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29//
30// Author: wan@google.com (Zhanyong Wan)
31
32// Google Test - The Google C++ Testing Framework
33//
34// This file implements a universal value printer that can print a
35// value of any type T:
36//
37//   void ::testing::internal::UniversalPrinter<T>::Print(value, ostream_ptr);
38//
39// It uses the << operator when possible, and prints the bytes in the
40// object otherwise.  A user can override its behavior for a class
41// type Foo by defining either operator<<(::std::ostream&, const Foo&)
42// or void PrintTo(const Foo&, ::std::ostream*) in the namespace that
43// defines Foo.
44
45#include "gtest/gtest-printers.h"
46#include <ctype.h>
47#include <stdio.h>
48#include <ostream>  // NOLINT
49#include <string>
50#include "gtest/internal/gtest-port.h"
51
52namespace testing {
53
54namespace {
55
56using ::std::ostream;
57
58#if GTEST_OS_WINDOWS_MOBILE  // Windows CE does not define _snprintf_s.
59# define snprintf _snprintf
60#elif _MSC_VER >= 1400  // VC 8.0 and later deprecate snprintf and _snprintf.
61# define snprintf _snprintf_s
62#elif _MSC_VER
63# define snprintf _snprintf
64#endif  // GTEST_OS_WINDOWS_MOBILE
65
66// Prints a segment of bytes in the given object.
67void PrintByteSegmentInObjectTo(const unsigned char* obj_bytes, size_t start,
68                                size_t count, ostream* os) {
69  char text[5] = "";
70  for (size_t i = 0; i != count; i++) {
71    const size_t j = start + i;
72    if (i != 0) {
73      // Organizes the bytes into groups of 2 for easy parsing by
74      // human.
75      if ((j % 2) == 0)
76        *os << ' ';
77      else
78        *os << '-';
79    }
80    snprintf(text, sizeof(text), "%02X", obj_bytes[j]);
81    *os << text;
82  }
83}
84
85// Prints the bytes in the given value to the given ostream.
86void PrintBytesInObjectToImpl(const unsigned char* obj_bytes, size_t count,
87                              ostream* os) {
88  // Tells the user how big the object is.
89  *os << count << "-byte object <";
90
91  const size_t kThreshold = 132;
92  const size_t kChunkSize = 64;
93  // If the object size is bigger than kThreshold, we'll have to omit
94  // some details by printing only the first and the last kChunkSize
95  // bytes.
96  // TODO(wan): let the user control the threshold using a flag.
97  if (count < kThreshold) {
98    PrintByteSegmentInObjectTo(obj_bytes, 0, count, os);
99  } else {
100    PrintByteSegmentInObjectTo(obj_bytes, 0, kChunkSize, os);
101    *os << " ... ";
102    // Rounds up to 2-byte boundary.
103    const size_t resume_pos = (count - kChunkSize + 1)/2*2;
104    PrintByteSegmentInObjectTo(obj_bytes, resume_pos, count - resume_pos, os);
105  }
106  *os << ">";
107}
108
109}  // namespace
110
111namespace internal2 {
112
113// Delegates to PrintBytesInObjectToImpl() to print the bytes in the
114// given object.  The delegation simplifies the implementation, which
115// uses the << operator and thus is easier done outside of the
116// ::testing::internal namespace, which contains a << operator that
117// sometimes conflicts with the one in STL.
118void PrintBytesInObjectTo(const unsigned char* obj_bytes, size_t count,
119                          ostream* os) {
120  PrintBytesInObjectToImpl(obj_bytes, count, os);
121}
122
123}  // namespace internal2
124
125namespace internal {
126
127// Depending on the value of a char (or wchar_t), we print it in one
128// of three formats:
129//   - as is if it's a printable ASCII (e.g. 'a', '2', ' '),
130//   - as a hexadecimal escape sequence (e.g. '\x7F'), or
131//   - as a special escape sequence (e.g. '\r', '\n').
132enum CharFormat {
133  kAsIs,
134  kHexEscape,
135  kSpecialEscape
136};
137
138// Returns true if c is a printable ASCII character.  We test the
139// value of c directly instead of calling isprint(), which is buggy on
140// Windows Mobile.
141inline bool IsPrintableAscii(wchar_t c) {
142  return 0x20 <= c && c <= 0x7E;
143}
144
145// Prints a wide or narrow char c as a character literal without the
146// quotes, escaping it when necessary; returns how c was formatted.
147// The template argument UnsignedChar is the unsigned version of Char,
148// which is the type of c.
149template <typename UnsignedChar, typename Char>
150static CharFormat PrintAsCharLiteralTo(Char c, ostream* os) {
151  switch (static_cast<wchar_t>(c)) {
152    case L'\0':
153      *os << "\\0";
154      break;
155    case L'\'':
156      *os << "\\'";
157      break;
158    case L'\\':
159      *os << "\\\\";
160      break;
161    case L'\a':
162      *os << "\\a";
163      break;
164    case L'\b':
165      *os << "\\b";
166      break;
167    case L'\f':
168      *os << "\\f";
169      break;
170    case L'\n':
171      *os << "\\n";
172      break;
173    case L'\r':
174      *os << "\\r";
175      break;
176    case L'\t':
177      *os << "\\t";
178      break;
179    case L'\v':
180      *os << "\\v";
181      break;
182    default:
183      if (IsPrintableAscii(c)) {
184        *os << static_cast<char>(c);
185        return kAsIs;
186      } else {
187        *os << String::Format("\\x%X", static_cast<UnsignedChar>(c));
188        return kHexEscape;
189      }
190  }
191  return kSpecialEscape;
192}
193
194// Prints a char c as if it's part of a string literal, escaping it when
195// necessary; returns how c was formatted.
196static CharFormat PrintAsWideStringLiteralTo(wchar_t c, ostream* os) {
197  switch (c) {
198    case L'\'':
199      *os << "'";
200      return kAsIs;
201    case L'"':
202      *os << "\\\"";
203      return kSpecialEscape;
204    default:
205      return PrintAsCharLiteralTo<wchar_t>(c, os);
206  }
207}
208
209// Prints a char c as if it's part of a string literal, escaping it when
210// necessary; returns how c was formatted.
211static CharFormat PrintAsNarrowStringLiteralTo(char c, ostream* os) {
212  return PrintAsWideStringLiteralTo(static_cast<unsigned char>(c), os);
213}
214
215// Prints a wide or narrow character c and its code.  '\0' is printed
216// as "'\\0'", other unprintable characters are also properly escaped
217// using the standard C++ escape sequence.  The template argument
218// UnsignedChar is the unsigned version of Char, which is the type of c.
219template <typename UnsignedChar, typename Char>
220void PrintCharAndCodeTo(Char c, ostream* os) {
221  // First, print c as a literal in the most readable form we can find.
222  *os << ((sizeof(c) > 1) ? "L'" : "'");
223  const CharFormat format = PrintAsCharLiteralTo<UnsignedChar>(c, os);
224  *os << "'";
225
226  // To aid user debugging, we also print c's code in decimal, unless
227  // it's 0 (in which case c was printed as '\\0', making the code
228  // obvious).
229  if (c == 0)
230    return;
231  *os << " (" << String::Format("%d", c).c_str();
232
233  // For more convenience, we print c's code again in hexadecimal,
234  // unless c was already printed in the form '\x##' or the code is in
235  // [1, 9].
236  if (format == kHexEscape || (1 <= c && c <= 9)) {
237    // Do nothing.
238  } else {
239    *os << String::Format(", 0x%X",
240                          static_cast<UnsignedChar>(c)).c_str();
241  }
242  *os << ")";
243}
244
245void PrintTo(unsigned char c, ::std::ostream* os) {
246  PrintCharAndCodeTo<unsigned char>(c, os);
247}
248void PrintTo(signed char c, ::std::ostream* os) {
249  PrintCharAndCodeTo<unsigned char>(c, os);
250}
251
252// Prints a wchar_t as a symbol if it is printable or as its internal
253// code otherwise and also as its code.  L'\0' is printed as "L'\\0'".
254void PrintTo(wchar_t wc, ostream* os) {
255  PrintCharAndCodeTo<wchar_t>(wc, os);
256}
257
258// Prints the given array of characters to the ostream.
259// The array starts at *begin, the length is len, it may include '\0' characters
260// and may not be null-terminated.
261static void PrintCharsAsStringTo(const char* begin, size_t len, ostream* os) {
262  *os << "\"";
263  bool is_previous_hex = false;
264  for (size_t index = 0; index < len; ++index) {
265    const char cur = begin[index];
266    if (is_previous_hex && IsXDigit(cur)) {
267      // Previous character is of '\x..' form and this character can be
268      // interpreted as another hexadecimal digit in its number. Break string to
269      // disambiguate.
270      *os << "\" \"";
271    }
272    is_previous_hex = PrintAsNarrowStringLiteralTo(cur, os) == kHexEscape;
273  }
274  *os << "\"";
275}
276
277// Prints a (const) char array of 'len' elements, starting at address 'begin'.
278void UniversalPrintArray(const char* begin, size_t len, ostream* os) {
279  PrintCharsAsStringTo(begin, len, os);
280}
281
282// Prints the given array of wide characters to the ostream.
283// The array starts at *begin, the length is len, it may include L'\0'
284// characters and may not be null-terminated.
285static void PrintWideCharsAsStringTo(const wchar_t* begin, size_t len,
286                                     ostream* os) {
287  *os << "L\"";
288  bool is_previous_hex = false;
289  for (size_t index = 0; index < len; ++index) {
290    const wchar_t cur = begin[index];
291    if (is_previous_hex && isascii(cur) && IsXDigit(static_cast<char>(cur))) {
292      // Previous character is of '\x..' form and this character can be
293      // interpreted as another hexadecimal digit in its number. Break string to
294      // disambiguate.
295      *os << "\" L\"";
296    }
297    is_previous_hex = PrintAsWideStringLiteralTo(cur, os) == kHexEscape;
298  }
299  *os << "\"";
300}
301
302// Prints the given C string to the ostream.
303void PrintTo(const char* s, ostream* os) {
304  if (s == NULL) {
305    *os << "NULL";
306  } else {
307    *os << ImplicitCast_<const void*>(s) << " pointing to ";
308    PrintCharsAsStringTo(s, strlen(s), os);
309  }
310}
311
312// MSVC compiler can be configured to define whar_t as a typedef
313// of unsigned short. Defining an overload for const wchar_t* in that case
314// would cause pointers to unsigned shorts be printed as wide strings,
315// possibly accessing more memory than intended and causing invalid
316// memory accesses. MSVC defines _NATIVE_WCHAR_T_DEFINED symbol when
317// wchar_t is implemented as a native type.
318#if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
319// Prints the given wide C string to the ostream.
320void PrintTo(const wchar_t* s, ostream* os) {
321  if (s == NULL) {
322    *os << "NULL";
323  } else {
324    *os << ImplicitCast_<const void*>(s) << " pointing to ";
325    PrintWideCharsAsStringTo(s, wcslen(s), os);
326  }
327}
328#endif  // wchar_t is native
329
330// Prints a ::string object.
331#if GTEST_HAS_GLOBAL_STRING
332void PrintStringTo(const ::string& s, ostream* os) {
333  PrintCharsAsStringTo(s.data(), s.size(), os);
334}
335#endif  // GTEST_HAS_GLOBAL_STRING
336
337void PrintStringTo(const ::std::string& s, ostream* os) {
338  PrintCharsAsStringTo(s.data(), s.size(), os);
339}
340
341// Prints a ::wstring object.
342#if GTEST_HAS_GLOBAL_WSTRING
343void PrintWideStringTo(const ::wstring& s, ostream* os) {
344  PrintWideCharsAsStringTo(s.data(), s.size(), os);
345}
346#endif  // GTEST_HAS_GLOBAL_WSTRING
347
348#if GTEST_HAS_STD_WSTRING
349void PrintWideStringTo(const ::std::wstring& s, ostream* os) {
350  PrintWideCharsAsStringTo(s.data(), s.size(), os);
351}
352#endif  // GTEST_HAS_STD_WSTRING
353
354}  // namespace internal
355
356}  // namespace testing
357