lix/src/libexpr/common-eval-args.cc
Eelco Dolstra 462421d345 Backport libfetchers from the flakes branch
This provides a pluggable mechanism for defining new fetchers. It adds
a builtin function 'fetchTree' that generalizes existing fetchers like
'fetchGit', 'fetchMercurial' and 'fetchTarball'. 'fetchTree' takes a
set of attributes, e.g.

  fetchTree {
    type = "git";
    url = "https://example.org/repo.git";
    ref = "some-branch";
    rev = "abcdef...";
  }

The existing fetchers are just wrappers around this. Note that the
input attributes to fetchTree are the same as flake input
specifications and flake lock file entries.

All fetchers share a common cache stored in
~/.cache/nix/fetcher-cache-v1.sqlite. This replaces the ad hoc caching
mechanisms in fetchGit and download.cc (e.g. ~/.cache/nix/{tarballs,git-revs*}).

This also adds support for Git worktrees (c169ea5904).
2020-04-07 09:03:14 +02:00

62 lines
1.8 KiB
C++

#include "common-eval-args.hh"
#include "shared.hh"
#include "download.hh"
#include "util.hh"
#include "eval.hh"
#include "fetchers.hh"
#include "store-api.hh"
namespace nix {
MixEvalArgs::MixEvalArgs()
{
mkFlag()
.longName("arg")
.description("argument to be passed to Nix functions")
.labels({"name", "expr"})
.handler([&](std::vector<std::string> ss) { autoArgs[ss[0]] = 'E' + ss[1]; });
mkFlag()
.longName("argstr")
.description("string-valued argument to be passed to Nix functions")
.labels({"name", "string"})
.handler([&](std::vector<std::string> ss) { autoArgs[ss[0]] = 'S' + ss[1]; });
mkFlag()
.shortName('I')
.longName("include")
.description("add a path to the list of locations used to look up <...> file names")
.label("path")
.handler([&](std::string s) { searchPath.push_back(s); });
}
Bindings * MixEvalArgs::getAutoArgs(EvalState & state)
{
Bindings * res = state.allocBindings(autoArgs.size());
for (auto & i : autoArgs) {
Value * v = state.allocValue();
if (i.second[0] == 'E')
state.mkThunk_(*v, state.parseExprFromString(string(i.second, 1), absPath(".")));
else
mkString(*v, string(i.second, 1));
res->push_back(Attr(state.symbols.create(i.first), v));
}
res->sort();
return res;
}
Path lookupFileArg(EvalState & state, string s)
{
if (isUri(s)) {
return state.store->toRealPath(
fetchers::downloadTarball(
state.store, resolveUri(s), "source", false).storePath);
} else if (s.size() > 2 && s.at(0) == '<' && s.at(s.size() - 1) == '>') {
Path p = s.substr(1, s.size() - 2);
return state.findFile(p);
} else
return absPath(s);
}
}