[vector] Rename {is_empty} to {empty}

All standard containers provide a method named {empty} to check whether
the container is empty. On {base::Vector}, that method is named
{is_empty}, while {empty} is an unused factory method for creating an
empty {Vector}.
This CL renames {is_empty} to {empty} and removes the unused factory
method.

R=leszeks@chromium.org

Bug: v8:8834
Change-Id: I686bd07527801fbe783c412bc241221d8ec3660a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1547862
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60584}

src/log.cc

@@ -234,7 +234,7 @@ void CodeEventLogger::CodeCreateEvent(LogEventsAndTags tag,
                                       const wasm::WasmCode* code,
                                       wasm::WasmName name) {
   name_buffer_->Init(tag);
-  if (name.is_empty()) {
+  if (name.empty()) {
     name_buffer_->AppendBytes("<wasm-unknown>");
   } else {
     name_buffer_->AppendBytes(name.start(), name.length());
@@ -1228,7 +1228,7 @@ void Logger::CodeCreateEvent(CodeEventListener::LogEventsAndTags tag,
   AppendCodeCreateHeader(msg, tag, AbstractCode::Kind::WASM_FUNCTION,
                          code->instructions().start(),
                          code->instructions().length(), &timer_);
-  if (name.is_empty()) {
+  if (name.empty()) {
     msg << "<unknown wasm>";
   } else {
     msg.AppendString(name);

src/optimized-compilation-info.cc

@@ -154,7 +154,7 @@ std::unique_ptr<char[]> OptimizedCompilationInfo::GetDebugName() const {
     return shared_info()->DebugName()->ToCString();
   }
   Vector<const char> name_vec = debug_name_;
-  if (name_vec.is_empty()) name_vec = ArrayVector("unknown");
+  if (name_vec.empty()) name_vec = ArrayVector("unknown");
   std::unique_ptr<char[]> name(new char[name_vec.length() + 1]);
   memcpy(name.get(), name_vec.start(), name_vec.length());
   name[name_vec.length()] = '\0';

src/parsing/parser.h

@@ -69,7 +69,7 @@ class FunctionEntry {
   }
   int num_inner_functions() const { return backing_[kNumInnerFunctionsIndex]; }
 
-  bool is_valid() const { return !backing_.is_empty(); }
+  bool is_valid() const { return !backing_.empty(); }
 
  private:
   Vector<unsigned> backing_;

src/parsing/preparse-data.cc

@@ -229,7 +229,7 @@ void PreparseDataBuilder::DataGatheringScope::SetSkippableFunction(
 }
 
 bool PreparseDataBuilder::HasInnerFunctions() const {
-  return !children_.is_empty();
+  return !children_.empty();
 }
 
 bool PreparseDataBuilder::HasData() const { return !bailed_out_ && has_data_; }

src/vector.h

@@ -51,7 +51,7 @@ class Vector {
   constexpr size_t size() const { return length_; }
 
   // Returns whether or not the vector is empty.
-  constexpr bool is_empty() const { return length_ == 0; }
+  constexpr bool empty() const { return length_ == 0; }
 
   // Returns the pointer to the start of the data in the vector.
   constexpr T* start() const { return start_; }
@@ -140,9 +140,6 @@ class Vector {
     return Vector<const T>::cast(*this);
   }
 
-  // Factory method for creating empty vectors.
-  static Vector<T> empty() { return Vector<T>(nullptr, 0); }
-
   template <typename S>
   static constexpr Vector<T> cast(Vector<S> input) {
     return Vector<T>(reinterpret_cast<T*>(input.start()),
@@ -214,7 +211,7 @@ class OwnedVector {
   constexpr size_t size() const { return length_; }
 
   // Returns whether or not the vector is empty.
-  constexpr bool is_empty() const { return length_ == 0; }
+  constexpr bool empty() const { return length_ == 0; }
 
   // Returns the pointer to the start of the data in the vector.
   T* start() const {

src/wasm/streaming-decoder.h

@@ -256,7 +256,7 @@ class V8_EXPORT_PRIVATE StreamingDecoder {
 
   uint32_t module_offset() const { return module_offset_; }
 
-  bool deserializing() const { return !compiled_module_bytes_.is_empty(); }
+  bool deserializing() const { return !compiled_module_bytes_.empty(); }
 
   std::unique_ptr<StreamingProcessor> processor_;
   std::unique_ptr<DecodingState> state_;

src/wasm/wasm-code-manager.cc

@@ -126,7 +126,7 @@ void WasmCode::set_trap_handler_index(size_t value) {
 void WasmCode::RegisterTrapHandlerData() {
   DCHECK(!HasTrapHandlerIndex());
   if (kind() != WasmCode::kFunction) return;
-  if (protected_instructions_.is_empty()) return;
+  if (protected_instructions_.empty()) return;
 
   Address base = instruction_start();
 
@@ -159,7 +159,7 @@ void WasmCode::LogCode(Isolate* isolate) const {
   WireBytesRef name_ref =
       native_module()->module()->LookupFunctionName(wire_bytes, index());
   WasmName name_vec = wire_bytes.GetNameOrNull(name_ref);
-  if (!name_vec.is_empty()) {
+  if (!name_vec.empty()) {
     HandleScope scope(isolate);
     MaybeHandle<String> maybe_name = isolate->factory()->NewStringFromUtf8(
         Vector<const char>::cast(name_vec));
@@ -182,7 +182,7 @@ void WasmCode::LogCode(Isolate* isolate) const {
                                      generated_name));
   }
 
-  if (!source_positions().is_empty()) {
+  if (!source_positions().empty()) {
     LOG_CODE_EVENT(isolate, CodeLinePosInfoRecordEvent(instruction_start(),
                                                        source_positions()));
   }
@@ -289,7 +289,7 @@ void WasmCode::Disassemble(const char* name, std::ostream& os,
     os << "\n";
   }
 
-  if (!protected_instructions_.is_empty()) {
+  if (!protected_instructions_.empty()) {
     os << "Protected instructions:\n pc offset  land pad\n";
     for (auto& data : protected_instructions()) {
       os << std::setw(10) << std::hex << data.instr_offset << std::setw(10)
@@ -298,7 +298,7 @@ void WasmCode::Disassemble(const char* name, std::ostream& os,
     os << "\n";
   }
 
-  if (!source_positions().is_empty()) {
+  if (!source_positions().empty()) {
     os << "Source positions:\n pc offset  position\n";
     for (SourcePositionTableIterator it(source_positions()); !it.done();
          it.Advance()) {
@@ -954,7 +954,7 @@ void NativeModule::SetWireBytes(OwnedVector<const uint8_t> wire_bytes) {
   auto shared_wire_bytes =
       std::make_shared<OwnedVector<const uint8_t>>(std::move(wire_bytes));
   wire_bytes_ = shared_wire_bytes;
-  if (!shared_wire_bytes->is_empty()) {
+  if (!shared_wire_bytes->empty()) {
     compilation_state_->SetWireBytesStorage(
         std::make_shared<NativeModuleWireBytesStorage>(
             std::move(shared_wire_bytes)));
@@ -1302,7 +1302,7 @@ WasmCodeUpdate NativeModule::AddCompiledCode(WasmCompilationResult result) {
 
 std::vector<WasmCodeUpdate> NativeModule::AddCompiledCode(
     Vector<WasmCompilationResult> results) {
-  DCHECK(!results.is_empty());
+  DCHECK(!results.empty());
   // First, allocate code space for all the results.
   size_t total_code_space = 0;
   for (auto& result : results) {

src/wasm/wasm-module-builder.cc

@@ -363,7 +363,7 @@ void WasmModuleBuilder::WriteTo(ZoneBuffer& buffer) const {
     buffer.write_size(functions_.size());
     for (auto function : functions_) {
       function->WriteSignature(buffer);
-      if (!function->name_.is_empty()) ++num_function_names;
+      if (!function->name_.empty()) ++num_function_names;
     }
     FixupSection(buffer, start);
   }
@@ -544,7 +544,7 @@ void WasmModuleBuilder::WriteTo(ZoneBuffer& buffer) const {
     uint32_t function_index = 0;
     for (; function_index < num_imports; ++function_index) {
       const WasmFunctionImport* import = &function_imports_[function_index];
-      DCHECK(!import->name.is_empty());
+      DCHECK(!import->name.empty());
       buffer.write_u32v(function_index);
       buffer.write_string(import->name);
     }
@@ -552,7 +552,7 @@ void WasmModuleBuilder::WriteTo(ZoneBuffer& buffer) const {
       for (auto function : functions_) {
         DCHECK_EQ(function_index,
                   function->func_index() + function_imports_.size());
-        if (!function->name_.is_empty()) {
+        if (!function->name_.empty()) {
           buffer.write_u32v(function_index);
           buffer.write_string(function->name_);
         }

src/wasm/wasm-module.cc

@@ -63,7 +63,7 @@ WasmName ModuleWireBytes::GetNameOrNull(const WasmFunction* function,
 
 std::ostream& operator<<(std::ostream& os, const WasmFunctionName& name) {
   os << "#" << name.function_->func_index;
-  if (!name.name_.is_empty()) {
+  if (!name.name_.empty()) {
     if (name.name_.start()) {
       os << ":";
       os.write(name.name_.start(), name.name_.length());

src/wasm/wasm-text.cc

@@ -20,7 +20,7 @@ namespace wasm {
 
 namespace {
 bool IsValidFunctionName(const Vector<const char> &name) {
-  if (name.is_empty()) return false;
+  if (name.empty()) return false;
   const char *special_chars = "_.+-*/\\^~=<>!?@#$%&|:'`";
   for (char c : name) {
     bool valid_char = (c >= '0' && c <= '9') || (c >= 'a' && c <= 'z') ||

test/fuzzer/wasm-fuzzer-common.cc

@@ -275,8 +275,8 @@ void WasmExecutionFuzzer::FuzzWasmModule(Vector<const uint8_t> data,
   std::unique_ptr<Handle<Object>[]> compiler_args;
   // The first byte builds the bitmask to control which function will be
   // compiled with Turbofan and which one with Liftoff.
-  uint8_t tier_mask = data.is_empty() ? 0 : data[0];
-  if (!data.is_empty()) data += 1;
+  uint8_t tier_mask = data.empty() ? 0 : data[0];
+  if (!data.empty()) data += 1;
   if (!GenerateModule(i_isolate, &zone, data, buffer, num_args,
                       interpreter_args, compiler_args)) {
     return;