[objects] Remove unused {Code::trap_handler_index} field.

R=titzer@chromium.org
BUG=v8:7549

Change-Id: Ie77a22f0a6204d673d130be45ca20d5986cddd88
Reviewed-on: https://chromium-review.googlesource.com/962423
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51928}

src/heap/heap.cc

@@ -56,7 +56,6 @@
 #include "src/snapshot/serializer-common.h"
 #include "src/snapshot/snapshot.h"
 #include "src/tracing/trace-event.h"
-#include "src/trap-handler/trap-handler.h"
 #include "src/unicode-decoder.h"
 #include "src/unicode-inl.h"
 #include "src/utils-inl.h"
@@ -3288,7 +3287,6 @@ AllocationResult Heap::AllocateCode(
   code->set_source_position_table(source_position_table);
   code->set_constant_pool_offset(desc.instr_size - desc.constant_pool_size);
   code->set_builtin_index(builtin_index);
-  code->set_trap_handler_index(Smi::FromInt(-1));
 
   switch (code->kind()) {
     case Code::OPTIMIZED_FUNCTION:
@@ -3344,11 +3342,6 @@ AllocationResult Heap::CopyCode(Code* code, CodeDataContainer* data_container) {
   // Set the {CodeDataContainer}, it cannot be shared.
   new_code->set_code_data_container(data_container);
 
-  // Clear the trap handler index since they can't be shared between code. We
-  // have to do this before calling Relocate because relocate would adjust the
-  // base pointer for the old code.
-  new_code->set_trap_handler_index(Smi::FromInt(trap_handler::kInvalidIndex));
-
   // Relocate the copy.
   new_code->Relocate(new_addr - old_addr);
   // We have to iterate over the object and process its pointers when black

src/objects.cc

@@ -73,7 +73,6 @@
 #include "src/string-builder.h"
 #include "src/string-search.h"
 #include "src/string-stream.h"
-#include "src/trap-handler/trap-handler.h"
 #include "src/unicode-cache-inl.h"
 #include "src/unicode-decoder.h"
 #include "src/utils-inl.h"
@@ -13901,12 +13900,6 @@ void Code::InvalidateEmbeddedObjects() {
 
 
 void Code::Relocate(intptr_t delta) {
-  if (trap_handler::IsTrapHandlerEnabled() && is_wasm_code()) {
-    const int index = trap_handler_index()->value();
-    if (index >= 0) {
-      trap_handler::UpdateHandlerDataCodePointer(index, instruction_start());
-    }
-  }
   for (RelocIterator it(this, RelocInfo::kApplyMask); !it.done(); it.next()) {
     it.rinfo()->apply(delta);
   }

src/objects/code-inl.h

@@ -183,7 +183,6 @@ CODE_ACCESSORS(relocation_info, ByteArray, kRelocationInfoOffset)
 CODE_ACCESSORS(deoptimization_data, FixedArray, kDeoptimizationDataOffset)
 CODE_ACCESSORS(source_position_table, Object, kSourcePositionTableOffset)
 CODE_ACCESSORS(code_data_container, CodeDataContainer, kCodeDataContainerOffset)
-CODE_ACCESSORS(trap_handler_index, Smi, kTrapHandlerIndex)
 #undef CODE_ACCESSORS
 
 void Code::WipeOutHeader() {

src/objects/code.h

@@ -83,10 +83,6 @@ class Code : public HeapObject {
   // [code_data_container]: A container indirection for all mutable fields.
   DECL_ACCESSORS(code_data_container, CodeDataContainer)
 
-  // [trap_handler_index]: An index into the trap handler's master list of code
-  // objects.
-  DECL_ACCESSORS(trap_handler_index, Smi)
-
   // [stub_key]: The major/minor key of a code stub.
   inline uint32_t stub_key() const;
   inline void set_stub_key(uint32_t key);
@@ -388,8 +384,7 @@ class Code : public HeapObject {
   static const int kConstantPoolOffset = kStubKeyOffset + kIntSize;
   static const int kBuiltinIndexOffset =
       kConstantPoolOffset + kConstantPoolSize;
-  static const int kTrapHandlerIndex = kBuiltinIndexOffset + kIntSize;
-  static const int kHeaderPaddingStart = kTrapHandlerIndex + kPointerSize;
+  static const int kHeaderPaddingStart = kBuiltinIndexOffset + kIntSize;
 
   // Add padding to align the instruction start following right after
   // the Code object header.
@@ -401,8 +396,6 @@ class Code : public HeapObject {
   // Objects embedded into code is visited via reloc info.
   static const int kDataStart = kInstructionSizeOffset;
 
-  enum TrapFields { kTrapCodeOffset, kTrapLandingOffset, kTrapDataSize };
-
   inline int GetUnwindingInfoSizeOffset() const;
 
   class BodyDescriptor;