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

src/x64/deoptimizer-x64.cc

 // Copyright 2012 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
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 33 matching lines @@
 int Deoptimizer::patch_size() {
   return Assembler::kCallSequenceLength;
 }
 
 
 void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) {
   // 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()->int3();
+
+    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()->int3();
+    }
+  }
+
   // For each LLazyBailout instruction insert a absolute call to the
   // corresponding deoptimization entry, or a short call to an absolute
   // jump if space is short. The absolute jumps are put in a table just
   // before the safepoint table (space was allocated there when the Code
   // object was created, if necessary).
 
   Address instruction_start = code->instruction_start();
 #ifdef DEBUG
   Address prev_call_address = NULL;
 #endif
@@ skipping 270 matching lines @@
   SetFrameSlot(offset, value);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64