firmware/ksupport: improve comments and syscall name

artiq/compiler/embedding.py

@@ -88,9 +88,9 @@ class EmbeddingMap:
                 self.subkernel_message_map[msg_type.name] = msg_id
                 self.object_reverse_map[obj_id] = msg_id
 
-        # Keep this list of exceptions in sync with `EXCEPTION_ID_LOOKUP` in `artiq.firmware.ksupport.eh_artiq``
-        # The exceptions declared here should be defined in `artiq.coredeive.exceptions``
-        # Without sync, test cases in artiq.test.coredevice.test_exceptions would fail
+        # Keep this list of exceptions in sync with `EXCEPTION_ID_LOOKUP` in `artiq::firmware::ksupport::eh_artiq`
+        # The exceptions declared here must be defined in `artiq.coredevice.exceptions`
+        # Verify synchronization by running the test cases in `artiq.test.coredevice.test_exceptions`
         self.preallocate_runtime_exception_names([
             "RTIOUnderflow",
             "RTIOOverflow",

artiq/coredevice/core.py

@@ -54,7 +54,7 @@ def rtio_get_counter() -> TInt64:
     raise NotImplementedError("syscall not simulated")
 
 @syscall
-def raise_exception(id: TInt32) -> TNone:
+def test_exception_id_sync(id: TInt32) -> TNone:
     raise NotImplementedError("syscall not simulated")
 
 def get_target_cls(target):

artiq/coredevice/exceptions.py

@@ -7,10 +7,10 @@ from artiq import __artiq_dir__ as artiq_dir
 from artiq.coredevice.runtime import source_loader
 
 """
-This file should provide class definition for all the exceptions declared in `EmbeddingMap` in artiq.compiler.embedding
+This file provides class definition for all the exceptions declared in `EmbeddingMap` in `artiq.compiler.embedding`
 
-For python builtin exceptions, use the `builtins` module
-For artiq specific exceptions, inherit from `Exception` class
+For Python builtin exceptions, use the `builtins` module
+For ARTIQ specific exceptions, inherit from `Exception` class
 """
 
 AssertionError = builtins.AssertionError

artiq/firmware/ksupport/api.rs

@@ -177,7 +177,8 @@ static mut API: &'static [(&'static str, *const ())] = &[
     /*
      * syscall for unit tests
      * Used in `artiq.tests.coredevice.test_exceptions.ExceptionTest.test_raise_exceptions_kernel`
-     * `EmbeddingMap` (`artiq.compiler.embedding`) and `EXCEPTION_ID_LOOKUP` (`artiq.firmware.ksupport.eh_artiq`)
+     * This syscall checks that the exception IDs used in the Python `EmbeddingMap` (in `artiq.compiler.embedding`)
+     * match the `EXCEPTION_ID_LOOKUP` defined in the firmware (`artiq::firmware::ksupport::eh_artiq`)
      */
     api!(test_exception_id_sync = ::eh_artiq::test_exception_id_sync)
 ];

artiq/firmware/ksupport/eh_artiq.rs

@@ -361,14 +361,19 @@ pub fn get_exception_id(name: &str) -> u32 {
     unimplemented!("unallocated internal exception id")
 }
 
-// Performs a reverse lookup on `EXCEPTION_ID_LOOKUP` 
-// Unconditionally raises an exception given its id
+/// 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-unwind" 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("Unknown exception ID");
+        .unwrap_or("unallocated internal exception id");
     
     let exn = Exception {
         id:       exn_id,

artiq/test/coredevice/test_exceptions.py

@@ -4,16 +4,16 @@ import artiq.coredevice.exceptions as exceptions
 from artiq.experiment import *
 from artiq.test.hardware_testbench import ExperimentCase
 from artiq.compiler.embedding import EmbeddingMap
-from artiq.coredevice.core import raise_exception
+from artiq.coredevice.core import test_exception_id_sync
 
 """
 Test sync in exceptions raised between host and kernel
-Check artiq.compiler.embedding and artiq.frontend.ksupport.eh_artiq
+Check `artiq.compiler.embedding` and `artiq::firmware::ksupport::eh_artiq`
 
 Considers the following two cases:
     1) Exception raised on kernel and passed to host
-    2) Exception raised in host function called from kernel
-Ensures integirty of exceptions is maintained as it passes between kernel and host
+    2) Exception raised in a host function called from kernel
+Ensures same exception is raised on both kernel and host in either case
 """
 
 exception_names = EmbeddingMap().str_reverse_map
@@ -35,7 +35,7 @@ class _TestExceptionSync(EnvExperiment):
 
     @kernel
     def raise_exception_kernel(self, id):
-        raise_exception(id)
+        test_exception_id_sync(id)
 
     
 class ExceptionTest(ExperimentCase):