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 "java/ProguardRules.h"
18 
19 #include <memory>
20 #include <string>
21 
22 #include "android-base/macros.h"
23 #include "androidfw/StringPiece.h"
24 
25 #include "JavaClassGenerator.h"
26 #include "ResourceUtils.h"
27 #include "ValueVisitor.h"
28 #include "text/Printer.h"
29 #include "util/Util.h"
30 #include "xml/XmlDom.h"
31 
32 using ::aapt::text::Printer;
33 using ::android::OutputStream;
34 
35 namespace aapt {
36 namespace proguard {
37 
38 class BaseVisitor : public xml::Visitor {
39  public:
40   using xml::Visitor::Visit;
41 
BaseVisitor(const ResourceFile & file,KeepSet * keep_set)42   BaseVisitor(const ResourceFile& file, KeepSet* keep_set) : BaseVisitor(file, keep_set, "...") {
43   }
44 
BaseVisitor(const ResourceFile & file,KeepSet * keep_set,const std::string & ctor_signature)45   BaseVisitor(const ResourceFile& file, KeepSet* keep_set, const std::string& ctor_signature)
46       : file_(file), keep_set_(keep_set), ctor_signature_(ctor_signature) {
47   }
48 
Visit(xml::Element * node)49   void Visit(xml::Element* node) override {
50     if (!node->namespace_uri.empty()) {
51       std::optional<xml::ExtractedPackage> maybe_package =
52           xml::ExtractPackageFromNamespace(node->namespace_uri);
53       if (maybe_package) {
54         // This is a custom view, let's figure out the class name from this.
55         std::string package = maybe_package.value().package + "." + node->name;
56         if (util::IsJavaClassName(package)) {
57           AddClass(node->line_number, package, ctor_signature_);
58         }
59       }
60     } else if (util::IsJavaClassName(node->name)) {
61       AddClass(node->line_number, node->name, ctor_signature_);
62     }
63 
64     for (const auto& child : node->children) {
65       child->Accept(this);
66     }
67 
68     for (const auto& attr : node->attributes) {
69       if (attr.compiled_value) {
70         auto ref = ValueCast<Reference>(attr.compiled_value.get());
71         if (ref) {
72           AddReference(node->line_number, ref);
73         }
74       }
75     }
76   }
77 
78  protected:
79   ResourceFile file_;
80   KeepSet* keep_set_;
81   std::string ctor_signature_;
82 
AddClass(size_t line_number,const std::string & class_name,const std::string & ctor_signature)83   virtual void AddClass(size_t line_number, const std::string& class_name,
84                         const std::string& ctor_signature) {
85     keep_set_->AddConditionalClass({file_.name, file_.source.WithLine(line_number)},
86         {class_name, ctor_signature});
87   }
88 
AddMethod(size_t line_number,const std::string & method_name,const std::string & method_signature)89   void AddMethod(size_t line_number, const std::string& method_name,
90                  const std::string& method_signature) {
91     keep_set_->AddMethod({file_.name, file_.source.WithLine(line_number)},
92         {method_name, method_signature});
93   }
94 
AddReference(size_t line_number,Reference * ref)95   void AddReference(size_t line_number, Reference* ref) {
96     if (ref && ref->name) {
97       ResourceName ref_name = ref->name.value();
98       if (ref_name.package.empty()) {
99         ref_name = ResourceName(file_.name.package, ref_name.type, ref_name.entry);
100       }
101       keep_set_->AddReference({file_.name, file_.source.WithLine(line_number)}, ref_name);
102     }
103   }
104 
105  private:
106   DISALLOW_COPY_AND_ASSIGN(BaseVisitor);
107 
108 };
109 
110 class LayoutVisitor : public BaseVisitor {
111  public:
LayoutVisitor(const ResourceFile & file,KeepSet * keep_set)112   LayoutVisitor(const ResourceFile& file, KeepSet* keep_set)
113       : BaseVisitor(file, keep_set, "android.content.Context, android.util.AttributeSet") {
114   }
115 
Visit(xml::Element * node)116   void Visit(xml::Element* node) override {
117     bool is_view = false;
118     if (node->namespace_uri.empty()) {
119       if (node->name == "view") {
120         is_view = true;
121       }
122     }
123 
124     for (const auto& attr : node->attributes) {
125       if (attr.namespace_uri.empty() && attr.name == "class") {
126         if (util::IsJavaClassName(attr.value)) {
127           if (is_view) {
128             AddClass(node->line_number, attr.value,
129                 "android.content.Context, android.util.AttributeSet");
130           } else {
131             AddClass(node->line_number, attr.value, "");
132           }
133         }
134       } else if (attr.namespace_uri == xml::kSchemaAndroid && attr.name == "name") {
135         if (util::IsJavaClassName(attr.value)) {
136           AddClass(node->line_number, attr.value, "");
137         }
138       } else if (attr.namespace_uri == xml::kSchemaAndroid && attr.name == "onClick") {
139         AddMethod(node->line_number, attr.value, "android.view.View");
140       }
141     }
142 
143     BaseVisitor::Visit(node);
144   }
145 
146  private:
147   DISALLOW_COPY_AND_ASSIGN(LayoutVisitor);
148 };
149 
150 class MenuVisitor : public BaseVisitor {
151  public:
MenuVisitor(const ResourceFile & file,KeepSet * keep_set)152   MenuVisitor(const ResourceFile& file, KeepSet* keep_set) : BaseVisitor(file, keep_set) {
153   }
154 
Visit(xml::Element * node)155   void Visit(xml::Element* node) override {
156     if (node->namespace_uri.empty() && node->name == "item") {
157       for (const auto& attr : node->attributes) {
158         // AppCompat-v7 defines its own versions of Android attributes if
159         // they're defined after SDK 7 (the below are from 11 and 14,
160         // respectively), so don't bother checking the XML namespace.
161         //
162         // Given the names of the containing XML files and the attribute
163         // names, it's unlikely that keeping these classes would be wrong.
164         if ((attr.name == "actionViewClass" || attr.name == "actionProviderClass") &&
165             util::IsJavaClassName(attr.value)) {
166           AddClass(node->line_number, attr.value, "android.content.Context");
167         }
168 
169         if (attr.namespace_uri == xml::kSchemaAndroid && attr.name == "onClick") {
170           AddMethod(node->line_number, attr.value, "android.view.MenuItem");
171         }
172       }
173     }
174 
175     BaseVisitor::Visit(node);
176   }
177 
178  private:
179   DISALLOW_COPY_AND_ASSIGN(MenuVisitor);
180 };
181 
182 class XmlResourceVisitor : public BaseVisitor {
183  public:
XmlResourceVisitor(const ResourceFile & file,KeepSet * keep_set)184   XmlResourceVisitor(const ResourceFile& file, KeepSet* keep_set) : BaseVisitor(file, keep_set) {
185   }
186 
Visit(xml::Element * node)187   void Visit(xml::Element* node) override {
188     bool check_fragment = false;
189     if (node->namespace_uri.empty()) {
190       check_fragment =
191           node->name == "PreferenceScreen" || node->name == "header";
192     }
193 
194     if (check_fragment) {
195       xml::Attribute* attr =
196           node->FindAttribute(xml::kSchemaAndroid, "fragment");
197       if (attr && util::IsJavaClassName(attr->value)) {
198         AddClass(node->line_number, attr->value, "");
199       }
200     }
201 
202     BaseVisitor::Visit(node);
203   }
204 
205  private:
206   DISALLOW_COPY_AND_ASSIGN(XmlResourceVisitor);
207 };
208 
209 class NavigationVisitor : public BaseVisitor {
210  public:
NavigationVisitor(const ResourceFile & file,KeepSet * keep_set,const std::string & package)211   NavigationVisitor(const ResourceFile& file, KeepSet* keep_set, const std::string& package)
212       : BaseVisitor(file, keep_set), package_(package) {
213   }
214 
Visit(xml::Element * node)215   void Visit(xml::Element* node) override {
216     const auto& attr = node->FindAttribute(xml::kSchemaAndroid, "name");
217     if (attr != nullptr && !attr->value.empty()) {
218       std::string name = (attr->value[0] == '.') ? package_ + attr->value : attr->value;
219       if (util::IsJavaClassName(name)) {
220         AddClass(node->line_number, name, "...");
221       }
222     }
223 
224     BaseVisitor::Visit(node);
225   }
226 
227  private:
228   DISALLOW_COPY_AND_ASSIGN(NavigationVisitor);
229   const std::string package_;
230 };
231 
232 class TransitionVisitor : public BaseVisitor {
233  public:
TransitionVisitor(const ResourceFile & file,KeepSet * keep_set)234   TransitionVisitor(const ResourceFile& file, KeepSet* keep_set) : BaseVisitor(file, keep_set) {
235   }
236 
Visit(xml::Element * node)237   void Visit(xml::Element* node) override {
238     bool check_class =
239         node->namespace_uri.empty() && (node->name == "transition" || node->name == "pathMotion");
240     if (check_class) {
241       xml::Attribute* attr = node->FindAttribute({}, "class");
242       if (attr && util::IsJavaClassName(attr->value)) {
243         AddClass(node->line_number, attr->value,
244             "android.content.Context, android.util.AttributeSet");
245       }
246     }
247 
248     BaseVisitor::Visit(node);
249   }
250 
251  private:
252   DISALLOW_COPY_AND_ASSIGN(TransitionVisitor);
253 };
254 
255 class ManifestVisitor : public BaseVisitor {
256  public:
ManifestVisitor(const ResourceFile & file,KeepSet * keep_set,bool main_dex_only)257   ManifestVisitor(const ResourceFile& file, KeepSet* keep_set, bool main_dex_only)
258       : BaseVisitor(file, keep_set), main_dex_only_(main_dex_only) {
259   }
260 
Visit(xml::Element * node)261   void Visit(xml::Element* node) override {
262     if (node->namespace_uri.empty()) {
263       bool get_name = false;
264       if (node->name == "manifest") {
265         xml::Attribute* attr = node->FindAttribute({}, "package");
266         if (attr) {
267           package_ = attr->value;
268         }
269       } else if (node->name == "application") {
270         get_name = true;
271         xml::Attribute* attr = node->FindAttribute(xml::kSchemaAndroid, "backupAgent");
272         if (attr) {
273           std::optional<std::string> result =
274               util::GetFullyQualifiedClassName(package_, attr->value);
275           if (result) {
276             AddClass(node->line_number, result.value(), "");
277           }
278         }
279         attr = node->FindAttribute(xml::kSchemaAndroid, "appComponentFactory");
280         if (attr) {
281           std::optional<std::string> result =
282               util::GetFullyQualifiedClassName(package_, attr->value);
283           if (result) {
284             AddClass(node->line_number, result.value(), "");
285           }
286         }
287 
288         attr = node->FindAttribute(xml::kSchemaAndroid, "zygotePreloadName");
289         if (attr) {
290           std::optional<std::string> result =
291               util::GetFullyQualifiedClassName(package_, attr->value);
292           if (result) {
293             AddClass(node->line_number, result.value(), "");
294           }
295         }
296 
297         if (main_dex_only_) {
298           xml::Attribute* default_process = node->FindAttribute(xml::kSchemaAndroid, "process");
299           if (default_process) {
300             default_process_ = default_process->value;
301           }
302         }
303       } else if (node->name == "activity" || node->name == "service" ||
304                  node->name == "receiver" || node->name == "provider") {
305         get_name = true;
306 
307         if (main_dex_only_) {
308           xml::Attribute* component_process = node->FindAttribute(xml::kSchemaAndroid, "process");
309 
310           const std::string& process =
311               component_process ? component_process->value : default_process_;
312           get_name = !process.empty() && process[0] != ':';
313         }
314       } else if (node->name == "instrumentation" || node->name == "process") {
315         get_name = true;
316       }
317 
318       if (get_name) {
319         xml::Attribute* attr = node->FindAttribute(xml::kSchemaAndroid, "name");
320         get_name = attr != nullptr;
321 
322         if (get_name) {
323           std::optional<std::string> result =
324               util::GetFullyQualifiedClassName(package_, attr->value);
325           if (result) {
326             AddClass(node->line_number, result.value(), "");
327           }
328         }
329       }
330     }
331     BaseVisitor::Visit(node);
332   }
333 
AddClass(size_t line_number,const std::string & class_name,const std::string & ctor_signature)334   virtual void AddClass(size_t line_number, const std::string& class_name,
335                         const std::string& ctor_signature) override {
336     keep_set_->AddManifestClass({file_.name, file_.source.WithLine(line_number)}, class_name);
337   }
338 
339  private:
340   DISALLOW_COPY_AND_ASSIGN(ManifestVisitor);
341 
342   std::string package_;
343   const bool main_dex_only_;
344   std::string default_process_;
345 };
346 
CollectProguardRulesForManifest(xml::XmlResource * res,KeepSet * keep_set,bool main_dex_only)347 bool CollectProguardRulesForManifest(xml::XmlResource* res, KeepSet* keep_set, bool main_dex_only) {
348   ManifestVisitor visitor(res->file, keep_set, main_dex_only);
349   if (res->root) {
350     res->root->Accept(&visitor);
351     return true;
352   }
353   return false;
354 }
355 
CollectProguardRules(IAaptContext * context_,xml::XmlResource * res,KeepSet * keep_set)356 bool CollectProguardRules(IAaptContext* context_, xml::XmlResource* res, KeepSet* keep_set) {
357   if (!res->root) {
358     return false;
359   }
360 
361   switch (res->file.name.type.type) {
362     case ResourceType::kLayout: {
363       LayoutVisitor visitor(res->file, keep_set);
364       res->root->Accept(&visitor);
365       break;
366     }
367 
368     case ResourceType::kXml: {
369       XmlResourceVisitor visitor(res->file, keep_set);
370       res->root->Accept(&visitor);
371       break;
372     }
373 
374     case ResourceType::kNavigation: {
375       NavigationVisitor visitor(res->file, keep_set, context_->GetCompilationPackage());
376       res->root->Accept(&visitor);
377       break;
378     }
379 
380     case ResourceType::kTransition: {
381       TransitionVisitor visitor(res->file, keep_set);
382       res->root->Accept(&visitor);
383       break;
384     }
385 
386     case ResourceType::kMenu: {
387       MenuVisitor visitor(res->file, keep_set);
388       res->root->Accept(&visitor);
389       break;
390     }
391 
392     default: {
393       BaseVisitor visitor(res->file, keep_set);
394       res->root->Accept(&visitor);
395       break;
396     }
397   }
398   return true;
399 }
400 
WriteKeepSet(const KeepSet & keep_set,OutputStream * out,bool minimal_keep,bool no_location_reference)401 void WriteKeepSet(const KeepSet& keep_set, OutputStream* out, bool minimal_keep,
402                   bool no_location_reference) {
403 
404   Printer printer(out);
405   for (const auto& entry : keep_set.manifest_class_set_) {
406     if (!no_location_reference) {
407       for (const UsageLocation& location : entry.second) {
408         printer.Print("# Referenced at ").Println(location.source.to_string());
409       }
410     }
411     printer.Print("-keep class ").Print(entry.first).Println(" { <init>(); }");
412   }
413 
414   for (const auto& entry : keep_set.conditional_class_set_) {
415     std::set<UsageLocation> locations;
416     bool can_be_conditional = false;
417     if (keep_set.conditional_keep_rules_) {
418       can_be_conditional = true;
419       for (const UsageLocation& location : entry.second) {
420         can_be_conditional &= CollectLocations(location, keep_set, &locations);
421       }
422     }
423 
424     if (can_be_conditional) {
425       for (const UsageLocation& location : locations) {
426         if (!no_location_reference) {
427           printer.Print("# Referenced at ").Println(location.source.to_string());
428         }
429         printer.Print("-if class **.R$layout { int ")
430             .Print(JavaClassGenerator::TransformToFieldName(location.name.entry))
431             .Println("; }");
432 
433         printer.Print("-keep class ").Print(entry.first.name).Print(" { <init>(");
434         printer.Print((minimal_keep) ? entry.first.signature : "...");
435         printer.Println("); }");
436       }
437     } else {
438       if (!no_location_reference) {
439         for (const UsageLocation& location : entry.second) {
440           printer.Print("# Referenced at ").Println(location.source.to_string());
441         }
442       }
443 
444       printer.Print("-keep class ").Print(entry.first.name).Print(" { <init>(");
445       printer.Print((minimal_keep) ? entry.first.signature : "...");
446       printer.Println("); }");
447     }
448     printer.Println();
449   }
450 
451   for (const auto& entry : keep_set.method_set_) {
452     if (!no_location_reference) {
453       for (const UsageLocation& location : entry.second) {
454         printer.Print("# Referenced at ").Println(location.source.to_string());
455       }
456     }
457     printer.Print("-keepclassmembers class * { *** ").Print(entry.first.name)
458         .Print("(").Print(entry.first.signature).Println("); }");
459     printer.Println();
460   }
461 }
462 
CollectLocations(const UsageLocation & location,const KeepSet & keep_set,std::set<UsageLocation> * locations)463 bool CollectLocations(const UsageLocation& location, const KeepSet& keep_set,
464                       std::set<UsageLocation>* locations) {
465   locations->insert(location);
466 
467   // TODO: allow for more reference types if we can determine its safe.
468   if (location.name.type.type != ResourceType::kLayout) {
469     return false;
470   }
471 
472   for (const auto& entry : keep_set.reference_set_) {
473     if (entry.first == location.name) {
474       for (auto& refLocation : entry.second) {
475         // Don't get stuck in loops
476         if (locations->find(refLocation) != locations->end()) {
477           return false;
478         }
479         if (!CollectLocations(refLocation, keep_set, locations)) {
480           return false;
481         }
482       }
483     }
484   }
485 
486   return true;
487 }
488 
489 class ReferenceVisitor : public ValueVisitor {
490  public:
491   using ValueVisitor::Visit;
492 
ReferenceVisitor(aapt::IAaptContext * context,ResourceName from,KeepSet * keep_set)493   ReferenceVisitor(aapt::IAaptContext* context, ResourceName from, KeepSet* keep_set)
494       : context_(context), from_(from), keep_set_(keep_set) {
495   }
496 
Visit(Reference * reference)497   void Visit(Reference* reference) override {
498     if (reference->name) {
499       ResourceName reference_name = reference->name.value();
500       if (reference_name.package.empty()) {
501         reference_name = ResourceName(context_->GetCompilationPackage(), reference_name.type,
502                                       reference_name.entry);
503       }
504       keep_set_->AddReference({from_, reference->GetSource()}, reference_name);
505     }
506   }
507 
508  private:
509   aapt::IAaptContext* context_;
510   ResourceName from_;
511   KeepSet* keep_set_;
512 };
513 
CollectResourceReferences(aapt::IAaptContext * context,ResourceTable * table,KeepSet * keep_set)514 bool CollectResourceReferences(aapt::IAaptContext* context, ResourceTable* table,
515                                KeepSet* keep_set) {
516   for (auto& pkg : table->packages) {
517     for (auto& type : pkg->types) {
518       for (auto& entry : type->entries) {
519         for (auto& config_value : entry->values) {
520           ResourceName from(pkg->name, type->named_type, entry->name);
521           ReferenceVisitor visitor(context, from, keep_set);
522           config_value->value->Accept(&visitor);
523         }
524       }
525     }
526   }
527   return true;
528 }
529 
530 }  // namespace proguard
531 }  // namespace aapt
532