Merge pull request #11014 from obsidiansystems/plugins-libmain

Move plugins infra to `libnixmain`

src/libstore/daemon.cc

@@ -246,10 +246,9 @@ struct ClientSettings
                     // the daemon, as that could cause some pretty weird stuff
                     if (parseFeatures(tokenizeString<StringSet>(value)) != experimentalFeatureSettings.experimentalFeatures.get())
                         debug("Ignoring the client-specified experimental features");
-                } else if (name == settings.pluginFiles.name) {
-                    if (tokenizeString<Paths>(value) != settings.pluginFiles.get())
-                        warn("Ignoring the client-specified plugin-files.\n"
-                             "The client specifying plugins to the daemon never made sense, and was removed in Nix >=2.14.");
+                } else if (name == "plugin-files") {
+                    warn("Ignoring the client-specified plugin-files.\n"
+                         "The client specifying plugins to the daemon never made sense, and was removed in Nix >=2.14.");
                 }
                 else if (trusted
                     || name == settings.buildTimeout.name

src/libstore/globals.cc

@@ -15,7 +15,6 @@
 #include <nlohmann/json.hpp>
 
 #ifndef _WIN32
-# include <dlfcn.h>
 # include <sys/utsname.h>
 #endif
 
@@ -335,60 +334,6 @@ unsigned int MaxBuildJobsSetting::parse(const std::string & str) const
 }
 
 
-Paths PluginFilesSetting::parse(const std::string & str) const
-{
-    if (pluginsLoaded)
-        throw UsageError("plugin-files set after plugins were loaded, you may need to move the flag before the subcommand");
-    return BaseSetting<Paths>::parse(str);
-}
-
-
-void initPlugins()
-{
-    assert(!settings.pluginFiles.pluginsLoaded);
-    for (const auto & pluginFile : settings.pluginFiles.get()) {
-        std::vector<std::filesystem::path> pluginFiles;
-        try {
-            auto ents = std::filesystem::directory_iterator{pluginFile};
-            for (const auto & ent : ents) {
-                checkInterrupt();
-                pluginFiles.emplace_back(ent.path());
-            }
-        } catch (std::filesystem::filesystem_error & e) {
-            if (e.code() != std::errc::not_a_directory)
-                throw;
-            pluginFiles.emplace_back(pluginFile);
-        }
-        for (const auto & file : pluginFiles) {
-            checkInterrupt();
-            /* handle is purposefully leaked as there may be state in the
-               DSO needed by the action of the plugin. */
-#ifndef _WIN32 // TODO implement via DLL loading on Windows
-            void *handle =
-                dlopen(file.c_str(), RTLD_LAZY | RTLD_LOCAL);
-            if (!handle)
-                throw Error("could not dynamically open plugin file '%s': %s", file, dlerror());
-
-            /* Older plugins use a statically initialized object to run their code.
-               Newer plugins can also export nix_plugin_entry() */
-            void (*nix_plugin_entry)() = (void (*)())dlsym(handle, "nix_plugin_entry");
-            if (nix_plugin_entry)
-                nix_plugin_entry();
-#else
-                throw Error("could not dynamically open plugin file '%s'", file);
-#endif
-        }
-    }
-
-    /* Since plugins can add settings, try to re-apply previously
-       unknown settings. */
-    globalConfig.reapplyUnknownSettings();
-    globalConfig.warnUnknownSettings();
-
-    /* Tell the user if they try to set plugin-files after we've already loaded */
-    settings.pluginFiles.pluginsLoaded = true;
-}
-
 static void preloadNSS()
 {
     /* builtin:fetchurl can trigger a DNS lookup, which with glibc can trigger a dynamic library load of

src/libstore/globals.hh

@@ -31,23 +31,6 @@ struct MaxBuildJobsSetting : public BaseSetting<unsigned int>
     unsigned int parse(const std::string & str) const override;
 };
 
-struct PluginFilesSetting : public BaseSetting<Paths>
-{
-    bool pluginsLoaded = false;
-
-    PluginFilesSetting(Config * options,
-        const Paths & def,
-        const std::string & name,
-        const std::string & description,
-        const std::set<std::string> & aliases = {})
-        : BaseSetting<Paths>(def, true, name, description, aliases)
-    {
-        options->addSetting(this);
-    }
-
-    Paths parse(const std::string & str) const override;
-};
-
 const uint32_t maxIdsPerBuild =
     #if __linux__
     1 << 16
@@ -1158,33 +1141,6 @@ public:
     Setting<uint64_t> minFreeCheckInterval{this, 5, "min-free-check-interval",
         "Number of seconds between checking free disk space."};
 
-    PluginFilesSetting pluginFiles{
-        this, {}, "plugin-files",
-        R"(
-          A list of plugin files to be loaded by Nix. Each of these files will
-          be dlopened by Nix. If they contain the symbol `nix_plugin_entry()`,
-          this symbol will be called. Alternatively, they can affect execution
-          through static initialization. In particular, these plugins may construct
-          static instances of RegisterPrimOp to add new primops or constants to the
-          expression language, RegisterStoreImplementation to add new store
-          implementations, RegisterCommand to add new subcommands to the `nix`
-          command, and RegisterSetting to add new nix config settings. See the
-          constructors for those types for more details.
-
-          Warning! These APIs are inherently unstable and may change from
-          release to release.
-
-          Since these files are loaded into the same address space as Nix
-          itself, they must be DSOs compatible with the instance of Nix
-          running at the time (i.e. compiled against the same headers, not
-          linked to any incompatible libraries). They should not be linked to
-          any Nix libs directly, as those will be available already at load
-          time.
-
-          If an entry in the list is a directory, all files in the directory
-          are loaded as plugins (non-recursively).
-        )"};
-
     Setting<size_t> narBufferSize{this, 32 * 1024 * 1024, "nar-buffer-size",
         "Maximum size of NARs before spilling them to disk."};
 
@@ -1278,12 +1234,6 @@ public:
 // FIXME: don't use a global variable.
 extern Settings settings;
 
-/**
- * This should be called after settings are initialized, but before
- * anything else
- */
-void initPlugins();
-
 /**
  * Load the configuration (from `nix.conf`, `NIX_CONFIG`, etc.) into the
  * given configuration object.

src/libstore/remote-store.cc

@@ -128,7 +128,7 @@ void RemoteStore::setOptions(Connection & conn)
         overrides.erase(settings.useSubstitutes.name);
         overrides.erase(loggerSettings.showTrace.name);
         overrides.erase(experimentalFeatureSettings.experimentalFeatures.name);
-        overrides.erase(settings.pluginFiles.name);
+        overrides.erase("plugin-files");
         conn.to << overrides.size();
         for (auto & i : overrides)
             conn.to << i.first << i.second.value;