internal void Read(ushort pc, BigEndianBinaryReader br, ClassFile classFile)
{
this.pc = pc;
ByteCode bc = (ByteCode)br.ReadByte();
switch(ByteCodeMetaData.GetMode(bc))
{
case ByteCodeMode.Simple:
break;
case ByteCodeMode.Constant_1:
arg1 = br.ReadByte();
classFile.MarkLinkRequiredConstantPoolItem(arg1);
break;
case ByteCodeMode.Local_1:
arg1 = br.ReadByte();
break;
case ByteCodeMode.Constant_2:
arg1 = br.ReadUInt16();
classFile.MarkLinkRequiredConstantPoolItem(arg1);
break;
case ByteCodeMode.Branch_2:
arg1 = br.ReadInt16();
break;
case ByteCodeMode.Branch_4:
arg1 = br.ReadInt32();
break;
case ByteCodeMode.Constant_2_1_1:
arg1 = br.ReadUInt16();
classFile.MarkLinkRequiredConstantPoolItem(arg1);
arg2 = br.ReadByte();
if(br.ReadByte() != 0)
{
throw new ClassFormatError("invokeinterface filler must be zero");
}
break;
case ByteCodeMode.Immediate_1:
arg1 = br.ReadSByte();
break;
case ByteCodeMode.Immediate_2:
arg1 = br.ReadInt16();
break;
case ByteCodeMode.Local_1_Immediate_1:
arg1 = br.ReadByte();
arg2 = br.ReadSByte();
break;
case ByteCodeMode.Constant_2_Immediate_1:
arg1 = br.ReadUInt16();
classFile.MarkLinkRequiredConstantPoolItem(arg1);
arg2 = br.ReadSByte();
break;
case ByteCodeMode.Tableswitch:
{
// skip the padding
uint p = pc + 1u;
uint align = ((p + 3) & 0x7ffffffc) - p;
br.Skip(align);
int default_offset = br.ReadInt32();
this.arg1 = default_offset;
int low = br.ReadInt32();
int high = br.ReadInt32();
if(low > high || high > 16384L + low)
{
throw new ClassFormatError("Incorrect tableswitch");
}
SwitchEntry[] entries = new SwitchEntry[high - low + 1];
for(int i = low; i < high; i++)
{
entries[i - low].value = i;
entries[i - low].target = br.ReadInt32();
}
// do the last entry outside the loop, to avoid overflowing "i", if high == int.MaxValue
entries[high - low].value = high;
entries[high - low].target = br.ReadInt32();
this.switch_entries = entries;
break;
}
case ByteCodeMode.Lookupswitch:
{
// skip the padding
uint p = pc + 1u;
uint align = ((p + 3) & 0x7ffffffc) - p;
br.Skip(align);
int default_offset = br.ReadInt32();
this.arg1 = default_offset;
int count = br.ReadInt32();
if(count < 0 || count > 16384)
{
throw new ClassFormatError("Incorrect lookupswitch");
}
SwitchEntry[] entries = new SwitchEntry[count];
for(int i = 0; i < count; i++)
{
entries[i].value = br.ReadInt32();
entries[i].target = br.ReadInt32();
}
this.switch_entries = entries;
break;
}
case ByteCodeMode.WidePrefix:
bc = (ByteCode)br.ReadByte();
// NOTE the PC of a wide instruction is actually the PC of the
// wide prefix, not the following instruction (vmspec 4.9.2)
switch(ByteCodeMetaData.GetWideMode(bc))
{
case ByteCodeModeWide.Local_2:
arg1 = br.ReadUInt16();
break;
case ByteCodeModeWide.Local_2_Immediate_2:
arg1 = br.ReadUInt16();
arg2 = br.ReadInt16();
break;
default:
throw new ClassFormatError("Invalid wide prefix on opcode: {0}", bc);
}
break;
default:
throw new ClassFormatError("Invalid opcode: {0}", bc);
}
this.normopcode = ByteCodeMetaData.GetNormalizedByteCode(bc);
arg1 = ByteCodeMetaData.GetArg(bc, arg1);
}
internal void Read(ClassFile classFile, string[] utf8_cp, Method method, BigEndianBinaryReader br, ClassFileParseOptions options)
{
max_stack = br.ReadUInt16();
max_locals = br.ReadUInt16();
uint code_length = br.ReadUInt32();
if(code_length > 65535)
{
throw new ClassFormatError("{0} (Invalid Code length {1})", classFile.Name, code_length);
}
Instruction[] instructions = new Instruction[code_length + 1];
int basePosition = br.Position;
int instructionIndex = 0;
try
{
BigEndianBinaryReader rdr = br.Section(code_length);
while(!rdr.IsAtEnd)
{
instructions[instructionIndex].Read((ushort)(rdr.Position - basePosition), rdr, classFile);
hasJsr |= instructions[instructionIndex].NormalizedOpCode == NormalizedByteCode.__jsr;
instructionIndex++;
}
// we add an additional nop instruction to make it easier for consumers of the code array
instructions[instructionIndex++].SetTermNop((ushort)(rdr.Position - basePosition));
}
catch(ClassFormatError x)
{
// any class format errors in the code block are actually verify errors
verifyError = x.Message;
}
this.instructions = new Instruction[instructionIndex];
Array.Copy(instructions, 0, this.instructions, 0, instructionIndex);
// build the pcIndexMap
int[] pcIndexMap = new int[this.instructions[instructionIndex - 1].PC + 1];
for(int i = 0; i < pcIndexMap.Length; i++)
{
pcIndexMap[i] = -1;
}
for(int i = 0; i < instructionIndex - 1; i++)
{
pcIndexMap[this.instructions[i].PC] = i;
}
// convert branch offsets to indexes
for(int i = 0; i < instructionIndex - 1; i++)
{
switch(this.instructions[i].NormalizedOpCode)
{
case NormalizedByteCode.__ifeq:
case NormalizedByteCode.__ifne:
case NormalizedByteCode.__iflt:
case NormalizedByteCode.__ifge:
case NormalizedByteCode.__ifgt:
case NormalizedByteCode.__ifle:
case NormalizedByteCode.__if_icmpeq:
case NormalizedByteCode.__if_icmpne:
case NormalizedByteCode.__if_icmplt:
case NormalizedByteCode.__if_icmpge:
case NormalizedByteCode.__if_icmpgt:
case NormalizedByteCode.__if_icmple:
case NormalizedByteCode.__if_acmpeq:
case NormalizedByteCode.__if_acmpne:
case NormalizedByteCode.__ifnull:
case NormalizedByteCode.__ifnonnull:
case NormalizedByteCode.__goto:
case NormalizedByteCode.__jsr:
this.instructions[i].SetTargetIndex(pcIndexMap[this.instructions[i].Arg1 + this.instructions[i].PC]);
break;
case NormalizedByteCode.__tableswitch:
case NormalizedByteCode.__lookupswitch:
this.instructions[i].MapSwitchTargets(pcIndexMap);
break;
}
}
// read exception table
ushort exception_table_length = br.ReadUInt16();
exception_table = new ExceptionTableEntry[exception_table_length];
for(int i = 0; i < exception_table_length; i++)
{
ushort start_pc = br.ReadUInt16();
ushort end_pc = br.ReadUInt16();
ushort handler_pc = br.ReadUInt16();
ushort catch_type = br.ReadUInt16();
if(start_pc >= end_pc
|| end_pc > code_length
|| handler_pc >= code_length
|| (catch_type != 0 && !classFile.SafeIsConstantPoolClass(catch_type)))
{
throw new ClassFormatError("Illegal exception table: {0}.{1}{2}", classFile.Name, method.Name, method.Signature);
}
classFile.MarkLinkRequiredConstantPoolItem(catch_type);
// if start_pc, end_pc or handler_pc is invalid (i.e. doesn't point to the start of an instruction),
// the index will be -1 and this will be handled by the verifier
int startIndex = pcIndexMap[start_pc];
int endIndex;
if (end_pc == code_length)
{
// it is legal for end_pc to point to just after the last instruction,
// but since there isn't an entry in our pcIndexMap for that, we have
// a special case for this
endIndex = instructionIndex - 1;
}
else
{
endIndex = pcIndexMap[end_pc];
}
int handlerIndex = pcIndexMap[handler_pc];
exception_table[i] = new ExceptionTableEntry(startIndex, endIndex, handlerIndex, catch_type, i);
}
ushort attributes_count = br.ReadUInt16();
for(int i = 0; i < attributes_count; i++)
{
switch(classFile.GetConstantPoolUtf8String(utf8_cp, br.ReadUInt16()))
{
case "LineNumberTable":
if((options & ClassFileParseOptions.LineNumberTable) != 0)
{
BigEndianBinaryReader rdr = br.Section(br.ReadUInt32());
int count = rdr.ReadUInt16();
lineNumberTable = new LineNumberTableEntry[count];
for(int j = 0; j < count; j++)
{
lineNumberTable[j].start_pc = rdr.ReadUInt16();
lineNumberTable[j].line_number = rdr.ReadUInt16();
if(lineNumberTable[j].start_pc >= code_length)
{
throw new ClassFormatError("{0} (LineNumberTable has invalid pc)", classFile.Name);
}
}
if(!rdr.IsAtEnd)
{
throw new ClassFormatError("{0} (LineNumberTable attribute has wrong length)", classFile.Name);
}
}
else
{
br.Skip(br.ReadUInt32());
}
break;
case "LocalVariableTable":
if((options & ClassFileParseOptions.LocalVariableTable) != 0)
{
BigEndianBinaryReader rdr = br.Section(br.ReadUInt32());
int count = rdr.ReadUInt16();
localVariableTable = new LocalVariableTableEntry[count];
for(int j = 0; j < count; j++)
{
localVariableTable[j].start_pc = rdr.ReadUInt16();
localVariableTable[j].length = rdr.ReadUInt16();
localVariableTable[j].name = classFile.GetConstantPoolUtf8String(utf8_cp, rdr.ReadUInt16());
localVariableTable[j].descriptor = classFile.GetConstantPoolUtf8String(utf8_cp, rdr.ReadUInt16()).Replace('/', '.');
localVariableTable[j].index = rdr.ReadUInt16();
}
// NOTE we're intentionally not checking that we're at the end of the section
// (optional attributes shouldn't cause ClassFormatError)
}
else
{
br.Skip(br.ReadUInt32());
}
break;
default:
br.Skip(br.ReadUInt32());
break;
}
}
// build the argmap
string sig = method.Signature;
List<int> args = new List<int>();
int pos = 0;
if(!method.IsStatic)
{
args.Add(pos++);
}
for(int i = 1; sig[i] != ')'; i++)
{
args.Add(pos++);
switch(sig[i])
{
case 'L':
i = sig.IndexOf(';', i);
break;
case 'D':
case 'J':
args.Add(-1);
break;
case '[':
{
while(sig[i] == '[')
{
i++;
}
if(sig[i] == 'L')
{
i = sig.IndexOf(';', i);
}
break;
}
}
}
argmap = args.ToArray();
if(args.Count > max_locals)
{
throw new ClassFormatError("{0} (Arguments can't fit into locals)", classFile.Name);
}
}