1 files changed, 294 insertions, 0 deletions

diff --git a/src/lj_clib.c b/src/lj_clib.c
new file mode 100644
index 00000000..91309eb2
--- /dev/null
+++ b/src/lj_clib.c
@@ -0,0 +1,294 @@
+/*
+** FFI C library loader.
+** Copyright (C) 2005-2011 Mike Pall. See Copyright Notice in luajit.h
+*/
+
+#include "lj_obj.h"
+
+#if LJ_HASFFI
+
+#include "lj_gc.h"
+#include "lj_err.h"
+#include "lj_tab.h"
+#include "lj_str.h"
+#include "lj_udata.h"
+#include "lj_ctype.h"
+#include "lj_cconv.h"
+#include "lj_cdata.h"
+#include "lj_clib.h"
+
+/* -- OS-specific functions ----------------------------------------------- */
+
+#if LJ_TARGET_DLOPEN
+
+#include <dlfcn.h>
+
+#if defined(RTLD_DEFAULT)
+#define CLIB_DEFHANDLE  RTLD_DEFAULT
+#elif LJ_TARGET_OSX || LJ_TARGET_BSD
+#define CLIB_DEFHANDLE  ((void *)-2)
+#else
+#define CLIB_DEFHANDLE  NULL
+#endif
+
+LJ_NORET LJ_NOINLINE static void clib_error(lua_State *L)
+{
+  lj_err_callermsg(L, dlerror());
+}
+
+#if LJ_TARGET_OSX
+#define CLIB_SOEXT      "%s.dylib"
+#else
+#define CLIB_SOEXT      "%s.so"
+#endif
+
+static const char *clib_extname(lua_State *L, GCstr *name)
+{
+  const char *s = strdata(name);
+  if (!strchr(s, '/')) {
+    if (!strchr(s, '.')) {
+      s = lj_str_pushf(L, CLIB_SOEXT, s);
+      L->top--;
+    }
+    if (!(s[0] == 'l' && s[1] == 'i' && s[2] == 'b')) {
+      s = lj_str_pushf(L, "lib%s", s);
+      L->top--;
+    }
+  }
+  return s;
+}
+
+static void *clib_loadlib(lua_State *L, GCstr *name, int global)
+{
+  void *h = dlopen(clib_extname(L, name),
+                   RTLD_LAZY | (global?RTLD_GLOBAL:RTLD_LOCAL));
+  if (!h) clib_error(L);
+  return h;
+}
+
+static void clib_unloadlib(CLibrary *cl)
+{
+  if (!cl->handle && cl->handle != CLIB_DEFHANDLE)
+    dlclose(cl->handle);
+}
+
+static void *clib_getsym(lua_State *L, CLibrary *cl, GCstr *name)
+{
+  void *p = dlsym(cl->handle, strdata(name));
+  if (!p) clib_error(L);
+  return p;
+}
+
+#elif LJ_TARGET_WINDOWS
+
+#define WIN32_LEAN_AND_MEAN
+#ifndef WINVER
+#define WINVER 0x0500
+#endif
+#include <windows.h>
+
+#ifndef GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS
+#define GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS  4
+BOOL WINAPI GetModuleHandleExA(DWORD, LPCSTR, HMODULE*);
+#endif
+
+#define CLIB_DEFHANDLE  ((void *)-1)
+
+/* Default libraries. */
+enum {
+  CLIB_HANDLE_EXE,
+  CLIB_HANDLE_DLL,
+  CLIB_HANDLE_CRT,
+  CLIB_HANDLE_KERNEL32,
+  CLIB_HANDLE_USER32,
+  CLIB_HANDLE_GDI32,
+  CLIB_HANDLE_MAX
+};
+
+static void *clib_def_handle[CLIB_HANDLE_MAX];
+
+LJ_NORET LJ_NOINLINE static void clib_error(lua_State *L, const char *fmt,
+                                            const char *name)
+{
+  DWORD err = GetLastError();
+  char buf[128];
+  if (!FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS|FORMAT_MESSAGE_FROM_SYSTEM,
+                      NULL, err, 0, buf, sizeof(buf), NULL))
+    buf[0] = '\0';
+  lj_err_callermsg(L, lj_str_pushf(L, fmt, name, buf));
+}
+
+static int clib_needext(const char *s)
+{
+  while (*s) {
+    if (*s == '/' || *s == '\\' || *s == '.') return 0;
+    s++;
+  }
+  return 1;
+}
+
+static const char *clib_extname(lua_State *L, GCstr *name)
+{
+  const char *s = strdata(name);
+  if (clib_needext(s)) {
+    s = lj_str_pushf(L, "%s.dll", s);
+    L->top--;
+  }
+  return s;
+}
+
+static void *clib_loadlib(lua_State *L, GCstr *name, int global)
+{
+  void *h = (void *)LoadLibraryA(clib_extname(L, name));
+  if (!h) clib_error(L, "cannot load module " LUA_QS ": %s", strdata(name));
+  UNUSED(global);
+  return h;
+}
+
+static void clib_unloadlib(CLibrary *cl)
+{
+  if (cl->handle == CLIB_DEFHANDLE) {
+    MSize i;
+    for (i = 0; i < CLIB_HANDLE_MAX; i++)
+      if (clib_def_handle[i])
+        FreeLibrary((HINSTANCE)clib_def_handle[i]);
+  } else if (!cl->handle) {
+    FreeLibrary((HINSTANCE)cl->handle);
+  }
+}
+
+static void *clib_getsym(lua_State *L, CLibrary *cl, GCstr *name)
+{
+  const char *sym = strdata(name);
+  void *p;
+  if (cl->handle == CLIB_DEFHANDLE) {  /* Search default libraries. */
+    MSize i;
+    for (i = 0; i < CLIB_HANDLE_MAX; i++) {
+      HINSTANCE h = (HINSTANCE)clib_def_handle[i];
+      if (!(void *)h) {  /* Resolve default library handles (once). */
+        switch (i) {
+        case CLIB_HANDLE_EXE: GetModuleHandleExA(0, NULL, &h); break;
+        case CLIB_HANDLE_DLL:
+          GetModuleHandleExA(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
+                             (const char *)clib_def_handle, &h);
+          break;
+        case CLIB_HANDLE_CRT:
+          GetModuleHandleExA(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
+                             (const char *)&_fmode, &h);
+          break;
+        case CLIB_HANDLE_KERNEL32: h = LoadLibraryA("kernel32.dll"); break;
+        case CLIB_HANDLE_USER32: h = LoadLibraryA("user32.dll"); break;
+        case CLIB_HANDLE_GDI32: h = LoadLibraryA("gdi32.dll"); break;
+        }
+        if (!h) continue;
+        clib_def_handle[i] = (void *)h;
+      }
+      p = (void *)GetProcAddress(h, sym);
+      if (p) break;
+    }
+  } else {
+    p = (void *)GetProcAddress((HINSTANCE)cl->handle, sym);
+  }
+  if (!p) clib_error(L, "cannot resolve symbol " LUA_QS ": %s", sym);
+  return p;
+}
+
+#else
+
+#define CLIB_DEFHANDLE  NULL
+
+static void *clib_loadlib(lua_State *L, GCstr *name, int global)
+{
+  lj_err_callermsg(L, "no support for loading dynamic libraries for this OS");
+  UNUSED(name); UNUSED(global);
+  return NULL;
+}
+
+static void clib_unloadlib(CLibrary *cl)
+{
+  UNUSED(cl);
+}
+
+static void *clib_getsym(lua_State *L, CLibrary *cl, GCstr *name)
+{
+  lj_err_callermsg(L, "no support for resolving symbols for this OS");
+  UNUSED(cl); UNUSED(name);
+  return NULL;
+}
+
+#endif
+
+/* -- C library indexing -------------------------------------------------- */
+
+/* Namespace for C library indexing. */
+#define CLNS_INDEX \
+  ((1u<<CT_FUNC)|(1u<<CT_EXTERN)|(1u<<CT_CONSTVAL))
+
+/* Index a C library by name. */
+TValue *lj_clib_index(lua_State *L, CLibrary *cl, GCstr *name)
+{
+  TValue *tv = lj_tab_setstr(L, cl->cache, name);
+  if (LJ_UNLIKELY(tvisnil(tv))) {
+    CTState *cts = ctype_cts(L);
+    CType *ct;
+    CTypeID id = lj_ctype_getname(cts, &ct, name, CLNS_INDEX);
+    if (!id)
+      lj_err_callerv(L, LJ_ERR_FFI_NODECL, strdata(name));
+    if (ctype_isconstval(ct->info)) {
+      CType *ctt = ctype_child(cts, ct);
+      lua_assert(ctype_isinteger(ctt->info) && ctt->size <= 4);
+      if ((ctt->info & CTF_UNSIGNED) && ctt->size == 4)
+        setnumV(tv, (lua_Number)(uint32_t)ct->size);
+      else
+        setnumV(tv, (lua_Number)(int32_t)ct->size);
+    } else {
+      void *p = clib_getsym(L, cl, name);
+      GCcdata *cd;
+      lua_assert(ctype_isfunc(ct->info) || ctype_isextern(ct->info));
+      cd = lj_cdata_new(cts, id, CTSIZE_PTR);
+      *(void **)cdataptr(cd) = p;
+      setcdataV(L, tv, cd);
+    }
+  }
+  return tv;
+}
+
+/* -- C library management ------------------------------------------------ */
+
+/* Create a new CLibrary object and push it on the stack. */
+static CLibrary *clib_new(lua_State *L, GCtab *mt)
+{
+  GCtab *t = lj_tab_new(L, 0, 0);
+  GCudata *ud = lj_udata_new(L, sizeof(CLibrary), t);
+  CLibrary *cl = (CLibrary *)uddata(ud);
+  cl->cache = t;
+  ud->udtype = UDTYPE_FFI_CLIB;
+  /* NOBARRIER: The GCudata is new (marked white). */
+  setgcref(ud->metatable, obj2gco(mt));
+  setudataV(L, L->top++, ud);
+  return cl;
+}
+
+/* Load a C library. */
+void lj_clib_load(lua_State *L, GCtab *mt, GCstr *name, int global)
+{
+  void *handle = clib_loadlib(L, name, global);
+  CLibrary *cl = clib_new(L, mt);
+  cl->handle = handle;
+}
+
+/* Unload a C library. */
+void lj_clib_unload(CLibrary *cl)
+{
+  clib_unloadlib(cl);
+  cl->handle = NULL;
+}
+
+/* Create the default C library object. */
+void lj_clib_default(lua_State *L, GCtab *mt)
+{
+  CLibrary *cl = clib_new(L, mt);
+  cl->handle = CLIB_DEFHANDLE;
+}
+
+#endif