/* * TOOLS.C Copyright (c) 2002-10, Asko Kauppi * * Lua tools to support Lanes. */ /* =============================================================================== Copyright (C) 2002-10 Asko Kauppi 2011-17 benoit Germain Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. =============================================================================== */ #include #include #include #include #include #if !defined(__APPLE__) #include #endif // __APPLE__ #include "tools.h" #include "compat.h" #include "universe.h" #include "keeper.h" #include "lanes.h" #include "uniquekey.h" // functions implemented in deep.c extern bool_t copydeep( Universe* U, lua_State* L2, uint_t L2_cache_i, lua_State* L, uint_t i, LookupMode mode_, char const* upName_); extern void push_registry_subtable( lua_State* L, UniqueKey key_); DEBUGSPEW_CODE( char const* debugspew_indent = "----+----!----+----!----+----!----+----!----+----!----+----!----+----!----+"); // ################################################################################################ /* * Does what the original 'push_registry_subtable' function did, but adds an optional mode argument to it */ void push_registry_subtable_mode( lua_State* L, UniqueKey key_, const char* mode_) { STACK_GROW( L, 3); STACK_CHECK( L, 0); REGISTRY_GET( L, key_); // {}|nil STACK_MID( L, 1); if( lua_isnil( L, -1)) { lua_pop( L, 1); // lua_newtable( L); // {} // _R[key_] = {} REGISTRY_SET( L, key_, lua_pushvalue( L, -2)); // {} STACK_MID( L, 1); // Set its metatable if requested if( mode_) { lua_newtable( L); // {} mt lua_pushliteral( L, "__mode"); // {} mt "__mode" lua_pushstring( L, mode_); // {} mt "__mode" mode lua_rawset( L, -3); // {} mt lua_setmetatable( L, -2); // {} } } STACK_END( L, 1); ASSERT_L( lua_istable( L, -1)); } // ################################################################################################ /* * Push a registry subtable (keyed by unique 'key_') onto the stack. * If the subtable does not exist, it is created and chained. */ void push_registry_subtable( lua_State* L, UniqueKey key_) { push_registry_subtable_mode( L, key_, NULL); } // ################################################################################################ /*---=== luaG_dump ===---*/ #ifdef _DEBUG void luaG_dump( lua_State* L) { int top = lua_gettop( L); int i; fprintf( stderr, "\n\tDEBUG STACK:\n"); if( top == 0) fprintf( stderr, "\t(none)\n"); for( i = 1; i <= top; ++ i) { int type = lua_type( L, i); fprintf( stderr, "\t[%d]= (%s) ", i, lua_typename( L, type)); // Print item contents here... // // Note: this requires 'tostring()' to be defined. If it is NOT, // enable it for more debugging. // STACK_CHECK( L, 0); STACK_GROW( L, 2); lua_getglobal( L, "tostring"); // // [-1]: tostring function, or nil if( !lua_isfunction( L, -1)) { fprintf( stderr, "('tostring' not available)"); } else { lua_pushvalue( L, i); lua_call( L, 1 /*args*/, 1 /*retvals*/); // Don't trust the string contents // fprintf( stderr, "%s", lua_tostring( L, -1)); } lua_pop( L, 1); STACK_END( L, 0); fprintf( stderr, "\n"); } fprintf( stderr, "\n"); } #endif // _DEBUG // ################################################################################################ static void* protected_lua_Alloc( void *ud, void *ptr, size_t osize, size_t nsize) { void* p; ProtectedAllocator* s = (ProtectedAllocator*) ud; MUTEX_LOCK( &s->lock); p = s->definition.allocF( s->definition.allocUD, ptr, osize, nsize); MUTEX_UNLOCK( &s->lock); return p; } static int luaG_provide_protected_allocator( lua_State* L) { Universe* U = universe_get( L); AllocatorDefinition* def = lua_newuserdatauv( L, sizeof(AllocatorDefinition), 0); def->allocF = protected_lua_Alloc; def->allocUD = &U->protected_allocator; return 1; } // Do I need to disable this when compiling for LuaJIT to prevent issues? void initialize_allocator_function( Universe* U, lua_State* L) { STACK_CHECK( L, 0); lua_getfield( L, -1, "allocator"); // settings allocator|nil|"protected" if( !lua_isnil( L, -1)) { // store C function pointer in an internal variable U->provide_allocator = lua_tocfunction( L, -1); // settings allocator if( U->provide_allocator != NULL) { // make sure the function doesn't have upvalues char const* upname = lua_getupvalue( L, -1, 1); // settings allocator upval? if( upname != NULL) // should be "" for C functions with upvalues if any { (void) luaL_error( L, "config.allocator() shouldn't have upvalues"); } // remove this C function from the config table so that it doesn't cause problems // when we transfer the config table in newly created Lua states lua_pushnil( L); // settings allocator nil lua_setfield( L, -3, "allocator"); // settings allocator } else if( lua_type( L, -1) == LUA_TSTRING) { // initialize all we need for the protected allocator MUTEX_INIT( &U->protected_allocator.lock); // the mutex // and the original allocator to call from inside protection by the mutex U->protected_allocator.definition.allocF = lua_getallocf( L, &U->protected_allocator.definition.allocUD); // before a state is created, this function will be called to obtain the allocator U->provide_allocator = luaG_provide_protected_allocator; lua_setallocf( L, protected_lua_Alloc, &U->protected_allocator); } } lua_pop( L, 1); // settings STACK_END( L, 0); } void cleanup_allocator_function( Universe* U, lua_State* L) { // remove the protected allocator, if any if( U->protected_allocator.definition.allocF != NULL) { // install the non-protected allocator lua_setallocf( L, U->protected_allocator.definition.allocF, U->protected_allocator.definition.allocUD); // release the mutex MUTEX_FREE( &U->protected_allocator.lock); } } // ################################################################################################ static int dummy_writer( lua_State* L, void const* p, size_t sz, void* ud) { (void)L; (void)p; (void)sz; (void) ud; // unused return 666; } /* * differentiation between C, bytecode and JIT-fast functions * * * +----------+------------+----------+ * | bytecode | C function | JIT-fast | * +-----------------+----------+------------+----------+ * | lua_topointer | | | | * +-----------------+----------+------------+----------+ * | lua_tocfunction | NULL | | NULL | * +-----------------+----------+------------+----------+ * | lua_dump | 666 | 1 | 1 | * +-----------------+----------+------------+----------+ */ typedef enum { FST_Bytecode, FST_Native, FST_FastJIT } FuncSubType; FuncSubType luaG_getfuncsubtype( lua_State *L, int _i) { if( lua_tocfunction( L, _i)) { return FST_Native; } { int mustpush = 0, dumpres; if( lua_absindex( L, _i) != lua_gettop( L)) { lua_pushvalue( L, _i); mustpush = 1; } // the provided writer fails with code 666 // therefore, anytime we get 666, this means that lua_dump() attempted a dump // all other cases mean this is either a C or LuaJIT-fast function dumpres = lua504_dump( L, dummy_writer, NULL, 0); lua_pop( L, mustpush); if( dumpres == 666) { return FST_Bytecode; } } return FST_FastJIT; } static lua_CFunction luaG_tocfunction( lua_State *L, int _i, FuncSubType *_out) { lua_CFunction p = lua_tocfunction( L, _i); *_out = luaG_getfuncsubtype( L, _i); return p; } // crc64/we of string "LOOKUPCACHE_REGKEY" generated at http://www.nitrxgen.net/hashgen/ static DECLARE_CONST_UNIQUE_KEY( LOOKUPCACHE_REGKEY, 0x837a68dfc6fcb716); // inspired from tconcat() in ltablib.c static char const* luaG_pushFQN( lua_State* L, int t, int last, size_t* length) { int i = 1; luaL_Buffer b; STACK_CHECK( L, 0); // Lua 5.4 pushes &b as light userdata on the stack. be aware of it... luaL_buffinit( L, &b); // ... {} ... &b? for( ; i < last; ++ i) { lua_rawgeti( L, t, i); luaL_addvalue( &b); luaL_addlstring(&b, "/", 1); } if( i == last) // add last value (if interval was not empty) { lua_rawgeti( L, t, i); luaL_addvalue( &b); } // &b is popped at that point (-> replaced by the result) luaL_pushresult( &b); // ... {} ... "" STACK_END( L, 1); return lua_tolstring( L, -1, length); } /* * receives 2 arguments: a name k and an object o * add two entries ["fully.qualified.name"] = o * and [o] = "fully.qualified.name" * where is either a table or a function * if we already had an entry of type [o] = ..., replace the name if the new one is shorter * pops the processed object from the stack */ static void update_lookup_entry( DEBUGSPEW_PARAM_COMMA( Universe* U) lua_State* L, int _ctx_base, int _depth) { // slot 1 in the stack contains the table that receives everything we found int const dest = _ctx_base; // slot 2 contains a table that, when concatenated, produces the fully qualified name of scanned elements in the table provided at slot _i int const fqn = _ctx_base + 1; size_t prevNameLength, newNameLength; char const* prevName; DEBUGSPEW_CODE( char const *newName); DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "update_lookup_entry()\n" INDENT_END)); DEBUGSPEW_CODE( ++ U->debugspew_indent_depth); STACK_CHECK( L, 0); // first, raise an error if the function is already known lua_pushvalue( L, -1); // ... {bfc} k o o lua_rawget( L, dest); // ... {bfc} k o name? prevName = lua_tolstring( L, -1, &prevNameLength); // NULL if we got nil (first encounter of this object) // push name in fqn stack (note that concatenation will crash if name is a not string or a number) lua_pushvalue( L, -3); // ... {bfc} k o name? k ASSERT_L( lua_type( L, -1) == LUA_TNUMBER || lua_type( L, -1) == LUA_TSTRING); ++ _depth; lua_rawseti( L, fqn, _depth); // ... {bfc} k o name? // generate name DEBUGSPEW_CODE( newName =) luaG_pushFQN( L, fqn, _depth, &newNameLength); // ... {bfc} k o name? "f.q.n" // Lua 5.2 introduced a hash randomizer seed which causes table iteration to yield a different key order // on different VMs even when the tables are populated the exact same way. // When Lua is built with compatibility options (such as LUA_COMPAT_ALL), // this causes several base libraries to register functions under multiple names. // This, with the randomizer, can cause the first generated name of an object to be different on different VMs, // which breaks function transfer. // Also, nothing prevents any external module from exposing a given object under several names, so... // Therefore, when we encounter an object for which a name was previously registered, we need to select the names // based on some sorting order so that we end up with the same name in all databases whatever order the table walk yielded if( prevName != NULL && (prevNameLength < newNameLength || lua_lessthan( L, -2, -1))) { DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "%s '%s' remained named '%s'\n" INDENT_END, lua_typename( L, lua_type( L, -3)), newName, prevName)); // the previous name is 'smaller' than the one we just generated: keep it! lua_pop( L, 3); // ... {bfc} k } else { // the name we generated is either the first one, or a better fit for our purposes if( prevName) { // clear the previous name for the database to avoid clutter lua_insert( L, -2); // ... {bfc} k o "f.q.n" prevName // t[prevName] = nil lua_pushnil( L); // ... {bfc} k o "f.q.n" prevName nil lua_rawset( L, dest); // ... {bfc} k o "f.q.n" } else { lua_remove( L, -2); // ... {bfc} k o "f.q.n" } DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "%s '%s'\n" INDENT_END, lua_typename( L, lua_type( L, -2)), newName)); // prepare the stack for database feed lua_pushvalue( L, -1); // ... {bfc} k o "f.q.n" "f.q.n" lua_pushvalue( L, -3); // ... {bfc} k o "f.q.n" "f.q.n" o ASSERT_L( lua_rawequal( L, -1, -4)); ASSERT_L( lua_rawequal( L, -2, -3)); // t["f.q.n"] = o lua_rawset( L, dest); // ... {bfc} k o "f.q.n" // t[o] = "f.q.n" lua_rawset( L, dest); // ... {bfc} k // remove table name from fqn stack lua_pushnil( L); // ... {bfc} k nil lua_rawseti( L, fqn, _depth); // ... {bfc} k } -- _depth; STACK_END( L, -1); DEBUGSPEW_CODE( -- U->debugspew_indent_depth); } static void populate_func_lookup_table_recur( DEBUGSPEW_PARAM_COMMA( Universe* U) lua_State* L, int _ctx_base, int _i, int _depth) { lua_Integer visit_count; // slot 2 contains a table that, when concatenated, produces the fully qualified name of scanned elements in the table provided at slot _i int const fqn = _ctx_base + 1; // slot 3 contains a cache that stores all already visited tables to avoid infinite recursion loops int const cache = _ctx_base + 2; // we need to remember subtables to process them after functions encountered at the current depth (breadth-first search) int const breadth_first_cache = lua_gettop( L) + 1; DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "populate_func_lookup_table_recur()\n" INDENT_END)); DEBUGSPEW_CODE( ++ U->debugspew_indent_depth); STACK_GROW( L, 6); // slot _i contains a table where we search for functions (or a full userdata with a metatable) STACK_CHECK( L, 0); // ... {_i} // if object is a userdata, replace it by its metatable if( lua_type( L, _i) == LUA_TUSERDATA) { lua_getmetatable( L, _i); // ... {_i} mt lua_replace( L, _i); // ... {_i} } // if table is already visited, we are done lua_pushvalue( L, _i); // ... {_i} {} lua_rawget( L, cache); // ... {_i} nil|n visit_count = lua_tointeger( L, -1); // 0 if nil, else n lua_pop( L, 1); // ... {_i} STACK_MID( L, 0); if( visit_count > 0) { DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "already visited\n" INDENT_END)); DEBUGSPEW_CODE( -- U->debugspew_indent_depth); return; } // remember we visited this table (1-visit count) lua_pushvalue( L, _i); // ... {_i} {} lua_pushinteger( L, visit_count + 1); // ... {_i} {} 1 lua_rawset( L, cache); // ... {_i} STACK_MID( L, 0); // this table is at breadth_first_cache index lua_newtable( L); // ... {_i} {bfc} ASSERT_L( lua_gettop( L) == breadth_first_cache); // iterate over all entries in the processed table lua_pushnil( L); // ... {_i} {bfc} nil while( lua_next( L, _i) != 0) // ... {_i} {bfc} k v { // just for debug, not actually needed //char const* key = (lua_type( L, -2) == LUA_TSTRING) ? lua_tostring( L, -2) : "not a string"; // subtable: process it recursively if( lua_istable( L, -1)) // ... {_i} {bfc} k {} { // increment visit count to make sure we will actually scan it at this recursive level lua_pushvalue( L, -1); // ... {_i} {bfc} k {} {} lua_pushvalue( L, -1); // ... {_i} {bfc} k {} {} {} lua_rawget( L, cache); // ... {_i} {bfc} k {} {} n? visit_count = lua_tointeger( L, -1) + 1; // 1 if we got nil, else n+1 lua_pop( L, 1); // ... {_i} {bfc} k {} {} lua_pushinteger( L, visit_count); // ... {_i} {bfc} k {} {} n lua_rawset( L, cache); // ... {_i} {bfc} k {} // store the table in the breadth-first cache lua_pushvalue( L, -2); // ... {_i} {bfc} k {} k lua_pushvalue( L, -2); // ... {_i} {bfc} k {} k {} lua_rawset( L, breadth_first_cache); // ... {_i} {bfc} k {} // generate a name, and if we already had one name, keep whichever is the shorter update_lookup_entry( DEBUGSPEW_PARAM_COMMA( U) L, _ctx_base, _depth); // ... {_i} {bfc} k } else if( lua_isfunction( L, -1) && (luaG_getfuncsubtype( L, -1) != FST_Bytecode)) // ... {_i} {bfc} k func { // generate a name, and if we already had one name, keep whichever is the shorter update_lookup_entry( DEBUGSPEW_PARAM_COMMA( U) L, _ctx_base, _depth); // ... {_i} {bfc} k } else { lua_pop( L, 1); // ... {_i} {bfc} k } STACK_MID( L, 2); } // now process the tables we encountered at that depth ++ _depth; lua_pushnil( L); // ... {_i} {bfc} nil while( lua_next( L, breadth_first_cache) != 0) // ... {_i} {bfc} k {} { DEBUGSPEW_CODE( char const* key = (lua_type( L, -2) == LUA_TSTRING) ? lua_tostring( L, -2) : "not a string"); DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "table '%s'\n" INDENT_END, key)); DEBUGSPEW_CODE( ++ U->debugspew_indent_depth); // un-visit this table in case we do need to process it lua_pushvalue( L, -1); // ... {_i} {bfc} k {} {} lua_rawget( L, cache); // ... {_i} {bfc} k {} n ASSERT_L( lua_type( L, -1) == LUA_TNUMBER); visit_count = lua_tointeger( L, -1) - 1; lua_pop( L, 1); // ... {_i} {bfc} k {} lua_pushvalue( L, -1); // ... {_i} {bfc} k {} {} if( visit_count > 0) { lua_pushinteger( L, visit_count); // ... {_i} {bfc} k {} {} n } else { lua_pushnil( L); // ... {_i} {bfc} k {} {} nil } lua_rawset( L, cache); // ... {_i} {bfc} k {} // push table name in fqn stack (note that concatenation will crash if name is a not string!) lua_pushvalue( L, -2); // ... {_i} {bfc} k {} k lua_rawseti( L, fqn, _depth); // ... {_i} {bfc} k {} populate_func_lookup_table_recur( DEBUGSPEW_PARAM_COMMA( U) L, _ctx_base, lua_gettop( L), _depth); lua_pop( L, 1); // ... {_i} {bfc} k STACK_MID( L, 2); DEBUGSPEW_CODE( -- U->debugspew_indent_depth); } // remove table name from fqn stack lua_pushnil( L); // ... {_i} {bfc} nil lua_rawseti( L, fqn, _depth); // ... {_i} {bfc} -- _depth; // we are done with our cache lua_pop( L, 1); // ... {_i} STACK_END( L, 0); // we are done // ... {_i} {bfc} DEBUGSPEW_CODE( -- U->debugspew_indent_depth); } /* * create a "fully.qualified.name" <-> function equivalence database */ void populate_func_lookup_table( lua_State* L, int _i, char const* name_) { int const ctx_base = lua_gettop( L) + 1; int const in_base = lua_absindex( L, _i); int start_depth = 0; DEBUGSPEW_CODE( Universe* U = universe_get( L)); DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "%p: populate_func_lookup_table('%s')\n" INDENT_END, L, name_ ? name_ : "NULL")); DEBUGSPEW_CODE( ++ U->debugspew_indent_depth); STACK_GROW( L, 3); STACK_CHECK( L, 0); REGISTRY_GET( L, LOOKUP_REGKEY); // {} STACK_MID( L, 1); ASSERT_L( lua_istable( L, -1)); if( lua_type( L, in_base) == LUA_TFUNCTION) // for example when a module is a simple function { name_ = name_ ? name_ : "NULL"; lua_pushvalue( L, in_base); // {} f lua_pushstring( L, name_); // {} f _name lua_rawset( L, -3); // {} lua_pushstring( L, name_); // {} _name lua_pushvalue( L, in_base); // {} _name f lua_rawset( L, -3); // {} lua_pop( L, 1); // } else if( lua_type( L, in_base) == LUA_TTABLE) { lua_newtable( L); // {} {fqn} if( name_) { STACK_MID( L, 2); lua_pushstring( L, name_); // {} {fqn} "name" // generate a name, and if we already had one name, keep whichever is the shorter lua_pushvalue( L, in_base); // {} {fqn} "name" t update_lookup_entry( DEBUGSPEW_PARAM_COMMA( U) L, ctx_base, start_depth); // {} {fqn} "name" // don't forget to store the name at the bottom of the fqn stack ++ start_depth; lua_rawseti( L, -2, start_depth); // {} {fqn} STACK_MID( L, 2); } // retrieve the cache, create it if we haven't done it yet REGISTRY_GET( L, LOOKUPCACHE_REGKEY); // {} {fqn} {cache}? if( lua_isnil( L, -1)) { lua_pop( L, 1); // {} {fqn} lua_newtable( L); // {} {fqn} {cache} REGISTRY_SET( L, LOOKUPCACHE_REGKEY, lua_pushvalue( L, -2)); STACK_MID( L, 3); } // process everything we find in that table, filling in lookup data for all functions and tables we see there populate_func_lookup_table_recur( DEBUGSPEW_PARAM_COMMA( U) L, ctx_base, in_base, start_depth); lua_pop( L, 3); } else { lua_pop( L, 1); // (void) luaL_error( L, "unsupported module type %s", lua_typename( L, lua_type( L, in_base))); } STACK_END( L, 0); DEBUGSPEW_CODE( -- U->debugspew_indent_depth); } /*---=== Inter-state copying ===---*/ // crc64/we of string "REG_MTID" generated at http://www.nitrxgen.net/hashgen/ static DECLARE_CONST_UNIQUE_KEY( REG_MTID, 0x2e68f9b4751584dc); /* * Get a unique ID for metatable at [i]. */ static lua_Integer get_mt_id( Universe* U, lua_State* L, int i) { lua_Integer id; i = lua_absindex( L, i); STACK_GROW( L, 3); STACK_CHECK( L, 0); push_registry_subtable( L, REG_MTID); // ... _R[REG_MTID] lua_pushvalue( L, i); // ... _R[REG_MTID] {mt} lua_rawget( L, -2); // ... _R[REG_MTID] mtk? id = lua_tointeger( L, -1); // 0 for nil lua_pop( L, 1); // ... _R[REG_MTID] STACK_MID( L, 1); if( id == 0) { MUTEX_LOCK( &U->mtid_lock); id = ++ U->last_mt_id; MUTEX_UNLOCK( &U->mtid_lock); /* Create two-way references: id_uint <-> table */ lua_pushvalue( L, i); // ... _R[REG_MTID] {mt} lua_pushinteger( L, id); // ... _R[REG_MTID] {mt} id lua_rawset( L, -3); // ... _R[REG_MTID] lua_pushinteger( L, id); // ... _R[REG_MTID] id lua_pushvalue( L, i); // ... _R[REG_MTID] id {mt} lua_rawset( L, -3); // ... _R[REG_MTID] } lua_pop( L, 1); // ... STACK_END( L, 0); return id; } // function sentinel used to transfer native functions from/to keeper states static int func_lookup_sentinel( lua_State* L) { return luaL_error( L, "function lookup sentinel for %s, should never be called", lua_tostring( L, lua_upvalueindex( 1))); } // function sentinel used to transfer native table from/to keeper states static int table_lookup_sentinel( lua_State* L) { return luaL_error( L, "table lookup sentinel for %s, should never be called", lua_tostring( L, lua_upvalueindex( 1))); } // function sentinel used to transfer cloned full userdata from/to keeper states static int userdata_clone_sentinel( lua_State* L) { return luaL_error( L, "userdata clone sentinel for %s, should never be called", lua_tostring( L, lua_upvalueindex( 1))); } /* * retrieve the name of a function/table in the lookup database */ static char const* find_lookup_name( lua_State* L, uint_t i, LookupMode mode_, char const* upName_, size_t* len_) { DEBUGSPEW_CODE( Universe* const U = universe_get( L)); char const* fqn; ASSERT_L( lua_isfunction( L, i) || lua_istable( L, i)); // ... v ... STACK_CHECK( L, 0); STACK_GROW( L, 3); // up to 3 slots are necessary on error if( mode_ == eLM_FromKeeper) { lua_CFunction f = lua_tocfunction( L, i); // should *always* be func_lookup_sentinel or table_lookup_sentinel! if( f == func_lookup_sentinel || f == table_lookup_sentinel || f == userdata_clone_sentinel) { lua_getupvalue( L, i, 1); // ... v ... "f.q.n" } else { // if this is not a sentinel, this is some user-created table we wanted to lookup ASSERT_L( NULL == f && lua_istable( L, i)); // push anything that will convert to NULL string lua_pushnil( L); // ... v ... nil } } else { // fetch the name from the source state's lookup table REGISTRY_GET( L, LOOKUP_REGKEY); // ... v ... {} STACK_MID( L, 1); ASSERT_L( lua_istable( L, -1)); lua_pushvalue( L, i); // ... v ... {} v lua_rawget( L, -2); // ... v ... {} "f.q.n" } fqn = lua_tolstring( L, -1, len_); DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "function [C] %s \n" INDENT_END, fqn)); // popping doesn't invalidate the pointer since this is an interned string gotten from the lookup database lua_pop( L, (mode_ == eLM_FromKeeper) ? 1 : 2); // ... v ... STACK_MID( L, 0); if( NULL == fqn && !lua_istable( L, i)) // raise an error if we try to send an unknown function (but not for tables) { char const *from, *typewhat, *what, *gotchaA, *gotchaB; // try to discover the name of the function we want to send lua_getglobal( L, "decoda_name"); // ... v ... decoda_name from = lua_tostring( L, -1); lua_pushcfunction( L, luaG_nameof); // ... v ... decoda_name luaG_nameof lua_pushvalue( L, i); // ... v ... decoda_name luaG_nameof t lua_call( L, 1, 2); // ... v ... decoda_name "type" "name"|nil typewhat = (lua_type( L, -2) == LUA_TSTRING) ? lua_tostring( L, -2) : luaL_typename( L, -2); // second return value can be nil if the table was not found // probable reason: the function was removed from the source Lua state before Lanes was required. if( lua_isnil( L, -1)) { gotchaA = " referenced by"; gotchaB = "\n(did you remove it from the source Lua state before requiring Lanes?)"; what = upName_; } else { gotchaA = ""; gotchaB = ""; what = (lua_type( L, -1) == LUA_TSTRING) ? lua_tostring( L, -1) : luaL_typename( L, -1); } (void) luaL_error( L, "%s%s '%s' not found in %s origin transfer database.%s", typewhat, gotchaA, what, from ? from : "main", gotchaB); *len_ = 0; return NULL; } STACK_END( L, 0); return fqn; } /* * Push a looked-up table, or nothing if we found nothing */ static bool_t lookup_table( lua_State* L2, lua_State* L, uint_t i, LookupMode mode_, char const* upName_) { // get the name of the table we want to send size_t len; char const* fqn = find_lookup_name( L, i, mode_, upName_, &len); if( NULL == fqn) // name not found, it is some user-created table { return FALSE; } // push the equivalent table in the destination's stack, retrieved from the lookup table STACK_CHECK( L2, 0); // L // L2 STACK_GROW( L2, 3); // up to 3 slots are necessary on error switch( mode_) { default: // shouldn't happen, in theory... (void) luaL_error( L, "internal error: unknown lookup mode"); return FALSE; case eLM_ToKeeper: // push a sentinel closure that holds the lookup name as upvalue lua_pushlstring( L2, fqn, len); // "f.q.n" lua_pushcclosure( L2, table_lookup_sentinel, 1); // f break; case eLM_LaneBody: case eLM_FromKeeper: REGISTRY_GET( L2, LOOKUP_REGKEY); // {} STACK_MID( L2, 1); ASSERT_L( lua_istable( L2, -1)); lua_pushlstring( L2, fqn, len); // {} "f.q.n" lua_rawget( L2, -2); // {} t // we accept destination lookup failures in the case of transfering the Lanes body function (this will result in the source table being cloned instead) // but not when we extract something out of a keeper, as there is nothing to clone! if( lua_isnil( L2, -1) && mode_ == eLM_LaneBody) { lua_pop( L2, 2); // STACK_MID( L2, 0); return FALSE; } else if( !lua_istable( L2, -1)) { char const* from, *to; lua_getglobal( L, "decoda_name"); // ... t ... decoda_name from = lua_tostring( L, -1); lua_pop( L, 1); // ... t ... lua_getglobal( L2, "decoda_name"); // {} t decoda_name to = lua_tostring( L2, -1); lua_pop( L2, 1); // {} t // when mode_ == eLM_FromKeeper, L is a keeper state and L2 is not, therefore L2 is the state where we want to raise the error (void) luaL_error( (mode_ == eLM_FromKeeper) ? L2 : L , "INTERNAL ERROR IN %s: table '%s' not found in %s destination transfer database." , from ? from : "main" , fqn , to ? to : "main" ); return FALSE; } lua_remove( L2, -2); // t break; } STACK_END( L2, 1); return TRUE; } /* * Check if we've already copied the same table from 'L', and * reuse the old copy. This allows table upvalues shared by multiple * local functions to point to the same table, also in the target. * * Always pushes a table to 'L2'. * * Returns TRUE if the table was cached (no need to fill it!); FALSE if * it's a virgin. */ static bool_t push_cached_table( lua_State* L2, uint_t L2_cache_i, lua_State* L, uint_t i) { bool_t not_found_in_cache; // L2 DECLARE_CONST_UNIQUE_KEY( p, lua_topointer( L, i)); ASSERT_L( L2_cache_i != 0); STACK_GROW( L2, 3); STACK_CHECK( L2, 0); // We don't need to use the from state ('L') in ID since the life span // is only for the duration of a copy (both states are locked). // push a light userdata uniquely representing the table push_unique_key( L2, p); // ... p //fprintf( stderr, "<< ID: %s >>\n", lua_tostring( L2, -1)); lua_rawget( L2, L2_cache_i); // ... {cached|nil} not_found_in_cache = lua_isnil( L2, -1); if( not_found_in_cache) { lua_pop( L2, 1); // ... lua_newtable( L2); // ... {} push_unique_key( L2, p); // ... {} p lua_pushvalue( L2, -2); // ... {} p {} lua_rawset( L2, L2_cache_i); // ... {} } STACK_END( L2, 1); ASSERT_L( lua_istable( L2, -1)); return !not_found_in_cache; } /* * Return some name helping to identify an object */ static int discover_object_name_recur( lua_State* L, int shortest_, int depth_) { int const what = 1; // o "r" {c} {fqn} ... {?} int const result = 2; int const cache = 3; int const fqn = 4; // no need to scan this table if the name we will discover is longer than one we already know if( shortest_ <= depth_ + 1) { return shortest_; } STACK_GROW( L, 3); STACK_CHECK( L, 0); // stack top contains the table to search in lua_pushvalue( L, -1); // o "r" {c} {fqn} ... {?} {?} lua_rawget( L, cache); // o "r" {c} {fqn} ... {?} nil/1 // if table is already visited, we are done if( !lua_isnil( L, -1)) { lua_pop( L, 1); // o "r" {c} {fqn} ... {?} return shortest_; } // examined table is not in the cache, add it now lua_pop( L, 1); // o "r" {c} {fqn} ... {?} lua_pushvalue( L, -1); // o "r" {c} {fqn} ... {?} {?} lua_pushinteger( L, 1); // o "r" {c} {fqn} ... {?} {?} 1 lua_rawset( L, cache); // o "r" {c} {fqn} ... {?} // scan table contents lua_pushnil( L); // o "r" {c} {fqn} ... {?} nil while( lua_next( L, -2)) // o "r" {c} {fqn} ... {?} k v { //char const *const strKey = (lua_type( L, -2) == LUA_TSTRING) ? lua_tostring( L, -2) : NULL; // only for debugging //lua_Number const numKey = (lua_type( L, -2) == LUA_TNUMBER) ? lua_tonumber( L, -2) : -6666; // only for debugging STACK_MID( L, 2); // append key name to fqn stack ++ depth_; lua_pushvalue( L, -2); // o "r" {c} {fqn} ... {?} k v k lua_rawseti( L, fqn, depth_); // o "r" {c} {fqn} ... {?} k v if( lua_rawequal( L, -1, what)) // is it what we are looking for? { STACK_MID( L, 2); // update shortest name if( depth_ < shortest_) { shortest_ = depth_; luaG_pushFQN( L, fqn, depth_, NULL); // o "r" {c} {fqn} ... {?} k v "fqn" lua_replace( L, result); // o "r" {c} {fqn} ... {?} k v } // no need to search further at this level lua_pop( L, 2); // o "r" {c} {fqn} ... {?} STACK_MID( L, 0); break; } switch( lua_type( L, -1)) // o "r" {c} {fqn} ... {?} k v { default: // nil, boolean, light userdata, number and string aren't identifiable break; case LUA_TTABLE: // o "r" {c} {fqn} ... {?} k {} STACK_MID( L, 2); shortest_ = discover_object_name_recur( L, shortest_, depth_); // search in the table's metatable too if( lua_getmetatable( L, -1)) // o "r" {c} {fqn} ... {?} k {} {mt} { if( lua_istable( L, -1)) { ++ depth_; lua_pushliteral( L, "__metatable"); // o "r" {c} {fqn} ... {?} k {} {mt} "__metatable" lua_rawseti( L, fqn, depth_); // o "r" {c} {fqn} ... {?} k {} {mt} shortest_ = discover_object_name_recur( L, shortest_, depth_); lua_pushnil( L); // o "r" {c} {fqn} ... {?} k {} {mt} nil lua_rawseti( L, fqn, depth_); // o "r" {c} {fqn} ... {?} k {} {mt} -- depth_; } lua_pop( L, 1); // o "r" {c} {fqn} ... {?} k {} } STACK_MID( L, 2); break; case LUA_TTHREAD: // o "r" {c} {fqn} ... {?} k T // TODO: explore the thread's stack frame looking for our culprit? break; case LUA_TUSERDATA: // o "r" {c} {fqn} ... {?} k U STACK_MID( L, 2); // search in the object's metatable (some modules are built that way) if( lua_getmetatable( L, -1)) // o "r" {c} {fqn} ... {?} k U {mt} { if( lua_istable( L, -1)) { ++ depth_; lua_pushliteral( L, "__metatable"); // o "r" {c} {fqn} ... {?} k U {mt} "__metatable" lua_rawseti( L, fqn, depth_); // o "r" {c} {fqn} ... {?} k U {mt} shortest_ = discover_object_name_recur( L, shortest_, depth_); lua_pushnil( L); // o "r" {c} {fqn} ... {?} k U {mt} nil lua_rawseti( L, fqn, depth_); // o "r" {c} {fqn} ... {?} k U {mt} -- depth_; } lua_pop( L, 1); // o "r" {c} {fqn} ... {?} k U } STACK_MID( L, 2); // search in the object's uservalues { int uvi = 1; while( lua_getiuservalue( L, -1, uvi) != LUA_TNONE) // o "r" {c} {fqn} ... {?} k U {u} { if( lua_istable( L, -1)) // if it is a table, look inside { ++ depth_; lua_pushliteral( L, "uservalue"); // o "r" {c} {fqn} ... {?} k v {u} "uservalue" lua_rawseti( L, fqn, depth_); // o "r" {c} {fqn} ... {?} k v {u} shortest_ = discover_object_name_recur( L, shortest_, depth_); lua_pushnil( L); // o "r" {c} {fqn} ... {?} k v {u} nil lua_rawseti( L, fqn, depth_); // o "r" {c} {fqn} ... {?} k v {u} -- depth_; } lua_pop( L, 1); // o "r" {c} {fqn} ... {?} k U ++ uvi; } // when lua_getiuservalue() returned LUA_TNONE, it pushed a nil. pop it now lua_pop( L, 1); // o "r" {c} {fqn} ... {?} k U } STACK_MID( L, 2); break; } // make ready for next iteration lua_pop( L, 1); // o "r" {c} {fqn} ... {?} k // remove name from fqn stack lua_pushnil( L); // o "r" {c} {fqn} ... {?} k nil lua_rawseti( L, fqn, depth_); // o "r" {c} {fqn} ... {?} k STACK_MID( L, 1); -- depth_; } // o "r" {c} {fqn} ... {?} STACK_MID( L, 0); // remove the visited table from the cache, in case a shorter path to the searched object exists lua_pushvalue( L, -1); // o "r" {c} {fqn} ... {?} {?} lua_pushnil( L); // o "r" {c} {fqn} ... {?} {?} nil lua_rawset( L, cache); // o "r" {c} {fqn} ... {?} STACK_END( L, 0); return shortest_; } /* * "type", "name" = lanes.nameof( o) */ int luaG_nameof( lua_State* L) { int what = lua_gettop( L); if( what > 1) { luaL_argerror( L, what, "too many arguments."); } // nil, boolean, light userdata, number and string aren't identifiable if( lua_type( L, 1) < LUA_TTABLE) { lua_pushstring( L, luaL_typename( L, 1)); // o "type" lua_insert( L, -2); // "type" o return 2; } STACK_GROW( L, 4); STACK_CHECK( L, 0); // this slot will contain the shortest name we found when we are done lua_pushnil( L); // o nil // push a cache that will contain all already visited tables lua_newtable( L); // o nil {c} // push a table whose contents are strings that, when concatenated, produce unique name lua_newtable( L); // o nil {c} {fqn} lua_pushliteral( L, "_G"); // o nil {c} {fqn} "_G" lua_rawseti( L, -2, 1); // o nil {c} {fqn} // this is where we start the search lua_pushglobaltable( L); // o nil {c} {fqn} _G (void) discover_object_name_recur( L, 6666, 1); if( lua_isnil( L, 2)) // try again with registry, just in case... { lua_pop( L, 1); // o nil {c} {fqn} lua_pushliteral( L, "_R"); // o nil {c} {fqn} "_R" lua_rawseti( L, -2, 1); // o nil {c} {fqn} lua_pushvalue( L, LUA_REGISTRYINDEX); // o nil {c} {fqn} _R (void) discover_object_name_recur( L, 6666, 1); } lua_pop( L, 3); // o "result" STACK_END( L, 1); lua_pushstring( L, luaL_typename( L, 1)); // o "result" "type" lua_replace( L, -3); // "type" "result" return 2; } /* * Push a looked-up native/LuaJIT function. */ static void lookup_native_func( lua_State* L2, lua_State* L, uint_t i, LookupMode mode_, char const* upName_) { // get the name of the function we want to send size_t len; char const* fqn = find_lookup_name( L, i, mode_, upName_, &len); // push the equivalent function in the destination's stack, retrieved from the lookup table STACK_CHECK( L2, 0); // L // L2 STACK_GROW( L2, 3); // up to 3 slots are necessary on error switch( mode_) { default: // shouldn't happen, in theory... (void) luaL_error( L, "internal error: unknown lookup mode"); return; case eLM_ToKeeper: // push a sentinel closure that holds the lookup name as upvalue lua_pushlstring( L2, fqn, len); // "f.q.n" lua_pushcclosure( L2, func_lookup_sentinel, 1); // f break; case eLM_LaneBody: case eLM_FromKeeper: REGISTRY_GET( L2, LOOKUP_REGKEY); // {} STACK_MID( L2, 1); ASSERT_L( lua_istable( L2, -1)); lua_pushlstring( L2, fqn, len); // {} "f.q.n" lua_rawget( L2, -2); // {} f // nil means we don't know how to transfer stuff: user should do something // anything other than function or table should not happen! if( !lua_isfunction( L2, -1) && !lua_istable( L2, -1)) { char const* from, * to; lua_getglobal( L, "decoda_name"); // ... f ... decoda_name from = lua_tostring( L, -1); lua_pop( L, 1); // ... f ... lua_getglobal( L2, "decoda_name"); // {} f decoda_name to = lua_tostring( L2, -1); lua_pop( L2, 1); // {} f // when mode_ == eLM_FromKeeper, L is a keeper state and L2 is not, therefore L2 is the state where we want to raise the error (void) luaL_error( (mode_ == eLM_FromKeeper) ? L2 : L , "%s%s: function '%s' not found in %s destination transfer database." , lua_isnil( L2, -1) ? "" : "INTERNAL ERROR IN " , from ? from : "main" , fqn , to ? to : "main" ); return; } lua_remove( L2, -2); // f break; /* keep it in case I need it someday, who knows... case eLM_RawFunctions: { int n; char const* upname; lua_CFunction f = lua_tocfunction( L, i); // copy upvalues for( n = 0; (upname = lua_getupvalue( L, i, 1 + n)) != NULL; ++ n) { luaG_inter_move( U, L, L2, 1, mode_); // [up[,up ...]] } lua_pushcclosure( L2, f, n); // } break; */ } STACK_END( L2, 1); } /* * Copy a function over, which has not been found in the cache. * L2 has the cache key for this function at the top of the stack */ #if USE_DEBUG_SPEW static char const* lua_type_names[] = { "LUA_TNIL" , "LUA_TBOOLEAN" , "LUA_TLIGHTUSERDATA" , "LUA_TNUMBER" , "LUA_TSTRING" , "LUA_TTABLE" , "LUA_TFUNCTION" , "LUA_TUSERDATA" , "LUA_TTHREAD" , "" // not really a type , "LUA_TJITCDATA" // LuaJIT specific }; static char const* vt_names[] = { "VT_NORMAL" , "VT_KEY" , "VT_METATABLE" }; #endif // USE_DEBUG_SPEW // Lua 5.4.3 style of dumping (see lstrlib.c) // we have to do it that way because we can't unbalance the stack between buffer operations // namely, this means we can't push a function on top of the stack *after* we initialize the buffer! // luckily, this also works with earlier Lua versions static int buf_writer( lua_State* L, void const* b, size_t size, void* ud) { luaL_Buffer* B = (luaL_Buffer*) ud; if( !B->L) { luaL_buffinit( L, B); } luaL_addlstring( B, (char const*) b, size); return 0; } static void copy_func( Universe* U, lua_State* L2, uint_t L2_cache_i, lua_State* L, uint_t i, LookupMode mode_, char const* upName_) { int n, needToPush; luaL_Buffer B; B.L = NULL; ASSERT_L( L2_cache_i != 0); // ... {cache} ... p STACK_GROW( L, 2); STACK_CHECK( L, 0); // 'lua_dump()' needs the function at top of stack // if already on top of the stack, no need to push again needToPush = (i != (uint_t)lua_gettop( L)); if( needToPush) { lua_pushvalue( L, i); // ... f } // // "value returned is the error code returned by the last call // to the writer" (and we only return 0) // not sure this could ever fail but for memory shortage reasons // last parameter is Lua 5.4-specific (no stripping) if( lua504_dump( L, buf_writer, &B, 0) != 0) { luaL_error( L, "internal error: function dump failed."); } // pushes dumped string on 'L' luaL_pushresult( &B); // ... f b // if not pushed, no need to pop if( needToPush) { lua_remove( L, -2); // ... b } // transfer the bytecode, then the upvalues, to create a similar closure { char const* name = NULL; #if LOG_FUNC_INFO // "To get information about a function you push it onto the // stack and start the what string with the character '>'." // { lua_Debug ar; lua_pushvalue( L, i); // ... b f // fills 'name' 'namewhat' and 'linedefined', pops function lua_getinfo( L, ">nS", &ar); // ... b name = ar.namewhat; fprintf( stderr, INDENT_BEGIN "FNAME: %s @ %d\n", i, s_indent, ar.short_src, ar.linedefined); // just gives NULL } #endif // LOG_FUNC_INFO { size_t sz; char const* s = lua_tolstring( L, -1, &sz); // ... b ASSERT_L( s && sz); STACK_GROW( L2, 2); // Note: Line numbers seem to be taken precisely from the // original function. 'name' is not used since the chunk // is precompiled (it seems...). // // TBD: Can we get the function's original name through, as well? // if( luaL_loadbuffer( L2, s, sz, name) != 0) // ... {cache} ... p function { // chunk is precompiled so only LUA_ERRMEM can happen // "Otherwise, it pushes an error message" // STACK_GROW( L, 1); luaL_error( L, "%s: %s", upName_, lua_tostring( L2, -1)); } // remove the dumped string lua_pop( L, 1); // ... // now set the cache as soon as we can. // this is necessary if one of the function's upvalues references it indirectly // we need to find it in the cache even if it isn't fully transfered yet lua_insert( L2, -2); // ... {cache} ... function p lua_pushvalue( L2, -2); // ... {cache} ... function p function // cache[p] = function lua_rawset( L2, L2_cache_i); // ... {cache} ... function } STACK_MID( L, 0); /* push over any upvalues; references to this function will come from * cache so we don't end up in eternal loop. * Lua5.2 and Lua5.3: one of the upvalues is _ENV, which we don't want to copy! * instead, the function shall have LUA_RIDX_GLOBALS taken in the destination state! */ { char const* upname; #if LUA_VERSION_NUM >= 502 // Starting with Lua 5.2, each Lua function gets its environment as one of its upvalues (named LUA_ENV, aka "_ENV" by default) // Generally this is LUA_RIDX_GLOBALS, which we don't want to copy from the source to the destination state... // -> if we encounter an upvalue equal to the global table in the source, bind it to the destination's global table lua_pushglobaltable( L); // ... _G #endif // LUA_VERSION_NUM for( n = 0; (upname = lua_getupvalue( L, i, 1 + n)) != NULL; ++ n) { // ... _G up[n] DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "UPNAME[%d]: %s -> " INDENT_END, n, upname)); #if LUA_VERSION_NUM >= 502 if( lua_rawequal( L, -1, -2)) // is the upvalue equal to the global table? { DEBUGSPEW_CODE( fprintf( stderr, "pushing destination global scope\n")); lua_pushglobaltable( L2); // ... {cache} ... function } else #endif // LUA_VERSION_NUM { DEBUGSPEW_CODE( fprintf( stderr, "copying value\n")); if( !inter_copy_one( U, L2, L2_cache_i, L, lua_gettop( L), VT_NORMAL, mode_, upname)) // ... {cache} ... function { luaL_error( L, "Cannot copy upvalue type '%s'", luaL_typename( L, -1)); } } lua_pop( L, 1); // ... _G } #if LUA_VERSION_NUM >= 502 lua_pop( L, 1); // ... #endif // LUA_VERSION_NUM } // L2: function + 'n' upvalues (>=0) STACK_MID( L, 0); // Set upvalues (originally set to 'nil' by 'lua_load') { int func_index = lua_gettop( L2) - n; for( ; n > 0; -- n) { char const* rc = lua_setupvalue( L2, func_index, n); // ... {cache} ... function // // "assigns the value at the top of the stack to the upvalue and returns its name. // It also pops the value from the stack." ASSERT_L( rc); // not having enough slots? } // once all upvalues have been set we are left // with the function at the top of the stack // ... {cache} ... function } } STACK_END( L, 0); } /* * Check if we've already copied the same function from 'L', and reuse the old * copy. * * Always pushes a function to 'L2'. */ static void copy_cached_func( Universe* U, lua_State* L2, uint_t L2_cache_i, lua_State* L, uint_t i, LookupMode mode_, char const* upName_) { FuncSubType funcSubType; /*lua_CFunction cfunc =*/ luaG_tocfunction( L, i, &funcSubType); // NULL for LuaJIT-fast && bytecode functions if( funcSubType == FST_Bytecode) { void* const aspointer = (void*)lua_topointer( L, i); // TBD: Merge this and same code for tables ASSERT_L( L2_cache_i != 0); STACK_GROW( L2, 2); // L2_cache[id_str]= function // STACK_CHECK( L2, 0); // We don't need to use the from state ('L') in ID since the life span // is only for the duration of a copy (both states are locked). // // push a light userdata uniquely representing the function lua_pushlightuserdata( L2, aspointer); // ... {cache} ... p //fprintf( stderr, "<< ID: %s >>\n", lua_tostring( L2, -1)); lua_pushvalue( L2, -1); // ... {cache} ... p p lua_rawget( L2, L2_cache_i); // ... {cache} ... p function|nil|true if( lua_isnil( L2, -1)) // function is unknown { lua_pop( L2, 1); // ... {cache} ... p // Set to 'true' for the duration of creation; need to find self-references // via upvalues // // pushes a copy of the func, stores a reference in the cache copy_func( U, L2, L2_cache_i, L, i, mode_, upName_); // ... {cache} ... function } else // found function in the cache { lua_remove( L2, -2); // ... {cache} ... function } STACK_END( L2, 1); ASSERT_L( lua_isfunction( L2, -1)); } else // function is native/LuaJIT: no need to cache { lookup_native_func( L2, L, i, mode_, upName_); // ... {cache} ... function // if the function was in fact a lookup sentinel, we can either get a function or a table here ASSERT_L( lua_isfunction( L2, -1) || lua_istable( L2, -1)); } } static bool_t push_cached_metatable( Universe* U, lua_State* L2, uint_t L2_cache_i, lua_State* L, uint_t i, enum eLookupMode mode_, char const* upName_) { STACK_CHECK( L, 0); if( lua_getmetatable( L, i)) // ... mt { lua_Integer const mt_id = get_mt_id( U, L, -1); // Unique id for the metatable STACK_CHECK( L2, 0); STACK_GROW( L2, 4); // do we already know this metatable? push_registry_subtable( L2, REG_MTID); // _R[REG_MTID] lua_pushinteger( L2, mt_id); // _R[REG_MTID] id lua_rawget( L2, -2); // _R[REG_MTID] mt? STACK_MID( L2, 2); if( lua_isnil( L2, -1)) { // L2 did not know the metatable lua_pop( L2, 1); // _R[REG_MTID] if( inter_copy_one( U, L2, L2_cache_i, L, lua_gettop( L), VT_METATABLE, mode_, upName_)) // _R[REG_MTID] mt { STACK_MID( L2, 2); // mt_id -> metatable lua_pushinteger( L2, mt_id); // _R[REG_MTID] mt id lua_pushvalue( L2, -2); // _R[REG_MTID] mt id mt lua_rawset( L2, -4); // _R[REG_MTID] mt // metatable -> mt_id lua_pushvalue( L2, -1); // _R[REG_MTID] mt mt lua_pushinteger( L2, mt_id); // _R[REG_MTID] mt mt id lua_rawset( L2, -4); // _R[REG_MTID] mt } else { (void) luaL_error( L, "Error copying a metatable"); } STACK_MID( L2, 2); } lua_remove( L2, -2); // mt lua_pop( L, 1); // ... STACK_END( L2, 1); STACK_MID( L, 0); return TRUE; } STACK_END( L, 0); return FALSE; } static void inter_copy_keyvaluepair( Universe* U, lua_State* L2, uint_t L2_cache_i, lua_State* L, enum e_vt vt, LookupMode mode_, char const* upName_) { uint_t val_i = lua_gettop( L); uint_t key_i = val_i - 1; // Only basic key types are copied over; others ignored if( inter_copy_one( U, L2, 0 /*key*/, L, key_i, VT_KEY, mode_, upName_)) { char* valPath = (char*) upName_; if( U->verboseErrors) { // for debug purposes, let's try to build a useful name if( lua_type( L, key_i) == LUA_TSTRING) { char const* key = lua_tostring( L, key_i); size_t const keyRawLen = lua_rawlen( L, key_i); size_t const bufLen = strlen( upName_) + keyRawLen + 2; valPath = (char*) alloca( bufLen); sprintf( valPath, "%s.%*s", upName_, (int) keyRawLen, key); key = NULL; } #if defined LUA_LNUM || LUA_VERSION_NUM >= 503 else if( lua_isinteger( L, key_i)) { lua_Integer key = lua_tointeger( L, key_i); valPath = (char*) alloca( strlen( upName_) + 32 + 3); sprintf( valPath, "%s[" LUA_INTEGER_FMT "]", upName_, key); } #endif // defined LUA_LNUM || LUA_VERSION_NUM >= 503 else if( lua_type( L, key_i) == LUA_TNUMBER) { lua_Number key = lua_tonumber( L, key_i); valPath = (char*) alloca( strlen( upName_) + 32 + 3); sprintf( valPath, "%s[" LUA_NUMBER_FMT "]", upName_, key); } else if( lua_type( L, key_i) == LUA_TLIGHTUSERDATA) { void* key = lua_touserdata( L, key_i); valPath = (char*) alloca( strlen( upName_) + 16 + 5); sprintf( valPath, "%s[U:%p]", upName_, key); } else if( lua_type( L, key_i) == LUA_TBOOLEAN) { int key = lua_toboolean( L, key_i); valPath = (char*) alloca( strlen( upName_) + 8); sprintf( valPath, "%s[%s]", upName_, key ? "true" : "false"); } } /* * Contents of metatables are copied with cache checking; * important to detect loops. */ if( inter_copy_one( U, L2, L2_cache_i, L, val_i, VT_NORMAL, mode_, valPath)) { ASSERT_L( lua_istable( L2, -3)); lua_rawset( L2, -3); // add to table (pops key & val) } else { luaL_error( L, "Unable to copy %s entry '%s' because of value is of type '%s'", (vt == VT_NORMAL) ? "table" : "metatable", valPath, luaL_typename( L, val_i)); } } } /* * The clone cache is a weak valued table listing all clones, indexed by their userdatapointer * fnv164 of string "CLONABLES_CACHE_KEY" generated at https://www.pelock.com/products/hash-calculator */ static DECLARE_CONST_UNIQUE_KEY( CLONABLES_CACHE_KEY, 0xD04EE018B3DEE8F5); static bool_t copyclone( Universe* U, lua_State* L2, uint_t L2_cache_i, lua_State* L, uint_t i, LookupMode mode_, char const* upName_) { void* const source = lua_touserdata( L, i); STACK_CHECK( L, 0); STACK_CHECK( L2, 0); // Check if the source was already cloned during this copy lua_pushlightuserdata( L2, source); // ... source lua_rawget( L2, L2_cache_i); // ... clone? if ( !lua_isnil( L2, -1)) { STACK_MID( L2, 1); return TRUE; } else { lua_pop( L2, 1); // ... } STACK_MID( L2, 0); // no metatable? -> not clonable if( !lua_getmetatable( L, i)) // ... mt? { STACK_MID( L, 0); return FALSE; } // no __lanesclone? -> not clonable lua_getfield( L, -1, "__lanesclone"); // ... mt __lanesclone? if( lua_isnil( L, -1)) { lua_pop( L, 2); // ... STACK_MID( L, 0); return FALSE; } { int const mt = lua_absindex( L, -2); size_t userdata_size = 0; void* clone = NULL; lua_pushvalue( L, -1); // ... mt __lanesclone __lanesclone // call the cloning function with 1 argument, should return the number of bytes to allocate for the clone lua_pushlightuserdata( L, source); // ... mt __lanesclone __lanesclone source lua_call( L, 1, 1); // ... mt __lanesclone size STACK_MID( L, 3); userdata_size = (size_t) lua_tointeger( L, -1); // ... mt __lanesclone size lua_pop( L, 1); // ... mt __lanesclone // we need to copy over the uservalues of the userdata as well { // extract all the uservalues, but don't transfer them yet int uvi = 0; while( lua_getiuservalue( L, i, uvi + 1) != LUA_TNONE) // ... mt __lanesclone [uv]+ nil { ++ uvi; } // when lua_getiuservalue() returned LUA_TNONE, it pushed a nil. pop it now lua_pop( L, 1); // ... mt __lanesclone [uv]+ // create the clone userdata with the required number of uservalue slots clone = lua_newuserdatauv( L2, userdata_size, uvi); // ... u // copy the metatable in the target state, and give it to the clone we put there if( inter_copy_one( U, L2, L2_cache_i, L, mt, VT_NORMAL, mode_, upName_)) // ... u mt|sentinel { if( eLM_ToKeeper == mode_) // ... u sentinel { ASSERT_L( lua_tocfunction( L2, -1) == table_lookup_sentinel); // we want to create a new closure with a 'clone sentinel' function, where the upvalues are the userdata and the metatable fqn lua_getupvalue( L2, -1, 1); // ... u sentinel fqn lua_remove( L2, -2); // ... u fqn lua_insert( L2, -2); // ... fqn u lua_pushcclosure( L2, userdata_clone_sentinel, 2); // ... userdata_clone_sentinel } else // from keeper or direct // ... u mt { ASSERT_L( lua_istable( L2, -1)); lua_setmetatable( L2, -2); // ... u } STACK_MID( L2, 1); } else { (void) luaL_error( L, "Error copying a metatable"); } // first, add the entry in the cache (at this point it is either the actual userdata or the keeper sentinel lua_pushlightuserdata( L2, source); // ... u source lua_pushvalue( L2, -2); // ... u source u lua_rawset( L2, L2_cache_i); // ... u // make sure we have the userdata now if( eLM_ToKeeper == mode_) // ... userdata_clone_sentinel { lua_getupvalue( L2, -1, 2); // ... userdata_clone_sentinel u } // assign uservalues while( uvi > 0) { inter_copy_one( U, L2, L2_cache_i, L, lua_absindex( L, -1), VT_NORMAL, mode_, upName_); // ... u uv lua_pop( L, 1); // ... mt __lanesclone [uv]* // this pops the value from the stack lua_setiuservalue( L2, -2, uvi); // ... u -- uvi; } // when we are done, all uservalues are popped from the source stack, and we want only the single transferred value in the destination if( eLM_ToKeeper == mode_) // ... userdata_clone_sentinel u { lua_pop( L2, 1); // ... userdata_clone_sentinel } STACK_MID( L2, 1); STACK_MID( L, 2); // call cloning function in source state to perform the actual memory cloning lua_pushlightuserdata( L, clone); // ... mt __lanesclone clone lua_pushlightuserdata( L, source); // ... mt __lanesclone clone source lua_call( L, 2, 0); // ... mt STACK_MID( L, 1); } } STACK_END( L2, 1); lua_pop( L, 1); // ... STACK_END( L, 0); return TRUE; } static bool_t inter_copy_userdata( Universe* U, lua_State* L2, uint_t L2_cache_i, lua_State* L, uint_t i, enum e_vt vt, LookupMode mode_, char const* upName_) { STACK_CHECK( L, 0); STACK_CHECK( L2, 0); if( vt == VT_KEY) { return FALSE; } // try clonable userdata first if( copyclone( U, L2, L2_cache_i, L, i, mode_, upName_)) { STACK_MID( L, 0); STACK_MID( L2, 1); return TRUE; } STACK_MID( L, 0); STACK_MID( L2, 0); // Allow only deep userdata entities to be copied across DEBUGSPEW_CODE( fprintf( stderr, "USERDATA\n")); if( copydeep( U, L2, L2_cache_i, L, i, mode_, upName_)) { STACK_MID( L, 0); STACK_MID( L2, 1); return TRUE; } STACK_MID( L, 0); STACK_MID( L2, 0); // Not a deep or clonable full userdata if( U->demoteFullUserdata) // attempt demotion to light userdata { void* lud = lua_touserdata( L, i); lua_pushlightuserdata( L2, lud); } else // raise an error { (void) luaL_error( L, "can't copy non-deep full userdata across lanes"); } STACK_END( L2, 1); STACK_END( L, 0); return TRUE; } static bool_t inter_copy_function( Universe* U, lua_State* L2, uint_t L2_cache_i, lua_State* L, uint_t i, enum e_vt vt, LookupMode mode_, char const* upName_) { if( vt == VT_KEY) { return FALSE; } STACK_CHECK( L, 0); STACK_CHECK( L2, 0); DEBUGSPEW_CODE( fprintf( stderr, "FUNCTION %s\n", upName_)); if( lua_tocfunction( L, i) == userdata_clone_sentinel) // we are actually copying a clonable full userdata from a keeper { // clone the full userdata again size_t userdata_size = 0; void* source; void* clone; // let's see if we already restored this userdata lua_getupvalue( L, i, 2); // ... u source = lua_touserdata( L, -1); lua_pushlightuserdata( L2, source); // ... source lua_rawget( L2, L2_cache_i); // ... u? if( !lua_isnil( L2, -1)) { lua_pop( L, 1); // ... STACK_MID( L, 0); STACK_MID( L2, 1); return TRUE; } lua_pop( L2, 1); // ... // this function has 2 upvalues: the fqn of its metatable, and the userdata itself lookup_table( L2, L, i, mode_, upName_); // ... mt // __lanesclone should always exist because we wouldn't be restoring data from a userdata_clone_sentinel closure to begin with lua_getfield( L2, -1, "__lanesclone"); // ... mt __lanesclone lua_pushvalue( L2, -1); // ... mt __lanesclone __lanesclone // 'i' slot is the closure, but from now on it is the actual userdata i = lua_gettop( L); source = lua_touserdata( L, -1); // call the cloning function with 1 argument, should return the number of bytes to allocate for the clone lua_pushlightuserdata( L2, source); // ... mt __lanesclone __lanesclone source lua_call( L2, 1, 1); // ... mt __lanesclone size userdata_size = (size_t) lua_tointeger( L2, -1); // ... mt __lanesclone size lua_pop( L2, 1); // ... mt __lanesclone { // extract uservalues (don't transfer them yet) int uvi = 0; while( lua_getiuservalue( L, i, uvi + 1) != LUA_TNONE) // ... u uv { ++ uvi; } // when lua_getiuservalue() returned LUA_TNONE, it pushed a nil. pop it now lua_pop( L, 1); // ... u [uv]* STACK_MID( L, uvi + 1); // create the clone userdata with the required number of uservalue slots clone = lua_newuserdatauv( L2, userdata_size, uvi); // ... mt __lanesclone u // add it in the cache lua_pushlightuserdata( L2, source); // ... mt __lanesclone u source lua_pushvalue( L2, -2); // ... mt __lanesclone u source u lua_rawset( L2, L2_cache_i); // ... mt __lanesclone u // set metatable lua_pushvalue( L2, -3); // ... mt __lanesclone u mt lua_setmetatable( L2, -2); // ... mt __lanesclone u // transfer and assign uservalues while( uvi > 0) { inter_copy_one( U, L2, L2_cache_i, L, lua_absindex( L, -1), vt, mode_, upName_); // ... mt __lanesclone u uv lua_pop( L, 1); // ... u [uv]* // this pops the value from the stack lua_setiuservalue( L2, -2, uvi); // ... mt __lanesclone u -- uvi; } // when we are done, all uservalues are popped from the stack lua_pop( L, 1); // ... STACK_MID( L, 0); STACK_MID( L2, 3); // ... mt __lanesclone u } // perform the custom cloning part lua_replace( L2, -3); // ... u __lanesclone lua_pushlightuserdata( L2, clone); // ... u __lanesclone clone lua_pushlightuserdata( L2, source); // ... u __lanesclone clone source lua_call( L2, 2, 0); // ... u } else { DEBUGSPEW_CODE( fprintf( stderr, "FUNCTION %s\n", upName_)); DEBUGSPEW_CODE( ++ U->debugspew_indent_depth); STACK_CHECK( L2, 0); copy_cached_func( U, L2, L2_cache_i, L, i, mode_, upName_); STACK_END( L2, 1); DEBUGSPEW_CODE( -- U->debugspew_indent_depth); } STACK_END( L2, 1); STACK_END( L, 0); return TRUE; } static bool_t inter_copy_table( Universe* U, lua_State* L2, uint_t L2_cache_i, lua_State* L, uint_t i, enum e_vt vt, LookupMode mode_, char const* upName_) { if( vt == VT_KEY) { return FALSE; } STACK_CHECK( L, 0); STACK_CHECK( L2, 0); DEBUGSPEW_CODE( fprintf( stderr, "TABLE %s\n", upName_)); /* * First, let's try to see if this table is special (aka is it some table that we registered in our lookup databases during module registration?) * Note that this table CAN be a module table, but we just didn't register it, in which case we'll send it through the table cloning mechanism */ if( lookup_table( L2, L, i, mode_, upName_)) { ASSERT_L( lua_istable( L2, -1) || (lua_tocfunction( L2, -1) == table_lookup_sentinel)); // from lookup datables // can also be table_lookup_sentinel if this is a table we know return TRUE; } /* Check if we've already copied the same table from 'L' (during this transmission), and * reuse the old copy. This allows table upvalues shared by multiple * local functions to point to the same table, also in the target. * Also, this takes care of cyclic tables and multiple references * to the same subtable. * * Note: Even metatables need to go through this test; to detect * loops such as those in required module tables (getmetatable(lanes).lanes == lanes) */ if( push_cached_table( L2, L2_cache_i, L, i)) { ASSERT_L( lua_istable( L2, -1)); // from cache return TRUE; } ASSERT_L( lua_istable( L2, -1)); STACK_GROW( L, 2); STACK_GROW( L2, 2); lua_pushnil( L); // start iteration while( lua_next( L, i)) { // need a function to prevent overflowing the stack with verboseErrors-induced alloca() inter_copy_keyvaluepair( U, L2, L2_cache_i, L, vt, mode_, upName_); lua_pop( L, 1); // pop value (next round) } STACK_MID( L, 0); STACK_MID( L2, 1); // Metatables are expected to be immutable, and copied only once. if( push_cached_metatable( U, L2, L2_cache_i, L, i, mode_, upName_)) // ... t mt? { lua_setmetatable( L2, -2); // ... t } STACK_END( L2, 1); STACK_END( L, 0); return TRUE; } /* * Copies a value from 'L' state (at index 'i') to 'L2' state. Does not remove * the original value. * * NOTE: Both the states must be solely in the current OS thread's possession. * * 'i' is an absolute index (no -1, ...) * * Returns TRUE if value was pushed, FALSE if its type is non-supported. */ bool_t inter_copy_one( Universe* U, lua_State* L2, uint_t L2_cache_i, lua_State* L, uint_t i, enum e_vt vt, LookupMode mode_, char const* upName_) { bool_t ret = TRUE; int val_type = lua_type( L, i); static int const pod_mask = (1 << LUA_TNIL) | (1 << LUA_TBOOLEAN) | (1 << LUA_TLIGHTUSERDATA) | (1 << LUA_TNUMBER) | (1 << LUA_TSTRING); STACK_GROW( L2, 1); STACK_CHECK( L, 0); // L // L2 STACK_CHECK( L2, 0); // L // L2 DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "inter_copy_one()\n" INDENT_END)); DEBUGSPEW_CODE( ++ U->debugspew_indent_depth); DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "%s %s: " INDENT_END, lua_type_names[val_type], vt_names[vt])); // Non-POD can be skipped if its metatable contains { __lanesignore = true } if( ((1 << val_type) & pod_mask) == 0) { if( lua_getmetatable( L, i)) // ... mt { lua_getfield( L, -1, "__lanesignore"); // ... mt ignore? if( lua_isboolean( L, -1) && lua_toboolean( L, -1)) { DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "__lanesignore -> LUA_TNIL\n" INDENT_END)); val_type = LUA_TNIL; } lua_pop( L, 2); // ... } } STACK_MID( L, 0); /* Lets push nil to L2 if the object should be ignored */ switch( val_type) { /* Basic types allowed both as values, and as table keys */ case LUA_TBOOLEAN: { bool_t v = lua_toboolean( L, i); DEBUGSPEW_CODE( fprintf( stderr, "%s\n", v ? "true" : "false")); lua_pushboolean( L2, v); } break; case LUA_TNUMBER: /* LNUM patch support (keeping integer accuracy) */ #if defined LUA_LNUM || LUA_VERSION_NUM >= 503 if( lua_isinteger( L, i)) { lua_Integer v = lua_tointeger( L, i); DEBUGSPEW_CODE( fprintf( stderr, LUA_INTEGER_FMT "\n", v)); lua_pushinteger( L2, v); break; } else #endif // defined LUA_LNUM || LUA_VERSION_NUM >= 503 { lua_Number v = lua_tonumber( L, i); DEBUGSPEW_CODE( fprintf( stderr, LUA_NUMBER_FMT "\n", v)); lua_pushnumber( L2, v); } break; case LUA_TSTRING: { size_t len; char const* s = lua_tolstring( L, i, &len); DEBUGSPEW_CODE( fprintf( stderr, "'%s'\n", s)); lua_pushlstring( L2, s, len); } break; case LUA_TLIGHTUSERDATA: { void* p = lua_touserdata( L, i); DEBUGSPEW_CODE( fprintf( stderr, "%p\n", p)); lua_pushlightuserdata( L2, p); } break; /* The following types are not allowed as table keys */ case LUA_TUSERDATA: ret = inter_copy_userdata( U, L2, L2_cache_i, L, i, vt, mode_, upName_); break; case LUA_TNIL: if( vt == VT_KEY) { ret = FALSE; break; } lua_pushnil( L2); break; case LUA_TFUNCTION: ret = inter_copy_function( U, L2, L2_cache_i, L, i, vt, mode_, upName_); break; case LUA_TTABLE: ret = inter_copy_table( U, L2, L2_cache_i, L, i, vt, mode_, upName_); break; /* The following types cannot be copied */ case 10: // LuaJIT CDATA case LUA_TTHREAD: ret = FALSE; break; } DEBUGSPEW_CODE( -- U->debugspew_indent_depth); STACK_END( L2, ret ? 1 : 0); STACK_END( L, 0); return ret; } /* * Akin to 'lua_xmove' but copies values between _any_ Lua states. * * NOTE: Both the states must be solely in the current OS thread's posession. * * Note: Parameters are in this order ('L' = from first) to be same as 'lua_xmove'. */ int luaG_inter_copy( Universe* U, lua_State* L, lua_State* L2, uint_t n, LookupMode mode_) { uint_t top_L = lua_gettop( L); // ... {}n uint_t top_L2 = lua_gettop( L2); // ... uint_t i, j; char tmpBuf[16]; char const* pBuf = U->verboseErrors ? tmpBuf : "?"; bool_t copyok = TRUE; DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "luaG_inter_copy()\n" INDENT_END)); DEBUGSPEW_CODE( ++ U->debugspew_indent_depth); if( n > top_L) { // requesting to copy more than is available? DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "nothing to copy()\n" INDENT_END)); DEBUGSPEW_CODE( -- U->debugspew_indent_depth); return -1; } STACK_CHECK( L2, 0); STACK_GROW( L2, n + 1); /* * Make a cache table for the duration of this copy. Collects tables and * function entries, avoiding the same entries to be passed on as multiple * copies. ESSENTIAL i.e. for handling upvalue tables in the right manner! */ lua_newtable( L2); // ... cache STACK_CHECK( L, 0); for( i = top_L - n + 1, j = 1; i <= top_L; ++ i, ++ j) { if( U->verboseErrors) { sprintf( tmpBuf, "arg_%d", j); } copyok = inter_copy_one( U, L2, top_L2 + 1, L, i, VT_NORMAL, mode_, pBuf); // ... cache {}n if( !copyok) { break; } } STACK_END( L, 0); DEBUGSPEW_CODE( -- U->debugspew_indent_depth); if( copyok) { STACK_MID( L2, n + 1); // Remove the cache table. Persistent caching would cause i.e. multiple // messages passed in the same table to use the same table also in receiving end. lua_remove( L2, top_L2 + 1); return 0; } // error -> pop everything from the target state stack lua_settop( L2, top_L2); STACK_END( L2, 0); return -2; } int luaG_inter_move( Universe* U, lua_State* L, lua_State* L2, uint_t n, LookupMode mode_) { int ret = luaG_inter_copy( U, L, L2, n, mode_); lua_pop( L, (int) n); return ret; } int luaG_inter_copy_package( Universe* U, lua_State* L, lua_State* L2, int package_idx_, LookupMode mode_) { DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "luaG_inter_copy_package()\n" INDENT_END)); DEBUGSPEW_CODE( ++ U->debugspew_indent_depth); // package STACK_CHECK( L, 0); STACK_CHECK( L2, 0); package_idx_ = lua_absindex( L, package_idx_); if( lua_type( L, package_idx_) != LUA_TTABLE) { lua_pushfstring( L, "expected package as table, got %s", luaL_typename( L, package_idx_)); STACK_MID( L, 1); // raise the error when copying from lane to lane, else just leave it on the stack to be raised later return ( mode_ == eLM_LaneBody) ? lua_error( L) : 1; } lua_getglobal( L2, "package"); if( !lua_isnil( L2, -1)) // package library not loaded: do nothing { int i; // package.loaders is renamed package.searchers in Lua 5.2 // but don't copy it anyway, as the function names change depending on the slot index! // users should provide an on_state_create function to setup custom loaders instead // don't copy package.preload in keeper states (they don't know how to translate functions) char const* entries[] = { "path", "cpath", (mode_ == eLM_LaneBody) ? "preload" : NULL/*, (LUA_VERSION_NUM == 501) ? "loaders" : "searchers"*/, NULL}; for( i = 0; entries[i]; ++ i) { DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "package.%s\n" INDENT_END, entries[i])); lua_getfield( L, package_idx_, entries[i]); if( lua_isnil( L, -1)) { lua_pop( L, 1); } else { DEBUGSPEW_CODE( ++ U->debugspew_indent_depth); luaG_inter_move( U, L, L2, 1, mode_); // moves the entry to L2 DEBUGSPEW_CODE( -- U->debugspew_indent_depth); lua_setfield( L2, -2, entries[i]); // set package[entries[i]] } } } else { DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "'package' not loaded, nothing to do\n" INDENT_END)); } lua_pop( L2, 1); STACK_END( L2, 0); STACK_END( L, 0); DEBUGSPEW_CODE( -- U->debugspew_indent_depth); return 0; }