/*
* Created by Phil on 19/07/2017.
*
* Distributed under the Boost Software License, Version 1.0. (See accompanying
* file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
*/
#include "catch_xmlwriter.h"
#include "catch_enforce.h"
#include <iomanip>
using uchar = unsigned char;
namespace Catch {
namespace {
size_t trailingBytes(unsigned char c) {
if ((c & 0xE0) == 0xC0) {
return 2;
}
if ((c & 0xF0) == 0xE0) {
return 3;
}
if ((c & 0xF8) == 0xF0) {
return 4;
}
CATCH_INTERNAL_ERROR("Invalid multibyte utf-8 start byte encountered");
}
uint32_t headerValue(unsigned char c) {
if ((c & 0xE0) == 0xC0) {
return c & 0x1F;
}
if ((c & 0xF0) == 0xE0) {
return c & 0x0F;
}
if ((c & 0xF8) == 0xF0) {
return c & 0x07;
}
CATCH_INTERNAL_ERROR("Invalid multibyte utf-8 start byte encountered");
}
void hexEscapeChar(std::ostream& os, unsigned char c) {
std::ios_base::fmtflags f(os.flags());
os << "\\x"
<< std::uppercase << std::hex << std::setfill('0') << std::setw(2)
<< static_cast<int>(c);
os.flags(f);
}
} // anonymous namespace
XmlEncode::XmlEncode( std::string const& str, ForWhat forWhat )
: m_str( str ),
m_forWhat( forWhat )
{}
void XmlEncode::encodeTo( std::ostream& os ) const {
// Apostrophe escaping not necessary if we always use " to write attributes
// (see: http://www.w3.org/TR/xml/#syntax)
for( std::size_t idx = 0; idx < m_str.size(); ++ idx ) {
uchar c = m_str[idx];
switch (c) {
case '<': os << "<"; break;
case '&': os << "&"; break;
case '>':
// See: http://www.w3.org/TR/xml/#syntax
if (idx > 2 && m_str[idx - 1] == ']' && m_str[idx - 2] == ']')
os << ">";
else
os << c;
break;
case '\"':
if (m_forWhat == ForAttributes)
os << """;
else
os << c;
break;
default:
// Check for control characters and invalid utf-8
// Escape control characters in standard ascii
// see http://stackoverflow.com/questions/404107/why-are-control-characters-illegal-in-xml-1-0
if (c < 0x09 || (c > 0x0D && c < 0x20) || c == 0x7F) {
hexEscapeChar(os, c);
break;
}
// Plain ASCII: Write it to stream
if (c < 0x7F) {
os << c;
break;
}
// UTF-8 territory
// Check if the encoding is valid and if it is not, hex escape bytes.
// Important: We do not check the exact decoded values for validity, only the encoding format
// First check that this bytes is a valid lead byte:
// This means that it is not encoded as 1111 1XXX
// Or as 10XX XXXX
if (c < 0xC0 ||
c >= 0xF8) {
hexEscapeChar(os, c);
break;
}
auto encBytes = trailingBytes(c);
// Are there enough bytes left to avoid accessing out-of-bounds memory?
if (idx + encBytes - 1 >= m_str.size()) {
hexEscapeChar(os, c);
break;
}
// The header is valid, check data
// The next encBytes bytes must together be a valid utf-8
// This means: bitpattern 10XX XXXX and the extracted value is sane (ish)
bool valid = true;
uint32_t value = headerValue(c);
for (std::size_t n = 1; n < encBytes; ++n) {
uchar nc = m_str[idx + n];
valid &= ((nc & 0xC0) == 0x80);
value = (value << 6) | (nc & 0x3F);
}
if (
// Wrong bit pattern of following bytes
(!valid) ||
// Overlong encodings
(value < 0x80) ||
(0x80 <= value && value < 0x800 && encBytes > 2) ||
(0x800 < value && value < 0x10000 && encBytes > 3) ||
// Encoded value out of range
(value >= 0x110000)
) {
hexEscapeChar(os, c);
break;
}
// If we got here, this is in fact a valid(ish) utf-8 sequence
for (std::size_t n = 0; n < encBytes; ++n) {
os << m_str[idx + n];
}
idx += encBytes - 1;
break;
}
}
}
std::ostream& operator << ( std::ostream& os, XmlEncode const& xmlEncode ) {
xmlEncode.encodeTo( os );
return os;
}
XmlWriter::ScopedElement::ScopedElement( XmlWriter* writer )
: m_writer( writer )
{}
XmlWriter::ScopedElement::ScopedElement( ScopedElement&& other ) noexcept
: m_writer( other.m_writer ){
other.m_writer = nullptr;
}
XmlWriter::ScopedElement& XmlWriter::ScopedElement::operator=( ScopedElement&& other ) noexcept {
if ( m_writer ) {
m_writer->endElement();
}
m_writer = other.m_writer;
other.m_writer = nullptr;
return *this;
}
XmlWriter::ScopedElement::~ScopedElement() {
if( m_writer )
m_writer->endElement();
}
XmlWriter::ScopedElement& XmlWriter::ScopedElement::writeText( std::string const& text, bool indent ) {
m_writer->writeText( text, indent );
return *this;
}
XmlWriter::XmlWriter( std::ostream& os ) : m_os( os )
{
writeDeclaration();
}
XmlWriter::~XmlWriter() {
while( !m_tags.empty() )
endElement();
}
XmlWriter& XmlWriter::startElement( std::string const& name ) {
ensureTagClosed();
newlineIfNecessary();
m_os << m_indent << '<' << name;
m_tags.push_back( name );
m_indent += " ";
m_tagIsOpen = true;
return *this;
}
XmlWriter::ScopedElement XmlWriter::scopedElement( std::string const& name ) {
ScopedElement scoped( this );
startElement( name );
return scoped;
}
XmlWriter& XmlWriter::endElement() {
newlineIfNecessary();
m_indent = m_indent.substr( 0, m_indent.size()-2 );
if( m_tagIsOpen ) {
m_os << "/>";
m_tagIsOpen = false;
}
else {
m_os << m_indent << "</" << m_tags.back() << ">";
}
m_os << std::endl;
m_tags.pop_back();
return *this;
}
XmlWriter& XmlWriter::writeAttribute( std::string const& name, std::string const& attribute ) {
if( !name.empty() && !attribute.empty() )
m_os << ' ' << name << "=\"" << XmlEncode( attribute, XmlEncode::ForAttributes ) << '"';
return *this;
}
XmlWriter& XmlWriter::writeAttribute( std::string const& name, bool attribute ) {
m_os << ' ' << name << "=\"" << ( attribute ? "true" : "false" ) << '"';
return *this;
}
XmlWriter& XmlWriter::writeText( std::string const& text, bool indent ) {
if( !text.empty() ){
bool tagWasOpen = m_tagIsOpen;
ensureTagClosed();
if( tagWasOpen && indent )
m_os << m_indent;
m_os << XmlEncode( text );
m_needsNewline = true;
}
return *this;
}
XmlWriter& XmlWriter::writeComment( std::string const& text ) {
ensureTagClosed();
m_os << m_indent << "<!--" << text << "-->";
m_needsNewline = true;
return *this;
}
void XmlWriter::writeStylesheetRef( std::string const& url ) {
m_os << "<?xml-stylesheet type=\"text/xsl\" href=\"" << url << "\"?>\n";
}
XmlWriter& XmlWriter::writeBlankLine() {
ensureTagClosed();
m_os << '\n';
return *this;
}
void XmlWriter::ensureTagClosed() {
if( m_tagIsOpen ) {
m_os << ">" << std::endl;
m_tagIsOpen = false;
}
}
void XmlWriter::writeDeclaration() {
m_os << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
}
void XmlWriter::newlineIfNecessary() {
if( m_needsNewline ) {
m_os << std::endl;
m_needsNewline = false;
}
}
}