Add exception handler cache to isolate

runtime/vm/stack_frame.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/stack_frame.h"
 
 #include "platform/memory_sanitizer.h"
 #include "vm/assembler.h"
 #include "vm/deopt_instructions.h"
 #include "vm/isolate.h"
@@ skipping 239 matching lines @@
 bool StackFrame::FindExceptionHandler(Thread* thread,
                                       uword* handler_pc,
                                       bool* needs_stacktrace,
                                       bool* has_catch_all) const {
   REUSABLE_CODE_HANDLESCOPE(thread);
   Code& code = reused_code_handle.Handle();
   code = LookupDartCode();
   if (code.IsNull()) {
     return false;  // Stub frames do not have exception handlers.
   }
+  HandlerInfoCache* cache = thread->isolate()->handler_info_cache();
+  ExceptionHandlerInfo* info = cache->Lookup(pc());
+  if (info != NULL) {
+    *handler_pc = code.PayloadStart() + info->handler_pc_offset;
+    *needs_stacktrace = info->needs_stacktrace;
+    *has_catch_all = info->has_catch_all;
+    return true;
+  }
   uword pc_offset = pc() - code.PayloadStart();
 
   REUSABLE_EXCEPTION_HANDLERS_HANDLESCOPE(thread);
   ExceptionHandlers& handlers = reused_exception_handlers_handle.Handle();
   handlers = code.exception_handlers();
   if (handlers.num_entries() == 0) {
     return false;
   }
 
   // Find pc descriptor for the current pc.
   REUSABLE_PC_DESCRIPTORS_HANDLESCOPE(thread);
   PcDescriptors& descriptors = reused_pc_descriptors_handle.Handle();
   descriptors = code.pc_descriptors();
   PcDescriptors::Iterator iter(descriptors, RawPcDescriptors::kAnyKind);
   while (iter.MoveNext()) {
     const intptr_t current_try_index = iter.TryIndex();
     if ((iter.PcOffset() == pc_offset) && (current_try_index != -1)) {
-      RawExceptionHandlers::HandlerInfo handler_info;
+      ExceptionHandlerInfo handler_info;
       handlers.GetHandlerInfo(current_try_index, &handler_info);
       *handler_pc = code.PayloadStart() + handler_info.handler_pc_offset;
       *needs_stacktrace = handler_info.needs_stacktrace;
       *has_catch_all = handler_info.has_catch_all;
+      cache->Insert(pc(), handler_info);
       return true;
     }
   }
   return false;
 }
 
 
 TokenPosition StackFrame::GetTokenPos() const {
   const Code& code = Code::Handle(LookupDartCode());
   if (code.IsNull()) {
@@ skipping 280 matching lines @@
   StackFrameIterator frames(StackFrameIterator::kValidateFrames);
   StackFrame* frame = frames.NextFrame();
   while (frame != NULL) {
     frame = frames.NextFrame();
   }
 }
 #endif
 
 
 }  // namespace dart