support static libretro

Cargo.toml

@@ -20,3 +20,6 @@ itertools = "0.10"
 rand = "0.8"
 rand_xoshiro = "0.6"
 regex = "1.5"
+
+[features]
+static = ["ferretro_components/static"]

lib/README.txt

@@ -0,0 +1 @@
+put "libretro.a" here if you wish to compile with the "static" feature.

src/main.rs

@@ -37,11 +37,11 @@ mod gui;
 
 #[derive(StructOpt)]
 struct Opt {
-    /// Core module to use.
+    /// Core module to use. If not provided, falls back to statically-linked core.
     #[structopt(short, long, parse(from_os_str))]
-    core: PathBuf,
+    core: Option<PathBuf>,
     /// ROM to load using the core.
-    #[structopt(short, long, parse(from_os_str))]
+    #[structopt(parse(from_os_str))]
     rom: PathBuf,
     /// System directory, often containing BIOS files
     #[structopt(short, long, parse(from_os_str))]
@@ -65,7 +65,11 @@ struct Zretro {
 
 impl Zretro {
     fn new(opt: Opt) -> Result<Self> {
-        let mut emu = RetroComponentBase::new(&opt.core);
+        let mut emu = match &opt.core {
+            Some(core_path) => RetroComponentBase::new(core_path),
+            None if cfg!(feature = "static") => RetroComponentBase::new_static(),
+            _ => panic!("--core is required when frontend is not built with the 'static' feature."),
+        };
 
         let sys_info = emu.libretro_core().get_system_info();
         let title = format!(
@@ -83,7 +87,7 @@ impl Zretro {
 
         emu.register_component(PathBufComponent {
             sys_path: opt.system.clone(),
-            libretro_path: Some(opt.core.to_path_buf()),
+            libretro_path: opt.core.clone(),
             core_assets_path: None,
             save_path: Some(std::env::temp_dir()),
         })?;