void CmdNext::stepCurrentLine(CmdInterrupt& interrupt, ActRec* fp, PC pc) {
// Special handling for yields from generators and awaits from
// async. The destination of these instructions is somewhat counter
// intuitive so we take care to ensure that we step to the most
// appropriate place. For yields, we want to land on the next
// statement when driven from a C++ iterator like ASIO. If the
// generator is driven directly from PHP (i.e., a loop calling
// send($foo)) then we'll land back at the callsite of send(). For
// returns from generators, we follow the execution stack for now,
// and end up at the caller of ASIO or send(). For async functions
// stepping over an await, we land on the next statement.
auto const op = peek_op(pc);
if (op == OpAwait) {
assertx(fp->func()->isAsync());
auto wh = c_Awaitable::fromCell(*vmsp());
if (wh && !wh->isFinished()) {
TRACE(2, "CmdNext: encountered blocking await\n");
if (fp->resumed()) {
setupStepSuspend(fp, pc);
removeLocationFilter();
} else {
// Eager execution in non-resumed mode is supported only by async
// functions. We need to step over this opcode, then grab the created
// AsyncFunctionWaitHandle and setup stepping like we do for
// OpAwait.
assertx(fp->func()->isAsyncFunction());
m_skippingAwait = true;
m_needsVMInterrupt = true;
removeLocationFilter();
}
return;
}
} else if (op == OpYield || op == OpYieldK) {
assertx(fp->resumed());
assertx(fp->func()->isGenerator());
TRACE(2, "CmdNext: encountered yield from generator\n");
setupStepOuts();
setupStepSuspend(fp, pc);
removeLocationFilter();
return;
} else if (op == OpRetC && fp->resumed()) {
assertx(fp->func()->isResumable());
TRACE(2, "CmdNext: encountered return from resumed resumable\n");
setupStepOuts();
removeLocationFilter();
return;
}
installLocationFilterForLine(interrupt.getSite());
m_needsVMInterrupt = true;
}
void CmdNext::stepCurrentLine(CmdInterrupt& interrupt, ActRec* fp, PC pc) {
// Special handling for yields from generators. The destination of these
// instructions is somewhat counter intuitive so we take care to ensure that
// we step to the most appropriate place. For yeilds, we want to land on the
// next statement when driven from a C++ iterator like ASIO. If the generator
// is driven directly from PHP (i.e., a loop calling send($foo)) then we'll
// land back at the callsite of send(). For returns from generators, we follow
// the execution stack for now, and end up at the caller of ASIO or send().
auto op = toOp(*pc);
if (fp->m_func->isGenerator() &&
(op == OpContSuspend || op == OpContSuspendK || op == OpContRetC)) {
TRACE(2, "CmdNext: encountered yield or return from generator\n");
// Patch the projected return point(s) in both cases, to catch if we exit
// the the asio iterator or if we are being iterated directly by PHP.
setupStepOuts();
op = toOp(*pc);
if (op == OpContSuspend || op == OpContSuspendK) {
// Patch the next normal execution point so we can pickup the stepping
// from there if the caller is C++.
setupStepCont(fp, pc);
}
removeLocationFilter();
return;
}
installLocationFilterForLine(interrupt.getSite());
m_needsVMInterrupt = true;
}
void CmdOut::onBeginInterrupt(DebuggerProxy &proxy, CmdInterrupt &interrupt) {
TRACE(2, "CmdNext::onBeginInterrupt\n");
assert(!m_complete); // Complete cmds should not be asked to do work.
if (interrupt.getInterruptType() == ExceptionThrown) {
// If an exception is thrown we turn interrupts on to ensure we stop when
// control reaches the first catch clause.
removeLocationFilter();
m_needsVMInterrupt = true;
return;
}
int currentVMDepth = g_vmContext->m_nesting;
int currentStackDepth = proxy.getStackDepth();
if (currentVMDepth < m_vmDepth) {
// Cut corner here, just break when cross VM boundary no matter how
// many levels we want to go out of
TRACE(2, "CmdOut: shallower VM depth, done.\n");
cleanupStepOuts();
m_complete = true;
} else if ((currentVMDepth == m_vmDepth) &&
(currentStackDepth < m_stackDepth)) {
TRACE(2, "CmdOut: same VM depth, shallower stack depth, done.\n");
cleanupStepOuts();
m_complete = (decCount() == 0);
if (!m_complete) {
TRACE(2, "CmdOut: not complete, step out again.\n");
setupStepOuts();
}
}
m_needsVMInterrupt = false;
}
void CmdOut::onBeginInterrupt(DebuggerProxy &proxy, CmdInterrupt &interrupt) {
TRACE(2, "CmdNext::onBeginInterrupt\n");
assert(!m_complete); // Complete cmds should not be asked to do work.
if (interrupt.getInterruptType() == ExceptionThrown) {
// If an exception is thrown we turn interrupts on to ensure we stop when
// control reaches the first catch clause.
removeLocationFilter();
m_needsVMInterrupt = true;
return;
}
int currentVMDepth = g_vmContext->m_nesting;
int currentStackDepth = proxy.getStackDepth();
// Deeper or same depth? Keep running.
if ((currentVMDepth > m_vmDepth) ||
((currentVMDepth == m_vmDepth) && (currentStackDepth >= m_stackDepth))) {
return;
}
TRACE(2, "CmdOut: shallower stack depth, done.\n");
cleanupStepOuts();
m_complete = (decCount() == 0);
if (!m_complete) {
TRACE(2, "CmdOut: not complete, step out again.\n");
onSetup(proxy, interrupt);
}
m_needsVMInterrupt = false;
}
void CmdNext::onBeginInterrupt(DebuggerProxy &proxy, CmdInterrupt &interrupt) {
TRACE(2, "CmdNext::onBeginInterrupt\n");
assert(!m_complete); // Complete cmds should not be asked to do work.
if (interrupt.getInterruptType() == ExceptionThrown) {
// If an exception is thrown we turn interrupts on to ensure we stop when
// control reaches the first catch clause.
removeLocationFilter();
m_needsVMInterrupt = true;
return;
}
int currentVMDepth = g_vmContext->m_nesting;
int currentStackDepth = proxy.getStackDepth();
if ((currentVMDepth < m_vmDepth) ||
((currentVMDepth == m_vmDepth) && (currentStackDepth <= m_stackDepth))) {
// We're at the same depth as when we started, or perhaps even shallower, so
// there's no need for any step out breakpoint anymore.
cleanupStepOut();
if (m_loc != interrupt.getFileLine()) {
TRACE(2, "CmdNext: same depth, off original line.\n");
m_complete = (decCount() == 0);
}
if (!m_complete) {
TRACE(2, "CmdNext: not complete, filter new line and keep stepping.\n");
m_loc = interrupt.getFileLine();
installLocationFilterForLine(interrupt.getSite());
m_needsVMInterrupt = true;
}
} else {
// Deeper, so let's setup a step out operation and turn interrupts off.
if (!m_stepOutUnit) {
// 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();
setupStepOut();
}
m_needsVMInterrupt = false;
}
}
void CmdNext::stepCurrentLine(CmdInterrupt& interrupt, ActRec* fp, PC pc) {
// Special handling for yields from generators and awaits from
// async. The destination of these instructions is somewhat counter
// intuitive so we take care to ensure that we step to the most
// appropriate place. For yields, we want to land on the next
// statement when driven from a C++ iterator like ASIO. If the
// generator is driven directly from PHP (i.e., a loop calling
// send($foo)) then we'll land back at the callsite of send(). For
// returns from generators, we follow the execution stack for now,
// and end up at the caller of ASIO or send(). For async functions
// stepping over an await, we land on the next statement.
auto op = *reinterpret_cast<const Op*>(pc);
if (fp->resumed() &&
(op == OpYield || op == OpYieldK ||
op == OpAsyncSuspend || op == OpRetC)) {
TRACE(2, "CmdNext: encountered yield, await or return from generator\n");
// Patch the projected return point(s) in both cases for
// generators, to catch if we exit the the asio iterator or if we
// are being iterated directly by PHP.
if ((op == OpRetC) || !fp->m_func->isAsync()) setupStepOuts();
op = *reinterpret_cast<const Op*>(pc);
if (op == OpAsyncSuspend || op == OpYield || op == OpYieldK) {
// Patch the next normal execution point so we can pickup the stepping
// from there if the caller is C++.
setupStepCont(fp, pc);
}
removeLocationFilter();
return;
} else if (op == OpAsyncSuspend) {
// We need to step over this opcode, then grab the continuation
// and setup continuation stepping like we do for OpYield.
TRACE(2, "CmdNext: encountered create async\n");
m_skippingAsyncSuspend = true;
m_needsVMInterrupt = true;
removeLocationFilter();
return;
}
installLocationFilterForLine(interrupt.getSite());
m_needsVMInterrupt = true;
}
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 = g_context->getPC();
// Step over PopR following a call
if (toOp(*pc) == OpPopR) {
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::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);
}
}
CmdFlowControl::~CmdFlowControl() {
// Remove any location filter that may have been setup.
removeLocationFilter();
}