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
200
201
202
203
204
205
206
207
208
|
//===--- LayoutOverrideSource.cpp --Override Record Layouts ---------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "clang/Frontend/LayoutOverrideSource.h"
#include "clang/AST/Decl.h"
#include "clang/Basic/CharInfo.h"
#include "llvm/Support/raw_ostream.h"
#include <fstream>
#include <string>
using namespace clang;
/// \brief Parse a simple identifier.
static std::string parseName(StringRef S) {
if (S.empty() || !isIdentifierHead(S[0]))
return "";
unsigned Offset = 1;
while (Offset < S.size() && isIdentifierBody(S[Offset]))
++Offset;
return S.substr(0, Offset).str();
}
LayoutOverrideSource::LayoutOverrideSource(StringRef Filename) {
std::ifstream Input(Filename.str().c_str());
if (!Input.is_open())
return;
// Parse the output of -fdump-record-layouts.
std::string CurrentType;
Layout CurrentLayout;
bool ExpectingType = false;
while (Input.good()) {
std::string Line;
getline(Input, Line);
StringRef LineStr(Line);
// Determine whether the following line will start a
if (LineStr.find("*** Dumping AST Record Layout") != StringRef::npos) {
// Flush the last type/layout, if there is one.
if (!CurrentType.empty())
Layouts[CurrentType] = CurrentLayout;
CurrentLayout = Layout();
ExpectingType = true;
continue;
}
// If we're expecting a type, grab it.
if (ExpectingType) {
ExpectingType = false;
StringRef::size_type Pos;
if ((Pos = LineStr.find("struct ")) != StringRef::npos)
LineStr = LineStr.substr(Pos + strlen("struct "));
else if ((Pos = LineStr.find("class ")) != StringRef::npos)
LineStr = LineStr.substr(Pos + strlen("class "));
else if ((Pos = LineStr.find("union ")) != StringRef::npos)
LineStr = LineStr.substr(Pos + strlen("union "));
else
continue;
// Find the name of the type.
CurrentType = parseName(LineStr);
CurrentLayout = Layout();
continue;
}
// Check for the size of the type.
StringRef::size_type Pos = LineStr.find(" Size:");
if (Pos != StringRef::npos) {
// Skip past the " Size:" prefix.
LineStr = LineStr.substr(Pos + strlen(" Size:"));
unsigned long long Size = 0;
(void)LineStr.getAsInteger(10, Size);
CurrentLayout.Size = Size;
continue;
}
// Check for the alignment of the type.
Pos = LineStr.find("Alignment:");
if (Pos != StringRef::npos) {
// Skip past the "Alignment:" prefix.
LineStr = LineStr.substr(Pos + strlen("Alignment:"));
unsigned long long Alignment = 0;
(void)LineStr.getAsInteger(10, Alignment);
CurrentLayout.Align = Alignment;
continue;
}
// Check for the size/alignment of the type.
Pos = LineStr.find("sizeof=");
if (Pos != StringRef::npos) {
/* Skip past the sizeof= prefix. */
LineStr = LineStr.substr(Pos + strlen("sizeof="));
// Parse size.
unsigned long long Size = 0;
(void)LineStr.getAsInteger(10, Size);
CurrentLayout.Size = Size;
Pos = LineStr.find("align=");
if (Pos != StringRef::npos) {
/* Skip past the align= prefix. */
LineStr = LineStr.substr(Pos + strlen("align="));
// Parse alignment.
unsigned long long Alignment = 0;
(void)LineStr.getAsInteger(10, Alignment);
CurrentLayout.Align = Alignment;
}
continue;
}
// Check for the field offsets of the type.
Pos = LineStr.find("FieldOffsets: [");
if (Pos == StringRef::npos)
continue;
LineStr = LineStr.substr(Pos + strlen("FieldOffsets: ["));
while (!LineStr.empty() && isDigit(LineStr[0])) {
// Parse this offset.
unsigned Idx = 1;
while (Idx < LineStr.size() && isDigit(LineStr[Idx]))
++Idx;
unsigned long long Offset = 0;
(void)LineStr.substr(0, Idx).getAsInteger(10, Offset);
CurrentLayout.FieldOffsets.push_back(Offset);
// Skip over this offset, the following comma, and any spaces.
LineStr = LineStr.substr(Idx + 1);
while (!LineStr.empty() && isWhitespace(LineStr[0]))
LineStr = LineStr.substr(1);
}
}
// Flush the last type/layout, if there is one.
if (!CurrentType.empty())
Layouts[CurrentType] = CurrentLayout;
}
bool
LayoutOverrideSource::layoutRecordType(const RecordDecl *Record,
uint64_t &Size, uint64_t &Alignment,
llvm::DenseMap<const FieldDecl *, uint64_t> &FieldOffsets,
llvm::DenseMap<const CXXRecordDecl *, CharUnits> &BaseOffsets,
llvm::DenseMap<const CXXRecordDecl *, CharUnits> &VirtualBaseOffsets)
{
// We can't override unnamed declarations.
if (!Record->getIdentifier())
return false;
// Check whether we have a layout for this record.
llvm::StringMap<Layout>::iterator Known = Layouts.find(Record->getName());
if (Known == Layouts.end())
return false;
// Provide field layouts.
unsigned NumFields = 0;
for (RecordDecl::field_iterator F = Record->field_begin(),
FEnd = Record->field_end();
F != FEnd; ++F, ++NumFields) {
if (NumFields >= Known->second.FieldOffsets.size())
continue;
FieldOffsets[*F] = Known->second.FieldOffsets[NumFields];
}
// Wrong number of fields.
if (NumFields != Known->second.FieldOffsets.size())
return false;
Size = Known->second.Size;
Alignment = Known->second.Align;
return true;
}
void LayoutOverrideSource::dump() {
raw_ostream &OS = llvm::errs();
for (llvm::StringMap<Layout>::iterator L = Layouts.begin(),
LEnd = Layouts.end();
L != LEnd; ++L) {
OS << "Type: blah " << L->first() << '\n';
OS << " Size:" << L->second.Size << '\n';
OS << " Alignment:" << L->second.Align << '\n';
OS << " FieldOffsets: [";
for (unsigned I = 0, N = L->second.FieldOffsets.size(); I != N; ++I) {
if (I)
OS << ", ";
OS << L->second.FieldOffsets[I];
}
OS << "]\n";
}
}
|