1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc. All rights reserved.
3 // https://developers.google.com/protocol-buffers/
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions are
7 // met:
8 //
9 // * Redistributions of source code must retain the above copyright
10 // notice, this list of conditions and the following disclaimer.
11 // * Redistributions in binary form must reproduce the above
12 // copyright notice, this list of conditions and the following disclaimer
13 // in the documentation and/or other materials provided with the
14 // distribution.
15 // * Neither the name of Google Inc. nor the names of its
16 // contributors may be used to endorse or promote products derived from
17 // this software without specific prior written permission.
18 //
19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30
31 // Author: kenton@google.com (Kenton Varda)
32 // Based on original Protocol Buffers design by
33 // Sanjay Ghemawat, Jeff Dean, and others.
34 //
35 // This file contains miscellaneous helper code used by generated code --
36 // including lite types -- but which should not be used directly by users.
37
38 #ifndef GOOGLE_PROTOBUF_GENERATED_MESSAGE_UTIL_H__
39 #define GOOGLE_PROTOBUF_GENERATED_MESSAGE_UTIL_H__
40
41 #include <assert.h>
42
43 #include <atomic>
44 #include <climits>
45 #include <string>
46 #include <vector>
47
48 #include <google/protobuf/stubs/common.h>
49 #include <google/protobuf/any.h>
50 #include <google/protobuf/has_bits.h>
51 #include <google/protobuf/implicit_weak_message.h>
52 #include <google/protobuf/message_lite.h>
53 #include <google/protobuf/stubs/once.h> // Add direct dep on port for pb.cc
54 #include <google/protobuf/port.h>
55 #include <google/protobuf/repeated_field.h>
56 #include <google/protobuf/wire_format_lite.h>
57 #include <google/protobuf/stubs/strutil.h>
58 #include <google/protobuf/stubs/casts.h>
59
60 #include <google/protobuf/port_def.inc>
61
62 #ifdef SWIG
63 #error "You cannot SWIG proto headers"
64 #endif
65
66 namespace google {
67 namespace protobuf {
68
69 class Arena;
70 class Message;
71
72 namespace io {
73 class CodedInputStream;
74 }
75
76 namespace internal {
77
78 template <typename To, typename From>
DownCast(From * f)79 inline To DownCast(From* f) {
80 return PROTOBUF_NAMESPACE_ID::internal::down_cast<To>(f);
81 }
82 template <typename To, typename From>
DownCast(From & f)83 inline To DownCast(From& f) {
84 return PROTOBUF_NAMESPACE_ID::internal::down_cast<To>(f);
85 }
86
87
88 // This fastpath inlines a single branch instead of having to make the
89 // InitProtobufDefaults function call.
90 // It also generates less inlined code than a function-scope static initializer.
91 PROTOBUF_EXPORT extern std::atomic<bool> init_protobuf_defaults_state;
92 PROTOBUF_EXPORT void InitProtobufDefaultsSlow();
InitProtobufDefaults()93 PROTOBUF_EXPORT inline void InitProtobufDefaults() {
94 if (PROTOBUF_PREDICT_FALSE(
95 !init_protobuf_defaults_state.load(std::memory_order_acquire))) {
96 InitProtobufDefaultsSlow();
97 }
98 }
99
100 // This used by proto1
GetEmptyString()101 PROTOBUF_EXPORT inline const std::string& GetEmptyString() {
102 InitProtobufDefaults();
103 return GetEmptyStringAlreadyInited();
104 }
105
106
107 // True if IsInitialized() is true for all elements of t. Type is expected
108 // to be a RepeatedPtrField<some message type>. It's useful to have this
109 // helper here to keep the protobuf compiler from ever having to emit loops in
110 // IsInitialized() methods. We want the C++ compiler to inline this or not
111 // as it sees fit.
112 template <typename Msg>
AllAreInitialized(const RepeatedPtrField<Msg> & t)113 bool AllAreInitialized(const RepeatedPtrField<Msg>& t) {
114 for (int i = t.size(); --i >= 0;) {
115 if (!t.Get(i).IsInitialized()) return false;
116 }
117 return true;
118 }
119
120 // "Weak" variant of AllAreInitialized, used to implement implicit weak fields.
121 // This version operates on MessageLite to avoid introducing a dependency on the
122 // concrete message type.
123 template <class T>
AllAreInitializedWeak(const RepeatedPtrField<T> & t)124 bool AllAreInitializedWeak(const RepeatedPtrField<T>& t) {
125 for (int i = t.size(); --i >= 0;) {
126 if (!reinterpret_cast<const RepeatedPtrFieldBase&>(t)
127 .Get<ImplicitWeakTypeHandler<T> >(i)
128 .IsInitialized()) {
129 return false;
130 }
131 }
132 return true;
133 }
134
IsPresent(const void * base,uint32 hasbit)135 inline bool IsPresent(const void* base, uint32 hasbit) {
136 const uint32* has_bits_array = static_cast<const uint32*>(base);
137 return (has_bits_array[hasbit / 32] & (1u << (hasbit & 31))) != 0;
138 }
139
IsOneofPresent(const void * base,uint32 offset,uint32 tag)140 inline bool IsOneofPresent(const void* base, uint32 offset, uint32 tag) {
141 const uint32* oneof =
142 reinterpret_cast<const uint32*>(static_cast<const uint8*>(base) + offset);
143 return *oneof == tag >> 3;
144 }
145
146 typedef void (*SpecialSerializer)(const uint8* base, uint32 offset, uint32 tag,
147 uint32 has_offset,
148 io::CodedOutputStream* output);
149
150 PROTOBUF_EXPORT void ExtensionSerializer(const uint8* base, uint32 offset,
151 uint32 tag, uint32 has_offset,
152 io::CodedOutputStream* output);
153 PROTOBUF_EXPORT void UnknownFieldSerializerLite(const uint8* base,
154 uint32 offset, uint32 tag,
155 uint32 has_offset,
156 io::CodedOutputStream* output);
157
158 PROTOBUF_EXPORT MessageLite* DuplicateIfNonNullInternal(MessageLite* message);
159 PROTOBUF_EXPORT MessageLite* GetOwnedMessageInternal(Arena* message_arena,
160 MessageLite* submessage,
161 Arena* submessage_arena);
162 PROTOBUF_EXPORT void GenericSwap(MessageLite* m1, MessageLite* m2);
163 // We specialize GenericSwap for non-lite messages to benefit from reflection.
164 PROTOBUF_EXPORT void GenericSwap(Message* m1, Message* m2);
165
166 template <typename T>
DuplicateIfNonNull(T * message)167 T* DuplicateIfNonNull(T* message) {
168 // The casts must be reinterpret_cast<> because T might be a forward-declared
169 // type that the compiler doesn't know is related to MessageLite.
170 return reinterpret_cast<T*>(
171 DuplicateIfNonNullInternal(reinterpret_cast<MessageLite*>(message)));
172 }
173
174 template <typename T>
GetOwnedMessage(Arena * message_arena,T * submessage,Arena * submessage_arena)175 T* GetOwnedMessage(Arena* message_arena, T* submessage,
176 Arena* submessage_arena) {
177 // The casts must be reinterpret_cast<> because T might be a forward-declared
178 // type that the compiler doesn't know is related to MessageLite.
179 return reinterpret_cast<T*>(GetOwnedMessageInternal(
180 message_arena, reinterpret_cast<MessageLite*>(submessage),
181 submessage_arena));
182 }
183
184 // Hide atomic from the public header and allow easy change to regular int
185 // on platforms where the atomic might have a perf impact.
186 class PROTOBUF_EXPORT CachedSize {
187 public:
Get()188 int Get() const { return size_.load(std::memory_order_relaxed); }
Set(int size)189 void Set(int size) { size_.store(size, std::memory_order_relaxed); }
190
191 private:
192 std::atomic<int> size_{0};
193 };
194
195 // SCCInfo represents information of a strongly connected component of
196 // mutual dependent messages.
197 struct PROTOBUF_EXPORT SCCInfoBase {
198 // We use 0 for the Initialized state, because test eax,eax, jnz is smaller
199 // and is subject to macro fusion.
200 enum {
201 kInitialized = 0, // final state
202 kRunning = 1,
203 kUninitialized = -1, // initial state
204 };
205 #if defined(_MSC_VER) && !defined(__clang__)
206 // MSVC doesn't make std::atomic constant initialized. This union trick
207 // makes it so.
208 union {
209 int visit_status_to_make_linker_init;
210 std::atomic<int> visit_status;
211 };
212 #else
213 std::atomic<int> visit_status;
214 #endif
215 int num_deps;
216 int num_implicit_weak_deps;
217 void (*init_func)();
218 // This is followed by an array of num_deps
219 // const SCCInfoBase* deps[];
220 };
221
222 // Zero-length arrays are a language extension available in GCC and Clang but
223 // not MSVC.
224 #ifdef __GNUC__
225 #define PROTOBUF_ARRAY_SIZE(n) (n)
226 #else
227 #define PROTOBUF_ARRAY_SIZE(n) ((n) ? (n) : 1)
228 #endif
229
230 template <int N>
231 struct SCCInfo {
232 SCCInfoBase base;
233 // Semantically this is const SCCInfo<T>* which is is a templated type.
234 // The obvious inheriting from SCCInfoBase mucks with struct initialization.
235 // Attempts showed the compiler was generating dynamic initialization code.
236 // This deps array consists of base.num_deps pointers to SCCInfoBase followed
237 // by base.num_implicit_weak_deps pointers to SCCInfoBase*. We need the extra
238 // pointer indirection for implicit weak fields. We cannot use a union type
239 // here, since that would prevent the array from being linker-initialized.
240 void* deps[PROTOBUF_ARRAY_SIZE(N)];
241 };
242
243 #undef PROTOBUF_ARRAY_SIZE
244
245 PROTOBUF_EXPORT void InitSCCImpl(SCCInfoBase* scc);
246
InitSCC(SCCInfoBase * scc)247 inline void InitSCC(SCCInfoBase* scc) {
248 auto status = scc->visit_status.load(std::memory_order_acquire);
249 if (PROTOBUF_PREDICT_FALSE(status != SCCInfoBase::kInitialized))
250 InitSCCImpl(scc);
251 }
252
253 PROTOBUF_EXPORT void DestroyMessage(const void* message);
254 PROTOBUF_EXPORT void DestroyString(const void* s);
255 // Destroy (not delete) the message
OnShutdownDestroyMessage(const void * ptr)256 inline void OnShutdownDestroyMessage(const void* ptr) {
257 OnShutdownRun(DestroyMessage, ptr);
258 }
259 // Destroy the string (call std::string destructor)
OnShutdownDestroyString(const std::string * ptr)260 inline void OnShutdownDestroyString(const std::string* ptr) {
261 OnShutdownRun(DestroyString, ptr);
262 }
263
264 } // namespace internal
265 } // namespace protobuf
266 } // namespace google
267
268 #include <google/protobuf/port_undef.inc>
269
270 #endif // GOOGLE_PROTOBUF_GENERATED_MESSAGE_UTIL_H__
271