1/*
2 * Copyright 2014 Google Inc. All rights reserved.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef FLATBUFFERS_UTIL_H_
18#define FLATBUFFERS_UTIL_H_
19
20#include <errno.h>
21
22#include "flatbuffers/base.h"
23#include "flatbuffers/stl_emulation.h"
24
25#ifndef FLATBUFFERS_PREFER_PRINTF
26# include <sstream>
27#else // FLATBUFFERS_PREFER_PRINTF
28# include <float.h>
29# include <stdio.h>
30#endif // FLATBUFFERS_PREFER_PRINTF
31
32#include <iomanip>
33#include <string>
34
35namespace flatbuffers {
36
37// @locale-independent functions for ASCII characters set.
38
39// Fast checking that character lies in closed range: [a <= x <= b]
40// using one compare (conditional branch) operator.
41inline bool check_ascii_range(char x, char a, char b) {
42 FLATBUFFERS_ASSERT(a <= b);
43 // (Hacker's Delight): `a <= x <= b` <=> `(x-a) <={u} (b-a)`.
44 // The x, a, b will be promoted to int and subtracted without overflow.
45 return static_cast<unsigned int>(x - a) <= static_cast<unsigned int>(b - a);
46}
47
48// Case-insensitive isalpha
49inline bool is_alpha(char c) {
50 // ASCII only: alpha to upper case => reset bit 0x20 (~0x20 = 0xDF).
51 return check_ascii_range(c & 0xDF, 'a' & 0xDF, 'z' & 0xDF);
52}
53
54// Check for uppercase alpha
55inline bool is_alpha_upper(char c) { return check_ascii_range(c, 'A', 'Z'); }
56
57// Check (case-insensitive) that `c` is equal to alpha.
58inline bool is_alpha_char(char c, char alpha) {
59 FLATBUFFERS_ASSERT(is_alpha(alpha));
60 // ASCII only: alpha to upper case => reset bit 0x20 (~0x20 = 0xDF).
61 return ((c & 0xDF) == (alpha & 0xDF));
62}
63
64// https://en.cppreference.com/w/cpp/string/byte/isxdigit
65// isdigit and isxdigit are the only standard narrow character classification
66// functions that are not affected by the currently installed C locale. although
67// some implementations (e.g. Microsoft in 1252 codepage) may classify
68// additional single-byte characters as digits.
69inline bool is_digit(char c) { return check_ascii_range(c, '0', '9'); }
70
71inline bool is_xdigit(char c) {
72 // Replace by look-up table.
73 return is_digit(c) || check_ascii_range(c & 0xDF, 'a' & 0xDF, 'f' & 0xDF);
74}
75
76// Case-insensitive isalnum
77inline bool is_alnum(char c) { return is_alpha(c) || is_digit(c); }
78
79inline char CharToUpper(char c) {
80 return static_cast<char>(::toupper(static_cast<unsigned char>(c)));
81}
82
83inline char CharToLower(char c) {
84 return static_cast<char>(::tolower(static_cast<unsigned char>(c)));
85}
86
87// @end-locale-independent functions for ASCII character set
88
89#ifdef FLATBUFFERS_PREFER_PRINTF
90template<typename T> size_t IntToDigitCount(T t) {
91 size_t digit_count = 0;
92 // Count the sign for negative numbers
93 if (t < 0) digit_count++;
94 // Count a single 0 left of the dot for fractional numbers
95 if (-1 < t && t < 1) digit_count++;
96 // Count digits until fractional part
97 T eps = std::numeric_limits<float>::epsilon();
98 while (t <= (-1 + eps) || (1 - eps) <= t) {
99 t /= 10;
100 digit_count++;
101 }
102 return digit_count;
103}
104
105template<typename T> size_t NumToStringWidth(T t, int precision = 0) {
106 size_t string_width = IntToDigitCount(t);
107 // Count the dot for floating point numbers
108 if (precision) string_width += (precision + 1);
109 return string_width;
110}
111
112template<typename T>
113std::string NumToStringImplWrapper(T t, const char *fmt, int precision = 0) {
114 size_t string_width = NumToStringWidth(t, precision);
115 std::string s(string_width, 0x00);
116 // Allow snprintf to use std::string trailing null to detect buffer overflow
117 snprintf(const_cast<char *>(s.data()), (s.size() + 1), fmt, string_width, t);
118 return s;
119}
120#endif // FLATBUFFERS_PREFER_PRINTF
121
122// Convert an integer or floating point value to a string.
123// In contrast to std::stringstream, "char" values are
124// converted to a string of digits, and we don't use scientific notation.
125template<typename T> std::string NumToString(T t) {
126 // clang-format off
127
128 #ifndef FLATBUFFERS_PREFER_PRINTF
129 std::stringstream ss;
130 ss << t;
131 return ss.str();
132 #else // FLATBUFFERS_PREFER_PRINTF
133 auto v = static_cast<long long>(t);
134 return NumToStringImplWrapper(v, "%.*lld");
135 #endif // FLATBUFFERS_PREFER_PRINTF
136 // clang-format on
137}
138// Avoid char types used as character data.
139template<> inline std::string NumToString<signed char>(signed char t) {
140 return NumToString(static_cast<int>(t));
141}
142template<> inline std::string NumToString<unsigned char>(unsigned char t) {
143 return NumToString(static_cast<int>(t));
144}
145template<> inline std::string NumToString<char>(char t) {
146 return NumToString(static_cast<int>(t));
147}
148#if defined(FLATBUFFERS_CPP98_STL)
149template<> inline std::string NumToString<long long>(long long t) {
150 char buf[21]; // (log((1 << 63) - 1) / log(10)) + 2
151 snprintf(buf, sizeof(buf), "%lld", t);
152 return std::string(buf);
153}
154
155template<>
156inline std::string NumToString<unsigned long long>(unsigned long long t) {
157 char buf[22]; // (log((1 << 63) - 1) / log(10)) + 1
158 snprintf(buf, sizeof(buf), "%llu", t);
159 return std::string(buf);
160}
161#endif // defined(FLATBUFFERS_CPP98_STL)
162
163// Special versions for floats/doubles.
164template<typename T> std::string FloatToString(T t, int precision) {
165 // clang-format off
166
167 #ifndef FLATBUFFERS_PREFER_PRINTF
168 // to_string() prints different numbers of digits for floats depending on
169 // platform and isn't available on Android, so we use stringstream
170 std::stringstream ss;
171 // Use std::fixed to suppress scientific notation.
172 ss << std::fixed;
173 // Default precision is 6, we want that to be higher for doubles.
174 ss << std::setprecision(precision);
175 ss << t;
176 auto s = ss.str();
177 #else // FLATBUFFERS_PREFER_PRINTF
178 auto v = static_cast<double>(t);
179 auto s = NumToStringImplWrapper(v, "%0.*f", precision);
180 #endif // FLATBUFFERS_PREFER_PRINTF
181 // clang-format on
182 // Sadly, std::fixed turns "1" into "1.00000", so here we undo that.
183 auto p = s.find_last_not_of('0');
184 if (p != std::string::npos) {
185 // Strip trailing zeroes. If it is a whole number, keep one zero.
186 s.resize(p + (s[p] == '.' ? 2 : 1));
187 }
188 return s;
189}
190
191template<> inline std::string NumToString<double>(double t) {
192 return FloatToString(t, 12);
193}
194template<> inline std::string NumToString<float>(float t) {
195 return FloatToString(t, 6);
196}
197
198// Convert an integer value to a hexadecimal string.
199// The returned string length is always xdigits long, prefixed by 0 digits.
200// For example, IntToStringHex(0x23, 8) returns the string "00000023".
201inline std::string IntToStringHex(int i, int xdigits) {
202 FLATBUFFERS_ASSERT(i >= 0);
203 // clang-format off
204
205 #ifndef FLATBUFFERS_PREFER_PRINTF
206 std::stringstream ss;
207 ss << std::setw(xdigits) << std::setfill('0') << std::hex << std::uppercase
208 << i;
209 return ss.str();
210 #else // FLATBUFFERS_PREFER_PRINTF
211 return NumToStringImplWrapper(i, "%.*X", xdigits);
212 #endif // FLATBUFFERS_PREFER_PRINTF
213 // clang-format on
214}
215
216// clang-format off
217// Use locale independent functions {strtod_l, strtof_l, strtoll_l, strtoull_l}.
218#if defined(FLATBUFFERS_LOCALE_INDEPENDENT) && (FLATBUFFERS_LOCALE_INDEPENDENT > 0)
219 class ClassicLocale {
220 #ifdef _MSC_VER
221 typedef _locale_t locale_type;
222 #else
223 typedef locale_t locale_type; // POSIX.1-2008 locale_t type
224 #endif
225 ClassicLocale();
226 ~ClassicLocale();
227 locale_type locale_;
228 static ClassicLocale instance_;
229 public:
230 static locale_type Get() { return instance_.locale_; }
231 };
232
233 #ifdef _MSC_VER
234 #define __strtoull_impl(s, pe, b) _strtoui64_l(s, pe, b, ClassicLocale::Get())
235 #define __strtoll_impl(s, pe, b) _strtoi64_l(s, pe, b, ClassicLocale::Get())
236 #define __strtod_impl(s, pe) _strtod_l(s, pe, ClassicLocale::Get())
237 #define __strtof_impl(s, pe) _strtof_l(s, pe, ClassicLocale::Get())
238 #else
239 #define __strtoull_impl(s, pe, b) strtoull_l(s, pe, b, ClassicLocale::Get())
240 #define __strtoll_impl(s, pe, b) strtoll_l(s, pe, b, ClassicLocale::Get())
241 #define __strtod_impl(s, pe) strtod_l(s, pe, ClassicLocale::Get())
242 #define __strtof_impl(s, pe) strtof_l(s, pe, ClassicLocale::Get())
243 #endif
244#else
245 #define __strtod_impl(s, pe) strtod(s, pe)
246 #define __strtof_impl(s, pe) static_cast<float>(strtod(s, pe))
247 #ifdef _MSC_VER
248 #define __strtoull_impl(s, pe, b) _strtoui64(s, pe, b)
249 #define __strtoll_impl(s, pe, b) _strtoi64(s, pe, b)
250 #else
251 #define __strtoull_impl(s, pe, b) strtoull(s, pe, b)
252 #define __strtoll_impl(s, pe, b) strtoll(s, pe, b)
253 #endif
254#endif
255
256inline void strtoval_impl(int64_t *val, const char *str, char **endptr,
257 int base) {
258 *val = __strtoll_impl(str, endptr, base);
259}
260
261inline void strtoval_impl(uint64_t *val, const char *str, char **endptr,
262 int base) {
263 *val = __strtoull_impl(str, endptr, base);
264}
265
266inline void strtoval_impl(double *val, const char *str, char **endptr) {
267 *val = __strtod_impl(str, endptr);
268}
269
270// UBSAN: double to float is safe if numeric_limits<float>::is_iec559 is true.
271__supress_ubsan__("float-cast-overflow")
272inline void strtoval_impl(float *val, const char *str, char **endptr) {
273 *val = __strtof_impl(str, endptr);
274}
275#undef __strtoull_impl
276#undef __strtoll_impl
277#undef __strtod_impl
278#undef __strtof_impl
279// clang-format on
280
281// Adaptor for strtoull()/strtoll().
282// Flatbuffers accepts numbers with any count of leading zeros (-009 is -9),
283// while strtoll with base=0 interprets first leading zero as octal prefix.
284// In future, it is possible to add prefixed 0b0101.
285// 1) Checks errno code for overflow condition (out of range).
286// 2) If base <= 0, function try to detect base of number by prefix.
287//
288// Return value (like strtoull and strtoll, but reject partial result):
289// - If successful, an integer value corresponding to the str is returned.
290// - If full string conversion can't be performed, 0 is returned.
291// - If the converted value falls out of range of corresponding return type, a
292// range error occurs. In this case value MAX(T)/MIN(T) is returned.
293template<typename T>
294inline bool StringToIntegerImpl(T *val, const char *const str,
295 const int base = 0,
296 const bool check_errno = true) {
297 // T is int64_t or uint64_T
298 FLATBUFFERS_ASSERT(str);
299 if (base <= 0) {
300 auto s = str;
301 while (*s && !is_digit(*s)) s++;
302 if (s[0] == '0' && is_alpha_char(s[1], 'X'))
303 return StringToIntegerImpl(val, str, 16, check_errno);
304 // if a prefix not match, try base=10
305 return StringToIntegerImpl(val, str, 10, check_errno);
306 } else {
307 if (check_errno) errno = 0; // clear thread-local errno
308 auto endptr = str;
309 strtoval_impl(val, str, const_cast<char **>(&endptr), base);
310 if ((*endptr != '\0') || (endptr == str)) {
311 *val = 0; // erase partial result
312 return false; // invalid string
313 }
314 // errno is out-of-range, return MAX/MIN
315 if (check_errno && errno) return false;
316 return true;
317 }
318}
319
320template<typename T>
321inline bool StringToFloatImpl(T *val, const char *const str) {
322 // Type T must be either float or double.
323 FLATBUFFERS_ASSERT(str && val);
324 auto end = str;
325 strtoval_impl(val, str, const_cast<char **>(&end));
326 auto done = (end != str) && (*end == '\0');
327 if (!done) *val = 0; // erase partial result
328 return done;
329}
330
331// Convert a string to an instance of T.
332// Return value (matched with StringToInteger64Impl and strtod):
333// - If successful, a numeric value corresponding to the str is returned.
334// - If full string conversion can't be performed, 0 is returned.
335// - If the converted value falls out of range of corresponding return type, a
336// range error occurs. In this case value MAX(T)/MIN(T) is returned.
337template<typename T> inline bool StringToNumber(const char *s, T *val) {
338 // Assert on `unsigned long` and `signed long` on LP64.
339 // If it is necessary, it could be solved with flatbuffers::enable_if<B,T>.
340 static_assert(sizeof(T) < sizeof(int64_t), "unexpected type T");
341 FLATBUFFERS_ASSERT(s && val);
342 int64_t i64;
343 // The errno check isn't needed, will return MAX/MIN on overflow.
344 if (StringToIntegerImpl(&i64, s, 0, false)) {
345 const int64_t max = (flatbuffers::numeric_limits<T>::max)();
346 const int64_t min = flatbuffers::numeric_limits<T>::lowest();
347 if (i64 > max) {
348 *val = static_cast<T>(max);
349 return false;
350 }
351 if (i64 < min) {
352 // For unsigned types return max to distinguish from
353 // "no conversion can be performed" when 0 is returned.
354 *val = static_cast<T>(flatbuffers::is_unsigned<T>::value ? max : min);
355 return false;
356 }
357 *val = static_cast<T>(i64);
358 return true;
359 }
360 *val = 0;
361 return false;
362}
363
364template<> inline bool StringToNumber<int64_t>(const char *str, int64_t *val) {
365 return StringToIntegerImpl(val, str);
366}
367
368template<>
369inline bool StringToNumber<uint64_t>(const char *str, uint64_t *val) {
370 if (!StringToIntegerImpl(val, str)) return false;
371 // The strtoull accepts negative numbers:
372 // If the minus sign was part of the input sequence, the numeric value
373 // calculated from the sequence of digits is negated as if by unary minus
374 // in the result type, which applies unsigned integer wraparound rules.
375 // Fix this behaviour (except -0).
376 if (*val) {
377 auto s = str;
378 while (*s && !is_digit(*s)) s++;
379 s = (s > str) ? (s - 1) : s; // step back to one symbol
380 if (*s == '-') {
381 // For unsigned types return the max to distinguish from
382 // "no conversion can be performed".
383 *val = (flatbuffers::numeric_limits<uint64_t>::max)();
384 return false;
385 }
386 }
387 return true;
388}
389
390template<> inline bool StringToNumber(const char *s, float *val) {
391 return StringToFloatImpl(val, s);
392}
393
394template<> inline bool StringToNumber(const char *s, double *val) {
395 return StringToFloatImpl(val, s);
396}
397
398inline int64_t StringToInt(const char *s, int base = 10) {
399 int64_t val;
400 return StringToIntegerImpl(&val, s, base) ? val : 0;
401}
402
403inline uint64_t StringToUInt(const char *s, int base = 10) {
404 uint64_t val;
405 return StringToIntegerImpl(&val, s, base) ? val : 0;
406}
407
408typedef bool (*LoadFileFunction)(const char *filename, bool binary,
409 std::string *dest);
410typedef bool (*FileExistsFunction)(const char *filename);
411
412LoadFileFunction SetLoadFileFunction(LoadFileFunction load_file_function);
413
414FileExistsFunction SetFileExistsFunction(
415 FileExistsFunction file_exists_function);
416
417// Check if file "name" exists.
418bool FileExists(const char *name);
419
420// Check if "name" exists and it is also a directory.
421bool DirExists(const char *name);
422
423// Load file "name" into "buf" returning true if successful
424// false otherwise. If "binary" is false data is read
425// using ifstream's text mode, otherwise data is read with
426// no transcoding.
427bool LoadFile(const char *name, bool binary, std::string *buf);
428
429// Save data "buf" of length "len" bytes into a file
430// "name" returning true if successful, false otherwise.
431// If "binary" is false data is written using ifstream's
432// text mode, otherwise data is written with no
433// transcoding.
434bool SaveFile(const char *name, const char *buf, size_t len, bool binary);
435
436// Save data "buf" into file "name" returning true if
437// successful, false otherwise. If "binary" is false
438// data is written using ifstream's text mode, otherwise
439// data is written with no transcoding.
440inline bool SaveFile(const char *name, const std::string &buf, bool binary) {
441 return SaveFile(name, buf.c_str(), buf.size(), binary);
442}
443
444// Functionality for minimalistic portable path handling.
445
446// The functions below behave correctly regardless of whether posix ('/') or
447// Windows ('/' or '\\') separators are used.
448
449// Any new separators inserted are always posix.
450FLATBUFFERS_CONSTEXPR char kPathSeparator = '/';
451
452// Returns the path with the extension, if any, removed.
453std::string StripExtension(const std::string &filepath);
454
455// Returns the extension, if any.
456std::string GetExtension(const std::string &filepath);
457
458// Return the last component of the path, after the last separator.
459std::string StripPath(const std::string &filepath);
460
461// Strip the last component of the path + separator.
462std::string StripFileName(const std::string &filepath);
463
464// Concatenates a path with a filename, regardless of whether the path
465// ends in a separator or not.
466std::string ConCatPathFileName(const std::string &path,
467 const std::string &filename);
468
469// Replaces any '\\' separators with '/'
470std::string PosixPath(const char *path);
471
472// This function ensure a directory exists, by recursively
473// creating dirs for any parts of the path that don't exist yet.
474void EnsureDirExists(const std::string &filepath);
475
476// Obtains the absolute path from any other path.
477// Returns the input path if the absolute path couldn't be resolved.
478std::string AbsolutePath(const std::string &filepath);
479
480// To and from UTF-8 unicode conversion functions
481
482// Convert a unicode code point into a UTF-8 representation by appending it
483// to a string. Returns the number of bytes generated.
484inline int ToUTF8(uint32_t ucc, std::string *out) {
485 FLATBUFFERS_ASSERT(!(ucc & 0x80000000)); // Top bit can't be set.
486 // 6 possible encodings: http://en.wikipedia.org/wiki/UTF-8
487 for (int i = 0; i < 6; i++) {
488 // Max bits this encoding can represent.
489 uint32_t max_bits = 6 + i * 5 + static_cast<int>(!i);
490 if (ucc < (1u << max_bits)) { // does it fit?
491 // Remaining bits not encoded in the first byte, store 6 bits each
492 uint32_t remain_bits = i * 6;
493 // Store first byte:
494 (*out) += static_cast<char>((0xFE << (max_bits - remain_bits)) |
495 (ucc >> remain_bits));
496 // Store remaining bytes:
497 for (int j = i - 1; j >= 0; j--) {
498 (*out) += static_cast<char>(((ucc >> (j * 6)) & 0x3F) | 0x80);
499 }
500 return i + 1; // Return the number of bytes added.
501 }
502 }
503 FLATBUFFERS_ASSERT(0); // Impossible to arrive here.
504 return -1;
505}
506
507// Converts whatever prefix of the incoming string corresponds to a valid
508// UTF-8 sequence into a unicode code. The incoming pointer will have been
509// advanced past all bytes parsed.
510// returns -1 upon corrupt UTF-8 encoding (ignore the incoming pointer in
511// this case).
512inline int FromUTF8(const char **in) {
513 int len = 0;
514 // Count leading 1 bits.
515 for (int mask = 0x80; mask >= 0x04; mask >>= 1) {
516 if (**in & mask) {
517 len++;
518 } else {
519 break;
520 }
521 }
522 if ((static_cast<unsigned char>(**in) << len) & 0x80)
523 return -1; // Bit after leading 1's must be 0.
524 if (!len) return *(*in)++;
525 // UTF-8 encoded values with a length are between 2 and 4 bytes.
526 if (len < 2 || len > 4) { return -1; }
527 // Grab initial bits of the code.
528 int ucc = *(*in)++ & ((1 << (7 - len)) - 1);
529 for (int i = 0; i < len - 1; i++) {
530 if ((**in & 0xC0) != 0x80) return -1; // Upper bits must 1 0.
531 ucc <<= 6;
532 ucc |= *(*in)++ & 0x3F; // Grab 6 more bits of the code.
533 }
534 // UTF-8 cannot encode values between 0xD800 and 0xDFFF (reserved for
535 // UTF-16 surrogate pairs).
536 if (ucc >= 0xD800 && ucc <= 0xDFFF) { return -1; }
537 // UTF-8 must represent code points in their shortest possible encoding.
538 switch (len) {
539 case 2:
540 // Two bytes of UTF-8 can represent code points from U+0080 to U+07FF.
541 if (ucc < 0x0080 || ucc > 0x07FF) { return -1; }
542 break;
543 case 3:
544 // Three bytes of UTF-8 can represent code points from U+0800 to U+FFFF.
545 if (ucc < 0x0800 || ucc > 0xFFFF) { return -1; }
546 break;
547 case 4:
548 // Four bytes of UTF-8 can represent code points from U+10000 to U+10FFFF.
549 if (ucc < 0x10000 || ucc > 0x10FFFF) { return -1; }
550 break;
551 }
552 return ucc;
553}
554
555#ifndef FLATBUFFERS_PREFER_PRINTF
556// Wraps a string to a maximum length, inserting new lines where necessary. Any
557// existing whitespace will be collapsed down to a single space. A prefix or
558// suffix can be provided, which will be inserted before or after a wrapped
559// line, respectively.
560inline std::string WordWrap(const std::string in, size_t max_length,
561 const std::string wrapped_line_prefix,
562 const std::string wrapped_line_suffix) {
563 std::istringstream in_stream(in);
564 std::string wrapped, line, word;
565
566 in_stream >> word;
567 line = word;
568
569 while (in_stream >> word) {
570 if ((line.length() + 1 + word.length() + wrapped_line_suffix.length()) <
571 max_length) {
572 line += " " + word;
573 } else {
574 wrapped += line + wrapped_line_suffix + "\n";
575 line = wrapped_line_prefix + word;
576 }
577 }
578 wrapped += line;
579
580 return wrapped;
581}
582#endif // !FLATBUFFERS_PREFER_PRINTF
583
584inline bool EscapeString(const char *s, size_t length, std::string *_text,
585 bool allow_non_utf8, bool natural_utf8) {
586 std::string &text = *_text;
587 text += "\"";
588 for (uoffset_t i = 0; i < length; i++) {
589 char c = s[i];
590 switch (c) {
591 case '\n': text += "\\n"; break;
592 case '\t': text += "\\t"; break;
593 case '\r': text += "\\r"; break;
594 case '\b': text += "\\b"; break;
595 case '\f': text += "\\f"; break;
596 case '\"': text += "\\\""; break;
597 case '\\': text += "\\\\"; break;
598 default:
599 if (c >= ' ' && c <= '~') {
600 text += c;
601 } else {
602 // Not printable ASCII data. Let's see if it's valid UTF-8 first:
603 const char *utf8 = s + i;
604 int ucc = FromUTF8(&utf8);
605 if (ucc < 0) {
606 if (allow_non_utf8) {
607 text += "\\x";
608 text += IntToStringHex(static_cast<uint8_t>(c), 2);
609 } else {
610 // There are two cases here:
611 //
612 // 1) We reached here by parsing an IDL file. In that case,
613 // we previously checked for non-UTF-8, so we shouldn't reach
614 // here.
615 //
616 // 2) We reached here by someone calling GenerateText()
617 // on a previously-serialized flatbuffer. The data might have
618 // non-UTF-8 Strings, or might be corrupt.
619 //
620 // In both cases, we have to give up and inform the caller
621 // they have no JSON.
622 return false;
623 }
624 } else {
625 if (natural_utf8) {
626 // utf8 points to past all utf-8 bytes parsed
627 text.append(s + i, static_cast<size_t>(utf8 - s - i));
628 } else if (ucc <= 0xFFFF) {
629 // Parses as Unicode within JSON's \uXXXX range, so use that.
630 text += "\\u";
631 text += IntToStringHex(ucc, 4);
632 } else if (ucc <= 0x10FFFF) {
633 // Encode Unicode SMP values to a surrogate pair using two \u
634 // escapes.
635 uint32_t base = ucc - 0x10000;
636 auto high_surrogate = (base >> 10) + 0xD800;
637 auto low_surrogate = (base & 0x03FF) + 0xDC00;
638 text += "\\u";
639 text += IntToStringHex(high_surrogate, 4);
640 text += "\\u";
641 text += IntToStringHex(low_surrogate, 4);
642 }
643 // Skip past characters recognized.
644 i = static_cast<uoffset_t>(utf8 - s - 1);
645 }
646 }
647 break;
648 }
649 }
650 text += "\"";
651 return true;
652}
653
654inline std::string BufferToHexText(const void *buffer, size_t buffer_size,
655 size_t max_length,
656 const std::string &wrapped_line_prefix,
657 const std::string &wrapped_line_suffix) {
658 std::string text = wrapped_line_prefix;
659 size_t start_offset = 0;
660 const char *s = reinterpret_cast<const char *>(buffer);
661 for (size_t i = 0; s && i < buffer_size; i++) {
662 // Last iteration or do we have more?
663 bool have_more = i + 1 < buffer_size;
664 text += "0x";
665 text += IntToStringHex(static_cast<uint8_t>(s[i]), 2);
666 if (have_more) { text += ','; }
667 // If we have more to process and we reached max_length
668 if (have_more &&
669 text.size() + wrapped_line_suffix.size() >= start_offset + max_length) {
670 text += wrapped_line_suffix;
671 text += '\n';
672 start_offset = text.size();
673 text += wrapped_line_prefix;
674 }
675 }
676 text += wrapped_line_suffix;
677 return text;
678}
679
680// Remove paired quotes in a string: "text"|'text' -> text.
681std::string RemoveStringQuotes(const std::string &s);
682
683// Change th global C-locale to locale with name <locale_name>.
684// Returns an actual locale name in <_value>, useful if locale_name is "" or
685// null.
686bool SetGlobalTestLocale(const char *locale_name,
687 std::string *_value = nullptr);
688
689// Read (or test) a value of environment variable.
690bool ReadEnvironmentVariable(const char *var_name,
691 std::string *_value = nullptr);
692
693// MSVC specific: Send all assert reports to STDOUT to prevent CI hangs.
694void SetupDefaultCRTReportMode();
695
696} // namespace flatbuffers
697
698#endif // FLATBUFFERS_UTIL_H_