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/stubs/strutil.h>
46
47namespace google {
48namespace protobuf {
49namespace compiler {
50namespace java {
51
52namespace {
53
54// Recursively searches the given message to see if it contains any extensions.
55bool UsesExtensions(const Message& message) {
56  const Reflection* reflection = message.GetReflection();
57
58  // We conservatively assume that unknown fields are extensions.
59  if (reflection->GetUnknownFields(message).field_count() > 0) return true;
60
61  vector<const FieldDescriptor*> fields;
62  reflection->ListFields(message, &fields);
63
64  for (int i = 0; i < fields.size(); i++) {
65    if (fields[i]->is_extension()) return true;
66
67    if (GetJavaType(fields[i]) == JAVATYPE_MESSAGE) {
68      if (fields[i]->is_repeated()) {
69        int size = reflection->FieldSize(message, fields[i]);
70        for (int j = 0; j < size; j++) {
71          const Message& sub_message =
72            reflection->GetRepeatedMessage(message, fields[i], j);
73          if (UsesExtensions(sub_message)) return true;
74        }
75      } else {
76        const Message& sub_message = reflection->GetMessage(message, fields[i]);
77        if (UsesExtensions(sub_message)) return true;
78      }
79    }
80  }
81
82  return false;
83}
84
85
86}  // namespace
87
88FileGenerator::FileGenerator(const FileDescriptor* file)
89  : file_(file),
90    java_package_(FileJavaPackage(file)),
91    classname_(FileClassName(file)) {}
92
93FileGenerator::~FileGenerator() {}
94
95bool FileGenerator::Validate(string* error) {
96  // Check that no class name matches the file's class name.  This is a common
97  // problem that leads to Java compile errors that can be hard to understand.
98  // It's especially bad when using the java_multiple_files, since we would
99  // end up overwriting the outer class with one of the inner ones.
100
101  bool found_conflict = false;
102  for (int i = 0; i < file_->enum_type_count() && !found_conflict; i++) {
103    if (file_->enum_type(i)->name() == classname_) {
104      found_conflict = true;
105    }
106  }
107  for (int i = 0; i < file_->message_type_count() && !found_conflict; i++) {
108    if (file_->message_type(i)->name() == classname_) {
109      found_conflict = true;
110    }
111  }
112  for (int i = 0; i < file_->service_count() && !found_conflict; i++) {
113    if (file_->service(i)->name() == classname_) {
114      found_conflict = true;
115    }
116  }
117
118  if (found_conflict) {
119    error->assign(file_->name());
120    error->append(
121      ": Cannot generate Java output because the file's outer class name, \"");
122    error->append(classname_);
123    error->append(
124      "\", matches the name of one of the types declared inside it.  "
125      "Please either rename the type or use the java_outer_classname "
126      "option to specify a different outer class name for the .proto file.");
127    return false;
128  }
129
130  return true;
131}
132
133void FileGenerator::Generate(io::Printer* printer) {
134  // We don't import anything because we refer to all classes by their
135  // fully-qualified names in the generated source.
136  printer->Print(
137    "// Generated by the protocol buffer compiler.  DO NOT EDIT!\n"
138    "// source: $filename$\n"
139    "\n",
140    "filename", file_->name());
141  if (!java_package_.empty()) {
142    printer->Print(
143      "package $package$;\n"
144      "\n",
145      "package", java_package_);
146  }
147  printer->Print(
148    "public final class $classname$ {\n"
149    "  private $classname$() {}\n",
150    "classname", classname_);
151  printer->Indent();
152
153  // -----------------------------------------------------------------
154
155  printer->Print(
156    "public static void registerAllExtensions(\n"
157    "    com.google.protobuf.ExtensionRegistry$lite$ registry) {\n",
158    "lite", HasDescriptorMethods(file_) ? "" : "Lite");
159
160  printer->Indent();
161
162  for (int i = 0; i < file_->extension_count(); i++) {
163    ExtensionGenerator(file_->extension(i)).GenerateRegistrationCode(printer);
164  }
165
166  for (int i = 0; i < file_->message_type_count(); i++) {
167    MessageGenerator(file_->message_type(i))
168      .GenerateExtensionRegistrationCode(printer);
169  }
170
171  printer->Outdent();
172  printer->Print(
173    "}\n");
174
175  // -----------------------------------------------------------------
176
177  if (!file_->options().java_multiple_files()) {
178    for (int i = 0; i < file_->enum_type_count(); i++) {
179      EnumGenerator(file_->enum_type(i)).Generate(printer);
180    }
181    for (int i = 0; i < file_->message_type_count(); i++) {
182      MessageGenerator(file_->message_type(i)).Generate(printer);
183    }
184    if (HasGenericServices(file_)) {
185      for (int i = 0; i < file_->service_count(); i++) {
186        ServiceGenerator(file_->service(i)).Generate(printer);
187      }
188    }
189  }
190
191  // Extensions must be generated in the outer class since they are values,
192  // not classes.
193  for (int i = 0; i < file_->extension_count(); i++) {
194    ExtensionGenerator(file_->extension(i)).Generate(printer);
195  }
196
197  // Static variables.
198  for (int i = 0; i < file_->message_type_count(); i++) {
199    // TODO(kenton):  Reuse MessageGenerator objects?
200    MessageGenerator(file_->message_type(i)).GenerateStaticVariables(printer);
201  }
202
203  printer->Print("\n");
204
205  if (HasDescriptorMethods(file_)) {
206    GenerateEmbeddedDescriptor(printer);
207  } else {
208    printer->Print(
209      "static {\n");
210    printer->Indent();
211
212    for (int i = 0; i < file_->message_type_count(); i++) {
213      // TODO(kenton):  Reuse MessageGenerator objects?
214      MessageGenerator(file_->message_type(i))
215        .GenerateStaticVariableInitializers(printer);
216    }
217
218    for (int i = 0; i < file_->extension_count(); i++) {
219      // TODO(kenton):  Reuse ExtensionGenerator objects?
220      ExtensionGenerator(file_->extension(i))
221        .GenerateInitializationCode(printer);
222    }
223
224    printer->Outdent();
225    printer->Print(
226      "}\n");
227  }
228
229  // Dummy function we can use to force the static initialization block to
230  // run.  Needed by inner classes.  Cannot be private due to
231  // java_multiple_files option.
232  printer->Print(
233    "\n"
234    "public static void internalForceInit() {}\n");
235
236  printer->Print(
237    "\n"
238    "// @@protoc_insertion_point(outer_class_scope)\n");
239
240  printer->Outdent();
241  printer->Print("}\n");
242}
243
244void FileGenerator::GenerateEmbeddedDescriptor(io::Printer* printer) {
245  // Embed the descriptor.  We simply serialize the entire FileDescriptorProto
246  // and embed it as a string literal, which is parsed and built into real
247  // descriptors at initialization time.  We unfortunately have to put it in
248  // a string literal, not a byte array, because apparently using a literal
249  // byte array causes the Java compiler to generate *instructions* to
250  // initialize each and every byte of the array, e.g. as if you typed:
251  //   b[0] = 123; b[1] = 456; b[2] = 789;
252  // This makes huge bytecode files and can easily hit the compiler's internal
253  // code size limits (error "code to large").  String literals are apparently
254  // embedded raw, which is what we want.
255  FileDescriptorProto file_proto;
256  file_->CopyTo(&file_proto);
257
258  string file_data;
259  file_proto.SerializeToString(&file_data);
260
261  printer->Print(
262    "public static com.google.protobuf.Descriptors.FileDescriptor\n"
263    "    getDescriptor() {\n"
264    "  return descriptor;\n"
265    "}\n"
266    "private static com.google.protobuf.Descriptors.FileDescriptor\n"
267    "    descriptor;\n"
268    "static {\n"
269    "  java.lang.String[] descriptorData = {\n");
270  printer->Indent();
271  printer->Indent();
272
273  // Only write 40 bytes per line.
274  static const int kBytesPerLine = 40;
275  for (int i = 0; i < file_data.size(); i += kBytesPerLine) {
276    if (i > 0) {
277      // Every 400 lines, start a new string literal, in order to avoid the
278      // 64k length limit.
279      if (i % 400 == 0) {
280        printer->Print(",\n");
281      } else {
282        printer->Print(" +\n");
283      }
284    }
285    printer->Print("\"$data$\"",
286      "data", CEscape(file_data.substr(i, kBytesPerLine)));
287  }
288
289  printer->Outdent();
290  printer->Print("\n};\n");
291
292  // -----------------------------------------------------------------
293  // Create the InternalDescriptorAssigner.
294
295  printer->Print(
296    "com.google.protobuf.Descriptors.FileDescriptor."
297      "InternalDescriptorAssigner assigner =\n"
298    "  new com.google.protobuf.Descriptors.FileDescriptor."
299      "InternalDescriptorAssigner() {\n"
300    "    public com.google.protobuf.ExtensionRegistry assignDescriptors(\n"
301    "        com.google.protobuf.Descriptors.FileDescriptor root) {\n"
302    "      descriptor = root;\n");
303
304  printer->Indent();
305  printer->Indent();
306  printer->Indent();
307
308  for (int i = 0; i < file_->message_type_count(); i++) {
309    // TODO(kenton):  Reuse MessageGenerator objects?
310    MessageGenerator(file_->message_type(i))
311      .GenerateStaticVariableInitializers(printer);
312  }
313
314  for (int i = 0; i < file_->extension_count(); i++) {
315    // TODO(kenton):  Reuse ExtensionGenerator objects?
316    ExtensionGenerator(file_->extension(i))
317      .GenerateInitializationCode(printer);
318  }
319
320  if (UsesExtensions(file_proto)) {
321    // Must construct an ExtensionRegistry containing all possible extensions
322    // and return it.
323    printer->Print(
324      "com.google.protobuf.ExtensionRegistry registry =\n"
325      "  com.google.protobuf.ExtensionRegistry.newInstance();\n"
326      "registerAllExtensions(registry);\n");
327    for (int i = 0; i < file_->dependency_count(); i++) {
328      printer->Print(
329        "$dependency$.registerAllExtensions(registry);\n",
330        "dependency", ClassName(file_->dependency(i)));
331    }
332    printer->Print(
333      "return registry;\n");
334  } else {
335    printer->Print(
336      "return null;\n");
337  }
338
339  printer->Outdent();
340  printer->Outdent();
341  printer->Outdent();
342
343  printer->Print(
344    "    }\n"
345    "  };\n");
346
347  // -----------------------------------------------------------------
348  // Invoke internalBuildGeneratedFileFrom() to build the file.
349
350  printer->Print(
351    "com.google.protobuf.Descriptors.FileDescriptor\n"
352    "  .internalBuildGeneratedFileFrom(descriptorData,\n"
353    "    new com.google.protobuf.Descriptors.FileDescriptor[] {\n");
354
355  for (int i = 0; i < file_->dependency_count(); i++) {
356    if (ShouldIncludeDependency(file_->dependency(i))) {
357      printer->Print(
358        "      $dependency$.getDescriptor(),\n",
359        "dependency", ClassName(file_->dependency(i)));
360    }
361  }
362
363  printer->Print(
364    "    }, assigner);\n");
365
366  printer->Outdent();
367  printer->Print(
368    "}\n");
369}
370
371template<typename GeneratorClass, typename DescriptorClass>
372static void GenerateSibling(const string& package_dir,
373                            const string& java_package,
374                            const DescriptorClass* descriptor,
375                            OutputDirectory* output_directory,
376                            vector<string>* file_list) {
377  string filename = package_dir + descriptor->name() + ".java";
378  file_list->push_back(filename);
379
380  scoped_ptr<io::ZeroCopyOutputStream> output(
381    output_directory->Open(filename));
382  io::Printer printer(output.get(), '$');
383
384  printer.Print(
385    "// Generated by the protocol buffer compiler.  DO NOT EDIT!\n"
386    "\n");
387  if (!java_package.empty()) {
388    printer.Print(
389      "package $package$;\n"
390      "\n",
391      "package", java_package);
392  }
393
394  GeneratorClass(descriptor).Generate(&printer);
395}
396
397void FileGenerator::GenerateSiblings(const string& package_dir,
398                                     OutputDirectory* output_directory,
399                                     vector<string>* file_list) {
400  if (file_->options().java_multiple_files()) {
401    for (int i = 0; i < file_->enum_type_count(); i++) {
402      GenerateSibling<EnumGenerator>(package_dir, java_package_,
403                                     file_->enum_type(i),
404                                     output_directory, file_list);
405    }
406    for (int i = 0; i < file_->message_type_count(); i++) {
407      GenerateSibling<MessageGenerator>(package_dir, java_package_,
408                                        file_->message_type(i),
409                                        output_directory, file_list);
410    }
411    if (HasGenericServices(file_)) {
412      for (int i = 0; i < file_->service_count(); i++) {
413        GenerateSibling<ServiceGenerator>(package_dir, java_package_,
414                                          file_->service(i),
415                                          output_directory, file_list);
416      }
417    }
418  }
419}
420
421bool FileGenerator::ShouldIncludeDependency(const FileDescriptor* descriptor) {
422  return true;
423}
424
425}  // namespace java
426}  // namespace compiler
427}  // namespace protobuf
428}  // namespace google
429