lua/ldebug.c
2001-09-28 13:48:16 -03:00

568 lines
14 KiB
C

/*
** $Id: ldebug.c,v 1.88 2001/09/07 17:39:10 roberto Exp $
** Debug Interface
** See Copyright Notice in lua.h
*/
#include <stdlib.h>
#define LUA_PRIVATE
#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 "luadebug.h"
#include "lvm.h"
static const l_char *getfuncname (lua_State *L, CallInfo *ci,
const l_char **name);
static int isLmark (CallInfo *ci) {
lua_assert(ci == NULL || ttype(ci->base - 1) == LUA_TFUNCTION);
return (ci && ci->prev && !ci_func(ci)->isC);
}
LUA_API lua_Hook lua_setcallhook (lua_State *L, lua_Hook func) {
lua_Hook oldhook;
lua_lock(L);
oldhook = L->callhook;
L->callhook = func;
lua_unlock(L);
return oldhook;
}
LUA_API lua_Hook lua_setlinehook (lua_State *L, lua_Hook func) {
lua_Hook oldhook;
lua_lock(L);
oldhook = L->linehook;
L->linehook = func;
lua_unlock(L);
return oldhook;
}
static CallInfo *ci_stack (lua_State *L, StkId obj) {
CallInfo *ci = L->ci;
while (ci->base > obj) ci = ci->prev;
return (ci != &L->basefunc) ? ci : NULL;
}
LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {
CallInfo *ci;
int status;
lua_lock(L);
ci = L->ci;
while (level-- && ci != &L->basefunc) {
lua_assert(ci->base > ci->prev->base);
ci = ci->prev;
}
if (ci == &L->basefunc) status = 0; /* there is no such level */
else {
ar->_ci = ci;
status = 1;
}
lua_unlock(L);
return status;
}
int luaG_getline (int *lineinfo, int pc, int refline, int *prefi) {
int refi;
if (lineinfo == NULL || pc == -1)
return -1; /* no line info or function is not active */
refi = prefi ? *prefi : 0;
if (lineinfo[refi] < 0)
refline += -lineinfo[refi++];
lua_assert(lineinfo[refi] >= 0);
while (lineinfo[refi] > pc) {
refline--;
refi--;
if (lineinfo[refi] < 0)
refline -= -lineinfo[refi--];
lua_assert(lineinfo[refi] >= 0);
}
for (;;) {
int nextline = refline + 1;
int nextref = refi + 1;
if (lineinfo[nextref] < 0)
nextline += -lineinfo[nextref++];
lua_assert(lineinfo[nextref] >= 0);
if (lineinfo[nextref] > pc)
break;
refline = nextline;
refi = nextref;
}
if (prefi) *prefi = refi;
return refline;
}
static int currentpc (CallInfo *ci) {
lua_assert(isLmark(ci));
if (ci->pc)
return (*ci->pc - ci_func(ci)->u.l.p->code) - 1;
else
return -1; /* function is not active */
}
static int currentline (CallInfo *ci) {
if (!isLmark(ci))
return -1; /* only active lua functions have current-line information */
else {
int *lineinfo = ci_func(ci)->u.l.p->lineinfo;
return luaG_getline(lineinfo, currentpc(ci), 1, NULL);
}
}
static Proto *getluaproto (CallInfo *ci) {
return (isLmark(ci) ? ci_func(ci)->u.l.p : NULL);
}
LUA_API const l_char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {
const l_char *name;
CallInfo *ci;
Proto *fp;
lua_lock(L);
name = NULL;
ci = ar->_ci;
fp = getluaproto(ci);
if (fp) { /* is a Lua function? */
name = luaF_getlocalname(fp, n, currentpc(ci));
if (name)
luaA_pushobject(L, ci->base+(n-1)); /* push value */
}
lua_unlock(L);
return name;
}
LUA_API const l_char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
const l_char *name;
CallInfo *ci;
Proto *fp;
lua_lock(L);
name = NULL;
ci = ar->_ci;
fp = getluaproto(ci);
L->top--; /* pop new value */
if (fp) { /* is a Lua function? */
name = luaF_getlocalname(fp, n, currentpc(ci));
if (!name || name[0] == l_c('(')) /* `(' starts private locals */
name = NULL;
else
setobj(ci->base+(n-1), L->top);
}
lua_unlock(L);
return name;
}
static void infoLproto (lua_Debug *ar, Proto *f) {
ar->source = getstr(f->source);
ar->linedefined = f->lineDefined;
ar->what = l_s("Lua");
}
static void funcinfo (lua_State *L, lua_Debug *ar, StkId func) {
Closure *cl;
if (ttype(func) == LUA_TFUNCTION)
cl = clvalue(func);
else {
luaD_error(L, l_s("value for `lua_getinfo' is not a function"));
cl = NULL; /* to avoid warnings */
}
if (cl->isC) {
ar->source = l_s("=C");
ar->linedefined = -1;
ar->what = l_s("C");
}
else
infoLproto(ar, cl->u.l.p);
luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
if (ar->linedefined == 0)
ar->what = l_s("main");
}
static const l_char *travtagmethods (global_State *G, const TObject *o) {
if (ttype(o) == LUA_TFUNCTION) {
int e;
for (e=0; e<TM_N; e++) {
int t;
for (t=0; t<G->ntag; t++)
if (clvalue(o) == luaT_gettm(G, t, e))
return luaT_eventname[e];
}
}
return NULL;
}
static const l_char *travglobals (lua_State *L, const TObject *o) {
Hash *g = L->gt;
int i;
for (i=0; i<g->size; i++) {
if (luaO_equalObj(o, val(node(g, i))) &&
ttype(key(node(g, i))) == LUA_TSTRING)
return getstr(tsvalue(key(node(g, i))));
}
return NULL;
}
static void getname (lua_State *L, const TObject *f, lua_Debug *ar) {
/* try to find a name for given function */
if ((ar->name = travglobals(L, f)) != NULL)
ar->namewhat = l_s("global");
/* not found: try tag methods */
else if ((ar->name = travtagmethods(G(L), f)) != NULL)
ar->namewhat = l_s("tag-method");
else ar->namewhat = l_s(""); /* not found at all */
}
LUA_API int lua_getinfo (lua_State *L, const l_char *what, lua_Debug *ar) {
StkId f;
CallInfo *ci;
int status = 1;
lua_lock(L);
if (*what != l_c('>')) { /* function is active? */
ci = ar->_ci;
f = ci->base - 1;
}
else {
what++; /* skip the `>' */
ci = NULL;
f = L->top - 1;
}
for (; *what; what++) {
switch (*what) {
case l_c('S'): {
funcinfo(L, ar, f);
break;
}
case l_c('l'): {
ar->currentline = currentline(ci);
break;
}
case l_c('u'): {
ar->nups = (ttype(f) == LUA_TFUNCTION) ? clvalue(f)->nupvalues : 0;
break;
}
case l_c('n'): {
ar->namewhat = (ci) ? getfuncname(L, ci, &ar->name) : NULL;
if (ar->namewhat == NULL)
getname(L, f, ar);
break;
}
case l_c('f'): {
setobj(L->top, f);
incr_top; /* push function */
break;
}
default: status = 0; /* invalid option */
}
}
if (!ci) L->top--; /* pop function */
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 checklineinfo (const Proto *pt) {
int *lineinfo = pt->lineinfo;
if (lineinfo == NULL) return 1;
check(pt->sizelineinfo >= 2 && lineinfo[pt->sizelineinfo-1] == MAX_INT);
if (*lineinfo < 0) lineinfo++;
check(*lineinfo == 0);
return 1;
}
static int precheck (const Proto *pt) {
check(checklineinfo(pt));
check(pt->maxstacksize <= MAXSTACK);
check(pt->numparams+pt->is_vararg <= pt->maxstacksize);
check(GET_OPCODE(pt->code[pt->sizecode-1]) == OP_RETURN);
return 1;
}
static int checkopenop (const Proto *pt, int pc) {
Instruction i = pt->code[pc+1];
switch (GET_OPCODE(i)) {
case OP_CALL:
case OP_RETURN: {
check(GETARG_B(i) == NO_REG);
return 1;
}
case OP_SETLISTO: return 1;
default: return 0; /* invalid instruction after an open call */
}
}
static Instruction luaG_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) */
if (reg == NO_REG) /* full check? */
check(precheck(pt));
for (pc = 0; pc < lastpc; pc++) {
const Instruction i = pt->code[pc];
OpCode op = GET_OPCODE(i);
int a = GETARG_A(i);
int b = 0;
int c = 0;
checkreg(pt, a);
switch (getOpMode(op)) {
case iABC: {
b = GETARG_B(i);
c = GETARG_C(i);
if (testOpMode(op, OpModeBreg))
checkreg(pt, b);
if (testOpMode(op, OpModeCreg))
check(c < pt->maxstacksize ||
(c >= MAXSTACK && c-MAXSTACK < pt->sizek));
break;
}
case iABc: {
b = GETARG_Bc(i);
if (testOpMode(op, OpModeK)) check(b < pt->sizek);
break;
}
case iAsBc: {
b = GETARG_sBc(i);
break;
}
}
if (testOpMode(op, OpModesetA)) {
if (a == reg) last = pc; /* change register `a' */
}
if (testOpMode(op, OpModeT))
check(GET_OPCODE(pt->code[pc+1]) == OP_CJMP);
switch (op) {
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->nupvalues);
break;
}
case OP_GETGLOBAL:
case OP_SETGLOBAL: {
check(ttype(&pt->k[b]) == LUA_TSTRING);
break;
}
case OP_SELF: {
checkreg(pt, a+1);
if (reg == a+1) last = pc;
break;
}
case OP_CONCAT: {
/* `c' is a register, and at least two operands */
check(c < MAXSTACK && b < c);
break;
}
case OP_JMP:
case OP_CJMP: {
int dest = pc+1+b;
check(0 <= dest && dest < pt->sizecode);
/* 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_NILJMP: {
check(pc+2 < pt->sizecode); /* check its jump */
break;
}
case OP_CALL: {
if (b != NO_REG) {
checkreg(pt, a+b);
}
if (c == NO_REG) {
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: {
if (b != NO_REG && b != 0)
checkreg(pt, a+b-1);
break;
}
case OP_FORPREP:
case OP_TFORPREP: {
int dest = pc-b; /* jump is negated here */
check(0 <= dest && dest < pt->sizecode &&
GET_OPCODE(pt->code[dest]) == op+1);
break;
}
case OP_FORLOOP:
case OP_TFORLOOP: {
int dest = pc+b;
check(0 <= dest && dest < pt->sizecode &&
pt->code[dest] == SET_OPCODE(i, op-1));
checkreg(pt, a + ((op == OP_FORLOOP) ? 2 : 3));
break;
}
case OP_SETLIST: {
checkreg(pt, a + (b&(LFIELDS_PER_FLUSH-1)) + 1);
break;
}
case OP_CLOSURE: {
check(b < pt->sizep);
check(pc + pt->p[b]->nupvalues < pt->sizecode);
break;
}
default: break;
}
}
return pt->code[last];
}
/* }====================================================== */
int luaG_checkcode (const Proto *pt) {
return luaG_symbexec(pt, pt->sizecode, NO_REG);
}
static const l_char *getobjname (lua_State *L, StkId obj, const l_char **name) {
CallInfo *ci = ci_stack(L, obj);
if (isLmark(ci)) { /* an active Lua function? */
Proto *p = ci_func(ci)->u.l.p;
int pc = currentpc(ci);
int stackpos = obj - ci->base;
Instruction i;
*name = luaF_getlocalname(p, stackpos+1, pc);
if (*name) /* is a local? */
return l_s("local");
i = luaG_symbexec(p, pc, stackpos); /* try symbolic execution */
lua_assert(pc != -1);
switch (GET_OPCODE(i)) {
case OP_GETGLOBAL: {
lua_assert(ttype(&p->k[GETARG_Bc(i)]) == LUA_TSTRING);
*name = svalue(&p->k[GETARG_Bc(i)]);
return l_s("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->base+b, name); /* get name for `b' */
break;
}
case OP_GETTABLE:
case OP_SELF: {
int c = GETARG_C(i) - MAXSTACK;
if (c >= 0 && ttype(&p->k[c]) == LUA_TSTRING) {
*name = svalue(&p->k[c]);
return l_s("field");
}
break;
}
default: break;
}
}
return NULL; /* no useful name found */
}
static const l_char *getfuncname (lua_State *L, CallInfo *ci,
const l_char **name) {
ci = ci->prev; /* calling function */
if (ci == &L->basefunc || !isLmark(ci))
return NULL; /* not an active Lua function */
else {
Proto *p = ci_func(ci)->u.l.p;
int pc = currentpc(ci);
Instruction i;
if (pc == -1) return NULL; /* function is not activated */
i = p->code[pc];
return (GET_OPCODE(i) == OP_CALL
? getobjname(L, ci->base+GETARG_A(i), name)
: NULL); /* no useful name found */
}
}
void luaG_typeerror (lua_State *L, StkId o, const l_char *op) {
const l_char *name;
const l_char *kind = getobjname(L, o, &name);
const l_char *t = luaT_typename(G(L), o);
if (kind)
luaO_verror(L, l_s("attempt to %.30s %.20s `%.40s' (a %.10s value)"),
op, kind, name, t);
else
luaO_verror(L, l_s("attempt to %.30s a %.10s value"), op, t);
}
void luaG_concaterror (lua_State *L, StkId p1, StkId p2) {
if (ttype(p1) == LUA_TSTRING) p1 = p2;
lua_assert(ttype(p1) != LUA_TSTRING);
luaG_typeerror(L, p1, l_s("concat"));
}
void luaG_aritherror (lua_State *L, StkId p1, TObject *p2) {
TObject temp;
if (luaV_tonumber(p1, &temp) != NULL)
p1 = p2; /* first operand is OK; error is in the second */
luaG_typeerror(L, p1, l_s("perform arithmetic on"));
}
void luaG_ordererror (lua_State *L, const TObject *p1, const TObject *p2) {
const l_char *t1 = luaT_typename(G(L), p1);
const l_char *t2 = luaT_typename(G(L), p2);
if (t1[2] == t2[2])
luaO_verror(L, l_s("attempt to compare two %.10s values"), t1);
else
luaO_verror(L, l_s("attempt to compare %.10s with %.10s"), t1, t2);
}