feat: add some initialization helpers to the sdk

This replaces the custom assert macros. Instead of overriding the assert
macros, the user would:

1. Call `fvm_sdk::initialize()` at the top of their actor/tests.
2. Use the default `assert` macros.

replaces #660

sdk/Cargo.toml

@@ -23,5 +23,4 @@ fvm_ipld_encoding = { version = "0.2", path = "../ipld/encoding" }
 [features]
 default = ["debug"]
 debug = ["lazy_static"]
-testing = []
 m2-native = []

sdk/src/debug.rs

@@ -32,6 +32,7 @@ mod inner {
         }
     }
     /// Initialize logging if debugging is enabled.
+    #[inline(always)]
     pub fn init_logging() {
         if enabled() {
             log::set_logger(&Logger).expect("failed to enable logging");

sdk/src/lib.rs

@@ -12,9 +12,6 @@ pub mod sself;
 pub mod sys;
 pub mod vm;
 
-#[cfg(feature = "testing")]
-pub mod testing;
-
 /// The maximum actor address length (class 2 addresses).
 pub const MAX_ACTOR_ADDR_LEN: usize = 21;
 
@@ -35,3 +32,17 @@ pub(crate) fn status_code_to_bool(code: i32) -> bool {
 /// Error messages don't make it across the boundary, but are logged at the FVM
 /// level for debugging and informational purposes.
 pub type SyscallResult<T> = core::result::Result<T, fvm_shared::error::ErrorNumber>;
+
+/// Initialize the FVM SDK. Calling this function optional but encouraged.
+///
+/// At the moment, this will:
+///
+/// 1. Initialize logging (if "debug mode" is enabled).
+/// 2. Setup a panic handler for easier debugging.
+///
+/// In the future, this may perform additional setup operations, but will never incure more than a
+/// minimal runtime cost.
+pub fn initialize() {
+    debug::init_logging();
+    vm::set_panic_handler();
+}

sdk/src/vm.rs

@@ -1,5 +1,6 @@
 use std::ptr;
 
+use fvm_shared::error::ExitCode;
 use fvm_shared::sys::out::vm::InvocationContext;
 
 use crate::sys;
@@ -27,3 +28,16 @@ pub fn abort(code: u32, message: Option<&str>) -> ! {
         sys::vm::abort(code, message, message_len as u32);
     }
 }
+
+/// Sets a panic handler to turn all panics into aborts with `USR_ASSERTION_FAILED`. This should be
+/// called early in the actor to improve debuggability.
+///
+/// NOTE: This will incure a small cost on failure (to format an error message).
+pub fn set_panic_handler() {
+    std::panic::set_hook(Box::new(|info| {
+        abort(
+            ExitCode::USR_ASSERTION_FAILED.value(),
+            Some(&format!("{}", info)),
+        )
+    }));
+}