[wasm] Initial signal handler

src/objects.h

 // Copyright 2015 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.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 #include <memory>
 
@@ skipping 4897 matching lines @@
 
   // [handler_table]: Fixed array containing offsets of exception handlers.
   DECL_ACCESSORS(handler_table, FixedArray)
 
   // [deoptimization_data]: Array containing data for deopt.
   DECL_ACCESSORS(deoptimization_data, FixedArray)
 
   // [source_position_table]: ByteArray for the source positions table.
   DECL_ACCESSORS(source_position_table, ByteArray)
 
+  // [trap_handler_index]: An index into the trap handler's master list of code
+  // objects.
+  DECL_ACCESSORS(trap_handler_index, Smi)
+
   // [raw_type_feedback_info]: This field stores various things, depending on
   // the kind of the code object.
   //   FUNCTION           => type feedback information.
   //   STUB and ICs       => major/minor key as Smi.
   DECL_ACCESSORS(raw_type_feedback_info, Object)
   inline Object* type_feedback_info();
   inline void set_type_feedback_info(
       Object* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
   inline uint32_t stub_key();
   inline void set_stub_key(uint32_t key);
@@ skipping 368 matching lines @@
   static const int kICAgeOffset = kInstructionSizeOffset + kIntSize;
   static const int kFlagsOffset = kICAgeOffset + kIntSize;
   static const int kKindSpecificFlags1Offset = kFlagsOffset + kIntSize;
   static const int kKindSpecificFlags2Offset =
       kKindSpecificFlags1Offset + kIntSize;
   // Note: We might be able to squeeze this into the flags above.
   static const int kPrologueOffset = kKindSpecificFlags2Offset + kIntSize;
   static const int kConstantPoolOffset = kPrologueOffset + kIntSize;
   static const int kBuiltinIndexOffset =
       kConstantPoolOffset + kConstantPoolSize;
-  static const int kHeaderPaddingStart = kBuiltinIndexOffset + kIntSize;
+  static const int kTrapHandlerIndex = kBuiltinIndexOffset + kIntSize;
+  static const int kHeaderPaddingStart = kTrapHandlerIndex + kPointerSize;
 
   enum TrapFields { kTrapCodeOffset, kTrapLandingOffset, kTrapDataSize };
 
 
   // Add padding to align the instruction start following right after
   // the Code object header.
   static const int kHeaderSize =
       (kHeaderPaddingStart + kCodeAlignmentMask) & ~kCodeAlignmentMask;
 
   inline int GetUnwindingInfoSizeOffset() const;
@@ skipping 6254 matching lines @@
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #include "src/objects/object-macros-undef.h"
 
 #endif  // V8_OBJECTS_H_