py/viper: Allow casting of Python integers to viper pointers.

This allows you to pass a number (being an address) to a viper function
that expects a pointer, and also allows casting of integers to pointers
within viper functions.

This was actually the original behaviour, but it regressed due to native
type identifiers being promoted to 4 bits in width.

1 files changed, 29 insertions, 0 deletions

diff --git a/tests/micropython/viper_addr.py b/tests/micropython/viper_addr.py
new file mode 100644
index 000000000..cd953ce07
--- /dev/null
+++ b/tests/micropython/viper_addr.py
@@ -0,0 +1,29 @@
+# test passing addresses to viper
+
+@micropython.viper
+def get_addr(x:ptr) -> ptr:
+    return x
+
+@micropython.viper
+def memset(dest:ptr8, c:int, n:int):
+    for i in range(n):
+        dest[i] = c
+
+# create array and get its address
+ar = bytearray('0000')
+addr = get_addr(ar)
+print(type(ar))
+print(type(addr))
+print(ar)
+
+# pass array as an object
+memset(ar, ord('1'), len(ar))
+print(ar)
+
+# pass direct pointer to array buffer
+memset(addr, ord('2'), len(ar))
+print(ar)
+
+# pass direct pointer to array buffer, with offset
+memset(addr + 2, ord('3'), len(ar) - 2)
+print(ar)