py/objexcept: Allow compression of exception message text.

The decompression of error-strings is only done if the string is accessed
via printing or via er.args.  Tests are added for this feature to ensure
the decompression works.

1 files changed, 48 insertions, 0 deletions

diff --git a/tests/micropython/heapalloc_exc_compressed.py b/tests/micropython/heapalloc_exc_compressed.py
new file mode 100644
index 000000000..79e423ca0
--- /dev/null
+++ b/tests/micropython/heapalloc_exc_compressed.py
@@ -0,0 +1,48 @@
+import micropython
+
+# Tests both code paths for built-in exception raising.
+# mp_obj_new_exception_msg_varg (exception requires decompression at raise-time to format)
+# mp_obj_new_exception_msg (decompression can be deferred)
+
+# NameError uses mp_obj_new_exception_msg_varg for NameError("name '%q' isn't defined")
+# set.pop uses mp_obj_new_exception_msg for KeyError("pop from an empty set")
+
+# Tests that deferred decompression works both via print(e) and accessing the message directly via e.args.
+
+a = set()
+
+# First test the regular case (can use heap for allocating the decompression buffer).
+try:
+    name()
+except NameError as e:
+    print(type(e).__name__, e)
+
+try:
+    a.pop()
+except KeyError as e:
+    print(type(e).__name__, e)
+
+try:
+    name()
+except NameError as e:
+    print(e.args[0])
+
+try:
+    a.pop()
+except KeyError as e:
+    print(e.args[0])
+
+# Then test that it still works when the heap is locked (i.e. in ISR context).
+micropython.heap_lock()
+
+try:
+    name()
+except NameError as e:
+    print(type(e).__name__)
+
+try:
+    a.pop()
+except KeyError as e:
+    print(type(e).__name__)
+
+micropython.heap_unlock()