proxygen
gtest-printers.cc
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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 <cwchar>
49 #include <ostream> // NOLINT
50 #include <string>
51 #include "gtest/internal/gtest-port.h"
52 
53 namespace testing {
54 
55 namespace {
56 
57 using ::std::ostream;
58 
59 // Prints a segment of bytes in the given object.
63 void PrintByteSegmentInObjectTo(const unsigned char* obj_bytes, size_t start,
64  size_t count, ostream* os) {
65  char text[5] = "";
66  for (size_t i = 0; i != count; i++) {
67  const size_t j = start + i;
68  if (i != 0) {
69  // Organizes the bytes into groups of 2 for easy parsing by
70  // human.
71  if ((j % 2) == 0)
72  *os << ' ';
73  else
74  *os << '-';
75  }
76  GTEST_SNPRINTF_(text, sizeof(text), "%02X", obj_bytes[j]);
77  *os << text;
78  }
79 }
80 
81 // Prints the bytes in the given value to the given ostream.
82 void PrintBytesInObjectToImpl(const unsigned char* obj_bytes, size_t count,
83  ostream* os) {
84  // Tells the user how big the object is.
85  *os << count << "-byte object <";
86 
87  const size_t kThreshold = 132;
88  const size_t kChunkSize = 64;
89  // If the object size is bigger than kThreshold, we'll have to omit
90  // some details by printing only the first and the last kChunkSize
91  // bytes.
92  // TODO(wan): let the user control the threshold using a flag.
93  if (count < kThreshold) {
94  PrintByteSegmentInObjectTo(obj_bytes, 0, count, os);
95  } else {
96  PrintByteSegmentInObjectTo(obj_bytes, 0, kChunkSize, os);
97  *os << " ... ";
98  // Rounds up to 2-byte boundary.
99  const size_t resume_pos = (count - kChunkSize + 1)/2*2;
100  PrintByteSegmentInObjectTo(obj_bytes, resume_pos, count - resume_pos, os);
101  }
102  *os << ">";
103 }
104 
105 } // namespace
106 
107 namespace internal2 {
108 
109 // Delegates to PrintBytesInObjectToImpl() to print the bytes in the
110 // given object. The delegation simplifies the implementation, which
111 // uses the << operator and thus is easier done outside of the
112 // ::testing::internal namespace, which contains a << operator that
113 // sometimes conflicts with the one in STL.
114 void PrintBytesInObjectTo(const unsigned char* obj_bytes, size_t count,
115  ostream* os) {
116  PrintBytesInObjectToImpl(obj_bytes, count, os);
117 }
118 
119 } // namespace internal2
120 
121 namespace internal {
122 
123 // Depending on the value of a char (or wchar_t), we print it in one
124 // of three formats:
125 // - as is if it's a printable ASCII (e.g. 'a', '2', ' '),
126 // - as a hexidecimal escape sequence (e.g. '\x7F'), or
127 // - as a special escape sequence (e.g. '\r', '\n').
132 };
133 
134 // Returns true if c is a printable ASCII character. We test the
135 // value of c directly instead of calling isprint(), which is buggy on
136 // Windows Mobile.
137 inline bool IsPrintableAscii(wchar_t c) {
138  return 0x20 <= c && c <= 0x7E;
139 }
140 
141 // Prints a wide or narrow char c as a character literal without the
142 // quotes, escaping it when necessary; returns how c was formatted.
143 // The template argument UnsignedChar is the unsigned version of Char,
144 // which is the type of c.
145 template <typename UnsignedChar, typename Char>
146 static CharFormat PrintAsCharLiteralTo(Char c, ostream* os) {
147  switch (static_cast<wchar_t>(c)) {
148  case L'\0':
149  *os << "\\0";
150  break;
151  case L'\'':
152  *os << "\\'";
153  break;
154  case L'\\':
155  *os << "\\\\";
156  break;
157  case L'\a':
158  *os << "\\a";
159  break;
160  case L'\b':
161  *os << "\\b";
162  break;
163  case L'\f':
164  *os << "\\f";
165  break;
166  case L'\n':
167  *os << "\\n";
168  break;
169  case L'\r':
170  *os << "\\r";
171  break;
172  case L'\t':
173  *os << "\\t";
174  break;
175  case L'\v':
176  *os << "\\v";
177  break;
178  default:
179  if (IsPrintableAscii(c)) {
180  *os << static_cast<char>(c);
181  return kAsIs;
182  } else {
183  *os << "\\x" + String::FormatHexInt(static_cast<UnsignedChar>(c));
184  return kHexEscape;
185  }
186  }
187  return kSpecialEscape;
188 }
189 
190 // Prints a wchar_t c as if it's part of a string literal, escaping it when
191 // necessary; returns how c was formatted.
192 static CharFormat PrintAsStringLiteralTo(wchar_t c, ostream* os) {
193  switch (c) {
194  case L'\'':
195  *os << "'";
196  return kAsIs;
197  case L'"':
198  *os << "\\\"";
199  return kSpecialEscape;
200  default:
201  return PrintAsCharLiteralTo<wchar_t>(c, os);
202  }
203 }
204 
205 // Prints a char c as if it's part of a string literal, escaping it when
206 // necessary; returns how c was formatted.
207 static CharFormat PrintAsStringLiteralTo(char c, ostream* os) {
208  return PrintAsStringLiteralTo(
209  static_cast<wchar_t>(static_cast<unsigned char>(c)), os);
210 }
211 
212 // Prints a wide or narrow character c and its code. '\0' is printed
213 // as "'\\0'", other unprintable characters are also properly escaped
214 // using the standard C++ escape sequence. The template argument
215 // UnsignedChar is the unsigned version of Char, which is the type of c.
216 template <typename UnsignedChar, typename Char>
217 void PrintCharAndCodeTo(Char c, ostream* os) {
218  // First, print c as a literal in the most readable form we can find.
219  *os << ((sizeof(c) > 1) ? "L'" : "'");
220  const CharFormat format = PrintAsCharLiteralTo<UnsignedChar>(c, os);
221  *os << "'";
222 
223  // To aid user debugging, we also print c's code in decimal, unless
224  // it's 0 (in which case c was printed as '\\0', making the code
225  // obvious).
226  if (c == 0)
227  return;
228  *os << " (" << static_cast<int>(c);
229 
230  // For more convenience, we print c's code again in hexidecimal,
231  // unless c was already printed in the form '\x##' or the code is in
232  // [1, 9].
233  if (format == kHexEscape || (1 <= c && c <= 9)) {
234  // Do nothing.
235  } else {
236  *os << ", 0x" << String::FormatHexInt(static_cast<UnsignedChar>(c));
237  }
238  *os << ")";
239 }
240 
241 void PrintTo(unsigned char c, ::std::ostream* os) {
242  PrintCharAndCodeTo<unsigned char>(c, os);
243 }
244 void PrintTo(signed char c, ::std::ostream* os) {
245  PrintCharAndCodeTo<unsigned char>(c, os);
246 }
247 
248 // Prints a wchar_t as a symbol if it is printable or as its internal
249 // code otherwise and also as its code. L'\0' is printed as "L'\\0'".
250 void PrintTo(wchar_t wc, ostream* os) {
251  PrintCharAndCodeTo<wchar_t>(wc, os);
252 }
253 
254 // Prints the given array of characters to the ostream. CharType must be either
255 // char or wchar_t.
256 // The array starts at begin, the length is len, it may include '\0' characters
257 // and may not be NUL-terminated.
258 template <typename CharType>
263  const CharType* begin, size_t len, ostream* os) {
264  const char* const kQuoteBegin = sizeof(CharType) == 1 ? "\"" : "L\"";
265  *os << kQuoteBegin;
266  bool is_previous_hex = false;
267  for (size_t index = 0; index < len; ++index) {
268  const CharType cur = begin[index];
269  if (is_previous_hex && IsXDigit(cur)) {
270  // Previous character is of '\x..' form and this character can be
271  // interpreted as another hexadecimal digit in its number. Break string to
272  // disambiguate.
273  *os << "\" " << kQuoteBegin;
274  }
275  is_previous_hex = PrintAsStringLiteralTo(cur, os) == kHexEscape;
276  }
277  *os << "\"";
278 }
279 
280 // Prints a (const) char/wchar_t array of 'len' elements, starting at address
281 // 'begin'. CharType must be either char or wchar_t.
282 template <typename CharType>
287  const CharType* begin, size_t len, ostream* os) {
288  // The code
289  // const char kFoo[] = "foo";
290  // generates an array of 4, not 3, elements, with the last one being '\0'.
291  //
292  // Therefore when printing a char array, we don't print the last element if
293  // it's '\0', such that the output matches the string literal as it's
294  // written in the source code.
295  if (len > 0 && begin[len - 1] == '\0') {
296  PrintCharsAsStringTo(begin, len - 1, os);
297  return;
298  }
299 
300  // If, however, the last element in the array is not '\0', e.g.
301  // const char kFoo[] = { 'f', 'o', 'o' };
302  // we must print the entire array. We also print a message to indicate
303  // that the array is not NUL-terminated.
304  PrintCharsAsStringTo(begin, len, os);
305  *os << " (no terminating NUL)";
306 }
307 
308 // Prints a (const) char array of 'len' elements, starting at address 'begin'.
309 void UniversalPrintArray(const char* begin, size_t len, ostream* os) {
310  UniversalPrintCharArray(begin, len, os);
311 }
312 
313 // Prints a (const) wchar_t array of 'len' elements, starting at address
314 // 'begin'.
315 void UniversalPrintArray(const wchar_t* begin, size_t len, ostream* os) {
316  UniversalPrintCharArray(begin, len, os);
317 }
318 
319 // Prints the given C string to the ostream.
320 void PrintTo(const char* s, ostream* os) {
321  if (s == NULL) {
322  *os << "NULL";
323  } else {
324  *os << ImplicitCast_<const void*>(s) << " pointing to ";
325  PrintCharsAsStringTo(s, strlen(s), os);
326  }
327 }
328 
329 // MSVC compiler can be configured to define whar_t as a typedef
330 // of unsigned short. Defining an overload for const wchar_t* in that case
331 // would cause pointers to unsigned shorts be printed as wide strings,
332 // possibly accessing more memory than intended and causing invalid
333 // memory accesses. MSVC defines _NATIVE_WCHAR_T_DEFINED symbol when
334 // wchar_t is implemented as a native type.
335 #if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
336 // Prints the given wide C string to the ostream.
337 void PrintTo(const wchar_t* s, ostream* os) {
338  if (s == NULL) {
339  *os << "NULL";
340  } else {
341  *os << ImplicitCast_<const void*>(s) << " pointing to ";
342  PrintCharsAsStringTo(s, std::wcslen(s), os);
343  }
344 }
345 #endif // wchar_t is native
346 
347 // Prints a ::string object.
348 #if GTEST_HAS_GLOBAL_STRING
349 void PrintStringTo(const ::string& s, ostream* os) {
350  PrintCharsAsStringTo(s.data(), s.size(), os);
351 }
352 #endif // GTEST_HAS_GLOBAL_STRING
353 
354 void PrintStringTo(const ::std::string& s, ostream* os) {
355  PrintCharsAsStringTo(s.data(), s.size(), os);
356 }
357 
358 // Prints a ::wstring object.
359 #if GTEST_HAS_GLOBAL_WSTRING
360 void PrintWideStringTo(const ::wstring& s, ostream* os) {
361  PrintCharsAsStringTo(s.data(), s.size(), os);
362 }
363 #endif // GTEST_HAS_GLOBAL_WSTRING
364 
365 #if GTEST_HAS_STD_WSTRING
366 void PrintWideStringTo(const ::std::wstring& s, ostream* os) {
367  PrintCharsAsStringTo(s.data(), s.size(), os);
368 }
369 #endif // GTEST_HAS_STD_WSTRING
370 
371 } // namespace internal
372 
373 } // namespace testing
bool IsXDigit(char ch)
Definition: gtest-port.h:2269
void PrintCharAndCodeTo(Char c, ostream *os)
static CharFormat PrintAsStringLiteralTo(char c, ostream *os)
GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_ GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_ static GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_ void UniversalPrintCharArray(const CharType *begin, size_t len, ostream *os)
auto begin(TestAdlIterable &instance)
Definition: ForeachTest.cpp:56
void PrintStringTo(const ::std::string &s, ostream *os)
static CharFormat PrintAsCharLiteralTo(Char c, ostream *os)
GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_ GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_ static GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_ void PrintCharsAsStringTo(const CharType *begin, size_t len, ostream *os)
void PrintTo(const wchar_t *s, ostream *os)
::std::wstring wstring
Definition: gtest-port.h:1103
GTEST_API_ void PrintBytesInObjectTo(const unsigned char *obj_bytes, size_t count,::std::ostream *os)
bool IsPrintableAscii(wchar_t c)
auto start
int * count
const char * string
Definition: Conv.cpp:212
static set< string > s
Formatter< false, Args... > format(StringPiece fmt, Args &&...args)
Definition: Format.h:271
#define GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
Definition: gtest-port.h:961
#define GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
Definition: gtest-port.h:973
char c
void UniversalPrintArray(const wchar_t *begin, size_t len, ostream *os)
#define GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
Definition: gtest-port.h:985
#define GTEST_SNPRINTF_
Definition: gtest-port.h:2429