AAPT2: Multi APK generator by version

- Added an additional axis for generating a multi-apk split by minimum
Android SDK version. This removes any resources that will not be used
for the desired minimum SDK version. If there are multiple resources
that would be valid for any version newer than the requested minimum,
then all would be kept so that the best match can be found.

- Added a context wrapper to set the appropriate Android SDK version for
each generated artifact.

- Split out the FilterTable method to allow it to be directly tested
without the need to mock the APK writing steps.

Test: Unit tests
Test: manually run optimize command

Change-Id: I7e6018df081af9ed5d9e8aaf40ed216c1275f138

1 files changed, 160 insertions, 53 deletions

diff --git a/tools/aapt2/optimize/MultiApkGenerator.cpp b/tools/aapt2/optimize/MultiApkGenerator.cpp
index e7a4f8578529..5ff890832371 100644
--- a/tools/aapt2/optimize/MultiApkGenerator.cpp
+++ b/tools/aapt2/optimize/MultiApkGenerator.cpp
@@ -26,25 +26,77 @@
 #include "filter/AbiFilter.h"
 #include "filter/Filter.h"
 #include "flatten/Archive.h"
+#include "optimize/VersionCollapser.h"
 #include "process/IResourceTableConsumer.h"
 #include "split/TableSplitter.h"
 #include "util/Files.h"
 
 namespace aapt {
 
+using ::aapt::configuration::AndroidSdk;
 using ::aapt::configuration::Artifact;
 using ::aapt::configuration::PostProcessingConfiguration;
 using ::android::StringPiece;
 
+/**
+ * Context wrapper that allows the min Android SDK value to be overridden.
+ */
+class ContextWrapper : public IAaptContext {
+ public:
+  explicit ContextWrapper(IAaptContext* context)
+      : context_(context), min_sdk_(context_->GetMinSdkVersion()) {
+  }
+
+  PackageType GetPackageType() override {
+    return context_->GetPackageType();
+  }
+
+  SymbolTable* GetExternalSymbols() override {
+    return context_->GetExternalSymbols();
+  }
+
+  IDiagnostics* GetDiagnostics() override {
+    return context_->GetDiagnostics();
+  }
+
+  const std::string& GetCompilationPackage() override {
+    return context_->GetCompilationPackage();
+  }
+
+  uint8_t GetPackageId() override {
+    return context_->GetPackageId();
+  }
+
+  NameMangler* GetNameMangler() override {
+    return context_->GetNameMangler();
+  }
+
+  bool IsVerbose() override {
+    return context_->IsVerbose();
+  }
+
+  int GetMinSdkVersion() override {
+    return min_sdk_;
+  }
+
+  void SetMinSdkVersion(int min_sdk) {
+    min_sdk_ = min_sdk;
+  }
+
+ private:
+  IAaptContext* context_;
+
+  int min_sdk_ = -1;
+};
+
 MultiApkGenerator::MultiApkGenerator(LoadedApk* apk, IAaptContext* context)
     : apk_(apk), context_(context) {
 }
 
-bool MultiApkGenerator::FromBaseApk(const std::string& out_dir,
-                                    const PostProcessingConfiguration& config,
-                                    const TableFlattenerOptions& table_flattener_options) {
+bool MultiApkGenerator::FromBaseApk(const MultiApkGeneratorOptions& options) {
   // TODO(safarmer): Handle APK version codes for the generated APKs.
   IDiagnostics* diag = context_->GetDiagnostics();
+  const PostProcessingConfiguration& config = options.config;
 
   const std::string& apk_name = file::GetFilename(apk_->GetSource().path).to_string();
   const StringPiece ext = file::GetExtension(apk_name);
@@ -53,8 +105,6 @@ bool MultiApkGenerator::FromBaseApk(const std::string& out_dir,
   // For now, just write out the stripped APK since ABI splitting doesn't modify anything else.
   for (const Artifact& artifact : config.artifacts) {
     FilterChain filters;
-    TableSplitterOptions splits;
-    AxisConfigFilter axis_filter;
 
     if (!artifact.name && !config.artifact_format) {
       diag->Error(
@@ -71,74 +121,131 @@ bool MultiApkGenerator::FromBaseApk(const std::string& out_dir,
       return false;
     }
 
-    if (artifact.abi_group) {
-      const std::string& group_name = artifact.abi_group.value();
+    std::unique_ptr<ResourceTable> table =
+        FilterTable(artifact, config, *apk_->GetResourceTable(), &filters);
+    if (!table) {
+      return false;
+    }
+
+    std::string out = options.out_dir;
+    if (!file::mkdirs(out)) {
+      context_->GetDiagnostics()->Warn(DiagMessage() << "could not create out dir: " << out);
+    }
+    file::AppendPath(&out, artifact_name.value());
 
-      auto group = config.abi_groups.find(group_name);
-      // TODO: Remove validation when configuration parser ensures referential integrity.
-      if (group == config.abi_groups.end()) {
-        diag->Error(DiagMessage() << "could not find referenced ABI group '" << group_name << "'");
-        return false;
-      }
-      filters.AddFilter(AbiFilter::FromAbiList(group->second));
+    if (context_->IsVerbose()) {
+      context_->GetDiagnostics()->Note(DiagMessage() << "Generating split: " << out);
     }
 
-    if (artifact.screen_density_group) {
-      const std::string& group_name = artifact.screen_density_group.value();
+    std::unique_ptr<IArchiveWriter> writer =
+        CreateZipFileArchiveWriter(context_->GetDiagnostics(), out);
 
-      auto group = config.screen_density_groups.find(group_name);
-      // TODO: Remove validation when configuration parser ensures referential integrity.
-      if (group == config.screen_density_groups.end()) {
-        diag->Error(DiagMessage() << "could not find referenced group '" << group_name << "'");
-        return false;
-      }
+    if (context_->IsVerbose()) {
+      diag->Note(DiagMessage() << "Writing output: " << out);
+    }
 
-      const std::vector<ConfigDescription>& densities = group->second;
-      std::for_each(densities.begin(), densities.end(), [&](const ConfigDescription& c) {
-        splits.preferred_densities.push_back(c.density);
-      });
+    if (!apk_->WriteToArchive(context_, table.get(), options.table_flattener_options, &filters,
+                              writer.get())) {
+      return false;
     }
+  }
 
-    if (artifact.locale_group) {
-      const std::string& group_name = artifact.locale_group.value();
-      auto group = config.locale_groups.find(group_name);
-      // TODO: Remove validation when configuration parser ensures referential integrity.
-      if (group == config.locale_groups.end()) {
-        diag->Error(DiagMessage() << "could not find referenced group '" << group_name << "'");
-        return false;
-      }
-
-      const std::vector<ConfigDescription>& locales = group->second;
-      std::for_each(locales.begin(), locales.end(),
-                    [&](const ConfigDescription& c) { axis_filter.AddConfig(c); });
-      splits.config_filter = &axis_filter;
+  return true;
+}
+
+std::unique_ptr<ResourceTable> MultiApkGenerator::FilterTable(
+    const configuration::Artifact& artifact,
+    const configuration::PostProcessingConfiguration& config, const ResourceTable& old_table,
+    FilterChain* filters) {
+  TableSplitterOptions splits;
+  AxisConfigFilter axis_filter;
+  ContextWrapper wrappedContext{context_};
+
+  if (artifact.abi_group) {
+    const std::string& group_name = artifact.abi_group.value();
+
+    auto group = config.abi_groups.find(group_name);
+    // TODO: Remove validation when configuration parser ensures referential integrity.
+    if (group == config.abi_groups.end()) {
+      context_->GetDiagnostics()->Error(DiagMessage() << "could not find referenced ABI group '"
+                                                      << group_name << "'");
+      return {};
     }
+    filters->AddFilter(AbiFilter::FromAbiList(group->second));
+  }
 
-    std::unique_ptr<ResourceTable> table = apk_->GetResourceTable()->Clone();
+  if (artifact.screen_density_group) {
+    const std::string& group_name = artifact.screen_density_group.value();
 
+    auto group = config.screen_density_groups.find(group_name);
+    // TODO: Remove validation when configuration parser ensures referential integrity.
+    if (group == config.screen_density_groups.end()) {
+      context_->GetDiagnostics()->Error(DiagMessage() << "could not find referenced group '"
+                                                      << group_name << "'");
+      return {};
+    }
 
-    TableSplitter splitter{{}, splits};
-    splitter.SplitTable(table.get());
+    const std::vector<ConfigDescription>& densities = group->second;
+    for(const auto& density_config : densities) {
+      splits.preferred_densities.push_back(density_config.density);
+    }
+  }
 
-    std::string out = out_dir;
-    if (!file::mkdirs(out)) {
-      context_->GetDiagnostics()->Warn(DiagMessage() << "could not create out dir: " << out);
+  if (artifact.locale_group) {
+    const std::string& group_name = artifact.locale_group.value();
+    auto group = config.locale_groups.find(group_name);
+    // TODO: Remove validation when configuration parser ensures referential integrity.
+    if (group == config.locale_groups.end()) {
+      context_->GetDiagnostics()->Error(DiagMessage() << "could not find referenced group '"
+                                                      << group_name << "'");
+      return {};
     }
-    file::AppendPath(&out, artifact_name.value());
 
-    std::unique_ptr<IArchiveWriter> writer = CreateZipFileArchiveWriter(diag, out);
+    const std::vector<ConfigDescription>& locales = group->second;
+    for (const auto& locale : locales) {
+      axis_filter.AddConfig(locale);
+    }
+    splits.config_filter = &axis_filter;
+  }
 
-    if (context_->IsVerbose()) {
-      diag->Note(DiagMessage() << "Writing output: " << out);
+  if (artifact.android_sdk_group) {
+    const std::string& group_name = artifact.android_sdk_group.value();
+    auto group = config.android_sdk_groups.find(group_name);
+    // TODO: Remove validation when configuration parser ensures referential integrity.
+    if (group == config.android_sdk_groups.end()) {
+      context_->GetDiagnostics()->Error(DiagMessage() << "could not find referenced group '"
+                                                      << group_name << "'");
+      return {};
     }
 
-    if (!apk_->WriteToArchive(context_, table.get(), table_flattener_options, &filters,
-                              writer.get())) {
-      return false;
+    const AndroidSdk& sdk = group->second;
+    if (!sdk.min_sdk_version) {
+      context_->GetDiagnostics()->Error(DiagMessage()
+                                        << "skipping SDK version. No min SDK: " << group_name);
+      return {};
     }
+
+    ConfigDescription c;
+    const std::string& version = sdk.min_sdk_version.value();
+    if (!ConfigDescription::Parse(version, &c)) {
+      context_->GetDiagnostics()->Error(DiagMessage() << "could not parse min SDK: " << version);
+      return {};
+    }
+
+    wrappedContext.SetMinSdkVersion(c.sdkVersion);
   }
 
-  return true;
+  std::unique_ptr<ResourceTable> table = old_table.Clone();
+
+  VersionCollapser collapser;
+  if (!collapser.Consume(context_, table.get())) {
+    context_->GetDiagnostics()->Error(DiagMessage() << "Failed to strip versioned resources");
+    return {};
+  }
+
+  TableSplitter splitter{{}, splits};
+  splitter.SplitTable(table.get());
+  return table;
 }
 
 }  // namespace aapt