Configuration: Split options into global and per-module configuration

include/common/mir/shared_library.h

@@ -17,6 +17,7 @@
 #ifndef MIR_SHARED_LIBRARY_H_
 #define MIR_SHARED_LIBRARY_H_
 
+#include <compare>
 #include <string>
 
 namespace mir
@@ -49,6 +50,22 @@ class SharedLibrary
         (void*&)result = load_symbol(function_name.c_str(), version.c_str());
         return result;
     }
+
+    class Handle
+    {
+    public:
+        auto operator<=>(Handle const& rhs) const -> std::strong_ordering;
+        auto operator==(Handle const& rhs) const -> bool = default;
+        auto operator!=(Handle const& rhs) const -> bool = default;
+    private:
+        friend class SharedLibrary;
+        friend struct std::hash<Handle>;
+
+        Handle(void* handle);
+        void* handle;
+    };
+
+    auto get_handle() const -> Handle;
 private:
     void* const so;
     void* load_symbol(char const* function_name) const;
@@ -58,5 +75,10 @@ class SharedLibrary
 };
 }
 
+template<>
+struct std::hash<mir::SharedLibrary::Handle>
+{
+    auto operator()(mir::SharedLibrary::Handle const& h) const noexcept -> std::size_t;
+};
 
 #endif /* MIR_SHARED_LIBRARY_H_ */

include/platform/mir/options/configuration.h

@@ -23,6 +23,8 @@
 
 namespace mir
 {
+class SharedLibrary;
+
 namespace options
 {
 extern char const* const arw_server_socket_opt;
@@ -69,12 +71,19 @@ extern char const* const vt_option_name;
 class Configuration
 {
 public:
-    virtual std::shared_ptr<options::Option> the_options() const = 0;
+    /**
+     * The options not associated with a specific loaded module
+     */
+    virtual std::shared_ptr<options::Option> global_options() const = 0;
+    /**
+     * All options, including those added by the specified module
+     */
+    virtual auto options_for(SharedLibrary const& module) const -> std::shared_ptr<options::Option> = 0;
 
 protected:
-
     Configuration() = default;
     virtual ~Configuration() = default;
+
     Configuration(Configuration const&) = delete;
     Configuration& operator=(Configuration const&) = delete;
 };

include/platform/mir/options/default_configuration.h

@@ -19,12 +19,13 @@
 
 #include "mir/options/configuration.h"
 #include "mir/options/program_option.h"
+#include "mir/shared_library.h"
 #include <boost/program_options/options_description.hpp>
 #include <vector>
+#include <unordered_map>
 
 namespace mir
 {
-class SharedLibrary;
 namespace options
 {
 class DefaultConfiguration : public Configuration
@@ -54,7 +55,8 @@ class DefaultConfiguration : public Configuration
 
     void add_platform_options();
     // accessed via the base interface, when access to add_options() has been "lost"
-    std::shared_ptr<options::Option> the_options() const override;
+    std::shared_ptr<options::Option> global_options() const override;
+    auto options_for(SharedLibrary const& module) const -> std::shared_ptr<Option> override;
 
     virtual void parse_arguments(
         boost::program_options::options_description desc,
@@ -74,6 +76,9 @@ class DefaultConfiguration : public Configuration
     char const** const argv;
     std::function<void(int argc, char const* const* argv)> const unparsed_arguments_handler;
     std::shared_ptr<boost::program_options::options_description> const program_options;
+
+    std::unordered_map<SharedLibrary::Handle, boost::program_options::options_description> module_options_desc;
+    std::unordered_map<SharedLibrary::Handle, std::shared_ptr<Option>> mutable module_options;
     std::shared_ptr<Option> mutable options;
 };
 }

include/platform/mir/options/program_option.h

@@ -39,7 +39,7 @@ class ProgramOption : public Option
 
     void parse_environment(
         boost::program_options::options_description const& description,
-        char const* prefix);
+        std::function<std::string(std::string)> env_var_name_mapper);
 
     void parse_file(
         boost::program_options::options_description const& description,

src/common/sharedlibrary/shared_library.cpp

@@ -15,6 +15,8 @@
  */
 
 #include "mir/shared_library.h"
+#include <compare>
+#include <cstddef>
 
 #ifdef MIR_DONT_USE_DLVSYM
 #include <mir/log.h>
@@ -74,3 +76,24 @@ void* mir::SharedLibrary::load_symbol(char const* function_name, char const* ver
     }
 #endif
 }
+
+auto mir::SharedLibrary::get_handle() const -> Handle
+{
+    return Handle{so};
+}
+
+mir::SharedLibrary::Handle::Handle(void* handle)
+    : handle{handle}
+{
+}
+
+auto mir::SharedLibrary::Handle::operator<=>(Handle const& rhs) const -> std::strong_ordering
+{
+    return handle <=> rhs.handle;
+}
+
+auto std::hash<mir::SharedLibrary::Handle>::operator()(mir::SharedLibrary::Handle const& handle) const noexcept
+    -> std::size_t
+{
+    return std::hash<void*>{}(handle.handle);
+}

src/common/symbols.map

@@ -485,6 +485,7 @@ global:
     non-virtual?thunk?to?mir::logging::Logger::log*;
     non-virtual?thunk?to?mir::logging::MultiLogger::log*;
     operator*;
+    std::hash?mir::SharedLibrary::Handle?::operator*;
     typeinfo?for?MirInputConfig;
     typeinfo?for?MirInputDevice;
     typeinfo?for?MirKeyboardConfig;
@@ -499,6 +500,7 @@ global:
     typeinfo?for?mir::IntOwnedFd;
     typeinfo?for?mir::NonBlockingExecutor;
     typeinfo?for?mir::PosixRWMutex;
+    typeinfo?for?mir::SharedLibrary::Handle;
     typeinfo?for?mir::SharedLibrary;
     typeinfo?for?mir::SharedLibraryProberReport;
     typeinfo?for?mir::Signal;
@@ -695,4 +697,12 @@ MIR_COMMON_2.18 {
     MirTouchpadConfig::disable_with_external_mouse*;
     mir::event_type_to_c_str*;
   };
-} MIR_COMMON_2.17;
+} MIR_COMMON_2.17;
+
+MIR_COMMON_2.19 {
+  global: extern "C++" {
+    mir::SharedLibrary::Handle::?Handle*;
+    mir::SharedLibrary::Handle::operator*;
+    mir::SharedLibrary::get_handle*;
+  };
+} MIR_COMMON_2.18;

src/include/server/mir/default_server_configuration.h

@@ -17,6 +17,7 @@
 #define MIR_DEFAULT_SERVER_CONFIGURATION_H_
 
 #include "mir/cached_ptr.h"
+#include "mir/options/option.h"
 #include "mir/server_configuration.h"
 #include "mir/shell/window_manager_builder.h"
 
@@ -347,6 +348,7 @@ class DefaultServerConfiguration : public virtual ServerConfiguration
 
 protected:
     std::shared_ptr<options::Option> the_options() const;
+    auto the_options_provider() const -> std::shared_ptr<options::Configuration>;
     std::shared_ptr<input::DefaultInputDeviceHub>  the_default_input_device_hub();
     std::shared_ptr<graphics::DisplayConfigurationObserver> the_display_configuration_observer();
     std::shared_ptr<input::SeatObserver> the_seat_observer();