Fix FindSharedFunctionInfoInScript to not optimize.

src/runtime.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 11403 matching lines @@
   Handle<SharedFunctionInfo> shared(fun->shared());
   // Find the number of break points
   Handle<Object> break_locations = Debug::GetSourceBreakLocations(shared);
   if (break_locations->IsUndefined()) return isolate->heap()->undefined_value();
   // Return array as JS array
   return *isolate->factory()->NewJSArrayWithElements(
       Handle<FixedArray>::cast(break_locations));
 }
 
 
-Object* Runtime::FindSharedFunctionInfoInScript(Isolate* isolate,
-                                                Handle<Script> script,
-                                                int position) {
-  // The below fix-point iteration depends on all functions that cannot be
-  // compiled lazily without a context to not be compiled at all. Compilation
-  // will be triggered at points where we do not need a context.
-  isolate->debug()->PrepareForBreakPoints();
-
-  // Iterate the heap looking for SharedFunctionInfo generated from the
-  // script. The inner most SharedFunctionInfo containing the source position
-  // for the requested break point is found.
-  // NOTE: This might require several heap iterations. If the SharedFunctionInfo
-  // which is found is not compiled it is compiled and the heap is iterated
-  // again as the compilation might create inner functions from the newly
-  // compiled function and the actual requested break point might be in one of
-  // these functions.
-  bool done = false;
-  // The current candidate for the source position:
-  int target_start_position = RelocInfo::kNoPosition;
-  Handle<JSFunction> target_function;
-  Handle<SharedFunctionInfo> target;
-  while (!done) {
-    { // Extra scope for iterator and no-allocation.
-      isolate->heap()->EnsureHeapIsIterable();
-      AssertNoAllocation no_alloc_during_heap_iteration;
-      HeapIterator iterator;
-      for (HeapObject* obj = iterator.next();
-           obj != NULL; obj = iterator.next()) {
-        bool found_next_candidate = false;
-        Handle<JSFunction> function;
-        Handle<SharedFunctionInfo> shared;
-        if (obj->IsJSFunction()) {
-          function = Handle<JSFunction>(JSFunction::cast(obj));
-          shared = Handle<SharedFunctionInfo>(function->shared());
-          ASSERT(shared->allows_lazy_compilation() || shared->is_compiled());
-          found_next_candidate = true;
-        } else if (obj->IsSharedFunctionInfo()) {
-          shared = Handle<SharedFunctionInfo>(SharedFunctionInfo::cast(obj));
-          // Skip functions that we cannot compile lazily without a context,
-          // which is not available here, because there is no closure.
-          found_next_candidate = shared->is_compiled() ||
-              shared->allows_lazy_compilation_without_context();
-        }
-        if (!found_next_candidate) continue;
-        if (shared->script() == *script) {
-          // If the SharedFunctionInfo found has the requested script data and
-          // contains the source position it is a candidate.
-          int start_position = shared->function_token_position();
-          if (start_position == RelocInfo::kNoPosition) {
-            start_position = shared->start_position();
-          }
-          if (start_position <= position &&
-              position <= shared->end_position()) {
-            // If there is no candidate or this function is within the current
-            // candidate this is the new candidate.
-            if (target.is_null()) {
-              target_start_position = start_position;
-              target_function = function;
-              target = shared;
-            } else {
-              if (target_start_position == start_position &&
-                  shared->end_position() == target->end_position()) {
-                // If a top-level function contains only one function
-                // declaration the source for the top-level and the function
-                // is the same. In that case prefer the non top-level function.
-                if (!shared->is_toplevel()) {
-                  target_start_position = start_position;
-                  target_function = function;
-                  target = shared;
-                }
-              } else if (target_start_position <= start_position &&
-                         shared->end_position() <= target->end_position()) {
-                // This containment check includes equality as a function
-                // inside a top-level function can share either start or end
-                // position with the top-level function.
-                target_start_position = start_position;
-                target_function = function;
-                target = shared;
-              }
-            }
-          }
-        }
-      }  // End for loop.
-    }  // End no-allocation scope.
-
-    if (target.is_null()) {
-      return isolate->heap()->undefined_value();
-    }
-
-    // If the candidate found is compiled we are done.
-    done = target->is_compiled();
-    if (!done) {
-      // If the candidate is not compiled, compile it to reveal any inner
-      // functions which might contain the requested source position. This
-      // will compile all inner functions that cannot be compiled without a
-      // context, because Compiler::BuildFunctionInfo checks whether the
-      // debugger is active.
-      if (target_function.is_null()) {
-        SharedFunctionInfo::CompileLazy(target, KEEP_EXCEPTION);
-      } else {
-        JSFunction::CompileLazy(target_function, KEEP_EXCEPTION);
-      }
-    }
-  }  // End while loop.
-
-  return *target;
-}
-
-
 // Set a break point in a function.
 // args[0]: function
 // args[1]: number: break source position (within the function source)
 // args[2]: number: break point object
 RUNTIME_FUNCTION(MaybeObject*, Runtime_SetFunctionBreakPoint) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 3);
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 0);
   CONVERT_NUMBER_CHECKED(int32_t, source_position, Int32, args[1]);
   RUNTIME_ASSERT(source_position >= 0);
@@ skipping 1853 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal