kicad/include/boost/property_tree/detail/info_parser_read.hpp

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C++

// ----------------------------------------------------------------------------
// Copyright (C) 2002-2006 Marcin Kalicinski
//
// 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)
//
// For more information, see www.boost.org
// ----------------------------------------------------------------------------
#ifndef BOOST_PROPERTY_TREE_DETAIL_INFO_PARSER_READ_HPP_INCLUDED
#define BOOST_PROPERTY_TREE_DETAIL_INFO_PARSER_READ_HPP_INCLUDED
#include "boost/property_tree/ptree.hpp"
#include "boost/property_tree/detail/info_parser_error.hpp"
#include "boost/property_tree/detail/info_parser_utils.hpp"
#include <iterator>
#include <string>
#include <stack>
#include <fstream>
#include <cctype>
namespace boost { namespace property_tree { namespace info_parser
{
// Expand known escape sequences
template<class It>
std::basic_string<typename std::iterator_traits<It>::value_type>
expand_escapes(It b, It e)
{
typedef typename std::iterator_traits<It>::value_type Ch;
std::basic_string<Ch> result;
while (b != e)
{
if (*b == Ch('\\'))
{
++b;
if (b == e)
{
BOOST_PROPERTY_TREE_THROW(info_parser_error(
"character expected after backslash", "", 0));
}
else if (*b == Ch('0')) result += Ch('\0');
else if (*b == Ch('a')) result += Ch('\a');
else if (*b == Ch('b')) result += Ch('\b');
else if (*b == Ch('f')) result += Ch('\f');
else if (*b == Ch('n')) result += Ch('\n');
else if (*b == Ch('r')) result += Ch('\r');
else if (*b == Ch('t')) result += Ch('\t');
else if (*b == Ch('v')) result += Ch('\v');
else if (*b == Ch('"')) result += Ch('"');
else if (*b == Ch('\'')) result += Ch('\'');
else if (*b == Ch('\\')) result += Ch('\\');
else
BOOST_PROPERTY_TREE_THROW(info_parser_error(
"unknown escape sequence", "", 0));
}
else
result += *b;
++b;
}
return result;
}
// Advance pointer past whitespace
template<class Ch>
void skip_whitespace(const Ch *&text)
{
using namespace std;
while (isspace(*text))
++text;
}
// Extract word (whitespace delimited) and advance pointer accordingly
template<class Ch>
std::basic_string<Ch> read_word(const Ch *&text)
{
using namespace std;
skip_whitespace(text);
const Ch *start = text;
while (!isspace(*text) && *text != Ch(';') && *text != Ch('\0'))
++text;
return expand_escapes(start, text);
}
// Extract line (eol delimited) and advance pointer accordingly
template<class Ch>
std::basic_string<Ch> read_line(const Ch *&text)
{
using namespace std;
skip_whitespace(text);
const Ch *start = text;
while (*text != Ch('\0') && *text != Ch(';'))
++text;
while (text > start && isspace(*(text - 1)))
--text;
return expand_escapes(start, text);
}
// Extract string (inside ""), and advance pointer accordingly
// Set need_more_lines to true if \ continuator found
template<class Ch>
std::basic_string<Ch> read_string(const Ch *&text, bool *need_more_lines)
{
skip_whitespace(text);
if (*text == Ch('\"'))
{
// Skip "
++text;
// Find end of string, but skip escaped "
bool escaped = false;
const Ch *start = text;
while ((escaped || *text != Ch('\"')) && *text != Ch('\0'))
{
escaped = (!escaped && *text == Ch('\\'));
++text;
}
// If end of string found
if (*text == Ch('\"'))
{
std::basic_string<Ch> result = expand_escapes(start, text++);
skip_whitespace(text);
if (*text == Ch('\\'))
{
if (!need_more_lines)
BOOST_PROPERTY_TREE_THROW(info_parser_error(
"unexpected \\", "", 0));
++text;
skip_whitespace(text);
if (*text == Ch('\0') || *text == Ch(';'))
*need_more_lines = true;
else
BOOST_PROPERTY_TREE_THROW(info_parser_error(
"expected end of line after \\", "", 0));
}
else
if (need_more_lines)
*need_more_lines = false;
return result;
}
else
BOOST_PROPERTY_TREE_THROW(info_parser_error(
"unexpected end of line", "", 0));
}
else
BOOST_PROPERTY_TREE_THROW(info_parser_error("expected \"", "", 0));
}
// Extract key
template<class Ch>
std::basic_string<Ch> read_key(const Ch *&text)
{
skip_whitespace(text);
if (*text == Ch('\"'))
return read_string(text, NULL);
else
return read_word(text);
}
// Extract data
template<class Ch>
std::basic_string<Ch> read_data(const Ch *&text, bool *need_more_lines)
{
skip_whitespace(text);
if (*text == Ch('\"'))
return read_string(text, need_more_lines);
else
{
*need_more_lines = false;
return read_word(text);
}
}
// Build ptree from info stream
template<class Ptree, class Ch>
void read_info_internal(std::basic_istream<Ch> &stream,
Ptree &pt,
const std::string &filename,
int include_depth)
{
typedef std::basic_string<Ch> str_t;
// Possible parser states
enum state_t {
s_key, // Parser expects key
s_data, // Parser expects data
s_data_cont // Parser expects data continuation
};
unsigned long line_no = 0;
state_t state = s_key; // Parser state
Ptree *last = NULL; // Pointer to last created ptree
// Define line here to minimize reallocations
str_t line;
// Initialize ptree stack (used to handle nesting)
std::stack<Ptree *> stack;
stack.push(&pt); // Push root ptree on stack initially
try {
// While there are characters in the stream
while (stream.good()) {
// Read one line from stream
++line_no;
std::getline(stream, line);
if (!stream.good() && !stream.eof())
BOOST_PROPERTY_TREE_THROW(info_parser_error(
"read error", filename, line_no));
const Ch *text = line.c_str();
// If directive found
skip_whitespace(text);
if (*text == Ch('#')) {
// Determine directive type
++text; // skip #
std::basic_string<Ch> directive = read_word(text);
if (directive == convert_chtype<Ch, char>("include")) {
// #include
if (include_depth > 100) {
BOOST_PROPERTY_TREE_THROW(info_parser_error(
"include depth too large, "
"probably recursive include",
filename, line_no));
}
str_t s = read_string(text, NULL);
std::string inc_name =
convert_chtype<char, Ch>(s.c_str());
std::basic_ifstream<Ch> inc_stream(inc_name.c_str());
if (!inc_stream.good())
BOOST_PROPERTY_TREE_THROW(info_parser_error(
"cannot open include file " + inc_name,
filename, line_no));
read_info_internal(inc_stream, *stack.top(),
inc_name, include_depth + 1);
} else { // Unknown directive
BOOST_PROPERTY_TREE_THROW(info_parser_error(
"unknown directive", filename, line_no));
}
// Directive must be followed by end of line
skip_whitespace(text);
if (*text != Ch('\0')) {
BOOST_PROPERTY_TREE_THROW(info_parser_error(
"expected end of line", filename, line_no));
}
// Go to next line
continue;
}
// While there are characters left in line
while (1) {
// Stop parsing on end of line or comment
skip_whitespace(text);
if (*text == Ch('\0') || *text == Ch(';')) {
if (state == s_data) // If there was no data set state to s_key
state = s_key;
break;
}
// Process according to current parser state
switch (state)
{
// Parser expects key
case s_key:
{
if (*text == Ch('{')) // Brace opening found
{
if (!last)
BOOST_PROPERTY_TREE_THROW(info_parser_error("unexpected {", "", 0));
stack.push(last);
last = NULL;
++text;
}
else if (*text == Ch('}')) // Brace closing found
{
if (stack.size() <= 1)
BOOST_PROPERTY_TREE_THROW(info_parser_error("unmatched }", "", 0));
stack.pop();
last = NULL;
++text;
}
else // Key text found
{
std::basic_string<Ch> key = read_key(text);
last = &stack.top()->push_back(
std::make_pair(key, Ptree()))->second;
state = s_data;
}
}; break;
// Parser expects data
case s_data:
{
// Last ptree must be defined because we are going to add data to it
BOOST_ASSERT(last);
if (*text == Ch('{')) // Brace opening found
{
stack.push(last);
last = NULL;
++text;
state = s_key;
}
else if (*text == Ch('}')) // Brace closing found
{
if (stack.size() <= 1)
BOOST_PROPERTY_TREE_THROW(info_parser_error("unmatched }", "", 0));
stack.pop();
last = NULL;
++text;
state = s_key;
}
else // Data text found
{
bool need_more_lines;
std::basic_string<Ch> data = read_data(text, &need_more_lines);
last->data() = data;
state = need_more_lines ? s_data_cont : s_key;
}
}; break;
// Parser expects continuation of data after \ on previous line
case s_data_cont:
{
// Last ptree must be defined because we are going to update its data
BOOST_ASSERT(last);
if (*text == Ch('\"')) // Continuation must start with "
{
bool need_more_lines;
std::basic_string<Ch> data = read_string(text, &need_more_lines);
last->put_value(last->template get_value<std::basic_string<Ch> >() + data);
state = need_more_lines ? s_data_cont : s_key;
}
else
BOOST_PROPERTY_TREE_THROW(info_parser_error("expected \" after \\ in previous line", "", 0));
}; break;
// Should never happen
default:
BOOST_ASSERT(0);
}
}
}
// Check if stack has initial size, otherwise some {'s have not been closed
if (stack.size() != 1)
BOOST_PROPERTY_TREE_THROW(info_parser_error("unmatched {", "", 0));
}
catch (info_parser_error &e)
{
// If line undefined rethrow error with correct filename and line
if (e.line() == 0)
{
BOOST_PROPERTY_TREE_THROW(info_parser_error(e.message(), filename, line_no));
}
else
BOOST_PROPERTY_TREE_THROW(e);
}
}
} } }
#endif