std main() support

Author: MaxVerevkin

psp/src/lib.rs

@@ -13,6 +13,7 @@
 // For unwinding support
 #![feature(std_internals, panic_info_message, panic_internals, c_unwind)]
 #![cfg_attr(not(feature = "stub-only"), feature(panic_unwind))]
+#![cfg_attr(feature = "std", feature(psp_std))]
 // For the `const_generics` feature.
 #![allow(incomplete_features)]
 #![cfg_attr(not(feature = "std"), no_std)]
@@ -115,6 +116,58 @@ core::arch::global_asm!(
     "#
 );
 
+#[cfg(feature = "std")]
+extern "C" {
+    #[link_name = "main"]
+    #[doc(hidden)]
+    pub fn c_main(argc: isize, argv: *const *const u8) -> isize;
+}
+
+// Because code generated by `module!()` lives in user's crate, cfg attribute cannot be used there.
+// Hence this macro.
+#[cfg(feature = "std")]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! _start {
+    ($_:expr, $argc:expr, $argv:expr) => {
+        unsafe { $crate::c_main($argc as _, $argv as _) as _ }
+    };
+}
+#[cfg(not(feature = "std"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! _start {
+    ($psp_main:expr, $argc:expr, $argv:expr) => {{
+        unsafe fn init_cwd(arg0: *mut u8) {
+            let mut len = 0;
+            while *arg0.add(len) != 0 {
+                len += 1;
+            }
+
+            // Truncate until last '/'
+            while len > 0 && *arg0.add(len - 1) != b'/' {
+                len -= 1;
+            }
+
+            if len > 0 {
+                let tmp = *arg0.add(len);
+                *arg0.add(len) = 0;
+                $crate::sys::sceIoChdir(arg0 as *const u8);
+                *arg0.add(len) = tmp;
+            }
+        }
+
+        if $argc > 0 {
+            unsafe { init_cwd($argv as *mut u8) };
+        }
+
+        // TODO: Maybe print any error to debug screen?
+        let _ = $crate::catch_unwind($psp_main);
+
+        0
+    }};
+}
+
 /// Declare a PSP module.
 ///
 /// You must also define a `fn psp_main() { ... }` function in conjunction with
@@ -177,36 +230,8 @@ macro_rules! module {
 
             #[no_mangle]
             extern "C" fn module_start(argc_bytes: usize, argv: *mut c_void) -> isize {
-                use $crate::sys::ThreadAttributes;
-
-                unsafe fn init_cwd(arg0: *mut u8) {
-                    let mut len = 0;
-                    while *arg0.add(len) != 0 {
-                        len += 1;
-                    }
-
-                    // Truncate until last '/'
-                    while len > 0 && *arg0.add(len - 1) != b'/' {
-                        len -= 1;
-                    }
-
-                    if len > 0 {
-                        let tmp = *arg0.add(len);
-                        *arg0.add(len) = 0;
-                        $crate::sys::sceIoChdir(arg0 as *const u8);
-                        *arg0.add(len) = tmp;
-                    }
-                }
-
-                extern "C" fn main_thread(argc_bytes: usize, argv: *mut c_void) -> i32 {
-                    if argc_bytes > 0 {
-                        unsafe { init_cwd(argv as *mut u8) };
-                    }
-
-                    // TODO: Maybe print any error to debug screen?
-                    let _ = $crate::catch_unwind(super::psp_main);
-
-                    0
+                extern "C" fn main_thread(argc: usize, argv: *mut c_void) -> i32 {
+                    $crate::_start!(super::psp_main, argc, argv)
                 }
 
                 unsafe {
@@ -217,7 +242,7 @@ macro_rules! module {
                         32,
                         // 256kb stack
                         256 * 1024,
-                        ThreadAttributes::USER | ThreadAttributes::VFPU,
+                        $crate::sys::ThreadAttributes::USER | $crate::sys::ThreadAttributes::VFPU,
                         core::ptr::null_mut(),
                     );