1// Protocol Buffers - Google's data interchange format 2// Copyright 2008 Google Inc. All rights reserved. 3// http://code.google.com/p/protobuf/ 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 <google/protobuf/compiler/java/java_file.h> 36#include <google/protobuf/compiler/java/java_enum.h> 37#include <google/protobuf/compiler/java/java_service.h> 38#include <google/protobuf/compiler/java/java_extension.h> 39#include <google/protobuf/compiler/java/java_helpers.h> 40#include <google/protobuf/compiler/java/java_message.h> 41#include <google/protobuf/compiler/code_generator.h> 42#include <google/protobuf/io/printer.h> 43#include <google/protobuf/io/zero_copy_stream.h> 44#include <google/protobuf/descriptor.pb.h> 45#include <google/protobuf/dynamic_message.h> 46#include <google/protobuf/stubs/strutil.h> 47 48namespace google { 49namespace protobuf { 50namespace compiler { 51namespace java { 52 53namespace { 54 55 56// Recursively searches the given message to collect extensions. 57// Returns true if all the extensions can be recognized. The extensions will be 58// appended in to the extensions parameter. 59// Returns false when there are unknown fields, in which case the data in the 60// extensions output parameter is not reliable and should be discarded. 61bool CollectExtensions(const Message& message, 62 vector<const FieldDescriptor*>* extensions) { 63 const Reflection* reflection = message.GetReflection(); 64 65 // There are unknown fields that could be extensions, thus this call fails. 66 if (reflection->GetUnknownFields(message).field_count() > 0) return false; 67 68 vector<const FieldDescriptor*> fields; 69 reflection->ListFields(message, &fields); 70 71 for (int i = 0; i < fields.size(); i++) { 72 if (fields[i]->is_extension()) extensions->push_back(fields[i]); 73 74 if (GetJavaType(fields[i]) == JAVATYPE_MESSAGE) { 75 if (fields[i]->is_repeated()) { 76 int size = reflection->FieldSize(message, fields[i]); 77 for (int j = 0; j < size; j++) { 78 const Message& sub_message = 79 reflection->GetRepeatedMessage(message, fields[i], j); 80 if (!CollectExtensions(sub_message, extensions)) return false; 81 } 82 } else { 83 const Message& sub_message = reflection->GetMessage(message, fields[i]); 84 if (!CollectExtensions(sub_message, extensions)) return false; 85 } 86 } 87 } 88 89 return true; 90} 91 92// Finds all extensions in the given message and its sub-messages. If the 93// message contains unknown fields (which could be extensions), then those 94// extensions are defined in alternate_pool. 95// The message will be converted to a DynamicMessage backed by alternate_pool 96// in order to handle this case. 97void CollectExtensions(const FileDescriptorProto& file_proto, 98 const DescriptorPool& alternate_pool, 99 vector<const FieldDescriptor*>* extensions, 100 const string& file_data) { 101 if (!CollectExtensions(file_proto, extensions)) { 102 // There are unknown fields in the file_proto, which are probably 103 // extensions. We need to parse the data into a dynamic message based on the 104 // builder-pool to find out all extensions. 105 const Descriptor* file_proto_desc = alternate_pool.FindMessageTypeByName( 106 file_proto.GetDescriptor()->full_name()); 107 GOOGLE_CHECK(file_proto_desc) 108 << "Find unknown fields in FileDescriptorProto when building " 109 << file_proto.name() 110 << ". It's likely that those fields are custom options, however, " 111 "descriptor.proto is not in the transitive dependencies. " 112 "This normally should not happen. Please report a bug."; 113 DynamicMessageFactory factory; 114 scoped_ptr<Message> dynamic_file_proto( 115 factory.GetPrototype(file_proto_desc)->New()); 116 GOOGLE_CHECK(dynamic_file_proto.get() != NULL); 117 GOOGLE_CHECK(dynamic_file_proto->ParseFromString(file_data)); 118 119 // Collect the extensions again from the dynamic message. There should be no 120 // more unknown fields this time, i.e. all the custom options should be 121 // parsed as extensions now. 122 extensions->clear(); 123 GOOGLE_CHECK(CollectExtensions(*dynamic_file_proto, extensions)) 124 << "Find unknown fields in FileDescriptorProto when building " 125 << file_proto.name() 126 << ". It's likely that those fields are custom options, however, " 127 "those options cannot be recognized in the builder pool. " 128 "This normally should not happen. Please report a bug."; 129 } 130} 131 132 133} // namespace 134 135FileGenerator::FileGenerator(const FileDescriptor* file) 136 : file_(file), 137 java_package_(FileJavaPackage(file)), 138 classname_(FileClassName(file)) { 139} 140 141FileGenerator::~FileGenerator() {} 142 143bool FileGenerator::Validate(string* error) { 144 // Check that no class name matches the file's class name. This is a common 145 // problem that leads to Java compile errors that can be hard to understand. 146 // It's especially bad when using the java_multiple_files, since we would 147 // end up overwriting the outer class with one of the inner ones. 148 149 bool found_conflict = false; 150 for (int i = 0; i < file_->enum_type_count() && !found_conflict; i++) { 151 if (file_->enum_type(i)->name() == classname_) { 152 found_conflict = true; 153 } 154 } 155 for (int i = 0; i < file_->message_type_count() && !found_conflict; i++) { 156 if (file_->message_type(i)->name() == classname_) { 157 found_conflict = true; 158 } 159 } 160 for (int i = 0; i < file_->service_count() && !found_conflict; i++) { 161 if (file_->service(i)->name() == classname_) { 162 found_conflict = true; 163 } 164 } 165 166 if (found_conflict) { 167 error->assign(file_->name()); 168 error->append( 169 ": Cannot generate Java output because the file's outer class name, \""); 170 error->append(classname_); 171 error->append( 172 "\", matches the name of one of the types declared inside it. " 173 "Please either rename the type or use the java_outer_classname " 174 "option to specify a different outer class name for the .proto file."); 175 return false; 176 } 177 178 return true; 179} 180 181void FileGenerator::Generate(io::Printer* printer) { 182 // We don't import anything because we refer to all classes by their 183 // fully-qualified names in the generated source. 184 printer->Print( 185 "// Generated by the protocol buffer compiler. DO NOT EDIT!\n" 186 "// source: $filename$\n" 187 "\n", 188 "filename", file_->name()); 189 if (!java_package_.empty()) { 190 printer->Print( 191 "package $package$;\n" 192 "\n", 193 "package", java_package_); 194 } 195 printer->Print( 196 "public final class $classname$ {\n" 197 " private $classname$() {}\n", 198 "classname", classname_); 199 printer->Indent(); 200 201 // ----------------------------------------------------------------- 202 203 printer->Print( 204 "public static void registerAllExtensions(\n" 205 " com.google.protobuf.ExtensionRegistry$lite$ registry) {\n", 206 "lite", HasDescriptorMethods(file_) ? "" : "Lite"); 207 208 printer->Indent(); 209 210 for (int i = 0; i < file_->extension_count(); i++) { 211 ExtensionGenerator(file_->extension(i)).GenerateRegistrationCode(printer); 212 } 213 214 for (int i = 0; i < file_->message_type_count(); i++) { 215 MessageGenerator(file_->message_type(i)) 216 .GenerateExtensionRegistrationCode(printer); 217 } 218 219 printer->Outdent(); 220 printer->Print( 221 "}\n"); 222 223 // ----------------------------------------------------------------- 224 225 if (!file_->options().java_multiple_files()) { 226 for (int i = 0; i < file_->enum_type_count(); i++) { 227 EnumGenerator(file_->enum_type(i)).Generate(printer); 228 } 229 for (int i = 0; i < file_->message_type_count(); i++) { 230 MessageGenerator messageGenerator(file_->message_type(i)); 231 messageGenerator.GenerateInterface(printer); 232 messageGenerator.Generate(printer); 233 } 234 if (HasGenericServices(file_)) { 235 for (int i = 0; i < file_->service_count(); i++) { 236 ServiceGenerator(file_->service(i)).Generate(printer); 237 } 238 } 239 } 240 241 // Extensions must be generated in the outer class since they are values, 242 // not classes. 243 for (int i = 0; i < file_->extension_count(); i++) { 244 ExtensionGenerator(file_->extension(i)).Generate(printer); 245 } 246 247 // Static variables. 248 for (int i = 0; i < file_->message_type_count(); i++) { 249 // TODO(kenton): Reuse MessageGenerator objects? 250 MessageGenerator(file_->message_type(i)).GenerateStaticVariables(printer); 251 } 252 253 printer->Print("\n"); 254 255 if (HasDescriptorMethods(file_)) { 256 GenerateEmbeddedDescriptor(printer); 257 } else { 258 printer->Print( 259 "static {\n"); 260 printer->Indent(); 261 262 for (int i = 0; i < file_->message_type_count(); i++) { 263 // TODO(kenton): Reuse MessageGenerator objects? 264 MessageGenerator(file_->message_type(i)) 265 .GenerateStaticVariableInitializers(printer); 266 } 267 268 printer->Outdent(); 269 printer->Print( 270 "}\n"); 271 } 272 273 printer->Print( 274 "\n" 275 "// @@protoc_insertion_point(outer_class_scope)\n"); 276 277 printer->Outdent(); 278 printer->Print("}\n"); 279} 280 281void FileGenerator::GenerateEmbeddedDescriptor(io::Printer* printer) { 282 // Embed the descriptor. We simply serialize the entire FileDescriptorProto 283 // and embed it as a string literal, which is parsed and built into real 284 // descriptors at initialization time. We unfortunately have to put it in 285 // a string literal, not a byte array, because apparently using a literal 286 // byte array causes the Java compiler to generate *instructions* to 287 // initialize each and every byte of the array, e.g. as if you typed: 288 // b[0] = 123; b[1] = 456; b[2] = 789; 289 // This makes huge bytecode files and can easily hit the compiler's internal 290 // code size limits (error "code to large"). String literals are apparently 291 // embedded raw, which is what we want. 292 FileDescriptorProto file_proto; 293 file_->CopyTo(&file_proto); 294 295 string file_data; 296 file_proto.SerializeToString(&file_data); 297 298 printer->Print( 299 "public static com.google.protobuf.Descriptors.FileDescriptor\n" 300 " getDescriptor() {\n" 301 " return descriptor;\n" 302 "}\n" 303 "private static com.google.protobuf.Descriptors.FileDescriptor\n" 304 " descriptor;\n" 305 "static {\n" 306 " java.lang.String[] descriptorData = {\n"); 307 printer->Indent(); 308 printer->Indent(); 309 310 // Only write 40 bytes per line. 311 static const int kBytesPerLine = 40; 312 for (int i = 0; i < file_data.size(); i += kBytesPerLine) { 313 if (i > 0) { 314 // Every 400 lines, start a new string literal, in order to avoid the 315 // 64k length limit. 316 if (i % 400 == 0) { 317 printer->Print(",\n"); 318 } else { 319 printer->Print(" +\n"); 320 } 321 } 322 printer->Print("\"$data$\"", 323 "data", CEscape(file_data.substr(i, kBytesPerLine))); 324 } 325 326 printer->Outdent(); 327 printer->Print("\n};\n"); 328 329 // ----------------------------------------------------------------- 330 // Create the InternalDescriptorAssigner. 331 332 printer->Print( 333 "com.google.protobuf.Descriptors.FileDescriptor." 334 "InternalDescriptorAssigner assigner =\n" 335 " new com.google.protobuf.Descriptors.FileDescriptor." 336 "InternalDescriptorAssigner() {\n" 337 " public com.google.protobuf.ExtensionRegistry assignDescriptors(\n" 338 " com.google.protobuf.Descriptors.FileDescriptor root) {\n" 339 " descriptor = root;\n"); 340 341 printer->Indent(); 342 printer->Indent(); 343 printer->Indent(); 344 345 for (int i = 0; i < file_->message_type_count(); i++) { 346 // TODO(kenton): Reuse MessageGenerator objects? 347 MessageGenerator(file_->message_type(i)) 348 .GenerateStaticVariableInitializers(printer); 349 } 350 for (int i = 0; i < file_->extension_count(); i++) { 351 // TODO(kenton): Reuse ExtensionGenerator objects? 352 ExtensionGenerator(file_->extension(i)) 353 .GenerateNonNestedInitializationCode(printer); 354 } 355 356 // Proto compiler builds a DescriptorPool, which holds all the descriptors to 357 // generate, when processing the ".proto" files. We call this DescriptorPool 358 // the parsed pool (a.k.a. file_->pool()). 359 // 360 // Note that when users try to extend the (.*)DescriptorProto in their 361 // ".proto" files, it does not affect the pre-built FileDescriptorProto class 362 // in proto compiler. When we put the descriptor data in the file_proto, those 363 // extensions become unknown fields. 364 // 365 // Now we need to find out all the extension value to the (.*)DescriptorProto 366 // in the file_proto message, and prepare an ExtensionRegistry to return. 367 // 368 // To find those extensions, we need to parse the data into a dynamic message 369 // of the FileDescriptor based on the builder-pool, then we can use 370 // reflections to find all extension fields 371 vector<const FieldDescriptor*> extensions; 372 CollectExtensions(file_proto, *file_->pool(), &extensions, file_data); 373 374 if (extensions.size() > 0) { 375 // Must construct an ExtensionRegistry containing all existing extensions 376 // and return it. 377 printer->Print( 378 "com.google.protobuf.ExtensionRegistry registry =\n" 379 " com.google.protobuf.ExtensionRegistry.newInstance();\n"); 380 for (int i = 0; i < extensions.size(); i++) { 381 ExtensionGenerator(extensions[i]).GenerateRegistrationCode(printer); 382 } 383 printer->Print( 384 "return registry;\n"); 385 } else { 386 printer->Print( 387 "return null;\n"); 388 } 389 390 printer->Outdent(); 391 printer->Outdent(); 392 printer->Outdent(); 393 394 printer->Print( 395 " }\n" 396 " };\n"); 397 398 // ----------------------------------------------------------------- 399 // Invoke internalBuildGeneratedFileFrom() to build the file. 400 401 printer->Print( 402 "com.google.protobuf.Descriptors.FileDescriptor\n" 403 " .internalBuildGeneratedFileFrom(descriptorData,\n" 404 " new com.google.protobuf.Descriptors.FileDescriptor[] {\n"); 405 406 for (int i = 0; i < file_->dependency_count(); i++) { 407 if (ShouldIncludeDependency(file_->dependency(i))) { 408 printer->Print( 409 " $dependency$.getDescriptor(),\n", 410 "dependency", ClassName(file_->dependency(i))); 411 } 412 } 413 414 printer->Print( 415 " }, assigner);\n"); 416 417 printer->Outdent(); 418 printer->Print( 419 "}\n"); 420} 421 422template<typename GeneratorClass, typename DescriptorClass> 423static void GenerateSibling(const string& package_dir, 424 const string& java_package, 425 const DescriptorClass* descriptor, 426 GeneratorContext* context, 427 vector<string>* file_list, 428 const string& name_suffix, 429 void (GeneratorClass::*pfn)(io::Printer* printer)) { 430 string filename = package_dir + descriptor->name() + name_suffix + ".java"; 431 file_list->push_back(filename); 432 433 scoped_ptr<io::ZeroCopyOutputStream> output(context->Open(filename)); 434 io::Printer printer(output.get(), '$'); 435 436 printer.Print( 437 "// Generated by the protocol buffer compiler. DO NOT EDIT!\n" 438 "// source: $filename$\n" 439 "\n", 440 "filename", descriptor->file()->name()); 441 if (!java_package.empty()) { 442 printer.Print( 443 "package $package$;\n" 444 "\n", 445 "package", java_package); 446 } 447 448 GeneratorClass generator(descriptor); 449 (generator.*pfn)(&printer); 450} 451 452void FileGenerator::GenerateSiblings(const string& package_dir, 453 GeneratorContext* context, 454 vector<string>* file_list) { 455 if (file_->options().java_multiple_files()) { 456 for (int i = 0; i < file_->enum_type_count(); i++) { 457 GenerateSibling<EnumGenerator>(package_dir, java_package_, 458 file_->enum_type(i), 459 context, file_list, "", 460 &EnumGenerator::Generate); 461 } 462 for (int i = 0; i < file_->message_type_count(); i++) { 463 GenerateSibling<MessageGenerator>(package_dir, java_package_, 464 file_->message_type(i), 465 context, file_list, "OrBuilder", 466 &MessageGenerator::GenerateInterface); 467 GenerateSibling<MessageGenerator>(package_dir, java_package_, 468 file_->message_type(i), 469 context, file_list, "", 470 &MessageGenerator::Generate); 471 } 472 if (HasGenericServices(file_)) { 473 for (int i = 0; i < file_->service_count(); i++) { 474 GenerateSibling<ServiceGenerator>(package_dir, java_package_, 475 file_->service(i), 476 context, file_list, "", 477 &ServiceGenerator::Generate); 478 } 479 } 480 } 481} 482 483bool FileGenerator::ShouldIncludeDependency(const FileDescriptor* descriptor) { 484 return true; 485} 486 487} // namespace java 488} // namespace compiler 489} // namespace protobuf 490} // namespace google 491