1 #ifndef FLATBUFFERS_BASE_H_
2 #define FLATBUFFERS_BASE_H_
3
4 // clang-format off
5
6 // If activate should be declared and included first.
7 #if defined(FLATBUFFERS_MEMORY_LEAK_TRACKING) && \
8 defined(_MSC_VER) && defined(_DEBUG)
9 // The _CRTDBG_MAP_ALLOC inside <crtdbg.h> will replace
10 // calloc/free (etc) to its debug version using #define directives.
11 #define _CRTDBG_MAP_ALLOC
12 #include <stdlib.h>
13 #include <crtdbg.h>
14 // Replace operator new by trace-enabled version.
15 #define DEBUG_NEW new(_NORMAL_BLOCK, __FILE__, __LINE__)
16 #define new DEBUG_NEW
17 #endif
18
19 #if !defined(FLATBUFFERS_ASSERT)
20 #include <assert.h>
21 #define FLATBUFFERS_ASSERT assert
22 #elif defined(FLATBUFFERS_ASSERT_INCLUDE)
23 // Include file with forward declaration
24 #include FLATBUFFERS_ASSERT_INCLUDE
25 #endif
26
27 #ifndef ARDUINO
28 #include <cstdint>
29 #endif
30
31 #include <cstddef>
32 #include <cstdlib>
33 #include <cstring>
34
35 #if defined(ARDUINO) && !defined(ARDUINOSTL_M_H)
36 #include <utility.h>
37 #else
38 #include <utility>
39 #endif
40
41 #include <type_traits>
42 #include <vector>
43 #include <algorithm>
44 #include <iterator>
45
46 #ifndef FLATBUFFERS_CHRE
47 #include <memory>
48 #include <set>
49 #include <string>
50 #endif
51
52 #ifdef _STLPORT_VERSION
53 #define FLATBUFFERS_CPP98_STL
54 #endif
55 #if !defined(FLATBUFFERS_CPP98_STL) && !defined(FLATBUFFERS_CHRE)
56 #include <functional>
57 #endif
58
59 #include "flatbuffers/stl_emulation.h"
60
61 #if defined(__ICCARM__)
62 #include <intrinsics.h>
63 #endif
64
65 // Note the __clang__ check is needed, because clang presents itself
66 // as an older GNUC compiler (4.2).
67 // Clang 3.3 and later implement all of the ISO C++ 2011 standard.
68 // Clang 3.4 and later implement all of the ISO C++ 2014 standard.
69 // http://clang.llvm.org/cxx_status.html
70
71 // Note the MSVC value '__cplusplus' may be incorrect:
72 // The '__cplusplus' predefined macro in the MSVC stuck at the value 199711L,
73 // indicating (erroneously!) that the compiler conformed to the C++98 Standard.
74 // This value should be correct starting from MSVC2017-15.7-Preview-3.
75 // The '__cplusplus' will be valid only if MSVC2017-15.7-P3 and the `/Zc:__cplusplus` switch is set.
76 // Workaround (for details see MSDN):
77 // Use the _MSC_VER and _MSVC_LANG definition instead of the __cplusplus for compatibility.
78 // The _MSVC_LANG macro reports the Standard version regardless of the '/Zc:__cplusplus' switch.
79
80 #if defined(__GNUC__) && !defined(__clang__)
81 #define FLATBUFFERS_GCC (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
82 #else
83 #define FLATBUFFERS_GCC 0
84 #endif
85
86 #if defined(__clang__)
87 #define FLATBUFFERS_CLANG (__clang_major__ * 10000 + __clang_minor__ * 100 + __clang_patchlevel__)
88 #else
89 #define FLATBUFFERS_CLANG 0
90 #endif
91
92 /// @cond FLATBUFFERS_INTERNAL
93 #if __cplusplus <= 199711L && \
94 (!defined(_MSC_VER) || _MSC_VER < 1600) && \
95 (!defined(__GNUC__) || \
96 (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__ < 40400))
97 #error A C++11 compatible compiler with support for the auto typing is \
98 required for FlatBuffers.
99 #error __cplusplus _MSC_VER __GNUC__ __GNUC_MINOR__ __GNUC_PATCHLEVEL__
100 #endif
101
102 #if !defined(__clang__) && \
103 defined(__GNUC__) && \
104 (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__ < 40600)
105 // Backwards compatibility for g++ 4.4, and 4.5 which don't have the nullptr
106 // and constexpr keywords. Note the __clang__ check is needed, because clang
107 // presents itself as an older GNUC compiler.
108 #ifndef nullptr_t
109 const class nullptr_t {
110 public:
111 template<class T> inline operator T*() const { return 0; }
112 private:
113 void operator&() const;
114 } nullptr = {};
115 #endif
116 #ifndef constexpr
117 #define constexpr const
118 #endif
119 #endif
120
121 // The wire format uses a little endian encoding (since that's efficient for
122 // the common platforms).
123 #if defined(__s390x__)
124 #define FLATBUFFERS_LITTLEENDIAN 0
125 #endif // __s390x__
126 #if !defined(FLATBUFFERS_LITTLEENDIAN)
127 #if defined(__GNUC__) || defined(__clang__) || defined(__ICCARM__)
128 #if (defined(__BIG_ENDIAN__) || \
129 (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
130 #define FLATBUFFERS_LITTLEENDIAN 0
131 #else
132 #define FLATBUFFERS_LITTLEENDIAN 1
133 #endif // __BIG_ENDIAN__
134 #elif defined(_MSC_VER)
135 #if defined(_M_PPC)
136 #define FLATBUFFERS_LITTLEENDIAN 0
137 #else
138 #define FLATBUFFERS_LITTLEENDIAN 1
139 #endif
140 #else
141 #error Unable to determine endianness, define FLATBUFFERS_LITTLEENDIAN.
142 #endif
143 #endif // !defined(FLATBUFFERS_LITTLEENDIAN)
144
145 #define FLATBUFFERS_VERSION_MAJOR 1
146 #define FLATBUFFERS_VERSION_MINOR 12
147 #define FLATBUFFERS_VERSION_REVISION 0
148 #define FLATBUFFERS_STRING_EXPAND(X) #X
149 #define FLATBUFFERS_STRING(X) FLATBUFFERS_STRING_EXPAND(X)
150 namespace flatbuffers {
151 // Returns version as string "MAJOR.MINOR.REVISION".
152 const char* FLATBUFFERS_VERSION();
153 }
154
155 #if (!defined(_MSC_VER) || _MSC_VER > 1600) && \
156 (!defined(__GNUC__) || (__GNUC__ * 100 + __GNUC_MINOR__ >= 407)) || \
157 defined(__clang__)
158 #define FLATBUFFERS_FINAL_CLASS final
159 #define FLATBUFFERS_OVERRIDE override
160 #define FLATBUFFERS_VTABLE_UNDERLYING_TYPE : flatbuffers::voffset_t
161 #else
162 #define FLATBUFFERS_FINAL_CLASS
163 #define FLATBUFFERS_OVERRIDE
164 #define FLATBUFFERS_VTABLE_UNDERLYING_TYPE
165 #endif
166
167 #if (!defined(_MSC_VER) || _MSC_VER >= 1900) && \
168 (!defined(__GNUC__) || (__GNUC__ * 100 + __GNUC_MINOR__ >= 406)) || \
169 (defined(__cpp_constexpr) && __cpp_constexpr >= 200704)
170 #define FLATBUFFERS_CONSTEXPR constexpr
171 #else
172 #define FLATBUFFERS_CONSTEXPR const
173 #endif
174
175 #if (defined(__cplusplus) && __cplusplus >= 201402L) || \
176 (defined(__cpp_constexpr) && __cpp_constexpr >= 201304)
177 #define FLATBUFFERS_CONSTEXPR_CPP14 FLATBUFFERS_CONSTEXPR
178 #else
179 #define FLATBUFFERS_CONSTEXPR_CPP14
180 #endif
181
182 #if (defined(__GXX_EXPERIMENTAL_CXX0X__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 406)) || \
183 (defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 190023026)) || \
184 defined(__clang__)
185 #define FLATBUFFERS_NOEXCEPT noexcept
186 #else
187 #define FLATBUFFERS_NOEXCEPT
188 #endif
189
190 // NOTE: the FLATBUFFERS_DELETE_FUNC macro may change the access mode to
191 // private, so be sure to put it at the end or reset access mode explicitly.
192 #if (!defined(_MSC_VER) || _MSC_FULL_VER >= 180020827) && \
193 (!defined(__GNUC__) || (__GNUC__ * 100 + __GNUC_MINOR__ >= 404)) || \
194 defined(__clang__)
195 #define FLATBUFFERS_DELETE_FUNC(func) func = delete;
196 #else
197 #define FLATBUFFERS_DELETE_FUNC(func) private: func;
198 #endif
199
200 #ifndef FLATBUFFERS_HAS_STRING_VIEW
201 // Only provide flatbuffers::string_view if __has_include can be used
202 // to detect a header that provides an implementation
203 #if defined(__has_include)
204 // Check for std::string_view (in c++17)
205 #if __has_include(<string_view>) && (__cplusplus >= 201606 || (defined(_HAS_CXX17) && _HAS_CXX17))
206 #include <string_view>
207 namespace flatbuffers {
208 typedef std::string_view string_view;
209 }
210 #define FLATBUFFERS_HAS_STRING_VIEW 1
211 // Check for std::experimental::string_view (in c++14, compiler-dependent)
212 #elif __has_include(<experimental/string_view>) && (__cplusplus >= 201411)
213 #include <experimental/string_view>
214 namespace flatbuffers {
215 typedef std::experimental::string_view string_view;
216 }
217 #define FLATBUFFERS_HAS_STRING_VIEW 1
218 // Check for absl::string_view
219 #elif __has_include("absl/strings/string_view.h")
220 #include "absl/strings/string_view.h"
221 namespace flatbuffers {
222 typedef absl::string_view string_view;
223 }
224 #define FLATBUFFERS_HAS_STRING_VIEW 1
225 #endif
226 #endif // __has_include
227 #endif // !FLATBUFFERS_HAS_STRING_VIEW
228
229 #ifndef FLATBUFFERS_HAS_NEW_STRTOD
230 // Modern (C++11) strtod and strtof functions are available for use.
231 // 1) nan/inf strings as argument of strtod;
232 // 2) hex-float as argument of strtod/strtof.
233 #if (defined(_MSC_VER) && _MSC_VER >= 1900) || \
234 (defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 409)) || \
235 (defined(__clang__))
236 #define FLATBUFFERS_HAS_NEW_STRTOD 1
237 #endif
238 #endif // !FLATBUFFERS_HAS_NEW_STRTOD
239
240 #ifndef FLATBUFFERS_LOCALE_INDEPENDENT
241 // Enable locale independent functions {strtof_l, strtod_l,strtoll_l, strtoull_l}.
242 // They are part of the POSIX-2008 but not part of the C/C++ standard.
243 // GCC/Clang have definition (_XOPEN_SOURCE>=700) if POSIX-2008.
244 #if ((defined(_MSC_VER) && _MSC_VER >= 1800) || \
245 (defined(_XOPEN_SOURCE) && (_XOPEN_SOURCE>=700)))
246 #define FLATBUFFERS_LOCALE_INDEPENDENT 1
247 #else
248 #define FLATBUFFERS_LOCALE_INDEPENDENT 0
249 #endif
250 #endif // !FLATBUFFERS_LOCALE_INDEPENDENT
251
252 // Suppress Undefined Behavior Sanitizer (recoverable only). Usage:
253 // - __supress_ubsan__("undefined")
254 // - __supress_ubsan__("signed-integer-overflow")
255 #if defined(__clang__) && (__clang_major__ > 3 || (__clang_major__ == 3 && __clang_minor__ >=7))
256 #define __supress_ubsan__(type) __attribute__((no_sanitize(type)))
257 #elif defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 409)
258 #define __supress_ubsan__(type) __attribute__((no_sanitize_undefined))
259 #else
260 #define __supress_ubsan__(type)
261 #endif
262
263 // This is constexpr function used for checking compile-time constants.
264 // Avoid `#pragma warning(disable: 4127) // C4127: expression is constant`.
IsConstTrue(T t)265 template<typename T> FLATBUFFERS_CONSTEXPR inline bool IsConstTrue(T t) {
266 return !!t;
267 }
268
269 // Enable C++ attribute [[]] if std:c++17 or higher.
270 #if ((__cplusplus >= 201703L) \
271 || (defined(_MSVC_LANG) && (_MSVC_LANG >= 201703L)))
272 // All attributes unknown to an implementation are ignored without causing an error.
273 #define FLATBUFFERS_ATTRIBUTE(attr) [[attr]]
274
275 #define FLATBUFFERS_FALLTHROUGH() [[fallthrough]]
276 #else
277 #define FLATBUFFERS_ATTRIBUTE(attr)
278
279 #if FLATBUFFERS_CLANG >= 30800
280 #define FLATBUFFERS_FALLTHROUGH() [[clang::fallthrough]]
281 #elif FLATBUFFERS_GCC >= 70300
282 #define FLATBUFFERS_FALLTHROUGH() [[gnu::fallthrough]]
283 #else
284 #define FLATBUFFERS_FALLTHROUGH()
285 #endif
286 #endif
287
288 /// @endcond
289
290 /// @file
291 namespace flatbuffers {
292
293 /// @cond FLATBUFFERS_INTERNAL
294 // Our default offset / size type, 32bit on purpose on 64bit systems.
295 // Also, using a consistent offset type maintains compatibility of serialized
296 // offset values between 32bit and 64bit systems.
297 typedef uint32_t uoffset_t;
298
299 // Signed offsets for references that can go in both directions.
300 typedef int32_t soffset_t;
301
302 // Offset/index used in v-tables, can be changed to uint8_t in
303 // format forks to save a bit of space if desired.
304 typedef uint16_t voffset_t;
305
306 typedef uintmax_t largest_scalar_t;
307
308 // In 32bits, this evaluates to 2GB - 1
309 #define FLATBUFFERS_MAX_BUFFER_SIZE ((1ULL << (sizeof(::flatbuffers::soffset_t) * 8 - 1)) - 1)
310
311 // We support aligning the contents of buffers up to this size.
312 #define FLATBUFFERS_MAX_ALIGNMENT 16
313
314 #if defined(_MSC_VER)
315 #pragma warning(push)
316 #pragma warning(disable: 4127) // C4127: conditional expression is constant
317 #endif
318
EndianSwap(T t)319 template<typename T> T EndianSwap(T t) {
320 #if defined(_MSC_VER)
321 #define FLATBUFFERS_BYTESWAP16 _byteswap_ushort
322 #define FLATBUFFERS_BYTESWAP32 _byteswap_ulong
323 #define FLATBUFFERS_BYTESWAP64 _byteswap_uint64
324 #elif defined(__ICCARM__)
325 #define FLATBUFFERS_BYTESWAP16 __REV16
326 #define FLATBUFFERS_BYTESWAP32 __REV
327 #define FLATBUFFERS_BYTESWAP64(x) \
328 ((__REV(static_cast<uint32_t>(x >> 32U))) | (static_cast<uint64_t>(__REV(static_cast<uint32_t>(x)))) << 32U)
329 #else
330 #if defined(__GNUC__) && __GNUC__ * 100 + __GNUC_MINOR__ < 408 && !defined(__clang__)
331 // __builtin_bswap16 was missing prior to GCC 4.8.
332 #define FLATBUFFERS_BYTESWAP16(x) \
333 static_cast<uint16_t>(__builtin_bswap32(static_cast<uint32_t>(x) << 16))
334 #else
335 #define FLATBUFFERS_BYTESWAP16 __builtin_bswap16
336 #endif
337 #define FLATBUFFERS_BYTESWAP32 __builtin_bswap32
338 #define FLATBUFFERS_BYTESWAP64 __builtin_bswap64
339 #endif
340 if (sizeof(T) == 1) { // Compile-time if-then's.
341 return t;
342 } else if (sizeof(T) == 2) {
343 union { T t; uint16_t i; } u = { t };
344 u.i = FLATBUFFERS_BYTESWAP16(u.i);
345 return u.t;
346 } else if (sizeof(T) == 4) {
347 union { T t; uint32_t i; } u = { t };
348 u.i = FLATBUFFERS_BYTESWAP32(u.i);
349 return u.t;
350 } else if (sizeof(T) == 8) {
351 union { T t; uint64_t i; } u = { t };
352 u.i = FLATBUFFERS_BYTESWAP64(u.i);
353 return u.t;
354 } else {
355 FLATBUFFERS_ASSERT(0);
356 return t;
357 }
358 }
359
360 #if defined(_MSC_VER)
361 #pragma warning(pop)
362 #endif
363
364
EndianScalar(T t)365 template<typename T> T EndianScalar(T t) {
366 #if FLATBUFFERS_LITTLEENDIAN
367 return t;
368 #else
369 return EndianSwap(t);
370 #endif
371 }
372
373 template<typename T>
374 // UBSAN: C++ aliasing type rules, see std::bit_cast<> for details.
375 __supress_ubsan__("alignment")
ReadScalar(const void * p)376 T ReadScalar(const void *p) {
377 return EndianScalar(*reinterpret_cast<const T *>(p));
378 }
379
380 template<typename T>
381 // UBSAN: C++ aliasing type rules, see std::bit_cast<> for details.
382 __supress_ubsan__("alignment")
WriteScalar(void * p,T t)383 void WriteScalar(void *p, T t) {
384 *reinterpret_cast<T *>(p) = EndianScalar(t);
385 }
386
387 template<typename T> struct Offset;
WriteScalar(void * p,Offset<T> t)388 template<typename T> __supress_ubsan__("alignment") void WriteScalar(void *p, Offset<T> t) {
389 *reinterpret_cast<uoffset_t *>(p) = EndianScalar(t.o);
390 }
391
392 // Computes how many bytes you'd have to pad to be able to write an
393 // "scalar_size" scalar if the buffer had grown to "buf_size" (downwards in
394 // memory).
395 __supress_ubsan__("unsigned-integer-overflow")
PaddingBytes(size_t buf_size,size_t scalar_size)396 inline size_t PaddingBytes(size_t buf_size, size_t scalar_size) {
397 return ((~buf_size) + 1) & (scalar_size - 1);
398 }
399
400 } // namespace flatbuffers
401 #endif // FLATBUFFERS_BASE_H_
402
