text: // Copyright 2007, Google Inc.
  // All rights reserved.
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  //
  //     * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  //
  // Author: wan@google.com (Zhanyong Wan)
  
  // Google Test - The Google C++ Testing Framework
  //
  // This file implements a universal value printer that can print a
  // value of any type T:
  //
  //   void ::testing::internal::UniversalPrinter<T>::Print(value, ostream_ptr);
  //
  // It uses the << operator when possible, and prints the bytes in the
  // object otherwise.  A user can override its behavior for a class
  // type Foo by defining either operator<<(::std::ostream&, const Foo&)
  // or void PrintTo(const Foo&, ::std::ostream*) in the namespace that
  // defines Foo.
  
  #include "gtest/gtest-printers.h"
  #include <ctype.h>
  #include <stdio.h>
  #include <cwchar>
  #include <ostream>  // NOLINT
  #include <string>
  #include "gtest/internal/gtest-port.h"
  
  namespace testing {
  
  namespace {
  
  using ::std::ostream;
  
  // Prints a segment of bytes in the given object.
  GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
  GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
  GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
  void PrintByteSegmentInObjectTo(const unsigned char* obj_bytes, size_t start,
                                  size_t count, ostream* os) {
    char text[5] = "";
    for (size_t i = 0; i != count; i++) {
      const size_t j = start + i;
      if (i != 0) {
        // Organizes the bytes into groups of 2 for easy parsing by
        // human.
        if ((j % 2) == 0)
          *os << ' ';
        else
          *os << '-';
      }
      GTEST_SNPRINTF_(text, sizeof(text), "%02X", obj_bytes[j]);
      *os << text;
    }
  }
  
  // Prints the bytes in the given value to the given ostream.
  void PrintBytesInObjectToImpl(const unsigned char* obj_bytes, size_t count,
                                ostream* os) {
    // Tells the user how big the object is.
    *os << count << "-byte object <";
  
    const size_t kThreshold = 132;
    const size_t kChunkSize = 64;
    // If the object size is bigger than kThreshold, we'll have to omit
    // some details by printing only the first and the last kChunkSize
    // bytes.
    // TODO(wan): let the user control the threshold using a flag.
    if (count < kThreshold) {
      PrintByteSegmentInObjectTo(obj_bytes, 0, count, os);
    } else {
      PrintByteSegmentInObjectTo(obj_bytes, 0, kChunkSize, os);
      *os << " ... ";
      // Rounds up to 2-byte boundary.
      const size_t resume_pos = (count - kChunkSize + 1)/2*2;
      PrintByteSegmentInObjectTo(obj_bytes, resume_pos, count - resume_pos, os);
    }
    *os << ">";
  }
  
  }  // namespace
  
  namespace internal2 {
  
  // Delegates to PrintBytesInObjectToImpl() to print the bytes in the
  // given object.  The delegation simplifies the implementation, which
  // uses the << operator and thus is easier done outside of the
  // ::testing::internal namespace, which contains a << operator that
  // sometimes conflicts with the one in STL.
  void PrintBytesInObjectTo(const unsigned char* obj_bytes, size_t count,
                            ostream* os) {
    PrintBytesInObjectToImpl(obj_bytes, count, os);
  }
  
  }  // namespace internal2
  
  namespace internal {
  
  // Depending on the value of a char (or wchar_t), we print it in one
  // of three formats:
  //   - as is if it's a printable ASCII (e.g. 'a', '2', ' '),
  //   - as a hexidecimal escape sequence (e.g. '\x7F'), or
  //   - as a special escape sequence (e.g. '\r', '\n').
  enum CharFormat {
    kAsIs,
    kHexEscape,
    kSpecialEscape
  };
  
  // Returns true if c is a printable ASCII character.  We test the
  // value of c directly instead of calling isprint(), which is buggy on
  // Windows Mobile.
  inline bool IsPrintableAscii(wchar_t c) {
    return 0x20 <= c && c <= 0x7E;
  }
  
  // Prints a wide or narrow char c as a character literal without the
  // quotes, escaping it when necessary; returns how c was formatted.
  // The template argument UnsignedChar is the unsigned version of Char,
  // which is the type of c.
  template <typename UnsignedChar, typename Char>
  static CharFormat PrintAsCharLiteralTo(Char c, ostream* os) {
    switch (static_cast<wchar_t>(c)) {
      case L'\0':
        *os << "\\0";
        break;
      case L'\'':
        *os << "\\'";
        break;
      case L'\\':
        *os << "\\\\";
        break;
      case L'\a':
        *os << "\\a";
        break;
      case L'\b':
        *os << "\\b";
        break;
      case L'\f':
        *os << "\\f";
        break;
      case L'\n':
        *os << "\\n";
        break;
      case L'\r':
        *os << "\\r";
        break;
      case L'\t':
        *os << "\\t";
        break;
      case L'\v':
        *os << "\\v";
        break;
      default:
        if (IsPrintableAscii(c)) {
          *os << static_cast<char>(c);
          return kAsIs;
        } else {
          *os << "\\x" + String::FormatHexInt(static_cast<UnsignedChar>(c));
          return kHexEscape;
        }
    }
    return kSpecialEscape;
  }
  
  // Prints a wchar_t c as if it's part of a string literal, escaping it when
  // necessary; returns how c was formatted.
  static CharFormat PrintAsStringLiteralTo(wchar_t c, ostream* os) {
    switch (c) {
      case L'\'':
        *os << "'";
        return kAsIs;
      case L'"':
        *os << "\\\"";
        return kSpecialEscape;
      default:
        return PrintAsCharLiteralTo<wchar_t>(c, os);
    }
  }
  
  // Prints a char c as if it's part of a string literal, escaping it when
  // necessary; returns how c was formatted.
  static CharFormat PrintAsStringLiteralTo(char c, ostream* os) {
    return PrintAsStringLiteralTo(
        static_cast<wchar_t>(static_cast<unsigned char>(c)), os);
  }
  
  // Prints a wide or narrow character c and its code.  '\0' is printed
  // as "'\\0'", other unprintable characters are also properly escaped
  // using the standard C++ escape sequence.  The template argument
  // UnsignedChar is the unsigned version of Char, which is the type of c.
  template <typename UnsignedChar, typename Char>
  void PrintCharAndCodeTo(Char c, ostream* os) {
    // First, print c as a literal in the most readable form we can find.
    *os << ((sizeof(c) > 1) ? "L'" : "'");
    const CharFormat format = PrintAsCharLiteralTo<UnsignedChar>(c, os);
    *os << "'";
  
    // To aid user debugging, we also print c's code in decimal, unless
    // it's 0 (in which case c was printed as '\\0', making the code
    // obvious).
    if (c == 0)
      return;
    *os << " (" << static_cast<int>(c);
  
    // For more convenience, we print c's code again in hexidecimal,
    // unless c was already printed in the form '\x##' or the code is in
    // [1, 9].
    if (format == kHexEscape || (1 <= c && c <= 9)) {
      // Do nothing.
    } else {
      *os << ", 0x" << String::FormatHexInt(static_cast<UnsignedChar>(c));
    }
    *os << ")";
  }
  
  void PrintTo(unsigned char c, ::std::ostream* os) {
    PrintCharAndCodeTo<unsigned char>(c, os);
  }
  void PrintTo(signed char c, ::std::ostream* os) {
    PrintCharAndCodeTo<unsigned char>(c, os);
  }
  
  // Prints a wchar_t as a symbol if it is printable or as its internal
  // code otherwise and also as its code.  L'\0' is printed as "L'\\0'".
  void PrintTo(wchar_t wc, ostream* os) {
    PrintCharAndCodeTo<wchar_t>(wc, os);
  }
  
  // Prints the given array of characters to the ostream.  CharType must be either
  // char or wchar_t.
  // The array starts at begin, the length is len, it may include '\0' characters
  // and may not be NUL-terminated.
  template <typename CharType>
  GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
  GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
  GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
  static void PrintCharsAsStringTo(
      const CharType* begin, size_t len, ostream* os) {
    const char* const kQuoteBegin = sizeof(CharType) == 1 ? "\"" : "L\"";
    *os << kQuoteBegin;
    bool is_previous_hex = false;
    for (size_t index = 0; index < len; ++index) {
      const CharType cur = begin[index];
      if (is_previous_hex && IsXDigit(cur)) {
        // Previous character is of '\x..' form and this character can be
        // interpreted as another hexadecimal digit in its number. Break string to
        // disambiguate.
        *os << "\" " << kQuoteBegin;
      }
      is_previous_hex = PrintAsStringLiteralTo(cur, os) == kHexEscape;
    }
    *os << "\"";
  }
  
  // Prints a (const) char/wchar_t array of 'len' elements, starting at address
  // 'begin'.  CharType must be either char or wchar_t.
  template <typename CharType>
  GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
  GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
  GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
  static void UniversalPrintCharArray(
      const CharType* begin, size_t len, ostream* os) {
    // The code
    //   const char kFoo[] = "foo";
    // generates an array of 4, not 3, elements, with the last one being '\0'.
    //
    // Therefore when printing a char array, we don't print the last element if
    // it's '\0', such that the output matches the string literal as it's
    // written in the source code.
    if (len > 0 && begin[len - 1] == '\0') {
      PrintCharsAsStringTo(begin, len - 1, os);
      return;
    }
  
    // If, however, the last element in the array is not '\0', e.g.
    //    const char kFoo[] = { 'f', 'o', 'o' };
    // we must print the entire array.  We also print a message to indicate
    // that the array is not NUL-terminated.
    PrintCharsAsStringTo(begin, len, os);
    *os << " (no terminating NUL)";
  }
  
  // Prints a (const) char array of 'len' elements, starting at address 'begin'.
  void UniversalPrintArray(const char* begin, size_t len, ostream* os) {
    UniversalPrintCharArray(begin, len, os);
  }
  
  // Prints a (const) wchar_t array of 'len' elements, starting at address
  // 'begin'.
  void UniversalPrintArray(const wchar_t* begin, size_t len, ostream* os) {
    UniversalPrintCharArray(begin, len, os);
  }
  
  // Prints the given C string to the ostream.
  void PrintTo(const char* s, ostream* os) {
    if (s == NULL) {
      *os << "NULL";
    } else {
      *os << ImplicitCast_<const void*>(s) << " pointing to ";
      PrintCharsAsStringTo(s, strlen(s), os);
    }
  }
  
  // MSVC compiler can be configured to define whar_t as a typedef
  // of unsigned short. Defining an overload for const wchar_t* in that case
  // would cause pointers to unsigned shorts be printed as wide strings,
  // possibly accessing more memory than intended and causing invalid
  // memory accesses. MSVC defines _NATIVE_WCHAR_T_DEFINED symbol when
  // wchar_t is implemented as a native type.
  #if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
  // Prints the given wide C string to the ostream.
  void PrintTo(const wchar_t* s, ostream* os) {
    if (s == NULL) {
      *os << "NULL";
    } else {
      *os << ImplicitCast_<const void*>(s) << " pointing to ";
      PrintCharsAsStringTo(s, std::wcslen(s), os);
    }
  }
  #endif  // wchar_t is native
  
  // Prints a ::string object.
  #if GTEST_HAS_GLOBAL_STRING
  void PrintStringTo(const ::string& s, ostream* os) {
    PrintCharsAsStringTo(s.data(), s.size(), os);
  }
  #endif  // GTEST_HAS_GLOBAL_STRING
  
  void PrintStringTo(const ::std::string& s, ostream* os) {
    PrintCharsAsStringTo(s.data(), s.size(), os);
  }
  
  // Prints a ::wstring object.
  #if GTEST_HAS_GLOBAL_WSTRING
  void PrintWideStringTo(const ::wstring& s, ostream* os) {
    PrintCharsAsStringTo(s.data(), s.size(), os);
  }
  #endif  // GTEST_HAS_GLOBAL_WSTRING
  
  #if GTEST_HAS_STD_WSTRING
  void PrintWideStringTo(const ::std::wstring& s, ostream* os) {
    PrintCharsAsStringTo(s.data(), s.size(), os);
  }
  #endif  // GTEST_HAS_STD_WSTRING
  
  }  // namespace internal
  
  }  // namespace testing
  