static Instruction *getjumpcontrol (FuncState *fs, int pc) { Instruction *pi = &fs->f->code[pc]; if (pc >= 1 && testOpMode(GET_OPCODE(*(pi-1)), OpModeT)) return pi-1; else return pi; }
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) */ 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); } else if (testOpMode(op, OpModeBrk)) check(checkRK(pt, b)); if (testOpMode(op, OpModeCrk)) check(checkRK(pt, c)); break; } case iABx: { b = GETARG_Bx(i); if (testOpMode(op, OpModeK)) check(b < pt->sizek); break; } case iAsBx: { b = GETARG_sBx(i); break; } } if (testOpMode(op, OpModesetA)) { if (a == reg) last = pc; /* change register `a' */ } if (testOpMode(op, OpModeT)) { 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: { /* `c' is a register, and at least two operands */ check(c < MAXSTACK && b < c); break; } case OP_TFORLOOP: checkreg(pt, a+c+5); if (reg >= a) last = pc; /* affect all registers above base */ /* go through */ case OP_FORLOOP: checkreg(pt, a+2); /* go through */ case OP_JMP: { 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_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: { checkreg(pt, a + (b&(LFIELDS_PER_FLUSH-1)) + 1); 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; } default: break; } } return pt->code[last]; }