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
66namespace google {
67namespace protobuf {
68
69class Arena;
70class Message;
71
72namespace io {
73class CodedInputStream;
74}
75
76namespace internal {
77
78template <typename To, typename From>
79inline To DownCast(From* f) {
80 return PROTOBUF_NAMESPACE_ID::internal::down_cast<To>(f);
81}
82template <typename To, typename From>
83inline To DownCast(From& f) {
84 return PROTOBUF_NAMESPACE_ID::internal::down_cast<To>(f);
85}
86
87
88PROTOBUF_EXPORT void InitProtobufDefaults();
89
90// This used by proto1
91PROTOBUF_EXPORT inline const std::string& GetEmptyString() {
92 InitProtobufDefaults();
93 return GetEmptyStringAlreadyInited();
94}
95
96
97// True if IsInitialized() is true for all elements of t. Type is expected
98// to be a RepeatedPtrField<some message type>. It's useful to have this
99// helper here to keep the protobuf compiler from ever having to emit loops in
100// IsInitialized() methods. We want the C++ compiler to inline this or not
101// as it sees fit.
102template <typename Msg>
103bool AllAreInitialized(const RepeatedPtrField<Msg>& t) {
104 for (int i = t.size(); --i >= 0;) {
105 if (!t.Get(i).IsInitialized()) return false;
106 }
107 return true;
108}
109
110// "Weak" variant of AllAreInitialized, used to implement implicit weak fields.
111// This version operates on MessageLite to avoid introducing a dependency on the
112// concrete message type.
113template <class T>
114bool AllAreInitializedWeak(const RepeatedPtrField<T>& t) {
115 for (int i = t.size(); --i >= 0;) {
116 if (!reinterpret_cast<const RepeatedPtrFieldBase&>(t)
117 .Get<ImplicitWeakTypeHandler<T> >(i)
118 .IsInitialized()) {
119 return false;
120 }
121 }
122 return true;
123}
124
125inline bool IsPresent(const void* base, uint32 hasbit) {
126 const uint32* has_bits_array = static_cast<const uint32*>(base);
127 return (has_bits_array[hasbit / 32] & (1u << (hasbit & 31))) != 0;
128}
129
130inline bool IsOneofPresent(const void* base, uint32 offset, uint32 tag) {
131 const uint32* oneof =
132 reinterpret_cast<const uint32*>(static_cast<const uint8*>(base) + offset);
133 return *oneof == tag >> 3;
134}
135
136typedef void (*SpecialSerializer)(const uint8* base, uint32 offset, uint32 tag,
137 uint32 has_offset,
138 io::CodedOutputStream* output);
139
140PROTOBUF_EXPORT void ExtensionSerializer(const uint8* base, uint32 offset,
141 uint32 tag, uint32 has_offset,
142 io::CodedOutputStream* output);
143PROTOBUF_EXPORT void UnknownFieldSerializerLite(const uint8* base,
144 uint32 offset, uint32 tag,
145 uint32 has_offset,
146 io::CodedOutputStream* output);
147
148PROTOBUF_EXPORT MessageLite* DuplicateIfNonNullInternal(MessageLite* message);
149PROTOBUF_EXPORT MessageLite* GetOwnedMessageInternal(Arena* message_arena,
150 MessageLite* submessage,
151 Arena* submessage_arena);
152PROTOBUF_EXPORT void GenericSwap(MessageLite* m1, MessageLite* m2);
153// We specialize GenericSwap for non-lite messages to benefit from reflection.
154PROTOBUF_EXPORT void GenericSwap(Message* m1, Message* m2);
155
156template <typename T>
157T* DuplicateIfNonNull(T* message) {
158 // The casts must be reinterpret_cast<> because T might be a forward-declared
159 // type that the compiler doesn't know is related to MessageLite.
160 return reinterpret_cast<T*>(
161 DuplicateIfNonNullInternal(message: reinterpret_cast<MessageLite*>(message)));
162}
163
164template <typename T>
165T* GetOwnedMessage(Arena* message_arena, T* submessage,
166 Arena* submessage_arena) {
167 // The casts must be reinterpret_cast<> because T might be a forward-declared
168 // type that the compiler doesn't know is related to MessageLite.
169 return reinterpret_cast<T*>(GetOwnedMessageInternal(
170 message_arena, submessage: reinterpret_cast<MessageLite*>(submessage),
171 submessage_arena));
172}
173
174// Hide atomic from the public header and allow easy change to regular int
175// on platforms where the atomic might have a perf impact.
176class PROTOBUF_EXPORT CachedSize {
177 public:
178 int Get() const { return size_.load(m: std::memory_order_relaxed); }
179 void Set(int size) { size_.store(i: size, m: std::memory_order_relaxed); }
180
181 private:
182 std::atomic<int> size_{0};
183};
184
185// SCCInfo represents information of a strongly connected component of
186// mutual dependent messages.
187struct PROTOBUF_EXPORT SCCInfoBase {
188 // We use 0 for the Initialized state, because test eax,eax, jnz is smaller
189 // and is subject to macro fusion.
190 enum {
191 kInitialized = 0, // final state
192 kRunning = 1,
193 kUninitialized = -1, // initial state
194 };
195#if defined(_MSC_VER) && !defined(__clang__)
196 // MSVC doesn't make std::atomic constant initialized. This union trick
197 // makes it so.
198 union {
199 int visit_status_to_make_linker_init;
200 std::atomic<int> visit_status;
201 };
202#else
203 std::atomic<int> visit_status;
204#endif
205 int num_deps;
206 int num_implicit_weak_deps;
207 void (*init_func)();
208 // This is followed by an array of num_deps
209 // const SCCInfoBase* deps[];
210};
211
212// Zero-length arrays are a language extension available in GCC and Clang but
213// not MSVC.
214#ifdef __GNUC__
215#define PROTOBUF_ARRAY_SIZE(n) (n)
216#else
217#define PROTOBUF_ARRAY_SIZE(n) ((n) ? (n) : 1)
218#endif
219
220template <int N>
221struct SCCInfo {
222 SCCInfoBase base;
223 // Semantically this is const SCCInfo<T>* which is is a templated type.
224 // The obvious inheriting from SCCInfoBase mucks with struct initialization.
225 // Attempts showed the compiler was generating dynamic initialization code.
226 // This deps array consists of base.num_deps pointers to SCCInfoBase followed
227 // by base.num_implicit_weak_deps pointers to SCCInfoBase*. We need the extra
228 // pointer indirection for implicit weak fields. We cannot use a union type
229 // here, since that would prevent the array from being linker-initialized.
230 void* deps[PROTOBUF_ARRAY_SIZE(N)];
231};
232
233#undef PROTOBUF_ARRAY_SIZE
234
235PROTOBUF_EXPORT void InitSCCImpl(SCCInfoBase* scc);
236
237inline void InitSCC(SCCInfoBase* scc) {
238 auto status = scc->visit_status.load(m: std::memory_order_acquire);
239 if (PROTOBUF_PREDICT_FALSE(status != SCCInfoBase::kInitialized))
240 InitSCCImpl(scc);
241}
242
243PROTOBUF_EXPORT void DestroyMessage(const void* message);
244PROTOBUF_EXPORT void DestroyString(const void* s);
245// Destroy (not delete) the message
246inline void OnShutdownDestroyMessage(const void* ptr) {
247 OnShutdownRun(f: DestroyMessage, arg: ptr);
248}
249// Destroy the string (call std::string destructor)
250inline void OnShutdownDestroyString(const std::string* ptr) {
251 OnShutdownRun(f: DestroyString, arg: ptr);
252}
253
254} // namespace internal
255} // namespace protobuf
256} // namespace google
257
258#include <google/protobuf/port_undef.inc>
259
260#endif // GOOGLE_PROTOBUF_GENERATED_MESSAGE_UTIL_H__
261

source code of include/google/protobuf/generated_message_util.h