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
|
//===- yaml2macho - Convert YAML to a Mach object file --------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief The Mach component of yaml2obj.
///
//===----------------------------------------------------------------------===//
#include "yaml2obj.h"
#include "llvm/ObjectYAML/MachOYAML.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/MachO.h"
#include "llvm/Support/YAMLTraits.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
class MachOWriter {
public:
MachOWriter(MachOYAML::Object &Obj) : Obj(Obj) {
is64Bit = Obj.Header.magic == MachO::MH_MAGIC_64 ||
Obj.Header.magic == MachO::MH_CIGAM_64;
memset(reinterpret_cast<void *>(&Header64), 0,
sizeof(MachO::mach_header_64));
assert((is64Bit || Obj.Header.reserved == 0xDEADBEEFu) &&
"32-bit MachO has reserved in header");
assert((!is64Bit || Obj.Header.reserved != 0xDEADBEEFu) &&
"64-bit MachO has missing reserved in header");
}
Error writeMachO(raw_ostream &OS);
private:
Error writeHeader(raw_ostream &OS);
Error writeLoadCommands(raw_ostream &OS);
MachOYAML::Object &Obj;
bool is64Bit;
union {
MachO::mach_header_64 Header64;
MachO::mach_header Header;
};
};
Error MachOWriter::writeMachO(raw_ostream &OS) {
if (auto Err = writeHeader(OS))
return Err;
if (auto Err = writeLoadCommands(OS))
return Err;
return Error::success();
}
Error MachOWriter::writeHeader(raw_ostream &OS) {
Header.magic = Obj.Header.magic;
Header.cputype = Obj.Header.cputype;
Header.cpusubtype = Obj.Header.cpusubtype;
Header.filetype = Obj.Header.filetype;
Header.ncmds = Obj.Header.ncmds;
Header.sizeofcmds = Obj.Header.sizeofcmds;
Header.flags = Obj.Header.flags;
Header64.reserved = Obj.Header.reserved;
if (is64Bit)
OS.write((const char *)&Header64, sizeof(MachO::mach_header_64));
else
OS.write((const char *)&Header, sizeof(MachO::mach_header));
return Error::success();
}
Error MachOWriter::writeLoadCommands(raw_ostream &OS) {
for (auto &LC : Obj.LoadCommands) {
size_t BytesWritten = 0;
#define HANDLE_LOAD_COMMAND(LCName, LCValue, LCStruct) \
case MachO::LCName: \
OS.write(reinterpret_cast<const char *>(&(LC.load_command_data.LCStruct)), \
sizeof(MachO::LCStruct)); \
BytesWritten = sizeof(MachO::LCStruct); \
break;
switch (LC.load_command_data.load_command.cmd) {
default:
OS.write(
reinterpret_cast<const char *>(&(LC.load_command_data.load_command)),
sizeof(MachO::load_command));
BytesWritten = sizeof(MachO::load_command);
break;
#include "llvm/Support/MachO.def"
}
auto BytesRemaining =
LC.load_command_data.load_command.cmdsize - BytesWritten;
if (BytesRemaining > 0) {
// TODO: Replace all this once the load command data is present in yaml.
// For now I fill with 0xDEADBEEF because it is easy to spot on a hex
// viewer.
std::vector<uint32_t> FillData;
FillData.insert(FillData.begin(), BytesRemaining / 4 + 1, 0xDEADBEEFu);
OS.write(reinterpret_cast<char *>(FillData.data()), BytesRemaining);
}
}
return Error::success();
}
} // end anonymous namespace
int yaml2macho(yaml::Input &YIn, raw_ostream &Out) {
MachOYAML::Object Doc;
YIn >> Doc;
if (YIn.error()) {
errs() << "yaml2obj: Failed to parse YAML file!\n";
return 1;
}
MachOWriter Writer(Doc);
if (auto Err = Writer.writeMachO(Out)) {
errs() << toString(std::move(Err));
return 1;
}
return 0;
}
|
