From 3e7c7039680f80f3fa90cf357e5448d42397ea16 Mon Sep 17 00:00:00 2001
From: Benoit Giannangeli <benoit.giannangeli@boursorama.fr>
Date: Fri, 3 Feb 2017 11:24:18 +0100
Subject: VM Tests, OP_MOVE, OP_LOAK, partial OP_RETURN

---
 luac.out               | Bin 0 -> 203 bytes
 sandbox/helloworld.lua |   1 +
 src/lstate.js          |  11 ++++++---
 src/lvm.js             |  27 +++++++++++++++-----
 tests/lvm.js           |  66 +++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 96 insertions(+), 9 deletions(-)
 create mode 100644 luac.out
 create mode 100644 sandbox/helloworld.lua
 create mode 100644 tests/lvm.js

diff --git a/luac.out b/luac.out
new file mode 100644
index 0000000..1c971ab
Binary files /dev/null and b/luac.out differ
diff --git a/sandbox/helloworld.lua b/sandbox/helloworld.lua
new file mode 100644
index 0000000..7785fb9
--- /dev/null
+++ b/sandbox/helloworld.lua
@@ -0,0 +1 @@
+local a = "hello world"
diff --git a/src/lstate.js b/src/lstate.js
index 9c7eec3..15dedcb 100644
--- a/src/lstate.js
+++ b/src/lstate.js
@@ -21,14 +21,19 @@ class lua_State {
     constructor(cl) {
         this.top = 1;
         this.ci = [
-            new CallInfo(0, 1, 1, null, null);
+            new CallInfo(0, 1, 1, null, null)
         ];
         this.ci[0].savedpc = cl.p.code;
         this.ciOff = 0;
         this.stack = [
-            closure
+            cl
         ];
         this.openupval = [];
     }
 
-}
\ No newline at end of file
+}
+
+module.exports = {
+    lua_State: lua_State,
+    CallInfo: CallInfo
+};
\ No newline at end of file
diff --git a/src/lvm.js b/src/lvm.js
index 349cccf..7a65d74 100644
--- a/src/lvm.js
+++ b/src/lvm.js
@@ -14,7 +14,7 @@ class LuaVM {
        return base + a;
     }
 
-    RB(base, opcode, base, b) {
+    RB(base, opcode, b) {
        return base + b;
     }
 
@@ -35,18 +35,21 @@ class LuaVM {
         let ci = L.ci[this.L.ciOff];
 
         newframe:
-        let cl = ci.func;
-        let k = cl.p.k;
-        let base = ci.base;
-
         for (;;) {
+            var cl = L.stack[ci.func];
+            let k = cl.p.k;
+            let base = ci.base;
+
             let i = ci.savedpc[ci.pcOff++];
-            let ra = this.RA(base, i.a);
+            let ra = this.RA(base, i.A);
 
+            console.log(OC.OpCodes[i.opcode]);
             switch (OC.OpCodes[i.opcode]) {
                 case "OP_MOVE":
+                    L.stack[ra] = RB(base, i.opcode, i.B);
                     break;
                 case "OP_LOADK":
+                    L.stack[ra] = k[i.Bx];
                     break;
                 case "OP_LOADKX":
                     break;
@@ -121,6 +124,18 @@ class LuaVM {
                 case "OP_TAILCALL":
                     break;
                 case "OP_RETURN":
+                    if (i.B >= 2) {
+                        for (let j = 0; j <= i.B-2; j++) {
+                            L.stack[L.ciOff + j] = L.stack[ra + j];
+                        }
+                    }
+                    L.ci = ci.previous;
+
+                    if (L.ci === null) return;
+
+                    if (i.B !== 0) L.top = ci.top;
+
+                    continue newframe;
                     break;
                 case "OP_FORLOOP":
                     break;
diff --git a/tests/lvm.js b/tests/lvm.js
new file mode 100644
index 0000000..6ee348d
--- /dev/null
+++ b/tests/lvm.js
@@ -0,0 +1,66 @@
+"use strict";
+
+const test           = require('tape');
+const fs             = require('fs');
+const child_process  = require('child_process');
+const beautify       = require('js-beautify').js_beautify;
+const tmp            = require('tmp');
+const DataView       = require('buffer-dataview');
+
+const BytecodeParser = require("../src/lundump.js");
+const lua_State      = require("../src/lstate.js").lua_State;
+const LuaVM          = require("../src/lvm.js").LuaVM;
+
+const toByteCode = function (luaCode) {
+    var luaFile = tmp.fileSync(),
+        bclist;
+
+    fs.writeSync(luaFile.fd, luaCode);
+
+    child_process.execSync(`luac-5.3 -o ${luaFile.name}.bc ${luaFile.name}`);
+    child_process.execSync(`luac-5.3 -l ${luaFile.name} > ${luaFile.name}.bc.txt`);
+
+    bclist = fs.readFileSync(`${luaFile.name}.bc.txt`, 'utf8');
+
+    console.log(bclist);
+
+    return {
+        dataView: new DataView(fs.readFileSync(`${luaFile.name}.bc`)),
+        bclist: bclist
+    };
+};
+
+const getVM = function (luaCode) {
+    var bc = toByteCode(luaCode),
+        dv = bc.dataView,
+        bcl = bc.bclist;
+
+    let p = new BytecodeParser(dv);
+    let cl = p.luaU_undump();
+
+    let L = new lua_State(cl);
+
+    return new LuaVM(L);
+};
+
+test('LOADK, RETURN', function (t) {
+    let luaCode = `
+        local a = "hello world"
+        return a
+    `, vm;
+    
+    t.plan(2);
+
+    t.comment("Running following code: \n" + luaCode);
+
+    t.doesNotThrow(function () {
+        vm = getVM(luaCode);
+        vm.execute();
+    }, "Program executed without errors");
+
+    t.strictEqual(
+        vm.L.stack[0].value,
+        "hello world",
+        "Program output is correct"
+    );
+});
\ No newline at end of file
-- 
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