C++ guidelins update and cleanup:

docs: Expanded C++ guidelines following suggestions by P. Mackinlay.

ui/inifile.cpp: Got rid of the check for "arcade" systems - it broke
managing favourites for the slotted Neo Geo.

luaengine.cpp: Removed the "type" property from system driver metadata.
It's effectively deprecated.

bus/vme/vme_fcisio.cpp, commodore/mps1230.cpp: Fixed inappropriate use
of machine type flag constants.

megadriv.xml: Made notes about the two Galaxy Force 2 sets more explcit.

docs/source/contributing/cxx.rst

@@ -42,6 +42,23 @@ Llama case:
     capitalised, with no separators between words: ``LlamaCaseSample``
 
 
+.. _contributing-cxx-fileformat:
+
+Source file format
+------------------
+
+MAME C++ source files are encoded as UTF-8 text, assuming fixed-width
+characters, with tab stops at four-space intervals.  Source files should
+end with a terminating end-of-line.  Any valid printable Unicode text is
+permitted in comments.  Outside comments and strings, only the printable
+ASCII subset of Unicode is permitted.
+
+The ``srcclean`` tool is used to enforce file format rules before each
+release.  You can build this tool and apply it to the files you modify
+before opening a pull request to avoid conflicts or surprising changes
+later.
+
+
 .. _contributing-cxx-naming:
 
 Naming conventions
@@ -84,6 +101,18 @@ Template parameters
     Template parameters should use llama case (both type and value
     parameters).
 
+Identifiers containing two consecutive underscores or starting with an
+underscore followed by an uppercase letter are always reserved and
+should not be used.
+
+Type names and other identifiers with a leading underscore should be
+avoided within the global namespace, as they are explicitly reserved
+according to the C++ standard.  Additionally, identifiers suffixed with
+``_t`` should be avoided within the global namespace, as they are also
+reserved according to POSIX standards.  While MAME violates this policy
+occasionally – most notably with ``device_t`` – it’s considered to be an
+unfortunate legacy decision that should be avoided in any new code.
+
 
 .. _contributing-cxx-literals:
 
@@ -109,6 +138,13 @@ the intended use of a given literal at a glance.  Uppercase long integer
 literal suffixes should be used to avoid confusion with the digit 1,
 e.g.  ``7LL`` rather than ``7ll``.
 
+Digit grouping should be used for longer numeric literals, as it aids in
+recognising order of magnitude or bit field positions at a glance.
+Decimal literals should use groups of three digits, and hexadecimal
+literals should use groups of four digits, outside of specific
+situations where different grouping would be easier to understand, e.g.
+``4'433'619`` or ``0xfff8'1fff``.
+
 Types that do not have a specifically defined size should be avoided if
 they are to be registered with MAME’s save-state system, as it harms
 portability.  In general, this means avoiding the use of ``int`` for
@@ -450,6 +486,16 @@ a pull request.
 Structural organization
 -----------------------
 
+All C++ source files must begin with a two comments listing the
+distribution license and copyright holders in a standard format.
+Licenses are specified by their SPDX short identifier if available.
+Here is an example of the standard format:
+
+.. code-block:: C++
+
+    // license:BSD-3-Clause
+    // copyright-holders:David Haywood, Tomasz Slanina
+
 Header includes should generally be grouped from most-dependent to
 least-dependent, and sorted alphabetically within said groups:
 
@@ -491,20 +537,37 @@ follows:
     #define VERBOSE (0)
     #include "logmacro.h"
 
-The class declaration for a machine driver should be within the
+In most cases, the class declaration for a system driver should be
-corresponding source file.  In such cases, the class declaration and all
+within the corresponding source file along with the implementation.  In
-contents of the source file, excluding the ``GAME``, ``COMP``, or
+such cases, the class declaration and all contents of the source file,
-``CONS`` macro, should be enclosed in an anonymous namespace.
+excluding the ``GAME``, ``COMP``, or ``CONS`` macro, should be enclosed
+in an anonymous namespace (this produces better compiler diagnostics,
+allows more aggressive optimisation, reduces the chance of duplicate
+symbols, and reduces linking time).
+
+Within a class declaration, there should be one section for each member
+access level (``public``, ``protected`` and ``private``) if practical.
+This may not be possible in cases where private constants and/or types
+need to be declared before public members.  Members should use the least
+public access level necessary.  Overridden virtual member functions
+should generally use the same access level as the corresponding member
+function in the base class.
+
+Class member declarations should be grouped to aid understanding:
+
+* Within a member access level section, constants, types, data members,
+  instance member functions and static member functions should be
+  grouped.
+* In device classes, configuration member functions should be grouped
+  separately from live signal member functions.
+* Overridden virtual member functions should be grouped according to the
+  base classes they are inherited from.
+
+For classes with multiple overloaded constructors, constructor
+delegation should be used where possible to avoid repeated member
+initialiser lists.
 
 Constants which are used by a device or machine driver should be in the
 form of explicitly-sized enumerated values within the class declaration,
 or be relegated to ``#define`` macros within the source file.  This
 helps avoid polluting the preprocessor.
-
-Type names and other identifiers with a leading underscore should be
-avoided within the global namespace, as they are explicitly reserved
-according to the C++ standard.  Additionally, identifiers suffixed with
-``_t`` should be avoided within the global namespace, as they are also
-reserved according to POSIX standards.  While MAME violates this policy
-occasionally – most notably with ``device_t`` – it’s considered to be an
-unfortunate legacy decision that should be avoided in any new code.

docs/source/techspecs/luareference.rst

@@ -615,10 +615,6 @@ driver.rotation (read-only)
     A string indicating the rotation applied to all screens in the system after
     the screen orientation specified in the machine configuration is applied.
     Will be one of ``"rot0"``, ``"rot90"``, ``"rot180"`` or ``"rot270"``.
-driver.type (read-only)
-    A string providing a system type.  Will be one of ``"arcade"``,
-    ``"console"``, ``"computer"`` or ``"other"``.  This is for informational
-    purposes only, and may not be supported in the future.
 driver.not_working (read-only)
     A Boolean indicating whether the system is marked as not working.
 driver.supports_save (read-only)

hash/megadriv.xml

@@ -3240,7 +3240,7 @@ Crashes after EA logo, requires better [VDP] irq handling
 	</software>
 
 
-<!-- Only Euro is confirmed -->
+	<!-- Only Euro is confirmed - this revision fixes graphical corruption on PAL consoles -->
 	<software name="gforce2">
 		<description>Galaxy Force II (World, rev. B)</description>
 		<year>1991</year>
@@ -16844,7 +16844,7 @@ https://segaretro.org/Feng_Shen_Ying_Jie_Chuan
 		</part>
 	</software>
 
-	<!-- heavy graphical corruption on PAL consoles -->
+	<!-- Heavy graphical corruption on PAL consoles - original game bug, fixed in rev. B (gforce2) -->
 	<software name="gforce2a" cloneof="gforce2">
 		<description>Galaxy Force II (World)</description>
 		<year>1991</year>

src/devices/bus/vme/vme_fcisio.cpp

@@ -461,4 +461,4 @@ uint8_t vme_fcisio1_card_device::config_rd(){
 
 // This info isn't kept in a card driver atm so storing it as a comment for later use
 //      YEAR  NAME           PARENT  COMPAT  MACHINE       INPUT    CLASS             INIT COMPANY                  FULLNAME           FLAGS
-//COMP( 1986, fcisio1,       0,      0,      fcisio1,      fcisio1, driver_device,     0,  "Force Computers Gmbh",  "SYS68K/ISIO-1",   MACHINE_NOT_WORKING | MACHINE_NO_SOUND_HW | MACHINE_TYPE_COMPUTER )
+//COMP( 1986, fcisio1,       0,      0,      fcisio1,      fcisio1, driver_device,     0,  "Force Computers Gmbh",  "SYS68K/ISIO-1",   MACHINE_NOT_WORKING | MACHINE_NO_SOUND_HW )

src/frontend/mame/luaengine.cpp

@@ -1315,29 +1315,6 @@ void lua_engine::initialize()
 				}
 				return rot;
 			});
-	game_driver_type["type"] = sol::property(
-			[] (game_driver const &driver)
-			{
-				// FIXME: this shouldn't be called type - there's potendial for confusion with the device type
-				// also, this should eventually go away in favour of richer flags
-				std::string type;
-				switch (driver.flags & machine_flags::MASK_TYPE)
-				{
-				case machine_flags::TYPE_ARCADE:
-					type = "arcade";
-					break;
-				case machine_flags::TYPE_CONSOLE:
-					type = "console";
-					break;
-				case machine_flags::TYPE_COMPUTER:
-					type = "computer";
-					break;
-				default:
-					type = "other";
-					break;
-				}
-				return type;
-			});
 	game_driver_type["not_working"] = sol::property([] (game_driver const &driver) { return (driver.flags & machine_flags::NOT_WORKING) != 0; });
 	game_driver_type["supports_save"] = sol::property([] (game_driver const &driver) { return (driver.flags & machine_flags::SUPPORTS_SAVE) != 0; });
 	game_driver_type["no_cocktail"] = sol::property([] (game_driver const &driver) { return (driver.flags & machine_flags::NO_COCKTAIL) != 0; });

src/frontend/mame/ui/inifile.cpp

@@ -488,31 +488,23 @@ void favorite_manager::apply_running_machine(running_machine &machine, T &&actio
 {
 	bool done(false);
 
-	// TODO: this should be changed - it interacts poorly with cartslots on arcade systems
+	bool have_software(false);
-	if ((machine.system().flags & machine_flags::MASK_TYPE) == machine_flags::TYPE_ARCADE)
+	for (device_image_interface &image_dev : image_interface_enumerator(machine.root_device()))
 	{
-		action(machine.system(), nullptr, nullptr, done);
+		software_info const *const sw(image_dev.software_entry());
-	}
+		if (image_dev.exists() && image_dev.loaded_through_softlist() && sw)
-	else
-	{
-		bool have_software(false);
-		for (device_image_interface &image_dev : image_interface_enumerator(machine.root_device()))
 		{
-			software_info const *const sw(image_dev.software_entry());
+			assert(image_dev.software_list_name());
-			if (image_dev.exists() && image_dev.loaded_through_softlist() && sw)
-			{
-				assert(image_dev.software_list_name());
 
-				have_software = true;
+			have_software = true;
-				action(machine.system(), &image_dev, sw, done);
+			action(machine.system(), &image_dev, sw, done);
-				if (done)
+			if (done)
-					return;
+				return;
-			}
 		}
-
-		if (!have_software)
-			action(machine.system(), nullptr, nullptr, done);
 	}
+
+	if (!have_software)
+		action(machine.system(), nullptr, nullptr, done);
 }
 
 void favorite_manager::update_sorted()

src/mame/commodore/mps1230.cpp

@@ -173,5 +173,5 @@ ROM_START(mps1230)
 ROM_END
 
 /*    YEAR  NAME     PARENT  COMPAT  MACHINE  INPUT    CLASS          INIT        COMPANY                        FULLNAME */
-COMP( 1986, mps1000, 0,      0,      mps1000, mps1230, mps1230_state, empty_init, "Commodore Business Machines", "MPS-1000 Printer",     MACHINE_NOT_WORKING | MACHINE_NO_SOUND_HW | MACHINE_TYPE_OTHER )
+SYST( 1986, mps1000, 0,      0,      mps1000, mps1230, mps1230_state, empty_init, "Commodore Business Machines", "MPS-1000 Printer",     MACHINE_NOT_WORKING | MACHINE_NO_SOUND_HW )
-COMP( 1988, mps1230, 0,      0,      mps1230, mps1230, mps1230_state, empty_init, "Commodore Business Machines", "MPS-1230 NLQ Printer", MACHINE_NOT_WORKING | MACHINE_NO_SOUND_HW | MACHINE_TYPE_OTHER )
+SYST( 1988, mps1230, 0,      0,      mps1230, mps1230, mps1230_state, empty_init, "Commodore Business Machines", "MPS-1230 NLQ Printer", MACHINE_NOT_WORKING | MACHINE_NO_SOUND_HW )