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#include "llvm/ExecutionEngine/Orc/RedirectionManager.h"
14
15using namespace llvm;
16using namespace llvm::jitlink;
17
18namespace {
19
20constexpr StringRef FnBodySuffix = "$orc_fnbody";
21
22} // anonymous namespace
23
24namespace llvm::orc {
25
26class LazyObjectLinkingLayer::RenamerPlugin
27 : public ObjectLinkingLayer::Plugin {
28public:
29 void modifyPassConfig(MaterializationResponsibility &MR,
30 jitlink::LinkGraph &LG,
31 jitlink::PassConfiguration &Config) override {
32 // We need to insert this before the mark-live pass to ensure that we don't
33 // delete the bodies (their names won't match the responsibility set until
34 // after this pass completes.
35 Config.PrePrunePasses.insert(
36 position: Config.PrePrunePasses.begin(),
37 x: [&MR](LinkGraph &G) { return renameFunctionBodies(G, MR); });
38 }
39
40 Error notifyFailed(MaterializationResponsibility &MR) override {
41 return Error::success();
42 }
43
44 Error notifyRemovingResources(JITDylib &JD, ResourceKey K) override {
45 return Error::success();
46 }
47
48 void notifyTransferringResources(JITDylib &JD, ResourceKey DstKey,
49 ResourceKey SrcKey) override {}
50
51private:
52 static Error renameFunctionBodies(LinkGraph &G,
53 MaterializationResponsibility &MR) {
54 DenseMap<StringRef, NonOwningSymbolStringPtr> SymsToRename;
55 for (auto &[Name, Flags] : MR.getSymbols())
56 if ((*Name).ends_with(Suffix: FnBodySuffix))
57 SymsToRename[(*Name).drop_back(N: FnBodySuffix.size())] =
58 NonOwningSymbolStringPtr(Name);
59
60 for (auto *Sym : G.defined_symbols()) {
61 if (!Sym->hasName())
62 continue;
63 auto I = SymsToRename.find(Val: *Sym->getName());
64 if (I == SymsToRename.end())
65 continue;
66 Sym->setName(G.intern(SymbolName: G.allocateName(Source: *I->second)));
67 }
68
69 return Error::success();
70 }
71};
72
73LazyObjectLinkingLayer::LazyObjectLinkingLayer(ObjectLinkingLayer &BaseLayer,
74 LazyReexportsManager &LRMgr)
75 : ObjectLayer(BaseLayer.getExecutionSession()), BaseLayer(BaseLayer),
76 LRMgr(LRMgr) {
77 BaseLayer.addPlugin(P: std::make_unique<RenamerPlugin>());
78}
79
80Error LazyObjectLinkingLayer::add(ResourceTrackerSP RT,
81 std::unique_ptr<MemoryBuffer> O,
82 MaterializationUnit::Interface I) {
83
84 // Object files with initializer symbols can't be lazy.
85 if (I.InitSymbol)
86 return BaseLayer.add(RT: std::move(RT), O: std::move(O), I: std::move(I));
87
88 auto &ES = getExecutionSession();
89 SymbolAliasMap LazySymbols;
90 for (auto &[Name, Flags] : I.SymbolFlags)
91 if (Flags.isCallable())
92 LazySymbols[Name] = {ES.intern(SymName: (*Name + FnBodySuffix).str()), Flags};
93
94 for (auto &[Name, AI] : LazySymbols) {
95 I.SymbolFlags.erase(Val: Name);
96 I.SymbolFlags[AI.Aliasee] = AI.AliasFlags;
97 }
98
99 if (auto Err = BaseLayer.add(RT, O: std::move(O), I: std::move(I)))
100 return Err;
101
102 auto &JD = RT->getJITDylib();
103 return JD.define(MU: lazyReexports(LRM&: LRMgr, Reexports: std::move(LazySymbols)), RT: std::move(RT));
104}
105
106void LazyObjectLinkingLayer::emit(
107 std::unique_ptr<MaterializationResponsibility> MR,
108 std::unique_ptr<MemoryBuffer> Obj) {
109 return BaseLayer.emit(R: std::move(MR), O: std::move(Obj));
110}
111
112} // namespace llvm::orc
113