AAPT2: Add Manifest fixing/validation

Change-Id: I7f6d8b74d1c590adc356b4da55cb6cb777cdf1da
diff --git a/tools/aapt2/link/ManifestFixer.cpp b/tools/aapt2/link/ManifestFixer.cpp
new file mode 100644
index 0000000..52d9426
--- /dev/null
+++ b/tools/aapt2/link/ManifestFixer.cpp
@@ -0,0 +1,100 @@
+/*
+ * 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 "ResourceUtils.h"
+#include "XmlDom.h"
+
+#include "link/ManifestFixer.h"
+#include "util/Util.h"
+
+namespace aapt {
+
+static bool verifyManifest(IAaptContext* context, const Source& source, xml::Element* manifestEl) {
+    bool error = false;
+
+    xml::Attribute* attr = manifestEl->findAttribute({}, u"package");
+    if (!attr) {
+        context->getDiagnostics()->error(DiagMessage(source.withLine(manifestEl->lineNumber))
+                                         << "missing 'package' attribute");
+        error = true;
+    } else if (ResourceUtils::isReference(attr->value)) {
+        context->getDiagnostics()->error(DiagMessage(source.withLine(manifestEl->lineNumber))
+                                         << "value for attribute 'package' must not be a "
+                                            "reference");
+        error = true;
+    } else if (!util::isJavaPackageName(attr->value)) {
+        context->getDiagnostics()->error(DiagMessage(source.withLine(manifestEl->lineNumber))
+                                         << "invalid package name '" << attr->value << "'");
+        error = true;
+    }
+
+    return !error;
+}
+
+static bool fixUsesSdk(IAaptContext* context, const Source& source, xml::Element* el,
+                       const ManifestFixerOptions& options) {
+    if (options.minSdkVersionDefault &&
+            el->findAttribute(xml::kSchemaAndroid, u"minSdkVersion") == nullptr) {
+        // There was no minSdkVersion defined and we have a default to assign.
+        el->attributes.push_back(xml::Attribute{
+                xml::kSchemaAndroid, u"minSdkVersion", options.minSdkVersionDefault.value() });
+    }
+
+    if (options.targetSdkVersionDefault &&
+            el->findAttribute(xml::kSchemaAndroid, u"targetSdkVersion") == nullptr) {
+        // There was no targetSdkVersion defined and we have a default to assign.
+        el->attributes.push_back(xml::Attribute{
+                xml::kSchemaAndroid, u"targetSdkVersion",
+                options.targetSdkVersionDefault.value() });
+    }
+    return true;
+}
+
+bool ManifestFixer::consume(IAaptContext* context, XmlResource* doc) {
+    xml::Element* root = xml::findRootElement(doc->root.get());
+    if (!root || !root->namespaceUri.empty() || root->name != u"manifest") {
+        context->getDiagnostics()->error(DiagMessage(doc->file.source)
+                                         << "root tag must be <manifest>");
+        return false;
+    }
+
+    if (!verifyManifest(context, doc->file.source, root)) {
+        return false;
+    }
+
+    bool foundUsesSdk = false;
+    for (xml::Element* el : root->getChildElements()) {
+        if (!el->namespaceUri.empty()) {
+            continue;
+        }
+
+        if (el->name == u"uses-sdk") {
+            foundUsesSdk = true;
+            fixUsesSdk(context, doc->file.source, el, mOptions);
+        }
+    }
+
+    if (!foundUsesSdk && (mOptions.minSdkVersionDefault || mOptions.targetSdkVersionDefault)) {
+        std::unique_ptr<xml::Element> usesSdk = util::make_unique<xml::Element>();
+        usesSdk->name = u"uses-sdk";
+        fixUsesSdk(context, doc->file.source, usesSdk.get(), mOptions);
+        root->addChild(std::move(usesSdk));
+    }
+
+    return true;
+}
+
+} // namespace aapt