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.
This commit is contained in:
Damien George 2016-02-09 13:29:20 +00:00
parent 9e78ab4b86
commit 3e02b1d19a
3 changed files with 42 additions and 3 deletions

View File

@ -50,10 +50,14 @@ mp_uint_t mp_convert_obj_to_native(mp_obj_t obj, mp_uint_t type) {
case MP_NATIVE_TYPE_BOOL:
case MP_NATIVE_TYPE_INT:
case MP_NATIVE_TYPE_UINT: return mp_obj_get_int_truncated(obj);
default: { // a pointer
default: { // cast obj to a pointer
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(obj, &bufinfo, MP_BUFFER_RW);
return (mp_uint_t)bufinfo.buf;
if (mp_get_buffer(obj, &bufinfo, MP_BUFFER_RW)) {
return (mp_uint_t)bufinfo.buf;
} else {
// assume obj is an integer that represents an address
return mp_obj_get_int_truncated(obj);
}
}
}
}

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@ -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)

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@ -0,0 +1,6 @@
<class 'bytearray'>
<class 'int'>
bytearray(b'0000')
bytearray(b'1111')
bytearray(b'2222')
bytearray(b'2233')