solidity/liblangutil/SourceReferenceExtractor.cpp

/*
	This file is part of solidity.

	solidity is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	solidity is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
*/
#include <liblangutil/SourceReferenceExtractor.h>
#include <liblangutil/CharStream.h>
#include <liblangutil/Exceptions.h>

#include <cmath>
#include <iomanip>

using namespace std;
using namespace dev;
using namespace langutil;

SourceReferenceExtractor::Message SourceReferenceExtractor::extract(Exception const& _exception, string _category)
{
	SourceLocation const* location = boost::get_error_info<errinfo_sourceLocation>(_exception);

	string const* message = boost::get_error_info<errinfo_comment>(_exception);
	SourceReference primary = extract(location, message ? *message : "");

	std::vector<SourceReference> secondary;
	auto secondaryLocation = boost::get_error_info<errinfo_secondarySourceLocation>(_exception);
	if (secondaryLocation && !secondaryLocation->infos.empty())
		for (auto const& info: secondaryLocation->infos)
			secondary.emplace_back(extract(&info.second, info.first));

	return Message{std::move(primary), _category, std::move(secondary)};
}

SourceReference SourceReferenceExtractor::extract(SourceLocation const* _location, std::string message)
{
	if (!_location || !_location->source.get()) // Nothing we can extract here
		return SourceReference::MessageOnly(std::move(message));

	shared_ptr<CharStream> const& source = _location->source;

	LineColumn const interest = source->translatePositionToLineColumn(_location->start);
	LineColumn start = interest;
	LineColumn end = source->translatePositionToLineColumn(_location->end);
	bool const isMultiline = start.line != end.line;

	string line = source->lineAtPosition(_location->start);

	int locationLength = isMultiline ? line.length() - start.column : end.column - start.column;
	if (locationLength > 150)
	{
		int const lhs = start.column + 35;
		int const rhs = (isMultiline ? line.length() : end.column) - 35;
		line = line.substr(0, lhs) + " ... " + line.substr(rhs);
		end.column = start.column + 75;
		locationLength = 75;
	}

	if (line.length() > 150)
	{
		int const len = line.length();
		line = line.substr(max(0, start.column - 35), min(start.column, 35) + min(locationLength + 35, len - start.column));
		if (start.column + locationLength + 35 < len)
			line += " ...";
		if (start.column > 35)
		{
			line = " ... " + line;
			start.column = 40;
		}
		end.column = start.column + locationLength;
	}

	return SourceReference{
		std::move(message),
		source->name(),
		interest,
		isMultiline,
		line,
		start.column,
		end.column,
	};
}