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
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
//===----- COFFLinkGraphBuilder.h - COFF LinkGraph builder ----*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// Generic COFF LinkGraph building code.
//
//===----------------------------------------------------------------------===//
#ifndef LIB_EXECUTIONENGINE_JITLINK_COFFLINKGRAPHBUILDER_H
#define LIB_EXECUTIONENGINE_JITLINK_COFFLINKGRAPHBUILDER_H
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ExecutionEngine/JITLink/JITLink.h"
#include "llvm/Object/COFF.h"
#include "EHFrameSupportImpl.h"
#include "JITLinkGeneric.h"
#define DEBUG_TYPE "jitlink"
#include <list>
namespace llvm {
namespace jitlink {
class COFFLinkGraphBuilder {
public:
virtual ~COFFLinkGraphBuilder();
Expected<std::unique_ptr<LinkGraph>> buildGraph();
protected:
using COFFSectionIndex = int32_t;
using COFFSymbolIndex = int32_t;
COFFLinkGraphBuilder(const object::COFFObjectFile &Obj, Triple TT,
LinkGraph::GetEdgeKindNameFunction GetEdgeKindName);
LinkGraph &getGraph() const { return *G; }
const object::COFFObjectFile &getObject() const { return Obj; }
virtual Error addRelocations() = 0;
Error graphifySections();
Error graphifySymbols();
void setGraphSymbol(COFFSectionIndex SecIndex, COFFSymbolIndex SymIndex,
Symbol &Sym) {
assert(!GraphSymbols[SymIndex] && "Duplicate symbol at index");
GraphSymbols[SymIndex] = &Sym;
if (!COFF::isReservedSectionNumber(SecIndex))
SymbolSets[SecIndex].insert({Sym.getOffset(), &Sym});
}
Symbol *getGraphSymbol(COFFSymbolIndex SymIndex) const {
if (SymIndex < 0 ||
SymIndex >= static_cast<COFFSymbolIndex>(GraphSymbols.size()))
return nullptr;
return GraphSymbols[SymIndex];
}
void setGraphBlock(COFFSectionIndex SecIndex, Block *B) {
assert(!GraphBlocks[SecIndex] && "Duplicate section at index");
assert(!COFF::isReservedSectionNumber(SecIndex) && "Invalid section index");
GraphBlocks[SecIndex] = B;
}
Block *getGraphBlock(COFFSectionIndex SecIndex) const {
if (SecIndex <= 0 ||
SecIndex >= static_cast<COFFSectionIndex>(GraphSymbols.size()))
return nullptr;
return GraphBlocks[SecIndex];
}
object::COFFObjectFile::section_iterator_range sections() const {
return Obj.sections();
}
/// Traverse all matching relocation records in the given section. The handler
/// function Func should be callable with this signature:
/// Error(const object::RelocationRef&,
/// const object::SectionRef&, Section &)
///
template <typename RelocHandlerFunction>
Error forEachRelocation(const object::SectionRef &RelSec,
RelocHandlerFunction &&Func,
bool ProcessDebugSections = false);
/// Traverse all matching relocation records in the given section. Convenience
/// wrapper to allow passing a member function for the handler.
///
template <typename ClassT, typename RelocHandlerMethod>
Error forEachRelocation(const object::SectionRef &RelSec, ClassT *Instance,
RelocHandlerMethod &&Method,
bool ProcessDebugSections = false) {
return forEachRelocation(
RelSec,
[Instance, Method](const auto &Rel, const auto &Target, auto &GS) {
return (Instance->*Method)(Rel, Target, GS);
},
ProcessDebugSections);
}
private:
// Pending comdat symbol export that is initiated by the first symbol of
// COMDAT sequence.
struct ComdatExportRequest {
COFFSymbolIndex SymbolIndex;
COFFSectionIndex SectionIndex;
jitlink::Linkage Linkage;
};
Optional<ComdatExportRequest> PendingComdatExport;
// This represents a pending request to create a weak external symbol with a
// name.
struct WeakAliasRequest {
COFFSymbolIndex Alias;
COFFSymbolIndex Target;
StringRef SymbolName;
};
std::vector<WeakAliasRequest> WeakAliasRequests;
// Per COFF section jitlink symbol set sorted by offset.
// Used for calculating implicit size of defined symbols.
using SymbolSet = std::set<std::pair<orc::ExecutorAddrDiff, Symbol *>>;
std::vector<SymbolSet> SymbolSets;
Section &getCommonSection();
Expected<Symbol *> createDefinedSymbol(COFFSymbolIndex SymIndex,
StringRef SymbolName,
object::COFFSymbolRef Symbol,
const object::coff_section *Section);
Expected<Symbol *> createCOMDATExportRequest(
COFFSymbolIndex SymIndex, object::COFFSymbolRef Symbol,
const object::coff_aux_section_definition *Definition);
Expected<Symbol *> exportCOMDATSymbol(COFFSymbolIndex SymIndex,
StringRef SymbolName,
object::COFFSymbolRef Symbol);
Error flushWeakAliasRequests();
Error calculateImplicitSizeOfSymbols();
static uint64_t getSectionAddress(const object::COFFObjectFile &Obj,
const object::coff_section *Section);
static uint64_t getSectionSize(const object::COFFObjectFile &Obj,
const object::coff_section *Section);
static bool isComdatSection(const object::coff_section *Section);
static unsigned getPointerSize(const object::COFFObjectFile &Obj);
static support::endianness getEndianness(const object::COFFObjectFile &Obj);
StringRef getCOFFSectionName(COFFSectionIndex SectionIndex,
const object::coff_section *Sec,
object::COFFSymbolRef Sym);
const object::COFFObjectFile &Obj;
std::unique_ptr<LinkGraph> G;
Section *CommonSection = nullptr;
std::vector<Block *> GraphBlocks;
std::vector<Symbol *> GraphSymbols;
};
template <typename RelocHandlerFunction>
Error COFFLinkGraphBuilder::forEachRelocation(const object::SectionRef &RelSec,
RelocHandlerFunction &&Func,
bool ProcessDebugSections) {
auto COFFRelSect = Obj.getCOFFSection(RelSec);
// Target sections have names in valid COFF object files.
Expected<StringRef> Name = Obj.getSectionName(COFFRelSect);
if (!Name)
return Name.takeError();
LLVM_DEBUG(dbgs() << " " << *Name << ":\n");
// Lookup the link-graph node corresponding to the target section name.
auto *BlockToFix = getGraphBlock(RelSec.getIndex() + 1);
if (!BlockToFix)
return make_error<StringError>(
"Referencing a section that wasn't added to the graph: " + *Name,
inconvertibleErrorCode());
// Let the callee process relocation entries one by one.
for (const auto &R : RelSec.relocations())
if (Error Err = Func(R, RelSec, *BlockToFix))
return Err;
LLVM_DEBUG(dbgs() << "\n");
return Error::success();
}
} // end namespace jitlink
} // end namespace llvm
#endif // LIB_EXECUTIONENGINE_JITLINK_COFFLINKGRAPHBUILDER_H
|
