Files
sdk/runtime/vm/deferred_objects.cc
T
turnidge@google.com 18a8d7fe4c Fixes bug where we would occasionally materialize a corrupted object.
On the slow path for a stack overflow check we manually spill the live
registers before our call to the runtime function.  We were updating
all uses of these spilled registers in the Environment object but this
was not enough - we also need to update any uses of these spilled
registers in MaterializeObjectInstrs which are hanging off of the
Environment.

This would fail when a deoptimization was triggered during a stack
overflow check and a materialized object happened to refer to
registers.

I've been chasing this for a while and I was able to get it to
reliably reproduce by using the --stacktrace_every=N and the
--stacktrace_filter flags, which were added for this purpose.

ALSO:

Set the top context to null on exceptions/errors.  This is needed for
the --verify-incoming-context flag.

Minor printing improvements.

R=fschneider@google.com

Review URL: https://codereview.chromium.org//246303004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@35443 260f80e4-7a28-3924-810f-c04153c831b5
2014-04-25 20:24:27 +00:00

151 lines
4.5 KiB
C++

// Copyright (c) 2013, 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/deferred_objects.h"
#include "vm/deopt_instructions.h"
#include "vm/flags.h"
#include "vm/object.h"
namespace dart {
DECLARE_FLAG(bool, trace_deoptimization_verbose);
void DeferredDouble::Materialize(DeoptContext* deopt_context) {
RawDouble** double_slot = reinterpret_cast<RawDouble**>(slot());
*double_slot = Double::New(value());
if (FLAG_trace_deoptimization_verbose) {
OS::PrintErr("materializing double at %" Px ": %g\n",
reinterpret_cast<uword>(slot()), value());
}
}
void DeferredMint::Materialize(DeoptContext* deopt_context) {
RawMint** mint_slot = reinterpret_cast<RawMint**>(slot());
ASSERT(!Smi::IsValid64(value()));
Mint& mint = Mint::Handle();
mint ^= Integer::New(value());
*mint_slot = mint.raw();
if (FLAG_trace_deoptimization_verbose) {
OS::PrintErr("materializing mint at %" Px ": %" Pd64 "\n",
reinterpret_cast<uword>(slot()), value());
}
}
void DeferredFloat32x4::Materialize(DeoptContext* deopt_context) {
RawFloat32x4** float32x4_slot = reinterpret_cast<RawFloat32x4**>(slot());
RawFloat32x4* raw_float32x4 = Float32x4::New(value());
*float32x4_slot = raw_float32x4;
if (FLAG_trace_deoptimization_verbose) {
float x = raw_float32x4->x();
float y = raw_float32x4->y();
float z = raw_float32x4->z();
float w = raw_float32x4->w();
OS::PrintErr("materializing Float32x4 at %" Px ": %g,%g,%g,%g\n",
reinterpret_cast<uword>(slot()), x, y, z, w);
}
}
void DeferredFloat64x2::Materialize(DeoptContext* deopt_context) {
RawFloat64x2** float64x2_slot = reinterpret_cast<RawFloat64x2**>(slot());
RawFloat64x2* raw_float64x2 = Float64x2::New(value());
*float64x2_slot = raw_float64x2;
if (FLAG_trace_deoptimization_verbose) {
double x = raw_float64x2->x();
double y = raw_float64x2->y();
OS::PrintErr("materializing Float64x2 at %" Px ": %g,%g\n",
reinterpret_cast<uword>(slot()), x, y);
}
}
void DeferredInt32x4::Materialize(DeoptContext* deopt_context) {
RawInt32x4** int32x4_slot = reinterpret_cast<RawInt32x4**>(slot());
RawInt32x4* raw_int32x4 = Int32x4::New(value());
*int32x4_slot = raw_int32x4;
if (FLAG_trace_deoptimization_verbose) {
uint32_t x = raw_int32x4->x();
uint32_t y = raw_int32x4->y();
uint32_t z = raw_int32x4->z();
uint32_t w = raw_int32x4->w();
OS::PrintErr("materializing Int32x4 at %" Px ": %x,%x,%x,%x\n",
reinterpret_cast<uword>(slot()), x, y, z, w);
}
}
void DeferredObjectRef::Materialize(DeoptContext* deopt_context) {
DeferredObject* obj = deopt_context->GetDeferredObject(index());
*slot() = obj->object();
if (FLAG_trace_deoptimization_verbose) {
OS::PrintErr("writing instance ref at %" Px ": %s\n",
reinterpret_cast<uword>(slot()),
Instance::Handle(obj->object()).ToCString());
}
}
RawInstance* DeferredObject::object() {
if (object_ == NULL) {
Materialize();
}
return object_->raw();
}
void DeferredObject::Materialize() {
Class& cls = Class::Handle();
cls ^= GetClass();
if (FLAG_trace_deoptimization_verbose) {
OS::PrintErr("materializing instance of %s (%" Px ", %" Pd " fields)\n",
cls.ToCString(),
reinterpret_cast<uword>(args_),
field_count_);
}
const Instance& obj = Instance::ZoneHandle(Instance::New(cls));
Smi& offset = Smi::Handle();
Field& field = Field::Handle();
Object& value = Object::Handle();
const Array& offset_map = Array::Handle(cls.OffsetToFieldMap());
for (intptr_t i = 0; i < field_count_; i++) {
offset ^= GetFieldOffset(i);
field ^= offset_map.At(offset.Value() / kWordSize);
value = GetValue(i);
if (!field.IsNull()) {
obj.SetField(field, value);
if (FLAG_trace_deoptimization_verbose) {
OS::PrintErr(" %s <- %s\n",
String::Handle(field.name()).ToCString(),
value.ToCString());
}
} else {
ASSERT(cls.IsSignatureClass() ||
(offset.Value() == cls.type_arguments_field_offset()));
obj.SetFieldAtOffset(offset.Value(), value);
if (FLAG_trace_deoptimization_verbose) {
OS::PrintErr(" null Field @ offset(%" Pd ") <- %s\n",
offset.Value(),
value.ToCString());
}
}
}
object_ = &obj;
}
} // namespace dart