diff options
Diffstat (limited to 'src/lua/ldebug.c')
| -rw-r--r-- | src/lua/ldebug.c | 700 |
1 files changed, 700 insertions, 0 deletions
diff --git a/src/lua/ldebug.c b/src/lua/ldebug.c new file mode 100644 index 0000000..00dbf29 --- /dev/null +++ b/src/lua/ldebug.c @@ -0,0 +1,700 @@ +/* +** $Id: ldebug.c,v 2.121.1.2 2017/07/10 17:21:50 roberto Exp $ +** Debug Interface +** See Copyright Notice in lua.h +*/ + +#define ldebug_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <stdarg.h> +#include <stddef.h> +#include "string.h" + +#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) + + +/* Active Lua function (given call info) */ +#define ci_func(ci) (clLvalue((ci)->func)) + + +static const char *funcnamefromcode (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)); +} + + +/* +** If function yielded, its 'func' can be in the 'extra' field. The +** next function restores 'func' to its correct value for debugging +** purposes. (It exchanges 'func' and 'extra'; so, when called again, +** after debugging, it also "re-restores" ** 'func' to its altered value. +*/ +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 asynchronously (e.g. during a signal). +** Fields 'oldpc', 'basehookcount', and 'hookcount' (set by +** 'resethookcount') are for debug only, and it is no problem if they +** get arbitrary values (causes at most one wrong hook call). 'hookmask' +** is an atomic value. We assume that pointers are atomic too (e.g., gcc +** ensures that for all platforms where it runs). Moreover, 'hook' is +** always checked before being called (see 'luaD_hook'). +*/ +LUA_API void 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); +} + + +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; + int nvararg = cast_int(ci->u.l.base - ci->func) - nparams; + if (n <= -nvararg) + 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 = NULL; /* 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 = NULL; /* 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 const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) { + if (ci == NULL) /* no 'ci'? */ + return NULL; /* no info */ + else if (ci->callstatus & CIST_FIN) { /* is this a finalizer? */ + *name = "__gc"; + return "metamethod"; /* report it as such */ + } + /* calling function is a known Lua function? */ + else if (!(ci->callstatus & CIST_TAIL) && isLua(ci->previous)) + return funcnamefromcode(L, ci->previous, name); + else return NULL; /* no way to find a name */ +} + + +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': { + ar->namewhat = getfuncname(L, ci, &ar->name); + 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); /* correct before option 'L', which can raise a mem. error */ + 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; + } + 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 */ +} + + +/* +** Try to find a name for a function based on the code that called it. +** (Only works when function was called by a Lua function.) +** Returns what the name is (e.g., "for iterator", "method", +** "metamethod") and sets '*name' to point to the name. +*/ +static const char *funcnamefromcode (lua_State *L, CallInfo *ci, + const char **name) { + TMS tm = (TMS)0; /* (initial value avoids warnings) */ + Proto *p = ci_func(ci)->p; /* calling function */ + int pc = currentpc(ci); /* calling instruction index */ + Instruction i = p->code[pc]; /* calling instruction */ + if (ci->callstatus & CIST_HOOKED) { /* was it called inside a hook? */ + *name = "?"; + return "hook"; + } + switch (GET_OPCODE(i)) { + case OP_CALL: + case OP_TAILCALL: + return getobjname(p, pc, GETARG_A(i), name); /* get function name */ + case OP_TFORCALL: { /* for iterator */ + *name = "for iterator"; + return "for iterator"; + } + /* other instructions can do calls 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_ADD: case OP_SUB: case OP_MUL: case OP_MOD: + case OP_POW: case OP_DIV: case OP_IDIV: case OP_BAND: + case OP_BOR: case OP_BXOR: case OP_SHL: case OP_SHR: { + int offset = cast_int(GET_OPCODE(i)) - cast_int(OP_ADD); /* ORDER OP */ + tm = cast(TMS, offset + cast_int(TM_ADD)); /* ORDER TM */ + break; + } + case OP_UNM: tm = TM_UNM; break; + case OP_BNOT: tm = TM_BNOT; break; + case OP_LEN: tm = TM_LEN; break; + case OP_CONCAT: tm = TM_CONCAT; break; + case OP_EQ: tm = TM_EQ; break; + case OP_LT: tm = TM_LT; break; + case OP_LE: tm = TM_LE; break; + default: + return NULL; /* cannot find a reasonable name */ + } + *name = getstr(G(L)->tmname[tm]); + return "metamethod"; +} + +/* }====================================================== */ + + + +/* +** The subtraction of two potentially unrelated pointers is +** not ISO C, but it should not crash a program; the subsequent +** checks are ISO C and ensure a correct result. +*/ +static int isinstack (CallInfo *ci, const TValue *o) { + ptrdiff_t i = o - ci->u.l.base; + return (0 <= i && i < (ci->top - ci->u.l.base) && ci->u.l.base + i == o); +} + + +/* +** Checks whether value 'o' came from an upvalue. (That can only happen +** with instructions OP_GETTABUP/OP_SETTABUP, which operate directly on +** upvalues.) +*/ +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; +} + + +static const char *varinfo (lua_State *L, const TValue *o) { + const char *name = NULL; /* to avoid warnings */ + CallInfo *ci = L->ci; + 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); + } + return (kind) ? luaO_pushfstring(L, " (%s '%s')", kind, name) : ""; +} + + +l_noret luaG_typeerror (lua_State *L, const TValue *o, const char *op) { + const char *t = luaT_objtypename(L, o); + luaG_runerror(L, "attempt to %s a %s value%s", op, t, varinfo(L, o)); +} + + +l_noret luaG_concaterror (lua_State *L, const TValue *p1, const TValue *p2) { + if (ttisstring(p1) || cvt2str(p1)) p1 = p2; + luaG_typeerror(L, p1, "concatenate"); +} + + +l_noret luaG_opinterror (lua_State *L, const TValue *p1, + const TValue *p2, const char *msg) { + lua_Number temp; + if (!tonumber(p1, &temp)) /* first operand is wrong? */ + p2 = p1; /* now second is wrong */ + luaG_typeerror(L, p2, msg); +} + + +/* +** Error when both values are convertible to numbers, but not to integers +*/ +l_noret luaG_tointerror (lua_State *L, const TValue *p1, const TValue *p2) { + lua_Integer temp; + if (!tointeger(p1, &temp)) + p2 = p1; + luaG_runerror(L, "number%s has no integer representation", varinfo(L, p2)); +} + + +l_noret luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) { + const char *t1 = luaT_objtypename(L, p1); + const char *t2 = luaT_objtypename(L, p2); + if (strcmp(t1, t2) == 0) + luaG_runerror(L, "attempt to compare two %s values", t1); + else + luaG_runerror(L, "attempt to compare %s with %s", t1, t2); +} + + +/* add src:line information to 'msg' */ +const char *luaG_addinfo (lua_State *L, const char *msg, TString *src, + int line) { + char buff[LUA_IDSIZE]; + if (src) + luaO_chunkid(buff, getstr(src), LUA_IDSIZE); + else { /* no source available; use "?" instead */ + buff[0] = '?'; buff[1] = '\0'; + } + return 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); + setobjs2s(L, L->top, L->top - 1); /* move argument */ + setobjs2s(L, L->top - 1, errfunc); /* push function */ + L->top++; /* assume EXTRA_STACK */ + luaD_callnoyield(L, L->top - 2, 1); /* call it */ + } + luaD_throw(L, LUA_ERRRUN); +} + + +l_noret luaG_runerror (lua_State *L, const char *fmt, ...) { + CallInfo *ci = L->ci; + const char *msg; + va_list argp; + luaC_checkGC(L); /* error message uses memory */ + va_start(argp, fmt); + msg = luaO_pushvfstring(L, fmt, argp); /* format message */ + va_end(argp); + if (isLua(ci)) /* if Lua function, add source:line information */ + luaG_addinfo(L, msg, ci_func(ci)->p->source, currentline(ci)); + luaG_errormsg(L); +} + + +void luaG_traceexec (lua_State *L) { + CallInfo *ci = L->ci; + lu_byte mask = L->hookmask; + int counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT)); + if (counthook) + resethookcount(L); /* reset count */ + else if (!(mask & LUA_MASKLINE)) + return; /* no line hook and count != 0; nothing to be done */ + if (ci->callstatus & CIST_HOOKYIELD) { /* called hook last time? */ + ci->callstatus &= ~CIST_HOOKYIELD; /* erase mark */ + return; /* do not call hook again (VM yielded, so it did not move) */ + } + if (counthook) + luaD_hook(L, LUA_HOOKCOUNT, -1); /* call count hook */ + if (mask & LUA_MASKLINE) { + Proto *p = ci_func(ci)->p; + int npc = pcRel(ci->u.l.savedpc, p); + int newline = getfuncline(p, npc); + if (npc == 0 || /* call linehook when enter a new function, */ + ci->u.l.savedpc <= L->oldpc || /* when jump back (loop), or when */ + newline != getfuncline(p, pcRel(L->oldpc, p))) /* enter a new line */ + luaD_hook(L, LUA_HOOKLINE, newline); /* call line hook */ + } + L->oldpc = ci->u.l.savedpc; + if (L->status == LUA_YIELD) { /* did hook yield? */ + if (counthook) + L->hookcount = 1; /* undo decrement to zero */ + ci->u.l.savedpc--; /* undo increment (resume will increment it again) */ + ci->callstatus |= CIST_HOOKYIELD; /* mark that it yielded */ + ci->func = L->top - 1; /* protect stack below results */ + luaD_throw(L, LUA_YIELD); + } +} + |