ref: e353ebb0dfd92b61cd0bbd35fde44f0576bde9c4
dir: /lua/src/ldebug.c/
/*
** $Id: ldebug.c,v 1.1 2006/12/23 01:55:12 rrt 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);
lua_assert(pt->numparams+(pt->is_vararg & VARARG_HASARG) <= pt->maxstacksize);
lua_assert(!(pt->is_vararg & VARARG_NEEDSARG) ||
(pt->is_vararg & VARARG_HASARG));
check(pt->sizeupvalues <= pt->nups);
check(pt->sizelineinfo == pt->sizecode || pt->sizelineinfo == 0);
check(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) */
check(precheck(pt));
for (pc = 0; pc < lastpc; pc++) {
Instruction i = pt->code[pc];
OpCode op = GET_OPCODE(i);
int a = GETARG_A(i);
int b = 0;
int c = 0;
check(op < NUM_OPCODES);
checkreg(pt, a);
switch (getOpMode(op)) {
case iABC: {
b = GETARG_B(i);
c = GETARG_C(i);
check(checkArgMode(pt, b, getBMode(op)));
check(checkArgMode(pt, c, getCMode(op)));
break;
}
case iABx: {
b = GETARG_Bx(i);
if (getBMode(op) == OpArgK) check(b < pt->sizek);
break;
}
case iAsBx: {
b = GETARG_sBx(i);
if (getBMode(op) == OpArgR) {
int dest = pc+1+b;
check(0 <= dest && dest < pt->sizecode);
if (dest > 0) {
/* cannot jump to a setlist count */
Instruction d = pt->code[dest-1];
check(!(GET_OPCODE(d) == OP_SETLIST && GETARG_C(d) == 0));
}
}
break;
}
}
if (testAMode(op)) {
if (a == reg) last = pc; /* change register `a' */
}
if (testTMode(op)) {
check(pc+2 < pt->sizecode); /* check skip */
check(GET_OPCODE(pt->code[pc+1]) == OP_JMP);
}
switch (op) {
case OP_LOADBOOL: {
check(c == 0 || pc+2 < pt->sizecode); /* check its jump */
break;
}
case OP_LOADNIL: {
if (a <= reg && reg <= b)
last = pc; /* set registers from `a' to `b' */
break;
}
case OP_GETUPVAL:
case OP_SETUPVAL: {
check(b < pt->nups);
break;
}
case OP_GETGLOBAL:
case OP_SETGLOBAL: {
check(ttisstring(&pt->k[b]));
break;
}
case OP_SELF: {
checkreg(pt, a+1);
if (reg == a+1) last = pc;
break;
}
case OP_CONCAT: {
check(b < c); /* at least two operands */
break;
}
case OP_TFORLOOP: {
check(c >= 1); /* at least one result (control variable) */
checkreg(pt, a+2+c); /* space for results */
if (reg >= a+2) last = pc; /* affect all regs above its base */
break;
}
case OP_FORLOOP:
case OP_FORPREP:
checkreg(pt, a+3);
/* go through */
case OP_JMP: {
int dest = pc+1+b;
/* not full check and jump is forward and do not skip `lastpc'? */
if (reg != NO_REG && pc < dest && dest <= lastpc)
pc += b; /* do the jump */
break;
}
case OP_CALL:
case OP_TAILCALL: {
if (b != 0) {
checkreg(pt, a+b-1);
}
c--; /* c = num. returns */
if (c == LUA_MULTRET) {
check(checkopenop(pt, pc));
}
else if (c != 0)
checkreg(pt, a+c-1);
if (reg >= a) last = pc; /* affect all registers above base */
break;
}
case OP_RETURN: {
b--; /* b = num. returns */
if (b > 0) checkreg(pt, a+b-1);
break;
}
case OP_SETLIST: {
if (b > 0) checkreg(pt, a + b);
if (c == 0) pc++;
break;
}
case OP_CLOSURE: {
int nup;
check(b < pt->sizep);
nup = pt->p[b]->nups;
check(pc + nup < pt->sizecode);
for (; nup>0; nup--) {
OpCode op1 = GET_OPCODE(pt->code[pc+nup]);
check(op1 == OP_GETUPVAL || op1 == OP_MOVE);
}
break;
}
case OP_VARARG: {
check((pt->is_vararg & VARARG_ISVARARG) &&
!(pt->is_vararg & VARARG_NEEDSARG));
b--;
if (b == LUA_MULTRET) check(checkopenop(pt, pc));
checkreg(pt, a+b-1);
break;
}
default: break;
}
}
return pt->code[last];
}
#undef check
#undef checkjump
#undef checkreg
/* }====================================================== */
int luaG_checkcode (const Proto *pt) {
return (symbexec(pt, pt->sizecode, NO_REG) != 0);
}
static const char *kname (Proto *p, int c) {
if (ISK(c) && ttisstring(&p->k[INDEXK(c)]))
return svalue(&p->k[INDEXK(c)]);
else
return "?";
}
static const char *getobjname (lua_State *L, CallInfo *ci, int stackpos,
const char **name) {
if (isLua(ci)) { /* a Lua function? */
Proto *p = ci_func(ci)->l.p;
int pc = currentpc(L, ci);
Instruction i;
*name = luaF_getlocalname(p, stackpos+1, pc);
if (*name) /* is a local? */
return "local";
i = symbexec(p, pc, stackpos); /* try symbolic execution */
lua_assert(pc != -1);
switch (GET_OPCODE(i)) {
case OP_GETGLOBAL: {
int g = GETARG_Bx(i); /* global index */
lua_assert(ttisstring(&p->k[g]));
*name = svalue(&p->k[g]);
return "global";
}
case OP_MOVE: {
int a = GETARG_A(i);
int b = GETARG_B(i); /* move from `b' to `a' */
if (b < a)
return getobjname(L, ci, b, name); /* get name for `b' */
break;
}
case OP_GETTABLE: {
int k = GETARG_C(i); /* key index */
*name = kname(p, k);
return "field";
}
case OP_GETUPVAL: {
int u = GETARG_B(i); /* upvalue index */
*name = p->upvalues ? getstr(p->upvalues[u]) : "?";
return "upvalue";
}
case OP_SELF: {
int k = GETARG_C(i); /* key index */
*name = kname(p, k);
return "method";
}
default: break;
}
}
return NULL; /* no useful name found */
}
static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
Instruction i;
if ((isLua(ci) && ci->tailcalls > 0) || !isLua(ci - 1))
return NULL; /* calling function is not Lua (or is unknown) */
ci--; /* calling function */
i = ci_func(ci)->l.p->code[currentpc(L, ci)];
if (GET_OPCODE(i) == OP_CALL || GET_OPCODE(i) == OP_TAILCALL ||
GET_OPCODE(i) == OP_TFORLOOP)
return getobjname(L, ci, GETARG_A(i), name);
else
return NULL; /* no useful name can be found */
}
/* only ANSI way to check whether a pointer points to an array */
static int isinstack (CallInfo *ci, const TValue *o) {
StkId p;
for (p = ci->base; p < ci->top; p++)
if (o == p) return 1;
return 0;
}
void luaG_typeerror (lua_State *L, const TValue *o, const char *op) {
const char *name = NULL;
const char *t = luaT_typenames[ttype(o)];
const char *kind = (isinstack(L->ci, o)) ?
getobjname(L, L->ci, cast_int(o - L->base), &name) :
NULL;
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);
}
void luaG_concaterror (lua_State *L, StkId p1, StkId p2) {
if (ttisstring(p1)) p1 = p2;
lua_assert(!ttisstring(p1));
luaG_typeerror(L, p1, "concatenate");
}
void 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");
}
int luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) {
const char *t1 = luaT_typenames[ttype(p1)];
const char *t2 = luaT_typenames[ttype(p2)];
if (t1[2] == t2[2])
luaG_runerror(L, "attempt to compare two %s values", t1);
else
luaG_runerror(L, "attempt to compare %s with %s", t1, t2);
return 0;
}
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(L, ci);
luaO_chunkid(buff, getstr(getluaproto(ci)->source), LUA_IDSIZE);
luaO_pushfstring(L, "%s:%d: %s", buff, line, msg);
}
}
void 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 */
incr_top(L);
luaD_call(L, L->top - 2, 1); /* call it */
}
luaD_throw(L, LUA_ERRRUN);
}
void 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);
}