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 #include <map>
36
37 #include <google/protobuf/compiler/cpp/cpp_enum.h>
38 #include <google/protobuf/compiler/cpp/cpp_helpers.h>
39 #include <google/protobuf/io/printer.h>
40 #include <google/protobuf/stubs/strutil.h>
41
42 namespace google {
43 namespace protobuf {
44 namespace compiler {
45 namespace cpp {
46
47 namespace {
48 // The GOOGLE_ARRAYSIZE constant is the max enum value plus 1. If the max enum value
49 // is kint32max, GOOGLE_ARRAYSIZE will overflow. In such cases we should omit the
50 // generation of the GOOGLE_ARRAYSIZE constant.
ShouldGenerateArraySize(const EnumDescriptor * descriptor)51 bool ShouldGenerateArraySize(const EnumDescriptor* descriptor) {
52 int32 max_value = descriptor->value(0)->number();
53 for (int i = 0; i < descriptor->value_count(); i++) {
54 if (descriptor->value(i)->number() > max_value) {
55 max_value = descriptor->value(i)->number();
56 }
57 }
58 return max_value != kint32max;
59 }
60
61 // Returns the number of unique numeric enum values. This is less than
62 // descriptor->value_count() when there are aliased values.
CountUniqueValues(const EnumDescriptor * descriptor)63 int CountUniqueValues(const EnumDescriptor* descriptor) {
64 std::set<int> values;
65 for (int i = 0; i < descriptor->value_count(); ++i) {
66 values.insert(descriptor->value(i)->number());
67 }
68 return values.size();
69 }
70
71 } // namespace
72
EnumGenerator(const EnumDescriptor * descriptor,const std::map<std::string,std::string> & vars,const Options & options)73 EnumGenerator::EnumGenerator(const EnumDescriptor* descriptor,
74 const std::map<std::string, std::string>& vars,
75 const Options& options)
76 : descriptor_(descriptor),
77 classname_(ClassName(descriptor, false)),
78 options_(options),
79 generate_array_size_(ShouldGenerateArraySize(descriptor)),
80 variables_(vars) {
81 variables_["classname"] = classname_;
82 variables_["classtype"] = QualifiedClassName(descriptor_, options);
83 variables_["short_name"] = descriptor_->name();
84 variables_["nested_name"] = descriptor_->name();
85 variables_["resolved_name"] = ResolveKeyword(descriptor_->name());
86 variables_["prefix"] =
87 (descriptor_->containing_type() == NULL) ? "" : classname_ + "_";
88 }
89
~EnumGenerator()90 EnumGenerator::~EnumGenerator() {}
91
GenerateDefinition(io::Printer * printer)92 void EnumGenerator::GenerateDefinition(io::Printer* printer) {
93 Formatter format(printer, variables_);
94 format("enum ${1$$classname$$}$ : int {\n", descriptor_);
95 format.Indent();
96
97 const EnumValueDescriptor* min_value = descriptor_->value(0);
98 const EnumValueDescriptor* max_value = descriptor_->value(0);
99
100 for (int i = 0; i < descriptor_->value_count(); i++) {
101 auto format_value = format;
102 format_value.Set("name", EnumValueName(descriptor_->value(i)));
103 // In C++, an value of -2147483648 gets interpreted as the negative of
104 // 2147483648, and since 2147483648 can't fit in an integer, this produces a
105 // compiler warning. This works around that issue.
106 format_value.Set("number", Int32ToString(descriptor_->value(i)->number()));
107 format_value.Set("deprecation",
108 DeprecatedAttribute(options_, descriptor_->value(i)));
109
110 if (i > 0) format_value(",\n");
111 format_value("${1$$prefix$$name$$}$ $deprecation$= $number$",
112 descriptor_->value(i));
113
114 if (descriptor_->value(i)->number() < min_value->number()) {
115 min_value = descriptor_->value(i);
116 }
117 if (descriptor_->value(i)->number() > max_value->number()) {
118 max_value = descriptor_->value(i);
119 }
120 }
121
122 if (descriptor_->file()->syntax() == FileDescriptor::SYNTAX_PROTO3) {
123 // For new enum semantics: generate min and max sentinel values equal to
124 // INT32_MIN and INT32_MAX
125 if (descriptor_->value_count() > 0) format(",\n");
126 format(
127 "$classname$_$prefix$INT_MIN_SENTINEL_DO_NOT_USE_ = "
128 "std::numeric_limits<$int32$>::min(),\n"
129 "$classname$_$prefix$INT_MAX_SENTINEL_DO_NOT_USE_ = "
130 "std::numeric_limits<$int32$>::max()");
131 }
132
133 format.Outdent();
134 format("\n};\n");
135
136 format(
137 "$dllexport_decl $bool $classname$_IsValid(int value);\n"
138 "constexpr $classname$ ${1$$prefix$$short_name$_MIN$}$ = "
139 "$prefix$$2$;\n"
140 "constexpr $classname$ ${1$$prefix$$short_name$_MAX$}$ = "
141 "$prefix$$3$;\n",
142 descriptor_, EnumValueName(min_value), EnumValueName(max_value));
143
144 if (generate_array_size_) {
145 format(
146 "constexpr int ${1$$prefix$$short_name$_ARRAYSIZE$}$ = "
147 "$prefix$$short_name$_MAX + 1;\n\n",
148 descriptor_);
149 }
150
151 if (HasDescriptorMethods(descriptor_->file(), options_)) {
152 format(
153 "$dllexport_decl $const ::$proto_ns$::EnumDescriptor* "
154 "$classname$_descriptor();\n");
155 }
156
157 // The _Name and _Parse functions. The lite implementation is table-based, so
158 // we make sure to keep the tables hidden in the .cc file.
159 if (!HasDescriptorMethods(descriptor_->file(), options_)) {
160 format("const std::string& $classname$_Name($classname$ value);\n");
161 }
162 // The _Name() function accepts the enum type itself but also any integral
163 // type.
164 format(
165 "template<typename T>\n"
166 "inline const std::string& $classname$_Name(T enum_t_value) {\n"
167 " static_assert(::std::is_same<T, $classname$>::value ||\n"
168 " ::std::is_integral<T>::value,\n"
169 " \"Incorrect type passed to function $classname$_Name.\");\n");
170 if (HasDescriptorMethods(descriptor_->file(), options_)) {
171 format(
172 " return ::$proto_ns$::internal::NameOfEnum(\n"
173 " $classname$_descriptor(), enum_t_value);\n");
174 } else {
175 format(
176 " return $classname$_Name(static_cast<$classname$>(enum_t_value));\n");
177 }
178 format("}\n");
179
180 if (HasDescriptorMethods(descriptor_->file(), options_)) {
181 format(
182 "inline bool $classname$_Parse(\n"
183 " ::PROTOBUF_NAMESPACE_ID::ConstStringParam name, $classname$* "
184 "value) "
185 "{\n"
186 " return ::$proto_ns$::internal::ParseNamedEnum<$classname$>(\n"
187 " $classname$_descriptor(), name, value);\n"
188 "}\n");
189 } else {
190 format(
191 "bool $classname$_Parse(\n"
192 " ::PROTOBUF_NAMESPACE_ID::ConstStringParam name, $classname$* "
193 "value);\n");
194 }
195 }
196
GenerateGetEnumDescriptorSpecializations(io::Printer * printer)197 void EnumGenerator::GenerateGetEnumDescriptorSpecializations(
198 io::Printer* printer) {
199 Formatter format(printer, variables_);
200 format(
201 "template <> struct is_proto_enum< $classtype$> : ::std::true_type "
202 "{};\n");
203 if (HasDescriptorMethods(descriptor_->file(), options_)) {
204 format(
205 "template <>\n"
206 "inline const EnumDescriptor* GetEnumDescriptor< $classtype$>() {\n"
207 " return $classtype$_descriptor();\n"
208 "}\n");
209 }
210 }
211
GenerateSymbolImports(io::Printer * printer) const212 void EnumGenerator::GenerateSymbolImports(io::Printer* printer) const {
213 Formatter format(printer, variables_);
214 format("typedef $classname$ $resolved_name$;\n");
215
216 for (int j = 0; j < descriptor_->value_count(); j++) {
217 std::string deprecated_attr =
218 DeprecatedAttribute(options_, descriptor_->value(j));
219 format(
220 "$1$static constexpr $resolved_name$ ${2$$3$$}$ =\n"
221 " $classname$_$3$;\n",
222 deprecated_attr, descriptor_->value(j),
223 EnumValueName(descriptor_->value(j)));
224 }
225
226 format(
227 "static inline bool $nested_name$_IsValid(int value) {\n"
228 " return $classname$_IsValid(value);\n"
229 "}\n"
230 "static constexpr $resolved_name$ ${1$$nested_name$_MIN$}$ =\n"
231 " $classname$_$nested_name$_MIN;\n"
232 "static constexpr $resolved_name$ ${1$$nested_name$_MAX$}$ =\n"
233 " $classname$_$nested_name$_MAX;\n",
234 descriptor_);
235 if (generate_array_size_) {
236 format(
237 "static constexpr int ${1$$nested_name$_ARRAYSIZE$}$ =\n"
238 " $classname$_$nested_name$_ARRAYSIZE;\n",
239 descriptor_);
240 }
241
242 if (HasDescriptorMethods(descriptor_->file(), options_)) {
243 format(
244 "static inline const ::$proto_ns$::EnumDescriptor*\n"
245 "$nested_name$_descriptor() {\n"
246 " return $classname$_descriptor();\n"
247 "}\n");
248 }
249
250 format(
251 "template<typename T>\n"
252 "static inline const std::string& $nested_name$_Name(T enum_t_value) {\n"
253 " static_assert(::std::is_same<T, $resolved_name$>::value ||\n"
254 " ::std::is_integral<T>::value,\n"
255 " \"Incorrect type passed to function $nested_name$_Name.\");\n"
256 " return $classname$_Name(enum_t_value);\n"
257 "}\n");
258 format(
259 "static inline bool "
260 "$nested_name$_Parse(::PROTOBUF_NAMESPACE_ID::ConstStringParam name,\n"
261 " $resolved_name$* value) {\n"
262 " return $classname$_Parse(name, value);\n"
263 "}\n");
264 }
265
GenerateMethods(int idx,io::Printer * printer)266 void EnumGenerator::GenerateMethods(int idx, io::Printer* printer) {
267 Formatter format(printer, variables_);
268 if (HasDescriptorMethods(descriptor_->file(), options_)) {
269 format(
270 "const ::$proto_ns$::EnumDescriptor* $classname$_descriptor() {\n"
271 " ::$proto_ns$::internal::AssignDescriptors(&$desc_table$);\n"
272 " return $file_level_enum_descriptors$[$1$];\n"
273 "}\n",
274 idx);
275 }
276
277 format(
278 "bool $classname$_IsValid(int value) {\n"
279 " switch (value) {\n");
280
281 // Multiple values may have the same number. Make sure we only cover
282 // each number once by first constructing a set containing all valid
283 // numbers, then printing a case statement for each element.
284
285 std::set<int> numbers;
286 for (int j = 0; j < descriptor_->value_count(); j++) {
287 const EnumValueDescriptor* value = descriptor_->value(j);
288 numbers.insert(value->number());
289 }
290
291 for (std::set<int>::iterator iter = numbers.begin(); iter != numbers.end();
292 ++iter) {
293 format(" case $1$:\n", Int32ToString(*iter));
294 }
295
296 format(
297 " return true;\n"
298 " default:\n"
299 " return false;\n"
300 " }\n"
301 "}\n"
302 "\n");
303
304 if (!HasDescriptorMethods(descriptor_->file(), options_)) {
305 // In lite mode (where descriptors are unavailable), we generate separate
306 // tables for mapping between enum names and numbers. The _entries table
307 // contains the bulk of the data and is sorted by name, while
308 // _entries_by_number is sorted by number and just contains pointers into
309 // _entries. The two tables allow mapping from name to number and number to
310 // name, both in time logarithmic in the number of enum entries. This could
311 // probably be made faster, but for now the tables are intended to be simple
312 // and compact.
313 //
314 // Enums with allow_alias = true support multiple entries with the same
315 // numerical value. In cases where there are multiple names for the same
316 // number, we treat the first name appearing in the .proto file as the
317 // canonical one.
318 std::map<std::string, int> name_to_number;
319 std::map<int, std::string> number_to_canonical_name;
320 for (int i = 0; i < descriptor_->value_count(); i++) {
321 const EnumValueDescriptor* value = descriptor_->value(i);
322 name_to_number.emplace(value->name(), value->number());
323 // The same number may appear with multiple names, so we use emplace() to
324 // let the first name win.
325 number_to_canonical_name.emplace(value->number(), value->name());
326 }
327
328 format(
329 "static ::$proto_ns$::internal::ExplicitlyConstructed<std::string> "
330 "$classname$_strings[$1$] = {};\n\n",
331 CountUniqueValues(descriptor_));
332
333 // We concatenate all the names for a given enum into one big string
334 // literal. If instead we store an array of string literals, the linker
335 // seems to put all enum strings for a given .proto file in the same
336 // section, which hinders its ability to strip out unused strings.
337 format("static const char $classname$_names[] =");
338 for (const auto& p : name_to_number) {
339 format("\n \"$1$\"", p.first);
340 }
341 format(";\n\n");
342
343 format(
344 "static const ::$proto_ns$::internal::EnumEntry $classname$_entries[] "
345 "= {\n");
346 int i = 0;
347 std::map<int, int> number_to_index;
348 int data_index = 0;
349 for (const auto& p : name_to_number) {
350 format(" { {$classname$_names + $1$, $2$}, $3$ },\n", data_index,
351 p.first.size(), p.second);
352 if (number_to_canonical_name[p.second] == p.first) {
353 number_to_index.emplace(p.second, i);
354 }
355 ++i;
356 data_index += p.first.size();
357 }
358
359 format(
360 "};\n"
361 "\n"
362 "static const int $classname$_entries_by_number[] = {\n");
363 for (const auto& p : number_to_index) {
364 format(" $1$, // $2$ -> $3$\n", p.second, p.first,
365 number_to_canonical_name[p.first]);
366 }
367 format(
368 "};\n"
369 "\n");
370
371 format(
372 "const std::string& $classname$_Name(\n"
373 " $classname$ value) {\n"
374 " static const bool dummy =\n"
375 " ::$proto_ns$::internal::InitializeEnumStrings(\n"
376 " $classname$_entries,\n"
377 " $classname$_entries_by_number,\n"
378 " $1$, $classname$_strings);\n"
379 " (void) dummy;\n"
380 " int idx = ::$proto_ns$::internal::LookUpEnumName(\n"
381 " $classname$_entries,\n"
382 " $classname$_entries_by_number,\n"
383 " $1$, value);\n"
384 " return idx == -1 ? ::$proto_ns$::internal::GetEmptyString() :\n"
385 " $classname$_strings[idx].get();\n"
386 "}\n",
387 CountUniqueValues(descriptor_));
388 format(
389 "bool $classname$_Parse(\n"
390 " ::PROTOBUF_NAMESPACE_ID::ConstStringParam name, $classname$* "
391 "value) "
392 "{\n"
393 " int int_value;\n"
394 " bool success = ::$proto_ns$::internal::LookUpEnumValue(\n"
395 " $classname$_entries, $1$, name, &int_value);\n"
396 " if (success) {\n"
397 " *value = static_cast<$classname$>(int_value);\n"
398 " }\n"
399 " return success;\n"
400 "}\n",
401 descriptor_->value_count());
402 }
403
404 if (descriptor_->containing_type() != NULL) {
405 std::string parent = ClassName(descriptor_->containing_type(), false);
406 // Before C++17, we must define the static constants which were
407 // declared in the header, to give the linker a place to put them.
408 // But pre-2015 MSVC++ insists that we not.
409 format(
410 "#if (__cplusplus < 201703) && "
411 "(!defined(_MSC_VER) || _MSC_VER >= 1900)\n");
412
413 for (int i = 0; i < descriptor_->value_count(); i++) {
414 format("constexpr $classname$ $1$::$2$;\n", parent,
415 EnumValueName(descriptor_->value(i)));
416 }
417 format(
418 "constexpr $classname$ $1$::$nested_name$_MIN;\n"
419 "constexpr $classname$ $1$::$nested_name$_MAX;\n",
420 parent);
421 if (generate_array_size_) {
422 format("constexpr int $1$::$nested_name$_ARRAYSIZE;\n", parent);
423 }
424
425 format(
426 "#endif // (__cplusplus < 201703) && "
427 "(!defined(_MSC_VER) || _MSC_VER >= 1900)\n");
428 }
429 }
430
431 } // namespace cpp
432 } // namespace compiler
433 } // namespace protobuf
434 } // namespace google
435