nix: Respect -I, --arg, --argstr

Also, random cleanup to argument handling.

src/libexpr/common-eval-args.cc

@@ -0,0 +1,57 @@
+#include "common-eval-args.hh"
+#include "shared.hh"
+#include "download.hh"
+#include "util.hh"
+#include "eval.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 getDownloader()->downloadCached(state.store, s, true);
+    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);
+}
+
+}

src/libexpr/common-eval-args.hh

@@ -0,0 +1,26 @@
+#pragma once
+
+#include "args.hh"
+
+namespace nix {
+
+class Store;
+class EvalState;
+struct Bindings;
+
+struct MixEvalArgs : virtual Args
+{
+    MixEvalArgs();
+
+    Bindings * getAutoArgs(EvalState & state);
+
+    Strings searchPath;
+
+private:
+
+    std::map<std::string, std::string> autoArgs;
+};
+
+Path lookupFileArg(EvalState & state, string s);
+
+}

src/libexpr/common-opts.cc

@@ -1,67 +0,0 @@
-#include "common-opts.hh"
-#include "shared.hh"
-#include "download.hh"
-#include "util.hh"
-
-
-namespace nix {
-
-
-bool parseAutoArgs(Strings::iterator & i,
-    const Strings::iterator & argsEnd, std::map<string, string> & res)
-{
-    string arg = *i;
-    if (arg != "--arg" && arg != "--argstr") return false;
-
-    UsageError error(format("'%1%' requires two arguments") % arg);
-
-    if (++i == argsEnd) throw error;
-    string name = *i;
-    if (++i == argsEnd) throw error;
-    string value = *i;
-
-    res[name] = (arg == "--arg" ? 'E' : 'S') + value;
-
-    return true;
-}
-
-
-Bindings * evalAutoArgs(EvalState & state, std::map<string, string> & in)
-{
-    Bindings * res = state.allocBindings(in.size());
-    for (auto & i : in) {
-        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;
-}
-
-
-bool parseSearchPathArg(Strings::iterator & i,
-    const Strings::iterator & argsEnd, Strings & searchPath)
-{
-    if (*i != "-I") return false;
-    if (++i == argsEnd) throw UsageError("'-I' requires an argument");
-    searchPath.push_back(*i);
-    return true;
-}
-
-
-Path lookupFileArg(EvalState & state, string s)
-{
-    if (isUri(s))
-        return getDownloader()->downloadCached(state.store, s, true);
-    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);
-}
-
-
-}

src/libexpr/common-opts.hh

@@ -1,20 +0,0 @@
-#pragma once
-
-#include "eval.hh"
-
-namespace nix {
-
-class Store;
-
-/* Some common option parsing between nix-env and nix-instantiate. */
-bool parseAutoArgs(Strings::iterator & i,
-    const Strings::iterator & argsEnd, std::map<string, string> & res);
-
-Bindings * evalAutoArgs(EvalState & state, std::map<string, string> & in);
-
-bool parseSearchPathArg(Strings::iterator & i,
-    const Strings::iterator & argsEnd, Strings & searchPath);
-
-Path lookupFileArg(EvalState & state, string s);
-
-}