Roll inspector_protocol library to inculude unified (de)serialization support

Note that changes in test expectation come from a more verbose
error diagnostics for expected errors around input parameter
validation.

Original change: https://chromium-review.googlesource.com/c/deps/inspector_protocol/+/2270757

Bug: chromium:1099809

Change-Id: I4fc2efc9c89d0af645dad937d719fa36e1d33489
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2277142Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Andrey Kosyakov <caseq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68657}

src/inspector/injected-script.cc

@@ -247,8 +247,7 @@ class InjectedScript::ProtocolPromiseHandler {
     // we try to capture a fresh stack trace.
     if (maybeMessage.ToLocal(&message)) {
       v8::Local<v8::Value> exception = result;
-      protocol::detail::PtrMaybe<protocol::Runtime::ExceptionDetails>
-          exceptionDetails;
+      protocol::PtrMaybe<protocol::Runtime::ExceptionDetails> exceptionDetails;
       response = scope.injectedScript()->createExceptionDetails(
           message, exception, m_objectGroup, &exceptionDetails);
       if (!response.IsSuccess()) {

src/inspector/string-util.cc

@@ -246,7 +246,66 @@ String16 stackTraceIdToString(uintptr_t id) {
 }  // namespace v8_inspector
 
 namespace v8_crdtp {
-void SerializerTraits<v8_inspector::protocol::Binary>::Serialize(
+
+using v8_inspector::String16;
+using v8_inspector::protocol::Binary;
+using v8_inspector::protocol::StringUtil;
+
+// static
+bool ProtocolTypeTraits<String16>::Deserialize(DeserializerState* state,
+                                               String16* value) {
+  auto* tokenizer = state->tokenizer();
+  if (tokenizer->TokenTag() == cbor::CBORTokenTag::STRING8) {
+    const auto str = tokenizer->GetString8();
+    *value = StringUtil::fromUTF8(str.data(), str.size());
+    return true;
+  }
+  if (tokenizer->TokenTag() == cbor::CBORTokenTag::STRING16) {
+    const auto str = tokenizer->GetString16WireRep();
+    *value = StringUtil::fromUTF16LE(
+        reinterpret_cast<const uint16_t*>(str.data()), str.size() / 2);
+    return true;
+  }
+  state->RegisterError(Error::BINDINGS_STRING_VALUE_EXPECTED);
+  return false;
+}
+
+// static
+void ProtocolTypeTraits<String16>::Serialize(const String16& value,
+                                             std::vector<uint8_t>* bytes) {
+  cbor::EncodeFromUTF16(
+      span<uint16_t>(reinterpret_cast<const uint16_t*>(value.characters16()),
+                     value.length()),
+      bytes);
+}
+
+// static
+bool ProtocolTypeTraits<Binary>::Deserialize(DeserializerState* state,
+                                             Binary* value) {
+  auto* tokenizer = state->tokenizer();
+  if (tokenizer->TokenTag() == cbor::CBORTokenTag::BINARY) {
+    const span<uint8_t> bin = tokenizer->GetBinary();
+    *value = Binary::fromSpan(bin.data(), bin.size());
+    return true;
+  }
+  if (tokenizer->TokenTag() == cbor::CBORTokenTag::STRING8) {
+    const auto str_span = tokenizer->GetString8();
+    auto str = StringUtil::fromUTF8(str_span.data(), str_span.size());
+    bool success = false;
+    *value = Binary::fromBase64(str, &success);
+    return success;
+  }
+  state->RegisterError(Error::BINDINGS_BINARY_VALUE_EXPECTED);
+  return false;
+}
+
+// static
+void ProtocolTypeTraits<Binary>::Serialize(const Binary& value,
+                                           std::vector<uint8_t>* bytes) {
+  cbor::EncodeBinary(span<uint8_t>(value.data(), value.size()), bytes);
+}
+
+void SerializerTraits<Binary>::Serialize(
     const v8_inspector::protocol::Binary& binary, std::vector<uint8_t>* out) {
   cbor::EncodeBinary(span<uint8_t>(binary.data(), binary.size()), out);
 }

src/inspector/string-util.h

@@ -6,14 +6,15 @@
 #define V8_INSPECTOR_STRING_UTIL_H_
 
 #include <stdint.h>
+
 #include <memory>
 
+#include "../../third_party/inspector_protocol/crdtp/protocol_core.h"
+#include "include/v8-inspector.h"
 #include "src/base/logging.h"
 #include "src/base/macros.h"
 #include "src/inspector/string-16.h"
 
-#include "include/v8-inspector.h"
-
 namespace v8_inspector {
 
 namespace protocol {
@@ -86,11 +87,42 @@ String16 stackTraceIdToString(uintptr_t id);
 
 // See third_party/inspector_protocol/crdtp/serializer_traits.h.
 namespace v8_crdtp {
+
+template <>
+struct ProtocolTypeTraits<v8_inspector::String16> {
+  static bool Deserialize(DeserializerState* state,
+                          v8_inspector::String16* value);
+  static void Serialize(const v8_inspector::String16& value,
+                        std::vector<uint8_t>* bytes);
+};
+
+template <>
+struct ProtocolTypeTraits<v8_inspector::protocol::Binary> {
+  static bool Deserialize(DeserializerState* state,
+                          v8_inspector::protocol::Binary* value);
+  static void Serialize(const v8_inspector::protocol::Binary& value,
+                        std::vector<uint8_t>* bytes);
+};
+
 template <>
 struct SerializerTraits<v8_inspector::protocol::Binary> {
   static void Serialize(const v8_inspector::protocol::Binary& binary,
                         std::vector<uint8_t>* out);
 };
+
+namespace detail {
+template <>
+struct MaybeTypedef<v8_inspector::String16> {
+  typedef ValueMaybe<v8_inspector::String16> type;
+};
+
+template <>
+struct MaybeTypedef<v8_inspector::protocol::Binary> {
+  typedef ValueMaybe<v8_inspector::protocol::Binary> type;
+};
+
+}  // namespace detail
+
 }  // namespace v8_crdtp
 
 #endif  // V8_INSPECTOR_STRING_UTIL_H_

src/inspector/v8-debugger-agent-impl.cc

@@ -1552,10 +1552,9 @@ void V8DebuggerAgentImpl::didParseSource(
   String16 scriptId = script->scriptId();
   String16 scriptURL = script->sourceURL();
   String16 scriptLanguage = getScriptLanguage(*script);
-  Maybe<int> codeOffset =
-      script->getLanguage() == V8DebuggerScript::Language::JavaScript
-          ? Maybe<int>()
-          : script->codeOffset();
+  Maybe<int> codeOffset;
+  if (script->getLanguage() == V8DebuggerScript::Language::WebAssembly)
+    codeOffset = script->codeOffset();
   std::unique_ptr<protocol::Debugger::DebugSymbols> debugSymbols =
       getDebugSymbols(*script);
 
@@ -1727,10 +1726,11 @@ void V8DebuggerAgentImpl::didPause(
                                  WrapMode::kNoPreview, &obj);
       std::unique_ptr<protocol::DictionaryValue> breakAuxData;
       if (obj) {
-        breakAuxData = obj->toValue();
+        std::vector<uint8_t> serialized;
+        obj->AppendSerialized(&serialized);
+        breakAuxData = protocol::DictionaryValue::cast(
+            protocol::Value::parseBinary(serialized.data(), serialized.size()));
         breakAuxData->setBoolean("uncaught", isUncaught);
-      } else {
-        breakAuxData = nullptr;
       }
       hitReasons.push_back(
           std::make_pair(breakReason, std::move(breakAuxData)));

test/inspector/debugger/evaluate-on-call-frame-return-values-expected.txt

@@ -108,14 +108,14 @@ Running test: testConsoleLog
                     functionName : eval
                     lineNumber : 0
                     scriptId : <scriptId>
-                    url :
+                    url : 
                 }
                 [1] : {
                     columnNumber : 0
-                    functionName :
+                    functionName : 
                     lineNumber : 0
                     scriptId : <scriptId>
-                    url :
+                    url : 
                 }
             ]
         }
@@ -232,7 +232,7 @@ ReleaseObject with invalid params.
 {
     error : {
         code : -32602
-        data : objectId: string value expected
+        data : Failed to deserialize params.objectId - BINDINGS: mandatory field missing at <some position>
         message : Invalid parameters
     }
     id : <messageId>
@@ -299,7 +299,7 @@ ReleaseObjectGroup with invalid params
 {
     error : {
         code : -32602
-        data : objectGroup: string value expected
+        data : Failed to deserialize params.objectGroup - BINDINGS: mandatory field missing at <some position>
         message : Invalid parameters
     }
     id : <messageId>
@@ -327,7 +327,7 @@ Running test: testCallFrameIdTypeError
 {
     error : {
         code : -32602
-        data : callFrameId: string value expected
+        data : Failed to deserialize params.callFrameId - BINDINGS: string value expected at <some position>
         message : Invalid parameters
     }
     id : <messageId>
@@ -347,7 +347,7 @@ Running test: testNullExpression
 {
     error : {
         code : -32602
-        data : expression: string value expected
+        data : Failed to deserialize params.expression - BINDINGS: string value expected at <some position>
         message : Invalid parameters
     }
     id : <messageId>

test/inspector/debugger/evaluate-on-call-frame-return-values.js

@@ -66,7 +66,7 @@ const {Protocol} = InspectorTest.start(
     async function testReleaseObjectInvalid() {
       const releaseObjectResult = await Protocol.Runtime.releaseObject({});
       InspectorTest.log('ReleaseObject with invalid params.');
-      InspectorTest.logMessage(releaseObjectResult);
+      InspectorTest.logMessage(InspectorTest.trimErrorMessage(releaseObjectResult));
     },
     async function testObjectGroups() {
       await Protocol.Runtime.evaluate({ expression: 'var a = {x:3};', callFrameId });
@@ -89,7 +89,7 @@ const {Protocol} = InspectorTest.start(
     async function testReleaseObjectGroupInvalid() {
       const releaseObjectGroupResult = await Protocol.Runtime.releaseObjectGroup({});
       InspectorTest.log('ReleaseObjectGroup with invalid params');
-      InspectorTest.logMessage(releaseObjectGroupResult);
+      InspectorTest.logMessage(InspectorTest.trimErrorMessage(releaseObjectGroupResult));
     },
     async function testEvaluateSyntaxError() {
       const result = await Protocol.Debugger.evaluateOnCallFrame({ expression: `[]]`, callFrameId });
@@ -101,7 +101,7 @@ const {Protocol} = InspectorTest.start(
     },
     async function testCallFrameIdTypeError() {
       const result = await Protocol.Debugger.evaluateOnCallFrame({ expression: `console.log(42)`, callFrameId: {} });
-      InspectorTest.logMessage(result);
+      InspectorTest.logMessage(InspectorTest.trimErrorMessage(result));
     },
     async function testCallFrameIdInvalidInput() {
       InspectorTest.log('Testing evaluateOnCallFrame with non-existent callFrameId');
@@ -115,7 +115,7 @@ const {Protocol} = InspectorTest.start(
 
   async function evalAndLog(expression, callFrameId, returnByValue) {
     const result = await Protocol.Debugger.evaluateOnCallFrame({ expression, callFrameId, returnByValue });
-    InspectorTest.logMessage(result);
+    InspectorTest.logMessage(InspectorTest.trimErrorMessage(result));
   }
 
   // Helper function that calls a function on all objects with ids in objectIds, then returns

test/inspector/debugger/set-breakpoint-before-enabling-expected.txt

@@ -3,5 +3,5 @@ setBreakpointByUrl error: undefined
 setBreakpoint error: {
   "code": -32602,
   "message": "Invalid parameters",
-  "data": "location: object expected"
+  "data": "Failed to deserialize params.location - BINDINGS: mandatory field missing at <some position>"
 }

test/inspector/debugger/set-breakpoint-before-enabling.js

@@ -8,12 +8,14 @@ Protocol.Debugger.setBreakpointByUrl({ url: "http://example.com", lineNumber: 10
 
 function didSetBreakpointByUrlBeforeEnable(message)
 {
-  InspectorTest.log("setBreakpointByUrl error: " + JSON.stringify(message.error, null, 2));
+  InspectorTest.log("setBreakpointByUrl error: " + JSON.stringify(
+      InspectorTest.trimErrorMessage(message).error, null, 2));
   Protocol.Debugger.setBreakpoint().then(didSetBreakpointBeforeEnable);
 }
 
 function didSetBreakpointBeforeEnable(message)
 {
-  InspectorTest.log("setBreakpoint error: " + JSON.stringify(message.error, null, 2));
+  InspectorTest.log("setBreakpoint error: " + JSON.stringify(
+      InspectorTest.trimErrorMessage(message).error, null, 2));
   InspectorTest.completeTest();
 }

test/inspector/debugger/set-variable-value-expected.txt

@@ -218,7 +218,7 @@ setVariableValue with invalid scopeNumber
 {
     error : {
         code : -32602
-        data : scopeNumber: integer value expected
+        data : Failed to deserialize params.scopeNumber - BINDINGS: int32 value expected at <some position>
         message : Invalid parameters
     }
     id : <messageId>
@@ -253,8 +253,8 @@ setVariableValue with invalid objectId
 {
     error : {
         code : -32602
-        data : newValue.objectId: string value expected
+        data : Failed to deserialize params.newValue.objectId - BINDINGS: string value expected at <some position>
         message : Invalid parameters
     }
     id : <messageId>
-}
+}
\ No newline at end of file

test/inspector/debugger/set-variable-value.js

@@ -66,24 +66,24 @@ const { contextGroup, Protocol } = InspectorTest.start(
     async function testInvalidFrame() {
       let result = await Protocol.Debugger.setVariableValue({ scopeNumber: 0, variableName: 'num', newValue: { unserializableValue: 'NaN' }, callFrameId: 'fakeCallFrame' });
       InspectorTest.log('setVariableValue with invalid callFrameId');
-      InspectorTest.logMessage(result);
+      InspectorTest.logMessage(InspectorTest.trimErrorMessage(result));
       result = await Protocol.Debugger.setVariableValue({ scopeNumber: 'invalidScopeType', variableName: 'num', newValue: { unserializableValue: 'NaN' }, callFrameId });
       InspectorTest.log('setVariableValue with invalid scopeNumber')
-      InspectorTest.logMessage(result);
+      InspectorTest.logMessage(InspectorTest.trimErrorMessage(result));
       result = await Protocol.Debugger.setVariableValue({ scopeNumber: 1000, variableName: 'num', newValue: { unserializableValue: 'NaN' }, callFrameId });
       InspectorTest.log('setVariableValue with invalid scopeNumber');
       InspectorTest.logMessage(result);
       result = await Protocol.Debugger.setVariableValue({ scopeNumber: 0, variableName: 'FakeObjectName', newValue: { unserializableValue: 'NaN' }, callFrameId });
       InspectorTest.log('setVariableValue with invalid variableName');
-      InspectorTest.logMessage(result);
+      InspectorTest.logMessage(InspectorTest.trimErrorMessage(result));
     },
     async function testNewValueErrors() {
       let result = await Protocol.Debugger.setVariableValue({ scopeNumber: 0, variableName: 'num', newValue: { unserializableValue: 'not unserializable value' }, callFrameId });
       InspectorTest.log('setVariableValue with invalid unserializableValue');
-      InspectorTest.logMessage(result);
+      InspectorTest.logMessage(InspectorTest.trimErrorMessage(result));
       result = await Protocol.Debugger.setVariableValue({ scopeNumber: 0, variableName: 'num', newValue: { objectId: 2000 }, callFrameId });
       InspectorTest.log('setVariableValue with invalid objectId');
-      InspectorTest.logMessage(result);
+      InspectorTest.logMessage(InspectorTest.trimErrorMessage(result));
     }
   ]);
 

test/inspector/protocol-test.js

@@ -129,6 +129,14 @@ InspectorTest.decodeBase64 = function(base64) {
   return bytes;
 }
 
+InspectorTest.trimErrorMessage = function(message) {
+  if (!message.error || !message.error.data)
+    return message;
+  message.error.data = message.error.data.replace(/at position \d+/,
+                                                  'at <some position>');
+  return message;
+}
+
 InspectorTest.ContextGroup = class {
   constructor() {
     this.id = utils.createContextGroup();

test/inspector/runtime/release-object-expected.txt

@@ -71,7 +71,7 @@ ReleaseObject with invalid params.
 {
     error : {
         code : -32602
-        data : objectId: string value expected
+        data : Failed to deserialize params.objectId - BINDINGS: mandatory field missing at <some position>
         message : Invalid parameters
     }
     id : <messageId>
@@ -150,8 +150,8 @@ ReleaseObjectGroup with invalid params
 {
     error : {
         code : -32602
-        data : objectGroup: string value expected
+        data : Failed to deserialize params.objectGroup - BINDINGS: mandatory field missing at <some position>
         message : Invalid parameters
     }
     id : <messageId>
-}
+}
\ No newline at end of file

test/inspector/runtime/release-object.js

@@ -31,7 +31,7 @@ const {Protocol} = InspectorTest.start(
     async function testReleaseObjectInvalid() {
       const releaseObjectResult = await Protocol.Runtime.releaseObject({});
       InspectorTest.log('ReleaseObject with invalid params.');
-      InspectorTest.logMessage(releaseObjectResult);
+      InspectorTest.logMessage(InspectorTest.trimErrorMessage(releaseObjectResult));
     },
     async function testObjectGroups() {
       await logAndEvaluate('var a = {x:3};');
@@ -58,7 +58,7 @@ const {Protocol} = InspectorTest.start(
     async function testReleaseObjectGroupInvalid() {
       const releaseObjectGroupResult = await Protocol.Runtime.releaseObjectGroup({});
       InspectorTest.log('ReleaseObjectGroup with invalid params');
-      InspectorTest.logMessage(releaseObjectGroupResult);
+      InspectorTest.logMessage(InspectorTest.trimErrorMessage(releaseObjectGroupResult));
     }
   ]);
 

third_party/inspector_protocol/BUILD.gn

@@ -20,10 +20,12 @@ v8_source_set("crdtp") {
     "crdtp/error_support.h",
     "crdtp/export.h",
     "crdtp/find_by_first.h",
-    "crdtp/glue.h",
     "crdtp/json.cc",
     "crdtp/json.h",
+    "crdtp/maybe.h",
     "crdtp/parser_handler.h",
+    "crdtp/protocol_core.cc",
+    "crdtp/protocol_core.h",
     "crdtp/serializable.cc",
     "crdtp/serializable.h",
     "crdtp/serializer_traits.h",

third_party/inspector_protocol/README.v8

@@ -2,7 +2,7 @@ Name: inspector protocol
 Short Name: inspector_protocol
 URL: https://chromium.googlesource.com/deps/inspector_protocol/
 Version: 0
-Revision: b7cda08cd6e522df2159413ba5f29d2a953cc1c4
+Revision: 22455bf37cd7a1913918e626a1997cbe77f32d1a
 License: BSD
 License File: LICENSE
 Security Critical: no

third_party/inspector_protocol/code_generator.py

@@ -371,7 +371,6 @@ class Protocol(object):
                                  for rule in config.imported.options]
 
     self.patch_full_qualified_refs()
-    self.create_notification_types()
     self.create_type_definitions()
     self.generate_used_types()
 
@@ -434,8 +433,6 @@ class Protocol(object):
         for event in domain["events"]:
           if self.generate_event(domain_name, event["name"]):
             all_refs |= self.all_references(event)
-            all_refs.add('%s.%sNotification' % (domain_name,
-                                                to_title_case(event["name"])))
 
     dependencies = self.generate_type_dependencies()
     queue = set(all_refs)
@@ -457,20 +454,6 @@ class Protocol(object):
           dependencies[domain_name + "." + type["id"]] = related_types
     return dependencies
 
-  def create_notification_types(self):
-    for domain in self.json_api["domains"]:
-      if "events" in domain:
-        for event in domain["events"]:
-          event_type = dict()
-          event_type["description"] = "Wrapper for notification params"
-          event_type["type"] = "object"
-          event_type["id"] = to_title_case(event["name"]) + "Notification"
-          if "parameters" in event:
-            event_type["properties"] = copy.deepcopy(event["parameters"])
-          if "types" not in domain:
-            domain["types"] = list()
-          domain["types"].append(event_type)
-
   def create_type_definitions(self):
     imported_namespace = ""
     if self.config.imported:
@@ -664,6 +647,7 @@ def main():
       "Protocol_cpp.template",
       "Values_cpp.template",
       "Object_cpp.template",
+      "ValueConversions_cpp.template",
     ]
 
     forward_h_templates = [

third_party/inspector_protocol/crdtp/dispatch.cc

@@ -9,6 +9,7 @@
 #include "error_support.h"
 #include "find_by_first.h"
 #include "frontend_channel.h"
+#include "protocol_core.h"
 
 namespace v8_crdtp {
 // =============================================================================
@@ -321,6 +322,18 @@ std::unique_ptr<Serializable> CreateErrorResponse(
   return protocol_error;
 }
 
+std::unique_ptr<Serializable> CreateErrorResponse(
+    int call_id,
+    DispatchResponse dispatch_response,
+    const DeserializerState& state) {
+  auto protocol_error =
+      std::make_unique<ProtocolError>(std::move(dispatch_response));
+  protocol_error->SetCallId(call_id);
+  // TODO(caseq): should we plumb the call name here?
+  protocol_error->SetData(state.ErrorMessage(MakeSpan("params")));
+  return protocol_error;
+}
+
 std::unique_ptr<Serializable> CreateErrorNotification(
     DispatchResponse dispatch_response) {
   return std::make_unique<ProtocolError>(std::move(dispatch_response));
@@ -475,6 +488,21 @@ bool DomainDispatcher::MaybeReportInvalidParams(
   return true;
 }
 
+bool DomainDispatcher::MaybeReportInvalidParams(
+    const Dispatchable& dispatchable,
+    const DeserializerState& state) {
+  if (state.status().ok())
+    return false;
+  if (frontend_channel_) {
+    frontend_channel_->SendProtocolResponse(
+        dispatchable.CallId(),
+        CreateErrorResponse(
+            dispatchable.CallId(),
+            DispatchResponse::InvalidParams("Invalid parameters"), state));
+  }
+  return true;
+}
+
 void DomainDispatcher::clearFrontend() {
   frontend_channel_ = nullptr;
   for (auto& weak : weak_ptrs_)

third_party/inspector_protocol/crdtp/dispatch.h

@@ -16,8 +16,9 @@
 #include "status.h"
 
 namespace v8_crdtp {
-class FrontendChannel;
+class DeserializerState;
 class ErrorSupport;
+class FrontendChannel;
 namespace cbor {
 class CBORTokenizer;
 }  // namespace cbor
@@ -234,6 +235,8 @@ class DomainDispatcher {
   // optimized for code size of the callee.
   bool MaybeReportInvalidParams(const Dispatchable& dispatchable,
                                 const ErrorSupport& errors);
+  bool MaybeReportInvalidParams(const Dispatchable& dispatchable,
+                                const DeserializerState& state);
 
   FrontendChannel* channel() { return frontend_channel_; }
 

third_party/inspector_protocol/crdtp/maybe.h

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+#ifndef V8_CRDTP_MAYBE_H_
+#define V8_CRDTP_MAYBE_H_
+
+#include <cassert>
+#include <memory>
+
+namespace v8_crdtp {
+
+// =============================================================================
+// detail::PtrMaybe, detail::ValueMaybe, templates for optional
+// pointers / values which are used in ../lib/Forward_h.template.
+// =============================================================================
+
+namespace detail {
+template <typename T>
+class PtrMaybe {
+ public:
+  PtrMaybe() = default;
+  PtrMaybe(std::unique_ptr<T> value) : value_(std::move(value)) {}
+  PtrMaybe(PtrMaybe&& other) noexcept : value_(std::move(other.value_)) {}
+  void operator=(std::unique_ptr<T> value) { value_ = std::move(value); }
+  T* fromJust() const {
+    assert(value_);
+    return value_.get();
+  }
+  T* fromMaybe(T* default_value) const {
+    return value_ ? value_.get() : default_value;
+  }
+  bool isJust() const { return value_ != nullptr; }
+  std::unique_ptr<T> takeJust() {
+    assert(value_);
+    return std::move(value_);
+  }
+
+ private:
+  std::unique_ptr<T> value_;
+};
+
+template <typename T>
+class ValueMaybe {
+ public:
+  ValueMaybe() : is_just_(false), value_() {}
+  ValueMaybe(T value) : is_just_(true), value_(std::move(value)) {}
+  ValueMaybe(ValueMaybe&& other) noexcept
+      : is_just_(other.is_just_), value_(std::move(other.value_)) {}
+  void operator=(T value) {
+    value_ = value;
+    is_just_ = true;
+  }
+  const T& fromJust() const {
+    assert(is_just_);
+    return value_;
+  }
+  const T& fromMaybe(const T& default_value) const {
+    return is_just_ ? value_ : default_value;
+  }
+  bool isJust() const { return is_just_; }
+  T takeJust() {
+    assert(is_just_);
+    is_just_ = false;
+    return std::move(value_);
+  }
+
+ private:
+  bool is_just_;
+  T value_;
+};
+
+template <typename T>
+struct MaybeTypedef {
+  typedef PtrMaybe<T> type;
+};
+
+template <>
+struct MaybeTypedef<bool> {
+  typedef ValueMaybe<bool> type;
+};
+
+template <>
+struct MaybeTypedef<int> {
+  typedef ValueMaybe<int> type;
+};
+
+template <>
+struct MaybeTypedef<double> {
+  typedef ValueMaybe<double> type;
+};
+
+template <>
+struct MaybeTypedef<std::string> {
+  typedef ValueMaybe<std::string> type;
+};
+
+}  // namespace detail
+
+template <typename T>
+using Maybe = typename detail::MaybeTypedef<T>::type;
+
+}  // namespace v8_crdtp
+
+#endif  // V8_CRDTP_MAYBE_H_

third_party/inspector_protocol/crdtp/maybe_test.cc

+// Copyright 2019 The Chromium 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 "maybe.h"
+
+#include <string>
+#include <vector>
+
+#include "test_platform.h"
+
+namespace v8_crdtp {
+
+// =============================================================================
+// detail::PtrMaybe, detail::ValueMaybe, templates for optional
+// pointers / values which are used in ../lib/Forward_h.template.
+// =============================================================================
+TEST(PtrMaybeTest, SmokeTest) {
+  detail::PtrMaybe<std::vector<uint32_t>> example;
+  EXPECT_FALSE(example.isJust());
+  EXPECT_TRUE(nullptr == example.fromMaybe(nullptr));
+  std::unique_ptr<std::vector<uint32_t>> v(new std::vector<uint32_t>);
+  v->push_back(42);
+  v->push_back(21);
+  example = std::move(v);
+  EXPECT_TRUE(example.isJust());
+  EXPECT_THAT(*example.fromJust(), testing::ElementsAre(42, 21));
+  std::unique_ptr<std::vector<uint32_t>> out = example.takeJust();
+  EXPECT_FALSE(example.isJust());
+  EXPECT_THAT(*out, testing::ElementsAre(42, 21));
+}
+
+TEST(PtrValueTest, SmokeTest) {
+  detail::ValueMaybe<int32_t> example;
+  EXPECT_FALSE(example.isJust());
+  EXPECT_EQ(-1, example.fromMaybe(-1));
+  example = 42;
+  EXPECT_TRUE(example.isJust());
+  EXPECT_EQ(42, example.fromJust());
+  int32_t out = example.takeJust();
+  EXPECT_EQ(out, 42);
+}
+
+}  // namespace v8_crdtp

third_party/inspector_protocol/crdtp/protocol_core.cc

+// Copyright 2020 The Chromium 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 "protocol_core.h"
+
+#include <cassert>
+#include <string>
+
+namespace v8_crdtp {
+
+DeserializerState::DeserializerState(std::vector<uint8_t> bytes)
+    : storage_(new std::vector<uint8_t>(std::move(bytes))),
+      tokenizer_(span<uint8_t>(storage_->data(), storage_->size())) {}
+
+DeserializerState::DeserializerState(Storage storage, span<uint8_t> span)
+    : storage_(std::move(storage)), tokenizer_(span) {}
+
+void DeserializerState::RegisterError(Error error) {
+  assert(Error::OK != error);
+  if (tokenizer_.Status().ok())
+    status_ = Status{error, tokenizer_.Status().pos};
+}
+
+void DeserializerState::RegisterFieldPath(span<char> name) {
+  field_path_.push_back(name);
+}
+
+std::string DeserializerState::ErrorMessage(span<char> message_name) const {
+  std::string msg = "Failed to deserialize ";
+  msg.append(message_name.begin(), message_name.end());
+  for (int field = static_cast<int>(field_path_.size()) - 1; field >= 0;
+       --field) {
+    msg.append(".");
+    msg.append(field_path_[field].begin(), field_path_[field].end());
+  }
+  Status s = status();
+  if (!s.ok())
+    msg += " - " + s.ToASCIIString();
+  return msg;
+}
+
+Status DeserializerState::status() const {
+  if (!tokenizer_.Status().ok())
+    return tokenizer_.Status();
+  return status_;
+}
+
+namespace {
+constexpr int32_t GetMandatoryFieldMask(
+    const DeserializerDescriptor::Field* fields,
+    size_t count) {
+  int32_t mask = 0;
+  for (size_t i = 0; i < count; ++i) {
+    if (!fields[i].is_optional)
+      mask |= (1 << i);
+  }
+  return mask;
+}
+}  // namespace
+
+DeserializerDescriptor::DeserializerDescriptor(const Field* fields,
+                                               size_t field_count)
+    : fields_(fields),
+      field_count_(field_count),
+      mandatory_field_mask_(GetMandatoryFieldMask(fields, field_count)) {}
+
+bool DeserializerDescriptor::Deserialize(DeserializerState* state,
+                                         void* obj) const {
+  auto* tokenizer = state->tokenizer();
+
+  // As a special compatibility quirk, allow empty objects if
+  // no mandatory fields are required.
+  if (tokenizer->TokenTag() == cbor::CBORTokenTag::DONE &&
+      !mandatory_field_mask_) {
+    return true;
+  }
+  if (tokenizer->TokenTag() == cbor::CBORTokenTag::ENVELOPE)
+    tokenizer->EnterEnvelope();
+  if (tokenizer->TokenTag() != cbor::CBORTokenTag::MAP_START) {
+    state->RegisterError(Error::CBOR_MAP_START_EXPECTED);
+    return false;
+  }
+  tokenizer->Next();
+  int32_t seen_mandatory_fields = 0;
+  for (; tokenizer->TokenTag() != cbor::CBORTokenTag::STOP; tokenizer->Next()) {
+    if (tokenizer->TokenTag() != cbor::CBORTokenTag::STRING8) {
+      state->RegisterError(Error::CBOR_INVALID_MAP_KEY);
+      return false;
+    }
+    span<uint8_t> u_key = tokenizer->GetString8();
+    span<char> key(reinterpret_cast<const char*>(u_key.data()), u_key.size());
+    tokenizer->Next();
+    if (!DeserializeField(state, key, &seen_mandatory_fields, obj))
+      return false;
+  }
+  // Only compute mandatory fields once per type.
+  int32_t missing_fields = seen_mandatory_fields ^ mandatory_field_mask_;
+  if (missing_fields) {
+    int32_t idx = 0;
+    while ((missing_fields & 1) == 0) {
+      missing_fields >>= 1;
+      ++idx;
+    }
+    state->RegisterError(Error::BINDINGS_MANDATORY_FIELD_MISSING);
+    state->RegisterFieldPath(fields_[idx].name);
+    return false;
+  }
+  return true;
+}
+
+bool DeserializerDescriptor::DeserializeField(DeserializerState* state,
+                                              span<char> name,
+                                              int* seen_mandatory_fields,
+                                              void* obj) const {
+  // TODO(caseq): consider checking if the sought field is the one
+  // after the last deserialized.
+  const auto* begin = fields_;
+  const auto* end = fields_ + field_count_;
+  auto entry = std::lower_bound(
+      begin, end, name, [](const Field& field_desc, span<char> field_name) {
+        return SpanLessThan(field_desc.name, field_name);
+      });
+  // Unknown field is not an error -- we may be working against an
+  // implementation of a later version of the protocol.
+  // TODO(caseq): support unknown arrays and maps not enclosed by an envelope.
+  if (entry == end || !SpanEquals(entry->name, name))
+    return true;
+  if (!entry->deserializer(state, obj)) {
+    state->RegisterFieldPath(name);
+    return false;
+  }
+  if (!entry->is_optional)
+    *seen_mandatory_fields |= 1 << (entry - begin);
+  return true;
+}
+
+bool ProtocolTypeTraits<bool>::Deserialize(DeserializerState* state,
+                                           bool* value) {
+  const auto tag = state->tokenizer()->TokenTag();
+  if (tag == cbor::CBORTokenTag::TRUE_VALUE) {
+    *value = true;
+    return true;
+  }
+  if (tag == cbor::CBORTokenTag::FALSE_VALUE) {
+    *value = false;
+    return true;
+  }
+  state->RegisterError(Error::BINDINGS_BOOL_VALUE_EXPECTED);
+  return false;
+}
+
+void ProtocolTypeTraits<bool>::Serialize(bool value,
+                                         std::vector<uint8_t>* bytes) {
+  bytes->push_back(value ? cbor::EncodeTrue() : cbor::EncodeFalse());
+}
+
+bool ProtocolTypeTraits<int32_t>::Deserialize(DeserializerState* state,
+                                              int32_t* value) {
+  if (state->tokenizer()->TokenTag() != cbor::CBORTokenTag::INT32) {
+    state->RegisterError(Error::BINDINGS_INT32_VALUE_EXPECTED);
+    return false;
+  }
+  *value = state->tokenizer()->GetInt32();
+  return true;
+}
+
+void ProtocolTypeTraits<int32_t>::Serialize(int32_t value,
+                                            std::vector<uint8_t>* bytes) {
+  cbor::EncodeInt32(value, bytes);
+}
+
+ContainerSerializer::ContainerSerializer(std::vector<uint8_t>* bytes,
+                                         uint8_t tag)
+    : bytes_(bytes) {
+  envelope_.EncodeStart(bytes_);
+  bytes_->push_back(tag);
+}
+
+void ContainerSerializer::EncodeStop() {
+  bytes_->push_back(cbor::EncodeStop());
+  envelope_.EncodeStop(bytes_);
+}
+
+ObjectSerializer::ObjectSerializer()
+    : serializer_(&owned_bytes_, cbor::EncodeIndefiniteLengthMapStart()) {}
+
+ObjectSerializer::~ObjectSerializer() = default;
+
+std::unique_ptr<Serializable> ObjectSerializer::Finish() {
+  serializer_.EncodeStop();
+  return Serializable::From(std::move(owned_bytes_));
+}
+
+bool ProtocolTypeTraits<double>::Deserialize(DeserializerState* state,
+                                             double* value) {
+  // Double values that round-trip through JSON may end up getting represented
+  // as an int32 (SIGNED, UNSIGNED) on the wire in CBOR. Therefore, we also
+  // accept an INT32 here.
+  if (state->tokenizer()->TokenTag() == cbor::CBORTokenTag::INT32) {
+    *value = state->tokenizer()->GetInt32();
+    return true;
+  }
+  if (state->tokenizer()->TokenTag() != cbor::CBORTokenTag::DOUBLE) {
+    state->RegisterError(Error::BINDINGS_DOUBLE_VALUE_EXPECTED);
+    return false;
+  }
+  *value = state->tokenizer()->GetDouble();
+  return true;
+}
+
+void ProtocolTypeTraits<double>::Serialize(double value,
+                                           std::vector<uint8_t>* bytes) {
+  cbor::EncodeDouble(value, bytes);
+}
+
+class IncomingDeferredMessage : public DeferredMessage {
+ public:
+  // Creates the state from the part of another message.
+  // Note storage is opaque and is mostly to retain ownership.
+  // It may be null in case caller owns the memory and will dispose
+  // of the message synchronously.
+  IncomingDeferredMessage(DeserializerState::Storage storage,
+                          span<uint8_t> span)
+      : storage_(storage), span_(span) {}
+
+ private:
+  DeserializerState MakeDeserializer() const override {
+    return DeserializerState(storage_, span_);
+  }
+  void AppendSerialized(std::vector<uint8_t>* out) const override {
+    out->insert(out->end(), span_.begin(), span_.end());
+  }
+
+  DeserializerState::Storage storage_;
+  span<uint8_t> span_;
+};
+
+class OutgoingDeferredMessage : public DeferredMessage {
+ public:
+  OutgoingDeferredMessage() = default;
+  explicit OutgoingDeferredMessage(std::unique_ptr<Serializable> serializable)
+      : serializable_(std::move(serializable)) {
+    assert(!!serializable_);
+  }
+
+ private:
+  DeserializerState MakeDeserializer() const override {
+    return DeserializerState(serializable_->Serialize());
+  }
+  void AppendSerialized(std::vector<uint8_t>* out) const override {
+    serializable_->AppendSerialized(out);
+  }
+
+  std::unique_ptr<Serializable> serializable_;
+};
+
+// static
+std::unique_ptr<DeferredMessage> DeferredMessage::FromSerializable(
+    std::unique_ptr<Serializable> serializeable) {
+  return std::make_unique<OutgoingDeferredMessage>(std::move(serializeable));
+}
+
+// static
+std::unique_ptr<DeferredMessage> DeferredMessage::FromSpan(
+    span<uint8_t> bytes) {
+  return std::make_unique<IncomingDeferredMessage>(nullptr, bytes);
+}
+
+bool ProtocolTypeTraits<std::unique_ptr<DeferredMessage>>::Deserialize(
+    DeserializerState* state,
+    std::unique_ptr<DeferredMessage>* value) {
+  if (state->tokenizer()->TokenTag() != cbor::CBORTokenTag::ENVELOPE) {
+    state->RegisterError(Error::CBOR_INVALID_ENVELOPE);
+    return false;
+  }
+  *value = std::make_unique<IncomingDeferredMessage>(
+      state->storage(), state->tokenizer()->GetEnvelope());
+  return true;
+}
+
+void ProtocolTypeTraits<std::unique_ptr<DeferredMessage>>::Serialize(
+    const std::unique_ptr<DeferredMessage>& value,
+    std::vector<uint8_t>* bytes) {
+  value->AppendSerialized(bytes);
+}
+
+}  // namespace v8_crdtp

third_party/inspector_protocol/crdtp/serializer_traits.h

@@ -9,7 +9,7 @@
 #include <string>
 #include <vector>
 #include "cbor.h"
-#include "glue.h"
+#include "maybe.h"
 #include "span.h"
 
 namespace v8_crdtp {
@@ -124,9 +124,9 @@ struct FieldSerializerTraits {
 };
 
 template <typename T>
-struct FieldSerializerTraits<glue::detail::PtrMaybe<T>> {
+struct FieldSerializerTraits<detail::PtrMaybe<T>> {
   static void Serialize(span<uint8_t> field_name,
-                        const glue::detail::PtrMaybe<T>& field_value,
+                        const detail::PtrMaybe<T>& field_value,
                         std::vector<uint8_t>* out) {
     if (!field_value.isJust())
       return;
@@ -136,9 +136,9 @@ struct FieldSerializerTraits<glue::detail::PtrMaybe<T>> {
 };
 
 template <typename T>
-struct FieldSerializerTraits<glue::detail::ValueMaybe<T>> {
+struct FieldSerializerTraits<detail::ValueMaybe<T>> {
   static void Serialize(span<uint8_t> field_name,
-                        const glue::detail::ValueMaybe<T>& field_value,
+                        const detail::ValueMaybe<T>& field_value,
                         std::vector<uint8_t>* out) {
     if (!field_value.isJust())
       return;

third_party/inspector_protocol/crdtp/serializer_traits_test.cc

@@ -172,12 +172,12 @@ TEST(FieldSerializerTraits, RequiredField) {
 template <typename T>
 class FieldSerializerTraits_MaybeTest : public ::testing::Test {};
 using MaybeTypes =
-    ::testing::Types<glue::detail::ValueMaybe<bool>,
-                     glue::detail::ValueMaybe<double>,
-                     glue::detail::ValueMaybe<int32_t>,
-                     glue::detail::ValueMaybe<std::string>,
-                     glue::detail::PtrMaybe<Foo>,
-                     glue::detail::PtrMaybe<std::vector<std::unique_ptr<Foo>>>>;
+    ::testing::Types<detail::ValueMaybe<bool>,
+                     detail::ValueMaybe<double>,
+                     detail::ValueMaybe<int32_t>,
+                     detail::ValueMaybe<std::string>,
+                     detail::PtrMaybe<Foo>,
+                     detail::PtrMaybe<std::vector<std::unique_ptr<Foo>>>>;
 TYPED_TEST_SUITE(FieldSerializerTraits_MaybeTest, MaybeTypes);
 
 TYPED_TEST(FieldSerializerTraits_MaybeTest, NoOutputForFieldsIfNotJust) {
@@ -188,9 +188,8 @@ TYPED_TEST(FieldSerializerTraits_MaybeTest, NoOutputForFieldsIfNotJust) {
 
 TEST(FieldSerializerTraits, MaybeBool) {
   std::vector<uint8_t> out;
-  SerializeField(SpanFrom("true"), glue::detail::ValueMaybe<bool>(true), &out);
-  SerializeField(SpanFrom("false"), glue::detail::ValueMaybe<bool>(false),
-                 &out);
+  SerializeField(SpanFrom("true"), detail::ValueMaybe<bool>(true), &out);
+  SerializeField(SpanFrom("false"), detail::ValueMaybe<bool>(false), &out);
 
   std::vector<uint8_t> expected;
   cbor::EncodeString8(SpanFrom("true"), &expected);
@@ -203,7 +202,7 @@ TEST(FieldSerializerTraits, MaybeBool) {
 
 TEST(FieldSerializerTraits, MaybeDouble) {
   std::vector<uint8_t> out;
-  SerializeField(SpanFrom("dbl"), glue::detail::ValueMaybe<double>(3.14), &out);
+  SerializeField(SpanFrom("dbl"), detail::ValueMaybe<double>(3.14), &out);
 
   std::vector<uint8_t> expected;
   cbor::EncodeString8(SpanFrom("dbl"), &expected);
@@ -215,7 +214,7 @@ TEST(FieldSerializerTraits, MaybeDouble) {
 TEST(FieldSerializerTraits, MaybePtrFoo) {
   std::vector<uint8_t> out;
   SerializeField(SpanFrom("foo"),
-                 glue::detail::PtrMaybe<Foo>(std::make_unique<Foo>(42)), &out);
+                 detail::PtrMaybe<Foo>(std::make_unique<Foo>(42)), &out);
 
   std::vector<uint8_t> expected;
   cbor::EncodeString8(SpanFrom("foo"), &expected);

third_party/inspector_protocol/crdtp/span.cc

@@ -21,4 +21,19 @@ bool SpanEquals(span<uint8_t> x, span<uint8_t> y) noexcept {
   return x.data() == y.data() || len == 0 ||
          std::memcmp(x.data(), y.data(), len) == 0;
 }
+
+bool SpanLessThan(span<char> x, span<char> y) noexcept {
+  auto min_size = std::min(x.size(), y.size());
+  const int r = min_size == 0 ? 0 : memcmp(x.data(), y.data(), min_size);
+  return (r < 0) || (r == 0 && x.size() < y.size());
+}
+
+bool SpanEquals(span<char> x, span<char> y) noexcept {
+  auto len = x.size();
+  if (len != y.size())
+    return false;
+  return x.data() == y.data() || len == 0 ||
+         std::memcmp(x.data(), y.data(), len) == 0;
+}
+
 }  // namespace v8_crdtp

third_party/inspector_protocol/crdtp/span.h

@@ -50,6 +50,11 @@ class span {
   index_type size_;
 };
 
+template <size_t N>
+constexpr span<char> MakeSpan(const char (&str)[N]) {
+  return span<char>(str, N - 1);
+}
+
 template <size_t N>
 constexpr span<uint8_t> SpanFrom(const char (&str)[N]) {
   return span<uint8_t>(reinterpret_cast<const uint8_t*>(str), N - 1);
@@ -75,11 +80,15 @@ inline span<typename C::value_type> SpanFrom(const C& v) {
 }
 
 // Less than / equality comparison functions for sorting / searching for byte
-// spans. These are similar to absl::string_view's < and == operators.
+// spans.
 bool SpanLessThan(span<uint8_t> x, span<uint8_t> y) noexcept;
-
 bool SpanEquals(span<uint8_t> x, span<uint8_t> y) noexcept;
 
+// Less than / equality comparison functions for sorting / searching for byte
+// spans.
+bool SpanLessThan(span<char> x, span<char> y) noexcept;
+bool SpanEquals(span<char> x, span<char> y) noexcept;
+
 struct SpanLt {
   bool operator()(span<uint8_t> l, span<uint8_t> r) const {
     return SpanLessThan(l, r);

third_party/inspector_protocol/crdtp/status.h

@@ -5,6 +5,7 @@
 #ifndef V8_CRDTP_STATUS_H_
 #define V8_CRDTP_STATUS_H_
 
+#include <cassert>
 #include <cstddef>
 #include <limits>
 #include <string>
@@ -103,6 +104,35 @@ struct Status {
   // includes the position.
   std::string ToASCIIString() const;
 };
+
+template <typename T>
+class StatusOr {
+ public:
+  explicit StatusOr(const T& value) : value_(value) {}
+  explicit StatusOr(T&& value) : value_(std::move(value)) {}
+  explicit StatusOr(const Status& status) : status_(status) {}
+
+  bool ok() const { return status_.ok(); }
+  T& operator*() & {
+    assert(ok());
+    return value_;
+  }
+  const T& operator*() const& { return value(); }
+  T&& operator*() && { return value(); }
+  const Status& status() const { return status_; }
+
+  T& value() & { return *this; }
+  T&& value() && {
+    assert(ok());
+    return std::move(value_);
+  }
+  const T& value() const& { return *this; }
+
+ private:
+  Status status_;
+  T value_;
+};
+
 }  // namespace v8_crdtp
 
 #endif  // V8_CRDTP_STATUS_H_

third_party/inspector_protocol/inspector_protocol.gni

@@ -37,6 +37,7 @@ template("inspector_protocol_generate") {
       "$inspector_protocol_dir/lib/Object_cpp.template",
       "$inspector_protocol_dir/lib/Object_h.template",
       "$inspector_protocol_dir/lib/Protocol_cpp.template",
+      "$inspector_protocol_dir/lib/ValueConversions_cpp.template",
       "$inspector_protocol_dir/lib/ValueConversions_h.template",
       "$inspector_protocol_dir/lib/Values_cpp.template",
       "$inspector_protocol_dir/lib/Values_h.template",

third_party/inspector_protocol/lib/Forward_h.template

@@ -21,7 +21,7 @@
 #include "{{config.crdtp.dir}}/error_support.h"
 #include "{{config.crdtp.dir}}/dispatch.h"
 #include "{{config.crdtp.dir}}/frontend_channel.h"
-#include "{{config.crdtp.dir}}/glue.h"
+#include "{{config.crdtp.dir}}/protocol_core.h"
 
 {% for namespace in config.protocol.namespace %}
 namespace {{namespace}} {
@@ -42,7 +42,14 @@ class SerializedValue;
 class StringValue;
 class Value;
 
+using {{config.crdtp.namespace}}::detail::PtrMaybe;
+using {{config.crdtp.namespace}}::detail::ValueMaybe;
+
+template<typename T>
+using Maybe = {{config.crdtp.namespace}}::Maybe<T>;
+
 namespace detail {
+
 template <typename T>
 struct ArrayTypedef { typedef std::vector<std::unique_ptr<T>> type; };
 
@@ -62,32 +69,6 @@ struct ArrayTypedef<bool> { typedef std::vector<bool> type; };
 template <typename T>
 using Array = typename detail::ArrayTypedef<T>::type;
 
-namespace detail {
-using {{config.crdtp.namespace}}::glue::detail::PtrMaybe;
-using {{config.crdtp.namespace}}::glue::detail::ValueMaybe;
-
-template <typename T>
-struct MaybeTypedef { typedef PtrMaybe<T> type; };
-
-template <>
-struct MaybeTypedef<bool> { typedef ValueMaybe<bool> type; };
-
-template <>
-struct MaybeTypedef<int> { typedef ValueMaybe<int> type; };
-
-template <>
-struct MaybeTypedef<double> { typedef ValueMaybe<double> type; };
-
-template <>
-struct MaybeTypedef<String> { typedef ValueMaybe<String> type; };
-
-template <>
-struct MaybeTypedef<Binary> { typedef ValueMaybe<Binary> type; };
-}  // namespace detail
-
-template <typename T>
-using Maybe = typename detail::MaybeTypedef<T>::type;
-
 {% for namespace in config.protocol.namespace %}
 } // namespace {{namespace}}
 {% endfor %}

third_party/inspector_protocol/lib/Object_h.template

@@ -28,7 +28,11 @@ public:
 
     std::unique_ptr<protocol::DictionaryValue> toValue() const;
     std::unique_ptr<Object> clone() const;
+
 private:
+    Object() = default;
+    friend struct {{config.crdtp.namespace}}::ProtocolTypeTraits<std::unique_ptr<Object>, void>;
+
     std::unique_ptr<protocol::DictionaryValue> m_object;
 };
 

third_party/inspector_protocol/lib/ValueConversions_cpp.template

+// This file is generated by ValueConversions_cpp.template.
+
+// Copyright 2020 The Chromium 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 {{format_include(config.protocol.package, "Protocol")}}
+
+#include <algorithm>
+#include <climits>
+#include <string>
+
+//#include "ValueConversions.h"
+//#include "Values.h"
+
+{% for namespace in config.protocol.namespace %}
+namespace {{namespace}} {
+{% endfor %}
+
+{% for namespace in config.protocol.namespace %}
+}  // namespce
+{% endfor %}
+
+
+namespace {{config.crdtp.namespace}} {
+
+namespace {
+
+using {{"::".join(config.protocol.namespace)}}::Binary;
+using {{"::".join(config.protocol.namespace)}}::Object;
+using {{"::".join(config.protocol.namespace)}}::Value;
+using {{"::".join(config.protocol.namespace)}}::String;
+using {{"::".join(config.protocol.namespace)}}::DictionaryValue;
+using {{"::".join(config.protocol.namespace)}}::FundamentalValue;
+using {{"::".join(config.protocol.namespace)}}::StringValue;
+using {{"::".join(config.protocol.namespace)}}::StringUtil;
+//using {{"::".join(config.protocol.namespace)}}::EncodeString;
+
+std::unique_ptr<Value> ReadValue(DeserializerState* state) {
+  cbor::CBORTokenizer* tokenizer = state->tokenizer();
+  switch (tokenizer->TokenTag()) {
+    case cbor::CBORTokenTag::TRUE_VALUE:
+      return FundamentalValue::create(true);
+    case cbor::CBORTokenTag::FALSE_VALUE:
+      return FundamentalValue::create(false);
+    case cbor::CBORTokenTag::NULL_VALUE:
+      return Value::null();
+    case cbor::CBORTokenTag::INT32:
+      return FundamentalValue::create(tokenizer->GetInt32());
+    case cbor::CBORTokenTag::DOUBLE:
+      return FundamentalValue::create(tokenizer->GetDouble());
+    case cbor::CBORTokenTag::STRING8: {
+      const auto str = tokenizer->GetString8();
+      return StringValue::create(StringUtil::fromUTF8(str.data(), str.size()));
+    }
+    case cbor::CBORTokenTag::STRING16: {
+      const auto str = tokenizer->GetString16WireRep();
+      return StringValue::create(StringUtil::fromUTF16LE(reinterpret_cast<const uint16_t*>(str.data()), str.size() / 2));
+    }
+    case cbor::CBORTokenTag::ENVELOPE: {
+      const auto env = tokenizer->GetEnvelope();
+      return Value::parseBinary(env.data(), env.size());
+    }
+    // Intentionally not supported.
+    case cbor::CBORTokenTag::BINARY:
+    // Should not be encountered outside of envelope.
+    case cbor::CBORTokenTag::MAP_START:
+    case cbor::CBORTokenTag::ARRAY_START:
+    default:
+      state->RegisterError(Error::CBOR_UNSUPPORTED_VALUE);
+      return nullptr;
+  }
+}
+
+}  // namespace
+
+// static
+bool ProtocolTypeTraits<std::unique_ptr<Value>>::Deserialize(
+    DeserializerState* state, std::unique_ptr<Value>* value) {
+  auto result = ReadValue(state);
+  if (!result)
+    return false;
+  *value = std::move(result);
+  return true;
+}
+
+// static
+void ProtocolTypeTraits<std::unique_ptr<Value>>::Serialize(
+    const std::unique_ptr<Value>& value, std::vector<uint8_t>* bytes) {
+  value->AppendSerialized(bytes);
+}
+
+// static
+bool ProtocolTypeTraits<std::unique_ptr<DictionaryValue>>::Deserialize(
+    DeserializerState* state, std::unique_ptr<DictionaryValue>* value) {
+  std::unique_ptr<Value> res;
+  if (!ProtocolTypeTraits<std::unique_ptr<Value>>::Deserialize(state, &res))
+    return false;
+  *value = DictionaryValue::cast(std::move(res));
+  return true;
+}
+
+// static
+void ProtocolTypeTraits<std::unique_ptr<DictionaryValue>>::Serialize(
+    const std::unique_ptr<DictionaryValue>& value, std::vector<uint8_t>* bytes) {
+  value->AppendSerialized(bytes);
+}
+
+// static
+bool ProtocolTypeTraits<std::unique_ptr<Object>>::Deserialize(DeserializerState* state, std::unique_ptr<Object>* value) {
+  auto res = DictionaryValue::create();
+  if (ProtocolTypeTraits<std::unique_ptr<DictionaryValue>>::Deserialize(state, &res)) {
+    *value = std::make_unique<Object>(std::move(res));
+    return true;
+  }
+  return false;
+}
+
+void ProtocolTypeTraits<std::unique_ptr<Object>>::Serialize(const std::unique_ptr<Object>& value, std::vector<uint8_t>* bytes) {
+  value->AppendSerialized(bytes);
+}
+
+}  // namespace {{config.crdtp.namespace}}

third_party/inspector_protocol/lib/ValueConversions_h.template

@@ -259,8 +259,61 @@ struct ValueConversions<ListValue> {
     }
 };
 
+template<typename T> struct ValueTypeConverter {
+  static std::unique_ptr<T> FromValue(const protocol::Value& value) {
+    std::vector<uint8_t> bytes;
+    value.AppendSerialized(&bytes);
+    return T::FromBinary(bytes.data(), bytes.size());
+  }
+
+  static std::unique_ptr<protocol::DictionaryValue> ToValue(const T& obj) {
+    std::vector<uint8_t> bytes;
+    obj.AppendSerialized(&bytes);
+    auto result = Value::parseBinary(bytes.data(), bytes.size());
+    return DictionaryValue::cast(std::move(result));
+  }
+};
+
 {% for namespace in config.protocol.namespace %}
 } // namespace {{namespace}}
 {% endfor %}
 
+namespace {{config.crdtp.namespace}} {
+
+template<typename T>
+struct ProtocolTypeTraits<T,
+     typename std::enable_if<std::is_base_of<{{"::".join(config.protocol.namespace)}}::Value, T>::value>::type> {
+  static void Serialize(const {{"::".join(config.protocol.namespace)}}::Value& value, std::vector<uint8_t>* bytes) {
+    value.AppendSerialized(bytes);
+  }
+};
+
+template <>
+struct ProtocolTypeTraits<std::unique_ptr<{{"::".join(config.protocol.namespace)}}::Value>> {
+  static bool Deserialize(DeserializerState* state, std::unique_ptr<{{"::".join(config.protocol.namespace)}}::Value>* value);
+  static void Serialize(const std::unique_ptr<{{"::".join(config.protocol.namespace)}}::Value>& value, std::vector<uint8_t>* bytes);
+};
+
+template <>
+struct ProtocolTypeTraits<std::unique_ptr<{{"::".join(config.protocol.namespace)}}::DictionaryValue>> {
+  static bool Deserialize(DeserializerState* state, std::unique_ptr<{{"::".join(config.protocol.namespace)}}::DictionaryValue>* value);
+  static void Serialize(const std::unique_ptr<{{"::".join(config.protocol.namespace)}}::DictionaryValue>& value, std::vector<uint8_t>* bytes);
+};
+
+// TODO(caseq): get rid of it, it's just a DictionaryValue really.
+template <>
+struct ProtocolTypeTraits<std::unique_ptr<{{"::".join(config.protocol.namespace)}}::Object>> {
+  static bool Deserialize(DeserializerState* state, std::unique_ptr<{{"::".join(config.protocol.namespace)}}::Object>* value);
+  static void Serialize(const std::unique_ptr<{{"::".join(config.protocol.namespace)}}::Object>& value, std::vector<uint8_t>* bytes);
+};
+
+template<>
+struct ProtocolTypeTraits<{{"::".join(config.protocol.namespace)}}::Object> {
+  static void Serialize(const {{"::".join(config.protocol.namespace)}}::Object& value, std::vector<uint8_t>* bytes) {
+    value.AppendSerialized(bytes);
+  }
+};
+
+}  // namespace {{config.crdtp.namespace}}
+
 #endif // !defined({{"_".join(config.protocol.namespace)}}_ValueConversions_h)

third_party/inspector_protocol/lib/Values_cpp.template

@@ -62,7 +62,7 @@ class ValueParserHandler : public ParserHandler {
     DCHECK(stack_.back().is_dict);
     stack_.pop_back();
   }
-  
+
   void HandleArrayBegin() override {
     if (!status_.ok()) return;
     std::unique_ptr<ListValue> list = ListValue::create();
@@ -91,19 +91,19 @@ class ValueParserHandler : public ParserHandler {
     AddValueToParent(
         BinaryValue::create(Binary::fromSpan(bytes.data(), bytes.size())));
   }
-   
+
   void HandleDouble(double value) override {
     AddValueToParent(FundamentalValue::create(value));
   }
-   
+
   void HandleInt32(int32_t value) override {
     AddValueToParent(FundamentalValue::create(value));
   }
-   
+
   void HandleBool(bool value) override {
     AddValueToParent(FundamentalValue::create(value));
   }
-   
+
   void HandleNull() override {
     AddValueToParent(Value::null());
   }
@@ -318,7 +318,6 @@ void EncodeString(const String& s, std::vector<uint8_t>* out) {
   }
 }
 }  // namespace
-
 void StringValue::AppendSerialized(std::vector<uint8_t>* bytes) const {
   EncodeString(m_stringValue, bytes);
 }

third_party/inspector_protocol/lib/Values_h.template

@@ -20,6 +20,11 @@ class ListValue;
 class DictionaryValue;
 class Value;
 
+#define PROTOCOL_DISALLOW_COPY(ClassName) \
+ private:                                 \
+  ClassName(const ClassName&) = delete;   \
+  ClassName& operator=(const ClassName&) = delete
+
 class {{config.lib.export_macro}} Value : public Serializable {
     PROTOCOL_DISALLOW_COPY(Value);
 public:

third_party/inspector_protocol/lib/base_string_adapter_cc.template

@@ -16,6 +16,13 @@
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "{{config.crdtp.dir}}/cbor.h"
+#include "{{config.crdtp.dir}}/protocol_core.h"
+
+using namespace {{config.crdtp.namespace}};
+
+using {{"::".join(config.protocol.namespace)}}::Binary;
+using {{"::".join(config.protocol.namespace)}}::String;
+using {{"::".join(config.protocol.namespace)}}::StringUtil;
 
 {% for namespace in config.protocol.namespace %}
 namespace {{namespace}} {
@@ -138,6 +145,28 @@ String StringUtil::fromUTF16LE(const uint16_t* data, size_t length) {
   return utf8;
 }
 
+bool StringUtil::ReadString(DeserializerState* state, String* value) {
+  auto* tokenizer = state->tokenizer();
+  if (tokenizer->TokenTag() == cbor::CBORTokenTag::STRING8) {
+    const auto str = tokenizer->GetString8();
+    *value = StringUtil::fromUTF8(str.data(), str.size());
+    return true;
+  }
+  if (tokenizer->TokenTag() == cbor::CBORTokenTag::STRING16) {
+    const auto str = tokenizer->GetString16WireRep();
+    *value = StringUtil::fromUTF16LE(reinterpret_cast<const uint16_t*>(str.data()), str.size() / 2);
+    return true;
+  }
+  state->RegisterError(Error::BINDINGS_STRING_VALUE_EXPECTED);
+  return false;
+}
+
+void StringUtil::WriteString(const String& str, std::vector<uint8_t>* bytes) {
+  cbor::EncodeString8(span<uint8_t>(StringUtil::CharactersUTF8(str),
+                                    StringUtil::CharacterCount(str)),
+                      bytes);
+}
+
 Binary::Binary() : bytes_(new base::RefCountedBytes) {}
 Binary::Binary(const Binary& binary) : bytes_(binary.bytes_) {}
 Binary::Binary(scoped_refptr<base::RefCountedMemory> bytes) : bytes_(bytes) {}
@@ -190,3 +219,31 @@ Binary Binary::fromSpan(const uint8_t* data, size_t size) {
 {% for namespace in config.protocol.namespace %}
 } // namespace {{namespace}}
 {% endfor %}
+
+namespace {{config.crdtp.namespace}} {
+
+// static
+bool ProtocolTypeTraits<Binary>::Deserialize(DeserializerState* state, Binary* value) {
+  auto* tokenizer = state->tokenizer();
+  if (tokenizer->TokenTag() == cbor::CBORTokenTag::BINARY) {
+    const span<uint8_t> bin = tokenizer->GetBinary();
+    *value = Binary::fromSpan(bin.data(), bin.size());
+    return true;
+  }
+  if (tokenizer->TokenTag() == cbor::CBORTokenTag::STRING8) {
+    const auto str_span = tokenizer->GetString8();
+    String str = StringUtil::fromUTF8(str_span.data(), str_span.size());
+    bool success = false;
+    *value = Binary::fromBase64(str, &success);
+    return success;
+  }
+  state->RegisterError(Error::BINDINGS_BINARY_VALUE_EXPECTED);
+  return false;
+}
+
+// static
+void ProtocolTypeTraits<Binary>::Serialize(const Binary& value, std::vector<uint8_t>* bytes) {
+  value.AppendSerialized(bytes);
+}
+
+}  // namespace {{config.crdtp.namespace}}
\ No newline at end of file

third_party/inspector_protocol/lib/base_string_adapter_h.template

@@ -15,6 +15,7 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted_memory.h"
 #include "{{config.crdtp.dir}}/serializable.h"
+#include "{{config.crdtp.dir}}/protocol_core.h"
 
 {% if config.lib.export_header %}
 #include "{{config.lib.export_header}}"
@@ -24,6 +25,10 @@ namespace base {
 class Value;
 }
 
+namespace {{config.crdtp.namespace}} {
+class DeserializerState;
+}
+
 {% for namespace in config.protocol.namespace %}
 namespace {{namespace}} {
 {% endfor %}
@@ -46,6 +51,9 @@ class {{config.lib.export_macro}} StringUtil {
   }
   static const uint16_t* CharactersUTF16(const String& s) { return nullptr; }
   static size_t CharacterCount(const String& s) { return s.size(); }
+
+  static bool ReadString({{config.crdtp.namespace}}::DeserializerState* state, String* str);
+  static void WriteString(const String& str, std::vector<uint8_t>* bytes);
 };
 
 // A read-only sequence of uninterpreted bytes with reference-counted storage.
@@ -81,4 +89,24 @@ std::unique_ptr<base::Value> toBaseValue(Value* value, int depth);
 } // namespace {{namespace}}
 {% endfor %}
 
+namespace {{config.crdtp.namespace}} {
+
+template <>
+struct ProtocolTypeTraits<{{"::".join(config.protocol.namespace)}}::String> {
+  static bool Deserialize(DeserializerState* state, {{"::".join(config.protocol.namespace)}}::String* value) {
+    return {{"::".join(config.protocol.namespace)}}::StringUtil::ReadString(state, value);
+  }
+  static void Serialize(const {{"::".join(config.protocol.namespace)}}::String& value, std::vector<uint8_t>* bytes) {
+    {{"::".join(config.protocol.namespace)}}::StringUtil::WriteString(value, bytes);
+  }
+};
+
+template <>
+struct ProtocolTypeTraits<{{"::".join(config.protocol.namespace)}}::Binary> {
+  static bool Deserialize(DeserializerState* state, {{"::".join(config.protocol.namespace)}}::Binary* value);
+  static void Serialize(const {{"::".join(config.protocol.namespace)}}::Binary& value, std::vector<uint8_t>* bytes);
+};
+
+}  // {{config.crdtp.namespace}}
+
 #endif // !defined({{"_".join(config.protocol.namespace)}}_BASE_STRING_ADAPTER_H)

third_party/inspector_protocol/roll.py

@@ -31,13 +31,16 @@ FILES_TO_SYNC = [
     'crdtp/find_by_first.h',
     'crdtp/find_by_first_test.cc',
     'crdtp/frontend_channel.h',
-    'crdtp/glue.h',
-    'crdtp/glue_test.cc',
+    'crdtp/maybe.h',
+    'crdtp/maybe_test.cc',
     'crdtp/json.cc',
     'crdtp/json.h',
     'crdtp/json_platform.h',
     'crdtp/json_test.cc',
     'crdtp/parser_handler.h',
+    'crdtp/protocol_core_test.cc',
+    'crdtp/protocol_core.cc',
+    'crdtp/protocol_core.h',
     'crdtp/serializable.h',
     'crdtp/serializable.cc',
     'crdtp/serializable_test.cc',

third_party/inspector_protocol/templates/Imported_h.template

@@ -14,6 +14,53 @@
 #include {{format_include(config.imported.package, domain.domain)}}
 {% endif %}
 
+#ifndef {{"_".join(config.protocol.namespace)}}_imported_imported_h
+
+namespace {{config.crdtp.namespace}} {
+
+template <typename T>
+struct ProtocolTypeTraits<
+    std::unique_ptr<T>,
+    typename std::enable_if<
+        std::is_base_of<{{"::".join(config.imported.namespace)}}::Exported, T>::value>::type> {
+  static bool Deserialize(DeserializerState* state, std::unique_ptr<T>* value) {
+    if (state->tokenizer()->TokenTag() != cbor::CBORTokenTag::ENVELOPE) {
+      state->RegisterError(Error::CBOR_INVALID_ENVELOPE);
+      return false;
+    }
+    span<uint8_t> env = state->tokenizer()->GetEnvelope();
+    auto res = T::fromBinary(env.data(), env.size());
+    if (!res) {
+      // TODO(caseq): properly plumb an error rather than returning a bogus code.
+      state->RegisterError(Error::MESSAGE_MUST_BE_AN_OBJECT);
+      return false;
+    }
+    *value = std::move(res);
+    return true;
+  }
+  static void Serialize(const std::unique_ptr<T>& value, std::vector<uint8_t>* bytes) {
+    // Use virtual method, so that outgoing protocol objects could be retained
+    // by a pointer to ProtocolObject.
+    value->AppendSerialized(bytes);
+  }
+};
+
+template <typename T>
+struct ProtocolTypeTraits<
+    T,
+    typename std::enable_if<
+        std::is_base_of<{{"::".join(config.imported.namespace)}}::Exported, T>::value>::type> {
+  static void Serialize(const T& value, std::vector<uint8_t>* bytes) {
+    // Use virtual method, so that outgoing protocol objects could be retained
+    // by a pointer to ProtocolObject.
+    value.AppendSerialized(bytes);
+  }
+};
+
+}  // namespace {{config.crdtp.namespace}}
+
+#endif  // {{"_".join(config.protocol.namespace)}}_imported_imported_h
+
 {% for namespace in config.protocol.namespace %}
 namespace {{namespace}} {
 {% endfor %}

third_party/inspector_protocol/templates/TypeBuilder_h.template

@@ -26,8 +26,6 @@
 namespace {{namespace}} {
 {% endfor %}
 namespace {{domain.domain}} {
-
-// ------------- Forward and enum declarations.
   {% for type in domain.types %}
     {% if not protocol.generate_type(domain.domain, type.id) %}{% continue %}{% endif %}
     {% if type.type == "object" %}
@@ -40,6 +38,8 @@ using {{type.id}} = Object;
 using {{type.id}} = {{protocol.resolve_type(type).type}};
     {% endif %}
   {% endfor %}
+
+// ------------- Forward and enum declarations.
   {% for type in domain.types %}
     {% if not protocol.generate_type(domain.domain, type.id) %}{% continue %}{% endif %}
     {% if "enum" in type %}
@@ -71,11 +71,9 @@ namespace {{param.name | to_title_case}}Enum {
     {% if not protocol.generate_type(domain.domain, type.id) %}{% continue %}{% endif %}
     {% if not (type.type == "object") or not ("properties" in type) %}{% continue %}{% endif %}
 
-class {{config.protocol.export_macro}} {{type.id}} : public Serializable{% if protocol.is_exported(domain.domain, type.id) %}, public API::{{type.id}}{% endif %}{
-    PROTOCOL_DISALLOW_COPY({{type.id}});
+class {{config.protocol.export_macro}} {{type.id}} : public ::{{config.crdtp.namespace}}::ProtocolObject<{{type.id}}>{% if protocol.is_exported(domain.domain, type.id) %},
+    public API::{{type.id}}{% endif %} {
 public:
-    static std::unique_ptr<{{type.id}}> fromValue(protocol::Value* value, ErrorSupport* errors);
-
     ~{{type.id}}() override { }
     {% for property in type.properties %}
       {% set property_type = protocol.resolve_type(property) %}
@@ -99,10 +97,6 @@ public:
     void {{"set" | to_method_case}}{{property_name}}({{property_type.pass_type}} value) { {{property_field}} = {{property_type.to_rvalue % "value"}}; }
     {% endfor %}
 
-    std::unique_ptr<protocol::DictionaryValue> toValue() const;
-    void AppendSerialized(std::vector<uint8_t>* out) const override;
-    std::unique_ptr<{{type.id}}> clone() const;
-
     template<int STATE>
     class {{type.id}}Builder {
     public:
@@ -160,6 +154,8 @@ public:
     }
 
 private:
+    DECLARE_SERIALIZATION_SUPPORT();
+
     {{type.id}}()
     {
     {% for property in type.properties %}