Space efficient panic

Author: LucasSte

Cargo.lock

@@ -31,6 +31,7 @@ define_syscall!(fn sol_remaining_compute_units() -> u64);
 define_syscall!(fn sol_alt_bn128_compression(op: u64, input: *const u8, input_size: u64, result: *mut u8) -> u64);
 define_syscall!(fn sol_get_sysvar(sysvar_id_addr: *const u8, result: *mut u8, offset: u64, length: u64) -> u64);
 define_syscall!(fn sol_get_epoch_stake(vote_address: *const u8) -> u64);
+define_syscall!(fn sol_panic_(filename: *const u8, filename_len: u64, line: u64, column: u64));
 
 // these are to be deprecated once they are superceded by sol_get_sysvar
 define_syscall!(fn sol_get_clock_sysvar(addr: *mut u8) -> u64);

define-syscall/src/definitions.rs

@@ -11,6 +11,7 @@ edition = { workspace = true }
 
 [dependencies]
 solana-account-info = { workspace = true }
+solana-define-syscall = { workspace = true }
 solana-msg = { workspace = true }
 solana-program-error = { workspace = true }
 solana-pubkey = { workspace = true, default-features = false }

program-entrypoint/Cargo.toml

@@ -5,6 +5,8 @@
 //! [`bpf_loader`]: crate::bpf_loader
 
 extern crate alloc;
+// Re-exporting for custom_panic
+pub use solana_define_syscall::definitions::{sol_log_ as __log, sol_panic_ as __panic};
 use {
     alloc::vec::Vec,
     solana_account_info::AccountInfo,
@@ -233,8 +235,8 @@ macro_rules! custom_heap_default {
 /// Define the default global panic handler.
 ///
 /// This must be used if the [`entrypoint`] macro is not used, and no other
-/// panic handler has been defined; otherwise compilation will fail with a
-/// missing `custom_panic` symbol.
+/// panic handler has been defined; otherwise a program will crash without an
+/// explicit panic message.
 ///
 /// The default global allocator is enabled only if the calling crate has not
 /// disabled it using [Cargo features] as described below. It is only defined
@@ -272,16 +274,28 @@ macro_rules! custom_heap_default {
 ///     $crate::msg!("{}", info);
 /// }
 /// ```
-///
-/// The above is how Solana defines the default panic handler.
 #[macro_export]
 macro_rules! custom_panic_default {
     () => {
         #[cfg(all(not(feature = "custom-panic"), target_os = "solana"))]
         #[no_mangle]
         fn custom_panic(info: &core::panic::PanicInfo<'_>) {
-            // Full panic reporting
-            $crate::__msg!("{}", info);
+            if let Some(mm) = info.message().as_str() {
+                unsafe {
+                    $crate::__log(mm.as_ptr(), mm.len() as u64);
+                }
+            }
+
+            if let Some(loc) = info.location() {
+                unsafe {
+                    $crate::__panic(
+                        loc.file().as_ptr(),
+                        loc.file().len() as u64,
+                        loc.line() as u64,
+                        loc.column() as u64,
+                    )
+                }
+            }
         }
     };
 }