[vm] Cleanup script tags

VM creates Script objects with kKernelTag only, so this CL cleans up
all uses of script tags and Script::kind() along with code
which is no longer reachable.

Change-Id: Ia765e7757264aa614e18eddd16d21937f855c129
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/123889
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>

Author: alexmarkov

runtime/lib/mirrors.cc

@@ -1697,10 +1697,8 @@ DEFINE_NATIVE_ENTRY(DeclarationMirror_location, 0, 1) {
       return Instance::null();  // No source.
     }
     const Array& scripts = Array::Handle(zone, lib.LoadedScripts());
-    for (intptr_t i = 0; i < scripts.Length(); i++) {
-      script ^= scripts.At(i);
-      if (script.kind() == RawScript::kLibraryTag) break;
-    }
+    ASSERT(scripts.Length() > 0);
+    script ^= scripts.At(scripts.Length() - 1);
     ASSERT(!script.IsNull());
     const String& uri = String::Handle(zone, script.url());
     return CreateSourceLocation(uri, 1, 1);

runtime/vm/clustered_snapshot.cc

@@ -1100,7 +1100,7 @@ class ScriptSerializationCluster : public SerializationCluster {
       WriteFromTo(script);
       s->Write<int32_t>(script->ptr()->line_offset_);
       s->Write<int32_t>(script->ptr()->col_offset_);
-      s->Write<uint8_t>(script->ptr()->kind_and_tags_);
+      s->Write<uint8_t>(script->ptr()->flags_);
       s->Write<int32_t>(script->ptr()->kernel_script_index_);
     }
   }
@@ -1133,7 +1133,7 @@ class ScriptDeserializationCluster : public DeserializationCluster {
       ReadFromTo(script);
       script->ptr()->line_offset_ = d->Read<int32_t>();
       script->ptr()->col_offset_ = d->Read<int32_t>();
-      script->ptr()->kind_and_tags_ = d->Read<uint8_t>();
+      script->ptr()->flags_ = d->Read<uint8_t>();
       script->ptr()->kernel_script_index_ = d->Read<int32_t>();
       script->ptr()->load_timestamp_ = 0;
     }

runtime/vm/compiler/frontend/bytecode_reader.cc

@@ -1540,7 +1540,7 @@ RawObject* BytecodeReaderHelper::ReadObjectContents(uint32_t header) {
             ReadSourceFile(uri, bytecode_component_->GetSourceFilesOffset() +
                                     reader_.ReadUInt());
       } else {
-        script = Script::New(uri, Object::null_string(), RawScript::kKernelTag);
+        script = Script::New(uri, Object::null_string());
       }
       script.set_kernel_program_info(H.GetKernelProgramInfo());
       return script.raw();
@@ -1910,8 +1910,8 @@ RawScript* BytecodeReaderHelper::ReadSourceFile(const String& uri,
     source = ReadString(/* is_canonical = */ false);
   }
 
-  const Script& script = Script::Handle(
-      Z, Script::New(import_uri, uri, source, RawScript::kKernelTag));
+  const Script& script =
+      Script::Handle(Z, Script::New(import_uri, uri, source));
   script.set_line_starts(line_starts);
 
   if (source.IsNull() && line_starts.IsNull()) {

runtime/vm/debugger.cc

@@ -1053,7 +1053,6 @@ void ActivationFrame::ExtractTokenPositionFromAsyncClosure() {
   }
 
   ASSERT(!IsInterpreted());
-  ASSERT(script.kind() == RawScript::kKernelTag);
   const intptr_t await_jump_var = GetAwaitJumpVariable();
   if (await_jump_var < 0) {
     return;
@@ -3063,7 +3062,6 @@ TokenPosition Debugger::ResolveBreakpointPos(bool in_bytecode,
     const TokenPosition begin_pos = best_fit_pos;
 
     TokenPosition end_of_line_pos;
-    ASSERT(script.kind() == RawScript::kKernelTag);
     if (best_line == -1) {
       script.GetTokenLocation(begin_pos, &best_line, NULL);
     }
@@ -4379,7 +4377,6 @@ bool Debugger::IsAtAsyncJump(ActivationFrame* top_frame) {
     }
     ASSERT(!top_frame->IsInterpreted());
     const Script& script = Script::Handle(zone, top_frame->SourceScript());
-    ASSERT(script.kind() == RawScript::kKernelTag);
     const auto& yield_positions = GrowableObjectArray::Handle(
         zone, script.GetYieldPositions(top_frame->function()));
     // No yield statements

runtime/vm/exceptions.cc

@@ -822,11 +822,7 @@ void Exceptions::CreateAndThrowTypeError(TokenPosition location,
   intptr_t column = -1;
   ASSERT(!script.IsNull());
   if (location.IsReal()) {
-    if (script.HasSource() || script.kind() == RawScript::kKernelTag) {
-      script.GetTokenLocation(location, &line, &column);
-    } else {
-      script.GetTokenLocation(location, &line, NULL);
-    }
+    script.GetTokenLocation(location, &line, &column);
   }
   // Initialize '_url', '_line', and '_column' arguments.
   args.SetAt(0, String::Handle(zone, script.url()));

runtime/vm/kernel_loader.cc

@@ -2059,7 +2059,7 @@ RawScript* KernelLoader::LoadScriptAt(intptr_t index,
       for (intptr_t i = 0; i < libs.Length(); i++) {
         lib ^= libs.At(i);
         script = lib.LookupScript(uri_string, /* useResolvedUri = */ true);
-        if (!script.IsNull() && script.kind() == RawScript::kKernelTag) {
+        if (!script.IsNull()) {
           sources = script.Source();
           line_starts = script.line_starts();
           break;
@@ -2071,8 +2071,7 @@ RawScript* KernelLoader::LoadScriptAt(intptr_t index,
   }
 
   const Script& script =
-      Script::Handle(Z, Script::New(import_uri_string, uri_string, sources,
-                                    RawScript::kKernelTag));
+      Script::Handle(Z, Script::New(import_uri_string, uri_string, sources));
   script.set_kernel_script_index(index);
   script.set_kernel_program_info(kernel_program_info_);
   script.set_line_starts(line_starts);

runtime/vm/object.cc

@@ -8067,43 +8067,36 @@ RawString* Function::GetSource() const {
   Zone* zone = Thread::Current()->zone();
   const Script& func_script = Script::Handle(zone, script());
 
-  if (func_script.kind() == RawScript::kKernelTag) {
-    intptr_t from_line;
-    intptr_t from_col;
-    intptr_t to_line;
-    intptr_t to_col;
-    intptr_t to_length;
-    func_script.GetTokenLocation(token_pos(), &from_line, &from_col);
-    func_script.GetTokenLocation(end_token_pos(), &to_line, &to_col,
-                                 &to_length);
-
-    if (to_length == 1) {
-      // Handle special cases for end tokens of closures (where we exclude the
-      // last token):
-      // (1) "foo(() => null, bar);": End token is `,', but we don't print it.
-      // (2) "foo(() => null);": End token is ')`, but we don't print it.
-      // (3) "var foo = () => null;": End token is `;', but in this case the
-      // token semicolon belongs to the assignment so we skip it.
-      const String& src = String::Handle(func_script.Source());
-      if (src.IsNull() || src.Length() == 0) {
-        return Symbols::OptimizedOut().raw();
-      }
-      uint16_t end_char = src.CharAt(end_token_pos().value());
-      if ((end_char == ',') ||  // Case 1.
-          (end_char == ')') ||  // Case 2.
-          (end_char == ';' &&
-           String::Handle(zone, name())
-               .Equals("<anonymous closure>"))) {  // Case 3.
-        to_length = 0;
-      }
-    }
+  intptr_t from_line;
+  intptr_t from_col;
+  intptr_t to_line;
+  intptr_t to_col;
+  intptr_t to_length;
+  func_script.GetTokenLocation(token_pos(), &from_line, &from_col);
+  func_script.GetTokenLocation(end_token_pos(), &to_line, &to_col, &to_length);
 
-    return func_script.GetSnippet(from_line, from_col, to_line,
-                                  to_col + to_length);
+  if (to_length == 1) {
+    // Handle special cases for end tokens of closures (where we exclude the
+    // last token):
+    // (1) "foo(() => null, bar);": End token is `,', but we don't print it.
+    // (2) "foo(() => null);": End token is ')`, but we don't print it.
+    // (3) "var foo = () => null;": End token is `;', but in this case the
+    // token semicolon belongs to the assignment so we skip it.
+    const String& src = String::Handle(func_script.Source());
+    if (src.IsNull() || src.Length() == 0) {
+      return Symbols::OptimizedOut().raw();
+    }
+    uint16_t end_char = src.CharAt(end_token_pos().value());
+    if ((end_char == ',') ||  // Case 1.
+        (end_char == ')') ||  // Case 2.
+        (end_char == ';' && String::Handle(zone, name())
+                                .Equals("<anonymous closure>"))) {  // Case 3.
+      to_length = 0;
+    }
   }
 
-  UNREACHABLE();
-  return String::null();
+  return func_script.GetSnippet(from_line, from_col, to_line,
+                                to_col + to_length);
 }
 
 // Construct fingerprint from token stream. The token stream contains also
@@ -9518,7 +9511,7 @@ void Script::LookupSourceAndLineStarts(Zone* zone) const {
     for (intptr_t i = 0; i < libs.Length(); i++) {
       lib ^= libs.At(i);
       script = lib.LookupScript(uri, /* useResolvedUri = */ true);
-      if (!script.IsNull() && script.kind() == RawScript::kKernelTag) {
+      if (!script.IsNull()) {
         const auto& source = String::Handle(zone, script.Source());
         const auto& line_starts = TypedData::Handle(zone, script.line_starts());
         if (!source.IsNull() || !line_starts.IsNull()) {
@@ -9534,7 +9527,6 @@ void Script::LookupSourceAndLineStarts(Zone* zone) const {
 }
 
 RawGrowableObjectArray* Script::GenerateLineNumberArray() const {
-  ASSERT(kind() == RawScript::kKernelTag);
   Zone* zone = Thread::Current()->zone();
   const GrowableObjectArray& info =
       GrowableObjectArray::Handle(zone, GrowableObjectArray::New());
@@ -9589,25 +9581,6 @@ RawGrowableObjectArray* Script::GenerateLineNumberArray() const {
   return info.raw();
 }
 
-const char* Script::GetKindAsCString() const {
-  switch (kind()) {
-    case RawScript::kScriptTag:
-      return "script";
-    case RawScript::kLibraryTag:
-      return "library";
-    case RawScript::kSourceTag:
-      return "source";
-    case RawScript::kEvaluateTag:
-      return "evaluate";
-    case RawScript::kKernelTag:
-      return "kernel";
-    default:
-      UNIMPLEMENTED();
-  }
-  UNREACHABLE();
-  return NULL;
-}
-
 void Script::set_url(const String& value) const {
   StorePointer(&raw_ptr()->url_, value.raw());
 }
@@ -9662,31 +9635,25 @@ RawTypedData* Script::line_starts() const {
 RawArray* Script::debug_positions() const {
 #if !defined(DART_PRECOMPILED_RUNTIME)
   Array& debug_positions_array = Array::Handle(raw_ptr()->debug_positions_);
-  if (debug_positions_array.IsNull() && kind() == RawScript::kKernelTag) {
+  if (debug_positions_array.IsNull()) {
     // This is created lazily. Now we need it.
     kernel::CollectTokenPositionsFor(*this);
   }
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)
   return raw_ptr()->debug_positions_;
 }
 
-void Script::set_kind(RawScript::Kind value) const {
-  set_kind_and_tags(
-      RawScript::KindBits::update(value, raw_ptr()->kind_and_tags_));
-}
-
-void Script::set_kind_and_tags(uint8_t value) const {
-  StoreNonPointer(&raw_ptr()->kind_and_tags_, value);
+void Script::set_flags(uint8_t value) const {
+  StoreNonPointer(&raw_ptr()->flags_, value);
 }
 
 void Script::SetLazyLookupSourceAndLineStarts(bool value) const {
-  set_kind_and_tags(RawScript::LazyLookupSourceAndLineStartsBit::update(
-      value, raw_ptr()->kind_and_tags_));
+  set_flags(RawScript::LazyLookupSourceAndLineStartsBit::update(
+      value, raw_ptr()->flags_));
 }
 
 bool Script::IsLazyLookupSourceAndLineStarts() const {
-  return RawScript::LazyLookupSourceAndLineStartsBit::decode(
-      raw_ptr()->kind_and_tags_);
+  return RawScript::LazyLookupSourceAndLineStartsBit::decode(raw_ptr()->flags_);
 }
 
 void Script::set_load_timestamp(int64_t value) const {
@@ -9715,31 +9682,12 @@ intptr_t Script::GetTokenLineUsingLineStarts(
     return 0;
   }
 
-  if (kind() == RawScript::kKernelTag) {
 #if !defined(DART_PRECOMPILED_RUNTIME)
-    kernel::KernelLineStartsReader line_starts_reader(line_starts_data, zone);
-    return line_starts_reader.LineNumberForPosition(target_token_pos.value());
+  kernel::KernelLineStartsReader line_starts_reader(line_starts_data, zone);
+  return line_starts_reader.LineNumberForPosition(target_token_pos.value());
 #else
-    return 0;
+  return 0;
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)
-  } else {
-    ASSERT(line_starts_data.Length() > 0);
-    intptr_t offset = target_token_pos.Pos();
-    intptr_t min = 0;
-    intptr_t max = line_starts_data.Length() - 1;
-
-    // Binary search to find the line containing this offset.
-    while (min < max) {
-      int midpoint = (max - min + 1) / 2 + min;
-      int32_t token_pos = line_starts_data.GetInt32(midpoint * 4);
-      if (token_pos > offset) {
-        max = midpoint - 1;
-      } else {
-        min = midpoint;
-      }
-    }
-    return min + 1;  // Line numbers start at 1.
-  }
 }
 
 #if !defined(DART_PRECOMPILED_RUNTIME)
@@ -9767,7 +9715,6 @@ void Script::GetTokenLocation(TokenPosition token_pos,
   ASSERT(line != NULL);
   Zone* zone = Thread::Current()->zone();
 
-  ASSERT(kind() == RawScript::kKernelTag);
   LookupSourceAndLineStarts(zone);
   if (line_starts() == TypedData::null()) {
     // Scripts in the AOT snapshot do not have a line starts array.
@@ -9806,7 +9753,6 @@ void Script::GetTokenLocation(TokenPosition token_pos,
 void Script::TokenRangeAtLine(intptr_t line_number,
                               TokenPosition* first_token_index,
                               TokenPosition* last_token_index) const {
-  ASSERT(kind() == RawScript::kKernelTag);
   ASSERT(first_token_index != NULL && last_token_index != NULL);
   ASSERT(line_number > 0);
 
@@ -9944,16 +9890,13 @@ RawScript* Script::New() {
   return reinterpret_cast<RawScript*>(raw);
 }
 
-RawScript* Script::New(const String& url,
-                       const String& source,
-                       RawScript::Kind kind) {
-  return Script::New(url, url, source, kind);
+RawScript* Script::New(const String& url, const String& source) {
+  return Script::New(url, url, source);
 }
 
 RawScript* Script::New(const String& url,
                        const String& resolved_url,
-                       const String& source,
-                       RawScript::Kind kind) {
+                       const String& source) {
   Thread* thread = Thread::Current();
   Zone* zone = thread->zone();
   const Script& result = Script::Handle(zone, Script::New());
@@ -9962,8 +9905,7 @@ RawScript* Script::New(const String& url,
       String::Handle(zone, Symbols::New(thread, resolved_url)));
   result.set_source(source);
   result.SetLocationOffset(0, 0);
-  result.set_kind_and_tags(0);
-  result.set_kind(kind);
+  result.set_flags(0);
   result.set_kernel_script_index(0);
   result.set_load_timestamp(
       FLAG_remove_script_timestamps_for_test ? 0 : OS::GetCurrentTimeMillis());
@@ -22009,11 +21951,7 @@ static void PrintStackTraceFrame(Zone* zone,
     line = token_pos.value();
   } else {
     if (!script.IsNull() && token_pos.IsSourcePosition()) {
-      if (script.HasSource() || script.kind() == RawScript::kKernelTag) {
-        script.GetTokenLocation(token_pos.SourcePosition(), &line, &column);
-      } else {
-        script.GetTokenLocation(token_pos.SourcePosition(), &line, NULL);
-      }
+      script.GetTokenLocation(token_pos.SourcePosition(), &line, &column);
     }
   }
 

runtime/vm/object.h

@@ -3904,11 +3904,6 @@ class Script : public Object {
   void LookupSourceAndLineStarts(Zone* zone) const;
   RawGrowableObjectArray* GenerateLineNumberArray() const;
 
-  RawScript::Kind kind() const {
-    return RawScript::KindBits::decode(raw_ptr()->kind_and_tags_);
-  }
-
-  const char* GetKindAsCString() const;
   intptr_t line_offset() const { return raw_ptr()->line_offset_; }
   intptr_t col_offset() const { return raw_ptr()->col_offset_; }
 
@@ -3973,14 +3968,11 @@ class Script : public Object {
     return RoundedAllocationSize(sizeof(RawScript));
   }
 
-  static RawScript* New(const String& url,
-                        const String& source,
-                        RawScript::Kind kind);
+  static RawScript* New(const String& url, const String& source);
 
   static RawScript* New(const String& url,
                         const String& resolved_url,
-                        const String& source,
-                        RawScript::Kind kind);
+                        const String& source);
 
 #if !defined(DART_PRECOMPILED_RUNTIME)
   void LoadSourceFromKernel(const uint8_t* kernel_buffer,
@@ -3993,8 +3985,7 @@ class Script : public Object {
  private:
   void set_resolved_url(const String& value) const;
   void set_source(const String& value) const;
-  void set_kind(RawScript::Kind value) const;
-  void set_kind_and_tags(uint8_t value) const;
+  void set_flags(uint8_t value) const;
   void set_load_timestamp(int64_t value) const;
   RawArray* debug_positions() const;