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/*
* 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 <expat.h>
#include <cassert>
#include <memory>
#include <stack>
#include <string>
#include <tuple>
#include "android-base/logging.h"
#include "XmlPullParser.h"
#include "util/Util.h"
namespace aapt {
namespace xml {
constexpr char kXmlNamespaceSep = 1;
struct Stack {
std::unique_ptr<xml::Node> root;
std::stack<xml::Node*> node_stack;
std::string pending_comment;
};
/**
* Extracts the namespace and name of an expanded element or attribute name.
*/
static void SplitName(const char* name, std::string* out_ns,
std::string* out_name) {
const char* p = name;
while (*p != 0 && *p != kXmlNamespaceSep) {
p++;
}
if (*p == 0) {
out_ns->clear();
*out_name = StringPiece(name).ToString();
} else {
*out_ns = StringPiece(name, (p - name)).ToString();
*out_name = StringPiece(p + 1).ToString();
}
}
static void AddToStack(Stack* stack, XML_Parser parser,
std::unique_ptr<Node> node) {
node->line_number = XML_GetCurrentLineNumber(parser);
node->column_number = XML_GetCurrentColumnNumber(parser);
Node* this_node = node.get();
if (!stack->node_stack.empty()) {
stack->node_stack.top()->AppendChild(std::move(node));
} else {
stack->root = std::move(node);
}
if (!NodeCast<Text>(this_node)) {
stack->node_stack.push(this_node);
}
}
static void XMLCALL StartNamespaceHandler(void* user_data, const char* prefix,
const char* uri) {
XML_Parser parser = reinterpret_cast<XML_Parser>(user_data);
Stack* stack = reinterpret_cast<Stack*>(XML_GetUserData(parser));
std::unique_ptr<Namespace> ns = util::make_unique<Namespace>();
if (prefix) {
ns->namespace_prefix = StringPiece(prefix).ToString();
}
if (uri) {
ns->namespace_uri = StringPiece(uri).ToString();
}
AddToStack(stack, parser, std::move(ns));
}
static void XMLCALL EndNamespaceHandler(void* user_data, const char* prefix) {
XML_Parser parser = reinterpret_cast<XML_Parser>(user_data);
Stack* stack = reinterpret_cast<Stack*>(XML_GetUserData(parser));
CHECK(!stack->node_stack.empty());
stack->node_stack.pop();
}
static bool less_attribute(const Attribute& lhs, const Attribute& rhs) {
return std::tie(lhs.namespace_uri, lhs.name, lhs.value) <
std::tie(rhs.namespace_uri, rhs.name, rhs.value);
}
static void XMLCALL StartElementHandler(void* user_data, const char* name,
const char** attrs) {
XML_Parser parser = reinterpret_cast<XML_Parser>(user_data);
Stack* stack = reinterpret_cast<Stack*>(XML_GetUserData(parser));
std::unique_ptr<Element> el = util::make_unique<Element>();
SplitName(name, &el->namespace_uri, &el->name);
while (*attrs) {
Attribute attribute;
SplitName(*attrs++, &attribute.namespace_uri, &attribute.name);
attribute.value = StringPiece(*attrs++).ToString();
// Insert in sorted order.
auto iter = std::lower_bound(el->attributes.begin(), el->attributes.end(),
attribute, less_attribute);
el->attributes.insert(iter, std::move(attribute));
}
el->comment = std::move(stack->pending_comment);
AddToStack(stack, parser, std::move(el));
}
static void XMLCALL EndElementHandler(void* user_data, const char* name) {
XML_Parser parser = reinterpret_cast<XML_Parser>(user_data);
Stack* stack = reinterpret_cast<Stack*>(XML_GetUserData(parser));
CHECK(!stack->node_stack.empty());
// stack->nodeStack.top()->comment = std::move(stack->pendingComment);
stack->node_stack.pop();
}
static void XMLCALL CharacterDataHandler(void* user_data, const char* s,
int len) {
XML_Parser parser = reinterpret_cast<XML_Parser>(user_data);
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->node_stack.empty()) {
Node* currentParent = stack->node_stack.top();
if (!currentParent->children.empty()) {
Node* last_child = currentParent->children.back().get();
if (Text* text = NodeCast<Text>(last_child)) {
text->text += StringPiece(s, len).ToString();
return;
}
}
}
std::unique_ptr<Text> text = util::make_unique<Text>();
text->text = StringPiece(s, len).ToString();
AddToStack(stack, parser, std::move(text));
}
static void XMLCALL CommentDataHandler(void* user_data, const char* comment) {
XML_Parser parser = reinterpret_cast<XML_Parser>(user_data);
Stack* stack = reinterpret_cast<Stack*>(XML_GetUserData(parser));
if (!stack->pending_comment.empty()) {
stack->pending_comment += '\n';
}
stack->pending_comment += 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 attr_count = parser->getAttributeCount();
if (attr_count > 0) {
el->attributes.reserve(attr_count);
for (size_t i = 0; i < attr_count; i++) {
Attribute attr;
size_t len;
const char16_t* str16 = parser->getAttributeNamespace(i, &len);
if (str16) {
attr.namespace_uri = util::Utf16ToUtf8(StringPiece16(str16, len));
}
str16 = parser->getAttributeName(i, &len);
if (str16) {
attr.name = util::Utf16ToUtf8(StringPiece16(str16, len));
}
str16 = parser->getAttributeStringValue(i, &len);
if (str16) {
attr.value = util::Utf16ToUtf8(StringPiece16(str16, len));
}
el->attributes.push_back(std::move(attr));
}
}
}
std::unique_ptr<XmlResource> Inflate(const void* data, size_t data_len,
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*> node_stack;
ResXMLTree tree;
if (tree.setTo(data, data_len) != NO_ERROR) {
return {};
}
ResXMLParser::event_code_t code;
while ((code = tree.next()) != ResXMLParser::BAD_DOCUMENT &&
code != ResXMLParser::END_DOCUMENT) {
std::unique_ptr<Node> new_node;
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->namespace_prefix = util::Utf16ToUtf8(StringPiece16(str16, len));
}
str16 = tree.getNamespaceUri(&len);
if (str16) {
node->namespace_uri = util::Utf16ToUtf8(StringPiece16(str16, len));
}
new_node = 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->namespace_uri = util::Utf16ToUtf8(StringPiece16(str16, len));
}
str16 = tree.getElementName(&len);
if (str16) {
node->name = util::Utf16ToUtf8(StringPiece16(str16, len));
}
CopyAttributes(node.get(), &tree);
new_node = 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 = util::Utf16ToUtf8(StringPiece16(str16, len));
}
new_node = std::move(node);
break;
}
case ResXMLParser::END_NAMESPACE:
case ResXMLParser::END_TAG:
CHECK(!node_stack.empty());
node_stack.pop();
break;
default:
LOG(FATAL) << "unhandled XML chunk type";
break;
}
if (new_node) {
new_node->line_number = tree.getLineNumber();
Node* this_node = new_node.get();
if (!root) {
CHECK(node_stack.empty()) << "node stack should be empty";
root = std::move(new_node);
} else {
CHECK(!node_stack.empty()) << "node stack should not be empty";
node_stack.top()->AppendChild(std::move(new_node));
}
if (!NodeCast<Text>(this_node)) {
node_stack.push(this_node);
}
}
}
return util::make_unique<XmlResource>(ResourceFile{}, std::move(root));
}
std::unique_ptr<Node> Namespace::Clone() {
auto ns = util::make_unique<Namespace>();
ns->comment = comment;
ns->line_number = line_number;
ns->column_number = column_number;
ns->namespace_prefix = namespace_prefix;
ns->namespace_uri = namespace_uri;
ns->children.reserve(children.size());
for (const std::unique_ptr<xml::Node>& child : children) {
ns->AppendChild(child->Clone());
}
return std::move(ns);
}
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::AppendChild(std::unique_ptr<Node> child) {
child->parent = this;
children.push_back(std::move(child));
}
void Node::InsertChild(size_t index, std::unique_ptr<Node> child) {
child->parent = this;
children.insert(children.begin() + index, std::move(child));
}
Attribute* Element::FindAttribute(const StringPiece& ns,
const StringPiece& name) {
for (auto& attr : attributes) {
if (ns == attr.namespace_uri && name == attr.name) {
return &attr;
}
}
return nullptr;
}
Element* Element::FindChild(const StringPiece& ns, const StringPiece& name) {
return FindChildWithAttribute(ns, name, {}, {}, {});
}
Element* Element::FindChildWithAttribute(const StringPiece& ns,
const StringPiece& name,
const StringPiece& attr_ns,
const StringPiece& attr_name,
const StringPiece& attr_value) {
for (auto& child_node : children) {
Node* child = child_node.get();
while (NodeCast<Namespace>(child)) {
if (child->children.empty()) {
break;
}
child = child->children[0].get();
}
if (Element* el = NodeCast<Element>(child)) {
if (ns == el->namespace_uri && name == el->name) {
if (attr_ns.empty() && attr_name.empty()) {
return el;
}
Attribute* attr = el->FindAttribute(attr_ns, attr_name);
if (attr && attr_value == attr->value) {
return el;
}
}
}
}
return nullptr;
}
std::vector<Element*> Element::GetChildElements() {
std::vector<Element*> elements;
for (auto& child_node : children) {
Node* child = child_node.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;
}
std::unique_ptr<Node> Element::Clone() {
auto el = util::make_unique<Element>();
el->comment = comment;
el->line_number = line_number;
el->column_number = column_number;
el->name = name;
el->namespace_uri = namespace_uri;
el->attributes.reserve(attributes.size());
for (xml::Attribute& attr : attributes) {
// Don't copy compiled values or attributes.
el->attributes.push_back(
xml::Attribute{attr.namespace_uri, attr.name, attr.value});
}
el->children.reserve(children.size());
for (const std::unique_ptr<xml::Node>& child : children) {
el->AppendChild(child->Clone());
}
return std::move(el);
}
std::unique_ptr<Node> Text::Clone() {
auto t = util::make_unique<Text>();
t->comment = comment;
t->line_number = line_number;
t->column_number = column_number;
t->text = text;
return std::move(t);
}
void PackageAwareVisitor::Visit(Namespace* ns) {
bool added = false;
if (Maybe<ExtractedPackage> maybe_package =
ExtractPackageFromNamespace(ns->namespace_uri)) {
ExtractedPackage& package = maybe_package.value();
package_decls_.push_back(
PackageDecl{ns->namespace_prefix, std::move(package)});
added = true;
}
Visitor::Visit(ns);
if (added) {
package_decls_.pop_back();
}
}
Maybe<ExtractedPackage> PackageAwareVisitor::TransformPackageAlias(
const StringPiece& alias, const StringPiece& local_package) const {
if (alias.empty()) {
return ExtractedPackage{local_package.ToString(), false /* private */};
}
const auto rend = package_decls_.rend();
for (auto iter = package_decls_.rbegin(); iter != rend; ++iter) {
if (alias == iter->prefix) {
if (iter->package.package.empty()) {
return ExtractedPackage{local_package.ToString(),
iter->package.private_namespace};
}
return iter->package;
}
}
return {};
}
} // namespace xml
} // namespace aapt