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 "Diagnostics.h"
18 #include "ResourceUtils.h"
19 #include "SdkConstants.h"
20 #include "link/Linkers.h"
21 #include "link/ReferenceLinker.h"
22 #include "process/IResourceTableConsumer.h"
23 #include "process/SymbolTable.h"
24 #include "util/Util.h"
25 #include "xml/XmlDom.h"
26 
27 namespace aapt {
28 
29 namespace {
30 
31 /**
32  * Visits all references (including parents of styles, references in styles, arrays, etc) and
33  * links their symbolic name to their Resource ID, performing mangling and package aliasing
34  * as needed.
35  */
36 class ReferenceVisitor : public ValueVisitor {
37 public:
38     using ValueVisitor::visit;
39 
ReferenceVisitor(IAaptContext * context,SymbolTable * symbols,xml::IPackageDeclStack * decls,CallSite * callSite)40     ReferenceVisitor(IAaptContext* context, SymbolTable* symbols, xml::IPackageDeclStack* decls,
41                      CallSite* callSite) :
42              mContext(context), mSymbols(symbols), mDecls(decls), mCallSite(callSite),
43              mError(false) {
44     }
45 
visit(Reference * ref)46     void visit(Reference* ref) override {
47         if (!ReferenceLinker::linkReference(ref, mContext, mSymbols, mDecls, mCallSite)) {
48             mError = true;
49         }
50     }
51 
hasError() const52     bool hasError() const {
53         return mError;
54     }
55 
56 private:
57     IAaptContext* mContext;
58     SymbolTable* mSymbols;
59     xml::IPackageDeclStack* mDecls;
60     CallSite* mCallSite;
61     bool mError;
62 };
63 
64 /**
65  * Visits each xml Element and compiles the attributes within.
66  */
67 class XmlVisitor : public xml::PackageAwareVisitor {
68 public:
69     using xml::PackageAwareVisitor::visit;
70 
XmlVisitor(IAaptContext * context,SymbolTable * symbols,const Source & source,std::set<int> * sdkLevelsFound,CallSite * callSite)71     XmlVisitor(IAaptContext* context, SymbolTable* symbols, const Source& source,
72                std::set<int>* sdkLevelsFound, CallSite* callSite) :
73             mContext(context), mSymbols(symbols), mSource(source), mSdkLevelsFound(sdkLevelsFound),
74             mCallSite(callSite), mReferenceVisitor(context, symbols, this, callSite) {
75     }
76 
visit(xml::Element * el)77     void visit(xml::Element* el) override {
78         const Source source = mSource.withLine(el->lineNumber);
79         for (xml::Attribute& attr : el->attributes) {
80             Maybe<xml::ExtractedPackage> maybePackage =
81                     xml::extractPackageFromNamespace(attr.namespaceUri);
82             if (maybePackage) {
83                 // There is a valid package name for this attribute. We will look this up.
84                 StringPiece16 package = maybePackage.value().package;
85                 if (package.empty()) {
86                     // Empty package means the 'current' or 'local' package.
87                     package = mContext->getCompilationPackage();
88                 }
89 
90                 Reference attrRef(ResourceNameRef(package, ResourceType::kAttr, attr.name));
91                 attrRef.privateReference = maybePackage.value().privateNamespace;
92 
93                 std::string errStr;
94                 attr.compiledAttribute = ReferenceLinker::compileXmlAttribute(
95                         attrRef, mContext->getNameMangler(), mSymbols, mCallSite, &errStr);
96 
97                 // Convert the string value into a compiled Value if this is a valid attribute.
98                 if (attr.compiledAttribute) {
99                     if (attr.compiledAttribute.value().id) {
100                         // Record all SDK levels from which the attributes were defined.
101                         const size_t sdkLevel = findAttributeSdkLevel(
102                                 attr.compiledAttribute.value().id.value());
103                         if (sdkLevel > 1) {
104                             mSdkLevelsFound->insert(sdkLevel);
105                         }
106                     }
107 
108                     const Attribute* attribute = &attr.compiledAttribute.value().attribute;
109                     attr.compiledValue = ResourceUtils::parseItemForAttribute(attr.value,
110                                                                               attribute);
111                     if (!attr.compiledValue &&
112                             !(attribute->typeMask & android::ResTable_map::TYPE_STRING)) {
113                         // We won't be able to encode this as a string.
114                         mContext->getDiagnostics()->error(
115                                 DiagMessage(source) << "'" << attr.value << "' "
116                                                     << "is incompatible with attribute "
117                                                     << package << ":" << attr.name << " "
118                                                     << *attribute);
119                         mError = true;
120                     }
121 
122                 } else {
123                     mContext->getDiagnostics()->error(DiagMessage(source)
124                                                       << "attribute '" << package << ":"
125                                                       << attr.name << "' " << errStr);
126                     mError = true;
127 
128                 }
129             } else {
130                 // We still encode references.
131                 attr.compiledValue = ResourceUtils::tryParseReference(attr.value);
132             }
133 
134             if (attr.compiledValue) {
135                 // With a compiledValue, we must resolve the reference and assign it an ID.
136                 attr.compiledValue->setSource(source);
137                 attr.compiledValue->accept(&mReferenceVisitor);
138             }
139         }
140 
141         // Call the super implementation.
142         xml::PackageAwareVisitor::visit(el);
143     }
144 
hasError()145     bool hasError() {
146         return mError || mReferenceVisitor.hasError();
147     }
148 
149 private:
150     IAaptContext* mContext;
151     SymbolTable* mSymbols;
152     Source mSource;
153     std::set<int>* mSdkLevelsFound;
154     CallSite* mCallSite;
155     ReferenceVisitor mReferenceVisitor;
156     bool mError = false;
157 };
158 
159 } // namespace
160 
consume(IAaptContext * context,xml::XmlResource * resource)161 bool XmlReferenceLinker::consume(IAaptContext* context, xml::XmlResource* resource) {
162     mSdkLevelsFound.clear();
163     CallSite callSite = { resource->file.name };
164     XmlVisitor visitor(context, context->getExternalSymbols(), resource->file.source,
165                        &mSdkLevelsFound, &callSite);
166     if (resource->root) {
167         resource->root->accept(&visitor);
168         return !visitor.hasError();
169     }
170     return false;
171 }
172 
173 } // namespace aapt
174