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[vm/aot] Avoid using most Code objects in stack traces with --dwarf-stack-traces

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The following changes are done in preparation for the removal of Code
objects in AOT with --dwarf-stack-traces:

* Stack trace objects are extended to hold uword PCs (which may not
  fit into Smi range).

* Scanning stack frames in GC (StackFrame::VisitObjectPointers)
  now avoids using Code objects.
  In order to find CompressedStackMaps it now calls
  ReversePc::FindCompressedStackMaps.

* Singleton Code object (StubCode::UnknownDartCode()) is prepared as
  a replacement for Code objects in stack traces. It has
  PayloadStart() == 0 and Size() == kUwordMax so it includes
  arbitrary PCs.

* In --dwarf-stack-traces mode, most Code objects obtained from stack
  frames are replaced with StubCode::UnknownDartCode().
  This simulates future behavior of ReversePc::Lookup when Code objects
  will be removed.

Issue: https://github.com/dart-lang/sdk/issues/44852
Change-Id: I7cec7b8b9396c9cfeca3c256a412ba4e82a7e0c4
TEST=ci
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/182720
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
This commit is contained in:
Alexander Markov
2021-02-17 20:12:32 +00:00
committed by commit-bot@chromium.org
parent dfd52f60a1
commit b6dc4dad4d
33 changed files with 343 additions and 218 deletions
Download Patch File Download Diff File Expand all files Collapse all files
runtime/lib/stacktrace.cc
+31 -24
View File
@@ -18,25 +18,35 @@ DECLARE_FLAG(bool, show_invisible_frames);
static const intptr_t kDefaultStackAllocation = 8;
static StackTracePtr CreateStackTraceObject(
Zone* zone,
const GrowableObjectArray& code_list,
const GrowableArray<uword>& pc_offset_list) {
const auto& code_array =
Array::Handle(zone, Array::MakeFixedLength(code_list));
const auto& pc_offset_array = TypedData::Handle(
zone, TypedData::New(kUintPtrCid, pc_offset_list.length()));
{
NoSafepointScope no_safepoint;
memmove(pc_offset_array.DataAddr(0), pc_offset_list.data(),
pc_offset_list.length() * kWordSize);
}
return StackTrace::New(code_array, pc_offset_array);
}
static StackTracePtr CurrentSyncStackTraceLazy(Thread* thread,
intptr_t skip_frames = 1) {
Zone* zone = thread->zone();
const auto& code_array = GrowableObjectArray::ZoneHandle(
zone, GrowableObjectArray::New(kDefaultStackAllocation));
const auto& pc_offset_array = GrowableObjectArray::ZoneHandle(
zone, GrowableObjectArray::New(kDefaultStackAllocation));
GrowableArray<uword> pc_offset_array;
// Collect the frames.
StackTraceUtils::CollectFramesLazy(thread, code_array, pc_offset_array,
StackTraceUtils::CollectFramesLazy(thread, code_array, &pc_offset_array,
skip_frames);
const auto& code_array_fixed =
Array::Handle(zone, Array::MakeFixedLength(code_array));
const auto& pc_offset_array_fixed =
Array::Handle(zone, Array::MakeFixedLength(pc_offset_array));
return StackTrace::New(code_array_fixed, pc_offset_array_fixed);
return CreateStackTraceObject(zone, code_array, pc_offset_array);
}
static StackTracePtr CurrentSyncStackTrace(Thread* thread,
@@ -51,8 +61,8 @@ static StackTracePtr CurrentSyncStackTrace(Thread* thread,
// Allocate once.
const Array& code_array =
Array::ZoneHandle(zone, Array::New(stack_trace_length));
const Array& pc_offset_array =
Array::ZoneHandle(zone, Array::New(stack_trace_length));
const TypedData& pc_offset_array = TypedData::ZoneHandle(
zone, TypedData::New(kUintPtrCid, stack_trace_length));
// Collect the frames.
const intptr_t collected_frames_count = StackTraceUtils::CollectFrames(
@@ -89,7 +99,7 @@ DEFINE_NATIVE_ENTRY(StackTrace_current, 0, 0) {
}
static void AppendFrames(const GrowableObjectArray& code_list,
const GrowableObjectArray& pc_offset_list,
GrowableArray<uword>* pc_offset_list,
int skip_frames) {
Thread* thread = Thread::Current();
Zone* zone = thread->zone();
@@ -98,7 +108,6 @@ static void AppendFrames(const GrowableObjectArray& code_list,
StackFrame* frame = frames.NextFrame();
ASSERT(frame != NULL); // We expect to find a dart invocation frame.
Code& code = Code::Handle(zone);
Smi& offset = Smi::Handle(zone);
for (; frame != NULL; frame = frames.NextFrame()) {
if (!frame->IsDartFrame()) {
continue;
@@ -109,9 +118,9 @@ static void AppendFrames(const GrowableObjectArray& code_list,
}
code = frame->LookupDartCode();
offset = Smi::New(frame->pc() - code.PayloadStart());
const intptr_t pc_offset = frame->pc() - code.PayloadStart();
code_list.Add(code);
pc_offset_list.Add(offset);
pc_offset_list->Add(pc_offset);
}
}
@@ -119,16 +128,14 @@ static void AppendFrames(const GrowableObjectArray& code_list,
//
// Skips the first skip_frames Dart frames.
const StackTrace& GetCurrentStackTrace(int skip_frames) {
Zone* zone = Thread::Current()->zone();
const GrowableObjectArray& code_list =
GrowableObjectArray::Handle(GrowableObjectArray::New());
const GrowableObjectArray& pc_offset_list =
GrowableObjectArray::Handle(GrowableObjectArray::New());
AppendFrames(code_list, pc_offset_list, skip_frames);
const Array& code_array = Array::Handle(Array::MakeFixedLength(code_list));
const Array& pc_offset_array =
Array::Handle(Array::MakeFixedLength(pc_offset_list));
const StackTrace& stacktrace =
StackTrace::Handle(StackTrace::New(code_array, pc_offset_array));
GrowableObjectArray::Handle(zone, GrowableObjectArray::New());
GrowableArray<uword> pc_offset_list;
AppendFrames(code_list, &pc_offset_list, skip_frames);
const StackTrace& stacktrace = StackTrace::Handle(
zone, CreateStackTraceObject(zone, code_list, pc_offset_list));
return stacktrace;
}