[inspector] store v8:StackTrace as FixedArray

src/isolate.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/isolate.h"
 
 #include <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
@@ skipping 602 matching lines @@
 
   // TODO(yangguo): Queue this structured stack trace for preprocessing on GC.
   return factory()->NewJSArrayWithElements(elements);
 }
 
 MaybeHandle<JSReceiver> Isolate::CaptureAndSetDetailedStackTrace(
     Handle<JSReceiver> error_object) {
   if (capture_stack_trace_for_uncaught_exceptions_) {
     // Capture stack trace for a detailed exception message.
     Handle<Name> key = factory()->detailed_stack_trace_symbol();
-    Handle<JSArray> stack_trace = CaptureCurrentStackTrace(
+    Handle<FixedArray> stack_trace = CaptureCurrentStackTrace(
         stack_trace_for_uncaught_exceptions_frame_limit_,
         stack_trace_for_uncaught_exceptions_options_);
     RETURN_ON_EXCEPTION(
         this, JSReceiver::SetProperty(error_object, key, stack_trace, STRICT),
         JSReceiver);
   }
   return error_object;
 }
 
 MaybeHandle<JSReceiver> Isolate::CaptureAndSetSimpleStackTrace(
     Handle<JSReceiver> error_object, FrameSkipMode mode,
     Handle<Object> caller) {
   // Capture stack trace for simple stack trace string formatting.
   Handle<Name> key = factory()->stack_trace_symbol();
   Handle<Object> stack_trace =
       CaptureSimpleStackTrace(error_object, mode, caller);
   RETURN_ON_EXCEPTION(
       this, JSReceiver::SetProperty(error_object, key, stack_trace, STRICT),
       JSReceiver);
   return error_object;
 }
 
-
-Handle<JSArray> Isolate::GetDetailedStackTrace(Handle<JSObject> error_object) {
+Handle<FixedArray> Isolate::GetDetailedStackTrace(
+    Handle<JSObject> error_object) {
   Handle<Name> key_detailed = factory()->detailed_stack_trace_symbol();
   Handle<Object> stack_trace =
       JSReceiver::GetDataProperty(error_object, key_detailed);
-  if (stack_trace->IsJSArray()) return Handle<JSArray>::cast(stack_trace);
-  return Handle<JSArray>();
+  if (stack_trace->IsFixedArray()) return Handle<FixedArray>::cast(stack_trace);
+  return Handle<FixedArray>();
 }
 
 
 class CaptureStackTraceHelper {
  public:
   explicit CaptureStackTraceHelper(Isolate* isolate) : isolate_(isolate) {}
 
   Handle<StackFrameInfo> NewStackFrameObject(FrameSummary& summ) {
     if (summ.IsJavaScript()) return NewStackFrameObject(summ.AsJavaScript());
     if (summ.IsWasm()) return NewStackFrameObject(summ.AsWasm());
@@ skipping 77 matching lines @@
     info->set_is_wasm(true);
     return info;
   }
 
  private:
   inline Factory* factory() { return isolate_->factory(); }
 
   Isolate* isolate_;
 };
 
-Handle<JSArray> Isolate::CaptureCurrentStackTrace(
+Handle<FixedArray> Isolate::CaptureCurrentStackTrace(
     int frame_limit, StackTrace::StackTraceOptions options) {
   DisallowJavascriptExecution no_js(this);
   CaptureStackTraceHelper helper(this);
 
   // Ensure no negative values.
   int limit = Max(frame_limit, 0);
-  Handle<JSArray> stack_trace = factory()->NewJSArray(frame_limit);
-  Handle<FixedArray> stack_trace_elems(
-      FixedArray::cast(stack_trace->elements()), this);
+  Handle<FixedArray> stack_trace_elems = factory()->NewFixedArray(limit);
 
   int frames_seen = 0;
   for (StackTraceFrameIterator it(this); !it.done() && (frames_seen < limit);
        it.Advance()) {
     StandardFrame* frame = it.frame();
     // Set initial size to the maximum inlining level + 1 for the outermost
     // function.
     List<FrameSummary> frames(FLAG_max_inlining_levels + 1);
     frame->Summarize(&frames);
     for (int i = frames.length() - 1; i >= 0 && frames_seen < limit; i--) {
       // Filter frames from other security contexts.
       if (!(options & StackTrace::kExposeFramesAcrossSecurityOrigins) &&
           !this->context()->HasSameSecurityTokenAs(*frames[i].native_context()))
         continue;
       Handle<StackFrameInfo> new_frame_obj =
           helper.NewStackFrameObject(frames[i]);
       stack_trace_elems->set(frames_seen, *new_frame_obj);
       frames_seen++;
     }
   }
-
-  stack_trace->set_length(Smi::FromInt(frames_seen));
-  return stack_trace;
+  stack_trace_elems->Shrink(frames_seen);
+  return stack_trace_elems;
 }
 
 
 void Isolate::PrintStack(FILE* out, PrintStackMode mode) {
   if (stack_trace_nesting_level_ == 0) {
     stack_trace_nesting_level_++;
     StringStream::ClearMentionedObjectCache(this);
     HeapStringAllocator allocator;
     StringStream accumulator(&allocator);
     incomplete_message_ = &accumulator;
@@ skipping 870 matching lines @@
       *target = MessageLocation(casted_script, pos, pos + 1);
       return true;
     }
   }
   return false;
 }
 
 
 Handle<JSMessageObject> Isolate::CreateMessage(Handle<Object> exception,
                                                MessageLocation* location) {
-  Handle<JSArray> stack_trace_object;
+  Handle<FixedArray> stack_trace_object;
   if (capture_stack_trace_for_uncaught_exceptions_) {
     if (exception->IsJSError()) {
       // We fetch the stack trace that corresponds to this error object.
       // If the lookup fails, the exception is probably not a valid Error
       // object. In that case, we fall through and capture the stack trace
       // at this throw site.
       stack_trace_object =
           GetDetailedStackTrace(Handle<JSObject>::cast(exception));
     }
     if (stack_trace_object.is_null()) {
@@ skipping 1706 matching lines @@
 
 void Isolate::SetPromiseRejectCallback(PromiseRejectCallback callback) {
   promise_reject_callback_ = callback;
 }
 
 
 void Isolate::ReportPromiseReject(Handle<JSObject> promise,
                                   Handle<Object> value,
                                   v8::PromiseRejectEvent event) {
   if (promise_reject_callback_ == NULL) return;
-  Handle<JSArray> stack_trace;
+  Handle<FixedArray> stack_trace;
   if (event == v8::kPromiseRejectWithNoHandler && value->IsJSObject()) {
     stack_trace = GetDetailedStackTrace(Handle<JSObject>::cast(value));
   }
   promise_reject_callback_(v8::PromiseRejectMessage(
       v8::Utils::PromiseToLocal(promise), event, v8::Utils::ToLocal(value),
       v8::Utils::StackTraceToLocal(stack_trace)));
 }
 
 void Isolate::PromiseReactionJob(Handle<PromiseReactionJobInfo> info,
                                  MaybeHandle<Object>* result,
@@ skipping 362 matching lines @@
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8