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 #include "llvm/ExecutionEngine/Orc/AbsoluteSymbols.h"
  12 #include "llvm/ExecutionEngine/Orc/DebugUtils.h"
  13 #include "llvm/Support/Error.h"
  14
  15 #define DEBUG_TYPE "orc"
  16
  17 namespace llvm {
  18 namespace orc {
  19
  20 Expected<std::unique_ptr<EPCDynamicLibrarySearchGenerator>>
  21 EPCDynamicLibrarySearchGenerator::Load(
  22     ExecutionSession &ES, const char *LibraryPath, SymbolPredicate Allow,
  23     AddAbsoluteSymbolsFn AddAbsoluteSymbols) {
  24   auto Handle =
  25       ES.getExecutorProcessControl().getDylibMgr().loadDylib(LibraryPath);
  26   if (!Handle)
  27     return Handle.takeError();
  28
  29   return std::make_unique<EPCDynamicLibrarySearchGenerator>(
  30       ES, *Handle, std::move(Allow), std::move(AddAbsoluteSymbols));
  31 }
  32
  33 Error EPCDynamicLibrarySearchGenerator::tryToGenerate(
  34     LookupState &LS, LookupKind K, JITDylib &JD,
  35     JITDylibLookupFlags JDLookupFlags, const SymbolLookupSet &Symbols) {
  36
  37   if (Symbols.empty())
  38     return Error::success();
  39
  40   LLVM_DEBUG({
  41       dbgs() << "EPCDynamicLibrarySearchGenerator trying to generate "
  42              << Symbols << "\n";
  43     });
  44
  45   SymbolLookupSet LookupSymbols;
  46
  47   for (auto &KV : Symbols) {
  48     // Skip symbols that don't match the filter.
  49     if (Allow && !Allow(KV.first))
  50       continue;
  51     LookupSymbols.add(KV.first, SymbolLookupFlags::WeaklyReferencedSymbol);
  52   }
  53
  54   DylibManager::LookupRequest Request(H, LookupSymbols);
  55   // Copy-capture LookupSymbols, since LookupRequest keeps a reference.
  56   EPC.getDylibMgr().lookupSymbolsAsync(Request, [this, &JD, LS = std::move(LS),
  57                                                  LookupSymbols](
  58                                                     auto Result) mutable {
  59     if (!Result) {
  60       LLVM_DEBUG({
  61         dbgs() << "EPCDynamicLibrarySearchGenerator lookup failed due to error";
  62       });
  63       return LS.continueLookup(Result.takeError());
  64     }
  65
  66     assert(Result->size() == 1 && "Results for more than one library returned");
  67     assert(Result->front().size() == LookupSymbols.size() &&
  68            "Result has incorrect number of elements");
  69
  70     SymbolMap NewSymbols;
  71     auto ResultI = Result->front().begin();
  72     for (auto &KV : LookupSymbols) {
  73       if (ResultI->getAddress())
  74         NewSymbols[KV.first] = *ResultI;
  75       ++ResultI;
  76     }
  77
  78     LLVM_DEBUG({
  79       dbgs() << "EPCDynamicLibrarySearchGenerator lookup returned "
  80              << NewSymbols << "\n";
  81     });
  82
  83     // If there were no resolved symbols bail out.
  84     if (NewSymbols.empty())
  85       return LS.continueLookup(Error::success());
  86
  87     // Define resolved symbols.
  88     Error Err = AddAbsoluteSymbols
  89                     ? AddAbsoluteSymbols(JD, std::move(NewSymbols))
  90                     : JD.define(absoluteSymbols(std::move(NewSymbols)));
  91
  92     LS.continueLookup(std::move(Err));
  93   });
  94
  95   return Error::success();
  96 }
  97
  98 } // end namespace orc
  99 } // end namespace llvm