void interpOne(IRGS& env,
folly::Optional<Type> outType,
int popped,
int pushed,
InterpOneData& idata) {
auto const unit = curUnit(env);
spillStack(env);
env.irb->exceptionStackBoundary();
auto const op = unit->getOpcode(bcOff(env));
auto& iInfo = getInstrInfo(op);
if (iInfo.type == jit::InstrFlags::OutFDesc) {
env.fpiStack.push(FPIInfo { sp(env), env.irb->spOffset(), nullptr });
} else if (isFCallStar(op) && !env.fpiStack.empty()) {
env.fpiStack.pop();
}
idata.bcOff = bcOff(env);
idata.cellsPopped = popped;
idata.cellsPushed = pushed;
idata.opcode = op;
gen(
env,
opcodeChangesPC(idata.opcode) ? InterpOneCF : InterpOne,
outType,
idata,
sp(env),
fp(env)
);
assertx(env.irb->stackDeficit() == 0);
}
static void recordActRecPush(const SrcKey sk,
const StringData* name,
const StringData* clsName,
bool staticCall) {
auto unit = sk.unit();
FTRACE(2, "annotation: recordActRecPush: {}@{} {}{}{} ({}static)\n",
unit->filepath()->data(),
sk.offset(),
clsName ? clsName->data() : "",
clsName ? "::" : "",
name,
!staticCall ? "non" : "");
SrcKey next(sk);
next.advance(unit);
const FPIEnt *fpi = sk.func()->findFPI(next.offset());
assert(fpi);
assert(name->isStatic());
assert(sk.offset() == fpi->m_fpushOff);
auto const fcall = SrcKey { sk.func(), fpi->m_fcallOff, sk.resumed() };
assert(isFCallStar(*reinterpret_cast<const Op*>(unit->at(fcall.offset()))));
auto const func = lookupDirectFunc(sk, name, clsName, staticCall);
if (func) {
recordFunc(fcall, func);
}
}
void handleStackOverflow(ActRec* calleeAR) {
/*
* First synchronize registers.
*
* We're called in two situations: either this is the first frame after a
* re-entry, in which case calleeAR->m_sfp is enterTCHelper's native stack,
* or we're called in the middle of one VM entry (from a func prologue). We
* want to raise the exception from the caller's FCall instruction in the
* second case, and in the first case we have to raise in a special way
* inside this re-entry.
*
* Either way the stack depth is below the calleeAR by numArgs, because we
* haven't run func prologue duties yet.
*/
auto& unsafeRegs = vmRegsUnsafe();
auto const isReentry = calleeAR == vmFirstAR();
auto const arToSync = isReentry ? calleeAR : calleeAR->m_sfp;
unsafeRegs.fp = arToSync;
unsafeRegs.stack.top() =
reinterpret_cast<Cell*>(calleeAR) - calleeAR->numArgs();
auto const func_base = arToSync->func()->base();
// calleeAR m_soff is 0 in the re-entry case, so we'll set pc to the func
// base. But it also doesn't matter because we're going to throw a special
// VMReenterStackOverflow in that case so the unwinder won't worry about it.
unsafeRegs.pc = arToSync->func()->unit()->at(func_base + calleeAR->m_soff);
tl_regState = VMRegState::CLEAN;
if (!isReentry) {
/*
* The normal case - we were called via FCall, or FCallArray. We need to
* construct the pc of the fcall from the return address (which will be
* after the fcall). Because fcall is a variable length instruction, and
* because we sometimes delete instructions from the instruction stream, we
* need to use fpi regions to find the fcall.
*/
const FPIEnt* fe = liveFunc()->findPrecedingFPI(
liveUnit()->offsetOf(vmpc()));
vmpc() = liveUnit()->at(fe->m_fcallOff);
assertx(isFCallStar(peek_op(vmpc())));
raise_error("Stack overflow");
} else {
/*
* We were called via re-entry. Leak the params and the ActRec, and tell
* the unwinder that there's nothing left to do in this "entry".
*
* Also, the caller hasn't set up the m_invName area on the ActRec (unless
* it was a magic call), since it's the prologue's responsibility if it's a
* non-magic call. We can just null it out since we're fatalling.
*/
vmsp() = reinterpret_cast<Cell*>(calleeAR + 1);
calleeAR->setVarEnv(nullptr);
throw VMReenterStackOverflow();
}
not_reached();
}
int instrSpToArDelta(const Op* opcode) {
// This function should only be called for instructions that read
// the current FPI
assert(instrReadsCurrentFpi(*opcode));
// The delta from sp to ar is equal to the number of values on the stack
// that will be consumed by this instruction (numPops) plus the number of
// parameters pushed onto the stack so far that are not being consumed by
// this instruction (numExtra). For the FPass* instructions, numExtra will
// be equal to the first immediate argument (param id). For the FCall
// instructions, numExtra will be 0 because all of the parameters on the
// stack are already accounted for by numPops.
int numPops = instrNumPops(opcode);
int numExtra = isFCallStar(*opcode) ? 0 : getImm(opcode, 0).u_IVA;
return numPops + numExtra;
}
bool instrIsNonCallControlFlow(Op opcode) {
if (!instrIsControlFlow(opcode) || isFCallStar(opcode)) return false;
switch (opcode) {
case OpContEnter:
case OpFCallBuiltin:
case OpIncl:
case OpInclOnce:
case OpReq:
case OpReqOnce:
case OpReqDoc:
return false;
default:
return true;
}
}
static void recordActRecPush(NormalizedInstruction& i,
const Unit* unit,
const StringData* name,
const StringData* clsName,
bool staticCall) {
const SrcKey& sk = i.source;
FTRACE(2, "annotation: recordActRecPush: {}@{} {}{}{} ({}static)\n",
unit->filepath()->data(),
sk.offset(),
clsName ? clsName->data() : "",
clsName ? "::" : "",
name,
!staticCall ? "non" : "");
SrcKey next(sk);
next.advance(unit);
const FPIEnt *fpi = curFunc()->findFPI(next.offset());
assert(fpi);
assert(name->isStatic());
assert(sk.offset() == fpi->m_fpushOff);
SrcKey fcall = sk;
fcall.m_offset = fpi->m_fcallOff;
assert(isFCallStar(*unit->at(fcall.offset())));
if (clsName) {
const Class* cls = Unit::lookupUniqueClass(clsName);
bool magic = false;
const Func* func = lookupImmutableMethod(cls, name, magic, staticCall);
if (func) {
recordFunc(i, fcall, func);
}
return;
}
const Func* func = Unit::lookupFunc(name);
if (func && func->isNameBindingImmutable(unit)) {
// this will never go into a call cache, so we dont need to
// encode the args. it will be used in OpFCall below to
// set the i->funcd.
recordFunc(i, fcall, func);
} else {
// It's not enough to remember the function name; we also need to encode
// the number of arguments and current flag disposition.
int numArgs = getImm(unit->at(sk.offset()), 0).u_IVA;
recordNameAndArgs(fcall, name, numArgs);
}
}
bool instrIsNonCallControlFlow(Op opcode) {
if (!instrIsControlFlow(opcode) || isFCallStar(opcode)) return false;
switch (opcode) {
case OpAwait:
case OpYield:
case OpYieldK:
case OpContEnter:
case OpContRaise:
case OpContEnterDelegate:
case OpYieldFromDelegate:
case OpFCallBuiltin:
case OpIncl:
case OpInclOnce:
case OpReq:
case OpReqOnce:
case OpReqDoc:
return false;
default:
return true;
}
}
