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stringlengths 9
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| dir
stringlengths 25
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| lang
stringclasses 163
values | created_date
timestamp[s] | updated_date
timestamp[s] | repo_name
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values | repo_full_name
stringclasses 752
values | star
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|---|---|---|---|---|---|---|---|---|
```go
package stack
import "jvmgo/ch10/instructions/base"
import "jvmgo/ch10/rtda"
// Duplicate the top operand stack value
type DUP struct{ base.NoOperandsInstruction }
func (self *DUP) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
slot := stack.PopSlot()
stack.PushSlot(slot)
stack.PushSlot(slot)
}
// Duplicate the top operand stack value and insert two values down
type DUP_X1 struct{ base.NoOperandsInstruction }
func (self *DUP_X1) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
slot1 := stack.PopSlot()
slot2 := stack.PopSlot()
stack.PushSlot(slot1)
stack.PushSlot(slot2)
stack.PushSlot(slot1)
}
// Duplicate the top operand stack value and insert two or three values down
type DUP_X2 struct{ base.NoOperandsInstruction }
func (self *DUP_X2) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
slot1 := stack.PopSlot()
slot2 := stack.PopSlot()
slot3 := stack.PopSlot()
stack.PushSlot(slot1)
stack.PushSlot(slot3)
stack.PushSlot(slot2)
stack.PushSlot(slot1)
}
// Duplicate the top one or two operand stack values
type DUP2 struct{ base.NoOperandsInstruction }
func (self *DUP2) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
slot1 := stack.PopSlot()
slot2 := stack.PopSlot()
stack.PushSlot(slot2)
stack.PushSlot(slot1)
stack.PushSlot(slot2)
stack.PushSlot(slot1)
}
// Duplicate the top one or two operand stack values and insert two or three values down
type DUP2_X1 struct{ base.NoOperandsInstruction }
func (self *DUP2_X1) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
slot1 := stack.PopSlot()
slot2 := stack.PopSlot()
slot3 := stack.PopSlot()
stack.PushSlot(slot2)
stack.PushSlot(slot1)
stack.PushSlot(slot3)
stack.PushSlot(slot2)
stack.PushSlot(slot1)
}
// Duplicate the top one or two operand stack values and insert two, three, or four values down
type DUP2_X2 struct{ base.NoOperandsInstruction }
func (self *DUP2_X2) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
slot1 := stack.PopSlot()
slot2 := stack.PopSlot()
slot3 := stack.PopSlot()
slot4 := stack.PopSlot()
stack.PushSlot(slot2)
stack.PushSlot(slot1)
stack.PushSlot(slot4)
stack.PushSlot(slot3)
stack.PushSlot(slot2)
stack.PushSlot(slot1)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/instructions/stack/dup.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 584
|
```go
package conversions
import "jvmgo/ch10/instructions/base"
import "jvmgo/ch10/rtda"
// Convert int to byte
type I2B struct{ base.NoOperandsInstruction }
func (self *I2B) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
i := stack.PopInt()
b := int32(int8(i))
stack.PushInt(b)
}
// Convert int to char
type I2C struct{ base.NoOperandsInstruction }
func (self *I2C) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
i := stack.PopInt()
c := int32(uint16(i))
stack.PushInt(c)
}
// Convert int to short
type I2S struct{ base.NoOperandsInstruction }
func (self *I2S) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
i := stack.PopInt()
s := int32(int16(i))
stack.PushInt(s)
}
// Convert int to long
type I2L struct{ base.NoOperandsInstruction }
func (self *I2L) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
i := stack.PopInt()
l := int64(i)
stack.PushLong(l)
}
// Convert int to float
type I2F struct{ base.NoOperandsInstruction }
func (self *I2F) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
i := stack.PopInt()
f := float32(i)
stack.PushFloat(f)
}
// Convert int to double
type I2D struct{ base.NoOperandsInstruction }
func (self *I2D) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
i := stack.PopInt()
d := float64(i)
stack.PushDouble(d)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/instructions/conversions/i2x.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
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|
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| 1,605
| 392
|
```go
package conversions
import "jvmgo/ch10/instructions/base"
import "jvmgo/ch10/rtda"
// Convert long to double
type L2D struct{ base.NoOperandsInstruction }
func (self *L2D) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
l := stack.PopLong()
d := float64(l)
stack.PushDouble(d)
}
// Convert long to float
type L2F struct{ base.NoOperandsInstruction }
func (self *L2F) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
l := stack.PopLong()
f := float32(l)
stack.PushFloat(f)
}
// Convert long to int
type L2I struct{ base.NoOperandsInstruction }
func (self *L2I) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
l := stack.PopLong()
i := int32(l)
stack.PushInt(i)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/instructions/conversions/l2x.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
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| 1,605
| 206
|
```go
package control
import "jvmgo/ch10/instructions/base"
import "jvmgo/ch10/rtda"
// Branch always
type GOTO struct{ base.BranchInstruction }
func (self *GOTO) Execute(frame *rtda.Frame) {
base.Branch(frame, self.Offset)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/instructions/control/goto.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 63
|
```go
package conversions
import "jvmgo/ch10/instructions/base"
import "jvmgo/ch10/rtda"
// Convert float to double
type F2D struct{ base.NoOperandsInstruction }
func (self *F2D) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
f := stack.PopFloat()
d := float64(f)
stack.PushDouble(d)
}
// Convert float to int
type F2I struct{ base.NoOperandsInstruction }
func (self *F2I) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
f := stack.PopFloat()
i := int32(f)
stack.PushInt(i)
}
// Convert float to long
type F2L struct{ base.NoOperandsInstruction }
func (self *F2L) Execute(frame *rtda.Frame) {
stack := frame.OperandStack()
f := stack.PopFloat()
l := int64(f)
stack.PushLong(l)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/instructions/conversions/f2x.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 206
|
```go
package control
import "jvmgo/ch10/instructions/base"
import "jvmgo/ch10/rtda"
/*
tableswitch
<0-3 byte pad>
defaultbyte1
defaultbyte2
defaultbyte3
defaultbyte4
lowbyte1
lowbyte2
lowbyte3
lowbyte4
highbyte1
highbyte2
highbyte3
highbyte4
jump offsets...
*/
// Access jump table by index and jump
type TABLE_SWITCH struct {
defaultOffset int32
low int32
high int32
jumpOffsets []int32
}
func (self *TABLE_SWITCH) FetchOperands(reader *base.BytecodeReader) {
reader.SkipPadding()
self.defaultOffset = reader.ReadInt32()
self.low = reader.ReadInt32()
self.high = reader.ReadInt32()
jumpOffsetsCount := self.high - self.low + 1
self.jumpOffsets = reader.ReadInt32s(jumpOffsetsCount)
}
func (self *TABLE_SWITCH) Execute(frame *rtda.Frame) {
index := frame.OperandStack().PopInt()
var offset int
if index >= self.low && index <= self.high {
offset = int(self.jumpOffsets[index-self.low])
} else {
offset = int(self.defaultOffset)
}
base.Branch(frame, offset)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/instructions/control/tableswitch.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 274
|
```go
package control
import "jvmgo/ch10/instructions/base"
import "jvmgo/ch10/rtda"
// Return void from method
type RETURN struct{ base.NoOperandsInstruction }
func (self *RETURN) Execute(frame *rtda.Frame) {
frame.Thread().PopFrame()
}
// Return reference from method
type ARETURN struct{ base.NoOperandsInstruction }
func (self *ARETURN) Execute(frame *rtda.Frame) {
thread := frame.Thread()
currentFrame := thread.PopFrame()
invokerFrame := thread.TopFrame()
ref := currentFrame.OperandStack().PopRef()
invokerFrame.OperandStack().PushRef(ref)
}
// Return double from method
type DRETURN struct{ base.NoOperandsInstruction }
func (self *DRETURN) Execute(frame *rtda.Frame) {
thread := frame.Thread()
currentFrame := thread.PopFrame()
invokerFrame := thread.TopFrame()
val := currentFrame.OperandStack().PopDouble()
invokerFrame.OperandStack().PushDouble(val)
}
// Return float from method
type FRETURN struct{ base.NoOperandsInstruction }
func (self *FRETURN) Execute(frame *rtda.Frame) {
thread := frame.Thread()
currentFrame := thread.PopFrame()
invokerFrame := thread.TopFrame()
val := currentFrame.OperandStack().PopFloat()
invokerFrame.OperandStack().PushFloat(val)
}
// Return int from method
type IRETURN struct{ base.NoOperandsInstruction }
func (self *IRETURN) Execute(frame *rtda.Frame) {
thread := frame.Thread()
currentFrame := thread.PopFrame()
invokerFrame := thread.TopFrame()
val := currentFrame.OperandStack().PopInt()
invokerFrame.OperandStack().PushInt(val)
}
// Return double from method
type LRETURN struct{ base.NoOperandsInstruction }
func (self *LRETURN) Execute(frame *rtda.Frame) {
thread := frame.Thread()
currentFrame := thread.PopFrame()
invokerFrame := thread.TopFrame()
val := currentFrame.OperandStack().PopLong()
invokerFrame.OperandStack().PushLong(val)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/instructions/control/return.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 454
|
```go
package control
import "jvmgo/ch10/instructions/base"
import "jvmgo/ch10/rtda"
/*
lookupswitch
<0-3 byte pad>
defaultbyte1
defaultbyte2
defaultbyte3
defaultbyte4
npairs1
npairs2
npairs3
npairs4
match-offset pairs...
*/
// Access jump table by key match and jump
type LOOKUP_SWITCH struct {
defaultOffset int32
npairs int32
matchOffsets []int32
}
func (self *LOOKUP_SWITCH) FetchOperands(reader *base.BytecodeReader) {
reader.SkipPadding()
self.defaultOffset = reader.ReadInt32()
self.npairs = reader.ReadInt32()
self.matchOffsets = reader.ReadInt32s(self.npairs * 2)
}
func (self *LOOKUP_SWITCH) Execute(frame *rtda.Frame) {
key := frame.OperandStack().PopInt()
for i := int32(0); i < self.npairs*2; i += 2 {
if self.matchOffsets[i] == key {
offset := self.matchOffsets[i+1]
base.Branch(frame, int(offset))
return
}
}
base.Branch(frame, int(self.defaultOffset))
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/instructions/control/lookupswitch.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 259
|
```go
package classfile
/*
EnclosingMethod_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 class_index;
u2 method_index;
}
*/
type EnclosingMethodAttribute struct {
cp ConstantPool
classIndex uint16
methodIndex uint16
}
func (self *EnclosingMethodAttribute) readInfo(reader *ClassReader) {
self.classIndex = reader.readUint16()
self.methodIndex = reader.readUint16()
}
func (self *EnclosingMethodAttribute) ClassName() string {
return self.cp.getClassName(self.classIndex)
}
func (self *EnclosingMethodAttribute) MethodNameAndDescriptor() (string, string) {
if self.methodIndex > 0 {
return self.cp.getNameAndType(self.methodIndex)
} else {
return "", ""
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/attr_enclosing_method.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 170
|
```go
package classfile
/*
field_info {
u2 access_flags;
u2 name_index;
u2 descriptor_index;
u2 attributes_count;
attribute_info attributes[attributes_count];
}
method_info {
u2 access_flags;
u2 name_index;
u2 descriptor_index;
u2 attributes_count;
attribute_info attributes[attributes_count];
}
*/
type MemberInfo struct {
cp ConstantPool
accessFlags uint16
nameIndex uint16
descriptorIndex uint16
attributes []AttributeInfo
}
// read field or method table
func readMembers(reader *ClassReader, cp ConstantPool) []*MemberInfo {
memberCount := reader.readUint16()
members := make([]*MemberInfo, memberCount)
for i := range members {
members[i] = readMember(reader, cp)
}
return members
}
func readMember(reader *ClassReader, cp ConstantPool) *MemberInfo {
return &MemberInfo{
cp: cp,
accessFlags: reader.readUint16(),
nameIndex: reader.readUint16(),
descriptorIndex: reader.readUint16(),
attributes: readAttributes(reader, cp),
}
}
func (self *MemberInfo) AccessFlags() uint16 {
return self.accessFlags
}
func (self *MemberInfo) Name() string {
return self.cp.getUtf8(self.nameIndex)
}
func (self *MemberInfo) Descriptor() string {
return self.cp.getUtf8(self.descriptorIndex)
}
func (self *MemberInfo) CodeAttribute() *CodeAttribute {
for _, attrInfo := range self.attributes {
switch attrInfo.(type) {
case *CodeAttribute:
return attrInfo.(*CodeAttribute)
}
}
return nil
}
func (self *MemberInfo) ConstantValueAttribute() *ConstantValueAttribute {
for _, attrInfo := range self.attributes {
switch attrInfo.(type) {
case *ConstantValueAttribute:
return attrInfo.(*ConstantValueAttribute)
}
}
return nil
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/member_info.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 438
|
```go
package classfile
/*
CONSTANT_MethodHandle_info {
u1 tag;
u1 reference_kind;
u2 reference_index;
}
*/
type ConstantMethodHandleInfo struct {
referenceKind uint8
referenceIndex uint16
}
func (self *ConstantMethodHandleInfo) readInfo(reader *ClassReader) {
self.referenceKind = reader.readUint8()
self.referenceIndex = reader.readUint16()
}
/*
CONSTANT_MethodType_info {
u1 tag;
u2 descriptor_index;
}
*/
type ConstantMethodTypeInfo struct {
descriptorIndex uint16
}
func (self *ConstantMethodTypeInfo) readInfo(reader *ClassReader) {
self.descriptorIndex = reader.readUint16()
}
/*
CONSTANT_InvokeDynamic_info {
u1 tag;
u2 bootstrap_method_attr_index;
u2 name_and_type_index;
}
*/
type ConstantInvokeDynamicInfo struct {
bootstrapMethodAttrIndex uint16
nameAndTypeIndex uint16
}
func (self *ConstantInvokeDynamicInfo) readInfo(reader *ClassReader) {
self.bootstrapMethodAttrIndex = reader.readUint16()
self.nameAndTypeIndex = reader.readUint16()
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/cp_invoke_dynamic.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 241
|
```go
package classfile
/*
BootstrapMethods_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 num_bootstrap_methods;
{ u2 bootstrap_method_ref;
u2 num_bootstrap_arguments;
u2 bootstrap_arguments[num_bootstrap_arguments];
} bootstrap_methods[num_bootstrap_methods];
}
*/
type BootstrapMethodsAttribute struct {
bootstrapMethods []*BootstrapMethod
}
func (self *BootstrapMethodsAttribute) readInfo(reader *ClassReader) {
numBootstrapMethods := reader.readUint16()
self.bootstrapMethods = make([]*BootstrapMethod, numBootstrapMethods)
for i := range self.bootstrapMethods {
self.bootstrapMethods[i] = &BootstrapMethod{
bootstrapMethodRef: reader.readUint16(),
bootstrapArguments: reader.readUint16s(),
}
}
}
type BootstrapMethod struct {
bootstrapMethodRef uint16
bootstrapArguments []uint16
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/attr_bootstrap_methods.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 184
|
```go
package classfile
import "fmt"
type ConstantPool []ConstantInfo
func readConstantPool(reader *ClassReader) ConstantPool {
cpCount := int(reader.readUint16())
cp := make([]ConstantInfo, cpCount)
// The constant_pool table is indexed from 1 to constant_pool_count - 1.
for i := 1; i < cpCount; i++ {
cp[i] = readConstantInfo(reader, cp)
// path_to_url#jvms-4.4.5
// All 8-byte constants take up two entries in the constant_pool table of the class file.
// If a CONSTANT_Long_info or CONSTANT_Double_info structure is the item in the constant_pool
// table at index n, then the next usable item in the pool is located at index n+2.
// The constant_pool index n+1 must be valid but is considered unusable.
switch cp[i].(type) {
case *ConstantLongInfo, *ConstantDoubleInfo:
i++
}
}
return cp
}
func (self ConstantPool) getConstantInfo(index uint16) ConstantInfo {
if cpInfo := self[index]; cpInfo != nil {
return cpInfo
}
panic(fmt.Errorf("Invalid constant pool index: %v!", index))
}
func (self ConstantPool) getNameAndType(index uint16) (string, string) {
ntInfo := self.getConstantInfo(index).(*ConstantNameAndTypeInfo)
name := self.getUtf8(ntInfo.nameIndex)
_type := self.getUtf8(ntInfo.descriptorIndex)
return name, _type
}
func (self ConstantPool) getClassName(index uint16) string {
classInfo := self.getConstantInfo(index).(*ConstantClassInfo)
return self.getUtf8(classInfo.nameIndex)
}
func (self ConstantPool) getUtf8(index uint16) string {
utf8Info := self.getConstantInfo(index).(*ConstantUtf8Info)
return utf8Info.str
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/constant_pool.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 421
|
```go
package classfile
/*
Exceptions_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 number_of_exceptions;
u2 exception_index_table[number_of_exceptions];
}
*/
type ExceptionsAttribute struct {
exceptionIndexTable []uint16
}
func (self *ExceptionsAttribute) readInfo(reader *ClassReader) {
self.exceptionIndexTable = reader.readUint16s()
}
func (self *ExceptionsAttribute) ExceptionIndexTable() []uint16 {
return self.exceptionIndexTable
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/attr_exceptions.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 104
|
```go
package classfile
/*
CONSTANT_NameAndType_info {
u1 tag;
u2 name_index;
u2 descriptor_index;
}
*/
type ConstantNameAndTypeInfo struct {
nameIndex uint16
descriptorIndex uint16
}
func (self *ConstantNameAndTypeInfo) readInfo(reader *ClassReader) {
self.nameIndex = reader.readUint16()
self.descriptorIndex = reader.readUint16()
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/cp_name_and_type.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 88
|
```go
package classfile
/*
LineNumberTable_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 line_number_table_length;
{ u2 start_pc;
u2 line_number;
} line_number_table[line_number_table_length];
}
*/
type LineNumberTableAttribute struct {
lineNumberTable []*LineNumberTableEntry
}
type LineNumberTableEntry struct {
startPc uint16
lineNumber uint16
}
func (self *LineNumberTableAttribute) readInfo(reader *ClassReader) {
lineNumberTableLength := reader.readUint16()
self.lineNumberTable = make([]*LineNumberTableEntry, lineNumberTableLength)
for i := range self.lineNumberTable {
self.lineNumberTable[i] = &LineNumberTableEntry{
startPc: reader.readUint16(),
lineNumber: reader.readUint16(),
}
}
}
func (self *LineNumberTableAttribute) GetLineNumber(pc int) int {
for i := len(self.lineNumberTable) - 1; i >= 0; i-- {
entry := self.lineNumberTable[i]
if pc >= int(entry.startPc) {
return int(entry.lineNumber)
}
}
return -1
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/attr_line_number_table.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 255
|
```go
package classfile
/*
attribute_info {
u2 attribute_name_index;
u4 attribute_length;
u1 info[attribute_length];
}
*/
type UnparsedAttribute struct {
name string
length uint32
info []byte
}
func (self *UnparsedAttribute) readInfo(reader *ClassReader) {
self.info = reader.readBytes(self.length)
}
func (self *UnparsedAttribute) Info() []byte {
return self.info
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/attr_unparsed.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 96
|
```go
package classfile
/*
Deprecated_attribute {
u2 attribute_name_index;
u4 attribute_length;
}
*/
type DeprecatedAttribute struct {
MarkerAttribute
}
/*
Synthetic_attribute {
u2 attribute_name_index;
u4 attribute_length;
}
*/
type SyntheticAttribute struct {
MarkerAttribute
}
type MarkerAttribute struct{}
func (self *MarkerAttribute) readInfo(reader *ClassReader) {
// read nothing
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/attr_markers.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 90
|
```go
package classfile
/*
CONSTANT_Class_info {
u1 tag;
u2 name_index;
}
*/
type ConstantClassInfo struct {
cp ConstantPool
nameIndex uint16
}
func (self *ConstantClassInfo) readInfo(reader *ClassReader) {
self.nameIndex = reader.readUint16()
}
func (self *ConstantClassInfo) Name() string {
return self.cp.getUtf8(self.nameIndex)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/cp_class.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 90
|
```go
package classfile
// Constant pool tags
const (
CONSTANT_Class = 7
CONSTANT_Fieldref = 9
CONSTANT_Methodref = 10
CONSTANT_InterfaceMethodref = 11
CONSTANT_String = 8
CONSTANT_Integer = 3
CONSTANT_Float = 4
CONSTANT_Long = 5
CONSTANT_Double = 6
CONSTANT_NameAndType = 12
CONSTANT_Utf8 = 1
CONSTANT_MethodHandle = 15
CONSTANT_MethodType = 16
CONSTANT_InvokeDynamic = 18
)
/*
cp_info {
u1 tag;
u1 info[];
}
*/
type ConstantInfo interface {
readInfo(reader *ClassReader)
}
func readConstantInfo(reader *ClassReader, cp ConstantPool) ConstantInfo {
tag := reader.readUint8()
c := newConstantInfo(tag, cp)
c.readInfo(reader)
return c
}
// todo ugly code
func newConstantInfo(tag uint8, cp ConstantPool) ConstantInfo {
switch tag {
case CONSTANT_Integer:
return &ConstantIntegerInfo{}
case CONSTANT_Float:
return &ConstantFloatInfo{}
case CONSTANT_Long:
return &ConstantLongInfo{}
case CONSTANT_Double:
return &ConstantDoubleInfo{}
case CONSTANT_Utf8:
return &ConstantUtf8Info{}
case CONSTANT_String:
return &ConstantStringInfo{cp: cp}
case CONSTANT_Class:
return &ConstantClassInfo{cp: cp}
case CONSTANT_Fieldref:
return &ConstantFieldrefInfo{ConstantMemberrefInfo{cp: cp}}
case CONSTANT_Methodref:
return &ConstantMethodrefInfo{ConstantMemberrefInfo{cp: cp}}
case CONSTANT_InterfaceMethodref:
return &ConstantInterfaceMethodrefInfo{ConstantMemberrefInfo{cp: cp}}
case CONSTANT_NameAndType:
return &ConstantNameAndTypeInfo{}
case CONSTANT_MethodType:
return &ConstantMethodTypeInfo{}
case CONSTANT_MethodHandle:
return &ConstantMethodHandleInfo{}
case CONSTANT_InvokeDynamic:
return &ConstantInvokeDynamicInfo{}
default:
panic("java.lang.ClassFormatError: constant pool tag!")
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/constant_info.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 468
|
```go
package classfile
import "math"
/*
CONSTANT_Integer_info {
u1 tag;
u4 bytes;
}
*/
type ConstantIntegerInfo struct {
val int32
}
func (self *ConstantIntegerInfo) readInfo(reader *ClassReader) {
bytes := reader.readUint32()
self.val = int32(bytes)
}
func (self *ConstantIntegerInfo) Value() int32 {
return self.val
}
/*
CONSTANT_Float_info {
u1 tag;
u4 bytes;
}
*/
type ConstantFloatInfo struct {
val float32
}
func (self *ConstantFloatInfo) readInfo(reader *ClassReader) {
bytes := reader.readUint32()
self.val = math.Float32frombits(bytes)
}
func (self *ConstantFloatInfo) Value() float32 {
return self.val
}
/*
CONSTANT_Long_info {
u1 tag;
u4 high_bytes;
u4 low_bytes;
}
*/
type ConstantLongInfo struct {
val int64
}
func (self *ConstantLongInfo) readInfo(reader *ClassReader) {
bytes := reader.readUint64()
self.val = int64(bytes)
}
func (self *ConstantLongInfo) Value() int64 {
return self.val
}
/*
CONSTANT_Double_info {
u1 tag;
u4 high_bytes;
u4 low_bytes;
}
*/
type ConstantDoubleInfo struct {
val float64
}
func (self *ConstantDoubleInfo) readInfo(reader *ClassReader) {
bytes := reader.readUint64()
self.val = math.Float64frombits(bytes)
}
func (self *ConstantDoubleInfo) Value() float64 {
return self.val
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/cp_numeric.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 341
|
```go
package classfile
/*
SourceFile_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 sourcefile_index;
}
*/
type SourceFileAttribute struct {
cp ConstantPool
sourceFileIndex uint16
}
func (self *SourceFileAttribute) readInfo(reader *ClassReader) {
self.sourceFileIndex = reader.readUint16()
}
func (self *SourceFileAttribute) FileName() string {
return self.cp.getUtf8(self.sourceFileIndex)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/attr_source_file.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 101
|
```go
package classfile
import "fmt"
/*
ClassFile {
u4 magic;
u2 minor_version;
u2 major_version;
u2 constant_pool_count;
cp_info constant_pool[constant_pool_count-1];
u2 access_flags;
u2 this_class;
u2 super_class;
u2 interfaces_count;
u2 interfaces[interfaces_count];
u2 fields_count;
field_info fields[fields_count];
u2 methods_count;
method_info methods[methods_count];
u2 attributes_count;
attribute_info attributes[attributes_count];
}
*/
type ClassFile struct {
//magic uint32
minorVersion uint16
majorVersion uint16
constantPool ConstantPool
accessFlags uint16
thisClass uint16
superClass uint16
interfaces []uint16
fields []*MemberInfo
methods []*MemberInfo
attributes []AttributeInfo
}
func Parse(classData []byte) (cf *ClassFile, err error) {
defer func() {
if r := recover(); r != nil {
var ok bool
err, ok = r.(error)
if !ok {
err = fmt.Errorf("%v", r)
}
}
}()
cr := &ClassReader{classData}
cf = &ClassFile{}
cf.read(cr)
return
}
func (self *ClassFile) read(reader *ClassReader) {
self.readAndCheckMagic(reader)
self.readAndCheckVersion(reader)
self.constantPool = readConstantPool(reader)
self.accessFlags = reader.readUint16()
self.thisClass = reader.readUint16()
self.superClass = reader.readUint16()
self.interfaces = reader.readUint16s()
self.fields = readMembers(reader, self.constantPool)
self.methods = readMembers(reader, self.constantPool)
self.attributes = readAttributes(reader, self.constantPool)
}
func (self *ClassFile) readAndCheckMagic(reader *ClassReader) {
magic := reader.readUint32()
if magic != 0xCAFEBABE {
panic("java.lang.ClassFormatError: magic!")
}
}
func (self *ClassFile) readAndCheckVersion(reader *ClassReader) {
self.minorVersion = reader.readUint16()
self.majorVersion = reader.readUint16()
switch self.majorVersion {
case 45:
return
case 46, 47, 48, 49, 50, 51, 52:
if self.minorVersion == 0 {
return
}
}
panic("java.lang.UnsupportedClassVersionError!")
}
func (self *ClassFile) MinorVersion() uint16 {
return self.minorVersion
}
func (self *ClassFile) MajorVersion() uint16 {
return self.majorVersion
}
func (self *ClassFile) ConstantPool() ConstantPool {
return self.constantPool
}
func (self *ClassFile) AccessFlags() uint16 {
return self.accessFlags
}
func (self *ClassFile) Fields() []*MemberInfo {
return self.fields
}
func (self *ClassFile) Methods() []*MemberInfo {
return self.methods
}
func (self *ClassFile) ClassName() string {
return self.constantPool.getClassName(self.thisClass)
}
func (self *ClassFile) SuperClassName() string {
if self.superClass > 0 {
return self.constantPool.getClassName(self.superClass)
}
return ""
}
func (self *ClassFile) InterfaceNames() []string {
interfaceNames := make([]string, len(self.interfaces))
for i, cpIndex := range self.interfaces {
interfaceNames[i] = self.constantPool.getClassName(cpIndex)
}
return interfaceNames
}
func (self *ClassFile) SourceFileAttribute() *SourceFileAttribute {
for _, attrInfo := range self.attributes {
switch attrInfo.(type) {
case *SourceFileAttribute:
return attrInfo.(*SourceFileAttribute)
}
}
return nil
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/class_file.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 845
|
```go
package classfile
/*
ConstantValue_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 constantvalue_index;
}
*/
type ConstantValueAttribute struct {
constantValueIndex uint16
}
func (self *ConstantValueAttribute) readInfo(reader *ClassReader) {
self.constantValueIndex = reader.readUint16()
}
func (self *ConstantValueAttribute) ConstantValueIndex() uint16 {
return self.constantValueIndex
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/attr_constant_value.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 95
|
```go
package classfile
/*
LocalVariableTable_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 local_variable_table_length;
{ u2 start_pc;
u2 length;
u2 name_index;
u2 descriptor_index;
u2 index;
} local_variable_table[local_variable_table_length];
}
*/
type LocalVariableTableAttribute struct {
localVariableTable []*LocalVariableTableEntry
}
type LocalVariableTableEntry struct {
startPc uint16
length uint16
nameIndex uint16
descriptorIndex uint16
index uint16
}
func (self *LocalVariableTableAttribute) readInfo(reader *ClassReader) {
localVariableTableLength := reader.readUint16()
self.localVariableTable = make([]*LocalVariableTableEntry, localVariableTableLength)
for i := range self.localVariableTable {
self.localVariableTable[i] = &LocalVariableTableEntry{
startPc: reader.readUint16(),
length: reader.readUint16(),
nameIndex: reader.readUint16(),
descriptorIndex: reader.readUint16(),
index: reader.readUint16(),
}
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/attr_local_variable_table.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 251
|
```go
package classfile
import "encoding/binary"
type ClassReader struct {
data []byte
}
// u1
func (self *ClassReader) readUint8() uint8 {
val := self.data[0]
self.data = self.data[1:]
return val
}
// u2
func (self *ClassReader) readUint16() uint16 {
val := binary.BigEndian.Uint16(self.data)
self.data = self.data[2:]
return val
}
// u4
func (self *ClassReader) readUint32() uint32 {
val := binary.BigEndian.Uint32(self.data)
self.data = self.data[4:]
return val
}
func (self *ClassReader) readUint64() uint64 {
val := binary.BigEndian.Uint64(self.data)
self.data = self.data[8:]
return val
}
func (self *ClassReader) readUint16s() []uint16 {
n := self.readUint16()
s := make([]uint16, n)
for i := range s {
s[i] = self.readUint16()
}
return s
}
func (self *ClassReader) readBytes(n uint32) []byte {
bytes := self.data[:n]
self.data = self.data[n:]
return bytes
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/class_reader.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 262
|
```go
package classfile
/*
Signature_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 signature_index;
}
*/
type SignatureAttribute struct {
cp ConstantPool
signatureIndex uint16
}
func (self *SignatureAttribute) readInfo(reader *ClassReader) {
self.signatureIndex = reader.readUint16()
}
func (self *SignatureAttribute) Signature() string {
return self.cp.getUtf8(self.signatureIndex)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/attr_signature.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 94
|
```go
package classfile
/*
InnerClasses_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 number_of_classes;
{ u2 inner_class_info_index;
u2 outer_class_info_index;
u2 inner_name_index;
u2 inner_class_access_flags;
} classes[number_of_classes];
}
*/
type InnerClassesAttribute struct {
classes []*InnerClassInfo
}
type InnerClassInfo struct {
innerClassInfoIndex uint16
outerClassInfoIndex uint16
innerNameIndex uint16
innerClassAccessFlags uint16
}
func (self *InnerClassesAttribute) readInfo(reader *ClassReader) {
numberOfClasses := reader.readUint16()
self.classes = make([]*InnerClassInfo, numberOfClasses)
for i := range self.classes {
self.classes[i] = &InnerClassInfo{
innerClassInfoIndex: reader.readUint16(),
outerClassInfoIndex: reader.readUint16(),
innerNameIndex: reader.readUint16(),
innerClassAccessFlags: reader.readUint16(),
}
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/attr_inner_classes.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 238
|
```go
package classfile
import "fmt"
import "unicode/utf16"
/*
CONSTANT_Utf8_info {
u1 tag;
u2 length;
u1 bytes[length];
}
*/
type ConstantUtf8Info struct {
str string
}
func (self *ConstantUtf8Info) readInfo(reader *ClassReader) {
length := uint32(reader.readUint16())
bytes := reader.readBytes(length)
self.str = decodeMUTF8(bytes)
}
func (self *ConstantUtf8Info) Str() string {
return self.str
}
/*
func decodeMUTF8(bytes []byte) string {
return string(bytes) // not correct!
}
*/
// mutf8 -> utf16 -> utf32 -> string
// see java.io.DataInputStream.readUTF(DataInput)
func decodeMUTF8(bytearr []byte) string {
utflen := len(bytearr)
chararr := make([]uint16, utflen)
var c, char2, char3 uint16
count := 0
chararr_count := 0
for count < utflen {
c = uint16(bytearr[count])
if c > 127 {
break
}
count++
chararr[chararr_count] = c
chararr_count++
}
for count < utflen {
c = uint16(bytearr[count])
switch c >> 4 {
case 0, 1, 2, 3, 4, 5, 6, 7:
/* 0xxxxxxx*/
count++
chararr[chararr_count] = c
chararr_count++
case 12, 13:
/* 110x xxxx 10xx xxxx*/
count += 2
if count > utflen {
panic("malformed input: partial character at end")
}
char2 = uint16(bytearr[count-1])
if char2&0xC0 != 0x80 {
panic(fmt.Errorf("malformed input around byte %v", count))
}
chararr[chararr_count] = c&0x1F<<6 | char2&0x3F
chararr_count++
case 14:
/* 1110 xxxx 10xx xxxx 10xx xxxx*/
count += 3
if count > utflen {
panic("malformed input: partial character at end")
}
char2 = uint16(bytearr[count-2])
char3 = uint16(bytearr[count-1])
if char2&0xC0 != 0x80 || char3&0xC0 != 0x80 {
panic(fmt.Errorf("malformed input around byte %v", (count - 1)))
}
chararr[chararr_count] = c&0x0F<<12 | char2&0x3F<<6 | char3&0x3F<<0
chararr_count++
default:
/* 10xx xxxx, 1111 xxxx */
panic(fmt.Errorf("malformed input around byte %v", count))
}
}
// The number of chars produced may be less than utflen
chararr = chararr[0:chararr_count]
runes := utf16.Decode(chararr)
return string(runes)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/cp_utf8.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 702
|
```go
package classfile
/*
Code_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 max_stack;
u2 max_locals;
u4 code_length;
u1 code[code_length];
u2 exception_table_length;
{ u2 start_pc;
u2 end_pc;
u2 handler_pc;
u2 catch_type;
} exception_table[exception_table_length];
u2 attributes_count;
attribute_info attributes[attributes_count];
}
*/
type CodeAttribute struct {
cp ConstantPool
maxStack uint16
maxLocals uint16
code []byte
exceptionTable []*ExceptionTableEntry
attributes []AttributeInfo
}
func (self *CodeAttribute) readInfo(reader *ClassReader) {
self.maxStack = reader.readUint16()
self.maxLocals = reader.readUint16()
codeLength := reader.readUint32()
self.code = reader.readBytes(codeLength)
self.exceptionTable = readExceptionTable(reader)
self.attributes = readAttributes(reader, self.cp)
}
func (self *CodeAttribute) MaxStack() uint {
return uint(self.maxStack)
}
func (self *CodeAttribute) MaxLocals() uint {
return uint(self.maxLocals)
}
func (self *CodeAttribute) Code() []byte {
return self.code
}
func (self *CodeAttribute) ExceptionTable() []*ExceptionTableEntry {
return self.exceptionTable
}
func (self *CodeAttribute) LineNumberTableAttribute() *LineNumberTableAttribute {
for _, attrInfo := range self.attributes {
switch attrInfo.(type) {
case *LineNumberTableAttribute:
return attrInfo.(*LineNumberTableAttribute)
}
}
return nil
}
type ExceptionTableEntry struct {
startPc uint16
endPc uint16
handlerPc uint16
catchType uint16
}
func readExceptionTable(reader *ClassReader) []*ExceptionTableEntry {
exceptionTableLength := reader.readUint16()
exceptionTable := make([]*ExceptionTableEntry, exceptionTableLength)
for i := range exceptionTable {
exceptionTable[i] = &ExceptionTableEntry{
startPc: reader.readUint16(),
endPc: reader.readUint16(),
handlerPc: reader.readUint16(),
catchType: reader.readUint16(),
}
}
return exceptionTable
}
func (self *ExceptionTableEntry) StartPc() uint16 {
return self.startPc
}
func (self *ExceptionTableEntry) EndPc() uint16 {
return self.endPc
}
func (self *ExceptionTableEntry) HandlerPc() uint16 {
return self.handlerPc
}
func (self *ExceptionTableEntry) CatchType() uint16 {
return self.catchType
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/attr_code.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 583
|
```go
package classfile
/*
CONSTANT_Fieldref_info {
u1 tag;
u2 class_index;
u2 name_and_type_index;
}
CONSTANT_Methodref_info {
u1 tag;
u2 class_index;
u2 name_and_type_index;
}
CONSTANT_InterfaceMethodref_info {
u1 tag;
u2 class_index;
u2 name_and_type_index;
}
*/
type ConstantFieldrefInfo struct{ ConstantMemberrefInfo }
type ConstantMethodrefInfo struct{ ConstantMemberrefInfo }
type ConstantInterfaceMethodrefInfo struct{ ConstantMemberrefInfo }
type ConstantMemberrefInfo struct {
cp ConstantPool
classIndex uint16
nameAndTypeIndex uint16
}
func (self *ConstantMemberrefInfo) readInfo(reader *ClassReader) {
self.classIndex = reader.readUint16()
self.nameAndTypeIndex = reader.readUint16()
}
func (self *ConstantMemberrefInfo) ClassName() string {
return self.cp.getClassName(self.classIndex)
}
func (self *ConstantMemberrefInfo) NameAndDescriptor() (string, string) {
return self.cp.getNameAndType(self.nameAndTypeIndex)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/cp_member_ref.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 241
|
```go
package classfile
var (
_attrDeprecated = &DeprecatedAttribute{}
_attrSynthetic = &SyntheticAttribute{}
)
/*
attribute_info {
u2 attribute_name_index;
u4 attribute_length;
u1 info[attribute_length];
}
*/
type AttributeInfo interface {
readInfo(reader *ClassReader)
}
func readAttributes(reader *ClassReader, cp ConstantPool) []AttributeInfo {
attributesCount := reader.readUint16()
attributes := make([]AttributeInfo, attributesCount)
for i := range attributes {
attributes[i] = readAttribute(reader, cp)
}
return attributes
}
func readAttribute(reader *ClassReader, cp ConstantPool) AttributeInfo {
attrNameIndex := reader.readUint16()
attrName := cp.getUtf8(attrNameIndex)
attrLen := reader.readUint32()
attrInfo := newAttributeInfo(attrName, attrLen, cp)
attrInfo.readInfo(reader)
return attrInfo
}
func newAttributeInfo(attrName string, attrLen uint32, cp ConstantPool) AttributeInfo {
switch attrName {
// case "AnnotationDefault":
case "BootstrapMethods":
return &BootstrapMethodsAttribute{}
case "Code":
return &CodeAttribute{cp: cp}
case "ConstantValue":
return &ConstantValueAttribute{}
case "Deprecated":
return _attrDeprecated
case "EnclosingMethod":
return &EnclosingMethodAttribute{cp: cp}
case "Exceptions":
return &ExceptionsAttribute{}
case "InnerClasses":
return &InnerClassesAttribute{}
case "LineNumberTable":
return &LineNumberTableAttribute{}
case "LocalVariableTable":
return &LocalVariableTableAttribute{}
case "LocalVariableTypeTable":
return &LocalVariableTypeTableAttribute{}
// case "MethodParameters":
// case "RuntimeInvisibleAnnotations":
// case "RuntimeInvisibleParameterAnnotations":
// case "RuntimeInvisibleTypeAnnotations":
// case "RuntimeVisibleAnnotations":
// case "RuntimeVisibleParameterAnnotations":
// case "RuntimeVisibleTypeAnnotations":
case "Signature":
return &SignatureAttribute{cp: cp}
case "SourceFile":
return &SourceFileAttribute{cp: cp}
// case "SourceDebugExtension":
// case "StackMapTable":
case "Synthetic":
return _attrSynthetic
default:
return &UnparsedAttribute{attrName, attrLen, nil}
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/attribute_info.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 496
|
```go
package classfile
/*
CONSTANT_String_info {
u1 tag;
u2 string_index;
}
*/
type ConstantStringInfo struct {
cp ConstantPool
stringIndex uint16
}
func (self *ConstantStringInfo) readInfo(reader *ClassReader) {
self.stringIndex = reader.readUint16()
}
func (self *ConstantStringInfo) String() string {
return self.cp.getUtf8(self.stringIndex)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/cp_string.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 90
|
```go
package native
import "jvmgo/ch10/rtda"
type NativeMethod func(frame *rtda.Frame)
var registry = map[string]NativeMethod{}
func emptyNativeMethod(frame *rtda.Frame) {
// do nothing
}
func Register(className, methodName, methodDescriptor string, method NativeMethod) {
key := className + "~" + methodName + "~" + methodDescriptor
registry[key] = method
}
func FindNativeMethod(className, methodName, methodDescriptor string) NativeMethod {
key := className + "~" + methodName + "~" + methodDescriptor
if method, ok := registry[key]; ok {
return method
}
if methodDescriptor == "()V" && methodName == "registerNatives" {
return emptyNativeMethod
}
return nil
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/native/registry.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 165
|
```go
package classfile
/*
LocalVariableTypeTable_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 local_variable_type_table_length;
{ u2 start_pc;
u2 length;
u2 name_index;
u2 signature_index;
u2 index;
} local_variable_type_table[local_variable_type_table_length];
}
*/
type LocalVariableTypeTableAttribute struct {
localVariableTypeTable []*LocalVariableTypeTableEntry
}
type LocalVariableTypeTableEntry struct {
startPc uint16
length uint16
nameIndex uint16
signatureIndex uint16
index uint16
}
func (self *LocalVariableTypeTableAttribute) readInfo(reader *ClassReader) {
localVariableTypeTableLength := reader.readUint16()
self.localVariableTypeTable = make([]*LocalVariableTypeTableEntry, localVariableTypeTableLength)
for i := range self.localVariableTypeTable {
self.localVariableTypeTable[i] = &LocalVariableTypeTableEntry{
startPc: reader.readUint16(),
length: reader.readUint16(),
nameIndex: reader.readUint16(),
signatureIndex: reader.readUint16(),
index: reader.readUint16(),
}
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classfile/attr_local_variable_type_table.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 267
|
```go
package lang
import "jvmgo/ch10/native"
import "jvmgo/ch10/rtda"
import "jvmgo/ch10/rtda/heap"
const jlString = "java/lang/String"
func init() {
native.Register(jlString, "intern", "()Ljava/lang/String;", intern)
}
// public native String intern();
// ()Ljava/lang/String;
func intern(frame *rtda.Frame) {
this := frame.LocalVars().GetThis()
interned := heap.InternString(this)
frame.OperandStack().PushRef(interned)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/native/java/lang/String.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 121
|
```go
package lang
import "fmt"
import "jvmgo/ch10/native"
import "jvmgo/ch10/rtda"
import "jvmgo/ch10/rtda/heap"
const jlThrowable = "java/lang/Throwable"
type StackTraceElement struct {
fileName string
className string
methodName string
lineNumber int
}
func (self *StackTraceElement) String() string {
return fmt.Sprintf("%s.%s(%s:%d)",
self.className, self.methodName, self.fileName, self.lineNumber)
}
func init() {
native.Register(jlThrowable, "fillInStackTrace", "(I)Ljava/lang/Throwable;", fillInStackTrace)
}
// private native Throwable fillInStackTrace(int dummy);
// (I)Ljava/lang/Throwable;
func fillInStackTrace(frame *rtda.Frame) {
this := frame.LocalVars().GetThis()
frame.OperandStack().PushRef(this)
stes := createStackTraceElements(this, frame.Thread())
this.SetExtra(stes)
}
func createStackTraceElements(tObj *heap.Object, thread *rtda.Thread) []*StackTraceElement {
skip := distanceToObject(tObj.Class()) + 2
frames := thread.GetFrames()[skip:]
stes := make([]*StackTraceElement, len(frames))
for i, frame := range frames {
stes[i] = createStackTraceElement(frame)
}
return stes
}
func distanceToObject(class *heap.Class) int {
distance := 0
for c := class.SuperClass(); c != nil; c = c.SuperClass() {
distance++
}
return distance
}
func createStackTraceElement(frame *rtda.Frame) *StackTraceElement {
method := frame.Method()
class := method.Class()
return &StackTraceElement{
fileName: class.SourceFile(),
className: class.JavaName(),
methodName: method.Name(),
lineNumber: method.GetLineNumber(frame.NextPC() - 1),
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/native/java/lang/Throwable.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 406
|
```go
package lang
import "jvmgo/ch10/native"
import "jvmgo/ch10/rtda"
import "jvmgo/ch10/rtda/heap"
const jlSystem = "java/lang/System"
func init() {
native.Register(jlSystem, "arraycopy", "(Ljava/lang/Object;ILjava/lang/Object;II)V", arraycopy)
}
// public static native void arraycopy(Object src, int srcPos, Object dest, int destPos, int length)
// (Ljava/lang/Object;ILjava/lang/Object;II)V
func arraycopy(frame *rtda.Frame) {
vars := frame.LocalVars()
src := vars.GetRef(0)
srcPos := vars.GetInt(1)
dest := vars.GetRef(2)
destPos := vars.GetInt(3)
length := vars.GetInt(4)
if src == nil || dest == nil {
panic("java.lang.NullPointerException")
}
if !checkArrayCopy(src, dest) {
panic("java.lang.ArrayStoreException")
}
if srcPos < 0 || destPos < 0 || length < 0 ||
srcPos+length > src.ArrayLength() ||
destPos+length > dest.ArrayLength() {
panic("java.lang.IndexOutOfBoundsException")
}
heap.ArrayCopy(src, dest, srcPos, destPos, length)
}
func checkArrayCopy(src, dest *heap.Object) bool {
srcClass := src.Class()
destClass := dest.Class()
if !srcClass.IsArray() || !destClass.IsArray() {
return false
}
if srcClass.ComponentClass().IsPrimitive() ||
destClass.ComponentClass().IsPrimitive() {
return srcClass == destClass
}
return true
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/native/java/lang/System.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 360
|
```go
package lang
import "unsafe"
import "jvmgo/ch10/native"
import "jvmgo/ch10/rtda"
const jlObject = "java/lang/Object"
func init() {
native.Register(jlObject, "getClass", "()Ljava/lang/Class;", getClass)
native.Register(jlObject, "hashCode", "()I", hashCode)
native.Register(jlObject, "clone", "()Ljava/lang/Object;", clone)
}
// public final native Class<?> getClass();
// ()Ljava/lang/Class;
func getClass(frame *rtda.Frame) {
this := frame.LocalVars().GetThis()
class := this.Class().JClass()
frame.OperandStack().PushRef(class)
}
// public native int hashCode();
// ()I
func hashCode(frame *rtda.Frame) {
this := frame.LocalVars().GetThis()
hash := int32(uintptr(unsafe.Pointer(this)))
frame.OperandStack().PushInt(hash)
}
// protected native Object clone() throws CloneNotSupportedException;
// ()Ljava/lang/Object;
func clone(frame *rtda.Frame) {
this := frame.LocalVars().GetThis()
cloneable := this.Class().Loader().LoadClass("java/lang/Cloneable")
if !this.Class().IsImplements(cloneable) {
panic("java.lang.CloneNotSupportedException")
}
frame.OperandStack().PushRef(this.Clone())
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/native/java/lang/Object.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 280
|
```go
package lang
import "math"
import "jvmgo/ch10/native"
import "jvmgo/ch10/rtda"
const jlDouble = "java/lang/Double"
func init() {
native.Register(jlDouble, "doubleToRawLongBits", "(D)J", doubleToRawLongBits)
native.Register(jlDouble, "longBitsToDouble", "(J)D", longBitsToDouble)
}
// public static native long doubleToRawLongBits(double value);
// (D)J
func doubleToRawLongBits(frame *rtda.Frame) {
value := frame.LocalVars().GetDouble(0)
bits := math.Float64bits(value) // todo
frame.OperandStack().PushLong(int64(bits))
}
// public static native double longBitsToDouble(long bits);
// (J)D
func longBitsToDouble(frame *rtda.Frame) {
bits := frame.LocalVars().GetLong(0)
value := math.Float64frombits(uint64(bits)) // todo
frame.OperandStack().PushDouble(value)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/native/java/lang/Double.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 226
|
```go
package lang
import "math"
import "jvmgo/ch10/native"
import "jvmgo/ch10/rtda"
const jlFloat = "java/lang/Float"
func init() {
native.Register(jlFloat, "floatToRawIntBits", "(F)I", floatToRawIntBits)
native.Register(jlFloat, "intBitsToFloat", "(I)F", intBitsToFloat)
}
// public static native int floatToRawIntBits(float value);
// (F)I
func floatToRawIntBits(frame *rtda.Frame) {
value := frame.LocalVars().GetFloat(0)
bits := math.Float32bits(value) // todo
frame.OperandStack().PushInt(int32(bits))
}
// public static native float intBitsToFloat(int bits);
// (I)F
func intBitsToFloat(frame *rtda.Frame) {
bits := frame.LocalVars().GetInt(0)
value := math.Float32frombits(uint32(bits)) // todo
frame.OperandStack().PushFloat(value)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/native/java/lang/Float.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 225
|
```go
package misc
import "jvmgo/ch10/instructions/base"
import "jvmgo/ch10/native"
import "jvmgo/ch10/rtda"
import "jvmgo/ch10/rtda/heap"
func init() {
native.Register("sun/misc/VM", "initialize", "()V", initialize)
}
// private static native void initialize();
// ()V
func initialize(frame *rtda.Frame) { // hack!
vmClass := frame.Method().Class()
savedProps := vmClass.GetRefVar("savedProps", "Ljava/util/Properties;")
key := heap.JString(vmClass.Loader(), "foo")
val := heap.JString(vmClass.Loader(), "bar")
frame.OperandStack().PushRef(savedProps)
frame.OperandStack().PushRef(key)
frame.OperandStack().PushRef(val)
propsClass := vmClass.Loader().LoadClass("java/util/Properties")
setPropMethod := propsClass.GetInstanceMethod("setProperty",
"(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Object;")
base.InvokeMethod(frame, setPropMethod)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/native/sun/misc/VM.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 224
|
```go
package lang
import "jvmgo/ch10/native"
import "jvmgo/ch10/rtda"
import "jvmgo/ch10/rtda/heap"
const jlClass = "java/lang/Class"
func init() {
native.Register(jlClass, "getPrimitiveClass", "(Ljava/lang/String;)Ljava/lang/Class;", getPrimitiveClass)
native.Register(jlClass, "getName0", "()Ljava/lang/String;", getName0)
native.Register(jlClass, "desiredAssertionStatus0", "(Ljava/lang/Class;)Z", desiredAssertionStatus0)
//native.Register(jlClass, "isInterface", "()Z", isInterface)
//native.Register(jlClass, "isPrimitive", "()Z", isPrimitive)
}
// static native Class<?> getPrimitiveClass(String name);
// (Ljava/lang/String;)Ljava/lang/Class;
func getPrimitiveClass(frame *rtda.Frame) {
nameObj := frame.LocalVars().GetRef(0)
name := heap.GoString(nameObj)
loader := frame.Method().Class().Loader()
class := loader.LoadClass(name).JClass()
frame.OperandStack().PushRef(class)
}
// private native String getName0();
// ()Ljava/lang/String;
func getName0(frame *rtda.Frame) {
this := frame.LocalVars().GetThis()
class := this.Extra().(*heap.Class)
name := class.JavaName()
nameObj := heap.JString(class.Loader(), name)
frame.OperandStack().PushRef(nameObj)
}
// private static native boolean desiredAssertionStatus0(Class<?> clazz);
// (Ljava/lang/Class;)Z
func desiredAssertionStatus0(frame *rtda.Frame) {
// todo
frame.OperandStack().PushBoolean(false)
}
// public native boolean isInterface();
// ()Z
func isInterface(frame *rtda.Frame) {
vars := frame.LocalVars()
this := vars.GetThis()
class := this.Extra().(*heap.Class)
stack := frame.OperandStack()
stack.PushBoolean(class.IsInterface())
}
// public native boolean isPrimitive();
// ()Z
func isPrimitive(frame *rtda.Frame) {
vars := frame.LocalVars()
this := vars.GetThis()
class := this.Extra().(*heap.Class)
stack := frame.OperandStack()
stack.PushBoolean(class.IsPrimitive())
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/native/java/lang/Class.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 483
|
```go
package rtda
import "jvmgo/ch10/rtda/heap"
/*
JVM
Thread
pc
Stack
Frame
LocalVars
OperandStack
*/
type Thread struct {
pc int // the address of the instruction currently being executed
stack *Stack
// todo
}
func NewThread() *Thread {
return &Thread{
stack: newStack(1024),
}
}
func (self *Thread) PC() int {
return self.pc
}
func (self *Thread) SetPC(pc int) {
self.pc = pc
}
func (self *Thread) PushFrame(frame *Frame) {
self.stack.push(frame)
}
func (self *Thread) PopFrame() *Frame {
return self.stack.pop()
}
func (self *Thread) CurrentFrame() *Frame {
return self.stack.top()
}
func (self *Thread) TopFrame() *Frame {
return self.stack.top()
}
func (self *Thread) GetFrames() []*Frame {
return self.stack.getFrames()
}
func (self *Thread) IsStackEmpty() bool {
return self.stack.isEmpty()
}
func (self *Thread) ClearStack() {
self.stack.clear()
}
func (self *Thread) NewFrame(method *heap.Method) *Frame {
return newFrame(self, method)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/thread.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 275
|
```go
package rtda
import "math"
import "jvmgo/ch10/rtda/heap"
type OperandStack struct {
size uint
slots []Slot
}
func newOperandStack(maxStack uint) *OperandStack {
if maxStack > 0 {
return &OperandStack{
slots: make([]Slot, maxStack),
}
}
return nil
}
func (self *OperandStack) PushInt(val int32) {
self.slots[self.size].num = val
self.size++
}
func (self *OperandStack) PopInt() int32 {
self.size--
return self.slots[self.size].num
}
func (self *OperandStack) PushFloat(val float32) {
bits := math.Float32bits(val)
self.slots[self.size].num = int32(bits)
self.size++
}
func (self *OperandStack) PopFloat() float32 {
self.size--
bits := uint32(self.slots[self.size].num)
return math.Float32frombits(bits)
}
// long consumes two slots
func (self *OperandStack) PushLong(val int64) {
self.slots[self.size].num = int32(val)
self.slots[self.size+1].num = int32(val >> 32)
self.size += 2
}
func (self *OperandStack) PopLong() int64 {
self.size -= 2
low := uint32(self.slots[self.size].num)
high := uint32(self.slots[self.size+1].num)
return int64(high)<<32 | int64(low)
}
// double consumes two slots
func (self *OperandStack) PushDouble(val float64) {
bits := math.Float64bits(val)
self.PushLong(int64(bits))
}
func (self *OperandStack) PopDouble() float64 {
bits := uint64(self.PopLong())
return math.Float64frombits(bits)
}
func (self *OperandStack) PushRef(ref *heap.Object) {
self.slots[self.size].ref = ref
self.size++
}
func (self *OperandStack) PopRef() *heap.Object {
self.size--
ref := self.slots[self.size].ref
self.slots[self.size].ref = nil
return ref
}
func (self *OperandStack) PushSlot(slot Slot) {
self.slots[self.size] = slot
self.size++
}
func (self *OperandStack) PopSlot() Slot {
self.size--
return self.slots[self.size]
}
func (self *OperandStack) Clear() {
self.size = 0
for i := range self.slots {
self.slots[i].ref = nil
}
}
func (self *OperandStack) GetRefFromTop(n uint) *heap.Object {
return self.slots[self.size-1-n].ref
}
func (self *OperandStack) PushBoolean(val bool) {
if val {
self.PushInt(1)
} else {
self.PushInt(0)
}
}
func (self *OperandStack) PopBoolean() bool {
return self.PopInt() == 1
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/operand_stack.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 643
|
```go
package rtda
import "math"
import "jvmgo/ch10/rtda/heap"
type LocalVars []Slot
func newLocalVars(maxLocals uint) LocalVars {
if maxLocals > 0 {
return make([]Slot, maxLocals)
}
return nil
}
func (self LocalVars) SetInt(index uint, val int32) {
self[index].num = val
}
func (self LocalVars) GetInt(index uint) int32 {
return self[index].num
}
func (self LocalVars) SetFloat(index uint, val float32) {
bits := math.Float32bits(val)
self[index].num = int32(bits)
}
func (self LocalVars) GetFloat(index uint) float32 {
bits := uint32(self[index].num)
return math.Float32frombits(bits)
}
// long consumes two slots
func (self LocalVars) SetLong(index uint, val int64) {
self[index].num = int32(val)
self[index+1].num = int32(val >> 32)
}
func (self LocalVars) GetLong(index uint) int64 {
low := uint32(self[index].num)
high := uint32(self[index+1].num)
return int64(high)<<32 | int64(low)
}
// double consumes two slots
func (self LocalVars) SetDouble(index uint, val float64) {
bits := math.Float64bits(val)
self.SetLong(index, int64(bits))
}
func (self LocalVars) GetDouble(index uint) float64 {
bits := uint64(self.GetLong(index))
return math.Float64frombits(bits)
}
func (self LocalVars) SetRef(index uint, ref *heap.Object) {
self[index].ref = ref
}
func (self LocalVars) GetRef(index uint) *heap.Object {
return self[index].ref
}
func (self LocalVars) SetSlot(index uint, slot Slot) {
self[index] = slot
}
func (self LocalVars) GetThis() *heap.Object {
return self.GetRef(0)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/local_vars.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 436
|
```go
package rtda
import "jvmgo/ch10/rtda/heap"
type Slot struct {
num int32
ref *heap.Object
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/slot.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 33
|
```go
package rtda
import "jvmgo/ch10/rtda/heap"
// stack frame
type Frame struct {
lower *Frame // stack is implemented as linked list
localVars LocalVars
operandStack *OperandStack
thread *Thread
method *heap.Method
nextPC int // the next instruction after the call
}
func newFrame(thread *Thread, method *heap.Method) *Frame {
return &Frame{
thread: thread,
method: method,
localVars: newLocalVars(method.MaxLocals()),
operandStack: newOperandStack(method.MaxStack()),
}
}
// getters & setters
func (self *Frame) LocalVars() LocalVars {
return self.localVars
}
func (self *Frame) OperandStack() *OperandStack {
return self.operandStack
}
func (self *Frame) Thread() *Thread {
return self.thread
}
func (self *Frame) Method() *heap.Method {
return self.method
}
func (self *Frame) NextPC() int {
return self.nextPC
}
func (self *Frame) SetNextPC(nextPC int) {
self.nextPC = nextPC
}
func (self *Frame) RevertNextPC() {
self.nextPC = self.thread.pc
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/frame.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 272
|
```go
package rtda
// jvm stack
type Stack struct {
maxSize uint
size uint
_top *Frame // stack is implemented as linked list
}
func newStack(maxSize uint) *Stack {
return &Stack{
maxSize: maxSize,
}
}
func (self *Stack) push(frame *Frame) {
if self.size >= self.maxSize {
panic("java.lang.StackOverflowError")
}
if self._top != nil {
frame.lower = self._top
}
self._top = frame
self.size++
}
func (self *Stack) pop() *Frame {
if self._top == nil {
panic("jvm stack is empty!")
}
top := self._top
self._top = top.lower
top.lower = nil
self.size--
return top
}
func (self *Stack) top() *Frame {
if self._top == nil {
panic("jvm stack is empty!")
}
return self._top
}
func (self *Stack) getFrames() []*Frame {
frames := make([]*Frame, 0, self.size)
for frame := self._top; frame != nil; frame = frame.lower {
frames = append(frames, frame)
}
return frames
}
func (self *Stack) isEmpty() bool {
return self._top == nil
}
func (self *Stack) clear() {
for !self.isEmpty() {
self.pop()
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/jvm_stack.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 303
|
```go
package heap
// symbolic reference
type SymRef struct {
cp *ConstantPool
className string
class *Class
}
func (self *SymRef) ResolvedClass() *Class {
if self.class == nil {
self.resolveClassRef()
}
return self.class
}
// jvms8 5.4.3.1
func (self *SymRef) resolveClassRef() {
d := self.cp.class
c := d.loader.LoadClass(self.className)
if !c.isAccessibleTo(d) {
panic("java.lang.IllegalAccessError")
}
self.class = c
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/cp_symref.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 129
|
```go
package heap
import "jvmgo/ch10/classfile"
type MethodRef struct {
MemberRef
method *Method
}
func newMethodRef(cp *ConstantPool, refInfo *classfile.ConstantMethodrefInfo) *MethodRef {
ref := &MethodRef{}
ref.cp = cp
ref.copyMemberRefInfo(&refInfo.ConstantMemberrefInfo)
return ref
}
func (self *MethodRef) ResolvedMethod() *Method {
if self.method == nil {
self.resolveMethodRef()
}
return self.method
}
// jvms8 5.4.3.3
func (self *MethodRef) resolveMethodRef() {
d := self.cp.class
c := self.ResolvedClass()
if c.IsInterface() {
panic("java.lang.IncompatibleClassChangeError")
}
method := lookupMethod(c, self.name, self.descriptor)
if method == nil {
panic("java.lang.NoSuchMethodError")
}
if !method.isAccessibleTo(d) {
panic("java.lang.IllegalAccessError")
}
self.method = method
}
func lookupMethod(class *Class, name, descriptor string) *Method {
method := LookupMethodInClass(class, name, descriptor)
if method == nil {
method = lookupMethodInInterfaces(class.interfaces, name, descriptor)
}
return method
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/cp_methodref.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 277
|
```go
package heap
import "fmt"
import "jvmgo/ch10/classfile"
type Constant interface{}
type ConstantPool struct {
class *Class
consts []Constant
}
func newConstantPool(class *Class, cfCp classfile.ConstantPool) *ConstantPool {
cpCount := len(cfCp)
consts := make([]Constant, cpCount)
rtCp := &ConstantPool{class, consts}
for i := 1; i < cpCount; i++ {
cpInfo := cfCp[i]
switch cpInfo.(type) {
case *classfile.ConstantIntegerInfo:
intInfo := cpInfo.(*classfile.ConstantIntegerInfo)
consts[i] = intInfo.Value()
case *classfile.ConstantFloatInfo:
floatInfo := cpInfo.(*classfile.ConstantFloatInfo)
consts[i] = floatInfo.Value()
case *classfile.ConstantLongInfo:
longInfo := cpInfo.(*classfile.ConstantLongInfo)
consts[i] = longInfo.Value()
i++
case *classfile.ConstantDoubleInfo:
doubleInfo := cpInfo.(*classfile.ConstantDoubleInfo)
consts[i] = doubleInfo.Value()
i++
case *classfile.ConstantStringInfo:
stringInfo := cpInfo.(*classfile.ConstantStringInfo)
consts[i] = stringInfo.String()
case *classfile.ConstantClassInfo:
classInfo := cpInfo.(*classfile.ConstantClassInfo)
consts[i] = newClassRef(rtCp, classInfo)
case *classfile.ConstantFieldrefInfo:
fieldrefInfo := cpInfo.(*classfile.ConstantFieldrefInfo)
consts[i] = newFieldRef(rtCp, fieldrefInfo)
case *classfile.ConstantMethodrefInfo:
methodrefInfo := cpInfo.(*classfile.ConstantMethodrefInfo)
consts[i] = newMethodRef(rtCp, methodrefInfo)
case *classfile.ConstantInterfaceMethodrefInfo:
methodrefInfo := cpInfo.(*classfile.ConstantInterfaceMethodrefInfo)
consts[i] = newInterfaceMethodRef(rtCp, methodrefInfo)
default:
// todo
}
}
return rtCp
}
func (self *ConstantPool) GetConstant(index uint) Constant {
if c := self.consts[index]; c != nil {
return c
}
panic(fmt.Sprintf("No constants at index %d", index))
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/constant_pool.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 517
|
```go
package heap
import "strings"
import "jvmgo/ch10/classfile"
// name, superClassName and interfaceNames are all binary names(jvms8-4.2.1)
type Class struct {
accessFlags uint16
name string // thisClassName
superClassName string
interfaceNames []string
constantPool *ConstantPool
fields []*Field
methods []*Method
sourceFile string
loader *ClassLoader
superClass *Class
interfaces []*Class
instanceSlotCount uint
staticSlotCount uint
staticVars Slots
initStarted bool
jClass *Object
}
func newClass(cf *classfile.ClassFile) *Class {
class := &Class{}
class.accessFlags = cf.AccessFlags()
class.name = cf.ClassName()
class.superClassName = cf.SuperClassName()
class.interfaceNames = cf.InterfaceNames()
class.constantPool = newConstantPool(class, cf.ConstantPool())
class.fields = newFields(class, cf.Fields())
class.methods = newMethods(class, cf.Methods())
class.sourceFile = getSourceFile(cf)
return class
}
func getSourceFile(cf *classfile.ClassFile) string {
if sfAttr := cf.SourceFileAttribute(); sfAttr != nil {
return sfAttr.FileName()
}
return "Unknown" // todo
}
func (self *Class) IsPublic() bool {
return 0 != self.accessFlags&ACC_PUBLIC
}
func (self *Class) IsFinal() bool {
return 0 != self.accessFlags&ACC_FINAL
}
func (self *Class) IsSuper() bool {
return 0 != self.accessFlags&ACC_SUPER
}
func (self *Class) IsInterface() bool {
return 0 != self.accessFlags&ACC_INTERFACE
}
func (self *Class) IsAbstract() bool {
return 0 != self.accessFlags&ACC_ABSTRACT
}
func (self *Class) IsSynthetic() bool {
return 0 != self.accessFlags&ACC_SYNTHETIC
}
func (self *Class) IsAnnotation() bool {
return 0 != self.accessFlags&ACC_ANNOTATION
}
func (self *Class) IsEnum() bool {
return 0 != self.accessFlags&ACC_ENUM
}
// getters
func (self *Class) Name() string {
return self.name
}
func (self *Class) ConstantPool() *ConstantPool {
return self.constantPool
}
func (self *Class) Fields() []*Field {
return self.fields
}
func (self *Class) Methods() []*Method {
return self.methods
}
func (self *Class) SourceFile() string {
return self.sourceFile
}
func (self *Class) Loader() *ClassLoader {
return self.loader
}
func (self *Class) SuperClass() *Class {
return self.superClass
}
func (self *Class) StaticVars() Slots {
return self.staticVars
}
func (self *Class) InitStarted() bool {
return self.initStarted
}
func (self *Class) JClass() *Object {
return self.jClass
}
func (self *Class) StartInit() {
self.initStarted = true
}
// jvms 5.4.4
func (self *Class) isAccessibleTo(other *Class) bool {
return self.IsPublic() ||
self.GetPackageName() == other.GetPackageName()
}
func (self *Class) GetPackageName() string {
if i := strings.LastIndex(self.name, "/"); i >= 0 {
return self.name[:i]
}
return ""
}
func (self *Class) GetMainMethod() *Method {
return self.getMethod("main", "([Ljava/lang/String;)V", true)
}
func (self *Class) GetClinitMethod() *Method {
return self.getMethod("<clinit>", "()V", true)
}
func (self *Class) getMethod(name, descriptor string, isStatic bool) *Method {
for c := self; c != nil; c = c.superClass {
for _, method := range c.methods {
if method.IsStatic() == isStatic &&
method.name == name &&
method.descriptor == descriptor {
return method
}
}
}
return nil
}
func (self *Class) getField(name, descriptor string, isStatic bool) *Field {
for c := self; c != nil; c = c.superClass {
for _, field := range c.fields {
if field.IsStatic() == isStatic &&
field.name == name &&
field.descriptor == descriptor {
return field
}
}
}
return nil
}
func (self *Class) isJlObject() bool {
return self.name == "java/lang/Object"
}
func (self *Class) isJlCloneable() bool {
return self.name == "java/lang/Cloneable"
}
func (self *Class) isJioSerializable() bool {
return self.name == "java/io/Serializable"
}
func (self *Class) NewObject() *Object {
return newObject(self)
}
func (self *Class) ArrayClass() *Class {
arrayClassName := getArrayClassName(self.name)
return self.loader.LoadClass(arrayClassName)
}
func (self *Class) JavaName() string {
return strings.Replace(self.name, "/", ".", -1)
}
func (self *Class) IsPrimitive() bool {
_, ok := primitiveTypes[self.name]
return ok
}
func (self *Class) GetInstanceMethod(name, descriptor string) *Method {
return self.getMethod(name, descriptor, false)
}
func (self *Class) GetRefVar(fieldName, fieldDescriptor string) *Object {
field := self.getField(fieldName, fieldDescriptor, true)
return self.staticVars.GetRef(field.slotId)
}
func (self *Class) SetRefVar(fieldName, fieldDescriptor string, ref *Object) {
field := self.getField(fieldName, fieldDescriptor, true)
self.staticVars.SetRef(field.slotId, ref)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/class.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 1,239
|
```go
package heap
import "jvmgo/ch10/classfile"
type FieldRef struct {
MemberRef
field *Field
}
func newFieldRef(cp *ConstantPool, refInfo *classfile.ConstantFieldrefInfo) *FieldRef {
ref := &FieldRef{}
ref.cp = cp
ref.copyMemberRefInfo(&refInfo.ConstantMemberrefInfo)
return ref
}
func (self *FieldRef) ResolvedField() *Field {
if self.field == nil {
self.resolveFieldRef()
}
return self.field
}
// jvms 5.4.3.2
func (self *FieldRef) resolveFieldRef() {
d := self.cp.class
c := self.ResolvedClass()
field := lookupField(c, self.name, self.descriptor)
if field == nil {
panic("java.lang.NoSuchFieldError")
}
if !field.isAccessibleTo(d) {
panic("java.lang.IllegalAccessError")
}
self.field = field
}
func lookupField(c *Class, name, descriptor string) *Field {
for _, field := range c.fields {
if field.name == name && field.descriptor == descriptor {
return field
}
}
for _, iface := range c.interfaces {
if field := lookupField(iface, name, descriptor); field != nil {
return field
}
}
if c.superClass != nil {
return lookupField(c.superClass, name, descriptor)
}
return nil
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/cp_fieldref.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 308
|
```go
package heap
// jvms8 6.5.instanceof
// jvms8 6.5.checkcast
func (self *Class) isAssignableFrom(other *Class) bool {
s, t := other, self
if s == t {
return true
}
if !s.IsArray() {
if !s.IsInterface() {
// s is class
if !t.IsInterface() {
// t is not interface
return s.IsSubClassOf(t)
} else {
// t is interface
return s.IsImplements(t)
}
} else {
// s is interface
if !t.IsInterface() {
// t is not interface
return t.isJlObject()
} else {
// t is interface
return t.isSuperInterfaceOf(s)
}
}
} else {
// s is array
if !t.IsArray() {
if !t.IsInterface() {
// t is class
return t.isJlObject()
} else {
// t is interface
return t.isJlCloneable() || t.isJioSerializable()
}
} else {
// t is array
sc := s.ComponentClass()
tc := t.ComponentClass()
return sc == tc || tc.isAssignableFrom(sc)
}
}
return false
}
// self extends c
func (self *Class) IsSubClassOf(other *Class) bool {
for c := self.superClass; c != nil; c = c.superClass {
if c == other {
return true
}
}
return false
}
// self implements iface
func (self *Class) IsImplements(iface *Class) bool {
for c := self; c != nil; c = c.superClass {
for _, i := range c.interfaces {
if i == iface || i.isSubInterfaceOf(iface) {
return true
}
}
}
return false
}
// self extends iface
func (self *Class) isSubInterfaceOf(iface *Class) bool {
for _, superInterface := range self.interfaces {
if superInterface == iface || superInterface.isSubInterfaceOf(iface) {
return true
}
}
return false
}
// c extends self
func (self *Class) IsSuperClassOf(other *Class) bool {
return other.IsSubClassOf(self)
}
// iface extends self
func (self *Class) isSuperInterfaceOf(iface *Class) bool {
return iface.isSubInterfaceOf(self)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/class_hierarchy.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 568
|
```go
package heap
import "jvmgo/ch10/classfile"
type ClassRef struct {
SymRef
}
func newClassRef(cp *ConstantPool, classInfo *classfile.ConstantClassInfo) *ClassRef {
ref := &ClassRef{}
ref.cp = cp
ref.className = classInfo.Name()
return ref
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/cp_classref.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 68
|
```go
package heap
import "strings"
type MethodDescriptorParser struct {
raw string
offset int
parsed *MethodDescriptor
}
func parseMethodDescriptor(descriptor string) *MethodDescriptor {
parser := &MethodDescriptorParser{}
return parser.parse(descriptor)
}
func (self *MethodDescriptorParser) parse(descriptor string) *MethodDescriptor {
self.raw = descriptor
self.parsed = &MethodDescriptor{}
self.startParams()
self.parseParamTypes()
self.endParams()
self.parseReturnType()
self.finish()
return self.parsed
}
func (self *MethodDescriptorParser) startParams() {
if self.readUint8() != '(' {
self.causePanic()
}
}
func (self *MethodDescriptorParser) endParams() {
if self.readUint8() != ')' {
self.causePanic()
}
}
func (self *MethodDescriptorParser) finish() {
if self.offset != len(self.raw) {
self.causePanic()
}
}
func (self *MethodDescriptorParser) causePanic() {
panic("BAD descriptor: " + self.raw)
}
func (self *MethodDescriptorParser) readUint8() uint8 {
b := self.raw[self.offset]
self.offset++
return b
}
func (self *MethodDescriptorParser) unreadUint8() {
self.offset--
}
func (self *MethodDescriptorParser) parseParamTypes() {
for {
t := self.parseFieldType()
if t != "" {
self.parsed.addParameterType(t)
} else {
break
}
}
}
func (self *MethodDescriptorParser) parseReturnType() {
if self.readUint8() == 'V' {
self.parsed.returnType = "V"
return
}
self.unreadUint8()
t := self.parseFieldType()
if t != "" {
self.parsed.returnType = t
return
}
self.causePanic()
}
func (self *MethodDescriptorParser) parseFieldType() string {
switch self.readUint8() {
case 'B':
return "B"
case 'C':
return "C"
case 'D':
return "D"
case 'F':
return "F"
case 'I':
return "I"
case 'J':
return "J"
case 'S':
return "S"
case 'Z':
return "Z"
case 'L':
return self.parseObjectType()
case '[':
return self.parseArrayType()
default:
self.unreadUint8()
return ""
}
}
func (self *MethodDescriptorParser) parseObjectType() string {
unread := self.raw[self.offset:]
semicolonIndex := strings.IndexRune(unread, ';')
if semicolonIndex == -1 {
self.causePanic()
return ""
} else {
objStart := self.offset - 1
objEnd := self.offset + semicolonIndex + 1
self.offset = objEnd
descriptor := self.raw[objStart:objEnd]
return descriptor
}
}
func (self *MethodDescriptorParser) parseArrayType() string {
arrStart := self.offset - 1
self.parseFieldType()
arrEnd := self.offset
descriptor := self.raw[arrStart:arrEnd]
return descriptor
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/method_descriptor_parser.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 675
|
```go
package heap
import "jvmgo/ch10/classfile"
type ClassMember struct {
accessFlags uint16
name string
descriptor string
class *Class
}
func (self *ClassMember) copyMemberInfo(memberInfo *classfile.MemberInfo) {
self.accessFlags = memberInfo.AccessFlags()
self.name = memberInfo.Name()
self.descriptor = memberInfo.Descriptor()
}
func (self *ClassMember) IsPublic() bool {
return 0 != self.accessFlags&ACC_PUBLIC
}
func (self *ClassMember) IsPrivate() bool {
return 0 != self.accessFlags&ACC_PRIVATE
}
func (self *ClassMember) IsProtected() bool {
return 0 != self.accessFlags&ACC_PROTECTED
}
func (self *ClassMember) IsStatic() bool {
return 0 != self.accessFlags&ACC_STATIC
}
func (self *ClassMember) IsFinal() bool {
return 0 != self.accessFlags&ACC_FINAL
}
func (self *ClassMember) IsSynthetic() bool {
return 0 != self.accessFlags&ACC_SYNTHETIC
}
// getters
func (self *ClassMember) Name() string {
return self.name
}
func (self *ClassMember) Descriptor() string {
return self.descriptor
}
func (self *ClassMember) Class() *Class {
return self.class
}
// jvms 5.4.4
func (self *ClassMember) isAccessibleTo(d *Class) bool {
if self.IsPublic() {
return true
}
c := self.class
if self.IsProtected() {
return d == c || d.IsSubClassOf(c) ||
c.GetPackageName() == d.GetPackageName()
}
if !self.IsPrivate() {
return c.GetPackageName() == d.GetPackageName()
}
return d == c
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/class_member.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 387
|
```go
package heap
import "unicode/utf16"
var internedStrings = map[string]*Object{}
// todo
// go string -> java.lang.String
func JString(loader *ClassLoader, goStr string) *Object {
if internedStr, ok := internedStrings[goStr]; ok {
return internedStr
}
chars := stringToUtf16(goStr)
jChars := &Object{loader.LoadClass("[C"), chars, nil}
jStr := loader.LoadClass("java/lang/String").NewObject()
jStr.SetRefVar("value", "[C", jChars)
internedStrings[goStr] = jStr
return jStr
}
// java.lang.String -> go string
func GoString(jStr *Object) string {
charArr := jStr.GetRefVar("value", "[C")
return utf16ToString(charArr.Chars())
}
// utf8 -> utf16
func stringToUtf16(s string) []uint16 {
runes := []rune(s) // utf32
return utf16.Encode(runes) // func Encode(s []rune) []uint16
}
// utf16 -> utf8
func utf16ToString(s []uint16) string {
runes := utf16.Decode(s) // func Decode(s []uint16) []rune
return string(runes)
}
// todo
func InternString(jStr *Object) *Object {
goStr := GoString(jStr)
if internedStr, ok := internedStrings[goStr]; ok {
return internedStr
}
internedStrings[goStr] = jStr
return jStr
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/string_pool.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 342
|
```go
package heap
var primitiveTypes = map[string]string{
"void": "V",
"boolean": "Z",
"byte": "B",
"short": "S",
"int": "I",
"long": "J",
"char": "C",
"float": "F",
"double": "D",
}
// [XXX -> [[XXX
// int -> [I
// XXX -> [LXXX;
func getArrayClassName(className string) string {
return "[" + toDescriptor(className)
}
// [[XXX -> [XXX
// [LXXX; -> XXX
// [I -> int
func getComponentClassName(className string) string {
if className[0] == '[' {
componentTypeDescriptor := className[1:]
return toClassName(componentTypeDescriptor)
}
panic("Not array: " + className)
}
// [XXX => [XXX
// int => I
// XXX => LXXX;
func toDescriptor(className string) string {
if className[0] == '[' {
// array
return className
}
if d, ok := primitiveTypes[className]; ok {
// primitive
return d
}
// object
return "L" + className + ";"
}
// [XXX => [XXX
// LXXX; => XXX
// I => int
func toClassName(descriptor string) string {
if descriptor[0] == '[' {
// array
return descriptor
}
if descriptor[0] == 'L' {
// object
return descriptor[1 : len(descriptor)-1]
}
for className, d := range primitiveTypes {
if d == descriptor {
// primitive
return className
}
}
panic("Invalid descriptor: " + descriptor)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/class_name_helper.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 387
|
```go
package heap
type Object struct {
class *Class
data interface{} // Slots for Object, []int32 for int[] ...
extra interface{}
}
// create normal (non-array) object
func newObject(class *Class) *Object {
return &Object{
class: class,
data: newSlots(class.instanceSlotCount),
}
}
// getters & setters
func (self *Object) Class() *Class {
return self.class
}
func (self *Object) Fields() Slots {
return self.data.(Slots)
}
func (self *Object) Extra() interface{} {
return self.extra
}
func (self *Object) SetExtra(extra interface{}) {
self.extra = extra
}
func (self *Object) IsInstanceOf(class *Class) bool {
return class.isAssignableFrom(self.class)
}
// reflection
func (self *Object) GetRefVar(name, descriptor string) *Object {
field := self.class.getField(name, descriptor, false)
slots := self.data.(Slots)
return slots.GetRef(field.slotId)
}
func (self *Object) SetRefVar(name, descriptor string, ref *Object) {
field := self.class.getField(name, descriptor, false)
slots := self.data.(Slots)
slots.SetRef(field.slotId, ref)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/object.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 266
|
```go
package heap
import "jvmgo/ch10/classfile"
type MemberRef struct {
SymRef
name string
descriptor string
}
func (self *MemberRef) copyMemberRefInfo(refInfo *classfile.ConstantMemberrefInfo) {
self.className = refInfo.ClassName()
self.name, self.descriptor = refInfo.NameAndDescriptor()
}
func (self *MemberRef) Name() string {
return self.name
}
func (self *MemberRef) Descriptor() string {
return self.descriptor
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/cp_memberref.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 107
|
```go
package heap
type MethodDescriptor struct {
parameterTypes []string
returnType string
}
func (self *MethodDescriptor) addParameterType(t string) {
pLen := len(self.parameterTypes)
if pLen == cap(self.parameterTypes) {
s := make([]string, pLen, pLen+4)
copy(s, self.parameterTypes)
self.parameterTypes = s
}
self.parameterTypes = append(self.parameterTypes, t)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/method_descriptor.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 97
|
```go
package heap
import "jvmgo/ch10/classfile"
type Method struct {
ClassMember
maxStack uint
maxLocals uint
code []byte
exceptionTable ExceptionTable
lineNumberTable *classfile.LineNumberTableAttribute
argSlotCount uint
}
func newMethods(class *Class, cfMethods []*classfile.MemberInfo) []*Method {
methods := make([]*Method, len(cfMethods))
for i, cfMethod := range cfMethods {
methods[i] = newMethod(class, cfMethod)
}
return methods
}
func newMethod(class *Class, cfMethod *classfile.MemberInfo) *Method {
method := &Method{}
method.class = class
method.copyMemberInfo(cfMethod)
method.copyAttributes(cfMethod)
md := parseMethodDescriptor(method.descriptor)
method.calcArgSlotCount(md.parameterTypes)
if method.IsNative() {
method.injectCodeAttribute(md.returnType)
}
return method
}
func (self *Method) copyAttributes(cfMethod *classfile.MemberInfo) {
if codeAttr := cfMethod.CodeAttribute(); codeAttr != nil {
self.maxStack = codeAttr.MaxStack()
self.maxLocals = codeAttr.MaxLocals()
self.code = codeAttr.Code()
self.lineNumberTable = codeAttr.LineNumberTableAttribute()
self.exceptionTable = newExceptionTable(codeAttr.ExceptionTable(),
self.class.constantPool)
}
}
func (self *Method) calcArgSlotCount(paramTypes []string) {
for _, paramType := range paramTypes {
self.argSlotCount++
if paramType == "J" || paramType == "D" {
self.argSlotCount++
}
}
if !self.IsStatic() {
self.argSlotCount++ // `this` reference
}
}
func (self *Method) injectCodeAttribute(returnType string) {
self.maxStack = 4 // todo
self.maxLocals = self.argSlotCount
switch returnType[0] {
case 'V':
self.code = []byte{0xfe, 0xb1} // return
case 'L', '[':
self.code = []byte{0xfe, 0xb0} // areturn
case 'D':
self.code = []byte{0xfe, 0xaf} // dreturn
case 'F':
self.code = []byte{0xfe, 0xae} // freturn
case 'J':
self.code = []byte{0xfe, 0xad} // lreturn
default:
self.code = []byte{0xfe, 0xac} // ireturn
}
}
func (self *Method) IsSynchronized() bool {
return 0 != self.accessFlags&ACC_SYNCHRONIZED
}
func (self *Method) IsBridge() bool {
return 0 != self.accessFlags&ACC_BRIDGE
}
func (self *Method) IsVarargs() bool {
return 0 != self.accessFlags&ACC_VARARGS
}
func (self *Method) IsNative() bool {
return 0 != self.accessFlags&ACC_NATIVE
}
func (self *Method) IsAbstract() bool {
return 0 != self.accessFlags&ACC_ABSTRACT
}
func (self *Method) IsStrict() bool {
return 0 != self.accessFlags&ACC_STRICT
}
// getters
func (self *Method) MaxStack() uint {
return self.maxStack
}
func (self *Method) MaxLocals() uint {
return self.maxLocals
}
func (self *Method) Code() []byte {
return self.code
}
func (self *Method) ArgSlotCount() uint {
return self.argSlotCount
}
func (self *Method) FindExceptionHandler(exClass *Class, pc int) int {
handler := self.exceptionTable.findExceptionHandler(exClass, pc)
if handler != nil {
return handler.handlerPc
}
return -1
}
func (self *Method) GetLineNumber(pc int) int {
if self.IsNative() {
return -2
}
if self.lineNumberTable == nil {
return -1
}
return self.lineNumberTable.GetLineNumber(pc)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/method.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 871
|
```go
package heap
import "jvmgo/ch10/classfile"
type ExceptionTable []*ExceptionHandler
type ExceptionHandler struct {
startPc int
endPc int
handlerPc int
catchType *ClassRef
}
func newExceptionTable(entries []*classfile.ExceptionTableEntry, cp *ConstantPool) ExceptionTable {
table := make([]*ExceptionHandler, len(entries))
for i, entry := range entries {
table[i] = &ExceptionHandler{
startPc: int(entry.StartPc()),
endPc: int(entry.EndPc()),
handlerPc: int(entry.HandlerPc()),
catchType: getCatchType(uint(entry.CatchType()), cp),
}
}
return table
}
func getCatchType(index uint, cp *ConstantPool) *ClassRef {
if index == 0 {
return nil // catch all
}
return cp.GetConstant(index).(*ClassRef)
}
func (self ExceptionTable) findExceptionHandler(exClass *Class, pc int) *ExceptionHandler {
for _, handler := range self {
// jvms: The start_pc is inclusive and end_pc is exclusive
if pc >= handler.startPc && pc < handler.endPc {
if handler.catchType == nil {
return handler
}
catchClass := handler.catchType.ResolvedClass()
if catchClass == exClass || catchClass.IsSuperClassOf(exClass) {
return handler
}
}
}
return nil
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/exception_table.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 315
|
```go
package heap
const (
ACC_PUBLIC = 0x0001 // class field method
ACC_PRIVATE = 0x0002 // field method
ACC_PROTECTED = 0x0004 // field method
ACC_STATIC = 0x0008 // field method
ACC_FINAL = 0x0010 // class field method
ACC_SUPER = 0x0020 // class
ACC_SYNCHRONIZED = 0x0020 // method
ACC_VOLATILE = 0x0040 // field
ACC_BRIDGE = 0x0040 // method
ACC_TRANSIENT = 0x0080 // field
ACC_VARARGS = 0x0080 // method
ACC_NATIVE = 0x0100 // method
ACC_INTERFACE = 0x0200 // class
ACC_ABSTRACT = 0x0400 // class method
ACC_STRICT = 0x0800 // method
ACC_SYNTHETIC = 0x1000 // class field method
ACC_ANNOTATION = 0x2000 // class
ACC_ENUM = 0x4000 // class field
)
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/access_flags.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 278
|
```go
package heap
import "fmt"
import "jvmgo/ch10/classfile"
import "jvmgo/ch10/classpath"
/*
class names:
- primitive types: boolean, byte, int ...
- primitive arrays: [Z, [B, [I ...
- non-array classes: java/lang/Object ...
- array classes: [Ljava/lang/Object; ...
*/
type ClassLoader struct {
cp *classpath.Classpath
verboseFlag bool
classMap map[string]*Class // loaded classes
}
func NewClassLoader(cp *classpath.Classpath, verboseFlag bool) *ClassLoader {
loader := &ClassLoader{
cp: cp,
verboseFlag: verboseFlag,
classMap: make(map[string]*Class),
}
loader.loadBasicClasses()
loader.loadPrimitiveClasses()
return loader
}
func (self *ClassLoader) loadBasicClasses() {
jlClassClass := self.LoadClass("java/lang/Class")
for _, class := range self.classMap {
if class.jClass == nil {
class.jClass = jlClassClass.NewObject()
class.jClass.extra = class
}
}
}
func (self *ClassLoader) loadPrimitiveClasses() {
for primitiveType, _ := range primitiveTypes {
self.loadPrimitiveClass(primitiveType)
}
}
func (self *ClassLoader) loadPrimitiveClass(className string) {
class := &Class{
accessFlags: ACC_PUBLIC, // todo
name: className,
loader: self,
initStarted: true,
}
class.jClass = self.classMap["java/lang/Class"].NewObject()
class.jClass.extra = class
self.classMap[className] = class
}
func (self *ClassLoader) LoadClass(name string) *Class {
if class, ok := self.classMap[name]; ok {
// already loaded
return class
}
var class *Class
if name[0] == '[' { // array class
class = self.loadArrayClass(name)
} else {
class = self.loadNonArrayClass(name)
}
if jlClassClass, ok := self.classMap["java/lang/Class"]; ok {
class.jClass = jlClassClass.NewObject()
class.jClass.extra = class
}
return class
}
func (self *ClassLoader) loadArrayClass(name string) *Class {
class := &Class{
accessFlags: ACC_PUBLIC, // todo
name: name,
loader: self,
initStarted: true,
superClass: self.LoadClass("java/lang/Object"),
interfaces: []*Class{
self.LoadClass("java/lang/Cloneable"),
self.LoadClass("java/io/Serializable"),
},
}
self.classMap[name] = class
return class
}
func (self *ClassLoader) loadNonArrayClass(name string) *Class {
data, entry := self.readClass(name)
class := self.defineClass(data)
link(class)
if self.verboseFlag {
fmt.Printf("[Loaded %s from %s]\n", name, entry)
}
return class
}
func (self *ClassLoader) readClass(name string) ([]byte, classpath.Entry) {
data, entry, err := self.cp.ReadClass(name)
if err != nil {
panic("java.lang.ClassNotFoundException: " + name)
}
return data, entry
}
// jvms 5.3.5
func (self *ClassLoader) defineClass(data []byte) *Class {
class := parseClass(data)
class.loader = self
resolveSuperClass(class)
resolveInterfaces(class)
self.classMap[class.name] = class
return class
}
func parseClass(data []byte) *Class {
cf, err := classfile.Parse(data)
if err != nil {
//panic("java.lang.ClassFormatError")
panic(err)
}
return newClass(cf)
}
// jvms 5.4.3.1
func resolveSuperClass(class *Class) {
if class.name != "java/lang/Object" {
class.superClass = class.loader.LoadClass(class.superClassName)
}
}
func resolveInterfaces(class *Class) {
interfaceCount := len(class.interfaceNames)
if interfaceCount > 0 {
class.interfaces = make([]*Class, interfaceCount)
for i, interfaceName := range class.interfaceNames {
class.interfaces[i] = class.loader.LoadClass(interfaceName)
}
}
}
func link(class *Class) {
verify(class)
prepare(class)
}
func verify(class *Class) {
// todo
}
// jvms 5.4.2
func prepare(class *Class) {
calcInstanceFieldSlotIds(class)
calcStaticFieldSlotIds(class)
allocAndInitStaticVars(class)
}
func calcInstanceFieldSlotIds(class *Class) {
slotId := uint(0)
if class.superClass != nil {
slotId = class.superClass.instanceSlotCount
}
for _, field := range class.fields {
if !field.IsStatic() {
field.slotId = slotId
slotId++
if field.isLongOrDouble() {
slotId++
}
}
}
class.instanceSlotCount = slotId
}
func calcStaticFieldSlotIds(class *Class) {
slotId := uint(0)
for _, field := range class.fields {
if field.IsStatic() {
field.slotId = slotId
slotId++
if field.isLongOrDouble() {
slotId++
}
}
}
class.staticSlotCount = slotId
}
func allocAndInitStaticVars(class *Class) {
class.staticVars = newSlots(class.staticSlotCount)
for _, field := range class.fields {
if field.IsStatic() && field.IsFinal() {
initStaticFinalVar(class, field)
}
}
}
func initStaticFinalVar(class *Class, field *Field) {
vars := class.staticVars
cp := class.constantPool
cpIndex := field.ConstValueIndex()
slotId := field.SlotId()
if cpIndex > 0 {
switch field.Descriptor() {
case "Z", "B", "C", "S", "I":
val := cp.GetConstant(cpIndex).(int32)
vars.SetInt(slotId, val)
case "J":
val := cp.GetConstant(cpIndex).(int64)
vars.SetLong(slotId, val)
case "F":
val := cp.GetConstant(cpIndex).(float32)
vars.SetFloat(slotId, val)
case "D":
val := cp.GetConstant(cpIndex).(float64)
vars.SetDouble(slotId, val)
case "Ljava/lang/String;":
goStr := cp.GetConstant(cpIndex).(string)
jStr := JString(class.Loader(), goStr)
vars.SetRef(slotId, jStr)
}
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/class_loader.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 1,449
|
```go
package heap
func LookupMethodInClass(class *Class, name, descriptor string) *Method {
for c := class; c != nil; c = c.superClass {
for _, method := range c.methods {
if method.name == name && method.descriptor == descriptor {
return method
}
}
}
return nil
}
func lookupMethodInInterfaces(ifaces []*Class, name, descriptor string) *Method {
for _, iface := range ifaces {
for _, method := range iface.methods {
if method.name == name && method.descriptor == descriptor {
return method
}
}
method := lookupMethodInInterfaces(iface.interfaces, name, descriptor)
if method != nil {
return method
}
}
return nil
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/method_lookup.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 164
|
```go
package heap
import "jvmgo/ch10/classfile"
type InterfaceMethodRef struct {
MemberRef
method *Method
}
func newInterfaceMethodRef(cp *ConstantPool, refInfo *classfile.ConstantInterfaceMethodrefInfo) *InterfaceMethodRef {
ref := &InterfaceMethodRef{}
ref.cp = cp
ref.copyMemberRefInfo(&refInfo.ConstantMemberrefInfo)
return ref
}
func (self *InterfaceMethodRef) ResolvedInterfaceMethod() *Method {
if self.method == nil {
self.resolveInterfaceMethodRef()
}
return self.method
}
// jvms8 5.4.3.4
func (self *InterfaceMethodRef) resolveInterfaceMethodRef() {
d := self.cp.class
c := self.ResolvedClass()
if !c.IsInterface() {
panic("java.lang.IncompatibleClassChangeError")
}
method := lookupInterfaceMethod(c, self.name, self.descriptor)
if method == nil {
panic("java.lang.NoSuchMethodError")
}
if !method.isAccessibleTo(d) {
panic("java.lang.IllegalAccessError")
}
self.method = method
}
// todo
func lookupInterfaceMethod(iface *Class, name, descriptor string) *Method {
for _, method := range iface.methods {
if method.name == name && method.descriptor == descriptor {
return method
}
}
return lookupMethodInInterfaces(iface.interfaces, name, descriptor)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/cp_interface_methodref.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 300
|
```go
package heap
import "math"
type Slot struct {
num int32
ref *Object
}
type Slots []Slot
func newSlots(slotCount uint) Slots {
if slotCount > 0 {
return make([]Slot, slotCount)
}
return nil
}
func (self Slots) SetInt(index uint, val int32) {
self[index].num = val
}
func (self Slots) GetInt(index uint) int32 {
return self[index].num
}
func (self Slots) SetFloat(index uint, val float32) {
bits := math.Float32bits(val)
self[index].num = int32(bits)
}
func (self Slots) GetFloat(index uint) float32 {
bits := uint32(self[index].num)
return math.Float32frombits(bits)
}
// long consumes two slots
func (self Slots) SetLong(index uint, val int64) {
self[index].num = int32(val)
self[index+1].num = int32(val >> 32)
}
func (self Slots) GetLong(index uint) int64 {
low := uint32(self[index].num)
high := uint32(self[index+1].num)
return int64(high)<<32 | int64(low)
}
// double consumes two slots
func (self Slots) SetDouble(index uint, val float64) {
bits := math.Float64bits(val)
self.SetLong(index, int64(bits))
}
func (self Slots) GetDouble(index uint) float64 {
bits := uint64(self.GetLong(index))
return math.Float64frombits(bits)
}
func (self Slots) SetRef(index uint, ref *Object) {
self[index].ref = ref
}
func (self Slots) GetRef(index uint) *Object {
return self[index].ref
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/slots.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 373
|
```go
package heap
import "jvmgo/ch10/classfile"
type Field struct {
ClassMember
constValueIndex uint
slotId uint
}
func newFields(class *Class, cfFields []*classfile.MemberInfo) []*Field {
fields := make([]*Field, len(cfFields))
for i, cfField := range cfFields {
fields[i] = &Field{}
fields[i].class = class
fields[i].copyMemberInfo(cfField)
fields[i].copyAttributes(cfField)
}
return fields
}
func (self *Field) copyAttributes(cfField *classfile.MemberInfo) {
if valAttr := cfField.ConstantValueAttribute(); valAttr != nil {
self.constValueIndex = uint(valAttr.ConstantValueIndex())
}
}
func (self *Field) IsVolatile() bool {
return 0 != self.accessFlags&ACC_VOLATILE
}
func (self *Field) IsTransient() bool {
return 0 != self.accessFlags&ACC_TRANSIENT
}
func (self *Field) IsEnum() bool {
return 0 != self.accessFlags&ACC_ENUM
}
func (self *Field) ConstValueIndex() uint {
return self.constValueIndex
}
func (self *Field) SlotId() uint {
return self.slotId
}
func (self *Field) isLongOrDouble() bool {
return self.descriptor == "J" || self.descriptor == "D"
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/field.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 296
|
```go
package heap
func (self *Object) Bytes() []int8 {
return self.data.([]int8)
}
func (self *Object) Shorts() []int16 {
return self.data.([]int16)
}
func (self *Object) Ints() []int32 {
return self.data.([]int32)
}
func (self *Object) Longs() []int64 {
return self.data.([]int64)
}
func (self *Object) Chars() []uint16 {
return self.data.([]uint16)
}
func (self *Object) Floats() []float32 {
return self.data.([]float32)
}
func (self *Object) Doubles() []float64 {
return self.data.([]float64)
}
func (self *Object) Refs() []*Object {
return self.data.([]*Object)
}
func (self *Object) ArrayLength() int32 {
switch self.data.(type) {
case []int8:
return int32(len(self.data.([]int8)))
case []int16:
return int32(len(self.data.([]int16)))
case []int32:
return int32(len(self.data.([]int32)))
case []int64:
return int32(len(self.data.([]int64)))
case []uint16:
return int32(len(self.data.([]uint16)))
case []float32:
return int32(len(self.data.([]float32)))
case []float64:
return int32(len(self.data.([]float64)))
case []*Object:
return int32(len(self.data.([]*Object)))
default:
panic("Not array!")
}
}
func ArrayCopy(src, dst *Object, srcPos, dstPos, length int32) {
switch src.data.(type) {
case []int8:
_src := src.data.([]int8)[srcPos : srcPos+length]
_dst := dst.data.([]int8)[dstPos : dstPos+length]
copy(_dst, _src)
case []int16:
_src := src.data.([]int16)[srcPos : srcPos+length]
_dst := dst.data.([]int16)[dstPos : dstPos+length]
copy(_dst, _src)
case []int32:
_src := src.data.([]int32)[srcPos : srcPos+length]
_dst := dst.data.([]int32)[dstPos : dstPos+length]
copy(_dst, _src)
case []int64:
_src := src.data.([]int64)[srcPos : srcPos+length]
_dst := dst.data.([]int64)[dstPos : dstPos+length]
copy(_dst, _src)
case []uint16:
_src := src.data.([]uint16)[srcPos : srcPos+length]
_dst := dst.data.([]uint16)[dstPos : dstPos+length]
copy(_dst, _src)
case []float32:
_src := src.data.([]float32)[srcPos : srcPos+length]
_dst := dst.data.([]float32)[dstPos : dstPos+length]
copy(_dst, _src)
case []float64:
_src := src.data.([]float64)[srcPos : srcPos+length]
_dst := dst.data.([]float64)[dstPos : dstPos+length]
copy(_dst, _src)
case []*Object:
_src := src.data.([]*Object)[srcPos : srcPos+length]
_dst := dst.data.([]*Object)[dstPos : dstPos+length]
copy(_dst, _src)
default:
panic("Not array!")
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/array_object.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 783
|
```go
package heap
func (self *Class) IsArray() bool {
return self.name[0] == '['
}
func (self *Class) ComponentClass() *Class {
componentClassName := getComponentClassName(self.name)
return self.loader.LoadClass(componentClassName)
}
func (self *Class) NewArray(count uint) *Object {
if !self.IsArray() {
panic("Not array class: " + self.name)
}
switch self.Name() {
case "[Z":
return &Object{self, make([]int8, count), nil}
case "[B":
return &Object{self, make([]int8, count), nil}
case "[C":
return &Object{self, make([]uint16, count), nil}
case "[S":
return &Object{self, make([]int16, count), nil}
case "[I":
return &Object{self, make([]int32, count), nil}
case "[J":
return &Object{self, make([]int64, count), nil}
case "[F":
return &Object{self, make([]float32, count), nil}
case "[D":
return &Object{self, make([]float64, count), nil}
default:
return &Object{self, make([]*Object, count), nil}
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/array_class.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 275
|
```go
package heap
func (self *Object) Clone() *Object {
return &Object{
class: self.class,
data: self.cloneData(),
}
}
func (self *Object) cloneData() interface{} {
switch self.data.(type) {
case []int8:
elements := self.data.([]int8)
elements2 := make([]int8, len(elements))
copy(elements2, elements)
return elements2
case []int16:
elements := self.data.([]int16)
elements2 := make([]int16, len(elements))
copy(elements2, elements)
return elements2
case []uint16:
elements := self.data.([]uint16)
elements2 := make([]uint16, len(elements))
copy(elements2, elements)
return elements2
case []int32:
elements := self.data.([]int32)
elements2 := make([]int32, len(elements))
copy(elements2, elements)
return elements2
case []int64:
elements := self.data.([]int64)
elements2 := make([]int64, len(elements))
copy(elements2, elements)
return elements2
case []float32:
elements := self.data.([]float32)
elements2 := make([]float32, len(elements))
copy(elements2, elements)
return elements2
case []float64:
elements := self.data.([]float64)
elements2 := make([]float64, len(elements))
copy(elements2, elements)
return elements2
case []*Object:
elements := self.data.([]*Object)
elements2 := make([]*Object, len(elements))
copy(elements2, elements)
return elements2
default: // []Slot
slots := self.data.(Slots)
slots2 := newSlots(uint(len(slots)))
copy(slots2, slots)
return slots2
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/rtda/heap/object_clone.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 423
|
```go
package classpath
import "os"
import "strings"
// :(linux/unix) or ;(windows)
const pathListSeparator = string(os.PathListSeparator)
type Entry interface {
// className: fully/qualified/ClassName.class
readClass(className string) ([]byte, Entry, error)
String() string
}
func newEntry(path string) Entry {
if strings.Contains(path, pathListSeparator) {
return newCompositeEntry(path)
}
if strings.HasSuffix(path, "*") {
return newWildcardEntry(path)
}
if strings.HasSuffix(path, ".jar") || strings.HasSuffix(path, ".JAR") ||
strings.HasSuffix(path, ".zip") || strings.HasSuffix(path, ".ZIP") {
return newZipEntry(path)
}
return newDirEntry(path)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classpath/entry.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 168
|
```go
package classpath
import "os"
import "path/filepath"
type Classpath struct {
bootClasspath Entry
extClasspath Entry
userClasspath Entry
}
func Parse(jreOption, cpOption string) *Classpath {
cp := &Classpath{}
cp.parseBootAndExtClasspath(jreOption)
cp.parseUserClasspath(cpOption)
return cp
}
func (self *Classpath) parseBootAndExtClasspath(jreOption string) {
jreDir := getJreDir(jreOption)
// jre/lib/*
jreLibPath := filepath.Join(jreDir, "lib", "*")
self.bootClasspath = newWildcardEntry(jreLibPath)
// jre/lib/ext/*
jreExtPath := filepath.Join(jreDir, "lib", "ext", "*")
self.extClasspath = newWildcardEntry(jreExtPath)
}
func getJreDir(jreOption string) string {
if jreOption != "" && exists(jreOption) {
return jreOption
}
if exists("./jre") {
return "./jre"
}
if jh := os.Getenv("JAVA_HOME"); jh != "" {
return filepath.Join(jh, "jre")
}
panic("Can not find jre folder!")
}
func exists(path string) bool {
if _, err := os.Stat(path); err != nil {
if os.IsNotExist(err) {
return false
}
}
return true
}
func (self *Classpath) parseUserClasspath(cpOption string) {
if cpOption == "" {
cpOption = "."
}
self.userClasspath = newEntry(cpOption)
}
// className: fully/qualified/ClassName
func (self *Classpath) ReadClass(className string) ([]byte, Entry, error) {
className = className + ".class"
if data, entry, err := self.bootClasspath.readClass(className); err == nil {
return data, entry, err
}
if data, entry, err := self.extClasspath.readClass(className); err == nil {
return data, entry, err
}
return self.userClasspath.readClass(className)
}
func (self *Classpath) String() string {
return self.userClasspath.String()
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classpath/classpath.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 476
|
```go
package classpath
import "errors"
import "strings"
type CompositeEntry []Entry
func newCompositeEntry(pathList string) CompositeEntry {
compositeEntry := []Entry{}
for _, path := range strings.Split(pathList, pathListSeparator) {
entry := newEntry(path)
compositeEntry = append(compositeEntry, entry)
}
return compositeEntry
}
func (self CompositeEntry) readClass(className string) ([]byte, Entry, error) {
for _, entry := range self {
data, from, err := entry.readClass(className)
if err == nil {
return data, from, nil
}
}
return nil, nil, errors.New("class not found: " + className)
}
func (self CompositeEntry) String() string {
strs := make([]string, len(self))
for i, entry := range self {
strs[i] = entry.String()
}
return strings.Join(strs, pathListSeparator)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classpath/entry_composite.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 202
|
```go
package classpath
import "os"
import "path/filepath"
import "strings"
func newWildcardEntry(path string) CompositeEntry {
baseDir := path[:len(path)-1] // remove *
compositeEntry := []Entry{}
walkFn := func(path string, info os.FileInfo, err error) error {
if err != nil {
return err
}
if info.IsDir() && path != baseDir {
return filepath.SkipDir
}
if strings.HasSuffix(path, ".jar") || strings.HasSuffix(path, ".JAR") {
jarEntry := newZipEntry(path)
compositeEntry = append(compositeEntry, jarEntry)
}
return nil
}
filepath.Walk(baseDir, walkFn)
return compositeEntry
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classpath/entry_wildcard.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 168
|
```go
package classpath
import "archive/zip"
import "errors"
import "io/ioutil"
import "path/filepath"
type ZipEntry struct {
absPath string
zipRC *zip.ReadCloser
}
func newZipEntry(path string) *ZipEntry {
absPath, err := filepath.Abs(path)
if err != nil {
panic(err)
}
return &ZipEntry{absPath, nil}
}
func (self *ZipEntry) readClass(className string) ([]byte, Entry, error) {
if self.zipRC == nil {
err := self.openJar()
if err != nil {
return nil, nil, err
}
}
classFile := self.findClass(className)
if classFile == nil {
return nil, nil, errors.New("class not found: " + className)
}
data, err := readClass(classFile)
return data, self, err
}
// todo: close zip
func (self *ZipEntry) openJar() error {
r, err := zip.OpenReader(self.absPath)
if err == nil {
self.zipRC = r
}
return err
}
func (self *ZipEntry) findClass(className string) *zip.File {
for _, f := range self.zipRC.File {
if f.Name == className {
return f
}
}
return nil
}
func readClass(classFile *zip.File) ([]byte, error) {
rc, err := classFile.Open()
if err != nil {
return nil, err
}
// read class data
data, err := ioutil.ReadAll(rc)
rc.Close()
if err != nil {
return nil, err
}
return data, nil
}
func (self *ZipEntry) String() string {
return self.absPath
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classpath/entry_zip.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 374
|
```go
package classpath
import "io/ioutil"
import "path/filepath"
type DirEntry struct {
absDir string
}
func newDirEntry(path string) *DirEntry {
absDir, err := filepath.Abs(path)
if err != nil {
panic(err)
}
return &DirEntry{absDir}
}
func (self *DirEntry) readClass(className string) ([]byte, Entry, error) {
fileName := filepath.Join(self.absDir, className)
data, err := ioutil.ReadFile(fileName)
return data, self, err
}
func (self *DirEntry) String() string {
return self.absDir
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch10/classpath/entry_dir.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 131
|
```go
package main
import "flag"
import "fmt"
import "os"
// java [-options] class [args...]
type Cmd struct {
helpFlag bool
versionFlag bool
cpOption string
XjreOption string
class string
args []string
}
func parseCmd() *Cmd {
cmd := &Cmd{}
flag.Usage = printUsage
flag.BoolVar(&cmd.helpFlag, "help", false, "print help message")
flag.BoolVar(&cmd.helpFlag, "?", false, "print help message")
flag.BoolVar(&cmd.versionFlag, "version", false, "print version and exit")
flag.StringVar(&cmd.cpOption, "classpath", "", "classpath")
flag.StringVar(&cmd.cpOption, "cp", "", "classpath")
flag.StringVar(&cmd.XjreOption, "Xjre", "", "path to jre")
flag.Parse()
args := flag.Args()
if len(args) > 0 {
cmd.class = args[0]
cmd.args = args[1:]
}
return cmd
}
func printUsage() {
fmt.Printf("Usage: %s [-options] class [args...]\n", os.Args[0])
//flag.PrintDefaults()
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/cmd.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 254
|
```go
package classfile
/*
EnclosingMethod_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 class_index;
u2 method_index;
}
*/
type EnclosingMethodAttribute struct {
cp ConstantPool
classIndex uint16
methodIndex uint16
}
func (self *EnclosingMethodAttribute) readInfo(reader *ClassReader) {
self.classIndex = reader.readUint16()
self.methodIndex = reader.readUint16()
}
func (self *EnclosingMethodAttribute) ClassName() string {
return self.cp.getClassName(self.classIndex)
}
func (self *EnclosingMethodAttribute) MethodNameAndDescriptor() (string, string) {
if self.methodIndex > 0 {
return self.cp.getNameAndType(self.methodIndex)
} else {
return "", ""
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/attr_enclosing_method.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 170
|
```go
package main
import "fmt"
import "strings"
import "jvmgo/ch03/classfile"
import "jvmgo/ch03/classpath"
func main() {
cmd := parseCmd()
if cmd.versionFlag {
fmt.Println("version 0.0.1")
} else if cmd.helpFlag || cmd.class == "" {
printUsage()
} else {
startJVM(cmd)
}
}
func startJVM(cmd *Cmd) {
cp := classpath.Parse(cmd.XjreOption, cmd.cpOption)
className := strings.Replace(cmd.class, ".", "/", -1)
cf := loadClass(className, cp)
fmt.Println(cmd.class)
printClassInfo(cf)
}
func loadClass(className string, cp *classpath.Classpath) *classfile.ClassFile {
classData, _, err := cp.ReadClass(className)
if err != nil {
panic(err)
}
cf, err := classfile.Parse(classData)
if err != nil {
panic(err)
}
return cf
}
func printClassInfo(cf *classfile.ClassFile) {
fmt.Printf("version: %v.%v\n", cf.MajorVersion(), cf.MinorVersion())
fmt.Printf("constants count: %v\n", len(cf.ConstantPool()))
fmt.Printf("access flags: 0x%x\n", cf.AccessFlags())
fmt.Printf("this class: %v\n", cf.ClassName())
fmt.Printf("super class: %v\n", cf.SuperClassName())
fmt.Printf("interfaces: %v\n", cf.InterfaceNames())
fmt.Printf("fields count: %v\n", len(cf.Fields()))
for _, f := range cf.Fields() {
fmt.Printf(" %s\n", f.Name())
}
fmt.Printf("methods count: %v\n", len(cf.Methods()))
for _, m := range cf.Methods() {
fmt.Printf(" %s\n", m.Name())
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/main.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 391
|
```go
package classfile
/*
field_info {
u2 access_flags;
u2 name_index;
u2 descriptor_index;
u2 attributes_count;
attribute_info attributes[attributes_count];
}
method_info {
u2 access_flags;
u2 name_index;
u2 descriptor_index;
u2 attributes_count;
attribute_info attributes[attributes_count];
}
*/
type MemberInfo struct {
cp ConstantPool
accessFlags uint16
nameIndex uint16
descriptorIndex uint16
attributes []AttributeInfo
}
// read field or method table
func readMembers(reader *ClassReader, cp ConstantPool) []*MemberInfo {
memberCount := reader.readUint16()
members := make([]*MemberInfo, memberCount)
for i := range members {
members[i] = readMember(reader, cp)
}
return members
}
func readMember(reader *ClassReader, cp ConstantPool) *MemberInfo {
return &MemberInfo{
cp: cp,
accessFlags: reader.readUint16(),
nameIndex: reader.readUint16(),
descriptorIndex: reader.readUint16(),
attributes: readAttributes(reader, cp),
}
}
func (self *MemberInfo) AccessFlags() uint16 {
return self.accessFlags
}
func (self *MemberInfo) Name() string {
return self.cp.getUtf8(self.nameIndex)
}
func (self *MemberInfo) Descriptor() string {
return self.cp.getUtf8(self.descriptorIndex)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/member_info.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 326
|
```go
package classfile
/*
CONSTANT_MethodHandle_info {
u1 tag;
u1 reference_kind;
u2 reference_index;
}
*/
type ConstantMethodHandleInfo struct {
referenceKind uint8
referenceIndex uint16
}
func (self *ConstantMethodHandleInfo) readInfo(reader *ClassReader) {
self.referenceKind = reader.readUint8()
self.referenceIndex = reader.readUint16()
}
/*
CONSTANT_MethodType_info {
u1 tag;
u2 descriptor_index;
}
*/
type ConstantMethodTypeInfo struct {
descriptorIndex uint16
}
func (self *ConstantMethodTypeInfo) readInfo(reader *ClassReader) {
self.descriptorIndex = reader.readUint16()
}
/*
CONSTANT_InvokeDynamic_info {
u1 tag;
u2 bootstrap_method_attr_index;
u2 name_and_type_index;
}
*/
type ConstantInvokeDynamicInfo struct {
bootstrapMethodAttrIndex uint16
nameAndTypeIndex uint16
}
func (self *ConstantInvokeDynamicInfo) readInfo(reader *ClassReader) {
self.bootstrapMethodAttrIndex = reader.readUint16()
self.nameAndTypeIndex = reader.readUint16()
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/cp_invoke_dynamic.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 241
|
```go
package classfile
/*
BootstrapMethods_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 num_bootstrap_methods;
{ u2 bootstrap_method_ref;
u2 num_bootstrap_arguments;
u2 bootstrap_arguments[num_bootstrap_arguments];
} bootstrap_methods[num_bootstrap_methods];
}
*/
type BootstrapMethodsAttribute struct {
bootstrapMethods []*BootstrapMethod
}
func (self *BootstrapMethodsAttribute) readInfo(reader *ClassReader) {
numBootstrapMethods := reader.readUint16()
self.bootstrapMethods = make([]*BootstrapMethod, numBootstrapMethods)
for i := range self.bootstrapMethods {
self.bootstrapMethods[i] = &BootstrapMethod{
bootstrapMethodRef: reader.readUint16(),
bootstrapArguments: reader.readUint16s(),
}
}
}
type BootstrapMethod struct {
bootstrapMethodRef uint16
bootstrapArguments []uint16
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/attr_bootstrap_methods.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 184
|
```go
package classfile
/*
Exceptions_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 number_of_exceptions;
u2 exception_index_table[number_of_exceptions];
}
*/
type ExceptionsAttribute struct {
exceptionIndexTable []uint16
}
func (self *ExceptionsAttribute) readInfo(reader *ClassReader) {
self.exceptionIndexTable = reader.readUint16s()
}
func (self *ExceptionsAttribute) ExceptionIndexTable() []uint16 {
return self.exceptionIndexTable
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/attr_exceptions.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 104
|
```go
package classfile
import "fmt"
type ConstantPool []ConstantInfo
func readConstantPool(reader *ClassReader) ConstantPool {
cpCount := int(reader.readUint16())
cp := make([]ConstantInfo, cpCount)
// The constant_pool table is indexed from 1 to constant_pool_count - 1.
for i := 1; i < cpCount; i++ {
cp[i] = readConstantInfo(reader, cp)
// path_to_url#jvms-4.4.5
// All 8-byte constants take up two entries in the constant_pool table of the class file.
// If a CONSTANT_Long_info or CONSTANT_Double_info structure is the item in the constant_pool
// table at index n, then the next usable item in the pool is located at index n+2.
// The constant_pool index n+1 must be valid but is considered unusable.
switch cp[i].(type) {
case *ConstantLongInfo, *ConstantDoubleInfo:
i++
}
}
return cp
}
func (self ConstantPool) getConstantInfo(index uint16) ConstantInfo {
if cpInfo := self[index]; cpInfo != nil {
return cpInfo
}
panic(fmt.Errorf("Invalid constant pool index: %v!", index))
}
func (self ConstantPool) getNameAndType(index uint16) (string, string) {
ntInfo := self.getConstantInfo(index).(*ConstantNameAndTypeInfo)
name := self.getUtf8(ntInfo.nameIndex)
_type := self.getUtf8(ntInfo.descriptorIndex)
return name, _type
}
func (self ConstantPool) getClassName(index uint16) string {
classInfo := self.getConstantInfo(index).(*ConstantClassInfo)
return self.getUtf8(classInfo.nameIndex)
}
func (self ConstantPool) getUtf8(index uint16) string {
utf8Info := self.getConstantInfo(index).(*ConstantUtf8Info)
return utf8Info.str
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/constant_pool.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 421
|
```go
package classfile
/*
CONSTANT_NameAndType_info {
u1 tag;
u2 name_index;
u2 descriptor_index;
}
*/
type ConstantNameAndTypeInfo struct {
nameIndex uint16
descriptorIndex uint16
}
func (self *ConstantNameAndTypeInfo) readInfo(reader *ClassReader) {
self.nameIndex = reader.readUint16()
self.descriptorIndex = reader.readUint16()
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/cp_name_and_type.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 88
|
```go
package classfile
/*
Deprecated_attribute {
u2 attribute_name_index;
u4 attribute_length;
}
*/
type DeprecatedAttribute struct {
MarkerAttribute
}
/*
Synthetic_attribute {
u2 attribute_name_index;
u4 attribute_length;
}
*/
type SyntheticAttribute struct {
MarkerAttribute
}
type MarkerAttribute struct{}
func (self *MarkerAttribute) readInfo(reader *ClassReader) {
// read nothing
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/attr_markers.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 90
|
```go
package classfile
/*
LineNumberTable_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 line_number_table_length;
{ u2 start_pc;
u2 line_number;
} line_number_table[line_number_table_length];
}
*/
type LineNumberTableAttribute struct {
lineNumberTable []*LineNumberTableEntry
}
type LineNumberTableEntry struct {
startPc uint16
lineNumber uint16
}
func (self *LineNumberTableAttribute) readInfo(reader *ClassReader) {
lineNumberTableLength := reader.readUint16()
self.lineNumberTable = make([]*LineNumberTableEntry, lineNumberTableLength)
for i := range self.lineNumberTable {
self.lineNumberTable[i] = &LineNumberTableEntry{
startPc: reader.readUint16(),
lineNumber: reader.readUint16(),
}
}
}
func (self *LineNumberTableAttribute) GetLineNumber(pc int) int {
for i := len(self.lineNumberTable) - 1; i >= 0; i-- {
entry := self.lineNumberTable[i]
if pc >= int(entry.startPc) {
return int(entry.lineNumber)
}
}
return -1
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/attr_line_number_table.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 255
|
```go
package classfile
/*
attribute_info {
u2 attribute_name_index;
u4 attribute_length;
u1 info[attribute_length];
}
*/
type UnparsedAttribute struct {
name string
length uint32
info []byte
}
func (self *UnparsedAttribute) readInfo(reader *ClassReader) {
self.info = reader.readBytes(self.length)
}
func (self *UnparsedAttribute) Info() []byte {
return self.info
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/attr_unparsed.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 96
|
```go
package classfile
/*
CONSTANT_Class_info {
u1 tag;
u2 name_index;
}
*/
type ConstantClassInfo struct {
cp ConstantPool
nameIndex uint16
}
func (self *ConstantClassInfo) readInfo(reader *ClassReader) {
self.nameIndex = reader.readUint16()
}
func (self *ConstantClassInfo) Name() string {
return self.cp.getUtf8(self.nameIndex)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/cp_class.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 90
|
```go
package classfile
// Constant pool tags
const (
CONSTANT_Class = 7
CONSTANT_Fieldref = 9
CONSTANT_Methodref = 10
CONSTANT_InterfaceMethodref = 11
CONSTANT_String = 8
CONSTANT_Integer = 3
CONSTANT_Float = 4
CONSTANT_Long = 5
CONSTANT_Double = 6
CONSTANT_NameAndType = 12
CONSTANT_Utf8 = 1
CONSTANT_MethodHandle = 15
CONSTANT_MethodType = 16
CONSTANT_InvokeDynamic = 18
)
/*
cp_info {
u1 tag;
u1 info[];
}
*/
type ConstantInfo interface {
readInfo(reader *ClassReader)
}
func readConstantInfo(reader *ClassReader, cp ConstantPool) ConstantInfo {
tag := reader.readUint8()
c := newConstantInfo(tag, cp)
c.readInfo(reader)
return c
}
// todo ugly code
func newConstantInfo(tag uint8, cp ConstantPool) ConstantInfo {
switch tag {
case CONSTANT_Integer:
return &ConstantIntegerInfo{}
case CONSTANT_Float:
return &ConstantFloatInfo{}
case CONSTANT_Long:
return &ConstantLongInfo{}
case CONSTANT_Double:
return &ConstantDoubleInfo{}
case CONSTANT_Utf8:
return &ConstantUtf8Info{}
case CONSTANT_String:
return &ConstantStringInfo{cp: cp}
case CONSTANT_Class:
return &ConstantClassInfo{cp: cp}
case CONSTANT_Fieldref:
return &ConstantFieldrefInfo{ConstantMemberrefInfo{cp: cp}}
case CONSTANT_Methodref:
return &ConstantMethodrefInfo{ConstantMemberrefInfo{cp: cp}}
case CONSTANT_InterfaceMethodref:
return &ConstantInterfaceMethodrefInfo{ConstantMemberrefInfo{cp: cp}}
case CONSTANT_NameAndType:
return &ConstantNameAndTypeInfo{}
case CONSTANT_MethodType:
return &ConstantMethodTypeInfo{}
case CONSTANT_MethodHandle:
return &ConstantMethodHandleInfo{}
case CONSTANT_InvokeDynamic:
return &ConstantInvokeDynamicInfo{}
default:
panic("java.lang.ClassFormatError: constant pool tag!")
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/constant_info.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 468
|
```go
package classfile
import "math"
/*
CONSTANT_Integer_info {
u1 tag;
u4 bytes;
}
*/
type ConstantIntegerInfo struct {
val int32
}
func (self *ConstantIntegerInfo) readInfo(reader *ClassReader) {
bytes := reader.readUint32()
self.val = int32(bytes)
}
func (self *ConstantIntegerInfo) Value() int32 {
return self.val
}
/*
CONSTANT_Float_info {
u1 tag;
u4 bytes;
}
*/
type ConstantFloatInfo struct {
val float32
}
func (self *ConstantFloatInfo) readInfo(reader *ClassReader) {
bytes := reader.readUint32()
self.val = math.Float32frombits(bytes)
}
func (self *ConstantFloatInfo) Value() float32 {
return self.val
}
/*
CONSTANT_Long_info {
u1 tag;
u4 high_bytes;
u4 low_bytes;
}
*/
type ConstantLongInfo struct {
val int64
}
func (self *ConstantLongInfo) readInfo(reader *ClassReader) {
bytes := reader.readUint64()
self.val = int64(bytes)
}
func (self *ConstantLongInfo) Value() int64 {
return self.val
}
/*
CONSTANT_Double_info {
u1 tag;
u4 high_bytes;
u4 low_bytes;
}
*/
type ConstantDoubleInfo struct {
val float64
}
func (self *ConstantDoubleInfo) readInfo(reader *ClassReader) {
bytes := reader.readUint64()
self.val = math.Float64frombits(bytes)
}
func (self *ConstantDoubleInfo) Value() float64 {
return self.val
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/cp_numeric.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 341
|
```go
package classfile
/*
SourceFile_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 sourcefile_index;
}
*/
type SourceFileAttribute struct {
cp ConstantPool
sourceFileIndex uint16
}
func (self *SourceFileAttribute) readInfo(reader *ClassReader) {
self.sourceFileIndex = reader.readUint16()
}
func (self *SourceFileAttribute) FileName() string {
return self.cp.getUtf8(self.sourceFileIndex)
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/attr_source_file.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 101
|
```go
package classfile
import "fmt"
/*
ClassFile {
u4 magic;
u2 minor_version;
u2 major_version;
u2 constant_pool_count;
cp_info constant_pool[constant_pool_count-1];
u2 access_flags;
u2 this_class;
u2 super_class;
u2 interfaces_count;
u2 interfaces[interfaces_count];
u2 fields_count;
field_info fields[fields_count];
u2 methods_count;
method_info methods[methods_count];
u2 attributes_count;
attribute_info attributes[attributes_count];
}
*/
type ClassFile struct {
//magic uint32
minorVersion uint16
majorVersion uint16
constantPool ConstantPool
accessFlags uint16
thisClass uint16
superClass uint16
interfaces []uint16
fields []*MemberInfo
methods []*MemberInfo
attributes []AttributeInfo
}
func Parse(classData []byte) (cf *ClassFile, err error) {
defer func() {
if r := recover(); r != nil {
var ok bool
err, ok = r.(error)
if !ok {
err = fmt.Errorf("%v", r)
}
}
}()
cr := &ClassReader{classData}
cf = &ClassFile{}
cf.read(cr)
return
}
func (self *ClassFile) read(reader *ClassReader) {
self.readAndCheckMagic(reader)
self.readAndCheckVersion(reader)
self.constantPool = readConstantPool(reader)
self.accessFlags = reader.readUint16()
self.thisClass = reader.readUint16()
self.superClass = reader.readUint16()
self.interfaces = reader.readUint16s()
self.fields = readMembers(reader, self.constantPool)
self.methods = readMembers(reader, self.constantPool)
self.attributes = readAttributes(reader, self.constantPool)
}
func (self *ClassFile) readAndCheckMagic(reader *ClassReader) {
magic := reader.readUint32()
if magic != 0xCAFEBABE {
panic("java.lang.ClassFormatError: magic!")
}
}
func (self *ClassFile) readAndCheckVersion(reader *ClassReader) {
self.minorVersion = reader.readUint16()
self.majorVersion = reader.readUint16()
switch self.majorVersion {
case 45:
return
case 46, 47, 48, 49, 50, 51, 52:
if self.minorVersion == 0 {
return
}
}
panic("java.lang.UnsupportedClassVersionError!")
}
func (self *ClassFile) MinorVersion() uint16 {
return self.minorVersion
}
func (self *ClassFile) MajorVersion() uint16 {
return self.majorVersion
}
func (self *ClassFile) ConstantPool() ConstantPool {
return self.constantPool
}
func (self *ClassFile) AccessFlags() uint16 {
return self.accessFlags
}
func (self *ClassFile) Fields() []*MemberInfo {
return self.fields
}
func (self *ClassFile) Methods() []*MemberInfo {
return self.methods
}
func (self *ClassFile) ClassName() string {
return self.constantPool.getClassName(self.thisClass)
}
func (self *ClassFile) SuperClassName() string {
if self.superClass > 0 {
return self.constantPool.getClassName(self.superClass)
}
return ""
}
func (self *ClassFile) InterfaceNames() []string {
interfaceNames := make([]string, len(self.interfaces))
for i, cpIndex := range self.interfaces {
interfaceNames[i] = self.constantPool.getClassName(cpIndex)
}
return interfaceNames
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/class_file.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 787
|
```go
package classfile
/*
LocalVariableTable_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 local_variable_table_length;
{ u2 start_pc;
u2 length;
u2 name_index;
u2 descriptor_index;
u2 index;
} local_variable_table[local_variable_table_length];
}
*/
type LocalVariableTableAttribute struct {
localVariableTable []*LocalVariableTableEntry
}
type LocalVariableTableEntry struct {
startPc uint16
length uint16
nameIndex uint16
descriptorIndex uint16
index uint16
}
func (self *LocalVariableTableAttribute) readInfo(reader *ClassReader) {
localVariableTableLength := reader.readUint16()
self.localVariableTable = make([]*LocalVariableTableEntry, localVariableTableLength)
for i := range self.localVariableTable {
self.localVariableTable[i] = &LocalVariableTableEntry{
startPc: reader.readUint16(),
length: reader.readUint16(),
nameIndex: reader.readUint16(),
descriptorIndex: reader.readUint16(),
index: reader.readUint16(),
}
}
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/attr_local_variable_table.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 251
|
```go
package classfile
/*
ConstantValue_attribute {
u2 attribute_name_index;
u4 attribute_length;
u2 constantvalue_index;
}
*/
type ConstantValueAttribute struct {
constantValueIndex uint16
}
func (self *ConstantValueAttribute) readInfo(reader *ClassReader) {
self.constantValueIndex = reader.readUint16()
}
func (self *ConstantValueAttribute) ConstantValueIndex() uint16 {
return self.constantValueIndex
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/attr_constant_value.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 95
|
```go
package classfile
import "encoding/binary"
type ClassReader struct {
data []byte
}
// u1
func (self *ClassReader) readUint8() uint8 {
val := self.data[0]
self.data = self.data[1:]
return val
}
// u2
func (self *ClassReader) readUint16() uint16 {
val := binary.BigEndian.Uint16(self.data)
self.data = self.data[2:]
return val
}
// u4
func (self *ClassReader) readUint32() uint32 {
val := binary.BigEndian.Uint32(self.data)
self.data = self.data[4:]
return val
}
func (self *ClassReader) readUint64() uint64 {
val := binary.BigEndian.Uint64(self.data)
self.data = self.data[8:]
return val
}
func (self *ClassReader) readUint16s() []uint16 {
n := self.readUint16()
s := make([]uint16, n)
for i := range s {
s[i] = self.readUint16()
}
return s
}
func (self *ClassReader) readBytes(n uint32) []byte {
bytes := self.data[:n]
self.data = self.data[n:]
return bytes
}
```
|
/content/code_sandbox/v1/code/go/src/jvmgo/ch03/classfile/class_reader.go
|
go
| 2016-01-06T13:13:45
| 2024-08-16T13:42:58
|
jvmgo-book
|
zxh0/jvmgo-book
| 1,605
| 262
|
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