[wasm] Move protected instruction info to RelocInfo

src/wasm/wasm-module.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 <memory>
 
 #include "src/assembler-inl.h"
 #include "src/base/adapters.h"
 #include "src/base/atomic-utils.h"
 #include "src/code-stubs.h"
@@ skipping 1389 matching lines @@
 
     // Patch new call sites and the context.
     PatchDirectCallsAndContext(code_table, compiled_module_, module_,
                                num_imported_functions);
 
     FlushICache(isolate_, code_table);
 
     //--------------------------------------------------------------------------
     // Unpack and notify signal handler of protected instructions.
     //--------------------------------------------------------------------------
-    {
+    if (FLAG_wasm_trap_handler) {
       for (int i = 0; i < code_table->length(); ++i) {
         Handle<Code> code = code_table->GetValueChecked<Code>(isolate_, i);
 
         if (code->kind() != Code::WASM_FUNCTION) {
           continue;
         }
 
-        FixedArray* protected_instructions = code->protected_instructions();
-        DCHECK(protected_instructions != nullptr);
+        const intptr_t base = reinterpret_cast<intptr_t>(code->entry());
+
         Zone zone(isolate_->allocator(), "Wasm Module");
         ZoneVector<trap_handler::ProtectedInstructionData> unpacked(&zone);
-        for (int i = 0; i < protected_instructions->length();
-             i += Code::kTrapDataSize) {
+        const int mode_mask =
+            RelocInfo::ModeMask(RelocInfo::WASM_PROTECTED_INSTRUCTION_LANDING);
+        for (RelocIterator it(*code, mode_mask); !it.done(); it.next()) {
           trap_handler::ProtectedInstructionData data;
-          data.instr_offset =
-              protected_instructions
-                  ->GetValueChecked<Smi>(isolate_, i + Code::kTrapCodeOffset)
-                  ->value();
+          data.instr_offset = it.rinfo()->data();
           data.landing_offset =
-              protected_instructions
-                  ->GetValueChecked<Smi>(isolate_, i + Code::kTrapLandingOffset)
-                  ->value();
+              reinterpret_cast<intptr_t>(it.rinfo()->pc()) - base;
           unpacked.emplace_back(data);
         }
         // TODO(eholk): Register the protected instruction information once the
         // trap handler is in place.
       }
     }
 
     //--------------------------------------------------------------------------
     // Set up and link the new instance.
     //--------------------------------------------------------------------------
@@ skipping 1379 matching lines @@
   Handle<FixedArray> storage = factory->NewFixedArray(num_custom_sections);
   JSArray::SetContent(array_object, storage);
   array_object->set_length(Smi::FromInt(num_custom_sections));
 
   for (int i = 0; i < num_custom_sections; i++) {
     storage->set(i, *matching_sections[i]);
   }
 
   return array_object;
 }