Fix asserts in StackFrameIterator which were effectively disabled

runtime/vm/stack_frame.cc

 // 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"
@@ skipping 50 matching lines @@
   }
 }
 
 
 void ExitFrame::VisitObjectPointers(ObjectPointerVisitor* visitor) {
   // There are no objects to visit in this frame.
 }
 
 
 void EntryFrame::VisitObjectPointers(ObjectPointerVisitor* visitor) {
-  ASSERT(thread() == Thread::Current());
   // Visit objects between SP and (FP - callee_save_area).
   ASSERT(visitor != NULL);
 #if !defined(TARGET_ARCH_DBC)
   RawObject** first = reinterpret_cast<RawObject**>(sp());
   RawObject** last = reinterpret_cast<RawObject**>(
       fp() + (kExitLinkSlotFromEntryFp - 1) * kWordSize);
   visitor->VisitPointers(first, last);
 #else
   // On DBC stack is growing upwards which implies fp() <= sp().
   RawObject** first = reinterpret_cast<RawObject**>(fp());
   RawObject** last = reinterpret_cast<RawObject**>(sp());
   visitor->VisitPointers(first, last);
 #endif
 }
 
 
 void StackFrame::VisitObjectPointers(ObjectPointerVisitor* visitor) {
-  ASSERT(thread() == Thread::Current());
   ASSERT(visitor != NULL);
   // 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.
   NoSafepointScope no_safepoint;
   Code code;
   code = GetCodeObject();
@@ skipping 239 matching lines @@
 
 // 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(uword fp) {
   ASSERT(fp != 0);
   uword size = OSThread::GetSpecifiedStackSize();
   MSAN_UNPOISON(reinterpret_cast<void*>(fp - size), 2 * size);
 }
 
 
-StackFrameIterator::StackFrameIterator(bool validate, Thread* thread)
+StackFrameIterator::StackFrameIterator(bool validate,
+                                       Thread* thread,
+                                       bool allow_iterating_other_thread)
     : validate_(validate),
       entry_(thread),
       exit_(thread),
       frames_(thread),
       current_frame_(NULL),
       thread_(thread) {
-  ASSERT((thread_ == Thread::Current()) ||
-         OS::AllowStackFrameIteratorFromAnotherThread());
+  ASSERT((allow_iterating_other_thread || thread_ == Thread::Current()));
   SetupLastExitFrameData();  // Setup data for last exit frame.
 }
 
 
 StackFrameIterator::StackFrameIterator(uword last_fp,
                                        bool validate,
-                                       Thread* thread)
+                                       Thread* thread,
+                                       bool allow_iterating_other_thread)
     : validate_(validate),
       entry_(thread),
       exit_(thread),
       frames_(thread),
       current_frame_(NULL),
       thread_(thread) {
-  ASSERT((thread_ == Thread::Current()) ||
-         OS::AllowStackFrameIteratorFromAnotherThread());
+  ASSERT((allow_iterating_other_thread || thread_ == Thread::Current()));
   frames_.fp_ = last_fp;
   frames_.sp_ = 0;
   frames_.pc_ = 0;
 }
 
 
 #if !defined(TARGET_ARCH_DBC)
 StackFrameIterator::StackFrameIterator(uword fp,
                                        uword sp,
                                        uword pc,
                                        bool validate,
-                                       Thread* thread)
+                                       Thread* thread,
+                                       bool allow_iterating_other_thread)
     : validate_(validate),
       entry_(thread),
       exit_(thread),
       frames_(thread),
       current_frame_(NULL),
       thread_(thread) {
-  ASSERT((thread_ == Thread::Current()) ||
-         OS::AllowStackFrameIteratorFromAnotherThread());
+  ASSERT((allow_iterating_other_thread || thread_ == Thread::Current()));
   frames_.fp_ = fp;
   frames_.sp_ = sp;
   frames_.pc_ = pc;
 }
 #endif
 
 
 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
@@ skipping 167 matching lines @@
       return fp_offset;
     }
   }
   UNREACHABLE();
   return 0;
 }
 
 
 #if defined(DEBUG)
 void ValidateFrames() {
-  StackFrameIterator frames(StackFrameIterator::kValidateFrames);
+  StackFrameIterator frames(StackFrameIterator::kValidateFrames,
+                            Thread::Current(), false);
   StackFrame* frame = frames.NextFrame();
   while (frame != NULL) {
     frame = frames.NextFrame();
   }
 }
 #endif
 
 
 }  // namespace dart