Fix issue with allocating game objects on CoW memory

Author: fwsGonzo

engine/src/main.cpp

@@ -32,20 +32,20 @@ int main()
 
 	/* The event_loop function can be resumed later, and can execute work
 	   that has been preemptively handed to it from other machines. */
-	auto events = Script("events", "scripts/gameplay.elf", debug);
+	Script events("events", "scripts/gameplay.elf", debug);
 	/* A VM function call. The function is looked up in the symbol table
 	   of the program binary. Without an entry in the table, we cannot
 	   know the address of the function, even if it exists in the code. */
 	assert(events.address_of("event_loop") != 0x0);
 	events.call("event_loop");
 
 	/* Create the gameplay machine by cloning 'events' (same binary, but new instance) */
-	auto gameplay = events.clone("gameplay");
+	Script gameplay = events.clone("gameplay");
 
 	/* This is the main start function, which would be something like the
 	   starting function for the current levels script. You can find the
 	   implementation in scripts/src/level1.cpp. */
-	auto level1 = Script("level1", "scripts/level1.elf", debug);
+	Script level1("level1", "scripts/level1.elf", debug);
 	/* level1 make remote calls to the gameplay program. */
 	level1.setup_remote_calls_to(gameplay);
 
@@ -55,7 +55,7 @@ int main()
 	}
 
 	/* Use strict remote calls for level2 */
-	auto level2 = Script("level2", "scripts/level2.elf", debug);
+	Script level2("level2", "scripts/level2.elf", debug);
 	/* level2 can make remote calls to the gameplay program. */
 	level2.setup_strict_remote_calls_to(gameplay);
 	/* Allow calling *only* this function remotely, when in strict mode */
@@ -142,15 +142,18 @@ int main()
 		"Calling '", gameplay.symbol_name(obj.onDeath), "' in '",
 		gameplay.name(), "' for object at 0x",
 		strf::hex(guest_objs.address(0)), "\n");
-	assert(obj.alive == true);
 	gameplay.call(obj.onDeath, guest_objs.address(0));
 	assert(obj.alive == false);
 
 	/* Guest-allocated objects can be moved */
-	auto other_guest_objs		 = std::move(guest_objs);
-	other_guest_objs.at(0).alive = true;
-	gameplay.call(other_guest_objs.at(0).onDeath, other_guest_objs.address(0));
-	assert(other_guest_objs.at(0).alive == false);
+	auto other_guest_objs	 = std::move(guest_objs);
+
+	GameObject& other_object = other_guest_objs.at(0);
+	other_object.alive   = true;
+	other_object.name	 = "otherobject";
+	other_object.onDeath = gameplay.address_of("myobject_death");
+	gameplay.call(other_object.onDeath, other_guest_objs.address(0));
+	assert(other_object.alive == false);
 
 	strf::to(stdout)("...\n");
 

engine/src/script/script.cpp

@@ -152,7 +152,6 @@ void Script::machine_setup()
 		const machine_t&, const char* p, size_t len) {
 		strf::to(stdout)(std::string_view {p, len});
 	});
-	machine().set_debug_printer(machine().get_printer());
 	machine().on_unhandled_csr = [](machine_t& machine, int csr, int, int)
 	{
 		auto& script = *machine.template get_userdata<Script>();

engine/src/script/script.hpp

@@ -545,7 +545,10 @@ template <typename T> inline GuestObjects<T> Script::guest_alloc(size_t n)
 	auto addr = this->guest_alloc_sequential(sizeof(T) * n);
 	if (addr != 0x0)
 	{
-		auto view = machine().memory.rvspan<T>(addr, n);
+		// Gather single writable buffer, making sure memory is not copy-on-write
+		std::array<riscv::vBuffer, 1> buf;
+		machine().memory.gather_writable_buffers_from_range(1, buf.data(), addr, sizeof(T) * n);
+		std::span<T> view(reinterpret_cast<T*>(buf[0].ptr), n);
 		// Default-initialize all objects
 		for (auto& o : view) o = T{};
 		// Note: this can fail and throw, but we don't care

ext/libriscv

@@ -1,19 +1,5 @@
-# We prefer a custom-built Newlib compiler (due to small binaries)
-if command -v "riscv64-unknown-elf-g++" &> /dev/null; then
-	echo "* Building game scripts with Newlib RISC-V compiler"
-	GCC_TRIPLE="riscv64-unknown-elf"
-	export CXX="ccache $GCC_TRIPLE-g++"
-	export CEXT="OFF"
-
-# Then, second a custom-built Linux compiler
-elif command -v "riscv64-unknown-linux-gnu-g++" &> /dev/null; then
-	echo "* Building game scripts with custom GCC/glibc compiler"
-	GCC_TRIPLE="riscv64-unknown-linux-gnu"
-	export CXX="ccache $GCC_TRIPLE-g++"
-	export CEXT="OFF"
-
 # System-provided GCC variants
-elif command -v "riscv64-linux-gnu-g++-13" &> /dev/null; then
+if command -v "riscv64-linux-gnu-g++-13" &> /dev/null; then
 	echo "* Building game scripts with system GCC/glibc compiler"
 	GCC_TRIPLE="riscv64-linux-gnu"
 	export CXX="ccache $GCC_TRIPLE-g++-13"

programs/detect_compiler.sh

@@ -43,7 +43,7 @@ inline void expect_check(
 
 #define EXPECT(expr)                                                          \
 	api::expect_check(                                                        \
-		[&]                                                                   \
+		[&] () -> bool                                                        \
 		{                                                                     \
 			return (expr);                                                    \
 		},                                                                    \