Debugger: consider try-finally scopes not catching wrt debug events.

src/isolate.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
 
 #include "src/v8.h"
@@ skipping 1049 matching lines @@
       code = frame->LookupCode();
       handler_sp = handler->address() + StackHandlerConstants::kSize;
       offset = Smi::cast(code->handler_table()->get(0))->value();
       break;
     }
 
     // For optimized frames we perform a lookup in the handler table.
     if (frame->is_optimized() && catchable_by_js) {
       OptimizedFrame* js_frame = static_cast<OptimizedFrame*>(frame);
       int stack_slots = 0;  // Will contain stack slot count of frame.
-      offset = js_frame->LookupExceptionHandlerInTable(&stack_slots);
+      offset = js_frame->LookupExceptionHandlerInTable(&stack_slots, NULL);
       if (offset >= 0) {
         // Compute the stack pointer from the frame pointer. This ensures that
         // argument slots on the stack are dropped as returning would.
         Address return_sp = frame->fp() -
                             StandardFrameConstants::kFixedFrameSizeFromFp -
                             stack_slots * kPointerSize;
 
         // Gather information from the frame.
         code = frame->LookupCode();
         handler_sp = return_sp;
         handler_fp = frame->fp();
         break;
       }
     }
 
     // For JavaScript frames we perform a range lookup in the handler table.
     if (frame->is_java_script() && catchable_by_js) {
       JavaScriptFrame* js_frame = static_cast<JavaScriptFrame*>(frame);
       int stack_slots = 0;  // Will contain operand stack depth of handler.
-      offset = js_frame->LookupExceptionHandlerInTable(&stack_slots);
+      offset = js_frame->LookupExceptionHandlerInTable(&stack_slots, NULL);
       if (offset >= 0) {
         // Compute the stack pointer from the frame pointer. This ensures that
         // operand stack slots are dropped for nested statements. Also restore
         // correct context for the handler which is pushed within the try-block.
         Address return_sp = frame->fp() -
                             StandardFrameConstants::kFixedFrameSizeFromFp -
                             stack_slots * kPointerSize;
         STATIC_ASSERT(TryBlockConstant::kElementCount == 1);
         context = Context::cast(Memory::Object_at(return_sp - kPointerSize));
 
@@ skipping 17 matching lines @@
   thread_local_top()->pending_handler_offset_ = offset;
   thread_local_top()->pending_handler_fp_ = handler_fp;
   thread_local_top()->pending_handler_sp_ = handler_sp;
 
   // Return and clear pending exception.
   clear_pending_exception();
   return exception;
 }
 
 
-Isolate::CatchType Isolate::PredictExceptionCatcher() {
+Isolate::CatchType Isolate::PredictExceptionCatcher(
+    Isolate::ExceptionPredictionMode mode) {
   Address external_handler = thread_local_top()->try_catch_handler_address();
   Address entry_handler = Isolate::handler(thread_local_top());
   if (IsExternalHandlerOnTop(nullptr)) return CAUGHT_BY_EXTERNAL;
 
   // Search for an exception handler by performing a full walk over the stack.
   for (StackFrameIterator iter(this); !iter.done(); iter.Advance()) {
     StackFrame* frame = iter.frame();
 
     // For JSEntryStub frames we update the JS_ENTRY handler.
     if (frame->is_entry() || frame->is_entry_construct()) {
       entry_handler = frame->top_handler()->next()->address();
     }
 
     // For JavaScript frames we perform a lookup in the handler table.
     if (frame->is_java_script()) {
       JavaScriptFrame* js_frame = static_cast<JavaScriptFrame*>(frame);
       int stack_slots = 0;  // The computed stack slot count is not used.
-      if (js_frame->LookupExceptionHandlerInTable(&stack_slots) > 0) {
-        return CAUGHT_BY_JAVASCRIPT;
+      HandlerTable::CatchPrediction prediction;
+      if (js_frame->LookupExceptionHandlerInTable(&stack_slots, &prediction) >
+          0) {
+        if (mode != CONSERVATIVE_PREDICTION ||
+            prediction != HandlerTable::UNCAUGHT) {
+          return CAUGHT_BY_JAVASCRIPT;
+        }
       }
     }
 
     // The exception has been externally caught if and only if there is an
     // external handler which is on top of the top-most JS_ENTRY handler.
     if (external_handler != nullptr && !try_catch_handler()->is_verbose_) {
       if (entry_handler == nullptr || entry_handler > external_handler) {
         return CAUGHT_BY_EXTERNAL;
       }
     }
@@ skipping 408 matching lines @@
 Handle<Object> Isolate::GetPromiseOnStackOnThrow() {
   Handle<Object> undefined = factory()->undefined_value();
   ThreadLocalTop* tltop = thread_local_top();
   if (tltop->promise_on_stack_ == NULL) return undefined;
   Handle<JSFunction> promise_function = tltop->promise_on_stack_->function();
   // Find the top-most try-catch or try-finally handler.
   if (PredictExceptionCatcher() != CAUGHT_BY_JAVASCRIPT) return undefined;
   for (JavaScriptFrameIterator it(this); !it.done(); it.Advance()) {
     JavaScriptFrame* frame = it.frame();
     int stack_slots = 0;  // The computed stack slot count is not used.
-    if (frame->LookupExceptionHandlerInTable(&stack_slots) > 0) {
+    if (frame->LookupExceptionHandlerInTable(&stack_slots, NULL) > 0) {
       // Throwing inside a Promise only leads to a reject if not caught by an
       // inner try-catch or try-finally.
       if (frame->function() == *promise_function) {
         return tltop->promise_on_stack_->promise();
       }
       return undefined;
     }
   }
   return undefined;
 }
@@ skipping 1195 matching lines @@
   if (prev_ && prev_->Intercept(flag)) return true;
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 } }  // namespace v8::internal