| // ---------------------------------------------------------------------------- |
| // parsing.hpp : implementation of the parsing member functions |
| // ( parse, parse_printf_directive) |
| // ---------------------------------------------------------------------------- |
| |
| // Copyright Samuel Krempp 2003. Use, modification, and distribution are |
| // subject to 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) |
| |
| // see http://www.boost.org/libs/format for library home page |
| |
| // ---------------------------------------------------------------------------- |
| |
| #ifndef BOOST_FORMAT_PARSING_HPP |
| #define BOOST_FORMAT_PARSING_HPP |
| |
| |
| #include <boost/format/format_class.hpp> |
| #include <boost/format/exceptions.hpp> |
| #include <boost/throw_exception.hpp> |
| #include <boost/assert.hpp> |
| #include <boost/config.hpp> |
| #include <boost/core/ignore_unused.hpp> |
| |
| namespace boost { |
| namespace io { |
| namespace detail { |
| |
| #if defined(BOOST_NO_STD_LOCALE) |
| // streams will be used for narrow / widen. but these methods are not const |
| template<class T> |
| T& const_or_not(const T& x) { |
| return const_cast<T&> (x); |
| } |
| #else |
| template<class T> |
| const T& const_or_not(const T& x) { |
| return x; |
| } |
| #endif |
| |
| template<class Ch, class Facet> inline |
| char wrap_narrow(const Facet& fac, Ch c, char deflt) { |
| return const_or_not(fac).narrow(c, deflt); |
| } |
| |
| template<class Ch, class Facet> inline |
| bool wrap_isdigit(const Facet& fac, Ch c) { |
| #if ! defined( BOOST_NO_LOCALE_ISDIGIT ) |
| return fac.is(std::ctype<Ch>::digit, c); |
| # else |
| ignore_unused(fac); |
| using namespace std; |
| return isdigit(c) != 0; |
| #endif |
| } |
| |
| template<class Iter, class Facet> |
| Iter wrap_scan_notdigit(const Facet & fac, Iter beg, Iter end) { |
| using namespace std; |
| for( ; beg!=end && wrap_isdigit(fac, *beg); ++beg) ; |
| return beg; |
| } |
| |
| |
| // Input : [start, last) iterators range and a |
| // a Facet to use its widen/narrow member function |
| // Effects : read sequence and convert digits into integral n, of type Res |
| // Returns : n |
| template<class Res, class Iter, class Facet> |
| Iter str2int (const Iter & start, const Iter & last, Res & res, |
| const Facet& fac) |
| { |
| using namespace std; |
| Iter it; |
| res=0; |
| for(it=start; it != last && wrap_isdigit(fac, *it); ++it ) { |
| char cur_ch = wrap_narrow(fac, *it, 0); // cant fail. |
| res *= 10; |
| res += cur_ch - '0'; // 22.2.1.1.2.13 of the C++ standard |
| } |
| return it; |
| } |
| |
| // auxiliary func called by parse_printf_directive |
| // for centralising error handling |
| // it either throws if user sets the corresponding flag, or does nothing. |
| inline void maybe_throw_exception(unsigned char exceptions, |
| std::size_t pos, std::size_t size) |
| { |
| if(exceptions & io::bad_format_string_bit) |
| boost::throw_exception(io::bad_format_string(pos, size) ); |
| } |
| |
| |
| // Input: the position of a printf-directive in the format-string |
| // a basic_ios& merely to use its widen/narrow member function |
| // a bitset'exceptions' telling whether to throw exceptions on errors. |
| // Returns: |
| // true if parse succeeded (ignore some errors if exceptions disabled) |
| // false if it failed so bad that the directive should be printed verbatim |
| // Effects: |
| // start is incremented so that *start is the first char after |
| // this directive |
| // *fpar is set with the parameters read in the directive |
| template<class Ch, class Tr, class Alloc, class Iter, class Facet> |
| bool parse_printf_directive(Iter & start, const Iter& last, |
| detail::format_item<Ch, Tr, Alloc> * fpar, |
| const Facet& fac, |
| std::size_t offset, unsigned char exceptions) |
| { |
| typedef typename basic_format<Ch, Tr, Alloc>::format_item_t format_item_t; |
| |
| fpar->argN_ = format_item_t::argN_no_posit; // if no positional-directive |
| bool precision_set = false; |
| bool in_brackets=false; |
| Iter start0 = start; |
| std::size_t fstring_size = last-start0+offset; |
| char mssiz = 0; |
| |
| if(start>= last) { // empty directive : this is a trailing % |
| maybe_throw_exception(exceptions, start-start0 + offset, fstring_size); |
| return false; |
| } |
| |
| if(*start== const_or_not(fac).widen( '|')) { |
| in_brackets=true; |
| if( ++start >= last ) { |
| maybe_throw_exception(exceptions, start-start0 + offset, fstring_size); |
| return false; |
| } |
| } |
| |
| // the flag '0' would be picked as a digit for argument order, but here it's a flag : |
| if(*start== const_or_not(fac).widen( '0')) |
| goto parse_flags; |
| |
| // handle argument order (%2$d) or possibly width specification: %2d |
| if(wrap_isdigit(fac, *start)) { |
| int n; |
| start = str2int(start, last, n, fac); |
| if( start >= last ) { |
| maybe_throw_exception(exceptions, start-start0+offset, fstring_size); |
| return false; |
| } |
| |
| // %N% case : this is already the end of the directive |
| if( *start == const_or_not(fac).widen( '%') ) { |
| fpar->argN_ = n-1; |
| ++start; |
| if( in_brackets) |
| maybe_throw_exception(exceptions, start-start0+offset, fstring_size); |
| return true; |
| } |
| |
| if ( *start== const_or_not(fac).widen( '$') ) { |
| fpar->argN_ = n-1; |
| ++start; |
| } |
| else { |
| // non-positional directive |
| fpar->fmtstate_.width_ = n; |
| fpar->argN_ = format_item_t::argN_no_posit; |
| goto parse_precision; |
| } |
| } |
| |
| parse_flags: |
| // handle flags |
| while (start != last) { // as long as char is one of + - = _ # 0 or ' ' |
| switch ( wrap_narrow(fac, *start, 0)) { |
| case '\'': |
| break; // no effect yet. (painful to implement) |
| case '-': |
| fpar->fmtstate_.flags_ |= std::ios_base::left; |
| break; |
| case '=': |
| fpar->pad_scheme_ |= format_item_t::centered; |
| break; |
| case '_': |
| fpar->fmtstate_.flags_ |= std::ios_base::internal; |
| break; |
| case ' ': |
| fpar->pad_scheme_ |= format_item_t::spacepad; |
| break; |
| case '+': |
| fpar->fmtstate_.flags_ |= std::ios_base::showpos; |
| break; |
| case '0': |
| fpar->pad_scheme_ |= format_item_t::zeropad; |
| // need to know alignment before really setting flags, |
| // so just add 'zeropad' flag for now, it will be processed later. |
| break; |
| case '#': |
| fpar->fmtstate_.flags_ |= std::ios_base::showpoint | std::ios_base::showbase; |
| break; |
| default: |
| goto parse_width; |
| } |
| ++start; |
| } // loop on flag. |
| |
| if( start>=last) { |
| maybe_throw_exception(exceptions, start-start0+offset, fstring_size); |
| return true; |
| } |
| |
| // first skip 'asterisk fields' : * or num (length) |
| parse_width: |
| if(*start == const_or_not(fac).widen( '*') ) |
| ++start; |
| else if(start!=last && wrap_isdigit(fac, *start)) |
| start = str2int(start, last, fpar->fmtstate_.width_, fac); |
| |
| parse_precision: |
| if( start>= last) { |
| maybe_throw_exception(exceptions, start-start0+offset, fstring_size); |
| return true; |
| } |
| // handle precision spec |
| if (*start== const_or_not(fac).widen( '.')) { |
| ++start; |
| if(start != last && *start == const_or_not(fac).widen( '*') ) |
| ++start; |
| else if(start != last && wrap_isdigit(fac, *start)) { |
| start = str2int(start, last, fpar->fmtstate_.precision_, fac); |
| precision_set = true; |
| } |
| else |
| fpar->fmtstate_.precision_ =0; |
| } |
| |
| // argument type modifiers |
| while (start != last) { |
| switch (wrap_narrow(fac, *start, 0)) { |
| case 'h': |
| case 'l': |
| case 'j': |
| case 'z': |
| case 'L': |
| // boost::format ignores argument type modifiers as it relies on |
| // the type of the argument fed into it by operator % |
| break; |
| |
| // Note that the ptrdiff_t argument type 't' from C++11 is not honored |
| // because it was already in use as the tabulation specifier in boost::format |
| // case 't': |
| |
| // Microsoft extensions: |
| // https://msdn.microsoft.com/en-us/library/tcxf1dw6.aspx |
| |
| case 'w': |
| break; |
| case 'I': |
| mssiz = 'I'; |
| break; |
| case '3': |
| if (mssiz != 'I') { |
| maybe_throw_exception(exceptions, start - start0 + offset, fstring_size); |
| return true; |
| } |
| mssiz = '3'; |
| break; |
| case '2': |
| if (mssiz != '3') { |
| maybe_throw_exception(exceptions, start - start0 + offset, fstring_size); |
| return true; |
| } |
| mssiz = 0x00; |
| break; |
| case '6': |
| if (mssiz != 'I') { |
| maybe_throw_exception(exceptions, start - start0 + offset, fstring_size); |
| return true; |
| } |
| mssiz = '6'; |
| break; |
| case '4': |
| if (mssiz != '6') { |
| maybe_throw_exception(exceptions, start - start0 + offset, fstring_size); |
| return true; |
| } |
| mssiz = 0x00; |
| break; |
| default: |
| if (mssiz && mssiz == 'I') { |
| mssiz = 0; |
| } |
| goto parse_conversion_specification; |
| } |
| ++start; |
| } // loop on argument type modifiers to pick up 'hh', 'll', and the more complex microsoft ones |
| |
| parse_conversion_specification: |
| if (start >= last || mssiz) { |
| maybe_throw_exception(exceptions, start - start0 + offset, fstring_size); |
| return true; |
| } |
| |
| if( in_brackets && *start== const_or_not(fac).widen( '|') ) { |
| ++start; |
| return true; |
| } |
| |
| // The default flags are "dec" and "skipws" |
| // so if changing the base, need to unset basefield first |
| |
| switch (wrap_narrow(fac, *start, 0)) |
| { |
| // Boolean |
| case 'b': |
| fpar->fmtstate_.flags_ |= std::ios_base::boolalpha; |
| break; |
| |
| // Decimal |
| case 'u': |
| case 'd': |
| case 'i': |
| // Defaults are sufficient |
| break; |
| |
| // Hex |
| case 'X': |
| fpar->fmtstate_.flags_ |= std::ios_base::uppercase; |
| BOOST_FALLTHROUGH; |
| case 'x': |
| case 'p': // pointer => set hex. |
| fpar->fmtstate_.flags_ &= ~std::ios_base::basefield; |
| fpar->fmtstate_.flags_ |= std::ios_base::hex; |
| break; |
| |
| // Octal |
| case 'o': |
| fpar->fmtstate_.flags_ &= ~std::ios_base::basefield; |
| fpar->fmtstate_.flags_ |= std::ios_base::oct; |
| break; |
| |
| // Floating |
| case 'A': |
| fpar->fmtstate_.flags_ |= std::ios_base::uppercase; |
| BOOST_FALLTHROUGH; |
| case 'a': |
| fpar->fmtstate_.flags_ &= ~std::ios_base::basefield; |
| fpar->fmtstate_.flags_ |= std::ios_base::fixed; |
| fpar->fmtstate_.flags_ |= std::ios_base::scientific; |
| break; |
| case 'E': |
| fpar->fmtstate_.flags_ |= std::ios_base::uppercase; |
| BOOST_FALLTHROUGH; |
| case 'e': |
| fpar->fmtstate_.flags_ |= std::ios_base::scientific; |
| break; |
| case 'F': |
| fpar->fmtstate_.flags_ |= std::ios_base::uppercase; |
| BOOST_FALLTHROUGH; |
| case 'f': |
| fpar->fmtstate_.flags_ |= std::ios_base::fixed; |
| break; |
| case 'G': |
| fpar->fmtstate_.flags_ |= std::ios_base::uppercase; |
| BOOST_FALLTHROUGH; |
| case 'g': |
| // default flags are correct here |
| break; |
| |
| // Tabulation (a boost::format extension) |
| case 'T': |
| ++start; |
| if( start >= last) { |
| maybe_throw_exception(exceptions, start-start0+offset, fstring_size); |
| return false; |
| } else { |
| fpar->fmtstate_.fill_ = *start; |
| } |
| fpar->pad_scheme_ |= format_item_t::tabulation; |
| fpar->argN_ = format_item_t::argN_tabulation; |
| break; |
| case 't': |
| fpar->fmtstate_.fill_ = const_or_not(fac).widen( ' '); |
| fpar->pad_scheme_ |= format_item_t::tabulation; |
| fpar->argN_ = format_item_t::argN_tabulation; |
| break; |
| |
| // Character |
| case 'C': |
| case 'c': |
| fpar->truncate_ = 1; |
| break; |
| |
| // String |
| case 'S': |
| case 's': |
| if(precision_set) // handle truncation manually, with own parameter. |
| fpar->truncate_ = fpar->fmtstate_.precision_; |
| fpar->fmtstate_.precision_ = 6; // default stream precision. |
| break; |
| |
| // %n is insecure and ignored by boost::format |
| case 'n' : |
| fpar->argN_ = format_item_t::argN_ignored; |
| break; |
| |
| default: |
| maybe_throw_exception(exceptions, start-start0+offset, fstring_size); |
| } |
| ++start; |
| |
| if( in_brackets ) { |
| if( start != last && *start== const_or_not(fac).widen( '|') ) { |
| ++start; |
| return true; |
| } |
| else maybe_throw_exception(exceptions, start-start0+offset, fstring_size); |
| } |
| return true; |
| } |
| // -end parse_printf_directive() |
| |
| template<class String, class Facet> |
| int upper_bound_from_fstring(const String& buf, |
| const typename String::value_type arg_mark, |
| const Facet& fac, |
| unsigned char exceptions) |
| { |
| // quick-parsing of the format-string to count arguments mark (arg_mark, '%') |
| // returns : upper bound on the number of format items in the format strings |
| using namespace boost::io; |
| typename String::size_type i1=0; |
| int num_items=0; |
| while( (i1=buf.find(arg_mark,i1)) != String::npos ) { |
| if( i1+1 >= buf.size() ) { |
| if(exceptions & bad_format_string_bit) |
| boost::throw_exception(bad_format_string(i1, buf.size() )); // must not end in ".. %" |
| else { |
| ++num_items; |
| break; |
| } |
| } |
| if(buf[i1+1] == buf[i1] ) {// escaped "%%" |
| i1+=2; continue; |
| } |
| |
| ++i1; |
| // in case of %N% directives, dont count it double (wastes allocations..) : |
| i1 = detail::wrap_scan_notdigit(fac, buf.begin()+i1, buf.end()) - buf.begin(); |
| if( i1 < buf.size() && buf[i1] == arg_mark ) |
| ++i1; |
| ++num_items; |
| } |
| return num_items; |
| } |
| template<class String> inline |
| void append_string(String& dst, const String& src, |
| const typename String::size_type beg, |
| const typename String::size_type end) { |
| dst.append(src.begin()+beg, src.begin()+end); |
| } |
| |
| } // detail namespace |
| } // io namespace |
| |
| |
| |
| // ----------------------------------------------- |
| // format :: parse(..) |
| |
| template<class Ch, class Tr, class Alloc> |
| basic_format<Ch, Tr, Alloc>& basic_format<Ch, Tr, Alloc>:: |
| parse (const string_type& buf) { |
| // parse the format-string |
| using namespace std; |
| #if !defined(BOOST_NO_STD_LOCALE) |
| const std::ctype<Ch> & fac = BOOST_USE_FACET( std::ctype<Ch>, getloc()); |
| #else |
| io::basic_oaltstringstream<Ch, Tr, Alloc> fac; |
| //has widen and narrow even on compilers without locale |
| #endif |
| |
| const Ch arg_mark = io::detail::const_or_not(fac).widen( '%'); |
| bool ordered_args=true; |
| int max_argN=-1; |
| |
| // A: find upper_bound on num_items and allocates arrays |
| int num_items = io::detail::upper_bound_from_fstring(buf, arg_mark, fac, exceptions()); |
| make_or_reuse_data(num_items); |
| |
| // B: Now the real parsing of the format string : |
| num_items=0; |
| typename string_type::size_type i0=0, i1=0; |
| typename string_type::const_iterator it; |
| bool special_things=false; |
| int cur_item=0; |
| while( (i1=buf.find(arg_mark,i1)) != string_type::npos ) { |
| string_type & piece = (cur_item==0) ? prefix_ : items_[cur_item-1].appendix_; |
| if( buf[i1+1] == buf[i1] ) { // escaped mark, '%%' |
| io::detail::append_string(piece, buf, i0, i1+1); |
| i1+=2; i0=i1; |
| continue; |
| } |
| BOOST_ASSERT( static_cast<unsigned int>(cur_item) < items_.size() || cur_item==0); |
| |
| if(i1!=i0) { |
| io::detail::append_string(piece, buf, i0, i1); |
| i0=i1; |
| } |
| ++i1; |
| it = buf.begin()+i1; |
| bool parse_ok = io::detail::parse_printf_directive( |
| it, buf.end(), &items_[cur_item], fac, i1, exceptions()); |
| i1 = it - buf.begin(); |
| if( ! parse_ok ) // the directive will be printed verbatim |
| continue; |
| i0=i1; |
| items_[cur_item].compute_states(); // process complex options, like zeropad, into params |
| |
| int argN=items_[cur_item].argN_; |
| if(argN == format_item_t::argN_ignored) |
| continue; |
| if(argN ==format_item_t::argN_no_posit) |
| ordered_args=false; |
| else if(argN == format_item_t::argN_tabulation) special_things=true; |
| else if(argN > max_argN) max_argN = argN; |
| ++num_items; |
| ++cur_item; |
| } // loop on %'s |
| BOOST_ASSERT(cur_item == num_items); |
| |
| // store the final piece of string |
| { |
| string_type & piece = (cur_item==0) ? prefix_ : items_[cur_item-1].appendix_; |
| io::detail::append_string(piece, buf, i0, buf.size()); |
| } |
| |
| if( !ordered_args) { |
| if(max_argN >= 0 ) { // dont mix positional with non-positionnal directives |
| if(exceptions() & io::bad_format_string_bit) |
| boost::throw_exception( |
| io::bad_format_string(static_cast<std::size_t>(max_argN), 0)); |
| // else do nothing. => positionnal arguments are processed as non-positionnal |
| } |
| // set things like it would have been with positional directives : |
| int non_ordered_items = 0; |
| for(int i=0; i< num_items; ++i) |
| if(items_[i].argN_ == format_item_t::argN_no_posit) { |
| items_[i].argN_ = non_ordered_items; |
| ++non_ordered_items; |
| } |
| max_argN = non_ordered_items-1; |
| } |
| |
| // C: set some member data : |
| items_.resize(num_items, format_item_t(io::detail::const_or_not(fac).widen( ' ')) ); |
| |
| if(special_things) style_ |= special_needs; |
| num_args_ = max_argN + 1; |
| if(ordered_args) style_ |= ordered; |
| else style_ &= ~ordered; |
| return *this; |
| } |
| |
| } // namespace boost |
| |
| |
| #endif // BOOST_FORMAT_PARSING_HPP |
