Add rust bpf allocator (#4426)

sdk/bpf/rust-utils/src/alloc.rs

@@ -0,0 +1,23 @@
+//! @brief Solana Rust-based BPF program memory allocator shim
+
+use crate::log::*;
+use core::alloc::{GlobalAlloc, Layout};
+
+pub struct Allocator;
+unsafe impl GlobalAlloc for Allocator {
+    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+        sol_alloc_free_(layout.size() as u64, 0)
+    }
+    unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
+        sol_alloc_free_(layout.size() as u64, ptr as u64);
+    }
+}
+extern "C" {
+    fn sol_alloc_free_(size: u64, ptr: u64) -> *mut u8;
+}
+
+#[alloc_error_handler]
+fn my_alloc_error_handler(_: core::alloc::Layout) -> ! {
+    sol_log("alloc_error_handler");
+    panic!();
+}

sdk/bpf/rust-utils/src/lib.rs

@@ -1,7 +1,13 @@
 //! @brief Solana Rust-based BPF program utility functions and types
 
 #![no_std]
+#![feature(allocator_api)]
+#![feature(alloc_error_handler)]
 
+pub mod alloc;
 pub mod entrypoint;
 pub mod log;
 pub mod panic;
+
+#[global_allocator]
+static A: alloc::Allocator = alloc::Allocator;

sdk/bpf/rust-utils/src/panic.rs

@@ -1,6 +1,5 @@
 //! @brief Solana Rust-based BPF program panic handling
 
-// #[cfg(not(test))]
 use crate::log::*;
 use core::panic::PanicInfo;
 
@@ -18,9 +17,15 @@ fn panic(info: &PanicInfo) -> ! {
                 sol_panic_();
             }
         }
-        sol_log_64(0, 0, 0, u64::from(location.line()), u64::from(location.column()));
+        sol_log_64(
+            0,
+            0,
+            0,
+            u64::from(location.line()),
+            u64::from(location.column()),
+        );
     } else {
-        sol_log("Panic! but could not get location information");
+        sol_log("Panic!, but could not get location information");
     }
     unsafe {
         sol_panic_();