CircuitPython - a Python implementation for teaching coding with microcontrollers https://git.suspectdevices.com/suspect-devices/circuitpython/atom?h=6.0.1 2020-09-12T19:07:23+00:00 2020-09-12T19:07:23+00:00 Jeff Epler jepler@gmail.com 2020-09-12T18:57:31+00:00 urn:sha1:54d97251fe2dd4939652a186bf703885e654b4d1 While checking whether we can enable -Wimplicit-fallthrough, I encountered a diagnostic in mp_binary_set_val_array_from_int which led to discovering the following bug: ``` >>> struct.pack("xb", 3) b'\x03\x03' ``` That is, the next value (3) was used as the value of a padding byte, while standard Python always fills "x" bytes with zeros. I initially thought this had to do with the unintentional fallthrough, but it doesn't. Instead, this code would relate to an array.array with a typecode of padding ('x'), which is ALSO not desktop Python compliant: ``` >>> array.array('x', (1, 2, 3)) array('x', [1, 0, 0]) ``` Possibly this is dead code that used to be shared between struct-setting and array-setting, but it no longer is. I also discovered that the argument list length for struct.pack and struct.pack_into were not checked, and that the length of binary data passed to array.array was not checked to be a multiple of the element size. I have corrected all of these to conform more closely to standard Python and revised some tests where necessary. Some tests for micropython-specific behavior that does not conform to standard Python and is not present in CircuitPython was deleted outright. 2020-07-06T18:16:25+00:00 Diego Elio Pettenò flameeyes@flameeyes.com 2020-06-03T22:40:05+00:00 urn:sha1:34b4993d63a6b576f29d624385c681f679b4124c 2019-01-20T20:12:34+00:00 Dan Halbert halbert@halwitz.org 2019-01-20T20:10:09+00:00 urn:sha1:7a09af73ec7f4a11a1404dff6276e09072d06983 2018-08-07T21:58:57+00:00 Scott Shawcroft scott@tannewt.org 2018-07-31T23:53:54+00:00 urn:sha1:933add6cd833bb6ba6682ad2b6eb478871415ff5 2017-09-01T01:11:09+00:00 Damien George damien.p.george@gmail.com 2017-09-01T01:11:09+00:00 urn:sha1:2daacc5ceef7e36ac3c88b8946088b6b3513993b Prior to this patch, the size of the buffer given to pack_into() was checked for being too small by using the count of the arguments, not their actual size. For example, a format spec of '4I' would only check that there was 4 bytes available, not 16; and 'I' would check for 1 byte, not 4. The pack() function is ok because its buffer is created to be exactly the correct size. The fix in this patch calculates the total size of the format spec at the start of pack_into() and verifies that the buffer is large enough. This adds some computational overhead, to iterate through the whole format spec. The alternative is to check during the packing, but that requires extra code to handle alignment, and the check is anyway not needed for pack(). So to maintain minimal code size the check is done using struct_calcsize. 2017-09-01T00:53:29+00:00 Damien George damien.p.george@gmail.com 2017-09-01T00:53:29+00:00 urn:sha1:79d5acbd01fed21e1c8e46b06690072375de0bfe Prior to this patch, the size of the buffer given to unpack/unpack_from was checked for being too small by using the count of the arguments, not their actual size. For example, a format spec of '4I' would only check that there was 4 bytes available, not 16; and 'I' would check for 1 byte, not 4. This bug is fixed in this patch by calculating the total size of the format spec at the start of the unpacking function. This function anyway needs to calculate the number of items at the start, so calculating the total size can be done at the same time. 2017-09-01T00:10:51+00:00 Damien George damien.p.george@gmail.com 2017-09-01T00:10:51+00:00 urn:sha1:793d826d9df67c3f544505beda63ca36d8dfa1c4 This patch makes a repeat counter behave the same as repeating the typecode, when there are not enough args. For example: struct.pack('2I', 1) now behave the same as struct.pack('II', 1). 2017-07-31T08:35:40+00:00 Alexander Steffen devel.20.webmeister@spamgourmet.com 2017-06-30T07:22:17+00:00 urn:sha1:55f33240f3d7051d4213629e92437a36f1fac50e There were several different spellings of MicroPython present in comments, when there should be only one. 2017-01-17T19:53:06+00:00 Paul Sokolovsky pfalcon@users.sourceforge.net 2017-01-17T19:50:20+00:00 urn:sha1:af9046193148084f008501434e4c9f49fedc053f Previouly, we had errors checked in callers, which led to duplicate code or missing checks in some places. 2016-10-07T01:54:14+00:00 Damien George damien.p.george@gmail.com 2016-10-07T01:54:14+00:00 urn:sha1:dffa383b062b0dd788abed0af242b66bde910e6b The deleted code is unreachable because calcsize_items guarantees that num_items corresponds to how many items there are in fmt to unpack.