AAPT2: Change how we generate Java classes

Previously we would be writing out the Manifest.java file as we
processed the AndroidManifest.xml. This would lead to empty
Manifest classes if there were no permissions or permission groups
defined in the AndroidManifest.xml.

This would pose problems for processes that checked for public classes
and considered them part of the API (support lib).

Now we collect the structure of the Java class in memory before deciding
if a file should be created.

Change-Id: I6b909f28d74356414c6ef5ad005180d6ea5e44ca
diff --git a/tools/aapt2/java/JavaClassGenerator.cpp b/tools/aapt2/java/JavaClassGenerator.cpp
index 01330dc..2d076c2 100644
--- a/tools/aapt2/java/JavaClassGenerator.cpp
+++ b/tools/aapt2/java/JavaClassGenerator.cpp
@@ -21,7 +21,7 @@
 #include "ValueVisitor.h"
 
 #include "java/AnnotationProcessor.h"
-#include "java/ClassDefinitionWriter.h"
+#include "java/ClassDefinition.h"
 #include "java/JavaClassGenerator.h"
 #include "process/SymbolTable.h"
 #include "util/StringPiece.h"
@@ -39,16 +39,6 @@
         mContext(context), mTable(table), mOptions(options) {
 }
 
-static void generateHeader(const StringPiece16& packageNameToGenerate, std::ostream* out) {
-    *out << "/* AUTO-GENERATED FILE. DO NOT MODIFY.\n"
-            " *\n"
-            " * This class was automatically generated by the\n"
-            " * aapt tool from the resource data it found. It\n"
-            " * should not be modified by hand.\n"
-            " */\n\n"
-            "package " << packageNameToGenerate << ";\n\n";
-}
-
 static const std::set<StringPiece16> sJavaIdentifiers = {
     u"abstract", u"assert", u"boolean", u"break", u"byte",
     u"case", u"catch", u"char", u"class", u"const", u"continue",
@@ -110,15 +100,15 @@
     if (typeMask & android::ResTable_map::TYPE_REFERENCE) {
         processor->appendComment(
                 "<p>May be a reference to another resource, in the form\n"
-                        "\"<code>@[+][<i>package</i>:]<i>type</i>/<i>name</i></code>\" or a theme\n"
-                        "attribute in the form\n"
-                        "\"<code>?[<i>package</i>:]<i>type</i>/<i>name</i></code>\".");
+                "\"<code>@[+][<i>package</i>:]<i>type</i>/<i>name</i></code>\" or a theme\n"
+                "attribute in the form\n"
+                "\"<code>?[<i>package</i>:]<i>type</i>/<i>name</i></code>\".");
     }
 
     if (typeMask & android::ResTable_map::TYPE_STRING) {
         processor->appendComment(
                 "<p>May be a string value, using '\\\\;' to escape characters such as\n"
-                        "'\\\\n' or '\\\\uxxxx' for a unicode character;");
+                "'\\\\n' or '\\\\uxxxx' for a unicode character;");
     }
 
     if (typeMask & android::ResTable_map::TYPE_INTEGER) {
@@ -128,14 +118,14 @@
     if (typeMask & android::ResTable_map::TYPE_BOOLEAN) {
         processor->appendComment(
                 "<p>May be a boolean value, such as \"<code>true</code>\" or\n"
-                        "\"<code>false</code>\".");
+                "\"<code>false</code>\".");
     }
 
     if (typeMask & android::ResTable_map::TYPE_COLOR) {
         processor->appendComment(
                 "<p>May be a color value, in the form of \"<code>#<i>rgb</i></code>\",\n"
-                        "\"<code>#<i>argb</i></code>\", \"<code>#<i>rrggbb</i></code\", or \n"
-                        "\"<code>#<i>aarrggbb</i></code>\".");
+                "\"<code>#<i>argb</i></code>\", \"<code>#<i>rrggbb</i></code\", or \n"
+                "\"<code>#<i>aarrggbb</i></code>\".");
     }
 
     if (typeMask & android::ResTable_map::TYPE_FLOAT) {
@@ -146,33 +136,33 @@
     if (typeMask & android::ResTable_map::TYPE_DIMENSION) {
         processor->appendComment(
                 "<p>May be a dimension value, which is a floating point number appended with a\n"
-                        "unit such as \"<code>14.5sp</code>\".\n"
-                        "Available units are: px (pixels), dp (density-independent pixels),\n"
-                        "sp (scaled pixels based on preferred font size), in (inches), and\n"
-                        "mm (millimeters).");
+                "unit such as \"<code>14.5sp</code>\".\n"
+                "Available units are: px (pixels), dp (density-independent pixels),\n"
+                "sp (scaled pixels based on preferred font size), in (inches), and\n"
+                "mm (millimeters).");
     }
 
     if (typeMask & android::ResTable_map::TYPE_FRACTION) {
         processor->appendComment(
                 "<p>May be a fractional value, which is a floating point number appended with\n"
-                        "either % or %p, such as \"<code>14.5%</code>\".\n"
-                        "The % suffix always means a percentage of the base size;\n"
-                        "the optional %p suffix provides a size relative to some parent container.");
+                "either % or %p, such as \"<code>14.5%</code>\".\n"
+                "The % suffix always means a percentage of the base size;\n"
+                "the optional %p suffix provides a size relative to some parent container.");
     }
 
     if (typeMask & (android::ResTable_map::TYPE_FLAGS | android::ResTable_map::TYPE_ENUM)) {
         if (typeMask & android::ResTable_map::TYPE_FLAGS) {
             processor->appendComment(
                     "<p>Must be one or more (separated by '|') of the following "
-                            "constant values.</p>");
+                    "constant values.</p>");
         } else {
             processor->appendComment("<p>Must be one of the following constant values.</p>");
         }
 
         processor->appendComment("<table>\n<colgroup align=\"left\" />\n"
-                                         "<colgroup align=\"left\" />\n"
-                                         "<colgroup align=\"left\" />\n"
-                                         "<tr><th>Constant</th><th>Value</th><th>Description</th></tr>\n");
+                                 "<colgroup align=\"left\" />\n"
+                                 "<colgroup align=\"left\" />\n"
+                                 "<tr><th>Constant</th><th>Value</th><th>Description</th></tr>\n");
         for (const Attribute::Symbol& symbol : attr->symbols) {
             std::stringstream line;
             line << "<tr><td>" << symbol.symbol.name.value().entry << "</td>"
@@ -214,13 +204,15 @@
     }
 }
 
-void JavaClassGenerator::writeStyleableEntryForClass(ClassDefinitionWriter* outClassDef,
-                                                     AnnotationProcessor* processor,
-                                                     const StringPiece16& packageNameToGenerate,
-                                                     const std::u16string& entryName,
-                                                     const Styleable* styleable) {
+void JavaClassGenerator::addMembersToStyleableClass(const StringPiece16& packageNameToGenerate,
+                                                    const std::u16string& entryName,
+                                                    const Styleable* styleable,
+                                                    ClassDefinition* outStyleableClassDef) {
     const std::string className = transform(entryName);
 
+    std::unique_ptr<ResourceArrayMember> styleableArrayDef =
+            util::make_unique<ResourceArrayMember>(className);
+
     // This must be sorted by resource ID.
     std::vector<StyleableAttr> sortedAttributes;
     sortedAttributes.reserve(styleable->entries.size());
@@ -230,6 +222,8 @@
         assert((!mOptions.useFinal || attr.id) && "no ID set for Styleable entry");
         assert(attr.name && "no name set for Styleable entry");
 
+        // We will need the unmangled, transformed name in the comments and the field,
+        // so create it once and cache it in this StyleableAttr data structure.
         StyleableAttr styleableAttr = {};
         styleableAttr.attrRef = &attr;
         styleableAttr.fieldName = transformNestedAttr(attr.name.value(), className,
@@ -247,6 +241,8 @@
             mangledReference.name = mangledName;
         }
 
+        // Look up the symbol so that we can write out in the comments what are possible
+        // legal values for this attribute.
         const SymbolTable::Symbol* symbol = mContext->getExternalSymbols()->findByReference(
                 mangledReference);
         if (symbol) {
@@ -254,10 +250,11 @@
         }
         sortedAttributes.push_back(std::move(styleableAttr));
     }
+
+    // Sort the attributes by ID.
     std::sort(sortedAttributes.begin(), sortedAttributes.end(), lessStyleableAttr);
 
     const size_t attrCount = sortedAttributes.size();
-
     if (attrCount > 0) {
         // Build the comment string for the Styleable. It includes details about the
         // child attributes.
@@ -267,6 +264,7 @@
         } else {
             styleableComment << "Attributes that can be used with a " << className << ".\n";
         }
+
         styleableComment <<
                 "<p>Includes the following attributes:</p>\n"
                 "<table>\n"
@@ -274,7 +272,7 @@
                 "<colgroup align=\"left\" />\n"
                 "<tr><th>Attribute</th><th>Description</th></tr>\n";
 
-        for (const auto& entry : sortedAttributes) {
+        for (const StyleableAttr& entry : sortedAttributes) {
             const ResourceName& attrName = entry.attrRef->name.value();
             styleableComment << "<tr><td>";
             styleableComment << "<code>{@link #"
@@ -292,21 +290,22 @@
             styleableComment << "</td></tr>\n";
         }
         styleableComment << "</table>\n";
-        for (const auto& entry : sortedAttributes) {
+
+        for (const StyleableAttr& entry : sortedAttributes) {
             styleableComment << "@see #" << entry.fieldName << "\n";
         }
-        processor->appendComment(styleableComment.str());
+
+        styleableArrayDef->getCommentBuilder()->appendComment(styleableComment.str());
     }
 
-    auto accessorFunc = [](const StyleableAttr& a) -> ResourceId {
-        return a.attrRef->id ? a.attrRef->id.value() : ResourceId(0);
-    };
+    // Add the ResourceIds to the array member.
+    for (const StyleableAttr& styleableAttr : sortedAttributes) {
+        styleableArrayDef->addElement(
+                styleableAttr.attrRef->id ? styleableAttr.attrRef->id.value() : ResourceId(0));
+    }
 
-    // First we emit the array containing the IDs of each attribute.
-    outClassDef->addArrayMember(className, processor,
-                                sortedAttributes.begin(),
-                                sortedAttributes.end(),
-                                accessorFunc);
+    // Add the Styleable array to the Styleable class.
+    outStyleableClassDef->addMember(std::move(styleableArrayDef));
 
     // Now we emit the indices into the array.
     for (size_t i = 0; i < attrCount; i++) {
@@ -318,7 +317,10 @@
             packageName = mContext->getCompilationPackage();
         }
 
-        AnnotationProcessor attrProcessor;
+        std::unique_ptr<IntMember> indexMember = util::make_unique<IntMember>(
+                sortedAttributes[i].fieldName, i);
+
+        AnnotationProcessor* attrProcessor = indexMember->getCommentBuilder();
 
         StringPiece16 comment = styleableAttr.attrRef->getComment();
         if (styleableAttr.attribute && comment.empty()) {
@@ -326,8 +328,8 @@
         }
 
         if (!comment.empty()) {
-            attrProcessor.appendComment("<p>\n@attr description");
-            attrProcessor.appendComment(comment);
+            attrProcessor->appendComment("<p>\n@attr description");
+            attrProcessor->appendComment(comment);
         } else {
             std::stringstream defaultComment;
             defaultComment
@@ -335,27 +337,29 @@
                     << "{@link " << packageName << ".R.attr#" << transform(attrName.entry) << "}\n"
                     << "attribute's value can be found in the "
                     << "{@link #" << className << "} array.";
-            attrProcessor.appendComment(defaultComment.str());
+            attrProcessor->appendComment(defaultComment.str());
         }
 
-        attrProcessor.appendNewLine();
+        attrProcessor->appendNewLine();
 
         if (styleableAttr.attribute) {
-            addAttributeFormatDoc(&attrProcessor, styleableAttr.attribute.get());
-            attrProcessor.appendNewLine();
+            addAttributeFormatDoc(attrProcessor, styleableAttr.attribute.get());
+            attrProcessor->appendNewLine();
         }
 
         std::stringstream doclavaName;
         doclavaName << "@attr name " << packageName << ":" << attrName.entry;;
-        attrProcessor.appendComment(doclavaName.str());
-        outClassDef->addIntMember(sortedAttributes[i].fieldName, &attrProcessor, i);
+        attrProcessor->appendComment(doclavaName.str());
+
+        outStyleableClassDef->addMember(std::move(indexMember));
     }
 }
 
-bool JavaClassGenerator::writeEntriesForClass(ClassDefinitionWriter* outClassDef,
-                                              const StringPiece16& packageNameToGenerate,
-                                              const ResourceTablePackage* package,
-                                              const ResourceTableType* type) {
+bool JavaClassGenerator::addMembersToTypeClass(const StringPiece16& packageNameToGenerate,
+                                               const ResourceTablePackage* package,
+                                               const ResourceTableType* type,
+                                               ClassDefinition* outTypeClassDef) {
+
     for (const auto& entry : type->entries) {
         if (skipSymbol(entry->symbolStatus.state)) {
             continue;
@@ -389,33 +393,41 @@
             return false;
         }
 
-        // Build the comments and annotations for this entry.
-
-        AnnotationProcessor processor;
-        if (entry->symbolStatus.state != SymbolState::kUndefined) {
-            processor.appendComment(entry->symbolStatus.comment);
-        }
-
-        for (const auto& configValue : entry->values) {
-            processor.appendComment(configValue->value->getComment());
-        }
-
-        // If this is an Attribute, append the format Javadoc.
-        if (!entry->values.empty()) {
-            if (Attribute* attr = valueCast<Attribute>(entry->values.front()->value.get())) {
-                // We list out the available values for the given attribute.
-                addAttributeFormatDoc(&processor, attr);
-            }
-        }
-
         if (type->type == ResourceType::kStyleable) {
             assert(!entry->values.empty());
+
             const Styleable* styleable = static_cast<const Styleable*>(
                     entry->values.front()->value.get());
-            writeStyleableEntryForClass(outClassDef, &processor, packageNameToGenerate,
-                                        unmangledName, styleable);
+
+            // Comments are handled within this method.
+            addMembersToStyleableClass(packageNameToGenerate, unmangledName, styleable,
+                                       outTypeClassDef);
         } else {
-            outClassDef->addResourceMember(transform(unmangledName), &processor, id);
+            std::unique_ptr<ResourceMember> resourceMember =
+                    util::make_unique<ResourceMember>(transform(unmangledName), id);
+
+            // Build the comments and annotations for this entry.
+            AnnotationProcessor* processor = resourceMember->getCommentBuilder();
+
+            // Add the comments from any <public> tags.
+            if (entry->symbolStatus.state != SymbolState::kUndefined) {
+                processor->appendComment(entry->symbolStatus.comment);
+            }
+
+            // Add the comments from all configurations of this entry.
+            for (const auto& configValue : entry->values) {
+                processor->appendComment(configValue->value->getComment());
+            }
+
+            // If this is an Attribute, append the format Javadoc.
+            if (!entry->values.empty()) {
+                if (Attribute* attr = valueCast<Attribute>(entry->values.front()->value.get())) {
+                    // We list out the available values for the given attribute.
+                    addAttributeFormatDoc(processor, attr);
+                }
+            }
+
+            outTypeClassDef->addMember(std::move(resourceMember));
         }
     }
     return true;
@@ -427,9 +439,8 @@
 
 bool JavaClassGenerator::generate(const StringPiece16& packageNameToGenerate,
                                   const StringPiece16& outPackageName, std::ostream* out) {
-    generateHeader(outPackageName, out);
 
-    *out << "public final class R {\n";
+    ClassDefinition rClass("R", ClassQualifier::None, true);
 
     for (const auto& package : mTable->packages) {
         for (const auto& type : package->types) {
@@ -437,13 +448,15 @@
                 continue;
             }
 
-            ClassDefinitionWriterOptions classOptions;
-            classOptions.useFinalQualifier = mOptions.useFinal;
-            classOptions.forceCreationIfEmpty =
+            const bool forceCreationIfEmpty =
                     (mOptions.types == JavaClassGeneratorOptions::SymbolTypes::kPublic);
-            ClassDefinitionWriter classDef(toString(type->type), classOptions);
-            bool result = writeEntriesForClass(&classDef, packageNameToGenerate,
-                                               package.get(), type.get());
+
+            std::unique_ptr<ClassDefinition> classDef = util::make_unique<ClassDefinition>(
+                    util::utf16ToUtf8(toString(type->type)), ClassQualifier::Static,
+                    forceCreationIfEmpty);
+
+            bool result = addMembersToTypeClass(packageNameToGenerate, package.get(), type.get(),
+                                                classDef.get());
             if (!result) {
                 return false;
             }
@@ -452,26 +465,31 @@
                 // Also include private attributes in this same class.
                 ResourceTableType* privType = package->findType(ResourceType::kAttrPrivate);
                 if (privType) {
-                    result = writeEntriesForClass(&classDef, packageNameToGenerate,
-                                                  package.get(), privType);
+                    result = addMembersToTypeClass(packageNameToGenerate, package.get(), privType,
+                                                   classDef.get());
                     if (!result) {
                         return false;
                     }
                 }
             }
 
-            AnnotationProcessor processor;
             if (type->type == ResourceType::kStyleable &&
                     mOptions.types == JavaClassGeneratorOptions::SymbolTypes::kPublic) {
                 // When generating a public R class, we don't want Styleable to be part of the API.
                 // It is only emitted for documentation purposes.
-                processor.appendComment("@doconly");
+                AnnotationProcessor* processor = classDef->getCommentBuilder();
+                processor->appendComment("@doconly");
             }
-            classDef.writeToStream(out, "  ", &processor);
+
+            rClass.addMember(std::move(classDef));
         }
     }
 
-    *out << "}\n";
+    if (!ClassDefinition::writeJavaFile(&rClass, util::utf16ToUtf8(outPackageName),
+                                        mOptions.useFinal, out)) {
+        return false;
+    }
+
     out->flush();
     return true;
 }