v8-debugger-script.cc

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// Copyright 2014 the V8 project 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 "src/inspector/v8-debugger-script.h"
 
#include "src/base/memory.h"
#include "src/inspector/inspected-context.h"
#include "src/inspector/protocol/Debugger.h"
#include "src/inspector/string-util.h"
#include "src/inspector/v8-debugger-agent-impl.h"
#include "src/inspector/v8-inspector-impl.h"
#include "src/utils/sha-256.h"
 
namespace v8_inspector {
 
namespace {
 
const char kGlobalDebuggerScriptHandleLabel[] = "DevTools debugger";
 
String16 calculateHash(v8::Isolate* isolate, v8::Local<v8::String> source) {
  uint32_t length = source->Length();
  std::unique_ptr<UChar[]> buffer(new UChar[length]);
  source->WriteV2(isolate, 0, length,
                  reinterpret_cast<uint16_t*>(buffer.get()));
 
  const uint8_t* data = nullptr;
  size_t sizeInBytes = sizeof(UChar) * length;
  data = reinterpret_cast<const uint8_t*>(buffer.get());
 
  uint8_t hash[kSizeOfSha256Digest];
  v8::internal::SHA256_hash(data, sizeInBytes, hash);
 
  String16Builder formatted_hash;
  for (size_t i = 0; i < kSizeOfSha256Digest; i++)
    formatted_hash.appendUnsignedAsHex(static_cast<uint8_t>(hash[i]));
 
  return formatted_hash.toString();
}
 
class ActualScript : public V8DebuggerScript {
  friend class V8DebuggerScript;
 
 public:
  ActualScript(v8::Isolate* isolate, v8::Local<v8::debug::Script> script,
               bool isLiveEdit, V8DebuggerAgentImpl* agent,
               V8InspectorClient* client)
      : V8DebuggerScript(isolate, String16::fromInteger(script->Id()),
                         GetScriptURL(isolate, script, client),
                         GetScriptName(isolate, script, client)),
        m_agent(agent),
        m_isLiveEdit(isLiveEdit) {
    Initialize(script);
  }
 
  bool isLiveEdit() const override { return m_isLiveEdit; }
  bool isModule() const override { return m_isModule; }
 
  String16 source(size_t pos, size_t len) const override {
    v8::HandleScope scope(m_isolate);
    v8::Local<v8::String> v8Source;
    if (!m_scriptSource.Get(m_isolate)->JavaScriptCode().ToLocal(&v8Source)) {
      return String16();
    }
    if (pos >= static_cast<size_t>(v8Source->Length())) return String16();
    size_t substringLength =
        std::min(len, static_cast<size_t>(v8Source->Length()) - pos);
    std::unique_ptr<UChar[]> buffer(new UChar[substringLength]);
    v8Source->WriteV2(m_isolate, static_cast<uint32_t>(pos),
                      static_cast<uint32_t>(substringLength),
                      reinterpret_cast<uint16_t*>(buffer.get()));
    return String16(buffer.get(), substringLength);
  }
  Language getLanguage() const override { return m_language; }
 
#if V8_ENABLE_WEBASSEMBLY
  v8::Maybe<v8::MemorySpan<const uint8_t>> wasmBytecode() const override {
    v8::HandleScope scope(m_isolate);
    v8::MemorySpan<const uint8_t> bytecode;
    if (m_scriptSource.Get(m_isolate)->WasmBytecode().To(&bytecode)) {
      return v8::Just(bytecode);
    }
    return v8::Nothing<v8::MemorySpan<const uint8_t>>();
  }
 
  std::vector<v8::debug::WasmScript::DebugSymbols> getDebugSymbols()
      const override {
    auto script = this->script();
    if (!script->IsWasm())
      return std::vector<v8::debug::WasmScript::DebugSymbols>();
    return v8::debug::WasmScript::Cast(*script)->GetDebugSymbols();
  }
 
  void Disassemble(v8::debug::DisassemblyCollector* collector,
                   std::vector<int>* function_body_offsets) const override {
    v8::HandleScope scope(m_isolate);
    v8::Local<v8::debug::Script> script = this->script();
    DCHECK(script->IsWasm());
    v8::debug::WasmScript::Cast(*script)->Disassemble(collector,
                                                      function_body_offsets);
  }
#endif  // V8_ENABLE_WEBASSEMBLY
 
  int startLine() const override { return m_startLine; }
  int startColumn() const override { return m_startColumn; }
  int endLine() const override { return m_endLine; }
  int endColumn() const override { return m_endColumn; }
  int codeOffset() const override {
#if V8_ENABLE_WEBASSEMBLY
    if (script()->IsWasm()) {
      return v8::debug::WasmScript::Cast(*script())->CodeOffset();
    }
#endif  // V8_ENABLE_WEBASSEMBLY
    return 0;
  }
  int length() const override {
    return static_cast<int>(m_scriptSource.Get(m_isolate)->Length());
  }
 
  const String16& sourceMappingURL() const override {
    return m_sourceMappingURL;
  }
 
  void setSourceMappingURL(const String16& sourceMappingURL) override {
    m_sourceMappingURL = sourceMappingURL;
  }
 
  void setSource(const String16& newSource, bool preview,
                 bool allowTopFrameLiveEditing,
                 v8::debug::LiveEditResult* result) override {
    v8::EscapableHandleScope scope(m_isolate);
    v8::Local<v8::String> v8Source = toV8String(m_isolate, newSource);
    if (!m_script.Get(m_isolate)->SetScriptSource(
            v8Source, preview, allowTopFrameLiveEditing, result)) {
      result->message = scope.Escape(result->message);
      return;
    }
    // NOP if preview or unchanged source (diffs.empty() in PatchScript)
    if (preview || result->script.IsEmpty()) return;
 
    m_hash = String16();
    Initialize(scope.Escape(result->script));
  }
 
  bool getPossibleBreakpoints(
      const v8::debug::Location& start, const v8::debug::Location& end,
      bool restrictToFunction,
      std::vector<v8::debug::BreakLocation>* locations) override {
    v8::HandleScope scope(m_isolate);
    v8::Local<v8::debug::Script> script = m_script.Get(m_isolate);
    std::vector<v8::debug::BreakLocation> allLocations;
    if (!script->GetPossibleBreakpoints(start, end, restrictToFunction,
                                        &allLocations)) {
      return false;
    }
    if (allLocations.empty()) return true;
    v8::debug::BreakLocation current = allLocations[0];
    for (size_t i = 1; i < allLocations.size(); ++i) {
      if (allLocations[i].GetLineNumber() == current.GetLineNumber() &&
          allLocations[i].GetColumnNumber() == current.GetColumnNumber()) {
        if (allLocations[i].type() != v8::debug::kCommonBreakLocation) {
          DCHECK(allLocations[i].type() == v8::debug::kCallBreakLocation ||
                 allLocations[i].type() == v8::debug::kReturnBreakLocation);
          // debugger can returns more then one break location at the same
          // source location, e.g. foo() - in this case there are two break
          // locations before foo: for statement and for function call, we can
          // merge them for inspector and report only one with call type.
          current = allLocations[i];
        }
      } else {
        // we assume that returned break locations are sorted.
        DCHECK(
            allLocations[i].GetLineNumber() > current.GetLineNumber() ||
            (allLocations[i].GetColumnNumber() >= current.GetColumnNumber() &&
             allLocations[i].GetLineNumber() == current.GetLineNumber()));
        locations->push_back(current);
        current = allLocations[i];
      }
    }
    locations->push_back(current);
    return true;
  }
 
  void resetBlackboxedStateCache() override {
    v8::HandleScope scope(m_isolate);
    v8::debug::ResetBlackboxedStateCache(m_isolate, m_script.Get(m_isolate));
  }
 
  v8::Maybe<int> offset(int lineNumber, int columnNumber) const override {
    v8::HandleScope scope(m_isolate);
    return m_script.Get(m_isolate)->GetSourceOffset(
        v8::debug::Location(lineNumber, columnNumber));
  }
 
  v8::debug::Location location(int offset) const override {
    v8::HandleScope scope(m_isolate);
    return m_script.Get(m_isolate)->GetSourceLocation(offset);
  }
 
  bool setBreakpoint(const String16& condition, v8::debug::Location* location,
                     int* id) const override {
    v8::HandleScope scope(m_isolate);
    return script()->SetBreakpoint(toV8String(m_isolate, condition), location,
                                   id);
  }
 
  bool setInstrumentationBreakpoint(int* id) const override {
    v8::HandleScope scope(m_isolate);
    return script()->SetInstrumentationBreakpoint(id);
  }
 
  const String16& hash() const override {
    if (!m_hash.isEmpty()) return m_hash;
    v8::HandleScope scope(m_isolate);
    v8::Local<v8::String> v8Source;
    if (!m_scriptSource.Get(m_isolate)->JavaScriptCode().ToLocal(&v8Source)) {
      v8Source = v8::String::Empty(m_isolate);
    }
    m_hash = calculateHash(m_isolate, v8Source);
    DCHECK(!m_hash.isEmpty());
    return m_hash;
  }
 
  String16 buildId() const override {
#if V8_ENABLE_WEBASSEMBLY
    if (m_language == Language::WebAssembly) {
      v8::Local<v8::debug::Script> script = this->script();
      auto maybe_build_id =
          v8::debug::WasmScript::Cast(*script)->GetModuleBuildId();
      if (maybe_build_id.IsJust()) {
        v8::MemorySpan<const uint8_t> buildId = maybe_build_id.FromJust();
        String16Builder buildIdFormatter;
        for (size_t i = 0; i < buildId.size(); i++) {
          buildIdFormatter.appendUnsignedAsHex(
              static_cast<uint8_t>(buildId[i]));
        }
        return buildIdFormatter.toString();
      }
    }
#endif  // V8_ENABLE_WEBASSEMBLY
    return {};
  }
 
 private:
  static String16 GetScriptURL(v8::Isolate* isolate,
                               v8::Local<v8::debug::Script> script,
                               V8InspectorClient* client) {
    v8::Local<v8::String> sourceURL;
    if (script->SourceURL().ToLocal(&sourceURL) && sourceURL->Length() > 0)
      return toProtocolString(isolate, sourceURL);
    return GetScriptName(isolate, script, client);
  }
 
  static String16 GetScriptName(v8::Isolate* isolate,
                                v8::Local<v8::debug::Script> script,
                                V8InspectorClient* client) {
    v8::Local<v8::String> v8Name;
    if (script->Name().ToLocal(&v8Name) && v8Name->Length() > 0) {
      String16 name = toProtocolString(isolate, v8Name);
      std::unique_ptr<StringBuffer> url =
          client->resourceNameToUrl(toStringView(name));
      return url ? toString16(url->string()) : name;
    }
    return String16();
  }
 
  v8::Local<v8::debug::Script> script() const override {
    return m_script.Get(m_isolate);
  }
 
  void Initialize(v8::Local<v8::debug::Script> script) {
    v8::Local<v8::String> tmp;
    m_hasSourceURLComment =
        script->SourceURL().ToLocal(&tmp) && tmp->Length() > 0;
    if (script->SourceMappingURL().ToLocal(&tmp))
      m_sourceMappingURL = toProtocolString(m_isolate, tmp);
    m_startLine = script->StartLine();
    m_startColumn = script->StartColumn();
    m_endLine = script->EndLine();
    m_endColumn = script->EndColumn();
 
    USE(script->ContextId().To(&m_executionContextId));
    m_language = V8DebuggerScript::Language::JavaScript;
#if V8_ENABLE_WEBASSEMBLY
    if (script->IsWasm()) {
      m_language = V8DebuggerScript::Language::WebAssembly;
    }
#endif  // V8_ENABLE_WEBASSEMBLY
 
    m_isModule = script->IsModule();
 
    bool hasHash = script->GetSha256Hash().ToLocal(&tmp) && tmp->Length() > 0;
    if (hasHash) {
      m_hash = toProtocolString(m_isolate, tmp);
    }
 
    m_script.Reset(m_isolate, script);
    m_script.AnnotateStrongRetainer(kGlobalDebuggerScriptHandleLabel);
    m_scriptSource.Reset(m_isolate, script->Source());
    m_scriptSource.AnnotateStrongRetainer(kGlobalDebuggerScriptHandleLabel);
  }
 
  void MakeWeak() override {
    m_script.SetWeak(
        this,
        [](const v8::WeakCallbackInfo<ActualScript>& data) {
          data.GetParameter()->WeakCallback();
        },
        v8::WeakCallbackType::kParameter);
  }
 
  void WeakCallback() {
    m_script.Reset();
    m_agent->ScriptCollected(this);
  }
 
  V8DebuggerAgentImpl* m_agent;
  String16 m_sourceMappingURL;
  Language m_language;
  bool m_isLiveEdit = false;
  bool m_isModule = false;
  mutable String16 m_hash;
  int m_startLine = 0;
  int m_startColumn = 0;
  int m_endLine = 0;
  int m_endColumn = 0;
  v8::Global<v8::debug::Script> m_script;
  v8::Global<v8::debug::ScriptSource> m_scriptSource;
};
 
}  // namespace
 
std::unique_ptr<V8DebuggerScript> V8DebuggerScript::Create(
    v8::Isolate* isolate, v8::Local<v8::debug::Script> scriptObj,
    bool isLiveEdit, V8DebuggerAgentImpl* agent, V8InspectorClient* client) {
  return std::make_unique<ActualScript>(isolate, scriptObj, isLiveEdit, agent,
                                        client);
}
 
V8DebuggerScript::V8DebuggerScript(v8::Isolate* isolate, String16 id,
                                   String16 url, String16 embedderName)
    : m_id(std::move(id)),
      m_url(std::move(url)),
      m_isolate(isolate),
      m_embedderName(embedderName) {}
 
V8DebuggerScript::~V8DebuggerScript() = default;
 
void V8DebuggerScript::setSourceURL(const String16& sourceURL) {
  if (sourceURL.length() > 0) {
    m_hasSourceURLComment = true;
    m_url = sourceURL;
  }
}
 
#if V8_ENABLE_WEBASSEMBLY
void V8DebuggerScript::removeWasmBreakpoint(int id) {
  v8::HandleScope scope(m_isolate);
  script()->RemoveWasmBreakpoint(id);
}
#endif  // V8_ENABLE_WEBASSEMBLY
 
}  // namespace v8_inspector