Move command plugin interface to libnixcmd

1 files changed, 274 insertions, 0 deletions

diff --git a/src/libcmd/command.hh b/src/libcmd/command.hh
new file mode 100644
index 000000000..ed6980075
--- /dev/null
+++ b/src/libcmd/command.hh
@@ -0,0 +1,274 @@
+#pragma once
+
+#include "installables.hh"
+#include "args.hh"
+#include "common-eval-args.hh"
+#include "path.hh"
+#include "flake/lockfile.hh"
+#include "store-api.hh"
+
+#include <optional>
+
+namespace nix {
+
+extern std::string programPath;
+
+extern char * * savedArgv;
+
+class EvalState;
+struct Pos;
+class Store;
+
+static constexpr Command::Category catSecondary = 100;
+static constexpr Command::Category catUtility = 101;
+static constexpr Command::Category catNixInstallation = 102;
+
+static constexpr auto installablesCategory = "Options that change the interpretation of installables";
+
+struct NixMultiCommand : virtual MultiCommand, virtual Command
+{
+    nlohmann::json toJSON() override;
+};
+
+/* A command that requires a Nix store. */
+struct StoreCommand : virtual Command
+{
+    StoreCommand();
+    void run() override;
+    ref<Store> getStore();
+    virtual ref<Store> createStore();
+    virtual void run(ref<Store>) = 0;
+
+private:
+    std::shared_ptr<Store> _store;
+};
+
+struct EvalCommand : virtual StoreCommand, MixEvalArgs
+{
+    ref<EvalState> getEvalState();
+
+    std::shared_ptr<EvalState> evalState;
+};
+
+struct MixFlakeOptions : virtual Args, EvalCommand
+{
+    flake::LockFlags lockFlags;
+
+    MixFlakeOptions();
+
+    virtual std::optional<FlakeRef> getFlakeRefForCompletion()
+    { return {}; }
+};
+
+/* How to handle derivations in commands that operate on store paths. */
+enum class OperateOn {
+    /* Operate on the output path. */
+    Output,
+    /* Operate on the .drv path. */
+    Derivation
+};
+
+struct SourceExprCommand : virtual Args, MixFlakeOptions
+{
+    std::optional<Path> file;
+    std::optional<std::string> expr;
+
+    // FIXME: move this; not all commands (e.g. 'nix run') use it.
+    OperateOn operateOn = OperateOn::Output;
+
+    SourceExprCommand();
+
+    std::vector<std::shared_ptr<Installable>> parseInstallables(
+        ref<Store> store, std::vector<std::string> ss);
+
+    std::shared_ptr<Installable> parseInstallable(
+        ref<Store> store, const std::string & installable);
+
+    virtual Strings getDefaultFlakeAttrPaths();
+
+    virtual Strings getDefaultFlakeAttrPathPrefixes();
+
+    void completeInstallable(std::string_view prefix);
+};
+
+enum class Realise {
+    /* Build the derivation. Postcondition: the
+       derivation outputs exist. */
+    Outputs,
+    /* Don't build the derivation. Postcondition: the store derivation
+       exists. */
+    Derivation,
+    /* Evaluate in dry-run mode. Postcondition: nothing. */
+    Nothing
+};
+
+/* A command that operates on a list of "installables", which can be
+   store paths, attribute paths, Nix expressions, etc. */
+struct InstallablesCommand : virtual Args, SourceExprCommand
+{
+    std::vector<std::shared_ptr<Installable>> installables;
+
+    InstallablesCommand();
+
+    void prepare() override;
+
+    virtual bool useDefaultInstallables() { return true; }
+
+    std::optional<FlakeRef> getFlakeRefForCompletion() override;
+
+private:
+
+    std::vector<std::string> _installables;
+};
+
+/* A command that operates on exactly one "installable" */
+struct InstallableCommand : virtual Args, SourceExprCommand
+{
+    std::shared_ptr<Installable> installable;
+
+    InstallableCommand();
+
+    void prepare() override;
+
+    std::optional<FlakeRef> getFlakeRefForCompletion() override
+    {
+        return parseFlakeRef(_installable, absPath("."));
+    }
+
+private:
+
+    std::string _installable{"."};
+};
+
+/* A command that operates on zero or more store paths. */
+struct StorePathsCommand : public InstallablesCommand
+{
+private:
+
+    bool recursive = false;
+    bool all = false;
+
+protected:
+
+    Realise realiseMode = Realise::Derivation;
+
+public:
+
+    StorePathsCommand(bool recursive = false);
+
+    using StoreCommand::run;
+
+    virtual void run(ref<Store> store, std::vector<StorePath> storePaths) = 0;
+
+    void run(ref<Store> store) override;
+
+    bool useDefaultInstallables() override { return !all; }
+};
+
+/* A command that operates on exactly one store path. */
+struct StorePathCommand : public InstallablesCommand
+{
+    using StoreCommand::run;
+
+    virtual void run(ref<Store> store, const StorePath & storePath) = 0;
+
+    void run(ref<Store> store) override;
+};
+
+/* A helper class for registering commands globally. */
+struct RegisterCommand
+{
+    typedef std::map<std::vector<std::string>, std::function<ref<Command>()>> Commands;
+    static Commands * commands;
+
+    RegisterCommand(std::vector<std::string> && name,
+        std::function<ref<Command>()> command)
+    {
+        if (!commands) commands = new Commands;
+        commands->emplace(name, command);
+    }
+
+    static nix::Commands getCommandsFor(const std::vector<std::string> & prefix);
+};
+
+template<class T>
+static RegisterCommand registerCommand(const std::string & name)
+{
+    return RegisterCommand({name}, [](){ return make_ref<T>(); });
+}
+
+template<class T>
+static RegisterCommand registerCommand2(std::vector<std::string> && name)
+{
+    return RegisterCommand(std::move(name), [](){ return make_ref<T>(); });
+}
+
+Buildables build(ref<Store> store, Realise mode,
+    std::vector<std::shared_ptr<Installable>> installables, BuildMode bMode = bmNormal);
+
+std::set<StorePath> toStorePaths(ref<Store> store,
+    Realise mode, OperateOn operateOn,
+    std::vector<std::shared_ptr<Installable>> installables);
+
+StorePath toStorePath(ref<Store> store,
+    Realise mode, OperateOn operateOn,
+    std::shared_ptr<Installable> installable);
+
+std::set<StorePath> toDerivations(ref<Store> store,
+    std::vector<std::shared_ptr<Installable>> installables,
+    bool useDeriver = false);
+
+/* Helper function to generate args that invoke $EDITOR on
+   filename:lineno. */
+Strings editorFor(const Pos & pos);
+
+struct MixProfile : virtual StoreCommand
+{
+    std::optional<Path> profile;
+
+    MixProfile();
+
+    /* If 'profile' is set, make it point at 'storePath'. */
+    void updateProfile(const StorePath & storePath);
+
+    /* If 'profile' is set, make it point at the store path produced
+       by 'buildables'. */
+    void updateProfile(const Buildables & buildables);
+};
+
+struct MixDefaultProfile : MixProfile
+{
+    MixDefaultProfile();
+};
+
+struct MixEnvironment : virtual Args {
+
+    StringSet keep, unset;
+    Strings stringsEnv;
+    std::vector<char*> vectorEnv;
+    bool ignoreEnvironment;
+
+    MixEnvironment();
+
+    /* Modify global environ based on ignoreEnvironment, keep, and unset. It's expected that exec will be called before this class goes out of scope, otherwise environ will become invalid. */
+    void setEnviron();
+};
+
+void completeFlakeRef(ref<Store> store, std::string_view prefix);
+
+void completeFlakeRefWithFragment(
+    ref<EvalState> evalState,
+    flake::LockFlags lockFlags,
+    Strings attrPathPrefixes,
+    const Strings & defaultFlakeAttrPaths,
+    std::string_view prefix);
+
+std::string showVersions(const std::set<std::string> & versions);
+
+void printClosureDiff(
+    ref<Store> store,
+    const StorePath & beforePath,
+    const StorePath & afterPath,
+    std::string_view indent);
+
+}