tools/aapt2/java/ProguardRules.cpp - platform/frameworks/base - Gitiles

 /*
  * Copyright (C) 2015 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "java/ProguardRules.h"

 #include <memory>
 #include <string>

 #include "android-base/macros.h"
 #include "androidfw/StringPiece.h"

 #include "JavaClassGenerator.h"
 #include "ResourceUtils.h"
 #include "ValueVisitor.h"
 #include "text/Printer.h"
 #include "util/Util.h"
 #include "xml/XmlDom.h"

 using ::aapt::io::OutputStream;
 using ::aapt::text::Printer;

 namespace aapt {
 namespace proguard {

 class BaseVisitor : public xml::Visitor {
  public:
   using xml::Visitor::Visit;

   BaseVisitor(const ResourceFile& file, KeepSet* keep_set) : file_(file), keep_set_(keep_set) {
   }

   void Visit(xml::Element* node) override {
     if (!node->namespace_uri.empty()) {
       Maybe<xml::ExtractedPackage> maybe_package =
           xml::ExtractPackageFromNamespace(node->namespace_uri);
       if (maybe_package) {
         // This is a custom view, let's figure out the class name from this.
         std::string package = maybe_package.value().package + "." + node->name;
         if (util::IsJavaClassName(package)) {
           AddClass(node->line_number, package);
         }
       }
     } else if (util::IsJavaClassName(node->name)) {
       AddClass(node->line_number, node->name);
     }

     for (const auto& child : node->children) {
       child->Accept(this);
     }

     for (const auto& attr : node->attributes) {
       if (attr.compiled_value) {
         auto ref = ValueCast<Reference>(attr.compiled_value.get());
         if (ref) {
           AddReference(node->line_number, ref);
         }
       }
     }
   }

  protected:
   ResourceFile file_;
   KeepSet* keep_set_;

   virtual void AddClass(size_t line_number, const std::string& class_name) {
     keep_set_->AddConditionalClass({file_.name, file_.source.WithLine(line_number)}, class_name);
   }

   void AddMethod(size_t line_number, const std::string& method_name) {
     keep_set_->AddMethod({file_.name, file_.source.WithLine(line_number)}, method_name);
   }

   void AddReference(size_t line_number, Reference* ref) {
     if (ref && ref->name) {
       ResourceName ref_name = ref->name.value();
       if (ref_name.package.empty()) {
         ref_name = ResourceName(file_.name.package, ref_name.type, ref_name.entry);
       }
       keep_set_->AddReference({file_.name, file_.source.WithLine(line_number)}, ref_name);
     }
   }

  private:
   DISALLOW_COPY_AND_ASSIGN(BaseVisitor);

 };

 class LayoutVisitor : public BaseVisitor {
  public:
   LayoutVisitor(const ResourceFile& file, KeepSet* keep_set) : BaseVisitor(file, keep_set) {
   }

   void Visit(xml::Element* node) override {
     bool check_class = false;
     bool check_name = false;
     if (node->namespace_uri.empty()) {
       if (node->name == "view") {
         check_class = true;
       } else if (node->name == "fragment") {
         check_class = check_name = true;
       }
     } else if (node->namespace_uri == xml::kSchemaAndroid) {
       check_name = node->name == "fragment";
     }

     for (const auto& attr : node->attributes) {
       if (check_class && attr.namespace_uri.empty() && attr.name == "class" &&
           util::IsJavaClassName(attr.value)) {
         AddClass(node->line_number, attr.value);
       } else if (check_name && attr.namespace_uri == xml::kSchemaAndroid &&
                  attr.name == "name" && util::IsJavaClassName(attr.value)) {
         AddClass(node->line_number, attr.value);
       } else if (attr.namespace_uri == xml::kSchemaAndroid &&
                  attr.name == "onClick") {
         AddMethod(node->line_number, attr.value);
       }
     }

     BaseVisitor::Visit(node);
   }

  private:
   DISALLOW_COPY_AND_ASSIGN(LayoutVisitor);
 };

 class MenuVisitor : public BaseVisitor {
  public:
   MenuVisitor(const ResourceFile& file, KeepSet* keep_set) : BaseVisitor(file, keep_set) {
   }

   void Visit(xml::Element* node) override {
     if (node->namespace_uri.empty() && node->name == "item") {
       for (const auto& attr : node->attributes) {
         if (attr.namespace_uri == xml::kSchemaAndroid) {
           if ((attr.name == "actionViewClass" || attr.name == "actionProviderClass") &&
               util::IsJavaClassName(attr.value)) {
             AddClass(node->line_number, attr.value);
           } else if (attr.name == "onClick") {
             AddMethod(node->line_number, attr.value);
           }
         }
       }
     }

     BaseVisitor::Visit(node);
   }

  private:
   DISALLOW_COPY_AND_ASSIGN(MenuVisitor);
 };

 class XmlResourceVisitor : public BaseVisitor {
  public:
   XmlResourceVisitor(const ResourceFile& file, KeepSet* keep_set) : BaseVisitor(file, keep_set) {
   }

   void Visit(xml::Element* node) override {
     bool check_fragment = false;
     if (node->namespace_uri.empty()) {
       check_fragment =
           node->name == "PreferenceScreen" || node->name == "header";
     }

     if (check_fragment) {
       xml::Attribute* attr =
           node->FindAttribute(xml::kSchemaAndroid, "fragment");
       if (attr && util::IsJavaClassName(attr->value)) {
         AddClass(node->line_number, attr->value);
       }
     }

     BaseVisitor::Visit(node);
   }

  private:
   DISALLOW_COPY_AND_ASSIGN(XmlResourceVisitor);
 };

 class TransitionVisitor : public BaseVisitor {
  public:
   TransitionVisitor(const ResourceFile& file, KeepSet* keep_set) : BaseVisitor(file, keep_set) {
   }

   void Visit(xml::Element* node) override {
     bool check_class =
         node->namespace_uri.empty() && (node->name == "transition" || node->name == "pathMotion");
     if (check_class) {
       xml::Attribute* attr = node->FindAttribute({}, "class");
       if (attr && util::IsJavaClassName(attr->value)) {
         AddClass(node->line_number, attr->value);
       }
     }

     BaseVisitor::Visit(node);
   }

  private:
   DISALLOW_COPY_AND_ASSIGN(TransitionVisitor);
 };

 class ManifestVisitor : public BaseVisitor {
  public:
   ManifestVisitor(const ResourceFile& file, KeepSet* keep_set, bool main_dex_only)
       : BaseVisitor(file, keep_set), main_dex_only_(main_dex_only) {
   }

   void Visit(xml::Element* node) override {
     if (node->namespace_uri.empty()) {
       bool get_name = false;
       if (node->name == "manifest") {
         xml::Attribute* attr = node->FindAttribute({}, "package");
         if (attr) {
           package_ = attr->value;
         }
       } else if (node->name == "application") {
         get_name = true;
         xml::Attribute* attr = node->FindAttribute(xml::kSchemaAndroid, "backupAgent");
         if (attr) {
           Maybe<std::string> result = util::GetFullyQualifiedClassName(package_, attr->value);
           if (result) {
             AddClass(node->line_number, result.value());
           }
         }
         if (main_dex_only_) {
           xml::Attribute* default_process = node->FindAttribute(xml::kSchemaAndroid, "process");
           if (default_process) {
             default_process_ = default_process->value;
           }
         }
       } else if (node->name == "activity" || node->name == "service" ||
                  node->name == "receiver" || node->name == "provider") {
         get_name = true;

         if (main_dex_only_) {
           xml::Attribute* component_process = node->FindAttribute(xml::kSchemaAndroid, "process");

           const std::string& process =
               component_process ? component_process->value : default_process_;
           get_name = !process.empty() && process[0] != ':';
         }
       } else if (node->name == "instrumentation") {
         get_name = true;
       }

       if (get_name) {
         xml::Attribute* attr = node->FindAttribute(xml::kSchemaAndroid, "name");
         get_name = attr != nullptr;

         if (get_name) {
           Maybe<std::string> result = util::GetFullyQualifiedClassName(package_, attr->value);
           if (result) {
             AddClass(node->line_number, result.value());
           }
         }
       }
     }
     BaseVisitor::Visit(node);
   }

   virtual void AddClass(size_t line_number, const std::string& class_name) override {
     keep_set_->AddManifestClass({file_.name, file_.source.WithLine(line_number)}, class_name);
   }

  private:
   DISALLOW_COPY_AND_ASSIGN(ManifestVisitor);

   std::string package_;
   const bool main_dex_only_;
   std::string default_process_;
 };

 bool CollectProguardRulesForManifest(xml::XmlResource* res, KeepSet* keep_set, bool main_dex_only) {
   ManifestVisitor visitor(res->file, keep_set, main_dex_only);
   if (res->root) {
     res->root->Accept(&visitor);
     return true;
   }
   return false;
 }

 bool CollectProguardRules(xml::XmlResource* res, KeepSet* keep_set) {
   if (!res->root) {
     return false;
   }

   switch (res->file.name.type) {
     case ResourceType::kLayout: {
       LayoutVisitor visitor(res->file, keep_set);
       res->root->Accept(&visitor);
       break;
     }

     case ResourceType::kXml: {
       XmlResourceVisitor visitor(res->file, keep_set);
       res->root->Accept(&visitor);
       break;
     }

     case ResourceType::kTransition: {
       TransitionVisitor visitor(res->file, keep_set);
       res->root->Accept(&visitor);
       break;
     }

     case ResourceType::kMenu: {
       MenuVisitor visitor(res->file, keep_set);
       res->root->Accept(&visitor);
       break;
     }

     default: {
       BaseVisitor visitor(res->file, keep_set);
       res->root->Accept(&visitor);
       break;
     }
   }
   return true;
 }

 void WriteKeepSet(const KeepSet& keep_set, OutputStream* out) {
   Printer printer(out);
   for (const auto& entry : keep_set.manifest_class_set_) {
     for (const UsageLocation& location : entry.second) {
       printer.Print("# Referenced at ").Println(location.source.to_string());
     }
     printer.Print("-keep class ").Print(entry.first).Println(" { <init>(...); }");
   }

   for (const auto& entry : keep_set.conditional_class_set_) {
     std::set<UsageLocation> locations;
     bool can_be_conditional = true;
     for (const UsageLocation& location : entry.second) {
       can_be_conditional &= CollectLocations(location, keep_set, &locations);
     }

     if (keep_set.conditional_keep_rules_ && can_be_conditional) {
       for (const UsageLocation& location : locations) {
         printer.Print("# Referenced at ").Println(location.source.to_string());
         printer.Print("-if class **.R$layout { int ")
             .Print(JavaClassGenerator::TransformToFieldName(location.name.entry))
             .Println("; }");
         printer.Print("-keep class ").Print(entry.first).Println(" { <init>(...); }");
       }
     } else {
       for (const UsageLocation& location : entry.second) {
         printer.Print("# Referenced at ").Println(location.source.to_string());
       }
       printer.Print("-keep class ").Print(entry.first).Println(" { <init>(...); }");
     }
     printer.Println();
   }

   for (const auto& entry : keep_set.method_set_) {
     for (const UsageLocation& location : entry.second) {
       printer.Print("# Referenced at ").Println(location.source.to_string());
     }
     printer.Print("-keepclassmembers class * { *** ").Print(entry.first).Println("(...); }");
     printer.Println();
   }
 }

 bool CollectLocations(const UsageLocation& location, const KeepSet& keep_set,
                       std::set<UsageLocation>* locations) {
   locations->insert(location);

   // TODO: allow for more reference types if we can determine its safe.
   if (location.name.type != ResourceType::kLayout) {
     return false;
   }

   for (const auto& entry : keep_set.reference_set_) {
     if (entry.first == location.name) {
       for (auto& refLocation : entry.second) {
         // Don't get stuck in loops
         if (locations->find(refLocation) != locations->end()) {
           return false;
         }
         if (!CollectLocations(refLocation, keep_set, locations)) {
           return false;
         }
       }
     }
   }

   return true;
 }

 class ReferenceVisitor : public ValueVisitor {
  public:
   using ValueVisitor::Visit;

   ReferenceVisitor(aapt::IAaptContext* context, ResourceName from, KeepSet* keep_set)
       : context_(context), from_(from), keep_set_(keep_set) {
   }

   void Visit(Reference* reference) override {
     if (reference->name) {
       ResourceName reference_name = reference->name.value();
       if (reference_name.package.empty()) {
         reference_name = ResourceName(context_->GetCompilationPackage(), reference_name.type,
                                       reference_name.entry);
       }
       keep_set_->AddReference({from_, reference->GetSource()}, reference_name);
     }
   }

  private:
   aapt::IAaptContext* context_;
   ResourceName from_;
   KeepSet* keep_set_;
 };

 bool CollectResourceReferences(aapt::IAaptContext* context, ResourceTable* table,
                                KeepSet* keep_set) {
   for (auto& pkg : table->packages) {
     for (auto& type : pkg->types) {
       for (auto& entry : type->entries) {
         for (auto& config_value : entry->values) {
           ResourceName from(pkg->name, type->type, entry->name);
           ReferenceVisitor visitor(context, from, keep_set);
           config_value->value->Accept(&visitor);
         }
       }
     }
   }
   return true;
 }

 }  // namespace proguard
 }  // namespace aapt
	/*
	* Copyright (C) 2015 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "java/ProguardRules.h"

	#include <memory>
	#include <string>

	#include "android-base/macros.h"
	#include "androidfw/StringPiece.h"

	#include "JavaClassGenerator.h"
	#include "ResourceUtils.h"
	#include "ValueVisitor.h"
	#include "text/Printer.h"
	#include "util/Util.h"
	#include "xml/XmlDom.h"

	using ::aapt::io::OutputStream;
	using ::aapt::text::Printer;

	namespace aapt {
	namespace proguard {

	class BaseVisitor : public xml::Visitor {
	public:
	using xml::Visitor::Visit;

	BaseVisitor(const ResourceFile& file, KeepSet* keep_set) : file_(file), keep_set_(keep_set) {
	}

	void Visit(xml::Element* node) override {
	if (!node->namespace_uri.empty()) {
	Maybe<xml::ExtractedPackage> maybe_package =
	xml::ExtractPackageFromNamespace(node->namespace_uri);
	if (maybe_package) {
	// This is a custom view, let's figure out the class name from this.
	std::string package = maybe_package.value().package + "." + node->name;
	if (util::IsJavaClassName(package)) {
	AddClass(node->line_number, package);
	}
	}
	} else if (util::IsJavaClassName(node->name)) {
	AddClass(node->line_number, node->name);
	}

	for (const auto& child : node->children) {
	child->Accept(this);
	}

	for (const auto& attr : node->attributes) {
	if (attr.compiled_value) {
	auto ref = ValueCast<Reference>(attr.compiled_value.get());
	if (ref) {
	AddReference(node->line_number, ref);
	}
	}
	}
	}

	protected:
	ResourceFile file_;
	KeepSet* keep_set_;

	virtual void AddClass(size_t line_number, const std::string& class_name) {
	keep_set_->AddConditionalClass({file_.name, file_.source.WithLine(line_number)}, class_name);
	}

	void AddMethod(size_t line_number, const std::string& method_name) {
	keep_set_->AddMethod({file_.name, file_.source.WithLine(line_number)}, method_name);
	}

	void AddReference(size_t line_number, Reference* ref) {
	if (ref && ref->name) {
	ResourceName ref_name = ref->name.value();
	if (ref_name.package.empty()) {
	ref_name = ResourceName(file_.name.package, ref_name.type, ref_name.entry);
	}
	keep_set_->AddReference({file_.name, file_.source.WithLine(line_number)}, ref_name);
	}
	}

	private:
	DISALLOW_COPY_AND_ASSIGN(BaseVisitor);

	};

	class LayoutVisitor : public BaseVisitor {
	public:
	LayoutVisitor(const ResourceFile& file, KeepSet* keep_set) : BaseVisitor(file, keep_set) {
	}

	void Visit(xml::Element* node) override {
	bool check_class = false;
	bool check_name = false;
	if (node->namespace_uri.empty()) {
	if (node->name == "view") {
	check_class = true;
	} else if (node->name == "fragment") {
	check_class = check_name = true;
	}
	} else if (node->namespace_uri == xml::kSchemaAndroid) {
	check_name = node->name == "fragment";
	}

	for (const auto& attr : node->attributes) {
	if (check_class && attr.namespace_uri.empty() && attr.name == "class" &&
	util::IsJavaClassName(attr.value)) {
	AddClass(node->line_number, attr.value);
	} else if (check_name && attr.namespace_uri == xml::kSchemaAndroid &&
	attr.name == "name" && util::IsJavaClassName(attr.value)) {
	AddClass(node->line_number, attr.value);
	} else if (attr.namespace_uri == xml::kSchemaAndroid &&
	attr.name == "onClick") {
	AddMethod(node->line_number, attr.value);
	}
	}

	BaseVisitor::Visit(node);
	}

	private:
	DISALLOW_COPY_AND_ASSIGN(LayoutVisitor);
	};

	class MenuVisitor : public BaseVisitor {
	public:
	MenuVisitor(const ResourceFile& file, KeepSet* keep_set) : BaseVisitor(file, keep_set) {
	}

	void Visit(xml::Element* node) override {
	if (node->namespace_uri.empty() && node->name == "item") {
	for (const auto& attr : node->attributes) {
	if (attr.namespace_uri == xml::kSchemaAndroid) {
	if ((attr.name == "actionViewClass" \|\| attr.name == "actionProviderClass") &&
	util::IsJavaClassName(attr.value)) {
	AddClass(node->line_number, attr.value);
	} else if (attr.name == "onClick") {
	AddMethod(node->line_number, attr.value);
	}
	}
	}
	}

	BaseVisitor::Visit(node);
	}

	private:
	DISALLOW_COPY_AND_ASSIGN(MenuVisitor);
	};

	class XmlResourceVisitor : public BaseVisitor {
	public:
	XmlResourceVisitor(const ResourceFile& file, KeepSet* keep_set) : BaseVisitor(file, keep_set) {
	}

	void Visit(xml::Element* node) override {
	bool check_fragment = false;
	if (node->namespace_uri.empty()) {
	check_fragment =
	node->name == "PreferenceScreen" \|\| node->name == "header";
	}

	if (check_fragment) {
	xml::Attribute* attr =
	node->FindAttribute(xml::kSchemaAndroid, "fragment");
	if (attr && util::IsJavaClassName(attr->value)) {
	AddClass(node->line_number, attr->value);
	}
	}

	BaseVisitor::Visit(node);
	}

	private:
	DISALLOW_COPY_AND_ASSIGN(XmlResourceVisitor);
	};

	class TransitionVisitor : public BaseVisitor {
	public:
	TransitionVisitor(const ResourceFile& file, KeepSet* keep_set) : BaseVisitor(file, keep_set) {
	}

	void Visit(xml::Element* node) override {
	bool check_class =
	node->namespace_uri.empty() && (node->name == "transition" \|\| node->name == "pathMotion");
	if (check_class) {
	xml::Attribute* attr = node->FindAttribute({}, "class");
	if (attr && util::IsJavaClassName(attr->value)) {
	AddClass(node->line_number, attr->value);
	}
	}

	BaseVisitor::Visit(node);
	}

	private:
	DISALLOW_COPY_AND_ASSIGN(TransitionVisitor);
	};

	class ManifestVisitor : public BaseVisitor {
	public:
	ManifestVisitor(const ResourceFile& file, KeepSet* keep_set, bool main_dex_only)
	: BaseVisitor(file, keep_set), main_dex_only_(main_dex_only) {
	}

	void Visit(xml::Element* node) override {
	if (node->namespace_uri.empty()) {
	bool get_name = false;
	if (node->name == "manifest") {
	xml::Attribute* attr = node->FindAttribute({}, "package");
	if (attr) {
	package_ = attr->value;
	}
	} else if (node->name == "application") {
	get_name = true;
	xml::Attribute* attr = node->FindAttribute(xml::kSchemaAndroid, "backupAgent");
	if (attr) {
	Maybe<std::string> result = util::GetFullyQualifiedClassName(package_, attr->value);
	if (result) {
	AddClass(node->line_number, result.value());
	}
	}
	if (main_dex_only_) {
	xml::Attribute* default_process = node->FindAttribute(xml::kSchemaAndroid, "process");
	if (default_process) {
	default_process_ = default_process->value;
	}
	}
	} else if (node->name == "activity" \|\| node->name == "service" \|\|
	node->name == "receiver" \|\| node->name == "provider") {
	get_name = true;

	if (main_dex_only_) {
	xml::Attribute* component_process = node->FindAttribute(xml::kSchemaAndroid, "process");

	const std::string& process =
	component_process ? component_process->value : default_process_;
	get_name = !process.empty() && process[0] != ':';
	}
	} else if (node->name == "instrumentation") {
	get_name = true;
	}

	if (get_name) {
	xml::Attribute* attr = node->FindAttribute(xml::kSchemaAndroid, "name");
	get_name = attr != nullptr;

	if (get_name) {
	Maybe<std::string> result = util::GetFullyQualifiedClassName(package_, attr->value);
	if (result) {
	AddClass(node->line_number, result.value());
	}
	}
	}
	}
	BaseVisitor::Visit(node);
	}

	virtual void AddClass(size_t line_number, const std::string& class_name) override {
	keep_set_->AddManifestClass({file_.name, file_.source.WithLine(line_number)}, class_name);
	}

	private:
	DISALLOW_COPY_AND_ASSIGN(ManifestVisitor);

	std::string package_;
	const bool main_dex_only_;
	std::string default_process_;
	};

	bool CollectProguardRulesForManifest(xml::XmlResource* res, KeepSet* keep_set, bool main_dex_only) {
	ManifestVisitor visitor(res->file, keep_set, main_dex_only);
	if (res->root) {
	res->root->Accept(&visitor);
	return true;
	}
	return false;
	}

	bool CollectProguardRules(xml::XmlResource* res, KeepSet* keep_set) {
	if (!res->root) {
	return false;
	}

	switch (res->file.name.type) {
	case ResourceType::kLayout: {
	LayoutVisitor visitor(res->file, keep_set);
	res->root->Accept(&visitor);
	break;
	}

	case ResourceType::kXml: {
	XmlResourceVisitor visitor(res->file, keep_set);
	res->root->Accept(&visitor);
	break;
	}

	case ResourceType::kTransition: {
	TransitionVisitor visitor(res->file, keep_set);
	res->root->Accept(&visitor);
	break;
	}

	case ResourceType::kMenu: {
	MenuVisitor visitor(res->file, keep_set);
	res->root->Accept(&visitor);
	break;
	}

	default: {
	BaseVisitor visitor(res->file, keep_set);
	res->root->Accept(&visitor);
	break;
	}
	}
	return true;
	}

	void WriteKeepSet(const KeepSet& keep_set, OutputStream* out) {
	Printer printer(out);
	for (const auto& entry : keep_set.manifest_class_set_) {
	for (const UsageLocation& location : entry.second) {
	printer.Print("# Referenced at ").Println(location.source.to_string());
	}
	printer.Print("-keep class ").Print(entry.first).Println(" { <init>(...); }");
	}

	for (const auto& entry : keep_set.conditional_class_set_) {
	std::set<UsageLocation> locations;
	bool can_be_conditional = true;
	for (const UsageLocation& location : entry.second) {
	can_be_conditional &= CollectLocations(location, keep_set, &locations);
	}

	if (keep_set.conditional_keep_rules_ && can_be_conditional) {
	for (const UsageLocation& location : locations) {
	printer.Print("# Referenced at ").Println(location.source.to_string());
	printer.Print("-if class **.R$layout { int ")
	.Print(JavaClassGenerator::TransformToFieldName(location.name.entry))
	.Println("; }");
	printer.Print("-keep class ").Print(entry.first).Println(" { <init>(...); }");
	}
	} else {
	for (const UsageLocation& location : entry.second) {
	printer.Print("# Referenced at ").Println(location.source.to_string());
	}
	printer.Print("-keep class ").Print(entry.first).Println(" { <init>(...); }");
	}
	printer.Println();
	}

	for (const auto& entry : keep_set.method_set_) {
	for (const UsageLocation& location : entry.second) {
	printer.Print("# Referenced at ").Println(location.source.to_string());
	}
	printer.Print("-keepclassmembers class * { *** ").Print(entry.first).Println("(...); }");
	printer.Println();
	}
	}

	bool CollectLocations(const UsageLocation& location, const KeepSet& keep_set,
	std::set<UsageLocation>* locations) {
	locations->insert(location);

	// TODO: allow for more reference types if we can determine its safe.
	if (location.name.type != ResourceType::kLayout) {
	return false;
	}

	for (const auto& entry : keep_set.reference_set_) {
	if (entry.first == location.name) {
	for (auto& refLocation : entry.second) {
	// Don't get stuck in loops
	if (locations->find(refLocation) != locations->end()) {
	return false;
	}
	if (!CollectLocations(refLocation, keep_set, locations)) {
	return false;
	}
	}
	}
	}

	return true;
	}

	class ReferenceVisitor : public ValueVisitor {
	public:
	using ValueVisitor::Visit;

	ReferenceVisitor(aapt::IAaptContext* context, ResourceName from, KeepSet* keep_set)
	: context_(context), from_(from), keep_set_(keep_set) {
	}

	void Visit(Reference* reference) override {
	if (reference->name) {
	ResourceName reference_name = reference->name.value();
	if (reference_name.package.empty()) {
	reference_name = ResourceName(context_->GetCompilationPackage(), reference_name.type,
	reference_name.entry);
	}
	keep_set_->AddReference({from_, reference->GetSource()}, reference_name);
	}
	}

	private:
	aapt::IAaptContext* context_;
	ResourceName from_;
	KeepSet* keep_set_;
	};

	bool CollectResourceReferences(aapt::IAaptContext* context, ResourceTable* table,
	KeepSet* keep_set) {
	for (auto& pkg : table->packages) {
	for (auto& type : pkg->types) {
	for (auto& entry : type->entries) {
	for (auto& config_value : entry->values) {
	ResourceName from(pkg->name, type->type, entry->name);
	ReferenceVisitor visitor(context, from, keep_set);
	config_value->value->Accept(&visitor);
	}
	}
	}
	}
	return true;
	}

	} // namespace proguard
	} // namespace aapt