From cdf8cf1806ca793c47095b69382b2dd733899af7 Mon Sep 17 00:00:00 2001
From: Benoit Giannangeli <benoit.giannangeli@boursorama.fr>
Date: Fri, 17 Feb 2017 12:25:28 +0100
Subject: lua can read globals set by js

---
 README.md     |  8 ++++----
 src/lapi.js   | 33 ++++++++++++++++++++++++++++++---
 src/lvm.js    |  3 ++-
 tests/lapi.js | 30 ++++++++++++++++++++++++++++++
 4 files changed, 66 insertions(+), 8 deletions(-)

diff --git a/README.md b/README.md
index e79a6a8..6bade18 100644
--- a/README.md
+++ b/README.md
@@ -21,6 +21,7 @@
     - [ ] `__tostring`
     - [ ] `__pairs`
 - [ ] C API
+    - [x] lua_version
     - [x] lua_atpanic
     - [x] lua_newstate
     - [x] lua_pushnil
@@ -30,6 +31,7 @@
     - [x] lua_pushboolean
     - [x] lua_pushinteger
     - [x] lua_pushnumber
+    - [x] lua_pushlstring
     - [x] lua_pushstring
     - [x] lua_pushvalue
     - [x] lua_tointeger
@@ -44,6 +46,8 @@
     - [x] lua_load
     - [x] lua_call
     - [x] lua_callk
+    - [x] lua_setglobal
+    - [x] lua_upvalueindex
     - [ ] lua_absindex
     - [ ] lua_arith
     - [ ] lua_checkstack
@@ -97,7 +101,6 @@
     - [ ] lua_pushglobaltable
     - [ ] lua_pushlightuserdata
     - [ ] lua_pushliteral
-    - [ ] lua_pushlstring
     - [ ] lua_pushthread
     - [ ] lua_pushvfstring
     - [ ] lua_rawequal
@@ -115,7 +118,6 @@
     - [ ] lua_rotate
     - [ ] lua_setallocf
     - [ ] lua_setfield
-    - [ ] lua_setglobal
     - [ ] lua_sethook
     - [ ] lua_seti
     - [ ] lua_setlocal
@@ -132,9 +134,7 @@
     - [ ] lua_tothread
     - [ ] lua_touserdata
     - [ ] lua_upvalueid
-    - [ ] lua_upvalueindex
     - [ ] lua_upvaluejoin
-    - [ ] lua_version
     - [ ] lua_xmove
     - [ ] lua_yield
     - [ ] lua_yieldk
diff --git a/src/lapi.js b/src/lapi.js
index 6cc95b2..6a88f6f 100644
--- a/src/lapi.js
+++ b/src/lapi.js
@@ -50,7 +50,6 @@ const index2addr = function(L, idx) {
             return idx <= ci.func.nupvalues ? ci.func.upvalue[idx - 1] : ldo.nil;
         }
     }
-
 };
 
 /*
@@ -190,6 +189,33 @@ const lua_pushlightuserdata = function(L, p) {
     assert(L.top <= L.ci.top, "stack overflow");
 };
 
+/*
+** set functions (stack -> Lua)
+*/
+
+/*
+** t[k] = value at the top of the stack (where 'k' is a string)
+*/
+const auxsetstr = function(L, t, k) {
+    let str = new TValue(CT.LUA_TLNGSTR, k);
+
+    assert(1 < L.top - L.ci.funcOff, "not enough elements in the stack");
+
+    if (t.ttistable() && !t.__index(t, k).ttisnil()) {
+        t.__newindex(t, k, L.stack[L.top - 1]);
+        L.top--; /* pop value */
+    } else {
+        L.stack[L.top] = str;
+        L.top++;
+        lvm.luaV_finishset(L, t, L.stack[L.top - 1], L.stack[L.top - 2], t.__index(t, k), 0);
+        L.top -= 2; /* pop value and key */
+    }
+};
+
+const lua_setglobal = function(L, name) {
+    auxsetstr(L, L.l_G.l_registry.value.array[lua.LUA_RIDX_GLOBALS], name);
+};
+
 
 /*
 ** access functions (stack -> JS)
@@ -251,7 +277,7 @@ const lua_load = function(L, data, chunckname) {
             let reg = L.l_G.l_registry;
             let gt = reg.value.array[lua.LUA_RIDX_GLOBALS];
             /* set global table as 1st upvalue of 'f' (may be LUA_ENV) */
-            f.upvals[0].v = gt; // TODO: is gt on the stack ? is that upvalue opened or closed ?
+            f.upvals[0].u.value = gt;
         }
     }
 
@@ -354,4 +380,5 @@ module.exports.lua_tostring       = lua_tostring;
 module.exports.lua_load           = lua_load;
 module.exports.lua_callk          = lua_callk;
 module.exports.lua_call           = lua_call;
-module.exports.lua_pop            = lua_pop;
\ No newline at end of file
+module.exports.lua_pop            = lua_pop;
+module.exports.lua_setglobal      = lua_setglobal;
\ No newline at end of file
diff --git a/src/lvm.js b/src/lvm.js
index 931b7a5..4f52678 100644
--- a/src/lvm.js
+++ b/src/lvm.js
@@ -1033,4 +1033,5 @@ module.exports.LEnum          = LEnum;
 module.exports.LEintfloat     = LEintfloat;
 module.exports.LTintfloat     = LTintfloat;
 module.exports.l_strcmp       = l_strcmp;
-module.exports.luaV_objlen    = luaV_objlen;
\ No newline at end of file
+module.exports.luaV_objlen    = luaV_objlen;
+module.exports.luaV_finishset = luaV_finishset;
\ No newline at end of file
diff --git a/tests/lapi.js b/tests/lapi.js
index ff76920..419e5c4 100644
--- a/tests/lapi.js
+++ b/tests/lapi.js
@@ -408,4 +408,34 @@ test('lua_load and lua_call it', function (t) {
         "JS > Lua > JS \o/",
         "Correct element(s) on the stack"
     );
+});
+
+
+test('lua script reads js upvalues', function (t) {
+    let luaCode = `
+        return js .. " world"
+    `, L;
+    
+    t.plan(2);
+
+    t.doesNotThrow(function () {
+
+        let bc = toByteCode(luaCode).dataView;
+
+        L = lauxlib.luaL_newstate();
+
+        lapi.lua_load(L, bc, "test-lua_load")
+
+        lapi.lua_pushstring(L, "hello");
+        lapi.lua_setglobal(L, "js");
+
+        lapi.lua_call(L, 0, 1);
+
+    }, "JS Lua program ran without error");
+
+    t.strictEqual(
+        lapi.lua_tostring(L, -1),
+        "hello world",
+        "Correct element(s) on the stack"
+    );
 });
\ No newline at end of file
-- 
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