nix-super/src/libexpr/eval-error.cc

#include "eval-error.hh"
#include "eval.hh"
#include "value.hh"

namespace nix {

template<class T>
EvalErrorBuilder<T> & EvalErrorBuilder<T>::withExitStatus(unsigned int exitStatus)
{
    error.withExitStatus(exitStatus);
    return *this;
}

template<class T>
EvalErrorBuilder<T> & EvalErrorBuilder<T>::atPos(PosIdx pos)
{
    error.err.pos = error.state.positions[pos];
    return *this;
}

template<class T>
EvalErrorBuilder<T> & EvalErrorBuilder<T>::atPos(Value & value, PosIdx fallback)
{
    return atPos(value.determinePos(fallback));
}

template<class T>
EvalErrorBuilder<T> & EvalErrorBuilder<T>::withTrace(PosIdx pos, const std::string_view text)
{
    error.addTrace(error.state.positions[pos], text);
    return *this;
}

template<class T>
EvalErrorBuilder<T> & EvalErrorBuilder<T>::withSuggestions(Suggestions & s)
{
    error.err.suggestions = s;
    return *this;
}

template<class T>
EvalErrorBuilder<T> & EvalErrorBuilder<T>::withFrame(const Env & env, const Expr & expr)
{
    // NOTE: This is abusing side-effects.
    // TODO: check compatibility with nested debugger calls.
    // TODO: What side-effects??
    error.state.debugTraces.push_front(DebugTrace{
        .pos = error.state.positions[expr.getPos()],
        .expr = expr,
        .env = env,
        .hint = HintFmt("Fake frame for debugging purposes"),
        .isError = true});
    return *this;
}

template<class T>
EvalErrorBuilder<T> & EvalErrorBuilder<T>::addTrace(PosIdx pos, HintFmt hint)
{
    error.addTrace(error.state.positions[pos], hint);
    return *this;
}

template<class T>
template<typename... Args>
EvalErrorBuilder<T> &
EvalErrorBuilder<T>::addTrace(PosIdx pos, std::string_view formatString, const Args &... formatArgs)
{

    addTrace(error.state.positions[pos], HintFmt(std::string(formatString), formatArgs...));
    return *this;
}

template<class T>
void EvalErrorBuilder<T>::debugThrow()
{
    if (error.state.debugRepl && !error.state.debugTraces.empty()) {
        const DebugTrace & last = error.state.debugTraces.front();
        const Env * env = &last.env;
        const Expr * expr = &last.expr;
        error.state.runDebugRepl(&error, *env, *expr);
    }

    // `EvalState` is the only class that can construct an `EvalErrorBuilder`,
    // and it does so in dynamic storage. This is the final method called on
    // any such instance and must delete itself before throwing the underlying
    // error.
    auto error = std::move(this->error);
    delete this;

    throw error;
}

template class EvalErrorBuilder<EvalError>;
template class EvalErrorBuilder<AssertionError>;
template class EvalErrorBuilder<ThrownError>;
template class EvalErrorBuilder<Abort>;
template class EvalErrorBuilder<TypeError>;
template class EvalErrorBuilder<UndefinedVarError>;
template class EvalErrorBuilder<MissingArgumentError>;
template class EvalErrorBuilder<InfiniteRecursionError>;
template class EvalErrorBuilder<InvalidPathError>;

}