Precompilation: don't include an object header for instructions in the text section.

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 10 matching lines @@
 
 
 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();
+  ASSERT(code != Object::null());
   const 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(thread_ == Thread::Current());
   Zone* zone = Thread::Current()->zone();
   if (IsDartFrame()) {
@@ skipping 52 matching lines @@
   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();
+    const uword entry = code.EntryPoint();
     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):
@@ skipping 28 matching lines @@
       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;
     }
+
+    // No stack map, fall through.
   }
   // 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);
 }
 
 
@@ skipping 210 matching lines @@
     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();

[Florian Schneider, 2016/03/28 22:15:47]

What's wrong with using the conditional expression?

[rmacnak, 2016/03/28 23:56:45]

Nothing, I had print here debugger earlier. Undone.

+  if (frames_.HasNext()) {
+    current_frame_ = frames_.NextFrame(validate_);
+  } else {
+    current_frame_ = NextEntryFrame();
+  }
   return current_frame_;
 }
 
 
 StackFrame* StackFrameIterator::FrameSetIterator::NextFrame(bool validate) {
   StackFrame* frame;
   ASSERT(HasNext());
   frame = &stack_frame_;
   frame->sp_ = sp_;
   frame->fp_ = fp_;
@@ skipping 95 matching lines @@
     if (deopt_instr->kind() == DeoptInstr::kCallerFp) {
       return (index - num_materializations_);
     }
   }
   UNREACHABLE();
   return 0;
 }
 
 
 }  // namespace dart