tests/micropython: Add set of tests for extreme cases of raising exc's.

tests/micropython/extreme_exc.py

+# test some extreme cases of allocating exceptions and tracebacks
+
+import micropython
+
+# some ports need to allocate heap for the emergency exception
+try:
+    micropython.alloc_emergency_exception_buf(256)
+except AttributeError:
+    pass
+
+def main():
+    # create an exception with many args while heap is locked
+    # should revert to empty tuple for args
+    micropython.heap_lock()
+    e = Exception(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)
+    micropython.heap_unlock()
+    print(repr(e))
+
+    # create an exception with a long formatted error message while heap is locked
+    # should use emergency exception buffer and truncate the message
+    def f():
+        pass
+    micropython.heap_lock()
+    try:
+        f(abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz=1)
+    except Exception as er:
+        e = er
+    micropython.heap_unlock()
+    print(repr(e)[:50])
+
+    # create an exception with a long formatted error message while heap is low
+    # should use the heap and truncate the message
+    lst = []
+    while 1:
+        try:
+            lst = [lst]
+        except MemoryError:
+            break
+    try:
+        f(abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz=1)
+    except Exception as er:
+        e = er
+    lst = None
+    print(repr(e))
+
+    # raise a deep exception with the heap locked
+    # should use emergency exception and be unable to resize traceback array
+    def g():
+        g()
+    micropython.heap_lock()
+    try:
+        g()
+    except Exception as er:
+        e = er
+    micropython.heap_unlock()
+    print(repr(e))
+
+    # create an exception on the heap with some traceback on the heap, but then
+    # raise it with the heap locked so it can't allocate any more traceback
+    exc = Exception('my exception')
+    try:
+        raise exc
+    except:
+        pass
+    def h(e):
+        raise e
+    micropython.heap_lock()
+    try:
+        h(exc)
+    except Exception as er:
+        e = er
+    micropython.heap_unlock()
+    print(repr(e))
+
+main()

tests/micropython/extreme_exc.py.exp

+Exception()
+TypeError("unexpected keyword argument 'abcdefghij
+TypeError("unexpected keyword argument 'abc",)
+RuntimeError('maximum recursion depth exceeded',)
+Exception('my exception',)