firmware: add unit tests for exception sync

src/runtime/src/eh_artiq.rs

@@ -13,7 +13,7 @@
 #![allow(non_camel_case_types)]
 
 use core::mem;
-use cslice::CSlice;
+use cslice::{AsCSlice, CSlice};
 use unwind as uw;
 use libc::{c_int, c_void, uintptr_t};
 use log::{trace, error};
@@ -218,8 +218,6 @@ pub unsafe fn artiq_personality(_state: uw::_Unwind_State,
 }
 
 pub unsafe extern fn raise(exception: *const Exception) -> ! {
-    use cslice::AsCSlice;
-
     let count = EXCEPTION_BUFFER.exception_count;
     let stack = &mut EXCEPTION_BUFFER.exception_stack;
     let diff = exception as isize - EXCEPTION_BUFFER.exceptions.as_ptr() as isize;
@@ -461,3 +459,29 @@ macro_rules! artiq_raise {
         artiq_raise!($name, $message, 0, 0, 0)
     });
 }
+
+/// Takes as input exception id from host
+/// Generates a new exception with:
+///   * `id` set to `exn_id`
+///   * `message` set to corresponding exception name from `EXCEPTION_ID_LOOKUP`
+///
+/// The message is matched on host to ensure correct exception is being referred
+/// This test checks the synchronization of exception ids for runtime errors
+#[no_mangle]
+pub extern "C" fn test_exception_id_sync(exn_id: u32) {
+    let message = EXCEPTION_ID_LOOKUP
+        .iter()
+        .find_map(|&(name, id)| if id == exn_id { Some(name) } else { None })
+        .unwrap_or("unallocated internal exception id");
+
+    let exn = Exception {
+        id: exn_id,
+        file: file!().as_c_slice(),
+        line: 0,
+        column: 0,
+        function: "test_exception_id_sync".as_c_slice(),
+        message: message.as_c_slice(),
+        param: [0, 0, 0],
+    };
+    unsafe { raise(&exn) };
+}

src/runtime/src/kernel/api.rs

@@ -280,6 +280,13 @@ pub fn resolve(required: &[u8]) -> Option<u32> {
             }
             api!(yn = yn)
         },
+        /*
+         * syscall for unit tests
+         * Used in `artiq.tests.coredevice.test_exceptions.ExceptionTest.test_raise_exceptions_kernel`
+         * This syscall checks that the exception IDs used in the Python `EmbeddingMap` (in `artiq.language.embedding`)
+         * match the `EXCEPTION_ID_LOOKUP` defined in the firmware (`libksupport::src::eh_artiq`)
+         */
+        api!(test_exception_id_sync = eh_artiq::test_exception_id_sync)
     ];
     api.iter()
        .find(|&&(exported, _)| exported.as_bytes() == required)