forked from cgvr/DeltaVR
652 lines
17 KiB
C#
652 lines
17 KiB
C#
//
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// Author:
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// Jb Evain (jbevain@gmail.com)
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//
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// Copyright (c) 2008 - 2015 Jb Evain
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// Copyright (c) 2008 - 2011 Novell, Inc.
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//
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// Licensed under the MIT/X11 license.
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//
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using MonoFN.Cecil.Metadata;
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using MonoFN.Cecil.PE;
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using MonoFN.Collections.Generic;
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using System;
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using System.Collections.Generic;
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using RVA = System.UInt32;
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namespace MonoFN.Cecil.Cil {
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sealed class CodeWriter : ByteBuffer {
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readonly RVA code_base;
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internal readonly MetadataBuilder metadata;
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readonly Dictionary<uint, MetadataToken> standalone_signatures;
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readonly Dictionary<ByteBuffer, RVA> tiny_method_bodies;
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MethodBody body;
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public CodeWriter (MetadataBuilder metadata)
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: base (0)
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{
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this.code_base = metadata.text_map.GetNextRVA (TextSegment.CLIHeader);
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this.metadata = metadata;
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this.standalone_signatures = new Dictionary<uint, MetadataToken> ();
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this.tiny_method_bodies = new Dictionary<ByteBuffer, RVA> (new ByteBufferEqualityComparer ());
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}
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public RVA WriteMethodBody (MethodDefinition method)
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{
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RVA rva;
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if (IsUnresolved (method)) {
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if (method.rva == 0)
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return 0;
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rva = WriteUnresolvedMethodBody (method);
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} else {
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if (IsEmptyMethodBody (method.Body))
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return 0;
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rva = WriteResolvedMethodBody (method);
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}
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return rva;
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}
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static bool IsEmptyMethodBody (MethodBody body)
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{
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return body.instructions.IsNullOrEmpty ()
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&& body.variables.IsNullOrEmpty ();
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}
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static bool IsUnresolved (MethodDefinition method)
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{
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return method.HasBody && method.HasImage && method.body == null;
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}
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RVA WriteUnresolvedMethodBody (MethodDefinition method)
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{
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var code_reader = metadata.module.reader.code;
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int code_size;
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MetadataToken local_var_token;
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var raw_body = code_reader.PatchRawMethodBody (method, this, out code_size, out local_var_token);
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var fat_header = (raw_body.buffer [0] & 0x3) == 0x3;
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if (fat_header)
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Align (4);
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var rva = BeginMethod ();
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if (fat_header || !GetOrMapTinyMethodBody (raw_body, ref rva)) {
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WriteBytes (raw_body);
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}
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if (method.debug_info == null)
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return rva;
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var symbol_writer = metadata.symbol_writer;
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if (symbol_writer != null) {
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method.debug_info.code_size = code_size;
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method.debug_info.local_var_token = local_var_token;
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symbol_writer.Write (method.debug_info);
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}
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return rva;
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}
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RVA WriteResolvedMethodBody (MethodDefinition method)
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{
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RVA rva;
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body = method.Body;
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ComputeHeader ();
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if (RequiresFatHeader ()) {
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Align (4);
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rva = BeginMethod ();
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WriteFatHeader ();
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WriteInstructions ();
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if (body.HasExceptionHandlers)
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WriteExceptionHandlers ();
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} else {
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rva = BeginMethod ();
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WriteByte ((byte)(0x2 | (body.CodeSize << 2))); // tiny
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WriteInstructions ();
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var start_position = (int)(rva - code_base);
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var body_size = position - start_position;
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var body_bytes = new byte [body_size];
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Array.Copy (buffer, start_position, body_bytes, 0, body_size);
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if (GetOrMapTinyMethodBody (new ByteBuffer (body_bytes), ref rva))
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position = start_position;
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}
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var symbol_writer = metadata.symbol_writer;
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if (symbol_writer != null && method.debug_info != null) {
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method.debug_info.code_size = body.CodeSize;
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method.debug_info.local_var_token = body.local_var_token;
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symbol_writer.Write (method.debug_info);
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}
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return rva;
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}
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bool GetOrMapTinyMethodBody (ByteBuffer body, ref RVA rva)
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{
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RVA existing_rva;
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if (tiny_method_bodies.TryGetValue (body, out existing_rva)) {
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rva = existing_rva;
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return true;
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}
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tiny_method_bodies.Add (body, rva);
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return false;
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}
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void WriteFatHeader ()
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{
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var body = this.body;
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byte flags = 0x3; // fat
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if (body.InitLocals)
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flags |= 0x10; // init locals
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if (body.HasExceptionHandlers)
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flags |= 0x8; // more sections
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WriteByte (flags);
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WriteByte (0x30);
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WriteInt16 ((short)body.max_stack_size);
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WriteInt32 (body.code_size);
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body.local_var_token = body.HasVariables
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? GetStandAloneSignature (body.Variables)
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: MetadataToken.Zero;
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WriteMetadataToken (body.local_var_token);
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}
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void WriteInstructions ()
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{
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var instructions = body.Instructions;
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var items = instructions.items;
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var size = instructions.size;
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for (int i = 0; i < size; i++) {
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var instruction = items [i];
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WriteOpCode (instruction.opcode);
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WriteOperand (instruction);
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}
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}
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void WriteOpCode (OpCode opcode)
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{
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if (opcode.Size == 1) {
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WriteByte (opcode.Op2);
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} else {
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WriteByte (opcode.Op1);
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WriteByte (opcode.Op2);
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}
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}
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void WriteOperand (Instruction instruction)
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{
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var opcode = instruction.opcode;
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var operand_type = opcode.OperandType;
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if (operand_type == OperandType.InlineNone)
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return;
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var operand = instruction.operand;
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if (operand == null && !(operand_type == OperandType.InlineBrTarget || operand_type == OperandType.ShortInlineBrTarget)) {
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throw new ArgumentException ();
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}
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switch (operand_type) {
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case OperandType.InlineSwitch: {
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var targets = (Instruction [])operand;
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WriteInt32 (targets.Length);
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var diff = instruction.Offset + opcode.Size + (4 * (targets.Length + 1));
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for (int i = 0; i < targets.Length; i++)
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WriteInt32 (GetTargetOffset (targets [i]) - diff);
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break;
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}
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case OperandType.ShortInlineBrTarget: {
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var target = (Instruction)operand;
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var offset = target != null ? GetTargetOffset (target) : body.code_size;
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WriteSByte ((sbyte)(offset - (instruction.Offset + opcode.Size + 1)));
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break;
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}
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case OperandType.InlineBrTarget: {
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var target = (Instruction)operand;
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var offset = target != null ? GetTargetOffset (target) : body.code_size;
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WriteInt32 (offset - (instruction.Offset + opcode.Size + 4));
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break;
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}
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case OperandType.ShortInlineVar:
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WriteByte ((byte)GetVariableIndex ((VariableDefinition)operand));
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break;
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case OperandType.ShortInlineArg:
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WriteByte ((byte)GetParameterIndex ((ParameterDefinition)operand));
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break;
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case OperandType.InlineVar:
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WriteInt16 ((short)GetVariableIndex ((VariableDefinition)operand));
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break;
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case OperandType.InlineArg:
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WriteInt16 ((short)GetParameterIndex ((ParameterDefinition)operand));
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break;
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case OperandType.InlineSig:
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WriteMetadataToken (GetStandAloneSignature ((CallSite)operand));
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break;
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case OperandType.ShortInlineI:
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if (opcode == OpCodes.Ldc_I4_S)
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WriteSByte ((sbyte)operand);
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else
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WriteByte ((byte)operand);
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break;
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case OperandType.InlineI:
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WriteInt32 ((int)operand);
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break;
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case OperandType.InlineI8:
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WriteInt64 ((long)operand);
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break;
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case OperandType.ShortInlineR:
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WriteSingle ((float)operand);
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break;
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case OperandType.InlineR:
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WriteDouble ((double)operand);
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break;
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case OperandType.InlineString:
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WriteMetadataToken (
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new MetadataToken (
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TokenType.String,
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GetUserStringIndex ((string)operand)));
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break;
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case OperandType.InlineType:
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case OperandType.InlineField:
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case OperandType.InlineMethod:
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case OperandType.InlineTok:
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WriteMetadataToken (metadata.LookupToken ((IMetadataTokenProvider)operand));
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break;
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default:
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throw new ArgumentException ();
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}
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}
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int GetTargetOffset (Instruction instruction)
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{
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if (instruction == null) {
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var last = body.instructions [body.instructions.size - 1];
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return last.offset + last.GetSize ();
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}
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return instruction.offset;
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}
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uint GetUserStringIndex (string @string)
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{
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if (@string == null)
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return 0;
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return metadata.user_string_heap.GetStringIndex (@string);
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}
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static int GetVariableIndex (VariableDefinition variable)
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{
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return variable.Index;
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}
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int GetParameterIndex (ParameterDefinition parameter)
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{
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if (body.method.HasThis) {
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if (parameter == body.this_parameter)
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return 0;
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return parameter.Index + 1;
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}
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return parameter.Index;
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}
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bool RequiresFatHeader ()
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{
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var body = this.body;
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return body.CodeSize >= 64
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|| body.InitLocals
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|| body.HasVariables
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|| body.HasExceptionHandlers
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|| body.MaxStackSize > 8;
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}
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void ComputeHeader ()
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{
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int offset = 0;
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var instructions = body.instructions;
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var items = instructions.items;
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var count = instructions.size;
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var stack_size = 0;
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var max_stack = 0;
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Dictionary<Instruction, int> stack_sizes = null;
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if (body.HasExceptionHandlers)
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ComputeExceptionHandlerStackSize (ref stack_sizes);
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for (int i = 0; i < count; i++) {
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var instruction = items [i];
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instruction.offset = offset;
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offset += instruction.GetSize ();
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ComputeStackSize (instruction, ref stack_sizes, ref stack_size, ref max_stack);
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}
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body.code_size = offset;
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body.max_stack_size = max_stack;
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}
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void ComputeExceptionHandlerStackSize (ref Dictionary<Instruction, int> stack_sizes)
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{
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var exception_handlers = body.ExceptionHandlers;
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for (int i = 0; i < exception_handlers.Count; i++) {
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var exception_handler = exception_handlers [i];
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switch (exception_handler.HandlerType) {
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case ExceptionHandlerType.Catch:
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AddExceptionStackSize (exception_handler.HandlerStart, ref stack_sizes);
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break;
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case ExceptionHandlerType.Filter:
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AddExceptionStackSize (exception_handler.FilterStart, ref stack_sizes);
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AddExceptionStackSize (exception_handler.HandlerStart, ref stack_sizes);
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break;
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}
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}
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}
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static void AddExceptionStackSize (Instruction handler_start, ref Dictionary<Instruction, int> stack_sizes)
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{
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if (handler_start == null)
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return;
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if (stack_sizes == null)
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stack_sizes = new Dictionary<Instruction, int> ();
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stack_sizes [handler_start] = 1;
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}
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static void ComputeStackSize (Instruction instruction, ref Dictionary<Instruction, int> stack_sizes, ref int stack_size, ref int max_stack)
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{
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int computed_size;
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if (stack_sizes != null && stack_sizes.TryGetValue (instruction, out computed_size))
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stack_size = computed_size;
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max_stack = System.Math.Max (max_stack, stack_size);
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ComputeStackDelta (instruction, ref stack_size);
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max_stack = System.Math.Max (max_stack, stack_size);
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CopyBranchStackSize (instruction, ref stack_sizes, stack_size);
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ComputeStackSize (instruction, ref stack_size);
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}
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static void CopyBranchStackSize (Instruction instruction, ref Dictionary<Instruction, int> stack_sizes, int stack_size)
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{
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if (stack_size == 0)
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return;
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switch (instruction.opcode.OperandType) {
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case OperandType.ShortInlineBrTarget:
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case OperandType.InlineBrTarget:
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CopyBranchStackSize (ref stack_sizes, (Instruction)instruction.operand, stack_size);
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break;
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case OperandType.InlineSwitch:
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var targets = (Instruction [])instruction.operand;
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for (int i = 0; i < targets.Length; i++)
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CopyBranchStackSize (ref stack_sizes, targets [i], stack_size);
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break;
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}
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}
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static void CopyBranchStackSize (ref Dictionary<Instruction, int> stack_sizes, Instruction target, int stack_size)
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{
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if (stack_sizes == null)
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stack_sizes = new Dictionary<Instruction, int> ();
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int branch_stack_size = stack_size;
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int computed_size;
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if (stack_sizes.TryGetValue (target, out computed_size))
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branch_stack_size = System.Math.Max (branch_stack_size, computed_size);
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stack_sizes [target] = branch_stack_size;
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}
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static void ComputeStackSize (Instruction instruction, ref int stack_size)
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{
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switch (instruction.opcode.FlowControl) {
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case FlowControl.Branch:
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case FlowControl.Throw:
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case FlowControl.Return:
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stack_size = 0;
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break;
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}
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}
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static void ComputeStackDelta (Instruction instruction, ref int stack_size)
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{
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switch (instruction.opcode.FlowControl) {
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case FlowControl.Call: {
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var method = (IMethodSignature)instruction.operand;
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// pop 'this' argument
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if (method.HasImplicitThis () && instruction.opcode.Code != Code.Newobj)
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stack_size--;
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// pop normal arguments
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if (method.HasParameters)
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stack_size -= method.Parameters.Count;
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// pop function pointer
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if (instruction.opcode.Code == Code.Calli)
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stack_size--;
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// push return value
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if (method.ReturnType.etype != ElementType.Void || instruction.opcode.Code == Code.Newobj)
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stack_size++;
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break;
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}
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default:
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ComputePopDelta (instruction.opcode.StackBehaviourPop, ref stack_size);
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ComputePushDelta (instruction.opcode.StackBehaviourPush, ref stack_size);
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break;
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}
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}
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static void ComputePopDelta (StackBehaviour pop_behavior, ref int stack_size)
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{
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switch (pop_behavior) {
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case StackBehaviour.Popi:
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case StackBehaviour.Popref:
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case StackBehaviour.Pop1:
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stack_size--;
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break;
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case StackBehaviour.Pop1_pop1:
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case StackBehaviour.Popi_pop1:
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case StackBehaviour.Popi_popi:
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case StackBehaviour.Popi_popi8:
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case StackBehaviour.Popi_popr4:
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case StackBehaviour.Popi_popr8:
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case StackBehaviour.Popref_pop1:
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case StackBehaviour.Popref_popi:
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stack_size -= 2;
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break;
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case StackBehaviour.Popi_popi_popi:
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case StackBehaviour.Popref_popi_popi:
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case StackBehaviour.Popref_popi_popi8:
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case StackBehaviour.Popref_popi_popr4:
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case StackBehaviour.Popref_popi_popr8:
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case StackBehaviour.Popref_popi_popref:
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stack_size -= 3;
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break;
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case StackBehaviour.PopAll:
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stack_size = 0;
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break;
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}
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}
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static void ComputePushDelta (StackBehaviour push_behaviour, ref int stack_size)
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{
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switch (push_behaviour) {
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case StackBehaviour.Push1:
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case StackBehaviour.Pushi:
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case StackBehaviour.Pushi8:
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case StackBehaviour.Pushr4:
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case StackBehaviour.Pushr8:
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case StackBehaviour.Pushref:
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stack_size++;
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break;
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case StackBehaviour.Push1_push1:
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stack_size += 2;
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break;
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}
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}
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void WriteExceptionHandlers ()
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{
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Align (4);
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var handlers = body.ExceptionHandlers;
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if (handlers.Count < 0x15 && !RequiresFatSection (handlers))
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WriteSmallSection (handlers);
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else
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WriteFatSection (handlers);
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}
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static bool RequiresFatSection (Collection<ExceptionHandler> handlers)
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{
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for (int i = 0; i < handlers.Count; i++) {
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var handler = handlers [i];
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if (IsFatRange (handler.TryStart, handler.TryEnd))
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return true;
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if (IsFatRange (handler.HandlerStart, handler.HandlerEnd))
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return true;
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if (handler.HandlerType == ExceptionHandlerType.Filter
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&& IsFatRange (handler.FilterStart, handler.HandlerStart))
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return true;
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}
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return false;
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}
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static bool IsFatRange (Instruction start, Instruction end)
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{
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if (start == null)
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throw new ArgumentException ();
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if (end == null)
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return true;
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return end.Offset - start.Offset > 255 || start.Offset > 65535;
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}
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void WriteSmallSection (Collection<ExceptionHandler> handlers)
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{
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const byte eh_table = 0x1;
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WriteByte (eh_table);
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WriteByte ((byte)(handlers.Count * 12 + 4));
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WriteBytes (2);
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WriteExceptionHandlers (
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handlers,
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i => WriteUInt16 ((ushort)i),
|
|
i => WriteByte ((byte)i));
|
|
}
|
|
|
|
void WriteFatSection (Collection<ExceptionHandler> handlers)
|
|
{
|
|
const byte eh_table = 0x1;
|
|
const byte fat_format = 0x40;
|
|
|
|
WriteByte (eh_table | fat_format);
|
|
|
|
int size = handlers.Count * 24 + 4;
|
|
WriteByte ((byte)(size & 0xff));
|
|
WriteByte ((byte)((size >> 8) & 0xff));
|
|
WriteByte ((byte)((size >> 16) & 0xff));
|
|
|
|
WriteExceptionHandlers (handlers, WriteInt32, WriteInt32);
|
|
}
|
|
|
|
void WriteExceptionHandlers (Collection<ExceptionHandler> handlers, Action<int> write_entry, Action<int> write_length)
|
|
{
|
|
for (int i = 0; i < handlers.Count; i++) {
|
|
var handler = handlers [i];
|
|
|
|
write_entry ((int)handler.HandlerType);
|
|
|
|
write_entry (handler.TryStart.Offset);
|
|
write_length (GetTargetOffset (handler.TryEnd) - handler.TryStart.Offset);
|
|
|
|
write_entry (handler.HandlerStart.Offset);
|
|
write_length (GetTargetOffset (handler.HandlerEnd) - handler.HandlerStart.Offset);
|
|
|
|
WriteExceptionHandlerSpecific (handler);
|
|
}
|
|
}
|
|
|
|
void WriteExceptionHandlerSpecific (ExceptionHandler handler)
|
|
{
|
|
switch (handler.HandlerType) {
|
|
case ExceptionHandlerType.Catch:
|
|
WriteMetadataToken (metadata.LookupToken (handler.CatchType));
|
|
break;
|
|
case ExceptionHandlerType.Filter:
|
|
WriteInt32 (handler.FilterStart.Offset);
|
|
break;
|
|
default:
|
|
WriteInt32 (0);
|
|
break;
|
|
}
|
|
}
|
|
|
|
public MetadataToken GetStandAloneSignature (Collection<VariableDefinition> variables)
|
|
{
|
|
var signature = metadata.GetLocalVariableBlobIndex (variables);
|
|
|
|
return GetStandAloneSignatureToken (signature);
|
|
}
|
|
|
|
public MetadataToken GetStandAloneSignature (CallSite call_site)
|
|
{
|
|
var signature = metadata.GetCallSiteBlobIndex (call_site);
|
|
var token = GetStandAloneSignatureToken (signature);
|
|
call_site.MetadataToken = token;
|
|
return token;
|
|
}
|
|
|
|
MetadataToken GetStandAloneSignatureToken (uint signature)
|
|
{
|
|
MetadataToken token;
|
|
if (standalone_signatures.TryGetValue (signature, out token))
|
|
return token;
|
|
|
|
token = new MetadataToken (TokenType.Signature, metadata.AddStandAloneSignature (signature));
|
|
standalone_signatures.Add (signature, token);
|
|
return token;
|
|
}
|
|
|
|
RVA BeginMethod ()
|
|
{
|
|
return (RVA)(code_base + position);
|
|
}
|
|
|
|
void WriteMetadataToken (MetadataToken token)
|
|
{
|
|
WriteUInt32 (token.ToUInt32 ());
|
|
}
|
|
|
|
void Align (int align)
|
|
{
|
|
align--;
|
|
WriteBytes (((position + align) & ~align) - position);
|
|
}
|
|
}
|
|
}
|