llvm/lib/ExecutionEngine/Orc/EPCEHFrameRegistrar.cpp

   1 //===------ EPCEHFrameRegistrar.cpp - EPC-based eh-frame registration -----===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/ExecutionEngine/Orc/EPCEHFrameRegistrar.h"
  10
  11 #include "llvm/ExecutionEngine/Orc/Core.h"
  12 #include "llvm/Support/BinaryStreamWriter.h"
  13
  14 using namespace llvm::orc::shared;
  15
  16 namespace llvm {
  17 namespace orc {
  18
  19 Expected<std::unique_ptr<EPCEHFrameRegistrar>>
  20 EPCEHFrameRegistrar::Create(ExecutionSession &ES) {
  21   // FIXME: Proper mangling here -- we really need to decouple linker mangling
  22   // from DataLayout.
  23
  24   // Find the addresses of the registration/deregistration functions in the
  25   // executor process.
  26   auto &EPC = ES.getExecutorProcessControl();
  27   auto ProcessHandle = EPC.loadDylib(nullptr);
  28   if (!ProcessHandle)
  29     return ProcessHandle.takeError();
  30
  31   std::string RegisterWrapperName, DeregisterWrapperName;
  32   if (EPC.getTargetTriple().isOSBinFormatMachO()) {
  33     RegisterWrapperName += '_';
  34     DeregisterWrapperName += '_';
  35   }
  36   RegisterWrapperName += "llvm_orc_registerEHFrameSectionWrapper";
  37   DeregisterWrapperName += "llvm_orc_deregisterEHFrameSectionWrapper";
  38
  39   SymbolLookupSet RegistrationSymbols;
  40   RegistrationSymbols.add(EPC.intern(RegisterWrapperName));
  41   RegistrationSymbols.add(EPC.intern(DeregisterWrapperName));
  42
  43   auto Result = EPC.lookupSymbols({{*ProcessHandle, RegistrationSymbols}});
  44   if (!Result)
  45     return Result.takeError();
  46
  47   assert(Result->size() == 1 && "Unexpected number of dylibs in result");
  48   assert((*Result)[0].size() == 2 &&
  49          "Unexpected number of addresses in result");
  50
  51   auto RegisterEHFrameWrapperFnAddr = (*Result)[0][0];
  52   auto DeregisterEHFrameWrapperFnAddr = (*Result)[0][1];
  53
  54   return std::make_unique<EPCEHFrameRegistrar>(ES, RegisterEHFrameWrapperFnAddr,
  55                                                DeregisterEHFrameWrapperFnAddr);
  56 }
  57
  58 Error EPCEHFrameRegistrar::registerEHFrames(JITTargetAddress EHFrameSectionAddr,
  59                                             size_t EHFrameSectionSize) {
  60   return ES.callSPSWrapper<void(SPSExecutorAddress, uint64_t)>(
  61       RegisterEHFrameWrapperFnAddr, EHFrameSectionAddr,
  62       static_cast<uint64_t>(EHFrameSectionSize));
  63 }
  64
  65 Error EPCEHFrameRegistrar::deregisterEHFrames(
  66     JITTargetAddress EHFrameSectionAddr, size_t EHFrameSectionSize) {
  67   return ES.callSPSWrapper<void(SPSExecutorAddress, uint64_t)>(
  68       DeregisterEHFrameWrapperFnAddr, EHFrameSectionAddr,
  69       static_cast<uint64_t>(EHFrameSectionSize));
  70 }
  71
  72 } // end namespace orc
  73 } // end namespace llvm