[wasm] Store trap handler index as int

The index is an {int} initially. We then store it as {intptr_t}, and
the accessor returns it as {size_t}.
This CL consolidates everything to {int}, fixes naming of
{HasTrapHandlerIndex} and defines the simple accessors inline.

R=titzer@chromium.org

Bug: v8:9183
Change-Id: I1afa792117201d4dda3fcc437a4e518489b9ff17
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1590079Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61146}

src/wasm/wasm-code-manager.cc

@@ -126,17 +126,8 @@ uint32_t WasmCode::code_comments_size() const {
   return static_cast<uint32_t>(unpadded_binary_size_ - code_comments_offset_);
 }
 
-size_t WasmCode::trap_handler_index() const {
-  CHECK(HasTrapHandlerIndex());
-  return static_cast<size_t>(trap_handler_index_);
-}
-
-void WasmCode::set_trap_handler_index(size_t value) {
-  trap_handler_index_ = value;
-}
-
 void WasmCode::RegisterTrapHandlerData() {
-  DCHECK(!HasTrapHandlerIndex());
+  DCHECK(!has_trap_handler_index());
   if (kind() != WasmCode::kFunction) return;
   if (protected_instructions_.empty()) return;
 
@@ -149,11 +140,10 @@ void WasmCode::RegisterTrapHandlerData() {
 
   // TODO(eholk): if index is negative, fail.
   CHECK_LE(0, index);
-  set_trap_handler_index(static_cast<size_t>(index));
+  set_trap_handler_index(index);
+  DCHECK(has_trap_handler_index());
 }
 
-bool WasmCode::HasTrapHandlerIndex() const { return trap_handler_index_ >= 0; }
-
 bool WasmCode::ShouldBeLogged(Isolate* isolate) {
   // The return value is cached in {WasmEngine::IsolateData::log_codes}. Ensure
   // to call {WasmEngine::EnableCodeLogging} if this return value would change
@@ -373,10 +363,8 @@ const char* GetWasmCodeKindAsString(WasmCode::Kind kind) {
 }
 
 WasmCode::~WasmCode() {
-  if (HasTrapHandlerIndex()) {
-    CHECK_LT(trap_handler_index(),
-             static_cast<size_t>(std::numeric_limits<int>::max()));
-    trap_handler::ReleaseHandlerData(static_cast<int>(trap_handler_index()));
+  if (has_trap_handler_index()) {
+    trap_handler::ReleaseHandlerData(trap_handler_index());
   }
 }
 

src/wasm/wasm-code-manager.h

@@ -213,9 +213,15 @@ class V8_EXPORT_PRIVATE WasmCode final {
 
   // Code objects that have been registered with the global trap handler within
   // this process, will have a {trap_handler_index} associated with them.
-  size_t trap_handler_index() const;
-  void set_trap_handler_index(size_t);
-  bool HasTrapHandlerIndex() const;
+  int trap_handler_index() const {
+    CHECK(has_trap_handler_index());
+    return trap_handler_index_;
+  }
+  void set_trap_handler_index(int value) {
+    CHECK(!has_trap_handler_index());
+    trap_handler_index_ = value;
+  }
+  bool has_trap_handler_index() const { return trap_handler_index_ >= 0; }
 
   // Register protected instruction information with the trap handler. Sets
   // trap_handler_index.
@@ -243,7 +249,7 @@ class V8_EXPORT_PRIVATE WasmCode final {
   size_t handler_table_offset_ = 0;
   size_t code_comments_offset_ = 0;
   size_t unpadded_binary_size_ = 0;
-  intptr_t trap_handler_index_ = -1;
+  int trap_handler_index_ = -1;
   OwnedVector<trap_handler::ProtectedInstructionData> protected_instructions_;
   ExecutionTier tier_;