Basis to load std lib

5 files changed, 356 insertions, 37 deletions

diff --git a/src/lapi.js b/src/lapi.js
index 1113eec..b5a8fab 100644
--- a/src/lapi.js
+++ b/src/lapi.js
@@ -8,6 +8,7 @@ const lobject   = require('./lobject.js');
 const ltm       = require('./ltm.js');
 const lfunc     = require('./lfunc.js');
 const lua       = require('./lua.js');
+const luaconf   = require('./luaconf.js');
 const lstate    = require('./lstate.js');
 const lvm       = require('./lvm.js');
 const lundump   = require('./lundump.js');
@@ -52,10 +53,23 @@ const index2addr = function(L, idx) {
     }
 };
 
+const lua_checkstack = function(L, n) {
+    return L.stack.length < luaconf.LUAI_MAXSTACK;
+};
+
 /*
 ** basic stack manipulation
 */
 
+/*
+** convert an acceptable stack index into an absolute index
+*/
+const lua_absindex = function(L, idx) {
+    return (idx > 0 || idx > lua.LUA_REGISTRYINDEX)
+         ? idx
+         : L.top - L.ci.funcOff + idx;
+};
+
 const lua_gettop = function(L) {
     return L.top - 1;
 };
@@ -83,6 +97,37 @@ const lua_pop = function(L, n) {
     lua_settop(L, -n - 1);
 }
 
+const reverse = function(L, from, to) {
+    for (; from < to; from++, to --) {
+        let temp = L.stack[from];
+        L.stack[from] = L.stack[to];
+        L.stack[to] = temp;
+    }
+};
+
+/*
+** Let x = AB, where A is a prefix of length 'n'. Then,
+** rotate x n == BA. But BA == (A^r . B^r)^r.
+*/
+const lua_rotate = function(L, idx, n) {
+    let t = L.stack[L.top - 1];
+    let p = index2addr(L, idx);
+
+    assert(!p.ttisnil() && idx > LUA_REGISTRYINDEX, "index not in the stack");
+    assert((n >= 0 ? n : -n) <= (L.top - idx), "invalid 'n'");
+
+    let m = n >= 0 ? L.top - 1 - n : idx - n - 1;  /* end of prefix */
+
+    reverse(L, idx, m);
+    reverse(L, m + 1, L.top - 1);
+    reverse(L, idx, L.top - 1);
+};
+
+const lua_remove = function(L, idx) {
+    lua_rotate(L, idx, -1);
+    lua_pop(L, 1);
+};
+
 /*
 ** push functions (JS -> stack)
 */
@@ -137,6 +182,8 @@ const lua_pushstring = function (L, s) {
     return s;
 };
 
+const lua_pushliteral = lua_pushstring;
+
 const lua_pushcclosure = function(L, fn, n) {
     assert(typeof fn === "function");
     assert(typeof n === "number");
@@ -183,6 +230,10 @@ const lua_pushlightuserdata = function(L, p) {
     assert(L.top <= L.ci.top, "stack overflow");
 };
 
+const lua_pushglobaltable = function(L) {
+    lua_rawgeti(L, lua.LUA_REGISTRYINDEX, lua.LUA_RIDX_GLOBALS);
+};
+
 /*
 ** set functions (stack -> Lua)
 */
@@ -218,11 +269,36 @@ const lua_settable = function(L, idx) {
     L.top -= 2;
 };
 
+const lua_setfield = function(L, idx, k) {
+    auxsetstr(L, index2addr(L, idx), k)
+};
 
 /*
 ** get functions (Lua -> stack)
 */
 
+const lua_rawgeti = function(L, idx, n) {
+    let t = index2addr(L, idx);
+
+    assert(t.ttistable(), "table expected");
+
+    L.stack[L.top++] = t.__index(t, n);
+
+    assert(L.top <= L.ci.top, "stack overflow");
+
+    return L.stack[L.top - 1].ttnov();
+};
+
+const lua_rawget = function(L, idx) {
+    let t = index2addr(L, idx);
+
+    assert(t.ttistable(t), "table expected");
+
+    L.stack[L.top - 1] = t.__index(t, L.stack[L.top - 1]);
+
+    return L.stack[L.top - 1].ttnov();
+};
+
 // narray and nrec are mostly useless for this implementation
 const lua_createtable = function(L, narray, nrec) {
     let t = new lobject.Table();
@@ -244,7 +320,6 @@ const lua_gettable = function(L, idx) {
     return L.stack[L.top - 1].ttnov();
 };
 
-
 /*
 ** access functions (stack -> JS)
 */
@@ -293,6 +368,11 @@ const lua_istable = function(L, idx) {
     return index2addr(L, idx).ttistable();
 };
 
+const lua_isstring = function(L, idx) {
+    let o = index2addr(L, idx);
+    return o.ttisstring() || o.ttisnumber();
+}
+
 /*
 ** 'load' and 'call' functions (run Lua code)
 */
@@ -391,36 +471,47 @@ const lua_pcall = function(L, n, r, f) {
     return lua_pcallk(L, n, r, f, 0, null);
 }
 
-module.exports.lua_pushvalue      = lua_pushvalue;
-module.exports.lua_pushnil        = lua_pushnil;
-module.exports.lua_pushnumber     = lua_pushnumber;
-module.exports.lua_pushinteger    = lua_pushinteger;
-module.exports.lua_pushlstring    = lua_pushlstring;
-module.exports.lua_pushstring     = lua_pushstring;
-module.exports.lua_pushboolean    = lua_pushboolean;
-module.exports.lua_pushcclosure   = lua_pushcclosure;
-module.exports.lua_pushcfunction  = lua_pushcfunction;
-module.exports.lua_pushjsclosure  = lua_pushjsclosure;
-module.exports.lua_pushjsfunction = lua_pushjsfunction;
-module.exports.lua_version        = lua_version;
-module.exports.lua_atpanic        = lua_atpanic;
-module.exports.lua_gettop         = lua_gettop;
-module.exports.lua_typename       = lua_typename;
-module.exports.lua_type           = lua_type;
-module.exports.lua_tonumber       = lua_tonumber;
-module.exports.lua_tointeger      = lua_tointeger;
-module.exports.lua_toboolean      = lua_toboolean;
-module.exports.lua_tolstring      = lua_tolstring;
-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_pcallk         = lua_pcallk;
-module.exports.lua_pcall          = lua_pcall;
-module.exports.lua_pop            = lua_pop;
-module.exports.lua_setglobal      = lua_setglobal;
-module.exports.lua_istable        = lua_istable;
-module.exports.lua_createtable    = lua_createtable;
-module.exports.lua_newtable       = lua_newtable;
-module.exports.lua_settable       = lua_settable;
-module.exports.lua_gettable       = lua_gettable;
\ No newline at end of file
+module.exports.lua_pushvalue       = lua_pushvalue;
+module.exports.lua_pushnil         = lua_pushnil;
+module.exports.lua_pushnumber      = lua_pushnumber;
+module.exports.lua_pushinteger     = lua_pushinteger;
+module.exports.lua_pushlstring     = lua_pushlstring;
+module.exports.lua_pushstring      = lua_pushstring;
+module.exports.lua_pushliteral     = lua_pushliteral;
+module.exports.lua_pushboolean     = lua_pushboolean;
+module.exports.lua_pushcclosure    = lua_pushcclosure;
+module.exports.lua_pushcfunction   = lua_pushcfunction;
+module.exports.lua_pushjsclosure   = lua_pushjsclosure;
+module.exports.lua_pushjsfunction  = lua_pushjsfunction;
+module.exports.lua_version         = lua_version;
+module.exports.lua_atpanic         = lua_atpanic;
+module.exports.lua_gettop          = lua_gettop;
+module.exports.lua_typename        = lua_typename;
+module.exports.lua_type            = lua_type;
+module.exports.lua_tonumber        = lua_tonumber;
+module.exports.lua_tointeger       = lua_tointeger;
+module.exports.lua_toboolean       = lua_toboolean;
+module.exports.lua_tolstring       = lua_tolstring;
+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_pcallk          = lua_pcallk;
+module.exports.lua_pcall           = lua_pcall;
+module.exports.lua_pop             = lua_pop;
+module.exports.lua_setglobal       = lua_setglobal;
+module.exports.lua_istable         = lua_istable;
+module.exports.lua_createtable     = lua_createtable;
+module.exports.lua_newtable        = lua_newtable;
+module.exports.lua_settable        = lua_settable;
+module.exports.lua_gettable        = lua_gettable;
+module.exports.lua_absindex        = lua_absindex;
+module.exports.index2addr          = index2addr;
+module.exports.lua_rawget          = lua_rawget;
+module.exports.lua_isstring        = lua_isstring;
+module.exports.lua_rotate          = lua_rotate;
+module.exports.lua_remove          = lua_remove;
+module.exports.lua_checkstack      = lua_checkstack;
+module.exports.lua_rawgeti         = lua_rawgeti;
+module.exports.lua_pushglobaltable = lua_pushglobaltable;
+module.exports.lua_setfield        = lua_setfield;
\ No newline at end of file
diff --git a/src/lauxlib.js b/src/lauxlib.js
index 6cc3d3c..af09df7 100644
--- a/src/lauxlib.js
+++ b/src/lauxlib.js
@@ -5,6 +5,8 @@ const assert = require('assert');
 
 const lstate = require('./lstate.js');
 const lapi   = require('./lapi.js');
+const lua    = require('./lua.js');
+const CT     = lua.constant_types;
 
 const panic = function(L) {
     console.log(`PANIC: unprotected error in call to Lua API (...)`);
@@ -20,8 +22,142 @@ const luaL_newstate = function() {
 
 const luaL_typename = function(L, i) {
     return lapi.lua_typename(L, lapi.lua_type(L, i));
-}
+};
+
+const luaL_checkany = function(L, arg) {
+    if (lapi.lua_type(L, arg) === CT.LUA_TNONE)
+        throw new Error("value expected"); // TODO: luaL_argerror(L, arg, "value expected");
+};
+
+const luaL_getmetafield = function(L, obj, event) {
+    if (!lapi.lua_getmetatable(L, obj))
+        return CT.LUA_TNIL;
+    else {
+        lapi.lua_pushstring(L, event);
+        let tt = lapi.lua_rawget(L, -2);
+        if (tt === CT.LUA_TNIL)
+            lapi.lua_pop(L, 2);
+        return tt;
+    }
+};
+
+const luaL_callmeta = function(L, obj, event) {
+    obj = lapi.lua_absindex(L, obj);
+    if (luaL_getmetafield(L, obj, event) === CT.LUA_TNIL)
+        return false;
+
+    lapi.lua_pushvalue(L, obj);
+    lapi.lua_call(L, 1, 1);
+
+    return true;
+};
 
+const luaL_tolstring = function(L, idx, len) {
+    if (luaL_callmeta(L, idx, "__tostring")) {
+        if (!lapi.lua_isstring(L, -1))
+            throw new Error("'__tostring' must return a string"); // TODO: luaL_error
+    } else {
+        switch(lapi.lua_type(L, idx)) {
+            case CT.LUA_TNUMBER:
+            case CT.LUA_TSTRING:
+            case CT.LUA_TBOOLEAN:
+                lapi.lua_pushstring(L, `${lapi.index2addr(L, idx).value}`);
+                break;
+            case CT.LUA_TNIL:
+                lapi.lua_pushstring(L, `nil`);
+                break;
+            default:
+                let tt = luaL_getmetafield(L, idx, "__name");
+                let kind = tt === CT.LUA_TSTRING ? lua_tostring(L, -1) : luaL_typename(L, idx);
+                lapi.lua_pushstring(L, `${kind}`); // We can't print memory address in JS
+                if (tt !== CT.LUA_TNIL)
+                    lapi.lua_remove(L, -2);
+                break;
+        }
+    }
+
+    return lapi.lua_tolstring(L, -1, len);
+};
+
+/*
+** Stripped-down 'require': After checking "loaded" table, calls 'openf'
+** to open a module, registers the result in 'package.loaded' table and,
+** if 'glb' is true, also registers the result in the global table.
+** Leaves resulting module on the top.
+*/
+const luaL_requiref = function(L, modname, openf, glb) {
+    luaL_getsubtable(L, lua.LUA_REGISTRYINDEX, lua.LUA_LOADED_TABLE);
+    lapi.lua_getfield(L, -1, modname); /* LOADED[modname] */
+    if (!lapi.lua_toboolean(L, -1)) {  /* package not already loaded? */
+        lapi.lua_pop(L, 1);  /* remove field */
+        lapi.lua_pushcfunction(L, openf);
+        lapi.lua_pushstring(L, modname);  /* argument to open function */
+        lapi.lua_call(L, 1, 1);  /* call 'openf' to open module */
+        lapi.lua_pushvalue(L, -1);  /* make copy of module (call result) */
+        lapi.lua_setfield(L, -3, modname);  /* LOADED[modname] = module */
+    }
+    lapi.lua_remove(L, -2);  /* remove LOADED table */
+    if (glb) {
+        lua_pushvalue(L, -1);  /* copy of module */
+        lua_setglobal(L, modname);  /* _G[modname] = module */
+    }
+};
+
+/*
+** ensure that stack[idx][fname] has a table and push that table
+** into the stack
+*/
+const luaL_getsubtable = function(L, idx, fname) {
+    if (lapi.lua_getfield(L, idx, fname) === CT.LUA_TTABLE)
+        return true;  /* table already there */
+    else {
+        lapi.lua_pop(L, 1);  /* remove previous result */
+        idx = lapi.lua_absindex(L, idx);
+        lapi.lua_newtable(L);
+        lapi.lua_pushvalue(L, -1);  /* copy to be left at top */
+        lapi.lua_setfield(L, idx, fname);  /* assign new table to field */
+        return false;  /* false, because did not find table there */
+    }
+};
+
+/*
+** set functions from list 'l' into table at top - 'nup'; each
+** function gets the 'nup' elements at the top as upvalues.
+** Returns with only the table at the stack.
+*/
+const luaL_setfuncs = function(L, l, nup) {
+    luaL_checkstack(L, nup, "too many upvalues");
+    for (lib in l) {  /* fill the table with given functions */
+        for (let i = 0; i < nup; i++)  /* copy upvalues to the top */
+            lapi.lua_pushvalue(L, -nup);
+        lapi.lua_pushcclosure(L, l[lib], nup);  /* closure with those upvalues */
+        lapi.lua_setfield(L, -(nup + 2), lib);
+    }
+    lapi.lua_pop(l, nup);  /* remove upvalues */
+};
+
+/*
+** Ensures the stack has at least 'space' extra slots, raising an error
+** if it cannot fulfill the request. (The error handling needs a few
+** extra slots to format the error message. In case of an error without
+** this extra space, Lua will generate the same 'stack overflow' error,
+** but without 'msg'.)
+*/
+const luaL_checkstack = function(L, space, msg) {
+    if (!lapi.luaL_checkstack(L, space)) {
+        if (msg)
+            throw new Error(L, `stack overflow (${msg})`);
+        else
+            throw new Error(L, 'stack overflow'); // TODO: luaL_error
+    }
+};
 
-module.exports.luaL_newstate = luaL_newstate;
-module.exports.luaL_typename = luaL_typename;
\ No newline at end of file
+module.exports.luaL_newstate     = luaL_newstate;
+module.exports.luaL_typename     = luaL_typename;
+module.exports.luaL_checkany     = luaL_checkany;
+module.exports.luaL_callmeta     = luaL_callmeta;
+module.exports.luaL_getmetafield = luaL_getmetafield;
+module.exports.luaL_requiref     = luaL_requiref;
+module.exports.luaL_getsubtable  = luaL_getsubtable;
+module.exports.luaL_setfuncs     = luaL_setfuncs;
+module.exports.luaL_checkstack   = luaL_checkstack;
\ No newline at end of file
diff --git a/src/lbaselib.js b/src/lbaselib.js
new file mode 100644
index 0000000..d28a3d5
--- /dev/null
+++ b/src/lbaselib.js
@@ -0,0 +1,56 @@
+/* jshint esversion: 6 */
+"use strict";
+
+const assert  = require('assert');
+
+const lapi    = require('./lapi.js');
+const lauxlib = require('./lauxlib.js');
+
+const luaB_print = function(L) {
+    let n = lapi.lua_gettop(L); /* number of arguments */
+    let str = "";
+
+    lapi.lua_getglobal(L, "tostring");
+    for (let i = 1; i <= n; i++) {
+        lapi.lua_pushvalue(L, -1);  /* function to be called */
+        lapi.lua_pushvalue(L, i);  /* value to print */
+        lapi.lua_call(L, 1, 1);
+        s = lapi.lua_tolstring(L, -1, null);
+        if (s === null)
+            throw new Error("'tostring' must return a string to 'print");
+        if (i > 1) s = `\t${s}`;
+        str = `${str}${s}`;
+        lapi.lua_pop(L, 1);
+    }
+
+    console.log(str);
+    return 0;
+};
+
+const luaB_tostring = function(L) {
+    lauxlib.luaL_checkany(L, 1);
+    lauxlib.luaL_tolstring(L, 1, null);
+
+    return true;
+};
+
+const base_funcs = {
+    "print":    luaB_print,
+    "tostring": luaB_tostring,
+};
+
+const luaopen_base = function(L) {
+    /* open lib into global table */
+    lapi.lua_pushglobaltable(L);
+    lauxlib.luaL_setfuncs(L, base_funcs, 0);
+    /* set global _G */
+    lapi.lua_pushvalue(L, -1);
+    lapi.lua_setfield(L, -2, "_G");
+    /* set global _VERSION */
+    lapi.lua_pushliteral(L, lua.LUA_VERSION);
+    lapi.lua_setfield(L, -2, "_VERSION");
+    return true;
+};
+
+module.exports.luaB_tostring = luaB_tostring;
+module.exports.luaB_print = luaB_print;
diff --git a/src/linit.js b/src/linit.js
new file mode 100644
index 0000000..2747fc2
--- /dev/null
+++ b/src/linit.js
@@ -0,0 +1,22 @@
+/* jshint esversion: 6 */
+"use strict";
+
+const assert = require('assert');
+
+const lapi     = require('./lapi.js');
+const lauxlib  = require('./lauxlib.js');
+const lbaselib = require('./lbaselib.js');
+
+const loadedlibs = {
+    "_G" = luaopen_base
+};
+
+const luaL_openlibs = function(L) {
+    /* "require" functions from 'loadedlibs' and set results to global table */
+    for (lib in loadedlibs) {
+        lauxlib.luaL_requiref(L, lib, loadedlibs[lib], 1);
+        lapi.lua_pop(L, 1); /* remove lib */
+    }
+}
+
+module.exports.luaL_openlibs = luaL_openlibs;
\ No newline at end of file
diff --git a/tests/lapi.js b/tests/lapi.js
index 8a1db31..2f5f459 100644
--- a/tests/lapi.js
+++ b/tests/lapi.js
@@ -561,4 +561,18 @@ test('lua_settable, lua_gettable', function (t) {
         "value",
         "Correct element(s) on the stack"
     );
+});
+
+
+test('print', function (t) {
+    let luaCode = `
+        print("hello world");
+    `, L;
+    
+    t.plan(1);
+
+    t.doesNotThrow(function () {
+        L = getState(luaCode);
+        lapi.lua_call(L, 0, -1);
+    }, "Program executed without errors");
 });
\ No newline at end of file