search for: resolveexternalsymbols

Hi, I ran into a problem migrating cling (finally!) to MCJIT: When an ("outer") MCJIT's finalization / llvm::RuntimeDyldImpl::resolveExternalSymbols() is called and a symbol is not known, cling can help by loading the suitable library and providing the symbol. It compiles the relevant C++ header as part of loading the library. This compilation emits symbols through the MCJIT. That "inner" MCJIT'ing then needs to finalize to resol...

Hi Lang, Can you please let me know you think it would be right to modify RuntimeDyldImpl::resolveExternalSymbols to allow resolvers to return 0 addresses? Something like this would be ideal for me: void RuntimeDyldImpl::resolveExternalSymbols() { while (!ExternalSymbolRelocations.empty()) { StringMap<RelocationList>::iterator i = ExternalSymbolRelocations.begin(); StringRef Name = i->firs...

...e client is via NotifyLoadedFtor notifications but I couldn't find a way of blocking a relocation resolution. One way to achieve that is to change the Resolver::findSymbol api to allow clients to indicate that the relocations for the symbol shouldn't be resolved and update RuntimeDyldImpl::resolveExternalSymbols accordingly. Would this be a reasonable approach? Thanks, Eugene -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20150624/4c4e0f4c/attachment.html>

Hi Lang, Yes, I can return a non-zero marker value. Are you ok with this version? void RuntimeDyldImpl::resolveExternalSymbols() { while (!ExternalSymbolRelocations.empty()) { StringMap<RelocationList>::iterator i = ExternalSymbolRelocations.begin(); StringRef Name = i->first(); if (Name.size() == 0) { // This is an absolute symbol, use an address of zero. DEBUG(dbgs() << "Res...

...ces. That's the behavior I'd expect. The JIT OTOH is deciding that it shall use the local version of the symbol; RuntimeDyld::getSymbol() doesn't care about the fact that the symbol is weak and has an existing occurrence. For weak symbols from a different module, RuntimeDyld would use resolveExternalSymbols() and all would be good - but here this doesn't happen. IIUC, RuntimeDyld::getSymbol() really needs to check whether the local symbol should survive or not, before handing out its address. But that seems to break the whole design of when relocs happen, so I'm sure I'm wrong. Can I get...

...make it testable) in r241383. Cheers, Lang. On Mon, Jun 29, 2015 at 7:31 PM, Eugene Rozenfeld <Eugene.Rozenfeld at microsoft.com<mailto:Eugene.Rozenfeld at microsoft.com>> wrote: Hi Lang, Yes, I can return a non-zero marker value. Are you ok with this version? void RuntimeDyldImpl::resolveExternalSymbols() { while (!ExternalSymbolRelocations.empty()) { StringMap<RelocationList>::iterator i = ExternalSymbolRelocations.begin(); StringRef Name = i->first(); if (Name.size() == 0) { // This is an absolute symbol, use an address of zero. DEBUG(dbgs() << "Res...

...rs, > > Lang. > > > > On Mon, Jun 29, 2015 at 7:31 PM, Eugene Rozenfeld < > Eugene.Rozenfeld at microsoft.com> wrote: > > Hi Lang, > > > > Yes, I can return a non-zero marker value. Are you ok with this version? > > > > void RuntimeDyldImpl::resolveExternalSymbols() { > > while (!ExternalSymbolRelocations.empty()) { > > StringMap<RelocationList>::iterator > i = ExternalSymbolRelocations.begin(); > > > > StringRef Name = i->first(); > > if (Name.size() == 0) { > > // This is an absolute symb...

...make it testable) in r241383. Cheers, Lang. On Mon, Jun 29, 2015 at 7:31 PM, Eugene Rozenfeld <Eugene.Rozenfeld at microsoft.com<mailto:Eugene.Rozenfeld at microsoft.com>> wrote: Hi Lang, Yes, I can return a non-zero marker value. Are you ok with this version? void RuntimeDyldImpl::resolveExternalSymbols() { while (!ExternalSymbolRelocations.empty()) { StringMap<RelocationList>::iterator i = ExternalSymbolRelocations.begin(); StringRef Name = i->first(); if (Name.size() == 0) { // This is an absolute symbol, use an address of zero. DEBUG(dbgs() << "Res...

...9 C llvm::RuntimeDyldCOFFX86_64::resolveRelocation(const llvm::RelocationEntry & RE, unsigned __int64 Value) Line 81 C++ llvm::RuntimeDyldImpl::resolveRelocationList(const llvm::SmallVector<llvm::RelocationEntry,64> & Relocs, unsigned __int64 Value) Line 796 C++ llvm::RuntimeDyldImpl::resolveExternalSymbols() Line 849 C++ llvm::RuntimeDyldImpl::resolveRelocations() Line 95 C++ llvm::RuntimeDyld::resolveRelocations() Line 961 C++ llvm::orc::ObjectLinkingLayer<llvm::orc::DoNothingOnNotifyLoaded>::ConcreteLinkedObjectSet<std::shared_ptr<llvm::SectionMemoryManager>,ClangClasses::LLVMExecuti...

...rs, > > Lang. > > > > On Mon, Jun 29, 2015 at 7:31 PM, Eugene Rozenfeld < > Eugene.Rozenfeld at microsoft.com> wrote: > > Hi Lang, > > > > Yes, I can return a non-zero marker value. Are you ok with this version? > > > > void RuntimeDyldImpl::resolveExternalSymbols() { > > while (!ExternalSymbolRelocations.empty()) { > > StringMap<RelocationList>::iterator > i = ExternalSymbolRelocations.begin(); > > > > StringRef Name = i->first(); > > if (Name.size() == 0) { > > // This is an absolute symb...

...st llvm::RelocationEntry > & RE, unsigned __int64 Value) Line 81 C++ > > llvm::RuntimeDyldImpl::resolveRelocationList(const > llvm::SmallVector<llvm::RelocationEntry,64> & Relocs, unsigned __int64 > Value) Line 796 C++ > > llvm::RuntimeDyldImpl::resolveExternalSymbols() Line 849 C++ > > llvm::RuntimeDyldImpl::resolveRelocations() Line 95 C++ > > llvm::RuntimeDyld::resolveRelocations() Line 961 C++ > > llvm::orc::ObjectLinkingLayer<llvm::orc::DoNothingOnNotifyLoaded>::ConcreteLinkedObjectSet<std::shared_ptr<llv...

...n 44; else if (Arch == Triple::x86_64) - return 8; // GOT + return 6; // 2-byte jmp instruction + 32-bit relative address else if (Arch == Triple::systemz) return 16; else @@ -292,6 +302,11 @@ protected: /// \brief Resolve relocations to external symbols. void resolveExternalSymbols(); + + /// \brief Update GOT entries for external symbols. + // The base class does nothing. ELF overrides this. + virtual void updateGOTEntries(StringRef Name, uint64_t Addr) {} + virtual ObjectImage *createObjectImage(ObjectBuffer *InputBuffer); public: RuntimeDyldImpl(RTDyldMemoryMana...