FreeBSD/Linux Kernel Cross Reference
sys/contrib/openzfs/module/lua/ldebug.c

     /*
     ** $Id: ldebug.c,v 2.90.1.4 2015/02/19 17:05:13 roberto Exp $
     ** Debug Interface
     ** See Copyright Notice in lua.h
     */
     
     
     #define ldebug_c
     #define LUA_CORE
    
    #include <sys/lua/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"
    
    
    
    #define noLuaClosure(f)         ((f) == NULL || (f)->c.tt == LUA_TCCL)
    
    
    static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name);
    
    
    static int currentpc (CallInfo *ci) {
      lua_assert(isLua(ci));
      return pcRel(ci->u.l.savedpc, ci_func(ci)->p);
    }
    
    
    static int currentline (CallInfo *ci) {
      return getfuncline(ci_func(ci)->p, currentpc(ci));
    }
    
    
    static void swapextra (lua_State *L) {
      if (L->status == LUA_YIELD) {
        CallInfo *ci = L->ci;  /* get function that yielded */
        StkId temp = ci->func;  /* exchange its 'func' and 'extra' values */
        ci->func = restorestack(L, ci->extra);
        ci->extra = savestack(L, temp);
      }
    }
    
    
    /*
    ** 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;
      }
      if (isLua(L->ci))
        L->oldpc = L->ci->u.l.savedpc;
      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;
      if (level < 0) return 0;  /* invalid (negative) level */
      lua_lock(L);
      for (ci = L->ci; level > 0 && ci != &L->base_ci; ci = ci->previous)
        level--;
      if (level == 0 && ci != &L->base_ci) {  /* level found? */
        status = 1;
        ar->i_ci = ci;
      }
      else status = 0;  /* no such level */
     lua_unlock(L);
     return status;
   }
   
   
   static const char *upvalname (Proto *p, int uv) {
     TString *s = check_exp(uv < p->sizeupvalues, p->upvalues[uv].name);
     if (s == NULL) return "?";
     else return getstr(s);
   }
   
   
   static const char *findvararg (CallInfo *ci, int n, StkId *pos) {
     int nparams = clLvalue(ci->func)->p->numparams;
     if (n >= ci->u.l.base - ci->func - nparams)
       return NULL;  /* no such vararg */
     else {
       *pos = ci->func + nparams + n;
       return "(*vararg)";  /* generic name for any vararg */
     }
   }
   
   
   static const char *findlocal (lua_State *L, CallInfo *ci, int n,
                                 StkId *pos) {
     const char *name = NULL;
     StkId base;
     if (isLua(ci)) {
       if (n < 0)  /* access to vararg values? */
         return findvararg(ci, -n, pos);
       else {
         base = ci->u.l.base;
         name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci));
       }
     }
     else
       base = ci->func + 1;
     if (name == NULL) {  /* no 'standard' name? */
       StkId limit = (ci == L->ci) ? L->top : ci->next->func;
       if (limit - base >= n && n > 0)  /* is 'n' inside 'ci' stack? */
         name = "(*temporary)";  /* generic name for any valid slot */
       else
         return NULL;  /* no name */
     }
     *pos = base + (n - 1);
     return name;
   }
   
   
   LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {
     const char *name;
     lua_lock(L);
     swapextra(L);
     if (ar == NULL) {  /* information about non-active function? */
       if (!isLfunction(L->top - 1))  /* not a Lua function? */
         name = NULL;
       else  /* consider live variables at function start (parameters) */
         name = luaF_getlocalname(clLvalue(L->top - 1)->p, n, 0);
     }
     else {  /* active function; get information through 'ar' */
       StkId pos = 0;  /* to avoid warnings */
       name = findlocal(L, ar->i_ci, n, &pos);
       if (name) {
         setobj2s(L, L->top, pos);
         api_incr_top(L);
       }
     }
     swapextra(L);
     lua_unlock(L);
     return name;
   }
   
   
   LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
     StkId pos = 0;  /* to avoid warnings */
     const char *name;
     lua_lock(L);
     swapextra(L);
     name = findlocal(L, ar->i_ci, n, &pos);
     if (name)
       setobjs2s(L, pos, L->top - 1);
     L->top--;  /* pop value */
     swapextra(L);
     lua_unlock(L);
     return name;
   }
   
   
   static void funcinfo (lua_Debug *ar, Closure *cl) {
     if (noLuaClosure(cl)) {
       ar->source = "=[C]";
       ar->linedefined = -1;
       ar->lastlinedefined = -1;
       ar->what = "C";
     }
     else {
       Proto *p = cl->l.p;
       ar->source = p->source ? getstr(p->source) : "=?";
       ar->linedefined = p->linedefined;
       ar->lastlinedefined = p->lastlinedefined;
       ar->what = (ar->linedefined == 0) ? "main" : "Lua";
     }
     luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
   }
   
   
   static void collectvalidlines (lua_State *L, Closure *f) {
     if (noLuaClosure(f)) {
       setnilvalue(L->top);
       api_incr_top(L);
     }
     else {
       int i;
       TValue v;
       int *lineinfo = f->l.p->lineinfo;
       Table *t = luaH_new(L);  /* new table to store active lines */
       sethvalue(L, L->top, t);  /* push it on stack */
       api_incr_top(L);
       setbvalue(&v, 1);  /* boolean 'true' to be the value of all indices */
       for (i = 0; i < f->l.p->sizelineinfo; i++)  /* for all lines with code */
         luaH_setint(L, t, lineinfo[i], &v);  /* table[line] = true */
     }
   }
   
   
   static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
                          Closure *f, CallInfo *ci) {
     int status = 1;
     for (; *what; what++) {
       switch (*what) {
         case 'S': {
           funcinfo(ar, f);
           break;
         }
         case 'l': {
           ar->currentline = (ci && isLua(ci)) ? currentline(ci) : -1;
           break;
         }
         case 'u': {
           ar->nups = (f == NULL) ? 0 : f->c.nupvalues;
           if (noLuaClosure(f)) {
             ar->isvararg = 1;
             ar->nparams = 0;
           }
           else {
             ar->isvararg = f->l.p->is_vararg;
             ar->nparams = f->l.p->numparams;
           }
           break;
         }
         case 't': {
           ar->istailcall = (ci) ? ci->callstatus & CIST_TAIL : 0;
           break;
         }
         case 'n': {
           /* calling function is a known Lua function? */
           if (ci && !(ci->callstatus & CIST_TAIL) && isLua(ci->previous))
             ar->namewhat = getfuncname(L, ci->previous, &ar->name);
           else
             ar->namewhat = 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 *cl;
     CallInfo *ci;
     StkId func;
     lua_lock(L);
     swapextra(L);
     if (*what == '>') {
       ci = NULL;
       func = L->top - 1;
       api_check(L, ttisfunction(func), "function expected");
       what++;  /* skip the '>' */
       L->top--;  /* pop function */
     }
     else {
       ci = ar->i_ci;
       func = ci->func;
       lua_assert(ttisfunction(ci->func));
     }
     cl = ttisclosure(func) ? clvalue(func) : NULL;
     status = auxgetinfo(L, what, ar, cl, ci);
     if (strchr(what, 'f')) {
       setobjs2s(L, L->top, func);
       api_incr_top(L);
     }
     swapextra(L);
     if (strchr(what, 'L'))
       collectvalidlines(L, cl);
     lua_unlock(L);
     return status;
   }
   
   
   /*
   ** {======================================================
   ** Symbolic Execution
   ** =======================================================
   */
   
   static const char *getobjname (Proto *p, int lastpc, int reg,
                                  const char **name);
   
   
   /*
   ** find a "name" for the RK value 'c'
   */
   static void kname (Proto *p, int pc, int c, const char **name) {
     if (ISK(c)) {  /* is 'c' a constant? */
       TValue *kvalue = &p->k[INDEXK(c)];
       if (ttisstring(kvalue)) {  /* literal constant? */
         *name = svalue(kvalue);  /* it is its own name */
         return;
       }
       /* else no reasonable name found */
     }
     else {  /* 'c' is a register */
       const char *what = getobjname(p, pc, c, name); /* search for 'c' */
       if (what && *what == 'c') {  /* found a constant name? */
         return;  /* 'name' already filled */
       }
       /* else no reasonable name found */
     }
     *name = "?";  /* no reasonable name found */
   }
   
   
   static int filterpc (int pc, int jmptarget) {
     if (pc < jmptarget)  /* is code conditional (inside a jump)? */
       return -1;  /* cannot know who sets that register */
     else return pc;  /* current position sets that register */
   }
   
   
   /*
   ** try to find last instruction before 'lastpc' that modified register 'reg'
   */
   static int findsetreg (Proto *p, int lastpc, int reg) {
     int pc;
     int setreg = -1;  /* keep last instruction that changed 'reg' */
     int jmptarget = 0;  /* any code before this address is conditional */
     for (pc = 0; pc < lastpc; pc++) {
       Instruction i = p->code[pc];
       OpCode op = GET_OPCODE(i);
       int a = GETARG_A(i);
       switch (op) {
         case OP_LOADNIL: {
           int b = GETARG_B(i);
           if (a <= reg && reg <= a + b)  /* set registers from 'a' to 'a+b' */
             setreg = filterpc(pc, jmptarget);
           break;
         }
         case OP_TFORCALL: {
           if (reg >= a + 2)  /* affect all regs above its base */
             setreg = filterpc(pc, jmptarget);
           break;
         }
         case OP_CALL:
         case OP_TAILCALL: {
           if (reg >= a)  /* affect all registers above base */
             setreg = filterpc(pc, jmptarget);
           break;
         }
         case OP_JMP: {
           int b = GETARG_sBx(i);
           int dest = pc + 1 + b;
           /* jump is forward and do not skip `lastpc'? */
           if (pc < dest && dest <= lastpc) {
             if (dest > jmptarget)
               jmptarget = dest;  /* update 'jmptarget' */
           }
           break;
         }
         case OP_TEST: {
           if (reg == a)  /* jumped code can change 'a' */
             setreg = filterpc(pc, jmptarget);
           break;
         }
         default:
           if (testAMode(op) && reg == a)  /* any instruction that set A */
             setreg = filterpc(pc, jmptarget);
           break;
       }
     }
     return setreg;
   }
   
   
   static const char *getobjname (Proto *p, int lastpc, int reg,
                                  const char **name) {
     int pc;
     *name = luaF_getlocalname(p, reg + 1, lastpc);
     if (*name)  /* is a local? */
       return "local";
     /* else try symbolic execution */
     pc = findsetreg(p, lastpc, reg);
     if (pc != -1) {  /* could find instruction? */
       Instruction i = p->code[pc];
       OpCode op = GET_OPCODE(i);
       switch (op) {
         case OP_MOVE: {
           int b = GETARG_B(i);  /* move from 'b' to 'a' */
           if (b < GETARG_A(i))
             return getobjname(p, pc, b, name);  /* get name for 'b' */
           break;
         }
         case OP_GETTABUP:
         case OP_GETTABLE: {
           int k = GETARG_C(i);  /* key index */
           int t = GETARG_B(i);  /* table index */
           const char *vn = (op == OP_GETTABLE)  /* name of indexed variable */
                            ? luaF_getlocalname(p, t + 1, pc)
                            : upvalname(p, t);
           kname(p, pc, k, name);
           return (vn && strcmp(vn, LUA_ENV) == 0) ? "global" : "field";
         }
         case OP_GETUPVAL: {
           *name = upvalname(p, GETARG_B(i));
           return "upvalue";
         }
         case OP_LOADK:
         case OP_LOADKX: {
           int b = (op == OP_LOADK) ? GETARG_Bx(i)
                                    : GETARG_Ax(p->code[pc + 1]);
           if (ttisstring(&p->k[b])) {
             *name = svalue(&p->k[b]);
             return "constant";
           }
           break;
         }
         case OP_SELF: {
           int k = GETARG_C(i);  /* key index */
           kname(p, pc, k, name);
           return "method";
         }
         default: break;  /* go through to return NULL */
       }
     }
     return NULL;  /* could not find reasonable name */
   }
   
   
   static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
     TMS tm;
     Proto *p = ci_func(ci)->p;  /* calling function */
     int pc = currentpc(ci);  /* calling instruction index */
     Instruction i = p->code[pc];  /* calling instruction */
     switch (GET_OPCODE(i)) {
       case OP_CALL:
       case OP_TAILCALL:  /* get function name */
         return getobjname(p, pc, GETARG_A(i), name);
       case OP_TFORCALL: {  /* for iterator */
         *name = "for iterator";
          return "for iterator";
       }
       /* all other instructions can call only through metamethods */
       case OP_SELF:
       case OP_GETTABUP:
       case OP_GETTABLE: tm = TM_INDEX; break;
       case OP_SETTABUP:
       case OP_SETTABLE: tm = TM_NEWINDEX; break;
       case OP_EQ: tm = TM_EQ; break;
       case OP_ADD: tm = TM_ADD; break;
       case OP_SUB: tm = TM_SUB; break;
       case OP_MUL: tm = TM_MUL; break;
       case OP_DIV: tm = TM_DIV; break;
       case OP_MOD: tm = TM_MOD; break;
       case OP_POW: tm = TM_POW; break;
       case OP_UNM: tm = TM_UNM; break;
       case OP_LEN: tm = TM_LEN; break;
       case OP_LT: tm = TM_LT; break;
       case OP_LE: tm = TM_LE; break;
       case OP_CONCAT: tm = TM_CONCAT; break;
       default:
         return NULL;  /* else no useful name can be found */
     }
     *name = getstr(G(L)->tmname[tm]);
     return "metamethod";
   }
   
   /* }====================================================== */
   
   
   
   /*
   ** only ANSI way to check whether a pointer points to an array
   ** (used only for error messages, so efficiency is not a big concern)
   */
   static int isinstack (CallInfo *ci, const TValue *o) {
     StkId p;
     for (p = ci->u.l.base; p < ci->top; p++)
       if (o == p) return 1;
     return 0;
   }
   
   
   static const char *getupvalname (CallInfo *ci, const TValue *o,
                                    const char **name) {
     LClosure *c = ci_func(ci);
     int i;
     for (i = 0; i < c->nupvalues; i++) {
       if (c->upvals[i]->v == o) {
         *name = upvalname(c->p, i);
         return "upvalue";
       }
     }
     return NULL;
   }
   
   
   l_noret luaG_typeerror (lua_State *L, const TValue *o, const char *op) {
     CallInfo *ci = L->ci;
     const char *name = NULL;
     const char *t = objtypename(o);
     const char *kind = NULL;
     if (isLua(ci)) {
       kind = getupvalname(ci, o, &name);  /* check whether 'o' is an upvalue */
       if (!kind && isinstack(ci, o))  /* no? try a register */
         kind = getobjname(ci_func(ci)->p, currentpc(ci),
                           cast_int(o - ci->u.l.base), &name);
     }
     if (kind)
       luaG_runerror(L, "attempt to %s %s " LUA_QS " (a %s value)",
                   op, kind, name, t);
     else
       luaG_runerror(L, "attempt to %s a %s value", op, t);
   }
   
   
   l_noret luaG_concaterror (lua_State *L, StkId p1, StkId p2) {
     if (ttisstring(p1) || ttisnumber(p1)) p1 = p2;
     lua_assert(!ttisstring(p1) && !ttisnumber(p1));
     luaG_typeerror(L, p1, "concatenate");
   }
   
   
   l_noret luaG_aritherror (lua_State *L, const TValue *p1, const TValue *p2) {
     TValue temp;
     if (luaV_tonumber(p1, &temp) == NULL)
       p2 = p1;  /* first operand is wrong */
     luaG_typeerror(L, p2, "perform arithmetic on");
   }
   
   
   l_noret luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) {
     const char *t1 = objtypename(p1);
     const char *t2 = objtypename(p2);
     if (t1 == t2)
       luaG_runerror(L, "attempt to compare two %s values", t1);
     else
       luaG_runerror(L, "attempt to compare %s with %s", t1, t2);
   }
   
   
   static void addinfo (lua_State *L, const char *msg) {
     CallInfo *ci = L->ci;
     if (isLua(ci)) {  /* is Lua code? */
       char buff[LUA_IDSIZE];  /* add file:line information */
       int line = currentline(ci);
       TString *src = ci_func(ci)->p->source;
       if (src)
         luaO_chunkid(buff, getstr(src), LUA_IDSIZE);
       else {  /* no source available; use "?" instead */
         buff[0] = '?'; buff[1] = '\0';
       }
       luaO_pushfstring(L, "%s:%d: %s", buff, line, msg);
     }
   }
   
   
   l_noret luaG_errormsg (lua_State *L) {
     if (L->errfunc != 0) {  /* is there an error handling function? */
       StkId errfunc = restorestack(L, L->errfunc);
       if (!ttisfunction(errfunc)) luaD_throw(L, LUA_ERRERR);
       setobjs2s(L, L->top, L->top - 1);  /* move argument */
       setobjs2s(L, L->top - 1, errfunc);  /* push function */
       L->top++;
       luaD_call(L, L->top - 2, 1, 0);  /* call it */
     }
     luaD_throw(L, LUA_ERRRUN);
   }
   
   
   l_noret luaG_runerror (lua_State *L, const char *fmt, ...) {
     L->runerror++;
     va_list argp;
     va_start(argp, fmt);
     addinfo(L, luaO_pushvfstring(L, fmt, argp));
     va_end(argp);
     luaG_errormsg(L);
     L->runerror--;
   }

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