llvm/lib/ExecutionEngine/Orc/EPCDynamicLibrarySearchGenerator.cpp

   1 //===---------------- EPCDynamicLibrarySearchGenerator.cpp ----------------===//
   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/EPCDynamicLibrarySearchGenerator.h"
  10
  11 namespace llvm {
  12 namespace orc {
  13
  14 Expected<std::unique_ptr<EPCDynamicLibrarySearchGenerator>>
  15 EPCDynamicLibrarySearchGenerator::Load(
  16     ExecutionSession &ES, const char *LibraryPath, SymbolPredicate Allow,
  17     AddAbsoluteSymbolsFn AddAbsoluteSymbols) {
  18   auto Handle = ES.getExecutorProcessControl().loadDylib(LibraryPath);
  19   if (!Handle)
  20     return Handle.takeError();
  21
  22   return std::make_unique<EPCDynamicLibrarySearchGenerator>(
  23       ES, *Handle, std::move(Allow), std::move(AddAbsoluteSymbols));
  24 }
  25
  26 Error EPCDynamicLibrarySearchGenerator::tryToGenerate(
  27     LookupState &LS, LookupKind K, JITDylib &JD,
  28     JITDylibLookupFlags JDLookupFlags, const SymbolLookupSet &Symbols) {
  29
  30   if (Symbols.empty())
  31     return Error::success();
  32
  33   SymbolLookupSet LookupSymbols;
  34
  35   for (auto &KV : Symbols) {
  36     // Skip symbols that don't match the filter.
  37     if (Allow && !Allow(KV.first))
  38       continue;
  39     LookupSymbols.add(KV.first, SymbolLookupFlags::WeaklyReferencedSymbol);
  40   }
  41
  42   SymbolMap NewSymbols;
  43
  44   ExecutorProcessControl::LookupRequest Request(H, LookupSymbols);
  45   auto Result = EPC.lookupSymbols(Request);
  46   if (!Result)
  47     return Result.takeError();
  48
  49   assert(Result->size() == 1 && "Results for more than one library returned");
  50   assert(Result->front().size() == LookupSymbols.size() &&
  51          "Result has incorrect number of elements");
  52
  53   auto ResultI = Result->front().begin();
  54   for (auto &KV : LookupSymbols) {
  55     if (ResultI->getAddress())
  56       NewSymbols[KV.first] = *ResultI;
  57     ++ResultI;
  58   }
  59
  60   // If there were no resolved symbols bail out.
  61   if (NewSymbols.empty())
  62     return Error::success();
  63
  64   // Define resolved symbols.
  65   if (AddAbsoluteSymbols)
  66     return AddAbsoluteSymbols(JD, std::move(NewSymbols));
  67   return JD.define(absoluteSymbols(std::move(NewSymbols)));
  68 }
  69
  70 } // end namespace orc
  71 } // end namespace llvm