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lua/ldebug.c

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/*
** $Id: ldebug.c,v 2.89 2012/01/20 22:05:50 roberto Exp roberto $
** 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"
#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));
}
/*
** 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);
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);
}
}
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 = findlocal(L, ar->i_ci, n, &pos);
lua_lock(L);
if (name)
setobjs2s(L, pos, L->top - 1);
L->top--; /* pop value */
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);
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);
}
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 */
}
/*
** 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' */
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 = pc;
break;
}
case OP_TFORCALL: {
if (reg >= a + 2) setreg = pc; /* affect all regs above its base */
break;
}
case OP_CALL:
case OP_TAILCALL: {
if (reg >= a) setreg = pc; /* affect all registers above base */
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)
pc += b; /* do the jump */
break;
}
case OP_TEST: {
if (reg == a) setreg = pc; /* jumped code can change 'a' */
break;
}
default:
if (testAMode(op) && reg == a) /* any instruction that set A */
setreg = pc;
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(p2));
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, ...) {
va_list argp;
va_start(argp, fmt);
addinfo(L, luaO_pushvfstring(L, fmt, argp));
va_end(argp);
luaG_errormsg(L);
}
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