1//===---------- LazyReexports.cpp - Utilities for lazy reexports ----------===//
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/LazyObjectLinkingLayer.h"
10
11#include "llvm/ExecutionEngine/Orc/LazyReexports.h"
12#include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
13
14using namespace llvm;
15using namespace llvm::jitlink;
16
17namespace {
18
19constexpr StringRef FnBodySuffix = "$orc_fnbody";
20
21} // anonymous namespace
22
23namespace llvm::orc {
24
25class LazyObjectLinkingLayer::RenamerPlugin
26 : public ObjectLinkingLayer::Plugin {
27public:
28 void modifyPassConfig(MaterializationResponsibility &MR,
29 jitlink::LinkGraph &LG,
30 jitlink::PassConfiguration &Config) override {
31 // We need to insert this before the mark-live pass to ensure that we don't
32 // delete the bodies (their names won't match the responsibility set until
33 // after this pass completes.
34 Config.PrePrunePasses.insert(
35 position: Config.PrePrunePasses.begin(),
36 x: [&MR](LinkGraph &G) { return renameFunctionBodies(G, MR); });
37 }
38
39 Error notifyFailed(MaterializationResponsibility &MR) override {
40 return Error::success();
41 }
42
43 Error notifyRemovingResources(JITDylib &JD, ResourceKey K) override {
44 return Error::success();
45 }
46
47 void notifyTransferringResources(JITDylib &JD, ResourceKey DstKey,
48 ResourceKey SrcKey) override {}
49
50private:
51 static Error renameFunctionBodies(LinkGraph &G,
52 MaterializationResponsibility &MR) {
53 DenseMap<StringRef, NonOwningSymbolStringPtr> SymsToRename;
54 for (auto &[Name, Flags] : MR.getSymbols())
55 if ((*Name).ends_with(Suffix: FnBodySuffix))
56 SymsToRename[(*Name).drop_back(N: FnBodySuffix.size())] =
57 NonOwningSymbolStringPtr(Name);
58
59 for (auto *Sym : G.defined_symbols()) {
60 if (!Sym->hasName())
61 continue;
62 auto I = SymsToRename.find(Val: *Sym->getName());
63 if (I == SymsToRename.end())
64 continue;
65 Sym->setName(G.intern(SymbolName: G.allocateName(Source: *I->second)));
66 }
67
68 return Error::success();
69 }
70};
71
72LazyObjectLinkingLayer::LazyObjectLinkingLayer(ObjectLinkingLayer &BaseLayer,
73 LazyReexportsManager &LRMgr)
74 : ObjectLayer(BaseLayer.getExecutionSession()), BaseLayer(BaseLayer),
75 LRMgr(LRMgr) {
76 BaseLayer.addPlugin(P: std::make_unique<RenamerPlugin>());
77}
78
79Error LazyObjectLinkingLayer::add(ResourceTrackerSP RT,
80 std::unique_ptr<MemoryBuffer> O,
81 MaterializationUnit::Interface I) {
82
83 // Object files with initializer symbols can't be lazy.
84 if (I.InitSymbol)
85 return BaseLayer.add(RT: std::move(RT), O: std::move(O), I: std::move(I));
86
87 auto &ES = getExecutionSession();
88 SymbolAliasMap LazySymbols;
89 for (auto &[Name, Flags] : I.SymbolFlags)
90 if (Flags.isCallable())
91 LazySymbols[Name] = {ES.intern(SymName: (*Name + FnBodySuffix).str()), Flags};
92
93 for (auto &[Name, AI] : LazySymbols) {
94 I.SymbolFlags.erase(Val: Name);
95 I.SymbolFlags[AI.Aliasee] = AI.AliasFlags;
96 }
97
98 if (auto Err = BaseLayer.add(RT, O: std::move(O), I: std::move(I)))
99 return Err;
100
101 auto &JD = RT->getJITDylib();
102 return JD.define(MU: lazyReexports(LRM&: LRMgr, Reexports: std::move(LazySymbols)), RT: std::move(RT));
103}
104
105void LazyObjectLinkingLayer::emit(
106 std::unique_ptr<MaterializationResponsibility> MR,
107 std::unique_ptr<MemoryBuffer> Obj) {
108 return BaseLayer.emit(R: std::move(MR), O: std::move(Obj));
109}
110
111} // namespace llvm::orc
112