core: Add Log backend, for capturing trace output specific to a movie

core/src/avm1/activation.rs

@@ -2056,6 +2056,7 @@ impl<'a, 'gc, 'gc_context> Activation<'a, 'gc, 'gc_context> {
         } else {
             val.coerce_to_string(self)?
         };
+        self.context.log.avm_trace(&out);
         log::info!(target: "avm_trace", "{}", out);
         Ok(FrameControl::Continue)
     }

core/src/avm1/object/script_object.rs

@@ -847,6 +847,7 @@ mod tests {
     use crate::backend::audio::NullAudioBackend;
     use crate::backend::input::NullInputBackend;
     use crate::backend::locale::NullLocaleBackend;
+    use crate::backend::log::NullLogBackend;
     use crate::backend::navigator::NullNavigatorBackend;
     use crate::backend::render::NullRenderer;
     use crate::backend::storage::MemoryStorageBackend;
@@ -897,6 +898,7 @@ mod tests {
                 navigator: &mut NullNavigatorBackend::new(),
                 renderer: &mut NullRenderer::new(),
                 locale: &mut NullLocaleBackend::new(),
+                log: &mut NullLogBackend::new(),
                 system_prototypes: avm1.prototypes().clone(),
                 mouse_hovered_object: None,
                 mouse_position: &(Twips::new(0), Twips::new(0)),

core/src/avm1/test_utils.rs

@@ -6,6 +6,7 @@ use crate::avm2::Avm2;
 use crate::backend::audio::NullAudioBackend;
 use crate::backend::input::NullInputBackend;
 use crate::backend::locale::NullLocaleBackend;
+use crate::backend::log::NullLogBackend;
 use crate::backend::navigator::NullNavigatorBackend;
 use crate::backend::render::NullRenderer;
 use crate::backend::storage::MemoryStorageBackend;
@@ -58,6 +59,7 @@ where
             navigator: &mut NullNavigatorBackend::new(),
             renderer: &mut NullRenderer::new(),
             locale: &mut NullLocaleBackend::new(),
+            log: &mut NullLogBackend::new(),
             system_prototypes: avm1.prototypes().clone(),
             mouse_hovered_object: None,
             mouse_position: &(Twips::new(0), Twips::new(0)),

core/src/backend.rs

@@ -1,6 +1,7 @@
 pub mod audio;
 pub mod input;
 pub mod locale;
+pub mod log;
 pub mod navigator;
 pub mod render;
 pub mod storage;

core/src/backend/log.rs

@@ -0,0 +1,22 @@
+pub trait LogBackend {
+    fn avm_trace(&self, message: &str);
+}
+
+/// Logging backend that does nothing.
+pub struct NullLogBackend {}
+
+impl NullLogBackend {
+    pub fn new() -> Self {
+        Self {}
+    }
+}
+
+impl LogBackend for NullLogBackend {
+    fn avm_trace(&self, _message: &str) {}
+}
+
+impl Default for NullLogBackend {
+    fn default() -> Self {
+        NullLogBackend::new()
+    }
+}

core/src/context.rs

@@ -6,6 +6,7 @@ use crate::avm1::{Avm1, Object, Timers, Value};
 use crate::avm2::Avm2;
 use crate::backend::input::InputBackend;
 use crate::backend::locale::LocaleBackend;
+use crate::backend::log::LogBackend;
 use crate::backend::storage::StorageBackend;
 use crate::backend::{audio::AudioBackend, navigator::NavigatorBackend, render::RenderBackend};
 use crate::display_object::EditText;
@@ -72,6 +73,9 @@ pub struct UpdateContext<'a, 'gc, 'gc_context> {
     /// The locale backend, used for localisation and personalisation
     pub locale: &'a mut dyn LocaleBackend,
 
+    /// The logging backend, used for trace output capturing
+    pub log: &'a mut dyn LogBackend,
+
     /// The RNG, used by the AVM `RandomNumber` opcode,  `Math.random(),` and `random()`.
     pub rng: &'a mut SmallRng,
 
@@ -185,6 +189,7 @@ impl<'a, 'gc, 'gc_context> UpdateContext<'a, 'gc, 'gc_context> {
             navigator: self.navigator,
             renderer: self.renderer,
             locale: self.locale,
+            log: self.log,
             input: self.input,
             storage: self.storage,
             rng: self.rng,

core/src/player.rs

@@ -8,7 +8,9 @@ use crate::backend::input::{InputBackend, MouseCursor};
 use crate::backend::locale::LocaleBackend;
 use crate::backend::navigator::{NavigatorBackend, RequestOptions};
 use crate::backend::storage::StorageBackend;
-use crate::backend::{audio::AudioBackend, render::Letterbox, render::RenderBackend};
+use crate::backend::{
+    audio::AudioBackend, log::LogBackend, render::Letterbox, render::RenderBackend,
+};
 use crate::context::{ActionQueue, ActionType, RenderContext, UpdateContext};
 use crate::display_object::{EditText, MorphShape, MovieClip};
 use crate::events::{ButtonKeyCode, ClipEvent, ClipEventResult, KeyCode, PlayerEvent};
@@ -123,6 +125,7 @@ type Renderer = Box<dyn RenderBackend>;
 type Input = Box<dyn InputBackend>;
 type Storage = Box<dyn StorageBackend>;
 type Locale = Box<dyn LocaleBackend>;
+type Log = Box<dyn LogBackend>;
 
 pub struct Player {
     /// The version of the player we're emulating.
@@ -147,6 +150,7 @@ pub struct Player {
     pub navigator: Navigator,
     input: Input,
     locale: Locale,
+    log: Log,
     transform_stack: TransformStack,
     view_matrix: Matrix,
     inverse_view_matrix: Matrix,
@@ -197,6 +201,7 @@ impl Player {
         input: Input,
         storage: Storage,
         locale: Locale,
+        log: Log,
     ) -> Result<Arc<Mutex<Self>>, Error> {
         let fake_movie = Arc::new(SwfMovie::empty(NEWEST_PLAYER_VERSION));
         let movie_width = 550;
@@ -261,6 +266,7 @@ impl Player {
             navigator,
             input,
             locale,
+            log,
             self_reference: None,
             system: SystemProperties::default(),
             instance_counter: 0,
@@ -1022,6 +1028,7 @@ impl Player {
             instance_counter,
             storage,
             locale,
+            logging,
             needs_render,
         ) = (
             self.player_version,
@@ -1040,6 +1047,7 @@ impl Player {
             &mut self.instance_counter,
             self.storage.deref_mut(),
             self.locale.deref_mut(),
+            self.log.deref_mut(),
             &mut self.needs_render,
         );
 
@@ -1084,6 +1092,7 @@ impl Player {
                 instance_counter,
                 storage,
                 locale,
+                log: logging,
                 shared_objects,
                 unbound_text_fields,
                 timers,

core/tests/regression_tests.rs

@@ -5,6 +5,7 @@
 use approx::assert_abs_diff_eq;
 use log::{Metadata, Record};
 use ruffle_core::backend::locale::NullLocaleBackend;
+use ruffle_core::backend::log::NullLogBackend;
 use ruffle_core::backend::navigator::{NullExecutor, NullNavigatorBackend};
 use ruffle_core::backend::storage::MemoryStorageBackend;
 use ruffle_core::backend::{
@@ -521,6 +522,7 @@ fn run_swf(
         Box::new(NullInputBackend::new()),
         Box::new(MemoryStorageBackend::default()),
         Box::new(NullLocaleBackend::new()),
+        Box::new(NullLogBackend::new()),
     )?;
     player.lock().unwrap().set_root_movie(Arc::new(movie));
 

desktop/src/main.rs

@@ -22,6 +22,7 @@ use std::sync::Arc;
 use std::time::Instant;
 
 use crate::storage::DiskStorageBackend;
+use ruffle_core::backend::log::NullLogBackend;
 use ruffle_core::tag_utils::SwfMovie;
 use std::rc::Rc;
 use winit::dpi::{LogicalSize, PhysicalPosition};
@@ -168,7 +169,15 @@ fn run_player(
         input_path.file_name().unwrap_or_default().as_ref(),
     ));
     let locale = Box::new(locale::DesktopLocaleBackend::new());
-    let player = Player::new(renderer, audio, navigator, input, storage, locale)?;
+    let player = Player::new(
+        renderer,
+        audio,
+        navigator,
+        input,
+        storage,
+        locale,
+        Box::new(NullLogBackend::new()),
+    )?;
     player.lock().unwrap().set_root_movie(Arc::new(movie));
     player.lock().unwrap().set_is_playing(true); // Desktop player will auto-play.
 

exporter/src/main.rs

@@ -5,6 +5,7 @@ use indicatif::{ProgressBar, ProgressStyle};
 use ruffle_core::backend::audio::NullAudioBackend;
 use ruffle_core::backend::input::NullInputBackend;
 use ruffle_core::backend::locale::NullLocaleBackend;
+use ruffle_core::backend::log::NullLogBackend;
 use ruffle_core::backend::navigator::NullNavigatorBackend;
 use ruffle_core::backend::storage::MemoryStorageBackend;
 use ruffle_core::tag_utils::SwfMovie;
@@ -89,6 +90,7 @@ fn take_screenshot(
         Box::new(NullInputBackend::new()),
         Box::new(MemoryStorageBackend::default()),
         Box::new(NullLocaleBackend::new()),
+        Box::new(NullLogBackend::new()),
     )?;
 
     player

web/src/lib.rs

@@ -14,6 +14,7 @@ use crate::{
 };
 use generational_arena::{Arena, Index};
 use js_sys::{Array, Function, Object, Uint8Array};
+use ruffle_core::backend::log::NullLogBackend;
 use ruffle_core::backend::render::RenderBackend;
 use ruffle_core::backend::storage::MemoryStorageBackend;
 use ruffle_core::backend::storage::StorageBackend;
@@ -231,8 +232,17 @@ impl Ruffle {
             })
             .unwrap_or_else(|| Box::new(MemoryStorageBackend::default()));
 
-        let core =
-            ruffle_core::Player::new(renderer, audio, navigator, input, local_storage, locale)?;
+        let log = Box::new(NullLogBackend::new());
+
+        let core = ruffle_core::Player::new(
+            renderer,
+            audio,
+            navigator,
+            input,
+            local_storage,
+            locale,
+            log,
+        )?;
 
         // Create instance.
         let instance = RuffleInstance {