1*0957b409SSimon J. Gerraty /* 2*0957b409SSimon J. Gerraty * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org> 3*0957b409SSimon J. Gerraty * 4*0957b409SSimon J. Gerraty * Permission is hereby granted, free of charge, to any person obtaining 5*0957b409SSimon J. Gerraty * a copy of this software and associated documentation files (the 6*0957b409SSimon J. Gerraty * "Software"), to deal in the Software without restriction, including 7*0957b409SSimon J. Gerraty * without limitation the rights to use, copy, modify, merge, publish, 8*0957b409SSimon J. Gerraty * distribute, sublicense, and/or sell copies of the Software, and to 9*0957b409SSimon J. Gerraty * permit persons to whom the Software is furnished to do so, subject to 10*0957b409SSimon J. Gerraty * the following conditions: 11*0957b409SSimon J. Gerraty * 12*0957b409SSimon J. Gerraty * The above copyright notice and this permission notice shall be 13*0957b409SSimon J. Gerraty * included in all copies or substantial portions of the Software. 14*0957b409SSimon J. Gerraty * 15*0957b409SSimon J. Gerraty * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 16*0957b409SSimon J. Gerraty * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 17*0957b409SSimon J. Gerraty * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 18*0957b409SSimon J. Gerraty * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 19*0957b409SSimon J. Gerraty * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 20*0957b409SSimon J. Gerraty * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 21*0957b409SSimon J. Gerraty * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 22*0957b409SSimon J. Gerraty * SOFTWARE. 23*0957b409SSimon J. Gerraty */ 24*0957b409SSimon J. Gerraty 25*0957b409SSimon J. Gerraty using System; 26*0957b409SSimon J. Gerraty using System.Collections.Generic; 27*0957b409SSimon J. Gerraty 28*0957b409SSimon J. Gerraty abstract class Opcode { 29*0957b409SSimon J. Gerraty Opcode()30*0957b409SSimon J. Gerraty internal Opcode() 31*0957b409SSimon J. Gerraty { 32*0957b409SSimon J. Gerraty } 33*0957b409SSimon J. Gerraty 34*0957b409SSimon J. Gerraty /* 35*0957b409SSimon J. Gerraty * Execute this opcode. 36*0957b409SSimon J. Gerraty */ Run(CPU cpu)37*0957b409SSimon J. Gerraty internal abstract void Run(CPU cpu); 38*0957b409SSimon J. Gerraty 39*0957b409SSimon J. Gerraty /* 40*0957b409SSimon J. Gerraty * Resolve the target (word reference) for this opcode. 41*0957b409SSimon J. Gerraty */ ResolveTarget(Word target)42*0957b409SSimon J. Gerraty internal virtual void ResolveTarget(Word target) 43*0957b409SSimon J. Gerraty { 44*0957b409SSimon J. Gerraty throw new Exception("Not a call opcode"); 45*0957b409SSimon J. Gerraty } 46*0957b409SSimon J. Gerraty 47*0957b409SSimon J. Gerraty /* 48*0957b409SSimon J. Gerraty * Resolve the jump offset for this opcode. Displacement is 49*0957b409SSimon J. Gerraty * relative to the address of the opcode that immediately follows 50*0957b409SSimon J. Gerraty * the jump code; thus, 0 implies no jump at all. 51*0957b409SSimon J. Gerraty */ ResolveJump(int disp)52*0957b409SSimon J. Gerraty internal virtual void ResolveJump(int disp) 53*0957b409SSimon J. Gerraty { 54*0957b409SSimon J. Gerraty throw new Exception("Not a jump opcode"); 55*0957b409SSimon J. Gerraty } 56*0957b409SSimon J. Gerraty 57*0957b409SSimon J. Gerraty /* 58*0957b409SSimon J. Gerraty * Get the Word that this opcode references; this can happen 59*0957b409SSimon J. Gerraty * only with "call" and "const" opcodes. For all other opcodes, 60*0957b409SSimon J. Gerraty * this method returns null. 61*0957b409SSimon J. Gerraty */ GetReference(T0Comp ctx)62*0957b409SSimon J. Gerraty internal virtual Word GetReference(T0Comp ctx) 63*0957b409SSimon J. Gerraty { 64*0957b409SSimon J. Gerraty return null; 65*0957b409SSimon J. Gerraty } 66*0957b409SSimon J. Gerraty 67*0957b409SSimon J. Gerraty /* 68*0957b409SSimon J. Gerraty * Get the data block that this opcode references; this can happen 69*0957b409SSimon J. Gerraty * only with "const" opcodes. For all other opcodes, this method 70*0957b409SSimon J. Gerraty * returns null. 71*0957b409SSimon J. Gerraty */ GetDataBlock(T0Comp ctx)72*0957b409SSimon J. Gerraty internal virtual ConstData GetDataBlock(T0Comp ctx) 73*0957b409SSimon J. Gerraty { 74*0957b409SSimon J. Gerraty return null; 75*0957b409SSimon J. Gerraty } 76*0957b409SSimon J. Gerraty 77*0957b409SSimon J. Gerraty /* 78*0957b409SSimon J. Gerraty * Test whether this opcode may "fall through", i.e. execution 79*0957b409SSimon J. Gerraty * may at least potentially proceed to the next opcode. 80*0957b409SSimon J. Gerraty */ 81*0957b409SSimon J. Gerraty internal virtual bool MayFallThrough { 82*0957b409SSimon J. Gerraty get { 83*0957b409SSimon J. Gerraty return true; 84*0957b409SSimon J. Gerraty } 85*0957b409SSimon J. Gerraty } 86*0957b409SSimon J. Gerraty 87*0957b409SSimon J. Gerraty /* 88*0957b409SSimon J. Gerraty * Get jump displacement. For non-jump opcodes, this returns 0. 89*0957b409SSimon J. Gerraty */ 90*0957b409SSimon J. Gerraty internal virtual int JumpDisp { 91*0957b409SSimon J. Gerraty get { 92*0957b409SSimon J. Gerraty return 0; 93*0957b409SSimon J. Gerraty } 94*0957b409SSimon J. Gerraty } 95*0957b409SSimon J. Gerraty 96*0957b409SSimon J. Gerraty /* 97*0957b409SSimon J. Gerraty * Get stack effect for this opcode (number of elements added to 98*0957b409SSimon J. Gerraty * the stack, could be negative). For OpcodeCall, this returns 99*0957b409SSimon J. Gerraty * 0. 100*0957b409SSimon J. Gerraty */ 101*0957b409SSimon J. Gerraty internal virtual int StackAction { 102*0957b409SSimon J. Gerraty get { 103*0957b409SSimon J. Gerraty return 0; 104*0957b409SSimon J. Gerraty } 105*0957b409SSimon J. Gerraty } 106*0957b409SSimon J. Gerraty ToCodeElement()107*0957b409SSimon J. Gerraty internal abstract CodeElement ToCodeElement(); 108*0957b409SSimon J. Gerraty 109*0957b409SSimon J. Gerraty /* 110*0957b409SSimon J. Gerraty * This method is called for the CodeElement corresponding to 111*0957b409SSimon J. Gerraty * this opcode, at gcode[off]; it is used to compute actual 112*0957b409SSimon J. Gerraty * byte jump offsets when converting code to C. 113*0957b409SSimon J. Gerraty */ FixUp(CodeElement[] gcode, int off)114*0957b409SSimon J. Gerraty internal virtual void FixUp(CodeElement[] gcode, int off) 115*0957b409SSimon J. Gerraty { 116*0957b409SSimon J. Gerraty } 117*0957b409SSimon J. Gerraty } 118