Rework the persistence mechanism of private C functions.

This modification takes the number of modified Lua files from 8
down to 3 and makes the patch slightly less intrusive.

src/eris.c

@@ -36,6 +36,7 @@ typedef int bool;
 #endif
 
 /* Mark us as part of the Lua core to get access to what we need. */
+#define eris_c
 #define LUA_CORE
 
 /* Public Lua headers. */
@@ -150,33 +151,6 @@ static const lua_Unsigned kMaxComplexity = 10000;
 #define eris_savestackidx(L, p) ((p) - (L)->stack)
 #define eris_restorestackidx(L, n) ((L)->stack + (n))
 
-/* Enabled if we have a patched version of Lua (for accessing internals). */
-#if 1
-
-/* Functions in Lua libraries used to access C functions we need to add to the
- * permanents table to fully support yielded coroutines. */
-extern void eris_permbaselib(lua_State *L, int forUnpersist);
-extern void eris_permcorolib(lua_State *L, int forUnpersist);
-extern void eris_permloadlib(lua_State *L, int forUnpersist);
-extern void eris_permiolib(lua_State *L, int forUnpersist);
-extern void eris_permstrlib(lua_State *L, int forUnpersist);
-
-/* Utility macro for populating the perms table with internal C functions. */
-#define populateperms(L, forUnpersist) {\
-  eris_permbaselib(L, forUnpersist);\
-  eris_permcorolib(L, forUnpersist);\
-  eris_permloadlib(L, forUnpersist);\
-  eris_permiolib(L, forUnpersist);\
-  eris_permstrlib(L, forUnpersist);\
-}
-
-#else
-
-/* Does nothing if we don't have a patched version of Lua. */
-#define populateperms(L, forUnpersist) ((void)0)
-
-#endif
-
 /*
 ** ============================================================================
 ** Language strings for errors.

src/lbaselib.c

@@ -456,39 +456,3 @@ LUAMOD_API int luaopen_base (lua_State *L) {
   return 1;
 }
 
-
-void eris_permbaselib(lua_State *L, int forUnpersist) {
-  luaL_checktype(L, -1, LUA_TTABLE);
-  luaL_checkstack(L, 2, NULL);
-
-  if (forUnpersist) {
-    lua_pushstring(L, "__eris.baselib_pcallcont");
-    lua_pushcfunction(L, pcallcont);
-  }
-  else {
-    lua_pushcfunction(L, pcallcont);
-    lua_pushstring(L, "__eris.baselib_pcallcont");
-  }
-  lua_rawset(L, -3);
-
-  if (forUnpersist) {
-    lua_pushstring(L, "__eris.baselib_luaB_next");
-    lua_pushcfunction(L, luaB_next);
-  }
-  else {
-    lua_pushcfunction(L, luaB_next);
-    lua_pushstring(L, "__eris.baselib_luaB_next");
-  }
-  lua_rawset(L, -3);
-
-  if (forUnpersist) {
-    lua_pushstring(L, "__eris.baselib_ipairsaux");
-    lua_pushcfunction(L, ipairsaux);
-  }
-  else {
-    lua_pushcfunction(L, ipairsaux);
-    lua_pushstring(L, "__eris.baselib_ipairsaux");
-  }
-  lua_rawset(L, -3);
-}
-

src/lcorolib.c

@@ -153,19 +153,3 @@ LUAMOD_API int luaopen_coroutine (lua_State *L) {
   return 1;
 }
 
-
-void eris_permcorolib(lua_State *L, int forUnpersist) {
-  luaL_checktype(L, -1, LUA_TTABLE);
-  luaL_checkstack(L, 2, NULL);
-
-  if (forUnpersist) {
-    lua_pushstring(L, "__eris.corolib_luaB_auxwrap");
-    lua_pushcfunction(L, luaB_auxwrap);
-  }
-  else {
-    lua_pushcfunction(L, luaB_auxwrap);
-    lua_pushstring(L, "__eris.corolib_luaB_auxwrap");
-  }
-  lua_rawset(L, -3);
-}
-

src/liolib.c

@@ -664,19 +664,3 @@ LUAMOD_API int luaopen_io (lua_State *L) {
   return 1;
 }
 
-
-void eris_permiolib(lua_State *L, int forUnpersist) {
-  luaL_checktype(L, -1, LUA_TTABLE);
-  luaL_checkstack(L, 2, NULL);
-
-  if (forUnpersist) {
-    lua_pushstring(L, "__eris.iolib_io_readline");
-    lua_pushcfunction(L, io_readline);
-  }
-  else {
-    lua_pushcfunction(L, io_readline);
-    lua_pushstring(L, "__eris.iolib_io_readline");
-  }
-  lua_rawset(L, -3);
-}
-

src/loadlib.c

@@ -723,37 +723,3 @@ LUAMOD_API int luaopen_package (lua_State *L) {
   return 1;  /* return 'package' table */
 }
 
-
-void eris_permloadlib(lua_State *L, int forUnpersist) {
-  static const lua_CFunction searchers[] = {
-    searcher_preload,
-    searcher_Lua,
-    searcher_C,
-    searcher_Croot,
-    NULL
-  };
-  static const char *const searchernames[] = {
-    "__eris.loadlib_searcher_preload",
-    "__eris.loadlib_searcher_Lua",
-    "__eris.loadlib_searcher_C",
-    "__eris.loadlib_searcher_Croot",
-    NULL
-  };
-  int i;
-
-  luaL_checktype(L, -1, LUA_TTABLE);
-  luaL_checkstack(L, 2, NULL);
-
-  for (i = 0; searchers[i]; ++i) {
-    if (forUnpersist) {
-      lua_pushstring(L, searchernames[i]);
-      lua_pushcfunction(L, searchers[i]);
-    }
-    else {
-      lua_pushcfunction(L, searchers[i]);
-      lua_pushstring(L, searchernames[i]);
-    }
-    lua_rawset(L, -3);
-  }
-}
-

src/lstrlib.c

@@ -1017,19 +1017,3 @@ LUAMOD_API int luaopen_string (lua_State *L) {
   return 1;
 }
 
-
-void eris_permstrlib(lua_State *L, int forUnpersist) {
-  luaL_checktype(L, -1, LUA_TTABLE);
-  luaL_checkstack(L, 2, NULL);
-
-  if (forUnpersist) {
-    lua_pushstring(L, "__eris.strlib_gmatch_aux");
-    lua_pushcfunction(L, gmatch_aux);
-  }
-  else {
-    lua_pushcfunction(L, gmatch_aux);
-    lua_pushstring(L, "__eris.strlib_gmatch_aux");
-  }
-  lua_rawset(L, -3);
-}
-

src/lua.h

@@ -347,6 +347,66 @@ LUA_API void      (lua_setallocf) (lua_State *L, lua_Alloc f, void *ud);
 
 
 
+/*
+** =======================================================================
+** Eris persistence
+** =======================================================================
+*/
+
+#if defined(eris_c)
+/* Utility macro for populating the perms table with internal C functions. */
+# define eris_persist(lib, fn)\
+    extern lua_CFunction __perm_##lib##_##fn;\
+    if (forUnpersist) {\
+      lua_pushstring(L, "__eris." #lib "_" #fn);\
+      lua_pushcfunction(L, *__perm_##lib##_##fn);\
+    }\
+    else {\
+      lua_pushcfunction(L, *__perm_##lib##_##fn);\
+      lua_pushstring(L, "__eris." #lib "_" #fn);\
+    }\
+    lua_rawset(L, -3);
+#else
+/* Utility macro to export internal C functions to eris. */
+# define eris_persist(lib, fn)\
+    static int fn (lua_State *L);\
+    lua_CFunction __perm_##lib##_##fn = fn;
+#endif
+
+#if defined(eris_c)
+/* Functions in Lua libraries used to access C functions we need to add to the
+ * permanents table to fully support yielded coroutines. */
+static void populateperms(lua_State *L, bool forUnpersist)
+{
+#endif
+#if defined(eris_c) || defined(lstrlib_c)
+  eris_persist(strlib, gmatch_aux)
+#endif
+#if defined(eris_c) || defined(loadlib_c)
+  eris_persist(loadlib, searcher_preload)
+  eris_persist(loadlib, searcher_Lua)
+  eris_persist(loadlib, searcher_C)
+  eris_persist(loadlib, searcher_Croot)
+#endif
+#if defined(eris_c) || defined(liolib_c)
+  eris_persist(iolib, io_readline)
+#endif
+#if defined(eris_c) || defined(lbaselib_c)
+  eris_persist(baselib, pcallcont)
+  eris_persist(baselib, luaB_next)
+  eris_persist(baselib, ipairsaux)
+#endif
+#if defined(eris_c) || defined(lcorolib_c)
+  eris_persist(corolib, luaB_auxwrap)
+#endif
+#if defined(eris_c)
+}
+#endif
+
+#undef eris_persist
+
+
+
 /*
 ** {======================================================================
 ** Debug API