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
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
|
// Copyright (C) 2017 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#include <private/qv4bytecodegenerator_p.h>
#include <private/qv4compilercontext_p.h>
#include <private/qqmljsastfwd_p.h>
QT_USE_NAMESPACE
using namespace QV4;
using namespace Moth;
void BytecodeGenerator::setLocation(const QQmlJS::SourceLocation &loc)
{
currentLine = static_cast<int>(loc.startLine);
currentSourceLocation = loc;
}
void BytecodeGenerator::incrementStatement()
{
++currentStatement;
}
int BytecodeGenerator::newRegister()
{
int t = currentReg++;
if (regCount < currentReg)
regCount = currentReg;
return t;
}
int BytecodeGenerator::newRegisterArray(int n)
{
int t = currentReg;
currentReg += n;
if (regCount < currentReg)
regCount = currentReg;
return t;
}
void BytecodeGenerator::packInstruction(I &i)
{
Instr::Type type = Instr::unpack(i.packed);
Q_ASSERT(int(type) < MOTH_NUM_INSTRUCTIONS());
type = Instr::narrowInstructionType(type);
int instructionsAsInts[sizeof(Instr)/sizeof(int)] = {};
int nMembers = Moth::InstrInfo::argumentCount[static_cast<int>(i.type)];
uchar *code = i.packed + Instr::encodedLength(type);
for (int j = 0; j < nMembers; ++j) {
instructionsAsInts[j] = qFromLittleEndian<qint32>(code + j * sizeof(int));
}
enum {
Normal,
Wide
} width = Normal;
for (int n = 0; n < nMembers; ++n) {
if (width == Normal && (static_cast<qint8>(instructionsAsInts[n]) != instructionsAsInts[n])) {
width = Wide;
break;
}
}
code = i.packed;
switch (width) {
case Normal:
code = Instr::pack(code, type);
for (int n = 0; n < nMembers; ++n) {
qint8 v = static_cast<qint8>(instructionsAsInts[n]);
memcpy(code, &v, 1);
code += 1;
}
i.size = code - i.packed;
if (i.offsetForJump != -1)
i.offsetForJump = i.size - 1;
break;
case Wide:
// nothing to do
break;
}
}
void BytecodeGenerator::adjustJumpOffsets()
{
for (int index = 0; index < instructions.size(); ++index) {
auto &i = instructions[index];
if (i.offsetForJump == -1) // no jump
continue;
Q_ASSERT(i.linkedLabel != -1 && labels.at(i.linkedLabel) != -1);
const auto &linkedInstruction = instructions.at(labels.at(i.linkedLabel));
qint8 *c = reinterpret_cast<qint8*>(i.packed + i.offsetForJump);
int jumpOffset = linkedInstruction.position - (i.position + i.size);
// qDebug() << "adjusting jump offset for instruction" << index << i.position << i.size << "offsetForJump" << i.offsetForJump << "target"
// << labels.at(i.linkedLabel) << linkedInstruction.position << "jumpOffset" << jumpOffset;
Instr::Type type = Instr::unpack(i.packed);
if (Instr::isWide(type)) {
Q_ASSERT(i.offsetForJump == i.size - 4);
qToLittleEndian<qint32>(jumpOffset, c);
} else {
Q_ASSERT(i.offsetForJump == i.size - 1);
qint8 o = jumpOffset;
Q_ASSERT(o == jumpOffset);
*c = o;
}
}
}
void BytecodeGenerator::compressInstructions()
{
// first round: compress all non jump instructions
int position = 0;
for (auto &i : instructions) {
i.position = position;
if (i.offsetForJump == -1)
packInstruction(i);
position += i.size;
}
adjustJumpOffsets();
// compress all jumps
position = 0;
for (auto &i : instructions) {
i.position = position;
if (i.offsetForJump != -1)
packInstruction(i);
position += i.size;
}
// adjust once again, as the packing above could have changed offsets
adjustJumpOffsets();
}
void BytecodeGenerator::finalize(Compiler::Context *context)
{
compressInstructions();
// collect content and line numbers
QByteArray code;
QVector<CompiledData::CodeOffsetToLineAndStatement> lineAndStatementNumbers;
currentLine = -1;
currentStatement = -1;
Q_UNUSED(startLine);
for (qsizetype i = 0; i < instructions.size(); i++) {
if (instructions[i].line != currentLine || instructions[i].statement != currentStatement) {
currentLine = instructions[i].line;
currentStatement = instructions[i].statement;
CompiledData::CodeOffsetToLineAndStatement entry;
entry.codeOffset = code.size();
entry.line = currentLine;
entry.statement = currentStatement;
lineAndStatementNumbers.append(entry);
}
if (m_sourceLocationTable)
m_sourceLocationTable->entries[i].offset = static_cast<quint32>(code.size());
code.append(reinterpret_cast<const char *>(instructions[i].packed), instructions[i].size);
}
context->code = code;
context->lineAndStatementNumberMapping = lineAndStatementNumbers;
context->sourceLocationTable = std::move(m_sourceLocationTable);
context->labelInfo.reserve(context->labelInfo.size() + _labelInfos.size());
for (const auto &li : _labelInfos)
context->labelInfo.push_back(instructions.at(labels.at(li.labelIndex)).position);
}
int BytecodeGenerator::addInstructionHelper(Instr::Type type, const Instr &i, int offsetOfOffset) {
if (lastInstrType == int(Instr::Type::StoreReg)) {
if (type == Instr::Type::LoadReg) {
if (i.LoadReg.reg == lastInstr.StoreReg.reg) {
// value is already in the accumulator
return -1;
}
}
if (type == Instr::Type::MoveReg) {
if (i.MoveReg.srcReg == lastInstr.StoreReg.reg) {
Instruction::StoreReg store;
store.reg = i.MoveReg.destReg;
addInstruction(store);
return -1;
}
}
}
lastInstrType = int(type);
lastInstr = i;
if (debugMode && type != Instr::Type::Debug) {
QT_WARNING_PUSH
QT_WARNING_DISABLE_GCC("-Wmaybe-uninitialized") // broken gcc warns about Instruction::Debug()
if (instructions.isEmpty() || currentLine != instructions.constLast().line) {
addInstruction(Instruction::Debug());
} else if (type == Instr::Type::Ret) {
currentLine = -currentLine;
addInstruction(Instruction::Debug());
currentLine = -currentLine;
currentSourceLocation = QQmlJS::SourceLocation();
}
QT_WARNING_POP
}
const int pos = instructions.size();
const int argCount = Moth::InstrInfo::argumentCount[static_cast<int>(type)];
int s = argCount*sizeof(int);
if (offsetOfOffset != -1)
offsetOfOffset += Instr::encodedLength(type);
I instr {
type,
static_cast<short>(s + Instr::encodedLength(type)),
0,
currentLine,
currentStatement,
offsetOfOffset,
-1,
"\0\0"
};
uchar *code = instr.packed;
code = Instr::pack(code, Instr::wideInstructionType(type));
for (int j = 0; j < argCount; ++j) {
qToLittleEndian<qint32>(i.argumentsAsInts[j], code);
code += sizeof(int);
}
instructions.append(instr);
if (m_sourceLocationTable)
m_sourceLocationTable->entries.append({ 0, currentSourceLocation });
return pos;
}
|
