[wasm] Fix location for error in asm.js ToNumber conversion

src/frames.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 "src/frames.h"
 
 #include <memory>
 #include <sstream>
 
 #include "src/base/bits.h"
@@ skipping 1518 matching lines @@
 }
 
 int WasmFrame::position() const {
   int position = StandardFrame::position();
   if (wasm::WasmIsAsmJs(wasm_instance(), isolate())) {
     Handle<WasmCompiledModule> compiled_module(
         WasmInstanceObject::cast(wasm_instance())->get_compiled_module(),
         isolate());
     DCHECK_LE(0, position);
     position = WasmCompiledModule::GetAsmJsSourcePosition(
-        compiled_module, function_index(), static_cast<uint32_t>(position));
+        compiled_module, function_index(), static_cast<uint32_t>(position),
+        at_to_number_conversion());
   }
   return position;
 }
 
+bool WasmFrame::at_to_number_conversion() const {
+  // WasmToJsFrame::ComputeCallerState encoded this for us in the constant pool
+  // address ;)
+  return !!constant_pool_address();
+}
+
 int WasmFrame::LookupExceptionHandlerInTable(int* stack_slots) {
   DCHECK_NOT_NULL(stack_slots);
   Code* code = LookupCode();
   HandlerTable* table = HandlerTable::cast(code->handler_table());
   int pc_offset = static_cast<int>(pc() - code->entry());
   *stack_slots = code->stack_slots();
   return table->LookupReturn(pc_offset);
 }
 
+void WasmToJsFrame::ComputeCallerState(State* state) const {
+  // Remember at which of the two calls inside it we are, and transfer this
+  // information to the subsequent WASM frame.
+  Code* code = unchecked_code();
+  AbstractCode* abstract_code = AbstractCode::cast(code);
+  int offset = static_cast<int>(pc() - code->instruction_start());
+  int at_to_number_call = abstract_code->SourcePosition(offset);
+  DCHECK(at_to_number_call == 0 || at_to_number_call == 1);
+  StubFrame::ComputeCallerState(state);
+  DCHECK_EQ(StackFrame::WASM, ComputeType(iterator_, state));
+  // Use a little hack here: The constant pool address is not used for wasm
+  // frames, so use it to encode whether we are at the to_number call.
+  state->constant_pool_address = reinterpret_cast<Address*>(at_to_number_call);
+}
+
 namespace {
 
 
 void PrintFunctionSource(StringStream* accumulator, SharedFunctionInfo* shared,
                          Code* code) {
   if (FLAG_max_stack_trace_source_length != 0 && code != NULL) {
     std::ostringstream os;
     os << "--------- s o u r c e   c o d e ---------\n"
        << SourceCodeOf(shared, FLAG_max_stack_trace_source_length)
        << "\n-----------------------------------------\n";
@@ skipping 418 matching lines @@
   for (StackFrameIterator it(isolate); !it.done(); it.Advance()) {
     StackFrame* frame = AllocateFrameCopy(it.frame(), zone);
     list.Add(frame, zone);
   }
   return list.ToVector();
 }
 
 
 }  // namespace internal
 }  // namespace v8