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();
}
void sync_regstate(_Unwind_Context* context) {
assertx(tl_regState == VMRegState::DIRTY);
uintptr_t frameRbp = _Unwind_GetGR(context, Debug::RBP);
uintptr_t frameRip = _Unwind_GetIP(context);
FTRACE(2, "syncing regstate for rbp: {:#x} rip: {:#x}\n", frameRbp, frameRip);
/*
* fixupWork expects to be looking at the first frame that is out of
* the TC. We have RBP/RIP for the TC frame that called out here,
* so we make a fake ActRec here to give it what it expects.
*
* Note: this doesn't work for IndirectFixup situations. However,
* currently IndirectFixup is only used for destructors, which
* aren't allowed to throw, so this is ok.
*/
ActRec fakeAr;
fakeAr.m_sfp = reinterpret_cast<ActRec*>(frameRbp);
fakeAr.m_savedRip = frameRip;
Stats::inc(Stats::TC_SyncUnwind);
mcg->fixupMap().fixupWork(g_context.getNoCheck(), &fakeAr);
tl_regState = VMRegState::CLEAN;
FTRACE(2, "synced vmfp: {} vmsp: {} vmpc: {}\n", vmfp(), vmsp(), vmpc());
}
void collectImpl(const char* phase) {
VMRegAnchor _;
if (t_eager_gc && RuntimeOption::EvalFilterGCPoints) {
t_eager_gc = false;
auto pc = vmpc();
if (t_surprise_filter.test(pc)) return;
t_surprise_filter.insert(pc);
TRACE(2, "eager gc %s at %p\n", phase, pc);
} else {
TRACE(2, "normal gc %s at %p\n", phase, vmpc());
}
Marker mkr;
mkr.init();
mkr.trace();
mkr.sweep();
}
TCA fcallHelper(ActRec* ar) {
assert_native_stack_aligned();
assertx(!ar->resumed());
if (LIKELY(!RuntimeOption::EvalFailJitPrologs)) {
auto const tca = mcg->getFuncPrologue(
const_cast<Func*>(ar->m_func),
ar->numArgs(),
ar
);
if (tca) return tca;
}
// Check for stack overflow in the same place func prologues make their
// StackCheck::Early check (see irgen-func-prologue.cpp). This handler also
// cleans and syncs vmRegs for us.
if (checkCalleeStackOverflow(ar)) handleStackOverflow(ar);
try {
VMRegAnchor _(ar);
if (doFCall(ar, vmpc())) {
return mcg->tx().uniqueStubs.resumeHelperRet;
}
// We've been asked to skip the function body (fb_intercept). The vmregs
// have already been fixed; indicate this with a nullptr return.
return nullptr;
} catch (...) {
// The VMRegAnchor above took care of us, but we need to tell the unwinder
// (since ~VMRegAnchor() will have reset tl_regState).
tl_regState = VMRegState::CLEAN;
throw;
}
}
// Unwind the frame for a builtin. Currently only used when switching
// modes for hphpd_break and fb_enable_code_coverage.
void unwindBuiltinFrame() {
auto& stack = vmStack();
auto& fp = vmfp();
assert(fp->m_func->methInfo());
assert(fp->m_func->name()->isame(s_hphpd_break.get()) ||
fp->m_func->name()->isame(s_fb_enable_code_coverage.get()));
// Free any values that may be on the eval stack. We know there
// can't be FPI regions and it can't be a generator body because
// it's a builtin frame.
auto const evalTop = reinterpret_cast<TypedValue*>(vmfp());
while (stack.topTV() < evalTop) {
stack.popTV();
}
// Free the locals and VarEnv if there is one
auto rv = make_tv<KindOfNull>();
frame_free_locals_inl(fp, fp->m_func->numLocals(), &rv);
// Tear down the frame
Offset pc = -1;
ActRec* sfp = g_context->getPrevVMState(fp, &pc);
assert(pc != -1);
fp = sfp;
vmpc() = fp->m_func->unit()->at(pc);
stack.discardAR();
stack.pushNull(); // return value
}
void
FixupMap::fixupWorkSimulated(ExecutionContext* ec) const {
TRACE(1, "fixup(begin):\n");
auto isVMFrame = [] (ActRec* ar, const vixl::Simulator* sim) {
// If this assert is failing, you may have forgotten a sync point somewhere
assert(ar);
bool ret =
uintptr_t(ar) - s_stackLimit >= s_stackSize &&
!sim->is_on_stack(ar);
assert(!ret ||
(ar >= vmStack().getStackLowAddress() &&
ar < vmStack().getStackHighAddress()) ||
ar->resumed());
return ret;
};
// For each nested simulator (corresponding to nested VM invocations), look at
// its PC to find a potential fixup key.
//
// Callstack walking is necessary, because we may get called from a
// uniqueStub.
for (int i = ec->m_activeSims.size() - 1; i >= 0; --i) {
auto const* sim = ec->m_activeSims[i];
auto* rbp = reinterpret_cast<ActRec*>(sim->xreg(JIT::ARM::rVmFp.code()));
auto tca = reinterpret_cast<TCA>(sim->pc());
TRACE(2, "considering frame %p, %p\n", rbp, tca);
while (rbp && !isVMFrame(rbp, sim)) {
tca = reinterpret_cast<TCA>(rbp->m_savedRip);
rbp = rbp->m_sfp;
}
if (!rbp) continue;
auto* ent = m_fixups.find(tca);
if (!ent) {
continue;
}
if (ent->isIndirect()) {
not_implemented();
}
VMRegs regs;
regsFromActRec(tca, rbp, ent->fixup, ®s);
TRACE(2, "fixup(end): func %s fp %p sp %p pc %p\b",
regs.m_fp->m_func->name()->data(),
regs.m_fp, regs.m_sp, regs.m_pc);
vmfp() = const_cast<ActRec*>(regs.m_fp);
vmpc() = reinterpret_cast<PC>(regs.m_pc);
vmsp() = regs.m_sp;
return;
}
// This shouldn't be reached.
always_assert(false);
}
UnwindAction enterUnwinder() {
auto fault = g_context->m_faults.back();
return unwind(
vmfp(), // by ref
vmStack(), // by ref
vmpc(), // by ref
fault
);
}
void CmdOut::onBeginInterrupt(DebuggerProxy &proxy, CmdInterrupt &interrupt) {
TRACE(2, "CmdOut::onBeginInterrupt\n");
assert(!m_complete); // Complete cmds should not be asked to do work.
m_needsVMInterrupt = false;
if (m_skippingOverPopR) {
m_complete = true;
return;
}
int currentVMDepth = g_context->m_nesting;
int currentStackDepth = proxy.getStackDepth();
// Deeper or same depth? Keep running.
if ((currentVMDepth > m_vmDepth) ||
((currentVMDepth == m_vmDepth) && (currentStackDepth >= m_stackDepth))) {
TRACE(2, "CmdOut: deeper, keep running...\n");
return;
}
if (interrupt.getInterruptType() == ExceptionHandler) {
// If we're about to enter an exception handler we turn interrupts on to
// ensure we stop when control reaches the handler. The normal logic below
// will decide if we're done at that point or not.
TRACE(2, "CmdOut: exception thrown\n");
removeLocationFilter();
m_needsVMInterrupt = true;
return;
}
TRACE(2, "CmdOut: shallower stack depth, done.\n");
cleanupStepOuts();
int depth = decCount();
if (depth == 0) {
PC pc = vmpc();
// Step over PopR following a call
if (*reinterpret_cast<const Op*>(pc) == Op::PopR) {
m_skippingOverPopR = true;
m_needsVMInterrupt = true;
} else {
m_complete = true;
}
return;
} else {
TRACE(2, "CmdOut: not complete, step out again.\n");
onSetup(proxy, interrupt);
}
}
void CmdNext::onSetup(DebuggerProxy& proxy, CmdInterrupt& interrupt) {
TRACE(2, "CmdNext::onSetup\n");
assertx(!m_complete); // Complete cmds should not be asked to do work.
m_stackDepth = proxy.getStackDepth();
m_vmDepth = g_context->m_nesting;
m_loc = interrupt.getFileLine();
ActRec *fp = vmfp();
if (!fp) {
// If we have no frame just wait for the next instruction to be interpreted.
m_needsVMInterrupt = true;
return;
}
PC pc = vmpc();
stepCurrentLine(interrupt, fp, pc);
}
TCA fcallHelper(ActRec* ar, void* sp) {
try {
assert(!ar->resumed());
TCA tca =
mcg->getFuncPrologue((Func*)ar->m_func, ar->numArgs(), ar);
if (tca) {
return tca;
}
if (!ar->m_func->isClonedClosure()) {
/*
* If the func is a cloned closure, then the original
* closure has already run the prologue, and the prologues
* array is just being used as entry points for the
* dv funclets. Dont run the prologue again.
*/
VMRegAnchor _(ar);
if (g_context->doFCall(ar, vmpc())) {
return tx->uniqueStubs.resumeHelperRet;
}
// We've been asked to skip the function body
// (fb_intercept). frame, stack and pc have
// already been fixed - flag that with a negative
// return address.
return (TCA)-ar->m_savedRip;
}
setupAfterPrologue(ar, sp);
assert(ar == vmfp());
return tx->uniqueStubs.resumeHelper;
} catch (...) {
/*
The return address is set to __fcallHelperThunk,
which has no unwind information. Its "logically"
part of the tc, but the c++ unwinder wont know
that. So point our return address at the called
function's return address (which will be in the
tc).
Note that the registers really are clean - we
cleaned them in the try above - so we just
have to tell the unwinder that.
*/
DECLARE_FRAME_POINTER(framePtr);
tl_regState = VMRegState::CLEAN;
framePtr->m_savedRip = ar->m_savedRip;
throw;
}
}
// stack trace helper
static ProfileStackTrace getStackTrace() {
ProfileStackTrace trace;
if (g_context.isNull()) return trace;
VMRegAnchor _;
ActRec *fp = vmfp();
if (!fp) return trace;
PC pc = vmpc();
const Func *f = fp->m_func;
Unit *u = f->unit();
Offset off = pc - u->entry();
for (;;) {
trace.push_back({ f, off, fp->resumed() });
fp = g_context->getPrevVMStateUNSAFE(fp, &off);
if (!fp) break;
f = fp->m_func;
}
return trace;
}
void enterTC(TCA start, ActRec* stashedAR) {
if (debug) {
fflush(stdout);
fflush(stderr);
}
assertx(tc::isValidCodeAddress(start));
assertx(((uintptr_t)vmsp() & (sizeof(Cell) - 1)) == 0);
assertx(((uintptr_t)vmfp() & (sizeof(Cell) - 1)) == 0);
INC_TPC(enter_tc);
if (Trace::moduleEnabled(Trace::ringbuffer, 1)) {
auto skData = SrcKey{liveFunc(), vmpc(), liveResumed()}.toAtomicInt();
Trace::ringbufferEntry(Trace::RBTypeEnterTC, skData, (uint64_t)start);
}
tl_regState = VMRegState::DIRTY;
enterTCImpl(start, stashedAR);
tl_regState = VMRegState::CLEAN;
assertx(isValidVMStackAddress(vmsp()));
vmfp() = nullptr;
}
void throwable_init(ObjectData* throwable) {
assertx(is_throwable(throwable));
assertx(throwable_has_expected_props());
auto trace = HHVM_FN(debug_backtrace)(exception_get_trace_options());
cellMove(
make_tv<KindOfArray>(trace.detach()), throwable->propVec()[s_traceIdx]);
VMRegAnchor _;
auto const fp = vmfp();
if (UNLIKELY(!fp)) return;
if (UNLIKELY(fp->func()->isBuiltin())) {
throwable_init_file_and_line_from_builtin(throwable);
} else {
assertx(throwable->propVec()[s_fileIdx].m_type == KindOfNull);
assertx(throwable->propVec()[s_lineIdx].m_type == KindOfNull);
auto const unit = fp->func()->unit();
auto const file = const_cast<StringData*>(unit->filepath());
auto const line = unit->getLineNumber(unit->offsetOf(vmpc()));
cellDup(make_tv<KindOfString>(file), throwable->propVec()[s_fileIdx]);
cellDup(make_tv<KindOfInt64>(line), throwable->propVec()[s_lineIdx]);
}
}
Array createBacktrace(const BacktraceArgs& btArgs) {
auto bt = Array::Create();
// If there is a parser frame, put it at the beginning of the backtrace.
if (btArgs.m_parserFrame) {
bt.append(
make_map_array(
s_file, btArgs.m_parserFrame->filename,
s_line, btArgs.m_parserFrame->lineNumber
)
);
}
VMRegAnchor _;
// If there are no VM frames, we're done.
if (!rds::header() || !vmfp()) return bt;
int depth = 0;
ActRec* fp = nullptr;
Offset pc = 0;
// Get the fp and pc of the top frame (possibly skipping one frame).
if (btArgs.m_skipTop) {
fp = getPrevActRec(vmfp(), &pc);
// We skipped over the only VM frame, we're done.
if (!fp) return bt;
} else {
fp = vmfp();
auto const unit = fp->func()->unit();
assert(unit);
pc = unit->offsetOf(vmpc());
}
// Handle the top frame.
if (btArgs.m_withSelf) {
// Builtins don't have a file and line number.
if (!fp->func()->isBuiltin()) {
auto const unit = fp->func()->unit();
assert(unit);
auto const filename = fp->func()->filename();
ArrayInit frame(btArgs.m_parserFrame ? 4 : 2, ArrayInit::Map{});
frame.set(s_file, Variant{const_cast<StringData*>(filename)});
frame.set(s_line, unit->getLineNumber(pc));
if (btArgs.m_parserFrame) {
frame.set(s_function, s_include);
frame.set(s_args, Array::Create(btArgs.m_parserFrame->filename));
}
bt.append(frame.toVariant());
depth++;
}
}
// Handle the subsequent VM frames.
Offset prevPc = 0;
for (auto prevFp = getPrevActRec(fp, &prevPc);
fp != nullptr && (btArgs.m_limit == 0 || depth < btArgs.m_limit);
fp = prevFp, pc = prevPc,
prevFp = getPrevActRec(fp, &prevPc)) {
// Do not capture frame for HPHP only functions.
if (fp->func()->isNoInjection()) continue;
ArrayInit frame(7, ArrayInit::Map{});
auto const curUnit = fp->func()->unit();
auto const curOp = *reinterpret_cast<const Op*>(curUnit->at(pc));
auto const isReturning =
curOp == Op::RetC || curOp == Op::RetV ||
curOp == Op::CreateCont || curOp == Op::Await ||
fp->localsDecRefd();
// Builtins and generators don't have a file and line number
if (prevFp && !prevFp->func()->isBuiltin()) {
auto const prevUnit = prevFp->func()->unit();
auto prevFile = prevUnit->filepath();
if (prevFp->func()->originalFilename()) {
prevFile = prevFp->func()->originalFilename();
}
assert(prevFile);
frame.set(s_file, Variant{const_cast<StringData*>(prevFile)});
// In the normal method case, the "saved pc" for line number printing is
// pointing at the cell conversion (Unbox/Pop) instruction, not the call
// itself. For multi-line calls, this instruction is associated with the
// subsequent line which results in an off-by-n. We're subtracting one
// in order to look up the line associated with the FCall/FCallArray
// instruction. Exception handling and the other opcodes (ex. BoxR)
// already do the right thing. The emitter associates object access with
// the subsequent expression and this would be difficult to modify.
auto const opAtPrevPc =
*reinterpret_cast<const Op*>(prevUnit->at(prevPc));
Offset pcAdjust = 0;
if (opAtPrevPc == Op::PopR ||
opAtPrevPc == Op::UnboxR ||
opAtPrevPc == Op::UnboxRNop) {
pcAdjust = 1;
}
frame.set(s_line,
prevFp->func()->unit()->getLineNumber(prevPc - pcAdjust));
}
// Check for include.
String funcname{const_cast<StringData*>(fp->func()->name())};
if (fp->func()->isClosureBody()) {
// Strip the file hash from the closure name.
String fullName{const_cast<StringData*>(fp->func()->baseCls()->name())};
funcname = fullName.substr(0, fullName.find(';'));
}
// Check for pseudomain.
if (funcname.empty()) {
if (!prevFp && !btArgs.m_withPseudoMain) continue;
else if (!prevFp) funcname = s_main;
else funcname = s_include;
}
frame.set(s_function, funcname);
if (!funcname.same(s_include)) {
// Closures have an m_this but they aren't in object context.
auto ctx = arGetContextClass(fp);
if (ctx != nullptr && !fp->func()->isClosureBody()) {
frame.set(s_class, Variant{const_cast<StringData*>(ctx->name())});
if (fp->hasThis() && !isReturning) {
if (btArgs.m_withThis) {
frame.set(s_object, Object(fp->getThis()));
}
frame.set(s_type, s_arrow);
} else {
frame.set(s_type, s_double_colon);
}
}
}
bool const mayUseVV = fp->func()->attrs() & AttrMayUseVV;
auto const withNames = btArgs.m_withArgNames;
auto const withValues = btArgs.m_withArgValues;
if (!btArgs.m_withArgNames && !btArgs.m_withArgValues) {
// do nothing
} else if (funcname.same(s_include)) {
if (depth != 0) {
auto filepath = const_cast<StringData*>(curUnit->filepath());
frame.set(s_args, make_packed_array(filepath));
}
} else if (!RuntimeOption::EnableArgsInBacktraces || isReturning) {
// Provide an empty 'args' array to be consistent with hphpc.
frame.set(s_args, empty_array());
} else {
auto args = Array::Create();
auto const nparams = fp->func()->numNonVariadicParams();
auto const nargs = fp->numArgs();
auto const nformals = std::min<int>(nparams, nargs);
if (UNLIKELY(mayUseVV) &&
UNLIKELY(fp->hasVarEnv() && fp->getVarEnv()->getFP() != fp)) {
// VarEnv is attached to eval or debugger frame, other than the current
// frame. Access locals thru VarEnv.
auto varEnv = fp->getVarEnv();
auto func = fp->func();
for (int i = 0; i < nformals; i++) {
auto const argname = func->localVarName(i);
auto const tv = varEnv->lookup(argname);
Variant val;
if (tv != nullptr) { // the variable hasn't been unset
val = withValues ? tvAsVariant(tv) : "";
}
if (withNames) {
args.set(String(const_cast<StringData*>(argname)), val);
} else {
args.append(val);
}
}
} else {
for (int i = 0; i < nformals; i++) {
Variant val = withValues ? tvAsVariant(frame_local(fp, i)) : "";
if (withNames) {
auto const argname = fp->func()->localVarName(i);
args.set(String(const_cast<StringData*>(argname)), val);
} else {
args.append(val);
}
}
}
// Builtin extra args are not stored in varenv.
if (UNLIKELY(mayUseVV) && nargs > nparams && fp->hasExtraArgs()) {
for (int i = nparams; i < nargs; i++) {
auto arg = fp->getExtraArg(i - nparams);
args.append(tvAsVariant(arg));
}
}
frame.set(s_args, args);
}
if (btArgs.m_withMetadata && !isReturning) {
if (UNLIKELY(mayUseVV) && UNLIKELY(fp->hasVarEnv())) {
auto tv = fp->getVarEnv()->lookup(s_86metadata.get());
if (tv != nullptr && tv->m_type != KindOfUninit) {
frame.set(s_metadata, tvAsVariant(tv));
}
} else {
auto local = fp->func()->lookupVarId(s_86metadata.get());
if (local != kInvalidId) {
auto tv = frame_local(fp, local);
if (tv->m_type != KindOfUninit) {
frame.set(s_metadata, tvAsVariant(tv));
}
}
}
}
bt.append(frame.toVariant());
depth++;
}
return bt;
}
void CmdNext::onBeginInterrupt(DebuggerProxy& proxy, CmdInterrupt& interrupt) {
TRACE(2, "CmdNext::onBeginInterrupt\n");
assertx(!m_complete); // Complete cmds should not be asked to do work.
ActRec *fp = vmfp();
if (!fp) {
// If we have no frame just wait for the next instruction to be interpreted.
m_needsVMInterrupt = true;
return;
}
PC pc = vmpc();
Unit* unit = fp->m_func->unit();
Offset offset = unit->offsetOf(pc);
TRACE(2, "CmdNext: pc %p, opcode %s at '%s' offset %d\n",
pc,
opcodeToName(peek_op(pc)),
fp->m_func->fullName()->data(),
offset);
int currentVMDepth = g_context->m_nesting;
int currentStackDepth = proxy.getStackDepth();
TRACE(2, "CmdNext: original depth %d:%d, current depth %d:%d\n",
m_vmDepth, m_stackDepth, currentVMDepth, currentStackDepth);
// Where are we on the stack now vs. when we started? Breaking the answer down
// into distinct variables helps the clarity of the algorithm below.
bool deeper = false;
bool originalDepth = false;
if ((currentVMDepth == m_vmDepth) && (currentStackDepth == m_stackDepth)) {
originalDepth = true;
} else if ((currentVMDepth > m_vmDepth) ||
((currentVMDepth == m_vmDepth) &&
(currentStackDepth > m_stackDepth))) {
deeper = true;
}
m_needsVMInterrupt = false; // Will be set again below if still needed.
// First consider if we've got internal breakpoints setup. These are used when
// we can make an accurate prediction of where execution should flow,
// eventually, and when we want to let the program run normally until we get
// there.
if (hasStepOuts() || hasStepResumable()) {
TRACE(2, "CmdNext: checking internal breakpoint(s)\n");
if (atStepOutOffset(unit, offset)) {
if (deeper) return; // Recursion
TRACE(2, "CmdNext: hit step-out\n");
} else if (atStepResumableOffset(unit, offset)) {
if (m_stepResumableId != getResumableId(fp)) return;
TRACE(2, "CmdNext: hit step-cont\n");
// We're in the resumable we expect. This may be at a
// different stack depth, though, especially if we've moved from
// the original function to the resumable. Update the depth
// accordingly.
if (!originalDepth) {
m_vmDepth = currentVMDepth;
m_stackDepth = currentStackDepth;
deeper = false;
originalDepth = true;
}
} else if (interrupt.getInterruptType() == ExceptionHandler) {
// Entering an exception handler may take us someplace we weren't
// expecting. Adjust internal breakpoints accordingly. First case is easy.
if (deeper) {
TRACE(2, "CmdNext: exception handler, deeper\n");
return;
}
// For step-conts, we ignore handlers at the original level if we're not
// in the original resumable. We don't care about exception handlers
// in resumables being driven at the same level.
if (hasStepResumable() && originalDepth &&
(m_stepResumableId != getResumableId(fp))) {
TRACE(2, "CmdNext: exception handler, original depth, wrong cont\n");
return;
}
// Sometimes we have handlers in generated code, i.e., Continuation::next.
// These just help propagate exceptions so ignore those.
if (fp->m_func->line1() == 0) {
TRACE(2, "CmdNext: exception handler, ignoring func with no source\n");
return;
}
if (fp->m_func->isBuiltin()) {
TRACE(2, "CmdNext: exception handler, ignoring builtin functions\n");
return;
}
TRACE(2, "CmdNext: exception handler altering expected flow\n");
} else {
// We have internal breakpoints setup, but we haven't hit one yet. Keep
// running until we reach one.
TRACE(2, "CmdNext: waiting to hit internal breakpoint...\n");
return;
}
// We've hit one internal breakpoint at a useful place, or decided we don't,
// need them, so we can remove them all now.
cleanupStepOuts();
cleanupStepResumable();
}
if (interrupt.getInterruptType() == ExceptionHandler) {
// If we're about to enter an exception handler we turn interrupts on to
// ensure we stop when control reaches the handler. The normal logic below
// will decide if we're done at that point or not.
TRACE(2, "CmdNext: exception handler\n");
removeLocationFilter();
m_needsVMInterrupt = true;
return;
}
if (m_skippingAwait) {
m_skippingAwait = false;
stepAfterAwait();
return;
}
if (deeper) {
TRACE(2, "CmdNext: deeper, setup step out to get back to original line\n");
setupStepOuts();
// We can nuke the entire location filter here since we'll re-install it
// when we get back to the old level. Keeping it installed may be more
// efficient if we were on a large line, but there is a penalty for every
// opcode executed while it's installed and that's bad if there's a lot of
// code called from that line.
removeLocationFilter();
return;
}
if (originalDepth && (m_loc == interrupt.getFileLine())) {
TRACE(2, "CmdNext: not complete, still on same line\n");
stepCurrentLine(interrupt, fp, pc);
return;
}
TRACE(2, "CmdNext: operation complete.\n");
m_complete = (decCount() == 0);
if (!m_complete) {
TRACE(2, "CmdNext: repeat count > 0, start fresh.\n");
onSetup(proxy, interrupt);
}
}
bool EventHook::RunInterceptHandler(ActRec* ar) {
const Func* func = ar->func();
if (LIKELY(func->maybeIntercepted() == 0)) return true;
// Intercept only original generator / async function calls, not resumption.
if (ar->resumed()) return true;
Variant* h = get_intercept_handler(func->fullNameStr(),
&func->maybeIntercepted());
if (!h) return true;
/*
* In production mode, only functions that we have assumed can be
* intercepted during static analysis should actually be
* intercepted.
*/
if (RuntimeOption::RepoAuthoritative &&
!RuntimeOption::EvalJitEnableRenameFunction) {
if (!(func->attrs() & AttrInterceptable)) {
raise_error("fb_intercept was used on a non-interceptable function (%s) "
"in RepoAuthoritative mode", func->fullName()->data());
}
}
VMRegAnchor _;
PC savePc = vmpc();
Variant doneFlag = true;
Variant called_on;
if (ar->hasThis()) {
called_on = Variant(ar->getThis());
} else if (ar->hasClass()) {
// For static methods, give handler the name of called class
called_on = Variant(const_cast<StringData*>(ar->getClass()->name()));
}
Variant intArgs =
PackedArrayInit(5)
.append(VarNR(ar->func()->fullName()))
.append(called_on)
.append(get_frame_args_with_ref(ar))
.append(h->asCArrRef()[1])
.appendRef(doneFlag)
.toArray();
Variant ret = vm_call_user_func(h->asCArrRef()[0], intArgs);
if (doneFlag.toBoolean()) {
Offset pcOff;
ActRec* outer = g_context->getPrevVMState(ar, &pcOff);
frame_free_locals_inl_no_hook<true>(ar, ar->func()->numLocals());
Stack& stack = vmStack();
stack.top() = (Cell*)(ar + 1);
cellDup(*ret.asCell(), *stack.allocTV());
vmfp() = outer;
vmpc() = outer ? outer->func()->unit()->at(pcOff) : nullptr;
return false;
}
vmfp() = ar;
vmpc() = savePc;
return true;
}
Array createBacktrace(const BacktraceArgs& btArgs) {
Array bt = Array::Create();
// If there is a parser frame, put it at the beginning of
// the backtrace
if (btArgs.m_parserFrame) {
bt.append(
make_map_array(
s_file, btArgs.m_parserFrame->filename,
s_line, btArgs.m_parserFrame->lineNumber
)
);
}
VMRegAnchor _;
if (!vmfp()) {
// If there are no VM frames, we're done
return bt;
}
int depth = 0;
ActRec* fp = nullptr;
Offset pc = 0;
// Get the fp and pc of the top frame (possibly skipping one frame)
{
if (btArgs.m_skipTop) {
fp = g_context->getPrevVMState(vmfp(), &pc);
if (!fp) {
// We skipped over the only VM frame, we're done
return bt;
}
} else {
fp = vmfp();
Unit *unit = vmfp()->m_func->unit();
assert(unit);
pc = unit->offsetOf(vmpc());
}
// Handle the top frame
if (btArgs.m_withSelf) {
// Builtins don't have a file and line number
if (!fp->m_func->isBuiltin()) {
Unit* unit = fp->m_func->unit();
assert(unit);
const char* filename = fp->m_func->filename()->data();
Offset off = pc;
ArrayInit frame(btArgs.m_parserFrame ? 4 : 2, ArrayInit::Map{});
frame.set(s_file, filename);
frame.set(s_line, unit->getLineNumber(off));
if (btArgs.m_parserFrame) {
frame.set(s_function, s_include);
frame.set(s_args, Array::Create(btArgs.m_parserFrame->filename));
}
bt.append(frame.toVariant());
depth++;
}
}
}
// Handle the subsequent VM frames
Offset prevPc = 0;
for (ActRec* prevFp = g_context->getPrevVMState(fp, &prevPc);
fp != nullptr && (btArgs.m_limit == 0 || depth < btArgs.m_limit);
fp = prevFp, pc = prevPc,
prevFp = g_context->getPrevVMState(fp, &prevPc)) {
// do not capture frame for HPHP only functions
if (fp->m_func->isNoInjection()) {
continue;
}
ArrayInit frame(7, ArrayInit::Map{});
auto const curUnit = fp->m_func->unit();
auto const curOp = *reinterpret_cast<const Op*>(curUnit->at(pc));
auto const isReturning =
curOp == Op::RetC || curOp == Op::RetV ||
curOp == Op::CreateCont || curOp == Op::Await ||
fp->localsDecRefd();
// Builtins and generators don't have a file and line number
if (prevFp && !prevFp->m_func->isBuiltin() && !fp->resumed()) {
auto const prevUnit = prevFp->m_func->unit();
auto prevFile = prevUnit->filepath();
if (prevFp->m_func->originalFilename()) {
prevFile = prevFp->m_func->originalFilename();
}
assert(prevFile);
frame.set(s_file, const_cast<StringData*>(prevFile));
// In the normal method case, the "saved pc" for line number printing is
// pointing at the cell conversion (Unbox/Pop) instruction, not the call
// itself. For multi-line calls, this instruction is associated with the
// subsequent line which results in an off-by-n. We're subtracting one
// in order to look up the line associated with the FCall/FCallArray
// instruction. Exception handling and the other opcodes (ex. BoxR)
// already do the right thing. The emitter associates object access with
// the subsequent expression and this would be difficult to modify.
auto const opAtPrevPc =
*reinterpret_cast<const Op*>(prevUnit->at(prevPc));
Offset pcAdjust = 0;
if (opAtPrevPc == OpPopR || opAtPrevPc == OpUnboxR) {
pcAdjust = 1;
}
frame.set(s_line,
prevFp->m_func->unit()->getLineNumber(prevPc - pcAdjust));
}
// check for include
String funcname = const_cast<StringData*>(fp->m_func->name());
if (fp->m_func->isClosureBody()) {
static StringData* s_closure_label =
makeStaticString("{closure}");
funcname = s_closure_label;
}
// check for pseudomain
if (funcname.empty()) {
if (!prevFp) continue;
funcname = s_include;
}
frame.set(s_function, funcname);
if (!funcname.same(s_include)) {
// Closures have an m_this but they aren't in object context
Class* ctx = arGetContextClass(fp);
if (ctx != nullptr && !fp->m_func->isClosureBody()) {
frame.set(s_class, ctx->name()->data());
if (fp->hasThis() && !isReturning) {
if (btArgs.m_withThis) {
frame.set(s_object, Object(fp->getThis()));
}
frame.set(s_type, "->");
} else {
frame.set(s_type, "::");
}
}
}
Array args = Array::Create();
if (btArgs.m_ignoreArgs) {
// do nothing
} else if (funcname.same(s_include)) {
if (depth) {
args.append(const_cast<StringData*>(curUnit->filepath()));
frame.set(s_args, args);
}
} else if (!RuntimeOption::EnableArgsInBacktraces || isReturning) {
// Provide an empty 'args' array to be consistent with hphpc
frame.set(s_args, args);
} else {
const int nparams = fp->m_func->numNonVariadicParams();
int nargs = fp->numArgs();
int nformals = std::min(nparams, nargs);
if (UNLIKELY(fp->hasVarEnv() && fp->getVarEnv()->getFP() != fp)) {
// VarEnv is attached to eval or debugger frame, other than the current
// frame. Access locals thru VarEnv.
auto varEnv = fp->getVarEnv();
auto func = fp->func();
for (int i = 0; i < nformals; i++) {
TypedValue *arg = varEnv->lookup(func->localVarName(i));
args.append(tvAsVariant(arg));
}
} else {
for (int i = 0; i < nformals; i++) {
TypedValue *arg = frame_local(fp, i);
args.append(tvAsVariant(arg));
}
}
/* builtin extra args are not stored in varenv */
if (nargs > nparams && fp->hasExtraArgs()) {
for (int i = nparams; i < nargs; i++) {
TypedValue *arg = fp->getExtraArg(i - nparams);
args.append(tvAsVariant(arg));
}
}
frame.set(s_args, args);
}
bt.append(frame.toVariant());
depth++;
}
return bt;
}
