1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "JavaClassGenerator.h"
18 #include "NameMangler.h"
19 #include "Resource.h"
20 #include "ResourceTable.h"
21 #include "ResourceValues.h"
22 #include "StringPiece.h"
23 
24 #include <algorithm>
25 #include <ostream>
26 #include <set>
27 #include <sstream>
28 #include <tuple>
29 
30 namespace aapt {
31 
32 // The number of attributes to emit per line in a Styleable array.
33 constexpr size_t kAttribsPerLine = 4;
34 
JavaClassGenerator(const std::shared_ptr<const ResourceTable> & table,Options options)35 JavaClassGenerator::JavaClassGenerator(const std::shared_ptr<const ResourceTable>& table,
36                                        Options options) :
37         mTable(table), mOptions(options) {
38 }
39 
generateHeader(std::ostream & out,const StringPiece16 & package)40 static void generateHeader(std::ostream& out, const StringPiece16& package) {
41     out << "/* AUTO-GENERATED FILE. DO NOT MODIFY.\n"
42            " *\n"
43            " * This class was automatically generated by the\n"
44            " * aapt tool from the resource data it found. It\n"
45            " * should not be modified by hand.\n"
46            " */\n\n";
47     out << "package " << package << ";"
48         << std::endl
49         << std::endl;
50 }
51 
52 static const std::set<StringPiece16> sJavaIdentifiers = {
53     u"abstract", u"assert", u"boolean", u"break", u"byte",
54     u"case", u"catch", u"char", u"class", u"const", u"continue",
55     u"default", u"do", u"double", u"else", u"enum", u"extends",
56     u"final", u"finally", u"float", u"for", u"goto", u"if",
57     u"implements", u"import", u"instanceof", u"int", u"interface",
58     u"long", u"native", u"new", u"package", u"private", u"protected",
59     u"public", u"return", u"short", u"static", u"strictfp", u"super",
60     u"switch", u"synchronized", u"this", u"throw", u"throws",
61     u"transient", u"try", u"void", u"volatile", u"while", u"true",
62     u"false", u"null"
63 };
64 
isValidSymbol(const StringPiece16 & symbol)65 static bool isValidSymbol(const StringPiece16& symbol) {
66     return sJavaIdentifiers.find(symbol) == sJavaIdentifiers.end();
67 }
68 
69 /*
70  * Java symbols can not contain . or -, but those are valid in a resource name.
71  * Replace those with '_'.
72  */
transform(const StringPiece16 & symbol)73 static std::u16string transform(const StringPiece16& symbol) {
74     std::u16string output = symbol.toString();
75     for (char16_t& c : output) {
76         if (c == u'.' || c == u'-') {
77             c = u'_';
78         }
79     }
80     return output;
81 }
82 
83 struct GenArgs : ValueVisitorArgs {
GenArgsaapt::GenArgs84     GenArgs(std::ostream* o, const std::u16string* p, std::u16string* e) :
85             out(o), package(p), entryName(e) {
86     }
87 
88     std::ostream* out;
89     const std::u16string* package;
90     std::u16string* entryName;
91 };
92 
visit(const Styleable & styleable,ValueVisitorArgs & a)93 void JavaClassGenerator::visit(const Styleable& styleable, ValueVisitorArgs& a) {
94     const StringPiece finalModifier = mOptions.useFinal ? " final" : "";
95     std::ostream* out = static_cast<GenArgs&>(a).out;
96     const std::u16string* package = static_cast<GenArgs&>(a).package;
97     std::u16string* entryName = static_cast<GenArgs&>(a).entryName;
98 
99     // This must be sorted by resource ID.
100     std::vector<std::pair<ResourceId, ResourceNameRef>> sortedAttributes;
101     sortedAttributes.reserve(styleable.entries.size());
102     for (const auto& attr : styleable.entries) {
103         // If we are not encoding final attributes, the styleable entry may have no ID
104         // if we are building a static library.
105         assert((!mOptions.useFinal || attr.id.isValid()) && "no ID set for Styleable entry");
106         assert(attr.name.isValid() && "no name set for Styleable entry");
107         sortedAttributes.emplace_back(attr.id, attr.name);
108     }
109     std::sort(sortedAttributes.begin(), sortedAttributes.end());
110 
111     // First we emit the array containing the IDs of each attribute.
112     *out << "        "
113          << "public static final int[] " << transform(*entryName) << " = {";
114 
115     const size_t attrCount = sortedAttributes.size();
116     for (size_t i = 0; i < attrCount; i++) {
117         if (i % kAttribsPerLine == 0) {
118             *out << std::endl << "            ";
119         }
120 
121         *out << sortedAttributes[i].first;
122         if (i != attrCount - 1) {
123             *out << ", ";
124         }
125     }
126     *out << std::endl << "        };" << std::endl;
127 
128     // Now we emit the indices into the array.
129     for (size_t i = 0; i < attrCount; i++) {
130         *out << "        "
131              << "public static" << finalModifier
132              << " int " << transform(*entryName);
133 
134         // We may reference IDs from other packages, so prefix the entry name with
135         // the package.
136         const ResourceNameRef& itemName = sortedAttributes[i].second;
137         if (itemName.package != *package) {
138             *out << "_" << transform(itemName.package);
139         }
140         *out << "_" << transform(itemName.entry) << " = " << i << ";" << std::endl;
141     }
142 }
143 
generateType(const std::u16string & package,size_t packageId,const ResourceTableType & type,std::ostream & out)144 bool JavaClassGenerator::generateType(const std::u16string& package, size_t packageId,
145                                       const ResourceTableType& type, std::ostream& out) {
146     const StringPiece finalModifier = mOptions.useFinal ? " final" : "";
147 
148     std::u16string unmangledPackage;
149     std::u16string unmangledName;
150     for (const auto& entry : type.entries) {
151         ResourceId id = { packageId, type.typeId, entry->entryId };
152         assert(id.isValid());
153 
154         unmangledName = entry->name;
155         if (NameMangler::unmangle(&unmangledName, &unmangledPackage)) {
156             // The entry name was mangled, and we successfully unmangled it.
157             // Check that we want to emit this symbol.
158             if (package != unmangledPackage) {
159                 // Skip the entry if it doesn't belong to the package we're writing.
160                 continue;
161             }
162         } else {
163             if (package != mTable->getPackage()) {
164                 // We are processing a mangled package name,
165                 // but this is a non-mangled resource.
166                 continue;
167             }
168         }
169 
170         if (!isValidSymbol(unmangledName)) {
171             ResourceNameRef resourceName = { package, type.type, unmangledName };
172             std::stringstream err;
173             err << "invalid symbol name '" << resourceName << "'";
174             mError = err.str();
175             return false;
176         }
177 
178         if (type.type == ResourceType::kStyleable) {
179             assert(!entry->values.empty());
180             entry->values.front().value->accept(*this, GenArgs{ &out, &package, &unmangledName });
181         } else {
182             out << "        " << "public static" << finalModifier
183                 << " int " << transform(unmangledName) << " = " << id << ";" << std::endl;
184         }
185     }
186     return true;
187 }
188 
generate(const std::u16string & package,std::ostream & out)189 bool JavaClassGenerator::generate(const std::u16string& package, std::ostream& out) {
190     const size_t packageId = mTable->getPackageId();
191 
192     generateHeader(out, package);
193 
194     out << "public final class R {" << std::endl;
195 
196     for (const auto& type : *mTable) {
197         out << "    public static final class " << type->type << " {" << std::endl;
198         if (!generateType(package, packageId, *type, out)) {
199             return false;
200         }
201         out << "    }" << std::endl;
202     }
203 
204     out << "}" << std::endl;
205     return true;
206 }
207 
208 } // namespace aapt
209