1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc.  All rights reserved.
3 // https://developers.google.com/protocol-buffers/
4 //
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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 #include <string>
37 
38 #include <google/protobuf/compiler/java/java_context.h>
39 #include <google/protobuf/compiler/java/java_enum.h>
40 #include <google/protobuf/compiler/java/java_doc_comment.h>
41 #include <google/protobuf/compiler/java/java_helpers.h>
42 #include <google/protobuf/compiler/java/java_name_resolver.h>
43 #include <google/protobuf/io/printer.h>
44 #include <google/protobuf/descriptor.pb.h>
45 #include <google/protobuf/stubs/strutil.h>
46 
47 namespace google {
48 namespace protobuf {
49 namespace compiler {
50 namespace java {
51 
52 namespace {
EnumHasCustomOptions(const EnumDescriptor * descriptor)53 bool EnumHasCustomOptions(const EnumDescriptor* descriptor) {
54   if (descriptor->options().unknown_fields().field_count() > 0) return true;
55   for (int i = 0; i < descriptor->value_count(); ++i) {
56     const EnumValueDescriptor* value = descriptor->value(i);
57     if (value->options().unknown_fields().field_count() > 0) return true;
58   }
59   return false;
60 }
61 }  // namespace
62 
EnumGenerator(const EnumDescriptor * descriptor,bool immutable_api,Context * context)63 EnumGenerator::EnumGenerator(const EnumDescriptor* descriptor,
64                              bool immutable_api,
65                              Context* context)
66   : descriptor_(descriptor), immutable_api_(immutable_api),
67     name_resolver_(context->GetNameResolver())  {
68   for (int i = 0; i < descriptor_->value_count(); i++) {
69     const EnumValueDescriptor* value = descriptor_->value(i);
70     const EnumValueDescriptor* canonical_value =
71       descriptor_->FindValueByNumber(value->number());
72 
73     if (value == canonical_value) {
74       canonical_values_.push_back(value);
75     } else {
76       Alias alias;
77       alias.value = value;
78       alias.canonical_value = canonical_value;
79       aliases_.push_back(alias);
80     }
81   }
82 }
83 
~EnumGenerator()84 EnumGenerator::~EnumGenerator() {}
85 
Generate(io::Printer * printer)86 void EnumGenerator::Generate(io::Printer* printer) {
87   WriteEnumDocComment(printer, descriptor_);
88   if (HasDescriptorMethods(descriptor_)) {
89     printer->Print(
90       "public enum $classname$\n"
91       "    implements com.google.protobuf.ProtocolMessageEnum {\n",
92       "classname", descriptor_->name());
93   } else {
94     printer->Print(
95       "public enum $classname$\n"
96       "    implements com.google.protobuf.Internal.EnumLite {\n",
97       "classname", descriptor_->name());
98   }
99   printer->Indent();
100 
101   for (int i = 0; i < canonical_values_.size(); i++) {
102     map<string, string> vars;
103     vars["name"] = canonical_values_[i]->name();
104     vars["index"] = SimpleItoa(canonical_values_[i]->index());
105     vars["number"] = SimpleItoa(canonical_values_[i]->number());
106     WriteEnumValueDocComment(printer, canonical_values_[i]);
107     if (canonical_values_[i]->options().deprecated()) {
108       printer->Print("@java.lang.Deprecated\n");
109     }
110     printer->Print(vars,
111       "$name$($index$, $number$),\n");
112   }
113 
114   printer->Print(
115     ";\n"
116     "\n");
117 
118   // -----------------------------------------------------------------
119 
120   for (int i = 0; i < aliases_.size(); i++) {
121     map<string, string> vars;
122     vars["classname"] = descriptor_->name();
123     vars["name"] = aliases_[i].value->name();
124     vars["canonical_name"] = aliases_[i].canonical_value->name();
125     WriteEnumValueDocComment(printer, aliases_[i].value);
126     printer->Print(vars,
127       "public static final $classname$ $name$ = $canonical_name$;\n");
128   }
129 
130   for (int i = 0; i < descriptor_->value_count(); i++) {
131     map<string, string> vars;
132     vars["name"] = descriptor_->value(i)->name();
133     vars["number"] = SimpleItoa(descriptor_->value(i)->number());
134     WriteEnumValueDocComment(printer, descriptor_->value(i));
135     printer->Print(vars,
136       "public static final int $name$_VALUE = $number$;\n");
137   }
138   printer->Print("\n");
139 
140   // -----------------------------------------------------------------
141 
142   printer->Print(
143     "\n"
144     "public final int getNumber() { return value; }\n"
145     "\n"
146     "public static $classname$ valueOf(int value) {\n"
147     "  switch (value) {\n",
148     "classname", descriptor_->name());
149   printer->Indent();
150   printer->Indent();
151 
152   for (int i = 0; i < canonical_values_.size(); i++) {
153     printer->Print(
154       "case $number$: return $name$;\n",
155       "name", canonical_values_[i]->name(),
156       "number", SimpleItoa(canonical_values_[i]->number()));
157   }
158 
159   printer->Outdent();
160   printer->Outdent();
161   printer->Print(
162     "    default: return null;\n"
163     "  }\n"
164     "}\n"
165     "\n"
166     "public static com.google.protobuf.Internal.EnumLiteMap<$classname$>\n"
167     "    internalGetValueMap() {\n"
168     "  return internalValueMap;\n"
169     "}\n"
170     "private static com.google.protobuf.Internal.EnumLiteMap<$classname$>\n"
171     "    internalValueMap =\n"
172     "      new com.google.protobuf.Internal.EnumLiteMap<$classname$>() {\n"
173     "        public $classname$ findValueByNumber(int number) {\n"
174     "          return $classname$.valueOf(number);\n"
175     "        }\n"
176     "      };\n"
177     "\n",
178     "classname", descriptor_->name());
179 
180   // -----------------------------------------------------------------
181   // Reflection
182 
183   if (HasDescriptorMethods(descriptor_)) {
184     printer->Print(
185       "public final com.google.protobuf.Descriptors.EnumValueDescriptor\n"
186       "    getValueDescriptor() {\n"
187       "  return getDescriptor().getValues().get(index);\n"
188       "}\n"
189       "public final com.google.protobuf.Descriptors.EnumDescriptor\n"
190       "    getDescriptorForType() {\n"
191       "  return getDescriptor();\n"
192       "}\n"
193       "public static final com.google.protobuf.Descriptors.EnumDescriptor\n"
194       "    getDescriptor() {\n");
195 
196     // TODO(kenton):  Cache statically?  Note that we can't access descriptors
197     //   at module init time because it wouldn't work with descriptor.proto, but
198     //   we can cache the value the first time getDescriptor() is called.
199     if (descriptor_->containing_type() == NULL) {
200       if (!MultipleJavaFiles(descriptor_->file(), immutable_api_)) {
201         printer->Print(
202           "  return $file$.getDescriptor().getEnumTypes().get($index$);\n",
203           "file", name_resolver_->GetClassName(descriptor_->file(),
204                                                immutable_api_),
205           "index", SimpleItoa(descriptor_->index()));
206       } else {
207         printer->Indent();
208         if (EnumHasCustomOptions(descriptor_)) {
209           // We need to load the immutable classes in order to parse custom
210           // options. However, since file level enums (no outer class) are
211           // shared by immutable code and mutable code, the immutable classes
212           // may not exist. So we try to use Java reflection to retrieve the
213           // descriptor from immutable classes.
214           printer->Print(
215             "try {\n"
216             "  java.lang.Class immutableFileClass =\n"
217             "      java.lang.Class.forName(\"$immutable_file_class_name$\");\n"
218             "  @java.lang.SuppressWarnings(\"unchecked\")\n"
219             "  java.lang.reflect.Method m =\n"
220             "      immutableFileClass.getMethod(\"getDescriptor\");\n"
221             "  com.google.protobuf.Descriptors.FileDescriptor file =\n"
222             "      (com.google.protobuf.Descriptors.FileDescriptor)\n"
223             "          m.invoke(immutableFileClass);\n"
224             "  return file.getEnumTypes().get($index$);\n"
225             "} catch (Exception e) {\n"
226             // Immutable classes cannot be found. Proceed as if custom options
227             // don't exist.
228             "}\n",
229             "immutable_file_class_name",
230             name_resolver_->GetImmutableClassName(descriptor_->file()),
231             "index", SimpleItoa(descriptor_->index()));
232         }
233         printer->Print(
234           "return $immutable_package$.$descriptor_class$.getDescriptor()\n"
235           "    .getEnumTypes().get($index$);\n",
236           "immutable_package", FileJavaPackage(descriptor_->file(), true),
237           "descriptor_class",
238           name_resolver_->GetDescriptorClassName(descriptor_->file()),
239           "index", SimpleItoa(descriptor_->index()));
240         printer->Outdent();
241       }
242     } else {
243       printer->Print(
244           "  return $parent$.$descriptor$.getEnumTypes().get($index$);\n",
245           "parent", name_resolver_->GetClassName(descriptor_->containing_type(),
246                                                  immutable_api_),
247           "descriptor", descriptor_->containing_type()->options()
248                         .no_standard_descriptor_accessor()
249                         ? "getDefaultInstance().getDescriptorForType()"
250                         : "getDescriptor()",
251           "index", SimpleItoa(descriptor_->index()));
252     }
253 
254     printer->Print(
255       "}\n"
256       "\n"
257       "private static final $classname$[] VALUES = ",
258       "classname", descriptor_->name());
259 
260     if (CanUseEnumValues()) {
261       // If the constants we are going to output are exactly the ones we
262       // have declared in the Java enum in the same order, then we can use
263       // the values() method that the Java compiler automatically generates
264       // for every enum.
265       printer->Print("values();\n");
266     } else {
267       printer->Print(
268         "{\n"
269         "  ");
270       for (int i = 0; i < descriptor_->value_count(); i++) {
271         printer->Print("$name$, ",
272           "name", descriptor_->value(i)->name());
273       }
274       printer->Print(
275           "\n"
276           "};\n");
277     }
278 
279     printer->Print(
280       "\n"
281       "public static $classname$ valueOf(\n"
282       "    com.google.protobuf.Descriptors.EnumValueDescriptor desc) {\n"
283       "  if (desc.getType() != getDescriptor()) {\n"
284       "    throw new java.lang.IllegalArgumentException(\n"
285       "      \"EnumValueDescriptor is not for this type.\");\n"
286       "  }\n"
287       "  return VALUES[desc.getIndex()];\n"
288       "}\n"
289       "\n",
290       "classname", descriptor_->name());
291 
292     // index is only used for reflection; lite implementation does not need it
293     printer->Print("private final int index;\n");
294   }
295 
296   // -----------------------------------------------------------------
297 
298   printer->Print(
299     "private final int value;\n\n"
300     "private $classname$(int index, int value) {\n",
301     "classname", descriptor_->name());
302   if (HasDescriptorMethods(descriptor_)) {
303     printer->Print("  this.index = index;\n");
304   }
305   printer->Print(
306     "  this.value = value;\n"
307     "}\n");
308 
309   printer->Print(
310     "\n"
311     "// @@protoc_insertion_point(enum_scope:$full_name$)\n",
312     "full_name", descriptor_->full_name());
313 
314   printer->Outdent();
315   printer->Print("}\n\n");
316 }
317 
CanUseEnumValues()318 bool EnumGenerator::CanUseEnumValues() {
319   if (canonical_values_.size() != descriptor_->value_count()) {
320     return false;
321   }
322   for (int i = 0; i < descriptor_->value_count(); i++) {
323     if (descriptor_->value(i)->name() != canonical_values_[i]->name()) {
324       return false;
325     }
326   }
327   return true;
328 }
329 
330 }  // namespace java
331 }  // namespace compiler
332 }  // namespace protobuf
333 }  // namespace google
334