[wasm] Initial signal handler

src/objects.cc

 // 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.
 
 #include "src/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <memory>
 #include <sstream>
@@ skipping 14240 matching lines @@
     if (mode == RelocInfo::EMBEDDED_OBJECT) {
       it.rinfo()->set_target_object(undefined, SKIP_WRITE_BARRIER);
     } else if (mode == RelocInfo::CELL) {
       it.rinfo()->set_target_cell(undefined_cell, SKIP_WRITE_BARRIER);
     }
   }
 }
 
 
 void Code::Relocate(intptr_t delta) {
+  if (trap_handler::EnableTrapHandler() && is_wasm_code()) {
+    fprintf(stderr, "Relocating Wasm code from %p to %p\n",
+            instruction_start() - delta, instruction_start());
+    const int index = trap_handler_index()->value();
+    if (index >= 0) {
+      trap_handler::UpdateCodePointer(index, instruction_start());
+    }
+  }
   for (RelocIterator it(this, RelocInfo::kApplyMask); !it.done(); it.next()) {
     it.rinfo()->apply(delta);
   }
   Assembler::FlushICache(GetIsolate(), instruction_start(), instruction_size());
 }
 
 
 void Code::CopyFrom(const CodeDesc& desc) {
   // copy code
   CopyBytes(instruction_start(), desc.buffer,
@@ skipping 6070 matching lines @@
       // depend on this.
       return DICTIONARY_ELEMENTS;
     }
     DCHECK_LE(kind, LAST_ELEMENTS_KIND);
     return kind;
   }
 }
 
 }  // namespace internal
 }  // namespace v8