lua_call

5 files changed, 134 insertions, 8 deletions

diff --git a/src/lapi.js b/src/lapi.js
index ee976e1..99955a3 100644
--- a/src/lapi.js
+++ b/src/lapi.js
@@ -219,10 +219,33 @@ const lua_typename = function(L, t) {
 ** 'load' and 'call' functions (run Lua code)
 */
 
+const lua_callk = function(L, nargs, nresults, ctx, k) {
+    assert(k === null || !(L.ci.callstatus & CIST_LUA), "cannot use continuations inside hooks");
+    assert(nargs + 1 < L.top - L.ci.funcOff, "not enough elements in the stack");
+    assert(L.status === TS.LUA_OK, "cannot do calls on non-normal thread");
+    assert(nargs === lua.LUA_MULTRET || (L.ci.top - L.top >= nargs - nresults, "results from function overflow current stack size"));
+
+    let func = L.top - (nargs + 1);
+    if (k !== null && L.nny === 0) { /* need to prepare continuation? */
+        L.ci.u.c.k = k;
+        L.ci.u.c.ctx = ctx;
+        ldo.luaD_call(L, func, nresults);
+    } else { /* no continuation or no yieldable */
+        ldo.luaD_callnoyield(L, func, nresults);
+    }
+
+    if (nresults == lua.LUA_MULTRET && L.ci.top < L.top)
+        L.ci.top = L.top;
+};
+
+const lua_call = function(L, n, r) {
+    lua_callk(L, n, r, 0, null);
+};
+
 const lua_pcallk = function(L, nargs, nresults, errfunc, ctx, k) {
-    assert(nargs + 1 < L.top - L.ci.func, "not enough elements in the stack");
+    assert(nargs + 1 < L.top - L.ci.funcOff, "not enough elements in the stack");
     assert(L.status === TS.LUA_OK, "cannot do calls on non-normal thread");
-    assert(nargs == lua.LUA_MULTRET || (L.ci.top - L.top >= nargs - nresults, "results from function overflow current stack size"));
+    assert(nargs === lua.LUA_MULTRET || (L.ci.top - L.top >= nargs - nresults, "results from function overflow current stack size"));
 
     let c = {
         func: null,
@@ -286,4 +309,6 @@ 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;
\ No newline at end of file
+module.exports.lua_tostring      = lua_tostring;
+module.exports.lua_callk         = lua_callk;
+module.exports.lua_call          = lua_call;
\ No newline at end of file
diff --git a/src/ldo.js b/src/ldo.js
index aa52b76..f965a47 100644
--- a/src/ldo.js
+++ b/src/ldo.js
@@ -1,6 +1,8 @@
 /*jshint esversion: 6 */
 "use strict";
 
+const assert         = require('assert');
+
 const lua            = require('./lua.js');
 const lobject        = require('./lobject.js');
 const lstate         = require('./lstate.js');
@@ -15,15 +17,51 @@ const TMS            = ltm.TMS;
 
 const nil            = new TValue(CT.LUA_TNIL, null);
 
+/*
+** Prepares a function call: checks the stack, creates a new CallInfo
+** entry, fills in the relevant information, calls hook if needed.
+** If function is a JS function, does the call, too. (Otherwise, leave
+** the execution ('luaV_execute') to the caller, to allow stackless
+** calls.) Returns true iff function has been executed (JS function).
+*/
 const luaD_precall = function(L, off, nresults) {
     let func = L.stack[off];
     let ci;
 
     switch(func.type) {
-        case CT.LUA_TCCL: // JS function ?
-            throw new Error("LUA_TCCL not implemeted yet");
-        case CT.LUA_TLCF: // still JS function ?
-            throw new Error("LUA_TLCF not implemeted yet");
+        case CT.LUA_TCCL:
+        case CT.LUA_TLCF: {
+            let f = func.type === CT.LUA_TCCL ? func.f : func.value;
+
+            // next_ci
+            if (L.ci.next) {
+                L.ci = L.ci.next;
+                ci = L.ci;
+            } else {
+                ci = new lstate.CallInfo(off);
+                L.ci.next = ci;
+                ci.previous = L.ci;
+                ci.next = null;
+
+                L.ci = ci;
+                L.ciOff++;
+            }
+
+            ci.nresults = nresults;
+            ci.func = func;
+            ci.funcOff = off;
+            ci.top = L.top + lua.LUA_MINSTACK;
+            ci.callstatus = 0;
+            // TODO: hook
+            let n = f(L); /* do the actual call */
+
+            assert(n < L.top - L.ci.funcOff, "not enough elements in the stack");
+            
+            luaD_poscall(L, ci, L.top - n, n);
+
+            return true;
+            break;
+        }
         case CT.LUA_TLCL: {
             let p = func.p;
             let n = L.top - off - 1;
diff --git a/tests/C/Makefile b/tests/C/Makefile
index 357bbbe..816be44 100644
--- a/tests/C/Makefile
+++ b/tests/C/Makefile
@@ -10,4 +10,5 @@ all:
 	$(CC) $(CFLAGS) $(LIBS) lua_pushstring.c          -o lua_pushstring.out
 	$(CC) $(CFLAGS) $(LIBS) lua_pushboolean.c         -o lua_pushboolean.out
 	$(CC) $(CFLAGS) $(LIBS) lua_pushvalue.c           -o lua_pushvalue.out
-	$(CC) $(CFLAGS) $(LIBS) lua_pushcclosure-light.c  -o lua_pushcclosure-light.out
\ No newline at end of file
+	$(CC) $(CFLAGS) $(LIBS) lua_pushcclosure-light.c  -o lua_pushcclosure-light.out
+	$(CC) $(CFLAGS) $(LIBS) lua_call.c 				  -o lua_call.out
\ No newline at end of file
diff --git a/tests/C/lua_call.c b/tests/C/lua_call.c
new file mode 100644
index 0000000..3e0e406
--- /dev/null
+++ b/tests/C/lua_call.c
@@ -0,0 +1,28 @@
+#include <lua.h>
+#include <lualib.h>
+#include <lauxlib.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+int func(lua_State *L) {
+    lua_pushstring(L, "hello");
+    return 1;
+}
+
+int main(void) {
+
+    lua_State *L = luaL_newstate();
+
+    luaL_openlibs(L);
+
+    lua_pushcfunction(L, func);
+
+    lua_call(L, 0, 1);
+
+    printf("Lua returned: %s\n", lua_tostring(L, -1));
+
+    lua_close(L);
+
+    return 0;
+
+}
\ No newline at end of file
diff --git a/tests/lapi.js b/tests/lapi.js
index ad39fe1..c0f1cdc 100644
--- a/tests/lapi.js
+++ b/tests/lapi.js
@@ -278,4 +278,38 @@ test('lua_pushcfunction', function (t) {
         "function",
         "Correct element(s) on the stack"
     );
+});
+
+
+test('lua_call (calling a light JS function)', function (t) {
+    let L;
+    
+    t.plan(3);
+
+    t.doesNotThrow(function () {
+
+        let fn = function(L) {
+            lapi.lua_pushstring(L, "hello");
+            return 1;
+        };
+
+        L = lauxlib.luaL_newstate();
+
+        lapi.lua_pushcfunction(L, fn);
+
+        lapi.lua_call(L, 0, 1);
+
+    }, "JS Lua program ran without error");
+
+    t.strictEqual(
+        lapi.lua_gettop(L),
+        1,
+        "top is correct"
+    );
+
+    t.strictEqual(
+        lapi.lua_tostring(L, -1),
+        "hello",
+        "top is correct"
+    );
 });
\ No newline at end of file