diff options
Diffstat (limited to 'src/lua/lvm.c')
-rw-r--r-- | src/lua/lvm.c | 710 |
1 files changed, 710 insertions, 0 deletions
diff --git a/src/lua/lvm.c b/src/lua/lvm.c new file mode 100644 index 00000000..e304e11e --- /dev/null +++ b/src/lua/lvm.c @@ -0,0 +1,710 @@ +/* +** $Id: lvm.c,v 1.5 2004/06/04 13:42:10 neil Exp $ +** Lua virtual machine +** See Copyright Notice in lua.h +*/ + + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "lua.h" + +#include "lapi.h" +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lgc.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" +#include "lvm.h" + + +#ifdef OLD_ANSI +#define strcoll(a,b) strcmp(a,b) +#endif + + + +/* +** Extra stack size to run a function: +** TAG_LINE(1), NAME(1), TM calls(3) (plus some extra...) +*/ +#define EXTRA_STACK 8 + + + +int luaV_tonumber (TObject *obj) { + if (ttype(obj) != LUA_TSTRING) + return 1; + else { + if (!luaO_str2d(svalue(obj), &nvalue(obj))) + return 2; + ttype(obj) = LUA_TNUMBER; + return 0; + } +} + + +int luaV_tostring (lua_State *L, TObject *obj) { /* LUA_NUMBER */ + if (ttype(obj) != LUA_TNUMBER) + return 1; + else { + char s[32]; /* 16 digits, sign, point and \0 (+ some extra...) */ + lua_number2str(s, nvalue(obj)); /* convert `s' to number */ + tsvalue(obj) = luaS_new(L, s); + ttype(obj) = LUA_TSTRING; + return 0; + } +} + + +static void traceexec (lua_State *L, StkId base, StkId top, lua_Hook linehook) { + CallInfo *ci = infovalue(base-1); + int *lineinfo = ci->func->f.l->lineinfo; + int pc = (*ci->pc - ci->func->f.l->code) - 1; + int newline; + if (pc == 0) { /* may be first time? */ + ci->line = 1; + ci->refi = 0; + ci->lastpc = pc+1; /* make sure it will call linehook */ + } + newline = luaG_getline(lineinfo, pc, ci->line, &ci->refi); + /* calls linehook when enters a new line or jumps back (loop) */ + if (newline != ci->line || pc <= ci->lastpc) { + ci->line = newline; + L->top = top; + luaD_lineHook(L, base-2, newline, linehook); + } + ci->lastpc = pc; +} + + +static Closure *luaV_closure (lua_State *L, int nelems) { + Closure *c = luaF_newclosure(L, nelems); + L->top -= nelems; + while (nelems--) + c->upvalue[nelems] = *(L->top+nelems); + clvalue(L->top) = c; + ttype(L->top) = LUA_TFUNCTION; + incr_top; + return c; +} + + +void luaV_Cclosure (lua_State *L, lua_CFunction c, int nelems) { + Closure *cl = luaV_closure(L, nelems); + cl->f.c = c; + cl->isC = 1; +} + + +void luaV_Lclosure (lua_State *L, Proto *l, int nelems) { + Closure *cl = luaV_closure(L, nelems); + cl->f.l = l; + cl->isC = 0; +} + + +/* +** Function to index a table. +** Receives the table at `t' and the key at top. +*/ +const TObject *luaV_gettable (lua_State *L, StkId t) { + Closure *tm; + int tg; + if (ttype(t) == LUA_TTABLE && /* `t' is a table? */ + ((tg = hvalue(t)->htag) == LUA_TTABLE || /* with default tag? */ + luaT_gettm(L, tg, TM_GETTABLE) == NULL)) { /* or no TM? */ + /* do a primitive get */ + const TObject *h = luaH_get(L, hvalue(t), L->top-1); + /* result is no nil or there is no `index' tag method? */ + if (ttype(h) != LUA_TNIL || ((tm=luaT_gettm(L, tg, TM_INDEX)) == NULL)) + return h; /* return result */ + /* else call `index' tag method */ + } + else { /* try a `gettable' tag method */ + tm = luaT_gettmbyObj(L, t, TM_GETTABLE); + } + if (tm != NULL) { /* is there a tag method? */ + luaD_checkstack(L, 2); + *(L->top+1) = *(L->top-1); /* key */ + *L->top = *t; /* table */ + clvalue(L->top-1) = tm; /* tag method */ + ttype(L->top-1) = LUA_TFUNCTION; + L->top += 2; + luaD_call(L, L->top - 3, 1); + return L->top - 1; /* call result */ + } + else { /* no tag method */ + luaG_typeerror(L, t, "index"); + return NULL; /* to avoid warnings */ + } +} + + +/* +** Receives table at `t', key at `key' and value at top. +*/ +void luaV_settable (lua_State *L, StkId t, StkId key) { + int tg; + if (ttype(t) == LUA_TTABLE && /* `t' is a table? */ + ((tg = hvalue(t)->htag) == LUA_TTABLE || /* with default tag? */ + luaT_gettm(L, tg, TM_SETTABLE) == NULL)) /* or no TM? */ + *luaH_set(L, hvalue(t), key) = *(L->top-1); /* do a primitive set */ + else { /* try a `settable' tag method */ + Closure *tm = luaT_gettmbyObj(L, t, TM_SETTABLE); + if (tm != NULL) { + luaD_checkstack(L, 3); + *(L->top+2) = *(L->top-1); + *(L->top+1) = *key; + *(L->top) = *t; + clvalue(L->top-1) = tm; + ttype(L->top-1) = LUA_TFUNCTION; + L->top += 3; + luaD_call(L, L->top - 4, 0); /* call `settable' tag method */ + } + else /* no tag method... */ + luaG_typeerror(L, t, "index"); + } +} + + +const TObject *luaV_getglobal (lua_State *L, TString *s) { + const TObject *value = luaH_getstr(L->gt, s); + Closure *tm = luaT_gettmbyObj(L, value, TM_GETGLOBAL); + if (tm == NULL) /* is there a tag method? */ + return value; /* default behavior */ + else { /* tag method */ + luaD_checkstack(L, 3); + clvalue(L->top) = tm; + ttype(L->top) = LUA_TFUNCTION; + tsvalue(L->top+1) = s; /* global name */ + ttype(L->top+1) = LUA_TSTRING; + *(L->top+2) = *value; + L->top += 3; + luaD_call(L, L->top - 3, 1); + return L->top - 1; + } +} + + +void luaV_setglobal (lua_State *L, TString *s) { + const TObject *oldvalue = luaH_getstr(L->gt, s); + Closure *tm = luaT_gettmbyObj(L, oldvalue, TM_SETGLOBAL); + if (tm == NULL) { /* is there a tag method? */ + if (oldvalue != &luaO_nilobject) { + /* cast to remove `const' is OK, because `oldvalue' != luaO_nilobject */ + *(TObject *)oldvalue = *(L->top - 1); + } + else { + TObject key; + ttype(&key) = LUA_TSTRING; + tsvalue(&key) = s; + *luaH_set(L, L->gt, &key) = *(L->top - 1); + } + } + else { + luaD_checkstack(L, 3); + *(L->top+2) = *(L->top-1); /* new value */ + *(L->top+1) = *oldvalue; + ttype(L->top) = LUA_TSTRING; + tsvalue(L->top) = s; + clvalue(L->top-1) = tm; + ttype(L->top-1) = LUA_TFUNCTION; + L->top += 3; + luaD_call(L, L->top - 4, 0); + } +} + + +static int call_binTM (lua_State *L, StkId top, TMS event) { + /* try first operand */ + Closure *tm = luaT_gettmbyObj(L, top-2, event); + L->top = top; + if (tm == NULL) { + tm = luaT_gettmbyObj(L, top-1, event); /* try second operand */ + if (tm == NULL) { + tm = luaT_gettm(L, 0, event); /* try a `global' method */ + if (tm == NULL) + return 0; /* error */ + } + } + lua_pushstring(L, luaT_eventname[event]); + luaD_callTM(L, tm, 3, 1); + return 1; +} + + +static void call_arith (lua_State *L, StkId top, TMS event) { + if (!call_binTM(L, top, event)) + luaG_binerror(L, top-2, LUA_TNUMBER, "perform arithmetic on"); +} + + +static int luaV_strcomp (const TString *ls, const TString *rs) { + const char *l = ls->str; + size_t ll = ls->len; + const char *r = rs->str; + size_t lr = rs->len; + for (;;) { + int temp = strcoll(l, r); + if (temp != 0) return temp; + else { /* strings are equal up to a '\0' */ + size_t len = strlen(l); /* index of first '\0' in both strings */ + if (len == ll) /* l is finished? */ + return (len == lr) ? 0 : -1; /* l is equal or smaller than r */ + else if (len == lr) /* r is finished? */ + return 1; /* l is greater than r (because l is not finished) */ + /* both strings longer than `len'; go on comparing (after the '\0') */ + len++; + l += len; ll -= len; r += len; lr -= len; + } + } +} + + +int luaV_lessthan (lua_State *L, const TObject *l, const TObject *r, StkId top) { + if (ttype(l) == LUA_TNUMBER && ttype(r) == LUA_TNUMBER) + return (nvalue(l) < nvalue(r)); + else if (ttype(l) == LUA_TSTRING && ttype(r) == LUA_TSTRING) + return (luaV_strcomp(tsvalue(l), tsvalue(r)) < 0); + else { /* call TM */ + luaD_checkstack(L, 2); + *top++ = *l; + *top++ = *r; + if (!call_binTM(L, top, TM_LT)) + luaG_ordererror(L, top-2); + L->top--; + return (ttype(L->top) != LUA_TNIL); + } +} + + +void luaV_strconc (lua_State *L, int total, StkId top) { + do { + int n = 2; /* number of elements handled in this pass (at least 2) */ + if (tostring(L, top-2) || tostring(L, top-1)) { + if (!call_binTM(L, top, TM_CONCAT)) + luaG_binerror(L, top-2, LUA_TSTRING, "concat"); + } + else if (tsvalue(top-1)->len > 0) { /* if len=0, do nothing */ + /* at least two string values; get as many as possible */ + lint32 tl = (lint32)tsvalue(top-1)->len + + (lint32)tsvalue(top-2)->len; + char *buffer; + int i; + while (n < total && !tostring(L, top-n-1)) { /* collect total length */ + tl += tsvalue(top-n-1)->len; + n++; + } + if (tl > MAX_SIZET) lua_error(L, "string size overflow"); + buffer = luaO_openspace(L, tl); + tl = 0; + for (i=n; i>0; i--) { /* concat all strings */ + size_t l = tsvalue(top-i)->len; + memcpy(buffer+tl, tsvalue(top-i)->str, l); + tl += l; + } + tsvalue(top-n) = luaS_newlstr(L, buffer, tl); + } + total -= n-1; /* got `n' strings to create 1 new */ + top -= n-1; + } while (total > 1); /* repeat until only 1 result left */ +} + + +static void luaV_pack (lua_State *L, StkId firstelem) { + int i; + Hash *htab = luaH_new(L, 0); + for (i=0; firstelem+i<L->top; i++) + *luaH_setint(L, htab, i+1) = *(firstelem+i); + /* store counter in field `n' */ + luaH_setstrnum(L, htab, luaS_new(L, "n"), i); + L->top = firstelem; /* remove elements from the stack */ + ttype(L->top) = LUA_TTABLE; + hvalue(L->top) = htab; + incr_top; +} + + +static void adjust_varargs (lua_State *L, StkId base, int nfixargs) { + int nvararg = (L->top-base) - nfixargs; + if (nvararg < 0) + luaD_adjusttop(L, base, nfixargs); + luaV_pack(L, base+nfixargs); +} + + + +#define dojump(pc, i) { int d = GETARG_S(i); pc += d; } + +/* +** Executes the given Lua function. Parameters are between [base,top). +** Returns n such that the the results are between [n,top). +*/ +StkId luaV_execute (lua_State *L, const Closure *cl, StkId base) { + const Proto *const tf = cl->f.l; + StkId top; /* keep top local, for performance */ + const Instruction *pc = tf->code; + TString **const kstr = tf->kstr; + const lua_Hook linehook = L->linehook; + infovalue(base-1)->pc = &pc; + luaD_checkstack(L, tf->maxstacksize+EXTRA_STACK); + if (tf->is_vararg) /* varargs? */ + adjust_varargs(L, base, tf->numparams); + else + luaD_adjusttop(L, base, tf->numparams); + top = L->top; + /* main loop of interpreter */ + for (;;) { + const Instruction i = *pc++; + if (linehook) + traceexec(L, base, top, linehook); + switch (GET_OPCODE(i)) { + case OP_END: { + L->top = top; + return top; + } + case OP_RETURN: { + L->top = top; + return base+GETARG_U(i); + } + case OP_CALL: { + int nres = GETARG_B(i); + if (nres == MULT_RET) nres = LUA_MULTRET; + L->top = top; + luaD_call(L, base+GETARG_A(i), nres); + top = L->top; + break; + } + case OP_TAILCALL: { + L->top = top; + luaD_call(L, base+GETARG_A(i), LUA_MULTRET); + return base+GETARG_B(i); + } + case OP_PUSHNIL: { + int n = GETARG_U(i); + LUA_ASSERT(n>0, "invalid argument"); + do { + ttype(top++) = LUA_TNIL; + } while (--n > 0); + break; + } + case OP_POP: { + top -= GETARG_U(i); + break; + } + case OP_PUSHINT: { + ttype(top) = LUA_TNUMBER; + nvalue(top) = (Number)GETARG_S(i); + top++; + break; + } + case OP_PUSHSTRING: { + ttype(top) = LUA_TSTRING; + tsvalue(top) = kstr[GETARG_U(i)]; + top++; + break; + } + case OP_PUSHNUM: { + ttype(top) = LUA_TNUMBER; + nvalue(top) = tf->knum[GETARG_U(i)]; + top++; + break; + } + case OP_PUSHNEGNUM: { + ttype(top) = LUA_TNUMBER; + nvalue(top) = -tf->knum[GETARG_U(i)]; + top++; + break; + } + case OP_PUSHUPVALUE: { + *top++ = cl->upvalue[GETARG_U(i)]; + break; + } + case OP_GETLOCAL: { + *top++ = *(base+GETARG_U(i)); + break; + } + case OP_GETGLOBAL: { + L->top = top; + *top = *luaV_getglobal(L, kstr[GETARG_U(i)]); + top++; + break; + } + case OP_GETTABLE: { + L->top = top; + top--; + *(top-1) = *luaV_gettable(L, top-1); + break; + } + case OP_GETDOTTED: { + ttype(top) = LUA_TSTRING; + tsvalue(top) = kstr[GETARG_U(i)]; + L->top = top+1; + *(top-1) = *luaV_gettable(L, top-1); + break; + } + case OP_GETINDEXED: { + *top = *(base+GETARG_U(i)); + L->top = top+1; + *(top-1) = *luaV_gettable(L, top-1); + break; + } + case OP_PUSHSELF: { + TObject receiver; + receiver = *(top-1); + ttype(top) = LUA_TSTRING; + tsvalue(top++) = kstr[GETARG_U(i)]; + L->top = top; + *(top-2) = *luaV_gettable(L, top-2); + *(top-1) = receiver; + break; + } + case OP_CREATETABLE: { + L->top = top; + luaC_checkGC(L); + hvalue(top) = luaH_new(L, GETARG_U(i)); + ttype(top) = LUA_TTABLE; + top++; + break; + } + case OP_SETLOCAL: { + *(base+GETARG_U(i)) = *(--top); + break; + } + case OP_SETGLOBAL: { + L->top = top; + luaV_setglobal(L, kstr[GETARG_U(i)]); + top--; + break; + } + case OP_SETTABLE: { + StkId t = top-GETARG_A(i); + L->top = top; + luaV_settable(L, t, t+1); + top -= GETARG_B(i); /* pop values */ + break; + } + case OP_SETLIST: { + int aux = GETARG_A(i) * LFIELDS_PER_FLUSH; + int n = GETARG_B(i); + Hash *arr = hvalue(top-n-1); + L->top = top-n; /* final value of `top' (in case of errors) */ + for (; n; n--) + *luaH_setint(L, arr, n+aux) = *(--top); + break; + } + case OP_SETMAP: { + int n = GETARG_U(i); + StkId finaltop = top-2*n; + Hash *arr = hvalue(finaltop-1); + L->top = finaltop; /* final value of `top' (in case of errors) */ + for (; n; n--) { + top-=2; + *luaH_set(L, arr, top) = *(top+1); + } + break; + } + case OP_ADD: { + if (tonumber(top-2) || tonumber(top-1)) + call_arith(L, top, TM_ADD); + else + nvalue(top-2) += nvalue(top-1); + top--; + break; + } + case OP_ADDI: { + if (tonumber(top-1)) { + ttype(top) = LUA_TNUMBER; + nvalue(top) = (Number)GETARG_S(i); + call_arith(L, top+1, TM_ADD); + } + else + nvalue(top-1) += (Number)GETARG_S(i); + break; + } + case OP_SUB: { + if (tonumber(top-2) || tonumber(top-1)) + call_arith(L, top, TM_SUB); + else + nvalue(top-2) -= nvalue(top-1); + top--; + break; + } + case OP_MULT: { + if (tonumber(top-2) || tonumber(top-1)) + call_arith(L, top, TM_MUL); + else + nvalue(top-2) *= nvalue(top-1); + top--; + break; + } + case OP_DIV: { + if (tonumber(top-2) || tonumber(top-1)) + call_arith(L, top, TM_DIV); + else + nvalue(top-2) /= nvalue(top-1); + top--; + break; + } + case OP_POW: { + if (!call_binTM(L, top, TM_POW)) + lua_error(L, "undefined operation"); + top--; + break; + } + case OP_CONCAT: { + int n = GETARG_U(i); + luaV_strconc(L, n, top); + top -= n-1; + L->top = top; + luaC_checkGC(L); + break; + } + case OP_MINUS: { + if (tonumber(top-1)) { + ttype(top) = LUA_TNIL; + call_arith(L, top+1, TM_UNM); + } + else + nvalue(top-1) = -nvalue(top-1); + break; + } + case OP_NOT: { + ttype(top-1) = + (ttype(top-1) == LUA_TNIL) ? LUA_TNUMBER : LUA_TNIL; + nvalue(top-1) = 1; + break; + } + case OP_JMPNE: { + top -= 2; + if (!luaO_equalObj(top, top+1)) dojump(pc, i); + break; + } + case OP_JMPEQ: { + top -= 2; + if (luaO_equalObj(top, top+1)) dojump(pc, i); + break; + } + case OP_JMPLT: { + top -= 2; + if (luaV_lessthan(L, top, top+1, top+2)) dojump(pc, i); + break; + } + case OP_JMPLE: { /* a <= b === !(b<a) */ + top -= 2; + if (!luaV_lessthan(L, top+1, top, top+2)) dojump(pc, i); + break; + } + case OP_JMPGT: { /* a > b === (b<a) */ + top -= 2; + if (luaV_lessthan(L, top+1, top, top+2)) dojump(pc, i); + break; + } + case OP_JMPGE: { /* a >= b === !(a<b) */ + top -= 2; + if (!luaV_lessthan(L, top, top+1, top+2)) dojump(pc, i); + break; + } + case OP_JMPT: { + if (ttype(--top) != LUA_TNIL) dojump(pc, i); + break; + } + case OP_JMPF: { + if (ttype(--top) == LUA_TNIL) dojump(pc, i); + break; + } + case OP_JMPONT: { + if (ttype(top-1) == LUA_TNIL) top--; + else dojump(pc, i); + break; + } + case OP_JMPONF: { + if (ttype(top-1) != LUA_TNIL) top--; + else dojump(pc, i); + break; + } + case OP_JMP: { + dojump(pc, i); + break; + } + case OP_PUSHNILJMP: { + ttype(top++) = LUA_TNIL; + pc++; + break; + } + case OP_FORPREP: { + if (tonumber(top-1)) + lua_error(L, "`for' step must be a number"); + if (tonumber(top-2)) + lua_error(L, "`for' limit must be a number"); + if (tonumber(top-3)) + lua_error(L, "`for' initial value must be a number"); + if (nvalue(top-1) > 0 ? + nvalue(top-3) > nvalue(top-2) : + nvalue(top-3) < nvalue(top-2)) { /* `empty' loop? */ + top -= 3; /* remove control variables */ + dojump(pc, i); /* jump to loop end */ + } + break; + } + case OP_FORLOOP: { + LUA_ASSERT(ttype(top-1) == LUA_TNUMBER, "invalid step"); + LUA_ASSERT(ttype(top-2) == LUA_TNUMBER, "invalid limit"); + if (ttype(top-3) != LUA_TNUMBER) + lua_error(L, "`for' index must be a number"); + nvalue(top-3) += nvalue(top-1); /* increment index */ + if (nvalue(top-1) > 0 ? + nvalue(top-3) > nvalue(top-2) : + nvalue(top-3) < nvalue(top-2)) + top -= 3; /* end loop: remove control variables */ + else + dojump(pc, i); /* repeat loop */ + break; + } + case OP_LFORPREP: { + Node *node; + if (ttype(top-1) != LUA_TTABLE) + lua_error(L, "`for' table must be a table"); + node = luaH_next(L, hvalue(top-1), &luaO_nilobject); + if (node == NULL) { /* `empty' loop? */ + top--; /* remove table */ + dojump(pc, i); /* jump to loop end */ + } + else { + top += 2; /* index,value */ + *(top-2) = *key(node); + *(top-1) = *val(node); + } + break; + } + case OP_LFORLOOP: { + Node *node; + LUA_ASSERT(ttype(top-3) == LUA_TTABLE, "invalid table"); + node = luaH_next(L, hvalue(top-3), top-2); + if (node == NULL) /* end loop? */ + top -= 3; /* remove table, key, and value */ + else { + *(top-2) = *key(node); + *(top-1) = *val(node); + dojump(pc, i); /* repeat loop */ + } + break; + } + case OP_CLOSURE: { + L->top = top; + luaV_Lclosure(L, tf->kproto[GETARG_A(i)], GETARG_B(i)); + top = L->top; + luaC_checkGC(L); + break; + } + } + } +} |