Lua TeamLua 5.3.0-rc348416b811 years agoHistory
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/*** $Id: ldblib.c,v 1.148 2015/01/02 12:52:22 roberto Exp $** Interface from Lua to its debug API** See Copyright Notice in lua.h*/ #define ldblib_c#define LUA_LIB #include "lprefix.h"  #include <stdio.h>#include <stdlib.h>#include <string.h> #include "lua.h" #include "lauxlib.h"#include "lualib.h"  /*** The hook table at registry[&HOOKKEY] maps threads to their current** hook function. (We only need the unique address of 'HOOKKEY'.)*/static const int HOOKKEY = 0;  static int db_getregistry (lua_State *L) {  lua_pushvalue(L, LUA_REGISTRYINDEX);  return 1;}  static int db_getmetatable (lua_State *L) {  luaL_checkany(L, 1);  if (!lua_getmetatable(L, 1)) {    lua_pushnil(L);  /* no metatable */  }  return 1;}  static int db_setmetatable (lua_State *L) {  int t = lua_type(L, 2);  luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,                    "nil or table expected");  lua_settop(L, 2);  lua_setmetatable(L, 1);  return 1;  /* return 1st argument */}  static int db_getuservalue (lua_State *L) {  if (lua_type(L, 1) != LUA_TUSERDATA)    lua_pushnil(L);  else    lua_getuservalue(L, 1);  return 1;}  static int db_setuservalue (lua_State *L) {  luaL_checktype(L, 1, LUA_TUSERDATA);  luaL_checkany(L, 2);  lua_settop(L, 2);  lua_setuservalue(L, 1);  return 1;}  /*** Auxiliary function used by several library functions: check for** an optional thread as function's first argument and set 'arg' with** 1 if this argument is present (so that functions can skip it to** access their other arguments)*/static lua_State *getthread (lua_State *L, int *arg) {  if (lua_isthread(L, 1)) {    *arg = 1;    return lua_tothread(L, 1);  }  else {    *arg = 0;    return L;  /* function will operate over current thread */  }}  /*** Variations of 'lua_settable', used by 'db_getinfo' to put results** from 'lua_getinfo' into result table. Key is always a string;** value can be a string, an int, or a boolean.*/static void settabss (lua_State *L, const char *k, const char *v) {  lua_pushstring(L, v);  lua_setfield(L, -2, k);} static void settabsi (lua_State *L, const char *k, int v) {  lua_pushinteger(L, v);  lua_setfield(L, -2, k);} static void settabsb (lua_State *L, const char *k, int v) {  lua_pushboolean(L, v);  lua_setfield(L, -2, k);}  /*** In function 'db_getinfo', the call to 'lua_getinfo' may push** results on the stack; later it creates the result table to put** these objects. Function 'treatstackoption' puts the result from** 'lua_getinfo' on top of the result table so that it can call** 'lua_setfield'.*/static void treatstackoption (lua_State *L, lua_State *L1, const char *fname) {  if (L == L1)    lua_rotate(L, -2, 1);  /* exchange object and table */  else    lua_xmove(L1, L, 1);  /* move object to the "main" stack */  lua_setfield(L, -2, fname);  /* put object into table */}  /*** Calls 'lua_getinfo' and collects all results in a new table.*/static int db_getinfo (lua_State *L) {  lua_Debug ar;  int arg;  lua_State *L1 = getthread(L, &arg);  const char *options = luaL_optstring(L, arg+2, "flnStu");  if (lua_isfunction(L, arg + 1)) {  /* info about a function? */    options = lua_pushfstring(L, ">%s", options);  /* add '>' to 'options' */    lua_pushvalue(L, arg + 1);  /* move function to 'L1' stack */    lua_xmove(L, L1, 1);  }  else {  /* stack level */    if (!lua_getstack(L1, (int)luaL_checkinteger(L, arg + 1), &ar)) {      lua_pushnil(L);  /* level out of range */      return 1;    }  }  if (!lua_getinfo(L1, options, &ar))    return luaL_argerror(L, arg+2, "invalid option");  lua_newtable(L);  /* table to collect results */  if (strchr(options, 'S')) {    settabss(L, "source", ar.source);    settabss(L, "short_src", ar.short_src);    settabsi(L, "linedefined", ar.linedefined);    settabsi(L, "lastlinedefined", ar.lastlinedefined);    settabss(L, "what", ar.what);  }  if (strchr(options, 'l'))    settabsi(L, "currentline", ar.currentline);  if (strchr(options, 'u')) {    settabsi(L, "nups", ar.nups);    settabsi(L, "nparams", ar.nparams);    settabsb(L, "isvararg", ar.isvararg);  }  if (strchr(options, 'n')) {    settabss(L, "name", ar.name);    settabss(L, "namewhat", ar.namewhat);  }  if (strchr(options, 't'))    settabsb(L, "istailcall", ar.istailcall);  if (strchr(options, 'L'))    treatstackoption(L, L1, "activelines");  if (strchr(options, 'f'))    treatstackoption(L, L1, "func");  return 1;  /* return table */}  static int db_getlocal (lua_State *L) {  int arg;  lua_State *L1 = getthread(L, &arg);  lua_Debug ar;  const char *name;  int nvar = (int)luaL_checkinteger(L, arg + 2);  /* local-variable index */  if (lua_isfunction(L, arg + 1)) {  /* function argument? */    lua_pushvalue(L, arg + 1);  /* push function */    lua_pushstring(L, lua_getlocal(L, NULL, nvar));  /* push local name */    return 1;  /* return only name (there is no value) */  }  else {  /* stack-level argument */    int level = (int)luaL_checkinteger(L, arg + 1);    if (!lua_getstack(L1, level, &ar))  /* out of range? */      return luaL_argerror(L, arg+1, "level out of range");    name = lua_getlocal(L1, &ar, nvar);    if (name) {      lua_xmove(L1, L, 1);  /* move local value */      lua_pushstring(L, name);  /* push name */      lua_rotate(L, -2, 1);  /* re-order */      return 2;    }    else {      lua_pushnil(L);  /* no name (nor value) */      return 1;    }  }}  static int db_setlocal (lua_State *L) {  int arg;  const char *name;  lua_State *L1 = getthread(L, &arg);  lua_Debug ar;  int level = (int)luaL_checkinteger(L, arg + 1);  int nvar = (int)luaL_checkinteger(L, arg + 2);  if (!lua_getstack(L1, level, &ar))  /* out of range? */    return luaL_argerror(L, arg+1, "level out of range");  luaL_checkany(L, arg+3);  lua_settop(L, arg+3);  lua_xmove(L, L1, 1);  name = lua_setlocal(L1, &ar, nvar);  if (name == NULL)    lua_pop(L1, 1);  /* pop value (if not popped by 'lua_setlocal') */  lua_pushstring(L, name);  return 1;}  /*** get (if 'get' is true) or set an upvalue from a closure*/static int auxupvalue (lua_State *L, int get) {  const char *name;  int n = (int)luaL_checkinteger(L, 2);  /* upvalue index */  luaL_checktype(L, 1, LUA_TFUNCTION);  /* closure */  name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n);  if (name == NULL) return 0;  lua_pushstring(L, name);  lua_insert(L, -(get+1));  /* no-op if get is false */  return get + 1;}  static int db_getupvalue (lua_State *L) {  return auxupvalue(L, 1);}  static int db_setupvalue (lua_State *L) {  luaL_checkany(L, 3);  return auxupvalue(L, 0);}  /*** Check whether a given upvalue from a given closure exists and** returns its index*/static int checkupval (lua_State *L, int argf, int argnup) {  int nup = (int)luaL_checkinteger(L, argnup);  /* upvalue index */  luaL_checktype(L, argf, LUA_TFUNCTION);  /* closure */  luaL_argcheck(L, (lua_getupvalue(L, argf, nup) != NULL), argnup,                   "invalid upvalue index");  return nup;}  static int db_upvalueid (lua_State *L) {  int n = checkupval(L, 1, 2);  lua_pushlightuserdata(L, lua_upvalueid(L, 1, n));  return 1;}  static int db_upvaluejoin (lua_State *L) {  int n1 = checkupval(L, 1, 2);  int n2 = checkupval(L, 3, 4);  luaL_argcheck(L, !lua_iscfunction(L, 1), 1, "Lua function expected");  luaL_argcheck(L, !lua_iscfunction(L, 3), 3, "Lua function expected");  lua_upvaluejoin(L, 1, n1, 3, n2);  return 0;}  /*** Call hook function registered at hook table for the current** thread (if there is one)*/static void hookf (lua_State *L, lua_Debug *ar) {  static const char *const hooknames[] =    {"call", "return", "line", "count", "tail call"};  lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY);  lua_pushthread(L);  if (lua_rawget(L, -2) == LUA_TFUNCTION) {  /* is there a hook function? */    lua_pushstring(L, hooknames[(int)ar->event]);  /* push event name */    if (ar->currentline >= 0)      lua_pushinteger(L, ar->currentline);  /* push current line */    else lua_pushnil(L);    lua_assert(lua_getinfo(L, "lS", ar));    lua_call(L, 2, 0);  /* call hook function */  }}  /*** Convert a string mask (for 'sethook') into a bit mask*/static int makemask (const char *smask, int count) {  int mask = 0;  if (strchr(smask, 'c')) mask |= LUA_MASKCALL;  if (strchr(smask, 'r')) mask |= LUA_MASKRET;  if (strchr(smask, 'l')) mask |= LUA_MASKLINE;  if (count > 0) mask |= LUA_MASKCOUNT;  return mask;}  /*** Convert a bit mask (for 'gethook') into a string mask*/static char *unmakemask (int mask, char *smask) {  int i = 0;  if (mask & LUA_MASKCALL) smask[i++] = 'c';  if (mask & LUA_MASKRET) smask[i++] = 'r';  if (mask & LUA_MASKLINE) smask[i++] = 'l';  smask[i] = '\0';  return smask;}  static int db_sethook (lua_State *L) {  int arg, mask, count;  lua_Hook func;  lua_State *L1 = getthread(L, &arg);  if (lua_isnoneornil(L, arg+1)) {  /* no hook? */    lua_settop(L, arg+1);    func = NULL; mask = 0; count = 0;  /* turn off hooks */  }  else {    const char *smask = luaL_checkstring(L, arg+2);    luaL_checktype(L, arg+1, LUA_TFUNCTION);    count = (int)luaL_optinteger(L, arg + 3, 0);    func = hookf; mask = makemask(smask, count);  }  if (lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY) == LUA_TNIL) {    lua_createtable(L, 0, 2);  /* create a hook table */    lua_pushvalue(L, -1);    lua_rawsetp(L, LUA_REGISTRYINDEX, &HOOKKEY);  /* set it in position */    lua_pushstring(L, "k");    lua_setfield(L, -2, "__mode");  /** hooktable.__mode = "k" */    lua_pushvalue(L, -1);    lua_setmetatable(L, -2);  /* setmetatable(hooktable) = hooktable */  }  lua_pushthread(L1); lua_xmove(L1, L, 1);  /* key (thread) */  lua_pushvalue(L, arg + 1);  /* value (hook function) */  lua_rawset(L, -3);  /* hooktable[L1] = new Lua hook */  lua_sethook(L1, func, mask, count);  return 0;}  static int db_gethook (lua_State *L) {  int arg;  lua_State *L1 = getthread(L, &arg);  char buff[5];  int mask = lua_gethookmask(L1);  lua_Hook hook = lua_gethook(L1);  if (hook == NULL)  /* no hook? */    lua_pushnil(L);  else if (hook != hookf)  /* external hook? */    lua_pushliteral(L, "external hook");  else {  /* hook table must exist */    lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY);    lua_pushthread(L1); lua_xmove(L1, L, 1);    lua_rawget(L, -2);   /* 1st result = hooktable[L1] */    lua_remove(L, -2);  /* remove hook table */  }  lua_pushstring(L, unmakemask(mask, buff));  /* 2nd result = mask */  lua_pushinteger(L, lua_gethookcount(L1));  /* 3rd result = count */  return 3;}  static int db_debug (lua_State *L) {  for (;;) {    char buffer[250];    lua_writestringerror("%s", "lua_debug> ");    if (fgets(buffer, sizeof(buffer), stdin) == 0 ||        strcmp(buffer, "cont\n") == 0)      return 0;    if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") ||        lua_pcall(L, 0, 0, 0))      lua_writestringerror("%s\n", lua_tostring(L, -1));    lua_settop(L, 0);  /* remove eventual returns */  }}  static int db_traceback (lua_State *L) {  int arg;  lua_State *L1 = getthread(L, &arg);  const char *msg = lua_tostring(L, arg + 1);  if (msg == NULL && !lua_isnoneornil(L, arg + 1))  /* non-string 'msg'? */    lua_pushvalue(L, arg + 1);  /* return it untouched */  else {    int level = (int)luaL_optinteger(L, arg + 2, (L == L1) ? 1 : 0);    luaL_traceback(L, L1, msg, level);  }  return 1;}  static const luaL_Reg dblib[] = {  {"debug", db_debug},  {"getuservalue", db_getuservalue},  {"gethook", db_gethook},  {"getinfo", db_getinfo},  {"getlocal", db_getlocal},  {"getregistry", db_getregistry},  {"getmetatable", db_getmetatable},  {"getupvalue", db_getupvalue},  {"upvaluejoin", db_upvaluejoin},  {"upvalueid", db_upvalueid},  {"setuservalue", db_setuservalue},  {"sethook", db_sethook},  {"setlocal", db_setlocal},  {"setmetatable", db_setmetatable},  {"setupvalue", db_setupvalue},  {"traceback", db_traceback},  {NULL, NULL}};  LUAMOD_API int luaopen_debug (lua_State *L) {  luaL_newlib(L, dblib);  return 1;}