[interpreter] Add a safety-net for interpreter entry.

src/arm64/builtins-arm64.cc

 // Copyright 2013 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.
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/arm64/frames-arm64.h"
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
@@ skipping 879 matching lines @@
 // count expected by the function.
 //
 // The live registers are:
 //   - x1: the JS function object being called.
 //   - x3: the new target
 //   - cp: our context.
 //   - fp: our caller's frame pointer.
 //   - jssp: stack pointer.
 //   - lr: return address.
 //
-// The function builds a JS frame.  Please see JavaScriptFrameConstants in
-// frames-arm64.h for its layout.
-// TODO(rmcilroy): We will need to include the current bytecode pointer in the
-// frame.
+// The function builds an interpreter frame.  See InterpreterFrameConstants in
+// frames.h for its layout.
 void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   // Open a frame scope to indicate that there is a frame on the stack.  The
   // MANUAL indicates that the scope shouldn't actually generate code to set up
   // the frame (that is done below).
   FrameScope frame_scope(masm, StackFrame::MANUAL);
   __ Push(lr, fp, cp, x1);
   __ Add(fp, jssp, StandardFrameConstants::kFixedFrameSizeFromFp);
   __ Push(x3);
 
   // Push zero for bytecode array offset.
@@ skipping 74 matching lines @@
 
   // Dispatch to the first bytecode handler for the function.
   __ Ldrb(x1, MemOperand(kInterpreterBytecodeArrayRegister,
                          kInterpreterBytecodeOffsetRegister));
   __ Mov(x1, Operand(x1, LSL, kPointerSizeLog2));
   __ Ldr(ip0, MemOperand(kInterpreterDispatchTableRegister, x1));
   // TODO(rmcilroy): Make dispatch table point to code entrys to avoid untagging
   // and header removal.
   __ Add(ip0, ip0, Operand(Code::kHeaderSize - kHeapObjectTag));
   __ Call(ip0);
+
+  // Even though the first bytecode handler was called, we will never return.
+  __ Abort(kUnexpectedReturnFromBytecodeHandler);
 }
 
 
 void Builtins::Generate_InterpreterExitTrampoline(MacroAssembler* masm) {
   // TODO(rmcilroy): List of things not currently dealt with here but done in
   // fullcodegen's EmitReturnSequence.
   //  - Supporting FLAG_trace for Runtime::TraceExit.
   //  - Support profiler (specifically decrementing profiling_counter
   //    appropriately and calling out to HandleInterrupts if necessary).
 
@@ skipping 1736 matching lines @@
   }
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM