/*
* 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 "XmlDom.h"
#include "XmlPullParser.h"
#include "util/Util.h"
#include <cassert>
#include <expat.h>
#include <memory>
#include <stack>
#include <string>
#include <tuple>
namespace aapt {
namespace xml {
constexpr char kXmlNamespaceSep = 1;
struct Stack {
std::unique_ptr<xml::Node> root;
std::stack<xml::Node*> nodeStack;
std::u16string pendingComment;
};
/**
* Extracts the namespace and name of an expanded element or attribute name.
*/
static void splitName(const char* name, std::u16string* outNs, std::u16string* outName) {
const char* p = name;
while (*p != 0 && *p != kXmlNamespaceSep) {
p++;
}
if (*p == 0) {
outNs->clear();
*outName = util::utf8ToUtf16(name);
} else {
*outNs = util::utf8ToUtf16(StringPiece(name, (p - name)));
*outName = util::utf8ToUtf16(p + 1);
}
}
static void addToStack(Stack* stack, XML_Parser parser, std::unique_ptr<Node> node) {
node->lineNumber = XML_GetCurrentLineNumber(parser);
node->columnNumber = XML_GetCurrentColumnNumber(parser);
Node* thisNode = node.get();
if (!stack->nodeStack.empty()) {
stack->nodeStack.top()->addChild(std::move(node));
} else {
stack->root = std::move(node);
}
if (!nodeCast<Text>(thisNode)) {
stack->nodeStack.push(thisNode);
}
}
static void XMLCALL startNamespaceHandler(void* userData, const char* prefix, const char* uri) {
XML_Parser parser = reinterpret_cast<XML_Parser>(userData);
Stack* stack = reinterpret_cast<Stack*>(XML_GetUserData(parser));
std::unique_ptr<Namespace> ns = util::make_unique<Namespace>();
if (prefix) {
ns->namespacePrefix = util::utf8ToUtf16(prefix);
}
if (uri) {
ns->namespaceUri = util::utf8ToUtf16(uri);
}
addToStack(stack, parser, std::move(ns));
}
static void XMLCALL endNamespaceHandler(void* userData, const char* prefix) {
XML_Parser parser = reinterpret_cast<XML_Parser>(userData);
Stack* stack = reinterpret_cast<Stack*>(XML_GetUserData(parser));
assert(!stack->nodeStack.empty());
stack->nodeStack.pop();
}
static bool lessAttribute(const Attribute& lhs, const Attribute& rhs) {
return std::tie(lhs.namespaceUri, lhs.name, lhs.value) <
std::tie(rhs.namespaceUri, rhs.name, rhs.value);
}
static void XMLCALL startElementHandler(void* userData, const char* name, const char** attrs) {
XML_Parser parser = reinterpret_cast<XML_Parser>(userData);
Stack* stack = reinterpret_cast<Stack*>(XML_GetUserData(parser));
std::unique_ptr<Element> el = util::make_unique<Element>();
splitName(name, &el->namespaceUri, &el->name);
while (*attrs) {
Attribute attribute;
splitName(*attrs++, &attribute.namespaceUri, &attribute.name);
attribute.value = util::utf8ToUtf16(*attrs++);
// Insert in sorted order.
auto iter = std::lower_bound(el->attributes.begin(), el->attributes.end(), attribute,
lessAttribute);
el->attributes.insert(iter, std::move(attribute));
}
el->comment = std::move(stack->pendingComment);
addToStack(stack, parser, std::move(el));
}
static void XMLCALL endElementHandler(void* userData, const char* name) {
XML_Parser parser = reinterpret_cast<XML_Parser>(userData);
Stack* stack = reinterpret_cast<Stack*>(XML_GetUserData(parser));
assert(!stack->nodeStack.empty());
//stack->nodeStack.top()->comment = std::move(stack->pendingComment);
stack->nodeStack.pop();
}
static void XMLCALL characterDataHandler(void* userData, const char* s, int len) {
XML_Parser parser = reinterpret_cast<XML_Parser>(userData);
Stack* stack = reinterpret_cast<Stack*>(XML_GetUserData(parser));
if (!s || len <= 0) {
return;
}
// See if we can just append the text to a previous text node.
if (!stack->nodeStack.empty()) {
Node* currentParent = stack->nodeStack.top();
if (!currentParent->children.empty()) {
Node* lastChild = currentParent->children.back().get();
if (Text* text = nodeCast<Text>(lastChild)) {
text->text += util::utf8ToUtf16(StringPiece(s, len));
return;
}
}
}
std::unique_ptr<Text> text = util::make_unique<Text>();
text->text = util::utf8ToUtf16(StringPiece(s, len));
addToStack(stack, parser, std::move(text));
}
static void XMLCALL commentDataHandler(void* userData, const char* comment) {
XML_Parser parser = reinterpret_cast<XML_Parser>(userData);
Stack* stack = reinterpret_cast<Stack*>(XML_GetUserData(parser));
if (!stack->pendingComment.empty()) {
stack->pendingComment += '\n';
}
stack->pendingComment += util::utf8ToUtf16(comment);
}
std::unique_ptr<XmlResource> inflate(std::istream* in, IDiagnostics* diag, const Source& source) {
Stack stack;
XML_Parser parser = XML_ParserCreateNS(nullptr, kXmlNamespaceSep);
XML_SetUserData(parser, &stack);
XML_UseParserAsHandlerArg(parser);
XML_SetElementHandler(parser, startElementHandler, endElementHandler);
XML_SetNamespaceDeclHandler(parser, startNamespaceHandler, endNamespaceHandler);
XML_SetCharacterDataHandler(parser, characterDataHandler);
XML_SetCommentHandler(parser, commentDataHandler);
char buffer[1024];
while (!in->eof()) {
in->read(buffer, sizeof(buffer) / sizeof(buffer[0]));
if (in->bad() && !in->eof()) {
stack.root = {};
diag->error(DiagMessage(source) << strerror(errno));
break;
}
if (XML_Parse(parser, buffer, in->gcount(), in->eof()) == XML_STATUS_ERROR) {
stack.root = {};
diag->error(DiagMessage(source.withLine(XML_GetCurrentLineNumber(parser)))
<< XML_ErrorString(XML_GetErrorCode(parser)));
break;
}
}
XML_ParserFree(parser);
if (stack.root) {
return util::make_unique<XmlResource>(ResourceFile{ {}, {}, source }, std::move(stack.root));
}
return {};
}
static void copyAttributes(Element* el, android::ResXMLParser* parser) {
const size_t attrCount = parser->getAttributeCount();
if (attrCount > 0) {
el->attributes.reserve(attrCount);
for (size_t i = 0; i < attrCount; i++) {
Attribute attr;
size_t len;
const char16_t* str16 = parser->getAttributeNamespace(i, &len);
if (str16) {
attr.namespaceUri.assign(str16, len);
}
str16 = parser->getAttributeName(i, &len);
if (str16) {
attr.name.assign(str16, len);
}
str16 = parser->getAttributeStringValue(i, &len);
if (str16) {
attr.value.assign(str16, len);
}
el->attributes.push_back(std::move(attr));
}
}
}
std::unique_ptr<XmlResource> inflate(const void* data, size_t dataLen, IDiagnostics* diag,
const Source& source) {
// We import the android namespace because on Windows NO_ERROR is a macro, not an enum, which
// causes errors when qualifying it with android::
using namespace android;
std::unique_ptr<Node> root;
std::stack<Node*> nodeStack;
ResXMLTree tree;
if (tree.setTo(data, dataLen) != NO_ERROR) {
return {};
}
ResXMLParser::event_code_t code;
while ((code = tree.next()) != ResXMLParser::BAD_DOCUMENT &&
code != ResXMLParser::END_DOCUMENT) {
std::unique_ptr<Node> newNode;
switch (code) {
case ResXMLParser::START_NAMESPACE: {
std::unique_ptr<Namespace> node = util::make_unique<Namespace>();
size_t len;
const char16_t* str16 = tree.getNamespacePrefix(&len);
if (str16) {
node->namespacePrefix.assign(str16, len);
}
str16 = tree.getNamespaceUri(&len);
if (str16) {
node->namespaceUri.assign(str16, len);
}
newNode = std::move(node);
break;
}
case ResXMLParser::START_TAG: {
std::unique_ptr<Element> node = util::make_unique<Element>();
size_t len;
const char16_t* str16 = tree.getElementNamespace(&len);
if (str16) {
node->namespaceUri.assign(str16, len);
}
str16 = tree.getElementName(&len);
if (str16) {
node->name.assign(str16, len);
}
copyAttributes(node.get(), &tree);
newNode = std::move(node);
break;
}
case ResXMLParser::TEXT: {
std::unique_ptr<Text> node = util::make_unique<Text>();
size_t len;
const char16_t* str16 = tree.getText(&len);
if (str16) {
node->text.assign(str16, len);
}
newNode = std::move(node);
break;
}
case ResXMLParser::END_NAMESPACE:
case ResXMLParser::END_TAG:
assert(!nodeStack.empty());
nodeStack.pop();
break;
default:
assert(false);
break;
}
if (newNode) {
newNode->lineNumber = tree.getLineNumber();
Node* thisNode = newNode.get();
if (!root) {
assert(nodeStack.empty());
root = std::move(newNode);
} else {
assert(!nodeStack.empty());
nodeStack.top()->addChild(std::move(newNode));
}
if (!nodeCast<Text>(thisNode)) {
nodeStack.push(thisNode);
}
}
}
return util::make_unique<XmlResource>(ResourceFile{}, std::move(root));
}
Element* findRootElement(XmlResource* doc) {
return findRootElement(doc->root.get());
}
Element* findRootElement(Node* node) {
if (!node) {
return nullptr;
}
Element* el = nullptr;
while ((el = nodeCast<Element>(node)) == nullptr) {
if (node->children.empty()) {
return nullptr;
}
// We are looking for the first element, and namespaces can only have one child.
node = node->children.front().get();
}
return el;
}
void Node::addChild(std::unique_ptr<Node> child) {
child->parent = this;
children.push_back(std::move(child));
}
Attribute* Element::findAttribute(const StringPiece16& ns, const StringPiece16& name) {
for (auto& attr : attributes) {
if (ns == attr.namespaceUri && name == attr.name) {
return &attr;
}
}
return nullptr;
}
Element* Element::findChild(const StringPiece16& ns, const StringPiece16& name) {
return findChildWithAttribute(ns, name, {}, {}, {});
}
Element* Element::findChildWithAttribute(const StringPiece16& ns, const StringPiece16& name,
const StringPiece16& attrNs, const StringPiece16& attrName,
const StringPiece16& attrValue) {
for (auto& childNode : children) {
Node* child = childNode.get();
while (nodeCast<Namespace>(child)) {
if (child->children.empty()) {
break;
}
child = child->children[0].get();
}
if (Element* el = nodeCast<Element>(child)) {
if (ns == el->namespaceUri && name == el->name) {
if (attrNs.empty() && attrName.empty()) {
return el;
}
Attribute* attr = el->findAttribute(attrNs, attrName);
if (attr && attrValue == attr->value) {
return el;
}
}
}
}
return nullptr;
}
std::vector<Element*> Element::getChildElements() {
std::vector<Element*> elements;
for (auto& childNode : children) {
Node* child = childNode.get();
while (nodeCast<Namespace>(child)) {
if (child->children.empty()) {
break;
}
child = child->children[0].get();
}
if (Element* el = nodeCast<Element>(child)) {
elements.push_back(el);
}
}
return elements;
}
void PackageAwareVisitor::visit(Namespace* ns) {
bool added = false;
if (Maybe<ExtractedPackage> maybePackage = extractPackageFromNamespace(ns->namespaceUri)) {
ExtractedPackage& package = maybePackage.value();
mPackageDecls.push_back(PackageDecl{ ns->namespacePrefix, std::move(package) });
added = true;
}
Visitor::visit(ns);
if (added) {
mPackageDecls.pop_back();
}
}
Maybe<ExtractedPackage> PackageAwareVisitor::transformPackageAlias(
const StringPiece16& alias, const StringPiece16& localPackage) const {
if (alias.empty()) {
return ExtractedPackage{ localPackage.toString(), false /* private */ };
}
const auto rend = mPackageDecls.rend();
for (auto iter = mPackageDecls.rbegin(); iter != rend; ++iter) {
if (alias == iter->prefix) {
if (iter->package.package.empty()) {
return ExtractedPackage{ localPackage.toString(),
iter->package.privateNamespace };
}
return iter->package;
}
}
return {};
}
} // namespace xml
} // namespace aapt