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
17namespace llvm {
18namespace orc {
19
20Expected<std::unique_ptr<EPCDynamicLibrarySearchGenerator>>
21EPCDynamicLibrarySearchGenerator::Load(
22 ExecutionSession &ES, const char *LibraryPath, SymbolPredicate Allow,
23 AddAbsoluteSymbolsFn AddAbsoluteSymbols) {
24 auto Handle =
25 ES.getExecutorProcessControl().getDylibMgr().loadDylib(DylibPath: LibraryPath);
26 if (!Handle)
27 return Handle.takeError();
28
29 return std::make_unique<EPCDynamicLibrarySearchGenerator>(
30 args&: ES, args&: *Handle, args: std::move(Allow), args: std::move(AddAbsoluteSymbols));
31}
32
33Error 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 // If there's no handle then resolve all requested symbols to null.
46 if (!H) {
47 assert(Allow && "No handle or filter?");
48 SymbolMap Nulls;
49 for (auto &[Name, LookupFlags] : Symbols) {
50 if (Allow(Name))
51 Nulls[Name] = {};
52 }
53 return addAbsolutes(JD, Symbols: std::move(Nulls));
54 }
55
56 // Otherwise proceed with lookup in the remote.
57 SymbolLookupSet LookupSymbols;
58
59 for (auto &KV : Symbols) {
60 // Skip symbols that don't match the filter.
61 if (Allow && !Allow(KV.first))
62 continue;
63 LookupSymbols.add(Name: KV.first, Flags: SymbolLookupFlags::WeaklyReferencedSymbol);
64 }
65
66 DylibManager::LookupRequest Request(*H, LookupSymbols);
67 // Copy-capture LookupSymbols, since LookupRequest keeps a reference.
68 EPC.getDylibMgr().lookupSymbolsAsync(Request, F: [this, &JD, LS = std::move(LS),
69 LookupSymbols](
70 auto Result) mutable {
71 if (!Result) {
72 LLVM_DEBUG({
73 dbgs() << "EPCDynamicLibrarySearchGenerator lookup failed due to error";
74 });
75 return LS.continueLookup(Err: Result.takeError());
76 }
77
78 assert(Result->size() == 1 && "Results for more than one library returned");
79 assert(Result->front().size() == LookupSymbols.size() &&
80 "Result has incorrect number of elements");
81
82 SymbolMap NewSymbols;
83 auto ResultI = Result->front().begin();
84 for (auto &KV : LookupSymbols) {
85 if (ResultI->getAddress())
86 NewSymbols[KV.first] = *ResultI;
87 ++ResultI;
88 }
89
90 LLVM_DEBUG({
91 dbgs() << "EPCDynamicLibrarySearchGenerator lookup returned "
92 << NewSymbols << "\n";
93 });
94
95 // If there were no resolved symbols bail out.
96 if (NewSymbols.empty())
97 return LS.continueLookup(Err: Error::success());
98
99 // Define resolved symbols.
100 Error Err = addAbsolutes(JD, Symbols: std::move(NewSymbols));
101
102 LS.continueLookup(Err: std::move(Err));
103 });
104
105 return Error::success();
106}
107
108Error EPCDynamicLibrarySearchGenerator::addAbsolutes(JITDylib &JD,
109 SymbolMap Symbols) {
110 return AddAbsoluteSymbols ? AddAbsoluteSymbols(JD, std::move(Symbols))
111 : JD.define(MU: absoluteSymbols(Symbols: std::move(Symbols)));
112}
113
114} // end namespace orc
115} // end namespace llvm
116