/* ** $Id: lauxlib.c $ ** Auxiliary functions for building Lua libraries ** See Copyright Notice in lua.h */ #define lauxlib_c #define LUA_LIB #include "lprefix.h" #include #include #include #include #include /* ** This file uses only the official API of Lua. ** Any function declared here could be written as an application function. */ #include "lua.h" #include "lauxlib.h" #include "llimits.h" /* ** {====================================================== ** Traceback ** ======================================================= */ #define LEVELS1 10 /* size of the first part of the stack */ #define LEVELS2 11 /* size of the second part of the stack */ /* ** Search for 'objidx' in table at index -1. ('objidx' must be an ** absolute index.) Return 1 + string at top if it found a good name. */ static int findfield (lua_State *L, int objidx, int level) { if (level == 0 || !lua_istable(L, -1)) return 0; /* not found */ lua_pushnil(L); /* start 'next' loop */ while (lua_next(L, -2)) { /* for each pair in table */ if (lua_type(L, -2) == LUA_TSTRING) { /* ignore non-string keys */ if (lua_rawequal(L, objidx, -1)) { /* found object? */ lua_pop(L, 1); /* remove value (but keep name) */ return 1; } else if (findfield(L, objidx, level - 1)) { /* try recursively */ /* stack: lib_name, lib_table, field_name (top) */ lua_pushliteral(L, "."); /* place '.' between the two names */ lua_replace(L, -3); /* (in the slot occupied by table) */ lua_concat(L, 3); /* lib_name.field_name */ return 1; } } lua_pop(L, 1); /* remove value */ } return 0; /* not found */ } /* ** Search for a name for a function in all loaded modules */ static int pushglobalfuncname (lua_State *L, lua_Debug *ar) { int top = lua_gettop(L); lua_getinfo(L, "f", ar); /* push function */ lua_getfield(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE); luaL_checkstack(L, 6, "not enough stack"); /* slots for 'findfield' */ if (findfield(L, top + 1, 2)) { const char *name = lua_tostring(L, -1); if (strncmp(name, LUA_GNAME ".", 3) == 0) { /* name start with '_G.'? */ lua_pushstring(L, name + 3); /* push name without prefix */ lua_remove(L, -2); /* remove original name */ } lua_copy(L, -1, top + 1); /* copy name to proper place */ lua_settop(L, top + 1); /* remove table "loaded" and name copy */ return 1; } else { lua_settop(L, top); /* remove function and global table */ return 0; } } static void pushfuncname (lua_State *L, lua_Debug *ar) { if (pushglobalfuncname(L, ar)) { /* try first a global name */ lua_pushfstring(L, "function '%s'", lua_tostring(L, -1)); lua_remove(L, -2); /* remove name */ } else if (*ar->namewhat != '\0') /* is there a name from code? */ lua_pushfstring(L, "%s '%s'", ar->namewhat, ar->name); /* use it */ else if (*ar->what == 'm') /* main? */ lua_pushliteral(L, "main chunk"); else if (*ar->what != 'C') /* for Lua functions, use */ lua_pushfstring(L, "function <%s:%d>", ar->short_src, ar->linedefined); else /* nothing left... */ lua_pushliteral(L, "?"); } static int lastlevel (lua_State *L) { lua_Debug ar; int li = 1, le = 1; /* find an upper bound */ while (lua_getstack(L, le, &ar)) { li = le; le *= 2; } /* do a binary search */ while (li < le) { int m = (li + le)/2; if (lua_getstack(L, m, &ar)) li = m + 1; else le = m; } return le - 1; } LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1, const char *msg, int level) { luaL_Buffer b; lua_Debug ar; int last = lastlevel(L1); int limit2show = (last - level > LEVELS1 + LEVELS2) ? LEVELS1 : -1; luaL_buffinit(L, &b); if (msg) { luaL_addstring(&b, msg); luaL_addchar(&b, '\n'); } luaL_addstring(&b, "stack traceback:"); while (lua_getstack(L1, level++, &ar)) { if (limit2show-- == 0) { /* too many levels? */ int n = last - level - LEVELS2 + 1; /* number of levels to skip */ lua_pushfstring(L, "\n\t...\t(skipping %d levels)", n); luaL_addvalue(&b); /* add warning about skip */ level += n; /* and skip to last levels */ } else { lua_getinfo(L1, "Slnt", &ar); if (ar.currentline <= 0) lua_pushfstring(L, "\n\t%s: in ", ar.short_src); else lua_pushfstring(L, "\n\t%s:%d: in ", ar.short_src, ar.currentline); luaL_addvalue(&b); pushfuncname(L, &ar); luaL_addvalue(&b); if (ar.istailcall) luaL_addstring(&b, "\n\t(...tail calls...)"); } } luaL_pushresult(&b); } /* }====================================================== */ /* ** {====================================================== ** Error-report functions ** ======================================================= */ LUALIB_API int luaL_argerror (lua_State *L, int arg, const char *extramsg) { lua_Debug ar; if (!lua_getstack(L, 0, &ar)) /* no stack frame? */ return luaL_error(L, "bad argument #%d (%s)", arg, extramsg); lua_getinfo(L, "n", &ar); if (strcmp(ar.namewhat, "method") == 0) { arg--; /* do not count 'self' */ if (arg == 0) /* error is in the self argument itself? */ return luaL_error(L, "calling '%s' on bad self (%s)", ar.name, extramsg); } if (ar.name == NULL) ar.name = (pushglobalfuncname(L, &ar)) ? lua_tostring(L, -1) : "?"; return luaL_error(L, "bad argument #%d to '%s' (%s)", arg, ar.name, extramsg); } LUALIB_API int luaL_typeerror (lua_State *L, int arg, const char *tname) { const char *msg; const char *typearg; /* name for the type of the actual argument */ if (luaL_getmetafield(L, arg, "__name") == LUA_TSTRING) typearg = lua_tostring(L, -1); /* use the given type name */ else if (lua_type(L, arg) == LUA_TLIGHTUSERDATA) typearg = "light userdata"; /* special name for messages */ else typearg = luaL_typename(L, arg); /* standard name */ msg = lua_pushfstring(L, "%s expected, got %s", tname, typearg); return luaL_argerror(L, arg, msg); } static void tag_error (lua_State *L, int arg, int tag) { luaL_typeerror(L, arg, lua_typename(L, tag)); } /* ** The use of 'lua_pushfstring' ensures this function does not ** need reserved stack space when called. */ LUALIB_API void luaL_where (lua_State *L, int level) { lua_Debug ar; if (lua_getstack(L, level, &ar)) { /* check function at level */ lua_getinfo(L, "Sl", &ar); /* get info about it */ if (ar.currentline > 0) { /* is there info? */ lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline); return; } } lua_pushfstring(L, ""); /* else, no information available... */ } /* ** Again, the use of 'lua_pushvfstring' ensures this function does ** not need reserved stack space when called. (At worst, it generates ** a memory error instead of the given message.) */ LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) { va_list argp; va_start(argp, fmt); luaL_where(L, 1); lua_pushvfstring(L, fmt, argp); va_end(argp); lua_concat(L, 2); return lua_error(L); } LUALIB_API int luaL_fileresult (lua_State *L, int stat, const char *fname) { int en = errno; /* calls to Lua API may change this value */ if (stat) { lua_pushboolean(L, 1); return 1; } else { const char *msg; luaL_pushfail(L); msg = (en != 0) ? strerror(en) : "(no extra info)"; if (fname) lua_pushfstring(L, "%s: %s", fname, msg); else lua_pushstring(L, msg); lua_pushinteger(L, en); return 3; } } #if !defined(l_inspectstat) /* { */ #if defined(LUA_USE_POSIX) #include /* ** use appropriate macros to interpret 'pclose' return status */ #define l_inspectstat(stat,what) \ if (WIFEXITED(stat)) { stat = WEXITSTATUS(stat); } \ else if (WIFSIGNALED(stat)) { stat = WTERMSIG(stat); what = "signal"; } #else #define l_inspectstat(stat,what) /* no op */ #endif #endif /* } */ LUALIB_API int luaL_execresult (lua_State *L, int stat) { if (stat != 0 && errno != 0) /* error with an 'errno'? */ return luaL_fileresult(L, 0, NULL); else { const char *what = "exit"; /* type of termination */ l_inspectstat(stat, what); /* interpret result */ if (*what == 'e' && stat == 0) /* successful termination? */ lua_pushboolean(L, 1); else luaL_pushfail(L); lua_pushstring(L, what); lua_pushinteger(L, stat); return 3; /* return true/fail,what,code */ } } /* }====================================================== */ /* ** {====================================================== ** Userdata's metatable manipulation ** ======================================================= */ LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) { if (luaL_getmetatable(L, tname) != LUA_TNIL) /* name already in use? */ return 0; /* leave previous value on top, but return 0 */ lua_pop(L, 1); lua_createtable(L, 0, 2); /* create metatable */ lua_pushstring(L, tname); lua_setfield(L, -2, "__name"); /* metatable.__name = tname */ lua_pushvalue(L, -1); lua_setfield(L, LUA_REGISTRYINDEX, tname); /* registry.name = metatable */ return 1; } LUALIB_API void luaL_setmetatable (lua_State *L, const char *tname) { luaL_getmetatable(L, tname); lua_setmetatable(L, -2); } LUALIB_API void *luaL_testudata (lua_State *L, int ud, const char *tname) { void *p = lua_touserdata(L, ud); if (p != NULL) { /* value is a userdata? */ if (lua_getmetatable(L, ud)) { /* does it have a metatable? */ luaL_getmetatable(L, tname); /* get correct metatable */ if (!lua_rawequal(L, -1, -2)) /* not the same? */ p = NULL; /* value is a userdata with wrong metatable */ lua_pop(L, 2); /* remove both metatables */ return p; } } return NULL; /* value is not a userdata with a metatable */ } LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) { void *p = luaL_testudata(L, ud, tname); luaL_argexpected(L, p != NULL, ud, tname); return p; } /* }====================================================== */ /* ** {====================================================== ** Argument check functions ** ======================================================= */ LUALIB_API int luaL_checkoption (lua_State *L, int arg, const char *def, const char *const lst[]) { const char *name = (def) ? luaL_optstring(L, arg, def) : luaL_checkstring(L, arg); int i; for (i=0; lst[i]; i++) if (strcmp(lst[i], name) == 0) return i; return luaL_argerror(L, arg, lua_pushfstring(L, "invalid option '%s'", name)); } /* ** Ensures the stack has at least 'space' extra slots, raising an error ** if it cannot fulfill the request. (The error handling needs a few ** extra slots to format the error message. In case of an error without ** this extra space, Lua will generate the same 'stack overflow' error, ** but without 'msg'.) */ LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) { if (l_unlikely(!lua_checkstack(L, space))) { if (msg) luaL_error(L, "stack overflow (%s)", msg); else luaL_error(L, "stack overflow"); } } LUALIB_API void luaL_checktype (lua_State *L, int arg, int t) { if (l_unlikely(lua_type(L, arg) != t)) tag_error(L, arg, t); } LUALIB_API void luaL_checkany (lua_State *L, int arg) { if (l_unlikely(lua_type(L, arg) == LUA_TNONE)) luaL_argerror(L, arg, "value expected"); } LUALIB_API const char *luaL_checklstring (lua_State *L, int arg, size_t *len) { const char *s = lua_tolstring(L, arg, len); if (l_unlikely(!s)) tag_error(L, arg, LUA_TSTRING); return s; } LUALIB_API const char *luaL_optlstring (lua_State *L, int arg, const char *def, size_t *len) { if (lua_isnoneornil(L, arg)) { if (len) *len = (def ? strlen(def) : 0); return def; } else return luaL_checklstring(L, arg, len); } LUALIB_API lua_Number luaL_checknumber (lua_State *L, int arg) { int isnum; lua_Number d = lua_tonumberx(L, arg, &isnum); if (l_unlikely(!isnum)) tag_error(L, arg, LUA_TNUMBER); return d; } LUALIB_API lua_Number luaL_optnumber (lua_State *L, int arg, lua_Number def) { return luaL_opt(L, luaL_checknumber, arg, def); } static void interror (lua_State *L, int arg) { if (lua_isnumber(L, arg)) luaL_argerror(L, arg, "number has no integer representation"); else tag_error(L, arg, LUA_TNUMBER); } LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int arg) { int isnum; lua_Integer d = lua_tointegerx(L, arg, &isnum); if (l_unlikely(!isnum)) { interror(L, arg); } return d; } LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int arg, lua_Integer def) { return luaL_opt(L, luaL_checkinteger, arg, def); } /* }====================================================== */ /* ** {====================================================== ** Generic Buffer manipulation ** ======================================================= */ /* userdata to box arbitrary data */ typedef struct UBox { void *box; size_t bsize; } UBox; /* Resize the buffer used by a box. Optimize for the common case of ** resizing to the old size. (For instance, __gc will resize the box ** to 0 even after it was closed. 'pushresult' may also resize it to a ** final size that is equal to the one set when the buffer was created.) */ static void *resizebox (lua_State *L, int idx, size_t newsize) { UBox *box = (UBox *)lua_touserdata(L, idx); if (box->bsize == newsize) /* not changing size? */ return box->box; /* keep the buffer */ else { void *ud; lua_Alloc allocf = lua_getallocf(L, &ud); void *temp = allocf(ud, box->box, box->bsize, newsize); if (l_unlikely(temp == NULL && newsize > 0)) { /* allocation error? */ lua_pushliteral(L, "not enough memory"); lua_error(L); /* raise a memory error */ } box->box = temp; box->bsize = newsize; return temp; } } static int boxgc (lua_State *L) { resizebox(L, 1, 0); return 0; } static const luaL_Reg boxmt[] = { /* box metamethods */ {"__gc", boxgc}, {"__close", boxgc}, {NULL, NULL} }; static void newbox (lua_State *L) { UBox *box = (UBox *)lua_newuserdatauv(L, sizeof(UBox), 0); box->box = NULL; box->bsize = 0; if (luaL_newmetatable(L, "_UBOX*")) /* creating metatable? */ luaL_setfuncs(L, boxmt, 0); /* set its metamethods */ lua_setmetatable(L, -2); } /* ** check whether buffer is using a userdata on the stack as a temporary ** buffer */ #define buffonstack(B) ((B)->b != (B)->init.b) /* ** Whenever buffer is accessed, slot 'idx' must either be a box (which ** cannot be NULL) or it is a placeholder for the buffer. */ #define checkbufferlevel(B,idx) \ lua_assert(buffonstack(B) ? lua_touserdata(B->L, idx) != NULL \ : lua_touserdata(B->L, idx) == (void*)B) /* ** Compute new size for buffer 'B', enough to accommodate extra 'sz' ** bytes plus one for a terminating zero. (The test for "not big enough" ** also gets the case when the computation of 'newsize' overflows.) */ static size_t newbuffsize (luaL_Buffer *B, size_t sz) { size_t newsize = (B->size / 2) * 3; /* buffer size * 1.5 */ if (l_unlikely(sz > MAX_SIZE - B->n - 1)) return cast_sizet(luaL_error(B->L, "resulting string too large")); if (newsize < B->n + sz + 1 || newsize > MAX_SIZE) { /* newsize was not big enough or too big */ newsize = B->n + sz + 1; } return newsize; } /* ** Returns a pointer to a free area with at least 'sz' bytes in buffer ** 'B'. 'boxidx' is the relative position in the stack where is the ** buffer's box or its placeholder. */ static char *prepbuffsize (luaL_Buffer *B, size_t sz, int boxidx) { checkbufferlevel(B, boxidx); if (B->size - B->n >= sz) /* enough space? */ return B->b + B->n; else { lua_State *L = B->L; char *newbuff; size_t newsize = newbuffsize(B, sz); /* create larger buffer */ if (buffonstack(B)) /* buffer already has a box? */ newbuff = (char *)resizebox(L, boxidx, newsize); /* resize it */ else { /* no box yet */ lua_remove(L, boxidx); /* remove placeholder */ newbox(L); /* create a new box */ lua_insert(L, boxidx); /* move box to its intended position */ lua_toclose(L, boxidx); newbuff = (char *)resizebox(L, boxidx, newsize); memcpy(newbuff, B->b, B->n * sizeof(char)); /* copy original content */ } B->b = newbuff; B->size = newsize; return newbuff + B->n; } } /* ** returns a pointer to a free area with at least 'sz' bytes */ LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) { return prepbuffsize(B, sz, -1); } LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) { if (l > 0) { /* avoid 'memcpy' when 's' can be NULL */ char *b = prepbuffsize(B, l, -1); memcpy(b, s, l * sizeof(char)); luaL_addsize(B, l); } } LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) { luaL_addlstring(B, s, strlen(s)); } LUALIB_API void luaL_pushresult (luaL_Buffer *B) { lua_State *L = B->L; checkbufferlevel(B, -1); if (!buffonstack(B)) /* using static buffer? */ lua_pushlstring(L, B->b, B->n); /* save result as regular string */ else { /* reuse buffer already allocated */ UBox *box = (UBox *)lua_touserdata(L, -1); void *ud; lua_Alloc allocf = lua_getallocf(L, &ud); /* function to free buffer */ size_t len = B->n; /* final string length */ char *s; resizebox(L, -1, len + 1); /* adjust box size to content size */ s = (char*)box->box; /* final buffer address */ s[len] = '\0'; /* add ending zero */ /* clear box, as 'lua_pushextlstring' will take control over buffer */ box->bsize = 0; box->box = NULL; lua_pushextlstring(L, s, len, allocf, ud); lua_closeslot(L, -2); /* close the box */ lua_gc(L, LUA_GCSTEP, len); } lua_remove(L, -2); /* remove box or placeholder from the stack */ } LUALIB_API void luaL_pushresultsize (luaL_Buffer *B, size_t sz) { luaL_addsize(B, sz); luaL_pushresult(B); } /* ** 'luaL_addvalue' is the only function in the Buffer system where the ** box (if existent) is not on the top of the stack. So, instead of ** calling 'luaL_addlstring', it replicates the code using -2 as the ** last argument to 'prepbuffsize', signaling that the box is (or will ** be) below the string being added to the buffer. (Box creation can ** trigger an emergency GC, so we should not remove the string from the ** stack before we have the space guaranteed.) */ LUALIB_API void luaL_addvalue (luaL_Buffer *B) { lua_State *L = B->L; size_t len; const char *s = lua_tolstring(L, -1, &len); char *b = prepbuffsize(B, len, -2); memcpy(b, s, len * sizeof(char)); luaL_addsize(B, len); lua_pop(L, 1); /* pop string */ } LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) { B->L = L; B->b = B->init.b; B->n = 0; B->size = LUAL_BUFFERSIZE; lua_pushlightuserdata(L, (void*)B); /* push placeholder */ } LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) { luaL_buffinit(L, B); return prepbuffsize(B, sz, -1); } /* }====================================================== */ /* ** {====================================================== ** Reference system ** ======================================================= */ /* ** The previously freed references form a linked list: t[1] is the index ** of a first free index, t[t[1]] is the index of the second element, ** etc. A zero signals the end of the list. */ LUALIB_API int luaL_ref (lua_State *L, int t) { int ref; if (lua_isnil(L, -1)) { lua_pop(L, 1); /* remove from stack */ return LUA_REFNIL; /* 'nil' has a unique fixed reference */ } t = lua_absindex(L, t); if (lua_rawgeti(L, t, 1) == LUA_TNUMBER) /* already initialized? */ ref = (int)lua_tointeger(L, -1); /* ref = t[1] */ else { /* first access */ lua_assert(!lua_toboolean(L, -1)); /* must be nil or false */ ref = 0; /* list is empty */ lua_pushinteger(L, 0); /* initialize as an empty list */ lua_rawseti(L, t, 1); /* ref = t[1] = 0 */ } lua_pop(L, 1); /* remove element from stack */ if (ref != 0) { /* any free element? */ lua_rawgeti(L, t, ref); /* remove it from list */ lua_rawseti(L, t, 1); /* (t[1] = t[ref]) */ } else /* no free elements */ ref = (int)lua_rawlen(L, t) + 1; /* get a new reference */ lua_rawseti(L, t, ref); return ref; } LUALIB_API void luaL_unref (lua_State *L, int t, int ref) { if (ref >= 0) { t = lua_absindex(L, t); lua_rawgeti(L, t, 1); lua_assert(lua_isinteger(L, -1)); lua_rawseti(L, t, ref); /* t[ref] = t[1] */ lua_pushinteger(L, ref); lua_rawseti(L, t, 1); /* t[1] = ref */ } } /* }====================================================== */ /* ** {====================================================== ** Load functions ** ======================================================= */ typedef struct LoadF { unsigned n; /* number of pre-read characters */ FILE *f; /* file being read */ char buff[BUFSIZ]; /* area for reading file */ } LoadF; static const char *getF (lua_State *L, void *ud, size_t *size) { LoadF *lf = (LoadF *)ud; (void)L; /* not used */ if (lf->n > 0) { /* are there pre-read characters to be read? */ *size = lf->n; /* return them (chars already in buffer) */ lf->n = 0; /* no more pre-read characters */ } else { /* read a block from file */ /* 'fread' can return > 0 *and* set the EOF flag. If next call to 'getF' called 'fread', it might still wait for user input. The next check avoids this problem. */ if (feof(lf->f)) return NULL; *size = fread(lf->buff, 1, sizeof(lf->buff), lf->f); /* read block */ } return lf->buff; } static int errfile (lua_State *L, const char *what, int fnameindex) { int err = errno; const char *filename = lua_tostring(L, fnameindex) + 1; if (err != 0) lua_pushfstring(L, "cannot %s %s: %s", what, filename, strerror(err)); else lua_pushfstring(L, "cannot %s %s", what, filename); lua_remove(L, fnameindex); return LUA_ERRFILE; } /* ** Skip an optional BOM at the start of a stream. If there is an ** incomplete BOM (the first character is correct but the rest is ** not), returns the first character anyway to force an error ** (as no chunk can start with 0xEF). */ static int skipBOM (FILE *f) { int c = getc(f); /* read first character */ if (c == 0xEF && getc(f) == 0xBB && getc(f) == 0xBF) /* correct BOM? */ return getc(f); /* ignore BOM and return next char */ else /* no (valid) BOM */ return c; /* return first character */ } /* ** reads the first character of file 'f' and skips an optional BOM mark ** in its beginning plus its first line if it starts with '#'. Returns ** true if it skipped the first line. In any case, '*cp' has the ** first "valid" character of the file (after the optional BOM and ** a first-line comment). */ static int skipcomment (FILE *f, int *cp) { int c = *cp = skipBOM(f); if (c == '#') { /* first line is a comment (Unix exec. file)? */ do { /* skip first line */ c = getc(f); } while (c != EOF && c != '\n'); *cp = getc(f); /* next character after comment, if present */ return 1; /* there was a comment */ } else return 0; /* no comment */ } LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename, const char *mode) { LoadF lf; int status, readstatus; int c; int fnameindex = lua_gettop(L) + 1; /* index of filename on the stack */ if (filename == NULL) { lua_pushliteral(L, "=stdin"); lf.f = stdin; } else { lua_pushfstring(L, "@%s", filename); errno = 0; lf.f = fopen(filename, "r"); if (lf.f == NULL) return errfile(L, "open", fnameindex); } lf.n = 0; if (skipcomment(lf.f, &c)) /* read initial portion */ lf.buff[lf.n++] = '\n'; /* add newline to correct line numbers */ if (c == LUA_SIGNATURE[0]) { /* binary file? */ lf.n = 0; /* remove possible newline */ if (filename) { /* "real" file? */ errno = 0; lf.f = freopen(filename, "rb", lf.f); /* reopen in binary mode */ if (lf.f == NULL) return errfile(L, "reopen", fnameindex); skipcomment(lf.f, &c); /* re-read initial portion */ } } if (c != EOF) lf.buff[lf.n++] = cast_char(c); /* 'c' is the first character */ status = lua_load(L, getF, &lf, lua_tostring(L, -1), mode); readstatus = ferror(lf.f); errno = 0; /* no useful error number until here */ if (filename) fclose(lf.f); /* close file (even in case of errors) */ if (readstatus) { lua_settop(L, fnameindex); /* ignore results from 'lua_load' */ return errfile(L, "read", fnameindex); } lua_remove(L, fnameindex); return status; } typedef struct LoadS { const char *s; size_t size; } LoadS; static const char *getS (lua_State *L, void *ud, size_t *size) { LoadS *ls = (LoadS *)ud; (void)L; /* not used */ if (ls->size == 0) return NULL; *size = ls->size; ls->size = 0; return ls->s; } LUALIB_API int luaL_loadbufferx (lua_State *L, const char *buff, size_t size, const char *name, const char *mode) { LoadS ls; ls.s = buff; ls.size = size; return lua_load(L, getS, &ls, name, mode); } LUALIB_API int luaL_loadstring (lua_State *L, const char *s) { return luaL_loadbuffer(L, s, strlen(s), s); } /* }====================================================== */ LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) { if (!lua_getmetatable(L, obj)) /* no metatable? */ return LUA_TNIL; else { int tt; lua_pushstring(L, event); tt = lua_rawget(L, -2); if (tt == LUA_TNIL) /* is metafield nil? */ lua_pop(L, 2); /* remove metatable and metafield */ else lua_remove(L, -2); /* remove only metatable */ return tt; /* return metafield type */ } } LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) { obj = lua_absindex(L, obj); if (luaL_getmetafield(L, obj, event) == LUA_TNIL) /* no metafield? */ return 0; lua_pushvalue(L, obj); lua_call(L, 1, 1); return 1; } LUALIB_API lua_Integer luaL_len (lua_State *L, int idx) { lua_Integer l; int isnum; lua_len(L, idx); l = lua_tointegerx(L, -1, &isnum); if (l_unlikely(!isnum)) luaL_error(L, "object length is not an integer"); lua_pop(L, 1); /* remove object */ return l; } LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) { idx = lua_absindex(L,idx); if (luaL_callmeta(L, idx, "__tostring")) { /* metafield? */ if (!lua_isstring(L, -1)) luaL_error(L, "'__tostring' must return a string"); } else { switch (lua_type(L, idx)) { case LUA_TNUMBER: { char buff[LUA_N2SBUFFSZ]; lua_numbertostrbuff(L, idx, buff); lua_pushstring(L, buff); break; } case LUA_TSTRING: lua_pushvalue(L, idx); break; case LUA_TBOOLEAN: lua_pushstring(L, (lua_toboolean(L, idx) ? "true" : "false")); break; case LUA_TNIL: lua_pushliteral(L, "nil"); break; default: { int tt = luaL_getmetafield(L, idx, "__name"); /* try name */ const char *kind = (tt == LUA_TSTRING) ? lua_tostring(L, -1) : luaL_typename(L, idx); lua_pushfstring(L, "%s: %p", kind, lua_topointer(L, idx)); if (tt != LUA_TNIL) lua_remove(L, -2); /* remove '__name' */ break; } } } return lua_tolstring(L, -1, len); } /* ** set functions from list 'l' into table at top - 'nup'; each ** function gets the 'nup' elements at the top as upvalues. ** Returns with only the table at the stack. */ LUALIB_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) { luaL_checkstack(L, nup, "too many upvalues"); for (; l->name != NULL; l++) { /* fill the table with given functions */ if (l->func == NULL) /* placeholder? */ lua_pushboolean(L, 0); else { int i; for (i = 0; i < nup; i++) /* copy upvalues to the top */ lua_pushvalue(L, -nup); lua_pushcclosure(L, l->func, nup); /* closure with those upvalues */ } lua_setfield(L, -(nup + 2), l->name); } lua_pop(L, nup); /* remove upvalues */ } /* ** ensure that stack[idx][fname] has a table and push that table ** into the stack */ LUALIB_API int luaL_getsubtable (lua_State *L, int idx, const char *fname) { if (lua_getfield(L, idx, fname) == LUA_TTABLE) return 1; /* table already there */ else { lua_pop(L, 1); /* remove previous result */ idx = lua_absindex(L, idx); lua_newtable(L); lua_pushvalue(L, -1); /* copy to be left at top */ lua_setfield(L, idx, fname); /* assign new table to field */ return 0; /* false, because did not find table there */ } } /* ** Stripped-down 'require': After checking "loaded" table, calls 'openf' ** to open a module, registers the result in 'package.loaded' table and, ** if 'glb' is true, also registers the result in the global table. ** Leaves resulting module on the top. */ LUALIB_API void luaL_requiref (lua_State *L, const char *modname, lua_CFunction openf, int glb) { luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE); lua_getfield(L, -1, modname); /* LOADED[modname] */ if (!lua_toboolean(L, -1)) { /* package not already loaded? */ lua_pop(L, 1); /* remove field */ lua_pushcfunction(L, openf); lua_pushstring(L, modname); /* argument to open function */ lua_call(L, 1, 1); /* call 'openf' to open module */ lua_pushvalue(L, -1); /* make copy of module (call result) */ lua_setfield(L, -3, modname); /* LOADED[modname] = module */ } lua_remove(L, -2); /* remove LOADED table */ if (glb) { lua_pushvalue(L, -1); /* copy of module */ lua_setglobal(L, modname); /* _G[modname] = module */ } } LUALIB_API void luaL_addgsub (luaL_Buffer *b, const char *s, const char *p, const char *r) { const char *wild; size_t l = strlen(p); while ((wild = strstr(s, p)) != NULL) { luaL_addlstring(b, s, ct_diff2sz(wild - s)); /* push prefix */ luaL_addstring(b, r); /* push replacement in place of pattern */ s = wild + l; /* continue after 'p' */ } luaL_addstring(b, s); /* push last suffix */ } LUALIB_API const char *luaL_gsub (lua_State *L, const char *s, const char *p, const char *r) { luaL_Buffer b; luaL_buffinit(L, &b); luaL_addgsub(&b, s, p, r); luaL_pushresult(&b); return lua_tostring(L, -1); } static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) { (void)ud; (void)osize; /* not used */ if (nsize == 0) { free(ptr); return NULL; } else return realloc(ptr, nsize); } /* ** Standard panic function just prints an error message. The test ** with 'lua_type' avoids possible memory errors in 'lua_tostring'. */ static int panic (lua_State *L) { const char *msg = (lua_type(L, -1) == LUA_TSTRING) ? lua_tostring(L, -1) : "error object is not a string"; lua_writestringerror("PANIC: unprotected error in call to Lua API (%s)\n", msg); return 0; /* return to Lua to abort */ } /* ** Warning functions: ** warnfoff: warning system is off ** warnfon: ready to start a new message ** warnfcont: previous message is to be continued */ static void warnfoff (void *ud, const char *message, int tocont); static void warnfon (void *ud, const char *message, int tocont); static void warnfcont (void *ud, const char *message, int tocont); /* ** Check whether message is a control message. If so, execute the ** control or ignore it if unknown. */ static int checkcontrol (lua_State *L, const char *message, int tocont) { if (tocont || *(message++) != '@') /* not a control message? */ return 0; else { if (strcmp(message, "off") == 0) lua_setwarnf(L, warnfoff, L); /* turn warnings off */ else if (strcmp(message, "on") == 0) lua_setwarnf(L, warnfon, L); /* turn warnings on */ return 1; /* it was a control message */ } } static void warnfoff (void *ud, const char *message, int tocont) { checkcontrol((lua_State *)ud, message, tocont); } /* ** Writes the message and handle 'tocont', finishing the message ** if needed and setting the next warn function. */ static void warnfcont (void *ud, const char *message, int tocont) { lua_State *L = (lua_State *)ud; lua_writestringerror("%s", message); /* write message */ if (tocont) /* not the last part? */ lua_setwarnf(L, warnfcont, L); /* to be continued */ else { /* last part */ lua_writestringerror("%s", "\n"); /* finish message with end-of-line */ lua_setwarnf(L, warnfon, L); /* next call is a new message */ } } static void warnfon (void *ud, const char *message, int tocont) { if (checkcontrol((lua_State *)ud, message, tocont)) /* control message? */ return; /* nothing else to be done */ lua_writestringerror("%s", "Lua warning: "); /* start a new warning */ warnfcont(ud, message, tocont); /* finish processing */ } /* ** A function to compute an unsigned int with some level of ** randomness. Rely on Address Space Layout Randomization (if present) ** and the current time. */ #if !defined(luai_makeseed) #include /* Size for the buffer, in bytes */ #define BUFSEEDB (sizeof(void*) + sizeof(time_t)) /* Size for the buffer in int's, rounded up */ #define BUFSEED ((BUFSEEDB + sizeof(int) - 1) / sizeof(int)) /* ** Copy the contents of variable 'v' into the buffer pointed by 'b'. ** (The '&b[0]' disguises 'b' to fix an absurd warning from clang.) */ #define addbuff(b,v) (memcpy(&b[0], &(v), sizeof(v)), b += sizeof(v)) static unsigned int luai_makeseed (void) { unsigned int buff[BUFSEED]; unsigned int res; unsigned int i; time_t t = time(NULL); char *b = (char*)buff; addbuff(b, b); /* local variable's address */ addbuff(b, t); /* time */ /* fill (rare but possible) remain of the buffer with zeros */ memset(b, 0, sizeof(buff) - BUFSEEDB); res = buff[0]; for (i = 1; i < BUFSEED; i++) res ^= (res >> 3) + (res << 7) + buff[i]; return res; } #endif LUALIB_API unsigned int luaL_makeseed (lua_State *L) { (void)L; /* unused */ return luai_makeseed(); } LUALIB_API lua_State *luaL_newstate (void) { lua_State *L = lua_newstate(l_alloc, NULL, luai_makeseed()); if (l_likely(L)) { lua_atpanic(L, &panic); lua_setwarnf(L, warnfoff, L); /* default is warnings off */ } return L; } LUALIB_API void luaL_checkversion_ (lua_State *L, lua_Number ver, size_t sz) { lua_Number v = lua_version(L); if (sz != LUAL_NUMSIZES) /* check numeric types */ luaL_error(L, "core and library have incompatible numeric types"); else if (v != ver) luaL_error(L, "version mismatch: app. needs %f, Lua core provides %f", (LUAI_UACNUMBER)ver, (LUAI_UACNUMBER)v); }