toml11/toml/source_location.hpp
2022-05-27 00:01:28 +09:00

240 lines
8.0 KiB
C++

// Copyright Toru Niina 2019.
// Distributed under the MIT License.
#ifndef TOML11_SOURCE_LOCATION_HPP
#define TOML11_SOURCE_LOCATION_HPP
#include <cstdint>
#include <sstream>
#include "region.hpp"
namespace toml
{
// A struct to contain location in a toml file.
// The interface imitates std::experimental::source_location,
// but not completely the same.
//
// It would be constructed by toml::value. It can be used to generate
// user-defined error messages.
//
// - std::uint_least32_t line() const noexcept
// - returns the line number where the region is on.
// - std::uint_least32_t column() const noexcept
// - returns the column number where the region starts.
// - std::uint_least32_t region() const noexcept
// - returns the size of the region.
//
// +-- line() +-- region of interest (region() == 9)
// v .---+---.
// 12 | value = "foo bar"
// ^
// +-- column()
//
// - std::string const& file_name() const noexcept;
// - name of the file.
// - std::string const& line_str() const noexcept;
// - the whole line that contains the region of interest.
//
struct source_location
{
public:
source_location()
: line_num_(1), column_num_(1), region_size_(1),
file_name_("unknown file"), line_str_("")
{}
explicit source_location(const detail::region_base* reg)
: line_num_(1), column_num_(1), region_size_(1),
file_name_("unknown file"), line_str_("")
{
if(reg)
{
if(reg->line_num() != detail::region_base().line_num())
{
line_num_ = static_cast<std::uint_least32_t>(
std::stoul(reg->line_num()));
}
column_num_ = static_cast<std::uint_least32_t>(reg->before() + 1);
region_size_ = static_cast<std::uint_least32_t>(reg->size());
file_name_ = reg->name();
line_str_ = reg->line();
}
}
explicit source_location(const detail::region& reg)
: line_num_(static_cast<std::uint_least32_t>(std::stoul(reg.line_num()))),
column_num_(static_cast<std::uint_least32_t>(reg.before() + 1)),
region_size_(static_cast<std::uint_least32_t>(reg.size())),
file_name_(reg.name()),
line_str_ (reg.line())
{}
explicit source_location(const detail::location& loc)
: line_num_(static_cast<std::uint_least32_t>(std::stoul(loc.line_num()))),
column_num_(static_cast<std::uint_least32_t>(loc.before() + 1)),
region_size_(static_cast<std::uint_least32_t>(loc.size())),
file_name_(loc.name()),
line_str_ (loc.line())
{}
~source_location() = default;
source_location(source_location const&) = default;
source_location(source_location &&) = default;
source_location& operator=(source_location const&) = default;
source_location& operator=(source_location &&) = default;
std::uint_least32_t line() const noexcept {return line_num_;}
std::uint_least32_t column() const noexcept {return column_num_;}
std::uint_least32_t region() const noexcept {return region_size_;}
std::string const& file_name() const noexcept {return file_name_;}
std::string const& line_str() const noexcept {return line_str_;}
private:
std::uint_least32_t line_num_;
std::uint_least32_t column_num_;
std::uint_least32_t region_size_;
std::string file_name_;
std::string line_str_;
};
namespace detail
{
// internal error message generation.
inline std::string format_underline(const std::string& message,
const std::vector<std::pair<source_location, std::string>>& loc_com,
const std::vector<std::string>& helps = {},
const bool colorize = TOML11_ERROR_MESSAGE_COLORIZED)
{
std::size_t line_num_width = 0;
for(const auto& lc : loc_com)
{
std::uint_least32_t line = lc.first.line();
std::size_t digit = 0;
while(line != 0)
{
line /= 10;
digit += 1;
}
line_num_width = (std::max)(line_num_width, digit);
}
// 1 is the minimum width
line_num_width = std::max<std::size_t>(line_num_width, 1);
std::ostringstream retval;
if(color::should_color() || colorize)
{
retval << color::colorize; // turn on ANSI color
}
// XXX
// Here, before `colorize` support, it does not output `[error]` prefix
// automatically. So some user may output it manually and this change may
// duplicate the prefix. To avoid it, check the first 7 characters and
// if it is "[error]", it removes that part from the message shown.
if(message.size() > 7 && message.substr(0, 7) == "[error]")
{
retval
#ifndef TOML11_NO_ERROR_PREFIX
<< color::bold << color::red << "[error]" << color::reset
#endif
<< color::bold << message.substr(7) << color::reset << '\n';
}
else
{
retval
#ifndef TOML11_NO_ERROR_PREFIX
<< color::bold << color::red << "[error] " << color::reset
#endif
<< color::bold << message << color::reset << '\n';
}
const auto format_one_location = [line_num_width]
(std::ostringstream& oss,
const source_location& loc, const std::string& comment) -> void
{
oss << ' ' << color::bold << color::blue
<< std::setw(static_cast<int>(line_num_width))
<< std::right << loc.line() << " | " << color::reset
<< loc.line_str() << '\n';
oss << make_string(line_num_width + 1, ' ')
<< color::bold << color::blue << " | " << color::reset
<< make_string(loc.column()-1 /*1-origin*/, ' ');
if(loc.region() == 1)
{
// invalid
// ^------
oss << color::bold << color::red << "^---" << color::reset;
}
else
{
// invalid
// ~~~~~~~
const auto underline_len = (std::min)(
static_cast<std::size_t>(loc.region()), loc.line_str().size());
oss << color::bold << color::red
<< make_string(underline_len, '~') << color::reset;
}
oss << ' ';
oss << comment;
return;
};
assert(!loc_com.empty());
// --> example.toml
// |
retval << color::bold << color::blue << " --> " << color::reset
<< loc_com.front().first.file_name() << '\n';
retval << make_string(line_num_width + 1, ' ')
<< color::bold << color::blue << " |\n" << color::reset;
// 1 | key value
// | ^--- missing =
format_one_location(retval, loc_com.front().first, loc_com.front().second);
// process the rest of the locations
for(std::size_t i=1; i<loc_com.size(); ++i)
{
const auto& prev = loc_com.at(i-1);
const auto& curr = loc_com.at(i);
retval << '\n';
// if the filenames are the same, print "..."
if(prev.first.file_name() == curr.first.file_name())
{
retval << color::bold << color::blue << " ...\n" << color::reset;
}
else // if filename differs, print " --> filename.toml" again
{
retval << color::bold << color::blue << " --> " << color::reset
<< curr.first.file_name() << '\n';
retval << make_string(line_num_width + 1, ' ')
<< color::bold << color::blue << " |\n" << color::reset;
}
format_one_location(retval, curr.first, curr.second);
}
if(!helps.empty())
{
retval << '\n';
retval << make_string(line_num_width + 1, ' ');
retval << color::bold << color::blue << " |" << color::reset;
for(const auto& help : helps)
{
retval << color::bold << "\nHint: " << color::reset;
retval << help;
}
}
return retval.str();
}
} // detail
} // toml
#endif// TOML11_SOURCE_LOCATION_HPP