1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
|
//===-- JITLinkRedirectableSymbolManager.cpp - JITLink redirection in Orc -===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/ExecutionEngine/Orc/JITLinkRedirectableSymbolManager.h"
#include "llvm/ExecutionEngine/Orc/Core.h"
#define DEBUG_TYPE "orc"
using namespace llvm;
using namespace llvm::orc;
namespace {
constexpr StringRef JumpStubSectionName = "__orc_stubs";
constexpr StringRef StubPtrSectionName = "__orc_stub_ptrs";
constexpr StringRef StubSuffix = "$__stub_ptr";
} // namespace
void JITLinkRedirectableSymbolManager::emitRedirectableSymbols(
std::unique_ptr<MaterializationResponsibility> R, SymbolMap InitialDests) {
auto &ES = ObjLinkingLayer.getExecutionSession();
auto G = std::make_unique<jitlink::LinkGraph>(
("<indirect stubs graph #" + Twine(++StubGraphIdx) + ">").str(),
ES.getSymbolStringPool(), ES.getTargetTriple(), SubtargetFeatures(),
jitlink::getGenericEdgeKindName);
auto &PointerSection =
G->createSection(StubPtrSectionName, MemProt::Write | MemProt::Read);
auto &StubsSection =
G->createSection(JumpStubSectionName, MemProt::Exec | MemProt::Read);
SymbolFlagsMap NewSymbols;
for (auto &[Name, Def] : InitialDests) {
jitlink::Symbol *TargetSym = nullptr;
if (Def.getAddress())
TargetSym = &G->addAbsoluteSymbol(
G->allocateName(*Name + "$__init_tgt"), Def.getAddress(), 0,
jitlink::Linkage::Strong, jitlink::Scope::Local, false);
auto PtrName = ES.intern((*Name + StubSuffix).str());
auto &Ptr = AnonymousPtrCreator(*G, PointerSection, TargetSym, 0);
Ptr.setName(PtrName);
Ptr.setScope(jitlink::Scope::Hidden);
auto &Stub = PtrJumpStubCreator(*G, StubsSection, Ptr);
Stub.setName(Name);
Stub.setScope(jitlink::Scope::Default);
NewSymbols[std::move(PtrName)] = JITSymbolFlags();
}
// Try to claim responsibility for the new stub symbols.
if (auto Err = R->defineMaterializing(std::move(NewSymbols))) {
ES.reportError(std::move(Err));
return R->failMaterialization();
}
ObjLinkingLayer.emit(std::move(R), std::move(G));
}
Error JITLinkRedirectableSymbolManager::redirect(JITDylib &JD,
const SymbolMap &NewDests) {
auto &ES = ObjLinkingLayer.getExecutionSession();
SymbolLookupSet LS;
DenseMap<NonOwningSymbolStringPtr, SymbolStringPtr> PtrToStub;
for (auto &[StubName, Sym] : NewDests) {
auto PtrName = ES.intern((*StubName + StubSuffix).str());
PtrToStub[NonOwningSymbolStringPtr(PtrName)] = StubName;
LS.add(std::move(PtrName));
}
auto PtrSyms =
ES.lookup({{&JD, JITDylibLookupFlags::MatchAllSymbols}}, std::move(LS));
if (!PtrSyms)
return PtrSyms.takeError();
std::vector<tpctypes::PointerWrite> PtrWrites;
for (auto &[PtrName, PtrSym] : *PtrSyms) {
auto DestSymI = NewDests.find(PtrToStub[NonOwningSymbolStringPtr(PtrName)]);
assert(DestSymI != NewDests.end() && "Bad ptr -> stub mapping");
auto &DestSym = DestSymI->second;
PtrWrites.push_back({PtrSym.getAddress(), DestSym.getAddress()});
}
return ObjLinkingLayer.getExecutionSession()
.getExecutorProcessControl()
.getMemoryAccess()
.writePointers(PtrWrites);
}
|
