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 <string>
42 #include <type_traits>
43 #include <vector>
44 #include <set>
45 #include <algorithm>
46 #include <iterator>
47 #include <memory>
48
49 #ifdef _STLPORT_VERSION
50 #define FLATBUFFERS_CPP98_STL
51 #endif
52 #ifndef FLATBUFFERS_CPP98_STL
53 #include <functional>
54 #endif
55
56 #include "flatbuffers/stl_emulation.h"
57
58 #if defined(__ICCARM__)
59 #include <intrinsics.h>
60 #endif
61
62 // Note the __clang__ check is needed, because clang presents itself
63 // as an older GNUC compiler (4.2).
64 // Clang 3.3 and later implement all of the ISO C++ 2011 standard.
65 // Clang 3.4 and later implement all of the ISO C++ 2014 standard.
66 // http://clang.llvm.org/cxx_status.html
67
68 // Note the MSVC value '__cplusplus' may be incorrect:
69 // The '__cplusplus' predefined macro in the MSVC stuck at the value 199711L,
70 // indicating (erroneously!) that the compiler conformed to the C++98 Standard.
71 // This value should be correct starting from MSVC2017-15.7-Preview-3.
72 // The '__cplusplus' will be valid only if MSVC2017-15.7-P3 and the `/Zc:__cplusplus` switch is set.
73 // Workaround (for details see MSDN):
74 // Use the _MSC_VER and _MSVC_LANG definition instead of the __cplusplus for compatibility.
75 // The _MSVC_LANG macro reports the Standard version regardless of the '/Zc:__cplusplus' switch.
76
77 #if defined(__GNUC__) && !defined(__clang__)
78 #define FLATBUFFERS_GCC (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
79 #else
80 #define FLATBUFFERS_GCC 0
81 #endif
82
83 #if defined(__clang__)
84 #define FLATBUFFERS_CLANG (__clang_major__ * 10000 + __clang_minor__ * 100 + __clang_patchlevel__)
85 #else
86 #define FLATBUFFERS_CLANG 0
87 #endif
88
89 /// @cond FLATBUFFERS_INTERNAL
90 #if __cplusplus <= 199711L && \
91 (!defined(_MSC_VER) || _MSC_VER < 1600) && \
92 (!defined(__GNUC__) || \
93 (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__ < 40400))
94 #error A C++11 compatible compiler with support for the auto typing is \
95 required for FlatBuffers.
96 #error __cplusplus _MSC_VER __GNUC__ __GNUC_MINOR__ __GNUC_PATCHLEVEL__
97 #endif
98
99 #if !defined(__clang__) && \
100 defined(__GNUC__) && \
101 (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__ < 40600)
102 // Backwards compatibility for g++ 4.4, and 4.5 which don't have the nullptr
103 // and constexpr keywords. Note the __clang__ check is needed, because clang
104 // presents itself as an older GNUC compiler.
105 #ifndef nullptr_t
106 const class nullptr_t {
107 public:
108 template<class T> inline operator T*() const { return 0; }
109 private:
110 void operator&() const;
111 } nullptr = {};
112 #endif
113 #ifndef constexpr
114 #define constexpr const
115 #endif
116 #endif
117
118 // The wire format uses a little endian encoding (since that's efficient for
119 // the common platforms).
120 #if defined(__s390x__)
121 #define FLATBUFFERS_LITTLEENDIAN 0
122 #endif // __s390x__
123 #if !defined(FLATBUFFERS_LITTLEENDIAN)
124 #if defined(__GNUC__) || defined(__clang__) || defined(__ICCARM__)
125 #if (defined(__BIG_ENDIAN__) || \
126 (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
127 #define FLATBUFFERS_LITTLEENDIAN 0
128 #else
129 #define FLATBUFFERS_LITTLEENDIAN 1
130 #endif // __BIG_ENDIAN__
131 #elif defined(_MSC_VER)
132 #if defined(_M_PPC)
133 #define FLATBUFFERS_LITTLEENDIAN 0
134 #else
135 #define FLATBUFFERS_LITTLEENDIAN 1
136 #endif
137 #else
138 #error Unable to determine endianness, define FLATBUFFERS_LITTLEENDIAN.
139 #endif
140 #endif // !defined(FLATBUFFERS_LITTLEENDIAN)
141
142 #define FLATBUFFERS_VERSION_MAJOR 1
143 #define FLATBUFFERS_VERSION_MINOR 12
144 #define FLATBUFFERS_VERSION_REVISION 0
145 #define FLATBUFFERS_STRING_EXPAND(X) #X
146 #define FLATBUFFERS_STRING(X) FLATBUFFERS_STRING_EXPAND(X)
147 namespace flatbuffers {
148 // Returns version as string "MAJOR.MINOR.REVISION".
149 const char* FLATBUFFERS_VERSION();
150 }
151
152 #if (!defined(_MSC_VER) || _MSC_VER > 1600) && \
153 (!defined(__GNUC__) || (__GNUC__ * 100 + __GNUC_MINOR__ >= 407)) || \
154 defined(__clang__)
155 #define FLATBUFFERS_FINAL_CLASS final
156 #define FLATBUFFERS_OVERRIDE override
157 #define FLATBUFFERS_VTABLE_UNDERLYING_TYPE : flatbuffers::voffset_t
158 #else
159 #define FLATBUFFERS_FINAL_CLASS
160 #define FLATBUFFERS_OVERRIDE
161 #define FLATBUFFERS_VTABLE_UNDERLYING_TYPE
162 #endif
163
164 #if (!defined(_MSC_VER) || _MSC_VER >= 1900) && \
165 (!defined(__GNUC__) || (__GNUC__ * 100 + __GNUC_MINOR__ >= 406)) || \
166 (defined(__cpp_constexpr) && __cpp_constexpr >= 200704)
167 #define FLATBUFFERS_CONSTEXPR constexpr
168 #else
169 #define FLATBUFFERS_CONSTEXPR const
170 #endif
171
172 #if (defined(__cplusplus) && __cplusplus >= 201402L) || \
173 (defined(__cpp_constexpr) && __cpp_constexpr >= 201304)
174 #define FLATBUFFERS_CONSTEXPR_CPP14 FLATBUFFERS_CONSTEXPR
175 #else
176 #define FLATBUFFERS_CONSTEXPR_CPP14
177 #endif
178
179 #if (defined(__GXX_EXPERIMENTAL_CXX0X__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 406)) || \
180 (defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 190023026)) || \
181 defined(__clang__)
182 #define FLATBUFFERS_NOEXCEPT noexcept
183 #else
184 #define FLATBUFFERS_NOEXCEPT
185 #endif
186
187 // NOTE: the FLATBUFFERS_DELETE_FUNC macro may change the access mode to
188 // private, so be sure to put it at the end or reset access mode explicitly.
189 #if (!defined(_MSC_VER) || _MSC_FULL_VER >= 180020827) && \
190 (!defined(__GNUC__) || (__GNUC__ * 100 + __GNUC_MINOR__ >= 404)) || \
191 defined(__clang__)
192 #define FLATBUFFERS_DELETE_FUNC(func) func = delete;
193 #else
194 #define FLATBUFFERS_DELETE_FUNC(func) private: func;
195 #endif
196
197 #ifndef FLATBUFFERS_HAS_STRING_VIEW
198 // Only provide flatbuffers::string_view if __has_include can be used
199 // to detect a header that provides an implementation
200 #if defined(__has_include)
201 // Check for std::string_view (in c++17)
202 #if __has_include(<string_view>) && (__cplusplus >= 201606 || (defined(_HAS_CXX17) && _HAS_CXX17))
203 #include <string_view>
204 namespace flatbuffers {
205 typedef std::string_view string_view;
206 }
207 #define FLATBUFFERS_HAS_STRING_VIEW 1
208 // Check for std::experimental::string_view (in c++14, compiler-dependent)
209 #elif __has_include(<experimental/string_view>) && (__cplusplus >= 201411)
210 #include <experimental/string_view>
211 namespace flatbuffers {
212 typedef std::experimental::string_view string_view;
213 }
214 #define FLATBUFFERS_HAS_STRING_VIEW 1
215 // Check for absl::string_view
216 #elif __has_include("absl/strings/string_view.h")
217 #include "absl/strings/string_view.h"
218 namespace flatbuffers {
219 typedef absl::string_view string_view;
220 }
221 #define FLATBUFFERS_HAS_STRING_VIEW 1
222 #endif
223 #endif // __has_include
224 #endif // !FLATBUFFERS_HAS_STRING_VIEW
225
226 #ifndef FLATBUFFERS_HAS_NEW_STRTOD
227 // Modern (C++11) strtod and strtof functions are available for use.
228 // 1) nan/inf strings as argument of strtod;
229 // 2) hex-float as argument of strtod/strtof.
230 #if (defined(_MSC_VER) && _MSC_VER >= 1900) || \
231 (defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 409)) || \
232 (defined(__clang__))
233 #define FLATBUFFERS_HAS_NEW_STRTOD 1
234 #endif
235 #endif // !FLATBUFFERS_HAS_NEW_STRTOD
236
237 #ifndef FLATBUFFERS_LOCALE_INDEPENDENT
238 // Enable locale independent functions {strtof_l, strtod_l,strtoll_l, strtoull_l}.
239 // They are part of the POSIX-2008 but not part of the C/C++ standard.
240 // GCC/Clang have definition (_XOPEN_SOURCE>=700) if POSIX-2008.
241 #if ((defined(_MSC_VER) && _MSC_VER >= 1800) || \
242 (defined(_XOPEN_SOURCE) && (_XOPEN_SOURCE>=700)))
243 #define FLATBUFFERS_LOCALE_INDEPENDENT 1
244 #else
245 #define FLATBUFFERS_LOCALE_INDEPENDENT 0
246 #endif
247 #endif // !FLATBUFFERS_LOCALE_INDEPENDENT
248
249 // Suppress Undefined Behavior Sanitizer (recoverable only). Usage:
250 // - __supress_ubsan__("undefined")
251 // - __supress_ubsan__("signed-integer-overflow")
252 #if defined(__clang__) && (__clang_major__ > 3 || (__clang_major__ == 3 && __clang_minor__ >=7))
253 #define __supress_ubsan__(type) __attribute__((no_sanitize(type)))
254 #elif defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 409)
255 #define __supress_ubsan__(type) __attribute__((no_sanitize_undefined))
256 #else
257 #define __supress_ubsan__(type)
258 #endif
259
260 // This is constexpr function used for checking compile-time constants.
261 // Avoid `#pragma warning(disable: 4127) // C4127: expression is constant`.
IsConstTrue(T t)262 template<typename T> FLATBUFFERS_CONSTEXPR inline bool IsConstTrue(T t) {
263 return !!t;
264 }
265
266 // Enable C++ attribute [[]] if std:c++17 or higher.
267 #if ((__cplusplus >= 201703L) \
268 || (defined(_MSVC_LANG) && (_MSVC_LANG >= 201703L)))
269 // All attributes unknown to an implementation are ignored without causing an error.
270 #define FLATBUFFERS_ATTRIBUTE(attr) [[attr]]
271
272 #define FLATBUFFERS_FALLTHROUGH() [[fallthrough]]
273 #else
274 #define FLATBUFFERS_ATTRIBUTE(attr)
275
276 #if FLATBUFFERS_CLANG >= 30800
277 #define FLATBUFFERS_FALLTHROUGH() [[clang::fallthrough]]
278 #elif FLATBUFFERS_GCC >= 70300
279 #define FLATBUFFERS_FALLTHROUGH() [[gnu::fallthrough]]
280 #else
281 #define FLATBUFFERS_FALLTHROUGH()
282 #endif
283 #endif
284
285 /// @endcond
286
287 /// @file
288 namespace flatbuffers {
289
290 /// @cond FLATBUFFERS_INTERNAL
291 // Our default offset / size type, 32bit on purpose on 64bit systems.
292 // Also, using a consistent offset type maintains compatibility of serialized
293 // offset values between 32bit and 64bit systems.
294 typedef uint32_t uoffset_t;
295
296 // Signed offsets for references that can go in both directions.
297 typedef int32_t soffset_t;
298
299 // Offset/index used in v-tables, can be changed to uint8_t in
300 // format forks to save a bit of space if desired.
301 typedef uint16_t voffset_t;
302
303 typedef uintmax_t largest_scalar_t;
304
305 // In 32bits, this evaluates to 2GB - 1
306 #define FLATBUFFERS_MAX_BUFFER_SIZE ((1ULL << (sizeof(::flatbuffers::soffset_t) * 8 - 1)) - 1)
307
308 // We support aligning the contents of buffers up to this size.
309 #define FLATBUFFERS_MAX_ALIGNMENT 16
310
311 #if defined(_MSC_VER)
312 #pragma warning(disable: 4351) // C4351: new behavior: elements of array ... will be default initialized
313 #pragma warning(push)
314 #pragma warning(disable: 4127) // C4127: conditional expression is constant
315 #endif
316
EndianSwap(T t)317 template<typename T> T EndianSwap(T t) {
318 #if defined(_MSC_VER)
319 #define FLATBUFFERS_BYTESWAP16 _byteswap_ushort
320 #define FLATBUFFERS_BYTESWAP32 _byteswap_ulong
321 #define FLATBUFFERS_BYTESWAP64 _byteswap_uint64
322 #elif defined(__ICCARM__)
323 #define FLATBUFFERS_BYTESWAP16 __REV16
324 #define FLATBUFFERS_BYTESWAP32 __REV
325 #define FLATBUFFERS_BYTESWAP64(x) \
326 ((__REV(static_cast<uint32_t>(x >> 32U))) | (static_cast<uint64_t>(__REV(static_cast<uint32_t>(x)))) << 32U)
327 #else
328 #if defined(__GNUC__) && __GNUC__ * 100 + __GNUC_MINOR__ < 408 && !defined(__clang__)
329 // __builtin_bswap16 was missing prior to GCC 4.8.
330 #define FLATBUFFERS_BYTESWAP16(x) \
331 static_cast<uint16_t>(__builtin_bswap32(static_cast<uint32_t>(x) << 16))
332 #else
333 #define FLATBUFFERS_BYTESWAP16 __builtin_bswap16
334 #endif
335 #define FLATBUFFERS_BYTESWAP32 __builtin_bswap32
336 #define FLATBUFFERS_BYTESWAP64 __builtin_bswap64
337 #endif
338 if (sizeof(T) == 1) { // Compile-time if-then's.
339 return t;
340 } else if (sizeof(T) == 2) {
341 union { T t; uint16_t i; } u = { t };
342 u.i = FLATBUFFERS_BYTESWAP16(u.i);
343 return u.t;
344 } else if (sizeof(T) == 4) {
345 union { T t; uint32_t i; } u = { t };
346 u.i = FLATBUFFERS_BYTESWAP32(u.i);
347 return u.t;
348 } else if (sizeof(T) == 8) {
349 union { T t; uint64_t i; } u = { t };
350 u.i = FLATBUFFERS_BYTESWAP64(u.i);
351 return u.t;
352 } else {
353 FLATBUFFERS_ASSERT(0);
354 return t;
355 }
356 }
357
358 #if defined(_MSC_VER)
359 #pragma warning(pop)
360 #endif
361
362
EndianScalar(T t)363 template<typename T> T EndianScalar(T t) {
364 #if FLATBUFFERS_LITTLEENDIAN
365 return t;
366 #else
367 return EndianSwap(t);
368 #endif
369 }
370
371 template<typename T>
372 // UBSAN: C++ aliasing type rules, see std::bit_cast<> for details.
373 __supress_ubsan__("alignment")
ReadScalar(const void * p)374 T ReadScalar(const void *p) {
375 return EndianScalar(*reinterpret_cast<const T *>(p));
376 }
377
378 template<typename T>
379 // UBSAN: C++ aliasing type rules, see std::bit_cast<> for details.
380 __supress_ubsan__("alignment")
WriteScalar(void * p,T t)381 void WriteScalar(void *p, T t) {
382 *reinterpret_cast<T *>(p) = EndianScalar(t);
383 }
384
385 template<typename T> struct Offset;
WriteScalar(void * p,Offset<T> t)386 template<typename T> __supress_ubsan__("alignment") void WriteScalar(void *p, Offset<T> t) {
387 *reinterpret_cast<uoffset_t *>(p) = EndianScalar(t.o);
388 }
389
390 // Computes how many bytes you'd have to pad to be able to write an
391 // "scalar_size" scalar if the buffer had grown to "buf_size" (downwards in
392 // memory).
393 __supress_ubsan__("unsigned-integer-overflow")
PaddingBytes(size_t buf_size,size_t scalar_size)394 inline size_t PaddingBytes(size_t buf_size, size_t scalar_size) {
395 return ((~buf_size) + 1) & (scalar_size - 1);
396 }
397
398 } // namespace flatbuffers
399 #endif // FLATBUFFERS_BASE_H_
400