Partial ia32 implementation of optimized try/catch (by Kevin Millikin)

src/isolate.h

 // 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 233 matching lines @@
   int pending_message_start_pos_;
   int pending_message_end_pos_;
   // Use a separate value for scheduled exceptions to preserve the
   // invariants that hold about pending_exception.  We may want to
   // unify them later.
   MaybeObject* scheduled_exception_;
   bool external_caught_exception_;
   SaveContext* save_context_;
   v8::TryCatch* catcher_;
 
+  // Fields for handling try-catch statements in optimized code.
+  byte* optimized_handler_patch_buffer_;
+  MaybeObject* optimized_pending_exception_;
+  int optimized_handler_handler_index_;
+  int optimized_handler_deopt_index_;
+  int optimized_handler_frame_pc_offset_;
+
   // Stack.
   Address c_entry_fp_;  // the frame pointer of the top c entry frame
   Address handler_;   // try-blocks are chained through the stack
 
 #ifdef USE_SIMULATOR
 #if defined(V8_TARGET_ARCH_ARM) || defined(V8_TARGET_ARCH_MIPS)
   Simulator* simulator_;
 #endif
 #endif  // USE_SIMULATOR
 
   Address js_entry_sp_;  // the stack pointer of the bottom JS entry frame
   Address external_callback_;  // the external callback we're currently in
   StateTag current_vm_state_;
 
   // Generated code scratch locations.
   int32_t formal_count_;
 
   // Call back function to report unsafe JS accesses.
   v8::FailedAccessCheckCallback failed_access_check_callback_;
 
   // Head of the list of live LookupResults.
   LookupResult* top_lookup_result_;
 
   // Whether out of memory exceptions should be ignored.
   bool ignore_out_of_memory_;
 
+  int thread_id() { return thread_id_.ToInteger(); }
+
  private:
   void InitializeInternal();
 
   Address try_catch_handler_address_;
 };
 
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
 
 #define ISOLATE_DEBUGGER_INIT_LIST(V)                                          \
@@ skipping 227 matching lines @@
   Address get_address_from_id(AddressId id);
 
   // Access to top context (where the current function object was created).
   Context* context() { return thread_local_top_.context_; }
   void set_context(Context* context) {
     ASSERT(context == NULL || context->IsContext());
     thread_local_top_.context_ = context;
   }
   Context** context_address() { return &thread_local_top_.context_; }
 
-  SaveContext* save_context() {return thread_local_top_.save_context_; }
+  SaveContext* save_context() { return thread_local_top_.save_context_; }
   void set_save_context(SaveContext* save) {
     thread_local_top_.save_context_ = save;
   }
 
   // Access to the map of "new Object()".
   Map* empty_object_map() {
     return context()->native_context()->object_function()->map();
   }
 
   // Access to current thread id.
   ThreadId thread_id() { return thread_local_top_.thread_id_; }
   void set_thread_id(ThreadId id) { thread_local_top_.thread_id_ = id; }
 
   // Interface to pending exception.
   MaybeObject* pending_exception() {
     ASSERT(has_pending_exception());
     return thread_local_top_.pending_exception_;
   }
   bool external_caught_exception() {
     return thread_local_top_.external_caught_exception_;
   }
   void set_external_caught_exception(bool value) {
     thread_local_top_.external_caught_exception_ = value;
   }
   void set_pending_exception(MaybeObject* exception) {
     thread_local_top_.pending_exception_ = exception;
   }
   void clear_pending_exception() {
     thread_local_top_.pending_exception_ = heap_.the_hole_value();
+
+    if (is_handling_optimized_catch_statement()) {
+      ClearOptimizedHandlerByAPI();
+    }
   }
   MaybeObject** pending_exception_address() {
     return &thread_local_top_.pending_exception_;
   }
   bool has_pending_exception() {
     return !thread_local_top_.pending_exception_->IsTheHole();
   }
   void clear_pending_message() {
     thread_local_top_.has_pending_message_ = false;
     thread_local_top_.pending_message_obj_ = heap_.the_hole_value();
     thread_local_top_.pending_message_script_ = NULL;
   }
   v8::TryCatch* try_catch_handler() {
     return thread_local_top_.TryCatchHandler();
   }
   Address try_catch_handler_address() {
     return thread_local_top_.try_catch_handler_address();
   }
   bool* external_caught_exception_address() {
     return &thread_local_top_.external_caught_exception_;
   }
   v8::TryCatch* catcher() {
     return thread_local_top_.catcher_;
   }
   void set_catcher(v8::TryCatch* catcher) {
     thread_local_top_.catcher_ = catcher;
   }
 
+  // Interface for supporting try-catch statements in optimized code.
+  bool is_handling_optimized_catch_statement() {
+    return thread_local_top_.optimized_handler_handler_index_ != -1;
+  }
+  byte* optimized_handler_patch_buffer() {
+    return thread_local_top_.optimized_handler_patch_buffer_;
+  }
+  void set_optimized_handler_patch_buffer(Address patch_address,
+                                          int patch_size) {
+    ASSERT(thread_local_top_.optimized_handler_patch_buffer_ == NULL);
+    thread_local_top_.optimized_handler_patch_buffer_ = new byte[patch_size];
+    memcpy(thread_local_top_.optimized_handler_patch_buffer_,
+           patch_address, patch_size);
+  }
+  void clear_optimized_handler_patch_buffer() {
+    ASSERT(thread_local_top_.optimized_handler_patch_buffer_ != NULL);
+    delete[] thread_local_top_.optimized_handler_patch_buffer_;
+    thread_local_top_.optimized_handler_patch_buffer_ = NULL;
+  }
+  MaybeObject* optimized_pending_exception() {
+    return thread_local_top_.optimized_pending_exception_;
+  }
+  void set_optimized_pending_exception(MaybeObject* v) {
+    thread_local_top_.optimized_pending_exception_ = v;
+  }
+  void clear_optimized_pending_exception() {
+    thread_local_top_.optimized_pending_exception_ = NULL;
+  }
+  int optimized_handler_handler_index() {
+    return thread_local_top_.optimized_handler_handler_index_;
+  }
+  void set_optimized_handler_handler_index(int v) {
+    ASSERT(thread_local_top_.optimized_handler_handler_index_ == -1);
+    thread_local_top_.optimized_handler_handler_index_ = v;
+  }
+  void clear_optimized_handler_handler_index() {
+    ASSERT(thread_local_top_.optimized_handler_handler_index_ != -1);
+    thread_local_top_.optimized_handler_handler_index_ = -1;
+  }
+  int optimized_handler_deopt_index() {
+    return thread_local_top_.optimized_handler_deopt_index_;
+  }
+  void set_optimized_handler_deopt_index(int v) {
+    ASSERT(thread_local_top_.optimized_handler_deopt_index_ == -1);
+    thread_local_top_.optimized_handler_deopt_index_ = v;
+  }
+  void clear_optimized_handler_deopt_index() {
+    ASSERT(thread_local_top_.optimized_handler_deopt_index_ != -1);
+    thread_local_top_.optimized_handler_deopt_index_ = -1;
+  }
+  int optimized_handler_frame_pc_offset() {
+    return thread_local_top_.optimized_handler_frame_pc_offset_;
+  }
+  void set_optimized_handler_frame_pc_offset(int v) {
+    ASSERT(thread_local_top_.optimized_handler_frame_pc_offset_ == -1);
+    thread_local_top_.optimized_handler_frame_pc_offset_ = v;
+  }
+  void clear_optimized_handler_frame_pc_offset() {
+    ASSERT(thread_local_top_.optimized_handler_frame_pc_offset_ != -1);
+    thread_local_top_.optimized_handler_frame_pc_offset_ = -1;
+  }
+
+
   MaybeObject** scheduled_exception_address() {
     return &thread_local_top_.scheduled_exception_;
   }
 
   Address pending_message_obj_address() {
     return reinterpret_cast<Address>(&thread_local_top_.pending_message_obj_);
   }
 
   Address has_pending_message_address() {
     return reinterpret_cast<Address>(&thread_local_top_.has_pending_message_);
@@ skipping 147 matching lines @@
   Failure* ThrowIllegalOperation();
 
   // Promote a scheduled exception to pending. Asserts has_scheduled_exception.
   Failure* PromoteScheduledException();
   void DoThrow(Object* exception, MessageLocation* location);
   // Checks if exception should be reported and finds out if it's
   // caught externally.
   bool ShouldReportException(bool* can_be_caught_externally,
                              bool catchable_by_javascript);
 
+  // The temporary optimized handler state is used by the deoptimizer when
+  // catching exceptions in optimized code.
+  void PrepareForOptimizedHandler();
+  void ClearOptimizedHandlerByDeopt(Code* optimized_code);
+  void ClearOptimizedHandlerByAPI();
+
   // Attempts to compute the current source location, storing the
   // result in the target out parameter.
   void ComputeLocation(MessageLocation* target);
 
   // Override command line flag.
   void TraceException(bool flag);
 
   // Out of resource exception helpers.
   Failure* StackOverflow();
   Failure* TerminateExecution();
@@ skipping 685 matching lines @@
 
 // Mark the native context with out of memory.
 inline void Context::mark_out_of_memory() {
   native_context()->set_out_of_memory(HEAP->true_value());
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_