Fail early when re-entering code that has been patched for lazy deopt

src/mips/deoptimizer-mips.cc

 
 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
@@ skipping 31 matching lines @@
   return kCallInstructionSizeInWords * Assembler::kInstrSize;
 }
 
 
 void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) {
   Address code_start_address = code->instruction_start();
   // Invalidate the relocation information, as it will become invalid by the
   // code patching below, and is not needed any more.
   code->InvalidateRelocation();
 
+  if (FLAG_zap_code_space) {
+    // Fail hard and early if we enter this code object again.
+    byte* pointer = code->FindCodeAgeSequence();
+    if (pointer != NULL) {
+      pointer += kNoCodeAgeSequenceLength;
+    } else {
+      pointer = code->instruction_start();
+    }
+    CodePatcher patcher(pointer, 1);
+    patcher.masm()->break_(0xCC);
+
+    DeoptimizationInputData* data =
+        DeoptimizationInputData::cast(code->deoptimization_data());
+    int osr_offset = data->OsrPcOffset()->value();
+    if (osr_offset > 0) {
+      CodePatcher osr_patcher(code->instruction_start() + osr_offset, 1);
+      osr_patcher.masm()->break_(0xCC);
+    }
+  }
+
   // For each LLazyBailout instruction insert a call to the corresponding
   // deoptimization entry.
   DeoptimizationInputData* deopt_data =
       DeoptimizationInputData::cast(code->deoptimization_data());
 #ifdef DEBUG
   Address prev_call_address = NULL;
 #endif
   for (int i = 0; i < deopt_data->DeoptCount(); i++) {
     if (deopt_data->Pc(i)->value() == -1) continue;
     Address call_address = code_start_address + deopt_data->Pc(i)->value();
@@ skipping 306 matching lines @@
 
 void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) {
   SetFrameSlot(offset, value);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal