Author: Valentin Churavy Date: 2020-11-26T00:34:52-05:00 New Revision: 075cca3448389e97d60a9bb61f313642c31653dc
URL: https://github.com/llvm/llvm-project/commit/075cca3448389e97d60a9bb61f313642c31653dc DIFF: https://github.com/llvm/llvm-project/commit/075cca3448389e97d60a9bb61f313642c31653dc.diff LOG: [RTDYLD] support absolute relocations where needed These appear in some sections, such as DWARF tables, since RuntimeDyldELF explicitly maps to this as a sentinel value: https://github.com/llvm/llvm-project/blob/29d1fba7b5335d969e3e5daa84b7a25cd1fa75ef/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp#L1199 That could then be a source of problems if it tried to examine these sections (for example, with either setProcessAllSections(true) or ORCv2 on i686). Replaces https://reviews.llvm.org/D89241 Reviewed By: lhames, vchuravy Differential Revision: https://reviews.llvm.org/D90722 (cherry picked from commit 85f4be09124cc53e1a18a884ac7caf19988ab2a5) Added: Modified: llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp Removed: ################################################################################ diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp index 7e9b0690ccea..04f541b59557 100644 --- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp +++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp @@ -308,7 +308,9 @@ RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) { << " SID: " << SectionID << " Offset: " << format("%p", (uintptr_t)Addr) << " flags: " << *FlagsOrErr << "\n"); - GlobalSymbolTable[Name] = SymbolTableEntry(SectionID, Addr, *JITSymFlags); + if (!Name.empty()) // Skip absolute symbol relocations. + GlobalSymbolTable[Name] = + SymbolTableEntry(SectionID, Addr, *JITSymFlags); } else if (SymType == object::SymbolRef::ST_Function || SymType == object::SymbolRef::ST_Data || SymType == object::SymbolRef::ST_Unknown || @@ -340,8 +342,9 @@ RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) { << " SID: " << SectionID << " Offset: " << format("%p", (uintptr_t)SectOffset) << " flags: " << *FlagsOrErr << "\n"); - GlobalSymbolTable[Name] = - SymbolTableEntry(SectionID, SectOffset, *JITSymFlags); + if (!Name.empty()) // Skip absolute symbol relocations + GlobalSymbolTable[Name] = + SymbolTableEntry(SectionID, SectOffset, *JITSymFlags); } } @@ -769,8 +772,9 @@ Error RuntimeDyldImpl::emitCommonSymbols(const ObjectFile &Obj, LLVM_DEBUG(dbgs() << "Allocating common symbol " << Name << " address " << format("%p", Addr) << "\n"); - GlobalSymbolTable[Name] = - SymbolTableEntry(SectionID, Offset, std::move(*JITSymFlags)); + if (!Name.empty()) // Skip absolute symbol relocations. + GlobalSymbolTable[Name] = + SymbolTableEntry(SectionID, Offset, std::move(*JITSymFlags)); Offset += Size; Addr += Size; } @@ -930,6 +934,8 @@ void RuntimeDyldImpl::addRelocationForSymbol(const RelocationEntry &RE, if (Loc == GlobalSymbolTable.end()) { ExternalSymbolRelocations[SymbolName].push_back(RE); } else { + assert(!SymbolName.empty() && + "Empty symbol should not be in GlobalSymbolTable"); // Copy the RE since we want to modify its addend. RelocationEntry RECopy = RE; const auto &SymInfo = Loc->second; @@ -1234,7 +1240,8 @@ void RuntimeDyldImpl::finalizeAsync( for (auto &RelocKV : SharedThis->ExternalSymbolRelocations) { StringRef Name = RelocKV.first(); - assert(!Name.empty() && "Symbol has no name?"); + if (Name.empty()) // Skip absolute symbol relocations. + continue; assert(!SharedThis->GlobalSymbolTable.count(Name) && "Name already processed. RuntimeDyld instances can not be re-used " "when finalizing with finalizeAsync."); _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
