Update mGBA usage, stuff it in a macros module

src/macros.rs

@@ -0,0 +1,183 @@
+//! Contains the macros for the crate.
+//!
+//! Because (unlike everything else in Rust) a macro has to be declared before
+//! use, we place them in their own module and then declare that module at the
+//! start of the crate.
+
+/// Assists in defining a newtype wrapper over some base type.
+///
+/// Note that rustdoc and derives are all the "meta" stuff, so you can write all
+/// of your docs and derives in front of your newtype in the same way you would
+/// for a normal struct. Then the inner type to be wrapped it name.
+///
+/// The macro _assumes_ that you'll be using it to wrap numeric types and that
+/// it's safe to have a `0` value, so it automatically provides a `const fn`
+/// method for `new` that just wraps `0`. Also, it derives Debug, Clone, Copy,
+/// Default, PartialEq, and Eq. If all this is not desired you can add `, no
+/// frills` to the invocation.
+///
+/// ```no_run
+/// newtype! {
+///   /// Records a particular key press combination.
+///   KeyInput, u16
+/// }
+/// newtype! {
+///   /// You can't derive most stuff above array size 32, so we add
+///   /// the `, no frills` modifier to this one.
+///   BigArray, [u8; 200], no frills
+/// }
+/// ```
+#[macro_export]
+macro_rules! newtype {
+  ($(#[$attr:meta])* $new_name:ident, $v:vis $old_name:ty) => {
+    $(#[$attr])*
+    #[derive(Debug, Clone, Copy, Default, PartialEq, Eq)]
+    #[repr(transparent)]
+    pub struct $new_name($v $old_name);
+    impl $new_name {
+      /// A `const` "zero value" constructor
+      pub const fn new() -> Self {
+        $new_name(0)
+      }
+    }
+  };
+  ($(#[$attr:meta])* $new_name:ident, $v:vis $old_name:ty, no frills) => {
+    $(#[$attr])*
+    #[repr(transparent)]
+    pub struct $new_name($v $old_name);
+  };
+}
+
+/// Assists in defining a newtype that's an enum.
+///
+/// First give `NewType = OldType,`, then define the tags and their explicit
+/// values with zero or more entries of `TagName = base_value,`. In both cases
+/// you can place doc comments or other attributes directly on to the type
+/// declaration or the tag declaration.
+///
+/// The generated enum will get an appropriate `repr` attribute as well as
+/// Debug, Clone, Copy, PartialEq, and Eq
+///
+/// ```no_run
+/// newtype_enum! {
+///   /// The Foo
+///   Foo = u16,
+///   /// The Bar
+///   Bar = 0,
+///   /// The Zap
+///   Zap = 1,
+/// }
+/// ```
+#[macro_export]
+macro_rules! newtype_enum {
+  (
+    $(#[$struct_attr:meta])*
+    $new_name:ident = $old_name:ident,
+    $($(#[$tag_attr:meta])* $tag_name:ident = $base_value:expr,)*
+  ) => {
+    $(#[$struct_attr])*
+    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+    #[repr($old_name)]
+    pub enum $new_name {
+      $(
+        $(#[$tag_attr])*
+        $tag_name = $base_value,
+      )*
+    }
+  };
+}
+
+/// Delivers a fatal message to the mGBA output, halting emulation.
+///
+/// This works basically like `println`. mGBA is a C program and all, so you
+/// should only attempt to print non-null ASCII values through this. There's
+/// also a maximum length of 255 bytes per message.
+///
+/// This has no effect if you're not using mGBA.
+#[macro_export]
+macro_rules! fatal {
+  ($($arg:tt)*) => {{
+    use $crate::mgba::{MGBADebug, MGBADebugLevel};
+    use core::fmt::Write;
+    if let Some(mut mgba) = MGBADebug::new() {
+      let _ = write!(mgba, $($arg)*);
+      mgba.send(MGBADebugLevel::Fatal);
+    }
+  }};
+}
+
+/// Delivers an error message to the mGBA output.
+///
+/// This works basically like `println`. mGBA is a C program and all, so you
+/// should only attempt to print non-null ASCII values through this. There's
+/// also a maximum length of 255 bytes per message.
+///
+/// This has no effect if you're not using mGBA.
+#[macro_export]
+macro_rules! error {
+  ($($arg:tt)*) => {{
+    use $crate::mgba::{MGBADebug, MGBADebugLevel};
+    use core::fmt::Write;
+    if let Some(mut mgba) = MGBADebug::new() {
+      let _ = write!(mgba, $($arg)*);
+      mgba.send(MGBADebugLevel::Error);
+    }
+  }};
+}
+
+/// Delivers a warning message to the mGBA output.
+///
+/// This works basically like `println`. mGBA is a C program and all, so you
+/// should only attempt to print non-null ASCII values through this. There's
+/// also a maximum length of 255 bytes per message.
+///
+/// This has no effect if you're not using mGBA.
+#[macro_export]
+macro_rules! warn {
+  ($($arg:tt)*) => {{
+    use $crate::mgba::{MGBADebug, MGBADebugLevel};
+    use core::fmt::Write;
+    if let Some(mut mgba) = MGBADebug::new() {
+      let _ = write!(mgba, $($arg)*);
+      mgba.send(MGBADebugLevel::Warning);
+    }
+  }};
+}
+
+/// Delivers an info message to the mGBA output.
+///
+/// This works basically like `println`. mGBA is a C program and all, so you
+/// should only attempt to print non-null ASCII values through this. There's
+/// also a maximum length of 255 bytes per message.
+///
+/// This has no effect if you're not using mGBA.
+#[macro_export]
+macro_rules! info {
+  ($($arg:tt)*) => {{
+    use $crate::mgba::{MGBADebug, MGBADebugLevel};
+    use core::fmt::Write;
+    if let Some(mut mgba) = MGBADebug::new() {
+      let _ = write!(mgba, $($arg)*);
+      mgba.send(MGBADebugLevel::Info);
+    }
+  }};
+}
+
+/// Delivers a debug message to the mGBA output.
+///
+/// This works basically like `println`. mGBA is a C program and all, so you
+/// should only attempt to print non-null ASCII values through this. There's
+/// also a maximum length of 255 bytes per message.
+///
+/// This has no effect if you're not using mGBA.
+#[macro_export]
+macro_rules! debug {
+  ($($arg:tt)*) => {{
+    use $crate::mgba::{MGBADebug, MGBADebugLevel};
+    use core::fmt::Write;
+    if let Some(mut mgba) = MGBADebug::new() {
+      let _ = write!(mgba, $($arg)*);
+      mgba.send(MGBADebugLevel::Debug);
+    }
+  }};
+}

src/mgba.rs

@@ -55,8 +55,6 @@ impl MGBADebug {
   /// it might accidentally be discarded.
   pub fn send(&mut self, level: MGBADebugLevel) {
     if level == MGBADebugLevel::Fatal {
-      Self::SEND_ADDRESS.write(Self::SEND_FLAG | MGBADebugLevel::Error as u16);
-
       // Note(Lokathor): A Fatal send causes the emulator to halt!
       Self::SEND_ADDRESS.write(Self::SEND_FLAG | MGBADebugLevel::Fatal as u16);
     } else {