blob: 7594b91cd222124e55bfa255753e627eaccf038a [file] [log] [blame]
// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/stack_frame.h"
#include "platform/memory_sanitizer.h"
#include "vm/assembler.h"
#include "vm/deopt_instructions.h"
#include "vm/isolate.h"
#include "vm/object.h"
#include "vm/object_store.h"
#include "vm/os.h"
#include "vm/parser.h"
#include "vm/raw_object.h"
#include "vm/reusable_handles.h"
#include "vm/stub_code.h"
#include "vm/visitor.h"
namespace dart {
bool StackFrame::IsStubFrame() const {
ASSERT(!(IsEntryFrame() || IsExitFrame()));
#if !defined(TARGET_OS_WINDOWS)
// On Windows, the profiler calls this from a separate thread where
// Thread::Current() is NULL, so we cannot create a NoSafepointScope.
NoSafepointScope no_safepoint;
#endif
RawCode* code = GetCodeObject();
intptr_t cid = code->ptr()->owner_->GetClassId();
ASSERT(cid == kNullCid || cid == kClassCid || cid == kFunctionCid);
return cid == kNullCid || cid == kClassCid;
}
const char* StackFrame::ToCString() const {
ASSERT(isolate_ == Isolate::Current());
Zone* zone = Thread::Current()->zone();
if (IsDartFrame()) {
const Code& code = Code::Handle(LookupDartCode());
ASSERT(!code.IsNull());
const Object& owner = Object::Handle(code.owner());
ASSERT(!owner.IsNull());
if (owner.IsFunction()) {
const Function& function = Function::Cast(owner);
return zone->PrintToString(
"[%-8s : sp(%#" Px ") fp(%#" Px ") pc(%#" Px ") %s ]",
GetName(), sp(), fp(), pc(),
function.ToFullyQualifiedCString());
} else {
return zone->PrintToString(
"[%-8s : sp(%#" Px ") fp(%#" Px ") pc(%#" Px ") %s ]",
GetName(), sp(), fp(), pc(),
owner.ToCString());
}
} else {
return zone->PrintToString(
"[%-8s : sp(%#" Px ") fp(%#" Px ") pc(%#" Px ")]",
GetName(), sp(), fp(), pc());
}
}
void ExitFrame::VisitObjectPointers(ObjectPointerVisitor* visitor) {
// There are no objects to visit in this frame.
}
void EntryFrame::VisitObjectPointers(ObjectPointerVisitor* visitor) {
ASSERT(isolate() == Isolate::Current());
// Visit objects between SP and (FP - callee_save_area).
ASSERT(visitor != NULL);
RawObject** first = reinterpret_cast<RawObject**>(sp());
RawObject** last = reinterpret_cast<RawObject**>(
fp() + (kExitLinkSlotFromEntryFp - 1) * kWordSize);
visitor->VisitPointers(first, last);
}
void StackFrame::VisitObjectPointers(ObjectPointerVisitor* visitor) {
// NOTE: This code runs while GC is in progress and runs within
// a NoHandleScope block. Hence it is not ok to use regular Zone or
// Scope handles. We use direct stack handles, the raw pointers in
// these handles are not traversed. The use of handles is mainly to
// be able to reuse the handle based code and avoid having to add
// helper functions to the raw object interface.
ASSERT(isolate_ == Isolate::Current());
ASSERT(visitor != NULL);
NoSafepointScope no_safepoint;
Code code;
code = LookupDartCode();
if (!code.IsNull()) {
// Visit the code object.
RawObject* raw_code = code.raw();
visitor->VisitPointer(&raw_code);
// Optimized frames have a stack map. We need to visit the frame based
// on the stack map.
Array maps;
maps = Array::null();
Stackmap map;
const uword entry = reinterpret_cast<uword>(code.instructions()->ptr()) +
Instructions::HeaderSize();
map = code.GetStackmap(pc() - entry, &maps, &map);
if (!map.IsNull()) {
RawObject** first = reinterpret_cast<RawObject**>(sp());
RawObject** last = reinterpret_cast<RawObject**>(
fp() + (kFirstLocalSlotFromFp * kWordSize));
// A stack map is present in the code object, use the stack map to
// visit frame slots which are marked as having objects.
//
// The layout of the frame is (lower addresses to the right):
// | spill slots | outgoing arguments | saved registers |
// |XXXXXXXXXXXXX|--------------------|XXXXXXXXXXXXXXXXX|
//
// The spill slots and any saved registers are described in the stack
// map. The outgoing arguments are assumed to be tagged; the number
// of outgoing arguments is not explicitly tracked.
//
// TODO(kmillikin): This does not handle slow path calls with
// arguments, where the arguments are pushed after the live registers.
// Enable such calls.
intptr_t length = map.Length();
// Spill slots are at the 'bottom' of the frame.
intptr_t spill_slot_count = length - map.RegisterBitCount();
for (intptr_t bit = 0; bit < spill_slot_count; ++bit) {
if (map.IsObject(bit)) {
visitor->VisitPointer(last);
}
--last;
}
// The live registers at the 'top' of the frame comprise the rest of the
// stack map.
for (intptr_t bit = length - 1; bit >= spill_slot_count; --bit) {
if (map.IsObject(bit)) {
visitor->VisitPointer(first);
}
++first;
}
// The last slot can be one slot (but not more) past the last slot
// in the case that all slots were covered by the stack map.
ASSERT((last + 1) >= first);
visitor->VisitPointers(first, last);
// Now visit other slots which might be part of the calling convention.
first = reinterpret_cast<RawObject**>(
fp() + ((kFirstLocalSlotFromFp + 1) * kWordSize));
last = reinterpret_cast<RawObject**>(
fp() + (kFirstObjectSlotFromFp * kWordSize));
visitor->VisitPointers(first, last);
return;
}
}
// For normal unoptimized Dart frames and Stub frames each slot
// between the first and last included are tagged objects.
RawObject** first = reinterpret_cast<RawObject**>(sp());
RawObject** last = reinterpret_cast<RawObject**>(
fp() + (kFirstObjectSlotFromFp * kWordSize));
visitor->VisitPointers(first, last);
}
RawFunction* StackFrame::LookupDartFunction() const {
ASSERT(isolate_ == Isolate::Current());
const Code& code = Code::Handle(LookupDartCode());
if (!code.IsNull()) {
return code.function();
}
return Function::null();
}
RawCode* StackFrame::LookupDartCode() const {
ASSERT(isolate_ == Isolate::Current());
// We add a no gc scope to ensure that the code below does not trigger
// a GC as we are handling raw object references here. It is possible
// that the code is called while a GC is in progress, that is ok.
#if !defined(TARGET_OS_WINDOWS)
// On Windows, the profiler calls this from a separate thread where
// Thread::Current() is NULL, so we cannot create a NoSafepointScope.
NoSafepointScope no_safepoint;
#endif
RawCode* code = GetCodeObject();
if ((code != Code::null()) &&
(code->ptr()->owner_->GetClassId() == kFunctionCid)) {
return code;
}
return Code::null();
}
RawCode* StackFrame::GetCodeObject() const {
const uword pc_marker =
*(reinterpret_cast<uword*>(fp() + (kPcMarkerSlotFromFp * kWordSize)));
ASSERT(pc_marker != 0);
ASSERT(reinterpret_cast<RawObject*>(pc_marker)->GetClassId() == kCodeCid ||
reinterpret_cast<RawObject*>(pc_marker) == Object::null());
return reinterpret_cast<RawCode*>(pc_marker);
}
bool StackFrame::FindExceptionHandler(Thread* thread,
uword* handler_pc,
bool* needs_stacktrace,
bool* has_catch_all) const {
REUSABLE_CODE_HANDLESCOPE(thread);
Code& code = reused_code_handle.Handle();
code = LookupDartCode();
if (code.IsNull()) {
return false; // Stub frames do not have exception handlers.
}
uword pc_offset = pc() - code.EntryPoint();
REUSABLE_EXCEPTION_HANDLERS_HANDLESCOPE(thread);
ExceptionHandlers& handlers = reused_exception_handlers_handle.Handle();
handlers = code.exception_handlers();
if (handlers.num_entries() == 0) {
return false;
}
// Find pc descriptor for the current pc.
REUSABLE_PC_DESCRIPTORS_HANDLESCOPE(thread);
PcDescriptors& descriptors = reused_pc_descriptors_handle.Handle();
descriptors = code.pc_descriptors();
PcDescriptors::Iterator iter(descriptors, RawPcDescriptors::kAnyKind);
while (iter.MoveNext()) {
const intptr_t current_try_index = iter.TryIndex();
if ((iter.PcOffset() == pc_offset) && (current_try_index != -1)) {
RawExceptionHandlers::HandlerInfo handler_info;
handlers.GetHandlerInfo(current_try_index, &handler_info);
*handler_pc = code.EntryPoint() + handler_info.handler_pc_offset;
*needs_stacktrace = handler_info.needs_stacktrace;
*has_catch_all = handler_info.has_catch_all;
return true;
}
}
return false;
}
intptr_t StackFrame::GetTokenPos() const {
const Code& code = Code::Handle(LookupDartCode());
if (code.IsNull()) {
return -1; // Stub frames do not have token_pos.
}
uword pc_offset = pc() - code.EntryPoint();
const PcDescriptors& descriptors =
PcDescriptors::Handle(code.pc_descriptors());
ASSERT(!descriptors.IsNull());
PcDescriptors::Iterator iter(descriptors, RawPcDescriptors::kAnyKind);
while (iter.MoveNext()) {
if (iter.PcOffset() == pc_offset) {
return iter.TokenPos();
}
}
return -1;
}
bool StackFrame::IsValid() const {
if (IsEntryFrame() || IsExitFrame() || IsStubFrame()) {
return true;
}
return (LookupDartCode() != Code::null());
}
void StackFrameIterator::SetupLastExitFrameData() {
uword exit_marker = isolate_->top_exit_frame_info();
frames_.fp_ = exit_marker;
}
void StackFrameIterator::SetupNextExitFrameData() {
uword exit_address = entry_.fp() + (kExitLinkSlotFromEntryFp * kWordSize);
uword exit_marker = *reinterpret_cast<uword*>(exit_address);
frames_.fp_ = exit_marker;
frames_.sp_ = 0;
frames_.pc_ = 0;
}
// Tell MemorySanitizer that generated code initializes part of the stack.
// TODO(koda): Limit to frames that are actually written by generated code.
static void UnpoisonStack(Isolate* isolate, uword fp) {
ASSERT(fp != 0);
uword size = isolate->GetSpecifiedStackSize();
MSAN_UNPOISON(reinterpret_cast<void*>(fp - size), 2 * size);
}
StackFrameIterator::StackFrameIterator(bool validate, Isolate* isolate)
: validate_(validate),
entry_(isolate),
exit_(isolate),
frames_(isolate),
current_frame_(NULL),
isolate_(isolate) {
ASSERT((isolate_ == Isolate::Current()) ||
OS::AllowStackFrameIteratorFromAnotherThread());
SetupLastExitFrameData(); // Setup data for last exit frame.
}
StackFrameIterator::StackFrameIterator(uword last_fp, bool validate,
Isolate* isolate)
: validate_(validate),
entry_(isolate),
exit_(isolate),
frames_(isolate),
current_frame_(NULL),
isolate_(isolate) {
ASSERT((isolate_ == Isolate::Current()) ||
OS::AllowStackFrameIteratorFromAnotherThread());
frames_.fp_ = last_fp;
frames_.sp_ = 0;
frames_.pc_ = 0;
}
StackFrameIterator::StackFrameIterator(uword fp, uword sp, uword pc,
bool validate, Isolate* isolate)
: validate_(validate),
entry_(isolate),
exit_(isolate),
frames_(isolate),
current_frame_(NULL),
isolate_(isolate) {
ASSERT((isolate_ == Isolate::Current()) ||
OS::AllowStackFrameIteratorFromAnotherThread());
frames_.fp_ = fp;
frames_.sp_ = sp;
frames_.pc_ = pc;
}
StackFrame* StackFrameIterator::NextFrame() {
// When we are at the start of iteration after having created an
// iterator object, current_frame_ will be NULL as we haven't seen
// any frames yet (unless we start iterating in the simulator from a given
// triplet of fp, sp, and pc). At this point, if NextFrame is called, it tries
// to set up the next exit frame by reading the top_exit_frame_info
// from the isolate. If we do not have any dart invocations yet,
// top_exit_frame_info will be 0 and so we would return NULL.
// current_frame_ will also be NULL, when we are at the end of having
// iterated through all the frames. If NextFrame is called at this
// point, we will try and set up the next exit frame, but since we are
// at the end of the iteration, fp_ will be 0 and we would return NULL.
if (current_frame_ == NULL) {
if (!HasNextFrame()) {
return NULL;
}
UnpoisonStack(isolate_, frames_.fp_);
if (frames_.pc_ == 0) {
// Iteration starts from an exit frame given by its fp.
current_frame_ = NextExitFrame();
} else if (*(reinterpret_cast<uword*>(
frames_.fp_ + (kSavedCallerFpSlotFromFp * kWordSize))) == 0) {
// Iteration starts from an entry frame given by its fp, sp, and pc.
current_frame_ = NextEntryFrame();
} else {
// Iteration starts from a Dart or stub frame given by its fp, sp, and pc.
current_frame_ = frames_.NextFrame(validate_);
}
return current_frame_;
}
ASSERT((validate_ == kDontValidateFrames) || current_frame_->IsValid());
if (current_frame_->IsEntryFrame()) {
if (HasNextFrame()) { // We have another chained block.
current_frame_ = NextExitFrame();
return current_frame_;
}
current_frame_ = NULL; // No more frames.
return current_frame_;
}
ASSERT(current_frame_->IsExitFrame() ||
current_frame_->IsDartFrame(validate_) ||
current_frame_->IsStubFrame());
// Consume dart/stub frames using StackFrameIterator::FrameSetIterator
// until we are out of dart/stub frames at which point we return the
// corresponding entry frame for that set of dart/stub frames.
current_frame_ =
(frames_.HasNext()) ? frames_.NextFrame(validate_) : NextEntryFrame();
return current_frame_;
}
StackFrame* StackFrameIterator::FrameSetIterator::NextFrame(bool validate) {
StackFrame* frame;
ASSERT(HasNext());
frame = &stack_frame_;
frame->sp_ = sp_;
frame->fp_ = fp_;
frame->pc_ = pc_;
sp_ = frame->GetCallerSp();
fp_ = frame->GetCallerFp();
pc_ = frame->GetCallerPc();
ASSERT((validate == kDontValidateFrames) || frame->IsValid());
return frame;
}
ExitFrame* StackFrameIterator::NextExitFrame() {
exit_.sp_ = frames_.sp_;
exit_.fp_ = frames_.fp_;
exit_.pc_ = frames_.pc_;
frames_.sp_ = exit_.GetCallerSp();
frames_.fp_ = exit_.GetCallerFp();
frames_.pc_ = exit_.GetCallerPc();
ASSERT(exit_.IsValid());
return &exit_;
}
EntryFrame* StackFrameIterator::NextEntryFrame() {
ASSERT(!frames_.HasNext());
entry_.sp_ = frames_.sp_;
entry_.fp_ = frames_.fp_;
entry_.pc_ = frames_.pc_;
SetupNextExitFrameData(); // Setup data for next exit frame in chain.
ASSERT(entry_.IsValid());
return &entry_;
}
InlinedFunctionsIterator::InlinedFunctionsIterator(const Code& code, uword pc)
: index_(0),
num_materializations_(0),
code_(Code::Handle(code.raw())),
deopt_info_(TypedData::Handle()),
function_(Function::Handle()),
pc_(pc),
deopt_instructions_(),
object_table_(ObjectPool::Handle()) {
ASSERT(code_.is_optimized());
ASSERT(pc_ != 0);
ASSERT(code.ContainsInstructionAt(pc));
ICData::DeoptReasonId deopt_reason = ICData::kDeoptUnknown;
uint32_t deopt_flags = 0;
deopt_info_ = code_.GetDeoptInfoAtPc(pc, &deopt_reason, &deopt_flags);
if (deopt_info_.IsNull()) {
// This is the case when a call without deopt info in optimized code
// throws an exception. (e.g. in the parameter copying prologue).
// In that case there won't be any inlined frames.
function_ = code_.function();
} else {
// Unpack deopt info into instructions (translate away suffixes).
const Array& deopt_table = Array::Handle(code_.deopt_info_array());
ASSERT(!deopt_table.IsNull());
DeoptInfo::Unpack(deopt_table, deopt_info_, &deopt_instructions_);
num_materializations_ = DeoptInfo::NumMaterializations(deopt_instructions_);
object_table_ = code_.GetObjectPool();
Advance();
}
}
void InlinedFunctionsIterator::Advance() {
// Iterate over the deopt instructions and determine the inlined
// functions if any and iterate over them.
ASSERT(!Done());
if (deopt_info_.IsNull()) {
SetDone();
return;
}
ASSERT(deopt_instructions_.length() != 0);
while (index_ < deopt_instructions_.length()) {
DeoptInstr* deopt_instr = deopt_instructions_[index_++];
if (deopt_instr->kind() == DeoptInstr::kRetAddress) {
pc_ = DeoptInstr::GetRetAddress(deopt_instr, object_table_, &code_);
function_ = code_.function();
return;
}
}
SetDone();
}
// Finds the potential offset for the current function's FP if the
// current frame were to be deoptimized.
intptr_t InlinedFunctionsIterator::GetDeoptFpOffset() const {
ASSERT(deopt_instructions_.length() != 0);
for (intptr_t index = index_;
index < deopt_instructions_.length();
index++) {
DeoptInstr* deopt_instr = deopt_instructions_[index];
if (deopt_instr->kind() == DeoptInstr::kCallerFp) {
return (index - num_materializations_);
}
}
UNREACHABLE();
return 0;
}
} // namespace dart