Profiler experiments: Fix debugger in the presence of self-optimization headers

src/arm/full-codegen-arm.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 91 matching lines @@
 
  private:
   MacroAssembler* masm_;
   Label patch_site_;
 #ifdef DEBUG
   bool info_emitted_;
 #endif
 };
 
 
+int FullCodeGenerator::self_optimization_header_size() {
+  return 24;
+}
+
+
 // Generate code for a JS function.  On entry to the function the receiver
 // and arguments have been pushed on the stack left to right.  The actual
 // argument count matches the formal parameter count expected by the
 // function.
 //
 // The live registers are:
 //   o r1: the JS function object being called (i.e., ourselves)
 //   o cp: our context
 //   o fp: our caller's frame pointer
 //   o sp: stack pointer
 //   o lr: return address
 //
 // The function builds a JS frame.  Please see JavaScriptFrameConstants in
 // frames-arm.h for its layout.
 void FullCodeGenerator::Generate() {
   CompilationInfo* info = info_;
   handler_table_ =
       isolate()->factory()->NewFixedArray(function()->handler_count(), TENURED);
   SetFunctionPosition(function());
   Comment cmnt(masm_, "[ function compiled by full code generator");
 
-#ifdef DEBUG
-  if (strlen(FLAG_stop_at) > 0 &&
-      info->function()->name()->IsEqualTo(CStrVector(FLAG_stop_at))) {
-    __ stop("stop-at");
-  }
-#endif
-
   // We can optionally optimize based on counters rather than statistical
   // sampling.
   if (info->ShouldSelfOptimize()) {
     if (FLAG_trace_opt_verbose) {
       PrintF("[adding self-optimization header to %s]\n",
              *info->function()->debug_name()->ToCString());
     }
+    has_self_optimization_header_ = true;
     MaybeObject* maybe_cell = isolate()->heap()->AllocateJSGlobalPropertyCell(
         Smi::FromInt(Compiler::kCallsUntilPrimitiveOpt));
     JSGlobalPropertyCell* cell;
     if (maybe_cell->To(&cell)) {
       __ mov(r2, Operand(Handle<JSGlobalPropertyCell>(cell)));
       __ ldr(r3, FieldMemOperand(r2, JSGlobalPropertyCell::kValueOffset));
       __ sub(r3, r3, Operand(Smi::FromInt(1)), SetCC);
       __ str(r3, FieldMemOperand(r2, JSGlobalPropertyCell::kValueOffset));
       Handle<Code> compile_stub(
           isolate()->builtins()->builtin(Builtins::kLazyRecompile));
       __ Jump(compile_stub, RelocInfo::CODE_TARGET, eq);
+      ASSERT(masm_->pc_offset() == self_optimization_header_size());
     }
   }
 
+#ifdef DEBUG
+  if (strlen(FLAG_stop_at) > 0 &&
+      info->function()->name()->IsEqualTo(CStrVector(FLAG_stop_at))) {
+    __ stop("stop-at");
+  }
+#endif
+
   // Strict mode functions and builtins need to replace the receiver
   // with undefined when called as functions (without an explicit
   // receiver object). r5 is zero for method calls and non-zero for
   // function calls.
   if (!info->is_classic_mode() || info->is_native()) {
     Label ok;
     __ cmp(r5, Operand(0));
     __ b(eq, &ok);
     int receiver_offset = info->scope()->num_parameters() * kPointerSize;
     __ LoadRoot(r2, Heap::kUndefinedValueRootIndex);
@@ skipping 4212 matching lines @@
   *context_length = 0;
   return previous_;
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM