FFI: Add callback support (for x86/x64).

1 files changed, 54 insertions, 5 deletions

diff --git a/src/lib_ffi.c b/src/lib_ffi.c
index af500118..850805e6 100644
--- a/src/lib_ffi.c
+++ b/src/lib_ffi.c
@@ -27,6 +27,7 @@
 #include "lj_cconv.h"
 #include "lj_carith.h"
 #include "lj_ccall.h"
+#include "lj_ccallback.h"
 #include "lj_clib.h"
 #include "lj_ff.h"
 #include "lj_lib.h"
@@ -384,6 +385,50 @@ LJLIB_CF(ffi_clib___gc)
 
 #include "lj_libdef.h"
 
+/* -- Callback function metamethods --------------------------------------- */
+
+#define LJLIB_MODULE_ffi_callback
+
+static int ffi_callback_set(lua_State *L, GCfunc *fn)
+{
+  GCcdata *cd = ffi_checkcdata(L, 1);
+  CTState *cts = ctype_cts(L);
+  CType *ct = ctype_raw(cts, cd->typeid);
+  if (ctype_isptr(ct->info) && (LJ_32 || ct->size == 8)) {
+    MSize slot = lj_ccallback_ptr2slot(cts, *(void **)cdataptr(cd));
+    if (slot < cts->cb.sizeid && cts->cb.cbid[slot] != 0) {
+      GCtab *t = cts->miscmap;
+      TValue *tv = lj_tab_setint(L, t, (int32_t)slot);
+      if (fn) {
+        setfuncV(L, tv, fn);
+        lj_gc_anybarriert(L, t);
+      } else {
+        setnilV(tv);
+        cts->cb.cbid[slot] = 0;
+        cts->cb.topid = slot < cts->cb.topid ? slot : cts->cb.topid;
+      }
+      return 0;
+    }
+  }
+  lj_err_caller(L, LJ_ERR_FFI_BADCBACK);
+  return 0;
+}
+
+LJLIB_CF(ffi_callback_free)
+{
+  return ffi_callback_set(L, NULL);
+}
+
+LJLIB_CF(ffi_callback_set)
+{
+  GCfunc *fn = lj_lib_checkfunc(L, 2);
+  return ffi_callback_set(L, fn);
+}
+
+LJLIB_PUSH(top-1) LJLIB_SET(__index)
+
+#include "lj_libdef.h"
+
 /* -- FFI library functions ----------------------------------------------- */
 
 #define LJLIB_MODULE_ffi
@@ -428,7 +473,7 @@ LJLIB_CF(ffi_new)	LJLIB_REC(.)
                    o, (MSize)(L->top - o));  /* Initialize cdata. */
   if (ctype_isstruct(ct->info)) {
     /* Handle ctype __gc metamethod. Use the fast lookup here. */
-    cTValue *tv = lj_tab_getint(cts->metatype, (int32_t)id);
+    cTValue *tv = lj_tab_getinth(cts->miscmap, -(int32_t)id);
     if (tv && tvistab(tv) && (tv = lj_meta_fast(L, tabV(tv), MM_gc))) {
       GCtab *t = cts->finalizer;
       if (gcref(t->metatable)) {
@@ -650,21 +695,21 @@ LJLIB_CF(ffi_abi)	LJLIB_REC(.)
 
 #undef H_
 
-LJLIB_PUSH(top-8) LJLIB_SET(!)  /* Store reference to metatype table. */
+LJLIB_PUSH(top-8) LJLIB_SET(!)  /* Store reference to miscmap table. */
 
 LJLIB_CF(ffi_metatype)
 {
   CTState *cts = ctype_cts(L);
   CTypeID id = ffi_checkctype(L, cts);
   GCtab *mt = lj_lib_checktab(L, 2);
-  GCtab *t = cts->metatype;
+  GCtab *t = cts->miscmap;
   CType *ct = ctype_get(cts, id);  /* Only allow raw types. */
   TValue *tv;
   GCcdata *cd;
   if (!(ctype_isstruct(ct->info) || ctype_iscomplex(ct->info) ||
         ctype_isvector(ct->info)))
     lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
-  tv = lj_tab_setint(L, t, (int32_t)id);
+  tv = lj_tab_setinth(L, t, -(int32_t)id);
   if (!tvisnil(tv))
     lj_err_caller(L, LJ_ERR_PROTMT);
   settabV(L, tv, mt);
@@ -745,12 +790,16 @@ static void ffi_register_module(lua_State *L)
 LUALIB_API int luaopen_ffi(lua_State *L)
 {
   CTState *cts = lj_ctype_init(L);
-  settabV(L, L->top++, (cts->metatype = lj_tab_new(L, 0, 0)));
+  settabV(L, L->top++, (cts->miscmap = lj_tab_new(L, 0, 1)));
   cts->finalizer = ffi_finalizer(L);
   LJ_LIB_REG(L, NULL, ffi_meta);
   /* NOBARRIER: basemt is a GC root. */
   setgcref(basemt_it(G(L), LJ_TCDATA), obj2gco(tabV(L->top-1)));
   LJ_LIB_REG(L, NULL, ffi_clib);
+  LJ_LIB_REG(L, NULL, ffi_callback);
+  /* NOBARRIER: the key is new and lj_tab_newkey() handles the barrier. */
+  settabV(L, lj_tab_setstr(L, cts->miscmap, &cts->g->strempty), tabV(L->top-1));
+  L->top--;
   lj_clib_default(L, tabV(L->top-1));  /* Create ffi.C default namespace. */
   lua_pushliteral(L, LJ_OS_NAME);
   lua_pushliteral(L, LJ_ARCH_NAME);