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

src/x87/builtins-x87.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.
 
 #if V8_TARGET_ARCH_X87
 
 #include "src/code-factory.h"
 #include "src/codegen.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 515 matching lines @@
 // stack left to right.  The actual argument count matches the formal parameter
 // count expected by the function.
 //
 // The live registers are:
 //   o edi: the JS function object being called
 //   o edx: the new target
 //   o esi: our context
 //   o ebp: the caller's frame pointer
 //   o esp: stack pointer (pointing to return address)
 //
-// The function builds a JS frame.  Please see JavaScriptFrameConstants in
-// frames-ia32.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(ebp);  // Caller's frame pointer.
   __ mov(ebp, esp);
   __ push(esi);  // Callee's context.
   __ push(edi);  // Callee's JS function.
   __ push(edx);  // Callee's new target.
@@ skipping 88 matching lines @@
                           kInterpreterBytecodeOffsetRegister, times_1, 0));
   __ mov(ebx, Operand(ebx, eax, times_pointer_size, 0));
   // Restore undefined_value in accumulator (eax)
   // TODO(rmcilroy): Remove this once we move the dispatch table back into a
   // register.
   __ mov(eax, Immediate(masm->isolate()->factory()->undefined_value()));
   // TODO(rmcilroy): Make dispatch table point to code entrys to avoid untagging
   // and header removal.
   __ add(ebx, Immediate(Code::kHeaderSize - kHeapObjectTag));
   __ call(ebx);
-  __ nop();  // Ensure that return address still counts as interpreter entry
-             // trampoline.
+
+  // 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 2023 matching lines @@
 
   __ bind(&ok);
   __ ret(0);
 }
 
 #undef __
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X87