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
|
//===--- llvm-jitlink-coff.cpp -- COFF parsing support for llvm-jitlink ---===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// COFF parsing support for llvm-jitlink.
//
//===----------------------------------------------------------------------===//
#include "llvm-jitlink.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/Path.h"
#define DEBUG_TYPE "llvm_jitlink"
using namespace llvm;
using namespace llvm::jitlink;
static bool isCOFFGOTSection(Section &S) { return S.getName() == "$__GOT"; }
static bool isCOFFStubsSection(Section &S) { return S.getName() == "$__STUBS"; }
static Expected<Edge &> getFirstRelocationEdge(LinkGraph &G, Block &B) {
auto EItr =
llvm::find_if(B.edges(), [](Edge &E) { return E.isRelocation(); });
if (EItr == B.edges().end())
return make_error<StringError>("GOT entry in " + G.getName() + ", \"" +
B.getSection().getName() +
"\" has no relocations",
inconvertibleErrorCode());
return *EItr;
}
static Expected<Symbol &> getCOFFGOTTarget(LinkGraph &G, Block &B) {
auto E = getFirstRelocationEdge(G, B);
if (!E)
return E.takeError();
auto &TargetSym = E->getTarget();
if (!TargetSym.hasName())
return make_error<StringError>(
"GOT entry in " + G.getName() + ", \"" +
TargetSym.getBlock().getSection().getName() +
"\" points to anonymous "
"symbol",
inconvertibleErrorCode());
return TargetSym;
}
static Expected<Symbol &> getCOFFStubTarget(LinkGraph &G, Block &B) {
auto E = getFirstRelocationEdge(G, B);
if (!E)
return E.takeError();
auto &GOTSym = E->getTarget();
if (!GOTSym.isDefined() || !isCOFFGOTSection(GOTSym.getBlock().getSection()))
return make_error<StringError>(
"Stubs entry in " + G.getName() + ", \"" +
GOTSym.getBlock().getSection().getName() +
"\" does not point to GOT entry",
inconvertibleErrorCode());
return getCOFFGOTTarget(G, GOTSym.getBlock());
}
namespace llvm {
Error registerCOFFGraphInfo(Session &S, LinkGraph &G) {
auto FileName = sys::path::filename(G.getName());
if (S.FileInfos.count(FileName)) {
return make_error<StringError>("When -check is passed, file names must be "
"distinct (duplicate: \"" +
FileName + "\")",
inconvertibleErrorCode());
}
auto &FileInfo = S.FileInfos[FileName];
LLVM_DEBUG(
{ dbgs() << "Registering COFF file info for \"" << FileName << "\"\n"; });
for (auto &Sec : G.sections()) {
LLVM_DEBUG({
dbgs() << " Section \"" << Sec.getName() << "\": "
<< (Sec.symbols().empty() ? "empty. skipping." : "processing...")
<< "\n";
});
// Skip empty sections.
if (Sec.symbols().empty())
continue;
if (FileInfo.SectionInfos.count(Sec.getName()))
return make_error<StringError>("Encountered duplicate section name \"" +
Sec.getName() + "\" in \"" + FileName +
"\"",
inconvertibleErrorCode());
bool isGOTSection = isCOFFGOTSection(Sec);
bool isStubsSection = isCOFFStubsSection(Sec);
bool SectionContainsContent = false;
bool SectionContainsZeroFill = false;
auto *FirstSym = *Sec.symbols().begin();
auto *LastSym = FirstSym;
for (auto *Sym : Sec.symbols()) {
if (Sym->getAddress() < FirstSym->getAddress())
FirstSym = Sym;
if (Sym->getAddress() > LastSym->getAddress())
LastSym = Sym;
if (isGOTSection) {
if (Sym->isSymbolZeroFill())
return make_error<StringError>("zero-fill atom in GOT section",
inconvertibleErrorCode());
// If this is a GOT symbol with size (i.e. not the GOT start symbol)
// then add it to the GOT entry info table.
if (Sym->getSize() != 0) {
if (auto TS = getCOFFGOTTarget(G, Sym->getBlock()))
FileInfo.GOTEntryInfos[TS->getName()] = {
Sym->getSymbolContent(), Sym->getAddress().getValue()};
else
return TS.takeError();
}
SectionContainsContent = true;
} else if (isStubsSection) {
if (Sym->isSymbolZeroFill())
return make_error<StringError>("zero-fill atom in Stub section",
inconvertibleErrorCode());
if (auto TS = getCOFFStubTarget(G, Sym->getBlock()))
FileInfo.StubInfos[TS->getName()] = {Sym->getSymbolContent(),
Sym->getAddress().getValue()};
else
return TS.takeError();
SectionContainsContent = true;
}
if (Sym->hasName()) {
if (Sym->isSymbolZeroFill()) {
S.SymbolInfos[Sym->getName()] = {Sym->getSize(),
Sym->getAddress().getValue()};
SectionContainsZeroFill = true;
} else {
S.SymbolInfos[Sym->getName()] = {Sym->getSymbolContent(),
Sym->getAddress().getValue()};
SectionContainsContent = true;
}
}
}
auto SecAddr = FirstSym->getAddress();
auto SecSize =
(LastSym->getBlock().getAddress() + LastSym->getBlock().getSize()) -
SecAddr;
if (SectionContainsZeroFill && SectionContainsContent)
return make_error<StringError>("Mixed zero-fill and content sections not "
"supported yet",
inconvertibleErrorCode());
if (SectionContainsZeroFill)
FileInfo.SectionInfos[Sec.getName()] = {SecSize, SecAddr.getValue()};
else
FileInfo.SectionInfos[Sec.getName()] = {
ArrayRef<char>(FirstSym->getBlock().getContent().data(), SecSize),
SecAddr.getValue()};
}
return Error::success();
}
} // end namespace llvm
|
