1 files changed, 64 insertions, 0 deletions
diff --git a/third_party/nix/src/libexpr/common-eval-args.cc b/third_party/nix/src/libexpr/common-eval-args.cc
new file mode 100644
index 000000000000..2059d5374195
--- /dev/null
+++ b/third_party/nix/src/libexpr/common-eval-args.cc
@@ -0,0 +1,64 @@
+#include "common-eval-args.hh"
+
+#include "download.hh"
+#include "eval.hh"
+#include "shared.hh"
+#include "util.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([&](const std::string& s) { searchPath.push_back(s); });
+}
+
+Bindings* MixEvalArgs::getAutoArgs(EvalState& state) {
+  Bindings* res = Bindings::NewGC();
+  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));
+  }
+  return res;
+}
+
+Path lookupFileArg(EvalState& state, std::string s) {
+  if (isUri(s)) {
+    CachedDownloadRequest request(s);
+    request.unpack = true;
+    return getDownloader()->downloadCached(state.store, request).path;
+  }
+  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);
+  }
+}
+
+}  // namespace nix