Merge pull request #8084 from edolstra/store-docs

Auto-generate store documentation

1 files changed, 60 insertions, 7 deletions

diff --git a/src/nix/main.cc b/src/nix/main.cc
index c79d39459..54c920b4e 100644
--- a/src/nix/main.cc
+++ b/src/nix/main.cc
@@ -64,6 +64,7 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs
     NixArgs() : MultiCommand(RegisterCommand::getCommandsFor({})), MixCommonArgs("nix")
     {
         categories.clear();
+        categories[catHelp] = "Help commands";
         categories[Command::catDefault] = "Main commands";
         categories[catSecondary] = "Infrequently used commands";
         categories[catUtility] = "Utility/scripting commands";
@@ -163,11 +164,29 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs
     {
         commands = RegisterCommand::getCommandsFor({});
     }
+
+    std::string dumpCli()
+    {
+        auto res = nlohmann::json::object();
+
+        res["args"] = toJSON();
+
+        auto stores = nlohmann::json::object();
+        for (auto & implem : *Implementations::registered) {
+            auto storeConfig = implem.getConfig();
+            auto storeName = storeConfig->name();
+            stores[storeName]["doc"] = storeConfig->doc();
+            stores[storeName]["settings"] = storeConfig->toJSON();
+        }
+        res["stores"] = std::move(stores);
+
+        return res.dump();
+    }
 };
 
 /* Render the help for the specified subcommand to stdout using
    lowdown. */
-static void showHelp(std::vector<std::string> subcommand, MultiCommand & toplevel)
+static void showHelp(std::vector<std::string> subcommand, NixArgs & toplevel)
 {
     auto mdName = subcommand.empty() ? "nix" : fmt("nix3-%s", concatStringsSep("-", subcommand));
 
@@ -188,11 +207,11 @@ static void showHelp(std::vector<std::string> subcommand, MultiCommand & topleve
             , "/"),
         *vUtils);
 
-    auto attrs = state.buildBindings(16);
-    attrs.alloc("toplevel").mkString(toplevel.toJSON().dump());
+    auto vDump = state.allocValue();
+    vDump->mkString(toplevel.dumpCli());
 
     auto vRes = state.allocValue();
-    state.callFunction(*vGenerateManpage, state.allocValue()->mkAttrs(attrs), *vRes, noPos);
+    state.callFunction(*vGenerateManpage, *vDump, *vRes, noPos);
 
     auto attr = vRes->attrs->get(state.symbols.create(mdName + ".md"));
     if (!attr)
@@ -204,6 +223,14 @@ static void showHelp(std::vector<std::string> subcommand, MultiCommand & topleve
     std::cout << renderMarkdownToTerminal(markdown) << "\n";
 }
 
+static NixArgs & getNixArgs(Command & cmd)
+{
+    assert(cmd.parent);
+    MultiCommand * toplevel = cmd.parent;
+    while (toplevel->parent) toplevel = toplevel->parent;
+    return dynamic_cast<NixArgs &>(*toplevel);
+}
+
 struct CmdHelp : Command
 {
     std::vector<std::string> subcommand;
@@ -228,17 +255,43 @@ struct CmdHelp : Command
           ;
     }
 
+    Category category() override { return catHelp; }
+
     void run() override
     {
         assert(parent);
         MultiCommand * toplevel = parent;
         while (toplevel->parent) toplevel = toplevel->parent;
-        showHelp(subcommand, *toplevel);
+        showHelp(subcommand, getNixArgs(*this));
     }
 };
 
 static auto rCmdHelp = registerCommand<CmdHelp>("help");
 
+struct CmdHelpStores : Command
+{
+    std::string description() override
+    {
+        return "show help about store types and their settings";
+    }
+
+    std::string doc() override
+    {
+        return
+          #include "help-stores.md"
+          ;
+    }
+
+    Category category() override { return catHelp; }
+
+    void run() override
+    {
+        showHelp({"help-stores"}, getNixArgs(*this));
+    }
+};
+
+static auto rCmdHelpStores = registerCommand<CmdHelpStores>("help-stores");
+
 void mainWrapped(int argc, char * * argv)
 {
     savedArgv = argv;
@@ -290,8 +343,8 @@ void mainWrapped(int argc, char * * argv)
 
     NixArgs args;
 
-    if (argc == 2 && std::string(argv[1]) == "__dump-args") {
-        logger->cout("%s", args.toJSON());
+    if (argc == 2 && std::string(argv[1]) == "__dump-cli") {
+        logger->cout(args.dumpCli());
         return;
     }