LiveEdit: patch positions in function

src/runtime.cc

 // Copyright 2006-2009 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 9045 matching lines @@
         SharedFunctionInfo::cast(wrapper->value()));
     LiveEdit::FunctionPatchabilityStatus check_res =
         FindFunctionCodeOnStacks(shared);
     SetElement(result, i, Handle<Smi>(Smi::FromInt(check_res)));
   }
 
   return *result;
 }
 
 
+// A testing entry. Returns statement position which is the closest to
+// source_position.
+static Object* Runtime_GetFunctionCodePositionFromSource(Arguments args) {
+  ASSERT(args.length() == 2);
+  HandleScope scope;
+  CONVERT_ARG_CHECKED(JSFunction, function, 0);
+  CONVERT_NUMBER_CHECKED(int32_t, source_position, Int32, args[1]);
+
+  Handle<Code> code(function->code());
+
+  RelocIterator it(*code, 1 << RelocInfo::STATEMENT_POSITION);
+  int closest_pc = 0;
+  int distance = kMaxInt;
+  while (!it.done()) {
+    int statement_position = static_cast<int>(it.rinfo()->data());
+    // Check if this break point is closer that what was previously found.
+    if (source_position <= statement_position &&
+        statement_position - source_position < distance) {
+      closest_pc = it.rinfo()->pc() - code->instruction_start();
+      distance = statement_position - source_position;
+      // Check whether we can't get any closer.
+      if (distance == 0) break;
+    }
+    it.next();
+  }
+
+  return Smi::FromInt(closest_pc);
+}
+
+
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
 
 static Object* Runtime_ProfilerResume(Arguments args) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
   CONVERT_CHECKED(Smi, smi_modules, args[0]);
   CONVERT_CHECKED(Smi, smi_tag, args[1]);
@@ skipping 265 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
     Heap::CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal