/*** $Id: ldebug.c,v 2.29.1.6 2008/05/08 16:56:26 roberto Exp $** Debug Interface** See Copyright Notice in lua.h*/#include <stdarg.h>#include <stddef.h>#include <string.h>#define ldebug_c#define LUA_CORE#include "lua.h"#include "lapi.h"#include "lcode.h"#include "ldebug.h"#include "ldo.h"#include "lfunc.h"#include "lobject.h"#include "lopcodes.h"#include "lstate.h"#include "lstring.h"#include "ltable.h"#include "ltm.h"#include "lvm.h"static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name);static int currentpc (lua_State *L, CallInfo *ci) {  if (!isLua(ci)) return -1;  /* function is not a Lua function? */  if (ci == L->ci)    ci->savedpc = L->savedpc;  return pcRel(ci->savedpc, ci_func(ci)->l.p);}static int currentline (lua_State *L, CallInfo *ci) {  int pc = currentpc(L, ci);  if (pc < 0)    return -1;  /* only active lua functions have current-line information */  else    return getline(ci_func(ci)->l.p, pc);}/*** this function can be called asynchronous (e.g. during a signal)*/LUA_API int lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {  if (func == NULL || mask == 0) {  /* turn off hooks? */    mask = 0;    func = NULL;  }  L->hook = func;  L->basehookcount = count;  resethookcount(L);  L->hookmask = cast_byte(mask);  return 1;}LUA_API lua_Hook lua_gethook (lua_State *L) {  return L->hook;}LUA_API int lua_gethookmask (lua_State *L) {  return L->hookmask;}LUA_API int lua_gethookcount (lua_State *L) {  return L->basehookcount;}LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {  int status;  CallInfo *ci;  lua_lock(L);  for (ci = L->ci; level > 0 && ci > L->base_ci; ci--) {    level--;    if (f_isLua(ci))  /* Lua function? */      level -= ci->tailcalls;  /* skip lost tail calls */  }  if (level == 0 && ci > L->base_ci) {  /* level found? */    status = 1;    ar->i_ci = cast_int(ci - L->base_ci);  }  else if (level < 0) {  /* level is of a lost tail call? */    status = 1;    ar->i_ci = 0;  }  else status = 0;  /* no such level */  lua_unlock(L);  return status;}static Proto *getluaproto (CallInfo *ci) {  return (isLua(ci) ? ci_func(ci)->l.p : NULL);}static const char *findlocal (lua_State *L, CallInfo *ci, int n) {  const char *name;  Proto *fp = getluaproto(ci);  if (fp && (name = luaF_getlocalname(fp, n, currentpc(L, ci))) != NULL)    return name;  /* is a local variable in a Lua function */  else {    StkId limit = (ci == L->ci) ? L->top : (ci+1)->func;    if (limit - ci->base >= n && n > 0)  /* is 'n' inside 'ci' stack? */      return "(*temporary)";    else      return NULL;  }}LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {  CallInfo *ci = L->base_ci + ar->i_ci;  const char *name = findlocal(L, ci, n);  lua_lock(L);  if (name)      luaA_pushobject(L, ci->base + (n - 1));  lua_unlock(L);  return name;}LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {  CallInfo *ci = L->base_ci + ar->i_ci;  const char *name = findlocal(L, ci, n);  lua_lock(L);  if (name)      setobjs2s(L, ci->base + (n - 1), L->top - 1);  L->top--;  /* pop value */  lua_unlock(L);  return name;}static void funcinfo (lua_Debug *ar, Closure *cl) {  if (cl->c.isC) {    ar->source = "=[C]";    ar->linedefined = -1;    ar->lastlinedefined = -1;    ar->what = "C";  }  else {    ar->source = getstr(cl->l.p->source);    ar->linedefined = cl->l.p->linedefined;    ar->lastlinedefined = cl->l.p->lastlinedefined;    ar->what = (ar->linedefined == 0) ? "main" : "Lua";  }  luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);}static void info_tailcall (lua_Debug *ar) {  ar->name = ar->namewhat = "";  ar->what = "tail";  ar->lastlinedefined = ar->linedefined = ar->currentline = -1;  ar->source = "=(tail call)";  luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);  ar->nups = 0;}static void collectvalidlines (lua_State *L, Closure *f) {  if (f == NULL || f->c.isC) {    setnilvalue(L->top);  }  else {    Table *t = luaH_new(L, 0, 0);    int *lineinfo = f->l.p->lineinfo;    int i;    for (i=0; i<f->l.p->sizelineinfo; i++)      setbvalue(luaH_setnum(L, t, lineinfo[i]), 1);    sethvalue(L, L->top, t);   }  incr_top(L);}static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,                    Closure *f, CallInfo *ci) {  int status = 1;  if (f == NULL) {    info_tailcall(ar);    return status;  }  for (; *what; what++) {    switch (*what) {      case 'S': {        funcinfo(ar, f);        break;      }      case 'l': {        ar->currentline = (ci) ? currentline(L, ci) : -1;        break;      }      case 'u': {        ar->nups = f->c.nupvalues;        break;      }      case 'n': {        ar->namewhat = (ci) ? getfuncname(L, ci, &ar->name) : NULL;        if (ar->namewhat == NULL) {          ar->namewhat = "";  /* not found */          ar->name = NULL;        }        break;      }      case 'L':      case 'f':  /* handled by lua_getinfo */        break;      default: status = 0;  /* invalid option */    }  }  return status;}LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {  int status;  Closure *f = NULL;  CallInfo *ci = NULL;  lua_lock(L);  if (*what == '>') {    StkId func = L->top - 1;    luai_apicheck(L, ttisfunction(func));    what++;  /* skip the '>' */    f = clvalue(func);    L->top--;  /* pop function */  }  else if (ar->i_ci != 0) {  /* no tail call? */    ci = L->base_ci + ar->i_ci;    lua_assert(ttisfunction(ci->func));    f = clvalue(ci->func);  }  status = auxgetinfo(L, what, ar, f, ci);  if (strchr(what, 'f')) {    if (f == NULL) setnilvalue(L->top);    else setclvalue(L, L->top, f);    incr_top(L);  }  if (strchr(what, 'L'))    collectvalidlines(L, f);  lua_unlock(L);  return status;}/*** {======================================================** Symbolic Execution and code checker** =======================================================*/#define check(x)		if (!(x)) return 0;#define checkjump(pt,pc)	check(0 <= pc && pc < pt->sizecode)#define checkreg(pt,reg)	check((reg) < (pt)->maxstacksize)static int precheck (const Proto *pt) {  check(pt->maxstacksize <= MAXSTACK);  check(pt->numparams+(pt->is_vararg & VARARG_HASARG) <= pt->maxstacksize);  check(!(pt->is_vararg & VARARG_NEEDSARG) ||              (pt->is_vararg & VARARG_HASARG));  check(pt->sizeupvalues <= pt->nups);  check(pt->sizelineinfo == pt->sizecode || pt->sizelineinfo == 0);  check(pt->sizecode > 0 && GET_OPCODE(pt->code[pt->sizecode-1]) == OP_RETURN);  return 1;}#define checkopenop(pt,pc)	luaG_checkopenop((pt)->code[(pc)+1])int luaG_checkopenop (Instruction i) {  switch (GET_OPCODE(i)) {    case OP_CALL:    case OP_TAILCALL:    case OP_RETURN:    case OP_SETLIST: {      check(GETARG_B(i) == 0);      return 1;    }    default: return 0;  /* invalid instruction after an open call */  }}static int checkArgMode (const Proto *pt, int r, enum OpArgMask mode) {  switch (mode) {    case OpArgN: check(r == 0); break;    case OpArgU: break;    case OpArgR: checkreg(pt, r); break;    case OpArgK:      check(ISK(r) ? INDEXK(r) < pt->sizek : r < pt->maxstacksize);      break;  }  return 1;}static Instruction symbexec (const Proto *pt, int lastpc, int reg) {  int pc;  int last;  /* stores position of last instruction that changed `reg' */  last = pt->sizecode-1;  /* points to final return (a `neutral' instruction) */