path: root/src/libexpr/get-drvs.cc

#include "get-drvs.hh"
#include "util.hh"
#include "eval-inline.hh"
#include "store-api.hh"

#include <cstring>
#include <regex>


namespace nix {


DrvInfo::DrvInfo(EvalState & state, const string & attrPath, Bindings * attrs)
    : state(&state), attrs(attrs), attrPath(attrPath)
{
}


DrvInfo::DrvInfo(EvalState & state, ref<Store> store, const std::string & drvPathWithOutputs)
    : state(&state), attrs(nullptr), attrPath("")
{
    auto [drvPath, selectedOutputs] = store->parsePathWithOutputs(drvPathWithOutputs);

    this->drvPath = store->printStorePath(drvPath);

    auto drv = store->derivationFromPath(drvPath);

    name = drvPath.name();

    if (selectedOutputs.size() > 1)
        throw Error("building more than one derivation output is not supported, in '%s'", drvPathWithOutputs);

    outputName =
        selectedOutputs.empty()
        ? get(drv.env, "outputName").value_or("out")
        : *selectedOutputs.begin();

    auto i = drv.outputs.find(outputName);
    if (i == drv.outputs.end())
        throw Error("derivation '%s' does not have output '%s'", store->printStorePath(drvPath), outputName);
    auto & [outputName, output] = *i;

    auto optStorePath = output.path(*store, drv.name, outputName);
    if (optStorePath)
        outPath = store->printStorePath(*optStorePath);
}


string DrvInfo::queryName() const
{
    if (name == "" && attrs) {
        auto i = attrs->find(state->sName);
        if (i == attrs->end()) throw TypeError("derivation name missing");
        name = state->forceStringNoCtx(*i->value);
    }
    return name;
}


string DrvInfo::querySystem() const
{
    if (system == "" && attrs) {
        auto i = attrs->find(state->sSystem);
        system = i == attrs->end() ? "unknown" : state->forceStringNoCtx(*i->value, *i->pos);
    }
    return system;
}


string DrvInfo::queryDrvPath() const
{
    if (drvPath == "" && attrs) {
        Bindings::iterator i = attrs->find(state->sDrvPath);
        PathSet context;
        drvPath = i != attrs->end() ? state->coerceToPath(*i->pos, *i->value, context) : "";
    }
    return drvPath;
}


string DrvInfo::queryOutPath() const
{
    if (!outPath && attrs) {
        Bindings::iterator i = attrs->find(state->sOutPath);
        PathSet context;
        if (i != attrs->end())
            outPath = state->coerceToPath(*i->pos, *i->value, context);
    }
    if (!outPath)
        throw UnimplementedError("CA derivations are not yet supported");
    return *outPath;
}


DrvInfo::Outputs DrvInfo::queryOutputs(bool onlyOutputsToInstall)
{
    if (outputs.empty()) {
        /* Get the ‘outputs’ list. */
        Bindings::iterator i;
        if (attrs && (i = attrs->find(state->sOutputs)) != attrs->end()) {
            state->forceList(*i->value, *i->pos);

            /* For each output... */
            for (unsigned int j = 0; j < i->value->listSize(); ++j) {
                /* Evaluate the corresponding set. */
                string name = state->forceStringNoCtx(*i->value->listElems()[j], *i->pos);
                Bindings::iterator out = attrs->find(state->symbols.create(name));
                if (out == attrs->end()) continue; // FIXME: throw error?
                state->forceAttrs(*out->value);

                /* And evaluate its ‘outPath’ attribute. */
                Bindings::iterator outPath = out->value->attrs->find(state->sOutPath);
                if (outPath == out->value->attrs->end()) continue; // FIXME: throw error?
                PathSet context;
                outputs[name] = state->coerceToPath(*outPath->pos, *outPath->value, context);
            }
        } else
            outputs["out"] = queryOutPath();
    }
    if (!onlyOutputsToInstall || !attrs)
        return outputs;

    /* Check for `meta.outputsToInstall` and return `outputs` reduced to that. */
    const Value * outTI = queryMeta("outputsToInstall");
    if (!outTI) return outputs;
    const auto errMsg = Error("this derivation has bad 'meta.outputsToInstall'");
        /* ^ this shows during `nix-env -i` right under the bad derivation */
    if (!outTI->isList()) throw errMsg;
    Outputs result;
    for (auto i = outTI->listElems(); i != outTI->listElems() + outTI->listSize(); ++i) {
        if ((*i)->type() != nString) throw errMsg;
        auto out = outputs.find((*i)->string.s);
        if (out == outputs.end()) throw errMsg;
        result.insert(*out);
    }
    return result;
}


string DrvInfo::queryOutputName() const
{
    if (outputName == "" && attrs) {
        Bindings::iterator i = attrs->find(state->sOutputName);
        outputName = i != attrs->end() ? state->forceStringNoCtx(*i->value) : "";
    }
    return outputName;
}


Bindings * DrvInfo::getMeta()
{
    if (meta) return meta;
    if (!attrs) return 0;
    Bindings::iterator a = attrs->find(state->sMeta);
    if (a == attrs->end()) return 0;
    state->forceAttrs(*a->value, *a->pos);
    meta = a->value->attrs;
    return meta;
}


StringSet DrvInfo::queryMetaNames()
{
    StringSet res;
    if (!getMeta()) return res;
    for (auto & i : *meta)
        res.insert(i.name);
    return res;
}


bool DrvInfo::checkMeta(Value & v)
{
    state->forceValue(v);
    if (v.type() == nList) {
        for (unsigned int n = 0; n < v.listSize(); ++n)
            if (!checkMeta(*v.listElems()[n])) return false;
        return true;
    }
    else if (v.type() == nAttrs) {
        Bindings::iterator i = v.attrs->find(state->sOutPath);
        if (i != v.attrs->end()) return false;
        for (auto & i : *v.attrs)
            if (!checkMeta(*i.value)) return false;
        return true;
    }
    else return v.type() == nInt || v.type() == nBool || v.type() == nString ||
                v.type() == nFloat;
}


Value * DrvInfo::queryMeta(const string &