic memory usage.<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Also a related but different question:
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">When using llvm::parseIRFile I need to pass it a LLVMContext - should this be a unique one for every module I pass or can I use a global one?<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Kind greetings and thank you all again,<u></u><u></u></span></p>
<p class="MsoNormal">Björn<u></u><u></u></p>
</div>
<p class="MsoNormal">Als GmbH eingetragen im Handelsregister Bad Homburg v.d.H. HRB 9816, USt.ID-Nr. DE 114 165 789 Geschäftsführer: Dr. Hiroshi Nakamura, Dr. Robert Plank, Markus Bode, Heiko Lampert, Takashi Nagano, Junichi Tajika, Ergin Cansiz.
<u></u><u></u></p>
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</blockquote>
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</div>
Als GmbH eingetragen im Handelsregister Bad Homburg v.d.H. HRB 9816, USt.ID-Nr. DE 114 165 789 Geschäftsführer: Dr. Hiroshi Nakamura, Dr. Robert Plank, Markus Bode, Heiko Lampert, Takashi Nagano, Junichi Tajika, Ergin Cansiz.
</div>
</blockquote></div>