From 7b844c5caf81ac843a210477ef47fd16e8af2f2c Mon Sep 17 00:00:00 2001
From: Benoit Giannangeli <giann008@gmail.com>
Date: Thu, 2 Feb 2017 22:38:35 +0100
Subject: Lua VM

---
 src/lundump.js | 63 ++++++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 42 insertions(+), 21 deletions(-)

(limited to 'src/lundump.js')

diff --git a/src/lundump.js b/src/lundump.js
index 46a9d70..07d86df 100644
--- a/src/lundump.js
+++ b/src/lundump.js
@@ -1,14 +1,14 @@
 /*jshint esversion: 6 */
 "use strict";
 
-const DataView      = require('buffer-dataview');
-const fs            = require('fs');
-const assert        = require('assert');
+const DataView       = require('buffer-dataview');
+const fs             = require('fs');
+const assert         = require('assert');
 
-const lua_State     = require('./lstate.js').lua_State;
-const LClosure      = require('./lobject.js').LClosure;
-const Proto         = require('./lfunc.js').Proto;
+const LClosure       = require('./lobject.js').LClosure;
+const Proto          = require('./lfunc.js').Proto;
 const constant_types = require('./lua.js').constant_types;
+const OpCodes        = require('./lopcodes.js');
 
 const LUAI_MAXSHORTLEN = 40;
 
@@ -24,14 +24,13 @@ class BytecodeParser {
      * @param {lua_State} Lua state object
      * @param {DataView} dataView Contains the binary data
      */
-    constructor(L, dataView) {
+    constructor(dataView) {
         this.intSize = 4;
         this.size_tSize = 8;
         this.instructionSize = 4;
         this.integerSize = 8;
         this.numberSize = 8;
 
-        this.L = L;
         this.dataView = dataView;
         this.offset = 0;
     }
@@ -97,21 +96,44 @@ class BytecodeParser {
         return string;
     }
 
+    /* creates a mask with 'n' 1 bits at position 'p' */
+    static MASK1(n, p) {
+        return ((~((~0)<<(n)))<<(p));
+    }
+
+    /* creates a mask with 'n' 0 bits at position 'p' */
+    static MASK0(n, p) {
+        return (~MASK1(n,p));
+    }
+
     readInstruction() {
         let ins = new DataView(new Buffer(this.instructionSize))
         for (let i = 0; i < this.instructionSize; i++)
             ins.setUint8(i, this.readByte());
 
-        console.log(ins);
-
-        return ins;
+        return ins.getUint32(0, true);
     }
 
     readCode(f) {
         let n = this.readInt();
+        let o = OpCodes;
+        let p = BytecodeParser;
 
-        for (let i = 0; i < n; i++)
-            f.code.push(this.readInstruction());
+        for (let i = 0; i < n; i++) {
+            let ins = this.readInstruction();
+            f.code[i] = {
+                code:   ins,
+                opcode: (ins >> o.POS_OP) & p.MASK1(o.SIZE_OP, 0),
+                A:      (ins >> o.POS_A)  & p.MASK1(o.SIZE_A,  0),
+                B:      (ins >> o.POS_B)  & p.MASK1(o.SIZE_B,  0),
+                C:      (ins >> o.POS_C)  & p.MASK1(o.SIZE_C,  0),
+                Bx:     (ins >> o.POS_Bx) & p.MASK1(o.SIZE_Bx, 0),
+                Ax:     (ins >> o.POS_Ax) & p.MASK1(o.SIZE_Ax, 0),
+                sBx:    (ins >> o.POS_Bx) & p.MASK1(o.SIZE_Bx, 0) - o.MAXARG_sBx
+            };
+
+            console.log(`   [${i}]    Op: ${o.OpCodes[f.code[i].opcode]}  A: ${f.code[i].A}  B: ${f.code[i].B}  C: ${f.code[i].C}  Ax: ${f.code[i].Ax}  Bx: ${f.code[i].Bx}  sBx: ${f.code[i].sBx}`);
+        }
     }
 
     readUpvalues(f) {
@@ -144,28 +166,28 @@ class BytecodeParser {
                     type: constant_types.LUA_TNIL,
                     value: null
                 });
-                console.log(`LUA_TNIL     = ${f.k[f.k.length - 1].value}`);
+                console.log(`   LUA_TNIL     = ${f.k[f.k.length - 1].value}`);
                 break;
             case constant_types.LUA_TBOOLEAN:
                 f.k.push({
                     type: constant_types.LUA_TBOOLEAN,
                     value: this.readByte()
                 });
-                console.log(`LUA_TBOOLEAN = ${f.k[f.k.length - 1].value}`);
+                console.log(`   LUA_TBOOLEAN = ${f.k[f.k.length - 1].value}`);
                 break;
             case constant_types.LUA_TNUMFLT:
                 f.k.push({
                     type: constant_types.LUA_TNUMFLT,
                     value: this.readNumber()
                 });
-                console.log(`LUA_TNUMFLT  = ${f.k[f.k.length - 1].value}`);
+                console.log(`   LUA_TNUMFLT  = ${f.k[f.k.length - 1].value}`);
                 break;
             case constant_types.LUA_TNUMINT:
                 f.k.push({
                     type: constant_types.LUA_TNUMINT,
                     value: this.readInteger()
                 });
-                console.log(`LUA_TNUMINT  = ${f.k[f.k.length - 1].value}`);
+                console.log(`   LUA_TNUMINT  = ${f.k[f.k.length - 1].value}`);
                 break;
             case constant_types.LUA_TSHRSTR:
             case constant_types.LUA_TLNGSTR:
@@ -173,7 +195,7 @@ class BytecodeParser {
                     type: constant_types.LUA_TLNGSTR,
                     value: this.readString()
                 });
-                console.log(`LUA_TLNGSTR  = ${f.k[f.k.length - 1].value}`);
+                console.log(`   LUA_TLNGSTR  = ${f.k[f.k.length - 1].value}`);
                 break;
             default:
                 throw new Error(`unrecognized constant '${t}'`);
@@ -284,9 +306,8 @@ class BytecodeParser {
     luaU_undump() {
         this.checkHeader();
 
-        let cl = new LClosure(this.L, this.readByte());
-        this.L.top++;
-        cl.p = new Proto(this.L);
+        let cl = new LClosure(this.readByte());
+        cl.p = new Proto();
 
         this.readFunction(cl.p);
 
-- 
cgit v1.2.3-54-g00ecf