Clarify the order of frame summaries and rename getters

src/frames.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/frames.h"
 
 #include <memory>
 #include <sstream>
 
 #include "src/base/bits.h"
@@ skipping 1245 matching lines @@
     field.~type();                                   \
     break;
   switch (base_.kind()) {
     FRAME_SUMMARY_VARIANTS(FRAME_SUMMARY_DESTR)
     default:
       UNREACHABLE();
   }
 #undef FRAME_SUMMARY_DESTR
 }
 
-FrameSummary FrameSummary::Get(const StandardFrame* frame, int index) {
-  DCHECK_LE(0, index);
+FrameSummary FrameSummary::GetTop(const StandardFrame* frame) {
   List<FrameSummary> frames(FLAG_max_inlining_levels + 1);
   frame->Summarize(&frames);
-  DCHECK_GT(frames.length(), index);
-  return frames[index];
+  DCHECK_LT(0, frames.length());
+  return frames.last();
+}
+
+FrameSummary FrameSummary::GetBottom(const StandardFrame* frame) {
+  return Get(frame, 0);
 }
 
 FrameSummary FrameSummary::GetSingle(const StandardFrame* frame) {
   List<FrameSummary> frames(1);
   frame->Summarize(&frames);
   DCHECK_EQ(1, frames.length());
   return frames.first();
 }
 
+FrameSummary FrameSummary::Get(const StandardFrame* frame, int index) {
+  DCHECK_LE(0, index);
+  List<FrameSummary> frames(FLAG_max_inlining_levels + 1);
+  frame->Summarize(&frames);
+  DCHECK_GT(frames.length(), index);
+  return frames[index];
+}
+
 #define FRAME_SUMMARY_DISPATCH(ret, name)        \
   ret FrameSummary::name() const {               \
     switch (base_.kind()) {                      \
       case JAVA_SCRIPT:                          \
         return java_script_summary_.name();      \
       case WASM_COMPILED:                        \
         return wasm_compiled_summary_.name();    \
       case WASM_INTERPRETED:                     \
         return wasm_interpreted_summary_.name(); \
       default:                                   \
@@ skipping 483 matching lines @@
   // This is a live stack frame, there must be a live wasm instance available.
   DCHECK_NOT_NULL(ret);
   return ret;
 }
 
 Script* WasmInterpreterEntryFrame::script() const {
   return wasm_instance()->compiled_module()->script();
 }
 
 int WasmInterpreterEntryFrame::position() const {
-  return FrameSummary::GetFirst(this).AsWasmInterpreted().SourcePosition();
+  return FrameSummary::GetBottom(this).AsWasmInterpreted().SourcePosition();
 }
 
 Address WasmInterpreterEntryFrame::GetCallerStackPointer() const {
   return fp() + ExitFrameConstants::kCallerSPOffset;
 }
 
 namespace {
 
 
 void PrintFunctionSource(StringStream* accumulator, SharedFunctionInfo* shared,
@@ skipping 424 matching lines @@
   for (StackFrameIterator it(isolate); !it.done(); it.Advance()) {
     StackFrame* frame = AllocateFrameCopy(it.frame(), zone);
     list.Add(frame, zone);
   }
   return list.ToVector();
 }
 
 
 }  // namespace internal
 }  // namespace v8