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