From c26f1550706f1f674d3040ebb42d2b35d21952ff Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Wed, 28 Dec 2022 17:35:15 +0200
Subject: [PATCH] Allow new component types to be registered at runtime

---
 source/lib/builder.cpp       |  1 -
 source/lib/builder.h         |  4 +++-
 source/lib/sourcepackage.cpp | 12 ++----------
 source/lib/sourcepackage.h   | 23 +++++++++++++++++++++++
 4 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/source/lib/builder.cpp b/source/lib/builder.cpp
index 53b9efb..1535c3e 100644
--- a/source/lib/builder.cpp
+++ b/source/lib/builder.cpp
@@ -20,7 +20,6 @@
 #include "package.h"
 #include "plugin.h"
 #include "sharedlibrary.h"
-#include "sourcepackage.h"
 #include "task.h"
 #include "virtualtarget.h"
 
diff --git a/source/lib/builder.h b/source/lib/builder.h
index 0455637..6dc29f0 100644
--- a/source/lib/builder.h
+++ b/source/lib/builder.h
@@ -12,6 +12,7 @@
 #include "config.h"
 #include "logger.h"
 #include "packagemanager.h"
+#include "sourcepackage.h"
 #include "target.h"
 #include "toolchain.h"
 #include "virtualfilesystem.h"
@@ -19,7 +20,6 @@
 class FileTarget;
 class Package;
 class Plugin;
-class SourcePackage;
 
 /**
 This class ties everything else together.  It also contains code for loading
@@ -59,6 +59,7 @@ private:
 
 	std::vector<LoadedPlugin> plugins;
 	PackageManager package_manager;
+	SourcePackage::ComponentRegistry component_registry;
 
 	Architecture native_arch;
 	Architecture *current_arch = 0;
@@ -82,6 +83,7 @@ public:
 
 	void load_plugins();
 	PackageManager &get_package_manager() { return package_manager; }
+	SourcePackage::ComponentRegistry &get_component_registry() { return component_registry; }
 
 	template<typename F>
 	void call_plugins(F) const;
diff --git a/source/lib/sourcepackage.cpp b/source/lib/sourcepackage.cpp
index dfbf16e..6261d2c 100644
--- a/source/lib/sourcepackage.cpp
+++ b/source/lib/sourcepackage.cpp
@@ -170,6 +170,8 @@ SourcePackage::Loader::Loader(SourcePackage &p, const Config::InputOptions *o):
 	add("source_tarball", &Loader::source_archive);
 	add("tarball",     &Loader::tarball);
 	add("version",     &Loader::version);
+
+	p.builder.get_component_registry().invoke_all(*this);
 }
 
 void SourcePackage::Loader::finish()
@@ -200,16 +202,6 @@ void SourcePackage::Loader::feature(const string &n, const string &d)
 	}
 }
 
-template<typename C, typename... Args>
-void SourcePackage::Loader::component(Args... args, const string &n)
-{
-	if(any_of(obj.components.begin(), obj.components.end(), [&n](const Component *c){ return c->get_name()==n; }))
-		throw key_error(n);
-	C *comp = new C(obj, n, args...);
-	load_sub(*comp);
-	obj.components.push_back(comp);
-}
-
 void SourcePackage::Loader::build_info()
 {
 	load_sub(obj.build_info);
diff --git a/source/lib/sourcepackage.h b/source/lib/sourcepackage.h
index d37ecf4..2c2e57c 100644
--- a/source/lib/sourcepackage.h
+++ b/source/lib/sourcepackage.h
@@ -1,8 +1,10 @@
 #ifndef SOURCEPACKAGE_H_
 #define SOURCEPACKAGE_H_
 
+#include <algorithm>
 #include <stdexcept>
 #include <string>
+#include <msp/core/typeregistry.h>
 #include "buildinfo.h"
 #include "cache.h"
 #include "component.h"
@@ -25,7 +27,15 @@ class SourcePackage: public Package
 public:
 	class Loader: public Msp::DataFile::DerivedObjectLoader<SourcePackage, Package::Loader>, public FeatureConditional
 	{
+		friend class SourcePackage;
+
 	private:
+		template<typename T>
+		struct AddComponent
+		{
+			void operator()(const std::string &n, Loader &l) const { l.add(n, &Loader::component<T>); }
+		};
+
 		const Config::InputOptions *options;
 
 	public:
@@ -44,6 +54,8 @@ public:
 		void version(const std::string &);
 	};
 
+	using ComponentRegistry = Msp::TypeRegistry<Loader::AddComponent, Loader &>;
+
 private:
 	std::string version;
 	std::string interface_version;
@@ -88,4 +100,15 @@ private:
 	void save_caches() override;
 };
 
+
+template<typename C, typename... Args>
+void SourcePackage::Loader::component(Args... args, const std::string &n)
+{
+	if(std::any_of(obj.components.begin(), obj.components.end(), [&n](const Component *c){ return c->get_name()==n; }))
+		throw Msp::key_error(n);
+	C *comp = new C(obj, n, args...);
+	load_sub(*comp);
+	obj.components.push_back(comp);
+}
+
 #endif
-- 
2.43.0