text: // Copyright 2009 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/log-utils.h"
  
  #include "src/assert-scope.h"
  #include "src/base/platform/platform.h"
  #include "src/objects-inl.h"
  #include "src/string-stream.h"
  #include "src/utils.h"
  #include "src/version.h"
  
  namespace v8 {
  namespace internal {
  
  
  const char* const Log::kLogToTemporaryFile = "&";
  const char* const Log::kLogToConsole = "-";
  
  Log::Log(Logger* logger)
      : is_stopped_(false),
        output_handle_(NULL),
        message_buffer_(NULL),
        logger_(logger) {}
  
  void Log::Initialize(const char* log_file_name) {
    message_buffer_ = NewArray<char>(kMessageBufferSize);
  
    // --log-all enables all the log flags.
    if (FLAG_log_all) {
      FLAG_log_api = true;
      FLAG_log_code = true;
      FLAG_log_gc = true;
      FLAG_log_suspect = true;
      FLAG_log_handles = true;
      FLAG_log_internal_timer_events = true;
    }
  
    // --prof implies --log-code.
    if (FLAG_prof) FLAG_log_code = true;
  
    // If we're logging anything, we need to open the log file.
    if (Log::InitLogAtStart()) {
      if (strcmp(log_file_name, kLogToConsole) == 0) {
        OpenStdout();
      } else if (strcmp(log_file_name, kLogToTemporaryFile) == 0) {
        OpenTemporaryFile();
      } else {
        OpenFile(log_file_name);
      }
  
      if (output_handle_ != nullptr) {
        Log::MessageBuilder msg(this);
        if (strlen(Version::GetEmbedder()) == 0) {
          msg.Append("v8-version,%d,%d,%d,%d,%d", Version::GetMajor(),
                     Version::GetMinor(), Version::GetBuild(),
                     Version::GetPatch(), Version::IsCandidate());
        } else {
          msg.Append("v8-version,%d,%d,%d,%d,%s,%d", Version::GetMajor(),
                     Version::GetMinor(), Version::GetBuild(),
                     Version::GetPatch(), Version::GetEmbedder(),
                     Version::IsCandidate());
        }
        msg.WriteToLogFile();
      }
    }
  }
  
  
  void Log::OpenStdout() {
    DCHECK(!IsEnabled());
    output_handle_ = stdout;
  }
  
  
  void Log::OpenTemporaryFile() {
    DCHECK(!IsEnabled());
    output_handle_ = base::OS::OpenTemporaryFile();
  }
  
  
  void Log::OpenFile(const char* name) {
    DCHECK(!IsEnabled());
    output_handle_ = base::OS::FOpen(name, base::OS::LogFileOpenMode);
  }
  
  FILE* Log::Close() {
    FILE* result = NULL;
    if (output_handle_ != NULL) {
      if (strcmp(FLAG_logfile, kLogToTemporaryFile) != 0) {
        fclose(output_handle_);
      } else {
        result = output_handle_;
      }
    }
    output_handle_ = NULL;
  
    DeleteArray(message_buffer_);
    message_buffer_ = NULL;
  
    is_stopped_ = false;
    return result;
  }
  
  
  Log::MessageBuilder::MessageBuilder(Log* log)
    : log_(log),
      lock_guard_(&log_->mutex_),
      pos_(0) {
    DCHECK(log_->message_buffer_ != NULL);
  }
  
  
  void Log::MessageBuilder::Append(const char* format, ...) {
    Vector<char> buf(log_->message_buffer_ + pos_,
                     Log::kMessageBufferSize - pos_);
    va_list args;
    va_start(args, format);
    AppendVA(format, args);
    va_end(args);
    DCHECK(pos_ <= Log::kMessageBufferSize);
  }
  
  
  void Log::MessageBuilder::AppendVA(const char* format, va_list args) {
    Vector<char> buf(log_->message_buffer_ + pos_,
                     Log::kMessageBufferSize - pos_);
    int result = v8::internal::VSNPrintF(buf, format, args);
  
    // Result is -1 if output was truncated.
    if (result >= 0) {
      pos_ += result;
    } else {
      pos_ = Log::kMessageBufferSize;
    }
    DCHECK(pos_ <= Log::kMessageBufferSize);
  }
  
  
  void Log::MessageBuilder::Append(const char c) {
    if (pos_ < Log::kMessageBufferSize) {
      log_->message_buffer_[pos_++] = c;
    }
    DCHECK(pos_ <= Log::kMessageBufferSize);
  }
  
  
  void Log::MessageBuilder::AppendDoubleQuotedString(const char* string) {
    Append('"');
    for (const char* p = string; *p != '\0'; p++) {
      if (*p == '"') {
        Append('\\');
      }
      Append(*p);
    }
    Append('"');
  }
  
  
  void Log::MessageBuilder::Append(String* str) {
    DisallowHeapAllocation no_gc;  // Ensure string stay valid.
    int length = str->length();
    for (int i = 0; i < length; i++) {
      Append(static_cast<char>(str->Get(i)));
    }
  }
  
  void Log::MessageBuilder::AppendAddress(Address addr) {
    Append("0x%" V8PRIxPTR, reinterpret_cast<intptr_t>(addr));
  }
  
  void Log::MessageBuilder::AppendSymbolName(Symbol* symbol) {
    DCHECK(symbol);
    Append("symbol(");
    if (!symbol->name()->IsUndefined(symbol->GetIsolate())) {
      Append("\"");
      AppendDetailed(String::cast(symbol->name()), false);
      Append("\" ");
    }
    Append("hash %x)", symbol->Hash());
  }
  
  
  void Log::MessageBuilder::AppendDetailed(String* str, bool show_impl_info) {
    if (str == NULL) return;
    DisallowHeapAllocation no_gc;  // Ensure string stay valid.
    int len = str->length();
    if (len > 0x1000)
      len = 0x1000;
    if (show_impl_info) {
      Append(str->IsOneByteRepresentation() ? 'a' : '2');
      if (StringShape(str).IsExternal())
        Append('e');
      if (StringShape(str).IsInternalized())
        Append('#');
      Append(":%i:", str->length());
    }
    for (int i = 0; i < len; i++) {
      uc32 c = str->Get(i);
      if (c > 0xff) {
        Append("\\u%04x", c);
      } else if (c < 32 || c > 126) {
        Append("\\x%02x", c);
      } else if (c == ',') {
        Append("\\,");
      } else if (c == '\\') {
        Append("\\\\");
      } else if (c == '\"') {
        Append("\"\"");
      } else {
        Append("%lc", c);
      }
    }
  }
  
  void Log::MessageBuilder::AppendUnbufferedHeapString(String* str) {
    if (str == NULL) return;
    DisallowHeapAllocation no_gc;  // Ensure string stay valid.
    ScopedVector<char> buffer(16);
    int len = str->length();
    for (int i = 0; i < len; i++) {
      uc32 c = str->Get(i);
      if (c >= 32 && c <= 126) {
        if (c == '\"') {
          AppendUnbufferedCString("\"\"");
        } else if (c == '\\') {
          AppendUnbufferedCString("\\\\");
        } else {
          AppendUnbufferedChar(c);
        }
      } else if (c > 0xff) {
        int length = v8::internal::SNPrintF(buffer, "\\u%04x", c);
        DCHECK_EQ(6, length);
        log_->WriteToFile(buffer.start(), length);
      } else {
        DCHECK(c <= 0xffff);
        int length = v8::internal::SNPrintF(buffer, "\\x%02x", c);
        DCHECK_EQ(4, length);
        log_->WriteToFile(buffer.start(), length);
      }
    }
  }
  
  void Log::MessageBuilder::AppendUnbufferedChar(char c) {
    log_->WriteToFile(&c, 1);
  }
  
  void Log::MessageBuilder::AppendUnbufferedCString(const char* str) {
    log_->WriteToFile(str, static_cast<int>(strlen(str)));
  }
  
  void Log::MessageBuilder::AppendStringPart(const char* str, int len) {
    if (pos_ + len > Log::kMessageBufferSize) {
      len = Log::kMessageBufferSize - pos_;
      DCHECK(len >= 0);
      if (len == 0) return;
    }
    Vector<char> buf(log_->message_buffer_ + pos_,
                     Log::kMessageBufferSize - pos_);
    StrNCpy(buf, str, len);
    pos_ += len;
    DCHECK(pos_ <= Log::kMessageBufferSize);
  }
  
  void Log::MessageBuilder::WriteToLogFile() {
    DCHECK(pos_ <= Log::kMessageBufferSize);
    // Assert that we do not already have a new line at the end.
    DCHECK(pos_ == 0 || log_->message_buffer_[pos_ - 1] != '\n');
    if (pos_ == Log::kMessageBufferSize) pos_--;
    log_->message_buffer_[pos_++] = '\n';
    const int written = log_->WriteToFile(log_->message_buffer_, pos_);
    if (written != pos_) {
      log_->stop();
      log_->logger_->LogFailure();
    }
  }
  
  }  // namespace internal
  }  // namespace v8
  