commit 012b7050e5cab68c7508620e03d2bbed90798324
author Régis Crelier <regis@google.com> Fri Sep 21 20:10:45 2018 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org> Fri Sep 21 20:10:45 2018 +0000
tree 7908c3670cf60cde2c4b4daa9acae5a5675f7436
parent e22dd19b13047c59e04b77595787d8e9bba4f5f1

[VM interpreter] Use a helper to test entry frame pc marker.

Change-Id: I6256f0337d2ab84722d32d4e6af97b966c619162
Reviewed-on: https://dart-review.googlesource.com/75987
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Régis Crelier <regis@google.com>

runtime/vm/interpreter.cc

diff --git a/runtime/vm/interpreter.cc b/runtime/vm/interpreter.cc
index 728ad6d..b0bbb27 100644
--- a/runtime/vm/interpreter.cc
+++ b/runtime/vm/interpreter.cc
@@ -943,7 +943,7 @@
       // Unwind to entry frame.
       fp_ = *FP;
       pc_ = reinterpret_cast<uword>(SavedCallerPC(fp_));
-      while ((pc_ & 2) == 0) {
+      while (!IsEntryFrameMarker(pc_)) {
         fp_ = SavedCallerFP(fp_);
         pc_ = reinterpret_cast<uword>(SavedCallerPC(fp_));
       }
@@ -1525,7 +1525,7 @@
   do {                                                                         \
     FP = reinterpret_cast<RawObject**>(fp_);                                   \
     pc = reinterpret_cast<uint32_t*>(pc_);                                     \
-    if ((reinterpret_cast<uword>(pc) & 2) != 0) { /* Entry frame? */           \
+    if (IsEntryFrameMarker(reinterpret_cast<uword>(pc))) {                     \
       pp_ = reinterpret_cast<RawObjectPool*>(fp_[kKBCSavedPpSlotFromEntryFp]); \
       argdesc_ =                                                               \
           reinterpret_cast<RawArray*>(fp_[kKBCSavedArgDescSlotFromEntryFp]);   \
@@ -1553,7 +1553,7 @@
   do {                                                                         \
     FP = reinterpret_cast<RawObject**>(fp_);                                   \
     pc = reinterpret_cast<uint32_t*>(pc_);                                     \
-    if ((reinterpret_cast<uword>(pc) & 2) != 0) { /* Entry frame? */           \
+    if (IsEntryFrameMarker(reinterpret_cast<uword>(pc))) {                     \
       pp_ = reinterpret_cast<RawObjectPool*>(fp_[kKBCSavedPpSlotFromEntryFp]); \
       argdesc_ =                                                               \
           reinterpret_cast<RawArray*>(fp_[kKBCSavedArgDescSlotFromEntryFp]);   \
@@ -1632,7 +1632,7 @@
   pc_ = reinterpret_cast<uword>(*pc);  // For the profiler.
 
   // Check if it is a fake PC marking the entry frame.
-  ASSERT((reinterpret_cast<uword>(*pc) & 2) == 0);
+  ASSERT(!IsEntryFrameMarker(reinterpret_cast<uword>(*pc)));
 
   // Restore SP, FP and PP.
   // Unoptimized frame SP is one below FrameArguments(...) because
@@ -3483,7 +3483,7 @@
     pc_ = reinterpret_cast<uword>(pc);  // For the profiler.
 
     // Check if it is a fake PC marking the entry frame.
-    if ((reinterpret_cast<uword>(pc) & 2) != 0) {
+    if (IsEntryFrameMarker(reinterpret_cast<uword>(pc))) {
       // Pop entry frame.
       fp_ = SavedCallerFP(FP);
       // Restore exit frame info saved in entry frame.
@@ -4798,7 +4798,8 @@
     // Restore caller context as we are going to throw NoSuchMethod.
     pc = SavedCallerPC(FP);
 
-    const bool has_dart_caller = (reinterpret_cast<uword>(pc) & 2) == 0;
+    const bool has_dart_caller =
+        !IsEntryFrameMarker(reinterpret_cast<uword>(pc));
     const intptr_t argc = has_dart_caller ? KernelBytecode::DecodeArgc(pc[-1])
                                           : (reinterpret_cast<uword>(pc) >> 2);
     const intptr_t type_args_len =

runtime/vm/interpreter.h

diff --git a/runtime/vm/interpreter.h b/runtime/vm/interpreter.h
index 3d98670..73fcadb 100644
--- a/runtime/vm/interpreter.h
+++ b/runtime/vm/interpreter.h
@@ -59,6 +59,9 @@
     return frame >= stack_base() && frame <= get_fp();
   }
 
+  // Identify an entry frame by looking at its pc marker value.
+  static bool IsEntryFrameMarker(uword pc) { return (pc & 2) != 0; }
+
   // Call on program start.
   static void InitOnce();
 

runtime/vm/stub_code.cc

diff --git a/runtime/vm/stub_code.cc b/runtime/vm/stub_code.cc
index 759469a..472a825 100644
--- a/runtime/vm/stub_code.cc
+++ b/runtime/vm/stub_code.cc
@@ -11,6 +11,7 @@
 #include "vm/compiler/assembler/disassembler.h"
 #include "vm/flags.h"
 #include "vm/heap/safepoint.h"
+#include "vm/interpreter.h"
 #include "vm/object_store.h"
 #include "vm/snapshot.h"
 #include "vm/virtual_memory.h"
@@ -96,7 +97,7 @@
   if (FLAG_enable_interpreter) {
     if (is_interpreted_frame) {
       // Recognize special marker set up by interpreter in entry frame.
-      return (pc & 2) != 0;
+      return Interpreter::IsEntryFrameMarker(pc);
     }
     {
       uword entry = StubCode::InvokeDartCodeFromBytecode_entry()->EntryPoint();