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#pragma once
#include "ref.hh"
#include <string>
#include <list>
#include <set>
#include <memory>
#include <map>
#include <boost/format.hpp>
/* Before 4.7, gcc's std::exception uses empty throw() specifiers for
* its (virtual) destructor and what() in c++11 mode, in violation of spec
*/
#ifdef __GNUC__
#if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 7)
#define EXCEPTION_NEEDS_THROW_SPEC
#endif
#endif
namespace nix {
/* Inherit some names from other namespaces for convenience. */
using std::string;
using std::list;
using std::set;
using std::vector;
using boost::format;
/* A variadic template that does nothing. Useful to call a function
for all variadic arguments but ignoring the result. */
struct nop { template<typename... T> nop(T...) {} };
struct FormatOrString
{
string s;
FormatOrString(const string & s) : s(s) { };
FormatOrString(const format & f) : s(f.str()) { };
FormatOrString(const char * s) : s(s) { };
};
/* A helper for formatting strings. ‘fmt(format, a_0, ..., a_n)’ is
equivalent to ‘boost::format(format) % a_0 % ... %
... a_n’. However, ‘fmt(s)’ is equivalent to ‘s’ (so no %-expansion
takes place). */
inline std::string fmt(const std::string & s)
{
return s;
}
inline std::string fmt(const char * s)
{
return s;
}
inline std::string fmt(const FormatOrString & fs)
{
return fs.s;
}
template<typename... Args>
inline std::string fmt(const std::string & fs, Args... args)
{
boost::format f(fs);
f.exceptions(boost::io::all_error_bits ^ boost::io::too_many_args_bit);
nop{boost::io::detail::feed(f, args)...};
return f.str();
}
/* BaseError should generally not be caught, as it has Interrupted as
a subclass. Catch Error instead. */
class BaseError : public std::exception
{
protected:
string prefix_; // used for location traces etc.
string err;
public:
unsigned int status = 1; // exit status
template<typename... Args>
BaseError(unsigned int status, Args... args)
: err(fmt(args...))
, status(status)
{
}
template<typename... Args>
BaseError(Args... args)
: err(fmt(args...))
{
}
#ifdef EXCEPTION_NEEDS_THROW_SPEC
~BaseError() throw () { };
const char * what() const throw () { return err.c_str(); }
#else
const char * what() const noexcept { return err.c_str(); }
#endif
const string & msg() const { return err; }
const string & prefix() const { return prefix_; }
BaseError & addPrefix(const FormatOrString & fs);
virtual bool isTransient() { return false; }
};
#define MakeError(newClass, superClass) \
class newClass : public superClass \
{ \
public: \
using superClass::superClass; \
};
MakeError(Error, BaseError)
class SysError : public Error
{
public:
int errNo;
template<typename... Args>
SysError(Args... args)
: Error(addErrno(fmt(args...)))
{ }
private:
std::string addErrno(const std::string & s);
};
typedef list<string> Strings;
typedef set<string> StringSet;
typedef std::map<std::string, std::string> StringMap;
/* Paths are just strings. */
typedef string Path;
typedef list<Path> Paths;
typedef set<Path> PathSet;
}
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