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construct/ircd/fmt.cc
Jason Volk 21aacf6509 ircd::fmt: Add syntax for specifier forced-termination.
This is available for a particular corner case due to our use of full-
word format specifiers.

Case: "%couch" is that %c followed by ouch, or is that the handled
format specifier '%couch' ?

If '%couch' is not registered there is no fallback to finding '%c'
(maybe one day), so in this case one must write "%c$ouch" and '%c'
becomes the specifier and the output for 'p' will be "pouch" and for
"%c$$ouch" the output will be "p$ouch."
2016-09-22 16:18:32 -07:00

602 lines
15 KiB
C++

/**
* Copyright (C) 2016 Charybdis Development Team
* Copyright (C) 2016 Jason Volk <jason@zemos.net>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice is present in all copies.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <ircd/rfc1459_parse.h>
#include <ircd/rfc1459_gen.h>
#include <ircd/lex_cast.h>
#include <ircd/fmt.h>
BOOST_FUSION_ADAPT_STRUCT
(
ircd::fmt::spec,
( char, sign )
( int, width )
( std::string, name )
)
namespace ircd {
namespace fmt {
namespace qi = boost::spirit::qi;
namespace karma = boost::spirit::karma;
const char SPECIFIER
{
'%'
};
const char SPECIFIER_TERMINATOR
{
'$'
};
std::map<std::string, specifier *> _specifiers;
template<class generator> bool generate_string(char *&out, const generator &, const arg &);
template<class integer> bool generate_integer(char *&out, const size_t &max, const spec &, const integer &i);
struct nick_specifier
:specifier
{
bool operator()(char *&out, const size_t &max, const spec &, const arg &) const override;
using specifier::specifier;
}
const nick_specifier
{
"nick"s
};
struct user_specifier
:specifier
{
bool operator()(char *&out, const size_t &max, const spec &, const arg &) const override;
using specifier::specifier;
}
const user_specifier
{
"user"s
};
struct host_specifier
:specifier
{
bool operator()(char *&out, const size_t &max, const spec &, const arg &) const override;
using specifier::specifier;
}
const host_specifier
{
"host"s
};
struct string_specifier
:specifier
{
bool operator()(char *&out, const size_t &max, const spec &, const arg &val) const override;
using specifier::specifier;
}
const string_specifier
{
"s"s
};
struct int_specifier
:specifier
{
bool operator()(char *&out, const size_t &max, const spec &, const arg &val) const override;
using specifier::specifier;
}
const int_specifier
{
{ "d"s, "ld"s, "u"s, "lu"s, "zd"s, "zu"s }
};
struct char_specifier
:specifier
{
bool operator()(char *&out, const size_t &max, const spec &, const arg &val) const override;
using specifier::specifier;
}
const char_specifier
{
"c"s
};
bool is_specifier(const std::string &name);
void handle_specifier(char *&out, const size_t &max, const uint &idx, const spec &, const arg &);
namespace parse
{
using qi::lit;
using qi::char_;
using qi::int_;
using qi::eps;
using qi::repeat;
using qi::omit;
template<class it,
class top>
struct grammar
:qi::grammar<it, top>
{
qi::rule<it> specsym;
qi::rule<it> specterm;
qi::rule<it, std::string()> name;
qi::rule<it, fmt::spec> spec;
grammar(qi::rule<it, top> &top_rule);
};
}
} // namespace fmt
} // namespace ircd
using namespace ircd;
template<class it,
class top>
fmt::parse::grammar<it, top>::grammar(qi::rule<it, top> &top_rule)
:grammar<it, top>::base_type
{
top_rule
}
,specsym
{
lit(SPECIFIER)
}
,specterm
{
char_(SPECIFIER_TERMINATOR)
}
,name
{
repeat(1,14)[char_("A-Za-z")] >> omit[-specterm]
}
{
spec %= specsym >> -char_("+-") >> -int_ >> name[([]
(auto &str, auto &ctx, auto &valid)
{
valid = is_specifier(str);
})];
}
ssize_t
fmt::_snprintf(char *const &buf,
const size_t &max,
const char *const &fmt,
const ptrs &p,
const types &t)
try
{
if(unlikely(!max))
return 0;
char *out(buf); // Always points at next place to write
const char *stop(fmt); // Saves the 'last' place to copy a literal from
const char *start(strchr(fmt, SPECIFIER)); // The running position of the format string parse
const char *const end(fmt + strlen(fmt)); // The end of the format string
// Calculates remaining room in output buffer
const auto remaining([&max, &buf, &out]() -> size_t
{
return max - std::distance(buf, out) - 1;
});
// Copies string data between format specifiers.
const auto copy_literal([&stop, &out, &remaining]
(const char *const &end)
{
const size_t len(std::distance(stop, end));
const size_t &cpsz(std::min(len, remaining()));
memcpy(out, stop, cpsz);
out += cpsz;
});
size_t index(0); // The current position for vectors p and t (specifier count)
for(; start; stop = start++, start = start < end? strchr(start, SPECIFIER) : nullptr)
{
// Copy literal data from where the last parse stopped up to the found specifier
copy_literal(start);
// Instantiate the format specifier grammar
struct parser
:parse::grammar<const char *, fmt::spec>
{
parser(): grammar{grammar::spec} {}
}
static const parser;
// Parse the specifier with the grammar
fmt::spec spec;
if(!qi::parse(start, end, parser, spec))
continue;
// Throws if the format string has more specifiers than arguments.
const arg val{p.at(index), t.at(index)};
handle_specifier(out, remaining(), index, spec, val);
index++;
}
// If the end of the string is not a format specifier itself, it needs to be copied
if(!start)
copy_literal(end);
*out = '\0';
return std::distance(buf, out);
}
catch(const std::out_of_range &e)
{
throw invalid_format("Format string requires more than %zu arguments.", p.size());
}
const decltype(fmt::_specifiers) &
fmt::specifiers()
{
return _specifiers;
}
fmt::specifier::specifier(const std::string &name)
:specifier{{name}}
{
}
fmt::specifier::specifier(const std::initializer_list<std::string> &names)
:names{names}
{
for(const auto &name : this->names)
if(is_specifier(name))
throw error("Specifier '%c%s' already registered\n",
SPECIFIER,
name.c_str());
for(const auto &name : this->names)
_specifiers.emplace(name, this);
}
fmt::specifier::~specifier()
noexcept
{
for(const auto &name : names)
_specifiers.erase(name);
}
fmt::spec::spec()
:sign('+')
,width(0)
{
name.reserve(14);
}
bool
fmt::is_specifier(const std::string &name)
{
return specifiers().count(name);
}
void
fmt::handle_specifier(char *&out,
const size_t &max,
const uint &idx,
const spec &spec,
const arg &val)
try
{
const auto &type(get<1>(val));
const auto &handler(*specifiers().at(spec.name));
if(!handler(out, max, spec, val))
throw invalid_type("`%s' for format specifier '%c%s' for argument #%u",
type.name(),
SPECIFIER,
spec.name.c_str(),
idx);
}
catch(const std::out_of_range &e)
{
throw invalid_format("Unhandled specifier `%c%s' for argument #%u in format string",
SPECIFIER,
spec.name.c_str(),
idx);
}
catch(const illegal &e)
{
throw illegal("Specifier `%c%s' for argument #%u: %s",
SPECIFIER,
spec.name.c_str(),
idx,
e.what());
}
bool
fmt::char_specifier::operator()(char *&out,
const size_t &max,
const spec &,
const arg &val)
const
{
using karma::char_;
using karma::eps;
using karma::maxwidth;
static const auto throw_illegal([]
{
throw illegal("Not a printable character");
});
struct generator
:rfc1459::gen::grammar<char *, char()>
{
karma::rule<char *, char()> printable
{
char_(rfc1459::character::gather(rfc1459::character::PRINT))
};
generator(): grammar{printable} {}
}
static const generator;
const auto &ptr(get<0>(val));
const auto &type(get<1>(val));
if(type == typeid(const char))
{
const auto &c(*reinterpret_cast<const char *>(ptr));
karma::generate(out, maxwidth(max)[generator] | eps[throw_illegal], c);
return true;
}
else return false;
}
bool
fmt::int_specifier::operator()(char *&out,
const size_t &max,
const spec &s,
const arg &val)
const
{
const auto &ptr(get<0>(val));
const auto &type(get<1>(val));
if(type == typeid(const char))
return generate_integer(out, max, s, *reinterpret_cast<const char *>(ptr));
if(type == typeid(const unsigned char))
return generate_integer(out, max, s, *reinterpret_cast<const unsigned char *>(ptr));
if(type == typeid(const short))
return generate_integer(out, max, s, *reinterpret_cast<const short *>(ptr));
if(type == typeid(const unsigned short))
return generate_integer(out, max, s, *reinterpret_cast<const unsigned short *>(ptr));
if(type == typeid(const int))
return generate_integer(out, max, s, *reinterpret_cast<const int *>(ptr));
if(type == typeid(const unsigned int))
return generate_integer(out, max, s, *reinterpret_cast<const unsigned int *>(ptr));
if(type == typeid(const long))
return generate_integer(out, max, s, *reinterpret_cast<const long *>(ptr));
if(type == typeid(const unsigned long))
return generate_integer(out, max, s, *reinterpret_cast<const unsigned long *>(ptr));
if(type == typeid(const long long))
return generate_integer(out, max, s, *reinterpret_cast<const long long *>(ptr));
if(type == typeid(const unsigned long long))
return generate_integer(out, max, s, *reinterpret_cast<const unsigned long long *>(ptr));
if(type == typeid(const char[]))
{
size_t test;
const auto &i(reinterpret_cast<const char *>(ptr));
const auto len(std::min(max, strlen(i)));
if(!boost::conversion::try_lexical_convert(i, test))
throw illegal("The string literal value for integer specifier is not a valid integer");
memcpy(out, i, len);
out += len;
return true;
}
if(type == typeid(const char *))
{
size_t test;
const auto &i(*reinterpret_cast<const char *const *>(ptr));
const auto len(std::min(max, strlen(i)));
if(!boost::conversion::try_lexical_convert(i, test))
throw illegal("The character buffer for integer specifier is not a valid integer");
memcpy(out, i, len);
out += len;
return true;
}
if(type == typeid(const std::string))
{
size_t test;
const auto &i(*reinterpret_cast<const std::string *>(ptr));
const auto len(std::min(max, i.size()));
if(!boost::conversion::try_lexical_convert(i, test))
throw illegal("The string argument for integer specifier is not a valid integer");
memcpy(out, i.data(), len);
out += len;
return true;
}
return false;
}
bool
fmt::string_specifier::operator()(char *&out,
const size_t &max,
const spec &,
const arg &val)
const
{
using karma::char_;
using karma::eps;
using karma::maxwidth;
static const auto throw_illegal([]
{
throw illegal("Not a printable string");
});
struct generator
:rfc1459::gen::grammar<char *, std::string()>
{
karma::rule<char *, std::string()> printable
{
+char_(rfc1459::character::gather(rfc1459::character::PRINT))
};
generator(): grammar{printable} {}
}
static const generator;
return generate_string(out, maxwidth(max)[generator] | eps[throw_illegal], val);
}
bool
fmt::host_specifier::operator()(char *&out,
const size_t &max,
const spec &spec,
const arg &val)
const
{
using karma::eps;
using karma::maxwidth;
static const auto throw_illegal([]
{
throw illegal("Argument is not a valid host string");
});
struct generator
:rfc1459::gen::grammar<char *, std::string()>
{
generator(): grammar{grammar::hostname} {}
}
static const generator;
return generate_string(out, maxwidth(max)[generator] | eps[throw_illegal], val);
}
bool
fmt::user_specifier::operator()(char *&out,
const size_t &max,
const spec &spec,
const arg &val)
const
{
using karma::eps;
using karma::maxwidth;
static const auto throw_illegal([]
{
throw illegal("Argument is not a valid user string");
});
struct generator
:rfc1459::gen::grammar<char *, std::string()>
{
generator(): grammar{grammar::user} {}
}
static const generator;
return generate_string(out, maxwidth(max)[generator] | eps[throw_illegal], val);
}
bool
fmt::nick_specifier::operator()(char *&out,
const size_t &max,
const spec &spec,
const arg &val)
const
{
using karma::eps;
using karma::maxwidth;
static const auto throw_illegal([]
{
throw illegal("Argument is not a valid nick string");
});
struct generator
:rfc1459::gen::grammar<char *, std::string()>
{
generator(): grammar{grammar::nick} {}
}
static const generator;
return generate_string(out, maxwidth(max)[generator] | eps[throw_illegal], val);
}
template<class integer>
bool
fmt::generate_integer(char *&out,
const size_t &max,
const spec &s,
const integer &i)
{
using karma::int_;
using karma::maxwidth;
struct generator
:rfc1459::gen::grammar<char *, integer()>
{
karma::rule<char *, integer()> rule
{
int_
};
generator(): rfc1459::gen::grammar<char *, integer()>{rule} {}
}
static const generator;
return karma::generate(out, maxwidth(max)[generator], i);
}
template<class generator>
bool
fmt::generate_string(char *&out,
const generator &gen,
const arg &val)
{
using karma::eps;
const auto &ptr(get<0>(val));
const auto &type(get<1>(val));
if(type == typeid(std::string))
{
const auto &str(*reinterpret_cast<const std::string *>(ptr));
karma::generate(out, gen, str);
return true;
}
else if(type == typeid(const char *))
{
const auto &str(*reinterpret_cast<const char *const *>(ptr));
karma::generate(out, gen, str);
return true;
}
// This for string literals which have unique array types depending on their size.
// There is no reasonable way to match them. The best that can be hoped for is the
// grammar will fail gracefully (most of the time) or not print something bogus when
// it happens to be legal.
const auto &str(reinterpret_cast<const char *>(ptr));
return karma::generate(out, gen, str);
}